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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 
455 
456  /* various PCM "codecs" */
457  AV_CODEC_ID_FIRST_AUDIO = 0x10000, ///< A dummy id pointing at the start of audio codecs
489 
495 
496  /* various ADPCM codecs */
528 
539 
540  /* AMR */
543 
544  /* RealAudio codecs*/
547 
548  /* various DPCM codecs */
553 
556 
557  /* audio codecs */
558  AV_CODEC_ID_MP2 = 0x15000,
559  AV_CODEC_ID_MP3, ///< preferred ID for decoding MPEG audio layer 1, 2 or 3
576  AV_CODEC_ID_GSM, ///< as in Berlin toast format
588  AV_CODEC_ID_GSM_MS, /* as found in WAV */
626 
648 
649  /* subtitle codecs */
650  AV_CODEC_ID_FIRST_SUBTITLE = 0x17000, ///< A dummy ID pointing at the start of subtitle codecs.
653  AV_CODEC_ID_TEXT, ///< raw UTF-8 text
660 
677 
678  /* other specific kind of codecs (generally used for attachments) */
679  AV_CODEC_ID_FIRST_UNKNOWN = 0x18000, ///< A dummy ID pointing at the start of various fake codecs.
680  AV_CODEC_ID_TTF = 0x18000,
681 
682  AV_CODEC_ID_SCTE_35, ///< Contain timestamp estimated through PCR of program stream.
691 
692 
693  AV_CODEC_ID_PROBE = 0x19000, ///< codec_id is not known (like AV_CODEC_ID_NONE) but lavf should attempt to identify it
694 
695  AV_CODEC_ID_MPEG2TS = 0x20000, /**< _FAKE_ codec to indicate a raw MPEG-2 TS
696  * stream (only used by libavformat) */
697  AV_CODEC_ID_MPEG4SYSTEMS = 0x20001, /**< _FAKE_ codec to indicate a MPEG-4 Systems
698  * stream (only used by libavformat) */
699  AV_CODEC_ID_FFMETADATA = 0x21000, ///< Dummy codec for streams containing only metadata information.
700  AV_CODEC_ID_WRAPPED_AVFRAME = 0x21001, ///< Passthrough codec, AVFrames wrapped in AVPacket
701 };
702 
703 /**
704  * This struct describes the properties of a single codec described by an
705  * AVCodecID.
706  * @see avcodec_descriptor_get()
707  */
708 typedef struct AVCodecDescriptor {
709  enum AVCodecID id;
711  /**
712  * Name of the codec described by this descriptor. It is non-empty and
713  * unique for each codec descriptor. It should contain alphanumeric
714  * characters and '_' only.
715  */
716  const char *name;
717  /**
718  * A more descriptive name for this codec. May be NULL.
719  */
720  const char *long_name;
721  /**
722  * Codec properties, a combination of AV_CODEC_PROP_* flags.
723  */
724  int props;
725  /**
726  * MIME type(s) associated with the codec.
727  * May be NULL; if not, a NULL-terminated array of MIME types.
728  * The first item is always non-NULL and is the preferred MIME type.
729  */
730  const char *const *mime_types;
731  /**
732  * If non-NULL, an array of profiles recognized for this codec.
733  * Terminated with FF_PROFILE_UNKNOWN.
734  */
735  const struct AVProfile *profiles;
737 
738 /**
739  * Codec uses only intra compression.
740  * Video and audio codecs only.
741  */
742 #define AV_CODEC_PROP_INTRA_ONLY (1 << 0)
743 /**
744  * Codec supports lossy compression. Audio and video codecs only.
745  * @note a codec may support both lossy and lossless
746  * compression modes
747  */
748 #define AV_CODEC_PROP_LOSSY (1 << 1)
749 /**
750  * Codec supports lossless compression. Audio and video codecs only.
751  */
752 #define AV_CODEC_PROP_LOSSLESS (1 << 2)
753 /**
754  * Codec supports frame reordering. That is, the coded order (the order in which
755  * the encoded packets are output by the encoders / stored / input to the
756  * decoders) may be different from the presentation order of the corresponding
757  * frames.
758  *
759  * For codecs that do not have this property set, PTS and DTS should always be
760  * equal.
761  */
762 #define AV_CODEC_PROP_REORDER (1 << 3)
763 /**
764  * Subtitle codec is bitmap based
765  * Decoded AVSubtitle data can be read from the AVSubtitleRect->pict field.
766  */
767 #define AV_CODEC_PROP_BITMAP_SUB (1 << 16)
768 /**
769  * Subtitle codec is text based.
770  * Decoded AVSubtitle data can be read from the AVSubtitleRect->ass field.
771  */
772 #define AV_CODEC_PROP_TEXT_SUB (1 << 17)
773 
774 /**
775  * @ingroup lavc_decoding
776  * Required number of additionally allocated bytes at the end of the input bitstream for decoding.
777  * This is mainly needed because some optimized bitstream readers read
778  * 32 or 64 bit at once and could read over the end.<br>
779  * Note: If the first 23 bits of the additional bytes are not 0, then damaged
780  * MPEG bitstreams could cause overread and segfault.
781  */
782 #define AV_INPUT_BUFFER_PADDING_SIZE 64
783 
784 /**
785  * @ingroup lavc_encoding
786  * minimum encoding buffer size
787  * Used to avoid some checks during header writing.
788  */
789 #define AV_INPUT_BUFFER_MIN_SIZE 16384
790 
791 /**
792  * @ingroup lavc_decoding
793  */
795  /* We leave some space between them for extensions (drop some
796  * keyframes for intra-only or drop just some bidir frames). */
797  AVDISCARD_NONE =-16, ///< discard nothing
798  AVDISCARD_DEFAULT = 0, ///< discard useless packets like 0 size packets in avi
799  AVDISCARD_NONREF = 8, ///< discard all non reference
800  AVDISCARD_BIDIR = 16, ///< discard all bidirectional frames
801  AVDISCARD_NONINTRA= 24, ///< discard all non intra frames
802  AVDISCARD_NONKEY = 32, ///< discard all frames except keyframes
803  AVDISCARD_ALL = 48, ///< discard all
804 };
805 
816  AV_AUDIO_SERVICE_TYPE_NB , ///< Not part of ABI
817 };
818 
819 /**
820  * @ingroup lavc_encoding
821  */
822 typedef struct RcOverride{
825  int qscale; // If this is 0 then quality_factor will be used instead.
827 } RcOverride;
828 
829 /* encoding support
830  These flags can be passed in AVCodecContext.flags before initialization.
831  Note: Not everything is supported yet.
832 */
833 
834 /**
835  * Allow decoders to produce frames with data planes that are not aligned
836  * to CPU requirements (e.g. due to cropping).
837  */
838 #define AV_CODEC_FLAG_UNALIGNED (1 << 0)
839 /**
840  * Use fixed qscale.
841  */
842 #define AV_CODEC_FLAG_QSCALE (1 << 1)
843 /**
844  * 4 MV per MB allowed / advanced prediction for H.263.
845  */
846 #define AV_CODEC_FLAG_4MV (1 << 2)
847 /**
848  * Output even those frames that might be corrupted.
849  */
850 #define AV_CODEC_FLAG_OUTPUT_CORRUPT (1 << 3)
851 /**
852  * Use qpel MC.
853  */
854 #define AV_CODEC_FLAG_QPEL (1 << 4)
855 /**
856  * Use internal 2pass ratecontrol in first pass mode.
857  */
858 #define AV_CODEC_FLAG_PASS1 (1 << 9)
859 /**
860  * Use internal 2pass ratecontrol in second pass mode.
861  */
862 #define AV_CODEC_FLAG_PASS2 (1 << 10)
863 /**
864  * loop filter.
865  */
866 #define AV_CODEC_FLAG_LOOP_FILTER (1 << 11)
867 /**
868  * Only decode/encode grayscale.
869  */
870 #define AV_CODEC_FLAG_GRAY (1 << 13)
871 /**
872  * error[?] variables will be set during encoding.
873  */
874 #define AV_CODEC_FLAG_PSNR (1 << 15)
875 /**
876  * Input bitstream might be truncated at a random location
877  * instead of only at frame boundaries.
878  */
879 #define AV_CODEC_FLAG_TRUNCATED (1 << 16)
880 /**
881  * Use interlaced DCT.
882  */
883 #define AV_CODEC_FLAG_INTERLACED_DCT (1 << 18)
884 /**
885  * Force low delay.
886  */
887 #define AV_CODEC_FLAG_LOW_DELAY (1 << 19)
888 /**
889  * Place global headers in extradata instead of every keyframe.
890  */
891 #define AV_CODEC_FLAG_GLOBAL_HEADER (1 << 22)
892 /**
893  * Use only bitexact stuff (except (I)DCT).
894  */
895 #define AV_CODEC_FLAG_BITEXACT (1 << 23)
896 /* Fx : Flag for H.263+ extra options */
897 /**
898  * H.263 advanced intra coding / MPEG-4 AC prediction
899  */
900 #define AV_CODEC_FLAG_AC_PRED (1 << 24)
901 /**
902  * interlaced motion estimation
903  */
904 #define AV_CODEC_FLAG_INTERLACED_ME (1 << 29)
905 #define AV_CODEC_FLAG_CLOSED_GOP (1U << 31)
906 
907 /**
908  * Allow non spec compliant speedup tricks.
909  */
910 #define AV_CODEC_FLAG2_FAST (1 << 0)
911 /**
912  * Skip bitstream encoding.
913  */
914 #define AV_CODEC_FLAG2_NO_OUTPUT (1 << 2)
915 /**
916  * Place global headers at every keyframe instead of in extradata.
917  */
918 #define AV_CODEC_FLAG2_LOCAL_HEADER (1 << 3)
919 
920 /**
921  * timecode is in drop frame format. DEPRECATED!!!!
922  */
923 #define AV_CODEC_FLAG2_DROP_FRAME_TIMECODE (1 << 13)
924 
925 /**
926  * Input bitstream might be truncated at a packet boundaries
927  * instead of only at frame boundaries.
928  */
929 #define AV_CODEC_FLAG2_CHUNKS (1 << 15)
930 /**
931  * Discard cropping information from SPS.
932  */
933 #define AV_CODEC_FLAG2_IGNORE_CROP (1 << 16)
934 
935 /**
936  * Show all frames before the first keyframe
937  */
938 #define AV_CODEC_FLAG2_SHOW_ALL (1 << 22)
939 /**
940  * Export motion vectors through frame side data
941  */
942 #define AV_CODEC_FLAG2_EXPORT_MVS (1 << 28)
943 /**
944  * Do not skip samples and export skip information as frame side data
945  */
946 #define AV_CODEC_FLAG2_SKIP_MANUAL (1 << 29)
947 /**
948  * Do not reset ASS ReadOrder field on flush (subtitles decoding)
949  */
950 #define AV_CODEC_FLAG2_RO_FLUSH_NOOP (1 << 30)
951 
952 /* Unsupported options :
953  * Syntax Arithmetic coding (SAC)
954  * Reference Picture Selection
955  * Independent Segment Decoding */
956 /* /Fx */
957 /* codec capabilities */
958 
959 /**
960  * Decoder can use draw_horiz_band callback.
961  */
962 #define AV_CODEC_CAP_DRAW_HORIZ_BAND (1 << 0)
963 /**
964  * Codec uses get_buffer() for allocating buffers and supports custom allocators.
965  * If not set, it might not use get_buffer() at all or use operations that
966  * assume the buffer was allocated by avcodec_default_get_buffer.
967  */
968 #define AV_CODEC_CAP_DR1 (1 << 1)
969 #define AV_CODEC_CAP_TRUNCATED (1 << 3)
970 /**
971  * Encoder or decoder requires flushing with NULL input at the end in order to
972  * give the complete and correct output.
973  *
974  * NOTE: If this flag is not set, the codec is guaranteed to never be fed with
975  * with NULL data. The user can still send NULL data to the public encode
976  * or decode function, but libavcodec will not pass it along to the codec
977  * unless this flag is set.
978  *
979  * Decoders:
980  * The decoder has a non-zero delay and needs to be fed with avpkt->data=NULL,
981  * avpkt->size=0 at the end to get the delayed data until the decoder no longer
982  * returns frames.
983  *
984  * Encoders:
985  * The encoder needs to be fed with NULL data at the end of encoding until the
986  * encoder no longer returns data.
987  *
988  * NOTE: For encoders implementing the AVCodec.encode2() function, setting this
989  * flag also means that the encoder must set the pts and duration for
990  * each output packet. If this flag is not set, the pts and duration will
991  * be determined by libavcodec from the input frame.
992  */
993 #define AV_CODEC_CAP_DELAY (1 << 5)
994 /**
995  * Codec can be fed a final frame with a smaller size.
996  * This can be used to prevent truncation of the last audio samples.
997  */
998 #define AV_CODEC_CAP_SMALL_LAST_FRAME (1 << 6)
999 
1000 /**
1001  * Codec can output multiple frames per AVPacket
1002  * Normally demuxers return one frame at a time, demuxers which do not do
1003  * are connected to a parser to split what they return into proper frames.
1004  * This flag is reserved to the very rare category of codecs which have a
1005  * bitstream that cannot be split into frames without timeconsuming
1006  * operations like full decoding. Demuxers carrying such bitstreams thus
1007  * may return multiple frames in a packet. This has many disadvantages like
1008  * prohibiting stream copy in many cases thus it should only be considered
1009  * as a last resort.
1010  */
1011 #define AV_CODEC_CAP_SUBFRAMES (1 << 8)
1012 /**
1013  * Codec is experimental and is thus avoided in favor of non experimental
1014  * encoders
1015  */
1016 #define AV_CODEC_CAP_EXPERIMENTAL (1 << 9)
1017 /**
1018  * Codec should fill in channel configuration and samplerate instead of container
1019  */
1020 #define AV_CODEC_CAP_CHANNEL_CONF (1 << 10)
1021 /**
1022  * Codec supports frame-level multithreading.
1023  */
1024 #define AV_CODEC_CAP_FRAME_THREADS (1 << 12)
1025 /**
1026  * Codec supports slice-based (or partition-based) multithreading.
1027  */
1028 #define AV_CODEC_CAP_SLICE_THREADS (1 << 13)
1029 /**
1030  * Codec supports changed parameters at any point.
1031  */
1032 #define AV_CODEC_CAP_PARAM_CHANGE (1 << 14)
1033 /**
1034  * Codec supports avctx->thread_count == 0 (auto).
1035  */
1036 #define AV_CODEC_CAP_AUTO_THREADS (1 << 15)
1037 /**
1038  * Audio encoder supports receiving a different number of samples in each call.
1039  */
1040 #define AV_CODEC_CAP_VARIABLE_FRAME_SIZE (1 << 16)
1041 /**
1042  * Decoder is not a preferred choice for probing.
1043  * This indicates that the decoder is not a good choice for probing.
1044  * It could for example be an expensive to spin up hardware decoder,
1045  * or it could simply not provide a lot of useful information about
1046  * the stream.
1047  * A decoder marked with this flag should only be used as last resort
1048  * choice for probing.
1049  */
1050 #define AV_CODEC_CAP_AVOID_PROBING (1 << 17)
1051 /**
1052  * Codec is intra only.
1053  */
1054 #define AV_CODEC_CAP_INTRA_ONLY 0x40000000
1055 /**
1056  * Codec is lossless.
1057  */
1058 #define AV_CODEC_CAP_LOSSLESS 0x80000000
1059 
1060 /**
1061  * Codec is backed by a hardware implementation. Typically used to
1062  * identify a non-hwaccel hardware decoder. For information about hwaccels, use
1063  * avcodec_get_hw_config() instead.
1064  */
1065 #define AV_CODEC_CAP_HARDWARE (1 << 18)
1066 
1067 /**
1068  * Codec is potentially backed by a hardware implementation, but not
1069  * necessarily. This is used instead of AV_CODEC_CAP_HARDWARE, if the
1070  * implementation provides some sort of internal fallback.
1071  */
1072 #define AV_CODEC_CAP_HYBRID (1 << 19)
1073 
1074 /**
1075  * This codec takes the reordered_opaque field from input AVFrames
1076  * and returns it in the corresponding field in AVCodecContext after
1077  * encoding.
1078  */
1079 #define AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE (1 << 20)
1080 
1081 /**
1082  * Pan Scan area.
1083  * This specifies the area which should be displayed.
1084  * Note there may be multiple such areas for one frame.
1085  */
1086 typedef struct AVPanScan {
1087  /**
1088  * id
1089  * - encoding: Set by user.
1090  * - decoding: Set by libavcodec.
1091  */
1092  int id;
1093 
1094  /**
1095  * width and height in 1/16 pel
1096  * - encoding: Set by user.
1097  * - decoding: Set by libavcodec.
1098  */
1099  int width;
1100  int height;
1101 
1102  /**
1103  * position of the top left corner in 1/16 pel for up to 3 fields/frames
1104  * - encoding: Set by user.
1105  * - decoding: Set by libavcodec.
1106  */
1107  int16_t position[3][2];
1108 } AVPanScan;
1109 
1110 /**
1111  * This structure describes the bitrate properties of an encoded bitstream. It
1112  * roughly corresponds to a subset the VBV parameters for MPEG-2 or HRD
1113  * parameters for H.264/HEVC.
1114  */
1115 typedef struct AVCPBProperties {
1116  /**
1117  * Maximum bitrate of the stream, in bits per second.
1118  * Zero if unknown or unspecified.
1119  */
1121  /**
1122  * Minimum bitrate of the stream, in bits per second.
1123  * Zero if unknown or unspecified.
1124  */
1126  /**
1127  * Average bitrate of the stream, in bits per second.
1128  * Zero if unknown or unspecified.
1129  */
1131 
1132  /**
1133  * The size of the buffer to which the ratecontrol is applied, in bits.
1134  * Zero if unknown or unspecified.
1135  */
1137 
1138  /**
1139  * The delay between the time the packet this structure is associated with
1140  * is received and the time when it should be decoded, in periods of a 27MHz
1141  * clock.
1142  *
1143  * UINT64_MAX when unknown or unspecified.
1144  */
1145  uint64_t vbv_delay;
1146 } AVCPBProperties;
1147 
1148 /**
1149  * The decoder will keep a reference to the frame and may reuse it later.
1150  */
1151 #define AV_GET_BUFFER_FLAG_REF (1 << 0)
1152 
1153 /**
1154  * @defgroup lavc_packet AVPacket
1155  *
1156  * Types and functions for working with AVPacket.
1157  * @{
1158  */
1160  /**
1161  * An AV_PKT_DATA_PALETTE side data packet contains exactly AVPALETTE_SIZE
1162  * bytes worth of palette. This side data signals that a new palette is
1163  * present.
1164  */
1166 
1167  /**
1168  * The AV_PKT_DATA_NEW_EXTRADATA is used to notify the codec or the format
1169  * that the extradata buffer was changed and the receiving side should
1170  * act upon it appropriately. The new extradata is embedded in the side
1171  * data buffer and should be immediately used for processing the current
1172  * frame or packet.
1173  */
1175 
1176  /**
1177  * An AV_PKT_DATA_PARAM_CHANGE side data packet is laid out as follows:
1178  * @code
1179  * u32le param_flags
1180  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT)
1181  * s32le channel_count
1182  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT)
1183  * u64le channel_layout
1184  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE)
1185  * s32le sample_rate
1186  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS)
1187  * s32le width
1188  * s32le height
1189  * @endcode
1190  */
1192 
1193  /**
1194  * An AV_PKT_DATA_H263_MB_INFO side data packet contains a number of
1195  * structures with info about macroblocks relevant to splitting the
1196  * packet into smaller packets on macroblock edges (e.g. as for RFC 2190).
1197  * That is, it does not necessarily contain info about all macroblocks,
1198  * as long as the distance between macroblocks in the info is smaller
1199  * than the target payload size.
