FFmpeg
avcodec.h
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1 /*
2  * copyright (c) 2001 Fabrice Bellard
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #ifndef AVCODEC_AVCODEC_H
22 #define AVCODEC_AVCODEC_H
23 
24 /**
25  * @file
26  * @ingroup libavc
27  * Libavcodec external API header
28  */
29 
30 #include <errno.h>
31 #include "libavutil/samplefmt.h"
32 #include "libavutil/attributes.h"
33 #include "libavutil/avutil.h"
34 #include "libavutil/buffer.h"
35 #include "libavutil/cpu.h"
37 #include "libavutil/dict.h"
38 #include "libavutil/frame.h"
39 #include "libavutil/hwcontext.h"
40 #include "libavutil/log.h"
41 #include "libavutil/pixfmt.h"
42 #include "libavutil/rational.h"
43 
44 #include "version.h"
45 
46 /**
47  * @defgroup libavc libavcodec
48  * Encoding/Decoding Library
49  *
50  * @{
51  *
52  * @defgroup lavc_decoding Decoding
53  * @{
54  * @}
55  *
56  * @defgroup lavc_encoding Encoding
57  * @{
58  * @}
59  *
60  * @defgroup lavc_codec Codecs
61  * @{
62  * @defgroup lavc_codec_native Native Codecs
63  * @{
64  * @}
65  * @defgroup lavc_codec_wrappers External library wrappers
66  * @{
67  * @}
68  * @defgroup lavc_codec_hwaccel Hardware Accelerators bridge
69  * @{
70  * @}
71  * @}
72  * @defgroup lavc_internal Internal
73  * @{
74  * @}
75  * @}
76  */
77 
78 /**
79  * @ingroup libavc
80  * @defgroup lavc_encdec send/receive encoding and decoding API overview
81  * @{
82  *
83  * The avcodec_send_packet()/avcodec_receive_frame()/avcodec_send_frame()/
84  * avcodec_receive_packet() functions provide an encode/decode API, which
85  * decouples input and output.
86  *
87  * The API is very similar for encoding/decoding and audio/video, and works as
88  * follows:
89  * - Set up and open the AVCodecContext as usual.
90  * - Send valid input:
91  * - For decoding, call avcodec_send_packet() to give the decoder raw
92  * compressed data in an AVPacket.
93  * - For encoding, call avcodec_send_frame() to give the encoder an AVFrame
94  * containing uncompressed audio or video.
95  * In both cases, it is recommended that AVPackets and AVFrames are
96  * refcounted, or libavcodec might have to copy the input data. (libavformat
97  * always returns refcounted AVPackets, and av_frame_get_buffer() allocates
98  * refcounted AVFrames.)
99  * - Receive output in a loop. Periodically call one of the avcodec_receive_*()
100  * functions and process their output:
101  * - For decoding, call avcodec_receive_frame(). On success, it will return
102  * an AVFrame containing uncompressed audio or video data.
103  * - For encoding, call avcodec_receive_packet(). On success, it will return
104  * an AVPacket with a compressed frame.
105  * Repeat this call until it returns AVERROR(EAGAIN) or an error. The
106  * AVERROR(EAGAIN) return value means that new input data is required to
107  * return new output. In this case, continue with sending input. For each
108  * input frame/packet, the codec will typically return 1 output frame/packet,
109  * but it can also be 0 or more than 1.
110  *
111  * At the beginning of decoding or encoding, the codec might accept multiple
112  * input frames/packets without returning a frame, until its internal buffers
113  * are filled. This situation is handled transparently if you follow the steps
114  * outlined above.
115  *
116  * In theory, sending input can result in EAGAIN - this should happen only if
117  * not all output was received. You can use this to structure alternative decode
118  * or encode loops other than the one suggested above. For example, you could
119  * try sending new input on each iteration, and try to receive output if that
120  * returns EAGAIN.
121  *
122  * End of stream situations. These require "flushing" (aka draining) the codec,
123  * as the codec might buffer multiple frames or packets internally for
124  * performance or out of necessity (consider B-frames).
125  * This is handled as follows:
126  * - Instead of valid input, send NULL to the avcodec_send_packet() (decoding)
127  * or avcodec_send_frame() (encoding) functions. This will enter draining
128  * mode.
129  * - Call avcodec_receive_frame() (decoding) or avcodec_receive_packet()
130  * (encoding) in a loop until AVERROR_EOF is returned. The functions will
131  * not return AVERROR(EAGAIN), unless you forgot to enter draining mode.
132  * - Before decoding can be resumed again, the codec has to be reset with
133  * avcodec_flush_buffers().
134  *
135  * Using the API as outlined above is highly recommended. But it is also
136  * possible to call functions outside of this rigid schema. For example, you can
137  * call avcodec_send_packet() repeatedly without calling
138  * avcodec_receive_frame(). In this case, avcodec_send_packet() will succeed
139  * until the codec's internal buffer has been filled up (which is typically of
140  * size 1 per output frame, after initial input), and then reject input with
141  * AVERROR(EAGAIN). Once it starts rejecting input, you have no choice but to
142  * read at least some output.
143  *
144  * Not all codecs will follow a rigid and predictable dataflow; the only
145  * guarantee is that an AVERROR(EAGAIN) return value on a send/receive call on
146  * one end implies that a receive/send call on the other end will succeed, or
147  * at least will not fail with AVERROR(EAGAIN). In general, no codec will
148  * permit unlimited buffering of input or output.
149  *
150  * This API replaces the following legacy functions:
151  * - avcodec_decode_video2() and avcodec_decode_audio4():
152  * Use avcodec_send_packet() to feed input to the decoder, then use
153  * avcodec_receive_frame() to receive decoded frames after each packet.
154  * Unlike with the old video decoding API, multiple frames might result from
155  * a packet. For audio, splitting the input packet into frames by partially
156  * decoding packets becomes transparent to the API user. You never need to
157  * feed an AVPacket to the API twice (unless it is rejected with AVERROR(EAGAIN) - then
158  * no data was read from the packet).
159  * Additionally, sending a flush/draining packet is required only once.
160  * - avcodec_encode_video2()/avcodec_encode_audio2():
161  * Use avcodec_send_frame() to feed input to the encoder, then use
162  * avcodec_receive_packet() to receive encoded packets.
163  * Providing user-allocated buffers for avcodec_receive_packet() is not
164  * possible.
165  * - The new API does not handle subtitles yet.
166  *
167  * Mixing new and old function calls on the same AVCodecContext is not allowed,
168  * and will result in undefined behavior.
169  *
170  * Some codecs might require using the new API; using the old API will return
171  * an error when calling it. All codecs support the new API.
172  *
173  * A codec is not allowed to return AVERROR(EAGAIN) for both sending and receiving. This
174  * would be an invalid state, which could put the codec user into an endless
175  * loop. The API has no concept of time either: it cannot happen that trying to
176  * do avcodec_send_packet() results in AVERROR(EAGAIN), but a repeated call 1 second
177  * later accepts the packet (with no other receive/flush API calls involved).
178  * The API is a strict state machine, and the passage of time is not supposed
179  * to influence it. Some timing-dependent behavior might still be deemed
180  * acceptable in certain cases. But it must never result in both send/receive
181  * returning EAGAIN at the same time at any point. It must also absolutely be
182  * avoided that the current state is "unstable" and can "flip-flop" between
183  * the send/receive APIs allowing progress. For example, it's not allowed that
184  * the codec randomly decides that it actually wants to consume a packet now
185  * instead of returning a frame, after it just returned AVERROR(EAGAIN) on an
186  * avcodec_send_packet() call.
187  * @}
188  */
189 
190 /**
191  * @defgroup lavc_core Core functions/structures.
192  * @ingroup libavc
193  *
194  * Basic definitions, functions for querying libavcodec capabilities,
195  * allocating core structures, etc.
196  * @{
197  */
198 
199 
200 /**
201  * Identify the syntax and semantics of the bitstream.
202  * The principle is roughly:
203  * Two decoders with the same ID can decode the same streams.
204  * Two encoders with the same ID can encode compatible streams.
205  * There may be slight deviations from the principle due to implementation
206  * details.
207  *
208  * If you add a codec ID to this list, add it so that
209  * 1. no value of an existing codec ID changes (that would break ABI),
210  * 2. it is as close as possible to similar codecs
211  *
212  * After adding new codec IDs, do not forget to add an entry to the codec
213  * descriptor list and bump libavcodec minor version.
214  */
215 enum AVCodecID {
217 
218  /* video codecs */
220  AV_CODEC_ID_MPEG2VIDEO, ///< preferred ID for MPEG-1/2 video decoding
355 #define AV_CODEC_ID_IFF_BYTERUN1 AV_CODEC_ID_IFF_ILBM
393 #define AV_CODEC_ID_H265 AV_CODEC_ID_HEVC
413 
463 
464  /* various PCM "codecs" */
465  AV_CODEC_ID_FIRST_AUDIO = 0x10000, ///< A dummy id pointing at the start of audio codecs
497 
503 
504  /* various ADPCM codecs */
536 
548 
549  /* AMR */
552 
553  /* RealAudio codecs*/
556 
557  /* various DPCM codecs */
562 
565 
566  /* audio codecs */
567  AV_CODEC_ID_MP2 = 0x15000,
568  AV_CODEC_ID_MP3, ///< preferred ID for decoding MPEG audio layer 1, 2 or 3
585  AV_CODEC_ID_GSM, ///< as in Berlin toast format
597  AV_CODEC_ID_GSM_MS, /* as found in WAV */
635 
660 
661  /* subtitle codecs */
662  AV_CODEC_ID_FIRST_SUBTITLE = 0x17000, ///< A dummy ID pointing at the start of subtitle codecs.
665  AV_CODEC_ID_TEXT, ///< raw UTF-8 text
672 
690 
691  /* other specific kind of codecs (generally used for attachments) */
692  AV_CODEC_ID_FIRST_UNKNOWN = 0x18000, ///< A dummy ID pointing at the start of various fake codecs.
693  AV_CODEC_ID_TTF = 0x18000,
694 
695  AV_CODEC_ID_SCTE_35, ///< Contain timestamp estimated through PCR of program stream.
705 
706 
707  AV_CODEC_ID_PROBE = 0x19000, ///< codec_id is not known (like AV_CODEC_ID_NONE) but lavf should attempt to identify it
708 
709  AV_CODEC_ID_MPEG2TS = 0x20000, /**< _FAKE_ codec to indicate a raw MPEG-2 TS
710  * stream (only used by libavformat) */
711  AV_CODEC_ID_MPEG4SYSTEMS = 0x20001, /**< _FAKE_ codec to indicate a MPEG-4 Systems
712  * stream (only used by libavformat) */
713  AV_CODEC_ID_FFMETADATA = 0x21000, ///< Dummy codec for streams containing only metadata information.
714  AV_CODEC_ID_WRAPPED_AVFRAME = 0x21001, ///< Passthrough codec, AVFrames wrapped in AVPacket
715 };
716 
717 /**
718  * This struct describes the properties of a single codec described by an
719  * AVCodecID.
720  * @see avcodec_descriptor_get()
721  */
722 typedef struct AVCodecDescriptor {
723  enum AVCodecID id;
725  /**
726  * Name of the codec described by this descriptor. It is non-empty and
727  * unique for each codec descriptor. It should contain alphanumeric
728  * characters and '_' only.
729  */
730  const char *name;
731  /**
732  * A more descriptive name for this codec. May be NULL.
733  */
734  const char *long_name;
735  /**
736  * Codec properties, a combination of AV_CODEC_PROP_* flags.
737  */
738  int props;
739  /**
740  * MIME type(s) associated with the codec.
741  * May be NULL; if not, a NULL-terminated array of MIME types.
742  * The first item is always non-NULL and is the preferred MIME type.
743  */
744  const char *const *mime_types;
745  /**
746  * If non-NULL, an array of profiles recognized for this codec.
747  * Terminated with FF_PROFILE_UNKNOWN.
748  */
749  const struct AVProfile *profiles;
751 
752 /**
753  * Codec uses only intra compression.
754  * Video and audio codecs only.
755  */
756 #define AV_CODEC_PROP_INTRA_ONLY (1 << 0)
757 /**
758  * Codec supports lossy compression. Audio and video codecs only.
759  * @note a codec may support both lossy and lossless
760  * compression modes
761  */
762 #define AV_CODEC_PROP_LOSSY (1 << 1)
763 /**
764  * Codec supports lossless compression. Audio and video codecs only.
765  */
766 #define AV_CODEC_PROP_LOSSLESS (1 << 2)
767 /**
768  * Codec supports frame reordering. That is, the coded order (the order in which
769  * the encoded packets are output by the encoders / stored / input to the
770  * decoders) may be different from the presentation order of the corresponding
771  * frames.
772  *
773  * For codecs that do not have this property set, PTS and DTS should always be
774  * equal.
775  */
776 #define AV_CODEC_PROP_REORDER (1 << 3)
777 /**
778  * Subtitle codec is bitmap based
779  * Decoded AVSubtitle data can be read from the AVSubtitleRect->pict field.
780  */
781 #define AV_CODEC_PROP_BITMAP_SUB (1 << 16)
782 /**
783  * Subtitle codec is text based.
784  * Decoded AVSubtitle data can be read from the AVSubtitleRect->ass field.
785  */
786 #define AV_CODEC_PROP_TEXT_SUB (1 << 17)
787 
788 /**
789  * @ingroup lavc_decoding
790  * Required number of additionally allocated bytes at the end of the input bitstream for decoding.
791  * This is mainly needed because some optimized bitstream readers read
792  * 32 or 64 bit at once and could read over the end.<br>
793  * Note: If the first 23 bits of the additional bytes are not 0, then damaged
794  * MPEG bitstreams could cause overread and segfault.
795  */
796 #define AV_INPUT_BUFFER_PADDING_SIZE 64
797 
798 /**
799  * @ingroup lavc_encoding
800  * minimum encoding buffer size
801  * Used to avoid some checks during header writing.
802  */
803 #define AV_INPUT_BUFFER_MIN_SIZE 16384
804 
805 /**
806  * @ingroup lavc_decoding
807  */
809  /* We leave some space between them for extensions (drop some
810  * keyframes for intra-only or drop just some bidir frames). */
811  AVDISCARD_NONE =-16, ///< discard nothing
812  AVDISCARD_DEFAULT = 0, ///< discard useless packets like 0 size packets in avi
813  AVDISCARD_NONREF = 8, ///< discard all non reference
814  AVDISCARD_BIDIR = 16, ///< discard all bidirectional frames
815  AVDISCARD_NONINTRA= 24, ///< discard all non intra frames
816  AVDISCARD_NONKEY = 32, ///< discard all frames except keyframes
817  AVDISCARD_ALL = 48, ///< discard all
818 };
819 
830  AV_AUDIO_SERVICE_TYPE_NB , ///< Not part of ABI
831 };
832 
833 /**
834  * @ingroup lavc_encoding
835  */
836 typedef struct RcOverride{
839  int qscale; // If this is 0 then quality_factor will be used instead.
841 } RcOverride;
842 
843 /* encoding support
844  These flags can be passed in AVCodecContext.flags before initialization.
845  Note: Not everything is supported yet.
846 */
847 
848 /**
849  * Allow decoders to produce frames with data planes that are not aligned
850  * to CPU requirements (e.g. due to cropping).
851  */
852 #define AV_CODEC_FLAG_UNALIGNED (1 << 0)
853 /**
854  * Use fixed qscale.
855  */
856 #define AV_CODEC_FLAG_QSCALE (1 << 1)
857 /**
858  * 4 MV per MB allowed / advanced prediction for H.263.
859  */
860 #define AV_CODEC_FLAG_4MV (1 << 2)
861 /**
862  * Output even those frames that might be corrupted.
863  */
864 #define AV_CODEC_FLAG_OUTPUT_CORRUPT (1 << 3)
865 /**
866  * Use qpel MC.
867  */
868 #define AV_CODEC_FLAG_QPEL (1 << 4)
869 /**
870  * Don't output frames whose parameters differ from first
871  * decoded frame in stream.
872  */
873 #define AV_CODEC_FLAG_DROPCHANGED (1 << 5)
874 /**
875  * Use internal 2pass ratecontrol in first pass mode.
876  */
877 #define AV_CODEC_FLAG_PASS1 (1 << 9)
878 /**
879  * Use internal 2pass ratecontrol in second pass mode.
880  */
881 #define AV_CODEC_FLAG_PASS2 (1 << 10)
882 /**
883  * loop filter.
884  */
885 #define AV_CODEC_FLAG_LOOP_FILTER (1 << 11)
886 /**
887  * Only decode/encode grayscale.
888  */
889 #define AV_CODEC_FLAG_GRAY (1 << 13)
890 /**
891  * error[?] variables will be set during encoding.
892  */
893 #define AV_CODEC_FLAG_PSNR (1 << 15)
894 /**
895  * Input bitstream might be truncated at a random location
896  * instead of only at frame boundaries.
897  */
898 #define AV_CODEC_FLAG_TRUNCATED (1 << 16)
899 /**
900  * Use interlaced DCT.
901  */
902 #define AV_CODEC_FLAG_INTERLACED_DCT (1 << 18)
903 /**
904  * Force low delay.
905  */
906 #define AV_CODEC_FLAG_LOW_DELAY (1 << 19)
907 /**
908  * Place global headers in extradata instead of every keyframe.
909  */
910 #define AV_CODEC_FLAG_GLOBAL_HEADER (1 << 22)
911 /**
912  * Use only bitexact stuff (except (I)DCT).
913  */
914 #define AV_CODEC_FLAG_BITEXACT (1 << 23)
915 /* Fx : Flag for H.263+ extra options */
916 /**
917  * H.263 advanced intra coding / MPEG-4 AC prediction
918  */
919 #define AV_CODEC_FLAG_AC_PRED (1 << 24)
920 /**
921  * interlaced motion estimation
922  */
923 #define AV_CODEC_FLAG_INTERLACED_ME (1 << 29)
924 #define AV_CODEC_FLAG_CLOSED_GOP (1U << 31)
925 
926 /**
927  * Allow non spec compliant speedup tricks.
928  */
929 #define AV_CODEC_FLAG2_FAST (1 << 0)
930 /**
931  * Skip bitstream encoding.
932  */
933 #define AV_CODEC_FLAG2_NO_OUTPUT (1 << 2)
934 /**
935  * Place global headers at every keyframe instead of in extradata.
936  */
937 #define AV_CODEC_FLAG2_LOCAL_HEADER (1 << 3)
938 
939 /**
940  * timecode is in drop frame format. DEPRECATED!!!!
941  */
942 #define AV_CODEC_FLAG2_DROP_FRAME_TIMECODE (1 << 13)
943 
944 /**
945  * Input bitstream might be truncated at a packet boundaries
946  * instead of only at frame boundaries.
947  */
948 #define AV_CODEC_FLAG2_CHUNKS (1 << 15)
949 /**
950  * Discard cropping information from SPS.
951  */
952 #define AV_CODEC_FLAG2_IGNORE_CROP (1 << 16)
953 
954 /**
955  * Show all frames before the first keyframe
956  */
957 #define AV_CODEC_FLAG2_SHOW_ALL (1 << 22)
958 /**
959  * Export motion vectors through frame side data
960  */
961 #define AV_CODEC_FLAG2_EXPORT_MVS (1 << 28)
962 /**
963  * Do not skip samples and export skip information as frame side data
964  */
965 #define AV_CODEC_FLAG2_SKIP_MANUAL (1 << 29)
966 /**
967  * Do not reset ASS ReadOrder field on flush (subtitles decoding)
968  */
969 #define AV_CODEC_FLAG2_RO_FLUSH_NOOP (1 << 30)
970 
971 /* Unsupported options :
972  * Syntax Arithmetic coding (SAC)
973  * Reference Picture Selection
974  * Independent Segment Decoding */
975 /* /Fx */
976 /* codec capabilities */
977 
978 /**
979  * Decoder can use draw_horiz_band callback.
980  */
981 #define AV_CODEC_CAP_DRAW_HORIZ_BAND (1 << 0)
982 /**
983  * Codec uses get_buffer() for allocating buffers and supports custom allocators.
984  * If not set, it might not use get_buffer() at all or use operations that
985  * assume the buffer was allocated by avcodec_default_get_buffer.
986  */
987 #define AV_CODEC_CAP_DR1 (1 << 1)
988 #define AV_CODEC_CAP_TRUNCATED (1 << 3)
989 /**
990  * Encoder or decoder requires flushing with NULL input at the end in order to
991  * give the complete and correct output.
992  *
993  * NOTE: If this flag is not set, the codec is guaranteed to never be fed with
994  * with NULL data. The user can still send NULL data to the public encode
995  * or decode function, but libavcodec will not pass it along to the codec
996  * unless this flag is set.
997  *
998  * Decoders:
999  * The decoder has a non-zero delay and needs to be fed with avpkt->data=NULL,
1000  * avpkt->size=0 at the end to get the delayed data until the decoder no longer
1001  * returns frames.
1002  *
1003  * Encoders:
1004  * The encoder needs to be fed with NULL data at the end of encoding until the
1005  * encoder no longer returns data.
1006  *
1007  * NOTE: For encoders implementing the AVCodec.encode2() function, setting this
1008  * flag also means that the encoder must set the pts and duration for
1009  * each output packet. If this flag is not set, the pts and duration will
1010  * be determined by libavcodec from the input frame.
1011  */
1012 #define AV_CODEC_CAP_DELAY (1 << 5)
1013 /**
1014  * Codec can be fed a final frame with a smaller size.
1015  * This can be used to prevent truncation of the last audio samples.
1016  */
1017 #define AV_CODEC_CAP_SMALL_LAST_FRAME (1 << 6)
1018 
1019 /**
1020  * Codec can output multiple frames per AVPacket
1021  * Normally demuxers return one frame at a time, demuxers which do not do
1022  * are connected to a parser to split what they return into proper frames.
