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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/log.h"
40 #include "libavutil/pixfmt.h"
41 #include "libavutil/rational.h"
42 
43 #include "version.h"
44 
45 /**
46  * @defgroup libavc libavcodec
47  * Encoding/Decoding Library
48  *
49  * @{
50  *
51  * @defgroup lavc_decoding Decoding
52  * @{
53  * @}
54  *
55  * @defgroup lavc_encoding Encoding
56  * @{
57  * @}
58  *
59  * @defgroup lavc_codec Codecs
60  * @{
61  * @defgroup lavc_codec_native Native Codecs
62  * @{
63  * @}
64  * @defgroup lavc_codec_wrappers External library wrappers
65  * @{
66  * @}
67  * @defgroup lavc_codec_hwaccel Hardware Accelerators bridge
68  * @{
69  * @}
70  * @}
71  * @defgroup lavc_internal Internal
72  * @{
73  * @}
74  * @}
75  */
76 
77 /**
78  * @ingroup libavc
79  * @defgroup lavc_encdec send/receive encoding and decoding API overview
80  * @{
81  *
82  * The avcodec_send_packet()/avcodec_receive_frame()/avcodec_send_frame()/
83  * avcodec_receive_packet() functions provide an encode/decode API, which
84  * decouples input and output.
85  *
86  * The API is very similar for encoding/decoding and audio/video, and works as
87  * follows:
88  * - Set up and open the AVCodecContext as usual.
89  * - Send valid input:
90  * - For decoding, call avcodec_send_packet() to give the decoder raw
91  * compressed data in an AVPacket.
92  * - For encoding, call avcodec_send_frame() to give the encoder an AVFrame
93  * containing uncompressed audio or video.
94  * In both cases, it is recommended that AVPackets and AVFrames are
95  * refcounted, or libavcodec might have to copy the input data. (libavformat
96  * always returns refcounted AVPackets, and av_frame_get_buffer() allocates
97  * refcounted AVFrames.)
98  * - Receive output in a loop. Periodically call one of the avcodec_receive_*()
99  * functions and process their output:
100  * - For decoding, call avcodec_receive_frame(). On success, it will return
101  * an AVFrame containing uncompressed audio or video data.
102  * - For encoding, call avcodec_receive_packet(). On success, it will return
103  * an AVPacket with a compressed frame.
104  * Repeat this call until it returns AVERROR(EAGAIN) or an error. The
105  * AVERROR(EAGAIN) return value means that new input data is required to
106  * return new output. In this case, continue with sending input. For each
107  * input frame/packet, the codec will typically return 1 output frame/packet,
108  * but it can also be 0 or more than 1.
109  *
110  * At the beginning of decoding or encoding, the codec might accept multiple
111  * input frames/packets without returning a frame, until its internal buffers
112  * are filled. This situation is handled transparently if you follow the steps
113  * outlined above.
114  *
115  * In theory, sending input can result in EAGAIN - this should happen only if
116  * not all output was received. You can use this to structure alternative decode
117  * or encode loops other than the one suggested above. For example, you could
118  * try sending new input on each iteration, and try to receive output if that
119  * returns EAGAIN.
120  *
121  * End of stream situations. These require "flushing" (aka draining) the codec,
122  * as the codec might buffer multiple frames or packets internally for
123  * performance or out of necessity (consider B-frames).
124  * This is handled as follows:
125  * - Instead of valid input, send NULL to the avcodec_send_packet() (decoding)
126  * or avcodec_send_frame() (encoding) functions. This will enter draining
127  * mode.
128  * - Call avcodec_receive_frame() (decoding) or avcodec_receive_packet()
129  * (encoding) in a loop until AVERROR_EOF is returned. The functions will
130  * not return AVERROR(EAGAIN), unless you forgot to enter draining mode.
131  * - Before decoding can be resumed again, the codec has to be reset with
132  * avcodec_flush_buffers().
133  *
134  * Using the API as outlined above is highly recommended. But it is also
135  * possible to call functions outside of this rigid schema. For example, you can
136  * call avcodec_send_packet() repeatedly without calling
137  * avcodec_receive_frame(). In this case, avcodec_send_packet() will succeed
138  * until the codec's internal buffer has been filled up (which is typically of
139  * size 1 per output frame, after initial input), and then reject input with
140  * AVERROR(EAGAIN). Once it starts rejecting input, you have no choice but to
141  * read at least some output.
142  *
143  * Not all codecs will follow a rigid and predictable dataflow; the only
144  * guarantee is that an AVERROR(EAGAIN) return value on a send/receive call on
145  * one end implies that a receive/send call on the other end will succeed, or
146  * at least will not fail with AVERROR(EAGAIN). In general, no codec will
147  * permit unlimited buffering of input or output.
148  *
149  * This API replaces the following legacy functions:
150  * - avcodec_decode_video2() and avcodec_decode_audio4():
151  * Use avcodec_send_packet() to feed input to the decoder, then use
152  * avcodec_receive_frame() to receive decoded frames after each packet.
153  * Unlike with the old video decoding API, multiple frames might result from
154  * a packet. For audio, splitting the input packet into frames by partially
155  * decoding packets becomes transparent to the API user. You never need to
156  * feed an AVPacket to the API twice (unless it is rejected with AVERROR(EAGAIN) - then
157  * no data was read from the packet).
158  * Additionally, sending a flush/draining packet is required only once.
159  * - avcodec_encode_video2()/avcodec_encode_audio2():
160  * Use avcodec_send_frame() to feed input to the encoder, then use
161  * avcodec_receive_packet() to receive encoded packets.
162  * Providing user-allocated buffers for avcodec_receive_packet() is not
163  * possible.
164  * - The new API does not handle subtitles yet.
165  *
166  * Mixing new and old function calls on the same AVCodecContext is not allowed,
167  * and will result in undefined behavior.
168  *
169  * Some codecs might require using the new API; using the old API will return
170  * an error when calling it. All codecs support the new API.
171  *
172  * A codec is not allowed to return AVERROR(EAGAIN) for both sending and receiving. This
173  * would be an invalid state, which could put the codec user into an endless
174  * loop. The API has no concept of time either: it cannot happen that trying to
175  * do avcodec_send_packet() results in AVERROR(EAGAIN), but a repeated call 1 second
176  * later accepts the packet (with no other receive/flush API calls involved).
177  * The API is a strict state machine, and the passage of time is not supposed
178  * to influence it. Some timing-dependent behavior might still be deemed
179  * acceptable in certain cases. But it must never result in both send/receive
180  * returning EAGAIN at the same time at any point. It must also absolutely be
181  * avoided that the current state is "unstable" and can "flip-flop" between
182  * the send/receive APIs allowing progress. For example, it's not allowed that
183  * the codec randomly decides that it actually wants to consume a packet now
184  * instead of returning a frame, after it just returned AVERROR(EAGAIN) on an
185  * avcodec_send_packet() call.
186  * @}
187  */
188 
189 /**
190  * @defgroup lavc_core Core functions/structures.
191  * @ingroup libavc
192  *
193  * Basic definitions, functions for querying libavcodec capabilities,
194  * allocating core structures, etc.
195  * @{
196  */
197 
198 
199 /**
200  * Identify the syntax and semantics of the bitstream.
201  * The principle is roughly:
202  * Two decoders with the same ID can decode the same streams.
203  * Two encoders with the same ID can encode compatible streams.
204  * There may be slight deviations from the principle due to implementation
205  * details.
206  *
207  * If you add a codec ID to this list, add it so that
208  * 1. no value of an existing codec ID changes (that would break ABI),
209  * 2. it is as close as possible to similar codecs
210  *
211  * After adding new codec IDs, do not forget to add an entry to the codec
212  * descriptor list and bump libavcodec minor version.
213  */
214 enum AVCodecID {
216 
217  /* video codecs */
219  AV_CODEC_ID_MPEG2VIDEO, ///< preferred ID for MPEG-1/2 video decoding
220 #if FF_API_XVMC
221  AV_CODEC_ID_MPEG2VIDEO_XVMC,
222 #endif /* FF_API_XVMC */
357 #define AV_CODEC_ID_IFF_BYTERUN1 AV_CODEC_ID_IFF_ILBM
395 #define AV_CODEC_ID_H265 AV_CODEC_ID_HEVC
414 
450 
451  /* various PCM "codecs" */
452  AV_CODEC_ID_FIRST_AUDIO = 0x10000, ///< A dummy id pointing at the start of audio codecs
484 
489 
490  /* various ADPCM codecs */
522 #if FF_API_VIMA_DECODER
524 #endif
525 
536 
537  /* AMR */
540 
541  /* RealAudio codecs*/
544 
545  /* various DPCM codecs */
550 
553 
554  /* audio codecs */
555  AV_CODEC_ID_MP2 = 0x15000,
556  AV_CODEC_ID_MP3, ///< preferred ID for decoding MPEG audio layer 1, 2 or 3
573  AV_CODEC_ID_GSM, ///< as in Berlin toast format
585  AV_CODEC_ID_GSM_MS, /* as found in WAV */
587 #if FF_API_VOXWARE
589 #endif
625 
642 
643  /* subtitle codecs */
644  AV_CODEC_ID_FIRST_SUBTITLE = 0x17000, ///< A dummy ID pointing at the start of subtitle codecs.
647  AV_CODEC_ID_TEXT, ///< raw UTF-8 text
654 
670 
671  /* other specific kind of codecs (generally used for attachments) */
672  AV_CODEC_ID_FIRST_UNKNOWN = 0x18000, ///< A dummy ID pointing at the start of various fake codecs.
673  AV_CODEC_ID_TTF = 0x18000,
674 
675  AV_CODEC_ID_SCTE_35, ///< Contain timestamp estimated through PCR of program stream.
684 
685 
686  AV_CODEC_ID_PROBE = 0x19000, ///< codec_id is not known (like AV_CODEC_ID_NONE) but lavf should attempt to identify it
687 
688  AV_CODEC_ID_MPEG2TS = 0x20000, /**< _FAKE_ codec to indicate a raw MPEG-2 TS
689  * stream (only used by libavformat) */
690  AV_CODEC_ID_MPEG4SYSTEMS = 0x20001, /**< _FAKE_ codec to indicate a MPEG-4 Systems
691  * stream (only used by libavformat) */
692  AV_CODEC_ID_FFMETADATA = 0x21000, ///< Dummy codec for streams containing only metadata information.
693  AV_CODEC_ID_WRAPPED_AVFRAME = 0x21001, ///< Passthrough codec, AVFrames wrapped in AVPacket
694 };
695 
696 /**
697  * This struct describes the properties of a single codec described by an
698  * AVCodecID.
699  * @see avcodec_descriptor_get()
700  */
701 typedef struct AVCodecDescriptor {
702  enum AVCodecID id;
704  /**
705  * Name of the codec described by this descriptor. It is non-empty and
706  * unique for each codec descriptor. It should contain alphanumeric
707  * characters and '_' only.
708  */
709  const char *name;
710  /**
711  * A more descriptive name for this codec. May be NULL.
712  */
713  const char *long_name;
714  /**
715  * Codec properties, a combination of AV_CODEC_PROP_* flags.
716  */
717  int props;
718  /**
719  * MIME type(s) associated with the codec.
720  * May be NULL; if not, a NULL-terminated array of MIME types.
721  * The first item is always non-NULL and is the preferred MIME type.
722  */
723  const char *const *mime_types;
724  /**
725  * If non-NULL, an array of profiles recognized for this codec.
726  * Terminated with FF_PROFILE_UNKNOWN.
727  */
728  const struct AVProfile *profiles;
730 
731 /**
732  * Codec uses only intra compression.
733  * Video and audio codecs only.
734  */
735 #define AV_CODEC_PROP_INTRA_ONLY (1 << 0)
736 /**
737  * Codec supports lossy compression. Audio and video codecs only.
738  * @note a codec may support both lossy and lossless
739  * compression modes
740  */
741 #define AV_CODEC_PROP_LOSSY (1 << 1)
742 /**
743  * Codec supports lossless compression. Audio and video codecs only.
744  */
745 #define AV_CODEC_PROP_LOSSLESS (1 << 2)
746 /**
747  * Codec supports frame reordering. That is, the coded order (the order in which
748  * the encoded packets are output by the encoders / stored / input to the
749  * decoders) may be different from the presentation order of the corresponding
750  * frames.
751  *
752  * For codecs that do not have this property set, PTS and DTS should always be
753  * equal.
754  */
755 #define AV_CODEC_PROP_REORDER (1 << 3)
756 /**
757  * Subtitle codec is bitmap based
758  * Decoded AVSubtitle data can be read from the AVSubtitleRect->pict field.
759  */
760 #define AV_CODEC_PROP_BITMAP_SUB (1 << 16)
761 /**
762  * Subtitle codec is text based.
763  * Decoded AVSubtitle data can be read from the AVSubtitleRect->ass field.
764  */
765 #define AV_CODEC_PROP_TEXT_SUB (1 << 17)
766 
767 /**
768  * @ingroup lavc_decoding
769  * Required number of additionally allocated bytes at the end of the input bitstream for decoding.
770  * This is mainly needed because some optimized bitstream readers read
771  * 32 or 64 bit at once and could read over the end.<br>
772  * Note: If the first 23 bits of the additional bytes are not 0, then damaged
773  * MPEG bitstreams could cause overread and segfault.
774  */
775 #define AV_INPUT_BUFFER_PADDING_SIZE 32
776 
777 /**
778  * @ingroup lavc_encoding
779  * minimum encoding buffer size
780  * Used to avoid some checks during header writing.
781  */
782 #define AV_INPUT_BUFFER_MIN_SIZE 16384
783 
784 #if FF_API_WITHOUT_PREFIX
785 /**
786  * @deprecated use AV_INPUT_BUFFER_PADDING_SIZE instead
787  */
788 #define FF_INPUT_BUFFER_PADDING_SIZE 32
789 
790 /**
791  * @deprecated use AV_INPUT_BUFFER_MIN_SIZE instead
792  */
793 #define FF_MIN_BUFFER_SIZE 16384
794 #endif /* FF_API_WITHOUT_PREFIX */
795 
796 /**
797  * @ingroup lavc_encoding
798  * motion estimation type.
799  * @deprecated use codec private option instead
800  */
801 #if FF_API_MOTION_EST
803  ME_ZERO = 1, ///< no search, that is use 0,0 vector whenever one is needed
807  ME_EPZS, ///< enhanced predictive zonal search
808  ME_X1, ///< reserved for experiments
809  ME_HEX, ///< hexagon based search
810  ME_UMH, ///< uneven multi-hexagon search
811  ME_TESA, ///< transformed exhaustive search algorithm
812  ME_ITER=50, ///< iterative search
813 };
814 #endif
815 
816 /**
817  * @ingroup lavc_decoding
818  */
820  /* We leave some space between them for extensions (drop some
821  * keyframes for intra-only or drop just some bidir frames). */
822  AVDISCARD_NONE =-16, ///< discard nothing
823  AVDISCARD_DEFAULT = 0, ///< discard useless packets like 0 size packets in avi
824  AVDISCARD_NONREF = 8, ///< discard all non reference
825  AVDISCARD_BIDIR = 16, ///< discard all bidirectional frames
826  AVDISCARD_NONINTRA= 24, ///< discard all non intra frames
827  AVDISCARD_NONKEY = 32, ///< discard all frames except keyframes
828  AVDISCARD_ALL = 48, ///< discard all
829 };
830 
841  AV_AUDIO_SERVICE_TYPE_NB , ///< Not part of ABI
842 };
843 
844 /**
845  * @ingroup lavc_encoding
846  */
847 typedef struct RcOverride{
850  int qscale; // If this is 0 then quality_factor will be used instead.
852 } RcOverride;
853 
854 #if FF_API_MAX_BFRAMES
855 /**
856  * @deprecated there is no libavcodec-wide limit on the number of B-frames
857  */
858 #define FF_MAX_B_FRAMES 16
859 #endif
860 
861 /* encoding support
862  These flags can be passed in AVCodecContext.flags before initialization.
863  Note: Not everything is supported yet.
864 */
865 
866 /**
867  * Allow decoders to produce frames with data planes that are not aligned
868  * to CPU requirements (e.g. due to cropping).
869  */
870 #define AV_CODEC_FLAG_UNALIGNED (1 << 0)
871 /**
872  * Use fixed qscale.
873  */
874 #define AV_CODEC_FLAG_QSCALE (1 << 1)
875 /**
876  * 4 MV per MB allowed / advanced prediction for H.263.
877  */
878 #define AV_CODEC_FLAG_4MV (1 << 2)
879 /**
880  * Output even those frames that might be corrupted.
881  */
882 #define AV_CODEC_FLAG_OUTPUT_CORRUPT (1 << 3)
883 /**
884  * Use qpel MC.
885  */
886 #define AV_CODEC_FLAG_QPEL (1 << 4)
887 /**
888  * Use internal 2pass ratecontrol in first pass mode.
889  */
890 #define AV_CODEC_FLAG_PASS1 (1 << 9)
891 /**
892  * Use internal 2pass ratecontrol in second pass mode.
893  */
894 #define AV_CODEC_FLAG_PASS2 (1 << 10)
895 /**
896  * loop filter.
897  */
898 #define AV_CODEC_FLAG_LOOP_FILTER (1 << 11)
899 /**
900  * Only decode/encode grayscale.
901  */
902 #define AV_CODEC_FLAG_GRAY (1 << 13)
903 /**
904  * error[?] variables will be set during encoding.
905  */
906 #define AV_CODEC_FLAG_PSNR (1 << 15)
907 /**
908  * Input bitstream might be truncated at a random location
909  * instead of only at frame boundaries.
910  */
911 #define AV_CODEC_FLAG_TRUNCATED (1 << 16)
912 /**
913  * Use interlaced DCT.
914  */
915 #define AV_CODEC_FLAG_INTERLACED_DCT (1 << 18)
916 /**
917  * Force low delay.
918  */
919 #define AV_CODEC_FLAG_LOW_DELAY (1 << 19)
920 /**
921  * Place global headers in extradata instead of every keyframe.
922  */
923 #define AV_CODEC_FLAG_GLOBAL_HEADER (1 << 22)
924 /**
925  * Use only bitexact stuff (except (I)DCT).
926  */
927 #define AV_CODEC_FLAG_BITEXACT (1 << 23)
928 /* Fx : Flag for H.263+ extra options */
929 /**
930  * H.263 advanced intra coding / MPEG-4 AC prediction
931  */
932 #define AV_CODEC_FLAG_AC_PRED (1 << 24)
933 /**
934  * interlaced motion estimation
935  */
936 #define AV_CODEC_FLAG_INTERLACED_ME (1 << 29)
937 #define AV_CODEC_FLAG_CLOSED_GOP (1U << 31)
938 
939 /**
940  * Allow non spec compliant speedup tricks.
941  */
942 #define AV_CODEC_FLAG2_FAST (1 << 0)
943 /**
944  * Skip bitstream encoding.
945  */
946 #define AV_CODEC_FLAG2_NO_OUTPUT (1 << 2)
947 /**
948  * Place global headers at every keyframe instead of in extradata.
949  */
950 #define AV_CODEC_FLAG2_LOCAL_HEADER (1 << 3)
951 
952 /**
953  * timecode is in drop frame format. DEPRECATED!!!!
954  */
955 #define AV_CODEC_FLAG2_DROP_FRAME_TIMECODE (1 << 13)
956 
957 /**
958  * Input bitstream might be truncated at a packet boundaries
959  * instead of only at frame boundaries.
960  */
961 #define AV_CODEC_FLAG2_CHUNKS (1 << 15)
962 /**
963  * Discard cropping information from SPS.
964  */
965 #define AV_CODEC_FLAG2_IGNORE_CROP (1 << 16)
966 
967 /**
968  * Show all frames before the first keyframe
969  */
970 #define AV_CODEC_FLAG2_SHOW_ALL (1 << 22)
971 /**
972  * Export motion vectors through frame side data
973  */
974 #define AV_CODEC_FLAG2_EXPORT_MVS (1 << 28)
975 /**
976  * Do not skip samples and export skip information as frame side data
977  */
978 #define AV_CODEC_FLAG2_SKIP_MANUAL (1 << 29)
979 /**
980  * Do not reset ASS ReadOrder field on flush (subtitles decoding)
981  */
982 #define AV_CODEC_FLAG2_RO_FLUSH_NOOP (1 << 30)
983 
984 /* Unsupported options :
985  * Syntax Arithmetic coding (SAC)
986  * Reference Picture Selection
987  * Independent Segment Decoding */
988 /* /Fx */
989 /* codec capabilities */
990 
991 /**
992  * Decoder can use draw_horiz_band callback.
993  */
994 #define AV_CODEC_CAP_DRAW_HORIZ_BAND (1 << 0)
995 /**
996  * Codec uses get_buffer() for allocating buffers and supports custom allocators.
997  * If not set, it might not use get_buffer() at all or use operations that
998  * assume the buffer was allocated by avcodec_default_get_buffer.
999  */
1000 #define AV_CODEC_CAP_DR1 (1 << 1)
1001 #define AV_CODEC_CAP_TRUNCATED (1 << 3)
1002 /**
1003  * Encoder or decoder requires flushing with NULL input at the end in order to
1004  * give the complete and correct output.