1200  * Each MB info structure is 12 bytes, and is laid out as follows:
1201  * @code
1202  * u32le bit offset from the start of the packet
1203  * u8 current quantizer at the start of the macroblock
1204  * u8 GOB number
1205  * u16le macroblock address within the GOB
1206  * u8 horizontal MV predictor
1207  * u8 vertical MV predictor
1208  * u8 horizontal MV predictor for block number 3
1209  * u8 vertical MV predictor for block number 3
1210  * @endcode
1211  */
1213 
1214  /**
1215  * This side data should be associated with an audio stream and contains
1216  * ReplayGain information in form of the AVReplayGain struct.
1217  */
1219 
1220  /**
1221  * This side data contains a 3x3 transformation matrix describing an affine
1222  * transformation that needs to be applied to the decoded video frames for
1223  * correct presentation.
1224  *
1225  * See libavutil/display.h for a detailed description of the data.
1226  */
1228 
1229  /**
1230  * This side data should be associated with a video stream and contains
1231  * Stereoscopic 3D information in form of the AVStereo3D struct.
1232  */
1234 
1235  /**
1236  * This side data should be associated with an audio stream and corresponds
1237  * to enum AVAudioServiceType.
1238  */
1240 
1241  /**
1242  * This side data contains quality related information from the encoder.
1243  * @code
1244  * u32le quality factor of the compressed frame. Allowed range is between 1 (good) and FF_LAMBDA_MAX (bad).
1245  * u8 picture type
1246  * u8 error count
1247  * u16 reserved
1248  * u64le[error count] sum of squared differences between encoder in and output
1249  * @endcode
1250  */
1252 
1253  /**
1254  * This side data contains an integer value representing the stream index
1255  * of a "fallback" track. A fallback track indicates an alternate
1256  * track to use when the current track can not be decoded for some reason.
1257  * e.g. no decoder available for codec.
1258  */
1260 
1261  /**
1262  * This side data corresponds to the AVCPBProperties struct.
1263  */
1265 
1266  /**
1267  * Recommmends skipping the specified number of samples
1268  * @code
1269  * u32le number of samples to skip from start of this packet
1270  * u32le number of samples to skip from end of this packet
1271  * u8 reason for start skip
1272  * u8 reason for end skip (0=padding silence, 1=convergence)
1273  * @endcode
1274  */
1276 
1277  /**
1278  * An AV_PKT_DATA_JP_DUALMONO side data packet indicates that
1279  * the packet may contain "dual mono" audio specific to Japanese DTV
1280  * and if it is true, recommends only the selected channel to be used.
1281  * @code
1282  * u8 selected channels (0=mail/left, 1=sub/right, 2=both)
1283  * @endcode
1284  */
1286 
1287  /**
1288  * A list of zero terminated key/value strings. There is no end marker for
1289  * the list, so it is required to rely on the side data size to stop.
1290  */
1292 
1293  /**
1294  * Subtitle event position
1295  * @code
1296  * u32le x1
1297  * u32le y1
1298  * u32le x2
1299  * u32le y2
1300  * @endcode
1301  */
1303 
1304  /**
1305  * Data found in BlockAdditional element of matroska container. There is
1306  * no end marker for the data, so it is required to rely on the side data
1307  * size to recognize the end. 8 byte id (as found in BlockAddId) followed
1308  * by data.
1309  */
1311 
1312  /**
1313  * The optional first identifier line of a WebVTT cue.
1314  */
1316 
1317  /**
1318  * The optional settings (rendering instructions) that immediately
1319  * follow the timestamp specifier of a WebVTT cue.
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. This
1326  * side data includes updated metadata which appeared in the stream.
1327  */
1329 
1330  /**
1331  * MPEGTS stream ID, this is required to pass the stream ID
1332  * information from the demuxer to the corresponding muxer.
1333  */
1335 
1336  /**
1337  * Mastering display metadata (based on SMPTE-2086:2014). This metadata
1338  * should be associated with a video stream and contains data in the form
1339  * of the AVMasteringDisplayMetadata struct.
1340  */
1342 
1343  /**
1344  * This side data should be associated with a video stream and corresponds
1345  * to the AVSphericalMapping structure.
1346  */
1348 
1349  /**
1350  * Content light level (based on CTA-861.3). This metadata should be
1351  * associated with a video stream and contains data in the form of the
1352  * AVContentLightMetadata struct.
1353  */
1355 
1356  /**
1357  * ATSC A53 Part 4 Closed Captions. This metadata should be associated with
1358  * a video stream. A53 CC bitstream is stored as uint8_t in AVPacketSideData.data.
1359  * The number of bytes of CC data is AVPacketSideData.size.
1360  */
1362 
1363  /**
1364  * This side data is encryption initialization data.
1365  * The format is not part of ABI, use av_encryption_init_info_* methods to
1366  * access.
1367  */
1369 
1370  /**
1371  * This side data contains encryption info for how to decrypt the packet.
1372  * The format is not part of ABI, use av_encryption_info_* methods to access.
1373  */
1375 
1376  /**
1377  * Active Format Description data consisting of a single byte as specified
1378  * in ETSI TS 101 154 using AVActiveFormatDescription enum.
1379  */
1381 
1382  /**
1383  * The number of side data types.
1384  * This is not part of the public API/ABI in the sense that it may
1385  * change when new side data types are added.
1386  * This must stay the last enum value.
1387  * If its value becomes huge, some code using it
1388  * needs to be updated as it assumes it to be smaller than other limits.
1389  */
1391 };
1392 
1393 #define AV_PKT_DATA_QUALITY_FACTOR AV_PKT_DATA_QUALITY_STATS //DEPRECATED
1394 
1395 typedef struct AVPacketSideData {
1397  int size;
1400 
1401 /**
1402  * This structure stores compressed data. It is typically exported by demuxers
1403  * and then passed as input to decoders, or received as output from encoders and
1404  * then passed to muxers.
1405  *
1406  * For video, it should typically contain one compressed frame. For audio it may
1407  * contain several compressed frames. Encoders are allowed to output empty
1408  * packets, with no compressed data, containing only side data
1409  * (e.g. to update some stream parameters at the end of encoding).
1410  *
1411  * AVPacket is one of the few structs in FFmpeg, whose size is a part of public
1412  * ABI. Thus it may be allocated on stack and no new fields can be added to it
1413  * without libavcodec and libavformat major bump.
1414  *
1415  * The semantics of data ownership depends on the buf field.
1416  * If it is set, the packet data is dynamically allocated and is
1417  * valid indefinitely until a call to av_packet_unref() reduces the
1418  * reference count to 0.
1419  *
1420  * If the buf field is not set av_packet_ref() would make a copy instead
1421  * of increasing the reference count.
1422  *
1423  * The side data is always allocated with av_malloc(), copied by
1424  * av_packet_ref() and freed by av_packet_unref().
1425  *
1426  * @see av_packet_ref
1427  * @see av_packet_unref
1428  */
1429 typedef struct AVPacket {
1430  /**
1431  * A reference to the reference-counted buffer where the packet data is
1432  * stored.
1433  * May be NULL, then the packet data is not reference-counted.
1434  */
1436  /**
1437  * Presentation timestamp in AVStream->time_base units; the time at which
1438  * the decompressed packet will be presented to the user.
1439  * Can be AV_NOPTS_VALUE if it is not stored in the file.
1440  * pts MUST be larger or equal to dts as presentation cannot happen before
1441  * decompression, unless one wants to view hex dumps. Some formats misuse
1442  * the terms dts and pts/cts to mean something different. Such timestamps
1443  * must be converted to true pts/dts before they are stored in AVPacket.
1444  */
1445  int64_t pts;
1446  /**
1447  * Decompression timestamp in AVStream->time_base units; the time at which
1448  * the packet is decompressed.
1449  * Can be AV_NOPTS_VALUE if it is not stored in the file.
1450  */
1451  int64_t dts;
1453  int size;
1455  /**
1456  * A combination of AV_PKT_FLAG values
1457  */
1458  int flags;
1459  /**
1460  * Additional packet data that can be provided by the container.
1461  * Packet can contain several types of side information.
1462  */
1465 
1466  /**
1467  * Duration of this packet in AVStream->time_base units, 0 if unknown.
1468  * Equals next_pts - this_pts in presentation order.
1469  */
1470  int64_t duration;
1471 
1472  int64_t pos; ///< byte position in stream, -1 if unknown
1473 
1474 #if FF_API_CONVERGENCE_DURATION
1475  /**
1476  * @deprecated Same as the duration field, but as int64_t. This was required
1477  * for Matroska subtitles, whose duration values could overflow when the
1478  * duration field was still an int.
1479  */
1482 #endif
1483 } AVPacket;
1484 #define AV_PKT_FLAG_KEY 0x0001 ///< The packet contains a keyframe
1485 #define AV_PKT_FLAG_CORRUPT 0x0002 ///< The packet content is corrupted
1486 /**
1487  * Flag is used to discard packets which are required to maintain valid
1488  * decoder state but are not required for output and should be dropped
1489  * after decoding.
1490  **/
1491 #define AV_PKT_FLAG_DISCARD 0x0004
1492 /**
1493  * The packet comes from a trusted source.
1494  *
1495  * Otherwise-unsafe constructs such as arbitrary pointers to data
1496  * outside the packet may be followed.
1497  */
1498 #define AV_PKT_FLAG_TRUSTED 0x0008
1499 /**
1500  * Flag is used to indicate packets that contain frames that can
1501  * be discarded by the decoder. I.e. Non-reference frames.
1502  */
1503 #define AV_PKT_FLAG_DISPOSABLE 0x0010
1504 
1505 
1511 };
1512 /**
1513  * @}
1514  */
1515 
1516 struct AVCodecInternal;
1517 
1521  AV_FIELD_TT, //< Top coded_first, top displayed first
1522  AV_FIELD_BB, //< Bottom coded first, bottom displayed first
1523  AV_FIELD_TB, //< Top coded first, bottom displayed first
1524  AV_FIELD_BT, //< Bottom coded first, top displayed first
1525 };
1526 
1527 /**
1528  * main external API structure.
1529  * New fields can be added to the end with minor version bumps.
1530  * Removal, reordering and changes to existing fields require a major
1531  * version bump.
1532  * You can use AVOptions (av_opt* / av_set/get*()) to access these fields from user
1533  * applications.
1534  * The name string for AVOptions options matches the associated command line
1535  * parameter name and can be found in libavcodec/options_table.h
1536  * The AVOption/command line parameter names differ in some cases from the C
1537  * structure field names for historic reasons or brevity.
1538  * sizeof(AVCodecContext) must not be used outside libav*.
1539  */
1540 typedef struct AVCodecContext {
1541  /**
1542  * information on struct for av_log
1543  * - set by avcodec_alloc_context3
1544  */
1547 
1548  enum AVMediaType codec_type; /* see AVMEDIA_TYPE_xxx */
1549  const struct AVCodec *codec;
1550  enum AVCodecID codec_id; /* see AV_CODEC_ID_xxx */
1551 
1552  /**
1553  * fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
1554  * This is used to work around some encoder bugs.
1555  * A demuxer should set this to what is stored in the field used to identify the codec.
1556  * If there are multiple such fields in a container then the demuxer should choose the one
1557  * which maximizes the information about the used codec.
1558  * If the codec tag field in a container is larger than 32 bits then the demuxer should
1559  * remap the longer ID to 32 bits with a table or other structure. Alternatively a new
1560  * extra_codec_tag + size could be added but for this a clear advantage must be demonstrated
1561  * first.
1562  * - encoding: Set by user, if not then the default based on codec_id will be used.
1563  * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
1564  */
1565  unsigned int codec_tag;
1566 
1567  void *priv_data;
1568 
1569  /**
1570  * Private context used for internal data.
1571  *
1572  * Unlike priv_data, this is not codec-specific. It is used in general
1573  * libavcodec functions.
1574  */
1575  struct AVCodecInternal *internal;
1576 
1577  /**
1578  * Private data of the user, can be used to carry app specific stuff.
1579  * - encoding: Set by user.
1580  * - decoding: Set by user.
1581  */
1582  void *opaque;
1583 
1584  /**
1585  * the average bitrate
1586  * - encoding: Set by user; unused for constant quantizer encoding.
1587  * - decoding: Set by user, may be overwritten by libavcodec
1588  * if this info is available in the stream
1589  */
1590  int64_t bit_rate;
1591 
1592  /**
1593  * number of bits the bitstream is allowed to diverge from the reference.
1594  * the reference can be CBR (for CBR pass1) or VBR (for pass2)
1595  * - encoding: Set by user; unused for constant quantizer encoding.
1596  * - decoding: unused
1597  */
1599 
1600  /**
1601  * Global quality for codecs which cannot change it per frame.
1602  * This should be proportional to MPEG-1/2/4 qscale.
1603  * - encoding: Set by user.
1604  * - decoding: unused
1605  */
1607 
1608  /**
1609  * - encoding: Set by user.
1610  * - decoding: unused
1611  */
1613 #define FF_COMPRESSION_DEFAULT -1
1614 
1615  /**
1616  * AV_CODEC_FLAG_*.
1617  * - encoding: Set by user.
1618  * - decoding: Set by user.
1619  */
1620  int flags;
1621 
1622  /**
1623  * AV_CODEC_FLAG2_*
1624  * - encoding: Set by user.
1625  * - decoding: Set by user.
1626  */
1627  int flags2;
1628 
1629  /**
1630  * some codecs need / can use extradata like Huffman tables.
1631  * MJPEG: Huffman tables
1632  * rv10: additional flags
1633  * MPEG-4: global headers (they can be in the bitstream or here)
1634  * The allocated memory should be AV_INPUT_BUFFER_PADDING_SIZE bytes larger
1635  * than extradata_size to avoid problems if it is read with the bitstream reader.
1636  * The bytewise contents of extradata must not depend on the architecture or CPU endianness.
1637  * Must be allocated with the av_malloc() family of functions.
1638  * - encoding: Set/allocated/freed by libavcodec.
1639  * - decoding: Set/allocated/freed by user.
1640  */
1643 
1644  /**
1645  * This is the fundamental unit of time (in seconds) in terms
1646  * of which frame timestamps are represented. For fixed-fps content,
1647  * timebase should be 1/framerate and timestamp increments should be
1648  * identically 1.
1649  * This often, but not always is the inverse of the frame rate or field rate
1650  * for video. 1/time_base is not the average frame rate if the frame rate is not
1651  * constant.
1652  *
1653  * Like containers, elementary streams also can store timestamps, 1/time_base
1654  * is the unit in which these timestamps are specified.
1655  * As example of such codec time base see ISO/IEC 14496-2:2001(E)
1656  * vop_time_increment_resolution and fixed_vop_rate
1657  * (fixed_vop_rate == 0 implies that it is different from the framerate)
1658  *
1659  * - encoding: MUST be set by user.
1660  * - decoding: the use of this field for decoding is deprecated.
1661  * Use framerate instead.
1662  */
1664 
1665  /**
1666  * For some codecs, the time base is closer to the field rate than the frame rate.
1667  * Most notably, H.264 and MPEG-2 specify time_base as half of frame duration
1668  * if no telecine is used ...
1669  *
1670  * Set to time_base ticks per frame. Default 1, e.g., H.264/MPEG-2 set it to 2.
1671  */
1673 
1674  /**
1675  * Codec delay.
1676  *
1677  * Encoding: Number of frames delay there will be from the encoder input to
1678  * the decoder output. (we assume the decoder matches the spec)
1679  * Decoding: Number of frames delay in addition to what a standard decoder
1680  * as specified in the spec would produce.
1681  *
1682  * Video:
1683  * Number of frames the decoded output will be delayed relative to the
1684  * encoded input.
1685  *
1686  * Audio:
1687  * For encoding, this field is unused (see initial_padding).
1688  *
1689  * For decoding, this is the number of samples the decoder needs to
1690  * output before the decoder's output is valid. When seeking, you should
1691  * start decoding this many samples prior to your desired seek point.
1692  *
1693  * - encoding: Set by libavcodec.
1694  * - decoding: Set by libavcodec.
1695  */
1696  int delay;
1697 
1698 
1699  /* video only */
1700  /**
1701  * picture width / height.
1702  *
1703  * @note Those fields may not match the values of the last
1704  * AVFrame output by avcodec_decode_video2 due frame
1705  * reordering.
1706  *
1707  * - encoding: MUST be set by user.
1708  * - decoding: May be set by the user before opening the decoder if known e.g.
1709  * from the container. Some decoders will require the dimensions
1710  * to be set by the caller. During decoding, the decoder may
1711  * overwrite those values as required while parsing the data.
1712  */
1714 
1715  /**
1716  * Bitstream width / height, may be different from width/height e.g. when
1717  * the decoded frame is cropped before being output or lowres is enabled.
1718  *
1719  * @note Those field may not match the value of the last
1720  * AVFrame output by avcodec_receive_frame() due frame
1721  * reordering.
1722  *
1723  * - encoding: unused
1724  * - decoding: May be set by the user before opening the decoder if known
1725  * e.g. from the container. During decoding, the decoder may
1726  * overwrite those values as required while parsing the data.
1727  */
1729 
1730  /**
1731  * the number of pictures in a group of pictures, or 0 for intra_only
1732  * - encoding: Set by user.
1733  * - decoding: unused
1734  */
1736 
1737  /**
1738  * Pixel format, see AV_PIX_FMT_xxx.
1739  * May be set by the demuxer if known from headers.
1740  * May be overridden by the decoder if it knows better.
1741  *
1742  * @note This field may not match the value of the last
1743  * AVFrame output by avcodec_receive_frame() due frame
1744  * reordering.
1745  *
1746  * - encoding: Set by user.
1747  * - decoding: Set by user if known, overridden by libavcodec while
1748  * parsing the data.
1749  */
1751 
1752  /**
1753  * If non NULL, 'draw_horiz_band' is called by the libavcodec
1754  * decoder to draw a horizontal band. It improves cache usage. Not
1755  * all codecs can do that. You must check the codec capabilities
1756  * beforehand.
1757  * When multithreading is used, it may be called from multiple threads
1758  * at the same time; threads might draw different parts of the same AVFrame,
1759  * or multiple AVFrames, and there is no guarantee that slices will be drawn
1760  * in order.
1761  * The function is also used by hardware acceleration APIs.
1762  * It is called at least once during frame decoding to pass
1763  * the data needed for hardware render.
1764  * In that mode instead of pixel data, AVFrame points to
1765  * a structure specific to the acceleration API. The application
1766  * reads the structure and can change some fields to indicate progress
1767  * or mark state.
1768  * - encoding: unused
1769  * - decoding: Set by user.
1770  * @param height the height of the slice
1771  * @param y the y position of the slice
1772  * @param type 1->top field, 2->bottom field, 3->frame
1773  * @param offset offset into the AVFrame.data from which the slice should be read
1774  */
1776  const AVFrame *src, int offset[AV_NUM_DATA_POINTERS],
1777  int y, int type, int height);
1778 
1779  /**
1780  * callback to negotiate the pixelFormat
1781  * @param fmt is the list of formats which are supported by the codec,
1782  * it is terminated by -1 as 0 is a valid format, the formats are ordered by quality.
1783  * The first is always the native one.
1784  * @note The callback may be called again immediately if initialization for
1785  * the selected (hardware-accelerated) pixel format failed.
1786  * @warning Behavior is undefined if the callback returns a value not
1787  * in the fmt list of formats.
1788  * @return the chosen format
1789  * - encoding: unused
1790  * - decoding: Set by user, if not set the native format will be chosen.
1791  */
1792  enum AVPixelFormat (*get_format)(struct AVCodecContext *s, const enum AVPixelFormat * fmt);
1793 
1794  /**
1795  * maximum number of B-frames between non-B-frames
1796  * Note: The output will be delayed by max_b_frames+1 relative to the input.
1797  * - encoding: Set by user.
1798  * - decoding: unused
1799  */
1801 
1802  /**
1803  * qscale factor between IP and B-frames
1804  * If > 0 then the last P-frame quantizer will be used (q= lastp_q*factor+offset).
1805  * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1806  * - encoding: Set by user.
1807  * - decoding: unused
1808  */
1810 
1811 #if FF_API_PRIVATE_OPT
1812  /** @deprecated use encoder private options instead */
1815 #endif
1816 
1817  /**
1818  * qscale offset between IP and B-frames
1819  * - encoding: Set by user.