1023  * This flag is reserved to the very rare category of codecs which have a
1024  * bitstream that cannot be split into frames without timeconsuming
1025  * operations like full decoding. Demuxers carrying such bitstreams thus
1026  * may return multiple frames in a packet. This has many disadvantages like
1027  * prohibiting stream copy in many cases thus it should only be considered
1028  * as a last resort.
1029  */
1030 #define AV_CODEC_CAP_SUBFRAMES (1 << 8)
1031 /**
1032  * Codec is experimental and is thus avoided in favor of non experimental
1033  * encoders
1034  */
1035 #define AV_CODEC_CAP_EXPERIMENTAL (1 << 9)
1036 /**
1037  * Codec should fill in channel configuration and samplerate instead of container
1038  */
1039 #define AV_CODEC_CAP_CHANNEL_CONF (1 << 10)
1040 /**
1041  * Codec supports frame-level multithreading.
1042  */
1043 #define AV_CODEC_CAP_FRAME_THREADS (1 << 12)
1044 /**
1045  * Codec supports slice-based (or partition-based) multithreading.
1046  */
1047 #define AV_CODEC_CAP_SLICE_THREADS (1 << 13)
1048 /**
1049  * Codec supports changed parameters at any point.
1050  */
1051 #define AV_CODEC_CAP_PARAM_CHANGE (1 << 14)
1052 /**
1053  * Codec supports avctx->thread_count == 0 (auto).
1054  */
1055 #define AV_CODEC_CAP_AUTO_THREADS (1 << 15)
1056 /**
1057  * Audio encoder supports receiving a different number of samples in each call.
1058  */
1059 #define AV_CODEC_CAP_VARIABLE_FRAME_SIZE (1 << 16)
1060 /**
1061  * Decoder is not a preferred choice for probing.
1062  * This indicates that the decoder is not a good choice for probing.
1063  * It could for example be an expensive to spin up hardware decoder,
1064  * or it could simply not provide a lot of useful information about
1065  * the stream.
1066  * A decoder marked with this flag should only be used as last resort
1067  * choice for probing.
1068  */
1069 #define AV_CODEC_CAP_AVOID_PROBING (1 << 17)
1070 /**
1071  * Codec is intra only.
1072  */
1073 #define AV_CODEC_CAP_INTRA_ONLY 0x40000000
1074 /**
1075  * Codec is lossless.
1076  */
1077 #define AV_CODEC_CAP_LOSSLESS 0x80000000
1078 
1079 /**
1080  * Codec is backed by a hardware implementation. Typically used to
1081  * identify a non-hwaccel hardware decoder. For information about hwaccels, use
1082  * avcodec_get_hw_config() instead.
1083  */
1084 #define AV_CODEC_CAP_HARDWARE (1 << 18)
1085 
1086 /**
1087  * Codec is potentially backed by a hardware implementation, but not
1088  * necessarily. This is used instead of AV_CODEC_CAP_HARDWARE, if the
1089  * implementation provides some sort of internal fallback.
1090  */
1091 #define AV_CODEC_CAP_HYBRID (1 << 19)
1092 
1093 /**
1094  * This codec takes the reordered_opaque field from input AVFrames
1095  * and returns it in the corresponding field in AVCodecContext after
1096  * encoding.
1097  */
1098 #define AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE (1 << 20)
1099 
1100 /**
1101  * Pan Scan area.
1102  * This specifies the area which should be displayed.
1103  * Note there may be multiple such areas for one frame.
1104  */
1105 typedef struct AVPanScan {
1106  /**
1107  * id
1108  * - encoding: Set by user.
1109  * - decoding: Set by libavcodec.
1110  */
1111  int id;
1112 
1113  /**
1114  * width and height in 1/16 pel
1115  * - encoding: Set by user.
1116  * - decoding: Set by libavcodec.
1117  */
1118  int width;
1119  int height;
1120 
1121  /**
1122  * position of the top left corner in 1/16 pel for up to 3 fields/frames
1123  * - encoding: Set by user.
1124  * - decoding: Set by libavcodec.
1125  */
1126  int16_t position[3][2];
1127 } AVPanScan;
1128 
1129 /**
1130  * This structure describes the bitrate properties of an encoded bitstream. It
1131  * roughly corresponds to a subset the VBV parameters for MPEG-2 or HRD
1132  * parameters for H.264/HEVC.
1133  */
1134 typedef struct AVCPBProperties {
1135  /**
1136  * Maximum bitrate of the stream, in bits per second.
1137  * Zero if unknown or unspecified.
1138  */
1139 #if FF_API_UNSANITIZED_BITRATES
1141 #else
1142  int64_t max_bitrate;
1143 #endif
1144  /**
1145  * Minimum bitrate of the stream, in bits per second.
1146  * Zero if unknown or unspecified.
1147  */
1148 #if FF_API_UNSANITIZED_BITRATES
1150 #else
1151  int64_t min_bitrate;
1152 #endif
1153  /**
1154  * Average bitrate of the stream, in bits per second.
1155  * Zero if unknown or unspecified.
1156  */
1157 #if FF_API_UNSANITIZED_BITRATES
1159 #else
1160  int64_t avg_bitrate;
1161 #endif
1162 
1163  /**
1164  * The size of the buffer to which the ratecontrol is applied, in bits.
1165  * Zero if unknown or unspecified.
1166  */
1168 
1169  /**
1170  * The delay between the time the packet this structure is associated with
1171  * is received and the time when it should be decoded, in periods of a 27MHz
1172  * clock.
1173  *
1174  * UINT64_MAX when unknown or unspecified.
1175  */
1176  uint64_t vbv_delay;
1177 } AVCPBProperties;
1178 
1179 typedef struct AVProducerReferenceTime {
1180  int64_t wallclock;
1181  int flags;
1183 
1184 /**
1185  * The decoder will keep a reference to the frame and may reuse it later.
1186  */
1187 #define AV_GET_BUFFER_FLAG_REF (1 << 0)
1188 
1189 /**
1190  * @defgroup lavc_packet AVPacket
1191  *
1192  * Types and functions for working with AVPacket.
1193  * @{
1194  */
1196  /**
1197  * An AV_PKT_DATA_PALETTE side data packet contains exactly AVPALETTE_SIZE
1198  * bytes worth of palette. This side data signals that a new palette is
1199  * present.
1200  */
1202 
1203  /**
1204  * The AV_PKT_DATA_NEW_EXTRADATA is used to notify the codec or the format
1205  * that the extradata buffer was changed and the receiving side should
1206  * act upon it appropriately. The new extradata is embedded in the side
1207  * data buffer and should be immediately used for processing the current
1208  * frame or packet.
1209  */
1211 
1212  /**
1213  * An AV_PKT_DATA_PARAM_CHANGE side data packet is laid out as follows:
1214  * @code
1215  * u32le param_flags
1216  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT)
1217  * s32le channel_count
1218  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT)
1219  * u64le channel_layout
1220  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE)
1221  * s32le sample_rate
1222  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS)
1223  * s32le width
1224  * s32le height
1225  * @endcode
1226  */
1228 
1229  /**
1230  * An AV_PKT_DATA_H263_MB_INFO side data packet contains a number of
1231  * structures with info about macroblocks relevant to splitting the
1232  * packet into smaller packets on macroblock edges (e.g. as for RFC 2190).
1233  * That is, it does not necessarily contain info about all macroblocks,
1234  * as long as the distance between macroblocks in the info is smaller
1235  * than the target payload size.
1236  * Each MB info structure is 12 bytes, and is laid out as follows:
1237  * @code
1238  * u32le bit offset from the start of the packet
1239  * u8 current quantizer at the start of the macroblock
1240  * u8 GOB number
1241  * u16le macroblock address within the GOB
1242  * u8 horizontal MV predictor
1243  * u8 vertical MV predictor
1244  * u8 horizontal MV predictor for block number 3
1245  * u8 vertical MV predictor for block number 3
1246  * @endcode
1247  */
1249 
1250  /**
1251  * This side data should be associated with an audio stream and contains
1252  * ReplayGain information in form of the AVReplayGain struct.
1253  */
1255 
1256  /**
1257  * This side data contains a 3x3 transformation matrix describing an affine
1258  * transformation that needs to be applied to the decoded video frames for
1259  * correct presentation.
1260  *
1261  * See libavutil/display.h for a detailed description of the data.
1262  */
1264 
1265  /**
1266  * This side data should be associated with a video stream and contains
1267  * Stereoscopic 3D information in form of the AVStereo3D struct.
1268  */
1270 
1271  /**
1272  * This side data should be associated with an audio stream and corresponds
1273  * to enum AVAudioServiceType.
1274  */
1276 
1277  /**
1278  * This side data contains quality related information from the encoder.
1279  * @code
1280  * u32le quality factor of the compressed frame. Allowed range is between 1 (good) and FF_LAMBDA_MAX (bad).
1281  * u8 picture type
1282  * u8 error count
1283  * u16 reserved
1284  * u64le[error count] sum of squared differences between encoder in and output
1285  * @endcode
1286  */
1288 
1289  /**
1290  * This side data contains an integer value representing the stream index
1291  * of a "fallback" track. A fallback track indicates an alternate
1292  * track to use when the current track can not be decoded for some reason.
1293  * e.g. no decoder available for codec.
1294  */
1296 
1297  /**
1298  * This side data corresponds to the AVCPBProperties struct.
1299  */
1301 
1302  /**
1303  * Recommmends skipping the specified number of samples
1304  * @code
1305  * u32le number of samples to skip from start of this packet
1306  * u32le number of samples to skip from end of this packet
1307  * u8 reason for start skip
1308  * u8 reason for end skip (0=padding silence, 1=convergence)
1309  * @endcode
1310  */
1312 
1313  /**
1314  * An AV_PKT_DATA_JP_DUALMONO side data packet indicates that
1315  * the packet may contain "dual mono" audio specific to Japanese DTV
1316  * and if it is true, recommends only the selected channel to be used.
1317  * @code
1318  * u8 selected channels (0=mail/left, 1=sub/right, 2=both)
1319  * @endcode
1320  */
1322 
1323  /**
1324  * A list of zero terminated key/value strings. There is no end marker for
1325  * the list, so it is required to rely on the side data size to stop.
1326  */
1328 
1329  /**
1330  * Subtitle event position
1331  * @code
1332  * u32le x1
1333  * u32le y1
1334  * u32le x2
1335  * u32le y2
1336  * @endcode
1337  */
1339 
1340  /**
1341  * Data found in BlockAdditional element of matroska container. There is
1342  * no end marker for the data, so it is required to rely on the side data
1343  * size to recognize the end. 8 byte id (as found in BlockAddId) followed
1344  * by data.
1345  */
1347 
1348  /**
1349  * The optional first identifier line of a WebVTT cue.
1350  */
1352 
1353  /**
1354  * The optional settings (rendering instructions) that immediately
1355  * follow the timestamp specifier of a WebVTT cue.
1356  */
1358 
1359  /**
1360  * A list of zero terminated key/value strings. There is no end marker for
1361  * the list, so it is required to rely on the side data size to stop. This
1362  * side data includes updated metadata which appeared in the stream.
1363  */
1365 
1366  /**
1367  * MPEGTS stream ID as uint8_t, this is required to pass the stream ID
1368  * information from the demuxer to the corresponding muxer.
1369  */
1371 
1372  /**
1373  * Mastering display metadata (based on SMPTE-2086:2014). This metadata
1374  * should be associated with a video stream and contains data in the form
1375  * of the AVMasteringDisplayMetadata struct.
1376  */
1378 
1379  /**
1380  * This side data should be associated with a video stream and corresponds
1381  * to the AVSphericalMapping structure.
1382  */
1384 
1385  /**
1386  * Content light level (based on CTA-861.3). This metadata should be
1387  * associated with a video stream and contains data in the form of the
1388  * AVContentLightMetadata struct.
1389  */
1391 
1392  /**
1393  * ATSC A53 Part 4 Closed Captions. This metadata should be associated with
1394  * a video stream. A53 CC bitstream is stored as uint8_t in AVPacketSideData.data.
1395  * The number of bytes of CC data is AVPacketSideData.size.
1396  */
1398 
1399  /**
1400  * This side data is encryption initialization data.
1401  * The format is not part of ABI, use av_encryption_init_info_* methods to
1402  * access.
1403  */
1405 
1406  /**
1407  * This side data contains encryption info for how to decrypt the packet.
1408  * The format is not part of ABI, use av_encryption_info_* methods to access.
1409  */
1411 
1412  /**
1413  * Active Format Description data consisting of a single byte as specified
1414  * in ETSI TS 101 154 using AVActiveFormatDescription enum.
1415  */
1417 
1418  /**
1419  * Producer Reference Time data corresponding to the AVProducerReferenceTime struct.
1420  */
1422 
1423  /**
1424  * The number of side data types.
1425  * This is not part of the public API/ABI in the sense that it may
1426  * change when new side data types are added.
1427  * This must stay the last enum value.
1428  * If its value becomes huge, some code using it
1429  * needs to be updated as it assumes it to be smaller than other limits.
1430  */
1432 };
1433 
1434 #define AV_PKT_DATA_QUALITY_FACTOR AV_PKT_DATA_QUALITY_STATS //DEPRECATED
1435 
1436 typedef struct AVPacketSideData {
1438  int size;
1441 
1442 /**
1443  * This structure stores compressed data. It is typically exported by demuxers
1444  * and then passed as input to decoders, or received as output from encoders and
1445  * then passed to muxers.
1446  *
1447  * For video, it should typically contain one compressed frame. For audio it may
1448  * contain several compressed frames. Encoders are allowed to output empty
1449  * packets, with no compressed data, containing only side data
1450  * (e.g. to update some stream parameters at the end of encoding).
1451  *
1452  * AVPacket is one of the few structs in FFmpeg, whose size is a part of public
1453  * ABI. Thus it may be allocated on stack and no new fields can be added to it
1454  * without libavcodec and libavformat major bump.
1455  *
1456  * The semantics of data ownership depends on the buf field.
1457  * If it is set, the packet data is dynamically allocated and is
1458  * valid indefinitely until a call to av_packet_unref() reduces the
1459  * reference count to 0.
1460  *
1461  * If the buf field is not set av_packet_ref() would make a copy instead
1462  * of increasing the reference count.
1463  *
1464  * The side data is always allocated with av_malloc(), copied by
1465  * av_packet_ref() and freed by av_packet_unref().
1466  *
1467  * @see av_packet_ref
1468  * @see av_packet_unref
1469  */
1470 typedef struct AVPacket {
1471  /**
1472  * A reference to the reference-counted buffer where the packet data is
1473  * stored.
1474  * May be NULL, then the packet data is not reference-counted.
1475  */
1477  /**
1478  * Presentation timestamp in AVStream->time_base units; the time at which
1479  * the decompressed packet will be presented to the user.
1480  * Can be AV_NOPTS_VALUE if it is not stored in the file.
1481  * pts MUST be larger or equal to dts as presentation cannot happen before
1482  * decompression, unless one wants to view hex dumps. Some formats misuse
1483  * the terms dts and pts/cts to mean something different. Such timestamps
1484  * must be converted to true pts/dts before they are stored in AVPacket.
1485  */
1486  int64_t pts;
1487  /**
1488  * Decompression timestamp in AVStream->time_base units; the time at which
1489  * the packet is decompressed.
1490  * Can be AV_NOPTS_VALUE if it is not stored in the file.
1491  */
1492  int64_t dts;
1494  int size;
1496  /**
1497  * A combination of AV_PKT_FLAG values
1498  */
1499  int flags;
1500  /**
1501  * Additional packet data that can be provided by the container.
1502  * Packet can contain several types of side information.
1503  */
1506 
1507  /**
1508  * Duration of this packet in AVStream->time_base units, 0 if unknown.
1509  * Equals next_pts - this_pts in presentation order.
1510  */
1511  int64_t duration;
1512 
1513  int64_t pos; ///< byte position in stream, -1 if unknown
1514 
1515 #if FF_API_CONVERGENCE_DURATION
1516  /**
1517  * @deprecated Same as the duration field, but as int64_t. This was required
1518  * for Matroska subtitles, whose duration values could overflow when the
1519  * duration field was still an int.
1520  */
1523 #endif
1524 } AVPacket;
1525 #define AV_PKT_FLAG_KEY 0x0001 ///< The packet contains a keyframe
1526 #define AV_PKT_FLAG_CORRUPT 0x0002 ///< The packet content is corrupted
1527 /**
1528  * Flag is used to discard packets which are required to maintain valid
1529  * decoder state but are not required for output and should be dropped
1530  * after decoding.
1531  **/
1532 #define AV_PKT_FLAG_DISCARD 0x0004
1533 /**
1534  * The packet comes from a trusted source.
1535  *
1536  * Otherwise-unsafe constructs such as arbitrary pointers to data
1537  * outside the packet may be followed.
1538  */
1539 #define AV_PKT_FLAG_TRUSTED 0x0008
1540 /**
1541  * Flag is used to indicate packets that contain frames that can
1542  * be discarded by the decoder. I.e. Non-reference frames.
1543  */
1544 #define AV_PKT_FLAG_DISPOSABLE 0x0010
1545 
1546 
1552 };
1553 /**
1554  * @}
1555  */
1556 
1557 struct AVCodecInternal;
1558 
1562  AV_FIELD_TT, //< Top coded_first, top displayed first
1563  AV_FIELD_BB, //< Bottom coded first, bottom displayed first
1564  AV_FIELD_TB, //< Top coded first, bottom displayed first
1565  AV_FIELD_BT, //< Bottom coded first, top displayed first
1566 };
1567 
1568 /**
1569  * main external API structure.
1570  * New fields can be added to the end with minor version bumps.
1571  * Removal, reordering and changes to existing fields require a major
1572  * version bump.
1573  * You can use AVOptions (av_opt* / av_set/get*()) to access these fields from user
1574  * applications.
1575  * The name string for AVOptions options matches the associated command line
1576  * parameter name and can be found in libavcodec/options_table.h
1577  * The AVOption/command line parameter names differ in some cases from the C
1578  * structure field names for historic reasons or brevity.
1579  * sizeof(AVCodecContext) must not be used outside libav*.
1580  */
1581 typedef struct AVCodecContext {
1582  /**
1583  * information on struct for av_log
1584  * - set by avcodec_alloc_context3
1585  */
1588 
1589  enum AVMediaType codec_type; /* see AVMEDIA_TYPE_xxx */
1590  const struct AVCodec *codec;
1591  enum AVCodecID codec_id; /* see AV_CODEC_ID_xxx */
1592 
1593  /**
1594  * fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
1595  * This is used to work around some encoder bugs.
1596  * A demuxer should set this to what is stored in the field used to identify the codec.
1597  * If there are multiple such fields in a container then the demuxer should choose the one
1598  * which maximizes the information about the used codec.
1599  * If the codec tag field in a container is larger than 32 bits then the demuxer should
1600  * remap the longer ID to 32 bits with a table or other structure. Alternatively a new
1601  * extra_codec_tag + size could be added but for this a clear advantage must be demonstrated
1602  * first.
1603  * - encoding: Set by user, if not then the default based on codec_id will be used.
1604  * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
1605  */
1606  unsigned int codec_tag;
1607 
1608  void *priv_data;
1609 
1610  /**
1611  * Private context used for internal data.
1612  *
1613  * Unlike priv_data, this is not codec-specific. It is used in general
1614  * libavcodec functions.
1615  */
1616  struct AVCodecInternal *internal;
1617 
1618  /**
1619  * Private data of the user, can be used to carry app specific stuff.
1620  * - encoding: Set by user.
1621  * - decoding: Set by user.
1622  */
1623  void *opaque;
1624 
1625  /**
1626  * the average bitrate
1627  * - encoding: Set by user; unused for constant quantizer encoding.
1628  * - decoding: Set by user, may be overwritten by libavcodec
1629  * if this info is available in the stream
1630  */
1631  int64_t bit_rate;
1632 
1633  /**
1634  * number of bits the bitstream is allowed to diverge from the reference.
1635  * the reference can be CBR (for CBR pass1) or VBR (for pass2)
1636  * - encoding: Set by user; unused for constant quantizer encoding.
1637  * - decoding: unused
1638  */
1640 
1641  /**
1642  * Global quality for codecs which cannot change it per frame.
1643  * This should be proportional to MPEG-1/2/4 qscale.
1644  * - encoding: Set by user.
1645  * - decoding: unused
1646  */
1648 
1649  /**
1650  * - encoding: Set by user.
1651  * - decoding: unused
1652  */
1654 #define FF_COMPRESSION_DEFAULT -1
1655 
1656  /**
1657  * AV_CODEC_FLAG_*.
1658  * - encoding: Set by user.
1659  * - decoding: Set by user.
1660  */
1661  int flags;
1662 
1663  /**
1664  * AV_CODEC_FLAG2_*
1665  * - encoding: Set by user.
1666  * - decoding: Set by user.
1667  */
1668  int flags2;
1669 
1670  /**
1671  * some codecs need / can use extradata like Huffman tables.
1672  * MJPEG: Huffman tables
1673  * rv10: additional flags
1674  * MPEG-4: global headers (they can be in the bitstream or here)
1675  * The allocated memory should be AV_INPUT_BUFFER_PADDING_SIZE bytes larger
1676  * than extradata_size to avoid problems if it is read with the bitstream reader.
1677  * The bytewise contents of extradata must not depend on the architecture or CPU endianness.
1678  * Must be allocated with the av_malloc() family of functions.
1679  * - encoding: Set/allocated/freed by libavcodec.
1680  * - decoding: Set/allocated/freed by user.
1681  */
1684 
1685  /**
1686  * This is the fundamental unit of time (in seconds) in terms
1687  * of which frame timestamps are represented. For fixed-fps content,
1688  * timebase should be 1/framerate and timestamp increments should be
1689  * identically 1.