1005  *
1006  * NOTE: If this flag is not set, the codec is guaranteed to never be fed with
1007  * with NULL data. The user can still send NULL data to the public encode
1008  * or decode function, but libavcodec will not pass it along to the codec
1009  * unless this flag is set.
1010  *
1011  * Decoders:
1012  * The decoder has a non-zero delay and needs to be fed with avpkt->data=NULL,
1013  * avpkt->size=0 at the end to get the delayed data until the decoder no longer
1014  * returns frames.
1015  *
1016  * Encoders:
1017  * The encoder needs to be fed with NULL data at the end of encoding until the
1018  * encoder no longer returns data.
1019  *
1020  * NOTE: For encoders implementing the AVCodec.encode2() function, setting this
1021  * flag also means that the encoder must set the pts and duration for
1022  * each output packet. If this flag is not set, the pts and duration will
1023  * be determined by libavcodec from the input frame.
1024  */
1025 #define AV_CODEC_CAP_DELAY (1 << 5)
1026 /**
1027  * Codec can be fed a final frame with a smaller size.
1028  * This can be used to prevent truncation of the last audio samples.
1029  */
1030 #define AV_CODEC_CAP_SMALL_LAST_FRAME (1 << 6)
1031 
1032 #if FF_API_CAP_VDPAU
1033 /**
1034  * Codec can export data for HW decoding (VDPAU).
1035  */
1036 #define AV_CODEC_CAP_HWACCEL_VDPAU (1 << 7)
1037 #endif
1038 
1039 /**
1040  * Codec can output multiple frames per AVPacket
1041  * Normally demuxers return one frame at a time, demuxers which do not do
1042  * are connected to a parser to split what they return into proper frames.
1043  * This flag is reserved to the very rare category of codecs which have a
1044  * bitstream that cannot be split into frames without timeconsuming
1045  * operations like full decoding. Demuxers carrying such bitstreams thus
1046  * may return multiple frames in a packet. This has many disadvantages like
1047  * prohibiting stream copy in many cases thus it should only be considered
1048  * as a last resort.
1049  */
1050 #define AV_CODEC_CAP_SUBFRAMES (1 << 8)
1051 /**
1052  * Codec is experimental and is thus avoided in favor of non experimental
1053  * encoders
1054  */
1055 #define AV_CODEC_CAP_EXPERIMENTAL (1 << 9)
1056 /**
1057  * Codec should fill in channel configuration and samplerate instead of container
1058  */
1059 #define AV_CODEC_CAP_CHANNEL_CONF (1 << 10)
1060 /**
1061  * Codec supports frame-level multithreading.
1062  */
1063 #define AV_CODEC_CAP_FRAME_THREADS (1 << 12)
1064 /**
1065  * Codec supports slice-based (or partition-based) multithreading.
1066  */
1067 #define AV_CODEC_CAP_SLICE_THREADS (1 << 13)
1068 /**
1069  * Codec supports changed parameters at any point.
1070  */
1071 #define AV_CODEC_CAP_PARAM_CHANGE (1 << 14)
1072 /**
1073  * Codec supports avctx->thread_count == 0 (auto).
1074  */
1075 #define AV_CODEC_CAP_AUTO_THREADS (1 << 15)
1076 /**
1077  * Audio encoder supports receiving a different number of samples in each call.
1078  */
1079 #define AV_CODEC_CAP_VARIABLE_FRAME_SIZE (1 << 16)
1080 /**
1081  * Decoder is not a preferred choice for probing.
1082  * This indicates that the decoder is not a good choice for probing.
1083  * It could for example be an expensive to spin up hardware decoder,
1084  * or it could simply not provide a lot of useful information about
1085  * the stream.
1086  * A decoder marked with this flag should only be used as last resort
1087  * choice for probing.
1088  */
1089 #define AV_CODEC_CAP_AVOID_PROBING (1 << 17)
1090 /**
1091  * Codec is intra only.
1092  */
1093 #define AV_CODEC_CAP_INTRA_ONLY 0x40000000
1094 /**
1095  * Codec is lossless.
1096  */
1097 #define AV_CODEC_CAP_LOSSLESS 0x80000000
1098 
1099 
1100 #if FF_API_WITHOUT_PREFIX
1101 /**
1102  * Allow decoders to produce frames with data planes that are not aligned
1103  * to CPU requirements (e.g. due to cropping).
1104  */
1105 #define CODEC_FLAG_UNALIGNED AV_CODEC_FLAG_UNALIGNED
1106 #define CODEC_FLAG_QSCALE AV_CODEC_FLAG_QSCALE
1107 #define CODEC_FLAG_4MV AV_CODEC_FLAG_4MV
1108 #define CODEC_FLAG_OUTPUT_CORRUPT AV_CODEC_FLAG_OUTPUT_CORRUPT
1109 #define CODEC_FLAG_QPEL AV_CODEC_FLAG_QPEL
1110 #if FF_API_GMC
1111 /**
1112  * @deprecated use the "gmc" private option of the libxvid encoder
1113  */
1114 #define CODEC_FLAG_GMC 0x0020 ///< Use GMC.
1115 #endif
1116 #if FF_API_MV0
1117 /**
1118  * @deprecated use the flag "mv0" in the "mpv_flags" private option of the
1119  * mpegvideo encoders
1120  */
1121 #define CODEC_FLAG_MV0 0x0040
1122 #endif
1123 #if FF_API_INPUT_PRESERVED
1124 /**
1125  * @deprecated passing reference-counted frames to the encoders replaces this
1126  * flag
1127  */
1128 #define CODEC_FLAG_INPUT_PRESERVED 0x0100
1129 #endif
1130 #define CODEC_FLAG_PASS1 AV_CODEC_FLAG_PASS1
1131 #define CODEC_FLAG_PASS2 AV_CODEC_FLAG_PASS2
1132 #define CODEC_FLAG_GRAY AV_CODEC_FLAG_GRAY
1133 #if FF_API_EMU_EDGE
1134 /**
1135  * @deprecated edges are not used/required anymore. I.e. this flag is now always
1136  * set.
1137  */
1138 #define CODEC_FLAG_EMU_EDGE 0x4000
1139 #endif
1140 #define CODEC_FLAG_PSNR AV_CODEC_FLAG_PSNR
1141 #define CODEC_FLAG_TRUNCATED AV_CODEC_FLAG_TRUNCATED
1142 
1143 #if FF_API_NORMALIZE_AQP
1144 /**
1145  * @deprecated use the flag "naq" in the "mpv_flags" private option of the
1146  * mpegvideo encoders
1147  */
1148 #define CODEC_FLAG_NORMALIZE_AQP 0x00020000
1149 #endif
1150 #define CODEC_FLAG_INTERLACED_DCT AV_CODEC_FLAG_INTERLACED_DCT
1151 #define CODEC_FLAG_LOW_DELAY AV_CODEC_FLAG_LOW_DELAY
1152 #define CODEC_FLAG_GLOBAL_HEADER AV_CODEC_FLAG_GLOBAL_HEADER
1153 #define CODEC_FLAG_BITEXACT AV_CODEC_FLAG_BITEXACT
1154 #define CODEC_FLAG_AC_PRED AV_CODEC_FLAG_AC_PRED
1155 #define CODEC_FLAG_LOOP_FILTER AV_CODEC_FLAG_LOOP_FILTER
1156 #define CODEC_FLAG_INTERLACED_ME AV_CODEC_FLAG_INTERLACED_ME
1157 #define CODEC_FLAG_CLOSED_GOP AV_CODEC_FLAG_CLOSED_GOP
1158 #define CODEC_FLAG2_FAST AV_CODEC_FLAG2_FAST
1159 #define CODEC_FLAG2_NO_OUTPUT AV_CODEC_FLAG2_NO_OUTPUT
1160 #define CODEC_FLAG2_LOCAL_HEADER AV_CODEC_FLAG2_LOCAL_HEADER
1161 #define CODEC_FLAG2_DROP_FRAME_TIMECODE AV_CODEC_FLAG2_DROP_FRAME_TIMECODE
1162 #define CODEC_FLAG2_IGNORE_CROP AV_CODEC_FLAG2_IGNORE_CROP
1163 
1164 #define CODEC_FLAG2_CHUNKS AV_CODEC_FLAG2_CHUNKS
1165 #define CODEC_FLAG2_SHOW_ALL AV_CODEC_FLAG2_SHOW_ALL
1166 #define CODEC_FLAG2_EXPORT_MVS AV_CODEC_FLAG2_EXPORT_MVS
1167 #define CODEC_FLAG2_SKIP_MANUAL AV_CODEC_FLAG2_SKIP_MANUAL
1168 
1169 /* Unsupported options :
1170  * Syntax Arithmetic coding (SAC)
1171  * Reference Picture Selection
1172  * Independent Segment Decoding */
1173 /* /Fx */
1174 /* codec capabilities */
1175 
1176 #define CODEC_CAP_DRAW_HORIZ_BAND AV_CODEC_CAP_DRAW_HORIZ_BAND ///< Decoder can use draw_horiz_band callback.
1177 /**
1178  * Codec uses get_buffer() for allocating buffers and supports custom allocators.
1179  * If not set, it might not use get_buffer() at all or use operations that
1180  * assume the buffer was allocated by avcodec_default_get_buffer.
1181  */
1182 #define CODEC_CAP_DR1 AV_CODEC_CAP_DR1
1183 #define CODEC_CAP_TRUNCATED AV_CODEC_CAP_TRUNCATED
1184 #if FF_API_XVMC
1185 /* Codec can export data for HW decoding. This flag indicates that
1186  * the codec would call get_format() with list that might contain HW accelerated
1187  * pixel formats (XvMC, VDPAU, VAAPI, etc). The application can pick any of them
1188  * including raw image format.
1189  * The application can use the passed context to determine bitstream version,
1190  * chroma format, resolution etc.
1191  */
1192 #define CODEC_CAP_HWACCEL 0x0010
1193 #endif /* FF_API_XVMC */
1194 /**
1195  * Encoder or decoder requires flushing with NULL input at the end in order to
1196  * give the complete and correct output.
1197  *
1198  * NOTE: If this flag is not set, the codec is guaranteed to never be fed with
1199  * with NULL data. The user can still send NULL data to the public encode
1200  * or decode function, but libavcodec will not pass it along to the codec
1201  * unless this flag is set.
1202  *
1203  * Decoders:
1204  * The decoder has a non-zero delay and needs to be fed with avpkt->data=NULL,
1205  * avpkt->size=0 at the end to get the delayed data until the decoder no longer
1206  * returns frames.
1207  *
1208  * Encoders:
1209  * The encoder needs to be fed with NULL data at the end of encoding until the
1210  * encoder no longer returns data.
1211  *
1212  * NOTE: For encoders implementing the AVCodec.encode2() function, setting this
1213  * flag also means that the encoder must set the pts and duration for
1214  * each output packet. If this flag is not set, the pts and duration will
1215  * be determined by libavcodec from the input frame.
1216  */
1217 #define CODEC_CAP_DELAY AV_CODEC_CAP_DELAY
1218 /**
1219  * Codec can be fed a final frame with a smaller size.
1220  * This can be used to prevent truncation of the last audio samples.
1221  */
1222 #define CODEC_CAP_SMALL_LAST_FRAME AV_CODEC_CAP_SMALL_LAST_FRAME
1223 #if FF_API_CAP_VDPAU
1224 /**
1225  * Codec can export data for HW decoding (VDPAU).
1226  */
1227 #define CODEC_CAP_HWACCEL_VDPAU AV_CODEC_CAP_HWACCEL_VDPAU
1228 #endif
1229 /**
1230  * Codec can output multiple frames per AVPacket
1231  * Normally demuxers return one frame at a time, demuxers which do not do
1232  * are connected to a parser to split what they return into proper frames.
1233  * This flag is reserved to the very rare category of codecs which have a
1234  * bitstream that cannot be split into frames without timeconsuming
1235  * operations like full decoding. Demuxers carrying such bitstreams thus
1236  * may return multiple frames in a packet. This has many disadvantages like
1237  * prohibiting stream copy in many cases thus it should only be considered
1238  * as a last resort.
1239  */
1240 #define CODEC_CAP_SUBFRAMES AV_CODEC_CAP_SUBFRAMES
1241 /**
1242  * Codec is experimental and is thus avoided in favor of non experimental
1243  * encoders
1244  */
1245 #define CODEC_CAP_EXPERIMENTAL AV_CODEC_CAP_EXPERIMENTAL
1246 /**
1247  * Codec should fill in channel configuration and samplerate instead of container
1248  */
1249 #define CODEC_CAP_CHANNEL_CONF AV_CODEC_CAP_CHANNEL_CONF
1250 #if FF_API_NEG_LINESIZES
1251 /**
1252  * @deprecated no codecs use this capability
1253  */
1254 #define CODEC_CAP_NEG_LINESIZES 0x0800
1255 #endif
1256 /**
1257  * Codec supports frame-level multithreading.
1258  */
1259 #define CODEC_CAP_FRAME_THREADS AV_CODEC_CAP_FRAME_THREADS
1260 /**
1261  * Codec supports slice-based (or partition-based) multithreading.
1262  */
1263 #define CODEC_CAP_SLICE_THREADS AV_CODEC_CAP_SLICE_THREADS
1264 /**
1265  * Codec supports changed parameters at any point.
1266  */
1267 #define CODEC_CAP_PARAM_CHANGE AV_CODEC_CAP_PARAM_CHANGE
1268 /**
1269  * Codec supports avctx->thread_count == 0 (auto).
1270  */
1271 #define CODEC_CAP_AUTO_THREADS AV_CODEC_CAP_AUTO_THREADS
1272 /**
1273  * Audio encoder supports receiving a different number of samples in each call.
1274  */
1275 #define CODEC_CAP_VARIABLE_FRAME_SIZE AV_CODEC_CAP_VARIABLE_FRAME_SIZE
1276 /**
1277  * Codec is intra only.
1278  */
1279 #define CODEC_CAP_INTRA_ONLY AV_CODEC_CAP_INTRA_ONLY
1280 /**
1281  * Codec is lossless.
1282  */
1283 #define CODEC_CAP_LOSSLESS AV_CODEC_CAP_LOSSLESS
1284 
1285 /**
1286  * HWAccel is experimental and is thus avoided in favor of non experimental
1287  * codecs
1288  */
1289 #define HWACCEL_CODEC_CAP_EXPERIMENTAL 0x0200
1290 #endif /* FF_API_WITHOUT_PREFIX */
1291 
1292 #if FF_API_MB_TYPE
1293 //The following defines may change, don't expect compatibility if you use them.
1294 #define MB_TYPE_INTRA4x4 0x0001
1295 #define MB_TYPE_INTRA16x16 0x0002 //FIXME H.264-specific
1296 #define MB_TYPE_INTRA_PCM 0x0004 //FIXME H.264-specific
1297 #define MB_TYPE_16x16 0x0008
1298 #define MB_TYPE_16x8 0x0010
1299 #define MB_TYPE_8x16 0x0020
1300 #define MB_TYPE_8x8 0x0040
1301 #define MB_TYPE_INTERLACED 0x0080
1302 #define MB_TYPE_DIRECT2 0x0100 //FIXME
1303 #define MB_TYPE_ACPRED 0x0200
1304 #define MB_TYPE_GMC 0x0400
1305 #define MB_TYPE_SKIP 0x0800
1306 #define MB_TYPE_P0L0 0x1000
1307 #define MB_TYPE_P1L0 0x2000
1308 #define MB_TYPE_P0L1 0x4000
1309 #define MB_TYPE_P1L1 0x8000
1310 #define MB_TYPE_L0 (MB_TYPE_P0L0 | MB_TYPE_P1L0)
1311 #define MB_TYPE_L1 (MB_TYPE_P0L1 | MB_TYPE_P1L1)
1312 #define MB_TYPE_L0L1 (MB_TYPE_L0 | MB_TYPE_L1)
1313 #define MB_TYPE_QUANT 0x00010000
1314 #define MB_TYPE_CBP 0x00020000
1315 // Note bits 24-31 are reserved for codec specific use (H.264 ref0, MPEG-1 0mv, ...)
1316 #endif
1317 
1318 /**
1319  * Pan Scan area.
1320  * This specifies the area which should be displayed.
1321  * Note there may be multiple such areas for one frame.
1322  */
1323 typedef struct AVPanScan{
1324  /**
1325  * id
1326  * - encoding: Set by user.
1327  * - decoding: Set by libavcodec.
1328  */
1329  int id;
1330 
1331  /**
1332  * width and height in 1/16 pel
1333  * - encoding: Set by user.
1334  * - decoding: Set by libavcodec.
1335  */
1336  int width;
1337  int height;
1338 
1339  /**
1340  * position of the top left corner in 1/16 pel for up to 3 fields/frames
1341  * - encoding: Set by user.
1342  * - decoding: Set by libavcodec.
1343  */
1344  int16_t position[3][2];
1345 }AVPanScan;
1346 
1347 /**
1348  * This structure describes the bitrate properties of an encoded bitstream. It
1349  * roughly corresponds to a subset the VBV parameters for MPEG-2 or HRD
1350  * parameters for H.264/HEVC.
1351  */
1352 typedef struct AVCPBProperties {
1353  /**
1354  * Maximum bitrate of the stream, in bits per second.
1355  * Zero if unknown or unspecified.
1356  */
1358  /**
1359  * Minimum bitrate of the stream, in bits per second.
1360  * Zero if unknown or unspecified.
1361  */
1363  /**
1364  * Average bitrate of the stream, in bits per second.
1365  * Zero if unknown or unspecified.
1366  */
1368 
1369  /**
1370  * The size of the buffer to which the ratecontrol is applied, in bits.
1371  * Zero if unknown or unspecified.
1372  */
1374 
1375  /**
1376  * The delay between the time the packet this structure is associated with
1377  * is received and the time when it should be decoded, in periods of a 27MHz
1378  * clock.
1379  *
1380  * UINT64_MAX when unknown or unspecified.
1381  */
1382  uint64_t vbv_delay;
1383 } AVCPBProperties;
1384 
1385 #if FF_API_QSCALE_TYPE
1386 #define FF_QSCALE_TYPE_MPEG1 0
1387 #define FF_QSCALE_TYPE_MPEG2 1
1388 #define FF_QSCALE_TYPE_H264 2
1389 #define FF_QSCALE_TYPE_VP56 3
1390 #endif
1391 
1392 /**
1393  * The decoder will keep a reference to the frame and may reuse it later.
1394  */
1395 #define AV_GET_BUFFER_FLAG_REF (1 << 0)
1396 
1397 /**
1398  * @defgroup lavc_packet AVPacket
1399  *
1400  * Types and functions for working with AVPacket.
1401  * @{
1402  */
1404  /**
1405  * An AV_PKT_DATA_PALETTE side data packet contains exactly AVPALETTE_SIZE
1406  * bytes worth of palette. This side data signals that a new palette is
1407  * present.
1408  */
1410 
1411  /**
1412  * The AV_PKT_DATA_NEW_EXTRADATA is used to notify the codec or the format
1413  * that the extradata buffer was changed and the receiving side should
1414  * act upon it appropriately. The new extradata is embedded in the side
1415  * data buffer and should be immediately used for processing the current
1416  * frame or packet.
1417  */
1419 
1420  /**
1421  * An AV_PKT_DATA_PARAM_CHANGE side data packet is laid out as follows:
1422  * @code
1423  * u32le param_flags
1424  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT)
1425  * s32le channel_count
1426  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT)
1427  * u64le channel_layout
1428  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE)
1429  * s32le sample_rate
1430  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS)
1431  * s32le width
1432  * s32le height
1433  * @endcode
1434  */
1436 
1437  /**
1438  * An AV_PKT_DATA_H263_MB_INFO side data packet contains a number of
1439  * structures with info about macroblocks relevant to splitting the
1440  * packet into smaller packets on macroblock edges (e.g. as for RFC 2190).
1441  * That is, it does not necessarily contain info about all macroblocks,
1442  * as long as the distance between macroblocks in the info is smaller
1443  * than the target payload size.
1444  * Each MB info structure is 12 bytes, and is laid out as follows:
1445  * @code
1446  * u32le bit offset from the start of the packet
1447  * u8 current quantizer at the start of the macroblock
1448  * u8 GOB number
1449  * u16le macroblock address within the GOB
1450  * u8 horizontal MV predictor
1451  * u8 vertical MV predictor
1452  * u8 horizontal MV predictor for block number 3
1453  * u8 vertical MV predictor for block number 3
1454  * @endcode
1455  */
1457 
1458  /**
1459  * This side data should be associated with an audio stream and contains
1460  * ReplayGain information in form of the AVReplayGain struct.
1461  */
1463 
1464  /**
1465  * This side data contains a 3x3 transformation matrix describing an affine
1466  * transformation that needs to be applied to the decoded video frames for
1467  * correct presentation.
1468  *
1469  * See libavutil/display.h for a detailed description of the data.
1470  */
1472 
1473  /**
1474  * This side data should be associated with a video stream and contains
1475  * Stereoscopic 3D information in form of the AVStereo3D struct.
1476  */
1478 
1479  /**
1480  * This side data should be associated with an audio stream and corresponds
1481  * to enum AVAudioServiceType.
1482  */
1484 
1485  /**
1486  * This side data contains quality related information from the encoder.
