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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  * Pan Scan area.
1076  * This specifies the area which should be displayed.
1077  * Note there may be multiple such areas for one frame.
1078  */
1079 typedef struct AVPanScan {
1080  /**
1081  * id
1082  * - encoding: Set by user.
1083  * - decoding: Set by libavcodec.
1084  */
1085  int id;
1086 
1087  /**
1088  * width and height in 1/16 pel
1089  * - encoding: Set by user.
1090  * - decoding: Set by libavcodec.
1091  */
1092  int width;
1093  int height;
1094 
1095  /**
1096  * position of the top left corner in 1/16 pel for up to 3 fields/frames
1097  * - encoding: Set by user.
1098  * - decoding: Set by libavcodec.
1099  */
1100  int16_t position[3][2];
1101 } AVPanScan;
1102 
1103 /**
1104  * This structure describes the bitrate properties of an encoded bitstream. It
1105  * roughly corresponds to a subset the VBV parameters for MPEG-2 or HRD
1106  * parameters for H.264/HEVC.
1107  */
1108 typedef struct AVCPBProperties {
1109  /**
1110  * Maximum bitrate of the stream, in bits per second.
1111  * Zero if unknown or unspecified.
1112  */
1114  /**
1115  * Minimum bitrate of the stream, in bits per second.
1116  * Zero if unknown or unspecified.
1117  */
1119  /**
1120  * Average bitrate of the stream, in bits per second.
1121  * Zero if unknown or unspecified.
1122  */
1124 
1125  /**
1126  * The size of the buffer to which the ratecontrol is applied, in bits.
1127  * Zero if unknown or unspecified.
1128  */
1130 
1131  /**
1132  * The delay between the time the packet this structure is associated with
1133  * is received and the time when it should be decoded, in periods of a 27MHz
1134  * clock.
1135  *
1136  * UINT64_MAX when unknown or unspecified.
1137  */
1138  uint64_t vbv_delay;
1139 } AVCPBProperties;
1140 
1141 /**
1142  * The decoder will keep a reference to the frame and may reuse it later.
1143  */
1144 #define AV_GET_BUFFER_FLAG_REF (1 << 0)
1145 
1146 /**
1147  * @defgroup lavc_packet AVPacket
1148  *
1149  * Types and functions for working with AVPacket.
1150  * @{
1151  */
1153  /**
1154  * An AV_PKT_DATA_PALETTE side data packet contains exactly AVPALETTE_SIZE
1155  * bytes worth of palette. This side data signals that a new palette is
1156  * present.
1157  */
1159 
1160  /**
1161  * The AV_PKT_DATA_NEW_EXTRADATA is used to notify the codec or the format
1162  * that the extradata buffer was changed and the receiving side should
1163  * act upon it appropriately. The new extradata is embedded in the side
1164  * data buffer and should be immediately used for processing the current
1165  * frame or packet.
1166  */
1168 
1169  /**
1170  * An AV_PKT_DATA_PARAM_CHANGE side data packet is laid out as follows:
1171  * @code
1172  * u32le param_flags
1173  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT)
1174  * s32le channel_count
1175  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT)
1176  * u64le channel_layout
1177  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE)
1178  * s32le sample_rate
1179  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS)
1180  * s32le width
1181  * s32le height
1182  * @endcode
1183  */
1185 
1186  /**
1187  * An AV_PKT_DATA_H263_MB_INFO side data packet contains a number of
1188  * structures with info about macroblocks relevant to splitting the
1189  * packet into smaller packets on macroblock edges (e.g. as for RFC 2190).
1190  * That is, it does not necessarily contain info about all macroblocks,
1191  * as long as the distance between macroblocks in the info is smaller
1192  * than the target payload size.
1193  * Each MB info structure is 12 bytes, and is laid out as follows:
1194  * @code
1195  * u32le bit offset from the start of the packet
1196  * u8 current quantizer at the start of the macroblock
1197  * u8 GOB number
1198  * u16le macroblock address within the GOB
1199  * u8 horizontal MV predictor
1200  * u8 vertical MV predictor
1201  * u8 horizontal MV predictor for block number 3
1202  * u8 vertical MV predictor for block number 3
1203  * @endcode
1204  */
1206 
1207  /**
1208  * This side data should be associated with an audio stream and contains
1209  * ReplayGain information in form of the AVReplayGain struct.
1210  */
1212 
1213  /**
1214  * This side data contains a 3x3 transformation matrix describing an affine
1215  * transformation that needs to be applied to the decoded video frames for
1216  * correct presentation.
1217  *
1218  * See libavutil/display.h for a detailed description of the data.
1219  */
1221 
1222  /**
1223  * This side data should be associated with a video stream and contains
1224  * Stereoscopic 3D information in form of the AVStereo3D struct.
1225  */
1227 
1228  /**
1229  * This side data should be associated with an audio stream and corresponds
1230  * to enum AVAudioServiceType.
1231  */
1233 
1234  /**
1235  * This side data contains quality related information from the encoder.
1236  * @code
1237  * u32le quality factor of the compressed frame. Allowed range is between 1 (good) and FF_LAMBDA_MAX (bad).
1238  * u8 picture type
1239  * u8 error count
1240  * u16 reserved
1241  * u64le[error count] sum of squared differences between encoder in and output
1242  * @endcode
1243  */
1245 
1246  /**
1247  * This side data contains an integer value representing the stream index
1248  * of a "fallback" track. A fallback track indicates an alternate
1249  * track to use when the current track can not be decoded for some reason.
1250  * e.g. no decoder available for codec.
1251  */
1253 
1254  /**
1255  * This side data corresponds to the AVCPBProperties struct.
1256  */
1258 
1259  /**
1260  * Recommmends skipping the specified number of samples
1261  * @code
1262  * u32le number of samples to skip from start of this packet
1263  * u32le number of samples to skip from end of this packet
1264  * u8 reason for start skip
1265  * u8 reason for end skip (0=padding silence, 1=convergence)
1266  * @endcode
1267  */
1269 
1270  /**
1271  * An AV_PKT_DATA_JP_DUALMONO side data packet indicates that
1272  * the packet may contain "dual mono" audio specific to Japanese DTV
1273  * and if it is true, recommends only the selected channel to be used.
1274  * @code
1275  * u8 selected channels (0=mail/left, 1=sub/right, 2=both)
1276  * @endcode
1277  */
1279 
1280  /**
1281  * A list of zero terminated key/value strings. There is no end marker for
1282  * the list, so it is required to rely on the side data size to stop.
1283  */
1285 
1286  /**
1287  * Subtitle event position
1288  * @code
1289  * u32le x1
1290  * u32le y1
1291  * u32le x2
1292  * u32le y2
1293  * @endcode
1294  */
1296 
1297  /**
1298  * Data found in BlockAdditional element of matroska container. There is
1299  * no end marker for the data, so it is required to rely on the side data
1300  * size to recognize the end. 8 byte id (as found in BlockAddId) followed
1301  * by data.
1302  */
1304 
1305  /**
1306  * The optional first identifier line of a WebVTT cue.
1307  */
1309 
1310  /**
1311  * The optional settings (rendering instructions) that immediately
1312  * follow the timestamp specifier of a WebVTT cue.
1313  */
1315 
1316  /**
1317  * A list of zero terminated key/value strings. There is no end marker for
1318  * the list, so it is required to rely on the side data size to stop. This
1319  * side data includes updated metadata which appeared in the stream.
1320  */
1322 
1323  /**
1324  * MPEGTS stream ID, this is required to pass the stream ID
1325  * information from the demuxer to the corresponding muxer.
1326  */
1328 
1329  /**
1330  * Mastering display metadata (based on SMPTE-2086:2014). This metadata
1331  * should be associated with a video stream and contains data in the form
1332  * of the AVMasteringDisplayMetadata struct.
1333  */
1335 
1336  /**
1337  * This side data should be associated with a video stream and corresponds
1338  * to the AVSphericalMapping structure.
1339  */
1341 
1342  /**
1343  * Content light level (based on CTA-861.3). This metadata should be
1344  * associated with a video stream and contains data in the form of the
1345  * AVContentLightMetadata struct.
1346  */
1348 
1349  /**
1350  * ATSC A53 Part 4 Closed Captions. This metadata should be associated with
1351  * a video stream. A53 CC bitstream is stored as uint8_t in AVPacketSideData.data.
1352  * The number of bytes of CC data is AVPacketSideData.size.
1353  */
1355 
1356  /**
1357  * This side data is encryption initialization data.
1358  * The format is not part of ABI, use av_encryption_init_info_* methods to
1359  * access.
1360  */
1362 
1363  /**
1364  * This side data contains encryption info for how to decrypt the packet.
1365  * The format is not part of ABI, use av_encryption_info_* methods to access.
1366  */
1368 
1369  /**
1370  * Active Format Description data consisting of a single byte as specified
1371  * in ETSI TS 101 154 using AVActiveFormatDescription enum.
1372  */
1374 
1375  /**
1376  * The number of side data types.
1377  * This is not part of the public API/ABI in the sense that it may
1378  * change when new side data types are added.
1379  * This must stay the last enum value.
1380  * If its value becomes huge, some code using it
1381  * needs to be updated as it assumes it to be smaller than other limits.
1382  */
1384 };
1385 
1386 #define AV_PKT_DATA_QUALITY_FACTOR AV_PKT_DATA_QUALITY_STATS //DEPRECATED
1387 
1388 typedef struct AVPacketSideData {
1390  int size;
1393 
1394 /**
1395  * This structure stores compressed data. It is typically exported by demuxers
1396  * and then passed as input to decoders, or received as output from encoders and
1397  * then passed to muxers.
1398  *
1399  * For video, it should typically contain one compressed frame. For audio it may
1400  * contain several compressed frames. Encoders are allowed to output empty
1401  * packets, with no compressed data, containing only side data
1402  * (e.g. to update some stream parameters at the end of encoding).
1403  *
1404  * AVPacket is one of the few structs in FFmpeg, whose size is a part of public
1405  * ABI. Thus it may be allocated on stack and no new fields can be added to it
1406  * without libavcodec and libavformat major bump.
1407  *
1408  * The semantics of data ownership depends on the buf field.
1409  * If it is set, the packet data is dynamically allocated and is
1410  * valid indefinitely until a call to av_packet_unref() reduces the
1411  * reference count to 0.
1412  *
1413  * If the buf field is not set av_packet_ref() would make a copy instead
1414  * of increasing the reference count.
1415  *
1416  * The side data is always allocated with av_malloc(), copied by
1417  * av_packet_ref() and freed by av_packet_unref().
1418  *
1419  * @see av_packet_ref
1420  * @see av_packet_unref
1421  */
1422 typedef struct AVPacket {
1423  /**
1424  * A reference to the reference-counted buffer where the packet data is
1425  * stored.
1426  * May be NULL, then the packet data is not reference-counted.
1427  */
1429  /**
1430  * Presentation timestamp in AVStream->time_base units; the time at which
1431  * the decompressed packet will be presented to the user.
1432  * Can be AV_NOPTS_VALUE if it is not stored in the file.
1433  * pts MUST be larger or equal to dts as presentation cannot happen before
1434  * decompression, unless one wants to view hex dumps. Some formats misuse
1435  * the terms dts and pts/cts to mean something different. Such timestamps
1436  * must be converted to true pts/dts before they are stored in AVPacket.
1437  */
1438  int64_t pts;
1439  /**
1440  * Decompression timestamp in AVStream->time_base units; the time at which
1441  * the packet is decompressed.
1442  * Can be AV_NOPTS_VALUE if it is not stored in the file.
1443  */
1444  int64_t dts;
1446  int size;
1448  /**
1449  * A combination of AV_PKT_FLAG values
1450  */
1451  int flags;
1452  /**
1453  * Additional packet data that can be provided by the container.
1454  * Packet can contain several types of side information.
1455  */
1458 
1459  /**
1460  * Duration of this packet in AVStream->time_base units, 0 if unknown.
1461  * Equals next_pts - this_pts in presentation order.
1462  */
1463  int64_t duration;
1464 
1465  int64_t pos; ///< byte position in stream, -1 if unknown
1466 
1467 #if FF_API_CONVERGENCE_DURATION
1468  /**
1469  * @deprecated Same as the duration field, but as int64_t. This was required
1470  * for Matroska subtitles, whose duration values could overflow when the
1471  * duration field was still an int.
1472  */
1475 #endif
1476 } AVPacket;
1477 #define AV_PKT_FLAG_KEY 0x0001 ///< The packet contains a keyframe
1478 #define AV_PKT_FLAG_CORRUPT 0x0002 ///< The packet content is corrupted
1479 /**
1480  * Flag is used to discard packets which are required to maintain valid
1481  * decoder state but are not required for output and should be dropped
1482  * after decoding.
1483  **/
1484 #define AV_PKT_FLAG_DISCARD 0x0004
1485 /**
1486  * The packet comes from a trusted source.
1487  *
1488  * Otherwise-unsafe constructs such as arbitrary pointers to data
1489  * outside the packet may be followed.
1490  */
1491 #define AV_PKT_FLAG_TRUSTED 0x0008
1492 /**
1493  * Flag is used to indicate packets that contain frames that can
1494  * be discarded by the decoder. I.e. Non-reference frames.
1495  */
1496 #define AV_PKT_FLAG_DISPOSABLE 0x0010
1497 
1498 
1504 };
1505 /**
1506  * @}
1507  */
1508 
1509 struct AVCodecInternal;
1510 
1514  AV_FIELD_TT, //< Top coded_first, top displayed first
1515  AV_FIELD_BB, //< Bottom coded first, bottom displayed first
1516  AV_FIELD_TB, //< Top coded first, bottom displayed first
1517  AV_FIELD_BT, //< Bottom coded first, top displayed first
1518 };
1519 
1520 /**
1521  * main external API structure.
1522  * New fields can be added to the end with minor version bumps.
1523  * Removal, reordering and changes to existing fields require a major
1524  * version bump.
1525  * You can use AVOptions (av_opt* / av_set/get*()) to access these fields from user
1526  * applications.
1527  * The name string for AVOptions options matches the associated command line
1528  * parameter name and can be found in libavcodec/options_table.h
1529  * The AVOption/command line parameter names differ in some cases from the C
1530  * structure field names for historic reasons or brevity.
1531  * sizeof(AVCodecContext) must not be used outside libav*.
1532  */
1533 typedef struct AVCodecContext {
1534  /**
1535  * information on struct for av_log
1536  * - set by avcodec_alloc_context3
1537  */
1540 
1541  enum AVMediaType codec_type; /* see AVMEDIA_TYPE_xxx */
1542  const struct AVCodec *codec;
1543  enum AVCodecID codec_id; /* see AV_CODEC_ID_xxx */
1544 
1545  /**
1546  * fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
1547  * This is used to work around some encoder bugs.
1548  * A demuxer should set this to what is stored in the field used to identify the codec.
1549  * If there are multiple such fields in a container then the demuxer should choose the one
1550  * which maximizes the information about the used codec.
1551  * If the codec tag field in a container is larger than 32 bits then the demuxer should
1552  * remap the longer ID to 32 bits with a table or other structure. Alternatively a new
1553  * extra_codec_tag + size could be added but for this a clear advantage must be demonstrated
1554  * first.
1555  * - encoding: Set by user, if not then the default based on codec_id will be used.
1556  * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
1557  */
1558  unsigned int codec_tag;
1559 
1560  void *priv_data;
1561 
1562  /**
1563  * Private context used for internal data.
1564  *
1565  * Unlike priv_data, this is not codec-specific. It is used in general
1566  * libavcodec functions.
1567  */
1568  struct AVCodecInternal *internal;
1569 
1570  /**
1571  * Private data of the user, can be used to carry app specific stuff.
1572  * - encoding: Set by user.
1573  * - decoding: Set by user.
1574  */
1575  void *opaque;
1576 
1577  /**
1578  * the average bitrate
1579  * - encoding: Set by user; unused for constant quantizer encoding.
1580  * - decoding: Set by user, may be overwritten by libavcodec
1581  * if this info is available in the stream
1582  */
1583  int64_t bit_rate;
1584 
1585  /**
1586  * number of bits the bitstream is allowed to diverge from the reference.
1587  * the reference can be CBR (for CBR pass1) or VBR (for pass2)
1588  * - encoding: Set by user; unused for constant quantizer encoding.
1589  * - decoding: unused
1590  */
1592 
1593  /**
1594  * Global quality for codecs which cannot change it per frame.
1595  * This should be proportional to MPEG-1/2/4 qscale.
1596  * - encoding: Set by user.
1597  * - decoding: unused
1598  */
1600 
1601  /**
1602  * - encoding: Set by user.
1603  * - decoding: unused
1604  */
1606 #define FF_COMPRESSION_DEFAULT -1
1607 
1608  /**
1609  * AV_CODEC_FLAG_*.
1610  * - encoding: Set by user.
1611  * - decoding: Set by user.
1612  */
1613  int flags;
1614 
1615  /**
1616  * AV_CODEC_FLAG2_*
1617  * - encoding: Set by user.
1618  * - decoding: Set by user.
1619  */
1620  int flags2;
1621 
1622  /**
1623  * some codecs need / can use extradata like Huffman tables.
1624  * MJPEG: Huffman tables
1625  * rv10: additional flags
1626  * MPEG-4: global headers (they can be in the bitstream or here)
1627  * The allocated memory should be AV_INPUT_BUFFER_PADDING_SIZE bytes larger
1628  * than extradata_size to avoid problems if it is read with the bitstream reader.
1629  * The bytewise contents of extradata must not depend on the architecture or CPU endianness.
1630  * Must be allocated with the av_malloc() family of functions.
1631  * - encoding: Set/allocated/freed by libavcodec.
1632  * - decoding: Set/allocated/freed by user.
1633  */
1636 
1637  /**
1638  * This is the fundamental unit of time (in seconds) in terms
1639  * of which frame timestamps are represented. For fixed-fps content,
1640  * timebase should be 1/framerate and timestamp increments should be
1641  * identically 1.
1642  * This often, but not always is the inverse of the frame rate or field rate
1643  * for video. 1/time_base is not the average frame rate if the frame rate is not
1644  * constant.