1820  * - decoding: unused
1821  */
1823 
1824  /**
1825  * Size of the frame reordering buffer in the decoder.
1826  * For MPEG-2 it is 1 IPB or 0 low delay IP.
1827  * - encoding: Set by libavcodec.
1828  * - decoding: Set by libavcodec.
1829  */
1831 
1832 #if FF_API_PRIVATE_OPT
1833  /** @deprecated use encoder private options instead */
1836 #endif
1837 
1838  /**
1839  * qscale factor between P- and I-frames
1840  * If > 0 then the last P-frame quantizer will be used (q = lastp_q * factor + offset).
1841  * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1842  * - encoding: Set by user.
1843  * - decoding: unused
1844  */
1846 
1847  /**
1848  * qscale offset between P and I-frames
1849  * - encoding: Set by user.
1850  * - decoding: unused
1851  */
1853 
1854  /**
1855  * luminance masking (0-> disabled)
1856  * - encoding: Set by user.
1857  * - decoding: unused
1858  */
1860 
1861  /**
1862  * temporary complexity masking (0-> disabled)
1863  * - encoding: Set by user.
1864  * - decoding: unused
1865  */
1867 
1868  /**
1869  * spatial complexity masking (0-> disabled)
1870  * - encoding: Set by user.
1871  * - decoding: unused
1872  */
1874 
1875  /**
1876  * p block masking (0-> disabled)
1877  * - encoding: Set by user.
1878  * - decoding: unused
1879  */
1880  float p_masking;
1881 
1882  /**
1883  * darkness masking (0-> disabled)
1884  * - encoding: Set by user.
1885  * - decoding: unused
1886  */
1888 
1889  /**
1890  * slice count
1891  * - encoding: Set by libavcodec.
1892  * - decoding: Set by user (or 0).
1893  */
1895 
1896 #if FF_API_PRIVATE_OPT
1897  /** @deprecated use encoder private options instead */
1900 #define FF_PRED_LEFT 0
1901 #define FF_PRED_PLANE 1
1902 #define FF_PRED_MEDIAN 2
1903 #endif
1904 
1905  /**
1906  * slice offsets in the frame in bytes
1907  * - encoding: Set/allocated by libavcodec.
1908  * - decoding: Set/allocated by user (or NULL).
1909  */
1911 
1912  /**
1913  * sample aspect ratio (0 if unknown)
1914  * That is the width of a pixel divided by the height of the pixel.
1915  * Numerator and denominator must be relatively prime and smaller than 256 for some video standards.
1916  * - encoding: Set by user.
1917  * - decoding: Set by libavcodec.
1918  */
1920 
1921  /**
1922  * motion estimation comparison function
1923  * - encoding: Set by user.
1924  * - decoding: unused
1925  */
1926  int me_cmp;
1927  /**
1928  * subpixel motion estimation comparison function
1929  * - encoding: Set by user.
1930  * - decoding: unused
1931  */
1933  /**
1934  * macroblock comparison function (not supported yet)
1935  * - encoding: Set by user.
1936  * - decoding: unused
1937  */
1938  int mb_cmp;
1939  /**
1940  * interlaced DCT comparison function
1941  * - encoding: Set by user.
1942  * - decoding: unused
1943  */
1945 #define FF_CMP_SAD 0
1946 #define FF_CMP_SSE 1
1947 #define FF_CMP_SATD 2
1948 #define FF_CMP_DCT 3
1949 #define FF_CMP_PSNR 4
1950 #define FF_CMP_BIT 5
1951 #define FF_CMP_RD 6
1952 #define FF_CMP_ZERO 7
1953 #define FF_CMP_VSAD 8
1954 #define FF_CMP_VSSE 9
1955 #define FF_CMP_NSSE 10
1956 #define FF_CMP_W53 11
1957 #define FF_CMP_W97 12
1958 #define FF_CMP_DCTMAX 13
1959 #define FF_CMP_DCT264 14
1960 #define FF_CMP_MEDIAN_SAD 15
1961 #define FF_CMP_CHROMA 256
1962 
1963  /**
1964  * ME diamond size & shape
1965  * - encoding: Set by user.
1966  * - decoding: unused
1967  */
1969 
1970  /**
1971  * amount of previous MV predictors (2a+1 x 2a+1 square)
1972  * - encoding: Set by user.
1973  * - decoding: unused
1974  */
1976 
1977 #if FF_API_PRIVATE_OPT
1978  /** @deprecated use encoder private options instead */
1980  int pre_me;
1981 #endif
1982 
1983  /**
1984  * motion estimation prepass comparison function
1985  * - encoding: Set by user.
1986  * - decoding: unused
1987  */
1989 
1990  /**
1991  * ME prepass diamond size & shape
1992  * - encoding: Set by user.
1993  * - decoding: unused
1994  */
1996 
1997  /**
1998  * subpel ME quality
1999  * - encoding: Set by user.
2000  * - decoding: unused
2001  */
2003 
2004  /**
2005  * maximum motion estimation search range in subpel units
2006  * If 0 then no limit.
2007  *
2008  * - encoding: Set by user.
2009  * - decoding: unused
2010  */
2012 
2013  /**
2014  * slice flags
2015  * - encoding: unused
2016  * - decoding: Set by user.
2017  */
2019 #define SLICE_FLAG_CODED_ORDER 0x0001 ///< draw_horiz_band() is called in coded order instead of display
2020 #define SLICE_FLAG_ALLOW_FIELD 0x0002 ///< allow draw_horiz_band() with field slices (MPEG-2 field pics)
2021 #define SLICE_FLAG_ALLOW_PLANE 0x0004 ///< allow draw_horiz_band() with 1 component at a time (SVQ1)
2022 
2023  /**
2024  * macroblock decision mode
2025  * - encoding: Set by user.
2026  * - decoding: unused
2027  */
2029 #define FF_MB_DECISION_SIMPLE 0 ///< uses mb_cmp
2030 #define FF_MB_DECISION_BITS 1 ///< chooses the one which needs the fewest bits
2031 #define FF_MB_DECISION_RD 2 ///< rate distortion
2032 
2033  /**
2034  * custom intra quantization matrix
2035  * - encoding: Set by user, can be NULL.
2036  * - decoding: Set by libavcodec.
2037  */
2038  uint16_t *intra_matrix;
2039 
2040  /**
2041  * custom inter quantization matrix
2042  * - encoding: Set by user, can be NULL.
2043  * - decoding: Set by libavcodec.
2044  */
2045  uint16_t *inter_matrix;
2046 
2047 #if FF_API_PRIVATE_OPT
2048  /** @deprecated use encoder private options instead */
2051 
2052  /** @deprecated use encoder private options instead */
2055 #endif
2056 
2057  /**
2058  * precision of the intra DC coefficient - 8
2059  * - encoding: Set by user.
2060  * - decoding: Set by libavcodec
2061  */
2063 
2064  /**
2065  * Number of macroblock rows at the top which are skipped.
2066  * - encoding: unused
2067  * - decoding: Set by user.
2068  */
2070 
2071  /**
2072  * Number of macroblock rows at the bottom which are skipped.
2073  * - encoding: unused
2074  * - decoding: Set by user.
2075  */
2077 
2078  /**
2079  * minimum MB Lagrange multiplier
2080  * - encoding: Set by user.
2081  * - decoding: unused
2082  */
2083  int mb_lmin;
2084 
2085  /**
2086  * maximum MB Lagrange multiplier
2087  * - encoding: Set by user.
2088  * - decoding: unused
2089  */
2090  int mb_lmax;
2091 
2092 #if FF_API_PRIVATE_OPT
2093  /**
2094  * @deprecated use encoder private options instead
2095  */
2098 #endif
2099 
2100  /**
2101  * - encoding: Set by user.
2102  * - decoding: unused
2103  */
2105 
2106 #if FF_API_PRIVATE_OPT
2107  /** @deprecated use encoder private options instead */
2110 #endif
2111 
2112  /**
2113  * minimum GOP size
2114  * - encoding: Set by user.
2115  * - decoding: unused
2116  */
2118 
2119  /**
2120  * number of reference frames
2121  * - encoding: Set by user.
2122  * - decoding: Set by lavc.
2123  */
2124  int refs;
2125 
2126 #if FF_API_PRIVATE_OPT
2127  /** @deprecated use encoder private options instead */
2130 #endif
2131 
2132  /**
2133  * Note: Value depends upon the compare function used for fullpel ME.
2134  * - encoding: Set by user.
2135  * - decoding: unused
2136  */
2138 
2139 #if FF_API_PRIVATE_OPT
2140  /** @deprecated use encoder private options instead */
2143 #endif
2144 
2145  /**
2146  * Chromaticity coordinates of the source primaries.
2147  * - encoding: Set by user
2148  * - decoding: Set by libavcodec
2149  */
2151 
2152  /**
2153  * Color Transfer Characteristic.
2154  * - encoding: Set by user
2155  * - decoding: Set by libavcodec
2156  */
2158 
2159  /**
2160  * YUV colorspace type.
2161  * - encoding: Set by user
2162  * - decoding: Set by libavcodec
2163  */
2165 
2166  /**
2167  * MPEG vs JPEG YUV range.
2168  * - encoding: Set by user
2169  * - decoding: Set by libavcodec
2170  */
2172 
2173  /**
2174  * This defines the location of chroma samples.
2175  * - encoding: Set by user
2176  * - decoding: Set by libavcodec
2177  */
2179 
2180  /**
2181  * Number of slices.
2182  * Indicates number of picture subdivisions. Used for parallelized
2183  * decoding.
2184  * - encoding: Set by user
2185  * - decoding: unused
2186  */
2187  int slices;
2188 
2189  /** Field order
2190  * - encoding: set by libavcodec
2191  * - decoding: Set by user.
2192  */
2194 
2195  /* audio only */
2196  int sample_rate; ///< samples per second
2197  int channels; ///< number of audio channels
2198 
2199  /**
2200  * audio sample format
2201  * - encoding: Set by user.
2202  * - decoding: Set by libavcodec.
2203  */
2204  enum AVSampleFormat sample_fmt; ///< sample format
2205 
2206  /* The following data should not be initialized. */
2207  /**
2208  * Number of samples per channel in an audio frame.
2209  *
2210  * - encoding: set by libavcodec in avcodec_open2(). Each submitted frame
2211  * except the last must contain exactly frame_size samples per channel.
2212  * May be 0 when the codec has AV_CODEC_CAP_VARIABLE_FRAME_SIZE set, then the
2213  * frame size is not restricted.
2214  * - decoding: may be set by some decoders to indicate constant frame size
2215  */
2217 
2218  /**
2219  * Frame counter, set by libavcodec.
2220  *
2221  * - decoding: total number of frames returned from the decoder so far.
2222  * - encoding: total number of frames passed to the encoder so far.
2223  *
2224  * @note the counter is not incremented if encoding/decoding resulted in
2225  * an error.
2226  */
2228 
2229  /**
2230  * number of bytes per packet if constant and known or 0
2231  * Used by some WAV based audio codecs.
2232  */
2234 
2235  /**
2236  * Audio cutoff bandwidth (0 means "automatic")
2237  * - encoding: Set by user.
2238  * - decoding: unused
2239  */
2240  int cutoff;
2241 
2242  /**
2243  * Audio channel layout.
2244  * - encoding: set by user.
2245  * - decoding: set by user, may be overwritten by libavcodec.
2246  */
2247  uint64_t channel_layout;
2248 
2249  /**
2250  * Request decoder to use this channel layout if it can (0 for default)
2251  * - encoding: unused
2252  * - decoding: Set by user.
2253  */
2255 
2256  /**
2257  * Type of service that the audio stream conveys.
2258  * - encoding: Set by user.
2259  * - decoding: Set by libavcodec.
2260  */
2262 
2263  /**
2264  * desired sample format
2265  * - encoding: Not used.
2266  * - decoding: Set by user.
2267  * Decoder will decode to this format if it can.
2268  */
2270 
2271  /**
2272  * This callback is called at the beginning of each frame to get data
2273  * buffer(s) for it. There may be one contiguous buffer for all the data or
2274  * there may be a buffer per each data plane or anything in between. What
2275  * this means is, you may set however many entries in buf[] you feel necessary.
2276  * Each buffer must be reference-counted using the AVBuffer API (see description
2277  * of buf[] below).
2278  *
2279  * The following fields will be set in the frame before this callback is
2280  * called:
2281  * - format
2282  * - width, height (video only)
2283  * - sample_rate, channel_layout, nb_samples (audio only)
2284  * Their values may differ from the corresponding values in
2285  * AVCodecContext. This callback must use the frame values, not the codec
2286  * context values, to calculate the required buffer size.
2287  *
2288  * This callback must fill the following fields in the frame:
2289  * - data[]
2290  * - linesize[]
2291  * - extended_data:
2292  * * if the data is planar audio with more than 8 channels, then this
2293  * callback must allocate and fill extended_data to contain all pointers
2294  * to all data planes. data[] must hold as many pointers as it can.
2295  * extended_data must be allocated with av_malloc() and will be freed in
2296  * av_frame_unref().
2297  * * otherwise extended_data must point to data
2298  * - buf[] must contain one or more pointers to AVBufferRef structures. Each of
2299  * the frame's data and extended_data pointers must be contained in these. That
2300  * is, one AVBufferRef for each allocated chunk of memory, not necessarily one
2301  * AVBufferRef per data[] entry. See: av_buffer_create(), av_buffer_alloc(),
2302  * and av_buffer_ref().
2303  * - extended_buf and nb_extended_buf must be allocated with av_malloc() by
2304  * this callback and filled with the extra buffers if there are more
2305  * buffers than buf[] can hold. extended_buf will be freed in
2306  * av_frame_unref().
2307  *
2308  * If AV_CODEC_CAP_DR1 is not set then get_buffer2() must call
2309  * avcodec_default_get_buffer2() instead of providing buffers allocated by
2310  * some other means.
2311  *
2312  * Each data plane must be aligned to the maximum required by the target
2313  * CPU.
2314  *
2315  * @see avcodec_default_get_buffer2()
2316  *
2317  * Video:
2318  *
2319  * If AV_GET_BUFFER_FLAG_REF is set in flags then the frame may be reused
2320  * (read and/or written to if it is writable) later by libavcodec.
2321  *
2322  * avcodec_align_dimensions2() should be used to find the required width and
2323  * height, as they normally need to be rounded up to the next multiple of 16.
2324  *
2325  * Some decoders do not support linesizes changing between frames.
2326  *
2327  * If frame multithreading is used and thread_safe_callbacks is set,
2328  * this callback may be called from a different thread, but not from more
2329  * than one at once. Does not need to be reentrant.
2330  *
2331  * @see avcodec_align_dimensions2()
2332  *
2333  * Audio:
2334  *
2335  * Decoders request a buffer of a particular size by setting
2336  * AVFrame.nb_samples prior to calling get_buffer2(). The decoder may,
2337  * however, utilize only part of the buffer by setting AVFrame.nb_samples
2338  * to a smaller value in the output frame.
2339  *
2340  * As a convenience, av_samples_get_buffer_size() and
2341  * av_samples_fill_arrays() in libavutil may be used by custom get_buffer2()
2342  * functions to find the required data size and to fill data pointers and
2343  * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
2344  * since all planes must be the same size.
2345  *
2346  * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
2347  *
2348  * - encoding: unused
2349  * - decoding: Set by libavcodec, user can override.
2350  */
2352 
2353  /**
2354  * If non-zero, the decoded audio and video frames returned from
2355  * avcodec_decode_video2() and avcodec_decode_audio4() are reference-counted
2356  * and are valid indefinitely. The caller must free them with
2357  * av_frame_unref() when they are not needed anymore.
2358  * Otherwise, the decoded frames must not be freed by the caller and are
2359  * only valid until the next decode call.
2360  *
2361  * This is always automatically enabled if avcodec_receive_frame() is used.
2362  *
2363  * - encoding: unused
2364  * - decoding: set by the caller before avcodec_open2().
2365  */
2368 
2369  /* - encoding parameters */
2370  float qcompress; ///< amount of qscale change between easy & hard scenes (0.0-1.0)
2371  float qblur; ///< amount of qscale smoothing over time (0.0-1.0)
2372 
2373  /**
2374  * minimum quantizer
2375  * - encoding: Set by user.
2376  * - decoding: unused
2377  */
2378  int qmin;
2379 
2380  /**
2381  * maximum quantizer
2382  * - encoding: Set by user.
2383  * - decoding: unused
2384  */
2385  int qmax;
2386 
2387  /**
2388  * maximum quantizer difference between frames
2389  * - encoding: Set by user.
2390  * - decoding: unused
2391  */
2393 
2394  /**
2395  * decoder bitstream buffer size
2396  * - encoding: Set by user.
2397  * - decoding: unused
2398  */
2400 
2401  /**
2402  * ratecontrol override, see RcOverride
2403  * - encoding: Allocated/set/freed by user.
2404  * - decoding: unused
2405  */
2408 
2409  /**
2410  * maximum bitrate
2411  * - encoding: Set by user.
2412  * - decoding: Set by user, may be overwritten by libavcodec.
2413  */
2414  int64_t rc_max_rate;
2415 
2416  /**
2417  * minimum bitrate
2418  * - encoding: Set by user.
2419  * - decoding: unused
2420  */
2421  int64_t rc_min_rate;
2422 
2423  /**
2424  * Ratecontrol attempt to use, at maximum, <value> of what can be used without an underflow.
2425  * - encoding: Set by user.
2426  * - decoding: unused.
2427  */
2429 
2430  /**
2431  * Ratecontrol attempt to use, at least, <value> times the amount needed to prevent a vbv overflow.
2432  * - encoding: Set by user.
2433  * - decoding: unused.
2434  */
2436 
2437  /**
2438  * Number of bits which should be loaded into the rc buffer before decoding starts.
2439  * - encoding: Set by user.
2440  * - decoding: unused
2441  */
2443 
2444 #if FF_API_CODER_TYPE
2445 #define FF_CODER_TYPE_VLC 0
2446 #define FF_CODER_TYPE_AC 1
2447 #define FF_CODER_TYPE_RAW 2
2448 #define FF_CODER_TYPE_RLE 3
2449  /**
2450  * @deprecated use encoder private options instead
2451  */
2454 #endif /* FF_API_CODER_TYPE */
2455 
2456 #if FF_API_PRIVATE_OPT
2457  /** @deprecated use encoder private options instead */
2460 #endif
2461 
2462 #if FF_API_PRIVATE_OPT
2463  /** @deprecated use encoder private options instead */
2466 
2467  /** @deprecated use encoder private options instead */
2470 
2471  /** @deprecated use encoder private options instead */
2474 
2475  /** @deprecated use encoder private options instead */
2478 #endif /* FF_API_PRIVATE_OPT */
2479 
2480  /**
2481  * trellis RD quantization
2482  * - encoding: Set by user.
2483  * - decoding: unused
2484  */
2485  int trellis;
2486 
2487 #if FF_API_PRIVATE_OPT
2488  /** @deprecated use encoder private options instead */
2491 
2492  /** @deprecated use encoder private options instead */
2495 
2496  /** @deprecated use encoder private options instead */
2499 #endif
2500 
2501 #if FF_API_RTP_CALLBACK
2502  /**
2503  * @deprecated unused
2504  */
2505  /* The RTP callback: This function is called */
2506  /* every time the encoder has a packet to send. */
2507  /* It depends on the encoder if the data starts */
2508  /* with a Start Code (it should). H.263 does. */
2509  /* mb_nb contains the number of macroblocks */
2510  /* encoded in the RTP payload. */
2512  void (*rtp_callback)(struct AVCodecContext *avctx, void *data, int size, int mb_nb);
2513 #endif
2514 
2515 #if FF_API_PRIVATE_OPT
2516  /** @deprecated use encoder private options instead */
2518  int rtp_payload_size; /* The size of the RTP payload: the coder will */
2519  /* do its best to deliver a chunk with size */
2520  /* below rtp_payload_size, the chunk will start */
2521  /* with a start code on some codecs like H.263. */
2522  /* This doesn't take account of any particular */
2523  /* headers inside the transmitted RTP payload. */
2524 #endif
2525 
2526 #if FF_API_STAT_BITS
2527  /* statistics, used for 2-pass encoding */
2529  int mv_bits;
2537  int i_count;
2539  int p_count;
2544 
2545  /** @deprecated this field is unused */
2548 #endif
2549 
2550  /**
2551  * pass1 encoding statistics output buffer
2552  * - encoding: Set by libavcodec.