1487  * @code
1488  * u32le quality factor of the compressed frame. Allowed range is between 1 (good) and FF_LAMBDA_MAX (bad).
1489  * u8 picture type
1490  * u8 error count
1491  * u16 reserved
1492  * u64le[error count] sum of squared differences between encoder in and output
1493  * @endcode
1494  */
1496 
1497  /**
1498  * This side data contains an integer value representing the stream index
1499  * of a "fallback" track. A fallback track indicates an alternate
1500  * track to use when the current track can not be decoded for some reason.
1501  * e.g. no decoder available for codec.
1502  */
1504 
1505  /**
1506  * This side data corresponds to the AVCPBProperties struct.
1507  */
1509 
1510  /**
1511  * Recommmends skipping the specified number of samples
1512  * @code
1513  * u32le number of samples to skip from start of this packet
1514  * u32le number of samples to skip from end of this packet
1515  * u8 reason for start skip
1516  * u8 reason for end skip (0=padding silence, 1=convergence)
1517  * @endcode
1518  */
1520 
1521  /**
1522  * An AV_PKT_DATA_JP_DUALMONO side data packet indicates that
1523  * the packet may contain "dual mono" audio specific to Japanese DTV
1524  * and if it is true, recommends only the selected channel to be used.
1525  * @code
1526  * u8 selected channels (0=mail/left, 1=sub/right, 2=both)
1527  * @endcode
1528  */
1530 
1531  /**
1532  * A list of zero terminated key/value strings. There is no end marker for
1533  * the list, so it is required to rely on the side data size to stop.
1534  */
1536 
1537  /**
1538  * Subtitle event position
1539  * @code
1540  * u32le x1
1541  * u32le y1
1542  * u32le x2
1543  * u32le y2
1544  * @endcode
1545  */
1547 
1548  /**
1549  * Data found in BlockAdditional element of matroska container. There is
1550  * no end marker for the data, so it is required to rely on the side data
1551  * size to recognize the end. 8 byte id (as found in BlockAddId) followed
1552  * by data.
1553  */
1555 
1556  /**
1557  * The optional first identifier line of a WebVTT cue.
1558  */
1560 
1561  /**
1562  * The optional settings (rendering instructions) that immediately
1563  * follow the timestamp specifier of a WebVTT cue.
1564  */
1566 
1567  /**
1568  * A list of zero terminated key/value strings. There is no end marker for
1569  * the list, so it is required to rely on the side data size to stop. This
1570  * side data includes updated metadata which appeared in the stream.
1571  */
1573 
1574  /**
1575  * MPEGTS stream ID, this is required to pass the stream ID
1576  * information from the demuxer to the corresponding muxer.
1577  */
1579 
1580  /**
1581  * Mastering display metadata (based on SMPTE-2086:2014). This metadata
1582  * should be associated with a video stream and contains data in the form
1583  * of the AVMasteringDisplayMetadata struct.
1584  */
1586 
1587  /**
1588  * This side data should be associated with a video stream and corresponds
1589  * to the AVSphericalMapping structure.
1590  */
1592 
1593  /**
1594  * Content light level (based on CTA-861.3). This metadata should be
1595  * associated with a video stream and contains data in the form of the
1596  * AVContentLightMetadata struct.
1597  */
1599 
1600  /**
1601  * The number of side data elements (in fact a bit more than it).
1602  * This is not part of the public API/ABI in the sense that it may
1603  * change when new side data types are added.
1604  * This must stay the last enum value.
1605  * If its value becomes huge, some code using it
1606  * needs to be updated as it assumes it to be smaller than other limits.
1607  */
1609 };
1610 
1611 #define AV_PKT_DATA_QUALITY_FACTOR AV_PKT_DATA_QUALITY_STATS //DEPRECATED
1612 
1613 typedef struct AVPacketSideData {
1615  int size;
1618 
1619 /**
1620  * This structure stores compressed data. It is typically exported by demuxers
1621  * and then passed as input to decoders, or received as output from encoders and
1622  * then passed to muxers.
1623  *
1624  * For video, it should typically contain one compressed frame. For audio it may
1625  * contain several compressed frames. Encoders are allowed to output empty
1626  * packets, with no compressed data, containing only side data
1627  * (e.g. to update some stream parameters at the end of encoding).
1628  *
1629  * AVPacket is one of the few structs in FFmpeg, whose size is a part of public
1630  * ABI. Thus it may be allocated on stack and no new fields can be added to it
1631  * without libavcodec and libavformat major bump.
1632  *
1633  * The semantics of data ownership depends on the buf field.
1634  * If it is set, the packet data is dynamically allocated and is
1635  * valid indefinitely until a call to av_packet_unref() reduces the
1636  * reference count to 0.
1637  *
1638  * If the buf field is not set av_packet_ref() would make a copy instead
1639  * of increasing the reference count.
1640  *
1641  * The side data is always allocated with av_malloc(), copied by
1642  * av_packet_ref() and freed by av_packet_unref().
1643  *
1644  * @see av_packet_ref
1645  * @see av_packet_unref
1646  */
1647 typedef struct AVPacket {
1648  /**
1649  * A reference to the reference-counted buffer where the packet data is
1650  * stored.
1651  * May be NULL, then the packet data is not reference-counted.
1652  */
1654  /**
1655  * Presentation timestamp in AVStream->time_base units; the time at which
1656  * the decompressed packet will be presented to the user.
1657  * Can be AV_NOPTS_VALUE if it is not stored in the file.
1658  * pts MUST be larger or equal to dts as presentation cannot happen before
1659  * decompression, unless one wants to view hex dumps. Some formats misuse
1660  * the terms dts and pts/cts to mean something different. Such timestamps
1661  * must be converted to true pts/dts before they are stored in AVPacket.
1662  */
1663  int64_t pts;
1664  /**
1665  * Decompression timestamp in AVStream->time_base units; the time at which
1666  * the packet is decompressed.
1667  * Can be AV_NOPTS_VALUE if it is not stored in the file.
1668  */
1669  int64_t dts;
1671  int size;
1673  /**
1674  * A combination of AV_PKT_FLAG values
1675  */
1676  int flags;
1677  /**
1678  * Additional packet data that can be provided by the container.
1679  * Packet can contain several types of side information.
1680  */
1683 
1684  /**
1685  * Duration of this packet in AVStream->time_base units, 0 if unknown.
1686  * Equals next_pts - this_pts in presentation order.
1687  */
1688  int64_t duration;
1689 
1690  int64_t pos; ///< byte position in stream, -1 if unknown
1691 
1692 #if FF_API_CONVERGENCE_DURATION
1693  /**
1694  * @deprecated Same as the duration field, but as int64_t. This was required
1695  * for Matroska subtitles, whose duration values could overflow when the
1696  * duration field was still an int.
1697  */
1700 #endif
1701 } AVPacket;
1702 #define AV_PKT_FLAG_KEY 0x0001 ///< The packet contains a keyframe
1703 #define AV_PKT_FLAG_CORRUPT 0x0002 ///< The packet content is corrupted
1704 /**
1705  * Flag is used to discard packets which are required to maintain valid
1706  * decoder state but are not required for output and should be dropped
1707  * after decoding.
1708  **/
1709 #define AV_PKT_FLAG_DISCARD 0x0004
1710 
1716 };
1717 /**
1718  * @}
1719  */
1720 
1721 struct AVCodecInternal;
1722 
1726  AV_FIELD_TT, //< Top coded_first, top displayed first
1727  AV_FIELD_BB, //< Bottom coded first, bottom displayed first
1728  AV_FIELD_TB, //< Top coded first, bottom displayed first
1729  AV_FIELD_BT, //< Bottom coded first, top displayed first
1730 };
1731 
1732 /**
1733  * main external API structure.
1734  * New fields can be added to the end with minor version bumps.
1735  * Removal, reordering and changes to existing fields require a major
1736  * version bump.
1737  * You can use AVOptions (av_opt* / av_set/get*()) to access these fields from user
1738  * applications.
1739  * The name string for AVOptions options matches the associated command line
1740  * parameter name and can be found in libavcodec/options_table.h
1741  * The AVOption/command line parameter names differ in some cases from the C
1742  * structure field names for historic reasons or brevity.
1743  * sizeof(AVCodecContext) must not be used outside libav*.
1744  */
1745 typedef struct AVCodecContext {
1746  /**
1747  * information on struct for av_log
1748  * - set by avcodec_alloc_context3
1749  */
1752 
1753  enum AVMediaType codec_type; /* see AVMEDIA_TYPE_xxx */
1754  const struct AVCodec *codec;
1755 #if FF_API_CODEC_NAME
1756  /**
1757  * @deprecated this field is not used for anything in libavcodec
1758  */
1760  char codec_name[32];
1761 #endif
1762  enum AVCodecID codec_id; /* see AV_CODEC_ID_xxx */
1763 
1764  /**
1765  * fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
1766  * This is used to work around some encoder bugs.
1767  * A demuxer should set this to what is stored in the field used to identify the codec.
1768  * If there are multiple such fields in a container then the demuxer should choose the one
1769  * which maximizes the information about the used codec.
1770  * If the codec tag field in a container is larger than 32 bits then the demuxer should
1771  * remap the longer ID to 32 bits with a table or other structure. Alternatively a new
1772  * extra_codec_tag + size could be added but for this a clear advantage must be demonstrated
1773  * first.
1774  * - encoding: Set by user, if not then the default based on codec_id will be used.
1775  * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
1776  */
1777  unsigned int codec_tag;
1778 
1779 #if FF_API_STREAM_CODEC_TAG
1780  /**
1781  * @deprecated this field is unused
1782  */
1784  unsigned int stream_codec_tag;
1785 #endif
1786 
1787  void *priv_data;
1788 
1789  /**
1790  * Private context used for internal data.
1791  *
1792  * Unlike priv_data, this is not codec-specific. It is used in general
1793  * libavcodec functions.
1794  */
1795  struct AVCodecInternal *internal;
1796 
1797  /**
1798  * Private data of the user, can be used to carry app specific stuff.
1799  * - encoding: Set by user.
1800  * - decoding: Set by user.
1801  */
1802  void *opaque;
1803 
1804  /**
1805  * the average bitrate
1806  * - encoding: Set by user; unused for constant quantizer encoding.
1807  * - decoding: Set by user, may be overwritten by libavcodec
1808  * if this info is available in the stream
1809  */
1810  int64_t bit_rate;
1811 
1812  /**
1813  * number of bits the bitstream is allowed to diverge from the reference.
1814  * the reference can be CBR (for CBR pass1) or VBR (for pass2)
1815  * - encoding: Set by user; unused for constant quantizer encoding.
1816  * - decoding: unused
1817  */
1819 
1820  /**
1821  * Global quality for codecs which cannot change it per frame.
1822  * This should be proportional to MPEG-1/2/4 qscale.
1823  * - encoding: Set by user.
1824  * - decoding: unused
1825  */
1827 
1828  /**
1829  * - encoding: Set by user.
1830  * - decoding: unused
1831  */
1833 #define FF_COMPRESSION_DEFAULT -1
1834 
1835  /**
1836  * AV_CODEC_FLAG_*.
1837  * - encoding: Set by user.
1838  * - decoding: Set by user.
1839  */
1840  int flags;
1841 
1842  /**
1843  * AV_CODEC_FLAG2_*
1844  * - encoding: Set by user.
1845  * - decoding: Set by user.
1846  */
1847  int flags2;
1848 
1849  /**
1850  * some codecs need / can use extradata like Huffman tables.
1851  * MJPEG: Huffman tables
1852  * rv10: additional flags
1853  * MPEG-4: global headers (they can be in the bitstream or here)
1854  * The allocated memory should be AV_INPUT_BUFFER_PADDING_SIZE bytes larger
1855  * than extradata_size to avoid problems if it is read with the bitstream reader.
1856  * The bytewise contents of extradata must not depend on the architecture or CPU endianness.
1857  * - encoding: Set/allocated/freed by libavcodec.
1858  * - decoding: Set/allocated/freed by user.
1859  */
1862 
1863  /**
1864  * This is the fundamental unit of time (in seconds) in terms
1865  * of which frame timestamps are represented. For fixed-fps content,
1866  * timebase should be 1/framerate and timestamp increments should be
1867  * identically 1.
1868  * This often, but not always is the inverse of the frame rate or field rate
1869  * for video. 1/time_base is not the average frame rate if the frame rate is not
1870  * constant.
1871  *
1872  * Like containers, elementary streams also can store timestamps, 1/time_base
1873  * is the unit in which these timestamps are specified.
1874  * As example of such codec time base see ISO/IEC 14496-2:2001(E)
1875  * vop_time_increment_resolution and fixed_vop_rate
1876  * (fixed_vop_rate == 0 implies that it is different from the framerate)
1877  *
1878  * - encoding: MUST be set by user.
1879  * - decoding: the use of this field for decoding is deprecated.
1880  * Use framerate instead.
1881  */
1883 
1884  /**
1885  * For some codecs, the time base is closer to the field rate than the frame rate.
1886  * Most notably, H.264 and MPEG-2 specify time_base as half of frame duration
1887  * if no telecine is used ...
1888  *
1889  * Set to time_base ticks per frame. Default 1, e.g., H.264/MPEG-2 set it to 2.
1890  */
1892 
1893  /**
1894  * Codec delay.
1895  *
1896  * Encoding: Number of frames delay there will be from the encoder input to
1897  * the decoder output. (we assume the decoder matches the spec)
1898  * Decoding: Number of frames delay in addition to what a standard decoder
1899  * as specified in the spec would produce.
1900  *
1901  * Video:
1902  * Number of frames the decoded output will be delayed relative to the
1903  * encoded input.
1904  *
1905  * Audio:
1906  * For encoding, this field is unused (see initial_padding).
1907  *
1908  * For decoding, this is the number of samples the decoder needs to
1909  * output before the decoder's output is valid. When seeking, you should
1910  * start decoding this many samples prior to your desired seek point.
1911  *
1912  * - encoding: Set by libavcodec.
1913  * - decoding: Set by libavcodec.
1914  */
1915  int delay;
1916 
1917 
1918  /* video only */
1919  /**
1920  * picture width / height.
1921  *
1922  * @note Those fields may not match the values of the last
1923  * AVFrame output by avcodec_decode_video2 due frame
1924  * reordering.
1925  *
1926  * - encoding: MUST be set by user.
1927  * - decoding: May be set by the user before opening the decoder if known e.g.
1928  * from the container. Some decoders will require the dimensions
1929  * to be set by the caller. During decoding, the decoder may
1930  * overwrite those values as required while parsing the data.
1931  */
1933 
1934  /**
1935  * Bitstream width / height, may be different from width/height e.g. when
1936  * the decoded frame is cropped before being output or lowres is enabled.
1937  *
1938  * @note Those field may not match the value of the last
1939  * AVFrame output by avcodec_receive_frame() due frame
1940  * reordering.
1941  *
1942  * - encoding: unused
1943  * - decoding: May be set by the user before opening the decoder if known
1944  * e.g. from the container. During decoding, the decoder may
1945  * overwrite those values as required while parsing the data.
1946  */
1948 
1949 #if FF_API_ASPECT_EXTENDED
1950 #define FF_ASPECT_EXTENDED 15
1951 #endif
1952 
1953  /**
1954  * the number of pictures in a group of pictures, or 0 for intra_only
1955  * - encoding: Set by user.
1956  * - decoding: unused
1957  */
1959 
1960  /**
1961  * Pixel format, see AV_PIX_FMT_xxx.
1962  * May be set by the demuxer if known from headers.
1963  * May be overridden by the decoder if it knows better.
1964  *
1965  * @note This field may not match the value of the last
1966  * AVFrame output by avcodec_receive_frame() due frame
1967  * reordering.
1968  *
1969  * - encoding: Set by user.
1970  * - decoding: Set by user if known, overridden by libavcodec while
1971  * parsing the data.
1972  */
1974 
1975 #if FF_API_MOTION_EST
1976  /**
1977  * This option does nothing
1978  * @deprecated use codec private options instead
1979  */
1981 #endif
1982 
1983  /**
1984  * If non NULL, 'draw_horiz_band' is called by the libavcodec
1985  * decoder to draw a horizontal band. It improves cache usage. Not
1986  * all codecs can do that. You must check the codec capabilities
1987  * beforehand.
1988  * When multithreading is used, it may be called from multiple threads
1989  * at the same time; threads might draw different parts of the same AVFrame,
1990  * or multiple AVFrames, and there is no guarantee that slices will be drawn
1991  * in order.
1992  * The function is also used by hardware acceleration APIs.
1993  * It is called at least once during frame decoding to pass
1994  * the data needed for hardware render.
1995  * In that mode instead of pixel data, AVFrame points to
1996  * a structure specific to the acceleration API. The application
1997  * reads the structure and can change some fields to indicate progress
1998  * or mark state.
1999  * - encoding: unused
2000  * - decoding: Set by user.
2001  * @param height the height of the slice
2002  * @param y the y position of the slice
2003  * @param type 1->top field, 2->bottom field, 3->frame
2004  * @param offset offset into the AVFrame.data from which the slice should be read
2005  */
2007  const AVFrame *src, int offset[AV_NUM_DATA_POINTERS],
2008  int y, int type, int height);
2009 
2010  /**
2011  * callback to negotiate the pixelFormat
2012  * @param fmt is the list of formats which are supported by the codec,
2013  * it is terminated by -1 as 0 is a valid format, the formats are ordered by quality.
2014  * The first is always the native one.
2015  * @note The callback may be called again immediately if initialization for
2016  * the selected (hardware-accelerated) pixel format failed.
2017  * @warning Behavior is undefined if the callback returns a value not
2018  * in the fmt list of formats.
2019  * @return the chosen format
2020  * - encoding: unused
2021  * - decoding: Set by user, if not set the native format will be chosen.
2022  */
2023  enum AVPixelFormat (*get_format)(struct AVCodecContext *s, const enum AVPixelFormat * fmt);
2024 
2025  /**
2026  * maximum number of B-frames between non-B-frames
2027  * Note: The output will be delayed by max_b_frames+1 relative to the input.
2028  * - encoding: Set by user.
2029  * - decoding: unused
2030  */
2032 
2033  /**
2034  * qscale factor between IP and B-frames
2035  * If > 0 then the last P-frame quantizer will be used (q= lastp_q*factor+offset).
2036  * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
2037  * - encoding: Set by user.
2038  * - decoding: unused
2039  */
2041 
2042 #if FF_API_RC_STRATEGY
2043  /** @deprecated use codec private option instead */
2045 #define FF_RC_STRATEGY_XVID 1
2046 #endif
2047 
2048 #if FF_API_PRIVATE_OPT
2049  /** @deprecated use encoder private options instead */
2052 #endif
2053 
2054  /**
2055  * qscale offset between IP and B-frames
2056  * - encoding: Set by user.
2057  * - decoding: unused
2058  */
2060 
2061  /**
2062  * Size of the frame reordering buffer in the decoder.
2063  * For MPEG-2 it is 1 IPB or 0 low delay IP.
2064  * - encoding: Set by libavcodec.
2065  * - decoding: Set by libavcodec.
2066  */
2068 
2069 #if FF_API_PRIVATE_OPT
2070  /** @deprecated use encoder private options instead */
2073 #endif
2074 
2075  /**
2076  * qscale factor between P- and I-frames
2077  * If > 0 then the last P-frame quantizer will be used (q = lastp_q * factor + offset).
2078  * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
2079  * - encoding: Set by user.
2080  * - decoding: unused
2081  */
2083 
2084  /**
2085  * qscale offset between P and I-frames
2086  * - encoding: Set by user.
2087  * - decoding: unused
2088  */
2090 
2091  /**
2092  * luminance masking (0-> disabled)
2093  * - encoding: Set by user.
2094  * - decoding: unused
2095  */
2097 
2098  /**
2099  * temporary complexity masking (0-> disabled)
2100  * - encoding: Set by user.
2101  * - decoding: unused
2102  */
2104 
2105  /**
2106  * spatial complexity masking (0-> disabled)
2107  * - encoding: Set by user.
2108  * - decoding: unused
2109  */
2111 
2112  /**
2113  * p block masking (0-> disabled)
2114  * - encoding: Set by user.
2115  * - decoding: unused
2116  */
2117  float p_masking;
2118 
2119  /**
2120  * darkness masking (0-> disabled)
2121  * - encoding: Set by user.
2122  * - decoding: unused
2123  */
2125 
2126  /**
2127  * slice count
2128  * - encoding: Set by libavcodec.
2129  * - decoding: Set by user (or 0).
2130  */
2132 
2133 #if FF_API_PRIVATE_OPT
2134  /** @deprecated use encoder private options instead */
2137 #define FF_PRED_LEFT 0
2138 #define FF_PRED_PLANE 1
2139 #define FF_PRED_MEDIAN 2
2140 #endif
2141 
2142  /**
2143  * slice offsets in the frame in bytes
2144  * - encoding: Set/allocated by libavcodec.
2145  * - decoding: Set/allocated by user (or NULL).
2146  */
2148 
2149  /**
2150  * sample aspect ratio (0 if unknown)
2151  * That is the width of a pixel divided by the height of the pixel.
2152  * Numerator and denominator must be relatively prime and smaller than 256 for some video standards.
2153  * - encoding: Set by user.