1645  *
1646  * Like containers, elementary streams also can store timestamps, 1/time_base
1647  * is the unit in which these timestamps are specified.
1648  * As example of such codec time base see ISO/IEC 14496-2:2001(E)
1649  * vop_time_increment_resolution and fixed_vop_rate
1650  * (fixed_vop_rate == 0 implies that it is different from the framerate)
1651  *
1652  * - encoding: MUST be set by user.
1653  * - decoding: the use of this field for decoding is deprecated.
1654  * Use framerate instead.
1655  */
1657 
1658  /**
1659  * For some codecs, the time base is closer to the field rate than the frame rate.
1660  * Most notably, H.264 and MPEG-2 specify time_base as half of frame duration
1661  * if no telecine is used ...
1662  *
1663  * Set to time_base ticks per frame. Default 1, e.g., H.264/MPEG-2 set it to 2.
1664  */
1666 
1667  /**
1668  * Codec delay.
1669  *
1670  * Encoding: Number of frames delay there will be from the encoder input to
1671  * the decoder output. (we assume the decoder matches the spec)
1672  * Decoding: Number of frames delay in addition to what a standard decoder
1673  * as specified in the spec would produce.
1674  *
1675  * Video:
1676  * Number of frames the decoded output will be delayed relative to the
1677  * encoded input.
1678  *
1679  * Audio:
1680  * For encoding, this field is unused (see initial_padding).
1681  *
1682  * For decoding, this is the number of samples the decoder needs to
1683  * output before the decoder's output is valid. When seeking, you should
1684  * start decoding this many samples prior to your desired seek point.
1685  *
1686  * - encoding: Set by libavcodec.
1687  * - decoding: Set by libavcodec.
1688  */
1689  int delay;
1690 
1691 
1692  /* video only */
1693  /**
1694  * picture width / height.
1695  *
1696  * @note Those fields may not match the values of the last
1697  * AVFrame output by avcodec_decode_video2 due frame
1698  * reordering.
1699  *
1700  * - encoding: MUST be set by user.
1701  * - decoding: May be set by the user before opening the decoder if known e.g.
1702  * from the container. Some decoders will require the dimensions
1703  * to be set by the caller. During decoding, the decoder may
1704  * overwrite those values as required while parsing the data.
1705  */
1707 
1708  /**
1709  * Bitstream width / height, may be different from width/height e.g. when
1710  * the decoded frame is cropped before being output or lowres is enabled.
1711  *
1712  * @note Those field may not match the value of the last
1713  * AVFrame output by avcodec_receive_frame() due frame
1714  * reordering.
1715  *
1716  * - encoding: unused
1717  * - decoding: May be set by the user before opening the decoder if known
1718  * e.g. from the container. During decoding, the decoder may
1719  * overwrite those values as required while parsing the data.
1720  */
1722 
1723  /**
1724  * the number of pictures in a group of pictures, or 0 for intra_only
1725  * - encoding: Set by user.
1726  * - decoding: unused
1727  */
1729 
1730  /**
1731  * Pixel format, see AV_PIX_FMT_xxx.
1732  * May be set by the demuxer if known from headers.
1733  * May be overridden by the decoder if it knows better.
1734  *
1735  * @note This field may not match the value of the last
1736  * AVFrame output by avcodec_receive_frame() due frame
1737  * reordering.
1738  *
1739  * - encoding: Set by user.
1740  * - decoding: Set by user if known, overridden by libavcodec while
1741  * parsing the data.
1742  */
1744 
1745  /**
1746  * If non NULL, 'draw_horiz_band' is called by the libavcodec
1747  * decoder to draw a horizontal band. It improves cache usage. Not
1748  * all codecs can do that. You must check the codec capabilities
1749  * beforehand.
1750  * When multithreading is used, it may be called from multiple threads
1751  * at the same time; threads might draw different parts of the same AVFrame,
1752  * or multiple AVFrames, and there is no guarantee that slices will be drawn
1753  * in order.
1754  * The function is also used by hardware acceleration APIs.
1755  * It is called at least once during frame decoding to pass
1756  * the data needed for hardware render.
1757  * In that mode instead of pixel data, AVFrame points to
1758  * a structure specific to the acceleration API. The application
1759  * reads the structure and can change some fields to indicate progress
1760  * or mark state.
1761  * - encoding: unused
1762  * - decoding: Set by user.
1763  * @param height the height of the slice
1764  * @param y the y position of the slice
1765  * @param type 1->top field, 2->bottom field, 3->frame
1766  * @param offset offset into the AVFrame.data from which the slice should be read
1767  */
1769  const AVFrame *src, int offset[AV_NUM_DATA_POINTERS],
1770  int y, int type, int height);
1771 
1772  /**
1773  * callback to negotiate the pixelFormat
1774  * @param fmt is the list of formats which are supported by the codec,
1775  * it is terminated by -1 as 0 is a valid format, the formats are ordered by quality.
1776  * The first is always the native one.
1777  * @note The callback may be called again immediately if initialization for
1778  * the selected (hardware-accelerated) pixel format failed.
1779  * @warning Behavior is undefined if the callback returns a value not
1780  * in the fmt list of formats.
1781  * @return the chosen format
1782  * - encoding: unused
1783  * - decoding: Set by user, if not set the native format will be chosen.
1784  */
1785  enum AVPixelFormat (*get_format)(struct AVCodecContext *s, const enum AVPixelFormat * fmt);
1786 
1787  /**
1788  * maximum number of B-frames between non-B-frames
1789  * Note: The output will be delayed by max_b_frames+1 relative to the input.
1790  * - encoding: Set by user.
1791  * - decoding: unused
1792  */
1794 
1795  /**
1796  * qscale factor between IP and B-frames
1797  * If > 0 then the last P-frame quantizer will be used (q= lastp_q*factor+offset).
1798  * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1799  * - encoding: Set by user.
1800  * - decoding: unused
1801  */
1803 
1804 #if FF_API_PRIVATE_OPT
1805  /** @deprecated use encoder private options instead */
1808 #endif
1809 
1810  /**
1811  * qscale offset between IP and B-frames
1812  * - encoding: Set by user.
1813  * - decoding: unused
1814  */
1816 
1817  /**
1818  * Size of the frame reordering buffer in the decoder.
1819  * For MPEG-2 it is 1 IPB or 0 low delay IP.
1820  * - encoding: Set by libavcodec.
1821  * - decoding: Set by libavcodec.
1822  */
1824 
1825 #if FF_API_PRIVATE_OPT
1826  /** @deprecated use encoder private options instead */
1829 #endif
1830 
1831  /**
1832  * qscale factor between P- and I-frames
1833  * If > 0 then the last P-frame quantizer will be used (q = lastp_q * factor + offset).
1834  * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1835  * - encoding: Set by user.
1836  * - decoding: unused
1837  */
1839 
1840  /**
1841  * qscale offset between P and I-frames
1842  * - encoding: Set by user.
1843  * - decoding: unused
1844  */
1846 
1847  /**
1848  * luminance masking (0-> disabled)
1849  * - encoding: Set by user.
1850  * - decoding: unused
1851  */
1853 
1854  /**
1855  * temporary complexity masking (0-> disabled)
1856  * - encoding: Set by user.
1857  * - decoding: unused
1858  */
1860 
1861  /**
1862  * spatial complexity masking (0-> disabled)
1863  * - encoding: Set by user.
1864  * - decoding: unused
1865  */
1867 
1868  /**
1869  * p block masking (0-> disabled)
1870  * - encoding: Set by user.
1871  * - decoding: unused
1872  */
1873  float p_masking;
1874 
1875  /**
1876  * darkness masking (0-> disabled)
1877  * - encoding: Set by user.
1878  * - decoding: unused
1879  */
1881 
1882  /**
1883  * slice count
1884  * - encoding: Set by libavcodec.
1885  * - decoding: Set by user (or 0).
1886  */
1888 
1889 #if FF_API_PRIVATE_OPT
1890  /** @deprecated use encoder private options instead */
1893 #define FF_PRED_LEFT 0
1894 #define FF_PRED_PLANE 1
1895 #define FF_PRED_MEDIAN 2
1896 #endif
1897 
1898  /**
1899  * slice offsets in the frame in bytes
1900  * - encoding: Set/allocated by libavcodec.
1901  * - decoding: Set/allocated by user (or NULL).
1902  */
1904 
1905  /**
1906  * sample aspect ratio (0 if unknown)
1907  * That is the width of a pixel divided by the height of the pixel.
1908  * Numerator and denominator must be relatively prime and smaller than 256 for some video standards.
1909  * - encoding: Set by user.
1910  * - decoding: Set by libavcodec.
1911  */
1913 
1914  /**
1915  * motion estimation comparison function
1916  * - encoding: Set by user.
1917  * - decoding: unused
1918  */
1919  int me_cmp;
1920  /**
1921  * subpixel motion estimation comparison function
1922  * - encoding: Set by user.
1923  * - decoding: unused
1924  */
1926  /**
1927  * macroblock comparison function (not supported yet)
1928  * - encoding: Set by user.
1929  * - decoding: unused
1930  */
1931  int mb_cmp;
1932  /**
1933  * interlaced DCT comparison function
1934  * - encoding: Set by user.
1935  * - decoding: unused
1936  */
1938 #define FF_CMP_SAD 0
1939 #define FF_CMP_SSE 1
1940 #define FF_CMP_SATD 2
1941 #define FF_CMP_DCT 3
1942 #define FF_CMP_PSNR 4
1943 #define FF_CMP_BIT 5
1944 #define FF_CMP_RD 6
1945 #define FF_CMP_ZERO 7
1946 #define FF_CMP_VSAD 8
1947 #define FF_CMP_VSSE 9
1948 #define FF_CMP_NSSE 10
1949 #define FF_CMP_W53 11
1950 #define FF_CMP_W97 12
1951 #define FF_CMP_DCTMAX 13
1952 #define FF_CMP_DCT264 14
1953 #define FF_CMP_MEDIAN_SAD 15
1954 #define FF_CMP_CHROMA 256
1955 
1956  /**
1957  * ME diamond size & shape
1958  * - encoding: Set by user.
1959  * - decoding: unused
1960  */
1962 
1963  /**
1964  * amount of previous MV predictors (2a+1 x 2a+1 square)
1965  * - encoding: Set by user.
1966  * - decoding: unused
1967  */
1969 
1970 #if FF_API_PRIVATE_OPT
1971  /** @deprecated use encoder private options instead */
1973  int pre_me;
1974 #endif
1975 
1976  /**
1977  * motion estimation prepass comparison function
1978  * - encoding: Set by user.
1979  * - decoding: unused
1980  */
1982 
1983  /**
1984  * ME prepass diamond size & shape
1985  * - encoding: Set by user.
1986  * - decoding: unused
1987  */
1989 
1990  /**
1991  * subpel ME quality
1992  * - encoding: Set by user.
1993  * - decoding: unused
1994  */
1996 
1997  /**
1998  * maximum motion estimation search range in subpel units
1999  * If 0 then no limit.
2000  *
2001  * - encoding: Set by user.
2002  * - decoding: unused
2003  */
2005 
2006  /**
2007  * slice flags
2008  * - encoding: unused
2009  * - decoding: Set by user.
2010  */
2012 #define SLICE_FLAG_CODED_ORDER 0x0001 ///< draw_horiz_band() is called in coded order instead of display
2013 #define SLICE_FLAG_ALLOW_FIELD 0x0002 ///< allow draw_horiz_band() with field slices (MPEG-2 field pics)
2014 #define SLICE_FLAG_ALLOW_PLANE 0x0004 ///< allow draw_horiz_band() with 1 component at a time (SVQ1)
2015 
2016  /**
2017  * macroblock decision mode
2018  * - encoding: Set by user.
2019  * - decoding: unused
2020  */
2022 #define FF_MB_DECISION_SIMPLE 0 ///< uses mb_cmp
2023 #define FF_MB_DECISION_BITS 1 ///< chooses the one which needs the fewest bits
2024 #define FF_MB_DECISION_RD 2 ///< rate distortion
2025 
2026  /**
2027  * custom intra quantization matrix
2028  * - encoding: Set by user, can be NULL.
2029  * - decoding: Set by libavcodec.
2030  */
2031  uint16_t *intra_matrix;
2032 
2033  /**
2034  * custom inter quantization matrix
2035  * - encoding: Set by user, can be NULL.
2036  * - decoding: Set by libavcodec.
2037  */
2038  uint16_t *inter_matrix;
2039 
2040 #if FF_API_PRIVATE_OPT
2041  /** @deprecated use encoder private options instead */
2044 
2045  /** @deprecated use encoder private options instead */
2048 #endif
2049 
2050  /**
2051  * precision of the intra DC coefficient - 8
2052  * - encoding: Set by user.
2053  * - decoding: Set by libavcodec
2054  */
2056 
2057  /**
2058  * Number of macroblock rows at the top which are skipped.
2059  * - encoding: unused
2060  * - decoding: Set by user.
2061  */
2063 
2064  /**
2065  * Number of macroblock rows at the bottom which are skipped.
2066  * - encoding: unused
2067  * - decoding: Set by user.
2068  */
2070 
2071  /**
2072  * minimum MB Lagrange multiplier
2073  * - encoding: Set by user.
2074  * - decoding: unused
2075  */
2076  int mb_lmin;
2077 
2078  /**
2079  * maximum MB Lagrange multiplier
2080  * - encoding: Set by user.
2081  * - decoding: unused
2082  */
2083  int mb_lmax;
2084 
2085 #if FF_API_PRIVATE_OPT
2086  /**
2087  * @deprecated use encoder private options instead
2088  */
2091 #endif
2092 
2093  /**
2094  * - encoding: Set by user.
2095  * - decoding: unused
2096  */
2098 
2099 #if FF_API_PRIVATE_OPT
2100  /** @deprecated use encoder private options instead */
2103 #endif
2104 
2105  /**
2106  * minimum GOP size
2107  * - encoding: Set by user.
2108  * - decoding: unused
2109  */
2111 
2112  /**
2113  * number of reference frames
2114  * - encoding: Set by user.
2115  * - decoding: Set by lavc.
2116  */
2117  int refs;
2118 
2119 #if FF_API_PRIVATE_OPT
2120  /** @deprecated use encoder private options instead */
2123 #endif
2124 
2125  /**
2126  * Note: Value depends upon the compare function used for fullpel ME.
2127  * - encoding: Set by user.
2128  * - decoding: unused
2129  */
2131 
2132 #if FF_API_PRIVATE_OPT
2133  /** @deprecated use encoder private options instead */
2136 #endif
2137 
2138  /**
2139  * Chromaticity coordinates of the source primaries.
2140  * - encoding: Set by user
2141  * - decoding: Set by libavcodec
2142  */
2144 
2145  /**
2146  * Color Transfer Characteristic.
2147  * - encoding: Set by user
2148  * - decoding: Set by libavcodec
2149  */
2151 
2152  /**
2153  * YUV colorspace type.
2154  * - encoding: Set by user
2155  * - decoding: Set by libavcodec
2156  */
2158 
2159  /**
2160  * MPEG vs JPEG YUV range.
2161  * - encoding: Set by user
2162  * - decoding: Set by libavcodec
2163  */
2165 
2166  /**
2167  * This defines the location of chroma samples.
2168  * - encoding: Set by user
2169  * - decoding: Set by libavcodec
2170  */
2172 
2173  /**
2174  * Number of slices.
2175  * Indicates number of picture subdivisions. Used for parallelized
2176  * decoding.
2177  * - encoding: Set by user
2178  * - decoding: unused
2179  */
2180  int slices;
2181 
2182  /** Field order
2183  * - encoding: set by libavcodec
2184  * - decoding: Set by user.
2185  */
2187 
2188  /* audio only */
2189  int sample_rate; ///< samples per second
2190  int channels; ///< number of audio channels
2191 
2192  /**
2193  * audio sample format
2194  * - encoding: Set by user.
2195  * - decoding: Set by libavcodec.
2196  */
2197  enum AVSampleFormat sample_fmt; ///< sample format
2198 
2199  /* The following data should not be initialized. */
2200  /**
2201  * Number of samples per channel in an audio frame.
2202  *
2203  * - encoding: set by libavcodec in avcodec_open2(). Each submitted frame
2204  * except the last must contain exactly frame_size samples per channel.
2205  * May be 0 when the codec has AV_CODEC_CAP_VARIABLE_FRAME_SIZE set, then the
2206  * frame size is not restricted.
2207  * - decoding: may be set by some decoders to indicate constant frame size
2208  */
2210 
2211  /**
2212  * Frame counter, set by libavcodec.
2213  *
2214  * - decoding: total number of frames returned from the decoder so far.
2215  * - encoding: total number of frames passed to the encoder so far.
2216  *
2217  * @note the counter is not incremented if encoding/decoding resulted in
2218  * an error.
2219  */
2221 
2222  /**
2223  * number of bytes per packet if constant and known or 0
2224  * Used by some WAV based audio codecs.
2225  */
2227 
2228  /**
2229  * Audio cutoff bandwidth (0 means "automatic")
2230  * - encoding: Set by user.
2231  * - decoding: unused
2232  */
2233  int cutoff;
2234 
2235  /**
2236  * Audio channel layout.
2237  * - encoding: set by user.
2238  * - decoding: set by user, may be overwritten by libavcodec.
2239  */
2240  uint64_t channel_layout;
2241 
2242  /**
2243  * Request decoder to use this channel layout if it can (0 for default)
2244  * - encoding: unused
2245  * - decoding: Set by user.
2246  */
2248 
2249  /**
2250  * Type of service that the audio stream conveys.
2251  * - encoding: Set by user.
2252  * - decoding: Set by libavcodec.
2253  */
2255 
2256  /**
2257  * desired sample format
2258  * - encoding: Not used.
2259  * - decoding: Set by user.
2260  * Decoder will decode to this format if it can.
2261  */
2263 
2264  /**
2265  * This callback is called at the beginning of each frame to get data
2266  * buffer(s) for it. There may be one contiguous buffer for all the data or
2267  * there may be a buffer per each data plane or anything in between. What
2268  * this means is, you may set however many entries in buf[] you feel necessary.