1690  * This often, but not always is the inverse of the frame rate or field rate
1691  * for video. 1/time_base is not the average frame rate if the frame rate is not
1692  * constant.
1693  *
1694  * Like containers, elementary streams also can store timestamps, 1/time_base
1695  * is the unit in which these timestamps are specified.
1696  * As example of such codec time base see ISO/IEC 14496-2:2001(E)
1697  * vop_time_increment_resolution and fixed_vop_rate
1698  * (fixed_vop_rate == 0 implies that it is different from the framerate)
1699  *
1700  * - encoding: MUST be set by user.
1701  * - decoding: the use of this field for decoding is deprecated.
1702  * Use framerate instead.
1703  */
1705 
1706  /**
1707  * For some codecs, the time base is closer to the field rate than the frame rate.
1708  * Most notably, H.264 and MPEG-2 specify time_base as half of frame duration
1709  * if no telecine is used ...
1710  *
1711  * Set to time_base ticks per frame. Default 1, e.g., H.264/MPEG-2 set it to 2.
1712  */
1714 
1715  /**
1716  * Codec delay.
1717  *
1718  * Encoding: Number of frames delay there will be from the encoder input to
1719  * the decoder output. (we assume the decoder matches the spec)
1720  * Decoding: Number of frames delay in addition to what a standard decoder
1721  * as specified in the spec would produce.
1722  *
1723  * Video:
1724  * Number of frames the decoded output will be delayed relative to the
1725  * encoded input.
1726  *
1727  * Audio:
1728  * For encoding, this field is unused (see initial_padding).
1729  *
1730  * For decoding, this is the number of samples the decoder needs to
1731  * output before the decoder's output is valid. When seeking, you should
1732  * start decoding this many samples prior to your desired seek point.
1733  *
1734  * - encoding: Set by libavcodec.
1735  * - decoding: Set by libavcodec.
1736  */
1737  int delay;
1738 
1739 
1740  /* video only */
1741  /**
1742  * picture width / height.
1743  *
1744  * @note Those fields may not match the values of the last
1745  * AVFrame output by avcodec_decode_video2 due frame
1746  * reordering.
1747  *
1748  * - encoding: MUST be set by user.
1749  * - decoding: May be set by the user before opening the decoder if known e.g.
1750  * from the container. Some decoders will require the dimensions
1751  * to be set by the caller. During decoding, the decoder may
1752  * overwrite those values as required while parsing the data.
1753  */
1755 
1756  /**
1757  * Bitstream width / height, may be different from width/height e.g. when
1758  * the decoded frame is cropped before being output or lowres is enabled.
1759  *
1760  * @note Those field may not match the value of the last
1761  * AVFrame output by avcodec_receive_frame() due frame
1762  * reordering.
1763  *
1764  * - encoding: unused
1765  * - decoding: May be set by the user before opening the decoder if known
1766  * e.g. from the container. During decoding, the decoder may
1767  * overwrite those values as required while parsing the data.
1768  */
1769  int coded_width, coded_height;
1770 
1771  /**
1772  * the number of pictures in a group of pictures, or 0 for intra_only
1773  * - encoding: Set by user.
1774  * - decoding: unused
1775  */
1777 
1778  /**
1779  * Pixel format, see AV_PIX_FMT_xxx.
1780  * May be set by the demuxer if known from headers.
1781  * May be overridden by the decoder if it knows better.
1782  *
1783  * @note This field may not match the value of the last
1784  * AVFrame output by avcodec_receive_frame() due frame
1785  * reordering.
1786  *
1787  * - encoding: Set by user.
1788  * - decoding: Set by user if known, overridden by libavcodec while
1789  * parsing the data.
1790  */
1792 
1793  /**
1794  * If non NULL, 'draw_horiz_band' is called by the libavcodec
1795  * decoder to draw a horizontal band. It improves cache usage. Not
1796  * all codecs can do that. You must check the codec capabilities
1797  * beforehand.
1798  * When multithreading is used, it may be called from multiple threads
1799  * at the same time; threads might draw different parts of the same AVFrame,
1800  * or multiple AVFrames, and there is no guarantee that slices will be drawn
1801  * in order.
1802  * The function is also used by hardware acceleration APIs.
1803  * It is called at least once during frame decoding to pass
1804  * the data needed for hardware render.
1805  * In that mode instead of pixel data, AVFrame points to
1806  * a structure specific to the acceleration API. The application
1807  * reads the structure and can change some fields to indicate progress
1808  * or mark state.
1809  * - encoding: unused
1810  * - decoding: Set by user.
1811  * @param height the height of the slice
1812  * @param y the y position of the slice
1813  * @param type 1->top field, 2->bottom field, 3->frame
1814  * @param offset offset into the AVFrame.data from which the slice should be read
1815  */
1817  const AVFrame *src, int offset[AV_NUM_DATA_POINTERS],
1818  int y, int type, int height);
1819 
1820  /**
1821  * callback to negotiate the pixelFormat
1822  * @param fmt is the list of formats which are supported by the codec,
1823  * it is terminated by -1 as 0 is a valid format, the formats are ordered by quality.
1824  * The first is always the native one.
1825  * @note The callback may be called again immediately if initialization for
1826  * the selected (hardware-accelerated) pixel format failed.
1827  * @warning Behavior is undefined if the callback returns a value not
1828  * in the fmt list of formats.
1829  * @return the chosen format
1830  * - encoding: unused
1831  * - decoding: Set by user, if not set the native format will be chosen.
1832  */
1833  enum AVPixelFormat (*get_format)(struct AVCodecContext *s, const enum AVPixelFormat * fmt);
1834 
1835  /**
1836  * maximum number of B-frames between non-B-frames
1837  * Note: The output will be delayed by max_b_frames+1 relative to the input.
1838  * - encoding: Set by user.
1839  * - decoding: unused
1840  */
1842 
1843  /**
1844  * qscale factor between IP and B-frames
1845  * If > 0 then the last P-frame quantizer will be used (q= lastp_q*factor+offset).
1846  * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1847  * - encoding: Set by user.
1848  * - decoding: unused
1849  */
1851 
1852 #if FF_API_PRIVATE_OPT
1853  /** @deprecated use encoder private options instead */
1856 #endif
1857 
1858  /**
1859  * qscale offset between IP and B-frames
1860  * - encoding: Set by user.
1861  * - decoding: unused
1862  */
1864 
1865  /**
1866  * Size of the frame reordering buffer in the decoder.
1867  * For MPEG-2 it is 1 IPB or 0 low delay IP.
1868  * - encoding: Set by libavcodec.
1869  * - decoding: Set by libavcodec.
1870  */
1872 
1873 #if FF_API_PRIVATE_OPT
1874  /** @deprecated use encoder private options instead */
1877 #endif
1878 
1879  /**
1880  * qscale factor between P- and I-frames
1881  * If > 0 then the last P-frame quantizer will be used (q = lastp_q * factor + offset).
1882  * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1883  * - encoding: Set by user.
1884  * - decoding: unused
1885  */
1887 
1888  /**
1889  * qscale offset between P and I-frames
1890  * - encoding: Set by user.
1891  * - decoding: unused
1892  */
1894 
1895  /**
1896  * luminance masking (0-> disabled)
1897  * - encoding: Set by user.
1898  * - decoding: unused
1899  */
1901 
1902  /**
1903  * temporary complexity masking (0-> disabled)
1904  * - encoding: Set by user.
1905  * - decoding: unused
1906  */
1908 
1909  /**
1910  * spatial complexity masking (0-> disabled)
1911  * - encoding: Set by user.
1912  * - decoding: unused
1913  */
1915 
1916  /**
1917  * p block masking (0-> disabled)
1918  * - encoding: Set by user.
1919  * - decoding: unused
1920  */
1921  float p_masking;
1922 
1923  /**
1924  * darkness masking (0-> disabled)
1925  * - encoding: Set by user.
1926  * - decoding: unused
1927  */
1929 
1930  /**
1931  * slice count
1932  * - encoding: Set by libavcodec.
1933  * - decoding: Set by user (or 0).
1934  */
1936 
1937 #if FF_API_PRIVATE_OPT
1938  /** @deprecated use encoder private options instead */
1941 #define FF_PRED_LEFT 0
1942 #define FF_PRED_PLANE 1
1943 #define FF_PRED_MEDIAN 2
1944 #endif
1945 
1946  /**
1947  * slice offsets in the frame in bytes
1948  * - encoding: Set/allocated by libavcodec.
1949  * - decoding: Set/allocated by user (or NULL).
1950  */
1952 
1953  /**
1954  * sample aspect ratio (0 if unknown)
1955  * That is the width of a pixel divided by the height of the pixel.
1956  * Numerator and denominator must be relatively prime and smaller than 256 for some video standards.
1957  * - encoding: Set by user.
1958  * - decoding: Set by libavcodec.
1959  */
1961 
1962  /**
1963  * motion estimation comparison function
1964  * - encoding: Set by user.
1965  * - decoding: unused
1966  */
1967  int me_cmp;
1968  /**
1969  * subpixel motion estimation comparison function
1970  * - encoding: Set by user.
1971  * - decoding: unused
1972  */
1974  /**
1975  * macroblock comparison function (not supported yet)
1976  * - encoding: Set by user.
1977  * - decoding: unused
1978  */
1979  int mb_cmp;
1980  /**
1981  * interlaced DCT comparison function
1982  * - encoding: Set by user.
1983  * - decoding: unused
1984  */
1986 #define FF_CMP_SAD 0
1987 #define FF_CMP_SSE 1
1988 #define FF_CMP_SATD 2
1989 #define FF_CMP_DCT 3
1990 #define FF_CMP_PSNR 4
1991 #define FF_CMP_BIT 5
1992 #define FF_CMP_RD 6
1993 #define FF_CMP_ZERO 7
1994 #define FF_CMP_VSAD 8
1995 #define FF_CMP_VSSE 9
1996 #define FF_CMP_NSSE 10
1997 #define FF_CMP_W53 11
1998 #define FF_CMP_W97 12
1999 #define FF_CMP_DCTMAX 13
2000 #define FF_CMP_DCT264 14
2001 #define FF_CMP_MEDIAN_SAD 15
2002 #define FF_CMP_CHROMA 256
2003 
2004  /**
2005  * ME diamond size & shape
2006  * - encoding: Set by user.
2007  * - decoding: unused
2008  */
2010 
2011  /**
2012  * amount of previous MV predictors (2a+1 x 2a+1 square)
2013  * - encoding: Set by user.
2014  * - decoding: unused
2015  */
2017 
2018 #if FF_API_PRIVATE_OPT
2019  /** @deprecated use encoder private options instead */
2021  int pre_me;
2022 #endif
2023 
2024  /**
2025  * motion estimation prepass comparison function
2026  * - encoding: Set by user.
2027  * - decoding: unused
2028  */
2030 
2031  /**
2032  * ME prepass diamond size & shape
2033  * - encoding: Set by user.
2034  * - decoding: unused
2035  */
2037 
2038  /**
2039  * subpel ME quality
2040  * - encoding: Set by user.
2041  * - decoding: unused
2042  */
2044 
2045  /**
2046  * maximum motion estimation search range in subpel units
2047  * If 0 then no limit.
2048  *
2049  * - encoding: Set by user.
2050  * - decoding: unused
2051  */
2053 
2054  /**
2055  * slice flags
2056  * - encoding: unused
2057  * - decoding: Set by user.
2058  */
2060 #define SLICE_FLAG_CODED_ORDER 0x0001 ///< draw_horiz_band() is called in coded order instead of display
2061 #define SLICE_FLAG_ALLOW_FIELD 0x0002 ///< allow draw_horiz_band() with field slices (MPEG-2 field pics)
2062 #define SLICE_FLAG_ALLOW_PLANE 0x0004 ///< allow draw_horiz_band() with 1 component at a time (SVQ1)
2063 
2064  /**
2065  * macroblock decision mode
2066  * - encoding: Set by user.
2067  * - decoding: unused
2068  */
2070 #define FF_MB_DECISION_SIMPLE 0 ///< uses mb_cmp
2071 #define FF_MB_DECISION_BITS 1 ///< chooses the one which needs the fewest bits
2072 #define FF_MB_DECISION_RD 2 ///< rate distortion
2073 
2074  /**
2075  * custom intra quantization matrix
2076  * Must be allocated with the av_malloc() family of functions, and will be freed in
2077  * avcodec_free_context().
2078  * - encoding: Set/allocated by user, freed by libavcodec. Can be NULL.
2079  * - decoding: Set/allocated/freed by libavcodec.
2080  */
2081  uint16_t *intra_matrix;
2082 
2083  /**
2084  * custom inter quantization matrix
2085  * Must be allocated with the av_malloc() family of functions, and will be freed in
2086  * avcodec_free_context().
2087  * - encoding: Set/allocated by user, freed by libavcodec. Can be NULL.
2088  * - decoding: Set/allocated/freed by libavcodec.
2089  */
2090  uint16_t *inter_matrix;
2091 
2092 #if FF_API_PRIVATE_OPT
2093  /** @deprecated use encoder private options instead */
2096 
2097  /** @deprecated use encoder private options instead */
2100 #endif
2101 
2102  /**
2103  * precision of the intra DC coefficient - 8
2104  * - encoding: Set by user.
2105  * - decoding: Set by libavcodec
2106  */
2108 
2109  /**
2110  * Number of macroblock rows at the top which are skipped.
2111  * - encoding: unused
2112  * - decoding: Set by user.
2113  */
2115 
2116  /**
2117  * Number of macroblock rows at the bottom which are skipped.
2118  * - encoding: unused
2119  * - decoding: Set by user.
2120  */
2122 
2123  /**
2124  * minimum MB Lagrange multiplier
2125  * - encoding: Set by user.
2126  * - decoding: unused
2127  */
2128  int mb_lmin;
2129 
2130  /**
2131  * maximum MB Lagrange multiplier
2132  * - encoding: Set by user.
2133  * - decoding: unused
2134  */
2135  int mb_lmax;
2136 
2137 #if FF_API_PRIVATE_OPT
2138  /**
2139  * @deprecated use encoder private options instead
2140  */
2143 #endif
2144 
2145  /**
2146  * - encoding: Set by user.
2147  * - decoding: unused
2148  */
2150 
2151 #if FF_API_PRIVATE_OPT
2152  /** @deprecated use encoder private options instead */
2155 #endif
2156 
2157  /**
2158  * minimum GOP size
2159  * - encoding: Set by user.
2160  * - decoding: unused
2161  */
2163 
2164  /**
2165  * number of reference frames
2166  * - encoding: Set by user.
2167  * - decoding: Set by lavc.
2168  */
2169  int refs;
2170 
2171 #if FF_API_PRIVATE_OPT
2172  /** @deprecated use encoder private options instead */
2175 #endif
2176 
2177  /**
2178  * Note: Value depends upon the compare function used for fullpel ME.
2179  * - encoding: Set by user.
2180  * - decoding: unused
2181  */
2183 
2184 #if FF_API_PRIVATE_OPT
2185  /** @deprecated use encoder private options instead */
2188 #endif
2189 
2190  /**
2191  * Chromaticity coordinates of the source primaries.
2192  * - encoding: Set by user
2193  * - decoding: Set by libavcodec
2194  */
2196 
2197  /**
2198  * Color Transfer Characteristic.
2199  * - encoding: Set by user
2200  * - decoding: Set by libavcodec
2201  */
2203 
2204  /**
2205  * YUV colorspace type.
2206  * - encoding: Set by user
2207  * - decoding: Set by libavcodec
2208  */
2210 
2211  /**
2212  * MPEG vs JPEG YUV range.
2213  * - encoding: Set by user
2214  * - decoding: Set by libavcodec
2215  */
2217 
2218  /**
2219  * This defines the location of chroma samples.
2220  * - encoding: Set by user
2221  * - decoding: Set by libavcodec
2222  */
2224 
2225  /**
2226  * Number of slices.
2227  * Indicates number of picture subdivisions. Used for parallelized
2228  * decoding.
2229  * - encoding: Set by user
2230  * - decoding: unused
2231  */
2232  int slices;
2233 
2234  /** Field order
2235  * - encoding: set by libavcodec
2236  * - decoding: Set by user.
2237  */
2239 
2240  /* audio only */
2241  int sample_rate; ///< samples per second
2242  int channels; ///< number of audio channels
2243 
2244  /**
2245  * audio sample format
2246  * - encoding: Set by user.
2247  * - decoding: Set by libavcodec.
2248  */
2249  enum AVSampleFormat sample_fmt; ///< sample format
2250 
2251  /* The following data should not be initialized. */
2252  /**
2253  * Number of samples per channel in an audio frame.
2254  *
2255  * - encoding: set by libavcodec in avcodec_open2(). Each submitted frame
2256  * except the last must contain exactly frame_size samples per channel.
2257  * May be 0 when the codec has AV_CODEC_CAP_VARIABLE_FRAME_SIZE set, then the
2258  * frame size is not restricted.
2259  * - decoding: may be set by some decoders to indicate constant frame size
2260  */
2262 
2263  /**
2264  * Frame counter, set by libavcodec.
2265  *
2266  * - decoding: total number of frames returned from the decoder so far.
2267  * - encoding: total number of frames passed to the encoder so far.
2268  *
2269  * @note the counter is not incremented if encoding/decoding resulted in
2270  * an error.
2271  */
2273 
2274  /**
2275  * number of bytes per packet if constant and known or 0
2276  * Used by some WAV based audio codecs.
2277  */
2279 
2280  /**
2281  * Audio cutoff bandwidth (0 means "automatic")
2282  * - encoding: Set by user.
2283  * - decoding: unused
2284  */
2285  int cutoff;
2286 
2287  /**
2288  * Audio channel layout.
2289  * - encoding: set by user.
2290  * - decoding: set by user, may be overwritten by libavcodec.
2291  */
2292  uint64_t channel_layout;
2293 
2294  /**
2295  * Request decoder to use this channel layout if it can (0 for default)
2296  * - encoding: unused
2297  * - decoding: Set by user.
2298  */
2300 
2301  /**
2302  * Type of service that the audio stream conveys.
2303  * - encoding: Set by user.
2304  * - decoding: Set by libavcodec.
2305  */
2307 
2308  /**
2309  * desired sample format
2310  * - encoding: Not used.
2311  * - decoding: Set by user.
2312  * Decoder will decode to this format if it can.
2313  */
2315 
2316  /**
2317  * This callback is called at the beginning of each frame to get data
2318  * buffer(s) for it. There may be one contiguous buffer for all the data or
2319  * there may be a buffer per each data plane or anything in between. What
2320  * this means is, you may set however many entries in buf[] you feel necessary.
2321  * Each buffer must be reference-counted using the AVBuffer API (see description
2322  * of buf[] below).
2323  *
2324  * The following fields will be set in the frame before this callback is
2325  * called:
2326  * - format
2327  * - width, height (video only)
2328  * - sample_rate, channel_layout, nb_samples (audio only)
2329  * Their values may differ from the corresponding values in
2330  * AVCodecContext. This callback must use the frame values, not the codec
2331  * context values, to calculate the required buffer size.
2332  *
2333  * This callback must fill the following fields in the frame:
2334  * - data[]
2335  * - linesize[]
2336  * - extended_data:
2337  * * if the data is planar audio with more than 8 channels, then this
2338  * callback must allocate and fill extended_data to contain all pointers
2339  * to all data planes. data[] must hold as many pointers as it can.
2340  * extended_data must be allocated with av_malloc() and will be freed in
2341  * av_frame_unref().
2342  * * otherwise extended_data must point to data
2343  * - buf[] must contain one or more pointers to AVBufferRef structures. Each of
2344  * the frame's data and extended_data pointers must be contained in these. That
2345  * is, one AVBufferRef for each allocated chunk of memory, not necessarily one
2346  * AVBufferRef per data[] entry. See: av_buffer_create(), av_buffer_alloc(),
2347  * and av_buffer_ref().
2348  * - extended_buf and nb_extended_buf must be allocated with av_malloc() by
2349  * this callback and filled with the extra buffers if there are more
2350  * buffers than buf[] can hold. extended_buf will be freed in
2351  * av_frame_unref().
2352  *
2353  * If AV_CODEC_CAP_DR1 is not set then get_buffer2() must call
2354  * avcodec_default_get_buffer2() instead of providing buffers allocated by
2355  * some other means.
2356  *
2357  * Each data plane must be aligned to the maximum required by the target
2358  * CPU.
2359  *
2360  * @see avcodec_default_get_buffer2()
2361  *
2362  * Video:
2363  *
2364  * If AV_GET_BUFFER_FLAG_REF is set in flags then the frame may be reused
2365  * (read and/or written to if it is writable) later by libavcodec.
2366  *
2367  * avcodec_align_dimensions2() should be used to find the required width and
2368  * height, as they normally need to be rounded up to the next multiple of 16.
2369  *
2370  * Some decoders do not support linesizes changing between frames.
2371  *
2372  * If frame multithreading is used and thread_safe_callbacks is set,
2373  * this callback may be called from a different thread, but not from more
2374  * than one at once. Does not need to be reentrant.
2375  *
2376  * @see avcodec_align_dimensions2()
2377  *
2378  * Audio:
2379  *
2380  * Decoders request a buffer of a particular size by setting
2381  * AVFrame.nb_samples prior to calling get_buffer2(). The decoder may,
2382  * however, utilize only part of the buffer by setting AVFrame.nb_samples
2383  * to a smaller value in the output frame.
2384  *
2385  * As a convenience, av_samples_get_buffer_size() and
2386  * av_samples_fill_arrays() in libavutil may be used by custom get_buffer2()
2387  * functions to find the required data size and to fill data pointers and
2388  * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
2389  * since all planes must be the same size.
2390  *
2391  * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
2392  *
2393  * - encoding: unused
2394  * - decoding: Set by libavcodec, user can override.