2154  * - decoding: Set by libavcodec.
2155  */
2157 
2158  /**
2159  * motion estimation comparison function
2160  * - encoding: Set by user.
2161  * - decoding: unused
2162  */
2163  int me_cmp;
2164  /**
2165  * subpixel motion estimation comparison function
2166  * - encoding: Set by user.
2167  * - decoding: unused
2168  */
2170  /**
2171  * macroblock comparison function (not supported yet)
2172  * - encoding: Set by user.
2173  * - decoding: unused
2174  */
2175  int mb_cmp;
2176  /**
2177  * interlaced DCT comparison function
2178  * - encoding: Set by user.
2179  * - decoding: unused
2180  */
2182 #define FF_CMP_SAD 0
2183 #define FF_CMP_SSE 1
2184 #define FF_CMP_SATD 2
2185 #define FF_CMP_DCT 3
2186 #define FF_CMP_PSNR 4
2187 #define FF_CMP_BIT 5
2188 #define FF_CMP_RD 6
2189 #define FF_CMP_ZERO 7
2190 #define FF_CMP_VSAD 8
2191 #define FF_CMP_VSSE 9
2192 #define FF_CMP_NSSE 10
2193 #define FF_CMP_W53 11
2194 #define FF_CMP_W97 12
2195 #define FF_CMP_DCTMAX 13
2196 #define FF_CMP_DCT264 14
2197 #define FF_CMP_MEDIAN_SAD 15
2198 #define FF_CMP_CHROMA 256
2199 
2200  /**
2201  * ME diamond size & shape
2202  * - encoding: Set by user.
2203  * - decoding: unused
2204  */
2206 
2207  /**
2208  * amount of previous MV predictors (2a+1 x 2a+1 square)
2209  * - encoding: Set by user.
2210  * - decoding: unused
2211  */
2213 
2214 #if FF_API_PRIVATE_OPT
2215  /** @deprecated use encoder private options instead */
2217  int pre_me;
2218 #endif
2219 
2220  /**
2221  * motion estimation prepass comparison function
2222  * - encoding: Set by user.
2223  * - decoding: unused
2224  */
2226 
2227  /**
2228  * ME prepass diamond size & shape
2229  * - encoding: Set by user.
2230  * - decoding: unused
2231  */
2233 
2234  /**
2235  * subpel ME quality
2236  * - encoding: Set by user.
2237  * - decoding: unused
2238  */
2240 
2241 #if FF_API_AFD
2242  /**
2243  * DTG active format information (additional aspect ratio
2244  * information only used in DVB MPEG-2 transport streams)
2245  * 0 if not set.
2246  *
2247  * - encoding: unused
2248  * - decoding: Set by decoder.
2249  * @deprecated Deprecated in favor of AVSideData
2250  */
2252 #define FF_DTG_AFD_SAME 8
2253 #define FF_DTG_AFD_4_3 9
2254 #define FF_DTG_AFD_16_9 10
2255 #define FF_DTG_AFD_14_9 11
2256 #define FF_DTG_AFD_4_3_SP_14_9 13
2257 #define FF_DTG_AFD_16_9_SP_14_9 14
2258 #define FF_DTG_AFD_SP_4_3 15
2259 #endif /* FF_API_AFD */
2260 
2261  /**
2262  * maximum motion estimation search range in subpel units
2263  * If 0 then no limit.
2264  *
2265  * - encoding: Set by user.
2266  * - decoding: unused
2267  */
2269 
2270 #if FF_API_QUANT_BIAS
2271  /**
2272  * @deprecated use encoder private option instead
2273  */
2275 #define FF_DEFAULT_QUANT_BIAS 999999
2276 
2277  /**
2278  * @deprecated use encoder private option instead
2279  */
2281 #endif
2282 
2283  /**
2284  * slice flags
2285  * - encoding: unused
2286  * - decoding: Set by user.
2287  */
2289 #define SLICE_FLAG_CODED_ORDER 0x0001 ///< draw_horiz_band() is called in coded order instead of display
2290 #define SLICE_FLAG_ALLOW_FIELD 0x0002 ///< allow draw_horiz_band() with field slices (MPEG-2 field pics)
2291 #define SLICE_FLAG_ALLOW_PLANE 0x0004 ///< allow draw_horiz_band() with 1 component at a time (SVQ1)
2292 
2293 #if FF_API_XVMC
2294  /**
2295  * XVideo Motion Acceleration
2296  * - encoding: forbidden
2297  * - decoding: set by decoder
2298  * @deprecated XvMC doesn't need it anymore.
2299  */
2300  attribute_deprecated int xvmc_acceleration;
2301 #endif /* FF_API_XVMC */
2302 
2303  /**
2304  * macroblock decision mode
2305  * - encoding: Set by user.
2306  * - decoding: unused
2307  */
2309 #define FF_MB_DECISION_SIMPLE 0 ///< uses mb_cmp
2310 #define FF_MB_DECISION_BITS 1 ///< chooses the one which needs the fewest bits
2311 #define FF_MB_DECISION_RD 2 ///< rate distortion
2312 
2313  /**
2314  * custom intra quantization matrix
2315  * - encoding: Set by user, can be NULL.
2316  * - decoding: Set by libavcodec.
2317  */
2318  uint16_t *intra_matrix;
2319 
2320  /**
2321  * custom inter quantization matrix
2322  * - encoding: Set by user, can be NULL.
2323  * - decoding: Set by libavcodec.
2324  */
2325  uint16_t *inter_matrix;
2326 
2327 #if FF_API_PRIVATE_OPT
2328  /** @deprecated use encoder private options instead */
2331 
2332  /** @deprecated use encoder private options instead */
2335 #endif
2336 
2337 #if FF_API_MPV_OPT
2338  /**
2339  * @deprecated this field is unused
2340  */
2343 
2344  /**
2345  * @deprecated this field is unused
2346  */
2349 #endif
2350 
2351  /**
2352  * precision of the intra DC coefficient - 8
2353  * - encoding: Set by user.
2354  * - decoding: Set by libavcodec
2355  */
2357 
2358  /**
2359  * Number of macroblock rows at the top which are skipped.
2360  * - encoding: unused
2361  * - decoding: Set by user.
2362  */
2364 
2365  /**
2366  * Number of macroblock rows at the bottom which are skipped.
2367  * - encoding: unused
2368  * - decoding: Set by user.
2369  */
2371 
2372 #if FF_API_MPV_OPT
2373  /**
2374  * @deprecated use encoder private options instead
2375  */
2378 #endif
2379 
2380  /**
2381  * minimum MB Lagrange multiplier
2382  * - encoding: Set by user.
2383  * - decoding: unused
2384  */
2385  int mb_lmin;
2386 
2387  /**
2388  * maximum MB Lagrange multiplier
2389  * - encoding: Set by user.
2390  * - decoding: unused
2391  */
2392  int mb_lmax;
2393 
2394 #if FF_API_PRIVATE_OPT
2395  /**
2396  * @deprecated use encoder private options instead
2397  */
2400 #endif
2401 
2402  /**
2403  * - encoding: Set by user.
2404  * - decoding: unused
2405  */
2407 
2408 #if FF_API_PRIVATE_OPT
2409  /** @deprecated use encoder private options instead */
2412 #endif
2413 
2414  /**
2415  * minimum GOP size
2416  * - encoding: Set by user.
2417  * - decoding: unused
2418  */
2420 
2421  /**
2422  * number of reference frames
2423  * - encoding: Set by user.
2424  * - decoding: Set by lavc.
2425  */
2426  int refs;
2427 
2428 #if FF_API_PRIVATE_OPT
2429  /** @deprecated use encoder private options instead */
2432 #endif
2433 
2434 #if FF_API_UNUSED_MEMBERS
2435  /**
2436  * Multiplied by qscale for each frame and added to scene_change_score.
2437  * - encoding: Set by user.
2438  * - decoding: unused
2439  */
2441 #endif
2442 
2443  /**
2444  * Note: Value depends upon the compare function used for fullpel ME.
2445  * - encoding: Set by user.
2446  * - decoding: unused
2447  */
2449 
2450 #if FF_API_PRIVATE_OPT
2451  /** @deprecated use encoder private options instead */
2454 #endif
2455 
2456  /**
2457  * Chromaticity coordinates of the source primaries.
2458  * - encoding: Set by user
2459  * - decoding: Set by libavcodec
2460  */
2462 
2463  /**
2464  * Color Transfer Characteristic.
2465  * - encoding: Set by user
2466  * - decoding: Set by libavcodec
2467  */
2469 
2470  /**
2471  * YUV colorspace type.
2472  * - encoding: Set by user
2473  * - decoding: Set by libavcodec
2474  */
2476 
2477  /**
2478  * MPEG vs JPEG YUV range.
2479  * - encoding: Set by user
2480  * - decoding: Set by libavcodec
2481  */
2483 
2484  /**
2485  * This defines the location of chroma samples.
2486  * - encoding: Set by user
2487  * - decoding: Set by libavcodec
2488  */
2490 
2491  /**
2492  * Number of slices.
2493  * Indicates number of picture subdivisions. Used for parallelized
2494  * decoding.
2495  * - encoding: Set by user
2496  * - decoding: unused
2497  */
2498  int slices;
2499 
2500  /** Field order
2501  * - encoding: set by libavcodec
2502  * - decoding: Set by user.
2503  */
2505 
2506  /* audio only */
2507  int sample_rate; ///< samples per second
2508  int channels; ///< number of audio channels
2509 
2510  /**
2511  * audio sample format
2512  * - encoding: Set by user.
2513  * - decoding: Set by libavcodec.
2514  */
2515  enum AVSampleFormat sample_fmt; ///< sample format
2516 
2517  /* The following data should not be initialized. */
2518  /**
2519  * Number of samples per channel in an audio frame.
2520  *
2521  * - encoding: set by libavcodec in avcodec_open2(). Each submitted frame
2522  * except the last must contain exactly frame_size samples per channel.
2523  * May be 0 when the codec has AV_CODEC_CAP_VARIABLE_FRAME_SIZE set, then the
2524  * frame size is not restricted.
2525  * - decoding: may be set by some decoders to indicate constant frame size
2526  */
2528 
2529  /**
2530  * Frame counter, set by libavcodec.
2531  *
2532  * - decoding: total number of frames returned from the decoder so far.
2533  * - encoding: total number of frames passed to the encoder so far.
2534  *
2535  * @note the counter is not incremented if encoding/decoding resulted in
2536  * an error.
2537  */
2539 
2540  /**
2541  * number of bytes per packet if constant and known or 0
2542  * Used by some WAV based audio codecs.
2543  */
2545 
2546  /**
2547  * Audio cutoff bandwidth (0 means "automatic")
2548  * - encoding: Set by user.
2549  * - decoding: unused
2550  */
2551  int cutoff;
2552 
2553  /**
2554  * Audio channel layout.
2555  * - encoding: set by user.
2556  * - decoding: set by user, may be overwritten by libavcodec.
2557  */
2558  uint64_t channel_layout;
2559 
2560  /**
2561  * Request decoder to use this channel layout if it can (0 for default)
2562  * - encoding: unused
2563  * - decoding: Set by user.
2564  */
2566 
2567  /**
2568  * Type of service that the audio stream conveys.
2569  * - encoding: Set by user.
2570  * - decoding: Set by libavcodec.
2571  */
2573 
2574  /**
2575  * desired sample format
2576  * - encoding: Not used.
2577  * - decoding: Set by user.
2578  * Decoder will decode to this format if it can.
2579  */
2581 
2582  /**
2583  * This callback is called at the beginning of each frame to get data
2584  * buffer(s) for it. There may be one contiguous buffer for all the data or
2585  * there may be a buffer per each data plane or anything in between. What
2586  * this means is, you may set however many entries in buf[] you feel necessary.
2587  * Each buffer must be reference-counted using the AVBuffer API (see description
2588  * of buf[] below).
2589  *
2590  * The following fields will be set in the frame before this callback is
2591  * called:
2592  * - format
2593  * - width, height (video only)
2594  * - sample_rate, channel_layout, nb_samples (audio only)
2595  * Their values may differ from the corresponding values in
2596  * AVCodecContext. This callback must use the frame values, not the codec
2597  * context values, to calculate the required buffer size.
2598  *
2599  * This callback must fill the following fields in the frame:
2600  * - data[]
2601  * - linesize[]
2602  * - extended_data:
2603  * * if the data is planar audio with more than 8 channels, then this
2604  * callback must allocate and fill extended_data to contain all pointers
2605  * to all data planes. data[] must hold as many pointers as it can.
2606  * extended_data must be allocated with av_malloc() and will be freed in
2607  * av_frame_unref().
2608  * * otherwise extended_data must point to data
2609  * - buf[] must contain one or more pointers to AVBufferRef structures. Each of
2610  * the frame's data and extended_data pointers must be contained in these. That
2611  * is, one AVBufferRef for each allocated chunk of memory, not necessarily one
2612  * AVBufferRef per data[] entry. See: av_buffer_create(), av_buffer_alloc(),
2613  * and av_buffer_ref().
2614  * - extended_buf and nb_extended_buf must be allocated with av_malloc() by
2615  * this callback and filled with the extra buffers if there are more
2616  * buffers than buf[] can hold. extended_buf will be freed in
2617  * av_frame_unref().
2618  *
2619  * If AV_CODEC_CAP_DR1 is not set then get_buffer2() must call
2620  * avcodec_default_get_buffer2() instead of providing buffers allocated by
2621  * some other means.
2622  *
2623  * Each data plane must be aligned to the maximum required by the target
2624  * CPU.
2625  *
2626  * @see avcodec_default_get_buffer2()
2627  *
2628  * Video:
2629  *
2630  * If AV_GET_BUFFER_FLAG_REF is set in flags then the frame may be reused
2631  * (read and/or written to if it is writable) later by libavcodec.
2632  *
2633  * avcodec_align_dimensions2() should be used to find the required width and
2634  * height, as they normally need to be rounded up to the next multiple of 16.
2635  *
2636  * Some decoders do not support linesizes changing between frames.
2637  *
2638  * If frame multithreading is used and thread_safe_callbacks is set,
2639  * this callback may be called from a different thread, but not from more
2640  * than one at once. Does not need to be reentrant.
2641  *
2642  * @see avcodec_align_dimensions2()
2643  *
2644  * Audio:
2645  *
2646  * Decoders request a buffer of a particular size by setting
2647  * AVFrame.nb_samples prior to calling get_buffer2(). The decoder may,
2648  * however, utilize only part of the buffer by setting AVFrame.nb_samples
2649  * to a smaller value in the output frame.
2650  *
2651  * As a convenience, av_samples_get_buffer_size() and
2652  * av_samples_fill_arrays() in libavutil may be used by custom get_buffer2()
2653  * functions to find the required data size and to fill data pointers and
2654  * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
2655  * since all planes must be the same size.
2656  *
2657  * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
2658  *
2659  * - encoding: unused
2660  * - decoding: Set by libavcodec, user can override.
2661  */
2663 
2664  /**
2665  * If non-zero, the decoded audio and video frames returned from
2666  * avcodec_decode_video2() and avcodec_decode_audio4() are reference-counted
2667  * and are valid indefinitely. The caller must free them with
2668  * av_frame_unref() when they are not needed anymore.
2669  * Otherwise, the decoded frames must not be freed by the caller and are
2670  * only valid until the next decode call.
2671  *
2672  * This is always automatically enabled if avcodec_receive_frame() is used.
2673  *
2674  * - encoding: unused
2675  * - decoding: set by the caller before avcodec_open2().
2676  */
2678 
2679  /* - encoding parameters */
2680  float qcompress; ///< amount of qscale change between easy & hard scenes (0.0-1.0)
2681  float qblur; ///< amount of qscale smoothing over time (0.0-1.0)
2682 
2683  /**
2684  * minimum quantizer
2685  * - encoding: Set by user.
2686  * - decoding: unused
2687  */
2688  int qmin;
2689 
2690  /**
2691  * maximum quantizer
2692  * - encoding: Set by user.
2693  * - decoding: unused
2694  */
2695  int qmax;
2696 
2697  /**
2698  * maximum quantizer difference between frames
2699  * - encoding: Set by user.
2700  * - decoding: unused
2701  */
2703 
2704 #if FF_API_MPV_OPT
2705  /**
2706  * @deprecated use encoder private options instead
2707  */
2709  float rc_qsquish;
2710 
2715 #endif
2716 
2717  /**
2718  * decoder bitstream buffer size
2719  * - encoding: Set by user.
2720  * - decoding: unused
2721  */
2723 
2724  /**
2725  * ratecontrol override, see RcOverride
2726  * - encoding: Allocated/set/freed by user.
2727  * - decoding: unused
2728  */
2731 
2732 #if FF_API_MPV_OPT
2733  /**
2734  * @deprecated use encoder private options instead
2735  */
2737  const char *rc_eq;
2738 #endif
2739 
2740  /**
2741  * maximum bitrate
2742  * - encoding: Set by user.
2743  * - decoding: Set by user, may be overwritten by libavcodec.
2744  */
2745  int64_t rc_max_rate;
2746 
2747  /**
2748  * minimum bitrate
2749  * - encoding: Set by user.
2750  * - decoding: unused
2751  */
2752  int64_t rc_min_rate;
2753 
2754 #if FF_API_MPV_OPT
2755  /**
2756  * @deprecated use encoder private options instead
2757  */
2760 
2763 #endif
2764 
2765  /**
2766  * Ratecontrol attempt to use, at maximum, <value> of what can be used without an underflow.
2767  * - encoding: Set by user.
2768  * - decoding: unused.
2769  */
2771 
2772  /**
2773  * Ratecontrol attempt to use, at least, <value> times the amount needed to prevent a vbv overflow.
2774  * - encoding: Set by user.
2775  * - decoding: unused.
2776  */
2778 
2779  /**
2780  * Number of bits which should be loaded into the rc buffer before decoding starts.
2781  * - encoding: Set by user.
2782  * - decoding: unused
2783  */
2785 
2786 #if FF_API_CODER_TYPE
2787 #define FF_CODER_TYPE_VLC 0
2788 #define FF_CODER_TYPE_AC 1
2789 #define FF_CODER_TYPE_RAW 2
2790 #define FF_CODER_TYPE_RLE 3
2791 #if FF_API_UNUSED_MEMBERS
2792 #define FF_CODER_TYPE_DEFLATE 4
2793 #endif /* FF_API_UNUSED_MEMBERS */
2794  /**
2795  * @deprecated use encoder private options instead
2796  */
2799 #endif /* FF_API_CODER_TYPE */
2800 
2801 #if FF_API_PRIVATE_OPT
2802  /** @deprecated use encoder private options instead */
2805 #endif
2806 
2807 #if FF_API_MPV_OPT
2808  /**
2809  * @deprecated use encoder private options instead
2810  */
2812  int lmin;
2813 
2814  /**
2815  * @deprecated use encoder private options instead
2816  */
2818  int lmax;
2819 #endif
2820 
2821 #if FF_API_PRIVATE_OPT
2822  /** @deprecated use encoder private options instead */
2825 
2826  /** @deprecated use encoder private options instead */
2829 
2830  /** @deprecated use encoder private options instead */
2833 
2834  /** @deprecated use encoder private options instead */
2837 #endif /* FF_API_PRIVATE_OPT */
2838 
2839  /**
2840  * trellis RD quantization
2841  * - encoding: Set by user.
2842  * - decoding: unused
2843  */
2844  int trellis;
2845 
2846 #if FF_API_PRIVATE_OPT
2847  /** @deprecated use encoder private options instead */
2850 
2851  /** @deprecated use encoder private options instead */
2854 
2855  /** @deprecated use encoder private options instead */
2858 #endif
2859 
2860 #if FF_API_RTP_CALLBACK
2861  /**
2862  * @deprecated unused
2863  */
2864  /* The RTP callback: This function is called */
2865  /* every time the encoder has a packet to send. */
2866  /* It depends on the encoder if the data starts */
2867  /* with a Start Code (it should). H.263 does. */
2868  /* mb_nb contains the number of macroblocks */
2869  /* encoded in the RTP payload. */
2871  void (*rtp_callback)(struct AVCodecContext *avctx, void *data, int size, int mb_nb);
2872 #endif
2873 
2874 #if FF_API_PRIVATE_OPT
2875  /** @deprecated use encoder private options instead */
2877  int rtp_payload_size; /* The size of the RTP payload: the coder will */
2878  /* do its best to deliver a chunk with size */
2879  /* below rtp_payload_size, the chunk will start */
2880  /* with a start code on some codecs like H.263. */
2881  /* This doesn't take account of any particular */
2882  /* headers inside the transmitted RTP payload. */
2883 #endif
2884 
2885 #if FF_API_STAT_BITS
2886  /* statistics, used for 2-pass encoding */
2888  int mv_bits;
2896  int i_count;
2898  int p_count;
2903 
2904  /** @deprecated this field is unused */
2907 #endif
2908 
2909  /**
2910  * pass1 encoding statistics output buffer
2911  * - encoding: Set by libavcodec.
2912  * - decoding: unused
2913  */
2914  char *stats_out;
2915 
2916  /**
2917  * pass2 encoding statistics input buffer
2918  * Concatenated stuff from stats_out of pass1 should be placed here.
2919  * - encoding: Allocated/set/freed by user.