2269  * Each buffer must be reference-counted using the AVBuffer API (see description
2270  * of buf[] below).
2271  *
2272  * The following fields will be set in the frame before this callback is
2273  * called:
2274  * - format
2275  * - width, height (video only)
2276  * - sample_rate, channel_layout, nb_samples (audio only)
2277  * Their values may differ from the corresponding values in
2278  * AVCodecContext. This callback must use the frame values, not the codec
2279  * context values, to calculate the required buffer size.
2280  *
2281  * This callback must fill the following fields in the frame:
2282  * - data[]
2283  * - linesize[]
2284  * - extended_data:
2285  * * if the data is planar audio with more than 8 channels, then this
2286  * callback must allocate and fill extended_data to contain all pointers
2287  * to all data planes. data[] must hold as many pointers as it can.
2288  * extended_data must be allocated with av_malloc() and will be freed in
2289  * av_frame_unref().
2290  * * otherwise extended_data must point to data
2291  * - buf[] must contain one or more pointers to AVBufferRef structures. Each of
2292  * the frame's data and extended_data pointers must be contained in these. That
2293  * is, one AVBufferRef for each allocated chunk of memory, not necessarily one
2294  * AVBufferRef per data[] entry. See: av_buffer_create(), av_buffer_alloc(),
2295  * and av_buffer_ref().
2296  * - extended_buf and nb_extended_buf must be allocated with av_malloc() by
2297  * this callback and filled with the extra buffers if there are more
2298  * buffers than buf[] can hold. extended_buf will be freed in
2299  * av_frame_unref().
2300  *
2301  * If AV_CODEC_CAP_DR1 is not set then get_buffer2() must call
2302  * avcodec_default_get_buffer2() instead of providing buffers allocated by
2303  * some other means.
2304  *
2305  * Each data plane must be aligned to the maximum required by the target
2306  * CPU.
2307  *
2308  * @see avcodec_default_get_buffer2()
2309  *
2310  * Video:
2311  *
2312  * If AV_GET_BUFFER_FLAG_REF is set in flags then the frame may be reused
2313  * (read and/or written to if it is writable) later by libavcodec.
2314  *
2315  * avcodec_align_dimensions2() should be used to find the required width and
2316  * height, as they normally need to be rounded up to the next multiple of 16.
2317  *
2318  * Some decoders do not support linesizes changing between frames.
2319  *
2320  * If frame multithreading is used and thread_safe_callbacks is set,
2321  * this callback may be called from a different thread, but not from more
2322  * than one at once. Does not need to be reentrant.
2323  *
2324  * @see avcodec_align_dimensions2()
2325  *
2326  * Audio:
2327  *
2328  * Decoders request a buffer of a particular size by setting
2329  * AVFrame.nb_samples prior to calling get_buffer2(). The decoder may,
2330  * however, utilize only part of the buffer by setting AVFrame.nb_samples
2331  * to a smaller value in the output frame.
2332  *
2333  * As a convenience, av_samples_get_buffer_size() and
2334  * av_samples_fill_arrays() in libavutil may be used by custom get_buffer2()
2335  * functions to find the required data size and to fill data pointers and
2336  * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
2337  * since all planes must be the same size.
2338  *
2339  * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
2340  *
2341  * - encoding: unused
2342  * - decoding: Set by libavcodec, user can override.
2343  */
2345 
2346  /**
2347  * If non-zero, the decoded audio and video frames returned from
2348  * avcodec_decode_video2() and avcodec_decode_audio4() are reference-counted
2349  * and are valid indefinitely. The caller must free them with
2350  * av_frame_unref() when they are not needed anymore.
2351  * Otherwise, the decoded frames must not be freed by the caller and are
2352  * only valid until the next decode call.
2353  *
2354  * This is always automatically enabled if avcodec_receive_frame() is used.
2355  *
2356  * - encoding: unused
2357  * - decoding: set by the caller before avcodec_open2().
2358  */
2361 
2362  /* - encoding parameters */
2363  float qcompress; ///< amount of qscale change between easy & hard scenes (0.0-1.0)
2364  float qblur; ///< amount of qscale smoothing over time (0.0-1.0)
2365 
2366  /**
2367  * minimum quantizer
2368  * - encoding: Set by user.
2369  * - decoding: unused
2370  */
2371  int qmin;
2372 
2373  /**
2374  * maximum quantizer
2375  * - encoding: Set by user.
2376  * - decoding: unused
2377  */
2378  int qmax;
2379 
2380  /**
2381  * maximum quantizer difference between frames
2382  * - encoding: Set by user.
2383  * - decoding: unused
2384  */
2386 
2387  /**
2388  * decoder bitstream buffer size
2389  * - encoding: Set by user.
2390  * - decoding: unused
2391  */
2393 
2394  /**
2395  * ratecontrol override, see RcOverride
2396  * - encoding: Allocated/set/freed by user.
2397  * - decoding: unused
2398  */
2401 
2402  /**
2403  * maximum bitrate
2404  * - encoding: Set by user.
2405  * - decoding: Set by user, may be overwritten by libavcodec.
2406  */
2407  int64_t rc_max_rate;
2408 
2409  /**
2410  * minimum bitrate
2411  * - encoding: Set by user.
2412  * - decoding: unused
2413  */
2414  int64_t rc_min_rate;
2415 
2416  /**
2417  * Ratecontrol attempt to use, at maximum, <value> of what can be used without an underflow.
2418  * - encoding: Set by user.
2419  * - decoding: unused.
2420  */
2422 
2423  /**
2424  * Ratecontrol attempt to use, at least, <value> times the amount needed to prevent a vbv overflow.
2425  * - encoding: Set by user.
2426  * - decoding: unused.
2427  */
2429 
2430  /**
2431  * Number of bits which should be loaded into the rc buffer before decoding starts.
2432  * - encoding: Set by user.
2433  * - decoding: unused
2434  */
2436 
2437 #if FF_API_CODER_TYPE
2438 #define FF_CODER_TYPE_VLC 0
2439 #define FF_CODER_TYPE_AC 1
2440 #define FF_CODER_TYPE_RAW 2
2441 #define FF_CODER_TYPE_RLE 3
2442  /**
2443  * @deprecated use encoder private options instead
2444  */
2447 #endif /* FF_API_CODER_TYPE */
2448 
2449 #if FF_API_PRIVATE_OPT
2450  /** @deprecated use encoder private options instead */
2453 #endif
2454 
2455 #if FF_API_PRIVATE_OPT
2456  /** @deprecated use encoder private options instead */
2459 
2460  /** @deprecated use encoder private options instead */
2463 
2464  /** @deprecated use encoder private options instead */
2467 
2468  /** @deprecated use encoder private options instead */
2471 #endif /* FF_API_PRIVATE_OPT */
2472 
2473  /**
2474  * trellis RD quantization
2475  * - encoding: Set by user.
2476  * - decoding: unused
2477  */
2478  int trellis;
2479 
2480 #if FF_API_PRIVATE_OPT
2481  /** @deprecated use encoder private options instead */
2484 
2485  /** @deprecated use encoder private options instead */
2488 
2489  /** @deprecated use encoder private options instead */
2492 #endif
2493 
2494 #if FF_API_RTP_CALLBACK
2495  /**
2496  * @deprecated unused
2497  */
2498  /* The RTP callback: This function is called */
2499  /* every time the encoder has a packet to send. */
2500  /* It depends on the encoder if the data starts */
2501  /* with a Start Code (it should). H.263 does. */
2502  /* mb_nb contains the number of macroblocks */
2503  /* encoded in the RTP payload. */
2505  void (*rtp_callback)(struct AVCodecContext *avctx, void *data, int size, int mb_nb);
2506 #endif
2507 
2508 #if FF_API_PRIVATE_OPT
2509  /** @deprecated use encoder private options instead */
2511  int rtp_payload_size; /* The size of the RTP payload: the coder will */
2512  /* do its best to deliver a chunk with size */
2513  /* below rtp_payload_size, the chunk will start */
2514  /* with a start code on some codecs like H.263. */
2515  /* This doesn't take account of any particular */
2516  /* headers inside the transmitted RTP payload. */
2517 #endif
2518 
2519 #if FF_API_STAT_BITS
2520  /* statistics, used for 2-pass encoding */
2522  int mv_bits;
2530  int i_count;
2532  int p_count;
2537 
2538  /** @deprecated this field is unused */
2541 #endif
2542 
2543  /**
2544  * pass1 encoding statistics output buffer
2545  * - encoding: Set by libavcodec.
2546  * - decoding: unused
2547  */
2548  char *stats_out;
2549 
2550  /**
2551  * pass2 encoding statistics input buffer
2552  * Concatenated stuff from stats_out of pass1 should be placed here.
2553  * - encoding: Allocated/set/freed by user.
2554  * - decoding: unused
2555  */
2556  char *stats_in;
2557 
2558  /**
2559  * Work around bugs in encoders which sometimes cannot be detected automatically.
2560  * - encoding: Set by user
2561  * - decoding: Set by user
2562  */
2564 #define FF_BUG_AUTODETECT 1 ///< autodetection
2565 #define FF_BUG_XVID_ILACE 4
2566 #define FF_BUG_UMP4 8
2567 #define FF_BUG_NO_PADDING 16
2568 #define FF_BUG_AMV 32
2569 #define FF_BUG_QPEL_CHROMA 64
2570 #define FF_BUG_STD_QPEL 128
2571 #define FF_BUG_QPEL_CHROMA2 256
2572 #define FF_BUG_DIRECT_BLOCKSIZE 512
2573 #define FF_BUG_EDGE 1024
2574 #define FF_BUG_HPEL_CHROMA 2048
2575 #define FF_BUG_DC_CLIP 4096
2576 #define FF_BUG_MS 8192 ///< Work around various bugs in Microsoft's broken decoders.
2577 #define FF_BUG_TRUNCATED 16384
2578 #define FF_BUG_IEDGE 32768
2579 
2580  /**
2581  * strictly follow the standard (MPEG-4, ...).
2582  * - encoding: Set by user.
2583  * - decoding: Set by user.
2584  * Setting this to STRICT or higher means the encoder and decoder will
2585  * generally do stupid things, whereas setting it to unofficial or lower
2586  * will mean the encoder might produce output that is not supported by all
2587  * spec-compliant decoders. Decoders don't differentiate between normal,
2588  * unofficial and experimental (that is, they always try to decode things
2589  * when they can) unless they are explicitly asked to behave stupidly
2590  * (=strictly conform to the specs)
2591  */
2593 #define FF_COMPLIANCE_VERY_STRICT 2 ///< Strictly conform to an older more strict version of the spec or reference software.
2594 #define FF_COMPLIANCE_STRICT 1 ///< Strictly conform to all the things in the spec no matter what consequences.
2595 #define FF_COMPLIANCE_NORMAL 0
2596 #define FF_COMPLIANCE_UNOFFICIAL -1 ///< Allow unofficial extensions
2597 #define FF_COMPLIANCE_EXPERIMENTAL -2 ///< Allow nonstandardized experimental things.
2598 
2599  /**
2600  * error concealment flags
2601  * - encoding: unused
2602  * - decoding: Set by user.
2603  */
2605 #define FF_EC_GUESS_MVS 1
2606 #define FF_EC_DEBLOCK 2
2607 #define FF_EC_FAVOR_INTER 256
2608 
2609  /**
2610  * debug
2611  * - encoding: Set by user.
2612  * - decoding: Set by user.
2613  */
2614  int debug;
2615 #define FF_DEBUG_PICT_INFO 1
2616 #define FF_DEBUG_RC 2
2617 #define FF_DEBUG_BITSTREAM 4
2618 #define FF_DEBUG_MB_TYPE 8
2619 #define FF_DEBUG_QP 16
2620 #if FF_API_DEBUG_MV
2621 /**
2622  * @deprecated this option does nothing
2623  */
2624 #define FF_DEBUG_MV 32
2625 #endif
2626 #define FF_DEBUG_DCT_COEFF 0x00000040
2627 #define FF_DEBUG_SKIP 0x00000080
2628 #define FF_DEBUG_STARTCODE 0x00000100
2629 #define FF_DEBUG_ER 0x00000400
2630 #define FF_DEBUG_MMCO 0x00000800
2631 #define FF_DEBUG_BUGS 0x00001000
2632 #if FF_API_DEBUG_MV
2633 #define FF_DEBUG_VIS_QP 0x00002000
2634 #define FF_DEBUG_VIS_MB_TYPE 0x00004000
2635 #endif
2636 #define FF_DEBUG_BUFFERS 0x00008000
2637 #define FF_DEBUG_THREADS 0x00010000
2638 #define FF_DEBUG_GREEN_MD 0x00800000
2639 #define FF_DEBUG_NOMC 0x01000000
2640 
2641 #if FF_API_DEBUG_MV
2642  /**
2643  * debug
2644  * - encoding: Set by user.
2645  * - decoding: Set by user.
2646  */
2647  int debug_mv;
2648 #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 // visualize forward predicted MVs of P-frames
2649 #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 // visualize forward predicted MVs of B-frames
2650 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 // visualize backward predicted MVs of B-frames
2651 #endif
2652 
2653  /**
2654  * Error recognition; may misdetect some more or less valid parts as errors.
2655  * - encoding: unused
2656  * - decoding: Set by user.
2657  */
2659 
2660 /**
2661  * Verify checksums embedded in the bitstream (could be of either encoded or
2662  * decoded data, depending on the codec) and print an error message on mismatch.
2663  * If AV_EF_EXPLODE is also set, a mismatching checksum will result in the
2664  * decoder returning an error.
2665  */
2666 #define AV_EF_CRCCHECK (1<<0)
2667 #define AV_EF_BITSTREAM (1<<1) ///< detect bitstream specification deviations
2668 #define AV_EF_BUFFER (1<<2) ///< detect improper bitstream length
2669 #define AV_EF_EXPLODE (1<<3) ///< abort decoding on minor error detection
2670 
2671 #define AV_EF_IGNORE_ERR (1<<15) ///< ignore errors and continue
2672 #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
2673 #define AV_EF_COMPLIANT (1<<17) ///< consider all spec non compliances as errors
2674 #define AV_EF_AGGRESSIVE (1<<18) ///< consider things that a sane encoder should not do as an error
2675 
2676 
2677  /**
2678  * opaque 64-bit number (generally a PTS) that will be reordered and
2679  * output in AVFrame.reordered_opaque
2680  * - encoding: unused
2681  * - decoding: Set by user.
2682  */
2684 
2685  /**
2686  * Hardware accelerator in use
2687  * - encoding: unused.
2688  * - decoding: Set by libavcodec
2689  */
2690  const struct AVHWAccel *hwaccel;
2691 
2692  /**
2693  * Hardware accelerator context.
2694  * For some hardware accelerators, a global context needs to be
2695  * provided by the user. In that case, this holds display-dependent
2696  * data FFmpeg cannot instantiate itself. Please refer to the
2697  * FFmpeg HW accelerator documentation to know how to fill this
2698  * is. e.g. for VA API, this is a struct vaapi_context.
2699  * - encoding: unused
2700  * - decoding: Set by user
2701  */
2703 
2704  /**
2705  * error
2706  * - encoding: Set by libavcodec if flags & AV_CODEC_FLAG_PSNR.
2707  * - decoding: unused
2708  */
2710 
2711  /**
2712  * DCT algorithm, see FF_DCT_* below
2713  * - encoding: Set by user.
2714  * - decoding: unused
2715  */
2717 #define FF_DCT_AUTO 0
2718 #define FF_DCT_FASTINT 1
2719 #define FF_DCT_INT 2
2720 #define FF_DCT_MMX 3
2721 #define FF_DCT_ALTIVEC 5
2722 #define FF_DCT_FAAN 6
2723 
2724  /**
2725  * IDCT algorithm, see FF_IDCT_* below.
2726  * - encoding: Set by user.
2727  * - decoding: Set by user.
2728  */
2730 #define FF_IDCT_AUTO 0
2731 #define FF_IDCT_INT 1
2732 #define FF_IDCT_SIMPLE 2
2733 #define FF_IDCT_SIMPLEMMX 3
2734 #define FF_IDCT_ARM 7
2735 #define FF_IDCT_ALTIVEC 8
2736 #define FF_IDCT_SIMPLEARM 10
2737 #define FF_IDCT_XVID 14
2738 #define FF_IDCT_SIMPLEARMV5TE 16
2739 #define FF_IDCT_SIMPLEARMV6 17
2740 #define FF_IDCT_FAAN 20
2741 #define FF_IDCT_SIMPLENEON 22
2742 #define FF_IDCT_NONE 24 /* Used by XvMC to extract IDCT coefficients with FF_IDCT_PERM_NONE */
2743 #define FF_IDCT_SIMPLEAUTO 128
2744 
2745  /**
2746  * bits per sample/pixel from the demuxer (needed for huffyuv).
2747  * - encoding: Set by libavcodec.
2748  * - decoding: Set by user.
2749  */
2751 
2752  /**
2753  * Bits per sample/pixel of internal libavcodec pixel/sample format.
2754  * - encoding: set by user.
2755  * - decoding: set by libavcodec.
2756  */
2758 
2759 #if FF_API_LOWRES
2760  /**
2761  * low resolution decoding, 1-> 1/2 size, 2->1/4 size
2762  * - encoding: unused
2763  * - decoding: Set by user.
2764  */
2765  int lowres;
2766 #endif
2767 
2768 #if FF_API_CODED_FRAME
2769  /**
2770  * the picture in the bitstream
2771  * - encoding: Set by libavcodec.
2772  * - decoding: unused
2773  *
2774  * @deprecated use the quality factor packet side data instead
2775  */
2777 #endif
2778 
2779  /**
2780  * thread count
2781  * is used to decide how many independent tasks should be passed to execute()
2782  * - encoding: Set by user.
2783  * - decoding: Set by user.
2784  */
2786 
2787  /**
2788  * Which multithreading methods to use.
2789  * Use of FF_THREAD_FRAME will increase decoding delay by one frame per thread,
2790  * so clients which cannot provide future frames should not use it.