2395  */
2397 
2398  /**
2399  * If non-zero, the decoded audio and video frames returned from
2400  * avcodec_decode_video2() and avcodec_decode_audio4() are reference-counted
2401  * and are valid indefinitely. The caller must free them with
2402  * av_frame_unref() when they are not needed anymore.
2403  * Otherwise, the decoded frames must not be freed by the caller and are
2404  * only valid until the next decode call.
2405  *
2406  * This is always automatically enabled if avcodec_receive_frame() is used.
2407  *
2408  * - encoding: unused
2409  * - decoding: set by the caller before avcodec_open2().
2410  */
2413 
2414  /* - encoding parameters */
2415  float qcompress; ///< amount of qscale change between easy & hard scenes (0.0-1.0)
2416  float qblur; ///< amount of qscale smoothing over time (0.0-1.0)
2417 
2418  /**
2419  * minimum quantizer
2420  * - encoding: Set by user.
2421  * - decoding: unused
2422  */
2423  int qmin;
2424 
2425  /**
2426  * maximum quantizer
2427  * - encoding: Set by user.
2428  * - decoding: unused
2429  */
2430  int qmax;
2431 
2432  /**
2433  * maximum quantizer difference between frames
2434  * - encoding: Set by user.
2435  * - decoding: unused
2436  */
2438 
2439  /**
2440  * decoder bitstream buffer size
2441  * - encoding: Set by user.
2442  * - decoding: unused
2443  */
2445 
2446  /**
2447  * ratecontrol override, see RcOverride
2448  * - encoding: Allocated/set/freed by user.
2449  * - decoding: unused
2450  */
2453 
2454  /**
2455  * maximum bitrate
2456  * - encoding: Set by user.
2457  * - decoding: Set by user, may be overwritten by libavcodec.
2458  */
2459  int64_t rc_max_rate;
2460 
2461  /**
2462  * minimum bitrate
2463  * - encoding: Set by user.
2464  * - decoding: unused
2465  */
2466  int64_t rc_min_rate;
2467 
2468  /**
2469  * Ratecontrol attempt to use, at maximum, <value> of what can be used without an underflow.
2470  * - encoding: Set by user.
2471  * - decoding: unused.
2472  */
2474 
2475  /**
2476  * Ratecontrol attempt to use, at least, <value> times the amount needed to prevent a vbv overflow.
2477  * - encoding: Set by user.
2478  * - decoding: unused.
2479  */
2481 
2482  /**
2483  * Number of bits which should be loaded into the rc buffer before decoding starts.
2484  * - encoding: Set by user.
2485  * - decoding: unused
2486  */
2488 
2489 #if FF_API_CODER_TYPE
2490 #define FF_CODER_TYPE_VLC 0
2491 #define FF_CODER_TYPE_AC 1
2492 #define FF_CODER_TYPE_RAW 2
2493 #define FF_CODER_TYPE_RLE 3
2494  /**
2495  * @deprecated use encoder private options instead
2496  */
2499 #endif /* FF_API_CODER_TYPE */
2500 
2501 #if FF_API_PRIVATE_OPT
2502  /** @deprecated use encoder private options instead */
2505 #endif
2506 
2507 #if FF_API_PRIVATE_OPT
2508  /** @deprecated use encoder private options instead */
2511 
2512  /** @deprecated use encoder private options instead */
2515 
2516  /** @deprecated use encoder private options instead */
2519 
2520  /** @deprecated use encoder private options instead */
2523 #endif /* FF_API_PRIVATE_OPT */
2524 
2525  /**
2526  * trellis RD quantization
2527  * - encoding: Set by user.
2528  * - decoding: unused
2529  */
2530  int trellis;
2531 
2532 #if FF_API_PRIVATE_OPT
2533  /** @deprecated use encoder private options instead */
2536 
2537  /** @deprecated use encoder private options instead */
2540 
2541  /** @deprecated use encoder private options instead */
2544 #endif
2545 
2546 #if FF_API_RTP_CALLBACK
2547  /**
2548  * @deprecated unused
2549  */
2550  /* The RTP callback: This function is called */
2551  /* every time the encoder has a packet to send. */
2552  /* It depends on the encoder if the data starts */
2553  /* with a Start Code (it should). H.263 does. */
2554  /* mb_nb contains the number of macroblocks */
2555  /* encoded in the RTP payload. */
2557  void (*rtp_callback)(struct AVCodecContext *avctx, void *data, int size, int mb_nb);
2558 #endif
2559 
2560 #if FF_API_PRIVATE_OPT
2561  /** @deprecated use encoder private options instead */
2563  int rtp_payload_size; /* The size of the RTP payload: the coder will */
2564  /* do its best to deliver a chunk with size */
2565  /* below rtp_payload_size, the chunk will start */
2566  /* with a start code on some codecs like H.263. */
2567  /* This doesn't take account of any particular */
2568  /* headers inside the transmitted RTP payload. */
2569 #endif
2570 
2571 #if FF_API_STAT_BITS
2572  /* statistics, used for 2-pass encoding */
2574  int mv_bits;
2582  int i_count;
2584  int p_count;
2589 
2590  /** @deprecated this field is unused */
2593 #endif
2594 
2595  /**
2596  * pass1 encoding statistics output buffer
2597  * - encoding: Set by libavcodec.
2598  * - decoding: unused
2599  */
2600  char *stats_out;
2601 
2602  /**
2603  * pass2 encoding statistics input buffer
2604  * Concatenated stuff from stats_out of pass1 should be placed here.
2605  * - encoding: Allocated/set/freed by user.
2606  * - decoding: unused
2607  */
2608  char *stats_in;
2609 
2610  /**
2611  * Work around bugs in encoders which sometimes cannot be detected automatically.
2612  * - encoding: Set by user
2613  * - decoding: Set by user
2614  */
2616 #define FF_BUG_AUTODETECT 1 ///< autodetection
2617 #define FF_BUG_XVID_ILACE 4
2618 #define FF_BUG_UMP4 8
2619 #define FF_BUG_NO_PADDING 16
2620 #define FF_BUG_AMV 32
2621 #define FF_BUG_QPEL_CHROMA 64
2622 #define FF_BUG_STD_QPEL 128
2623 #define FF_BUG_QPEL_CHROMA2 256
2624 #define FF_BUG_DIRECT_BLOCKSIZE 512
2625 #define FF_BUG_EDGE 1024
2626 #define FF_BUG_HPEL_CHROMA 2048
2627 #define FF_BUG_DC_CLIP 4096
2628 #define FF_BUG_MS 8192 ///< Work around various bugs in Microsoft's broken decoders.
2629 #define FF_BUG_TRUNCATED 16384
2630 #define FF_BUG_IEDGE 32768
2631 
2632  /**
2633  * strictly follow the standard (MPEG-4, ...).
2634  * - encoding: Set by user.
2635  * - decoding: Set by user.
2636  * Setting this to STRICT or higher means the encoder and decoder will
2637  * generally do stupid things, whereas setting it to unofficial or lower
2638  * will mean the encoder might produce output that is not supported by all
2639  * spec-compliant decoders. Decoders don't differentiate between normal,
2640  * unofficial and experimental (that is, they always try to decode things
2641  * when they can) unless they are explicitly asked to behave stupidly
2642  * (=strictly conform to the specs)
2643  */
2645 #define FF_COMPLIANCE_VERY_STRICT 2 ///< Strictly conform to an older more strict version of the spec or reference software.
2646 #define FF_COMPLIANCE_STRICT 1 ///< Strictly conform to all the things in the spec no matter what consequences.
2647 #define FF_COMPLIANCE_NORMAL 0
2648 #define FF_COMPLIANCE_UNOFFICIAL -1 ///< Allow unofficial extensions
2649 #define FF_COMPLIANCE_EXPERIMENTAL -2 ///< Allow nonstandardized experimental things.
2650 
2651  /**
2652  * error concealment flags
2653  * - encoding: unused
2654  * - decoding: Set by user.
2655  */
2657 #define FF_EC_GUESS_MVS 1
2658 #define FF_EC_DEBLOCK 2
2659 #define FF_EC_FAVOR_INTER 256
2660 
2661  /**
2662  * debug
2663  * - encoding: Set by user.
2664  * - decoding: Set by user.
2665  */
2666  int debug;
2667 #define FF_DEBUG_PICT_INFO 1
2668 #define FF_DEBUG_RC 2
2669 #define FF_DEBUG_BITSTREAM 4
2670 #define FF_DEBUG_MB_TYPE 8
2671 #define FF_DEBUG_QP 16
2672 #if FF_API_DEBUG_MV
2673 /**
2674  * @deprecated this option does nothing
2675  */
2676 #define FF_DEBUG_MV 32
2677 #endif
2678 #define FF_DEBUG_DCT_COEFF 0x00000040
2679 #define FF_DEBUG_SKIP 0x00000080
2680 #define FF_DEBUG_STARTCODE 0x00000100
2681 #define FF_DEBUG_ER 0x00000400
2682 #define FF_DEBUG_MMCO 0x00000800
2683 #define FF_DEBUG_BUGS 0x00001000
2684 #if FF_API_DEBUG_MV
2685 #define FF_DEBUG_VIS_QP 0x00002000
2686 #define FF_DEBUG_VIS_MB_TYPE 0x00004000
2687 #endif
2688 #define FF_DEBUG_BUFFERS 0x00008000
2689 #define FF_DEBUG_THREADS 0x00010000
2690 #define FF_DEBUG_GREEN_MD 0x00800000
2691 #define FF_DEBUG_NOMC 0x01000000
2692 
2693 #if FF_API_DEBUG_MV
2694  /**
2695  * debug
2696  * - encoding: Set by user.
2697  * - decoding: Set by user.
2698  */
2699  int debug_mv;
2700 #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 // visualize forward predicted MVs of P-frames
2701 #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 // visualize forward predicted MVs of B-frames
2702 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 // visualize backward predicted MVs of B-frames
2703 #endif
2704 
2705  /**
2706  * Error recognition; may misdetect some more or less valid parts as errors.
2707  * - encoding: unused
2708  * - decoding: Set by user.
2709  */
2711 
2712 /**
2713  * Verify checksums embedded in the bitstream (could be of either encoded or
2714  * decoded data, depending on the codec) and print an error message on mismatch.
2715  * If AV_EF_EXPLODE is also set, a mismatching checksum will result in the
2716  * decoder returning an error.
2717  */
2718 #define AV_EF_CRCCHECK (1<<0)
2719 #define AV_EF_BITSTREAM (1<<1) ///< detect bitstream specification deviations
2720 #define AV_EF_BUFFER (1<<2) ///< detect improper bitstream length
2721 #define AV_EF_EXPLODE (1<<3) ///< abort decoding on minor error detection
2722 
2723 #define AV_EF_IGNORE_ERR (1<<15) ///< ignore errors and continue
2724 #define AV_EF_CAREFUL (1<<16) ///< consider things that violate the spec, are fast to calculate and have not been seen in the wild as errors
2725 #define AV_EF_COMPLIANT (1<<17) ///< consider all spec non compliances as errors
2726 #define AV_EF_AGGRESSIVE (1<<18) ///< consider things that a sane encoder should not do as an error
2727 
2728 
2729  /**
2730  * opaque 64-bit number (generally a PTS) that will be reordered and
2731  * output in AVFrame.reordered_opaque
2732  * - encoding: Set by libavcodec to the reordered_opaque of the input
2733  * frame corresponding to the last returned packet. Only
2734  * supported by encoders with the
2735  * AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE capability.
2736  * - decoding: Set by user.
2737  */
2739 
2740  /**
2741  * Hardware accelerator in use
2742  * - encoding: unused.
2743  * - decoding: Set by libavcodec
2744  */
2745  const struct AVHWAccel *hwaccel;
2746 
2747  /**
2748  * Hardware accelerator context.
2749  * For some hardware accelerators, a global context needs to be
2750  * provided by the user. In that case, this holds display-dependent
2751  * data FFmpeg cannot instantiate itself. Please refer to the
2752  * FFmpeg HW accelerator documentation to know how to fill this
2753  * is. e.g. for VA API, this is a struct vaapi_context.
2754  * - encoding: unused
2755  * - decoding: Set by user
2756  */
2758 
2759  /**
2760  * error
2761  * - encoding: Set by libavcodec if flags & AV_CODEC_FLAG_PSNR.
2762  * - decoding: unused
2763  */
2765 
2766  /**
2767  * DCT algorithm, see FF_DCT_* below
2768  * - encoding: Set by user.
2769  * - decoding: unused
2770  */
2772 #define FF_DCT_AUTO 0
2773 #define FF_DCT_FASTINT 1
2774 #define FF_DCT_INT 2
2775 #define FF_DCT_MMX 3
2776 #define FF_DCT_ALTIVEC 5
2777 #define FF_DCT_FAAN 6
2778 
2779  /**
2780  * IDCT algorithm, see FF_IDCT_* below.
2781  * - encoding: Set by user.
2782  * - decoding: Set by user.
2783  */
2785 #define FF_IDCT_AUTO 0
2786 #define FF_IDCT_INT 1
2787 #define FF_IDCT_SIMPLE 2
2788 #define FF_IDCT_SIMPLEMMX 3
2789 #define FF_IDCT_ARM 7
2790 #define FF_IDCT_ALTIVEC 8
2791 #define FF_IDCT_SIMPLEARM 10
2792 #define FF_IDCT_XVID 14
2793 #define FF_IDCT_SIMPLEARMV5TE 16
2794 #define FF_IDCT_SIMPLEARMV6 17
2795 #define FF_IDCT_FAAN 20
2796 #define FF_IDCT_SIMPLENEON 22
2797 #define FF_IDCT_NONE 24 /* Used by XvMC to extract IDCT coefficients with FF_IDCT_PERM_NONE */
2798 #define FF_IDCT_SIMPLEAUTO 128
2799 
2800  /**
2801  * bits per sample/pixel from the demuxer (needed for huffyuv).
2802  * - encoding: Set by libavcodec.
2803  * - decoding: Set by user.
2804  */
2806 
2807  /**
2808  * Bits per sample/pixel of internal libavcodec pixel/sample format.
2809  * - encoding: set by user.
2810  * - decoding: set by libavcodec.
2811  */
2813 
2814 #if FF_API_LOWRES
2815  /**
2816  * low resolution decoding, 1-> 1/2 size, 2->1/4 size
2817  * - encoding: unused
2818  * - decoding: Set by user.
2819  */
2820  int lowres;
2821 #endif
2822 
2823 #if FF_API_CODED_FRAME
2824  /**
2825  * the picture in the bitstream
2826  * - encoding: Set by libavcodec.
2827  * - decoding: unused
2828  *
2829  * @deprecated use the quality factor packet side data instead
2830  */
2832 #endif
2833 
2834  /**
2835  * thread count
2836  * is used to decide how many independent tasks should be passed to execute()
2837  * - encoding: Set by user.
2838  * - decoding: Set by user.
2839  */
2841 
2842  /**
2843  * Which multithreading methods to use.
2844  * Use of FF_THREAD_FRAME will increase decoding delay by one frame per thread,
2845  * so clients which cannot provide future frames should not use it.
2846  *
2847  * - encoding: Set by user, otherwise the default is used.
2848  * - decoding: Set by user, otherwise the default is used.
2849  */
2851 #define FF_THREAD_FRAME 1 ///< Decode more than one frame at once
2852 #define FF_THREAD_SLICE 2 ///< Decode more than one part of a single frame at once
2853 
2854  /**
2855  * Which multithreading methods are in use by the codec.
2856  * - encoding: Set by libavcodec.
2857  * - decoding: Set by libavcodec.
2858  */
2860 
2861  /**
2862  * Set by the client if its custom get_buffer() callback can be called
2863  * synchronously from another thread, which allows faster multithreaded decoding.
2864  * draw_horiz_band() will be called from other threads regardless of this setting.
2865  * Ignored if the default get_buffer() is used.
2866  * - encoding: Set by user.
2867  * - decoding: Set by user.
2868  */
2870 
2871  /**
2872  * The codec may call this to execute several independent things.
2873  * It will return only after finishing all tasks.
2874  * The user may replace this with some multithreaded implementation,
2875  * the default implementation will execute the parts serially.
2876  * @param count the number of things to execute
2877  * - encoding: Set by libavcodec, user can override.
2878  * - decoding: Set by libavcodec, user can override.
2879  */
2880  int (*execute)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size);
2881 
2882  /**
2883  * The codec may call this to execute several independent things.
2884  * It will return only after finishing all tasks.
2885  * The user may replace this with some multithreaded implementation,
2886  * the default implementation will execute the parts serially.
2887  * Also see avcodec_thread_init and e.g. the --enable-pthread configure option.
2888  * @param c context passed also to func
2889  * @param count the number of things to execute
2890  * @param arg2 argument passed unchanged to func
2891  * @param ret return values of executed functions, must have space for "count" values. May be NULL.
2892  * @param func function that will be called count times, with jobnr from 0 to count-1.
2893  * threadnr will be in the range 0 to c->thread_count-1 < MAX_THREADS and so that no
2894  * two instances of func executing at the same time will have the same threadnr.
2895  * @return always 0 currently, but code should handle a future improvement where when any call to func
2896  * returns < 0 no further calls to func may be done and < 0 is returned.
2897  * - encoding: Set by libavcodec, user can override.
2898  * - decoding: Set by libavcodec, user can override.
2899  */
2900  int (*execute2)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count);
2901 
2902  /**
2903  * noise vs. sse weight for the nsse comparison function
2904  * - encoding: Set by user.
2905  * - decoding: unused
2906  */
2908 
2909  /**
2910  * profile
2911  * - encoding: Set by user.
2912  * - decoding: Set by libavcodec.
2913  */
2914  int profile;
2915 #define FF_PROFILE_UNKNOWN -99
2916 #define FF_PROFILE_RESERVED -100
2917 
2918 #define FF_PROFILE_AAC_MAIN 0
2919 #define FF_PROFILE_AAC_LOW 1
2920 #define FF_PROFILE_AAC_SSR 2
2921 #define FF_PROFILE_AAC_LTP 3
2922 #define FF_PROFILE_AAC_HE 4
2923 #define FF_PROFILE_AAC_HE_V2 28
2924 #define FF_PROFILE_AAC_LD 22
2925 #define FF_PROFILE_AAC_ELD 38
2926 #define FF_PROFILE_MPEG2_AAC_LOW 128
2927 #define FF_PROFILE_MPEG2_AAC_HE 131
2928 
2929 #define FF_PROFILE_DNXHD 0
2930 #define FF_PROFILE_DNXHR_LB 1
2931 #define FF_PROFILE_DNXHR_SQ 2
2932 #define FF_PROFILE_DNXHR_HQ 3
2933 #define FF_PROFILE_DNXHR_HQX 4
2934 #define FF_PROFILE_DNXHR_444 5
2935 
2936 #define FF_PROFILE_DTS 20
2937 #define FF_PROFILE_DTS_ES 30
2938 #define FF_PROFILE_DTS_96_24 40
2939 #define FF_PROFILE_DTS_HD_HRA 50
2940 #define FF_PROFILE_DTS_HD_MA 60
2941 #define FF_PROFILE_DTS_EXPRESS 70
2942 
2943 #define FF_PROFILE_MPEG2_422 0
2944 #define FF_PROFILE_MPEG2_HIGH 1
2945 #define FF_PROFILE_MPEG2_SS 2
2946 #define FF_PROFILE_MPEG2_SNR_SCALABLE 3
2947 #define FF_PROFILE_MPEG2_MAIN 4
2948 #define FF_PROFILE_MPEG2_SIMPLE 5
2949 
2950 #define FF_PROFILE_H264_CONSTRAINED (1<<9) // 8+1; constraint_set1_flag
2951 #define FF_PROFILE_H264_INTRA (1<<11) // 8+3; constraint_set3_flag
2952 
2953 #define FF_PROFILE_H264_BASELINE 66
2954 #define FF_PROFILE_H264_CONSTRAINED_BASELINE (66|FF_PROFILE_H264_CONSTRAINED)
2955 #define FF_PROFILE_H264_MAIN 77
2956 #define FF_PROFILE_H264_EXTENDED 88
2957 #define FF_PROFILE_H264_HIGH 100
2958 #define FF_PROFILE_H264_HIGH_10 110
2959 #define FF_PROFILE_H264_HIGH_10_INTRA (110|FF_PROFILE_H264_INTRA)
2960 #define FF_PROFILE_H264_MULTIVIEW_HIGH 118
2961 #define FF_PROFILE_H264_HIGH_422 122
2962 #define FF_PROFILE_H264_HIGH_422_INTRA (122|FF_PROFILE_H264_INTRA)
2963 #define FF_PROFILE_H264_STEREO_HIGH 128
2964 #define FF_PROFILE_H264_HIGH_444 144
2965 #define FF_PROFILE_H264_HIGH_444_PREDICTIVE 244
2966 #define FF_PROFILE_H264_HIGH_444_INTRA (244|FF_PROFILE_H264_INTRA)
2967 #define FF_PROFILE_H264_CAVLC_444 44
2968 
2969 #define FF_PROFILE_VC1_SIMPLE 0
2970 #define FF_PROFILE_VC1_MAIN 1
2971 #define FF_PROFILE_VC1_COMPLEX 2
2972 #define FF_PROFILE_VC1_ADVANCED 3
2973 
2974 #define FF_PROFILE_MPEG4_SIMPLE 0
2975 #define FF_PROFILE_MPEG4_SIMPLE_SCALABLE 1
2976 #define FF_PROFILE_MPEG4_CORE 2
2977 #define FF_PROFILE_MPEG4_MAIN 3
2978 #define FF_PROFILE_MPEG4_N_BIT 4
2979 #define FF_PROFILE_MPEG4_SCALABLE_TEXTURE 5
2980 #define FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION 6
2981 #define FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE 7
2982 #define FF_PROFILE_MPEG4_HYBRID 8
2983 #define FF_PROFILE_MPEG4_ADVANCED_REAL_TIME 9
2984 #define FF_PROFILE_MPEG4_CORE_SCALABLE 10
2985 #define FF_PROFILE_MPEG4_ADVANCED_CODING 11
2986 #define FF_PROFILE_MPEG4_ADVANCED_CORE 12
2987 #define FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE 13
2988 #define FF_PROFILE_MPEG4_SIMPLE_STUDIO 14
2989 #define FF_PROFILE_MPEG4_ADVANCED_SIMPLE 15
2990 
2991 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_0 1
2992 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_1 2
2993 #define FF_PROFILE_JPEG2000_CSTREAM_NO_RESTRICTION 32768
2994 #define FF_PROFILE_JPEG2000_DCINEMA_2K 3
2995 #define FF_PROFILE_JPEG2000_DCINEMA_4K 4
2996 
2997 #define FF_PROFILE_VP9_0 0
2998 #define FF_PROFILE_VP9_1 1
2999 #define FF_PROFILE_VP9_2 2
3000 #define FF_PROFILE_VP9_3 3
3001 
3002 #define FF_PROFILE_HEVC_MAIN 1
3003 #define FF_PROFILE_HEVC_MAIN_10 2
3004 #define FF_PROFILE_HEVC_MAIN_STILL_PICTURE 3
3005 #define FF_PROFILE_HEVC_REXT 4
3006 
3007 #define FF_PROFILE_AV1_MAIN 0
3008 #define FF_PROFILE_AV1_HIGH 1
3009 #define FF_PROFILE_AV1_PROFESSIONAL 2
3010 
3011 #define FF_PROFILE_MJPEG_HUFFMAN_BASELINE_DCT 0xc0
3012 #define FF_PROFILE_MJPEG_HUFFMAN_EXTENDED_SEQUENTIAL_DCT 0xc1
3013 #define FF_PROFILE_MJPEG_HUFFMAN_PROGRESSIVE_DCT 0xc2
3014 #define FF_PROFILE_MJPEG_HUFFMAN_LOSSLESS 0xc3
3015 #define FF_PROFILE_MJPEG_JPEG_LS 0xf7
3016 
3017 #define FF_PROFILE_SBC_MSBC 1
3018 
3019 #define FF_PROFILE_PRORES_PROXY 0
3020 #define FF_PROFILE_PRORES_LT 1
3021 #define FF_PROFILE_PRORES_STANDARD 2
3022 #define FF_PROFILE_PRORES_HQ 3
3023 #define FF_PROFILE_PRORES_4444 4
3024 #define FF_PROFILE_PRORES_XQ 5
3025 
3026 #define FF_PROFILE_ARIB_PROFILE_A 0
3027 #define FF_PROFILE_ARIB_PROFILE_C 1
3028 
3029  /**
3030  * level
3031  * - encoding: Set by user.