2920  * - decoding: unused
2921  */
2922  char *stats_in;
2923 
2924  /**
2925  * Work around bugs in encoders which sometimes cannot be detected automatically.
2926  * - encoding: Set by user
2927  * - decoding: Set by user
2928  */
2930 #define FF_BUG_AUTODETECT 1 ///< autodetection
2931 #if FF_API_OLD_MSMPEG4
2932 #define FF_BUG_OLD_MSMPEG4 2
2933 #endif
2934 #define FF_BUG_XVID_ILACE 4
2935 #define FF_BUG_UMP4 8
2936 #define FF_BUG_NO_PADDING 16
2937 #define FF_BUG_AMV 32
2938 #if FF_API_AC_VLC
2939 #define FF_BUG_AC_VLC 0 ///< Will be removed, libavcodec can now handle these non-compliant files by default.
2940 #endif
2941 #define FF_BUG_QPEL_CHROMA 64
2942 #define FF_BUG_STD_QPEL 128
2943 #define FF_BUG_QPEL_CHROMA2 256
2944 #define FF_BUG_DIRECT_BLOCKSIZE 512
2945 #define FF_BUG_EDGE 1024
2946 #define FF_BUG_HPEL_CHROMA 2048
2947 #define FF_BUG_DC_CLIP 4096
2948 #define FF_BUG_MS 8192 ///< Work around various bugs in Microsoft's broken decoders.
2949 #define FF_BUG_TRUNCATED 16384
2950 #define FF_BUG_IEDGE 32768
2951 
2952  /**
2953  * strictly follow the standard (MPEG-4, ...).
2954  * - encoding: Set by user.
2955  * - decoding: Set by user.
2956  * Setting this to STRICT or higher means the encoder and decoder will
2957  * generally do stupid things, whereas setting it to unofficial or lower
2958  * will mean the encoder might produce output that is not supported by all
2959  * spec-compliant decoders. Decoders don't differentiate between normal,
2960  * unofficial and experimental (that is, they always try to decode things
2961  * when they can) unless they are explicitly asked to behave stupidly
2962  * (=strictly conform to the specs)
2963  */
2965 #define FF_COMPLIANCE_VERY_STRICT 2 ///< Strictly conform to an older more strict version of the spec or reference software.
2966 #define FF_COMPLIANCE_STRICT 1 ///< Strictly conform to all the things in the spec no matter what consequences.
2967 #define FF_COMPLIANCE_NORMAL 0
2968 #define FF_COMPLIANCE_UNOFFICIAL -1 ///< Allow unofficial extensions
2969 #define FF_COMPLIANCE_EXPERIMENTAL -2 ///< Allow nonstandardized experimental things.
2970 
2971  /**
2972  * error concealment flags
2973  * - encoding: unused
2974  * - decoding: Set by user.
2975  */
2977 #define FF_EC_GUESS_MVS 1
2978 #define FF_EC_DEBLOCK 2
2979 #define FF_EC_FAVOR_INTER 256
2980 
2981  /**
2982  * debug
2983  * - encoding: Set by user.
2984  * - decoding: Set by user.
2985  */
2986  int debug;
2987 #define FF_DEBUG_PICT_INFO 1
2988 #define FF_DEBUG_RC 2
2989 #define FF_DEBUG_BITSTREAM 4
2990 #define FF_DEBUG_MB_TYPE 8
2991 #define FF_DEBUG_QP 16
2992 #if FF_API_DEBUG_MV
2993 /**
2994  * @deprecated this option does nothing
2995  */
2996 #define FF_DEBUG_MV 32
2997 #endif
2998 #define FF_DEBUG_DCT_COEFF 0x00000040
2999 #define FF_DEBUG_SKIP 0x00000080
3000 #define FF_DEBUG_STARTCODE 0x00000100
3001 #if FF_API_UNUSED_MEMBERS
3002 #define FF_DEBUG_PTS 0x00000200
3003 #endif /* FF_API_UNUSED_MEMBERS */
3004 #define FF_DEBUG_ER 0x00000400
3005 #define FF_DEBUG_MMCO 0x00000800
3006 #define FF_DEBUG_BUGS 0x00001000
3007 #if FF_API_DEBUG_MV
3008 #define FF_DEBUG_VIS_QP 0x00002000
3009 #define FF_DEBUG_VIS_MB_TYPE 0x00004000
3010 #endif
3011 #define FF_DEBUG_BUFFERS 0x00008000
3012 #define FF_DEBUG_THREADS 0x00010000
3013 #define FF_DEBUG_GREEN_MD 0x00800000
3014 #define FF_DEBUG_NOMC 0x01000000
3015 
3016 #if FF_API_DEBUG_MV
3017  /**
3018  * debug
3019  * - encoding: Set by user.
3020  * - decoding: Set by user.
3021  */
3023 #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 // visualize forward predicted MVs of P-frames
3024 #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 // visualize forward predicted MVs of B-frames
3025 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 // visualize backward predicted MVs of B-frames
3026 #endif
3027 
3028  /**
3029  * Error recognition; may misdetect some more or less valid parts as errors.
3030  * - encoding: unused
3031  * - decoding: Set by user.
3032  */
3034 
3035 /**
3036  * Verify checksums embedded in the bitstream (could be of either encoded or
3037  * decoded data, depending on the codec) and print an error message on mismatch.
3038  * If AV_EF_EXPLODE is also set, a mismatching checksum will result in the
3039  * decoder returning an error.
3040  */
3041 #define AV_EF_CRCCHECK (1<<0)
3042 #define AV_EF_BITSTREAM (1<<1) ///< detect bitstream specification deviations
3043 #define AV_EF_BUFFER (1<<2) ///< detect improper bitstream length
3044 #define AV_EF_EXPLODE (1<<3) ///< abort decoding on minor error detection
3045 
3046 #define AV_EF_IGNORE_ERR (1<<15) ///< ignore errors and continue
3047 #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
3048 #define AV_EF_COMPLIANT (1<<17) ///< consider all spec non compliances as errors
3049 #define AV_EF_AGGRESSIVE (1<<18) ///< consider things that a sane encoder should not do as an error
3050 
3051 
3052  /**
3053  * opaque 64-bit number (generally a PTS) that will be reordered and
3054  * output in AVFrame.reordered_opaque
3055  * - encoding: unused
3056  * - decoding: Set by user.
3057  */
3059 
3060  /**
3061  * Hardware accelerator in use
3062  * - encoding: unused.
3063  * - decoding: Set by libavcodec
3064  */
3066 
3067  /**
3068  * Hardware accelerator context.
3069  * For some hardware accelerators, a global context needs to be
3070  * provided by the user. In that case, this holds display-dependent
3071  * data FFmpeg cannot instantiate itself. Please refer to the
3072  * FFmpeg HW accelerator documentation to know how to fill this
3073  * is. e.g. for VA API, this is a struct vaapi_context.
3074  * - encoding: unused
3075  * - decoding: Set by user
3076  */
3078 
3079  /**
3080  * error
3081  * - encoding: Set by libavcodec if flags & AV_CODEC_FLAG_PSNR.
3082  * - decoding: unused
3083  */
3085 
3086  /**
3087  * DCT algorithm, see FF_DCT_* below
3088  * - encoding: Set by user.
3089  * - decoding: unused
3090  */
3092 #define FF_DCT_AUTO 0
3093 #define FF_DCT_FASTINT 1
3094 #define FF_DCT_INT 2
3095 #define FF_DCT_MMX 3
3096 #define FF_DCT_ALTIVEC 5
3097 #define FF_DCT_FAAN 6
3098 
3099  /**
3100  * IDCT algorithm, see FF_IDCT_* below.
3101  * - encoding: Set by user.
3102  * - decoding: Set by user.
3103  */
3105 #define FF_IDCT_AUTO 0
3106 #define FF_IDCT_INT 1
3107 #define FF_IDCT_SIMPLE 2
3108 #define FF_IDCT_SIMPLEMMX 3
3109 #define FF_IDCT_ARM 7
3110 #define FF_IDCT_ALTIVEC 8
3111 #if FF_API_ARCH_SH4
3112 #define FF_IDCT_SH4 9
3113 #endif
3114 #define FF_IDCT_SIMPLEARM 10
3115 #if FF_API_UNUSED_MEMBERS
3116 #define FF_IDCT_IPP 13
3117 #endif /* FF_API_UNUSED_MEMBERS */
3118 #define FF_IDCT_XVID 14
3119 #if FF_API_IDCT_XVIDMMX
3120 #define FF_IDCT_XVIDMMX 14
3121 #endif /* FF_API_IDCT_XVIDMMX */
3122 #define FF_IDCT_SIMPLEARMV5TE 16
3123 #define FF_IDCT_SIMPLEARMV6 17
3124 #if FF_API_ARCH_SPARC
3125 #define FF_IDCT_SIMPLEVIS 18
3126 #endif
3127 #define FF_IDCT_FAAN 20
3128 #define FF_IDCT_SIMPLENEON 22
3129 #if FF_API_ARCH_ALPHA
3130 #define FF_IDCT_SIMPLEALPHA 23
3131 #endif
3132 #define FF_IDCT_SIMPLEAUTO 128
3133 
3134  /**
3135  * bits per sample/pixel from the demuxer (needed for huffyuv).
3136  * - encoding: Set by libavcodec.
3137  * - decoding: Set by user.
3138  */
3140 
3141  /**
3142  * Bits per sample/pixel of internal libavcodec pixel/sample format.
3143  * - encoding: set by user.
3144  * - decoding: set by libavcodec.
3145  */
3147 
3148 #if FF_API_LOWRES
3149  /**
3150  * low resolution decoding, 1-> 1/2 size, 2->1/4 size
3151  * - encoding: unused
3152  * - decoding: Set by user.
3153  */
3154  int lowres;
3155 #endif
3156 
3157 #if FF_API_CODED_FRAME
3158  /**
3159  * the picture in the bitstream
3160  * - encoding: Set by libavcodec.
3161  * - decoding: unused
3162  *
3163  * @deprecated use the quality factor packet side data instead
3164  */
3166 #endif
3167 
3168  /**
3169  * thread count
3170  * is used to decide how many independent tasks should be passed to execute()
3171  * - encoding: Set by user.
3172  * - decoding: Set by user.
3173  */
3175 
3176  /**
3177  * Which multithreading methods to use.
3178  * Use of FF_THREAD_FRAME will increase decoding delay by one frame per thread,
3179  * so clients which cannot provide future frames should not use it.
3180  *
3181  * - encoding: Set by user, otherwise the default is used.
3182  * - decoding: Set by user, otherwise the default is used.
3183  */
3185 #define FF_THREAD_FRAME 1 ///< Decode more than one frame at once
3186 #define FF_THREAD_SLICE 2 ///< Decode more than one part of a single frame at once
3187 
3188  /**
3189  * Which multithreading methods are in use by the codec.
3190  * - encoding: Set by libavcodec.
3191  * - decoding: Set by libavcodec.
3192  */
3194 
3195  /**
3196  * Set by the client if its custom get_buffer() callback can be called
3197  * synchronously from another thread, which allows faster multithreaded decoding.
3198  * draw_horiz_band() will be called from other threads regardless of this setting.
3199  * Ignored if the default get_buffer() is used.
3200  * - encoding: Set by user.
3201  * - decoding: Set by user.
3202  */
3204 
3205  /**
3206  * The codec may call this to execute several independent things.
3207  * It will return only after finishing all tasks.
3208  * The user may replace this with some multithreaded implementation,
3209  * the default implementation will execute the parts serially.
3210  * @param count the number of things to execute
3211  * - encoding: Set by libavcodec, user can override.
3212  * - decoding: Set by libavcodec, user can override.
3213  */
3214  int (*execute)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size);
3215 
3216  /**
3217  * The codec may call this to execute several independent things.
3218  * It will return only after finishing all tasks.
3219  * The user may replace this with some multithreaded implementation,
3220  * the default implementation will execute the parts serially.
3221  * Also see avcodec_thread_init and e.g. the --enable-pthread configure option.
3222  * @param c context passed also to func
3223  * @param count the number of things to execute
3224  * @param arg2 argument passed unchanged to func
3225  * @param ret return values of executed functions, must have space for "count" values. May be NULL.
3226  * @param func function that will be called count times, with jobnr from 0 to count-1.
3227  * threadnr will be in the range 0 to c->thread_count-1 < MAX_THREADS and so that no
3228  * two instances of func executing at the same time will have the same threadnr.
3229  * @return always 0 currently, but code should handle a future improvement where when any call to func
3230  * returns < 0 no further calls to func may be done and < 0 is returned.
3231  * - encoding: Set by libavcodec, user can override.
3232  * - decoding: Set by libavcodec, user can override.
3233  */
3234  int (*execute2)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count);
3235 
3236  /**
3237  * noise vs. sse weight for the nsse comparison function
3238  * - encoding: Set by user.
3239  * - decoding: unused
3240  */
3242 
3243  /**
3244  * profile
3245  * - encoding: Set by user.
3246  * - decoding: Set by libavcodec.
3247  */
3248  int profile;
3249 #define FF_PROFILE_UNKNOWN -99
3250 #define FF_PROFILE_RESERVED -100
3251 
3252 #define FF_PROFILE_AAC_MAIN 0
3253 #define FF_PROFILE_AAC_LOW 1
3254 #define FF_PROFILE_AAC_SSR 2
3255 #define FF_PROFILE_AAC_LTP 3
3256 #define FF_PROFILE_AAC_HE 4
3257 #define FF_PROFILE_AAC_HE_V2 28
3258 #define FF_PROFILE_AAC_LD 22
3259 #define FF_PROFILE_AAC_ELD 38
3260 #define FF_PROFILE_MPEG2_AAC_LOW 128
3261 #define FF_PROFILE_MPEG2_AAC_HE 131
3262 
3263 #define FF_PROFILE_DNXHD 0
3264 #define FF_PROFILE_DNXHR_LB 1
3265 #define FF_PROFILE_DNXHR_SQ 2
3266 #define FF_PROFILE_DNXHR_HQ 3
3267 #define FF_PROFILE_DNXHR_HQX 4
3268 #define FF_PROFILE_DNXHR_444 5
3269 
3270 #define FF_PROFILE_DTS 20
3271 #define FF_PROFILE_DTS_ES 30
3272 #define FF_PROFILE_DTS_96_24 40
3273 #define FF_PROFILE_DTS_HD_HRA 50
3274 #define FF_PROFILE_DTS_HD_MA 60
3275 #define FF_PROFILE_DTS_EXPRESS 70
3276 
3277 #define FF_PROFILE_MPEG2_422 0
3278 #define FF_PROFILE_MPEG2_HIGH 1
3279 #define FF_PROFILE_MPEG2_SS 2
3280 #define FF_PROFILE_MPEG2_SNR_SCALABLE 3
3281 #define FF_PROFILE_MPEG2_MAIN 4
3282 #define FF_PROFILE_MPEG2_SIMPLE 5
3283 
3284 #define FF_PROFILE_H264_CONSTRAINED (1<<9) // 8+1; constraint_set1_flag
3285 #define FF_PROFILE_H264_INTRA (1<<11) // 8+3; constraint_set3_flag
3286 
3287 #define FF_PROFILE_H264_BASELINE 66
3288 #define FF_PROFILE_H264_CONSTRAINED_BASELINE (66|FF_PROFILE_H264_CONSTRAINED)
3289 #define FF_PROFILE_H264_MAIN 77
3290 #define FF_PROFILE_H264_EXTENDED 88
3291 #define FF_PROFILE_H264_HIGH 100
3292 #define FF_PROFILE_H264_HIGH_10 110
3293 #define FF_PROFILE_H264_HIGH_10_INTRA (110|FF_PROFILE_H264_INTRA)
3294 #define FF_PROFILE_H264_MULTIVIEW_HIGH 118
3295 #define FF_PROFILE_H264_HIGH_422 122
3296 #define FF_PROFILE_H264_HIGH_422_INTRA (122|FF_PROFILE_H264_INTRA)
3297 #define FF_PROFILE_H264_STEREO_HIGH 128
3298 #define FF_PROFILE_H264_HIGH_444 144
3299 #define FF_PROFILE_H264_HIGH_444_PREDICTIVE 244
3300 #define FF_PROFILE_H264_HIGH_444_INTRA (244|FF_PROFILE_H264_INTRA)
3301 #define FF_PROFILE_H264_CAVLC_444 44
3302 
3303 #define FF_PROFILE_VC1_SIMPLE 0
3304 #define FF_PROFILE_VC1_MAIN 1
3305 #define FF_PROFILE_VC1_COMPLEX 2
3306 #define FF_PROFILE_VC1_ADVANCED 3
3307 
3308 #define FF_PROFILE_MPEG4_SIMPLE 0
3309 #define FF_PROFILE_MPEG4_SIMPLE_SCALABLE 1
3310 #define FF_PROFILE_MPEG4_CORE 2
3311 #define FF_PROFILE_MPEG4_MAIN 3
3312 #define FF_PROFILE_MPEG4_N_BIT 4
3313 #define FF_PROFILE_MPEG4_SCALABLE_TEXTURE 5
3314 #define FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION 6
3315 #define FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE 7
3316 #define FF_PROFILE_MPEG4_HYBRID 8
3317 #define FF_PROFILE_MPEG4_ADVANCED_REAL_TIME 9
3318 #define FF_PROFILE_MPEG4_CORE_SCALABLE 10
3319 #define FF_PROFILE_MPEG4_ADVANCED_CODING 11
3320 #define FF_PROFILE_MPEG4_ADVANCED_CORE 12
3321 #define FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE 13
3322 #define FF_PROFILE_MPEG4_SIMPLE_STUDIO 14
3323 #define FF_PROFILE_MPEG4_ADVANCED_SIMPLE 15
3324 
3325 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_0 1
3326 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_1 2
3327 #define FF_PROFILE_JPEG2000_CSTREAM_NO_RESTRICTION 32768
3328 #define FF_PROFILE_JPEG2000_DCINEMA_2K 3
3329 #define FF_PROFILE_JPEG2000_DCINEMA_4K 4
3330 
3331 #define FF_PROFILE_VP9_0 0
3332 #define FF_PROFILE_VP9_1 1
3333 #define FF_PROFILE_VP9_2 2
3334 #define FF_PROFILE_VP9_3 3
3335 
3336 #define FF_PROFILE_HEVC_MAIN 1
3337 #define FF_PROFILE_HEVC_MAIN_10 2
3338 #define FF_PROFILE_HEVC_MAIN_STILL_PICTURE 3
3339 #define FF_PROFILE_HEVC_REXT 4
3340 
3341  /**
3342  * level
3343  * - encoding: Set by user.
3344  * - decoding: Set by libavcodec.
3345  */
3346  int level;
3347 #define FF_LEVEL_UNKNOWN -99
3348 
3349  /**
3350  * Skip loop filtering for selected frames.
3351  * - encoding: unused
3352  * - decoding: Set by user.
3353  */
3355 
3356  /**
3357  * Skip IDCT/dequantization for selected frames.
3358  * - encoding: unused
3359  * - decoding: Set by user.
3360  */
3362 
3363  /**
3364  * Skip decoding for selected frames.
3365  * - encoding: unused
3366  * - decoding: Set by user.
3367  */
3369 
3370  /**
3371  * Header containing style information for text subtitles.
3372  * For SUBTITLE_ASS subtitle type, it should contain the whole ASS
3373  * [Script Info] and [V4+ Styles] section, plus the [Events] line and
3374  * the Format line following. It shouldn't include any Dialogue line.
3375  * - encoding: Set/allocated/freed by user (before avcodec_open2())
3376  * - decoding: Set/allocated/freed by libavcodec (by avcodec_open2())
3377  */
3380 
3381 #if FF_API_ERROR_RATE
3382  /**
3383  * @deprecated use the 'error_rate' private AVOption of the mpegvideo
3384  * encoders
3385  */
3388 #endif
3389 
3390 #if FF_API_VBV_DELAY
3391  /**
3392  * VBV delay coded in the last frame (in periods of a 27 MHz clock).
3393  * Used for compliant TS muxing.
3394  * - encoding: Set by libavcodec.
3395  * - decoding: unused.
3396  * @deprecated this value is now exported as a part of
3397  * AV_PKT_DATA_CPB_PROPERTIES packet side data
3398  */
3400  uint64_t vbv_delay;
3401 #endif
3402 
3403 #if FF_API_SIDEDATA_ONLY_PKT
3404  /**
3405  * Encoding only and set by default. Allow encoders to output packets
3406  * that do not contain any encoded data, only side data.
3407  *
3408  * Some encoders need to output such packets, e.g. to update some stream
3409  * parameters at the end of encoding.
3410  *
3411  * @deprecated this field disables the default behaviour and
3412  * it is kept only for compatibility.
3413  */
3416 #endif
3417 
3418  /**
3419  * Audio only. The number of "priming" samples (padding) inserted by the
3420  * encoder at the beginning of the audio. I.e. this number of leading
3421  * decoded samples must be discarded by the caller to get the original audio
3422  * without leading padding.
3423  *
3424  * - decoding: unused
3425  * - encoding: Set by libavcodec. The timestamps on the output packets are
3426  * adjusted by the encoder so that they always refer to the
3427  * first sample of the data actually contained in the packet,
3428  * including any added padding. E.g. if the timebase is
3429  * 1/samplerate and the timestamp of the first input sample is
3430  * 0, the timestamp of the first output packet will be
3431  * -initial_padding.