2791  *
2792  * - encoding: Set by user, otherwise the default is used.
2793  * - decoding: Set by user, otherwise the default is used.
2794  */
2796 #define FF_THREAD_FRAME 1 ///< Decode more than one frame at once
2797 #define FF_THREAD_SLICE 2 ///< Decode more than one part of a single frame at once
2798 
2799  /**
2800  * Which multithreading methods are in use by the codec.
2801  * - encoding: Set by libavcodec.
2802  * - decoding: Set by libavcodec.
2803  */
2805 
2806  /**
2807  * Set by the client if its custom get_buffer() callback can be called
2808  * synchronously from another thread, which allows faster multithreaded decoding.
2809  * draw_horiz_band() will be called from other threads regardless of this setting.
2810  * Ignored if the default get_buffer() is used.
2811  * - encoding: Set by user.
2812  * - decoding: Set by user.
2813  */
2815 
2816  /**
2817  * The codec may call this to execute several independent things.
2818  * It will return only after finishing all tasks.
2819  * The user may replace this with some multithreaded implementation,
2820  * the default implementation will execute the parts serially.
2821  * @param count the number of things to execute
2822  * - encoding: Set by libavcodec, user can override.
2823  * - decoding: Set by libavcodec, user can override.
2824  */
2825  int (*execute)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size);
2826 
2827  /**
2828  * The codec may call this to execute several independent things.
2829  * It will return only after finishing all tasks.
2830  * The user may replace this with some multithreaded implementation,
2831  * the default implementation will execute the parts serially.
2832  * Also see avcodec_thread_init and e.g. the --enable-pthread configure option.
2833  * @param c context passed also to func
2834  * @param count the number of things to execute
2835  * @param arg2 argument passed unchanged to func
2836  * @param ret return values of executed functions, must have space for "count" values. May be NULL.
2837  * @param func function that will be called count times, with jobnr from 0 to count-1.
2838  * threadnr will be in the range 0 to c->thread_count-1 < MAX_THREADS and so that no
2839  * two instances of func executing at the same time will have the same threadnr.
2840  * @return always 0 currently, but code should handle a future improvement where when any call to func
2841  * returns < 0 no further calls to func may be done and < 0 is returned.
2842  * - encoding: Set by libavcodec, user can override.
2843  * - decoding: Set by libavcodec, user can override.
2844  */
2845  int (*execute2)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count);
2846 
2847  /**
2848  * noise vs. sse weight for the nsse comparison function
2849  * - encoding: Set by user.
2850  * - decoding: unused
2851  */
2853 
2854  /**
2855  * profile
2856  * - encoding: Set by user.
2857  * - decoding: Set by libavcodec.
2858  */
2859  int profile;
2860 #define FF_PROFILE_UNKNOWN -99
2861 #define FF_PROFILE_RESERVED -100
2862 
2863 #define FF_PROFILE_AAC_MAIN 0
2864 #define FF_PROFILE_AAC_LOW 1
2865 #define FF_PROFILE_AAC_SSR 2
2866 #define FF_PROFILE_AAC_LTP 3
2867 #define FF_PROFILE_AAC_HE 4
2868 #define FF_PROFILE_AAC_HE_V2 28
2869 #define FF_PROFILE_AAC_LD 22
2870 #define FF_PROFILE_AAC_ELD 38
2871 #define FF_PROFILE_MPEG2_AAC_LOW 128
2872 #define FF_PROFILE_MPEG2_AAC_HE 131
2873 
2874 #define FF_PROFILE_DNXHD 0
2875 #define FF_PROFILE_DNXHR_LB 1
2876 #define FF_PROFILE_DNXHR_SQ 2
2877 #define FF_PROFILE_DNXHR_HQ 3
2878 #define FF_PROFILE_DNXHR_HQX 4
2879 #define FF_PROFILE_DNXHR_444 5
2880 
2881 #define FF_PROFILE_DTS 20
2882 #define FF_PROFILE_DTS_ES 30
2883 #define FF_PROFILE_DTS_96_24 40
2884 #define FF_PROFILE_DTS_HD_HRA 50
2885 #define FF_PROFILE_DTS_HD_MA 60
2886 #define FF_PROFILE_DTS_EXPRESS 70
2887 
2888 #define FF_PROFILE_MPEG2_422 0
2889 #define FF_PROFILE_MPEG2_HIGH 1
2890 #define FF_PROFILE_MPEG2_SS 2
2891 #define FF_PROFILE_MPEG2_SNR_SCALABLE 3
2892 #define FF_PROFILE_MPEG2_MAIN 4
2893 #define FF_PROFILE_MPEG2_SIMPLE 5
2894 
2895 #define FF_PROFILE_H264_CONSTRAINED (1<<9) // 8+1; constraint_set1_flag
2896 #define FF_PROFILE_H264_INTRA (1<<11) // 8+3; constraint_set3_flag
2897 
2898 #define FF_PROFILE_H264_BASELINE 66
2899 #define FF_PROFILE_H264_CONSTRAINED_BASELINE (66|FF_PROFILE_H264_CONSTRAINED)
2900 #define FF_PROFILE_H264_MAIN 77
2901 #define FF_PROFILE_H264_EXTENDED 88
2902 #define FF_PROFILE_H264_HIGH 100
2903 #define FF_PROFILE_H264_HIGH_10 110
2904 #define FF_PROFILE_H264_HIGH_10_INTRA (110|FF_PROFILE_H264_INTRA)
2905 #define FF_PROFILE_H264_MULTIVIEW_HIGH 118
2906 #define FF_PROFILE_H264_HIGH_422 122
2907 #define FF_PROFILE_H264_HIGH_422_INTRA (122|FF_PROFILE_H264_INTRA)
2908 #define FF_PROFILE_H264_STEREO_HIGH 128
2909 #define FF_PROFILE_H264_HIGH_444 144
2910 #define FF_PROFILE_H264_HIGH_444_PREDICTIVE 244
2911 #define FF_PROFILE_H264_HIGH_444_INTRA (244|FF_PROFILE_H264_INTRA)
2912 #define FF_PROFILE_H264_CAVLC_444 44
2913 
2914 #define FF_PROFILE_VC1_SIMPLE 0
2915 #define FF_PROFILE_VC1_MAIN 1
2916 #define FF_PROFILE_VC1_COMPLEX 2
2917 #define FF_PROFILE_VC1_ADVANCED 3
2918 
2919 #define FF_PROFILE_MPEG4_SIMPLE 0
2920 #define FF_PROFILE_MPEG4_SIMPLE_SCALABLE 1
2921 #define FF_PROFILE_MPEG4_CORE 2
2922 #define FF_PROFILE_MPEG4_MAIN 3
2923 #define FF_PROFILE_MPEG4_N_BIT 4
2924 #define FF_PROFILE_MPEG4_SCALABLE_TEXTURE 5
2925 #define FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION 6
2926 #define FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE 7
2927 #define FF_PROFILE_MPEG4_HYBRID 8
2928 #define FF_PROFILE_MPEG4_ADVANCED_REAL_TIME 9
2929 #define FF_PROFILE_MPEG4_CORE_SCALABLE 10
2930 #define FF_PROFILE_MPEG4_ADVANCED_CODING 11
2931 #define FF_PROFILE_MPEG4_ADVANCED_CORE 12
2932 #define FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE 13
2933 #define FF_PROFILE_MPEG4_SIMPLE_STUDIO 14
2934 #define FF_PROFILE_MPEG4_ADVANCED_SIMPLE 15
2935 
2936 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_0 1
2937 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_1 2
2938 #define FF_PROFILE_JPEG2000_CSTREAM_NO_RESTRICTION 32768
2939 #define FF_PROFILE_JPEG2000_DCINEMA_2K 3
2940 #define FF_PROFILE_JPEG2000_DCINEMA_4K 4
2941 
2942 #define FF_PROFILE_VP9_0 0
2943 #define FF_PROFILE_VP9_1 1
2944 #define FF_PROFILE_VP9_2 2
2945 #define FF_PROFILE_VP9_3 3
2946 
2947 #define FF_PROFILE_HEVC_MAIN 1
2948 #define FF_PROFILE_HEVC_MAIN_10 2
2949 #define FF_PROFILE_HEVC_MAIN_STILL_PICTURE 3
2950 #define FF_PROFILE_HEVC_REXT 4
2951 
2952 #define FF_PROFILE_AV1_MAIN 0
2953 #define FF_PROFILE_AV1_HIGH 1
2954 #define FF_PROFILE_AV1_PROFESSIONAL 2
2955 
2956 #define FF_PROFILE_MJPEG_HUFFMAN_BASELINE_DCT 0xc0
2957 #define FF_PROFILE_MJPEG_HUFFMAN_EXTENDED_SEQUENTIAL_DCT 0xc1
2958 #define FF_PROFILE_MJPEG_HUFFMAN_PROGRESSIVE_DCT 0xc2
2959 #define FF_PROFILE_MJPEG_HUFFMAN_LOSSLESS 0xc3
2960 #define FF_PROFILE_MJPEG_JPEG_LS 0xf7
2961 
2962 #define FF_PROFILE_SBC_MSBC 1
2963 
2964  /**
2965  * level
2966  * - encoding: Set by user.
2967  * - decoding: Set by libavcodec.
2968  */
2969  int level;
2970 #define FF_LEVEL_UNKNOWN -99
2971 
2972  /**
2973  * Skip loop filtering for selected frames.
2974  * - encoding: unused
2975  * - decoding: Set by user.
2976  */
2978 
2979  /**
2980  * Skip IDCT/dequantization for selected frames.
2981  * - encoding: unused
2982  * - decoding: Set by user.
2983  */
2985 
2986  /**
2987  * Skip decoding for selected frames.
2988  * - encoding: unused
2989  * - decoding: Set by user.
2990  */
2992 
2993  /**
2994  * Header containing style information for text subtitles.
2995  * For SUBTITLE_ASS subtitle type, it should contain the whole ASS
2996  * [Script Info] and [V4+ Styles] section, plus the [Events] line and
2997  * the Format line following. It shouldn't include any Dialogue line.
2998  * - encoding: Set/allocated/freed by user (before avcodec_open2())
2999  * - decoding: Set/allocated/freed by libavcodec (by avcodec_open2())
3000  */
3003 
3004 #if FF_API_VBV_DELAY
3005  /**
3006  * VBV delay coded in the last frame (in periods of a 27 MHz clock).
3007  * Used for compliant TS muxing.
3008  * - encoding: Set by libavcodec.
3009  * - decoding: unused.
3010  * @deprecated this value is now exported as a part of
3011  * AV_PKT_DATA_CPB_PROPERTIES packet side data
3012  */
3014  uint64_t vbv_delay;
3015 #endif
3016 
3017 #if FF_API_SIDEDATA_ONLY_PKT
3018  /**
3019  * Encoding only and set by default. Allow encoders to output packets
3020  * that do not contain any encoded data, only side data.
3021  *
3022  * Some encoders need to output such packets, e.g. to update some stream
3023  * parameters at the end of encoding.
3024  *
3025  * @deprecated this field disables the default behaviour and
3026  * it is kept only for compatibility.
3027  */
3030 #endif
3031 
3032  /**
3033  * Audio only. The number of "priming" samples (padding) inserted by the
3034  * encoder at the beginning of the audio. I.e. this number of leading
3035  * decoded samples must be discarded by the caller to get the original audio
3036  * without leading padding.
3037  *
3038  * - decoding: unused
3039  * - encoding: Set by libavcodec. The timestamps on the output packets are
3040  * adjusted by the encoder so that they always refer to the
3041  * first sample of the data actually contained in the packet,
3042  * including any added padding. E.g. if the timebase is
3043  * 1/samplerate and the timestamp of the first input sample is
3044  * 0, the timestamp of the first output packet will be
3045  * -initial_padding.
3046  */
3048 
3049  /**
3050  * - decoding: For codecs that store a framerate value in the compressed
3051  * bitstream, the decoder may export it here. { 0, 1} when
3052  * unknown.
3053  * - encoding: May be used to signal the framerate of CFR content to an
3054  * encoder.
3055  */
3057 
3058  /**
3059  * Nominal unaccelerated pixel format, see AV_PIX_FMT_xxx.
3060  * - encoding: unused.
3061  * - decoding: Set by libavcodec before calling get_format()
3062  */
3064 
3065  /**
3066  * Timebase in which pkt_dts/pts and AVPacket.dts/pts are.
3067  * - encoding unused.
3068  * - decoding set by user.
3069  */
3071 
3072  /**
3073  * AVCodecDescriptor
3074  * - encoding: unused.
3075  * - decoding: set by libavcodec.
3076  */
3078 
3079 #if !FF_API_LOWRES
3080  /**
3081  * low resolution decoding, 1-> 1/2 size, 2->1/4 size
3082  * - encoding: unused
3083  * - decoding: Set by user.
3084  */
3085  int lowres;
3086 #endif
3087 
3088  /**
3089  * Current statistics for PTS correction.
3090  * - decoding: maintained and used by libavcodec, not intended to be used by user apps
3091  * - encoding: unused
3092  */
3093  int64_t pts_correction_num_faulty_pts; /// Number of incorrect PTS values so far
3094  int64_t pts_correction_num_faulty_dts; /// Number of incorrect DTS values so far
3095  int64_t pts_correction_last_pts; /// PTS of the last frame
3096  int64_t pts_correction_last_dts; /// DTS of the last frame
3097 
3098  /**
3099  * Character encoding of the input subtitles file.
3100  * - decoding: set by user
3101  * - encoding: unused
3102  */
3104 
3105  /**
3106  * Subtitles character encoding mode. Formats or codecs might be adjusting
3107  * this setting (if they are doing the conversion themselves for instance).
3108  * - decoding: set by libavcodec
3109  * - encoding: unused
3110  */
3112 #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)
3113 #define FF_SUB_CHARENC_MODE_AUTOMATIC 0 ///< libavcodec will select the mode itself
3114 #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
3115 #define FF_SUB_CHARENC_MODE_IGNORE 2 ///< neither convert the subtitles, nor check them for valid UTF-8
3116 
3117  /**
3118  * Skip processing alpha if supported by codec.
3119  * Note that if the format uses pre-multiplied alpha (common with VP6,
3120  * and recommended due to better video quality/compression)
3121  * the image will look as if alpha-blended onto a black background.
3122  * However for formats that do not use pre-multiplied alpha
3123  * there might be serious artefacts (though e.g. libswscale currently
3124  * assumes pre-multiplied alpha anyway).
3125  *
3126  * - decoding: set by user
3127  * - encoding: unused
3128  */
3130 
3131  /**
3132  * Number of samples to skip after a discontinuity
3133  * - decoding: unused
3134  * - encoding: set by libavcodec
3135  */
3137 
3138 #if !FF_API_DEBUG_MV
3139  /**
3140  * debug motion vectors
3141  * - encoding: Set by user.
3142  * - decoding: Set by user.
3143  */
3145 #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 //visualize forward predicted MVs of P frames
3146 #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 //visualize forward predicted MVs of B frames
3147 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
3148 #endif
3149 
3150  /**
3151  * custom intra quantization matrix
3152  * - encoding: Set by user, can be NULL.
3153  * - decoding: unused.
3154  */
3156 
3157  /**
3158  * dump format separator.
3159  * can be ", " or "\n " or anything else
3160  * - encoding: Set by user.
3161  * - decoding: Set by user.
3162  */
3164 
3165  /**
3166  * ',' separated list of allowed decoders.
3167  * If NULL then all are allowed
3168  * - encoding: unused
3169  * - decoding: set by user
3170  */
3172 
3173  /**
3174  * Properties of the stream that gets decoded
3175  * - encoding: unused
3176  * - decoding: set by libavcodec
3177  */
3178  unsigned properties;
3179 #define FF_CODEC_PROPERTY_LOSSLESS 0x00000001
3180 #define FF_CODEC_PROPERTY_CLOSED_CAPTIONS 0x00000002
3181 
3182  /**
3183  * Additional data associated with the entire coded stream.
3184  *
3185  * - decoding: unused
3186  * - encoding: may be set by libavcodec after avcodec_open2().
3187  */
3190 
3191  /**
3192  * A reference to the AVHWFramesContext describing the input (for encoding)
3193  * or output (decoding) frames. The reference is set by the caller and
3194  * afterwards owned (and freed) by libavcodec - it should never be read by
3195  * the caller after being set.
3196  *
3197  * - decoding: This field should be set by the caller from the get_format()
3198  * callback. The previous reference (if any) will always be
3199  * unreffed by libavcodec before the get_format() call.
3200  *
3201  * If the default get_buffer2() is used with a hwaccel pixel
3202  * format, then this AVHWFramesContext will be used for
3203  * allocating the frame buffers.
3204  *
3205  * - encoding: For hardware encoders configured to use a hwaccel pixel
3206  * format, this field should be set by the caller to a reference
3207  * to the AVHWFramesContext describing input frames.
3208  * AVHWFramesContext.format must be equal to
3209  * AVCodecContext.pix_fmt.
3210  *
3211  * This field should be set before avcodec_open2() is called.
3212  */
3214 
3215  /**
3216  * Control the form of AVSubtitle.rects[N]->ass
3217  * - decoding: set by user
3218  * - encoding: unused
3219  */
3221 #define FF_SUB_TEXT_FMT_ASS 0
3222 #if FF_API_ASS_TIMING
3223 #define FF_SUB_TEXT_FMT_ASS_WITH_TIMINGS 1
3224 #endif
3225 
3226  /**
3227  * Audio only. The amount of padding (in samples) appended by the encoder to
3228  * the end of the audio. I.e. this number of decoded samples must be
3229  * discarded by the caller from the end of the stream to get the original
3230  * audio without any trailing padding.
3231  *
3232  * - decoding: unused
3233  * - encoding: unused
3234  */
3236 
3237  /**
3238  * The number of pixels per image to maximally accept.
3239  *
3240  * - decoding: set by user
3241  * - encoding: set by user
3242  */
3243  int64_t max_pixels;
3244 
3245  /**
3246  * A reference to the AVHWDeviceContext describing the device which will
3247  * be used by a hardware encoder/decoder. The reference is set by the
3248  * caller and afterwards owned (and freed) by libavcodec.
