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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 
643 
644  /* subtitle codecs */
645  AV_CODEC_ID_FIRST_SUBTITLE = 0x17000, ///< A dummy ID pointing at the start of subtitle codecs.
648  AV_CODEC_ID_TEXT, ///< raw UTF-8 text
655 
671 
672  /* other specific kind of codecs (generally used for attachments) */
673  AV_CODEC_ID_FIRST_UNKNOWN = 0x18000, ///< A dummy ID pointing at the start of various fake codecs.
674  AV_CODEC_ID_TTF = 0x18000,
675 
676  AV_CODEC_ID_SCTE_35, ///< Contain timestamp estimated through PCR of program stream.
685 
686 
687  AV_CODEC_ID_PROBE = 0x19000, ///< codec_id is not known (like AV_CODEC_ID_NONE) but lavf should attempt to identify it
688 
689  AV_CODEC_ID_MPEG2TS = 0x20000, /**< _FAKE_ codec to indicate a raw MPEG-2 TS
690  * stream (only used by libavformat) */
691  AV_CODEC_ID_MPEG4SYSTEMS = 0x20001, /**< _FAKE_ codec to indicate a MPEG-4 Systems
692  * stream (only used by libavformat) */
693  AV_CODEC_ID_FFMETADATA = 0x21000, ///< Dummy codec for streams containing only metadata information.
694  AV_CODEC_ID_WRAPPED_AVFRAME = 0x21001, ///< Passthrough codec, AVFrames wrapped in AVPacket
695 };
696 
697 /**
698  * This struct describes the properties of a single codec described by an
699  * AVCodecID.
700  * @see avcodec_descriptor_get()
701  */
702 typedef struct AVCodecDescriptor {
703  enum AVCodecID id;
705  /**
706  * Name of the codec described by this descriptor. It is non-empty and
707  * unique for each codec descriptor. It should contain alphanumeric
708  * characters and '_' only.
709  */
710  const char *name;
711  /**
712  * A more descriptive name for this codec. May be NULL.
713  */
714  const char *long_name;
715  /**
716  * Codec properties, a combination of AV_CODEC_PROP_* flags.
717  */
718  int props;
719  /**
720  * MIME type(s) associated with the codec.
721  * May be NULL; if not, a NULL-terminated array of MIME types.
722  * The first item is always non-NULL and is the preferred MIME type.
723  */
724  const char *const *mime_types;
725  /**
726  * If non-NULL, an array of profiles recognized for this codec.
727  * Terminated with FF_PROFILE_UNKNOWN.
728  */
729  const struct AVProfile *profiles;
731 
732 /**
733  * Codec uses only intra compression.
734  * Video and audio codecs only.
735  */
736 #define AV_CODEC_PROP_INTRA_ONLY (1 << 0)
737 /**
738  * Codec supports lossy compression. Audio and video codecs only.
739  * @note a codec may support both lossy and lossless
740  * compression modes
741  */
742 #define AV_CODEC_PROP_LOSSY (1 << 1)
743 /**
744  * Codec supports lossless compression. Audio and video codecs only.
745  */
746 #define AV_CODEC_PROP_LOSSLESS (1 << 2)
747 /**
748  * Codec supports frame reordering. That is, the coded order (the order in which
749  * the encoded packets are output by the encoders / stored / input to the
750  * decoders) may be different from the presentation order of the corresponding
751  * frames.
752  *
753  * For codecs that do not have this property set, PTS and DTS should always be
754  * equal.
755  */
756 #define AV_CODEC_PROP_REORDER (1 << 3)
757 /**
758  * Subtitle codec is bitmap based
759  * Decoded AVSubtitle data can be read from the AVSubtitleRect->pict field.
760  */
761 #define AV_CODEC_PROP_BITMAP_SUB (1 << 16)
762 /**
763  * Subtitle codec is text based.
764  * Decoded AVSubtitle data can be read from the AVSubtitleRect->ass field.
765  */
766 #define AV_CODEC_PROP_TEXT_SUB (1 << 17)
767 
768 /**
769  * @ingroup lavc_decoding
770  * Required number of additionally allocated bytes at the end of the input bitstream for decoding.
771  * This is mainly needed because some optimized bitstream readers read
772  * 32 or 64 bit at once and could read over the end.<br>
773  * Note: If the first 23 bits of the additional bytes are not 0, then damaged
774  * MPEG bitstreams could cause overread and segfault.
775  */
776 #define AV_INPUT_BUFFER_PADDING_SIZE 32
777 
778 /**
779  * @ingroup lavc_encoding
780  * minimum encoding buffer size
781  * Used to avoid some checks during header writing.
782  */
783 #define AV_INPUT_BUFFER_MIN_SIZE 16384
784 
785 #if FF_API_WITHOUT_PREFIX
786 /**
787  * @deprecated use AV_INPUT_BUFFER_PADDING_SIZE instead
788  */
789 #define FF_INPUT_BUFFER_PADDING_SIZE 32
790 
791 /**
792  * @deprecated use AV_INPUT_BUFFER_MIN_SIZE instead
793  */
794 #define FF_MIN_BUFFER_SIZE 16384
795 #endif /* FF_API_WITHOUT_PREFIX */
796 
797 /**
798  * @ingroup lavc_encoding
799  * motion estimation type.
800  * @deprecated use codec private option instead
801  */
802 #if FF_API_MOTION_EST
804  ME_ZERO = 1, ///< no search, that is use 0,0 vector whenever one is needed
808  ME_EPZS, ///< enhanced predictive zonal search
809  ME_X1, ///< reserved for experiments
810  ME_HEX, ///< hexagon based search
811  ME_UMH, ///< uneven multi-hexagon search
812  ME_TESA, ///< transformed exhaustive search algorithm
813  ME_ITER=50, ///< iterative search
814 };
815 #endif
816 
817 /**
818  * @ingroup lavc_decoding
819  */
821  /* We leave some space between them for extensions (drop some
822  * keyframes for intra-only or drop just some bidir frames). */
823  AVDISCARD_NONE =-16, ///< discard nothing
824  AVDISCARD_DEFAULT = 0, ///< discard useless packets like 0 size packets in avi
825  AVDISCARD_NONREF = 8, ///< discard all non reference
826  AVDISCARD_BIDIR = 16, ///< discard all bidirectional frames
827  AVDISCARD_NONINTRA= 24, ///< discard all non intra frames
828  AVDISCARD_NONKEY = 32, ///< discard all frames except keyframes
829  AVDISCARD_ALL = 48, ///< discard all
830 };
831 
842  AV_AUDIO_SERVICE_TYPE_NB , ///< Not part of ABI
843 };
844 
845 /**
846  * @ingroup lavc_encoding
847  */
848 typedef struct RcOverride{
851  int qscale; // If this is 0 then quality_factor will be used instead.
853 } RcOverride;
854 
855 #if FF_API_MAX_BFRAMES
856 /**
857  * @deprecated there is no libavcodec-wide limit on the number of B-frames
858  */
859 #define FF_MAX_B_FRAMES 16
860 #endif
861 
862 /* encoding support
863  These flags can be passed in AVCodecContext.flags before initialization.
864  Note: Not everything is supported yet.
865 */
866 
867 /**
868  * Allow decoders to produce frames with data planes that are not aligned
869  * to CPU requirements (e.g. due to cropping).
870  */
871 #define AV_CODEC_FLAG_UNALIGNED (1 << 0)
872 /**
873  * Use fixed qscale.
874  */
875 #define AV_CODEC_FLAG_QSCALE (1 << 1)
876 /**
877  * 4 MV per MB allowed / advanced prediction for H.263.
878  */
879 #define AV_CODEC_FLAG_4MV (1 << 2)
880 /**
881  * Output even those frames that might be corrupted.
882  */
883 #define AV_CODEC_FLAG_OUTPUT_CORRUPT (1 << 3)
884 /**
885  * Use qpel MC.
886  */
887 #define AV_CODEC_FLAG_QPEL (1 << 4)
888 /**
889  * Use internal 2pass ratecontrol in first pass mode.
890  */
891 #define AV_CODEC_FLAG_PASS1 (1 << 9)
892 /**
893  * Use internal 2pass ratecontrol in second pass mode.
894  */
895 #define AV_CODEC_FLAG_PASS2 (1 << 10)
896 /**
897  * loop filter.
898  */
899 #define AV_CODEC_FLAG_LOOP_FILTER (1 << 11)
900 /**
901  * Only decode/encode grayscale.
902  */
903 #define AV_CODEC_FLAG_GRAY (1 << 13)
904 /**
905  * error[?] variables will be set during encoding.
906  */
907 #define AV_CODEC_FLAG_PSNR (1 << 15)
908 /**
909  * Input bitstream might be truncated at a random location
910  * instead of only at frame boundaries.
911  */
912 #define AV_CODEC_FLAG_TRUNCATED (1 << 16)
913 /**
914  * Use interlaced DCT.
915  */
916 #define AV_CODEC_FLAG_INTERLACED_DCT (1 << 18)
917 /**
918  * Force low delay.
919  */
920 #define AV_CODEC_FLAG_LOW_DELAY (1 << 19)
921 /**
922  * Place global headers in extradata instead of every keyframe.
923  */
924 #define AV_CODEC_FLAG_GLOBAL_HEADER (1 << 22)
925 /**
926  * Use only bitexact stuff (except (I)DCT).
927  */
928 #define AV_CODEC_FLAG_BITEXACT (1 << 23)
929 /* Fx : Flag for H.263+ extra options */
930 /**
931  * H.263 advanced intra coding / MPEG-4 AC prediction
932  */
933 #define AV_CODEC_FLAG_AC_PRED (1 << 24)
934 /**
935  * interlaced motion estimation
936  */
937 #define AV_CODEC_FLAG_INTERLACED_ME (1 << 29)
938 #define AV_CODEC_FLAG_CLOSED_GOP (1U << 31)
939 
940 /**
941  * Allow non spec compliant speedup tricks.
942  */
943 #define AV_CODEC_FLAG2_FAST (1 << 0)
944 /**
945  * Skip bitstream encoding.
946  */
947 #define AV_CODEC_FLAG2_NO_OUTPUT (1 << 2)
948 /**
949  * Place global headers at every keyframe instead of in extradata.
950  */
951 #define AV_CODEC_FLAG2_LOCAL_HEADER (1 << 3)
952 
953 /**
954  * timecode is in drop frame format. DEPRECATED!!!!
955  */
956 #define AV_CODEC_FLAG2_DROP_FRAME_TIMECODE (1 << 13)
957 
958 /**
959  * Input bitstream might be truncated at a packet boundaries
960  * instead of only at frame boundaries.
961  */
962 #define AV_CODEC_FLAG2_CHUNKS (1 << 15)
963 /**
964  * Discard cropping information from SPS.
965  */
966 #define AV_CODEC_FLAG2_IGNORE_CROP (1 << 16)
967 
968 /**
969  * Show all frames before the first keyframe
970  */
971 #define AV_CODEC_FLAG2_SHOW_ALL (1 << 22)
972 /**
973  * Export motion vectors through frame side data
974  */
975 #define AV_CODEC_FLAG2_EXPORT_MVS (1 << 28)
976 /**
977  * Do not skip samples and export skip information as frame side data
978  */
979 #define AV_CODEC_FLAG2_SKIP_MANUAL (1 << 29)
980 /**
981  * Do not reset ASS ReadOrder field on flush (subtitles decoding)
982  */
983 #define AV_CODEC_FLAG2_RO_FLUSH_NOOP (1 << 30)
984 
985 /* Unsupported options :
986  * Syntax Arithmetic coding (SAC)
987  * Reference Picture Selection
988  * Independent Segment Decoding */
989 /* /Fx */
990 /* codec capabilities */
991 
992 /**
993  * Decoder can use draw_horiz_band callback.
994  */
995 #define AV_CODEC_CAP_DRAW_HORIZ_BAND (1 << 0)
996 /**
997  * Codec uses get_buffer() for allocating buffers and supports custom allocators.
998  * If not set, it might not use get_buffer() at all or use operations that
999  * assume the buffer was allocated by avcodec_default_get_buffer.
1000  */
1001 #define AV_CODEC_CAP_DR1 (1 << 1)
1002 #define AV_CODEC_CAP_TRUNCATED (1 << 3)
1003 /**
1004  * Encoder or decoder requires flushing with NULL input at the end in order to
1005  * give the complete and correct output.
1006  *
1007  * NOTE: If this flag is not set, the codec is guaranteed to never be fed with
1008  * with NULL data. The user can still send NULL data to the public encode
1009  * or decode function, but libavcodec will not pass it along to the codec
1010  * unless this flag is set.
1011  *
1012  * Decoders:
1013  * The decoder has a non-zero delay and needs to be fed with avpkt->data=NULL,
1014  * avpkt->size=0 at the end to get the delayed data until the decoder no longer
1015  * returns frames.
1016  *
1017  * Encoders:
1018  * The encoder needs to be fed with NULL data at the end of encoding until the
1019  * encoder no longer returns data.
1020  *
1021  * NOTE: For encoders implementing the AVCodec.encode2() function, setting this
1022  * flag also means that the encoder must set the pts and duration for
1023  * each output packet. If this flag is not set, the pts and duration will
1024  * be determined by libavcodec from the input frame.
1025  */
1026 #define AV_CODEC_CAP_DELAY (1 << 5)
1027 /**
1028  * Codec can be fed a final frame with a smaller size.
1029  * This can be used to prevent truncation of the last audio samples.
1030  */
1031 #define AV_CODEC_CAP_SMALL_LAST_FRAME (1 << 6)
1032 
1033 #if FF_API_CAP_VDPAU
1034 /**
1035  * Codec can export data for HW decoding (VDPAU).
1036  */
1037 #define AV_CODEC_CAP_HWACCEL_VDPAU (1 << 7)
1038 #endif
1039 
1040 /**
1041  * Codec can output multiple frames per AVPacket
1042  * Normally demuxers return one frame at a time, demuxers which do not do
1043  * are connected to a parser to split what they return into proper frames.
1044  * This flag is reserved to the very rare category of codecs which have a
1045  * bitstream that cannot be split into frames without timeconsuming
1046  * operations like full decoding. Demuxers carrying such bitstreams thus
1047  * may return multiple frames in a packet. This has many disadvantages like
1048  * prohibiting stream copy in many cases thus it should only be considered
1049  * as a last resort.
1050  */
1051 #define AV_CODEC_CAP_SUBFRAMES (1 << 8)
1052 /**
1053  * Codec is experimental and is thus avoided in favor of non experimental
1054  * encoders
1055  */
1056 #define AV_CODEC_CAP_EXPERIMENTAL (1 << 9)
1057 /**
1058  * Codec should fill in channel configuration and samplerate instead of container
1059  */
1060 #define AV_CODEC_CAP_CHANNEL_CONF (1 << 10)
1061 /**
1062  * Codec supports frame-level multithreading.
1063  */
1064 #define AV_CODEC_CAP_FRAME_THREADS (1 << 12)
1065 /**
1066  * Codec supports slice-based (or partition-based) multithreading.
1067  */
1068 #define AV_CODEC_CAP_SLICE_THREADS (1 << 13)
1069 /**
1070  * Codec supports changed parameters at any point.
1071  */
1072 #define AV_CODEC_CAP_PARAM_CHANGE (1 << 14)
1073 /**
1074  * Codec supports avctx->thread_count == 0 (auto).
1075  */
1076 #define AV_CODEC_CAP_AUTO_THREADS (1 << 15)
1077 /**
1078  * Audio encoder supports receiving a different number of samples in each call.
1079  */
1080 #define AV_CODEC_CAP_VARIABLE_FRAME_SIZE (1 << 16)
1081 /**
1082  * Decoder is not a preferred choice for probing.
1083  * This indicates that the decoder is not a good choice for probing.
1084  * It could for example be an expensive to spin up hardware decoder,
1085  * or it could simply not provide a lot of useful information about
1086  * the stream.
1087  * A decoder marked with this flag should only be used as last resort
1088  * choice for probing.
1089  */
1090 #define AV_CODEC_CAP_AVOID_PROBING (1 << 17)
1091 /**
1092  * Codec is intra only.
1093  */
1094 #define AV_CODEC_CAP_INTRA_ONLY 0x40000000
1095 /**
1096  * Codec is lossless.
1097  */
1098 #define AV_CODEC_CAP_LOSSLESS 0x80000000
1099 
1100 
1101 #if FF_API_WITHOUT_PREFIX
1102 /**
1103  * Allow decoders to produce frames with data planes that are not aligned
1104  * to CPU requirements (e.g. due to cropping).
1105  */
1106 #define CODEC_FLAG_UNALIGNED AV_CODEC_FLAG_UNALIGNED
1107 #define CODEC_FLAG_QSCALE AV_CODEC_FLAG_QSCALE
1108 #define CODEC_FLAG_4MV AV_CODEC_FLAG_4MV
1109 #define CODEC_FLAG_OUTPUT_CORRUPT AV_CODEC_FLAG_OUTPUT_CORRUPT
1110 #define CODEC_FLAG_QPEL AV_CODEC_FLAG_QPEL
1111 #if FF_API_GMC
1112 /**
1113  * @deprecated use the "gmc" private option of the libxvid encoder
1114  */
1115 #define CODEC_FLAG_GMC 0x0020 ///< Use GMC.