3032  * - decoding: Set by libavcodec.
3033  */
3034  int level;
3035 #define FF_LEVEL_UNKNOWN -99
3036 
3037  /**
3038  * Skip loop filtering for selected frames.
3039  * - encoding: unused
3040  * - decoding: Set by user.
3041  */
3043 
3044  /**
3045  * Skip IDCT/dequantization for selected frames.
3046  * - encoding: unused
3047  * - decoding: Set by user.
3048  */
3050 
3051  /**
3052  * Skip decoding for selected frames.
3053  * - encoding: unused
3054  * - decoding: Set by user.
3055  */
3057 
3058  /**
3059  * Header containing style information for text subtitles.
3060  * For SUBTITLE_ASS subtitle type, it should contain the whole ASS
3061  * [Script Info] and [V4+ Styles] section, plus the [Events] line and
3062  * the Format line following. It shouldn't include any Dialogue line.
3063  * - encoding: Set/allocated/freed by user (before avcodec_open2())
3064  * - decoding: Set/allocated/freed by libavcodec (by avcodec_open2())
3065  */
3068 
3069 #if FF_API_VBV_DELAY
3070  /**
3071  * VBV delay coded in the last frame (in periods of a 27 MHz clock).
3072  * Used for compliant TS muxing.
3073  * - encoding: Set by libavcodec.
3074  * - decoding: unused.
3075  * @deprecated this value is now exported as a part of
3076  * AV_PKT_DATA_CPB_PROPERTIES packet side data
3077  */
3079  uint64_t vbv_delay;
3080 #endif
3081 
3082 #if FF_API_SIDEDATA_ONLY_PKT
3083  /**
3084  * Encoding only and set by default. Allow encoders to output packets
3085  * that do not contain any encoded data, only side data.
3086  *
3087  * Some encoders need to output such packets, e.g. to update some stream
3088  * parameters at the end of encoding.
3089  *
3090  * @deprecated this field disables the default behaviour and
3091  * it is kept only for compatibility.
3092  */
3095 #endif
3096 
3097  /**
3098  * Audio only. The number of "priming" samples (padding) inserted by the
3099  * encoder at the beginning of the audio. I.e. this number of leading
3100  * decoded samples must be discarded by the caller to get the original audio
3101  * without leading padding.
3102  *
3103  * - decoding: unused
3104  * - encoding: Set by libavcodec. The timestamps on the output packets are
3105  * adjusted by the encoder so that they always refer to the
3106  * first sample of the data actually contained in the packet,
3107  * including any added padding. E.g. if the timebase is
3108  * 1/samplerate and the timestamp of the first input sample is
3109  * 0, the timestamp of the first output packet will be
3110  * -initial_padding.
3111  */
3113 
3114  /**
3115  * - decoding: For codecs that store a framerate value in the compressed
3116  * bitstream, the decoder may export it here. { 0, 1} when
3117  * unknown.
3118  * - encoding: May be used to signal the framerate of CFR content to an
3119  * encoder.
3120  */
3122 
3123  /**
3124  * Nominal unaccelerated pixel format, see AV_PIX_FMT_xxx.
3125  * - encoding: unused.
3126  * - decoding: Set by libavcodec before calling get_format()
3127  */
3129 
3130  /**
3131  * Timebase in which pkt_dts/pts and AVPacket.dts/pts are.
3132  * - encoding unused.
3133  * - decoding set by user.
3134  */
3136 
3137  /**
3138  * AVCodecDescriptor
3139  * - encoding: unused.
3140  * - decoding: set by libavcodec.
3141  */
3143 
3144 #if !FF_API_LOWRES
3145  /**
3146  * low resolution decoding, 1-> 1/2 size, 2->1/4 size
3147  * - encoding: unused
3148  * - decoding: Set by user.
3149  */
3150  int lowres;
3151 #endif
3152 
3153  /**
3154  * Current statistics for PTS correction.
3155  * - decoding: maintained and used by libavcodec, not intended to be used by user apps
3156  * - encoding: unused
3157  */
3158  int64_t pts_correction_num_faulty_pts; /// Number of incorrect PTS values so far
3159  int64_t pts_correction_num_faulty_dts; /// Number of incorrect DTS values so far
3160  int64_t pts_correction_last_pts; /// PTS of the last frame
3161  int64_t pts_correction_last_dts; /// DTS of the last frame
3162 
3163  /**
3164  * Character encoding of the input subtitles file.
3165  * - decoding: set by user
3166  * - encoding: unused
3167  */
3169 
3170  /**
3171  * Subtitles character encoding mode. Formats or codecs might be adjusting
3172  * this setting (if they are doing the conversion themselves for instance).
3173  * - decoding: set by libavcodec
3174  * - encoding: unused
3175  */
3177 #define FF_SUB_CHARENC_MODE_DO_NOTHING -1 ///< do nothing (demuxer outputs a stream supposed to be already in UTF-8, or the codec is bitmap for instance)
3178 #define FF_SUB_CHARENC_MODE_AUTOMATIC 0 ///< libavcodec will select the mode itself
3179 #define FF_SUB_CHARENC_MODE_PRE_DECODER 1 ///< the AVPacket data needs to be recoded to UTF-8 before being fed to the decoder, requires iconv
3180 #define FF_SUB_CHARENC_MODE_IGNORE 2 ///< neither convert the subtitles, nor check them for valid UTF-8
3181 
3182  /**
3183  * Skip processing alpha if supported by codec.
3184  * Note that if the format uses pre-multiplied alpha (common with VP6,
3185  * and recommended due to better video quality/compression)
3186  * the image will look as if alpha-blended onto a black background.
3187  * However for formats that do not use pre-multiplied alpha
3188  * there might be serious artefacts (though e.g. libswscale currently
3189  * assumes pre-multiplied alpha anyway).
3190  *
3191  * - decoding: set by user
3192  * - encoding: unused
3193  */
3195 
3196  /**
3197  * Number of samples to skip after a discontinuity
3198  * - decoding: unused
3199  * - encoding: set by libavcodec
3200  */
3202 
3203 #if !FF_API_DEBUG_MV
3204  /**
3205  * debug motion vectors
3206  * - encoding: Set by user.
3207  * - decoding: Set by user.
3208  */
3210 #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 //visualize forward predicted MVs of P frames
3211 #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 //visualize forward predicted MVs of B frames
3212 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
3213 #endif
3214 
3215  /**
3216  * custom intra quantization matrix
3217  * - encoding: Set by user, can be NULL.
3218  * - decoding: unused.
3219  */
3221 
3222  /**
3223  * dump format separator.
3224  * can be ", " or "\n " or anything else
3225  * - encoding: Set by user.
3226  * - decoding: Set by user.
3227  */
3229 
3230  /**
3231  * ',' separated list of allowed decoders.
3232  * If NULL then all are allowed
3233  * - encoding: unused
3234  * - decoding: set by user
3235  */
3237 
3238  /**
3239  * Properties of the stream that gets decoded
3240  * - encoding: unused
3241  * - decoding: set by libavcodec
3242  */
3243  unsigned properties;
3244 #define FF_CODEC_PROPERTY_LOSSLESS 0x00000001
3245 #define FF_CODEC_PROPERTY_CLOSED_CAPTIONS 0x00000002
3246 
3247  /**
3248  * Additional data associated with the entire coded stream.
3249  *
3250  * - decoding: unused
3251  * - encoding: may be set by libavcodec after avcodec_open2().
3252  */
3255 
3256  /**
3257  * A reference to the AVHWFramesContext describing the input (for encoding)
3258  * or output (decoding) frames. The reference is set by the caller and
3259  * afterwards owned (and freed) by libavcodec - it should never be read by
3260  * the caller after being set.
3261  *
3262  * - decoding: This field should be set by the caller from the get_format()
3263  * callback. The previous reference (if any) will always be
3264  * unreffed by libavcodec before the get_format() call.
3265  *
3266  * If the default get_buffer2() is used with a hwaccel pixel
3267  * format, then this AVHWFramesContext will be used for
3268  * allocating the frame buffers.
3269  *
3270  * - encoding: For hardware encoders configured to use a hwaccel pixel
3271  * format, this field should be set by the caller to a reference
3272  * to the AVHWFramesContext describing input frames.
3273  * AVHWFramesContext.format must be equal to
3274  * AVCodecContext.pix_fmt.
3275  *
3276  * This field should be set before avcodec_open2() is called.
3277  */
3279 
3280  /**
3281  * Control the form of AVSubtitle.rects[N]->ass
3282  * - decoding: set by user
3283  * - encoding: unused
3284  */
3286 #define FF_SUB_TEXT_FMT_ASS 0
3287 #if FF_API_ASS_TIMING
3288 #define FF_SUB_TEXT_FMT_ASS_WITH_TIMINGS 1
3289 #endif
3290 
3291  /**
3292  * Audio only. The amount of padding (in samples) appended by the encoder to
3293  * the end of the audio. I.e. this number of decoded samples must be
3294  * discarded by the caller from the end of the stream to get the original
3295  * audio without any trailing padding.
3296  *
3297  * - decoding: unused
3298  * - encoding: unused
3299  */
3301 
3302  /**
3303  * The number of pixels per image to maximally accept.
3304  *
3305  * - decoding: set by user
3306  * - encoding: set by user
3307  */
3308  int64_t max_pixels;
3309 
3310  /**
3311  * A reference to the AVHWDeviceContext describing the device which will
3312  * be used by a hardware encoder/decoder. The reference is set by the
3313  * caller and afterwards owned (and freed) by libavcodec.
3314  *
3315  * This should be used if either the codec device does not require
3316  * hardware frames or any that are used are to be allocated internally by
3317  * libavcodec. If the user wishes to supply any of the frames used as
3318  * encoder input or decoder output then hw_frames_ctx should be used
3319  * instead. When hw_frames_ctx is set in get_format() for a decoder, this
3320  * field will be ignored while decoding the associated stream segment, but
3321  * may again be used on a following one after another get_format() call.
3322  *
3323  * For both encoders and decoders this field should be set before
3324  * avcodec_open2() is called and must not be written to thereafter.
3325  *
3326  * Note that some decoders may require this field to be set initially in
3327  * order to support hw_frames_ctx at all - in that case, all frames
3328  * contexts used must be created on the same device.
3329  */
3331 
3332  /**
3333  * Bit set of AV_HWACCEL_FLAG_* flags, which affect hardware accelerated
3334  * decoding (if active).
3335  * - encoding: unused
3336  * - decoding: Set by user (either before avcodec_open2(), or in the
3337  * AVCodecContext.get_format callback)
3338  */
3340 
3341  /**
3342  * Video decoding only. Certain video codecs support cropping, meaning that
3343  * only a sub-rectangle of the decoded frame is intended for display. This
3344  * option controls how cropping is handled by libavcodec.
3345  *
3346  * When set to 1 (the default), libavcodec will apply cropping internally.
3347  * I.e. it will modify the output frame width/height fields and offset the
3348  * data pointers (only by as much as possible while preserving alignment, or
3349  * by the full amount if the AV_CODEC_FLAG_UNALIGNED flag is set) so that
3350  * the frames output by the decoder refer only to the cropped area. The
3351  * crop_* fields of the output frames will be zero.
3352  *
3353  * When set to 0, the width/height fields of the output frames will be set
3354  * to the coded dimensions and the crop_* fields will describe the cropping
3355  * rectangle. Applying the cropping is left to the caller.
3356  *
3357  * @warning When hardware acceleration with opaque output frames is used,
3358  * libavcodec is unable to apply cropping from the top/left border.
3359  *
3360  * @note when this option is set to zero, the width/height fields of the
3361  * AVCodecContext and output AVFrames have different meanings. The codec
3362  * context fields store display dimensions (with the coded dimensions in
3363  * coded_width/height), while the frame fields store the coded dimensions
3364  * (with the display dimensions being determined by the crop_* fields).
3365  */
3367 
3368  /*
3369  * Video decoding only. Sets the number of extra hardware frames which
3370  * the decoder will allocate for use by the caller. This must be set
3371  * before avcodec_open2() is called.
3372  *
3373  * Some hardware decoders require all frames that they will use for
3374  * output to be defined in advance before decoding starts. For such
3375  * decoders, the hardware frame pool must therefore be of a fixed size.
3376  * The extra frames set here are on top of any number that the decoder
3377  * needs internally in order to operate normally (for example, frames
3378  * used as reference pictures).
3379  */
3381 
3382  /**
3383  * The percentage of damaged samples to discard a frame.
3384  *
3385  * - decoding: set by user
3386  * - encoding: unused
3387  */
3389 
3390  /**
3391  * The number of samples per frame to maximally accept.
3392  *
3393  * - decoding: set by user
3394  * - encoding: set by user
3395  */
3396  int64_t max_samples;
3397 } AVCodecContext;
3398 
3399 #if FF_API_CODEC_GET_SET
3400 /**
3401  * Accessors for some AVCodecContext fields. These used to be provided for ABI
3402  * compatibility, and do not need to be used anymore.
3403  */
3408 
3413 
3415 unsigned av_codec_get_codec_properties(const AVCodecContext *avctx);
3416 
3417 #if FF_API_LOWRES
3419 int av_codec_get_lowres(const AVCodecContext *avctx);
3421 void av_codec_set_lowres(AVCodecContext *avctx, int val);
3422 #endif
3423 
3425 int av_codec_get_seek_preroll(const AVCodecContext *avctx);
3427 void av_codec_set_seek_preroll(AVCodecContext *avctx, int val);
3428 
3430 uint16_t *av_codec_get_chroma_intra_matrix(const AVCodecContext *avctx);
3432 void av_codec_set_chroma_intra_matrix(AVCodecContext *avctx, uint16_t *val);
3433 #endif
3434 
3435 /**
3436  * AVProfile.
3437  */
3438 typedef struct AVProfile {
3439  int profile;
3440  const char *name; ///< short name for the profile
3441 } AVProfile;
3442 
3443 enum {
3444  /**
3445  * The codec supports this format via the hw_device_ctx interface.
3446  *
3447  * When selecting this format, AVCodecContext.hw_device_ctx should
3448  * have been set to a device of the specified type before calling
3449  * avcodec_open2().
3450  */
3452  /**
3453  * The codec supports this format via the hw_frames_ctx interface.
3454  *
3455  * When selecting this format for a decoder,
3456  * AVCodecContext.hw_frames_ctx should be set to a suitable frames
3457  * context inside the get_format() callback. The frames context
3458  * must have been created on a device of the specified type.
3459  */
3461  /**
3462  * The codec supports this format by some internal method.
3463  *
3464  * This format can be selected without any additional configuration -
3465  * no device or frames context is required.
3466  */
3468  /**
3469  * The codec supports this format by some ad-hoc method.
3470  *
3471  * Additional settings and/or function calls are required. See the
3472  * codec-specific documentation for details. (Methods requiring
3473  * this sort of configuration are deprecated and others should be
3474  * used in preference.)
3475  */
3477 };
3478 
3479 typedef struct AVCodecHWConfig {
3480  /**
3481  * A hardware pixel format which the codec can use.
3482  */
3484  /**
3485  * Bit set of AV_CODEC_HW_CONFIG_METHOD_* flags, describing the possible
3486  * setup methods which can be used with this configuration.
3487  */
3488  int methods;
3489  /**
3490  * The device type associated with the configuration.
3491  *
3492  * Must be set for AV_CODEC_HW_CONFIG_METHOD_HW_DEVICE_CTX and
3493  * AV_CODEC_HW_CONFIG_METHOD_HW_FRAMES_CTX, otherwise unused.
3494  */
3496 } AVCodecHWConfig;
3497 
3498 typedef struct AVCodecDefault AVCodecDefault;
3499 
3500 struct AVSubtitle;
3501 
3502 /**
3503  * AVCodec.
3504  */
3505 typedef struct AVCodec {
3506  /**
3507  * Name of the codec implementation.
3508  * The name is globally unique among encoders and among decoders (but an
3509  * encoder and a decoder can share the same name).
3510  * This is the primary way to find a codec from the user perspective.
3511  */
3512  const char *name;
3513  /**
3514  * Descriptive name for the codec, meant to be more human readable than name.
3515  * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
3516  */
3517  const char *long_name;
3520  /**
3521  * Codec capabilities.
3522  * see AV_CODEC_CAP_*
3523  */
3525  const AVRational *supported_framerates; ///< array of supported framerates, or NULL if any, array is terminated by {0,0}
3526  const enum AVPixelFormat *pix_fmts; ///< array of supported pixel formats, or NULL if unknown, array is terminated by -1
3527  const int *supported_samplerates; ///< array of supported audio samplerates, or NULL if unknown, array is terminated by 0
3528  const enum AVSampleFormat *sample_fmts; ///< array of supported sample formats, or NULL if unknown, array is terminated by -1
3529  const uint64_t *channel_layouts; ///< array of support channel layouts, or NULL if unknown. array is terminated by 0
3530  uint8_t max_lowres; ///< maximum value for lowres supported by the decoder
3531  const AVClass *priv_class; ///< AVClass for the private context
3532  const AVProfile *profiles; ///< array of recognized profiles, or NULL if unknown, array is terminated by {FF_PROFILE_UNKNOWN}
3533 
3534  /**
3535  * Group name of the codec implementation.
3536  * This is a short symbolic name of the wrapper backing this codec. A
3537  * wrapper uses some kind of external implementation for the codec, such
3538  * as an external library, or a codec implementation provided by the OS or
3539  * the hardware.
3540  * If this field is NULL, this is a builtin, libavcodec native codec.
3541  * If non-NULL, this will be the suffix in AVCodec.name in most cases
3542  * (usually AVCodec.name will be of the form "<codec_name>_<wrapper_name>").
3543  */
3544  const char *wrapper_name;
3545 
3546  /*****************************************************************
3547  * No fields below this line are part of the public API. They
3548  * may not be used outside of libavcodec and can be changed and
3549  * removed at will.
3550  * New public fields should be added right above.
3551  *****************************************************************
3552  */
3554  struct AVCodec *next;
3555  /**
3556  * @name Frame-level threading support functions
3557  * @{
3558  */
3559  /**
3560  * If defined, called on thread contexts when they are created.
3561  * If the codec allocates writable tables in init(), re-allocate them here.
3562  * priv_data will be set to a copy of the original.
3563  */
3565  /**
3566  * Copy necessary context variables from a previous thread context to the current one.
3567  * If not defined, the next thread will start automatically; otherwise, the codec
3568  * must call ff_thread_finish_setup().
3569  *
3570  * dst and src will (rarely) point to the same context, in which case memcpy should be skipped.
3571  */
3573  /** @} */
3574 
3575  /**
3576  * Private codec-specific defaults.
3577  */
3579 
3580  /**
3581  * Initialize codec static data, called from avcodec_register().
3582  *
3583  * This is not intended for time consuming operations as it is
3584  * run for every codec regardless of that codec being used.
3585  */
3586  void (*init_static_data)(struct AVCodec *codec);
3587 
3589  int (*encode_sub)(AVCodecContext *, uint8_t *buf, int buf_size,
3590  const struct AVSubtitle *sub);
3591  /**
3592  * Encode data to an AVPacket.