3249  *
3250  * This should be used if either the codec device does not require
3251  * hardware frames or any that are used are to be allocated internally by
3252  * libavcodec. If the user wishes to supply any of the frames used as
3253  * encoder input or decoder output then hw_frames_ctx should be used
3254  * instead. When hw_frames_ctx is set in get_format() for a decoder, this
3255  * field will be ignored while decoding the associated stream segment, but
3256  * may again be used on a following one after another get_format() call.
3257  *
3258  * For both encoders and decoders this field should be set before
3259  * avcodec_open2() is called and must not be written to thereafter.
3260  *
3261  * Note that some decoders may require this field to be set initially in
3262  * order to support hw_frames_ctx at all - in that case, all frames
3263  * contexts used must be created on the same device.
3264  */
3266 
3267  /**
3268  * Bit set of AV_HWACCEL_FLAG_* flags, which affect hardware accelerated
3269  * decoding (if active).
3270  * - encoding: unused
3271  * - decoding: Set by user (either before avcodec_open2(), or in the
3272  * AVCodecContext.get_format callback)
3273  */
3275 
3276  /**
3277  * Video decoding only. Certain video codecs support cropping, meaning that
3278  * only a sub-rectangle of the decoded frame is intended for display. This
3279  * option controls how cropping is handled by libavcodec.
3280  *
3281  * When set to 1 (the default), libavcodec will apply cropping internally.
3282  * I.e. it will modify the output frame width/height fields and offset the
3283  * data pointers (only by as much as possible while preserving alignment, or
3284  * by the full amount if the AV_CODEC_FLAG_UNALIGNED flag is set) so that
3285  * the frames output by the decoder refer only to the cropped area. The
3286  * crop_* fields of the output frames will be zero.
3287  *
3288  * When set to 0, the width/height fields of the output frames will be set
3289  * to the coded dimensions and the crop_* fields will describe the cropping
3290  * rectangle. Applying the cropping is left to the caller.
3291  *
3292  * @warning When hardware acceleration with opaque output frames is used,
3293  * libavcodec is unable to apply cropping from the top/left border.
3294  *
3295  * @note when this option is set to zero, the width/height fields of the
3296  * AVCodecContext and output AVFrames have different meanings. The codec
3297  * context fields store display dimensions (with the coded dimensions in
3298  * coded_width/height), while the frame fields store the coded dimensions
3299  * (with the display dimensions being determined by the crop_* fields).
3300  */
3302 
3303  /*
3304  * Video decoding only. Sets the number of extra hardware frames which
3305  * the decoder will allocate for use by the caller. This must be set
3306  * before avcodec_open2() is called.
3307  *
3308  * Some hardware decoders require all frames that they will use for
3309  * output to be defined in advance before decoding starts. For such
3310  * decoders, the hardware frame pool must therefore be of a fixed size.
3311  * The extra frames set here are on top of any number that the decoder
3312  * needs internally in order to operate normally (for example, frames
3313  * used as reference pictures).
3314  */
3316 } AVCodecContext;
3317 
3318 #if FF_API_CODEC_GET_SET
3319 /**
3320  * Accessors for some AVCodecContext fields. These used to be provided for ABI
3321  * compatibility, and do not need to be used anymore.
3322  */
3327 
3332 
3334 unsigned av_codec_get_codec_properties(const AVCodecContext *avctx);
3335 
3336 #if FF_API_LOWRES
3338 int av_codec_get_lowres(const AVCodecContext *avctx);
3340 void av_codec_set_lowres(AVCodecContext *avctx, int val);
3341 #endif
3342 
3344 int av_codec_get_seek_preroll(const AVCodecContext *avctx);
3346 void av_codec_set_seek_preroll(AVCodecContext *avctx, int val);
3347 
3349 uint16_t *av_codec_get_chroma_intra_matrix(const AVCodecContext *avctx);
3351 void av_codec_set_chroma_intra_matrix(AVCodecContext *avctx, uint16_t *val);
3352 #endif
3353 
3354 /**
3355  * AVProfile.
3356  */
3357 typedef struct AVProfile {
3358  int profile;
3359  const char *name; ///< short name for the profile
3360 } AVProfile;
3361 
3362 enum {
3363  /**
3364  * The codec supports this format via the hw_device_ctx interface.
3365  *
3366  * When selecting this format, AVCodecContext.hw_device_ctx should
3367  * have been set to a device of the specified type before calling
3368  * avcodec_open2().
3369  */
3371  /**
3372  * The codec supports this format via the hw_frames_ctx interface.
3373  *
3374  * When selecting this format for a decoder,
3375  * AVCodecContext.hw_frames_ctx should be set to a suitable frames
3376  * context inside the get_format() callback. The frames context
3377  * must have been created on a device of the specified type.
3378  */
3380  /**
3381  * The codec supports this format by some internal method.
3382  *
3383  * This format can be selected without any additional configuration -
3384  * no device or frames context is required.
3385  */
3387  /**
3388  * The codec supports this format by some ad-hoc method.
3389  *
3390  * Additional settings and/or function calls are required. See the
3391  * codec-specific documentation for details. (Methods requiring
3392  * this sort of configuration are deprecated and others should be
3393  * used in preference.)
3394  */
3396 };
3397 
3398 typedef struct AVCodecHWConfig {
3399  /**
3400  * A hardware pixel format which the codec can use.
3401  */
3403  /**
3404  * Bit set of AV_CODEC_HW_CONFIG_METHOD_* flags, describing the possible
3405  * setup methods which can be used with this configuration.
3406  */
3407  int methods;
3408  /**
3409  * The device type associated with the configuration.
3410  *
3411  * Must be set for AV_CODEC_HW_CONFIG_METHOD_HW_DEVICE_CTX and
3412  * AV_CODEC_HW_CONFIG_METHOD_HW_FRAMES_CTX, otherwise unused.
3413  */
3415 } AVCodecHWConfig;
3416 
3417 typedef struct AVCodecDefault AVCodecDefault;
3418 
3419 struct AVSubtitle;
3420 
3421 /**
3422  * AVCodec.
3423  */
3424 typedef struct AVCodec {
3425  /**
3426  * Name of the codec implementation.
3427  * The name is globally unique among encoders and among decoders (but an
3428  * encoder and a decoder can share the same name).
3429  * This is the primary way to find a codec from the user perspective.
3430  */
3431  const char *name;
3432  /**
3433  * Descriptive name for the codec, meant to be more human readable than name.
3434  * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
3435  */
3436  const char *long_name;
3439  /**
3440  * Codec capabilities.
3441  * see AV_CODEC_CAP_*
3442  */
3444  const AVRational *supported_framerates; ///< array of supported framerates, or NULL if any, array is terminated by {0,0}
3445  const enum AVPixelFormat *pix_fmts; ///< array of supported pixel formats, or NULL if unknown, array is terminated by -1
3446  const int *supported_samplerates; ///< array of supported audio samplerates, or NULL if unknown, array is terminated by 0
3447  const enum AVSampleFormat *sample_fmts; ///< array of supported sample formats, or NULL if unknown, array is terminated by -1
3448  const uint64_t *channel_layouts; ///< array of support channel layouts, or NULL if unknown. array is terminated by 0
3449  uint8_t max_lowres; ///< maximum value for lowres supported by the decoder
3450  const AVClass *priv_class; ///< AVClass for the private context
3451  const AVProfile *profiles; ///< array of recognized profiles, or NULL if unknown, array is terminated by {FF_PROFILE_UNKNOWN}
3452 
3453  /**
3454  * Group name of the codec implementation.
3455  * This is a short symbolic name of the wrapper backing this codec. A
3456  * wrapper uses some kind of external implementation for the codec, such
3457  * as an external library, or a codec implementation provided by the OS or
3458  * the hardware.
3459  * If this field is NULL, this is a builtin, libavcodec native codec.
3460  * If non-NULL, this will be the suffix in AVCodec.name in most cases
3461  * (usually AVCodec.name will be of the form "<codec_name>_<wrapper_name>").
3462  */
3463  const char *wrapper_name;
3464 
3465  /*****************************************************************
3466  * No fields below this line are part of the public API. They
3467  * may not be used outside of libavcodec and can be changed and
3468  * removed at will.
3469  * New public fields should be added right above.
3470  *****************************************************************
3471  */
3473  struct AVCodec *next;
3474  /**
3475  * @name Frame-level threading support functions
3476  * @{
3477  */
3478  /**
3479  * If defined, called on thread contexts when they are created.
3480  * If the codec allocates writable tables in init(), re-allocate them here.
3481  * priv_data will be set to a copy of the original.
3482  */
3484  /**
3485  * Copy necessary context variables from a previous thread context to the current one.
3486  * If not defined, the next thread will start automatically; otherwise, the codec
3487  * must call ff_thread_finish_setup().
3488  *
3489  * dst and src will (rarely) point to the same context, in which case memcpy should be skipped.
3490  */
3492  /** @} */
3493 
3494  /**
3495  * Private codec-specific defaults.
3496  */
3498 
3499  /**
3500  * Initialize codec static data, called from avcodec_register().
3501  *
3502  * This is not intended for time consuming operations as it is
3503  * run for every codec regardless of that codec being used.
3504  */
3505  void (*init_static_data)(struct AVCodec *codec);
3506 
3508  int (*encode_sub)(AVCodecContext *, uint8_t *buf, int buf_size,
3509  const struct AVSubtitle *sub);
3510  /**
3511  * Encode data to an AVPacket.
3512  *
3513  * @param avctx codec context
3514  * @param avpkt output AVPacket (may contain a user-provided buffer)
3515  * @param[in] frame AVFrame containing the raw data to be encoded
3516  * @param[out] got_packet_ptr encoder sets to 0 or 1 to indicate that a
3517  * non-empty packet was returned in avpkt.
3518  * @return 0 on success, negative error code on failure
3519  */
3520  int (*encode2)(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame,
3521  int *got_packet_ptr);
3522  int (*decode)(AVCodecContext *, void *outdata, int *outdata_size, AVPacket *avpkt);
3524  /**
3525  * Encode API with decoupled packet/frame dataflow. The API is the
3526  * same as the avcodec_ prefixed APIs (avcodec_send_frame() etc.), except
3527  * that:
3528  * - never called if the codec is closed or the wrong type,
3529  * - if AV_CODEC_CAP_DELAY is not set, drain frames are never sent,
3530  * - only one drain frame is ever passed down,
3531  */
3534 
3535  /**
3536  * Decode API with decoupled packet/frame dataflow. This function is called
3537  * to get one output frame. It should call ff_decode_get_packet() to obtain
3538  * input data.
3539  */
3541  /**
3542  * Flush buffers.
3543  * Will be called when seeking
3544  */
3546  /**
3547  * Internal codec capabilities.
3548  * See FF_CODEC_CAP_* in internal.h
3549  */
3551 
3552  /**
3553  * Decoding only, a comma-separated list of bitstream filters to apply to
3554  * packets before decoding.
3555  */
3556  const char *bsfs;
3557 
3558  /**
3559  * Array of pointers to hardware configurations supported by the codec,
3560  * or NULL if no hardware supported. The array is terminated by a NULL
3561  * pointer.
3562  *
3563  * The user can only access this field via avcodec_get_hw_config().
3564  */
3566 } AVCodec;
3567 
3568 #if FF_API_CODEC_GET_SET
3570 int av_codec_get_max_lowres(const AVCodec *codec);
3571 #endif
3572 
3573 struct MpegEncContext;
3574 
3575 /**
3576  * Retrieve supported hardware configurations for a codec.
3577  *
3578  * Values of index from zero to some maximum return the indexed configuration
3579  * descriptor; all other values return NULL. If the codec does not support
3580  * any hardware configurations then it will always return NULL.
3581  */
3582 const AVCodecHWConfig *avcodec_get_hw_config(const AVCodec *codec, int index);
3583 
3584 /**
3585  * @defgroup lavc_hwaccel AVHWAccel
3586  *
3587  * @note Nothing in this structure should be accessed by the user. At some
3588  * point in future it will not be externally visible at all.
3589  *
3590  * @{
3591  */
3592 typedef struct AVHWAccel {
3593  /**
3594  * Name of the hardware accelerated codec.
3595  * The name is globally unique among encoders and among decoders (but an
3596  * encoder and a decoder can share the same name).
3597  */
3598  const char *name;
3599 
3600  /**
3601  * Type of codec implemented by the hardware accelerator.
3602  *
3603  * See AVMEDIA_TYPE_xxx
3604  */
3606 
3607  /**
3608  * Codec implemented by the hardware accelerator.
3609  *
3610  * See AV_CODEC_ID_xxx
3611  */
3613 
3614  /**
3615  * Supported pixel format.
3616  *
3617  * Only hardware accelerated formats are supported here.
3618  */
3620 
3621  /**
3622  * Hardware accelerated codec capabilities.
3623  * see AV_HWACCEL_CODEC_CAP_*
3624  */
3626 
3627  /*****************************************************************
3628  * No fields below this line are part of the public API. They
3629  * may not be used outside of libavcodec and can be changed and
3630  * removed at will.
3631  * New public fields should be added right above.
3632  *****************************************************************
3633  */
3634 
3635  /**
3636  * Allocate a custom buffer
3637  */
3639 
3640  /**
3641  * Called at the beginning of each frame or field picture.
3642  *
3643  * Meaningful frame information (codec specific) is guaranteed to
3644  * be parsed at this point. This function is mandatory.
3645  *
3646  * Note that buf can be NULL along with buf_size set to 0.
3647  * Otherwise, this means the whole frame is available at this point.
3648  *
3649  * @param avctx the codec context
3650  * @param buf the frame data buffer base
3651  * @param buf_size the size of the frame in bytes
3652  * @return zero if successful, a negative value otherwise
3653  */
3654  int (*start_frame)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3655 
3656  /**
3657  * Callback for parameter data (SPS/PPS/VPS etc).
3658  *
3659  * Useful for hardware decoders which keep persistent state about the
3660  * video parameters, and need to receive any changes to update that state.
3661  *
3662  * @param avctx the codec context
3663  * @param type the nal unit type
3664  * @param buf the nal unit data buffer
3665  * @param buf_size the size of the nal unit in bytes
3666  * @return zero if successful, a negative value otherwise
3667  */
3668  int (*decode_params)(AVCodecContext *avctx, int type, const uint8_t *buf, uint32_t buf_size);
3669 
3670  /**
3671  * Callback for each slice.
3672  *
3673  * Meaningful slice information (codec specific) is guaranteed to
3674  * be parsed at this point. This function is mandatory.
3675  * The only exception is XvMC, that works on MB level.
3676  *
3677  * @param avctx the codec context
3678  * @param buf the slice data buffer base
3679  * @param buf_size the size of the slice in bytes
3680  * @return zero if successful, a negative value otherwise
3681  */
3682  int (*decode_slice)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3683 
3684  /**
3685  * Called at the end of each frame or field picture.
3686  *
3687  * The whole picture is parsed at this point and can now be sent
3688  * to the hardware accelerator. This function is mandatory.
3689  *
3690  * @param avctx the codec context
3691  * @return zero if successful, a negative value otherwise
3692  */
3694 
3695  /**
3696  * Size of per-frame hardware accelerator private data.
3697  *
3698  * Private data is allocated with av_mallocz() before
3699  * AVCodecContext.get_buffer() and deallocated after
3700  * AVCodecContext.release_buffer().
3701  */
3703 
3704  /**
3705  * Called for every Macroblock in a slice.
3706  *
3707  * XvMC uses it to replace the ff_mpv_reconstruct_mb().
3708  * Instead of decoding to raw picture, MB parameters are
3709  * stored in an array provided by the video driver.
3710  *
3711  * @param s the mpeg context
3712  */
3714 
3715  /**
3716  * Initialize the hwaccel private data.
3717  *
3718  * This will be called from ff_get_format(), after hwaccel and
3719  * hwaccel_context are set and the hwaccel private data in AVCodecInternal
3720  * is allocated.
3721  */
3723 
3724  /**
3725  * Uninitialize the hwaccel private data.
3726  *
3727  * This will be called from get_format() or avcodec_close(), after hwaccel
3728  * and hwaccel_context are already uninitialized.
3729  */
3731 
3732  /**
3733  * Size of the private data to allocate in
3734  * AVCodecInternal.hwaccel_priv_data.
3735  */
3737 
3738  /**
3739  * Internal hwaccel capabilities.
3740  */
3742 
3743  /**
3744  * Fill the given hw_frames context with current codec parameters. Called
3745  * from get_format. Refer to avcodec_get_hw_frames_parameters() for
3746  * details.
3747  *
3748  * This CAN be called before AVHWAccel.init is called, and you must assume
3749  * that avctx->hwaccel_priv_data is invalid.
3750  */
3752 } AVHWAccel;
3753 
3754 /**
3755  * HWAccel is experimental and is thus avoided in favor of non experimental
3756  * codecs
3757  */
3758 #define AV_HWACCEL_CODEC_CAP_EXPERIMENTAL 0x0200
3759 
3760 /**
3761  * Hardware acceleration should be used for decoding even if the codec level
3762  * used is unknown or higher than the maximum supported level reported by the
3763  * hardware driver.
3764  *
3765  * It's generally a good idea to pass this flag unless you have a specific
3766  * reason not to, as hardware tends to under-report supported levels.
3767  */
3768 #define AV_HWACCEL_FLAG_IGNORE_LEVEL (1 << 0)
3769 
3770 /**
3771  * Hardware acceleration can output YUV pixel formats with a different chroma
3772  * sampling than 4:2:0 and/or other than 8 bits per component.
3773  */
3774 #define AV_HWACCEL_FLAG_ALLOW_HIGH_DEPTH (1 << 1)
3775 
3776 /**
3777  * Hardware acceleration should still be attempted for decoding when the
3778  * codec profile does not match the reported capabilities of the hardware.
3779  *
3780  * For example, this can be used to try to decode baseline profile H.264
3781  * streams in hardware - it will often succeed, because many streams marked
3782  * as baseline profile actually conform to constrained baseline profile.