1116 #endif
1117 #if FF_API_MV0
1118 /**
1119  * @deprecated use the flag "mv0" in the "mpv_flags" private option of the
1120  * mpegvideo encoders
1121  */
1122 #define CODEC_FLAG_MV0 0x0040
1123 #endif
1124 #if FF_API_INPUT_PRESERVED
1125 /**
1126  * @deprecated passing reference-counted frames to the encoders replaces this
1127  * flag
1128  */
1129 #define CODEC_FLAG_INPUT_PRESERVED 0x0100
1130 #endif
1131 #define CODEC_FLAG_PASS1 AV_CODEC_FLAG_PASS1
1132 #define CODEC_FLAG_PASS2 AV_CODEC_FLAG_PASS2
1133 #define CODEC_FLAG_GRAY AV_CODEC_FLAG_GRAY
1134 #if FF_API_EMU_EDGE
1135 /**
1136  * @deprecated edges are not used/required anymore. I.e. this flag is now always
1137  * set.
1138  */
1139 #define CODEC_FLAG_EMU_EDGE 0x4000
1140 #endif
1141 #define CODEC_FLAG_PSNR AV_CODEC_FLAG_PSNR
1142 #define CODEC_FLAG_TRUNCATED AV_CODEC_FLAG_TRUNCATED
1143 
1144 #if FF_API_NORMALIZE_AQP
1145 /**
1146  * @deprecated use the flag "naq" in the "mpv_flags" private option of the
1147  * mpegvideo encoders
1148  */
1149 #define CODEC_FLAG_NORMALIZE_AQP 0x00020000
1150 #endif
1151 #define CODEC_FLAG_INTERLACED_DCT AV_CODEC_FLAG_INTERLACED_DCT
1152 #define CODEC_FLAG_LOW_DELAY AV_CODEC_FLAG_LOW_DELAY
1153 #define CODEC_FLAG_GLOBAL_HEADER AV_CODEC_FLAG_GLOBAL_HEADER
1154 #define CODEC_FLAG_BITEXACT AV_CODEC_FLAG_BITEXACT
1155 #define CODEC_FLAG_AC_PRED AV_CODEC_FLAG_AC_PRED
1156 #define CODEC_FLAG_LOOP_FILTER AV_CODEC_FLAG_LOOP_FILTER
1157 #define CODEC_FLAG_INTERLACED_ME AV_CODEC_FLAG_INTERLACED_ME
1158 #define CODEC_FLAG_CLOSED_GOP AV_CODEC_FLAG_CLOSED_GOP
1159 #define CODEC_FLAG2_FAST AV_CODEC_FLAG2_FAST
1160 #define CODEC_FLAG2_NO_OUTPUT AV_CODEC_FLAG2_NO_OUTPUT
1161 #define CODEC_FLAG2_LOCAL_HEADER AV_CODEC_FLAG2_LOCAL_HEADER
1162 #define CODEC_FLAG2_DROP_FRAME_TIMECODE AV_CODEC_FLAG2_DROP_FRAME_TIMECODE
1163 #define CODEC_FLAG2_IGNORE_CROP AV_CODEC_FLAG2_IGNORE_CROP
1164 
1165 #define CODEC_FLAG2_CHUNKS AV_CODEC_FLAG2_CHUNKS
1166 #define CODEC_FLAG2_SHOW_ALL AV_CODEC_FLAG2_SHOW_ALL
1167 #define CODEC_FLAG2_EXPORT_MVS AV_CODEC_FLAG2_EXPORT_MVS
1168 #define CODEC_FLAG2_SKIP_MANUAL AV_CODEC_FLAG2_SKIP_MANUAL
1169 
1170 /* Unsupported options :
1171  * Syntax Arithmetic coding (SAC)
1172  * Reference Picture Selection
1173  * Independent Segment Decoding */
1174 /* /Fx */
1175 /* codec capabilities */
1176 
1177 #define CODEC_CAP_DRAW_HORIZ_BAND AV_CODEC_CAP_DRAW_HORIZ_BAND ///< Decoder can use draw_horiz_band callback.
1178 /**
1179  * Codec uses get_buffer() for allocating buffers and supports custom allocators.
1180  * If not set, it might not use get_buffer() at all or use operations that
1181  * assume the buffer was allocated by avcodec_default_get_buffer.
1182  */
1183 #define CODEC_CAP_DR1 AV_CODEC_CAP_DR1
1184 #define CODEC_CAP_TRUNCATED AV_CODEC_CAP_TRUNCATED
1185 #if FF_API_XVMC
1186 /* Codec can export data for HW decoding. This flag indicates that
1187  * the codec would call get_format() with list that might contain HW accelerated
1188  * pixel formats (XvMC, VDPAU, VAAPI, etc). The application can pick any of them
1189  * including raw image format.
1190  * The application can use the passed context to determine bitstream version,
1191  * chroma format, resolution etc.
1192  */
1193 #define CODEC_CAP_HWACCEL 0x0010
1194 #endif /* FF_API_XVMC */
1195 /**
1196  * Encoder or decoder requires flushing with NULL input at the end in order to
1197  * give the complete and correct output.
1198  *
1199  * NOTE: If this flag is not set, the codec is guaranteed to never be fed with
1200  * with NULL data. The user can still send NULL data to the public encode
1201  * or decode function, but libavcodec will not pass it along to the codec
1202  * unless this flag is set.
1203  *
1204  * Decoders:
1205  * The decoder has a non-zero delay and needs to be fed with avpkt->data=NULL,
1206  * avpkt->size=0 at the end to get the delayed data until the decoder no longer
1207  * returns frames.
1208  *
1209  * Encoders:
1210  * The encoder needs to be fed with NULL data at the end of encoding until the
1211  * encoder no longer returns data.
1212  *
1213  * NOTE: For encoders implementing the AVCodec.encode2() function, setting this
1214  * flag also means that the encoder must set the pts and duration for
1215  * each output packet. If this flag is not set, the pts and duration will
1216  * be determined by libavcodec from the input frame.
1217  */
1218 #define CODEC_CAP_DELAY AV_CODEC_CAP_DELAY
1219 /**
1220  * Codec can be fed a final frame with a smaller size.
1221  * This can be used to prevent truncation of the last audio samples.
1222  */
1223 #define CODEC_CAP_SMALL_LAST_FRAME AV_CODEC_CAP_SMALL_LAST_FRAME
1224 #if FF_API_CAP_VDPAU
1225 /**
1226  * Codec can export data for HW decoding (VDPAU).
1227  */
1228 #define CODEC_CAP_HWACCEL_VDPAU AV_CODEC_CAP_HWACCEL_VDPAU
1229 #endif
1230 /**
1231  * Codec can output multiple frames per AVPacket
1232  * Normally demuxers return one frame at a time, demuxers which do not do
1233  * are connected to a parser to split what they return into proper frames.
1234  * This flag is reserved to the very rare category of codecs which have a
1235  * bitstream that cannot be split into frames without timeconsuming
1236  * operations like full decoding. Demuxers carrying such bitstreams thus
1237  * may return multiple frames in a packet. This has many disadvantages like
1238  * prohibiting stream copy in many cases thus it should only be considered
1239  * as a last resort.
1240  */
1241 #define CODEC_CAP_SUBFRAMES AV_CODEC_CAP_SUBFRAMES
1242 /**
1243  * Codec is experimental and is thus avoided in favor of non experimental
1244  * encoders
1245  */
1246 #define CODEC_CAP_EXPERIMENTAL AV_CODEC_CAP_EXPERIMENTAL
1247 /**
1248  * Codec should fill in channel configuration and samplerate instead of container
1249  */
1250 #define CODEC_CAP_CHANNEL_CONF AV_CODEC_CAP_CHANNEL_CONF
1251 #if FF_API_NEG_LINESIZES
1252 /**
1253  * @deprecated no codecs use this capability
1254  */
1255 #define CODEC_CAP_NEG_LINESIZES 0x0800
1256 #endif
1257 /**
1258  * Codec supports frame-level multithreading.
1259  */
1260 #define CODEC_CAP_FRAME_THREADS AV_CODEC_CAP_FRAME_THREADS
1261 /**
1262  * Codec supports slice-based (or partition-based) multithreading.
1263  */
1264 #define CODEC_CAP_SLICE_THREADS AV_CODEC_CAP_SLICE_THREADS
1265 /**
1266  * Codec supports changed parameters at any point.
1267  */
1268 #define CODEC_CAP_PARAM_CHANGE AV_CODEC_CAP_PARAM_CHANGE
1269 /**
1270  * Codec supports avctx->thread_count == 0 (auto).
1271  */
1272 #define CODEC_CAP_AUTO_THREADS AV_CODEC_CAP_AUTO_THREADS
1273 /**
1274  * Audio encoder supports receiving a different number of samples in each call.
1275  */
1276 #define CODEC_CAP_VARIABLE_FRAME_SIZE AV_CODEC_CAP_VARIABLE_FRAME_SIZE
1277 /**
1278  * Codec is intra only.
1279  */
1280 #define CODEC_CAP_INTRA_ONLY AV_CODEC_CAP_INTRA_ONLY
1281 /**
1282  * Codec is lossless.
1283  */
1284 #define CODEC_CAP_LOSSLESS AV_CODEC_CAP_LOSSLESS
1285 
1286 /**
1287  * HWAccel is experimental and is thus avoided in favor of non experimental
1288  * codecs
1289  */
1290 #define HWACCEL_CODEC_CAP_EXPERIMENTAL 0x0200
1291 #endif /* FF_API_WITHOUT_PREFIX */
1292 
1293 #if FF_API_MB_TYPE
1294 //The following defines may change, don't expect compatibility if you use them.
1295 #define MB_TYPE_INTRA4x4 0x0001
1296 #define MB_TYPE_INTRA16x16 0x0002 //FIXME H.264-specific
1297 #define MB_TYPE_INTRA_PCM 0x0004 //FIXME H.264-specific
1298 #define MB_TYPE_16x16 0x0008
1299 #define MB_TYPE_16x8 0x0010
1300 #define MB_TYPE_8x16 0x0020
1301 #define MB_TYPE_8x8 0x0040
1302 #define MB_TYPE_INTERLACED 0x0080
1303 #define MB_TYPE_DIRECT2 0x0100 //FIXME
1304 #define MB_TYPE_ACPRED 0x0200
1305 #define MB_TYPE_GMC 0x0400
1306 #define MB_TYPE_SKIP 0x0800
1307 #define MB_TYPE_P0L0 0x1000
1308 #define MB_TYPE_P1L0 0x2000
1309 #define MB_TYPE_P0L1 0x4000
1310 #define MB_TYPE_P1L1 0x8000
1311 #define MB_TYPE_L0 (MB_TYPE_P0L0 | MB_TYPE_P1L0)
1312 #define MB_TYPE_L1 (MB_TYPE_P0L1 | MB_TYPE_P1L1)
1313 #define MB_TYPE_L0L1 (MB_TYPE_L0 | MB_TYPE_L1)
1314 #define MB_TYPE_QUANT 0x00010000
1315 #define MB_TYPE_CBP 0x00020000
1316 // Note bits 24-31 are reserved for codec specific use (H.264 ref0, MPEG-1 0mv, ...)
1317 #endif
1318 
1319 /**
1320  * Pan Scan area.
1321  * This specifies the area which should be displayed.
1322  * Note there may be multiple such areas for one frame.
1323  */
1324 typedef struct AVPanScan{
1325  /**
1326  * id
1327  * - encoding: Set by user.
1328  * - decoding: Set by libavcodec.
1329  */
1330  int id;
1331 
1332  /**
1333  * width and height in 1/16 pel
1334  * - encoding: Set by user.
1335  * - decoding: Set by libavcodec.
1336  */
1337  int width;
1338  int height;
1339 
1340  /**
1341  * position of the top left corner in 1/16 pel for up to 3 fields/frames
1342  * - encoding: Set by user.
1343  * - decoding: Set by libavcodec.
1344  */
1345  int16_t position[3][2];
1346 }AVPanScan;
1347 
1348 /**
1349  * This structure describes the bitrate properties of an encoded bitstream. It
1350  * roughly corresponds to a subset the VBV parameters for MPEG-2 or HRD
1351  * parameters for H.264/HEVC.
1352  */
1353 typedef struct AVCPBProperties {
1354  /**
1355  * Maximum bitrate of the stream, in bits per second.
1356  * Zero if unknown or unspecified.
1357  */
1359  /**
1360  * Minimum bitrate of the stream, in bits per second.
1361  * Zero if unknown or unspecified.
1362  */
1364  /**
1365  * Average bitrate of the stream, in bits per second.
1366  * Zero if unknown or unspecified.
1367  */
1369 
1370  /**
1371  * The size of the buffer to which the ratecontrol is applied, in bits.
1372  * Zero if unknown or unspecified.
1373  */
1375 
1376  /**
1377  * The delay between the time the packet this structure is associated with
1378  * is received and the time when it should be decoded, in periods of a 27MHz
1379  * clock.
1380  *
1381  * UINT64_MAX when unknown or unspecified.
1382  */
1383  uint64_t vbv_delay;
1384 } AVCPBProperties;
1385 
1386 #if FF_API_QSCALE_TYPE
1387 #define FF_QSCALE_TYPE_MPEG1 0
1388 #define FF_QSCALE_TYPE_MPEG2 1
1389 #define FF_QSCALE_TYPE_H264 2
1390 #define FF_QSCALE_TYPE_VP56 3
1391 #endif
1392 
1393 /**
1394  * The decoder will keep a reference to the frame and may reuse it later.
1395  */
1396 #define AV_GET_BUFFER_FLAG_REF (1 << 0)
1397 
1398 /**
1399  * @defgroup lavc_packet AVPacket
1400  *
1401  * Types and functions for working with AVPacket.
1402  * @{
1403  */
1405  /**
1406  * An AV_PKT_DATA_PALETTE side data packet contains exactly AVPALETTE_SIZE
1407  * bytes worth of palette. This side data signals that a new palette is
1408  * present.
1409  */
1411 
1412  /**
1413  * The AV_PKT_DATA_NEW_EXTRADATA is used to notify the codec or the format
1414  * that the extradata buffer was changed and the receiving side should
1415  * act upon it appropriately. The new extradata is embedded in the side
1416  * data buffer and should be immediately used for processing the current
1417  * frame or packet.
1418  */
1420 
1421  /**
1422  * An AV_PKT_DATA_PARAM_CHANGE side data packet is laid out as follows:
1423  * @code
1424  * u32le param_flags
1425  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT)
1426  * s32le channel_count
1427  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT)
1428  * u64le channel_layout
1429  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE)
1430  * s32le sample_rate
1431  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS)
1432  * s32le width
1433  * s32le height
1434  * @endcode
1435  */
1437 
1438  /**
1439  * An AV_PKT_DATA_H263_MB_INFO side data packet contains a number of
1440  * structures with info about macroblocks relevant to splitting the
1441  * packet into smaller packets on macroblock edges (e.g. as for RFC 2190).
1442  * That is, it does not necessarily contain info about all macroblocks,
1443  * as long as the distance between macroblocks in the info is smaller
1444  * than the target payload size.
1445  * Each MB info structure is 12 bytes, and is laid out as follows:
1446  * @code
1447  * u32le bit offset from the start of the packet
1448  * u8 current quantizer at the start of the macroblock
1449  * u8 GOB number
1450  * u16le macroblock address within the GOB
1451  * u8 horizontal MV predictor
1452  * u8 vertical MV predictor
1453  * u8 horizontal MV predictor for block number 3
1454  * u8 vertical MV predictor for block number 3
1455  * @endcode
1456  */
1458 
1459  /**
1460  * This side data should be associated with an audio stream and contains
1461  * ReplayGain information in form of the AVReplayGain struct.
1462  */
1464 
1465  /**
1466  * This side data contains a 3x3 transformation matrix describing an affine
1467  * transformation that needs to be applied to the decoded video frames for
1468  * correct presentation.
1469  *
1470  * See libavutil/display.h for a detailed description of the data.
1471  */
1473 
1474  /**
1475  * This side data should be associated with a video stream and contains
1476  * Stereoscopic 3D information in form of the AVStereo3D struct.
1477  */
1479 
1480  /**
1481  * This side data should be associated with an audio stream and corresponds
1482  * to enum AVAudioServiceType.
1483  */
1485 
1486  /**
1487  * This side data contains quality related information from the encoder.
1488  * @code
1489  * u32le quality factor of the compressed frame. Allowed range is between 1 (good) and FF_LAMBDA_MAX (bad).
1490  * u8 picture type
1491  * u8 error count
1492  * u16 reserved
1493  * u64le[error count] sum of squared differences between encoder in and output
1494  * @endcode
1495  */
1497 
1498  /**
1499  * This side data contains an integer value representing the stream index
1500  * of a "fallback" track. A fallback track indicates an alternate
1501  * track to use when the current track can not be decoded for some reason.
1502  * e.g. no decoder available for codec.
1503  */
1505 
1506  /**
1507  * This side data corresponds to the AVCPBProperties struct.