3432  */
3434 
3435  /**
3436  * - decoding: For codecs that store a framerate value in the compressed
3437  * bitstream, the decoder may export it here. { 0, 1} when
3438  * unknown.
3439  * - encoding: May be used to signal the framerate of CFR content to an
3440  * encoder.
3441  */
3443 
3444  /**
3445  * Nominal unaccelerated pixel format, see AV_PIX_FMT_xxx.
3446  * - encoding: unused.
3447  * - decoding: Set by libavcodec before calling get_format()
3448  */
3450 
3451  /**
3452  * Timebase in which pkt_dts/pts and AVPacket.dts/pts are.
3453  * - encoding unused.
3454  * - decoding set by user.
3455  */
3457 
3458  /**
3459  * AVCodecDescriptor
3460  * - encoding: unused.
3461  * - decoding: set by libavcodec.
3462  */
3464 
3465 #if !FF_API_LOWRES
3466  /**
3467  * low resolution decoding, 1-> 1/2 size, 2->1/4 size
3468  * - encoding: unused
3469  * - decoding: Set by user.
3470  */
3471  int lowres;
3472 #endif
3473 
3474  /**
3475  * Current statistics for PTS correction.
3476  * - decoding: maintained and used by libavcodec, not intended to be used by user apps
3477  * - encoding: unused
3478  */
3479  int64_t pts_correction_num_faulty_pts; /// Number of incorrect PTS values so far
3480  int64_t pts_correction_num_faulty_dts; /// Number of incorrect DTS values so far
3481  int64_t pts_correction_last_pts; /// PTS of the last frame
3482  int64_t pts_correction_last_dts; /// DTS of the last frame
3483 
3484  /**
3485  * Character encoding of the input subtitles file.
3486  * - decoding: set by user
3487  * - encoding: unused
3488  */
3490 
3491  /**
3492  * Subtitles character encoding mode. Formats or codecs might be adjusting
3493  * this setting (if they are doing the conversion themselves for instance).
3494  * - decoding: set by libavcodec
3495  * - encoding: unused
3496  */
3498 #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)
3499 #define FF_SUB_CHARENC_MODE_AUTOMATIC 0 ///< libavcodec will select the mode itself
3500 #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
3501 
3502  /**
3503  * Skip processing alpha if supported by codec.
3504  * Note that if the format uses pre-multiplied alpha (common with VP6,
3505  * and recommended due to better video quality/compression)
3506  * the image will look as if alpha-blended onto a black background.
3507  * However for formats that do not use pre-multiplied alpha
3508  * there might be serious artefacts (though e.g. libswscale currently
3509  * assumes pre-multiplied alpha anyway).
3510  *
3511  * - decoding: set by user
3512  * - encoding: unused
3513  */
3515 
3516  /**
3517  * Number of samples to skip after a discontinuity
3518  * - decoding: unused
3519  * - encoding: set by libavcodec
3520  */
3522 
3523 #if !FF_API_DEBUG_MV
3524  /**
3525  * debug motion vectors
3526  * - encoding: Set by user.
3527  * - decoding: Set by user.
3528  */
3529  int debug_mv;
3530 #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 //visualize forward predicted MVs of P frames
3531 #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 //visualize forward predicted MVs of B frames
3532 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
3533 #endif
3534 
3535  /**
3536  * custom intra quantization matrix
3537  * - encoding: Set by user, can be NULL.
3538  * - decoding: unused.
3539  */
3541 
3542  /**
3543  * dump format separator.
3544  * can be ", " or "\n " or anything else
3545  * - encoding: Set by user.
3546  * - decoding: Set by user.
3547  */
3549 
3550  /**
3551  * ',' separated list of allowed decoders.
3552  * If NULL then all are allowed
3553  * - encoding: unused
3554  * - decoding: set by user
3555  */
3557 
3558  /*
3559  * Properties of the stream that gets decoded
3560  * - encoding: unused
3561  * - decoding: set by libavcodec
3562  */
3563  unsigned properties;
3564 #define FF_CODEC_PROPERTY_LOSSLESS 0x00000001
3565 #define FF_CODEC_PROPERTY_CLOSED_CAPTIONS 0x00000002
3566 
3567  /**
3568  * Additional data associated with the entire coded stream.
3569  *
3570  * - decoding: unused
3571  * - encoding: may be set by libavcodec after avcodec_open2().
3572  */
3575 
3576  /**
3577  * A reference to the AVHWFramesContext describing the input (for encoding)
3578  * or output (decoding) frames. The reference is set by the caller and
3579  * afterwards owned (and freed) by libavcodec - it should never be read by
3580  * the caller after being set.
3581  *
3582  * - decoding: This field should be set by the caller from the get_format()
3583  * callback. The previous reference (if any) will always be
3584  * unreffed by libavcodec before the get_format() call.
3585  *
3586  * If the default get_buffer2() is used with a hwaccel pixel
3587  * format, then this AVHWFramesContext will be used for
3588  * allocating the frame buffers.
3589  *
3590  * - encoding: For hardware encoders configured to use a hwaccel pixel
3591  * format, this field should be set by the caller to a reference
3592  * to the AVHWFramesContext describing input frames.
3593  * AVHWFramesContext.format must be equal to
3594  * AVCodecContext.pix_fmt.
3595  *
3596  * This field should be set before avcodec_open2() is called.
3597  */
3599 
3600  /**
3601  * Control the form of AVSubtitle.rects[N]->ass
3602  * - decoding: set by user
3603  * - encoding: unused
3604  */
3606 #define FF_SUB_TEXT_FMT_ASS 0
3607 #if FF_API_ASS_TIMING
3608 #define FF_SUB_TEXT_FMT_ASS_WITH_TIMINGS 1
3609 #endif
3610 
3611  /**
3612  * Audio only. The amount of padding (in samples) appended by the encoder to
3613  * the end of the audio. I.e. this number of decoded samples must be
3614  * discarded by the caller from the end of the stream to get the original
3615  * audio without any trailing padding.
3616  *
3617  * - decoding: unused
3618  * - encoding: unused
3619  */
3621 
3622  /**
3623  * The number of pixels per image to maximally accept.
3624  *
3625  * - decoding: set by user
3626  * - encoding: set by user
3627  */
3628  int64_t max_pixels;
3629 
3630  /**
3631  * A reference to the AVHWDeviceContext describing the device which will
3632  * be used by a hardware encoder/decoder. The reference is set by the
3633  * caller and afterwards owned (and freed) by libavcodec.
3634  *
3635  * This should be used if either the codec device does not require
3636  * hardware frames or any that are used are to be allocated internally by
3637  * libavcodec. If the user wishes to supply any of the frames used as
3638  * encoder input or decoder output then hw_frames_ctx should be used
3639  * instead. When hw_frames_ctx is set in get_format() for a decoder, this
3640  * field will be ignored while decoding the associated stream segment, but
3641  * may again be used on a following one after another get_format() call.
3642  *
3643  * For both encoders and decoders this field should be set before
3644  * avcodec_open2() is called and must not be written to thereafter.
3645  *
3646  * Note that some decoders may require this field to be set initially in
3647  * order to support hw_frames_ctx at all - in that case, all frames
3648  * contexts used must be created on the same device.
3649  */
3651 
3652  /**
3653  * Bit set of AV_HWACCEL_FLAG_* flags, which affect hardware accelerated
3654  * decoding (if active).
3655  * - encoding: unused
3656  * - decoding: Set by user (either before avcodec_open2(), or in the
3657  * AVCodecContext.get_format callback)
3658  */
3660 
3661  /**
3662  * Video decoding only. Certain video codecs support cropping, meaning that
3663  * only a sub-rectangle of the decoded frame is intended for display. This
3664  * option controls how cropping is handled by libavcodec.
3665  *
3666  * When set to 1 (the default), libavcodec will apply cropping internally.
3667  * I.e. it will modify the output frame width/height fields and offset the
3668  * data pointers (only by as much as possible while preserving alignment, or
3669  * by the full amount if the AV_CODEC_FLAG_UNALIGNED flag is set) so that
3670  * the frames output by the decoder refer only to the cropped area. The
3671  * crop_* fields of the output frames will be zero.
3672  *
3673  * When set to 0, the width/height fields of the output frames will be set
3674  * to the coded dimensions and the crop_* fields will describe the cropping
3675  * rectangle. Applying the cropping is left to the caller.
3676  *
3677  * @warning When hardware acceleration with opaque output frames is used,
3678  * libavcodec is unable to apply cropping from the top/left border.
3679  *
3680  * @note when this option is set to zero, the width/height fields of the
3681  * AVCodecContext and output AVFrames have different meanings. The codec
3682  * context fields store display dimensions (with the coded dimensions in
3683  * coded_width/height), while the frame fields store the coded dimensions
3684  * (with the display dimensions being determined by the crop_* fields).
3685  */
3687 } AVCodecContext;
3688 
3691 
3694 
3695 unsigned av_codec_get_codec_properties(const AVCodecContext *avctx);
3696 
3697 int av_codec_get_lowres(const AVCodecContext *avctx);
3698 void av_codec_set_lowres(AVCodecContext *avctx, int val);
3699 
3700 int av_codec_get_seek_preroll(const AVCodecContext *avctx);
3701 void av_codec_set_seek_preroll(AVCodecContext *avctx, int val);
3702 
3703 uint16_t *av_codec_get_chroma_intra_matrix(const AVCodecContext *avctx);
3704 void av_codec_set_chroma_intra_matrix(AVCodecContext *avctx, uint16_t *val);
3705 
3706 /**
3707  * AVProfile.
3708  */
3709 typedef struct AVProfile {
3710  int profile;
3711  const char *name; ///< short name for the profile
3712 } AVProfile;
3713 
3714 typedef struct AVCodecDefault AVCodecDefault;
3715 
3716 struct AVSubtitle;
3717 
3718 /**
3719  * AVCodec.
3720  */
3721 typedef struct AVCodec {
3722  /**
3723  * Name of the codec implementation.
3724  * The name is globally unique among encoders and among decoders (but an
3725  * encoder and a decoder can share the same name).
3726  * This is the primary way to find a codec from the user perspective.
3727  */
3728  const char *name;
3729  /**
3730  * Descriptive name for the codec, meant to be more human readable than name.
3731  * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
3732  */
3733  const char *long_name;
3736  /**
3737  * Codec capabilities.
3738  * see AV_CODEC_CAP_*
3739  */
3741  const AVRational *supported_framerates; ///< array of supported framerates, or NULL if any, array is terminated by {0,0}
3742  const enum AVPixelFormat *pix_fmts; ///< array of supported pixel formats, or NULL if unknown, array is terminated by -1
3743  const int *supported_samplerates; ///< array of supported audio samplerates, or NULL if unknown, array is terminated by 0
3744  const enum AVSampleFormat *sample_fmts; ///< array of supported sample formats, or NULL if unknown, array is terminated by -1
3745  const uint64_t *channel_layouts; ///< array of support channel layouts, or NULL if unknown. array is terminated by 0
3746  uint8_t max_lowres; ///< maximum value for lowres supported by the decoder
3747  const AVClass *priv_class; ///< AVClass for the private context
3748  const AVProfile *profiles; ///< array of recognized profiles, or NULL if unknown, array is terminated by {FF_PROFILE_UNKNOWN}
3749 
3750  /*****************************************************************
3751  * No fields below this line are part of the public API. They
3752  * may not be used outside of libavcodec and can be changed and
3753  * removed at will.
3754  * New public fields should be added right above.
3755  *****************************************************************
3756  */
3758  struct AVCodec *next;
3759  /**
3760  * @name Frame-level threading support functions
3761  * @{
3762  */
3763  /**
3764  * If defined, called on thread contexts when they are created.
3765  * If the codec allocates writable tables in init(), re-allocate them here.
3766  * priv_data will be set to a copy of the original.
3767  */
3769  /**
3770  * Copy necessary context variables from a previous thread context to the current one.
3771  * If not defined, the next thread will start automatically; otherwise, the codec
3772  * must call ff_thread_finish_setup().
3773  *
3774  * dst and src will (rarely) point to the same context, in which case memcpy should be skipped.
3775  */
3777  /** @} */
3778 
3779  /**
3780  * Private codec-specific defaults.
3781  */
3783 
3784  /**
3785  * Initialize codec static data, called from avcodec_register().
3786  */
3787  void (*init_static_data)(struct AVCodec *codec);
3788 
3790  int (*encode_sub)(AVCodecContext *, uint8_t *buf, int buf_size,
3791  const struct AVSubtitle *sub);
3792  /**
3793  * Encode data to an AVPacket.
3794  *
3795  * @param avctx codec context
3796  * @param avpkt output AVPacket (may contain a user-provided buffer)
3797  * @param[in] frame AVFrame containing the raw data to be encoded
3798  * @param[out] got_packet_ptr encoder sets to 0 or 1 to indicate that a
3799  * non-empty packet was returned in avpkt.
3800  * @return 0 on success, negative error code on failure
3801  */
3802  int (*encode2)(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame,
3803  int *got_packet_ptr);
3804  int (*decode)(AVCodecContext *, void *outdata, int *outdata_size, AVPacket *avpkt);
3806  /**
3807  * Encode API with decoupled packet/frame dataflow. The API is the
3808  * same as the avcodec_ prefixed APIs (avcodec_send_frame() etc.), except
3809  * that:
3810  * - never called if the codec is closed or the wrong type,
3811  * - if AV_CODEC_CAP_DELAY is not set, drain frames are never sent,
3812  * - only one drain frame is ever passed down,
3813  */
3816 
3817  /**
3818  * Decode API with decoupled packet/frame dataflow. This function is called
3819  * to get one output frame. It should call ff_decode_get_packet() to obtain
3820  * input data.
3821  */
3823  /**
3824  * Flush buffers.
3825  * Will be called when seeking
3826  */
3828  /**
3829  * Internal codec capabilities.
3830  * See FF_CODEC_CAP_* in internal.h
3831  */
3833 
3834  /**
3835  * Decoding only, a comma-separated list of bitstream filters to apply to
3836  * packets before decoding.
3837  */
3838  const char *bsfs;
3839 } AVCodec;
3840 
3841 int av_codec_get_max_lowres(const AVCodec *codec);
3842 
3843 struct MpegEncContext;
3844 
3845 /**
3846  * @defgroup lavc_hwaccel AVHWAccel
3847  * @{
3848  */
3849 typedef struct AVHWAccel {
3850  /**
3851  * Name of the hardware accelerated codec.
3852  * The name is globally unique among encoders and among decoders (but an
3853  * encoder and a decoder can share the same name).
3854  */
3855  const char *name;
3856 
3857  /**
3858  * Type of codec implemented by the hardware accelerator.
3859  *
3860  * See AVMEDIA_TYPE_xxx
3861  */
3863 
3864  /**
3865  * Codec implemented by the hardware accelerator.
3866  *
3867  * See AV_CODEC_ID_xxx
3868  */
3870 
3871  /**
3872  * Supported pixel format.
3873  *
3874  * Only hardware accelerated formats are supported here.
3875  */
3877 
3878  /**
3879  * Hardware accelerated codec capabilities.
3880  * see HWACCEL_CODEC_CAP_*
3881  */
3883 
3884  /*****************************************************************
3885  * No fields below this line are part of the public API. They
3886  * may not be used outside of libavcodec and can be changed and
3887  * removed at will.
3888  * New public fields should be added right above.
3889  *****************************************************************
3890  */
3891  struct AVHWAccel *next;
3892 
3893  /**
3894  * Allocate a custom buffer
3895  */
3897 
3898  /**
3899  * Called at the beginning of each frame or field picture.
3900  *
3901  * Meaningful frame information (codec specific) is guaranteed to
3902  * be parsed at this point. This function is mandatory.
3903  *
3904  * Note that buf can be NULL along with buf_size set to 0.
3905  * Otherwise, this means the whole frame is available at this point.
3906  *
3907  * @param avctx the codec context
3908  * @param buf the frame data buffer base
3909  * @param buf_size the size of the frame in bytes
3910  * @return zero if successful, a negative value otherwise
3911  */
3912  int (*start_frame)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3913 
3914  /**
3915  * Callback for each slice.
3916  *
3917  * Meaningful slice information (codec specific) is guaranteed to
3918  * be parsed at this point. This function is mandatory.
3919  * The only exception is XvMC, that works on MB level.
3920  *
3921  * @param avctx the codec context
3922  * @param buf the slice data buffer base
3923  * @param buf_size the size of the slice in bytes
3924  * @return zero if successful, a negative value otherwise
3925  */
3926  int (*decode_slice)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3927 
3928  /**
3929  * Called at the end of each frame or field picture.
3930  *
3931  * The whole picture is parsed at this point and can now be sent
3932  * to the hardware accelerator. This function is mandatory.
3933  *
3934  * @param avctx the codec context
3935  * @return zero if successful, a negative value otherwise
3936  */
3938 
3939  /**
3940  * Size of per-frame hardware accelerator private data.
3941  *
3942  * Private data is allocated with av_mallocz() before
3943  * AVCodecContext.get_buffer() and deallocated after
3944  * AVCodecContext.release_buffer().
3945  */
3947 
3948  /**
3949  * Called for every Macroblock in a slice.
3950  *
3951  * XvMC uses it to replace the ff_mpv_reconstruct_mb().
3952  * Instead of decoding to raw picture, MB parameters are
3953  * stored in an array provided by the video driver.
3954  *
3955  * @param s the mpeg context
3956  */
3958 
3959  /**
3960  * Initialize the hwaccel private data.
3961  *
3962  * This will be called from ff_get_format(), after hwaccel and
3963  * hwaccel_context are set and the hwaccel private data in AVCodecInternal
3964  * is allocated.
3965  */
3967 
3968  /**
3969  * Uninitialize the hwaccel private data.
3970  *
3971  * This will be called from get_format() or avcodec_close(), after hwaccel
3972  * and hwaccel_context are already uninitialized.
3973  */
3975 
3976  /**
3977  * Size of the private data to allocate in
3978  * AVCodecInternal.hwaccel_priv_data.
3979  */
3981 
3982  /**
3983  * Internal hwaccel capabilities.
3984  */
3986 } AVHWAccel;
3987 
3988 /**
3989  * Hardware acceleration should be used for decoding even if the codec level
3990  * used is unknown or higher than the maximum supported level reported by the
3991  * hardware driver.
3992  *
3993  * It's generally a good idea to pass this flag unless you have a specific
3994  * reason not to, as hardware tends to under-report supported levels.
3995  */
3996 #define AV_HWACCEL_FLAG_IGNORE_LEVEL (1 << 0)
3997 
3998 /**
3999  * Hardware acceleration can output YUV pixel formats with a different chroma
4000  * sampling than 4:2:0 and/or other than 8 bits per component.
4001  */
4002 #define AV_HWACCEL_FLAG_ALLOW_HIGH_DEPTH (1 << 1)
4003 
4004 /**
4005  * Hardware acceleration should still be attempted for decoding when the
4006  * codec profile does not match the reported capabilities of the hardware.
4007  *
4008  * For example, this can be used to try to decode baseline profile H.264
4009  * streams in hardware - it will often succeed, because many streams marked
4010  * as baseline profile actually conform to constrained baseline profile.
4011  *
4012  * @warning If the stream is actually not supported then the behaviour is
4013  * undefined, and may include returning entirely incorrect output
4014  * while indicating success.
4015  */
4016 #define AV_HWACCEL_FLAG_ALLOW_PROFILE_MISMATCH (1 << 2)
4017 
4018 /**
4019  * @}
4020  */
4021 
4022 #if FF_API_AVPICTURE
4023 /**
4024  * @defgroup lavc_picture AVPicture
4025  *
4026  * Functions for working with AVPicture
4027  * @{
4028  */
4029 
4030 /**
4031  * Picture data structure.
4032  *
4033  * Up to four components can be stored into it, the last component is
4034  * alpha.
4035  * @deprecated use AVFrame or imgutils functions instead
4036  */
4037 typedef struct AVPicture {
4039  uint8_t *data[AV_NUM_DATA_POINTERS]; ///< pointers to the image data planes
4041  int linesize[AV_NUM_DATA_POINTERS]; ///< number of bytes per line
4042 } AVPicture;
4043 
4044 /**
4045  * @}
4046  */
4047 #endif
4048 
4051 
4052  SUBTITLE_BITMAP, ///< A bitmap, pict will be set
4053 
4054  /**
4055  * Plain text, the text field must be set by the decoder and is
4056  * authoritative. ass and pict fields may contain approximations.
4057  */
4059 
4060  /**
4061  * Formatted text, the ass field must be set by the decoder and is
4062  * authoritative. pict and text fields may contain approximations.
4063  */
4065 };
4066 
4067 #define AV_SUBTITLE_FLAG_FORCED 0x00000001
4068 
4069 typedef struct AVSubtitleRect {
4070  int x; ///< top left corner of pict, undefined when pict is not set
4071  int y; ///< top left corner of pict, undefined when pict is not set
4072  int w; ///< width of pict, undefined when pict is not set
4073  int h; ///< height of pict, undefined when pict is not set
4074  int nb_colors; ///< number of colors in pict, undefined when pict is not set
4075 
4076 #if FF_API_AVPICTURE
4077  /**
4078  * @deprecated unused
4079  */
4082 #endif
4083  /**
4084  * data+linesize for the bitmap of this subtitle.