2553  * - decoding: unused
2554  */
2555  char *stats_out;
2556 
2557  /**
2558  * pass2 encoding statistics input buffer
2559  * Concatenated stuff from stats_out of pass1 should be placed here.
2560  * - encoding: Allocated/set/freed by user.
2561  * - decoding: unused
2562  */
2563  char *stats_in;
2564 
2565  /**
2566  * Work around bugs in encoders which sometimes cannot be detected automatically.
2567  * - encoding: Set by user
2568  * - decoding: Set by user
2569  */
2571 #define FF_BUG_AUTODETECT 1 ///< autodetection
2572 #define FF_BUG_XVID_ILACE 4
2573 #define FF_BUG_UMP4 8
2574 #define FF_BUG_NO_PADDING 16
2575 #define FF_BUG_AMV 32
2576 #define FF_BUG_QPEL_CHROMA 64
2577 #define FF_BUG_STD_QPEL 128
2578 #define FF_BUG_QPEL_CHROMA2 256
2579 #define FF_BUG_DIRECT_BLOCKSIZE 512
2580 #define FF_BUG_EDGE 1024
2581 #define FF_BUG_HPEL_CHROMA 2048
2582 #define FF_BUG_DC_CLIP 4096
2583 #define FF_BUG_MS 8192 ///< Work around various bugs in Microsoft's broken decoders.
2584 #define FF_BUG_TRUNCATED 16384
2585 #define FF_BUG_IEDGE 32768
2586 
2587  /**
2588  * strictly follow the standard (MPEG-4, ...).
2589  * - encoding: Set by user.
2590  * - decoding: Set by user.
2591  * Setting this to STRICT or higher means the encoder and decoder will
2592  * generally do stupid things, whereas setting it to unofficial or lower
2593  * will mean the encoder might produce output that is not supported by all
2594  * spec-compliant decoders. Decoders don't differentiate between normal,
2595  * unofficial and experimental (that is, they always try to decode things
2596  * when they can) unless they are explicitly asked to behave stupidly
2597  * (=strictly conform to the specs)
2598  */
2600 #define FF_COMPLIANCE_VERY_STRICT 2 ///< Strictly conform to an older more strict version of the spec or reference software.
2601 #define FF_COMPLIANCE_STRICT 1 ///< Strictly conform to all the things in the spec no matter what consequences.
2602 #define FF_COMPLIANCE_NORMAL 0
2603 #define FF_COMPLIANCE_UNOFFICIAL -1 ///< Allow unofficial extensions
2604 #define FF_COMPLIANCE_EXPERIMENTAL -2 ///< Allow nonstandardized experimental things.
2605 
2606  /**
2607  * error concealment flags
2608  * - encoding: unused
2609  * - decoding: Set by user.
2610  */
2612 #define FF_EC_GUESS_MVS 1
2613 #define FF_EC_DEBLOCK 2
2614 #define FF_EC_FAVOR_INTER 256
2615 
2616  /**
2617  * debug
2618  * - encoding: Set by user.
2619  * - decoding: Set by user.
2620  */
2621  int debug;
2622 #define FF_DEBUG_PICT_INFO 1
2623 #define FF_DEBUG_RC 2
2624 #define FF_DEBUG_BITSTREAM 4
2625 #define FF_DEBUG_MB_TYPE 8
2626 #define FF_DEBUG_QP 16
2627 #if FF_API_DEBUG_MV
2628 /**
2629  * @deprecated this option does nothing
2630  */
2631 #define FF_DEBUG_MV 32
2632 #endif
2633 #define FF_DEBUG_DCT_COEFF 0x00000040
2634 #define FF_DEBUG_SKIP 0x00000080
2635 #define FF_DEBUG_STARTCODE 0x00000100
2636 #define FF_DEBUG_ER 0x00000400
2637 #define FF_DEBUG_MMCO 0x00000800
2638 #define FF_DEBUG_BUGS 0x00001000
2639 #if FF_API_DEBUG_MV
2640 #define FF_DEBUG_VIS_QP 0x00002000
2641 #define FF_DEBUG_VIS_MB_TYPE 0x00004000
2642 #endif
2643 #define FF_DEBUG_BUFFERS 0x00008000
2644 #define FF_DEBUG_THREADS 0x00010000
2645 #define FF_DEBUG_GREEN_MD 0x00800000
2646 #define FF_DEBUG_NOMC 0x01000000
2647 
2648 #if FF_API_DEBUG_MV
2649  /**
2650  * debug
2651  * - encoding: Set by user.
2652  * - decoding: Set by user.
2653  */
2654  int debug_mv;
2655 #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 // visualize forward predicted MVs of P-frames
2656 #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 // visualize forward predicted MVs of B-frames
2657 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 // visualize backward predicted MVs of B-frames
2658 #endif
2659 
2660  /**
2661  * Error recognition; may misdetect some more or less valid parts as errors.
2662  * - encoding: unused
2663  * - decoding: Set by user.
2664  */
2666 
2667 /**
2668  * Verify checksums embedded in the bitstream (could be of either encoded or
2669  * decoded data, depending on the codec) and print an error message on mismatch.
2670  * If AV_EF_EXPLODE is also set, a mismatching checksum will result in the
2671  * decoder returning an error.
2672  */
2673 #define AV_EF_CRCCHECK (1<<0)
2674 #define AV_EF_BITSTREAM (1<<1) ///< detect bitstream specification deviations
2675 #define AV_EF_BUFFER (1<<2) ///< detect improper bitstream length
2676 #define AV_EF_EXPLODE (1<<3) ///< abort decoding on minor error detection
2677 
2678 #define AV_EF_IGNORE_ERR (1<<15) ///< ignore errors and continue
2679 #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
2680 #define AV_EF_COMPLIANT (1<<17) ///< consider all spec non compliances as errors
2681 #define AV_EF_AGGRESSIVE (1<<18) ///< consider things that a sane encoder should not do as an error
2682 
2683 
2684  /**
2685  * opaque 64-bit number (generally a PTS) that will be reordered and
2686  * output in AVFrame.reordered_opaque
2687  * - encoding: Set by libavcodec to the reordered_opaque of the input
2688  * frame corresponding to the last returned packet. Only
2689  * supported by encoders with the
2690  * AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE capability.
2691  * - decoding: Set by user.
2692  */
2694 
2695  /**
2696  * Hardware accelerator in use
2697  * - encoding: unused.
2698  * - decoding: Set by libavcodec
2699  */
2700  const struct AVHWAccel *hwaccel;
2701 
2702  /**
2703  * Hardware accelerator context.
2704  * For some hardware accelerators, a global context needs to be
2705  * provided by the user. In that case, this holds display-dependent
2706  * data FFmpeg cannot instantiate itself. Please refer to the
2707  * FFmpeg HW accelerator documentation to know how to fill this
2708  * is. e.g. for VA API, this is a struct vaapi_context.
2709  * - encoding: unused
2710  * - decoding: Set by user
2711  */
2713 
2714  /**
2715  * error
2716  * - encoding: Set by libavcodec if flags & AV_CODEC_FLAG_PSNR.
2717  * - decoding: unused
2718  */
2720 
2721  /**
2722  * DCT algorithm, see FF_DCT_* below
2723  * - encoding: Set by user.
2724  * - decoding: unused
2725  */
2727 #define FF_DCT_AUTO 0
2728 #define FF_DCT_FASTINT 1
2729 #define FF_DCT_INT 2
2730 #define FF_DCT_MMX 3
2731 #define FF_DCT_ALTIVEC 5
2732 #define FF_DCT_FAAN 6
2733 
2734  /**
2735  * IDCT algorithm, see FF_IDCT_* below.
2736  * - encoding: Set by user.
2737  * - decoding: Set by user.
2738  */
2740 #define FF_IDCT_AUTO 0
2741 #define FF_IDCT_INT 1
2742 #define FF_IDCT_SIMPLE 2
2743 #define FF_IDCT_SIMPLEMMX 3
2744 #define FF_IDCT_ARM 7
2745 #define FF_IDCT_ALTIVEC 8
2746 #define FF_IDCT_SIMPLEARM 10
2747 #define FF_IDCT_XVID 14
2748 #define FF_IDCT_SIMPLEARMV5TE 16
2749 #define FF_IDCT_SIMPLEARMV6 17
2750 #define FF_IDCT_FAAN 20
2751 #define FF_IDCT_SIMPLENEON 22
2752 #define FF_IDCT_NONE 24 /* Used by XvMC to extract IDCT coefficients with FF_IDCT_PERM_NONE */
2753 #define FF_IDCT_SIMPLEAUTO 128
2754 
2755  /**
2756  * bits per sample/pixel from the demuxer (needed for huffyuv).
2757  * - encoding: Set by libavcodec.
2758  * - decoding: Set by user.
2759  */
2761 
2762  /**
2763  * Bits per sample/pixel of internal libavcodec pixel/sample format.
2764  * - encoding: set by user.
2765  * - decoding: set by libavcodec.
2766  */
2768 
2769 #if FF_API_LOWRES
2770  /**
2771  * low resolution decoding, 1-> 1/2 size, 2->1/4 size
2772  * - encoding: unused
2773  * - decoding: Set by user.
2774  */
2775  int lowres;
2776 #endif
2777 
2778 #if FF_API_CODED_FRAME
2779  /**
2780  * the picture in the bitstream
2781  * - encoding: Set by libavcodec.
2782  * - decoding: unused
2783  *
2784  * @deprecated use the quality factor packet side data instead
2785  */
2787 #endif
2788 
2789  /**
2790  * thread count
2791  * is used to decide how many independent tasks should be passed to execute()
2792  * - encoding: Set by user.
2793  * - decoding: Set by user.
2794  */
2796 
2797  /**
2798  * Which multithreading methods to use.
2799  * Use of FF_THREAD_FRAME will increase decoding delay by one frame per thread,
2800  * so clients which cannot provide future frames should not use it.
2801  *
2802  * - encoding: Set by user, otherwise the default is used.
2803  * - decoding: Set by user, otherwise the default is used.
2804  */
2806 #define FF_THREAD_FRAME 1 ///< Decode more than one frame at once
2807 #define FF_THREAD_SLICE 2 ///< Decode more than one part of a single frame at once
2808 
2809  /**
2810  * Which multithreading methods are in use by the codec.
2811  * - encoding: Set by libavcodec.
2812  * - decoding: Set by libavcodec.
2813  */
2815 
2816  /**
2817  * Set by the client if its custom get_buffer() callback can be called
2818  * synchronously from another thread, which allows faster multithreaded decoding.
2819  * draw_horiz_band() will be called from other threads regardless of this setting.
2820  * Ignored if the default get_buffer() is used.
2821  * - encoding: Set by user.
2822  * - decoding: Set by user.
2823  */
2825 
2826  /**
2827  * The codec may call this to execute several independent things.
2828  * It will return only after finishing all tasks.
2829  * The user may replace this with some multithreaded implementation,
2830  * the default implementation will execute the parts serially.
2831  * @param count the number of things to execute
2832  * - encoding: Set by libavcodec, user can override.
2833  * - decoding: Set by libavcodec, user can override.
2834  */
2835  int (*execute)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size);
2836 
2837  /**
2838  * The codec may call this to execute several independent things.
2839  * It will return only after finishing all tasks.
2840  * The user may replace this with some multithreaded implementation,
2841  * the default implementation will execute the parts serially.
2842  * Also see avcodec_thread_init and e.g. the --enable-pthread configure option.
2843  * @param c context passed also to func
2844  * @param count the number of things to execute
2845  * @param arg2 argument passed unchanged to func
2846  * @param ret return values of executed functions, must have space for "count" values. May be NULL.
2847  * @param func function that will be called count times, with jobnr from 0 to count-1.
2848  * threadnr will be in the range 0 to c->thread_count-1 < MAX_THREADS and so that no
2849  * two instances of func executing at the same time will have the same threadnr.
2850  * @return always 0 currently, but code should handle a future improvement where when any call to func
2851  * returns < 0 no further calls to func may be done and < 0 is returned.
2852  * - encoding: Set by libavcodec, user can override.
2853  * - decoding: Set by libavcodec, user can override.
2854  */
2855  int (*execute2)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count);
2856 
2857  /**
2858  * noise vs. sse weight for the nsse comparison function
2859  * - encoding: Set by user.
2860  * - decoding: unused
2861  */
2863 
2864  /**
2865  * profile
2866  * - encoding: Set by user.
2867  * - decoding: Set by libavcodec.
2868  */
2869  int profile;
2870 #define FF_PROFILE_UNKNOWN -99
2871 #define FF_PROFILE_RESERVED -100
2872 
2873 #define FF_PROFILE_AAC_MAIN 0
2874 #define FF_PROFILE_AAC_LOW 1
2875 #define FF_PROFILE_AAC_SSR 2
2876 #define FF_PROFILE_AAC_LTP 3
2877 #define FF_PROFILE_AAC_HE 4
2878 #define FF_PROFILE_AAC_HE_V2 28
2879 #define FF_PROFILE_AAC_LD 22
2880 #define FF_PROFILE_AAC_ELD 38
2881 #define FF_PROFILE_MPEG2_AAC_LOW 128
2882 #define FF_PROFILE_MPEG2_AAC_HE 131
2883 
2884 #define FF_PROFILE_DNXHD 0
2885 #define FF_PROFILE_DNXHR_LB 1
2886 #define FF_PROFILE_DNXHR_SQ 2
2887 #define FF_PROFILE_DNXHR_HQ 3
2888 #define FF_PROFILE_DNXHR_HQX 4
2889 #define FF_PROFILE_DNXHR_444 5
2890 
2891 #define FF_PROFILE_DTS 20
2892 #define FF_PROFILE_DTS_ES 30
2893 #define FF_PROFILE_DTS_96_24 40
2894 #define FF_PROFILE_DTS_HD_HRA 50
2895 #define FF_PROFILE_DTS_HD_MA 60
2896 #define FF_PROFILE_DTS_EXPRESS 70
2897 
2898 #define FF_PROFILE_MPEG2_422 0
2899 #define FF_PROFILE_MPEG2_HIGH 1
2900 #define FF_PROFILE_MPEG2_SS 2
2901 #define FF_PROFILE_MPEG2_SNR_SCALABLE 3
2902 #define FF_PROFILE_MPEG2_MAIN 4
2903 #define FF_PROFILE_MPEG2_SIMPLE 5
2904 
2905 #define FF_PROFILE_H264_CONSTRAINED (1<<9) // 8+1; constraint_set1_flag
2906 #define FF_PROFILE_H264_INTRA (1<<11) // 8+3; constraint_set3_flag
2907 
2908 #define FF_PROFILE_H264_BASELINE 66
2909 #define FF_PROFILE_H264_CONSTRAINED_BASELINE (66|FF_PROFILE_H264_CONSTRAINED)
2910 #define FF_PROFILE_H264_MAIN 77
2911 #define FF_PROFILE_H264_EXTENDED 88
2912 #define FF_PROFILE_H264_HIGH 100
2913 #define FF_PROFILE_H264_HIGH_10 110
2914 #define FF_PROFILE_H264_HIGH_10_INTRA (110|FF_PROFILE_H264_INTRA)
2915 #define FF_PROFILE_H264_MULTIVIEW_HIGH 118
2916 #define FF_PROFILE_H264_HIGH_422 122
2917 #define FF_PROFILE_H264_HIGH_422_INTRA (122|FF_PROFILE_H264_INTRA)
2918 #define FF_PROFILE_H264_STEREO_HIGH 128
2919 #define FF_PROFILE_H264_HIGH_444 144
2920 #define FF_PROFILE_H264_HIGH_444_PREDICTIVE 244
2921 #define FF_PROFILE_H264_HIGH_444_INTRA (244|FF_PROFILE_H264_INTRA)
2922 #define FF_PROFILE_H264_CAVLC_444 44
2923 
2924 #define FF_PROFILE_VC1_SIMPLE 0
2925 #define FF_PROFILE_VC1_MAIN 1
2926 #define FF_PROFILE_VC1_COMPLEX 2
2927 #define FF_PROFILE_VC1_ADVANCED 3
2928 
2929 #define FF_PROFILE_MPEG4_SIMPLE 0
2930 #define FF_PROFILE_MPEG4_SIMPLE_SCALABLE 1
2931 #define FF_PROFILE_MPEG4_CORE 2
2932 #define FF_PROFILE_MPEG4_MAIN 3
2933 #define FF_PROFILE_MPEG4_N_BIT 4
2934 #define FF_PROFILE_MPEG4_SCALABLE_TEXTURE 5
2935 #define FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION 6
2936 #define FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE 7
2937 #define FF_PROFILE_MPEG4_HYBRID 8
2938 #define FF_PROFILE_MPEG4_ADVANCED_REAL_TIME 9
2939 #define FF_PROFILE_MPEG4_CORE_SCALABLE 10
2940 #define FF_PROFILE_MPEG4_ADVANCED_CODING 11
2941 #define FF_PROFILE_MPEG4_ADVANCED_CORE 12
2942 #define FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE 13
2943 #define FF_PROFILE_MPEG4_SIMPLE_STUDIO 14
2944 #define FF_PROFILE_MPEG4_ADVANCED_SIMPLE 15
2945 
2946 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_0 1
2947 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_1 2
2948 #define FF_PROFILE_JPEG2000_CSTREAM_NO_RESTRICTION 32768
2949 #define FF_PROFILE_JPEG2000_DCINEMA_2K 3
2950 #define FF_PROFILE_JPEG2000_DCINEMA_4K 4
2951 
2952 #define FF_PROFILE_VP9_0 0
2953 #define FF_PROFILE_VP9_1 1
2954 #define FF_PROFILE_VP9_2 2
2955 #define FF_PROFILE_VP9_3 3
2956 
2957 #define FF_PROFILE_HEVC_MAIN 1
2958 #define FF_PROFILE_HEVC_MAIN_10 2
2959 #define FF_PROFILE_HEVC_MAIN_STILL_PICTURE 3
2960 #define FF_PROFILE_HEVC_REXT 4
2961 
2962 #define FF_PROFILE_AV1_MAIN 0
2963 #define FF_PROFILE_AV1_HIGH 1
2964 #define FF_PROFILE_AV1_PROFESSIONAL 2
2965 
2966 #define FF_PROFILE_MJPEG_HUFFMAN_BASELINE_DCT 0xc0
2967 #define FF_PROFILE_MJPEG_HUFFMAN_EXTENDED_SEQUENTIAL_DCT 0xc1
2968 #define FF_PROFILE_MJPEG_HUFFMAN_PROGRESSIVE_DCT 0xc2
2969 #define FF_PROFILE_MJPEG_HUFFMAN_LOSSLESS 0xc3
2970 #define FF_PROFILE_MJPEG_JPEG_LS 0xf7
2971 
2972 #define FF_PROFILE_SBC_MSBC 1
2973 
2974 #define FF_PROFILE_PRORES_PROXY 0
2975 #define FF_PROFILE_PRORES_LT 1
2976 #define FF_PROFILE_PRORES_STANDARD 2
2977 #define FF_PROFILE_PRORES_HQ 3
2978 #define FF_PROFILE_PRORES_4444 4
2979 #define FF_PROFILE_PRORES_XQ 5
2980 
2981  /**
2982  * level
2983  * - encoding: Set by user.
2984  * - decoding: Set by libavcodec.
2985  */
2986  int level;
2987 #define FF_LEVEL_UNKNOWN -99
2988 
2989  /**
2990  * Skip loop filtering for selected frames.
2991  * - encoding: unused
2992  * - decoding: Set by user.
2993  */
2995 
2996  /**
2997  * Skip IDCT/dequantization for selected frames.