1508  */
1510 
1511  /**
1512  * Recommmends skipping the specified number of samples
1513  * @code
1514  * u32le number of samples to skip from start of this packet
1515  * u32le number of samples to skip from end of this packet
1516  * u8 reason for start skip
1517  * u8 reason for end skip (0=padding silence, 1=convergence)
1518  * @endcode
1519  */
1521 
1522  /**
1523  * An AV_PKT_DATA_JP_DUALMONO side data packet indicates that
1524  * the packet may contain "dual mono" audio specific to Japanese DTV
1525  * and if it is true, recommends only the selected channel to be used.
1526  * @code
1527  * u8 selected channels (0=mail/left, 1=sub/right, 2=both)
1528  * @endcode
1529  */
1531 
1532  /**
1533  * A list of zero terminated key/value strings. There is no end marker for
1534  * the list, so it is required to rely on the side data size to stop.
1535  */
1537 
1538  /**
1539  * Subtitle event position
1540  * @code
1541  * u32le x1
1542  * u32le y1
1543  * u32le x2
1544  * u32le y2
1545  * @endcode
1546  */
1548 
1549  /**
1550  * Data found in BlockAdditional element of matroska container. There is
1551  * no end marker for the data, so it is required to rely on the side data
1552  * size to recognize the end. 8 byte id (as found in BlockAddId) followed
1553  * by data.
1554  */
1556 
1557  /**
1558  * The optional first identifier line of a WebVTT cue.
1559  */
1561 
1562  /**
1563  * The optional settings (rendering instructions) that immediately
1564  * follow the timestamp specifier of a WebVTT cue.
1565  */
1567 
1568  /**
1569  * A list of zero terminated key/value strings. There is no end marker for
1570  * the list, so it is required to rely on the side data size to stop. This
1571  * side data includes updated metadata which appeared in the stream.
1572  */
1574 
1575  /**
1576  * MPEGTS stream ID, this is required to pass the stream ID
1577  * information from the demuxer to the corresponding muxer.
1578  */
1580 
1581  /**
1582  * Mastering display metadata (based on SMPTE-2086:2014). This metadata
1583  * should be associated with a video stream and contains data in the form
1584  * of the AVMasteringDisplayMetadata struct.
1585  */
1587 
1588  /**
1589  * This side data should be associated with a video stream and corresponds
1590  * to the AVSphericalMapping structure.
1591  */
1593 
1594  /**
1595  * Content light level (based on CTA-861.3). This metadata should be
1596  * associated with a video stream and contains data in the form of the
1597  * AVContentLightMetadata struct.
1598  */
1600 
1601  /**
1602  * The number of side data elements (in fact a bit more than it).
1603  * This is not part of the public API/ABI in the sense that it may
1604  * change when new side data types are added.
1605  * This must stay the last enum value.
1606  * If its value becomes huge, some code using it
1607  * needs to be updated as it assumes it to be smaller than other limits.
1608  */
1610 };
1611 
1612 #define AV_PKT_DATA_QUALITY_FACTOR AV_PKT_DATA_QUALITY_STATS //DEPRECATED
1613 
1614 typedef struct AVPacketSideData {
1616  int size;
1619 
1620 /**
1621  * This structure stores compressed data. It is typically exported by demuxers
1622  * and then passed as input to decoders, or received as output from encoders and
1623  * then passed to muxers.
1624  *
1625  * For video, it should typically contain one compressed frame. For audio it may
1626  * contain several compressed frames. Encoders are allowed to output empty
1627  * packets, with no compressed data, containing only side data
1628  * (e.g. to update some stream parameters at the end of encoding).
1629  *
1630  * AVPacket is one of the few structs in FFmpeg, whose size is a part of public
1631  * ABI. Thus it may be allocated on stack and no new fields can be added to it
1632  * without libavcodec and libavformat major bump.
1633  *
1634  * The semantics of data ownership depends on the buf field.
1635  * If it is set, the packet data is dynamically allocated and is
1636  * valid indefinitely until a call to av_packet_unref() reduces the
1637  * reference count to 0.
1638  *
1639  * If the buf field is not set av_packet_ref() would make a copy instead
1640  * of increasing the reference count.
1641  *
1642  * The side data is always allocated with av_malloc(), copied by
1643  * av_packet_ref() and freed by av_packet_unref().
1644  *
1645  * @see av_packet_ref
1646  * @see av_packet_unref
1647  */
1648 typedef struct AVPacket {
1649  /**
1650  * A reference to the reference-counted buffer where the packet data is
1651  * stored.
1652  * May be NULL, then the packet data is not reference-counted.
1653  */
1655  /**
1656  * Presentation timestamp in AVStream->time_base units; the time at which
1657  * the decompressed packet will be presented to the user.
1658  * Can be AV_NOPTS_VALUE if it is not stored in the file.
1659  * pts MUST be larger or equal to dts as presentation cannot happen before
1660  * decompression, unless one wants to view hex dumps. Some formats misuse
1661  * the terms dts and pts/cts to mean something different. Such timestamps
1662  * must be converted to true pts/dts before they are stored in AVPacket.
1663  */
1664  int64_t pts;
1665  /**
1666  * Decompression timestamp in AVStream->time_base units; the time at which
1667  * the packet is decompressed.
1668  * Can be AV_NOPTS_VALUE if it is not stored in the file.
1669  */
1670  int64_t dts;
1672  int size;
1674  /**
1675  * A combination of AV_PKT_FLAG values
1676  */
1677  int flags;
1678  /**
1679  * Additional packet data that can be provided by the container.
1680  * Packet can contain several types of side information.
1681  */
1684 
1685  /**
1686  * Duration of this packet in AVStream->time_base units, 0 if unknown.
1687  * Equals next_pts - this_pts in presentation order.
1688  */
1689  int64_t duration;
1690 
1691  int64_t pos; ///< byte position in stream, -1 if unknown
1692 
1693 #if FF_API_CONVERGENCE_DURATION
1694  /**
1695  * @deprecated Same as the duration field, but as int64_t. This was required
1696  * for Matroska subtitles, whose duration values could overflow when the
1697  * duration field was still an int.
1698  */
1701 #endif
1702 } AVPacket;
1703 #define AV_PKT_FLAG_KEY 0x0001 ///< The packet contains a keyframe
1704 #define AV_PKT_FLAG_CORRUPT 0x0002 ///< The packet content is corrupted
1705 /**
1706  * Flag is used to discard packets which are required to maintain valid
1707  * decoder state but are not required for output and should be dropped
1708  * after decoding.
1709  **/
1710 #define AV_PKT_FLAG_DISCARD 0x0004
1711 
1717 };
1718 /**
1719  * @}
1720  */
1721 
1722 struct AVCodecInternal;
1723 
1727  AV_FIELD_TT, //< Top coded_first, top displayed first
1728  AV_FIELD_BB, //< Bottom coded first, bottom displayed first
1729  AV_FIELD_TB, //< Top coded first, bottom displayed first
1730  AV_FIELD_BT, //< Bottom coded first, top displayed first
1731 };
1732 
1733 /**
1734  * main external API structure.
1735  * New fields can be added to the end with minor version bumps.
1736  * Removal, reordering and changes to existing fields require a major
1737  * version bump.
1738  * You can use AVOptions (av_opt* / av_set/get*()) to access these fields from user
1739  * applications.
1740  * The name string for AVOptions options matches the associated command line
1741  * parameter name and can be found in libavcodec/options_table.h
1742  * The AVOption/command line parameter names differ in some cases from the C
1743  * structure field names for historic reasons or brevity.
1744  * sizeof(AVCodecContext) must not be used outside libav*.
1745  */
1746 typedef struct AVCodecContext {
1747  /**
1748  * information on struct for av_log
1749  * - set by avcodec_alloc_context3
1750  */
1753 
1754  enum AVMediaType codec_type; /* see AVMEDIA_TYPE_xxx */
1755  const struct AVCodec *codec;
1756 #if FF_API_CODEC_NAME
1757  /**
1758  * @deprecated this field is not used for anything in libavcodec
1759  */
1761  char codec_name[32];
1762 #endif
1763  enum AVCodecID codec_id; /* see AV_CODEC_ID_xxx */
1764 
1765  /**
1766  * fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
1767  * This is used to work around some encoder bugs.
1768  * A demuxer should set this to what is stored in the field used to identify the codec.
1769  * If there are multiple such fields in a container then the demuxer should choose the one
1770  * which maximizes the information about the used codec.
1771  * If the codec tag field in a container is larger than 32 bits then the demuxer should
1772  * remap the longer ID to 32 bits with a table or other structure. Alternatively a new
1773  * extra_codec_tag + size could be added but for this a clear advantage must be demonstrated
1774  * first.
1775  * - encoding: Set by user, if not then the default based on codec_id will be used.
1776  * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
1777  */
1778  unsigned int codec_tag;
1779 
1780 #if FF_API_STREAM_CODEC_TAG
1781  /**
1782  * @deprecated this field is unused
1783  */
1785  unsigned int stream_codec_tag;
1786 #endif
1787 
1788  void *priv_data;
1789 
1790  /**
1791  * Private context used for internal data.
1792  *
1793  * Unlike priv_data, this is not codec-specific. It is used in general
1794  * libavcodec functions.
1795  */
1796  struct AVCodecInternal *internal;
1797 
1798  /**
1799  * Private data of the user, can be used to carry app specific stuff.
1800  * - encoding: Set by user.
1801  * - decoding: Set by user.
1802  */
1803  void *opaque;
1804 
1805  /**
1806  * the average bitrate
1807  * - encoding: Set by user; unused for constant quantizer encoding.
1808  * - decoding: Set by user, may be overwritten by libavcodec
1809  * if this info is available in the stream
1810  */
1811  int64_t bit_rate;
1812 
1813  /**
1814  * number of bits the bitstream is allowed to diverge from the reference.
1815  * the reference can be CBR (for CBR pass1) or VBR (for pass2)
1816  * - encoding: Set by user; unused for constant quantizer encoding.
1817  * - decoding: unused
1818  */
1820 
1821  /**
1822  * Global quality for codecs which cannot change it per frame.
1823  * This should be proportional to MPEG-1/2/4 qscale.
1824  * - encoding: Set by user.
1825  * - decoding: unused
1826  */
1828 
1829  /**
1830  * - encoding: Set by user.
1831  * - decoding: unused
1832  */
1834 #define FF_COMPRESSION_DEFAULT -1
1835 
1836  /**
1837  * AV_CODEC_FLAG_*.
1838  * - encoding: Set by user.
1839  * - decoding: Set by user.
1840  */
1841  int flags;
1842 
1843  /**
1844  * AV_CODEC_FLAG2_*
1845  * - encoding: Set by user.
1846  * - decoding: Set by user.
1847  */
1848  int flags2;
1849 
1850  /**
1851  * some codecs need / can use extradata like Huffman tables.
1852  * MJPEG: Huffman tables
1853  * rv10: additional flags
1854  * MPEG-4: global headers (they can be in the bitstream or here)
1855  * The allocated memory should be AV_INPUT_BUFFER_PADDING_SIZE bytes larger
1856  * than extradata_size to avoid problems if it is read with the bitstream reader.
1857  * The bytewise contents of extradata must not depend on the architecture or CPU endianness.
1858  * - encoding: Set/allocated/freed by libavcodec.
1859  * - decoding: Set/allocated/freed by user.
1860  */
1863 
1864  /**
1865  * This is the fundamental unit of time (in seconds) in terms
1866  * of which frame timestamps are represented. For fixed-fps content,
1867  * timebase should be 1/framerate and timestamp increments should be
1868  * identically 1.
1869  * This often, but not always is the inverse of the frame rate or field rate
1870  * for video. 1/time_base is not the average frame rate if the frame rate is not
1871  * constant.
1872  *
1873  * Like containers, elementary streams also can store timestamps, 1/time_base
1874  * is the unit in which these timestamps are specified.
1875  * As example of such codec time base see ISO/IEC 14496-2:2001(E)
1876  * vop_time_increment_resolution and fixed_vop_rate
1877  * (fixed_vop_rate == 0 implies that it is different from the framerate)
1878  *
1879  * - encoding: MUST be set by user.
1880  * - decoding: the use of this field for decoding is deprecated.
1881  * Use framerate instead.
1882  */
1884 
1885  /**
1886  * For some codecs, the time base is closer to the field rate than the frame rate.
1887  * Most notably, H.264 and MPEG-2 specify time_base as half of frame duration
1888  * if no telecine is used ...
1889  *
1890  * Set to time_base ticks per frame. Default 1, e.g., H.264/MPEG-2 set it to 2.
1891  */
1893 
1894  /**
1895  * Codec delay.
1896  *
1897  * Encoding: Number of frames delay there will be from the encoder input to
1898  * the decoder output. (we assume the decoder matches the spec)
1899  * Decoding: Number of frames delay in addition to what a standard decoder
1900  * as specified in the spec would produce.
1901  *
1902  * Video:
1903  * Number of frames the decoded output will be delayed relative to the
1904  * encoded input.
1905  *
1906  * Audio:
1907  * For encoding, this field is unused (see initial_padding).
1908  *
1909  * For decoding, this is the number of samples the decoder needs to
1910  * output before the decoder's output is valid. When seeking, you should
1911  * start decoding this many samples prior to your desired seek point.
1912  *
1913  * - encoding: Set by libavcodec.
1914  * - decoding: Set by libavcodec.
1915  */
1916  int delay;
1917 
1918 
1919  /* video only */
1920  /**
1921  * picture width / height.
1922  *
1923  * @note Those fields may not match the values of the last
1924  * AVFrame output by avcodec_decode_video2 due frame
1925  * reordering.
1926  *
1927  * - encoding: MUST be set by user.
1928  * - decoding: May be set by the user before opening the decoder if known e.g.
1929  * from the container. Some decoders will require the dimensions
1930  * to be set by the caller. During decoding, the decoder may
1931  * overwrite those values as required while parsing the data.
1932  */
1934 
1935  /**
1936  * Bitstream width / height, may be different from width/height e.g. when
1937  * the decoded frame is cropped before being output or lowres is enabled.
1938  *
1939  * @note Those field may not match the value of the last
1940  * AVFrame output by avcodec_receive_frame() due frame
1941  * reordering.
1942  *
1943  * - encoding: unused
1944  * - decoding: May be set by the user before opening the decoder if known
1945  * e.g. from the container. During decoding, the decoder may
1946  * overwrite those values as required while parsing the data.
1947  */
1949 
1950 #if FF_API_ASPECT_EXTENDED
1951 #define FF_ASPECT_EXTENDED 15
1952 #endif
1953 
1954  /**
1955  * the number of pictures in a group of pictures, or 0 for intra_only
1956  * - encoding: Set by user.
1957  * - decoding: unused
1958  */
1960 
1961  /**
1962  * Pixel format, see AV_PIX_FMT_xxx.
1963  * May be set by the demuxer if known from headers.
1964  * May be overridden by the decoder if it knows better.
1965  *
1966  * @note This field may not match the value of the last
1967  * AVFrame output by avcodec_receive_frame() due frame
1968  * reordering.
1969  *
1970  * - encoding: Set by user.
1971  * - decoding: Set by user if known, overridden by libavcodec while
1972  * parsing the data.
1973  */
1975 
1976 #if FF_API_MOTION_EST
1977  /**
1978  * This option does nothing
1979  * @deprecated use codec private options instead
1980  */
1982 #endif
1983 
1984  /**
1985  * If non NULL, 'draw_horiz_band' is called by the libavcodec
1986  * decoder to draw a horizontal band. It improves cache usage. Not
1987  * all codecs can do that. You must check the codec capabilities
1988  * beforehand.
1989  * When multithreading is used, it may be called from multiple threads
1990  * at the same time; threads might draw different parts of the same AVFrame,
1991  * or multiple AVFrames, and there is no guarantee that slices will be drawn
1992  * in order.
1993  * The function is also used by hardware acceleration APIs.
1994  * It is called at least once during frame decoding to pass
1995  * the data needed for hardware render.
1996  * In that mode instead of pixel data, AVFrame points to
1997  * a structure specific to the acceleration API. The application
1998  * reads the structure and can change some fields to indicate progress
1999  * or mark state.
2000  * - encoding: unused
2001  * - decoding: Set by user.
2002  * @param height the height of the slice
2003  * @param y the y position of the slice
2004  * @param type 1->top field, 2->bottom field, 3->frame
2005  * @param offset offset into the AVFrame.data from which the slice should be read
2006  */
2008  const AVFrame *src, int offset[AV_NUM_DATA_POINTERS],
2009  int y, int type, int height);
2010 
2011  /**
2012  * callback to negotiate the pixelFormat
2013  * @param fmt is the list of formats which are supported by the codec,
2014  * it is terminated by -1 as 0 is a valid format, the formats are ordered by quality.
2015  * The first is always the native one.
2016  * @note The callback may be called again immediately if initialization for
2017  * the selected (hardware-accelerated) pixel format failed.
2018  * @warning Behavior is undefined if the callback returns a value not
2019  * in the fmt list of formats.
2020  * @return the chosen format
2021  * - encoding: unused
2022  * - decoding: Set by user, if not set the native format will be chosen.