4085  * Can be set for text/ass as well once they are rendered.
4086  */
4088  int linesize[4];
4089 
4091 
4092  char *text; ///< 0 terminated plain UTF-8 text
4093 
4094  /**
4095  * 0 terminated ASS/SSA compatible event line.
4096  * The presentation of this is unaffected by the other values in this
4097  * struct.
4098  */
4099  char *ass;
4100 
4101  int flags;
4102 } AVSubtitleRect;
4103 
4104 typedef struct AVSubtitle {
4105  uint16_t format; /* 0 = graphics */
4106  uint32_t start_display_time; /* relative to packet pts, in ms */
4107  uint32_t end_display_time; /* relative to packet pts, in ms */
4108  unsigned num_rects;
4110  int64_t pts; ///< Same as packet pts, in AV_TIME_BASE
4111 } AVSubtitle;
4112 
4113 /**
4114  * This struct describes the properties of an encoded stream.
4115  *
4116  * sizeof(AVCodecParameters) is not a part of the public ABI, this struct must
4117  * be allocated with avcodec_parameters_alloc() and freed with
4118  * avcodec_parameters_free().
4119  */
4120 typedef struct AVCodecParameters {
4121  /**
4122  * General type of the encoded data.
4123  */
4125  /**
4126  * Specific type of the encoded data (the codec used).
4127  */
4129  /**
4130  * Additional information about the codec (corresponds to the AVI FOURCC).
4131  */
4132  uint32_t codec_tag;
4133 
4134  /**
4135  * Extra binary data needed for initializing the decoder, codec-dependent.
4136  *
4137  * Must be allocated with av_malloc() and will be freed by
4138  * avcodec_parameters_free(). The allocated size of extradata must be at
4139  * least extradata_size + AV_INPUT_BUFFER_PADDING_SIZE, with the padding
4140  * bytes zeroed.
4141  */
4143  /**
4144  * Size of the extradata content in bytes.
4145  */
4147 
4148  /**
4149  * - video: the pixel format, the value corresponds to enum AVPixelFormat.
4150  * - audio: the sample format, the value corresponds to enum AVSampleFormat.
4151  */
4152  int format;
4153 
4154  /**
4155  * The average bitrate of the encoded data (in bits per second).
4156  */
4157  int64_t bit_rate;
4158 
4159  /**
4160  * The number of bits per sample in the codedwords.
4161  *
4162  * This is basically the bitrate per sample. It is mandatory for a bunch of
4163  * formats to actually decode them. It's the number of bits for one sample in
4164  * the actual coded bitstream.
4165  *
4166  * This could be for example 4 for ADPCM
4167  * For PCM formats this matches bits_per_raw_sample
4168  * Can be 0
4169  */
4171 
4172  /**
4173  * This is the number of valid bits in each output sample. If the
4174  * sample format has more bits, the least significant bits are additional
4175  * padding bits, which are always 0. Use right shifts to reduce the sample
4176  * to its actual size. For example, audio formats with 24 bit samples will
4177  * have bits_per_raw_sample set to 24, and format set to AV_SAMPLE_FMT_S32.
4178  * To get the original sample use "(int32_t)sample >> 8"."
4179  *
4180  * For ADPCM this might be 12 or 16 or similar
4181  * Can be 0
4182  */
4184 
4185  /**
4186  * Codec-specific bitstream restrictions that the stream conforms to.
4187  */
4188  int profile;
4189  int level;
4190 
4191  /**
4192  * Video only. The dimensions of the video frame in pixels.
4193  */
4194  int width;
4195  int height;
4196 
4197  /**
4198  * Video only. The aspect ratio (width / height) which a single pixel
4199  * should have when displayed.
4200  *
4201  * When the aspect ratio is unknown / undefined, the numerator should be
4202  * set to 0 (the denominator may have any value).
4203  */
4205 
4206  /**
4207  * Video only. The order of the fields in interlaced video.
4208  */
4210 
4211  /**
4212  * Video only. Additional colorspace characteristics.
4213  */
4219 
4220  /**
4221  * Video only. Number of delayed frames.
4222  */
4224 
4225  /**
4226  * Audio only. The channel layout bitmask. May be 0 if the channel layout is
4227  * unknown or unspecified, otherwise the number of bits set must be equal to
4228  * the channels field.
4229  */
4230  uint64_t channel_layout;
4231  /**
4232  * Audio only. The number of audio channels.
4233  */
4235  /**
4236  * Audio only. The number of audio samples per second.
4237  */
4239  /**
4240  * Audio only. The number of bytes per coded audio frame, required by some
4241  * formats.
4242  *
4243  * Corresponds to nBlockAlign in WAVEFORMATEX.
4244  */
4246  /**
4247  * Audio only. Audio frame size, if known. Required by some formats to be static.
4248  */
4250 
4251  /**
4252  * Audio only. The amount of padding (in samples) inserted by the encoder at
4253  * the beginning of the audio. I.e. this number of leading decoded samples
4254  * must be discarded by the caller to get the original audio without leading
4255  * padding.
4256  */
4258  /**
4259  * Audio only. The amount of padding (in samples) appended by the encoder to
4260  * the end of the audio. I.e. this number of decoded samples must be
4261  * discarded by the caller from the end of the stream to get the original
4262  * audio without any trailing padding.
4263  */
4265  /**
4266  * Audio only. Number of samples to skip after a discontinuity.
4267  */
4270 
4271 /**
4272  * If c is NULL, returns the first registered codec,
4273  * if c is non-NULL, returns the next registered codec after c,
4274  * or NULL if c is the last one.
4275  */
4276 AVCodec *av_codec_next(const AVCodec *c);
4277 
4278 /**
4279  * Return the LIBAVCODEC_VERSION_INT constant.
4280  */
4281 unsigned avcodec_version(void);
4282 
4283 /**
4284  * Return the libavcodec build-time configuration.
4285  */
4286 const char *avcodec_configuration(void);
4287 
4288 /**
4289  * Return the libavcodec license.
4290  */
4291 const char *avcodec_license(void);
4292 
4293 /**
4294  * Register the codec codec and initialize libavcodec.
4295  *
4296  * @warning either this function or avcodec_register_all() must be called
4297  * before any other libavcodec functions.
4298  *
4299  * @see avcodec_register_all()
4300  */
4301 void avcodec_register(AVCodec *codec);
4302 
4303 /**
4304  * Register all the codecs, parsers and bitstream filters which were enabled at
4305  * configuration time. If you do not call this function you can select exactly
4306  * which formats you want to support, by using the individual registration
4307  * functions.
4308  *
4309  * @see avcodec_register
4310  * @see av_register_codec_parser
4311  * @see av_register_bitstream_filter
4312  */
4313 void avcodec_register_all(void);
4314 
4315 /**
4316  * Allocate an AVCodecContext and set its fields to default values. The
4317  * resulting struct should be freed with avcodec_free_context().
4318  *
4319  * @param codec if non-NULL, allocate private data and initialize defaults
4320  * for the given codec. It is illegal to then call avcodec_open2()
4321  * with a different codec.
4322  * If NULL, then the codec-specific defaults won't be initialized,
4323  * which may result in suboptimal default settings (this is
4324  * important mainly for encoders, e.g. libx264).
4325  *
4326  * @return An AVCodecContext filled with default values or NULL on failure.
4327  */
4329 
4330 /**
4331  * Free the codec context and everything associated with it and write NULL to
4332  * the provided pointer.
4333  */
4334 void avcodec_free_context(AVCodecContext **avctx);
4335 
4336 #if FF_API_GET_CONTEXT_DEFAULTS
4337 /**
4338  * @deprecated This function should not be used, as closing and opening a codec
4339  * context multiple time is not supported. A new codec context should be
4340  * allocated for each new use.
4341  */
4343 #endif
4344 
4345 /**
4346  * Get the AVClass for AVCodecContext. It can be used in combination with
4347  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
4348  *
4349  * @see av_opt_find().
4350  */
4351 const AVClass *avcodec_get_class(void);
4352 
4353 #if FF_API_COPY_CONTEXT
4354 /**
4355  * Get the AVClass for AVFrame. It can be used in combination with
4356  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
4357  *
4358  * @see av_opt_find().
4359  */
4360 const AVClass *avcodec_get_frame_class(void);
4361 
4362 /**
4363  * Get the AVClass for AVSubtitleRect. It can be used in combination with
4364  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
4365  *
4366  * @see av_opt_find().
4367  */
4369 
4370 /**
4371  * Copy the settings of the source AVCodecContext into the destination
4372  * AVCodecContext. The resulting destination codec context will be
4373  * unopened, i.e. you are required to call avcodec_open2() before you
4374  * can use this AVCodecContext to decode/encode video/audio data.
4375  *
4376  * @param dest target codec context, should be initialized with
4377  * avcodec_alloc_context3(NULL), but otherwise uninitialized
4378  * @param src source codec context
4379  * @return AVERROR() on error (e.g. memory allocation error), 0 on success
4380  *
4381  * @deprecated The semantics of this function are ill-defined and it should not
4382  * be used. If you need to transfer the stream parameters from one codec context
4383  * to another, use an intermediate AVCodecParameters instance and the
4384  * avcodec_parameters_from_context() / avcodec_parameters_to_context()
4385  * functions.
4386  */
4389 #endif
4390 
4391 /**
4392  * Allocate a new AVCodecParameters and set its fields to default values
4393  * (unknown/invalid/0). The returned struct must be freed with
4394  * avcodec_parameters_free().
4395  */
4397 
4398 /**
4399  * Free an AVCodecParameters instance and everything associated with it and
4400  * write NULL to the supplied pointer.
4401  */
4403 
4404 /**
4405  * Copy the contents of src to dst. Any allocated fields in dst are freed and
4406  * replaced with newly allocated duplicates of the corresponding fields in src.
4407  *
4408  * @return >= 0 on success, a negative AVERROR code on failure.
4409  */
4411 
4412 /**
4413  * Fill the parameters struct based on the values from the supplied codec
4414  * context. Any allocated fields in par are freed and replaced with duplicates
4415  * of the corresponding fields in codec.
4416  *
4417  * @return >= 0 on success, a negative AVERROR code on failure
4418  */
4420  const AVCodecContext *codec);
4421 
4422 /**
4423  * Fill the codec context based on the values from the supplied codec
4424  * parameters. Any allocated fields in codec that have a corresponding field in
4425  * par are freed and replaced with duplicates of the corresponding field in par.
4426  * Fields in codec that do not have a counterpart in par are not touched.
4427  *
4428  * @return >= 0 on success, a negative AVERROR code on failure.
4429  */
4431  const AVCodecParameters *par);
4432 
4433 /**
4434  * Initialize the AVCodecContext to use the given AVCodec. Prior to using this
4435  * function the context has to be allocated with avcodec_alloc_context3().
4436  *
4437  * The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(),
4438  * avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for
4439  * retrieving a codec.
4440  *
4441  * @warning This function is not thread safe!
4442  *
4443  * @note Always call this function before using decoding routines (such as
4444  * @ref avcodec_receive_frame()).
4445  *
4446  * @code
4447  * avcodec_register_all();
4448  * av_dict_set(&opts, "b", "2.5M", 0);
4449  * codec = avcodec_find_decoder(AV_CODEC_ID_H264);
4450  * if (!codec)
4451  * exit(1);
4452  *
4453  * context = avcodec_alloc_context3(codec);
4454  *
4455  * if (avcodec_open2(context, codec, opts) < 0)
4456  * exit(1);
4457  * @endcode
4458  *
4459  * @param avctx The context to initialize.
4460  * @param codec The codec to open this context for. If a non-NULL codec has been
4461  * previously passed to avcodec_alloc_context3() or
4462  * for this context, then this parameter MUST be either NULL or
4463  * equal to the previously passed codec.
4464  * @param options A dictionary filled with AVCodecContext and codec-private options.
4465  * On return this object will be filled with options that were not found.
4466  *
4467  * @return zero on success, a negative value on error
4468  * @see avcodec_alloc_context3(), avcodec_find_decoder(), avcodec_find_encoder(),
4469  * av_dict_set(), av_opt_find().
4470  */
4471 int avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options);
4472 
4473 /**
4474  * Close a given AVCodecContext and free all the data associated with it
4475  * (but not the AVCodecContext itself).
4476  *
4477  * Calling this function on an AVCodecContext that hasn't been opened will free
4478  * the codec-specific data allocated in avcodec_alloc_context3() with a non-NULL
4479  * codec. Subsequent calls will do nothing.
4480  *
4481  * @note Do not use this function. Use avcodec_free_context() to destroy a
4482  * codec context (either open or closed). Opening and closing a codec context
4483  * multiple times is not supported anymore -- use multiple codec contexts
4484  * instead.
4485  */
4486 int avcodec_close(AVCodecContext *avctx);
4487 
4488 /**
4489  * Free all allocated data in the given subtitle struct.
4490  *
4491  * @param sub AVSubtitle to free.
4492  */
4493 void avsubtitle_free(AVSubtitle *sub);
4494 
4495 /**
4496  * @}
4497  */
4498 
4499 /**
4500  * @addtogroup lavc_packet
4501  * @{
4502  */
4503 
4504 /**
4505  * Allocate an AVPacket and set its fields to default values. The resulting
4506  * struct must be freed using av_packet_free().
4507  *
4508  * @return An AVPacket filled with default values or NULL on failure.
4509  *
4510  * @note this only allocates the AVPacket itself, not the data buffers. Those
4511  * must be allocated through other means such as av_new_packet.
4512  *
4513  * @see av_new_packet
4514  */
4515 AVPacket *av_packet_alloc(void);
4516 
4517 /**
4518  * Create a new packet that references the same data as src.
4519  *
4520  * This is a shortcut for av_packet_alloc()+av_packet_ref().
4521  *
4522  * @return newly created AVPacket on success, NULL on error.
4523  *
4524  * @see av_packet_alloc
4525  * @see av_packet_ref
4526  */
4528 
4529 /**
4530  * Free the packet, if the packet is reference counted, it will be
4531  * unreferenced first.
4532  *
4533  * @param pkt packet to be freed. The pointer will be set to NULL.
4534  * @note passing NULL is a no-op.
4535  */
4536 void av_packet_free(AVPacket **pkt);
4537 
4538 /**
4539  * Initialize optional fields of a packet with default values.
4540  *
4541  * Note, this does not touch the data and size members, which have to be
4542  * initialized separately.
4543  *
4544  * @param pkt packet
4545  */
4546 void av_init_packet(AVPacket *pkt);
4547 
4548 /**
4549  * Allocate the payload of a packet and initialize its fields with
4550  * default values.
4551  *
4552  * @param pkt packet
4553  * @param size wanted payload size
4554  * @return 0 if OK, AVERROR_xxx otherwise
4555  */
4556 int av_new_packet(AVPacket *pkt, int size);
4557 
4558 /**
4559  * Reduce packet size, correctly zeroing padding
4560  *
4561  * @param pkt packet
4562  * @param size new size
4563  */
4564 void av_shrink_packet(AVPacket *pkt, int size);
4565 
4566 /**
4567  * Increase packet size, correctly zeroing padding
4568  *
4569  * @param pkt packet
4570  * @param grow_by number of bytes by which to increase the size of the packet
4571  */
4572 int av_grow_packet(AVPacket *pkt, int grow_by);
4573 
4574 /**
4575  * Initialize a reference-counted packet from av_malloc()ed data.
4576  *
4577  * @param pkt packet to be initialized. This function will set the data, size,
4578  * buf and destruct fields, all others are left untouched.
4579  * @param data Data allocated by av_malloc() to be used as packet data. If this
4580  * function returns successfully, the data is owned by the underlying AVBuffer.
4581  * The caller may not access the data through other means.
4582  * @param size size of data in bytes, without the padding. I.e. the full buffer
4583  * size is assumed to be size + AV_INPUT_BUFFER_PADDING_SIZE.
4584  *
4585  * @return 0 on success, a negative AVERROR on error
4586  */
4588 
4589 #if FF_API_AVPACKET_OLD_API
4590 /**
4591  * @warning This is a hack - the packet memory allocation stuff is broken. The
4592  * packet is allocated if it was not really allocated.
4593  *
4594  * @deprecated Use av_packet_ref
4595  */
4597 int av_dup_packet(AVPacket *pkt);
4598 /**
4599  * Copy packet, including contents
4600  *
4601  * @return 0 on success, negative AVERROR on fail
4602  */
4603 int av_copy_packet(AVPacket *dst, const AVPacket *src);
4604 
4605 /**
4606  * Copy packet side data
4607  *
4608  * @return 0 on success, negative AVERROR on fail
4609  */
4610 int av_copy_packet_side_data(AVPacket *dst, const AVPacket *src);
4611 
4612 /**
4613  * Free a packet.
4614  *
4615  * @deprecated Use av_packet_unref
4616  *
4617  * @param pkt packet to free
4618  */
4620 void av_free_packet(AVPacket *pkt);
4621 #endif
4622 /**
4623  * Allocate new information of a packet.
4624  *
4625  * @param pkt packet
4626  * @param type side information type
4627  * @param size side information size
4628  * @return pointer to fresh allocated data or NULL otherwise
4629  */
4631  int size);
4632 
4633 /**
4634  * Wrap an existing array as a packet side data.
4635  *
4636  * @param pkt packet
4637  * @param type side information type
4638  * @param data the side data array. It must be allocated with the av_malloc()
4639  * family of functions. The ownership of the data is transferred to
4640  * pkt.
4641  * @param size side information size
4642  * @return a non-negative number on success, a negative AVERROR code on
4643  * failure. On failure, the packet is unchanged and the data remains
4644  * owned by the caller.
4645  */
4647  uint8_t *data, size_t size);
4648 
4649 /**
4650  * Shrink the already allocated side data buffer
4651  *
4652  * @param pkt packet
4653  * @param type side information type
4654  * @param size new side information size
4655  * @return 0 on success, < 0 on failure
4656  */
4658  int size);
4659 
4660 /**
4661  * Get side information from packet.
4662  *
4663  * @param pkt packet
4664  * @param type desired side information type
4665  * @param size pointer for side information size to store (optional)
4666  * @return pointer to data if present or NULL otherwise
4667  */
4669  int *size);
4670 
4671 #if FF_API_MERGE_SD_API
4674 
4677 #endif
4678 
4680 
4681 /**
4682  * Pack a dictionary for use in side_data.
4683  *
4684  * @param dict The dictionary to pack.
4685  * @param size pointer to store the size of the returned data
4686  * @return pointer to data if successful, NULL otherwise
4687  */
4689 /**
4690  * Unpack a dictionary from side_data.
4691  *
4692  * @param data data from side_data
4693  * @param size size of the data
4694  * @param dict the metadata storage dictionary
4695  * @return 0 on success, < 0 on failure
4696  */
4697 int av_packet_unpack_dictionary(const uint8_t *data, int size, AVDictionary **dict);
4698 
4699 
4700 /**
4701  * Convenience function to free all the side data stored.
4702  * All the other fields stay untouched.
4703  *
4704  * @param pkt packet
4705  */
4707 
4708 /**
4709  * Setup a new reference to the data described by a given packet
4710  *
4711  * If src is reference-counted, setup dst as a new reference to the
4712  * buffer in src. Otherwise allocate a new buffer in dst and copy the
4713  * data from src into it.
4714  *
4715  * All the other fields are copied from src.
4716  *
4717  * @see av_packet_unref
4718  *
4719  * @param dst Destination packet
4720  * @param src Source packet
4721  *
4722  * @return 0 on success, a negative AVERROR on error.
4723  */
4724 int av_packet_ref(AVPacket *dst, const AVPacket *src);
4725 
4726 /**
4727  * Wipe the packet.
4728  *
4729  * Unreference the buffer referenced by the packet and reset the
4730  * remaining packet fields to their default values.
4731  *
4732  * @param pkt The packet to be unreferenced.
4733  */
4735 
4736 /**
4737  * Move every field in src to dst and reset src.
4738  *
4739  * @see av_packet_unref
4740  *
4741  * @param src Source packet, will be reset
4742  * @param dst Destination packet
4743  */
4745 
4746 /**
4747  * Copy only "properties" fields from src to dst.
4748  *
4749  * Properties for the purpose of this function are all the fields
4750  * beside those related to the packet data (buf, data, size)
4751  *
4752  * @param dst Destination packet
4753  * @param src Source packet
4754  *
4755  * @return 0 on success AVERROR on failure.
4756  */
4757 int av_packet_copy_props(AVPacket *dst, const AVPacket *src);
4758 
4759 /**
4760  * Convert valid timing fields (timestamps / durations) in a packet from one
4761  * timebase to another. Timestamps with unknown values (AV_NOPTS_VALUE) will be
4762  * ignored.
4763  *
4764  * @param pkt packet on which the conversion will be performed
4765  * @param tb_src source timebase, in which the timing fields in pkt are
4766  * expressed
4767  * @param tb_dst destination timebase, to which the timing fields will be
4768  * converted
4769  */
4770 void av_packet_rescale_ts(AVPacket *pkt, AVRational tb_src, AVRational tb_dst);
4771 
4772 /**
4773  * @}
4774  */
4775 
4776 /**
4777  * @addtogroup lavc_decoding
4778  * @{
4779  */
4780 
4781 /**
4782  * Find a registered decoder with a matching codec ID.