2998  * - encoding: unused
2999  * - decoding: Set by user.
3000  */
3002 
3003  /**
3004  * Skip decoding for selected frames.
3005  * - encoding: unused
3006  * - decoding: Set by user.
3007  */
3009 
3010  /**
3011  * Header containing style information for text subtitles.
3012  * For SUBTITLE_ASS subtitle type, it should contain the whole ASS
3013  * [Script Info] and [V4+ Styles] section, plus the [Events] line and
3014  * the Format line following. It shouldn't include any Dialogue line.
3015  * - encoding: Set/allocated/freed by user (before avcodec_open2())
3016  * - decoding: Set/allocated/freed by libavcodec (by avcodec_open2())
3017  */
3020 
3021 #if FF_API_VBV_DELAY
3022  /**
3023  * VBV delay coded in the last frame (in periods of a 27 MHz clock).
3024  * Used for compliant TS muxing.
3025  * - encoding: Set by libavcodec.
3026  * - decoding: unused.
3027  * @deprecated this value is now exported as a part of
3028  * AV_PKT_DATA_CPB_PROPERTIES packet side data
3029  */
3031  uint64_t vbv_delay;
3032 #endif
3033 
3034 #if FF_API_SIDEDATA_ONLY_PKT
3035  /**
3036  * Encoding only and set by default. Allow encoders to output packets
3037  * that do not contain any encoded data, only side data.
3038  *
3039  * Some encoders need to output such packets, e.g. to update some stream
3040  * parameters at the end of encoding.
3041  *
3042  * @deprecated this field disables the default behaviour and
3043  * it is kept only for compatibility.
3044  */
3047 #endif
3048 
3049  /**
3050  * Audio only. The number of "priming" samples (padding) inserted by the
3051  * encoder at the beginning of the audio. I.e. this number of leading
3052  * decoded samples must be discarded by the caller to get the original audio
3053  * without leading padding.
3054  *
3055  * - decoding: unused
3056  * - encoding: Set by libavcodec. The timestamps on the output packets are
3057  * adjusted by the encoder so that they always refer to the
3058  * first sample of the data actually contained in the packet,
3059  * including any added padding. E.g. if the timebase is
3060  * 1/samplerate and the timestamp of the first input sample is
3061  * 0, the timestamp of the first output packet will be
3062  * -initial_padding.
3063  */
3065 
3066  /**
3067  * - decoding: For codecs that store a framerate value in the compressed
3068  * bitstream, the decoder may export it here. { 0, 1} when
3069  * unknown.
3070  * - encoding: May be used to signal the framerate of CFR content to an
3071  * encoder.
3072  */
3074 
3075  /**
3076  * Nominal unaccelerated pixel format, see AV_PIX_FMT_xxx.
3077  * - encoding: unused.
3078  * - decoding: Set by libavcodec before calling get_format()
3079  */
3081 
3082  /**
3083  * Timebase in which pkt_dts/pts and AVPacket.dts/pts are.
3084  * - encoding unused.
3085  * - decoding set by user.
3086  */
3088 
3089  /**
3090  * AVCodecDescriptor
3091  * - encoding: unused.
3092  * - decoding: set by libavcodec.
3093  */
3095 
3096 #if !FF_API_LOWRES
3097  /**
3098  * low resolution decoding, 1-> 1/2 size, 2->1/4 size
3099  * - encoding: unused
3100  * - decoding: Set by user.
3101  */
3102  int lowres;
3103 #endif
3104 
3105  /**
3106  * Current statistics for PTS correction.
3107  * - decoding: maintained and used by libavcodec, not intended to be used by user apps
3108  * - encoding: unused
3109  */
3110  int64_t pts_correction_num_faulty_pts; /// Number of incorrect PTS values so far
3111  int64_t pts_correction_num_faulty_dts; /// Number of incorrect DTS values so far
3112  int64_t pts_correction_last_pts; /// PTS of the last frame
3113  int64_t pts_correction_last_dts; /// DTS of the last frame
3114 
3115  /**
3116  * Character encoding of the input subtitles file.
3117  * - decoding: set by user
3118  * - encoding: unused
3119  */
3121 
3122  /**
3123  * Subtitles character encoding mode. Formats or codecs might be adjusting
3124  * this setting (if they are doing the conversion themselves for instance).
3125  * - decoding: set by libavcodec
3126  * - encoding: unused
3127  */
3129 #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)
3130 #define FF_SUB_CHARENC_MODE_AUTOMATIC 0 ///< libavcodec will select the mode itself
3131 #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
3132 #define FF_SUB_CHARENC_MODE_IGNORE 2 ///< neither convert the subtitles, nor check them for valid UTF-8
3133 
3134  /**
3135  * Skip processing alpha if supported by codec.
3136  * Note that if the format uses pre-multiplied alpha (common with VP6,
3137  * and recommended due to better video quality/compression)
3138  * the image will look as if alpha-blended onto a black background.
3139  * However for formats that do not use pre-multiplied alpha
3140  * there might be serious artefacts (though e.g. libswscale currently
3141  * assumes pre-multiplied alpha anyway).
3142  *
3143  * - decoding: set by user
3144  * - encoding: unused
3145  */
3147 
3148  /**
3149  * Number of samples to skip after a discontinuity
3150  * - decoding: unused
3151  * - encoding: set by libavcodec
3152  */
3154 
3155 #if !FF_API_DEBUG_MV
3156  /**
3157  * debug motion vectors
3158  * - encoding: Set by user.
3159  * - decoding: Set by user.
3160  */
3162 #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 //visualize forward predicted MVs of P frames
3163 #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 //visualize forward predicted MVs of B frames
3164 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
3165 #endif
3166 
3167  /**
3168  * custom intra quantization matrix
3169  * - encoding: Set by user, can be NULL.
3170  * - decoding: unused.
3171  */
3173 
3174  /**
3175  * dump format separator.
3176  * can be ", " or "\n " or anything else
3177  * - encoding: Set by user.
3178  * - decoding: Set by user.
3179  */
3181 
3182  /**
3183  * ',' separated list of allowed decoders.
3184  * If NULL then all are allowed
3185  * - encoding: unused
3186  * - decoding: set by user
3187  */
3189 
3190  /**
3191  * Properties of the stream that gets decoded
3192  * - encoding: unused
3193  * - decoding: set by libavcodec
3194  */
3195  unsigned properties;
3196 #define FF_CODEC_PROPERTY_LOSSLESS 0x00000001
3197 #define FF_CODEC_PROPERTY_CLOSED_CAPTIONS 0x00000002
3198 
3199  /**
3200  * Additional data associated with the entire coded stream.
3201  *
3202  * - decoding: unused
3203  * - encoding: may be set by libavcodec after avcodec_open2().
3204  */
3207 
3208  /**
3209  * A reference to the AVHWFramesContext describing the input (for encoding)
3210  * or output (decoding) frames. The reference is set by the caller and
3211  * afterwards owned (and freed) by libavcodec - it should never be read by
3212  * the caller after being set.
3213  *
3214  * - decoding: This field should be set by the caller from the get_format()
3215  * callback. The previous reference (if any) will always be
3216  * unreffed by libavcodec before the get_format() call.
3217  *
3218  * If the default get_buffer2() is used with a hwaccel pixel
3219  * format, then this AVHWFramesContext will be used for
3220  * allocating the frame buffers.
3221  *
3222  * - encoding: For hardware encoders configured to use a hwaccel pixel
3223  * format, this field should be set by the caller to a reference
3224  * to the AVHWFramesContext describing input frames.
3225  * AVHWFramesContext.format must be equal to
3226  * AVCodecContext.pix_fmt.
3227  *
3228  * This field should be set before avcodec_open2() is called.
3229  */
3231 
3232  /**
3233  * Control the form of AVSubtitle.rects[N]->ass
3234  * - decoding: set by user
3235  * - encoding: unused
3236  */
3238 #define FF_SUB_TEXT_FMT_ASS 0
3239 #if FF_API_ASS_TIMING
3240 #define FF_SUB_TEXT_FMT_ASS_WITH_TIMINGS 1
3241 #endif
3242 
3243  /**
3244  * Audio only. The amount of padding (in samples) appended by the encoder to
3245  * the end of the audio. I.e. this number of decoded samples must be
3246  * discarded by the caller from the end of the stream to get the original
3247  * audio without any trailing padding.
3248  *
3249  * - decoding: unused
3250  * - encoding: unused
3251  */
3253 
3254  /**
3255  * The number of pixels per image to maximally accept.
3256  *
3257  * - decoding: set by user
3258  * - encoding: set by user
3259  */
3260  int64_t max_pixels;
3261 
3262  /**
3263  * A reference to the AVHWDeviceContext describing the device which will
3264  * be used by a hardware encoder/decoder. The reference is set by the
3265  * caller and afterwards owned (and freed) by libavcodec.
3266  *
3267  * This should be used if either the codec device does not require
3268  * hardware frames or any that are used are to be allocated internally by
3269  * libavcodec. If the user wishes to supply any of the frames used as
3270  * encoder input or decoder output then hw_frames_ctx should be used
3271  * instead. When hw_frames_ctx is set in get_format() for a decoder, this
3272  * field will be ignored while decoding the associated stream segment, but
3273  * may again be used on a following one after another get_format() call.
3274  *
3275  * For both encoders and decoders this field should be set before
3276  * avcodec_open2() is called and must not be written to thereafter.
3277  *
3278  * Note that some decoders may require this field to be set initially in
3279  * order to support hw_frames_ctx at all - in that case, all frames
3280  * contexts used must be created on the same device.
3281  */
3283 
3284  /**
3285  * Bit set of AV_HWACCEL_FLAG_* flags, which affect hardware accelerated
3286  * decoding (if active).
3287  * - encoding: unused
3288  * - decoding: Set by user (either before avcodec_open2(), or in the
3289  * AVCodecContext.get_format callback)
3290  */
3292 
3293  /**
3294  * Video decoding only. Certain video codecs support cropping, meaning that
3295  * only a sub-rectangle of the decoded frame is intended for display. This
3296  * option controls how cropping is handled by libavcodec.
3297  *
3298  * When set to 1 (the default), libavcodec will apply cropping internally.
3299  * I.e. it will modify the output frame width/height fields and offset the
3300  * data pointers (only by as much as possible while preserving alignment, or
3301  * by the full amount if the AV_CODEC_FLAG_UNALIGNED flag is set) so that
3302  * the frames output by the decoder refer only to the cropped area. The
3303  * crop_* fields of the output frames will be zero.
3304  *
3305  * When set to 0, the width/height fields of the output frames will be set
3306  * to the coded dimensions and the crop_* fields will describe the cropping
3307  * rectangle. Applying the cropping is left to the caller.
3308  *
3309  * @warning When hardware acceleration with opaque output frames is used,
3310  * libavcodec is unable to apply cropping from the top/left border.
3311  *
3312  * @note when this option is set to zero, the width/height fields of the
3313  * AVCodecContext and output AVFrames have different meanings. The codec
3314  * context fields store display dimensions (with the coded dimensions in
3315  * coded_width/height), while the frame fields store the coded dimensions
3316  * (with the display dimensions being determined by the crop_* fields).
3317  */
3319 
3320  /*
3321  * Video decoding only. Sets the number of extra hardware frames which
3322  * the decoder will allocate for use by the caller. This must be set
3323  * before avcodec_open2() is called.
3324  *
3325  * Some hardware decoders require all frames that they will use for
3326  * output to be defined in advance before decoding starts. For such
3327  * decoders, the hardware frame pool must therefore be of a fixed size.
3328  * The extra frames set here are on top of any number that the decoder
3329  * needs internally in order to operate normally (for example, frames
3330  * used as reference pictures).
3331  */
3333 } AVCodecContext;
3334 
3335 #if FF_API_CODEC_GET_SET
3336 /**
3337  * Accessors for some AVCodecContext fields. These used to be provided for ABI
3338  * compatibility, and do not need to be used anymore.
3339  */
3344 
3349 
3351 unsigned av_codec_get_codec_properties(const AVCodecContext *avctx);
3352 
3353 #if FF_API_LOWRES
3355 int av_codec_get_lowres(const AVCodecContext *avctx);
3357 void av_codec_set_lowres(AVCodecContext *avctx, int val);
3358 #endif
3359 
3361 int av_codec_get_seek_preroll(const AVCodecContext *avctx);
3363 void av_codec_set_seek_preroll(AVCodecContext *avctx, int val);
3364 
3366 uint16_t *av_codec_get_chroma_intra_matrix(const AVCodecContext *avctx);
3368 void av_codec_set_chroma_intra_matrix(AVCodecContext *avctx, uint16_t *val);
3369 #endif
3370 
3371 /**
3372  * AVProfile.
3373  */
3374 typedef struct AVProfile {
3375  int profile;
3376  const char *name; ///< short name for the profile
3377 } AVProfile;
3378 
3379 enum {
3380  /**
3381  * The codec supports this format via the hw_device_ctx interface.
3382  *
3383  * When selecting this format, AVCodecContext.hw_device_ctx should
3384  * have been set to a device of the specified type before calling
3385  * avcodec_open2().
3386  */
3388  /**
3389  * The codec supports this format via the hw_frames_ctx interface.
3390  *
3391  * When selecting this format for a decoder,
3392  * AVCodecContext.hw_frames_ctx should be set to a suitable frames
3393  * context inside the get_format() callback. The frames context
3394  * must have been created on a device of the specified type.
3395  */
3397  /**
3398  * The codec supports this format by some internal method.
3399  *
3400  * This format can be selected without any additional configuration -
3401  * no device or frames context is required.
3402  */
3404  /**
3405  * The codec supports this format by some ad-hoc method.
3406  *
3407  * Additional settings and/or function calls are required. See the
3408  * codec-specific documentation for details. (Methods requiring
3409  * this sort of configuration are deprecated and others should be
3410  * used in preference.)
3411  */
3413 };
3414 
3415 typedef struct AVCodecHWConfig {
3416  /**
3417  * A hardware pixel format which the codec can use.
3418  */
3420  /**
3421  * Bit set of AV_CODEC_HW_CONFIG_METHOD_* flags, describing the possible
3422  * setup methods which can be used with this configuration.
3423  */
3424  int methods;
3425  /**
3426  * The device type associated with the configuration.
3427  *
3428  * Must be set for AV_CODEC_HW_CONFIG_METHOD_HW_DEVICE_CTX and
3429  * AV_CODEC_HW_CONFIG_METHOD_HW_FRAMES_CTX, otherwise unused.
3430  */
3432 } AVCodecHWConfig;
3433 
3434 typedef struct AVCodecDefault AVCodecDefault;
3435 
3436 struct AVSubtitle;
3437 
3438 /**
3439  * AVCodec.
3440  */
3441 typedef struct AVCodec {
3442  /**
3443  * Name of the codec implementation.
3444  * The name is globally unique among encoders and among decoders (but an
3445  * encoder and a decoder can share the same name).
3446  * This is the primary way to find a codec from the user perspective.
3447  */
3448  const char *name;
3449  /**
3450  * Descriptive name for the codec, meant to be more human readable than name.
3451  * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
3452  */
3453  const char *long_name;
3456  /**
3457  * Codec capabilities.
3458  * see AV_CODEC_CAP_*
3459  */
3461  const AVRational *supported_framerates; ///< array of supported framerates, or NULL if any, array is terminated by {0,0}
3462  const enum AVPixelFormat *pix_fmts; ///< array of supported pixel formats, or NULL if unknown, array is terminated by -1
3463  const int *supported_samplerates; ///< array of supported audio samplerates, or NULL if unknown, array is terminated by 0
3464  const enum AVSampleFormat *sample_fmts; ///< array of supported sample formats, or NULL if unknown, array is terminated by -1
3465  const uint64_t *channel_layouts; ///< array of support channel layouts, or NULL if unknown. array is terminated by 0
3466  uint8_t max_lowres; ///< maximum value for lowres supported by the decoder
3467  const AVClass *priv_class; ///< AVClass for the private context
3468  const AVProfile *profiles; ///< array of recognized profiles, or NULL if unknown, array is terminated by {FF_PROFILE_UNKNOWN}
3469 
3470  /**
3471  * Group name of the codec implementation.
3472  * This is a short symbolic name of the wrapper backing this codec. A
3473  * wrapper uses some kind of external implementation for the codec, such
3474  * as an external library, or a codec implementation provided by the OS or
3475  * the hardware.
3476  * If this field is NULL, this is a builtin, libavcodec native codec.
3477  * If non-NULL, this will be the suffix in AVCodec.name in most cases
3478  * (usually AVCodec.name will be of the form "<codec_name>_<wrapper_name>").
3479  */
3480  const char *wrapper_name;
3481 
3482  /*****************************************************************
3483  * No fields below this line are part of the public API. They
3484  * may not be used outside of libavcodec and can be changed and
3485  * removed at will.
3486  * New public fields should be added right above.
3487  *****************************************************************
3488  */
3490  struct AVCodec *next;
3491  /**
3492  * @name Frame-level threading support functions
3493  * @{
3494  */
3495  /**
3496  * If defined, called on thread contexts when they are created.
3497  * If the codec allocates writable tables in init(), re-allocate them here.
3498  * priv_data will be set to a copy of the original.
3499  */
3501  /**
3502  * Copy necessary context variables from a previous thread context to the current one.
3503  * If not defined, the next thread will start automatically; otherwise, the codec
3504  * must call ff_thread_finish_setup().
3505  *
3506  * dst and src will (rarely) point to the same context, in which case memcpy should be skipped.
3507  */
3509  /** @} */
3510 
3511  /**
3512  * Private codec-specific defaults.
3513  */
3515 
3516  /**
3517  * Initialize codec static data, called from avcodec_register().
3518  *
3519  * This is not intended for time consuming operations as it is
3520  * run for every codec regardless of that codec being used.
3521  */
3522  void (*init_static_data)(struct AVCodec *codec);
3523 
3525  int (*encode_sub)(AVCodecContext *, uint8_t *buf, int buf_size,
3526  const struct AVSubtitle *sub);
3527  /**
3528  * Encode data to an AVPacket.
3529  *
3530  * @param avctx codec context
3531  * @param avpkt output AVPacket (may contain a user-provided buffer)
3532  * @param[in] frame AVFrame containing the raw data to be encoded
3533  * @param[out] got_packet_ptr encoder sets to 0 or 1 to indicate that a
3534  * non-empty packet was returned in avpkt.
3535  * @return 0 on success, negative error code on failure
3536  */
3537  int (*encode2)(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame,
3538  int *got_packet_ptr);
3539  int (*decode)(AVCodecContext *, void *outdata, int *outdata_size, AVPacket *avpkt);
3541  /**
3542  * Encode API with decoupled packet/frame dataflow. The API is the
3543  * same as the avcodec_ prefixed APIs (avcodec_send_frame() etc.), except
3544  * that:
3545  * - never called if the codec is closed or the wrong type,
3546  * - if AV_CODEC_CAP_DELAY is not set, drain frames are never sent,
3547  * - only one drain frame is ever passed down,
3548  */
3551 
3552  /**
3553  * Decode API with decoupled packet/frame dataflow. This function is called
3554  * to get one output frame. It should call ff_decode_get_packet() to obtain
3555  * input data.
3556  */
3558  /**
3559  * Flush buffers.
3560  * Will be called when seeking
3561  */
3563  /**
3564  * Internal codec capabilities.
3565  * See FF_CODEC_CAP_* in internal.h
3566  */
3568 
3569  /**
3570  * Decoding only, a comma-separated list of bitstream filters to apply to
3571  * packets before decoding.
3572  */
3573  const char *bsfs;
3574 
3575  /**
3576  * Array of pointers to hardware configurations supported by the codec,
3577  * or NULL if no hardware supported. The array is terminated by a NULL
3578  * pointer.
3579  *
3580  * The user can only access this field via avcodec_get_hw_config().
3581  */
3583 } AVCodec;
3584 
3585 #if FF_API_CODEC_GET_SET
3587 int av_codec_get_max_lowres(const AVCodec *codec);
3588 #endif
3589 
3590 struct MpegEncContext;
3591 
3592 /**
3593  * Retrieve supported hardware configurations for a codec.