2023  */
2024  enum AVPixelFormat (*get_format)(struct AVCodecContext *s, const enum AVPixelFormat * fmt);
2025 
2026  /**
2027  * maximum number of B-frames between non-B-frames
2028  * Note: The output will be delayed by max_b_frames+1 relative to the input.
2029  * - encoding: Set by user.
2030  * - decoding: unused
2031  */
2033 
2034  /**
2035  * qscale factor between IP and B-frames
2036  * If > 0 then the last P-frame quantizer will be used (q= lastp_q*factor+offset).
2037  * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
2038  * - encoding: Set by user.
2039  * - decoding: unused
2040  */
2042 
2043 #if FF_API_RC_STRATEGY
2044  /** @deprecated use codec private option instead */
2046 #define FF_RC_STRATEGY_XVID 1
2047 #endif
2048 
2049 #if FF_API_PRIVATE_OPT
2050  /** @deprecated use encoder private options instead */
2053 #endif
2054 
2055  /**
2056  * qscale offset between IP and B-frames
2057  * - encoding: Set by user.
2058  * - decoding: unused
2059  */
2061 
2062  /**
2063  * Size of the frame reordering buffer in the decoder.
2064  * For MPEG-2 it is 1 IPB or 0 low delay IP.
2065  * - encoding: Set by libavcodec.
2066  * - decoding: Set by libavcodec.
2067  */
2069 
2070 #if FF_API_PRIVATE_OPT
2071  /** @deprecated use encoder private options instead */
2074 #endif
2075 
2076  /**
2077  * qscale factor between P- and I-frames
2078  * If > 0 then the last P-frame quantizer will be used (q = lastp_q * factor + offset).
2079  * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
2080  * - encoding: Set by user.
2081  * - decoding: unused
2082  */
2084 
2085  /**
2086  * qscale offset between P and I-frames
2087  * - encoding: Set by user.
2088  * - decoding: unused
2089  */
2091 
2092  /**
2093  * luminance masking (0-> disabled)
2094  * - encoding: Set by user.
2095  * - decoding: unused
2096  */
2098 
2099  /**
2100  * temporary complexity masking (0-> disabled)
2101  * - encoding: Set by user.
2102  * - decoding: unused
2103  */
2105 
2106  /**
2107  * spatial complexity masking (0-> disabled)
2108  * - encoding: Set by user.
2109  * - decoding: unused
2110  */
2112 
2113  /**
2114  * p block masking (0-> disabled)
2115  * - encoding: Set by user.
2116  * - decoding: unused
2117  */
2118  float p_masking;
2119 
2120  /**
2121  * darkness masking (0-> disabled)
2122  * - encoding: Set by user.
2123  * - decoding: unused
2124  */
2126 
2127  /**
2128  * slice count
2129  * - encoding: Set by libavcodec.
2130  * - decoding: Set by user (or 0).
2131  */
2133 
2134 #if FF_API_PRIVATE_OPT
2135  /** @deprecated use encoder private options instead */
2138 #define FF_PRED_LEFT 0
2139 #define FF_PRED_PLANE 1
2140 #define FF_PRED_MEDIAN 2
2141 #endif
2142 
2143  /**
2144  * slice offsets in the frame in bytes
2145  * - encoding: Set/allocated by libavcodec.
2146  * - decoding: Set/allocated by user (or NULL).
2147  */
2149 
2150  /**
2151  * sample aspect ratio (0 if unknown)
2152  * That is the width of a pixel divided by the height of the pixel.
2153  * Numerator and denominator must be relatively prime and smaller than 256 for some video standards.
2154  * - encoding: Set by user.
2155  * - decoding: Set by libavcodec.
2156  */
2158 
2159  /**
2160  * motion estimation comparison function
2161  * - encoding: Set by user.
2162  * - decoding: unused
2163  */
2164  int me_cmp;
2165  /**
2166  * subpixel motion estimation comparison function
2167  * - encoding: Set by user.
2168  * - decoding: unused
2169  */
2171  /**
2172  * macroblock comparison function (not supported yet)
2173  * - encoding: Set by user.
2174  * - decoding: unused
2175  */
2176  int mb_cmp;
2177  /**
2178  * interlaced DCT comparison function
2179  * - encoding: Set by user.
2180  * - decoding: unused
2181  */
2183 #define FF_CMP_SAD 0
2184 #define FF_CMP_SSE 1
2185 #define FF_CMP_SATD 2
2186 #define FF_CMP_DCT 3
2187 #define FF_CMP_PSNR 4
2188 #define FF_CMP_BIT 5
2189 #define FF_CMP_RD 6
2190 #define FF_CMP_ZERO 7
2191 #define FF_CMP_VSAD 8
2192 #define FF_CMP_VSSE 9
2193 #define FF_CMP_NSSE 10
2194 #define FF_CMP_W53 11
2195 #define FF_CMP_W97 12
2196 #define FF_CMP_DCTMAX 13
2197 #define FF_CMP_DCT264 14
2198 #define FF_CMP_MEDIAN_SAD 15
2199 #define FF_CMP_CHROMA 256
2200 
2201  /**
2202  * ME diamond size & shape
2203  * - encoding: Set by user.
2204  * - decoding: unused
2205  */
2207 
2208  /**
2209  * amount of previous MV predictors (2a+1 x 2a+1 square)
2210  * - encoding: Set by user.
2211  * - decoding: unused
2212  */
2214 
2215 #if FF_API_PRIVATE_OPT
2216  /** @deprecated use encoder private options instead */
2218  int pre_me;
2219 #endif
2220 
2221  /**
2222  * motion estimation prepass comparison function
2223  * - encoding: Set by user.
2224  * - decoding: unused
2225  */
2227 
2228  /**
2229  * ME prepass diamond size & shape
2230  * - encoding: Set by user.
2231  * - decoding: unused
2232  */
2234 
2235  /**
2236  * subpel ME quality
2237  * - encoding: Set by user.
2238  * - decoding: unused
2239  */
2241 
2242 #if FF_API_AFD
2243  /**
2244  * DTG active format information (additional aspect ratio
2245  * information only used in DVB MPEG-2 transport streams)
2246  * 0 if not set.
2247  *
2248  * - encoding: unused
2249  * - decoding: Set by decoder.
2250  * @deprecated Deprecated in favor of AVSideData
2251  */
2253 #define FF_DTG_AFD_SAME 8
2254 #define FF_DTG_AFD_4_3 9
2255 #define FF_DTG_AFD_16_9 10
2256 #define FF_DTG_AFD_14_9 11
2257 #define FF_DTG_AFD_4_3_SP_14_9 13
2258 #define FF_DTG_AFD_16_9_SP_14_9 14
2259 #define FF_DTG_AFD_SP_4_3 15
2260 #endif /* FF_API_AFD */
2261 
2262  /**
2263  * maximum motion estimation search range in subpel units
2264  * If 0 then no limit.
2265  *
2266  * - encoding: Set by user.
2267  * - decoding: unused
2268  */
2270 
2271 #if FF_API_QUANT_BIAS
2272  /**
2273  * @deprecated use encoder private option instead
2274  */
2276 #define FF_DEFAULT_QUANT_BIAS 999999
2277 
2278  /**
2279  * @deprecated use encoder private option instead
2280  */
2282 #endif
2283 
2284  /**
2285  * slice flags
2286  * - encoding: unused
2287  * - decoding: Set by user.
2288  */
2290 #define SLICE_FLAG_CODED_ORDER 0x0001 ///< draw_horiz_band() is called in coded order instead of display
2291 #define SLICE_FLAG_ALLOW_FIELD 0x0002 ///< allow draw_horiz_band() with field slices (MPEG-2 field pics)
2292 #define SLICE_FLAG_ALLOW_PLANE 0x0004 ///< allow draw_horiz_band() with 1 component at a time (SVQ1)
2293 
2294 #if FF_API_XVMC
2295  /**
2296  * XVideo Motion Acceleration
2297  * - encoding: forbidden
2298  * - decoding: set by decoder
2299  * @deprecated XvMC doesn't need it anymore.
2300  */
2301  attribute_deprecated int xvmc_acceleration;
2302 #endif /* FF_API_XVMC */
2303 
2304  /**
2305  * macroblock decision mode
2306  * - encoding: Set by user.
2307  * - decoding: unused
2308  */
2310 #define FF_MB_DECISION_SIMPLE 0 ///< uses mb_cmp
2311 #define FF_MB_DECISION_BITS 1 ///< chooses the one which needs the fewest bits
2312 #define FF_MB_DECISION_RD 2 ///< rate distortion
2313 
2314  /**
2315  * custom intra quantization matrix
2316  * - encoding: Set by user, can be NULL.
2317  * - decoding: Set by libavcodec.
2318  */
2319  uint16_t *intra_matrix;
2320 
2321  /**
2322  * custom inter quantization matrix
2323  * - encoding: Set by user, can be NULL.
2324  * - decoding: Set by libavcodec.
2325  */
2326  uint16_t *inter_matrix;
2327 
2328 #if FF_API_PRIVATE_OPT
2329  /** @deprecated use encoder private options instead */
2332 
2333  /** @deprecated use encoder private options instead */
2336 #endif
2337 
2338 #if FF_API_MPV_OPT
2339  /**
2340  * @deprecated this field is unused
2341  */
2344 
2345  /**
2346  * @deprecated this field is unused
2347  */
2350 #endif
2351 
2352  /**
2353  * precision of the intra DC coefficient - 8
2354  * - encoding: Set by user.
2355  * - decoding: Set by libavcodec
2356  */
2358 
2359  /**
2360  * Number of macroblock rows at the top which are skipped.
2361  * - encoding: unused
2362  * - decoding: Set by user.
2363  */
2365 
2366  /**
2367  * Number of macroblock rows at the bottom which are skipped.
2368  * - encoding: unused
2369  * - decoding: Set by user.
2370  */
2372 
2373 #if FF_API_MPV_OPT
2374  /**
2375  * @deprecated use encoder private options instead
2376  */
2379 #endif
2380 
2381  /**
2382  * minimum MB Lagrange multiplier
2383  * - encoding: Set by user.
2384  * - decoding: unused
2385  */
2386  int mb_lmin;
2387 
2388  /**
2389  * maximum MB Lagrange multiplier
2390  * - encoding: Set by user.
2391  * - decoding: unused
2392  */
2393  int mb_lmax;
2394 
2395 #if FF_API_PRIVATE_OPT
2396  /**
2397  * @deprecated use encoder private options instead
2398  */
2401 #endif
2402 
2403  /**
2404  * - encoding: Set by user.
2405  * - decoding: unused
2406  */
2408 
2409 #if FF_API_PRIVATE_OPT
2410  /** @deprecated use encoder private options instead */
2413 #endif
2414 
2415  /**
2416  * minimum GOP size
2417  * - encoding: Set by user.
2418  * - decoding: unused
2419  */
2421 
2422  /**
2423  * number of reference frames
2424  * - encoding: Set by user.
2425  * - decoding: Set by lavc.
2426  */
2427  int refs;
2428 
2429 #if FF_API_PRIVATE_OPT
2430  /** @deprecated use encoder private options instead */
2433 #endif
2434 
2435 #if FF_API_UNUSED_MEMBERS
2436  /**
2437  * Multiplied by qscale for each frame and added to scene_change_score.
2438  * - encoding: Set by user.
2439  * - decoding: unused
2440  */
2442 #endif
2443 
2444  /**
2445  * Note: Value depends upon the compare function used for fullpel ME.
2446  * - encoding: Set by user.
2447  * - decoding: unused
2448  */
2450 
2451 #if FF_API_PRIVATE_OPT
2452  /** @deprecated use encoder private options instead */
2455 #endif
2456 
2457  /**
2458  * Chromaticity coordinates of the source primaries.
2459  * - encoding: Set by user
2460  * - decoding: Set by libavcodec
2461  */
2463 
2464  /**
2465  * Color Transfer Characteristic.
2466  * - encoding: Set by user
2467  * - decoding: Set by libavcodec
2468  */
2470 
2471  /**
2472  * YUV colorspace type.
2473  * - encoding: Set by user
2474  * - decoding: Set by libavcodec
2475  */
2477 
2478  /**
2479  * MPEG vs JPEG YUV range.
2480  * - encoding: Set by user
2481  * - decoding: Set by libavcodec
2482  */
2484 
2485  /**
2486  * This defines the location of chroma samples.
2487  * - encoding: Set by user
2488  * - decoding: Set by libavcodec
2489  */
2491 
2492  /**
2493  * Number of slices.
2494  * Indicates number of picture subdivisions. Used for parallelized
2495  * decoding.
2496  * - encoding: Set by user
2497  * - decoding: unused
2498  */
2499  int slices;
2500 
2501  /** Field order
2502  * - encoding: set by libavcodec
2503  * - decoding: Set by user.
2504  */
2506 
2507  /* audio only */
2508  int sample_rate; ///< samples per second
2509  int channels; ///< number of audio channels
2510 
2511  /**
2512  * audio sample format
2513  * - encoding: Set by user.
2514  * - decoding: Set by libavcodec.
2515  */
2516  enum AVSampleFormat sample_fmt; ///< sample format
2517 
2518  /* The following data should not be initialized. */
2519  /**
2520  * Number of samples per channel in an audio frame.
2521  *
2522  * - encoding: set by libavcodec in avcodec_open2(). Each submitted frame
2523  * except the last must contain exactly frame_size samples per channel.
2524  * May be 0 when the codec has AV_CODEC_CAP_VARIABLE_FRAME_SIZE set, then the
2525  * frame size is not restricted.
2526  * - decoding: may be set by some decoders to indicate constant frame size
2527  */
2529 
2530  /**
2531  * Frame counter, set by libavcodec.
2532  *
2533  * - decoding: total number of frames returned from the decoder so far.
2534  * - encoding: total number of frames passed to the encoder so far.
2535  *
2536  * @note the counter is not incremented if encoding/decoding resulted in
2537  * an error.
2538  */
2540 
2541  /**
2542  * number of bytes per packet if constant and known or 0
2543  * Used by some WAV based audio codecs.
2544  */
2546 
2547  /**
2548  * Audio cutoff bandwidth (0 means "automatic")
2549  * - encoding: Set by user.
2550  * - decoding: unused
2551  */
2552  int cutoff;
2553 
2554  /**
2555  * Audio channel layout.
2556  * - encoding: set by user.
2557  * - decoding: set by user, may be overwritten by libavcodec.
2558  */
2559  uint64_t channel_layout;
2560 
2561  /**
2562  * Request decoder to use this channel layout if it can (0 for default)
2563  * - encoding: unused
2564  * - decoding: Set by user.
2565  */
2567 
2568  /**
2569  * Type of service that the audio stream conveys.
2570  * - encoding: Set by user.
2571  * - decoding: Set by libavcodec.
2572  */
2574 
2575  /**
2576  * desired sample format
2577  * - encoding: Not used.
2578  * - decoding: Set by user.
2579  * Decoder will decode to this format if it can.
2580  */
2582 
2583  /**
2584  * This callback is called at the beginning of each frame to get data
2585  * buffer(s) for it. There may be one contiguous buffer for all the data or
2586  * there may be a buffer per each data plane or anything in between. What
2587  * this means is, you may set however many entries in buf[] you feel necessary.
2588  * Each buffer must be reference-counted using the AVBuffer API (see description
2589  * of buf[] below).
2590  *
2591  * The following fields will be set in the frame before this callback is
2592  * called:
2593  * - format
2594  * - width, height (video only)
2595  * - sample_rate, channel_layout, nb_samples (audio only)
2596  * Their values may differ from the corresponding values in
2597  * AVCodecContext. This callback must use the frame values, not the codec
2598  * context values, to calculate the required buffer size.
2599  *
2600  * This callback must fill the following fields in the frame:
2601  * - data[]
2602  * - linesize[]
2603  * - extended_data:
2604  * * if the data is planar audio with more than 8 channels, then this
2605  * callback must allocate and fill extended_data to contain all pointers
2606  * to all data planes. data[] must hold as many pointers as it can.
2607  * extended_data must be allocated with av_malloc() and will be freed in
2608  * av_frame_unref().
2609  * * otherwise extended_data must point to data
2610  * - buf[] must contain one or more pointers to AVBufferRef structures. Each of
2611  * the frame's data and extended_data pointers must be contained in these. That
2612  * is, one AVBufferRef for each allocated chunk of memory, not necessarily one
2613  * AVBufferRef per data[] entry. See: av_buffer_create(), av_buffer_alloc(),
2614  * and av_buffer_ref().
2615  * - extended_buf and nb_extended_buf must be allocated with av_malloc() by
2616  * this callback and filled with the extra buffers if there are more
2617  * buffers than buf[] can hold. extended_buf will be freed in
2618  * av_frame_unref().
2619  *
2620  * If AV_CODEC_CAP_DR1 is not set then get_buffer2() must call
2621  * avcodec_default_get_buffer2() instead of providing buffers allocated by
2622  * some other means.
2623  *
2624  * Each data plane must be aligned to the maximum required by the target
2625  * CPU.
2626  *
2627  * @see avcodec_default_get_buffer2()
2628  *
2629  * Video:
2630  *
2631  * If AV_GET_BUFFER_FLAG_REF is set in flags then the frame may be reused
2632  * (read and/or written to if it is writable) later by libavcodec.