3593  *
3594  * @param avctx codec context
3595  * @param avpkt output AVPacket (may contain a user-provided buffer)
3596  * @param[in] frame AVFrame containing the raw data to be encoded
3597  * @param[out] got_packet_ptr encoder sets to 0 or 1 to indicate that a
3598  * non-empty packet was returned in avpkt.
3599  * @return 0 on success, negative error code on failure
3600  */
3601  int (*encode2)(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame,
3602  int *got_packet_ptr);
3603  int (*decode)(AVCodecContext *, void *outdata, int *outdata_size, AVPacket *avpkt);
3604  int (*close)(AVCodecContext *);
3605  /**
3606  * Encode API with decoupled packet/frame dataflow. The API is the
3607  * same as the avcodec_ prefixed APIs (avcodec_send_frame() etc.), except
3608  * that:
3609  * - never called if the codec is closed or the wrong type,
3610  * - if AV_CODEC_CAP_DELAY is not set, drain frames are never sent,
3611  * - only one drain frame is ever passed down,
3612  */
3613  int (*send_frame)(AVCodecContext *avctx, const AVFrame *frame);
3614  int (*receive_packet)(AVCodecContext *avctx, AVPacket *avpkt);
3615 
3616  /**
3617  * Decode API with decoupled packet/frame dataflow. This function is called
3618  * to get one output frame. It should call ff_decode_get_packet() to obtain
3619  * input data.
3620  */
3622  /**
3623  * Flush buffers.
3624  * Will be called when seeking
3625  */
3627  /**
3628  * Internal codec capabilities.
3629  * See FF_CODEC_CAP_* in internal.h
3630  */
3632 
3633  /**
3634  * Decoding only, a comma-separated list of bitstream filters to apply to
3635  * packets before decoding.
3636  */
3637  const char *bsfs;
3638 
3639  /**
3640  * Array of pointers to hardware configurations supported by the codec,
3641  * or NULL if no hardware supported. The array is terminated by a NULL
3642  * pointer.
3643  *
3644  * The user can only access this field via avcodec_get_hw_config().
3645  */
3647 } AVCodec;
3648 
3649 #if FF_API_CODEC_GET_SET
3651 int av_codec_get_max_lowres(const AVCodec *codec);
3652 #endif
3653 
3654 struct MpegEncContext;
3655 
3656 /**
3657  * Retrieve supported hardware configurations for a codec.
3658  *
3659  * Values of index from zero to some maximum return the indexed configuration
3660  * descriptor; all other values return NULL. If the codec does not support
3661  * any hardware configurations then it will always return NULL.
3662  */
3663 const AVCodecHWConfig *avcodec_get_hw_config(const AVCodec *codec, int index);
3664 
3665 /**
3666  * @defgroup lavc_hwaccel AVHWAccel
3667  *
3668  * @note Nothing in this structure should be accessed by the user. At some
3669  * point in future it will not be externally visible at all.
3670  *
3671  * @{
3672  */
3673 typedef struct AVHWAccel {
3674  /**
3675  * Name of the hardware accelerated codec.
3676  * The name is globally unique among encoders and among decoders (but an
3677  * encoder and a decoder can share the same name).
3678  */
3679  const char *name;
3680 
3681  /**
3682  * Type of codec implemented by the hardware accelerator.
3683  *
3684  * See AVMEDIA_TYPE_xxx
3685  */
3687 
3688  /**
3689  * Codec implemented by the hardware accelerator.
3690  *
3691  * See AV_CODEC_ID_xxx
3692  */
3694 
3695  /**
3696  * Supported pixel format.
3697  *
3698  * Only hardware accelerated formats are supported here.
3699  */
3701 
3702  /**
3703  * Hardware accelerated codec capabilities.
3704  * see AV_HWACCEL_CODEC_CAP_*
3705  */
3707 
3708  /*****************************************************************
3709  * No fields below this line are part of the public API. They
3710  * may not be used outside of libavcodec and can be changed and
3711  * removed at will.
3712  * New public fields should be added right above.
3713  *****************************************************************
3714  */
3715 
3716  /**
3717  * Allocate a custom buffer
3718  */
3720 
3721  /**
3722  * Called at the beginning of each frame or field picture.
3723  *
3724  * Meaningful frame information (codec specific) is guaranteed to
3725  * be parsed at this point. This function is mandatory.
3726  *
3727  * Note that buf can be NULL along with buf_size set to 0.
3728  * Otherwise, this means the whole frame is available at this point.
3729  *
3730  * @param avctx the codec context
3731  * @param buf the frame data buffer base
3732  * @param buf_size the size of the frame in bytes
3733  * @return zero if successful, a negative value otherwise
3734  */
3735  int (*start_frame)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3736 
3737  /**
3738  * Callback for parameter data (SPS/PPS/VPS etc).
3739  *
3740  * Useful for hardware decoders which keep persistent state about the
3741  * video parameters, and need to receive any changes to update that state.
3742  *
3743  * @param avctx the codec context
3744  * @param type the nal unit type
3745  * @param buf the nal unit data buffer
3746  * @param buf_size the size of the nal unit in bytes
3747  * @return zero if successful, a negative value otherwise
3748  */
3749  int (*decode_params)(AVCodecContext *avctx, int type, const uint8_t *buf, uint32_t buf_size);
3750 
3751  /**
3752  * Callback for each slice.
3753  *
3754  * Meaningful slice information (codec specific) is guaranteed to
3755  * be parsed at this point. This function is mandatory.
3756  * The only exception is XvMC, that works on MB level.
3757  *
3758  * @param avctx the codec context
3759  * @param buf the slice data buffer base
3760  * @param buf_size the size of the slice in bytes
3761  * @return zero if successful, a negative value otherwise
3762  */
3763  int (*decode_slice)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3764 
3765  /**
3766  * Called at the end of each frame or field picture.
3767  *
3768  * The whole picture is parsed at this point and can now be sent
3769  * to the hardware accelerator. This function is mandatory.
3770  *
3771  * @param avctx the codec context
3772  * @return zero if successful, a negative value otherwise
3773  */
3774  int (*end_frame)(AVCodecContext *avctx);
3775 
3776  /**
3777  * Size of per-frame hardware accelerator private data.
3778  *
3779  * Private data is allocated with av_mallocz() before
3780  * AVCodecContext.get_buffer() and deallocated after
3781  * AVCodecContext.release_buffer().
3782  */
3784 
3785  /**
3786  * Called for every Macroblock in a slice.
3787  *
3788  * XvMC uses it to replace the ff_mpv_reconstruct_mb().
3789  * Instead of decoding to raw picture, MB parameters are
3790  * stored in an array provided by the video driver.
3791  *
3792  * @param s the mpeg context
3793  */
3795 
3796  /**
3797  * Initialize the hwaccel private data.
3798  *
3799  * This will be called from ff_get_format(), after hwaccel and
3800  * hwaccel_context are set and the hwaccel private data in AVCodecInternal
3801  * is allocated.
3802  */
3804 
3805  /**
3806  * Uninitialize the hwaccel private data.
3807  *
3808  * This will be called from get_format() or avcodec_close(), after hwaccel
3809  * and hwaccel_context are already uninitialized.
3810  */
3812 
3813  /**
3814  * Size of the private data to allocate in
3815  * AVCodecInternal.hwaccel_priv_data.
3816  */
3818 
3819  /**
3820  * Internal hwaccel capabilities.
3821  */
3823 
3824  /**
3825  * Fill the given hw_frames context with current codec parameters. Called
3826  * from get_format. Refer to avcodec_get_hw_frames_parameters() for
3827  * details.
3828  *
3829  * This CAN be called before AVHWAccel.init is called, and you must assume
3830  * that avctx->hwaccel_priv_data is invalid.
3831  */
3832  int (*frame_params)(AVCodecContext *avctx, AVBufferRef *hw_frames_ctx);
3833 } AVHWAccel;
3834 
3835 /**
3836  * HWAccel is experimental and is thus avoided in favor of non experimental
3837  * codecs
3838  */
3839 #define AV_HWACCEL_CODEC_CAP_EXPERIMENTAL 0x0200
3840 
3841 /**
3842  * Hardware acceleration should be used for decoding even if the codec level
3843  * used is unknown or higher than the maximum supported level reported by the
3844  * hardware driver.
3845  *
3846  * It's generally a good idea to pass this flag unless you have a specific
3847  * reason not to, as hardware tends to under-report supported levels.
3848  */
3849 #define AV_HWACCEL_FLAG_IGNORE_LEVEL (1 << 0)
3850 
3851 /**
3852  * Hardware acceleration can output YUV pixel formats with a different chroma
3853  * sampling than 4:2:0 and/or other than 8 bits per component.
3854  */
3855 #define AV_HWACCEL_FLAG_ALLOW_HIGH_DEPTH (1 << 1)
3856 
3857 /**
3858  * Hardware acceleration should still be attempted for decoding when the
3859  * codec profile does not match the reported capabilities of the hardware.
3860  *
3861  * For example, this can be used to try to decode baseline profile H.264
3862  * streams in hardware - it will often succeed, because many streams marked
3863  * as baseline profile actually conform to constrained baseline profile.
3864  *
3865  * @warning If the stream is actually not supported then the behaviour is
3866  * undefined, and may include returning entirely incorrect output
3867  * while indicating success.
3868  */
3869 #define AV_HWACCEL_FLAG_ALLOW_PROFILE_MISMATCH (1 << 2)
3870 
3871 /**
3872  * @}
3873  */
3874 
3875 #if FF_API_AVPICTURE
3876 /**
3877  * @defgroup lavc_picture AVPicture
3878  *
3879  * Functions for working with AVPicture
3880  * @{
3881  */
3882 
3883 /**
3884  * Picture data structure.
3885  *
3886  * Up to four components can be stored into it, the last component is
3887  * alpha.
3888  * @deprecated use AVFrame or imgutils functions instead
3889  */
3890 typedef struct AVPicture {
3892  uint8_t *data[AV_NUM_DATA_POINTERS]; ///< pointers to the image data planes
3894  int linesize[AV_NUM_DATA_POINTERS]; ///< number of bytes per line
3895 } AVPicture;
3896 
3897 /**
3898  * @}
3899  */
3900 #endif
3901 
3904 
3905  SUBTITLE_BITMAP, ///< A bitmap, pict will be set
3906 
3907  /**
3908  * Plain text, the text field must be set by the decoder and is
3909  * authoritative. ass and pict fields may contain approximations.
3910  */
3912 
3913  /**
3914  * Formatted text, the ass field must be set by the decoder and is
3915  * authoritative. pict and text fields may contain approximations.
3916  */
3918 };
3919 
3920 #define AV_SUBTITLE_FLAG_FORCED 0x00000001
3921 
3922 typedef struct AVSubtitleRect {
3923  int x; ///< top left corner of pict, undefined when pict is not set
3924  int y; ///< top left corner of pict, undefined when pict is not set
3925  int w; ///< width of pict, undefined when pict is not set
3926  int h; ///< height of pict, undefined when pict is not set
3927  int nb_colors; ///< number of colors in pict, undefined when pict is not set
3928 
3929 #if FF_API_AVPICTURE
3930  /**
3931  * @deprecated unused
3932  */
3935 #endif
3936  /**
3937  * data+linesize for the bitmap of this subtitle.
3938  * Can be set for text/ass as well once they are rendered.
3939  */
3941  int linesize[4];
3942 
3944 
3945  char *text; ///< 0 terminated plain UTF-8 text
3946 
3947  /**
3948  * 0 terminated ASS/SSA compatible event line.
3949  * The presentation of this is unaffected by the other values in this
3950  * struct.
3951  */
3952  char *ass;
3953 
3954  int flags;
3955 } AVSubtitleRect;
3956 
3957 typedef struct AVSubtitle {
3958  uint16_t format; /* 0 = graphics */
3959  uint32_t start_display_time; /* relative to packet pts, in ms */
3960  uint32_t end_display_time; /* relative to packet pts, in ms */
3961  unsigned num_rects;
3963  int64_t pts; ///< Same as packet pts, in AV_TIME_BASE
3964 } AVSubtitle;
3965 
3966 /**
3967  * This struct describes the properties of an encoded stream.
3968  *
3969  * sizeof(AVCodecParameters) is not a part of the public ABI, this struct must
3970  * be allocated with avcodec_parameters_alloc() and freed with
3971  * avcodec_parameters_free().
3972  */
3973 typedef struct AVCodecParameters {
3974  /**
3975  * General type of the encoded data.
3976  */
3978  /**
3979  * Specific type of the encoded data (the codec used).
3980  */
3982  /**
3983  * Additional information about the codec (corresponds to the AVI FOURCC).
3984  */
3985  uint32_t codec_tag;
3986 
3987  /**
3988  * Extra binary data needed for initializing the decoder, codec-dependent.
3989  *
3990  * Must be allocated with av_malloc() and will be freed by
3991  * avcodec_parameters_free(). The allocated size of extradata must be at
3992  * least extradata_size + AV_INPUT_BUFFER_PADDING_SIZE, with the padding
3993  * bytes zeroed.
3994  */
3996  /**
3997  * Size of the extradata content in bytes.
3998  */
4000 
4001  /**
4002  * - video: the pixel format, the value corresponds to enum AVPixelFormat.
4003  * - audio: the sample format, the value corresponds to enum AVSampleFormat.
4004  */
4005  int format;
4006 
4007  /**
4008  * The average bitrate of the encoded data (in bits per second).
4009  */
4010  int64_t bit_rate;
4011 
4012  /**
4013  * The number of bits per sample in the codedwords.
4014  *
4015  * This is basically the bitrate per sample. It is mandatory for a bunch of
4016  * formats to actually decode them. It's the number of bits for one sample in
4017  * the actual coded bitstream.
4018  *
4019  * This could be for example 4 for ADPCM
4020  * For PCM formats this matches bits_per_raw_sample
4021  * Can be 0
4022  */
4024 
4025  /**
4026  * This is the number of valid bits in each output sample. If the
4027  * sample format has more bits, the least significant bits are additional
4028  * padding bits, which are always 0. Use right shifts to reduce the sample
4029  * to its actual size. For example, audio formats with 24 bit samples will
4030  * have bits_per_raw_sample set to 24, and format set to AV_SAMPLE_FMT_S32.
4031  * To get the original sample use "(int32_t)sample >> 8"."
4032  *
4033  * For ADPCM this might be 12 or 16 or similar
4034  * Can be 0
4035  */
4037 
4038  /**
4039  * Codec-specific bitstream restrictions that the stream conforms to.
4040  */
4041  int profile;
4042  int level;
4043 
4044  /**
4045  * Video only. The dimensions of the video frame in pixels.
4046  */
4047  int width;
4048  int height;
4049 
4050  /**
4051  * Video only. The aspect ratio (width / height) which a single pixel
4052  * should have when displayed.
4053  *
4054  * When the aspect ratio is unknown / undefined, the numerator should be
4055  * set to 0 (the denominator may have any value).
4056  */
4058 
4059  /**
4060  * Video only. The order of the fields in interlaced video.
4061  */
4062  enum AVFieldOrder field_order;
4063 
4064  /**
4065  * Video only. Additional colorspace characteristics.
4066  */
4070  enum AVColorSpace color_space;
4071  enum AVChromaLocation chroma_location;
4072 
4073  /**
4074  * Video only. Number of delayed frames.
4075  */
4077 
4078  /**
4079  * Audio only. The channel layout bitmask. May be 0 if the channel layout is
4080  * unknown or unspecified, otherwise the number of bits set must be equal to
4081  * the channels field.
4082  */
4083  uint64_t channel_layout;
4084  /**
4085  * Audio only. The number of audio channels.
4086  */
4088  /**
4089  * Audio only. The number of audio samples per second.
4090  */
4092  /**
4093  * Audio only. The number of bytes per coded audio frame, required by some
4094  * formats.
4095  *
4096  * Corresponds to nBlockAlign in WAVEFORMATEX.
4097  */
4099  /**
4100  * Audio only. Audio frame size, if known. Required by some formats to be static.
4101  */
4103 
4104  /**
4105  * Audio only. The amount of padding (in samples) inserted by the encoder at
4106  * the beginning of the audio. I.e. this number of leading decoded samples
4107  * must be discarded by the caller to get the original audio without leading
4108  * padding.
4109  */
4111  /**
4112  * Audio only. The amount of padding (in samples) appended by the encoder to
4113  * the end of the audio. I.e. this number of decoded samples must be
4114  * discarded by the caller from the end of the stream to get the original
4115  * audio without any trailing padding.
4116  */
4118  /**
4119  * Audio only. Number of samples to skip after a discontinuity.
4120  */
4123 
4124 /**
4125  * Iterate over all registered codecs.
4126  *
4127  * @param opaque a pointer where libavcodec will store the iteration state. Must
4128  * point to NULL to start the iteration.
4129  *
4130  * @return the next registered codec or NULL when the iteration is
4131  * finished
4132  */
4133 const AVCodec *av_codec_iterate(void **opaque);
4134 
4135 #if FF_API_NEXT
4136 /**
4137  * If c is NULL, returns the first registered codec,
4138  * if c is non-NULL, returns the next registered codec after c,
4139  * or NULL if c is the last one.
4140  */
4142 AVCodec *av_codec_next(const AVCodec *c);
4143 #endif
4144 
4145 /**
4146  * Return the LIBAVCODEC_VERSION_INT constant.
4147  */
4148 unsigned avcodec_version(void);
4149 
4150 /**
4151  * Return the libavcodec build-time configuration.
4152  */
4153 const char *avcodec_configuration(void);
4154 
4155 /**
4156  * Return the libavcodec license.
4157  */
4158 const char *avcodec_license(void);
4159 
4160 #if FF_API_NEXT
4161 /**
4162  * Register the codec codec and initialize libavcodec.
4163  *
4164  * @warning either this function or avcodec_register_all() must be called
4165  * before any other libavcodec functions.
4166  *
4167  * @see avcodec_register_all()
4168  */
4170 void avcodec_register(AVCodec *codec);
4171 
4172 /**
4173  * Register all the codecs, parsers and bitstream filters which were enabled at
4174  * configuration time. If you do not call this function you can select exactly
4175  * which formats you want to support, by using the individual registration
4176  * functions.
4177  *
4178  * @see avcodec_register
4179  * @see av_register_codec_parser
4180  * @see av_register_bitstream_filter
4181  */
4183 void avcodec_register_all(void);
4184 #endif
4185 
4186 /**
4187  * Allocate an AVCodecContext and set its fields to default values. The
4188  * resulting struct should be freed with avcodec_free_context().
4189  *
4190  * @param codec if non-NULL, allocate private data and initialize defaults
4191  * for the given codec. It is illegal to then call avcodec_open2()
4192  * with a different codec.
4193  * If NULL, then the codec-specific defaults won't be initialized,
4194  * which may result in suboptimal default settings (this is
4195  * important mainly for encoders, e.g. libx264).
4196  *
4197  * @return An AVCodecContext filled with default values or NULL on failure.
4198  */
4200 
4201 /**
4202  * Free the codec context and everything associated with it and write NULL to
4203  * the provided pointer.
4204  */
4205 void avcodec_free_context(AVCodecContext **avctx);
4206 
4207 #if FF_API_GET_CONTEXT_DEFAULTS
4208 /**
4209  * @deprecated This function should not be used, as closing and opening a codec
4210  * context multiple time is not supported. A new codec context should be
4211  * allocated for each new use.
4212  */
4214 #endif
4215 
4216 /**
4217  * Get the AVClass for AVCodecContext. It can be used in combination with
4218  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
4219  *
4220  * @see av_opt_find().
4221  */
4222 const AVClass *avcodec_get_class(void);
4223 
4224 #if FF_API_COPY_CONTEXT
4225 /**
4226  * Get the AVClass for AVFrame. It can be used in combination with
4227  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
4228  *
4229  * @see av_opt_find().
4230  */
4231 const AVClass *avcodec_get_frame_class(void);
4232 
4233 /**
4234  * Get the AVClass for AVSubtitleRect. It can be used in combination with
4235  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
4236  *
4237  * @see av_opt_find().
4238  */
4240 
4241 /**
4242  * Copy the settings of the source AVCodecContext into the destination
4243  * AVCodecContext. The resulting destination codec context will be
4244  * unopened, i.e. you are required to call avcodec_open2() before you
4245  * can use this AVCodecContext to decode/encode video/audio data.
4246  *
4247  * @param dest target codec context, should be initialized with
4248  * avcodec_alloc_context3(NULL), but otherwise uninitialized
4249  * @param src source codec context
4250  * @return AVERROR() on error (e.g. memory allocation error), 0 on success
4251  *
4252  * @deprecated The semantics of this function are ill-defined and it should not
4253  * be used. If you need to transfer the stream parameters from one codec context
4254  * to another, use an intermediate AVCodecParameters instance and the
4255  * avcodec_parameters_from_context() / avcodec_parameters_to_context()
4256  * functions.
4257  */
4260 #endif
4261 
4262 /**
4263  * Allocate a new AVCodecParameters and set its fields to default values
4264  * (unknown/invalid/0). The returned struct must be freed with
4265  * avcodec_parameters_free().
4266  */
4268 
4269 /**
4270  * Free an AVCodecParameters instance and everything associated with it and
4271  * write NULL to the supplied pointer.
4272  */
4274 
4275 /**
4276  * Copy the contents of src to dst. Any allocated fields in dst are freed and
4277  * replaced with newly allocated duplicates of the corresponding fields in src.
4278  *
4279  * @return >= 0 on success, a negative AVERROR code on failure.
4280  */
4282 
4283 /**
4284  * Fill the parameters struct based on the values from the supplied codec
4285  * context. Any allocated fields in par are freed and replaced with duplicates
4286  * of the corresponding fields in codec.