3594  *
3595  * Values of index from zero to some maximum return the indexed configuration
3596  * descriptor; all other values return NULL. If the codec does not support
3597  * any hardware configurations then it will always return NULL.
3598  */
3599 const AVCodecHWConfig *avcodec_get_hw_config(const AVCodec *codec, int index);
3600 
3601 /**
3602  * @defgroup lavc_hwaccel AVHWAccel
3603  *
3604  * @note Nothing in this structure should be accessed by the user. At some
3605  * point in future it will not be externally visible at all.
3606  *
3607  * @{
3608  */
3609 typedef struct AVHWAccel {
3610  /**
3611  * Name of the hardware accelerated codec.
3612  * The name is globally unique among encoders and among decoders (but an
3613  * encoder and a decoder can share the same name).
3614  */
3615  const char *name;
3616 
3617  /**
3618  * Type of codec implemented by the hardware accelerator.
3619  *
3620  * See AVMEDIA_TYPE_xxx
3621  */
3623 
3624  /**
3625  * Codec implemented by the hardware accelerator.
3626  *
3627  * See AV_CODEC_ID_xxx
3628  */
3630 
3631  /**
3632  * Supported pixel format.
3633  *
3634  * Only hardware accelerated formats are supported here.
3635  */
3637 
3638  /**
3639  * Hardware accelerated codec capabilities.
3640  * see AV_HWACCEL_CODEC_CAP_*
3641  */
3643 
3644  /*****************************************************************
3645  * No fields below this line are part of the public API. They
3646  * may not be used outside of libavcodec and can be changed and
3647  * removed at will.
3648  * New public fields should be added right above.
3649  *****************************************************************
3650  */
3651 
3652  /**
3653  * Allocate a custom buffer
3654  */
3656 
3657  /**
3658  * Called at the beginning of each frame or field picture.
3659  *
3660  * Meaningful frame information (codec specific) is guaranteed to
3661  * be parsed at this point. This function is mandatory.
3662  *
3663  * Note that buf can be NULL along with buf_size set to 0.
3664  * Otherwise, this means the whole frame is available at this point.
3665  *
3666  * @param avctx the codec context
3667  * @param buf the frame data buffer base
3668  * @param buf_size the size of the frame in bytes
3669  * @return zero if successful, a negative value otherwise
3670  */
3671  int (*start_frame)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3672 
3673  /**
3674  * Callback for parameter data (SPS/PPS/VPS etc).
3675  *
3676  * Useful for hardware decoders which keep persistent state about the
3677  * video parameters, and need to receive any changes to update that state.
3678  *
3679  * @param avctx the codec context
3680  * @param type the nal unit type
3681  * @param buf the nal unit data buffer
3682  * @param buf_size the size of the nal unit in bytes
3683  * @return zero if successful, a negative value otherwise
3684  */
3685  int (*decode_params)(AVCodecContext *avctx, int type, const uint8_t *buf, uint32_t buf_size);
3686 
3687  /**
3688  * Callback for each slice.
3689  *
3690  * Meaningful slice information (codec specific) is guaranteed to
3691  * be parsed at this point. This function is mandatory.
3692  * The only exception is XvMC, that works on MB level.
3693  *
3694  * @param avctx the codec context
3695  * @param buf the slice data buffer base
3696  * @param buf_size the size of the slice in bytes
3697  * @return zero if successful, a negative value otherwise
3698  */
3699  int (*decode_slice)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3700 
3701  /**
3702  * Called at the end of each frame or field picture.
3703  *
3704  * The whole picture is parsed at this point and can now be sent
3705  * to the hardware accelerator. This function is mandatory.
3706  *
3707  * @param avctx the codec context
3708  * @return zero if successful, a negative value otherwise
3709  */
3711 
3712  /**
3713  * Size of per-frame hardware accelerator private data.
3714  *
3715  * Private data is allocated with av_mallocz() before
3716  * AVCodecContext.get_buffer() and deallocated after
3717  * AVCodecContext.release_buffer().
3718  */
3720 
3721  /**
3722  * Called for every Macroblock in a slice.
3723  *
3724  * XvMC uses it to replace the ff_mpv_reconstruct_mb().
3725  * Instead of decoding to raw picture, MB parameters are
3726  * stored in an array provided by the video driver.
3727  *
3728  * @param s the mpeg context
3729  */
3731 
3732  /**
3733  * Initialize the hwaccel private data.
3734  *
3735  * This will be called from ff_get_format(), after hwaccel and
3736  * hwaccel_context are set and the hwaccel private data in AVCodecInternal
3737  * is allocated.
3738  */
3740 
3741  /**
3742  * Uninitialize the hwaccel private data.
3743  *
3744  * This will be called from get_format() or avcodec_close(), after hwaccel
3745  * and hwaccel_context are already uninitialized.
3746  */
3748 
3749  /**
3750  * Size of the private data to allocate in
3751  * AVCodecInternal.hwaccel_priv_data.
3752  */
3754 
3755  /**
3756  * Internal hwaccel capabilities.
3757  */
3759 
3760  /**
3761  * Fill the given hw_frames context with current codec parameters. Called
3762  * from get_format. Refer to avcodec_get_hw_frames_parameters() for
3763  * details.
3764  *
3765  * This CAN be called before AVHWAccel.init is called, and you must assume
3766  * that avctx->hwaccel_priv_data is invalid.
3767  */
3769 } AVHWAccel;
3770 
3771 /**
3772  * HWAccel is experimental and is thus avoided in favor of non experimental
3773  * codecs
3774  */
3775 #define AV_HWACCEL_CODEC_CAP_EXPERIMENTAL 0x0200
3776 
3777 /**
3778  * Hardware acceleration should be used for decoding even if the codec level
3779  * used is unknown or higher than the maximum supported level reported by the
3780  * hardware driver.
3781  *
3782  * It's generally a good idea to pass this flag unless you have a specific
3783  * reason not to, as hardware tends to under-report supported levels.
3784  */
3785 #define AV_HWACCEL_FLAG_IGNORE_LEVEL (1 << 0)
3786 
3787 /**
3788  * Hardware acceleration can output YUV pixel formats with a different chroma
3789  * sampling than 4:2:0 and/or other than 8 bits per component.
3790  */
3791 #define AV_HWACCEL_FLAG_ALLOW_HIGH_DEPTH (1 << 1)
3792 
3793 /**
3794  * Hardware acceleration should still be attempted for decoding when the
3795  * codec profile does not match the reported capabilities of the hardware.
3796  *
3797  * For example, this can be used to try to decode baseline profile H.264
3798  * streams in hardware - it will often succeed, because many streams marked
3799  * as baseline profile actually conform to constrained baseline profile.
3800  *
3801  * @warning If the stream is actually not supported then the behaviour is
3802  * undefined, and may include returning entirely incorrect output
3803  * while indicating success.
3804  */
3805 #define AV_HWACCEL_FLAG_ALLOW_PROFILE_MISMATCH (1 << 2)
3806 
3807 /**
3808  * @}
3809  */
3810 
3811 #if FF_API_AVPICTURE
3812 /**
3813  * @defgroup lavc_picture AVPicture
3814  *
3815  * Functions for working with AVPicture
3816  * @{
3817  */
3818 
3819 /**
3820  * Picture data structure.
3821  *
3822  * Up to four components can be stored into it, the last component is
3823  * alpha.
3824  * @deprecated use AVFrame or imgutils functions instead
3825  */
3826 typedef struct AVPicture {
3828  uint8_t *data[AV_NUM_DATA_POINTERS]; ///< pointers to the image data planes
3830  int linesize[AV_NUM_DATA_POINTERS]; ///< number of bytes per line
3831 } AVPicture;
3832 
3833 /**
3834  * @}
3835  */
3836 #endif
3837 
3840 
3841  SUBTITLE_BITMAP, ///< A bitmap, pict will be set
3842 
3843  /**
3844  * Plain text, the text field must be set by the decoder and is
3845  * authoritative. ass and pict fields may contain approximations.
3846  */
3848 
3849  /**
3850  * Formatted text, the ass field must be set by the decoder and is
3851  * authoritative. pict and text fields may contain approximations.
3852  */
3854 };
3855 
3856 #define AV_SUBTITLE_FLAG_FORCED 0x00000001
3857 
3858 typedef struct AVSubtitleRect {
3859  int x; ///< top left corner of pict, undefined when pict is not set
3860  int y; ///< top left corner of pict, undefined when pict is not set
3861  int w; ///< width of pict, undefined when pict is not set
3862  int h; ///< height of pict, undefined when pict is not set
3863  int nb_colors; ///< number of colors in pict, undefined when pict is not set
3864 
3865 #if FF_API_AVPICTURE
3866  /**
3867  * @deprecated unused
3868  */
3871 #endif
3872  /**
3873  * data+linesize for the bitmap of this subtitle.
3874  * Can be set for text/ass as well once they are rendered.
3875  */
3877  int linesize[4];
3878 
3880 
3881  char *text; ///< 0 terminated plain UTF-8 text
3882 
3883  /**
3884  * 0 terminated ASS/SSA compatible event line.
3885  * The presentation of this is unaffected by the other values in this
3886  * struct.
3887  */
3888  char *ass;
3889 
3890  int flags;
3891 } AVSubtitleRect;
3892 
3893 typedef struct AVSubtitle {
3894  uint16_t format; /* 0 = graphics */
3895  uint32_t start_display_time; /* relative to packet pts, in ms */
3896  uint32_t end_display_time; /* relative to packet pts, in ms */
3897  unsigned num_rects;
3899  int64_t pts; ///< Same as packet pts, in AV_TIME_BASE
3900 } AVSubtitle;
3901 
3902 /**
3903  * This struct describes the properties of an encoded stream.
3904  *
3905  * sizeof(AVCodecParameters) is not a part of the public ABI, this struct must
3906  * be allocated with avcodec_parameters_alloc() and freed with
3907  * avcodec_parameters_free().
3908  */
3909 typedef struct AVCodecParameters {
3910  /**
3911  * General type of the encoded data.
3912  */
3914  /**
3915  * Specific type of the encoded data (the codec used).
3916  */
3918  /**
3919  * Additional information about the codec (corresponds to the AVI FOURCC).
3920  */
3921  uint32_t codec_tag;
3922 
3923  /**
3924  * Extra binary data needed for initializing the decoder, codec-dependent.
3925  *
3926  * Must be allocated with av_malloc() and will be freed by
3927  * avcodec_parameters_free(). The allocated size of extradata must be at
3928  * least extradata_size + AV_INPUT_BUFFER_PADDING_SIZE, with the padding
3929  * bytes zeroed.
3930  */
3932  /**
3933  * Size of the extradata content in bytes.
3934  */
3936 
3937  /**
3938  * - video: the pixel format, the value corresponds to enum AVPixelFormat.
3939  * - audio: the sample format, the value corresponds to enum AVSampleFormat.
3940  */
3941  int format;
3942 
3943  /**
3944  * The average bitrate of the encoded data (in bits per second).
3945  */
3946  int64_t bit_rate;
3947 
3948  /**
3949  * The number of bits per sample in the codedwords.
3950  *
3951  * This is basically the bitrate per sample. It is mandatory for a bunch of
3952  * formats to actually decode them. It's the number of bits for one sample in
3953  * the actual coded bitstream.
3954  *
3955  * This could be for example 4 for ADPCM
3956  * For PCM formats this matches bits_per_raw_sample
3957  * Can be 0
3958  */
3960 
3961  /**
3962  * This is the number of valid bits in each output sample. If the
3963  * sample format has more bits, the least significant bits are additional
3964  * padding bits, which are always 0. Use right shifts to reduce the sample
3965  * to its actual size. For example, audio formats with 24 bit samples will
3966  * have bits_per_raw_sample set to 24, and format set to AV_SAMPLE_FMT_S32.
3967  * To get the original sample use "(int32_t)sample >> 8"."
3968  *
3969  * For ADPCM this might be 12 or 16 or similar
3970  * Can be 0
3971  */
3973 
3974  /**
3975  * Codec-specific bitstream restrictions that the stream conforms to.
3976  */
3977  int profile;
3978  int level;
3979 
3980  /**
3981  * Video only. The dimensions of the video frame in pixels.
3982  */
3983  int width;
3984  int height;
3985 
3986  /**
3987  * Video only. The aspect ratio (width / height) which a single pixel
3988  * should have when displayed.
3989  *
3990  * When the aspect ratio is unknown / undefined, the numerator should be
3991  * set to 0 (the denominator may have any value).
3992  */
3994 
3995  /**
3996  * Video only. The order of the fields in interlaced video.
3997  */
3999 
4000  /**
4001  * Video only. Additional colorspace characteristics.
4002  */
4008 
4009  /**
4010  * Video only. Number of delayed frames.
4011  */
4013 
4014  /**
4015  * Audio only. The channel layout bitmask. May be 0 if the channel layout is
4016  * unknown or unspecified, otherwise the number of bits set must be equal to
4017  * the channels field.
4018  */
4019  uint64_t channel_layout;
4020  /**
4021  * Audio only. The number of audio channels.
4022  */
4024  /**
4025  * Audio only. The number of audio samples per second.
4026  */
4028  /**
4029  * Audio only. The number of bytes per coded audio frame, required by some
4030  * formats.
4031  *
4032  * Corresponds to nBlockAlign in WAVEFORMATEX.
4033  */
4035  /**
4036  * Audio only. Audio frame size, if known. Required by some formats to be static.
4037  */
4039 
4040  /**
4041  * Audio only. The amount of padding (in samples) inserted by the encoder at
4042  * the beginning of the audio. I.e. this number of leading decoded samples
4043  * must be discarded by the caller to get the original audio without leading
4044  * padding.
4045  */
4047  /**
4048  * Audio only. The amount of padding (in samples) appended by the encoder to
4049  * the end of the audio. I.e. this number of decoded samples must be
4050  * discarded by the caller from the end of the stream to get the original
4051  * audio without any trailing padding.
4052  */
4054  /**
4055  * Audio only. Number of samples to skip after a discontinuity.
4056  */
4059 
4060 /**
4061  * Iterate over all registered codecs.
4062  *
4063  * @param opaque a pointer where libavcodec will store the iteration state. Must
4064  * point to NULL to start the iteration.
4065  *
4066  * @return the next registered codec or NULL when the iteration is
4067  * finished
4068  */
4069 const AVCodec *av_codec_iterate(void **opaque);
4070 
4071 #if FF_API_NEXT
4072 /**
4073  * If c is NULL, returns the first registered codec,
4074  * if c is non-NULL, returns the next registered codec after c,
4075  * or NULL if c is the last one.
4076  */
4078 AVCodec *av_codec_next(const AVCodec *c);
4079 #endif
4080 
4081 /**
4082  * Return the LIBAVCODEC_VERSION_INT constant.
4083  */
4084 unsigned avcodec_version(void);
4085 
4086 /**
4087  * Return the libavcodec build-time configuration.
4088  */
4089 const char *avcodec_configuration(void);
4090 
4091 /**
4092  * Return the libavcodec license.
4093  */
4094 const char *avcodec_license(void);
4095 
4096 #if FF_API_NEXT
4097 /**
4098  * Register the codec codec and initialize libavcodec.
4099  *
4100  * @warning either this function or avcodec_register_all() must be called
4101  * before any other libavcodec functions.
4102  *
4103  * @see avcodec_register_all()
4104  */
4106 void avcodec_register(AVCodec *codec);
4107 
4108 /**
4109  * Register all the codecs, parsers and bitstream filters which were enabled at
4110  * configuration time. If you do not call this function you can select exactly
4111  * which formats you want to support, by using the individual registration
4112  * functions.
4113  *
4114  * @see avcodec_register
4115  * @see av_register_codec_parser
4116  * @see av_register_bitstream_filter
4117  */
4119 void avcodec_register_all(void);
4120 #endif
4121 
4122 /**
4123  * Allocate an AVCodecContext and set its fields to default values. The
4124  * resulting struct should be freed with avcodec_free_context().
4125  *
4126  * @param codec if non-NULL, allocate private data and initialize defaults
4127  * for the given codec. It is illegal to then call avcodec_open2()
4128  * with a different codec.
4129  * If NULL, then the codec-specific defaults won't be initialized,
4130  * which may result in suboptimal default settings (this is
4131  * important mainly for encoders, e.g. libx264).
4132  *
4133  * @return An AVCodecContext filled with default values or NULL on failure.
4134  */
4136 
4137 /**
4138  * Free the codec context and everything associated with it and write NULL to
4139  * the provided pointer.
4140  */
4141 void avcodec_free_context(AVCodecContext **avctx);
4142 
4143 #if FF_API_GET_CONTEXT_DEFAULTS
4144 /**
4145  * @deprecated This function should not be used, as closing and opening a codec
4146  * context multiple time is not supported. A new codec context should be
4147  * allocated for each new use.
4148  */
4150 #endif
4151 
4152 /**
4153  * Get the AVClass for AVCodecContext. It can be used in combination with
4154  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
4155  *
4156  * @see av_opt_find().
4157  */
4158 const AVClass *avcodec_get_class(void);
4159 
4160 #if FF_API_COPY_CONTEXT
4161 /**
4162  * Get the AVClass for AVFrame. It can be used in combination with
4163  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
4164  *
4165  * @see av_opt_find().
4166  */
4167 const AVClass *avcodec_get_frame_class(void);
4168 
4169 /**
4170  * Get the AVClass for AVSubtitleRect. It can be used in combination with
4171  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
4172  *
4173  * @see av_opt_find().
4174  */
4176 
4177 /**
4178  * Copy the settings of the source AVCodecContext into the destination
4179  * AVCodecContext. The resulting destination codec context will be
4180  * unopened, i.e. you are required to call avcodec_open2() before you
4181  * can use this AVCodecContext to decode/encode video/audio data.
4182  *
4183  * @param dest target codec context, should be initialized with
4184  * avcodec_alloc_context3(NULL), but otherwise uninitialized
4185  * @param src source codec context
4186  * @return AVERROR() on error (e.g. memory allocation error), 0 on success
4187  *
4188  * @deprecated The semantics of this function are ill-defined and it should not
4189  * be used. If you need to transfer the stream parameters from one codec context
4190  * to another, use an intermediate AVCodecParameters instance and the
4191  * avcodec_parameters_from_context() / avcodec_parameters_to_context()
4192  * functions.
4193  */
4196 #endif
4197 
4198 /**
4199  * Allocate a new AVCodecParameters and set its fields to default values
4200  * (unknown/invalid/0). The returned struct must be freed with
4201  * avcodec_parameters_free().
4202  */
4204 
4205 /**
4206  * Free an AVCodecParameters instance and everything associated with it and
4207  * write NULL to the supplied pointer.
4208  */
4210 
4211 /**
4212  * Copy the contents of src to dst. Any allocated fields in dst are freed and
4213  * replaced with newly allocated duplicates of the corresponding fields in src.
4214  *
4215  * @return >= 0 on success, a negative AVERROR code on failure.
4216  */
4218 
4219 /**
4220  * Fill the parameters struct based on the values from the supplied codec
4221  * context. Any allocated fields in par are freed and replaced with duplicates
4222  * of the corresponding fields in codec.
4223  *
4224  * @return >= 0 on success, a negative AVERROR code on failure
4225  */
4227  const AVCodecContext *codec);
4228 
4229 /**
4230  * Fill the codec context based on the values from the supplied codec
4231  * parameters. Any allocated fields in codec that have a corresponding field in
4232  * par are freed and replaced with duplicates of the corresponding field in par.
4233  * Fields in codec that do not have a counterpart in par are not touched.
4234  *
4235  * @return >= 0 on success, a negative AVERROR code on failure.
4236  */
4238  const AVCodecParameters *par);
4239 
4240 /**
4241  * Initialize the AVCodecContext to use the given AVCodec. Prior to using this
4242  * function the context has to be allocated with avcodec_alloc_context3().
4243  *
4244  * The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(),
4245  * avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for
4246  * retrieving a codec.
4247  *
4248  * @warning This function is not thread safe!