2633  *
2634  * avcodec_align_dimensions2() should be used to find the required width and
2635  * height, as they normally need to be rounded up to the next multiple of 16.
2636  *
2637  * Some decoders do not support linesizes changing between frames.
2638  *
2639  * If frame multithreading is used and thread_safe_callbacks is set,
2640  * this callback may be called from a different thread, but not from more
2641  * than one at once. Does not need to be reentrant.
2642  *
2643  * @see avcodec_align_dimensions2()
2644  *
2645  * Audio:
2646  *
2647  * Decoders request a buffer of a particular size by setting
2648  * AVFrame.nb_samples prior to calling get_buffer2(). The decoder may,
2649  * however, utilize only part of the buffer by setting AVFrame.nb_samples
2650  * to a smaller value in the output frame.
2651  *
2652  * As a convenience, av_samples_get_buffer_size() and
2653  * av_samples_fill_arrays() in libavutil may be used by custom get_buffer2()
2654  * functions to find the required data size and to fill data pointers and
2655  * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
2656  * since all planes must be the same size.
2657  *
2658  * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
2659  *
2660  * - encoding: unused
2661  * - decoding: Set by libavcodec, user can override.
2662  */
2664 
2665  /**
2666  * If non-zero, the decoded audio and video frames returned from
2667  * avcodec_decode_video2() and avcodec_decode_audio4() are reference-counted
2668  * and are valid indefinitely. The caller must free them with
2669  * av_frame_unref() when they are not needed anymore.
2670  * Otherwise, the decoded frames must not be freed by the caller and are
2671  * only valid until the next decode call.
2672  *
2673  * This is always automatically enabled if avcodec_receive_frame() is used.
2674  *
2675  * - encoding: unused
2676  * - decoding: set by the caller before avcodec_open2().
2677  */
2679 
2680  /* - encoding parameters */
2681  float qcompress; ///< amount of qscale change between easy & hard scenes (0.0-1.0)
2682  float qblur; ///< amount of qscale smoothing over time (0.0-1.0)
2683 
2684  /**
2685  * minimum quantizer
2686  * - encoding: Set by user.
2687  * - decoding: unused
2688  */
2689  int qmin;
2690 
2691  /**
2692  * maximum quantizer
2693  * - encoding: Set by user.
2694  * - decoding: unused
2695  */
2696  int qmax;
2697 
2698  /**
2699  * maximum quantizer difference between frames
2700  * - encoding: Set by user.
2701  * - decoding: unused
2702  */
2704 
2705 #if FF_API_MPV_OPT
2706  /**
2707  * @deprecated use encoder private options instead
2708  */
2710  float rc_qsquish;
2711 
2716 #endif
2717 
2718  /**
2719  * decoder bitstream buffer size
2720  * - encoding: Set by user.
2721  * - decoding: unused
2722  */
2724 
2725  /**
2726  * ratecontrol override, see RcOverride
2727  * - encoding: Allocated/set/freed by user.
2728  * - decoding: unused
2729  */
2732 
2733 #if FF_API_MPV_OPT
2734  /**
2735  * @deprecated use encoder private options instead
2736  */
2738  const char *rc_eq;
2739 #endif
2740 
2741  /**
2742  * maximum bitrate
2743  * - encoding: Set by user.
2744  * - decoding: Set by user, may be overwritten by libavcodec.
2745  */
2746  int64_t rc_max_rate;
2747 
2748  /**
2749  * minimum bitrate
2750  * - encoding: Set by user.
2751  * - decoding: unused
2752  */
2753  int64_t rc_min_rate;
2754 
2755 #if FF_API_MPV_OPT
2756  /**
2757  * @deprecated use encoder private options instead
2758  */
2761 
2764 #endif
2765 
2766  /**
2767  * Ratecontrol attempt to use, at maximum, <value> of what can be used without an underflow.
2768  * - encoding: Set by user.
2769  * - decoding: unused.
2770  */
2772 
2773  /**
2774  * Ratecontrol attempt to use, at least, <value> times the amount needed to prevent a vbv overflow.
2775  * - encoding: Set by user.
2776  * - decoding: unused.
2777  */
2779 
2780  /**
2781  * Number of bits which should be loaded into the rc buffer before decoding starts.
2782  * - encoding: Set by user.
2783  * - decoding: unused
2784  */
2786 
2787 #if FF_API_CODER_TYPE
2788 #define FF_CODER_TYPE_VLC 0
2789 #define FF_CODER_TYPE_AC 1
2790 #define FF_CODER_TYPE_RAW 2
2791 #define FF_CODER_TYPE_RLE 3
2792 #if FF_API_UNUSED_MEMBERS
2793 #define FF_CODER_TYPE_DEFLATE 4
2794 #endif /* FF_API_UNUSED_MEMBERS */
2795  /**
2796  * @deprecated use encoder private options instead
2797  */
2800 #endif /* FF_API_CODER_TYPE */
2801 
2802 #if FF_API_PRIVATE_OPT
2803  /** @deprecated use encoder private options instead */
2806 #endif
2807 
2808 #if FF_API_MPV_OPT
2809  /**
2810  * @deprecated use encoder private options instead
2811  */
2813  int lmin;
2814 
2815  /**
2816  * @deprecated use encoder private options instead
2817  */
2819  int lmax;
2820 #endif
2821 
2822 #if FF_API_PRIVATE_OPT
2823  /** @deprecated use encoder private options instead */
2826 
2827  /** @deprecated use encoder private options instead */
2830 
2831  /** @deprecated use encoder private options instead */
2834 
2835  /** @deprecated use encoder private options instead */
2838 #endif /* FF_API_PRIVATE_OPT */
2839 
2840  /**
2841  * trellis RD quantization
2842  * - encoding: Set by user.
2843  * - decoding: unused
2844  */
2845  int trellis;
2846 
2847 #if FF_API_PRIVATE_OPT
2848  /** @deprecated use encoder private options instead */
2851 
2852  /** @deprecated use encoder private options instead */
2855 
2856  /** @deprecated use encoder private options instead */
2859 #endif
2860 
2861 #if FF_API_RTP_CALLBACK
2862  /**
2863  * @deprecated unused
2864  */
2865  /* The RTP callback: This function is called */
2866  /* every time the encoder has a packet to send. */
2867  /* It depends on the encoder if the data starts */
2868  /* with a Start Code (it should). H.263 does. */
2869  /* mb_nb contains the number of macroblocks */
2870  /* encoded in the RTP payload. */
2872  void (*rtp_callback)(struct AVCodecContext *avctx, void *data, int size, int mb_nb);
2873 #endif
2874 
2875 #if FF_API_PRIVATE_OPT
2876  /** @deprecated use encoder private options instead */
2878  int rtp_payload_size; /* The size of the RTP payload: the coder will */
2879  /* do its best to deliver a chunk with size */
2880  /* below rtp_payload_size, the chunk will start */
2881  /* with a start code on some codecs like H.263. */
2882  /* This doesn't take account of any particular */
2883  /* headers inside the transmitted RTP payload. */
2884 #endif
2885 
2886 #if FF_API_STAT_BITS
2887  /* statistics, used for 2-pass encoding */
2889  int mv_bits;
2897  int i_count;
2899  int p_count;
2904 
2905  /** @deprecated this field is unused */
2908 #endif
2909 
2910  /**
2911  * pass1 encoding statistics output buffer
2912  * - encoding: Set by libavcodec.
2913  * - decoding: unused
2914  */
2915  char *stats_out;
2916 
2917  /**
2918  * pass2 encoding statistics input buffer
2919  * Concatenated stuff from stats_out of pass1 should be placed here.
2920  * - encoding: Allocated/set/freed by user.
2921  * - decoding: unused
2922  */
2923  char *stats_in;
2924 
2925  /**
2926  * Work around bugs in encoders which sometimes cannot be detected automatically.
2927  * - encoding: Set by user
2928  * - decoding: Set by user
2929  */
2931 #define FF_BUG_AUTODETECT 1 ///< autodetection
2932 #if FF_API_OLD_MSMPEG4
2933 #define FF_BUG_OLD_MSMPEG4 2
2934 #endif
2935 #define FF_BUG_XVID_ILACE 4
2936 #define FF_BUG_UMP4 8
2937 #define FF_BUG_NO_PADDING 16
2938 #define FF_BUG_AMV 32
2939 #if FF_API_AC_VLC
2940 #define FF_BUG_AC_VLC 0 ///< Will be removed, libavcodec can now handle these non-compliant files by default.
2941 #endif
2942 #define FF_BUG_QPEL_CHROMA 64
2943 #define FF_BUG_STD_QPEL 128
2944 #define FF_BUG_QPEL_CHROMA2 256
2945 #define FF_BUG_DIRECT_BLOCKSIZE 512
2946 #define FF_BUG_EDGE 1024
2947 #define FF_BUG_HPEL_CHROMA 2048
2948 #define FF_BUG_DC_CLIP 4096
2949 #define FF_BUG_MS 8192 ///< Work around various bugs in Microsoft's broken decoders.
2950 #define FF_BUG_TRUNCATED 16384
2951 #define FF_BUG_IEDGE 32768
2952 
2953  /**
2954  * strictly follow the standard (MPEG-4, ...).
2955  * - encoding: Set by user.
2956  * - decoding: Set by user.
2957  * Setting this to STRICT or higher means the encoder and decoder will
2958  * generally do stupid things, whereas setting it to unofficial or lower
2959  * will mean the encoder might produce output that is not supported by all
2960  * spec-compliant decoders. Decoders don't differentiate between normal,
2961  * unofficial and experimental (that is, they always try to decode things
2962  * when they can) unless they are explicitly asked to behave stupidly
2963  * (=strictly conform to the specs)
2964  */
2966 #define FF_COMPLIANCE_VERY_STRICT 2 ///< Strictly conform to an older more strict version of the spec or reference software.
2967 #define FF_COMPLIANCE_STRICT 1 ///< Strictly conform to all the things in the spec no matter what consequences.
2968 #define FF_COMPLIANCE_NORMAL 0
2969 #define FF_COMPLIANCE_UNOFFICIAL -1 ///< Allow unofficial extensions
2970 #define FF_COMPLIANCE_EXPERIMENTAL -2 ///< Allow nonstandardized experimental things.
2971 
2972  /**
2973  * error concealment flags
2974  * - encoding: unused
2975  * - decoding: Set by user.
2976  */
2978 #define FF_EC_GUESS_MVS 1
2979 #define FF_EC_DEBLOCK 2
2980 #define FF_EC_FAVOR_INTER 256
2981 
2982  /**
2983  * debug
2984  * - encoding: Set by user.
2985  * - decoding: Set by user.
2986  */
2987  int debug;
2988 #define FF_DEBUG_PICT_INFO 1
2989 #define FF_DEBUG_RC 2
2990 #define FF_DEBUG_BITSTREAM 4
2991 #define FF_DEBUG_MB_TYPE 8
2992 #define FF_DEBUG_QP 16
2993 #if FF_API_DEBUG_MV
2994 /**
2995  * @deprecated this option does nothing
2996  */
2997 #define FF_DEBUG_MV 32
2998 #endif
2999 #define FF_DEBUG_DCT_COEFF 0x00000040
3000 #define FF_DEBUG_SKIP 0x00000080
3001 #define FF_DEBUG_STARTCODE 0x00000100
3002 #if FF_API_UNUSED_MEMBERS
3003 #define FF_DEBUG_PTS 0x00000200
3004 #endif /* FF_API_UNUSED_MEMBERS */
3005 #define FF_DEBUG_ER 0x00000400
3006 #define FF_DEBUG_MMCO 0x00000800
3007 #define FF_DEBUG_BUGS 0x00001000
3008 #if FF_API_DEBUG_MV
3009 #define FF_DEBUG_VIS_QP 0x00002000
3010 #define FF_DEBUG_VIS_MB_TYPE 0x00004000
3011 #endif
3012 #define FF_DEBUG_BUFFERS 0x00008000
3013 #define FF_DEBUG_THREADS 0x00010000
3014 #define FF_DEBUG_GREEN_MD 0x00800000
3015 #define FF_DEBUG_NOMC 0x01000000
3016 
3017 #if FF_API_DEBUG_MV
3018  /**
3019  * debug
3020  * - encoding: Set by user.
3021  * - decoding: Set by user.
3022  */
3024 #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 // visualize forward predicted MVs of P-frames
3025 #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 // visualize forward predicted MVs of B-frames
3026 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 // visualize backward predicted MVs of B-frames
3027 #endif
3028 
3029  /**
3030  * Error recognition; may misdetect some more or less valid parts as errors.
3031  * - encoding: unused
3032  * - decoding: Set by user.
3033  */
3035 
3036 /**
3037  * Verify checksums embedded in the bitstream (could be of either encoded or
3038  * decoded data, depending on the codec) and print an error message on mismatch.
3039  * If AV_EF_EXPLODE is also set, a mismatching checksum will result in the
3040  * decoder returning an error.
3041  */
3042 #define AV_EF_CRCCHECK (1<<0)
3043 #define AV_EF_BITSTREAM (1<<1) ///< detect bitstream specification deviations
3044 #define AV_EF_BUFFER (1<<2) ///< detect improper bitstream length
3045 #define AV_EF_EXPLODE (1<<3) ///< abort decoding on minor error detection
3046 
3047 #define AV_EF_IGNORE_ERR (1<<15) ///< ignore errors and continue
3048 #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
3049 #define AV_EF_COMPLIANT (1<<17) ///< consider all spec non compliances as errors
3050 #define AV_EF_AGGRESSIVE (1<<18) ///< consider things that a sane encoder should not do as an error
3051 
3052 
3053  /**
3054  * opaque 64-bit number (generally a PTS) that will be reordered and
3055  * output in AVFrame.reordered_opaque
3056  * - encoding: unused
3057  * - decoding: Set by user.
3058  */
3060 
3061  /**
3062  * Hardware accelerator in use
3063  * - encoding: unused.
3064  * - decoding: Set by libavcodec
3065  */
3067 
3068  /**
3069  * Hardware accelerator context.
3070  * For some hardware accelerators, a global context needs to be
3071  * provided by the user. In that case, this holds display-dependent
3072  * data FFmpeg cannot instantiate itself. Please refer to the
3073  * FFmpeg HW accelerator documentation to know how to fill this
3074  * is. e.g. for VA API, this is a struct vaapi_context.
3075  * - encoding: unused
3076  * - decoding: Set by user
3077  */
3079 
3080  /**
3081  * error
3082  * - encoding: Set by libavcodec if flags & AV_CODEC_FLAG_PSNR.
3083  * - decoding: unused
3084  */
3086 
3087  /**
3088  * DCT algorithm, see FF_DCT_* below
3089  * - encoding: Set by user.
3090  * - decoding: unused
3091  */
3093 #define FF_DCT_AUTO 0
3094 #define FF_DCT_FASTINT 1
3095 #define FF_DCT_INT 2
3096 #define FF_DCT_MMX 3
3097 #define FF_DCT_ALTIVEC 5
3098 #define FF_DCT_FAAN 6
3099 
3100  /**
3101  * IDCT algorithm, see FF_IDCT_* below.
3102  * - encoding: Set by user.
3103  * - decoding: Set by user.
3104  */
3106 #define FF_IDCT_AUTO 0
3107 #define FF_IDCT_INT 1
3108 #define FF_IDCT_SIMPLE 2
3109 #define FF_IDCT_SIMPLEMMX 3
3110 #define FF_IDCT_ARM 7
3111 #define FF_IDCT_ALTIVEC 8
3112 #if FF_API_ARCH_SH4
3113 #define FF_IDCT_SH4 9
3114 #endif
3115 #define FF_IDCT_SIMPLEARM 10
3116 #if FF_API_UNUSED_MEMBERS
3117 #define FF_IDCT_IPP 13
3118 #endif /* FF_API_UNUSED_MEMBERS */
3119 #define FF_IDCT_XVID 14
3120 #if FF_API_IDCT_XVIDMMX
3121 #define FF_IDCT_XVIDMMX 14
3122 #endif /* FF_API_IDCT_XVIDMMX */
3123 #define FF_IDCT_SIMPLEARMV5TE 16
3124 #define FF_IDCT_SIMPLEARMV6 17
3125 #if FF_API_ARCH_SPARC
3126 #define FF_IDCT_SIMPLEVIS 18
3127 #endif
3128 #define FF_IDCT_FAAN 20
3129 #define FF_IDCT_SIMPLENEON 22
3130 #if FF_API_ARCH_ALPHA
3131 #define FF_IDCT_SIMPLEALPHA 23
3132 #endif
3133 #define FF_IDCT_SIMPLEAUTO 128
3134 
3135  /**
3136  * bits per sample/pixel from the demuxer (needed for huffyuv).
3137  * - encoding: Set by libavcodec.
3138  * - decoding: Set by user.
3139  */
3141 
3142  /**
3143  * Bits per sample/pixel of internal libavcodec pixel/sample format.
3144  * - encoding: set by user.
3145  * - decoding: set by libavcodec.
3146  */
3148 
3149 #if FF_API_LOWRES
3150  /**
3151  * low resolution decoding, 1-> 1/2 size, 2->1/4 size
3152  * - encoding: unused
3153  * - decoding: Set by user.