4287  *
4288  * @return >= 0 on success, a negative AVERROR code on failure
4289  */
4291  const AVCodecContext *codec);
4292 
4293 /**
4294  * Fill the codec context based on the values from the supplied codec
4295  * parameters. Any allocated fields in codec that have a corresponding field in
4296  * par are freed and replaced with duplicates of the corresponding field in par.
4297  * Fields in codec that do not have a counterpart in par are not touched.
4298  *
4299  * @return >= 0 on success, a negative AVERROR code on failure.
4300  */
4302  const AVCodecParameters *par);
4303 
4304 /**
4305  * Initialize the AVCodecContext to use the given AVCodec. Prior to using this
4306  * function the context has to be allocated with avcodec_alloc_context3().
4307  *
4308  * The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(),
4309  * avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for
4310  * retrieving a codec.
4311  *
4312  * @warning This function is not thread safe!
4313  *
4314  * @note Always call this function before using decoding routines (such as
4315  * @ref avcodec_receive_frame()).
4316  *
4317  * @code
4318  * avcodec_register_all();
4319  * av_dict_set(&opts, "b", "2.5M", 0);
4320  * codec = avcodec_find_decoder(AV_CODEC_ID_H264);
4321  * if (!codec)
4322  * exit(1);
4323  *
4324  * context = avcodec_alloc_context3(codec);
4325  *
4326  * if (avcodec_open2(context, codec, opts) < 0)
4327  * exit(1);
4328  * @endcode
4329  *
4330  * @param avctx The context to initialize.
4331  * @param codec The codec to open this context for. If a non-NULL codec has been
4332  * previously passed to avcodec_alloc_context3() or
4333  * for this context, then this parameter MUST be either NULL or
4334  * equal to the previously passed codec.
4335  * @param options A dictionary filled with AVCodecContext and codec-private options.
4336  * On return this object will be filled with options that were not found.
4337  *
4338  * @return zero on success, a negative value on error
4339  * @see avcodec_alloc_context3(), avcodec_find_decoder(), avcodec_find_encoder(),
4340  * av_dict_set(), av_opt_find().
4341  */
4342 int avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options);
4343 
4344 /**
4345  * Close a given AVCodecContext and free all the data associated with it
4346  * (but not the AVCodecContext itself).
4347  *
4348  * Calling this function on an AVCodecContext that hasn't been opened will free
4349  * the codec-specific data allocated in avcodec_alloc_context3() with a non-NULL
4350  * codec. Subsequent calls will do nothing.
4351  *
4352  * @note Do not use this function. Use avcodec_free_context() to destroy a
4353  * codec context (either open or closed). Opening and closing a codec context
4354  * multiple times is not supported anymore -- use multiple codec contexts
4355  * instead.
4356  */
4357 int avcodec_close(AVCodecContext *avctx);
4358 
4359 /**
4360  * Free all allocated data in the given subtitle struct.
4361  *
4362  * @param sub AVSubtitle to free.
4363  */
4364 void avsubtitle_free(AVSubtitle *sub);
4365 
4366 /**
4367  * @}
4368  */
4369 
4370 /**
4371  * @addtogroup lavc_packet
4372  * @{
4373  */
4374 
4375 /**
4376  * Allocate an AVPacket and set its fields to default values. The resulting
4377  * struct must be freed using av_packet_free().
4378  *
4379  * @return An AVPacket filled with default values or NULL on failure.
4380  *
4381  * @note this only allocates the AVPacket itself, not the data buffers. Those
4382  * must be allocated through other means such as av_new_packet.
4383  *
4384  * @see av_new_packet
4385  */
4386 AVPacket *av_packet_alloc(void);
4387 
4388 /**
4389  * Create a new packet that references the same data as src.
4390  *
4391  * This is a shortcut for av_packet_alloc()+av_packet_ref().
4392  *
4393  * @return newly created AVPacket on success, NULL on error.
4394  *
4395  * @see av_packet_alloc
4396  * @see av_packet_ref
4397  */
4399 
4400 /**
4401  * Free the packet, if the packet is reference counted, it will be
4402  * unreferenced first.
4403  *
4404  * @param pkt packet to be freed. The pointer will be set to NULL.
4405  * @note passing NULL is a no-op.
4406  */
4407 void av_packet_free(AVPacket **pkt);
4408 
4409 /**
4410  * Initialize optional fields of a packet with default values.
4411  *
4412  * Note, this does not touch the data and size members, which have to be
4413  * initialized separately.
4414  *
4415  * @param pkt packet
4416  */
4417 void av_init_packet(AVPacket *pkt);
4418 
4419 /**
4420  * Allocate the payload of a packet and initialize its fields with
4421  * default values.
4422  *
4423  * @param pkt packet
4424  * @param size wanted payload size
4425  * @return 0 if OK, AVERROR_xxx otherwise
4426  */
4427 int av_new_packet(AVPacket *pkt, int size);
4428 
4429 /**
4430  * Reduce packet size, correctly zeroing padding
4431  *
4432  * @param pkt packet
4433  * @param size new size
4434  */
4435 void av_shrink_packet(AVPacket *pkt, int size);
4436 
4437 /**
4438  * Increase packet size, correctly zeroing padding
4439  *
4440  * @param pkt packet
4441  * @param grow_by number of bytes by which to increase the size of the packet
4442  */
4443 int av_grow_packet(AVPacket *pkt, int grow_by);
4444 
4445 /**
4446  * Initialize a reference-counted packet from av_malloc()ed data.
4447  *
4448  * @param pkt packet to be initialized. This function will set the data, size,
4449  * and buf fields, all others are left untouched.
4450  * @param data Data allocated by av_malloc() to be used as packet data. If this
4451  * function returns successfully, the data is owned by the underlying AVBuffer.
4452  * The caller may not access the data through other means.
4453  * @param size size of data in bytes, without the padding. I.e. the full buffer
4454  * size is assumed to be size + AV_INPUT_BUFFER_PADDING_SIZE.
4455  *
4456  * @return 0 on success, a negative AVERROR on error
4457  */
4459 
4460 #if FF_API_AVPACKET_OLD_API
4461 /**
4462  * @warning This is a hack - the packet memory allocation stuff is broken. The
4463  * packet is allocated if it was not really allocated.
4464  *
4465  * @deprecated Use av_packet_ref or av_packet_make_refcounted
4466  */
4468 int av_dup_packet(AVPacket *pkt);
4469 /**
4470  * Copy packet, including contents
4471  *
4472  * @return 0 on success, negative AVERROR on fail
4473  *
4474  * @deprecated Use av_packet_ref
4475  */
4477 int av_copy_packet(AVPacket *dst, const AVPacket *src);
4478 
4479 /**
4480  * Copy packet side data
4481  *
4482  * @return 0 on success, negative AVERROR on fail
4483  *
4484  * @deprecated Use av_packet_copy_props
4485  */
4487 int av_copy_packet_side_data(AVPacket *dst, const AVPacket *src);
4488 
4489 /**
4490  * Free a packet.
4491  *
4492  * @deprecated Use av_packet_unref
4493  *
4494  * @param pkt packet to free
4495  */
4497 void av_free_packet(AVPacket *pkt);
4498 #endif
4499 /**
4500  * Allocate new information of a packet.
4501  *
4502  * @param pkt packet
4503  * @param type side information type
4504  * @param size side information size
4505  * @return pointer to fresh allocated data or NULL otherwise
4506  */
4508  int size);
4509 
4510 /**
4511  * Wrap an existing array as a packet side data.
4512  *
4513  * @param pkt packet
4514  * @param type side information type
4515  * @param data the side data array. It must be allocated with the av_malloc()
4516  * family of functions. The ownership of the data is transferred to
4517  * pkt.
4518  * @param size side information size
4519  * @return a non-negative number on success, a negative AVERROR code on
4520  * failure. On failure, the packet is unchanged and the data remains
4521  * owned by the caller.
4522  */
4524  uint8_t *data, size_t size);
4525 
4526 /**
4527  * Shrink the already allocated side data buffer
4528  *
4529  * @param pkt packet
4530  * @param type side information type
4531  * @param size new side information size
4532  * @return 0 on success, < 0 on failure
4533  */
4535  int size);
4536 
4537 /**
4538  * Get side information from packet.
4539  *
4540  * @param pkt packet
4541  * @param type desired side information type
4542  * @param size pointer for side information size to store (optional)
4543  * @return pointer to data if present or NULL otherwise
4544  */
4546  int *size);
4547 
4548 #if FF_API_MERGE_SD_API
4551 
4554 #endif
4555 
4557 
4558 /**
4559  * Pack a dictionary for use in side_data.
4560  *
4561  * @param dict The dictionary to pack.
4562  * @param size pointer to store the size of the returned data
4563  * @return pointer to data if successful, NULL otherwise
4564  */
4566 /**
4567  * Unpack a dictionary from side_data.
4568  *
4569  * @param data data from side_data
4570  * @param size size of the data
4571  * @param dict the metadata storage dictionary
4572  * @return 0 on success, < 0 on failure
4573  */
4574 int av_packet_unpack_dictionary(const uint8_t *data, int size, AVDictionary **dict);
4575 
4576 
4577 /**
4578  * Convenience function to free all the side data stored.
4579  * All the other fields stay untouched.
4580  *
4581  * @param pkt packet
4582  */
4584 
4585 /**
4586  * Setup a new reference to the data described by a given packet
4587  *
4588  * If src is reference-counted, setup dst as a new reference to the
4589  * buffer in src. Otherwise allocate a new buffer in dst and copy the
4590  * data from src into it.
4591  *
4592  * All the other fields are copied from src.
4593  *
4594  * @see av_packet_unref
4595  *
4596  * @param dst Destination packet
4597  * @param src Source packet
4598  *
4599  * @return 0 on success, a negative AVERROR on error.
4600  */
4601 int av_packet_ref(AVPacket *dst, const AVPacket *src);
4602 
4603 /**
4604  * Wipe the packet.
4605  *
4606  * Unreference the buffer referenced by the packet and reset the
4607  * remaining packet fields to their default values.
4608  *
4609  * @param pkt The packet to be unreferenced.
4610  */
4612 
4613 /**
4614  * Move every field in src to dst and reset src.
4615  *
4616  * @see av_packet_unref
4617  *
4618  * @param src Source packet, will be reset
4619  * @param dst Destination packet
4620  */
4622 
4623 /**
4624  * Copy only "properties" fields from src to dst.
4625  *
4626  * Properties for the purpose of this function are all the fields
4627  * beside those related to the packet data (buf, data, size)
4628  *
4629  * @param dst Destination packet
4630  * @param src Source packet
4631  *
4632  * @return 0 on success AVERROR on failure.
4633  */
4634 int av_packet_copy_props(AVPacket *dst, const AVPacket *src);
4635 
4636 /**
4637  * Ensure the data described by a given packet is reference counted.
4638  *
4639  * @note This function does not ensure that the reference will be writable.
4640  * Use av_packet_make_writable instead for that purpose.
4641  *
4642  * @see av_packet_ref
4643  * @see av_packet_make_writable
4644  *
4645  * @param pkt packet whose data should be made reference counted.
4646  *
4647  * @return 0 on success, a negative AVERROR on error. On failure, the
4648  * packet is unchanged.
4649  */
4651 
4652 /**
4653  * Create a writable reference for the data described by a given packet,
4654  * avoiding data copy if possible.
4655  *
4656  * @param pkt Packet whose data should be made writable.
4657  *
4658  * @return 0 on success, a negative AVERROR on failure. On failure, the
4659  * packet is unchanged.
4660  */
4662 
4663 /**
4664  * Convert valid timing fields (timestamps / durations) in a packet from one
4665  * timebase to another. Timestamps with unknown values (AV_NOPTS_VALUE) will be
4666  * ignored.
4667  *
4668  * @param pkt packet on which the conversion will be performed
4669  * @param tb_src source timebase, in which the timing fields in pkt are
4670  * expressed
4671  * @param tb_dst destination timebase, to which the timing fields will be
4672  * converted
4673  */
4674 void av_packet_rescale_ts(AVPacket *pkt, AVRational tb_src, AVRational tb_dst);
4675 
4676 /**
4677  * @}
4678  */
4679 
4680 /**
4681  * @addtogroup lavc_decoding
4682  * @{
4683  */
4684 
4685 /**
4686  * Find a registered decoder with a matching codec ID.
4687  *
4688  * @param id AVCodecID of the requested decoder
4689  * @return A decoder if one was found, NULL otherwise.
4690  */
4692 
4693 /**
4694  * Find a registered decoder with the specified name.
4695  *
4696  * @param name name of the requested decoder
4697  * @return A decoder if one was found, NULL otherwise.
4698  */
4700 
4701 /**
4702  * The default callback for AVCodecContext.get_buffer2(). It is made public so
4703  * it can be called by custom get_buffer2() implementations for decoders without
4704  * AV_CODEC_CAP_DR1 set.
4705  */
4707 
4708 /**
4709  * Modify width and height values so that they will result in a memory
4710  * buffer that is acceptable for the codec if you do not use any horizontal
4711  * padding.
4712  *
4713  * May only be used if a codec with AV_CODEC_CAP_DR1 has been opened.
4714  */
4716 
4717 /**
4718  * Modify width and height values so that they will result in a memory
4719  * buffer that is acceptable for the codec if you also ensure that all
4720  * line sizes are a multiple of the respective linesize_align[i].
4721  *
4722  * May only be used if a codec with AV_CODEC_CAP_DR1 has been opened.
4723  */
4725  int linesize_align[AV_NUM_DATA_POINTERS]);
4726 
4727 /**
4728  * Converts AVChromaLocation to swscale x/y chroma position.
4729  *
4730  * The positions represent the chroma (0,0) position in a coordinates system
4731  * with luma (0,0) representing the origin and luma(1,1) representing 256,256
4732  *
4733  * @param xpos horizontal chroma sample position
4734  * @param ypos vertical chroma sample position
4735  */
4736 int avcodec_enum_to_chroma_pos(int *xpos, int *ypos, enum AVChromaLocation pos);
4737 
4738 /**
4739  * Converts swscale x/y chroma position to AVChromaLocation.
4740  *
4741  * The positions represent the chroma (0,0) position in a coordinates system
4742  * with luma (0,0) representing the origin and luma(1,1) representing 256,256
4743  *
4744  * @param xpos horizontal chroma sample position
4745  * @param ypos vertical chroma sample position
4746  */
4747 enum AVChromaLocation avcodec_chroma_pos_to_enum(int xpos, int ypos);
4748 
4749 /**
4750  * Decode the audio frame of size avpkt->size from avpkt->data into frame.
4751  *
4752  * Some decoders may support multiple frames in a single AVPacket. Such
4753  * decoders would then just decode the first frame and the return value would be
4754  * less than the packet size. In this case, avcodec_decode_audio4 has to be
4755  * called again with an AVPacket containing the remaining data in order to
4756  * decode the second frame, etc... Even if no frames are returned, the packet
4757  * needs to be fed to the decoder with remaining data until it is completely
4758  * consumed or an error occurs.
4759  *
4760  * Some decoders (those marked with AV_CODEC_CAP_DELAY) have a delay between input
4761  * and output. This means that for some packets they will not immediately
4762  * produce decoded output and need to be flushed at the end of decoding to get
4763  * all the decoded data. Flushing is done by calling this function with packets
4764  * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
4765  * returning samples. It is safe to flush even those decoders that are not
4766  * marked with AV_CODEC_CAP_DELAY, then no samples will be returned.
4767  *
4768  * @warning The input buffer, avpkt->data must be AV_INPUT_BUFFER_PADDING_SIZE
4769  * larger than the actual read bytes because some optimized bitstream
4770  * readers read 32 or 64 bits at once and could read over the end.
4771  *
4772  * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
4773  * before packets may be fed to the decoder.
4774  *
4775  * @param avctx the codec context
4776  * @param[out] frame The AVFrame in which to store decoded audio samples.
4777  * The decoder will allocate a buffer for the decoded frame by
4778  * calling the AVCodecContext.get_buffer2() callback.
4779  * When AVCodecContext.refcounted_frames is set to 1, the frame is
4780  * reference counted and the returned reference belongs to the
4781  * caller. The caller must release the frame using av_frame_unref()
4782  * when the frame is no longer needed. The caller may safely write
4783  * to the frame if av_frame_is_writable() returns 1.
4784  * When AVCodecContext.refcounted_frames is set to 0, the returned
4785  * reference belongs to the decoder and is valid only until the
4786  * next call to this function or until closing or flushing the
4787  * decoder. The caller may not write to it.
4788  * @param[out] got_frame_ptr Zero if no frame could be decoded, otherwise it is
4789  * non-zero. Note that this field being set to zero
4790  * does not mean that an error has occurred. For
4791  * decoders with AV_CODEC_CAP_DELAY set, no given decode
4792  * call is guaranteed to produce a frame.
4793  * @param[in] avpkt The input AVPacket containing the input buffer.
4794  * At least avpkt->data and avpkt->size should be set. Some
4795  * decoders might also require additional fields to be set.
4796  * @return A negative error code is returned if an error occurred during
4797  * decoding, otherwise the number of bytes consumed from the input
4798  * AVPacket is returned.
4799  *
4800 * @deprecated Use avcodec_send_packet() and avcodec_receive_frame().
4801  */
4804  int *got_frame_ptr, const AVPacket *avpkt);
4805 
4806 /**
4807  * Decode the video frame of size avpkt->size from avpkt->data into picture.
4808  * Some decoders may support multiple frames in a single AVPacket, such
4809  * decoders would then just decode the first frame.
4810  *
4811  * @warning The input buffer must be AV_INPUT_BUFFER_PADDING_SIZE larger than
4812  * the actual read bytes because some optimized bitstream readers read 32 or 64
4813  * bits at once and could read over the end.
4814  *
4815  * @warning The end of the input buffer buf should be set to 0 to ensure that
4816  * no overreading happens for damaged MPEG streams.
4817  *
4818  * @note Codecs which have the AV_CODEC_CAP_DELAY capability set have a delay
4819  * between input and output, these need to be fed with avpkt->data=NULL,
4820  * avpkt->size=0 at the end to return the remaining frames.
4821  *
4822  * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
4823  * before packets may be fed to the decoder.
4824  *
4825  * @param avctx the codec context
4826  * @param[out] picture The AVFrame in which the decoded video frame will be stored.
4827  * Use av_frame_alloc() to get an AVFrame. The codec will
4828  * allocate memory for the actual bitmap by calling the
4829  * AVCodecContext.get_buffer2() callback.
4830  * When AVCodecContext.refcounted_frames is set to 1, the frame is
4831  * reference counted and the returned reference belongs to the
4832  * caller. The caller must release the frame using av_frame_unref()
4833  * when the frame is no longer needed. The caller may safely write
4834  * to the frame if av_frame_is_writable() returns 1.
4835  * When AVCodecContext.refcounted_frames is set to 0, the returned
4836  * reference belongs to the decoder and is valid only until the
4837  * next call to this function or until closing or flushing the
4838  * decoder. The caller may not write to it.
4839  *
4840  * @param[in] avpkt The input AVPacket containing the input buffer.
4841  * You can create such packet with av_init_packet() and by then setting
4842  * data and size, some decoders might in addition need other fields like
4843  * flags&AV_PKT_FLAG_KEY. All decoders are designed to use the least
4844  * fields possible.
4845  * @param[in,out] got_picture_ptr Zero if no frame could be decompressed, otherwise, it is nonzero.
4846  * @return On error a negative value is returned, otherwise the number of bytes
4847  * used or zero if no frame could be decompressed.
4848  *
4849  * @deprecated Use avcodec_send_packet() and avcodec_receive_frame().
4850  */
4852 int avcodec_decode_video2(AVCodecContext *avctx, AVFrame *picture,
4853  int *got_picture_ptr,
4854  const AVPacket *avpkt);
4855 
4856 /**
4857  * Decode a subtitle message.
4858  * Return a negative value on error, otherwise return the number of bytes used.
4859  * If no subtitle could be decompressed, got_sub_ptr is zero.
4860  * Otherwise, the subtitle is stored in *sub.
4861  * Note that AV_CODEC_CAP_DR1 is not available for subtitle codecs. This is for
4862  * simplicity, because the performance difference is expect to be negligible
4863  * and reusing a get_buffer written for video codecs would probably perform badly
4864  * due to a potentially very different allocation pattern.
4865  *
4866  * Some decoders (those marked with AV_CODEC_CAP_DELAY) have a delay between input
4867  * and output. This means that for some packets they will not immediately
4868  * produce decoded output and need to be flushed at the end of decoding to get
4869  * all the decoded data. Flushing is done by calling this function with packets
4870  * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
4871  * returning subtitles. It is safe to flush even those decoders that are not
4872  * marked with AV_CODEC_CAP_DELAY, then no subtitles will be returned.
4873  *
4874  * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
4875  * before packets may be fed to the decoder.
4876  *
4877  * @param avctx the codec context
4878  * @param[out] sub The Preallocated AVSubtitle in which the decoded subtitle will be stored,
4879  * must be freed with avsubtitle_free if *got_sub_ptr is set.
4880  * @param[in,out] got_sub_ptr Zero if no subtitle could be decompressed, otherwise, it is nonzero.
4881  * @param[in] avpkt The input AVPacket containing the input buffer.
4882  */
4884  int *got_sub_ptr,
4885  AVPacket *avpkt);
4886 
4887 /**
4888  * Supply raw packet data as input to a decoder.
4889  *
4890  * Internally, this call will copy relevant AVCodecContext fields, which can
4891  * influence decoding per-packet, and apply them when the packet is actually
4892  * decoded. (For example AVCodecContext.skip_frame, which might direct the
4893  * decoder to drop the frame contained by the packet sent with this function.)