4249  *
4250  * @note Always call this function before using decoding routines (such as
4251  * @ref avcodec_receive_frame()).
4252  *
4253  * @code
4254  * avcodec_register_all();
4255  * av_dict_set(&opts, "b", "2.5M", 0);
4256  * codec = avcodec_find_decoder(AV_CODEC_ID_H264);
4257  * if (!codec)
4258  * exit(1);
4259  *
4260  * context = avcodec_alloc_context3(codec);
4261  *
4262  * if (avcodec_open2(context, codec, opts) < 0)
4263  * exit(1);
4264  * @endcode
4265  *
4266  * @param avctx The context to initialize.
4267  * @param codec The codec to open this context for. If a non-NULL codec has been
4268  * previously passed to avcodec_alloc_context3() or
4269  * for this context, then this parameter MUST be either NULL or
4270  * equal to the previously passed codec.
4271  * @param options A dictionary filled with AVCodecContext and codec-private options.
4272  * On return this object will be filled with options that were not found.
4273  *
4274  * @return zero on success, a negative value on error
4275  * @see avcodec_alloc_context3(), avcodec_find_decoder(), avcodec_find_encoder(),
4276  * av_dict_set(), av_opt_find().
4277  */
4278 int avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options);
4279 
4280 /**
4281  * Close a given AVCodecContext and free all the data associated with it
4282  * (but not the AVCodecContext itself).
4283  *
4284  * Calling this function on an AVCodecContext that hasn't been opened will free
4285  * the codec-specific data allocated in avcodec_alloc_context3() with a non-NULL
4286  * codec. Subsequent calls will do nothing.
4287  *
4288  * @note Do not use this function. Use avcodec_free_context() to destroy a
4289  * codec context (either open or closed). Opening and closing a codec context
4290  * multiple times is not supported anymore -- use multiple codec contexts
4291  * instead.
4292  */
4293 int avcodec_close(AVCodecContext *avctx);
4294 
4295 /**
4296  * Free all allocated data in the given subtitle struct.
4297  *
4298  * @param sub AVSubtitle to free.
4299  */
4300 void avsubtitle_free(AVSubtitle *sub);
4301 
4302 /**
4303  * @}
4304  */
4305 
4306 /**
4307  * @addtogroup lavc_packet
4308  * @{
4309  */
4310 
4311 /**
4312  * Allocate an AVPacket and set its fields to default values. The resulting
4313  * struct must be freed using av_packet_free().
4314  *
4315  * @return An AVPacket filled with default values or NULL on failure.
4316  *
4317  * @note this only allocates the AVPacket itself, not the data buffers. Those
4318  * must be allocated through other means such as av_new_packet.
4319  *
4320  * @see av_new_packet
4321  */
4322 AVPacket *av_packet_alloc(void);
4323 
4324 /**
4325  * Create a new packet that references the same data as src.
4326  *
4327  * This is a shortcut for av_packet_alloc()+av_packet_ref().
4328  *
4329  * @return newly created AVPacket on success, NULL on error.
4330  *
4331  * @see av_packet_alloc
4332  * @see av_packet_ref
4333  */
4335 
4336 /**
4337  * Free the packet, if the packet is reference counted, it will be
4338  * unreferenced first.
4339  *
4340  * @param pkt packet to be freed. The pointer will be set to NULL.
4341  * @note passing NULL is a no-op.
4342  */
4343 void av_packet_free(AVPacket **pkt);
4344 
4345 /**
4346  * Initialize optional fields of a packet with default values.
4347  *
4348  * Note, this does not touch the data and size members, which have to be
4349  * initialized separately.
4350  *
4351  * @param pkt packet
4352  */
4353 void av_init_packet(AVPacket *pkt);
4354 
4355 /**
4356  * Allocate the payload of a packet and initialize its fields with
4357  * default values.
4358  *
4359  * @param pkt packet
4360  * @param size wanted payload size
4361  * @return 0 if OK, AVERROR_xxx otherwise
4362  */
4363 int av_new_packet(AVPacket *pkt, int size);
4364 
4365 /**
4366  * Reduce packet size, correctly zeroing padding
4367  *
4368  * @param pkt packet
4369  * @param size new size
4370  */
4371 void av_shrink_packet(AVPacket *pkt, int size);
4372 
4373 /**
4374  * Increase packet size, correctly zeroing padding
4375  *
4376  * @param pkt packet
4377  * @param grow_by number of bytes by which to increase the size of the packet
4378  */
4379 int av_grow_packet(AVPacket *pkt, int grow_by);
4380 
4381 /**
4382  * Initialize a reference-counted packet from av_malloc()ed data.
4383  *
4384  * @param pkt packet to be initialized. This function will set the data, size,
4385  * buf and destruct fields, all others are left untouched.
4386  * @param data Data allocated by av_malloc() to be used as packet data. If this
4387  * function returns successfully, the data is owned by the underlying AVBuffer.
4388  * The caller may not access the data through other means.
4389  * @param size size of data in bytes, without the padding. I.e. the full buffer
4390  * size is assumed to be size + AV_INPUT_BUFFER_PADDING_SIZE.
4391  *
4392  * @return 0 on success, a negative AVERROR on error
4393  */
4395 
4396 #if FF_API_AVPACKET_OLD_API
4397 /**
4398  * @warning This is a hack - the packet memory allocation stuff is broken. The
4399  * packet is allocated if it was not really allocated.
4400  *
4401  * @deprecated Use av_packet_ref or av_packet_make_refcounted
4402  */
4404 int av_dup_packet(AVPacket *pkt);
4405 /**
4406  * Copy packet, including contents
4407  *
4408  * @return 0 on success, negative AVERROR on fail
4409  *
4410  * @deprecated Use av_packet_ref
4411  */
4413 int av_copy_packet(AVPacket *dst, const AVPacket *src);
4414 
4415 /**
4416  * Copy packet side data
4417  *
4418  * @return 0 on success, negative AVERROR on fail
4419  *
4420  * @deprecated Use av_packet_copy_props
4421  */
4423 int av_copy_packet_side_data(AVPacket *dst, const AVPacket *src);
4424 
4425 /**
4426  * Free a packet.
4427  *
4428  * @deprecated Use av_packet_unref
4429  *
4430  * @param pkt packet to free
4431  */
4433 void av_free_packet(AVPacket *pkt);
4434 #endif
4435 /**
4436  * Allocate new information of a packet.
4437  *
4438  * @param pkt packet
4439  * @param type side information type
4440  * @param size side information size
4441  * @return pointer to fresh allocated data or NULL otherwise
4442  */
4444  int size);
4445 
4446 /**
4447  * Wrap an existing array as a packet side data.
4448  *
4449  * @param pkt packet
4450  * @param type side information type
4451  * @param data the side data array. It must be allocated with the av_malloc()
4452  * family of functions. The ownership of the data is transferred to
4453  * pkt.
4454  * @param size side information size
4455  * @return a non-negative number on success, a negative AVERROR code on
4456  * failure. On failure, the packet is unchanged and the data remains
4457  * owned by the caller.
4458  */
4460  uint8_t *data, size_t size);
4461 
4462 /**
4463  * Shrink the already allocated side data buffer
4464  *
4465  * @param pkt packet
4466  * @param type side information type
4467  * @param size new side information size
4468  * @return 0 on success, < 0 on failure
4469  */
4471  int size);
4472 
4473 /**
4474  * Get side information from packet.
4475  *
4476  * @param pkt packet
4477  * @param type desired side information type
4478  * @param size pointer for side information size to store (optional)
4479  * @return pointer to data if present or NULL otherwise
4480  */
4482  int *size);
4483 
4484 #if FF_API_MERGE_SD_API
4487 
4490 #endif
4491 
4493 
4494 /**
4495  * Pack a dictionary for use in side_data.
4496  *
4497  * @param dict The dictionary to pack.
4498  * @param size pointer to store the size of the returned data
4499  * @return pointer to data if successful, NULL otherwise
4500  */
4502 /**
4503  * Unpack a dictionary from side_data.
4504  *
4505  * @param data data from side_data
4506  * @param size size of the data
4507  * @param dict the metadata storage dictionary
4508  * @return 0 on success, < 0 on failure
4509  */
4510 int av_packet_unpack_dictionary(const uint8_t *data, int size, AVDictionary **dict);
4511 
4512 
4513 /**
4514  * Convenience function to free all the side data stored.
4515  * All the other fields stay untouched.
4516  *
4517  * @param pkt packet
4518  */
4520 
4521 /**
4522  * Setup a new reference to the data described by a given packet
4523  *
4524  * If src is reference-counted, setup dst as a new reference to the
4525  * buffer in src. Otherwise allocate a new buffer in dst and copy the
4526  * data from src into it.
4527  *
4528  * All the other fields are copied from src.
4529  *
4530  * @see av_packet_unref
4531  *
4532  * @param dst Destination packet
4533  * @param src Source packet
4534  *
4535  * @return 0 on success, a negative AVERROR on error.
4536  */
4537 int av_packet_ref(AVPacket *dst, const AVPacket *src);
4538 
4539 /**
4540  * Wipe the packet.
4541  *
4542  * Unreference the buffer referenced by the packet and reset the
4543  * remaining packet fields to their default values.
4544  *
4545  * @param pkt The packet to be unreferenced.
4546  */
4548 
4549 /**
4550  * Move every field in src to dst and reset src.
4551  *
4552  * @see av_packet_unref
4553  *
4554  * @param src Source packet, will be reset
4555  * @param dst Destination packet
4556  */
4558 
4559 /**
4560  * Copy only "properties" fields from src to dst.
4561  *
4562  * Properties for the purpose of this function are all the fields
4563  * beside those related to the packet data (buf, data, size)
4564  *
4565  * @param dst Destination packet
4566  * @param src Source packet
4567  *
4568  * @return 0 on success AVERROR on failure.
4569  */
4570 int av_packet_copy_props(AVPacket *dst, const AVPacket *src);
4571 
4572 /**
4573  * Ensure the data described by a given packet is reference counted.
4574  *
4575  * @note This function does not ensure that the reference will be writable.
4576  * Use av_packet_make_writable instead for that purpose.
4577  *
4578  * @see av_packet_ref
4579  * @see av_packet_make_writable
4580  *
4581  * @param pkt packet whose data should be made reference counted.
4582  *
4583  * @return 0 on success, a negative AVERROR on error. On failure, the
4584  * packet is unchanged.
4585  */
4587 
4588 /**
4589  * Create a writable reference for the data described by a given packet,
4590  * avoiding data copy if possible.
4591  *
4592  * @param pkt Packet whose data should be made writable.
4593  *
4594  * @return 0 on success, a negative AVERROR on failure. On failure, the
4595  * packet is unchanged.
4596  */
4598 
4599 /**
4600  * Convert valid timing fields (timestamps / durations) in a packet from one
4601  * timebase to another. Timestamps with unknown values (AV_NOPTS_VALUE) will be
4602  * ignored.
4603  *
4604  * @param pkt packet on which the conversion will be performed
4605  * @param tb_src source timebase, in which the timing fields in pkt are
4606  * expressed
4607  * @param tb_dst destination timebase, to which the timing fields will be
4608  * converted
4609  */
4610 void av_packet_rescale_ts(AVPacket *pkt, AVRational tb_src, AVRational tb_dst);
4611 
4612 /**
4613  * @}
4614  */
4615 
4616 /**
4617  * @addtogroup lavc_decoding
4618  * @{
4619  */
4620 
4621 /**
4622  * Find a registered decoder with a matching codec ID.
4623  *
4624  * @param id AVCodecID of the requested decoder
4625  * @return A decoder if one was found, NULL otherwise.
4626  */
4628 
4629 /**
4630  * Find a registered decoder with the specified name.
4631  *
4632  * @param name name of the requested decoder
4633  * @return A decoder if one was found, NULL otherwise.
4634  */
4636 
4637 /**
4638  * The default callback for AVCodecContext.get_buffer2(). It is made public so
4639  * it can be called by custom get_buffer2() implementations for decoders without
4640  * AV_CODEC_CAP_DR1 set.
4641  */
4643 
4644 /**
4645  * Modify width and height values so that they will result in a memory
4646  * buffer that is acceptable for the codec if you do not use any horizontal
4647  * padding.
4648  *
4649  * May only be used if a codec with AV_CODEC_CAP_DR1 has been opened.
4650  */
4652 
4653 /**
4654  * Modify width and height values so that they will result in a memory
4655  * buffer that is acceptable for the codec if you also ensure that all
4656  * line sizes are a multiple of the respective linesize_align[i].
4657  *
4658  * May only be used if a codec with AV_CODEC_CAP_DR1 has been opened.
4659  */
4661  int linesize_align[AV_NUM_DATA_POINTERS]);
4662 
4663 /**
4664  * Converts AVChromaLocation to swscale x/y chroma position.
4665  *
4666  * The positions represent the chroma (0,0) position in a coordinates system
4667  * with luma (0,0) representing the origin and luma(1,1) representing 256,256
4668  *
4669  * @param xpos horizontal chroma sample position
4670  * @param ypos vertical chroma sample position
4671  */
4672 int avcodec_enum_to_chroma_pos(int *xpos, int *ypos, enum AVChromaLocation pos);
4673 
4674 /**
4675  * Converts swscale x/y chroma position to AVChromaLocation.
4676  *
4677  * The positions represent the chroma (0,0) position in a coordinates system
4678  * with luma (0,0) representing the origin and luma(1,1) representing 256,256
4679  *
4680  * @param xpos horizontal chroma sample position
4681  * @param ypos vertical chroma sample position
4682  */
4683 enum AVChromaLocation avcodec_chroma_pos_to_enum(int xpos, int ypos);
4684 
4685 /**
4686  * Decode the audio frame of size avpkt->size from avpkt->data into frame.
4687  *
4688  * Some decoders may support multiple frames in a single AVPacket. Such
4689  * decoders would then just decode the first frame and the return value would be
4690  * less than the packet size. In this case, avcodec_decode_audio4 has to be
4691  * called again with an AVPacket containing the remaining data in order to
4692  * decode the second frame, etc... Even if no frames are returned, the packet
4693  * needs to be fed to the decoder with remaining data until it is completely
4694  * consumed or an error occurs.
4695  *
4696  * Some decoders (those marked with AV_CODEC_CAP_DELAY) have a delay between input
4697  * and output. This means that for some packets they will not immediately
4698  * produce decoded output and need to be flushed at the end of decoding to get
4699  * all the decoded data. Flushing is done by calling this function with packets
4700  * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
4701  * returning samples. It is safe to flush even those decoders that are not
4702  * marked with AV_CODEC_CAP_DELAY, then no samples will be returned.
4703  *
4704  * @warning The input buffer, avpkt->data must be AV_INPUT_BUFFER_PADDING_SIZE
4705  * larger than the actual read bytes because some optimized bitstream
4706  * readers read 32 or 64 bits at once and could read over the end.
4707  *
4708  * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
4709  * before packets may be fed to the decoder.
4710  *
4711  * @param avctx the codec context
4712  * @param[out] frame The AVFrame in which to store decoded audio samples.
4713  * The decoder will allocate a buffer for the decoded frame by
4714  * calling the AVCodecContext.get_buffer2() callback.
4715  * When AVCodecContext.refcounted_frames is set to 1, the frame is
4716  * reference counted and the returned reference belongs to the
4717  * caller. The caller must release the frame using av_frame_unref()
4718  * when the frame is no longer needed. The caller may safely write
4719  * to the frame if av_frame_is_writable() returns 1.
4720  * When AVCodecContext.refcounted_frames is set to 0, the returned
4721  * reference belongs to the decoder and is valid only until the
4722  * next call to this function or until closing or flushing the
4723  * decoder. The caller may not write to it.
4724  * @param[out] got_frame_ptr Zero if no frame could be decoded, otherwise it is
4725  * non-zero. Note that this field being set to zero
4726  * does not mean that an error has occurred. For
4727  * decoders with AV_CODEC_CAP_DELAY set, no given decode
4728  * call is guaranteed to produce a frame.
4729  * @param[in] avpkt The input AVPacket containing the input buffer.
4730  * At least avpkt->data and avpkt->size should be set. Some
4731  * decoders might also require additional fields to be set.
4732  * @return A negative error code is returned if an error occurred during
4733  * decoding, otherwise the number of bytes consumed from the input
4734  * AVPacket is returned.
4735  *
4736 * @deprecated Use avcodec_send_packet() and avcodec_receive_frame().
4737  */
4740  int *got_frame_ptr, const AVPacket *avpkt);
4741 
4742 /**
4743  * Decode the video frame of size avpkt->size from avpkt->data into picture.
4744  * Some decoders may support multiple frames in a single AVPacket, such
4745  * decoders would then just decode the first frame.
4746  *
4747  * @warning The input buffer must be AV_INPUT_BUFFER_PADDING_SIZE larger than
4748  * the actual read bytes because some optimized bitstream readers read 32 or 64
4749  * bits at once and could read over the end.
4750  *
4751  * @warning The end of the input buffer buf should be set to 0 to ensure that
4752  * no overreading happens for damaged MPEG streams.
4753  *
4754  * @note Codecs which have the AV_CODEC_CAP_DELAY capability set have a delay
4755  * between input and output, these need to be fed with avpkt->data=NULL,
4756  * avpkt->size=0 at the end to return the remaining frames.
4757  *
4758  * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
4759  * before packets may be fed to the decoder.
4760  *
4761  * @param avctx the codec context
4762  * @param[out] picture The AVFrame in which the decoded video frame will be stored.
4763  * Use av_frame_alloc() to get an AVFrame. The codec will
4764  * allocate memory for the actual bitmap by calling the
4765  * AVCodecContext.get_buffer2() callback.
4766  * When AVCodecContext.refcounted_frames is set to 1, the frame is
4767  * reference counted and the returned reference belongs to the
4768  * caller. The caller must release the frame using av_frame_unref()
4769  * when the frame is no longer needed. The caller may safely write
4770  * to the frame if av_frame_is_writable() returns 1.
4771  * When AVCodecContext.refcounted_frames is set to 0, the returned
4772  * reference belongs to the decoder and is valid only until the
4773  * next call to this function or until closing or flushing the
4774  * decoder. The caller may not write to it.
4775  *
4776  * @param[in] avpkt The input AVPacket containing the input buffer.
4777  * You can create such packet with av_init_packet() and by then setting
4778  * data and size, some decoders might in addition need other fields like
4779  * flags&AV_PKT_FLAG_KEY. All decoders are designed to use the least
4780  * fields possible.
4781  * @param[in,out] got_picture_ptr Zero if no frame could be decompressed, otherwise, it is nonzero.
4782  * @return On error a negative value is returned, otherwise the number of bytes
4783  * used or zero if no frame could be decompressed.
4784  *
4785  * @deprecated Use avcodec_send_packet() and avcodec_receive_frame().
4786  */
4788 int avcodec_decode_video2(AVCodecContext *avctx, AVFrame *picture,
4789  int *got_picture_ptr,
4790  const AVPacket *avpkt);
4791 
4792 /**
4793  * Decode a subtitle message.
4794  * Return a negative value on error, otherwise return the number of bytes used.
4795  * If no subtitle could be decompressed, got_sub_ptr is zero.
4796  * Otherwise, the subtitle is stored in *sub.
4797  * Note that AV_CODEC_CAP_DR1 is not available for subtitle codecs. This is for
4798  * simplicity, because the performance difference is expect to be negligible
4799  * and reusing a get_buffer written for video codecs would probably perform badly
4800  * due to a potentially very different allocation pattern.
4801  *
4802  * Some decoders (those marked with AV_CODEC_CAP_DELAY) have a delay between input
4803  * and output. This means that for some packets they will not immediately
4804  * produce decoded output and need to be flushed at the end of decoding to get
4805  * all the decoded data. Flushing is done by calling this function with packets
4806  * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
4807  * returning subtitles. It is safe to flush even those decoders that are not
4808  * marked with AV_CODEC_CAP_DELAY, then no subtitles will be returned.
4809  *
4810  * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
4811  * before packets may be fed to the decoder.