3154  */
3155  int lowres;
3156 #endif
3157 
3158 #if FF_API_CODED_FRAME
3159  /**
3160  * the picture in the bitstream
3161  * - encoding: Set by libavcodec.
3162  * - decoding: unused
3163  *
3164  * @deprecated use the quality factor packet side data instead
3165  */
3167 #endif
3168 
3169  /**
3170  * thread count
3171  * is used to decide how many independent tasks should be passed to execute()
3172  * - encoding: Set by user.
3173  * - decoding: Set by user.
3174  */
3176 
3177  /**
3178  * Which multithreading methods to use.
3179  * Use of FF_THREAD_FRAME will increase decoding delay by one frame per thread,
3180  * so clients which cannot provide future frames should not use it.
3181  *
3182  * - encoding: Set by user, otherwise the default is used.
3183  * - decoding: Set by user, otherwise the default is used.
3184  */
3186 #define FF_THREAD_FRAME 1 ///< Decode more than one frame at once
3187 #define FF_THREAD_SLICE 2 ///< Decode more than one part of a single frame at once
3188 
3189  /**
3190  * Which multithreading methods are in use by the codec.
3191  * - encoding: Set by libavcodec.
3192  * - decoding: Set by libavcodec.
3193  */
3195 
3196  /**
3197  * Set by the client if its custom get_buffer() callback can be called
3198  * synchronously from another thread, which allows faster multithreaded decoding.
3199  * draw_horiz_band() will be called from other threads regardless of this setting.
3200  * Ignored if the default get_buffer() is used.
3201  * - encoding: Set by user.
3202  * - decoding: Set by user.
3203  */
3205 
3206  /**
3207  * The codec may call this to execute several independent things.
3208  * It will return only after finishing all tasks.
3209  * The user may replace this with some multithreaded implementation,
3210  * the default implementation will execute the parts serially.
3211  * @param count the number of things to execute
3212  * - encoding: Set by libavcodec, user can override.
3213  * - decoding: Set by libavcodec, user can override.
3214  */
3215  int (*execute)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size);
3216 
3217  /**
3218  * The codec may call this to execute several independent things.
3219  * It will return only after finishing all tasks.
3220  * The user may replace this with some multithreaded implementation,
3221  * the default implementation will execute the parts serially.
3222  * Also see avcodec_thread_init and e.g. the --enable-pthread configure option.
3223  * @param c context passed also to func
3224  * @param count the number of things to execute
3225  * @param arg2 argument passed unchanged to func
3226  * @param ret return values of executed functions, must have space for "count" values. May be NULL.
3227  * @param func function that will be called count times, with jobnr from 0 to count-1.
3228  * threadnr will be in the range 0 to c->thread_count-1 < MAX_THREADS and so that no
3229  * two instances of func executing at the same time will have the same threadnr.
3230  * @return always 0 currently, but code should handle a future improvement where when any call to func
3231  * returns < 0 no further calls to func may be done and < 0 is returned.
3232  * - encoding: Set by libavcodec, user can override.
3233  * - decoding: Set by libavcodec, user can override.
3234  */
3235  int (*execute2)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count);
3236 
3237  /**
3238  * noise vs. sse weight for the nsse comparison function
3239  * - encoding: Set by user.
3240  * - decoding: unused
3241  */
3243 
3244  /**
3245  * profile
3246  * - encoding: Set by user.
3247  * - decoding: Set by libavcodec.
3248  */
3249  int profile;
3250 #define FF_PROFILE_UNKNOWN -99
3251 #define FF_PROFILE_RESERVED -100
3252 
3253 #define FF_PROFILE_AAC_MAIN 0
3254 #define FF_PROFILE_AAC_LOW 1
3255 #define FF_PROFILE_AAC_SSR 2
3256 #define FF_PROFILE_AAC_LTP 3
3257 #define FF_PROFILE_AAC_HE 4
3258 #define FF_PROFILE_AAC_HE_V2 28
3259 #define FF_PROFILE_AAC_LD 22
3260 #define FF_PROFILE_AAC_ELD 38
3261 #define FF_PROFILE_MPEG2_AAC_LOW 128
3262 #define FF_PROFILE_MPEG2_AAC_HE 131
3263 
3264 #define FF_PROFILE_DNXHD 0
3265 #define FF_PROFILE_DNXHR_LB 1
3266 #define FF_PROFILE_DNXHR_SQ 2
3267 #define FF_PROFILE_DNXHR_HQ 3
3268 #define FF_PROFILE_DNXHR_HQX 4
3269 #define FF_PROFILE_DNXHR_444 5
3270 
3271 #define FF_PROFILE_DTS 20
3272 #define FF_PROFILE_DTS_ES 30
3273 #define FF_PROFILE_DTS_96_24 40
3274 #define FF_PROFILE_DTS_HD_HRA 50
3275 #define FF_PROFILE_DTS_HD_MA 60
3276 #define FF_PROFILE_DTS_EXPRESS 70
3277 
3278 #define FF_PROFILE_MPEG2_422 0
3279 #define FF_PROFILE_MPEG2_HIGH 1
3280 #define FF_PROFILE_MPEG2_SS 2
3281 #define FF_PROFILE_MPEG2_SNR_SCALABLE 3
3282 #define FF_PROFILE_MPEG2_MAIN 4
3283 #define FF_PROFILE_MPEG2_SIMPLE 5
3284 
3285 #define FF_PROFILE_H264_CONSTRAINED (1<<9) // 8+1; constraint_set1_flag
3286 #define FF_PROFILE_H264_INTRA (1<<11) // 8+3; constraint_set3_flag
3287 
3288 #define FF_PROFILE_H264_BASELINE 66
3289 #define FF_PROFILE_H264_CONSTRAINED_BASELINE (66|FF_PROFILE_H264_CONSTRAINED)
3290 #define FF_PROFILE_H264_MAIN 77
3291 #define FF_PROFILE_H264_EXTENDED 88
3292 #define FF_PROFILE_H264_HIGH 100
3293 #define FF_PROFILE_H264_HIGH_10 110
3294 #define FF_PROFILE_H264_HIGH_10_INTRA (110|FF_PROFILE_H264_INTRA)
3295 #define FF_PROFILE_H264_MULTIVIEW_HIGH 118
3296 #define FF_PROFILE_H264_HIGH_422 122
3297 #define FF_PROFILE_H264_HIGH_422_INTRA (122|FF_PROFILE_H264_INTRA)
3298 #define FF_PROFILE_H264_STEREO_HIGH 128
3299 #define FF_PROFILE_H264_HIGH_444 144
3300 #define FF_PROFILE_H264_HIGH_444_PREDICTIVE 244
3301 #define FF_PROFILE_H264_HIGH_444_INTRA (244|FF_PROFILE_H264_INTRA)
3302 #define FF_PROFILE_H264_CAVLC_444 44
3303 
3304 #define FF_PROFILE_VC1_SIMPLE 0
3305 #define FF_PROFILE_VC1_MAIN 1
3306 #define FF_PROFILE_VC1_COMPLEX 2
3307 #define FF_PROFILE_VC1_ADVANCED 3
3308 
3309 #define FF_PROFILE_MPEG4_SIMPLE 0
3310 #define FF_PROFILE_MPEG4_SIMPLE_SCALABLE 1
3311 #define FF_PROFILE_MPEG4_CORE 2
3312 #define FF_PROFILE_MPEG4_MAIN 3
3313 #define FF_PROFILE_MPEG4_N_BIT 4
3314 #define FF_PROFILE_MPEG4_SCALABLE_TEXTURE 5
3315 #define FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION 6
3316 #define FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE 7
3317 #define FF_PROFILE_MPEG4_HYBRID 8
3318 #define FF_PROFILE_MPEG4_ADVANCED_REAL_TIME 9
3319 #define FF_PROFILE_MPEG4_CORE_SCALABLE 10
3320 #define FF_PROFILE_MPEG4_ADVANCED_CODING 11
3321 #define FF_PROFILE_MPEG4_ADVANCED_CORE 12
3322 #define FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE 13
3323 #define FF_PROFILE_MPEG4_SIMPLE_STUDIO 14
3324 #define FF_PROFILE_MPEG4_ADVANCED_SIMPLE 15
3325 
3326 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_0 1
3327 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_1 2
3328 #define FF_PROFILE_JPEG2000_CSTREAM_NO_RESTRICTION 32768
3329 #define FF_PROFILE_JPEG2000_DCINEMA_2K 3
3330 #define FF_PROFILE_JPEG2000_DCINEMA_4K 4
3331 
3332 #define FF_PROFILE_VP9_0 0
3333 #define FF_PROFILE_VP9_1 1
3334 #define FF_PROFILE_VP9_2 2
3335 #define FF_PROFILE_VP9_3 3
3336 
3337 #define FF_PROFILE_HEVC_MAIN 1
3338 #define FF_PROFILE_HEVC_MAIN_10 2
3339 #define FF_PROFILE_HEVC_MAIN_STILL_PICTURE 3
3340 #define FF_PROFILE_HEVC_REXT 4
3341 
3342  /**
3343  * level
3344  * - encoding: Set by user.
3345  * - decoding: Set by libavcodec.
3346  */
3347  int level;
3348 #define FF_LEVEL_UNKNOWN -99
3349 
3350  /**
3351  * Skip loop filtering for selected frames.
3352  * - encoding: unused
3353  * - decoding: Set by user.
3354  */
3356 
3357  /**
3358  * Skip IDCT/dequantization for selected frames.
3359  * - encoding: unused
3360  * - decoding: Set by user.
3361  */
3363 
3364  /**
3365  * Skip decoding for selected frames.
3366  * - encoding: unused
3367  * - decoding: Set by user.
3368  */
3370 
3371  /**
3372  * Header containing style information for text subtitles.
3373  * For SUBTITLE_ASS subtitle type, it should contain the whole ASS
3374  * [Script Info] and [V4+ Styles] section, plus the [Events] line and
3375  * the Format line following. It shouldn't include any Dialogue line.
3376  * - encoding: Set/allocated/freed by user (before avcodec_open2())
3377  * - decoding: Set/allocated/freed by libavcodec (by avcodec_open2())
3378  */
3381 
3382 #if FF_API_ERROR_RATE
3383  /**
3384  * @deprecated use the 'error_rate' private AVOption of the mpegvideo
3385  * encoders
3386  */
3389 #endif
3390 
3391 #if FF_API_VBV_DELAY
3392  /**
3393  * VBV delay coded in the last frame (in periods of a 27 MHz clock).
3394  * Used for compliant TS muxing.
3395  * - encoding: Set by libavcodec.
3396  * - decoding: unused.
3397  * @deprecated this value is now exported as a part of
3398  * AV_PKT_DATA_CPB_PROPERTIES packet side data
3399  */
3401  uint64_t vbv_delay;
3402 #endif
3403 
3404 #if FF_API_SIDEDATA_ONLY_PKT
3405  /**
3406  * Encoding only and set by default. Allow encoders to output packets
3407  * that do not contain any encoded data, only side data.
3408  *
3409  * Some encoders need to output such packets, e.g. to update some stream
3410  * parameters at the end of encoding.
3411  *
3412  * @deprecated this field disables the default behaviour and
3413  * it is kept only for compatibility.
3414  */
3417 #endif
3418 
3419  /**
3420  * Audio only. The number of "priming" samples (padding) inserted by the
3421  * encoder at the beginning of the audio. I.e. this number of leading
3422  * decoded samples must be discarded by the caller to get the original audio
3423  * without leading padding.
3424  *
3425  * - decoding: unused
3426  * - encoding: Set by libavcodec. The timestamps on the output packets are
3427  * adjusted by the encoder so that they always refer to the
3428  * first sample of the data actually contained in the packet,
3429  * including any added padding. E.g. if the timebase is
3430  * 1/samplerate and the timestamp of the first input sample is
3431  * 0, the timestamp of the first output packet will be
3432  * -initial_padding.
3433  */
3435 
3436  /**
3437  * - decoding: For codecs that store a framerate value in the compressed
3438  * bitstream, the decoder may export it here. { 0, 1} when
3439  * unknown.
3440  * - encoding: May be used to signal the framerate of CFR content to an
3441  * encoder.
3442  */
3444 
3445  /**
3446  * Nominal unaccelerated pixel format, see AV_PIX_FMT_xxx.
3447  * - encoding: unused.
3448  * - decoding: Set by libavcodec before calling get_format()
3449  */
3451 
3452  /**
3453  * Timebase in which pkt_dts/pts and AVPacket.dts/pts are.
3454  * - encoding unused.
3455  * - decoding set by user.
3456  */
3458 
3459  /**
3460  * AVCodecDescriptor
3461  * - encoding: unused.
3462  * - decoding: set by libavcodec.
3463  */
3465 
3466 #if !FF_API_LOWRES
3467  /**
3468  * low resolution decoding, 1-> 1/2 size, 2->1/4 size
3469  * - encoding: unused
3470  * - decoding: Set by user.
3471  */
3472  int lowres;
3473 #endif
3474 
3475  /**
3476  * Current statistics for PTS correction.
3477  * - decoding: maintained and used by libavcodec, not intended to be used by user apps
3478  * - encoding: unused
3479  */
3480  int64_t pts_correction_num_faulty_pts; /// Number of incorrect PTS values so far
3481  int64_t pts_correction_num_faulty_dts; /// Number of incorrect DTS values so far
3482  int64_t pts_correction_last_pts; /// PTS of the last frame
3483  int64_t pts_correction_last_dts; /// DTS of the last frame
3484 
3485  /**
3486  * Character encoding of the input subtitles file.
3487  * - decoding: set by user
3488  * - encoding: unused
3489  */
3491 
3492  /**
3493  * Subtitles character encoding mode. Formats or codecs might be adjusting
3494  * this setting (if they are doing the conversion themselves for instance).
3495  * - decoding: set by libavcodec
3496  * - encoding: unused
3497  */
3499 #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)
3500 #define FF_SUB_CHARENC_MODE_AUTOMATIC 0 ///< libavcodec will select the mode itself
3501 #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
3502 
3503  /**
3504  * Skip processing alpha if supported by codec.
3505  * Note that if the format uses pre-multiplied alpha (common with VP6,
3506  * and recommended due to better video quality/compression)
3507  * the image will look as if alpha-blended onto a black background.
3508  * However for formats that do not use pre-multiplied alpha
3509  * there might be serious artefacts (though e.g. libswscale currently
3510  * assumes pre-multiplied alpha anyway).
3511  *
3512  * - decoding: set by user
3513  * - encoding: unused
3514  */
3516 
3517  /**
3518  * Number of samples to skip after a discontinuity
3519  * - decoding: unused
3520  * - encoding: set by libavcodec
3521  */
3523 
3524 #if !FF_API_DEBUG_MV
3525  /**
3526  * debug motion vectors
3527  * - encoding: Set by user.
3528  * - decoding: Set by user.
3529  */
3530  int debug_mv;
3531 #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 //visualize forward predicted MVs of P frames
3532 #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 //visualize forward predicted MVs of B frames
3533 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
3534 #endif
3535 
3536  /**
3537  * custom intra quantization matrix
3538  * - encoding: Set by user, can be NULL.
3539  * - decoding: unused.
3540  */
3542 
3543  /**
3544  * dump format separator.
3545  * can be ", " or "\n " or anything else
3546  * - encoding: Set by user.
3547  * - decoding: Set by user.
3548  */
3550 
3551  /**
3552  * ',' separated list of allowed decoders.
3553  * If NULL then all are allowed
3554  * - encoding: unused
3555  * - decoding: set by user
3556  */
3558 
3559  /*
3560  * Properties of the stream that gets decoded
3561  * - encoding: unused
3562  * - decoding: set by libavcodec
3563  */
3564  unsigned properties;
3565 #define FF_CODEC_PROPERTY_LOSSLESS 0x00000001
3566 #define FF_CODEC_PROPERTY_CLOSED_CAPTIONS 0x00000002
3567 
3568  /**
3569  * Additional data associated with the entire coded stream.
3570  *
3571  * - decoding: unused
3572  * - encoding: may be set by libavcodec after avcodec_open2().
3573  */
3576 
3577  /**
3578  * A reference to the AVHWFramesContext describing the input (for encoding)
3579  * or output (decoding) frames. The reference is set by the caller and
3580  * afterwards owned (and freed) by libavcodec - it should never be read by
3581  * the caller after being set.
3582  *
3583  * - decoding: This field should be set by the caller from the get_format()
3584  * callback. The previous reference (if any) will always be
3585  * unreffed by libavcodec before the get_format() call.
3586  *
3587  * If the default get_buffer2() is used with a hwaccel pixel
3588  * format, then this AVHWFramesContext will be used for
3589  * allocating the frame buffers.
3590  *
3591  * - encoding: For hardware encoders configured to use a hwaccel pixel
3592  * format, this field should be set by the caller to a reference
3593  * to the AVHWFramesContext describing input frames.
3594  * AVHWFramesContext.format must be equal to
3595  * AVCodecContext.pix_fmt.
3596  *
3597  * This field should be set before avcodec_open2() is called.