4894  *
4895  * @warning The input buffer, avpkt->data must be AV_INPUT_BUFFER_PADDING_SIZE
4896  * larger than the actual read bytes because some optimized bitstream
4897  * readers read 32 or 64 bits at once and could read over the end.
4898  *
4899  * @warning Do not mix this API with the legacy API (like avcodec_decode_video2())
4900  * on the same AVCodecContext. It will return unexpected results now
4901  * or in future libavcodec versions.
4902  *
4903  * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
4904  * before packets may be fed to the decoder.
4905  *
4906  * @param avctx codec context
4907  * @param[in] avpkt The input AVPacket. Usually, this will be a single video
4908  * frame, or several complete audio frames.
4909  * Ownership of the packet remains with the caller, and the
4910  * decoder will not write to the packet. The decoder may create
4911  * a reference to the packet data (or copy it if the packet is
4912  * not reference-counted).
4913  * Unlike with older APIs, the packet is always fully consumed,
4914  * and if it contains multiple frames (e.g. some audio codecs),
4915  * will require you to call avcodec_receive_frame() multiple
4916  * times afterwards before you can send a new packet.
4917  * It can be NULL (or an AVPacket with data set to NULL and
4918  * size set to 0); in this case, it is considered a flush
4919  * packet, which signals the end of the stream. Sending the
4920  * first flush packet will return success. Subsequent ones are
4921  * unnecessary and will return AVERROR_EOF. If the decoder
4922  * still has frames buffered, it will return them after sending
4923  * a flush packet.
4924  *
4925  * @return 0 on success, otherwise negative error code:
4926  * AVERROR(EAGAIN): input is not accepted in the current state - user
4927  * must read output with avcodec_receive_frame() (once
4928  * all output is read, the packet should be resent, and
4929  * the call will not fail with EAGAIN).
4930  * AVERROR_EOF: the decoder has been flushed, and no new packets can
4931  * be sent to it (also returned if more than 1 flush
4932  * packet is sent)
4933  * AVERROR(EINVAL): codec not opened, it is an encoder, or requires flush
4934  * AVERROR(ENOMEM): failed to add packet to internal queue, or similar
4935  * other errors: legitimate decoding errors
4936  */
4937 int avcodec_send_packet(AVCodecContext *avctx, const AVPacket *avpkt);
4938 
4939 /**
4940  * Return decoded output data from a decoder.
4941  *
4942  * @param avctx codec context
4943  * @param frame This will be set to a reference-counted video or audio
4944  * frame (depending on the decoder type) allocated by the
4945  * decoder. Note that the function will always call
4946  * av_frame_unref(frame) before doing anything else.
4947  *
4948  * @return
4949  * 0: success, a frame was returned
4950  * AVERROR(EAGAIN): output is not available in this state - user must try
4951  * to send new input
4952  * AVERROR_EOF: the decoder has been fully flushed, and there will be
4953  * no more output frames
4954  * AVERROR(EINVAL): codec not opened, or it is an encoder
4955  * AVERROR_INPUT_CHANGED: current decoded frame has changed parameters
4956  * with respect to first decoded frame. Applicable
4957  * when flag AV_CODEC_FLAG_DROPCHANGED is set.
4958  * other negative values: legitimate decoding errors
4959  */
4961 
4962 /**
4963  * Supply a raw video or audio frame to the encoder. Use avcodec_receive_packet()
4964  * to retrieve buffered output packets.
4965  *
4966  * @param avctx codec context
4967  * @param[in] frame AVFrame containing the raw audio or video frame to be encoded.
4968  * Ownership of the frame remains with the caller, and the
4969  * encoder will not write to the frame. The encoder may create
4970  * a reference to the frame data (or copy it if the frame is
4971  * not reference-counted).
4972  * It can be NULL, in which case it is considered a flush
4973  * packet. This signals the end of the stream. If the encoder
4974  * still has packets buffered, it will return them after this
4975  * call. Once flushing mode has been entered, additional flush
4976  * packets are ignored, and sending frames will return
4977  * AVERROR_EOF.
4978  *
4979  * For audio:
4980  * If AV_CODEC_CAP_VARIABLE_FRAME_SIZE is set, then each frame
4981  * can have any number of samples.
4982  * If it is not set, frame->nb_samples must be equal to
4983  * avctx->frame_size for all frames except the last.
4984  * The final frame may be smaller than avctx->frame_size.
4985  * @return 0 on success, otherwise negative error code:
4986  * AVERROR(EAGAIN): input is not accepted in the current state - user
4987  * must read output with avcodec_receive_packet() (once
4988  * all output is read, the packet should be resent, and
4989  * the call will not fail with EAGAIN).
4990  * AVERROR_EOF: the encoder has been flushed, and no new frames can
4991  * be sent to it
4992  * AVERROR(EINVAL): codec not opened, refcounted_frames not set, it is a
4993  * decoder, or requires flush
4994  * AVERROR(ENOMEM): failed to add packet to internal queue, or similar
4995  * other errors: legitimate decoding errors
4996  */
4997 int avcodec_send_frame(AVCodecContext *avctx, const AVFrame *frame);
4998 
4999 /**
5000  * Read encoded data from the encoder.
5001  *
5002  * @param avctx codec context
5003  * @param avpkt This will be set to a reference-counted packet allocated by the
5004  * encoder. Note that the function will always call
5005  * av_frame_unref(frame) before doing anything else.
5006  * @return 0 on success, otherwise negative error code:
5007  * AVERROR(EAGAIN): output is not available in the current state - user
5008  * must try to send input
5009  * AVERROR_EOF: the encoder has been fully flushed, and there will be
5010  * no more output packets
5011  * AVERROR(EINVAL): codec not opened, or it is an encoder
5012  * other errors: legitimate decoding errors
5013  */
5014 int avcodec_receive_packet(AVCodecContext *avctx, AVPacket *avpkt);
5015 
5016 /**
5017  * Create and return a AVHWFramesContext with values adequate for hardware
5018  * decoding. This is meant to get called from the get_format callback, and is
5019  * a helper for preparing a AVHWFramesContext for AVCodecContext.hw_frames_ctx.
5020  * This API is for decoding with certain hardware acceleration modes/APIs only.
5021  *
5022  * The returned AVHWFramesContext is not initialized. The caller must do this
5023  * with av_hwframe_ctx_init().
5024  *
5025  * Calling this function is not a requirement, but makes it simpler to avoid
5026  * codec or hardware API specific details when manually allocating frames.
5027  *
5028  * Alternatively to this, an API user can set AVCodecContext.hw_device_ctx,
5029  * which sets up AVCodecContext.hw_frames_ctx fully automatically, and makes
5030  * it unnecessary to call this function or having to care about
5031  * AVHWFramesContext initialization at all.
5032  *
5033  * There are a number of requirements for calling this function:
5034  *
5035  * - It must be called from get_format with the same avctx parameter that was
5036  * passed to get_format. Calling it outside of get_format is not allowed, and
5037  * can trigger undefined behavior.
5038  * - The function is not always supported (see description of return values).
5039  * Even if this function returns successfully, hwaccel initialization could
5040  * fail later. (The degree to which implementations check whether the stream
5041  * is actually supported varies. Some do this check only after the user's
5042  * get_format callback returns.)
5043  * - The hw_pix_fmt must be one of the choices suggested by get_format. If the
5044  * user decides to use a AVHWFramesContext prepared with this API function,
5045  * the user must return the same hw_pix_fmt from get_format.
5046  * - The device_ref passed to this function must support the given hw_pix_fmt.
5047  * - After calling this API function, it is the user's responsibility to
5048  * initialize the AVHWFramesContext (returned by the out_frames_ref parameter),
5049  * and to set AVCodecContext.hw_frames_ctx to it. If done, this must be done
5050  * before returning from get_format (this is implied by the normal
5051  * AVCodecContext.hw_frames_ctx API rules).
5052  * - The AVHWFramesContext parameters may change every time time get_format is
5053  * called. Also, AVCodecContext.hw_frames_ctx is reset before get_format. So
5054  * you are inherently required to go through this process again on every
5055  * get_format call.
5056  * - It is perfectly possible to call this function without actually using
5057  * the resulting AVHWFramesContext. One use-case might be trying to reuse a
5058  * previously initialized AVHWFramesContext, and calling this API function
5059  * only to test whether the required frame parameters have changed.
5060  * - Fields that use dynamically allocated values of any kind must not be set
5061  * by the user unless setting them is explicitly allowed by the documentation.
5062  * If the user sets AVHWFramesContext.free and AVHWFramesContext.user_opaque,
5063  * the new free callback must call the potentially set previous free callback.
5064  * This API call may set any dynamically allocated fields, including the free
5065  * callback.
5066  *
5067  * The function will set at least the following fields on AVHWFramesContext
5068  * (potentially more, depending on hwaccel API):
5069  *
5070  * - All fields set by av_hwframe_ctx_alloc().
5071  * - Set the format field to hw_pix_fmt.
5072  * - Set the sw_format field to the most suited and most versatile format. (An
5073  * implication is that this will prefer generic formats over opaque formats
5074  * with arbitrary restrictions, if possible.)
5075  * - Set the width/height fields to the coded frame size, rounded up to the
5076  * API-specific minimum alignment.
5077  * - Only _if_ the hwaccel requires a pre-allocated pool: set the initial_pool_size
5078  * field to the number of maximum reference surfaces possible with the codec,
5079  * plus 1 surface for the user to work (meaning the user can safely reference
5080  * at most 1 decoded surface at a time), plus additional buffering introduced
5081  * by frame threading. If the hwaccel does not require pre-allocation, the
5082  * field is left to 0, and the decoder will allocate new surfaces on demand
5083  * during decoding.
5084  * - Possibly AVHWFramesContext.hwctx fields, depending on the underlying
5085  * hardware API.
5086  *
5087  * Essentially, out_frames_ref returns the same as av_hwframe_ctx_alloc(), but
5088  * with basic frame parameters set.
5089  *
5090  * The function is stateless, and does not change the AVCodecContext or the
5091  * device_ref AVHWDeviceContext.
5092  *
5093  * @param avctx The context which is currently calling get_format, and which
5094  * implicitly contains all state needed for filling the returned
5095  * AVHWFramesContext properly.
5096  * @param device_ref A reference to the AVHWDeviceContext describing the device
5097  * which will be used by the hardware decoder.
5098  * @param hw_pix_fmt The hwaccel format you are going to return from get_format.
5099  * @param out_frames_ref On success, set to a reference to an _uninitialized_
5100  * AVHWFramesContext, created from the given device_ref.
5101  * Fields will be set to values required for decoding.
5102  * Not changed if an error is returned.
5103  * @return zero on success, a negative value on error. The following error codes
5104  * have special semantics:
5105  * AVERROR(ENOENT): the decoder does not support this functionality. Setup
5106  * is always manual, or it is a decoder which does not
5107  * support setting AVCodecContext.hw_frames_ctx at all,
5108  * or it is a software format.
5109  * AVERROR(EINVAL): it is known that hardware decoding is not supported for
5110  * this configuration, or the device_ref is not supported
5111  * for the hwaccel referenced by hw_pix_fmt.
5112  */
5114  AVBufferRef *device_ref,
5116  AVBufferRef **out_frames_ref);
5117 
5118 
5119 
5120 /**
5121  * @defgroup lavc_parsing Frame parsing
5122  * @{
5123  */
5124 
5127  AV_PICTURE_STRUCTURE_TOP_FIELD, //< coded as top field
5128  AV_PICTURE_STRUCTURE_BOTTOM_FIELD, //< coded as bottom field
5129  AV_PICTURE_STRUCTURE_FRAME, //< coded as frame
5130 };
5131 
5132 typedef struct AVCodecParserContext {
5133  void *priv_data;
5135  int64_t frame_offset; /* offset of the current frame */
5136  int64_t cur_offset; /* current offset
5137  (incremented by each av_parser_parse()) */
5138  int64_t next_frame_offset; /* offset of the next frame */
5139  /* video info */
5140  int pict_type; /* XXX: Put it back in AVCodecContext. */
5141  /**
5142  * This field is used for proper frame duration computation in lavf.
5143  * It signals, how much longer the frame duration of the current frame
5144  * is compared to normal frame duration.
5145  *
5146  * frame_duration = (1 + repeat_pict) * time_base
5147  *
5148  * It is used by codecs like H.264 to display telecined material.
5149  */
5150  int repeat_pict; /* XXX: Put it back in AVCodecContext. */
5151  int64_t pts; /* pts of the current frame */
5152  int64_t dts; /* dts of the current frame */
5153 
5154  /* private data */
5155  int64_t last_pts;
5156  int64_t last_dts;
5158 
5159 #define AV_PARSER_PTS_NB 4
5161  int64_t cur_frame_offset[AV_PARSER_PTS_NB];
5162  int64_t cur_frame_pts[AV_PARSER_PTS_NB];
5163  int64_t cur_frame_dts[AV_PARSER_PTS_NB];
5164 
5165  int flags;
5166 #define PARSER_FLAG_COMPLETE_FRAMES 0x0001
5167 #define PARSER_FLAG_ONCE 0x0002
5168 /// Set if the parser has a valid file offset
5169 #define PARSER_FLAG_FETCHED_OFFSET 0x0004
5170 #define PARSER_FLAG_USE_CODEC_TS 0x1000
5171 
5172  int64_t offset; ///< byte offset from starting packet start
5173  int64_t cur_frame_end[AV_PARSER_PTS_NB];
5174 
5175  /**
5176  * Set by parser to 1 for key frames and 0 for non-key frames.
5177  * It is initialized to -1, so if the parser doesn't set this flag,
5178  * old-style fallback using AV_PICTURE_TYPE_I picture type as key frames
5179  * will be used.
5180  */
5182 
5183 #if FF_API_CONVERGENCE_DURATION
5184  /**
5185  * @deprecated unused
5186  */
5189 #endif
5190 
5191  // Timestamp generation support:
5192  /**
5193  * Synchronization point for start of timestamp generation.
5194  *
5195  * Set to >0 for sync point, 0 for no sync point and <0 for undefined
5196  * (default).
5197  *
5198  * For example, this corresponds to presence of H.264 buffering period
5199  * SEI message.
5200  */
5202 
5203  /**
5204  * Offset of the current timestamp against last timestamp sync point in
5205  * units of AVCodecContext.time_base.
5206  *
5207  * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
5208  * contain a valid timestamp offset.
5209  *
5210  * Note that the timestamp of sync point has usually a nonzero
5211  * dts_ref_dts_delta, which refers to the previous sync point. Offset of
5212  * the next frame after timestamp sync point will be usually 1.
5213  *
5214  * For example, this corresponds to H.264 cpb_removal_delay.
5215  */
5217 
5218  /**
5219  * Presentation delay of current frame in units of AVCodecContext.time_base.
5220  *
5221  * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
5222  * contain valid non-negative timestamp delta (presentation time of a frame
5223  * must not lie in the past).
5224  *
5225  * This delay represents the difference between decoding and presentation
5226  * time of the frame.
5227  *
5228  * For example, this corresponds to H.264 dpb_output_delay.
5229  */
5231 
5232  /**
5233  * Position of the packet in file.
5234  *
5235  * Analogous to cur_frame_pts/dts
5236  */
5237  int64_t cur_frame_pos[AV_PARSER_PTS_NB];
5238 
5239  /**
5240  * Byte position of currently parsed frame in stream.
5241  */
5242  int64_t pos;
5243 
5244  /**
5245  * Previous frame byte position.
5246  */
5247  int64_t last_pos;
5248 
5249  /**
5250  * Duration of the current frame.
5251  * For audio, this is in units of 1 / AVCodecContext.sample_rate.
5252  * For all other types, this is in units of AVCodecContext.time_base.
5253  */
5255 
5256  enum AVFieldOrder field_order;
5257 
5258  /**
5259  * Indicate whether a picture is coded as a frame, top field or bottom field.
5260  *
5261  * For example, H.264 field_pic_flag equal to 0 corresponds to
5262  * AV_PICTURE_STRUCTURE_FRAME. An H.264 picture with field_pic_flag
5263  * equal to 1 and bottom_field_flag equal to 0 corresponds to
5264  * AV_PICTURE_STRUCTURE_TOP_FIELD.
5265  */
5266  enum AVPictureStructure picture_structure;
5267 
5268  /**
5269  * Picture number incremented in presentation or output order.
5270  * This field may be reinitialized at the first picture of a new sequence.
5271  *
5272  * For example, this corresponds to H.264 PicOrderCnt.
5273  */
5275 
5276  /**
5277  * Dimensions of the decoded video intended for presentation.
5278  */
5279  int width;
5280  int height;
5281 
5282  /**
5283  * Dimensions of the coded video.
5284  */
5287 
5288  /**
5289  * The format of the coded data, corresponds to enum AVPixelFormat for video
5290  * and for enum AVSampleFormat for audio.
5291  *
5292  * Note that a decoder can have considerable freedom in how exactly it
5293  * decodes the data, so the format reported here might be different from the
5294  * one returned by a decoder.
5295  */
5296  int format;
5298 
5299 typedef struct AVCodecParser {
5300  int codec_ids[5]; /* several codec IDs are permitted */
5302  int (*parser_init)(AVCodecParserContext *s);
5303  /* This callback never returns an error, a negative value means that
5304  * the frame start was in a previous packet. */
5305  int (*parser_parse)(AVCodecParserContext *s,
5306  AVCodecContext *avctx,
5307  const uint8_t **poutbuf, int *poutbuf_size,
5308  const uint8_t *buf, int buf_size);
5309  void (*parser_close)(AVCodecParserContext *s);
5310  int (*split)(AVCodecContext *avctx, const uint8_t *buf, int buf_size);
5312 } AVCodecParser;
5313 
5314 /**
5315  * Iterate over all registered codec parsers.
5316  *
5317  * @param opaque a pointer where libavcodec will store the iteration state. Must
5318  * point to NULL to start the iteration.
5319  *
5320  * @return the next registered codec parser or NULL when the iteration is
5321  * finished
5322  */
5323 const AVCodecParser *av_parser_iterate(void **opaque);
5324 
5327 
5331 
5332 /**
5333  * Parse a packet.
5334  *
5335  * @param s parser context.
5336  * @param avctx codec context.
5337  * @param poutbuf set to pointer to parsed buffer or NULL if not yet finished.
5338  * @param poutbuf_size set to size of parsed buffer or zero if not yet finished.
5339  * @param buf input buffer.
5340  * @param buf_size buffer size in bytes without the padding. I.e. the full buffer
5341  size is assumed to be buf_size + AV_INPUT_BUFFER_PADDING_SIZE.
5342  To signal EOF, this should be 0 (so that the last frame
5343  can be output).
5344  * @param pts input presentation timestamp.
5345  * @param dts input decoding timestamp.
5346  * @param pos input byte position in stream.
5347  * @return the number of bytes of the input bitstream used.
5348  *
5349  * Example:
5350  * @code
5351  * while(in_len){
5352  * len = av_parser_parse2(myparser, AVCodecContext, &data, &size,
5353  * in_data, in_len,
5354  * pts, dts, pos);
5355  * in_data += len;
5356  * in_len -= len;
5357  *
5358  * if(size)
5359  * decode_frame(data, size);
5360  * }
5361  * @endcode
5362  */
5364  AVCodecContext *avctx,
5365  uint8_t **poutbuf, int *poutbuf_size,
5366  const uint8_t *buf, int buf_size,
5367  int64_t pts, int64_t dts,
5368  int64_t pos);
5369 
5370 /**
5371  * @return 0 if the output buffer is a subset of the input, 1 if it is allocated and must be freed
5372  * @deprecated use AVBitStreamFilter
5373  */
5375  AVCodecContext *avctx,
5376  uint8_t **poutbuf, int *poutbuf_size,
5377  const uint8_t *buf, int buf_size, int keyframe);
5379 
5380 /**
5381  * @}
5382  * @}
5383  */
5384 
5385 /**
5386  * @addtogroup lavc_encoding
5387  * @{
5388  */
5389 
5390 /**
5391  * Find a registered encoder with a matching codec ID.
5392  *
5393  * @param id AVCodecID of the requested encoder
5394  * @return An encoder if one was found, NULL otherwise.
5395  */
5397 
5398 /**
5399  * Find a registered encoder with the specified name.
5400  *
5401  * @param name name of the requested encoder
5402  * @return An encoder if one was found, NULL otherwise.
5403  */
5405 
5406 /**
5407  * Encode a frame of audio.
5408  *
5409  * Takes input samples from frame and writes the next output packet, if
5410  * available, to avpkt. The output packet does not necessarily contain data for
5411  * the most recent frame, as encoders can delay, split, and combine input frames
5412  * internally as needed.
5413  *
5414  * @param avctx codec context
5415  * @param avpkt output AVPacket.
5416  * The user can supply an output buffer by setting
5417  * avpkt->data and avpkt->size prior to calling the
5418  * function, but if the size of the user-provided data is not
5419  * large enough, encoding will fail. If avpkt->data and
5420  * avpkt->size are set, avpkt->destruct must also be set. All
5421  * other AVPacket fields will be reset by the encoder using
5422  * av_init_packet(). If avpkt->data is NULL, the encoder will
5423  * allocate it. The encoder will set avpkt->size to the size
5424  * of the output packet.
5425  *
5426  * If this function fails or produces no output, avpkt will be
5427  * freed using av_packet_unref().
5428  * @param[in] frame AVFrame containing the raw audio data to be encoded.
5429  * May be NULL when flushing an encoder that has the
5430  * AV_CODEC_CAP_DELAY capability set.
5431  * If AV_CODEC_CAP_VARIABLE_FRAME_SIZE is set, then each frame
5432  * can have any number of samples.
5433  * If it is not set, frame->nb_samples must be equal to
5434  * avctx->frame_size for all frames except the last.
5435  * The final frame may be smaller than avctx->frame_size.
5436  * @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
5437  * output packet is non-empty, and to 0 if it is
5438  * empty. If the funct