3783  *
3784  * @warning If the stream is actually not supported then the behaviour is
3785  * undefined, and may include returning entirely incorrect output
3786  * while indicating success.
3787  */
3788 #define AV_HWACCEL_FLAG_ALLOW_PROFILE_MISMATCH (1 << 2)
3789 
3790 /**
3791  * @}
3792  */
3793 
3794 #if FF_API_AVPICTURE
3795 /**
3796  * @defgroup lavc_picture AVPicture
3797  *
3798  * Functions for working with AVPicture
3799  * @{
3800  */
3801 
3802 /**
3803  * Picture data structure.
3804  *
3805  * Up to four components can be stored into it, the last component is
3806  * alpha.
3807  * @deprecated use AVFrame or imgutils functions instead
3808  */
3809 typedef struct AVPicture {
3811  uint8_t *data[AV_NUM_DATA_POINTERS]; ///< pointers to the image data planes
3813  int linesize[AV_NUM_DATA_POINTERS]; ///< number of bytes per line
3814 } AVPicture;
3815 
3816 /**
3817  * @}
3818  */
3819 #endif
3820 
3823 
3824  SUBTITLE_BITMAP, ///< A bitmap, pict will be set
3825 
3826  /**
3827  * Plain text, the text field must be set by the decoder and is
3828  * authoritative. ass and pict fields may contain approximations.
3829  */
3831 
3832  /**
3833  * Formatted text, the ass field must be set by the decoder and is
3834  * authoritative. pict and text fields may contain approximations.
3835  */
3837 };
3838 
3839 #define AV_SUBTITLE_FLAG_FORCED 0x00000001
3840 
3841 typedef struct AVSubtitleRect {
3842  int x; ///< top left corner of pict, undefined when pict is not set
3843  int y; ///< top left corner of pict, undefined when pict is not set
3844  int w; ///< width of pict, undefined when pict is not set
3845  int h; ///< height of pict, undefined when pict is not set
3846  int nb_colors; ///< number of colors in pict, undefined when pict is not set
3847 
3848 #if FF_API_AVPICTURE
3849  /**
3850  * @deprecated unused
3851  */
3854 #endif
3855  /**
3856  * data+linesize for the bitmap of this subtitle.
3857  * Can be set for text/ass as well once they are rendered.
3858  */
3860  int linesize[4];
3861 
3863 
3864  char *text; ///< 0 terminated plain UTF-8 text
3865 
3866  /**
3867  * 0 terminated ASS/SSA compatible event line.
3868  * The presentation of this is unaffected by the other values in this
3869  * struct.
3870  */
3871  char *ass;
3872 
3873  int flags;
3874 } AVSubtitleRect;
3875 
3876 typedef struct AVSubtitle {
3877  uint16_t format; /* 0 = graphics */
3878  uint32_t start_display_time; /* relative to packet pts, in ms */
3879  uint32_t end_display_time; /* relative to packet pts, in ms */
3880  unsigned num_rects;
3882  int64_t pts; ///< Same as packet pts, in AV_TIME_BASE
3883 } AVSubtitle;
3884 
3885 /**
3886  * This struct describes the properties of an encoded stream.
3887  *
3888  * sizeof(AVCodecParameters) is not a part of the public ABI, this struct must
3889  * be allocated with avcodec_parameters_alloc() and freed with
3890  * avcodec_parameters_free().
3891  */
3892 typedef struct AVCodecParameters {
3893  /**
3894  * General type of the encoded data.
3895  */
3897  /**
3898  * Specific type of the encoded data (the codec used).
3899  */
3901  /**
3902  * Additional information about the codec (corresponds to the AVI FOURCC).
3903  */
3904  uint32_t codec_tag;
3905 
3906  /**
3907  * Extra binary data needed for initializing the decoder, codec-dependent.
3908  *
3909  * Must be allocated with av_malloc() and will be freed by
3910  * avcodec_parameters_free(). The allocated size of extradata must be at
3911  * least extradata_size + AV_INPUT_BUFFER_PADDING_SIZE, with the padding
3912  * bytes zeroed.
3913  */
3915  /**
3916  * Size of the extradata content in bytes.
3917  */
3919 
3920  /**
3921  * - video: the pixel format, the value corresponds to enum AVPixelFormat.
3922  * - audio: the sample format, the value corresponds to enum AVSampleFormat.
3923  */
3924  int format;
3925 
3926  /**
3927  * The average bitrate of the encoded data (in bits per second).
3928  */
3929  int64_t bit_rate;
3930 
3931  /**
3932  * The number of bits per sample in the codedwords.
3933  *
3934  * This is basically the bitrate per sample. It is mandatory for a bunch of
3935  * formats to actually decode them. It's the number of bits for one sample in
3936  * the actual coded bitstream.
3937  *
3938  * This could be for example 4 for ADPCM
3939  * For PCM formats this matches bits_per_raw_sample
3940  * Can be 0
3941  */
3943 
3944  /**
3945  * This is the number of valid bits in each output sample. If the
3946  * sample format has more bits, the least significant bits are additional
3947  * padding bits, which are always 0. Use right shifts to reduce the sample
3948  * to its actual size. For example, audio formats with 24 bit samples will
3949  * have bits_per_raw_sample set to 24, and format set to AV_SAMPLE_FMT_S32.
3950  * To get the original sample use "(int32_t)sample >> 8"."
3951  *
3952  * For ADPCM this might be 12 or 16 or similar
3953  * Can be 0
3954  */
3956 
3957  /**
3958  * Codec-specific bitstream restrictions that the stream conforms to.
3959  */
3960  int profile;
3961  int level;
3962 
3963  /**
3964  * Video only. The dimensions of the video frame in pixels.
3965  */
3966  int width;
3967  int height;
3968 
3969  /**
3970  * Video only. The aspect ratio (width / height) which a single pixel
3971  * should have when displayed.
3972  *
3973  * When the aspect ratio is unknown / undefined, the numerator should be
3974  * set to 0 (the denominator may have any value).
3975  */
3977 
3978  /**
3979  * Video only. The order of the fields in interlaced video.
3980  */
3982 
3983  /**
3984  * Video only. Additional colorspace characteristics.
3985  */
3991 
3992  /**
3993  * Video only. Number of delayed frames.
3994  */
3996 
3997  /**
3998  * Audio only. The channel layout bitmask. May be 0 if the channel layout is
3999  * unknown or unspecified, otherwise the number of bits set must be equal to
4000  * the channels field.
4001  */
4002  uint64_t channel_layout;
4003  /**
4004  * Audio only. The number of audio channels.
4005  */
4007  /**
4008  * Audio only. The number of audio samples per second.
4009  */
4011  /**
4012  * Audio only. The number of bytes per coded audio frame, required by some
4013  * formats.
4014  *
4015  * Corresponds to nBlockAlign in WAVEFORMATEX.
4016  */
4018  /**
4019  * Audio only. Audio frame size, if known. Required by some formats to be static.
4020  */
4022 
4023  /**
4024  * Audio only. The amount of padding (in samples) inserted by the encoder at
4025  * the beginning of the audio. I.e. this number of leading decoded samples
4026  * must be discarded by the caller to get the original audio without leading
4027  * padding.
4028  */
4030  /**
4031  * Audio only. The amount of padding (in samples) appended by the encoder to
4032  * the end of the audio. I.e. this number of decoded samples must be
4033  * discarded by the caller from the end of the stream to get the original
4034  * audio without any trailing padding.
4035  */
4037  /**
4038  * Audio only. Number of samples to skip after a discontinuity.
4039  */
4042 
4043 /**
4044  * Iterate over all registered codecs.
4045  *
4046  * @param opaque a pointer where libavcodec will store the iteration state. Must
4047  * point to NULL to start the iteration.
4048  *
4049  * @return the next registered codec or NULL when the iteration is
4050  * finished
4051  */
4052 const AVCodec *av_codec_iterate(void **opaque);
4053 
4054 #if FF_API_NEXT
4055 /**
4056  * If c is NULL, returns the first registered codec,
4057  * if c is non-NULL, returns the next registered codec after c,
4058  * or NULL if c is the last one.
4059  */
4061 AVCodec *av_codec_next(const AVCodec *c);
4062 #endif
4063 
4064 /**
4065  * Return the LIBAVCODEC_VERSION_INT constant.
4066  */
4067 unsigned avcodec_version(void);
4068 
4069 /**
4070  * Return the libavcodec build-time configuration.
4071  */
4072 const char *avcodec_configuration(void);
4073 
4074 /**
4075  * Return the libavcodec license.
4076  */
4077 const char *avcodec_license(void);
4078 
4079 #if FF_API_NEXT
4080 /**
4081  * Register the codec codec and initialize libavcodec.
4082  *
4083  * @warning either this function or avcodec_register_all() must be called
4084  * before any other libavcodec functions.
4085  *
4086  * @see avcodec_register_all()
4087  */
4089 void avcodec_register(AVCodec *codec);
4090 
4091 /**
4092  * Register all the codecs, parsers and bitstream filters which were enabled at
4093  * configuration time. If you do not call this function you can select exactly
4094  * which formats you want to support, by using the individual registration
4095  * functions.
4096  *
4097  * @see avcodec_register
4098  * @see av_register_codec_parser
4099  * @see av_register_bitstream_filter
4100  */
4102 void avcodec_register_all(void);
4103 #endif
4104 
4105 /**
4106  * Allocate an AVCodecContext and set its fields to default values. The
4107  * resulting struct should be freed with avcodec_free_context().
4108  *
4109  * @param codec if non-NULL, allocate private data and initialize defaults
4110  * for the given codec. It is illegal to then call avcodec_open2()
4111  * with a different codec.
4112  * If NULL, then the codec-specific defaults won't be initialized,
4113  * which may result in suboptimal default settings (this is
4114  * important mainly for encoders, e.g. libx264).
4115  *
4116  * @return An AVCodecContext filled with default values or NULL on failure.
4117  */
4119 
4120 /**
4121  * Free the codec context and everything associated with it and write NULL to
4122  * the provided pointer.
4123  */
4124 void avcodec_free_context(AVCodecContext **avctx);
4125 
4126 #if FF_API_GET_CONTEXT_DEFAULTS
4127 /**
4128  * @deprecated This function should not be used, as closing and opening a codec
4129  * context multiple time is not supported. A new codec context should be
4130  * allocated for each new use.
4131  */
4133 #endif
4134 
4135 /**
4136  * Get the AVClass for AVCodecContext. It can be used in combination with
4137  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
4138  *
4139  * @see av_opt_find().
4140  */
4141 const AVClass *avcodec_get_class(void);
4142 
4143 #if FF_API_COPY_CONTEXT
4144 /**
4145  * Get the AVClass for AVFrame. It can be used in combination with
4146  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
4147  *
4148  * @see av_opt_find().
4149  */
4150 const AVClass *avcodec_get_frame_class(void);
4151 
4152 /**
4153  * Get the AVClass for AVSubtitleRect. It can be used in combination with
4154  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
4155  *
4156  * @see av_opt_find().
4157  */
4159 
4160 /**
4161  * Copy the settings of the source AVCodecContext into the destination
4162  * AVCodecContext. The resulting destination codec context will be
4163  * unopened, i.e. you are required to call avcodec_open2() before you
4164  * can use this AVCodecContext to decode/encode video/audio data.
4165  *
4166  * @param dest target codec context, should be initialized with
4167  * avcodec_alloc_context3(NULL), but otherwise uninitialized
4168  * @param src source codec context
4169  * @return AVERROR() on error (e.g. memory allocation error), 0 on success
4170  *
4171  * @deprecated The semantics of this function are ill-defined and it should not
4172  * be used. If you need to transfer the stream parameters from one codec context
4173  * to another, use an intermediate AVCodecParameters instance and the
4174  * avcodec_parameters_from_context() / avcodec_parameters_to_context()
4175  * functions.
4176  */
4179 #endif
4180 
4181 /**
4182  * Allocate a new AVCodecParameters and set its fields to default values
4183  * (unknown/invalid/0). The returned struct must be freed with
4184  * avcodec_parameters_free().
4185  */
4187 
4188 /**
4189  * Free an AVCodecParameters instance and everything associated with it and
4190  * write NULL to the supplied pointer.
4191  */
4193 
4194 /**
4195  * Copy the contents of src to dst. Any allocated fields in dst are freed and
4196  * replaced with newly allocated duplicates of the corresponding fields in src.
4197  *
4198  * @return >= 0 on success, a negative AVERROR code on failure.
4199  */
4201 
4202 /**
4203  * Fill the parameters struct based on the values from the supplied codec
4204  * context. Any allocated fields in par are freed and replaced with duplicates
4205  * of the corresponding fields in codec.
4206  *
4207  * @return >= 0 on success, a negative AVERROR code on failure
4208  */
4210  const AVCodecContext *codec);
4211 
4212 /**
4213  * Fill the codec context based on the values from the supplied codec
4214  * parameters. Any allocated fields in codec that have a corresponding field in
4215  * par are freed and replaced with duplicates of the corresponding field in par.
4216  * Fields in codec that do not have a counterpart in par are not touched.
4217  *
4218  * @return >= 0 on success, a negative AVERROR code on failure.
4219  */
4221  const AVCodecParameters *par);
4222 
4223 /**
4224  * Initialize the AVCodecContext to use the given AVCodec. Prior to using this
4225  * function the context has to be allocated with avcodec_alloc_context3().
4226  *
4227  * The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(),
4228  * avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for
4229  * retrieving a codec.
4230  *
4231  * @warning This function is not thread safe!
4232  *
4233  * @note Always call this function before using decoding routines (such as
4234  * @ref avcodec_receive_frame()).
4235  *
4236  * @code
4237  * avcodec_register_all();
4238  * av_dict_set(&opts, "b", "2.5M", 0);
4239  * codec = avcodec_find_decoder(AV_CODEC_ID_H264);
4240  * if (!codec)
4241  * exit(1);
4242  *
4243  * context = avcodec_alloc_context3(codec);
4244  *
4245  * if (avcodec_open2(context, codec, opts) < 0)
4246  * exit(1);
4247  * @endcode
4248  *
4249  * @param avctx The context to initialize.
4250  * @param codec The codec to open this context for. If a non-NULL codec has been
4251  * previously passed to avcodec_alloc_context3() or
4252  * for this context, then this parameter MUST be either NULL or
4253  * equal to the previously passed codec.
4254  * @param options A dictionary filled with AVCodecContext and codec-private options.
4255  * On return this object will be filled with options that were not found.
4256  *
4257  * @return zero on success, a negative value on error
4258  * @see avcodec_alloc_context3(), avcodec_find_decoder(), avcodec_find_encoder(),
4259  * av_dict_set(), av_opt_find().
4260  */
4261 int avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options);
4262 
4263 /**
4264  * Close a given AVCodecContext and free all the data associated with it
4265  * (but not the AVCodecContext itself).
4266  *
4267  * Calling this function on an AVCodecContext that hasn't been opened will free
4268  * the codec-specific data allocated in avcodec_alloc_context3() with a non-NULL
4269  * codec. Subsequent calls will do nothing.
4270  *
4271  * @note Do not use this function. Use avcodec_free_context() to destroy a
4272  * codec context (either open or closed). Opening and closing a codec context
4273  * multiple times is not supported anymore -- use multiple codec contexts
4274  * instead.
4275  */
4276 int avcodec_close(AVCodecContext *avctx);
4277 
4278 /**
4279  * Free all allocated data in the given subtitle struct.
4280  *
4281  * @param sub AVSubtitle to free.
4282  */
4283 void avsubtitle_free(AVSubtitle *sub);
4284 
4285 /**
4286  * @}
4287  */
4288 
4289 /**
4290  * @addtogroup lavc_packet
4291  * @{
4292  */
4293 
4294 /**
4295  * Allocate an AVPacket and set its fields to default values. The resulting
4296  * struct must be freed using av_packet_free().
4297  *
4298  * @return An AVPacket filled with default values or NULL on failure.
4299  *
4300  * @note this only allocates the AVPacket itself, not the data buffers. Those
4301  * must be allocated through other means such as av_new_packet.
4302  *
4303  * @see av_new_packet
4304  */
4305 AVPacket *av_packet_alloc(void);
4306 
4307 /**
4308  * Create a new packet that references the same data as src.
4309  *
4310  * This is a shortcut for av_packet_alloc()+av_packet_ref().
4311  *
4312  * @return newly created AVPacket on success, NULL on error.
4313  *
4314  * @see av_packet_alloc
4315  * @see av_packet_ref
4316  */
4318 
4319 /**
4320  * Free the packet, if the packet is reference counted, it will be
4321  * unreferenced first.
4322  *
4323  * @param pkt packet to be freed. The pointer will be set to NULL.
4324  * @note passing NULL is a no-op.
4325  */
4326 void av_packet_free(AVPacket **pkt);
4327 
4328 /**
4329  * Initialize optional fields of a packet with default values.
4330  *
4331  * Note, this does not touch the data and size members, which have to be
4332  * initialized separately.
4333  *
4334  * @param pkt packet
4335  */
4336 void av_init_packet(AVPacket *pkt);
4337 
4338 /**
4339  * Allocate the payload of a packet and initialize its fields with
4340  * default values.
4341  *
4342  * @param pkt packet
4343  * @param size wanted payload size
4344  * @return 0 if OK, AVERROR_xxx otherwise
4345  */
4346 int av_new_packet(AVPacket *pkt, int size);
4347 
4348 /**
4349  * Reduce packet size, correctly zeroing padding
4350  *
4351  * @param pkt packet
4352  * @param size new size
4353  */
4354 void av_shrink_packet(AVPacket *pkt, int size);
4355 
4356 /**
4357  * Increase packet size, correctly zeroing padding
4358  *
4359  * @param pkt packet
4360  * @param grow_by number of bytes by which to increase the size of the packet
4361  */
4362 int av_grow_packet(AVPacket *pkt, int grow_by);
4363 
4364 /**
4365  * Initialize a reference-counted packet from av_malloc()ed data.
4366  *
4367  * @param pkt packet to be initialized. This function will set the data, size,
4368  * buf and destruct fields, all others are left untouched.