3598  */
3600 
3601  /**
3602  * Control the form of AVSubtitle.rects[N]->ass
3603  * - decoding: set by user
3604  * - encoding: unused
3605  */
3607 #define FF_SUB_TEXT_FMT_ASS 0
3608 #if FF_API_ASS_TIMING
3609 #define FF_SUB_TEXT_FMT_ASS_WITH_TIMINGS 1
3610 #endif
3611 
3612  /**
3613  * Audio only. The amount of padding (in samples) appended by the encoder to
3614  * the end of the audio. I.e. this number of decoded samples must be
3615  * discarded by the caller from the end of the stream to get the original
3616  * audio without any trailing padding.
3617  *
3618  * - decoding: unused
3619  * - encoding: unused
3620  */
3622 
3623  /**
3624  * The number of pixels per image to maximally accept.
3625  *
3626  * - decoding: set by user
3627  * - encoding: set by user
3628  */
3629  int64_t max_pixels;
3630 
3631  /**
3632  * A reference to the AVHWDeviceContext describing the device which will
3633  * be used by a hardware encoder/decoder. The reference is set by the
3634  * caller and afterwards owned (and freed) by libavcodec.
3635  *
3636  * This should be used if either the codec device does not require
3637  * hardware frames or any that are used are to be allocated internally by
3638  * libavcodec. If the user wishes to supply any of the frames used as
3639  * encoder input or decoder output then hw_frames_ctx should be used
3640  * instead. When hw_frames_ctx is set in get_format() for a decoder, this
3641  * field will be ignored while decoding the associated stream segment, but
3642  * may again be used on a following one after another get_format() call.
3643  *
3644  * For both encoders and decoders this field should be set before
3645  * avcodec_open2() is called and must not be written to thereafter.
3646  *
3647  * Note that some decoders may require this field to be set initially in
3648  * order to support hw_frames_ctx at all - in that case, all frames
3649  * contexts used must be created on the same device.
3650  */
3652 
3653  /**
3654  * Bit set of AV_HWACCEL_FLAG_* flags, which affect hardware accelerated
3655  * decoding (if active).
3656  * - encoding: unused
3657  * - decoding: Set by user (either before avcodec_open2(), or in the
3658  * AVCodecContext.get_format callback)
3659  */
3661 
3662  /**
3663  * Video decoding only. Certain video codecs support cropping, meaning that
3664  * only a sub-rectangle of the decoded frame is intended for display. This
3665  * option controls how cropping is handled by libavcodec.
3666  *
3667  * When set to 1 (the default), libavcodec will apply cropping internally.
3668  * I.e. it will modify the output frame width/height fields and offset the
3669  * data pointers (only by as much as possible while preserving alignment, or
3670  * by the full amount if the AV_CODEC_FLAG_UNALIGNED flag is set) so that
3671  * the frames output by the decoder refer only to the cropped area. The
3672  * crop_* fields of the output frames will be zero.
3673  *
3674  * When set to 0, the width/height fields of the output frames will be set
3675  * to the coded dimensions and the crop_* fields will describe the cropping
3676  * rectangle. Applying the cropping is left to the caller.
3677  *
3678  * @warning When hardware acceleration with opaque output frames is used,
3679  * libavcodec is unable to apply cropping from the top/left border.
3680  *
3681  * @note when this option is set to zero, the width/height fields of the
3682  * AVCodecContext and output AVFrames have different meanings. The codec
3683  * context fields store display dimensions (with the coded dimensions in
3684  * coded_width/height), while the frame fields store the coded dimensions
3685  * (with the display dimensions being determined by the crop_* fields).
3686  */
3688 } AVCodecContext;
3689 
3692 
3695 
3696 unsigned av_codec_get_codec_properties(const AVCodecContext *avctx);
3697 
3698 int av_codec_get_lowres(const AVCodecContext *avctx);
3699 void av_codec_set_lowres(AVCodecContext *avctx, int val);
3700 
3701 int av_codec_get_seek_preroll(const AVCodecContext *avctx);
3702 void av_codec_set_seek_preroll(AVCodecContext *avctx, int val);
3703 
3704 uint16_t *av_codec_get_chroma_intra_matrix(const AVCodecContext *avctx);
3705 void av_codec_set_chroma_intra_matrix(AVCodecContext *avctx, uint16_t *val);
3706 
3707 /**
3708  * AVProfile.
3709  */
3710 typedef struct AVProfile {
3711  int profile;
3712  const char *name; ///< short name for the profile
3713 } AVProfile;
3714 
3715 typedef struct AVCodecDefault AVCodecDefault;
3716 
3717 struct AVSubtitle;
3718 
3719 /**
3720  * AVCodec.
3721  */
3722 typedef struct AVCodec {
3723  /**
3724  * Name of the codec implementation.
3725  * The name is globally unique among encoders and among decoders (but an
3726  * encoder and a decoder can share the same name).
3727  * This is the primary way to find a codec from the user perspective.
3728  */
3729  const char *name;
3730  /**
3731  * Descriptive name for the codec, meant to be more human readable than name.
3732  * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
3733  */
3734  const char *long_name;
3737  /**
3738  * Codec capabilities.
3739  * see AV_CODEC_CAP_*
3740  */
3742  const AVRational *supported_framerates; ///< array of supported framerates, or NULL if any, array is terminated by {0,0}
3743  const enum AVPixelFormat *pix_fmts; ///< array of supported pixel formats, or NULL if unknown, array is terminated by -1
3744  const int *supported_samplerates; ///< array of supported audio samplerates, or NULL if unknown, array is terminated by 0
3745  const enum AVSampleFormat *sample_fmts; ///< array of supported sample formats, or NULL if unknown, array is terminated by -1
3746  const uint64_t *channel_layouts; ///< array of support channel layouts, or NULL if unknown. array is terminated by 0
3747  uint8_t max_lowres; ///< maximum value for lowres supported by the decoder
3748  const AVClass *priv_class; ///< AVClass for the private context
3749  const AVProfile *profiles; ///< array of recognized profiles, or NULL if unknown, array is terminated by {FF_PROFILE_UNKNOWN}
3750 
3751  /*****************************************************************
3752  * No fields below this line are part of the public API. They
3753  * may not be used outside of libavcodec and can be changed and
3754  * removed at will.
3755  * New public fields should be added right above.
3756  *****************************************************************
3757  */
3759  struct AVCodec *next;
3760  /**
3761  * @name Frame-level threading support functions
3762  * @{
3763  */
3764  /**
3765  * If defined, called on thread contexts when they are created.
3766  * If the codec allocates writable tables in init(), re-allocate them here.
3767  * priv_data will be set to a copy of the original.
3768  */
3770  /**
3771  * Copy necessary context variables from a previous thread context to the current one.
3772  * If not defined, the next thread will start automatically; otherwise, the codec
3773  * must call ff_thread_finish_setup().
3774  *
3775  * dst and src will (rarely) point to the same context, in which case memcpy should be skipped.
3776  */
3778  /** @} */
3779 
3780  /**
3781  * Private codec-specific defaults.
3782  */
3784 
3785  /**
3786  * Initialize codec static data, called from avcodec_register().
3787  */
3788  void (*init_static_data)(struct AVCodec *codec);
3789 
3791  int (*encode_sub)(AVCodecContext *, uint8_t *buf, int buf_size,
3792  const struct AVSubtitle *sub);
3793  /**
3794  * Encode data to an AVPacket.
3795  *
3796  * @param avctx codec context
3797  * @param avpkt output AVPacket (may contain a user-provided buffer)
3798  * @param[in] frame AVFrame containing the raw data to be encoded
3799  * @param[out] got_packet_ptr encoder sets to 0 or 1 to indicate that a
3800  * non-empty packet was returned in avpkt.
3801  * @return 0 on success, negative error code on failure
3802  */
3803  int (*encode2)(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame,
3804  int *got_packet_ptr);
3805  int (*decode)(AVCodecContext *, void *outdata, int *outdata_size, AVPacket *avpkt);
3807  /**
3808  * Encode API with decoupled packet/frame dataflow. The API is the
3809  * same as the avcodec_ prefixed APIs (avcodec_send_frame() etc.), except
3810  * that:
3811  * - never called if the codec is closed or the wrong type,
3812  * - if AV_CODEC_CAP_DELAY is not set, drain frames are never sent,
3813  * - only one drain frame is ever passed down,
3814  */
3817 
3818  /**
3819  * Decode API with decoupled packet/frame dataflow. This function is called
3820  * to get one output frame. It should call ff_decode_get_packet() to obtain
3821  * input data.
3822  */
3824  /**
3825  * Flush buffers.
3826  * Will be called when seeking
3827  */
3829  /**
3830  * Internal codec capabilities.
3831  * See FF_CODEC_CAP_* in internal.h
3832  */
3834 
3835  /**
3836  * Decoding only, a comma-separated list of bitstream filters to apply to
3837  * packets before decoding.
3838  */
3839  const char *bsfs;
3840 } AVCodec;
3841 
3842 int av_codec_get_max_lowres(const AVCodec *codec);
3843 
3844 struct MpegEncContext;
3845 
3846 /**
3847  * @defgroup lavc_hwaccel AVHWAccel
3848  * @{
3849  */
3850 typedef struct AVHWAccel {
3851  /**
3852  * Name of the hardware accelerated codec.
3853  * The name is globally unique among encoders and among decoders (but an
3854  * encoder and a decoder can share the same name).
3855  */
3856  const char *name;
3857 
3858  /**
3859  * Type of codec implemented by the hardware accelerator.
3860  *
3861  * See AVMEDIA_TYPE_xxx
3862  */
3864 
3865  /**
3866  * Codec implemented by the hardware accelerator.
3867  *
3868  * See AV_CODEC_ID_xxx
3869  */
3871 
3872  /**
3873  * Supported pixel format.
3874  *
3875  * Only hardware accelerated formats are supported here.
3876  */
3878 
3879  /**
3880  * Hardware accelerated codec capabilities.
3881  * see HWACCEL_CODEC_CAP_*
3882  */
3884 
3885  /*****************************************************************
3886  * No fields below this line are part of the public API. They
3887  * may not be used outside of libavcodec and can be changed and
3888  * removed at will.
3889  * New public fields should be added right above.
3890  *****************************************************************
3891  */
3892  struct AVHWAccel *next;
3893 
3894  /**
3895  * Allocate a custom buffer
3896  */
3898 
3899  /**
3900  * Called at the beginning of each frame or field picture.
3901  *
3902  * Meaningful frame information (codec specific) is guaranteed to
3903  * be parsed at this point. This function is mandatory.
3904  *
3905  * Note that buf can be NULL along with buf_size set to 0.
3906  * Otherwise, this means the whole frame is available at this point.
3907  *
3908  * @param avctx the codec context
3909  * @param buf the frame data buffer base
3910  * @param buf_size the size of the frame in bytes
3911  * @return zero if successful, a negative value otherwise
3912  */
3913  int (*start_frame)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3914 
3915  /**
3916  * Callback for each slice.
3917  *
3918  * Meaningful slice information (codec specific) is guaranteed to
3919  * be parsed at this point. This function is mandatory.
3920  * The only exception is XvMC, that works on MB level.
3921  *
3922  * @param avctx the codec context
3923  * @param buf the slice data buffer base
3924  * @param buf_size the size of the slice in bytes
3925  * @return zero if successful, a negative value otherwise
3926  */
3927  int (*decode_slice)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3928 
3929  /**
3930  * Called at the end of each frame or field picture.
3931  *
3932  * The whole picture is parsed at this point and can now be sent
3933  * to the hardware accelerator. This function is mandatory.
3934  *
3935  * @param avctx the codec context
3936  * @return zero if successful, a negative value otherwise
3937  */
3939 
3940  /**
3941  * Size of per-frame hardware accelerator private data.
3942  *
3943  * Private data is allocated with av_mallocz() before
3944  * AVCodecContext.get_buffer() and deallocated after
3945  * AVCodecContext.release_buffer().
3946  */
3948 
3949  /**
3950  * Called for every Macroblock in a slice.
3951  *
3952  * XvMC uses it to replace the ff_mpv_reconstruct_mb().
3953  * Instead of decoding to raw picture, MB parameters are
3954  * stored in an array provided by the video driver.
3955  *
3956  * @param s the mpeg context
3957  */
3959 
3960  /**
3961  * Initialize the hwaccel private data.
3962  *
3963  * This will be called from ff_get_format(), after hwaccel and
3964  * hwaccel_context are set and the hwaccel private data in AVCodecInternal
3965  * is allocated.
3966  */
3968 
3969  /**
3970  * Uninitialize the hwaccel private data.
3971  *
3972  * This will be called from get_format() or avcodec_close(), after hwaccel
3973  * and hwaccel_context are already uninitialized.
3974  */
3976 
3977  /**
3978  * Size of the private data to allocate in
3979  * AVCodecInternal.hwaccel_priv_data.
3980  */
3982 
3983  /**
3984  * Internal hwaccel capabilities.
3985  */
3987 } AVHWAccel;
3988 
3989 /**
3990  * Hardware acceleration should be used for decoding even if the codec level
3991  * used is unknown or higher than the maximum supported level reported by the
3992  * hardware driver.
3993  *
3994  * It's generally a good idea to pass this flag unless you have a specific
3995  * reason not to, as hardware tends to under-report supported levels.
3996  */
3997 #define AV_HWACCEL_FLAG_IGNORE_LEVEL (1 << 0)
3998 
3999 /**
4000  * Hardware acceleration can output YUV pixel formats with a different chroma
4001  * sampling than 4:2:0 and/or other than 8 bits per component.
4002  */
4003 #define AV_HWACCEL_FLAG_ALLOW_HIGH_DEPTH (1 << 1)
4004 
4005 /**
4006  * Hardware acceleration should still be attempted for decoding when the
4007  * codec profile does not match the reported capabilities of the hardware.
4008  *
4009  * For example, this can be used to try to decode baseline profile H.264
4010  * streams in hardware - it will often succeed, because many streams marked
4011  * as baseline profile actually conform to constrained baseline profile.
4012  *
4013  * @warning If the stream is actually not supported then the behaviour is
4014  * undefined, and may include returning entirely incorrect output
4015  * while indicating success.
4016  */
4017 #define AV_HWACCEL_FLAG_ALLOW_PROFILE_MISMATCH (1 << 2)
4018 
4019 /**
4020  * @}
4021  */
4022 
4023 #if FF_API_AVPICTURE
4024 /**
4025  * @defgroup lavc_picture AVPicture
4026  *
4027  * Functions for working with AVPicture
4028  * @{
4029  */
4030 
4031 /**
4032  * Picture data structure.
4033  *
4034  * Up to four components can be stored into it, the last component is
4035  * alpha.
4036  * @deprecated use AVFrame or imgutils functions instead
4037  */
4038 typedef struct AVPicture {
4040  uint8_t *data[AV_NUM_DATA_POINTERS]; ///< pointers to the image data planes
4042  int linesize[AV_NUM_DATA_POINTERS]; ///< number of bytes per line
4043 } AVPicture;
4044 
4045 /**
4046  * @}
4047  */
4048 #endif
4049 
4052 
4053  SUBTITLE_BITMAP, ///< A bitmap, pict will be set
4054 
4055  /**
4056  * Plain text, the text field must be set by the decoder and is
4057  * authoritative. ass and pict fields may contain approximations.
4058  */
4060 
4061  /**
4062  * Formatted text, the ass field must be set by the decoder and is
4063  * authoritative. pict and text fields may contain approximations.
4064  */
4066 };
4067 
4068 #define AV_SUBTITLE_FLAG_FORCED 0x00000001
4069 
4070 typedef struct AVSubtitleRect {
4071  int x; ///< top left corner of pict, undefined when pict is not set
4072  int y; ///< top left corner of pict, undefined when pict is not set
4073  int w; ///< width of pict, undefined when pict is not set
4074  int h; ///< height of pict, undefined when pict is not set
4075  int nb_colors; ///< number of colors in pict, undefined when pict is not set
4076 
4077 #if FF_API_AVPICTURE
4078  /**
4079  * @deprecated unused
4080  */
4083 #endif
4084  /**
4085  * data+linesize for the bitmap of this subtitle.
4086  * Can be set for text/ass as well once they are rendered.
4087  */
4089  int linesize[4];
4090 
4092 
4093  char *text; ///< 0 terminated plain UTF-8 text
4094 
4095  /**
4096  * 0 terminated ASS/SSA compatible event line.
4097  * The presentation of this is unaffected by the other values in this
4098  * struct.
4099  */
4100  char *ass;
4101 
4102  int flags;
4103 } AVSubtitleRect;
4104 
4105 typedef struct AVSubtitle {
4106  uint16_t format; /* 0 = graphics */
4107  uint32_t start_display_time; /* relative to packet pts, in ms */
4108  uint32_t end_display_time; /* relative to packet pts, in ms */
4109  unsigned num_rects;
4111  int64_t pts; ///< Same as packet pts, in AV_TIME_BASE
4112 } AVSubtitle;
4113 
4114 /**
4115  * This struct describes the properties of an encoded stream.
4116  *
4117  * sizeof(AVCodecParameters) is not a part of the public ABI, this struct must
4118  * be allocated with avcodec_parameters_alloc() and freed with
4119  * avcodec_parameters_free().