4783  *
4784  * @param id AVCodecID of the requested decoder
4785  * @return A decoder if one was found, NULL otherwise.
4786  */
4788 
4789 /**
4790  * Find a registered decoder with the specified name.
4791  *
4792  * @param name name of the requested decoder
4793  * @return A decoder if one was found, NULL otherwise.
4794  */
4796 
4797 /**
4798  * The default callback for AVCodecContext.get_buffer2(). It is made public so
4799  * it can be called by custom get_buffer2() implementations for decoders without
4800  * AV_CODEC_CAP_DR1 set.
4801  */
4803 
4804 #if FF_API_EMU_EDGE
4805 /**
4806  * Return the amount of padding in pixels which the get_buffer callback must
4807  * provide around the edge of the image for codecs which do not have the
4808  * CODEC_FLAG_EMU_EDGE flag.
4809  *
4810  * @return Required padding in pixels.
4811  *
4812  * @deprecated CODEC_FLAG_EMU_EDGE is deprecated, so this function is no longer
4813  * needed
4814  */
4816 unsigned avcodec_get_edge_width(void);
4817 #endif
4818 
4819 /**
4820  * Modify width and height values so that they will result in a memory
4821  * buffer that is acceptable for the codec if you do not use any horizontal
4822  * padding.
4823  *
4824  * May only be used if a codec with AV_CODEC_CAP_DR1 has been opened.
4825  */
4827 
4828 /**
4829  * Modify width and height values so that they will result in a memory
4830  * buffer that is acceptable for the codec if you also ensure that all
4831  * line sizes are a multiple of the respective linesize_align[i].
4832  *
4833  * May only be used if a codec with AV_CODEC_CAP_DR1 has been opened.
4834  */
4836  int linesize_align[AV_NUM_DATA_POINTERS]);
4837 
4838 /**
4839  * Converts AVChromaLocation to swscale x/y chroma position.
4840  *
4841  * The positions represent the chroma (0,0) position in a coordinates system
4842  * with luma (0,0) representing the origin and luma(1,1) representing 256,256
4843  *
4844  * @param xpos horizontal chroma sample position
4845  * @param ypos vertical chroma sample position
4846  */
4847 int avcodec_enum_to_chroma_pos(int *xpos, int *ypos, enum AVChromaLocation pos);
4848 
4849 /**
4850  * Converts swscale x/y chroma position to AVChromaLocation.
4851  *
4852  * The positions represent the chroma (0,0) position in a coordinates system
4853  * with luma (0,0) representing the origin and luma(1,1) representing 256,256
4854  *
4855  * @param xpos horizontal chroma sample position
4856  * @param ypos vertical chroma sample position
4857  */
4858 enum AVChromaLocation avcodec_chroma_pos_to_enum(int xpos, int ypos);
4859 
4860 /**
4861  * Decode the audio frame of size avpkt->size from avpkt->data into frame.
4862  *
4863  * Some decoders may support multiple frames in a single AVPacket. Such
4864  * decoders would then just decode the first frame and the return value would be
4865  * less than the packet size. In this case, avcodec_decode_audio4 has to be
4866  * called again with an AVPacket containing the remaining data in order to
4867  * decode the second frame, etc... Even if no frames are returned, the packet
4868  * needs to be fed to the decoder with remaining data until it is completely
4869  * consumed or an error occurs.
4870  *
4871  * Some decoders (those marked with AV_CODEC_CAP_DELAY) have a delay between input
4872  * and output. This means that for some packets they will not immediately
4873  * produce decoded output and need to be flushed at the end of decoding to get
4874  * all the decoded data. Flushing is done by calling this function with packets
4875  * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
4876  * returning samples. It is safe to flush even those decoders that are not
4877  * marked with AV_CODEC_CAP_DELAY, then no samples will be returned.
4878  *
4879  * @warning The input buffer, avpkt->data must be AV_INPUT_BUFFER_PADDING_SIZE
4880  * larger than the actual read bytes because some optimized bitstream
4881  * readers read 32 or 64 bits at once and could read over the end.
4882  *
4883  * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
4884  * before packets may be fed to the decoder.
4885  *
4886  * @param avctx the codec context
4887  * @param[out] frame The AVFrame in which to store decoded audio samples.
4888  * The decoder will allocate a buffer for the decoded frame by
4889  * calling the AVCodecContext.get_buffer2() callback.
4890  * When AVCodecContext.refcounted_frames is set to 1, the frame is
4891  * reference counted and the returned reference belongs to the
4892  * caller. The caller must release the frame using av_frame_unref()
4893  * when the frame is no longer needed. The caller may safely write
4894  * to the frame if av_frame_is_writable() returns 1.
4895  * When AVCodecContext.refcounted_frames is set to 0, the returned
4896  * reference belongs to the decoder and is valid only until the
4897  * next call to this function or until closing or flushing the
4898  * decoder. The caller may not write to it.
4899  * @param[out] got_frame_ptr Zero if no frame could be decoded, otherwise it is
4900  * non-zero. Note that this field being set to zero
4901  * does not mean that an error has occurred. For
4902  * decoders with AV_CODEC_CAP_DELAY set, no given decode
4903  * call is guaranteed to produce a frame.
4904  * @param[in] avpkt The input AVPacket containing the input buffer.
4905  * At least avpkt->data and avpkt->size should be set. Some
4906  * decoders might also require additional fields to be set.
4907  * @return A negative error code is returned if an error occurred during
4908  * decoding, otherwise the number of bytes consumed from the input
4909  * AVPacket is returned.
4910  *
4911 * @deprecated Use avcodec_send_packet() and avcodec_receive_frame().
4912  */
4915  int *got_frame_ptr, const AVPacket *avpkt);
4916 
4917 /**
4918  * Decode the video frame of size avpkt->size from avpkt->data into picture.
4919  * Some decoders may support multiple frames in a single AVPacket, such
4920  * decoders would then just decode the first frame.
4921  *
4922  * @warning The input buffer must be AV_INPUT_BUFFER_PADDING_SIZE larger than
4923  * the actual read bytes because some optimized bitstream readers read 32 or 64
4924  * bits at once and could read over the end.
4925  *
4926  * @warning The end of the input buffer buf should be set to 0 to ensure that
4927  * no overreading happens for damaged MPEG streams.
4928  *
4929  * @note Codecs which have the AV_CODEC_CAP_DELAY capability set have a delay
4930  * between input and output, these need to be fed with avpkt->data=NULL,
4931  * avpkt->size=0 at the end to return the remaining frames.
4932  *
4933  * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
4934  * before packets may be fed to the decoder.
4935  *
4936  * @param avctx the codec context
4937  * @param[out] picture The AVFrame in which the decoded video frame will be stored.
4938  * Use av_frame_alloc() to get an AVFrame. The codec will
4939  * allocate memory for the actual bitmap by calling the
4940  * AVCodecContext.get_buffer2() callback.
4941  * When AVCodecContext.refcounted_frames is set to 1, the frame is
4942  * reference counted and the returned reference belongs to the
4943  * caller. The caller must release the frame using av_frame_unref()
4944  * when the frame is no longer needed. The caller may safely write
4945  * to the frame if av_frame_is_writable() returns 1.
4946  * When AVCodecContext.refcounted_frames is set to 0, the returned
4947  * reference belongs to the decoder and is valid only until the
4948  * next call to this function or until closing or flushing the
4949  * decoder. The caller may not write to it.
4950  *
4951  * @param[in] avpkt The input AVPacket containing the input buffer.
4952  * You can create such packet with av_init_packet() and by then setting
4953  * data and size, some decoders might in addition need other fields like
4954  * flags&AV_PKT_FLAG_KEY. All decoders are designed to use the least
4955  * fields possible.
4956  * @param[in,out] got_picture_ptr Zero if no frame could be decompressed, otherwise, it is nonzero.
4957  * @return On error a negative value is returned, otherwise the number of bytes
4958  * used or zero if no frame could be decompressed.
4959  *
4960  * @deprecated Use avcodec_send_packet() and avcodec_receive_frame().
4961  */
4963 int avcodec_decode_video2(AVCodecContext *avctx, AVFrame *picture,
4964  int *got_picture_ptr,
4965  const AVPacket *avpkt);
4966 
4967 /**
4968  * Decode a subtitle message.
4969  * Return a negative value on error, otherwise return the number of bytes used.
4970  * If no subtitle could be decompressed, got_sub_ptr is zero.
4971  * Otherwise, the subtitle is stored in *sub.
4972  * Note that AV_CODEC_CAP_DR1 is not available for subtitle codecs. This is for
4973  * simplicity, because the performance difference is expect to be negligible
4974  * and reusing a get_buffer written for video codecs would probably perform badly
4975  * due to a potentially very different allocation pattern.
4976  *
4977  * Some decoders (those marked with AV_CODEC_CAP_DELAY) have a delay between input
4978  * and output. This means that for some packets they will not immediately
4979  * produce decoded output and need to be flushed at the end of decoding to get
4980  * all the decoded data. Flushing is done by calling this function with packets
4981  * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
4982  * returning subtitles. It is safe to flush even those decoders that are not
4983  * marked with AV_CODEC_CAP_DELAY, then no subtitles will be returned.
4984  *
4985  * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
4986  * before packets may be fed to the decoder.
4987  *
4988  * @param avctx the codec context
4989  * @param[out] sub The Preallocated AVSubtitle in which the decoded subtitle will be stored,
4990  * must be freed with avsubtitle_free if *got_sub_ptr is set.
4991  * @param[in,out] got_sub_ptr Zero if no subtitle could be decompressed, otherwise, it is nonzero.
4992  * @param[in] avpkt The input AVPacket containing the input buffer.
4993  */
4995  int *got_sub_ptr,
4996  AVPacket *avpkt);
4997 
4998 /**
4999  * Supply raw packet data as input to a decoder.
5000  *
5001  * Internally, this call will copy relevant AVCodecContext fields, which can
5002  * influence decoding per-packet, and apply them when the packet is actually
5003  * decoded. (For example AVCodecContext.skip_frame, which might direct the
5004  * decoder to drop the frame contained by the packet sent with this function.)
5005  *
5006  * @warning The input buffer, avpkt->data must be AV_INPUT_BUFFER_PADDING_SIZE
5007  * larger than the actual read bytes because some optimized bitstream
5008  * readers read 32 or 64 bits at once and could read over the end.
5009  *
5010  * @warning Do not mix this API with the legacy API (like avcodec_decode_video2())
5011  * on the same AVCodecContext. It will return unexpected results now
5012  * or in future libavcodec versions.
5013  *
5014  * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
5015  * before packets may be fed to the decoder.
5016  *
5017  * @param avctx codec context
5018  * @param[in] avpkt The input AVPacket. Usually, this will be a single video
5019  * frame, or several complete audio frames.
5020  * Ownership of the packet remains with the caller, and the
5021  * decoder will not write to the packet. The decoder may create
5022  * a reference to the packet data (or copy it if the packet is
5023  * not reference-counted).
5024  * Unlike with older APIs, the packet is always fully consumed,
5025  * and if it contains multiple frames (e.g. some audio codecs),
5026  * will require you to call avcodec_receive_frame() multiple
5027  * times afterwards before you can send a new packet.
5028  * It can be NULL (or an AVPacket with data set to NULL and
5029  * size set to 0); in this case, it is considered a flush
5030  * packet, which signals the end of the stream. Sending the
5031  * first flush packet will return success. Subsequent ones are
5032  * unnecessary and will return AVERROR_EOF. If the decoder
5033  * still has frames buffered, it will return them after sending
5034  * a flush packet.
5035  *
5036  * @return 0 on success, otherwise negative error code:
5037  * AVERROR(EAGAIN): input is not accepted in the current state - user
5038  * must read output with avcodec_receive_frame() (once
5039  * all output is read, the packet should be resent, and
5040  * the call will not fail with EAGAIN).
5041  * AVERROR_EOF: the decoder has been flushed, and no new packets can
5042  * be sent to it (also returned if more than 1 flush
5043  * packet is sent)
5044  * AVERROR(EINVAL): codec not opened, it is an encoder, or requires flush
5045  * AVERROR(ENOMEM): failed to add packet to internal queue, or similar
5046  * other errors: legitimate decoding errors
5047  */
5048 int avcodec_send_packet(AVCodecContext *avctx, const AVPacket *avpkt);
5049 
5050 /**
5051  * Return decoded output data from a decoder.
5052  *
5053  * @param avctx codec context
5054  * @param frame This will be set to a reference-counted video or audio
5055  * frame (depending on the decoder type) allocated by the
5056  * decoder. Note that the function will always call
5057  * av_frame_unref(frame) before doing anything else.
5058  *
5059  * @return
5060  * 0: success, a frame was returned
5061  * AVERROR(EAGAIN): output is not available in this state - user must try
5062  * to send new input
5063  * AVERROR_EOF: the decoder has been fully flushed, and there will be
5064  * no more output frames
5065  * AVERROR(EINVAL): codec not opened, or it is an encoder
5066  * other negative values: legitimate decoding errors
5067  */
5069 
5070 /**
5071  * Supply a raw video or audio frame to the encoder. Use avcodec_receive_packet()
5072  * to retrieve buffered output packets.
5073  *
5074  * @param avctx codec context
5075  * @param[in] frame AVFrame containing the raw audio or video frame to be encoded.
5076  * Ownership of the frame remains with the caller, and the
5077  * encoder will not write to the frame. The encoder may create
5078  * a reference to the frame data (or copy it if the frame is
5079  * not reference-counted).
5080  * It can be NULL, in which case it is considered a flush
5081  * packet. This signals the end of the stream. If the encoder
5082  * still has packets buffered, it will return them after this
5083  * call. Once flushing mode has been entered, additional flush
5084  * packets are ignored, and sending frames will return
5085  * AVERROR_EOF.
5086  *
5087  * For audio:
5088  * If AV_CODEC_CAP_VARIABLE_FRAME_SIZE is set, then each frame
5089  * can have any number of samples.
5090  * If it is not set, frame->nb_samples must be equal to
5091  * avctx->frame_size for all frames except the last.
5092  * The final frame may be smaller than avctx->frame_size.
5093  * @return 0 on success, otherwise negative error code:
5094  * AVERROR(EAGAIN): input is not accepted in the current state - user
5095  * must read output with avcodec_receive_packet() (once
5096  * all output is read, the packet should be resent, and
5097  * the call will not fail with EAGAIN).
5098  * AVERROR_EOF: the encoder has been flushed, and no new frames can
5099  * be sent to it
5100  * AVERROR(EINVAL): codec not opened, refcounted_frames not set, it is a
5101  * decoder, or requires flush
5102  * AVERROR(ENOMEM): failed to add packet to internal queue, or similar
5103  * other errors: legitimate decoding errors
5104  */
5105 int avcodec_send_frame(AVCodecContext *avctx, const AVFrame *frame);
5106 
5107 /**
5108  * Read encoded data from the encoder.
5109  *
5110  * @param avctx codec context
5111  * @param avpkt This will be set to a reference-counted packet allocated by the
5112  * encoder. Note that the function will always call
5113  * av_frame_unref(frame) before doing anything else.
5114  * @return 0 on success, otherwise negative error code:
5115  * AVERROR(EAGAIN): output is not available in the current state - user
5116  * must try to send input
5117  * AVERROR_EOF: the encoder has been fully flushed, and there will be
5118  * no more output packets
5119  * AVERROR(EINVAL): codec not opened, or it is an encoder
5120  * other errors: legitimate decoding errors
5121  */
5122 int avcodec_receive_packet(AVCodecContext *avctx, AVPacket *avpkt);
5123 
5124 
5125 /**
5126  * @defgroup lavc_parsing Frame parsing
5127  * @{
5128  */
5129 
5132  AV_PICTURE_STRUCTURE_TOP_FIELD, //< coded as top field
5133  AV_PICTURE_STRUCTURE_BOTTOM_FIELD, //< coded as bottom field
5134  AV_PICTURE_STRUCTURE_FRAME, //< coded as frame
5135 };
5136 
5137 typedef struct AVCodecParserContext {
5138  void *priv_data;
5140  int64_t frame_offset; /* offset of the current frame */
5141  int64_t cur_offset; /* current offset
5142  (incremented by each av_parser_parse()) */
5143  int64_t next_frame_offset; /* offset of the next frame */
5144  /* video info */
5145  int pict_type; /* XXX: Put it back in AVCodecContext. */
5146  /**
5147  * This field is used for proper frame duration computation in lavf.
5148  * It signals, how much longer the frame duration of the current frame
5149  * is compared to normal frame duration.
5150  *
5151  * frame_duration = (1 + repeat_pict) * time_base
5152  *
5153  * It is used by codecs like H.264 to display telecined material.
5154  */
5155  int repeat_pict; /* XXX: Put it back in AVCodecContext. */
5156  int64_t pts; /* pts of the current frame */
5157  int64_t dts; /* dts of the current frame */
5158 
5159  /* private data */
5160  int64_t last_pts;
5161  int64_t last_dts;
5163 
5164 #define AV_PARSER_PTS_NB 4
5169 
5170  int flags;
5171 #define PARSER_FLAG_COMPLETE_FRAMES 0x0001
5172 #define PARSER_FLAG_ONCE 0x0002
5173 /// Set if the parser has a valid file offset
5174 #define PARSER_FLAG_FETCHED_OFFSET 0x0004
5175 #define PARSER_FLAG_USE_CODEC_TS 0x1000
5176 
5177  int64_t offset; ///< byte offset from starting packet start
5179 
5180  /**
5181  * Set by parser to 1 for key frames and 0 for non-key frames.
5182  * It is initialized to -1, so if the parser doesn't set this flag,
5183  * old-style fallback using AV_PICTURE_TYPE_I picture type as key frames
5184  * will be used.
5185  */
5187 
5188 #if FF_API_CONVERGENCE_DURATION
5189  /**
5190  * @deprecated unused
5191  */
5194 #endif
5195 
5196  // Timestamp generation support:
5197  /**
5198  * Synchronization point for start of timestamp generation.
5199  *
5200  * Set to >0 for sync point, 0 for no sync point and <0 for undefined
5201  * (default).
5202  *
5203  * For example, this corresponds to presence of H.264 buffering period
5204  * SEI message.
5205  */
5207 
5208  /**
5209  * Offset of the current timestamp against last timestamp sync point in
5210  * units of AVCodecContext.time_base.
5211  *
5212  * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
5213  * contain a valid timestamp offset.
5214  *
5215  * Note that the timestamp of sync point has usually a nonzero
5216  * dts_ref_dts_delta, which refers to the previous sync point. Offset of
5217  * the next frame after timestamp sync point will be usually 1.
5218  *
5219  * For example, this corresponds to H.264 cpb_removal_delay.
5220  */
5222 
5223  /**
5224  * Presentation delay of current frame in units of AVCodecContext.time_base.
5225  *
5226  * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
5227  * contain valid non-negative timestamp delta (presentation time of a frame
5228  * must not lie in the past).
5229  *
5230  * This delay represents the difference between decoding and presentation
5231  * time of the frame.
5232  *
5233  * For example, this corresponds to H.264 dpb_output_delay.
5234  */
5236 
5237  /**
5238  * Position of the packet in file.
5239  *
5240  * Analogous to cur_frame_pts/dts
5241  */
5243 
5244  /**
5245  * Byte position of currently parsed frame in stream.
5246  */
5247  int64_t pos;
5248 
5249  /**
5250  * Previous frame byte position.
5251  */
5252  int64_t last_pos;
5253 
5254  /**
5255  * Duration of the current frame.
5256  * For audio, this is in units of 1 / AVCodecContext.sample_rate.
5257  * For all other types, this is in units of AVCodecContext.time_base.
5258  */
5260 
5262 
5263  /**
5264  * Indicate whether a picture is coded as a frame, top field or bottom field.
5265  *
5266  * For example, H.264 field_pic_flag equal to 0 corresponds to
5267  * AV_PICTURE_STRUCTURE_FRAME. An H.264 picture with field_pic_flag
5268  * equal to 1 and bottom_field_flag equal to 0 corresponds to
5269  * AV_PICTURE_STRUCTURE_TOP_FIELD.
5270  */
5272 
5273  /**
5274  * Picture number incremented in presentation or output order.
5275  * This field may be reinitialized at the first picture of a new sequence.
5276  *
5277  * For example, this corresponds to H.264 PicOrderCnt.
5278  */
5280 
5281  /**
5282  * Dimensions of the decoded video intended for presentation.
5283  */
5284  int width;
5285  int height;
5286 
5287  /**
5288  * Dimensions of the coded video.
5289  */
5292 
5293  /**
5294  * The format of the coded data, corresponds to enum AVPixelFormat for video
5295  * and for enum AVSampleFormat for audio.
5296  *
5297  * Note that a decoder can have considerable freedom in how exactly it
5298  * decodes the data, so the format reported here might be different from the
5299  * one returned by a decoder.
5300  */
5301  int format;
5303 
5304 typedef struct AVCodecParser {
5305  int codec_ids[5]; /* several codec IDs are permitted */
5308  /* This callback never returns an error, a negative value means that
5309  * the frame start was in a previous packet. */