4369  * @param data Data allocated by av_malloc() to be used as packet data. If this
4370  * function returns successfully, the data is owned by the underlying AVBuffer.
4371  * The caller may not access the data through other means.
4372  * @param size size of data in bytes, without the padding. I.e. the full buffer
4373  * size is assumed to be size + AV_INPUT_BUFFER_PADDING_SIZE.
4374  *
4375  * @return 0 on success, a negative AVERROR on error
4376  */
4378 
4379 #if FF_API_AVPACKET_OLD_API
4380 /**
4381  * @warning This is a hack - the packet memory allocation stuff is broken. The
4382  * packet is allocated if it was not really allocated.
4383  *
4384  * @deprecated Use av_packet_ref or av_packet_make_refcounted
4385  */
4387 int av_dup_packet(AVPacket *pkt);
4388 /**
4389  * Copy packet, including contents
4390  *
4391  * @return 0 on success, negative AVERROR on fail
4392  *
4393  * @deprecated Use av_packet_ref
4394  */
4396 int av_copy_packet(AVPacket *dst, const AVPacket *src);
4397 
4398 /**
4399  * Copy packet side data
4400  *
4401  * @return 0 on success, negative AVERROR on fail
4402  *
4403  * @deprecated Use av_packet_copy_props
4404  */
4406 int av_copy_packet_side_data(AVPacket *dst, const AVPacket *src);
4407 
4408 /**
4409  * Free a packet.
4410  *
4411  * @deprecated Use av_packet_unref
4412  *
4413  * @param pkt packet to free
4414  */
4416 void av_free_packet(AVPacket *pkt);
4417 #endif
4418 /**
4419  * Allocate new information of a packet.
4420  *
4421  * @param pkt packet
4422  * @param type side information type
4423  * @param size side information size
4424  * @return pointer to fresh allocated data or NULL otherwise
4425  */
4427  int size);
4428 
4429 /**
4430  * Wrap an existing array as a packet side data.
4431  *
4432  * @param pkt packet
4433  * @param type side information type
4434  * @param data the side data array. It must be allocated with the av_malloc()
4435  * family of functions. The ownership of the data is transferred to
4436  * pkt.
4437  * @param size side information size
4438  * @return a non-negative number on success, a negative AVERROR code on
4439  * failure. On failure, the packet is unchanged and the data remains
4440  * owned by the caller.
4441  */
4443  uint8_t *data, size_t size);
4444 
4445 /**
4446  * Shrink the already allocated side data buffer
4447  *
4448  * @param pkt packet
4449  * @param type side information type
4450  * @param size new side information size
4451  * @return 0 on success, < 0 on failure
4452  */
4454  int size);
4455 
4456 /**
4457  * Get side information from packet.
4458  *
4459  * @param pkt packet
4460  * @param type desired side information type
4461  * @param size pointer for side information size to store (optional)
4462  * @return pointer to data if present or NULL otherwise
4463  */
4465  int *size);
4466 
4467 #if FF_API_MERGE_SD_API
4470 
4473 #endif
4474 
4476 
4477 /**
4478  * Pack a dictionary for use in side_data.
4479  *
4480  * @param dict The dictionary to pack.
4481  * @param size pointer to store the size of the returned data
4482  * @return pointer to data if successful, NULL otherwise
4483  */
4485 /**
4486  * Unpack a dictionary from side_data.
4487  *
4488  * @param data data from side_data
4489  * @param size size of the data
4490  * @param dict the metadata storage dictionary
4491  * @return 0 on success, < 0 on failure
4492  */
4493 int av_packet_unpack_dictionary(const uint8_t *data, int size, AVDictionary **dict);
4494 
4495 
4496 /**
4497  * Convenience function to free all the side data stored.
4498  * All the other fields stay untouched.
4499  *
4500  * @param pkt packet
4501  */
4503 
4504 /**
4505  * Setup a new reference to the data described by a given packet
4506  *
4507  * If src is reference-counted, setup dst as a new reference to the
4508  * buffer in src. Otherwise allocate a new buffer in dst and copy the
4509  * data from src into it.
4510  *
4511  * All the other fields are copied from src.
4512  *
4513  * @see av_packet_unref
4514  *
4515  * @param dst Destination packet
4516  * @param src Source packet
4517  *
4518  * @return 0 on success, a negative AVERROR on error.
4519  */
4520 int av_packet_ref(AVPacket *dst, const AVPacket *src);
4521 
4522 /**
4523  * Wipe the packet.
4524  *
4525  * Unreference the buffer referenced by the packet and reset the
4526  * remaining packet fields to their default values.
4527  *
4528  * @param pkt The packet to be unreferenced.
4529  */
4531 
4532 /**
4533  * Move every field in src to dst and reset src.
4534  *
4535  * @see av_packet_unref
4536  *
4537  * @param src Source packet, will be reset
4538  * @param dst Destination packet
4539  */
4541 
4542 /**
4543  * Copy only "properties" fields from src to dst.
4544  *
4545  * Properties for the purpose of this function are all the fields
4546  * beside those related to the packet data (buf, data, size)
4547  *
4548  * @param dst Destination packet
4549  * @param src Source packet
4550  *
4551  * @return 0 on success AVERROR on failure.
4552  */
4553 int av_packet_copy_props(AVPacket *dst, const AVPacket *src);
4554 
4555 /**
4556  * Ensure the data described by a given packet is reference counted.
4557  *
4558  * @note This function does not ensure that the reference will be writable.
4559  * Use av_packet_make_writable instead for that purpose.
4560  *
4561  * @see av_packet_ref
4562  * @see av_packet_make_writable
4563  *
4564  * @param pkt packet whose data should be made reference counted.
4565  *
4566  * @return 0 on success, a negative AVERROR on error. On failure, the
4567  * packet is unchanged.
4568  */
4570 
4571 /**
4572  * Create a writable reference for the data described by a given packet,
4573  * avoiding data copy if possible.
4574  *
4575  * @param pkt Packet whose data should be made writable.
4576  *
4577  * @return 0 on success, a negative AVERROR on failure. On failure, the
4578  * packet is unchanged.
4579  */
4581 
4582 /**
4583  * Convert valid timing fields (timestamps / durations) in a packet from one
4584  * timebase to another. Timestamps with unknown values (AV_NOPTS_VALUE) will be
4585  * ignored.
4586  *
4587  * @param pkt packet on which the conversion will be performed
4588  * @param tb_src source timebase, in which the timing fields in pkt are
4589  * expressed
4590  * @param tb_dst destination timebase, to which the timing fields will be
4591  * converted
4592  */
4593 void av_packet_rescale_ts(AVPacket *pkt, AVRational tb_src, AVRational tb_dst);
4594 
4595 /**
4596  * @}
4597  */
4598 
4599 /**
4600  * @addtogroup lavc_decoding
4601  * @{
4602  */
4603 
4604 /**
4605  * Find a registered decoder with a matching codec ID.
4606  *
4607  * @param id AVCodecID of the requested decoder
4608  * @return A decoder if one was found, NULL otherwise.
4609  */
4611 
4612 /**
4613  * Find a registered decoder with the specified name.
4614  *
4615  * @param name name of the requested decoder
4616  * @return A decoder if one was found, NULL otherwise.
4617  */
4619 
4620 /**
4621  * The default callback for AVCodecContext.get_buffer2(). It is made public so
4622  * it can be called by custom get_buffer2() implementations for decoders without
4623  * AV_CODEC_CAP_DR1 set.
4624  */
4626 
4627 /**
4628  * Modify width and height values so that they will result in a memory
4629  * buffer that is acceptable for the codec if you do not use any horizontal
4630  * padding.
4631  *
4632  * May only be used if a codec with AV_CODEC_CAP_DR1 has been opened.
4633  */
4635 
4636 /**
4637  * Modify width and height values so that they will result in a memory
4638  * buffer that is acceptable for the codec if you also ensure that all
4639  * line sizes are a multiple of the respective linesize_align[i].
4640  *
4641  * May only be used if a codec with AV_CODEC_CAP_DR1 has been opened.
4642  */
4644  int linesize_align[AV_NUM_DATA_POINTERS]);
4645 
4646 /**
4647  * Converts AVChromaLocation to swscale x/y chroma position.
4648  *
4649  * The positions represent the chroma (0,0) position in a coordinates system
4650  * with luma (0,0) representing the origin and luma(1,1) representing 256,256
4651  *
4652  * @param xpos horizontal chroma sample position
4653  * @param ypos vertical chroma sample position
4654  */
4655 int avcodec_enum_to_chroma_pos(int *xpos, int *ypos, enum AVChromaLocation pos);
4656 
4657 /**
4658  * Converts swscale x/y chroma position to AVChromaLocation.
4659  *
4660  * The positions represent the chroma (0,0) position in a coordinates system
4661  * with luma (0,0) representing the origin and luma(1,1) representing 256,256
4662  *
4663  * @param xpos horizontal chroma sample position
4664  * @param ypos vertical chroma sample position
4665  */
4666 enum AVChromaLocation avcodec_chroma_pos_to_enum(int xpos, int ypos);
4667 
4668 /**
4669  * Decode the audio frame of size avpkt->size from avpkt->data into frame.
4670  *
4671  * Some decoders may support multiple frames in a single AVPacket. Such
4672  * decoders would then just decode the first frame and the return value would be
4673  * less than the packet size. In this case, avcodec_decode_audio4 has to be
4674  * called again with an AVPacket containing the remaining data in order to
4675  * decode the second frame, etc... Even if no frames are returned, the packet
4676  * needs to be fed to the decoder with remaining data until it is completely
4677  * consumed or an error occurs.
4678  *
4679  * Some decoders (those marked with AV_CODEC_CAP_DELAY) have a delay between input
4680  * and output. This means that for some packets they will not immediately
4681  * produce decoded output and need to be flushed at the end of decoding to get
4682  * all the decoded data. Flushing is done by calling this function with packets
4683  * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
4684  * returning samples. It is safe to flush even those decoders that are not
4685  * marked with AV_CODEC_CAP_DELAY, then no samples will be returned.
4686  *
4687  * @warning The input buffer, avpkt->data must be AV_INPUT_BUFFER_PADDING_SIZE
4688  * larger than the actual read bytes because some optimized bitstream
4689  * readers read 32 or 64 bits at once and could read over the end.
4690  *
4691  * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
4692  * before packets may be fed to the decoder.
4693  *
4694  * @param avctx the codec context
4695  * @param[out] frame The AVFrame in which to store decoded audio samples.
4696  * The decoder will allocate a buffer for the decoded frame by
4697  * calling the AVCodecContext.get_buffer2() callback.
4698  * When AVCodecContext.refcounted_frames is set to 1, the frame is
4699  * reference counted and the returned reference belongs to the
4700  * caller. The caller must release the frame using av_frame_unref()
4701  * when the frame is no longer needed. The caller may safely write
4702  * to the frame if av_frame_is_writable() returns 1.
4703  * When AVCodecContext.refcounted_frames is set to 0, the returned
4704  * reference belongs to the decoder and is valid only until the
4705  * next call to this function or until closing or flushing the
4706  * decoder. The caller may not write to it.
4707  * @param[out] got_frame_ptr Zero if no frame could be decoded, otherwise it is
4708  * non-zero. Note that this field being set to zero
4709  * does not mean that an error has occurred. For
4710  * decoders with AV_CODEC_CAP_DELAY set, no given decode
4711  * call is guaranteed to produce a frame.
4712  * @param[in] avpkt The input AVPacket containing the input buffer.
4713  * At least avpkt->data and avpkt->size should be set. Some
4714  * decoders might also require additional fields to be set.
4715  * @return A negative error code is returned if an error occurred during
4716  * decoding, otherwise the number of bytes consumed from the input
4717  * AVPacket is returned.
4718  *
4719 * @deprecated Use avcodec_send_packet() and avcodec_receive_frame().
4720  */
4723  int *got_frame_ptr, const AVPacket *avpkt);
4724 
4725 /**
4726  * Decode the video frame of size avpkt->size from avpkt->data into picture.
4727  * Some decoders may support multiple frames in a single AVPacket, such
4728  * decoders would then just decode the first frame.
4729  *
4730  * @warning The input buffer must be AV_INPUT_BUFFER_PADDING_SIZE larger than
4731  * the actual read bytes because some optimized bitstream readers read 32 or 64
4732  * bits at once and could read over the end.
4733  *
4734  * @warning The end of the input buffer buf should be set to 0 to ensure that
4735  * no overreading happens for damaged MPEG streams.
4736  *
4737  * @note Codecs which have the AV_CODEC_CAP_DELAY capability set have a delay
4738  * between input and output, these need to be fed with avpkt->data=NULL,
4739  * avpkt->size=0 at the end to return the remaining frames.
4740  *
4741  * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
4742  * before packets may be fed to the decoder.
4743  *
4744  * @param avctx the codec context
4745  * @param[out] picture The AVFrame in which the decoded video frame will be stored.
4746  * Use av_frame_alloc() to get an AVFrame. The codec will
4747  * allocate memory for the actual bitmap by calling the
4748  * AVCodecContext.get_buffer2() callback.
4749  * When AVCodecContext.refcounted_frames is set to 1, the frame is
4750  * reference counted and the returned reference belongs to the
4751  * caller. The caller must release the frame using av_frame_unref()
4752  * when the frame is no longer needed. The caller may safely write
4753  * to the frame if av_frame_is_writable() returns 1.
4754  * When AVCodecContext.refcounted_frames is set to 0, the returned
4755  * reference belongs to the decoder and is valid only until the
4756  * next call to this function or until closing or flushing the
4757  * decoder. The caller may not write to it.
4758  *
4759  * @param[in] avpkt The input AVPacket containing the input buffer.
4760  * You can create such packet with av_init_packet() and by then setting
4761  * data and size, some decoders might in addition need other fields like
4762  * flags&AV_PKT_FLAG_KEY. All decoders are designed to use the least
4763  * fields possible.
4764  * @param[in,out] got_picture_ptr Zero if no frame could be decompressed, otherwise, it is nonzero.
4765  * @return On error a negative value is returned, otherwise the number of bytes
4766  * used or zero if no frame could be decompressed.
4767  *
4768  * @deprecated Use avcodec_send_packet() and avcodec_receive_frame().
4769  */
4771 int avcodec_decode_video2(AVCodecContext *avctx, AVFrame *picture,
4772  int *got_picture_ptr,
4773  const AVPacket *avpkt);
4774 
4775 /**
4776  * Decode a subtitle message.
4777  * Return a negative value on error, otherwise return the number of bytes used.
4778  * If no subtitle could be decompressed, got_sub_ptr is zero.
4779  * Otherwise, the subtitle is stored in *sub.
4780  * Note that AV_CODEC_CAP_DR1 is not available for subtitle codecs. This is for
4781  * simplicity, because the performance difference is expect to be negligible
4782  * and reusing a get_buffer written for video codecs would probably perform badly
4783  * due to a potentially very different allocation pattern.
4784  *
4785  * Some decoders (those marked with AV_CODEC_CAP_DELAY) have a delay between input
4786  * and output. This means that for some packets they will not immediately
4787  * produce decoded output and need to be flushed at the end of decoding to get
4788  * all the decoded data. Flushing is done by calling this function with packets
4789  * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
4790  * returning subtitles. It is safe to flush even those decoders that are not
4791  * marked with AV_CODEC_CAP_DELAY, then no subtitles will be returned.
4792  *
4793  * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
4794  * before packets may be fed to the decoder.
4795  *
4796  * @param avctx the codec context
4797  * @param[out] sub The Preallocated AVSubtitle in which the decoded subtitle will be stored,
4798  * must be freed with avsubtitle_free if *got_sub_ptr is set.
4799  * @param[in,out] got_sub_ptr Zero if no subtitle could be decompressed, otherwise, it is nonzero.
4800  * @param[in] avpkt The input AVPacket containing the input buffer.
4801  */
4803  int *got_sub_ptr,
4804  AVPacket *avpkt);
4805 
4806 /**
4807  * Supply raw packet data as input to a decoder.
4808  *
4809  * Internally, this call will copy relevant AVCodecContext fields, which can
4810  * influence decoding per-packet, and apply them when the packet is actually
4811  * decoded. (For example AVCodecContext.skip_frame, which might direct the
4812  * decoder to drop the frame contained by the packet sent with this function.)
4813  *
4814  * @warning The input buffer, avpkt->data must be AV_INPUT_BUFFER_PADDING_SIZE
4815  * larger than the actual read bytes because some optimized bitstream
4816  * readers read 32 or 64 bits at once and could read over the end.
4817  *
4818  * @warning Do not mix this API with the legacy API (like avcodec_decode_video2())
4819  * on the same AVCodecContext. It will return unexpected results now
4820  * or in future libavcodec versions.
4821  *
4822  * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
4823  * before packets may be fed to the decoder.
4824  *
4825  * @param avctx codec context
4826  * @param[in] avpkt The input AVPacket. Usually, this will be a single video
4827  * frame, or several complete audio frames.
4828  * Ownership of the packet remains with the caller, and the
4829  * decoder will not write to the packet. The decoder may create
4830  * a reference to the packet data (or copy it if the packet is
4831  * not reference-counted).
4832  * Unlike with older APIs, the packet is always fully consumed,
4833  * and if it contains multiple frames (e.g. some audio codecs),
4834  * will require you to call avcodec_receive_frame() multiple
4835  * times afterwards before you can send a new packet.
4836  * It can be NULL (or an AVPacket with data set to NULL and
4837  * size set to 0); in this case, it is considered a flush
4838  * packet, which signals the end of the stream. Sending the
4839  * first flush packet will return success. Subsequent ones are
4840  * unnecessary and will return AVERROR_EOF. If the decoder
4841  * still has frames buffered, it will return them after sending
4842  * a flush packet.
4843  *
4844  * @return 0 on success, otherwise negative error code:
4845  * AVERROR(EAGAIN): input is not accepted in the current state - user
4846  * must read output with avcodec_receive_frame() (once
4847  * all output is read, the packet should be resent, and
4848  * the call will not fail with EAGAIN).