4812  *
4813  * @param avctx the codec context
4814  * @param[out] sub The Preallocated AVSubtitle in which the decoded subtitle will be stored,
4815  * must be freed with avsubtitle_free if *got_sub_ptr is set.
4816  * @param[in,out] got_sub_ptr Zero if no subtitle could be decompressed, otherwise, it is nonzero.
4817  * @param[in] avpkt The input AVPacket containing the input buffer.
4818  */
4820  int *got_sub_ptr,
4821  AVPacket *avpkt);
4822 
4823 /**
4824  * Supply raw packet data as input to a decoder.
4825  *
4826  * Internally, this call will copy relevant AVCodecContext fields, which can
4827  * influence decoding per-packet, and apply them when the packet is actually
4828  * decoded. (For example AVCodecContext.skip_frame, which might direct the
4829  * decoder to drop the frame contained by the packet sent with this function.)
4830  *
4831  * @warning The input buffer, avpkt->data must be AV_INPUT_BUFFER_PADDING_SIZE
4832  * larger than the actual read bytes because some optimized bitstream
4833  * readers read 32 or 64 bits at once and could read over the end.
4834  *
4835  * @warning Do not mix this API with the legacy API (like avcodec_decode_video2())
4836  * on the same AVCodecContext. It will return unexpected results now
4837  * or in future libavcodec versions.
4838  *
4839  * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
4840  * before packets may be fed to the decoder.
4841  *
4842  * @param avctx codec context
4843  * @param[in] avpkt The input AVPacket. Usually, this will be a single video
4844  * frame, or several complete audio frames.
4845  * Ownership of the packet remains with the caller, and the
4846  * decoder will not write to the packet. The decoder may create
4847  * a reference to the packet data (or copy it if the packet is
4848  * not reference-counted).
4849  * Unlike with older APIs, the packet is always fully consumed,
4850  * and if it contains multiple frames (e.g. some audio codecs),
4851  * will require you to call avcodec_receive_frame() multiple
4852  * times afterwards before you can send a new packet.
4853  * It can be NULL (or an AVPacket with data set to NULL and
4854  * size set to 0); in this case, it is considered a flush
4855  * packet, which signals the end of the stream. Sending the
4856  * first flush packet will return success. Subsequent ones are
4857  * unnecessary and will return AVERROR_EOF. If the decoder
4858  * still has frames buffered, it will return them after sending
4859  * a flush packet.
4860  *
4861  * @return 0 on success, otherwise negative error code:
4862  * AVERROR(EAGAIN): input is not accepted in the current state - user
4863  * must read output with avcodec_receive_frame() (once
4864  * all output is read, the packet should be resent, and
4865  * the call will not fail with EAGAIN).
4866  * AVERROR_EOF: the decoder has been flushed, and no new packets can
4867  * be sent to it (also returned if more than 1 flush
4868  * packet is sent)
4869  * AVERROR(EINVAL): codec not opened, it is an encoder, or requires flush
4870  * AVERROR(ENOMEM): failed to add packet to internal queue, or similar
4871  * other errors: legitimate decoding errors
4872  */
4873 int avcodec_send_packet(AVCodecContext *avctx, const AVPacket *avpkt);
4874 
4875 /**
4876  * Return decoded output data from a decoder.
4877  *
4878  * @param avctx codec context
4879  * @param frame This will be set to a reference-counted video or audio
4880  * frame (depending on the decoder type) allocated by the
4881  * decoder. Note that the function will always call
4882  * av_frame_unref(frame) before doing anything else.
4883  *
4884  * @return
4885  * 0: success, a frame was returned
4886  * AVERROR(EAGAIN): output is not available in this state - user must try
4887  * to send new input
4888  * AVERROR_EOF: the decoder has been fully flushed, and there will be
4889  * no more output frames
4890  * AVERROR(EINVAL): codec not opened, or it is an encoder
4891  * other negative values: legitimate decoding errors
4892  */
4894 
4895 /**
4896  * Supply a raw video or audio frame to the encoder. Use avcodec_receive_packet()
4897  * to retrieve buffered output packets.
4898  *
4899  * @param avctx codec context
4900  * @param[in] frame AVFrame containing the raw audio or video frame to be encoded.
4901  * Ownership of the frame remains with the caller, and the
4902  * encoder will not write to the frame. The encoder may create
4903  * a reference to the frame data (or copy it if the frame is
4904  * not reference-counted).
4905  * It can be NULL, in which case it is considered a flush
4906  * packet. This signals the end of the stream. If the encoder
4907  * still has packets buffered, it will return them after this
4908  * call. Once flushing mode has been entered, additional flush
4909  * packets are ignored, and sending frames will return
4910  * AVERROR_EOF.
4911  *
4912  * For audio:
4913  * If AV_CODEC_CAP_VARIABLE_FRAME_SIZE is set, then each frame
4914  * can have any number of samples.
4915  * If it is not set, frame->nb_samples must be equal to
4916  * avctx->frame_size for all frames except the last.
4917  * The final frame may be smaller than avctx->frame_size.
4918  * @return 0 on success, otherwise negative error code:
4919  * AVERROR(EAGAIN): input is not accepted in the current state - user
4920  * must read output with avcodec_receive_packet() (once
4921  * all output is read, the packet should be resent, and
4922  * the call will not fail with EAGAIN).
4923  * AVERROR_EOF: the encoder has been flushed, and no new frames can
4924  * be sent to it
4925  * AVERROR(EINVAL): codec not opened, refcounted_frames not set, it is a
4926  * decoder, or requires flush
4927  * AVERROR(ENOMEM): failed to add packet to internal queue, or similar
4928  * other errors: legitimate decoding errors
4929  */
4930 int avcodec_send_frame(AVCodecContext *avctx, const AVFrame *frame);
4931 
4932 /**
4933  * Read encoded data from the encoder.
4934  *
4935  * @param avctx codec context
4936  * @param avpkt This will be set to a reference-counted packet allocated by the
4937  * encoder. Note that the function will always call
4938  * av_frame_unref(frame) before doing anything else.
4939  * @return 0 on success, otherwise negative error code:
4940  * AVERROR(EAGAIN): output is not available in the current state - user
4941  * must try to send input
4942  * AVERROR_EOF: the encoder has been fully flushed, and there will be
4943  * no more output packets
4944  * AVERROR(EINVAL): codec not opened, or it is an encoder
4945  * other errors: legitimate decoding errors
4946  */
4947 int avcodec_receive_packet(AVCodecContext *avctx, AVPacket *avpkt);
4948 
4949 /**
4950  * Create and return a AVHWFramesContext with values adequate for hardware
4951  * decoding. This is meant to get called from the get_format callback, and is
4952  * a helper for preparing a AVHWFramesContext for AVCodecContext.hw_frames_ctx.
4953  * This API is for decoding with certain hardware acceleration modes/APIs only.
4954  *
4955  * The returned AVHWFramesContext is not initialized. The caller must do this
4956  * with av_hwframe_ctx_init().
4957  *
4958  * Calling this function is not a requirement, but makes it simpler to avoid
4959  * codec or hardware API specific details when manually allocating frames.
4960  *
4961  * Alternatively to this, an API user can set AVCodecContext.hw_device_ctx,
4962  * which sets up AVCodecContext.hw_frames_ctx fully automatically, and makes
4963  * it unnecessary to call this function or having to care about
4964  * AVHWFramesContext initialization at all.
4965  *
4966  * There are a number of requirements for calling this function:
4967  *
4968  * - It must be called from get_format with the same avctx parameter that was
4969  * passed to get_format. Calling it outside of get_format is not allowed, and
4970  * can trigger undefined behavior.
4971  * - The function is not always supported (see description of return values).
4972  * Even if this function returns successfully, hwaccel initialization could
4973  * fail later. (The degree to which implementations check whether the stream
4974  * is actually supported varies. Some do this check only after the user's
4975  * get_format callback returns.)
4976  * - The hw_pix_fmt must be one of the choices suggested by get_format. If the
4977  * user decides to use a AVHWFramesContext prepared with this API function,
4978  * the user must return the same hw_pix_fmt from get_format.
4979  * - The device_ref passed to this function must support the given hw_pix_fmt.
4980  * - After calling this API function, it is the user's responsibility to
4981  * initialize the AVHWFramesContext (returned by the out_frames_ref parameter),
4982  * and to set AVCodecContext.hw_frames_ctx to it. If done, this must be done
4983  * before returning from get_format (this is implied by the normal
4984  * AVCodecContext.hw_frames_ctx API rules).
4985  * - The AVHWFramesContext parameters may change every time time get_format is
4986  * called. Also, AVCodecContext.hw_frames_ctx is reset before get_format. So
4987  * you are inherently required to go through this process again on every
4988  * get_format call.
4989  * - It is perfectly possible to call this function without actually using
4990  * the resulting AVHWFramesContext. One use-case might be trying to reuse a
4991  * previously initialized AVHWFramesContext, and calling this API function
4992  * only to test whether the required frame parameters have changed.
4993  * - Fields that use dynamically allocated values of any kind must not be set
4994  * by the user unless setting them is explicitly allowed by the documentation.
4995  * If the user sets AVHWFramesContext.free and AVHWFramesContext.user_opaque,
4996  * the new free callback must call the potentially set previous free callback.
4997  * This API call may set any dynamically allocated fields, including the free
4998  * callback.
4999  *
5000  * The function will set at least the following fields on AVHWFramesContext
5001  * (potentially more, depending on hwaccel API):
5002  *
5003  * - All fields set by av_hwframe_ctx_alloc().
5004  * - Set the format field to hw_pix_fmt.
5005  * - Set the sw_format field to the most suited and most versatile format. (An
5006  * implication is that this will prefer generic formats over opaque formats
5007  * with arbitrary restrictions, if possible.)
5008  * - Set the width/height fields to the coded frame size, rounded up to the
5009  * API-specific minimum alignment.
5010  * - Only _if_ the hwaccel requires a pre-allocated pool: set the initial_pool_size
5011  * field to the number of maximum reference surfaces possible with the codec,
5012  * plus 1 surface for the user to work (meaning the user can safely reference
5013  * at most 1 decoded surface at a time), plus additional buffering introduced
5014  * by frame threading. If the hwaccel does not require pre-allocation, the
5015  * field is left to 0, and the decoder will allocate new surfaces on demand
5016  * during decoding.
5017  * - Possibly AVHWFramesContext.hwctx fields, depending on the underlying
5018  * hardware API.
5019  *
5020  * Essentially, out_frames_ref returns the same as av_hwframe_ctx_alloc(), but
5021  * with basic frame parameters set.
5022  *
5023  * The function is stateless, and does not change the AVCodecContext or the
5024  * device_ref AVHWDeviceContext.
5025  *
5026  * @param avctx The context which is currently calling get_format, and which
5027  * implicitly contains all state needed for filling the returned
5028  * AVHWFramesContext properly.
5029  * @param device_ref A reference to the AVHWDeviceContext describing the device
5030  * which will be used by the hardware decoder.
5031  * @param hw_pix_fmt The hwaccel format you are going to return from get_format.
5032  * @param out_frames_ref On success, set to a reference to an _uninitialized_
5033  * AVHWFramesContext, created from the given device_ref.
5034  * Fields will be set to values required for decoding.
5035  * Not changed if an error is returned.
5036  * @return zero on success, a negative value on error. The following error codes
5037  * have special semantics:
5038  * AVERROR(ENOENT): the decoder does not support this functionality. Setup
5039  * is always manual, or it is a decoder which does not
5040  * support setting AVCodecContext.hw_frames_ctx at all,
5041  * or it is a software format.
5042  * AVERROR(EINVAL): it is known that hardware decoding is not supported for
5043  * this configuration, or the device_ref is not supported
5044  * for the hwaccel referenced by hw_pix_fmt.
5045  */
5047  AVBufferRef *device_ref,
5049  AVBufferRef **out_frames_ref);
5050 
5051 
5052 
5053 /**
5054  * @defgroup lavc_parsing Frame parsing
5055  * @{
5056  */
5057 
5060  AV_PICTURE_STRUCTURE_TOP_FIELD, //< coded as top field
5061  AV_PICTURE_STRUCTURE_BOTTOM_FIELD, //< coded as bottom field
5062  AV_PICTURE_STRUCTURE_FRAME, //< coded as frame
5063 };
5064 
5065 typedef struct AVCodecParserContext {
5066  void *priv_data;
5068  int64_t frame_offset; /* offset of the current frame */
5069  int64_t cur_offset; /* current offset
5070  (incremented by each av_parser_parse()) */
5071  int64_t next_frame_offset; /* offset of the next frame */
5072  /* video info */
5073  int pict_type; /* XXX: Put it back in AVCodecContext. */
5074  /**
5075  * This field is used for proper frame duration computation in lavf.
5076  * It signals, how much longer the frame duration of the current frame
5077  * is compared to normal frame duration.
5078  *
5079  * frame_duration = (1 + repeat_pict) * time_base
5080  *
5081  * It is used by codecs like H.264 to display telecined material.
5082  */
5083  int repeat_pict; /* XXX: Put it back in AVCodecContext. */
5084  int64_t pts; /* pts of the current frame */
5085  int64_t dts; /* dts of the current frame */
5086 
5087  /* private data */
5088  int64_t last_pts;
5089  int64_t last_dts;
5091 
5092 #define AV_PARSER_PTS_NB 4
5097 
5098  int flags;
5099 #define PARSER_FLAG_COMPLETE_FRAMES 0x0001
5100 #define PARSER_FLAG_ONCE 0x0002
5101 /// Set if the parser has a valid file offset
5102 #define PARSER_FLAG_FETCHED_OFFSET 0x0004
5103 #define PARSER_FLAG_USE_CODEC_TS 0x1000
5104 
5105  int64_t offset; ///< byte offset from starting packet start
5107 
5108  /**
5109  * Set by parser to 1 for key frames and 0 for non-key frames.
5110  * It is initialized to -1, so if the parser doesn't set this flag,
5111  * old-style fallback using AV_PICTURE_TYPE_I picture type as key frames
5112  * will be used.
5113  */
5115 
5116 #if FF_API_CONVERGENCE_DURATION
5117  /**
5118  * @deprecated unused
5119  */
5122 #endif
5123 
5124  // Timestamp generation support:
5125  /**
5126  * Synchronization point for start of timestamp generation.
5127  *
5128  * Set to >0 for sync point, 0 for no sync point and <0 for undefined
5129  * (default).
5130  *
5131  * For example, this corresponds to presence of H.264 buffering period
5132  * SEI message.
5133  */
5135 
5136  /**
5137  * Offset of the current timestamp against last timestamp sync point in
5138  * units of AVCodecContext.time_base.
5139  *
5140  * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
5141  * contain a valid timestamp offset.
5142  *
5143  * Note that the timestamp of sync point has usually a nonzero
5144  * dts_ref_dts_delta, which refers to the previous sync point. Offset of
5145  * the next frame after timestamp sync point will be usually 1.
5146  *
5147  * For example, this corresponds to H.264 cpb_removal_delay.
5148  */
5150 
5151  /**
5152  * Presentation delay of current frame in units of AVCodecContext.time_base.
5153  *
5154  * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
5155  * contain valid non-negative timestamp delta (presentation time of a frame
5156  * must not lie in the past).
5157  *
5158  * This delay represents the difference between decoding and presentation
5159  * time of the frame.
5160  *
5161  * For example, this corresponds to H.264 dpb_output_delay.
5162  */
5164 
5165  /**
5166  * Position of the packet in file.
5167  *
5168  * Analogous to cur_frame_pts/dts
5169  */
5171 
5172  /**
5173  * Byte position of currently parsed frame in stream.
5174  */
5175  int64_t pos;
5176 
5177  /**
5178  * Previous frame byte position.
5179  */
5180  int64_t last_pos;
5181 
5182  /**
5183  * Duration of the current frame.
5184  * For audio, this is in units of 1 / AVCodecContext.sample_rate.
5185  * For all other types, this is in units of AVCodecContext.time_base.
5186  */
5188 
5190 
5191  /**
5192  * Indicate whether a picture is coded as a frame, top field or bottom field.
5193  *
5194  * For example, H.264 field_pic_flag equal to 0 corresponds to
5195  * AV_PICTURE_STRUCTURE_FRAME. An H.264 picture with field_pic_flag
5196  * equal to 1 and bottom_field_flag equal to 0 corresponds to
5197  * AV_PICTURE_STRUCTURE_TOP_FIELD.
5198  */
5200 
5201  /**
5202  * Picture number incremented in presentation or output order.
5203  * This field may be reinitialized at the first picture of a new sequence.
5204  *
5205  * For example, this corresponds to H.264 PicOrderCnt.
5206  */
5208 
5209  /**
5210  * Dimensions of the decoded video intended for presentation.
5211  */
5212  int width;
5213  int height;
5214 
5215  /**
5216  * Dimensions of the coded video.
5217  */
5220 
5221  /**
5222  * The format of the coded data, corresponds to enum AVPixelFormat for video
5223  * and for enum AVSampleFormat for audio.
5224  *
5225  * Note that a decoder can have considerable freedom in how exactly it
5226  * decodes the data, so the format reported here might be different from the
5227  * one returned by a decoder.
5228  */
5229  int format;
5231 
5232 typedef struct AVCodecParser {
5233  int codec_ids[5]; /* several codec IDs are permitted */
5236  /* This callback never returns an error, a negative value means that
5237  * the frame start was in a previous packet. */
5239  AVCodecContext *avctx,
5240  const uint8_t **poutbuf, int *poutbuf_size,
5241  const uint8_t *buf, int buf_size);
5243  int (*split)(AVCodecContext *avctx, const uint8_t *buf, int buf_size);
5245 } AVCodecParser;
5246 
5247 /**
5248  * Iterate over all registered codec parsers.
5249  *
5250  * @param opaque a pointer where libavcodec will store the iteration state. Must
5251  * point to NULL to start the iteration.
5252  *
5253  * @return the next registered codec parser or NULL when the iteration is
5254  * finished
5255  */
5256 const AVCodecParser *av_parser_iterate(void **opaque);
5257 
5260 
5264 
5265 /**
5266  * Parse a packet.
5267  *
5268  * @param s parser context.
5269  * @param avctx codec context.
5270  * @param poutbuf set to pointer to parsed buffer or NULL if not yet finished.
5271  * @param poutbuf_size set to size of parsed buffer or zero if not yet finished.
5272  * @param buf input buffer.
5273  * @param buf_size buffer size in bytes without the padding. I.e. the full buffer
5274  size is assumed to be buf_size + AV_INPUT_BUFFER_PADDING_SIZE.
5275  To signal EOF, this should be 0 (so that the last frame
5276  can be output).
5277  * @param pts input presentation timestamp.
5278  * @param dts input decoding timestamp.
5279  * @param pos input byte position in stream.
5280  * @return the number of bytes of the input bitstream used.
5281  *
5282  * Example:
5283  * @code
5284  * while(in_len){
5285  * len = av_parser_parse2(myparser, AVCodecContext, &data, &size,
5286  * in_data, in_len,
5287  * pts, dts, pos);
5288  * in_data += len;
5289  * in_len -= len;
5290  *
5291  * if(size)
5292  * decode_frame(data, size);
5293  * }
5294  * @endcode
5295  */
5297  AVCodecContext *avctx,
5298  uint8_t **poutbuf, int *poutbuf_size,
5299  const uint8_t *buf, int buf_size,
5300  int64_t pts, int64_t dts,
5301  int64_t pos);
5302 
5303 /**
5304  * @return 0 if the output buffer is a subset of the input, 1 if it is allocated and must be freed
5305  * @deprecated use AVBitStreamFilter
5306  */
5308  AVCodecContext *avctx,
5309  uint8_t **poutbuf, int *poutbuf_size,
5310  const uint8_t *buf, int buf_size, int keyframe);
5312 
5313 /**
5314  * @}
5315  * @}
5316  */
5317 
5318 /**
5319  * @addtogroup lavc_encoding
5320  * @{
5321  */
5322 
5323 /**
5324  * Find a registered encoder with a matching codec ID.
5325  *
5326  * @param id AVCodecID of the requested encoder
5327  * @return An encoder if one was found, NULL otherwise.
5328  */