4849  * AVERROR_EOF: the decoder has been flushed, and no new packets can
4850  * be sent to it (also returned if more than 1 flush
4851  * packet is sent)
4852  * AVERROR(EINVAL): codec not opened, it is an encoder, or requires flush
4853  * AVERROR(ENOMEM): failed to add packet to internal queue, or similar
4854  * other errors: legitimate decoding errors
4855  */
4856 int avcodec_send_packet(AVCodecContext *avctx, const AVPacket *avpkt);
4857 
4858 /**
4859  * Return decoded output data from a decoder.
4860  *
4861  * @param avctx codec context
4862  * @param frame This will be set to a reference-counted video or audio
4863  * frame (depending on the decoder type) allocated by the
4864  * decoder. Note that the function will always call
4865  * av_frame_unref(frame) before doing anything else.
4866  *
4867  * @return
4868  * 0: success, a frame was returned
4869  * AVERROR(EAGAIN): output is not available in this state - user must try
4870  * to send new input
4871  * AVERROR_EOF: the decoder has been fully flushed, and there will be
4872  * no more output frames
4873  * AVERROR(EINVAL): codec not opened, or it is an encoder
4874  * other negative values: legitimate decoding errors
4875  */
4877 
4878 /**
4879  * Supply a raw video or audio frame to the encoder. Use avcodec_receive_packet()
4880  * to retrieve buffered output packets.
4881  *
4882  * @param avctx codec context
4883  * @param[in] frame AVFrame containing the raw audio or video frame to be encoded.
4884  * Ownership of the frame remains with the caller, and the
4885  * encoder will not write to the frame. The encoder may create
4886  * a reference to the frame data (or copy it if the frame is
4887  * not reference-counted).
4888  * It can be NULL, in which case it is considered a flush
4889  * packet. This signals the end of the stream. If the encoder
4890  * still has packets buffered, it will return them after this
4891  * call. Once flushing mode has been entered, additional flush
4892  * packets are ignored, and sending frames will return
4893  * AVERROR_EOF.
4894  *
4895  * For audio:
4896  * If AV_CODEC_CAP_VARIABLE_FRAME_SIZE is set, then each frame
4897  * can have any number of samples.
4898  * If it is not set, frame->nb_samples must be equal to
4899  * avctx->frame_size for all frames except the last.
4900  * The final frame may be smaller than avctx->frame_size.
4901  * @return 0 on success, otherwise negative error code:
4902  * AVERROR(EAGAIN): input is not accepted in the current state - user
4903  * must read output with avcodec_receive_packet() (once
4904  * all output is read, the packet should be resent, and
4905  * the call will not fail with EAGAIN).
4906  * AVERROR_EOF: the encoder has been flushed, and no new frames can
4907  * be sent to it
4908  * AVERROR(EINVAL): codec not opened, refcounted_frames not set, it is a
4909  * decoder, or requires flush
4910  * AVERROR(ENOMEM): failed to add packet to internal queue, or similar
4911  * other errors: legitimate decoding errors
4912  */
4913 int avcodec_send_frame(AVCodecContext *avctx, const AVFrame *frame);
4914 
4915 /**
4916  * Read encoded data from the encoder.
4917  *
4918  * @param avctx codec context
4919  * @param avpkt This will be set to a reference-counted packet allocated by the
4920  * encoder. Note that the function will always call
4921  * av_frame_unref(frame) before doing anything else.
4922  * @return 0 on success, otherwise negative error code:
4923  * AVERROR(EAGAIN): output is not available in the current state - user
4924  * must try to send input
4925  * AVERROR_EOF: the encoder has been fully flushed, and there will be
4926  * no more output packets
4927  * AVERROR(EINVAL): codec not opened, or it is an encoder
4928  * other errors: legitimate decoding errors
4929  */
4930 int avcodec_receive_packet(AVCodecContext *avctx, AVPacket *avpkt);
4931 
4932 /**
4933  * Create and return a AVHWFramesContext with values adequate for hardware
4934  * decoding. This is meant to get called from the get_format callback, and is
4935  * a helper for preparing a AVHWFramesContext for AVCodecContext.hw_frames_ctx.
4936  * This API is for decoding with certain hardware acceleration modes/APIs only.
4937  *
4938  * The returned AVHWFramesContext is not initialized. The caller must do this
4939  * with av_hwframe_ctx_init().
4940  *
4941  * Calling this function is not a requirement, but makes it simpler to avoid
4942  * codec or hardware API specific details when manually allocating frames.
4943  *
4944  * Alternatively to this, an API user can set AVCodecContext.hw_device_ctx,
4945  * which sets up AVCodecContext.hw_frames_ctx fully automatically, and makes
4946  * it unnecessary to call this function or having to care about
4947  * AVHWFramesContext initialization at all.
4948  *
4949  * There are a number of requirements for calling this function:
4950  *
4951  * - It must be called from get_format with the same avctx parameter that was
4952  * passed to get_format. Calling it outside of get_format is not allowed, and
4953  * can trigger undefined behavior.
4954  * - The function is not always supported (see description of return values).
4955  * Even if this function returns successfully, hwaccel initialization could
4956  * fail later. (The degree to which implementations check whether the stream
4957  * is actually supported varies. Some do this check only after the user's
4958  * get_format callback returns.)
4959  * - The hw_pix_fmt must be one of the choices suggested by get_format. If the
4960  * user decides to use a AVHWFramesContext prepared with this API function,
4961  * the user must return the same hw_pix_fmt from get_format.
4962  * - The device_ref passed to this function must support the given hw_pix_fmt.
4963  * - After calling this API function, it is the user's responsibility to
4964  * initialize the AVHWFramesContext (returned by the out_frames_ref parameter),
4965  * and to set AVCodecContext.hw_frames_ctx to it. If done, this must be done
4966  * before returning from get_format (this is implied by the normal
4967  * AVCodecContext.hw_frames_ctx API rules).
4968  * - The AVHWFramesContext parameters may change every time time get_format is
4969  * called. Also, AVCodecContext.hw_frames_ctx is reset before get_format. So
4970  * you are inherently required to go through this process again on every
4971  * get_format call.
4972  * - It is perfectly possible to call this function without actually using
4973  * the resulting AVHWFramesContext. One use-case might be trying to reuse a
4974  * previously initialized AVHWFramesContext, and calling this API function
4975  * only to test whether the required frame parameters have changed.
4976  * - Fields that use dynamically allocated values of any kind must not be set
4977  * by the user unless setting them is explicitly allowed by the documentation.
4978  * If the user sets AVHWFramesContext.free and AVHWFramesContext.user_opaque,
4979  * the new free callback must call the potentially set previous free callback.
4980  * This API call may set any dynamically allocated fields, including the free
4981  * callback.
4982  *
4983  * The function will set at least the following fields on AVHWFramesContext
4984  * (potentially more, depending on hwaccel API):
4985  *
4986  * - All fields set by av_hwframe_ctx_alloc().
4987  * - Set the format field to hw_pix_fmt.
4988  * - Set the sw_format field to the most suited and most versatile format. (An
4989  * implication is that this will prefer generic formats over opaque formats
4990  * with arbitrary restrictions, if possible.)
4991  * - Set the width/height fields to the coded frame size, rounded up to the
4992  * API-specific minimum alignment.
4993  * - Only _if_ the hwaccel requires a pre-allocated pool: set the initial_pool_size
4994  * field to the number of maximum reference surfaces possible with the codec,
4995  * plus 1 surface for the user to work (meaning the user can safely reference
4996  * at most 1 decoded surface at a time), plus additional buffering introduced
4997  * by frame threading. If the hwaccel does not require pre-allocation, the
4998  * field is left to 0, and the decoder will allocate new surfaces on demand
4999  * during decoding.
5000  * - Possibly AVHWFramesContext.hwctx fields, depending on the underlying
5001  * hardware API.
5002  *
5003  * Essentially, out_frames_ref returns the same as av_hwframe_ctx_alloc(), but
5004  * with basic frame parameters set.
5005  *
5006  * The function is stateless, and does not change the AVCodecContext or the
5007  * device_ref AVHWDeviceContext.
5008  *
5009  * @param avctx The context which is currently calling get_format, and which
5010  * implicitly contains all state needed for filling the returned
5011  * AVHWFramesContext properly.
5012  * @param device_ref A reference to the AVHWDeviceContext describing the device
5013  * which will be used by the hardware decoder.
5014  * @param hw_pix_fmt The hwaccel format you are going to return from get_format.
5015  * @param out_frames_ref On success, set to a reference to an _uninitialized_
5016  * AVHWFramesContext, created from the given device_ref.
5017  * Fields will be set to values required for decoding.
5018  * Not changed if an error is returned.
5019  * @return zero on success, a negative value on error. The following error codes
5020  * have special semantics:
5021  * AVERROR(ENOENT): the decoder does not support this functionality. Setup
5022  * is always manual, or it is a decoder which does not
5023  * support setting AVCodecContext.hw_frames_ctx at all,
5024  * or it is a software format.
5025  * AVERROR(EINVAL): it is known that hardware decoding is not supported for
5026  * this configuration, or the device_ref is not supported
5027  * for the hwaccel referenced by hw_pix_fmt.
5028  */
5030  AVBufferRef *device_ref,
5032  AVBufferRef **out_frames_ref);
5033 
5034 
5035 
5036 /**
5037  * @defgroup lavc_parsing Frame parsing
5038  * @{
5039  */
5040 
5043  AV_PICTURE_STRUCTURE_TOP_FIELD, //< coded as top field
5044  AV_PICTURE_STRUCTURE_BOTTOM_FIELD, //< coded as bottom field
5045  AV_PICTURE_STRUCTURE_FRAME, //< coded as frame
5046 };
5047 
5048 typedef struct AVCodecParserContext {
5049  void *priv_data;
5051  int64_t frame_offset; /* offset of the current frame */
5052  int64_t cur_offset; /* current offset
5053  (incremented by each av_parser_parse()) */
5054  int64_t next_frame_offset; /* offset of the next frame */
5055  /* video info */
5056  int pict_type; /* XXX: Put it back in AVCodecContext. */
5057  /**
5058  * This field is used for proper frame duration computation in lavf.
5059  * It signals, how much longer the frame duration of the current frame
5060  * is compared to normal frame duration.
5061  *
5062  * frame_duration = (1 + repeat_pict) * time_base
5063  *
5064  * It is used by codecs like H.264 to display telecined material.
5065  */
5066  int repeat_pict; /* XXX: Put it back in AVCodecContext. */
5067  int64_t pts; /* pts of the current frame */
5068  int64_t dts; /* dts of the current frame */
5069 
5070  /* private data */
5071  int64_t last_pts;
5072  int64_t last_dts;
5074 
5075 #define AV_PARSER_PTS_NB 4
5080 
5081  int flags;
5082 #define PARSER_FLAG_COMPLETE_FRAMES 0x0001
5083 #define PARSER_FLAG_ONCE 0x0002
5084 /// Set if the parser has a valid file offset
5085 #define PARSER_FLAG_FETCHED_OFFSET 0x0004
5086 #define PARSER_FLAG_USE_CODEC_TS 0x1000
5087 
5088  int64_t offset; ///< byte offset from starting packet start
5090 
5091  /**
5092  * Set by parser to 1 for key frames and 0 for non-key frames.
5093  * It is initialized to -1, so if the parser doesn't set this flag,
5094  * old-style fallback using AV_PICTURE_TYPE_I picture type as key frames
5095  * will be used.
5096  */
5098 
5099 #if FF_API_CONVERGENCE_DURATION
5100  /**
5101  * @deprecated unused
5102  */
5105 #endif
5106 
5107  // Timestamp generation support:
5108  /**
5109  * Synchronization point for start of timestamp generation.
5110  *
5111  * Set to >0 for sync point, 0 for no sync point and <0 for undefined
5112  * (default).
5113  *
5114  * For example, this corresponds to presence of H.264 buffering period
5115  * SEI message.
5116  */
5118 
5119  /**
5120  * Offset of the current timestamp against last timestamp sync point in
5121  * units of AVCodecContext.time_base.
5122  *
5123  * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
5124  * contain a valid timestamp offset.
5125  *
5126  * Note that the timestamp of sync point has usually a nonzero
5127  * dts_ref_dts_delta, which refers to the previous sync point. Offset of
5128  * the next frame after timestamp sync point will be usually 1.
5129  *
5130  * For example, this corresponds to H.264 cpb_removal_delay.
5131  */
5133 
5134  /**
5135  * Presentation delay of current frame in units of AVCodecContext.time_base.
5136  *
5137  * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
5138  * contain valid non-negative timestamp delta (presentation time of a frame
5139  * must not lie in the past).
5140  *
5141  * This delay represents the difference between decoding and presentation
5142  * time of the frame.
5143  *
5144  * For example, this corresponds to H.264 dpb_output_delay.
5145  */
5147 
5148  /**
5149  * Position of the packet in file.
5150  *
5151  * Analogous to cur_frame_pts/dts
5152  */
5154 
5155  /**
5156  * Byte position of currently parsed frame in stream.
5157  */
5158  int64_t pos;
5159 
5160  /**
5161  * Previous frame byte position.
5162  */
5163  int64_t last_pos;
5164 
5165  /**
5166  * Duration of the current frame.
5167  * For audio, this is in units of 1 / AVCodecContext.sample_rate.
5168  * For all other types, this is in units of AVCodecContext.time_base.
5169  */
5171 
5173 
5174  /**
5175  * Indicate whether a picture is coded as a frame, top field or bottom field.
5176  *
5177  * For example, H.264 field_pic_flag equal to 0 corresponds to
5178  * AV_PICTURE_STRUCTURE_FRAME. An H.264 picture with field_pic_flag
5179  * equal to 1 and bottom_field_flag equal to 0 corresponds to
5180  * AV_PICTURE_STRUCTURE_TOP_FIELD.
5181  */
5183 
5184  /**
5185  * Picture number incremented in presentation or output order.
5186  * This field may be reinitialized at the first picture of a new sequence.
5187  *
5188  * For example, this corresponds to H.264 PicOrderCnt.
5189  */
5191 
5192  /**
5193  * Dimensions of the decoded video intended for presentation.
5194  */
5195  int width;
5196  int height;
5197 
5198  /**
5199  * Dimensions of the coded video.
5200  */
5203 
5204  /**
5205  * The format of the coded data, corresponds to enum AVPixelFormat for video
5206  * and for enum AVSampleFormat for audio.
5207  *
5208  * Note that a decoder can have considerable freedom in how exactly it
5209  * decodes the data, so the format reported here might be different from the
5210  * one returned by a decoder.
5211  */
5212  int format;
5214 
5215 typedef struct AVCodecParser {
5216  int codec_ids[5]; /* several codec IDs are permitted */
5219  /* This callback never returns an error, a negative value means that
5220  * the frame start was in a previous packet. */
5222  AVCodecContext *avctx,
5223  const uint8_t **poutbuf, int *poutbuf_size,
5224  const uint8_t *buf, int buf_size);
5226  int (*split)(AVCodecContext *avctx, const uint8_t *buf, int buf_size);
5228 } AVCodecParser;
5229 
5230 /**
5231  * Iterate over all registered codec parsers.
5232  *
5233  * @param opaque a pointer where libavcodec will store the iteration state. Must
5234  * point to NULL to start the iteration.
5235  *
5236  * @return the next registered codec parser or NULL when the iteration is
5237  * finished
5238  */
5239 const AVCodecParser *av_parser_iterate(void **opaque);
5240 
5243 
5247 
5248 /**
5249  * Parse a packet.
5250  *
5251  * @param s parser context.
5252  * @param avctx codec context.
5253  * @param poutbuf set to pointer to parsed buffer or NULL if not yet finished.
5254  * @param poutbuf_size set to size of parsed buffer or zero if not yet finished.
5255  * @param buf input buffer.
5256  * @param buf_size buffer size in bytes without the padding. I.e. the full buffer
5257  size is assumed to be buf_size + AV_INPUT_BUFFER_PADDING_SIZE.
5258  To signal EOF, this should be 0 (so that the last frame
5259  can be output).
5260  * @param pts input presentation timestamp.
5261  * @param dts input decoding timestamp.
5262  * @param pos input byte position in stream.
5263  * @return the number of bytes of the input bitstream used.
5264  *
5265  * Example:
5266  * @code
5267  * while(in_len){
5268  * len = av_parser_parse2(myparser, AVCodecContext, &data, &size,
5269  * in_data, in_len,
5270  * pts, dts, pos);
5271  * in_data += len;
5272  * in_len -= len;
5273  *
5274  * if(size)
5275  * decode_frame(data, size);
5276  * }
5277  * @endcode
5278  */
5280  AVCodecContext *avctx,
5281  uint8_t **poutbuf, int *poutbuf_size,
5282  const uint8_t *buf, int buf_size,
5283  int64_t pts, int64_t dts,
5284  int64_t pos);
5285 
5286 /**
5287  * @return 0 if the output buffer is a subset of the input, 1 if it is allocated and must be freed
5288  * @deprecated use AVBitStreamFilter
5289  */
5291  AVCodecContext *avctx,
5292  uint8_t **poutbuf, int *poutbuf_size,
5293  const uint8_t *buf, int buf_size, int keyframe);
5295 
5296 /**
5297  * @}
5298  * @}
5299  */
5300 
5301 /**
5302  * @addtogroup lavc_encoding
5303  * @{
5304  */
5305 
5306 /**
5307  * Find a registered encoder with a matching codec ID.
5308  *
5309  * @param id AVCodecID of the requested encoder
5310  * @return An encoder if one was found, NULL otherwise.
5311  */
5313 
5314 /**
5315  * Find a registered encoder with the specified name.
5316  *
5317  * @param name name of the requested encoder
5318  * @return An encoder if one was found, NULL otherwise.
5319  */
5321 
5322 /**
5323  * Encode a frame of audio.
5324  *
5325  * Takes input samples from frame and writes the next output packet, if
5326  * available, to avpkt. The output packet does not necessarily contain data for
5327  * the most recent frame, as encoders can delay, split, and combine input frames
5328  * internally as needed.
5329  *
5330  * @param avctx codec context
5331  * @param avpkt output AVPacket.
5332  * The user can supply an output buffer by setting
5333  * avpkt->data and a