4120  */
4121 typedef struct AVCodecParameters {
4122  /**
4123  * General type of the encoded data.
4124  */
4126  /**
4127  * Specific type of the encoded data (the codec used).
4128  */
4130  /**
4131  * Additional information about the codec (corresponds to the AVI FOURCC).
4132  */
4133  uint32_t codec_tag;
4134 
4135  /**
4136  * Extra binary data needed for initializing the decoder, codec-dependent.
4137  *
4138  * Must be allocated with av_malloc() and will be freed by
4139  * avcodec_parameters_free(). The allocated size of extradata must be at
4140  * least extradata_size + AV_INPUT_BUFFER_PADDING_SIZE, with the padding
4141  * bytes zeroed.
4142  */
4144  /**
4145  * Size of the extradata content in bytes.
4146  */
4148 
4149  /**
4150  * - video: the pixel format, the value corresponds to enum AVPixelFormat.
4151  * - audio: the sample format, the value corresponds to enum AVSampleFormat.
4152  */
4153  int format;
4154 
4155  /**
4156  * The average bitrate of the encoded data (in bits per second).
4157  */
4158  int64_t bit_rate;
4159 
4160  /**
4161  * The number of bits per sample in the codedwords.
4162  *
4163  * This is basically the bitrate per sample. It is mandatory for a bunch of
4164  * formats to actually decode them. It's the number of bits for one sample in
4165  * the actual coded bitstream.
4166  *
4167  * This could be for example 4 for ADPCM
4168  * For PCM formats this matches bits_per_raw_sample
4169  * Can be 0
4170  */
4172 
4173  /**
4174  * This is the number of valid bits in each output sample. If the
4175  * sample format has more bits, the least significant bits are additional
4176  * padding bits, which are always 0. Use right shifts to reduce the sample
4177  * to its actual size. For example, audio formats with 24 bit samples will
4178  * have bits_per_raw_sample set to 24, and format set to AV_SAMPLE_FMT_S32.
4179  * To get the original sample use "(int32_t)sample >> 8"."
4180  *
4181  * For ADPCM this might be 12 or 16 or similar
4182  * Can be 0
4183  */
4185 
4186  /**
4187  * Codec-specific bitstream restrictions that the stream conforms to.
4188  */
4189  int profile;
4190  int level;
4191 
4192  /**
4193  * Video only. The dimensions of the video frame in pixels.
4194  */
4195  int width;
4196  int height;
4197 
4198  /**
4199  * Video only. The aspect ratio (width / height) which a single pixel
4200  * should have when displayed.
4201  *
4202  * When the aspect ratio is unknown / undefined, the numerator should be
4203  * set to 0 (the denominator may have any value).
4204  */
4206 
4207  /**
4208  * Video only. The order of the fields in interlaced video.
4209  */
4211 
4212  /**
4213  * Video only. Additional colorspace characteristics.
4214  */
4220 
4221  /**
4222  * Video only. Number of delayed frames.
4223  */
4225 
4226  /**
4227  * Audio only. The channel layout bitmask. May be 0 if the channel layout is
4228  * unknown or unspecified, otherwise the number of bits set must be equal to
4229  * the channels field.
4230  */
4231  uint64_t channel_layout;
4232  /**
4233  * Audio only. The number of audio channels.
4234  */
4236  /**
4237  * Audio only. The number of audio samples per second.
4238  */
4240  /**
4241  * Audio only. The number of bytes per coded audio frame, required by some
4242  * formats.
4243  *
4244  * Corresponds to nBlockAlign in WAVEFORMATEX.
4245  */
4247  /**
4248  * Audio only. Audio frame size, if known. Required by some formats to be static.
4249  */
4251 
4252  /**
4253  * Audio only. The amount of padding (in samples) inserted by the encoder at
4254  * the beginning of the audio. I.e. this number of leading decoded samples
4255  * must be discarded by the caller to get the original audio without leading
4256  * padding.
4257  */
4259  /**
4260  * Audio only. The amount of padding (in samples) appended by the encoder to
4261  * the end of the audio. I.e. this number of decoded samples must be
4262  * discarded by the caller from the end of the stream to get the original
4263  * audio without any trailing padding.
4264  */
4266  /**
4267  * Audio only. Number of samples to skip after a discontinuity.
4268  */
4271 
4272 /**
4273  * If c is NULL, returns the first registered codec,
4274  * if c is non-NULL, returns the next registered codec after c,
4275  * or NULL if c is the last one.
4276  */
4277 AVCodec *av_codec_next(const AVCodec *c);
4278 
4279 /**
4280  * Return the LIBAVCODEC_VERSION_INT constant.
4281  */
4282 unsigned avcodec_version(void);
4283 
4284 /**
4285  * Return the libavcodec build-time configuration.
4286  */
4287 const char *avcodec_configuration(void);
4288 
4289 /**
4290  * Return the libavcodec license.
4291  */
4292 const char *avcodec_license(void);
4293 
4294 /**
4295  * Register the codec codec and initialize libavcodec.
4296  *
4297  * @warning either this function or avcodec_register_all() must be called
4298  * before any other libavcodec functions.
4299  *
4300  * @see avcodec_register_all()
4301  */
4302 void avcodec_register(AVCodec *codec);
4303 
4304 /**
4305  * Register all the codecs, parsers and bitstream filters which were enabled at
4306  * configuration time. If you do not call this function you can select exactly
4307  * which formats you want to support, by using the individual registration
4308  * functions.
4309  *
4310  * @see avcodec_register
4311  * @see av_register_codec_parser
4312  * @see av_register_bitstream_filter
4313  */
4314 void avcodec_register_all(void);
4315 
4316 /**
4317  * Allocate an AVCodecContext and set its fields to default values. The
4318  * resulting struct should be freed with avcodec_free_context().
4319  *
4320  * @param codec if non-NULL, allocate private data and initialize defaults
4321  * for the given codec. It is illegal to then call avcodec_open2()
4322  * with a different codec.
4323  * If NULL, then the codec-specific defaults won't be initialized,
4324  * which may result in suboptimal default settings (this is
4325  * important mainly for encoders, e.g. libx264).
4326  *
4327  * @return An AVCodecContext filled with default values or NULL on failure.
4328  */
4330 
4331 /**
4332  * Free the codec context and everything associated with it and write NULL to
4333  * the provided pointer.
4334  */
4335 void avcodec_free_context(AVCodecContext **avctx);
4336 
4337 #if FF_API_GET_CONTEXT_DEFAULTS
4338 /**
4339  * @deprecated This function should not be used, as closing and opening a codec
4340  * context multiple time is not supported. A new codec context should be
4341  * allocated for each new use.
4342  */
4344 #endif
4345 
4346 /**
4347  * Get the AVClass for AVCodecContext. It can be used in combination with
4348  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
4349  *
4350  * @see av_opt_find().
4351  */
4352 const AVClass *avcodec_get_class(void);
4353 
4354 #if FF_API_COPY_CONTEXT
4355 /**
4356  * Get the AVClass for AVFrame. It can be used in combination with
4357  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
4358  *
4359  * @see av_opt_find().
4360  */
4361 const AVClass *avcodec_get_frame_class(void);
4362 
4363 /**
4364  * Get the AVClass for AVSubtitleRect. It can be used in combination with
4365  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
4366  *
4367  * @see av_opt_find().
4368  */
4370 
4371 /**
4372  * Copy the settings of the source AVCodecContext into the destination
4373  * AVCodecContext. The resulting destination codec context will be
4374  * unopened, i.e. you are required to call avcodec_open2() before you
4375  * can use this AVCodecContext to decode/encode video/audio data.
4376  *
4377  * @param dest target codec context, should be initialized with
4378  * avcodec_alloc_context3(NULL), but otherwise uninitialized
4379  * @param src source codec context
4380  * @return AVERROR() on error (e.g. memory allocation error), 0 on success
4381  *
4382  * @deprecated The semantics of this function are ill-defined and it should not
4383  * be used. If you need to transfer the stream parameters from one codec context
4384  * to another, use an intermediate AVCodecParameters instance and the
4385  * avcodec_parameters_from_context() / avcodec_parameters_to_context()
4386  * functions.
4387  */
4390 #endif
4391 
4392 /**
4393  * Allocate a new AVCodecParameters and set its fields to default values
4394  * (unknown/invalid/0). The returned struct must be freed with
4395  * avcodec_parameters_free().
4396  */
4398 
4399 /**
4400  * Free an AVCodecParameters instance and everything associated with it and
4401  * write NULL to the supplied pointer.
4402  */
4404 
4405 /**
4406  * Copy the contents of src to dst. Any allocated fields in dst are freed and
4407  * replaced with newly allocated duplicates of the corresponding fields in src.
4408  *
4409  * @return >= 0 on success, a negative AVERROR code on failure.
4410  */
4412 
4413 /**
4414  * Fill the parameters struct based on the values from the supplied codec
4415  * context. Any allocated fields in par are freed and replaced with duplicates
4416  * of the corresponding fields in codec.
4417  *
4418  * @return >= 0 on success, a negative AVERROR code on failure
4419  */
4421  const AVCodecContext *codec);
4422 
4423 /**
4424  * Fill the codec context based on the values from the supplied codec
4425  * parameters. Any allocated fields in codec that have a corresponding field in
4426  * par are freed and replaced with duplicates of the corresponding field in par.
4427  * Fields in codec that do not have a counterpart in par are not touched.
4428  *
4429  * @return >= 0 on success, a negative AVERROR code on failure.
4430  */
4432  const AVCodecParameters *par);
4433 
4434 /**
4435  * Initialize the AVCodecContext to use the given AVCodec. Prior to using this
4436  * function the context has to be allocated with avcodec_alloc_context3().
4437  *
4438  * The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(),
4439  * avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for
4440  * retrieving a codec.
4441  *
4442  * @warning This function is not thread safe!
4443  *
4444  * @note Always call this function before using decoding routines (such as
4445  * @ref avcodec_receive_frame()).
4446  *
4447  * @code
4448  * avcodec_register_all();
4449  * av_dict_set(&opts, "b", "2.5M", 0);
4450  * codec = avcodec_find_decoder(AV_CODEC_ID_H264);
4451  * if (!codec)
4452  * exit(1);
4453  *
4454  * context = avcodec_alloc_context3(codec);
4455  *
4456  * if (avcodec_open2(context, codec, opts) < 0)
4457  * exit(1);
4458  * @endcode
4459  *
4460  * @param avctx The context to initialize.
4461  * @param codec The codec to open this context for. If a non-NULL codec has been
4462  * previously passed to avcodec_alloc_context3() or
4463  * for this context, then this parameter MUST be either NULL or
4464  * equal to the previously passed codec.
4465  * @param options A dictionary filled with AVCodecContext and codec-private options.
4466  * On return this object will be filled with options that were not found.
4467  *
4468  * @return zero on success, a negative value on error
4469  * @see avcodec_alloc_context3(), avcodec_find_decoder(), avcodec_find_encoder(),
4470  * av_dict_set(), av_opt_find().
4471  */
4472 int avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options);
4473 
4474 /**
4475  * Close a given AVCodecContext and free all the data associated with it
4476  * (but not the AVCodecContext itself).
4477  *
4478  * Calling this function on an AVCodecContext that hasn't been opened will free
4479  * the codec-specific data allocated in avcodec_alloc_context3() with a non-NULL
4480  * codec. Subsequent calls will do nothing.
4481  *
4482  * @note Do not use this function. Use avcodec_free_context() to destroy a
4483  * codec context (either open or closed). Opening and closing a codec context
4484  * multiple times is not supported anymore -- use multiple codec contexts
4485  * instead.
4486  */
4487 int avcodec_close(AVCodecContext *avctx);
4488 
4489 /**
4490  * Free all allocated data in the given subtitle struct.
4491  *
4492  * @param sub AVSubtitle to free.
4493  */
4494 void avsubtitle_free(AVSubtitle *sub);
4495 
4496 /**
4497  * @}
4498  */
4499 
4500 /**
4501  * @addtogroup lavc_packet
4502  * @{
4503  */
4504 
4505 /**
4506  * Allocate an AVPacket and set its fields to default values. The resulting
4507  * struct must be freed using av_packet_free().
4508  *
4509  * @return An AVPacket filled with default values or NULL on failure.
4510  *
4511  * @note this only allocates the AVPacket itself, not the data buffers. Those
4512  * must be allocated through other means such as av_new_packet.
4513  *
4514  * @see av_new_packet
4515  */
4516 AVPacket *av_packet_alloc(void);
4517 
4518 /**
4519  * Create a new packet that references the same data as src.
4520  *
4521  * This is a shortcut for av_packet_alloc()+av_packet_ref().
4522  *
4523  * @return newly created AVPacket on success, NULL on error.
4524  *
4525  * @see av_packet_alloc
4526  * @see av_packet_ref
4527  */
4529 
4530 /**
4531  * Free the packet, if the packet is reference counted, it will be
4532  * unreferenced first.
4533  *
4534  * @param pkt packet to be freed. The pointer will be set to NULL.
4535  * @note passing NULL is a no-op.
4536  */
4537 void av_packet_free(AVPacket **pkt);
4538 
4539 /**
4540  * Initialize optional fields of a packet with default values.
4541  *
4542  * Note, this does not touch the data and size members, which have to be
4543  * initialized separately.
4544  *
4545  * @param pkt packet
4546  */
4547 void av_init_packet(AVPacket *pkt);
4548 
4549 /**
4550  * Allocate the payload of a packet and initialize its fields with
4551  * default values.
4552  *
4553  * @param pkt packet
4554  * @param size wanted payload size
4555  * @return 0 if OK, AVERROR_xxx otherwise
4556  */
4557 int av_new_packet(AVPacket *pkt, int size);
4558 
4559 /**
4560  * Reduce packet size, correctly zeroing padding
4561  *
4562  * @param pkt packet
4563  * @param size new size
4564  */
4565 void av_shrink_packet(AVPacket *pkt, int size);
4566 
4567 /**
4568  * Increase packet size, correctly zeroing padding
4569  *
4570  * @param pkt packet
4571  * @param grow_by number of bytes by which to increase the size of the packet
4572  */
4573 int av_grow_packet(AVPacket *pkt, int grow_by);
4574 
4575 /**
4576  * Initialize a reference-counted packet from av_malloc()ed data.
4577  *
4578  * @param pkt packet to be initialized. This function will set the data, size,
4579  * buf and destruct fields, all others are left untouched.
4580  * @param data Data allocated by av_malloc() to be used as packet data. If this
4581  * function returns successfully, the data is owned by the underlying AVBuffer.
4582  * The caller may not access the data through other means.
4583  * @param size size of data in bytes, without the padding. I.e. the full buffer
4584  * size is assumed to be size + AV_INPUT_BUFFER_PADDING_SIZE.
4585  *
4586  * @return 0 on success, a negative AVERROR on error
4587  */
4589 
4590 #if FF_API_AVPACKET_OLD_API
4591 /**
4592  * @warning This is a hack - the packet memory allocation stuff is broken. The
4593  * packet is allocated if it was not really allocated.
4594  *
4595  * @deprecated Use av_packet_ref
4596  */
4598 int av_dup_packet(AVPacket *pkt);
4599 /**
4600  * Copy packet, including contents
4601  *
4602  * @return 0 on success, negative AVERROR on fail
4603  */
4604 int av_copy_packet(AVPacket *dst, const AVPacket *src);
4605 
4606 /**
4607  * Copy packet side data
4608  *
4609  * @return 0 on success, negative AVERROR on fail
4610  */
4611 int av_copy_packet_side_data(AVPacket *dst, const AVPacket *src);
4612 
4613 /**
4614  * Free a packet.
4615  *
4616  * @deprecated Use av_packet_unref
4617  *
4618  * @param pkt packet to free
4619  */
4621 void av_free_packet(AVPacket *pkt);
4622 #endif
4623 /**
4624  * Allocate new information of a packet.
4625  *
4626  * @param pkt packet
4627  * @param type side information type
4628  * @param size side information size
4629  * @return pointer to fresh allocated data or NULL otherwise
4630  */
4632  int size);
4633 
4634 /**
4635  * Wrap an existing array as a packet side data.
4636  *
4637  * @param pkt packet
4638  * @param type side information type
4639  * @param data the side data array. It must be allocated with the av_malloc()
4640  * family of functions. The ownership of the data is transferred to
4641  * pkt.
4642  * @param size side information size
4643  * @return a non-negative number on success, a negative AVERROR code on
4644  * failure. On failure, the packet is unchanged and the data remains
4645  * owned by the caller.
4646  */
4648  uint8_t *data, size_t size);
4649 
4650 /**
4651  * Shrink the already allocated side data buffer
4652  *
4653  * @param pkt packet
4654  * @param type side information type
4655  * @param size new side information size
4656  * @return 0 on success, < 0 on failure
4657  */
4659  int size);
4660 
4661 /**
4662  * Get side information from packet.
4663  *
4664  * @param pkt packet
4665  * @param type desired side information type
4666  * @param size pointer for side information size to store (optional)
4667  * @return pointer to data if present or NULL otherwise
4668  */
4670  int *size);
4671 
4672 #if FF_API_MERGE_SD_API
4675 
4678 #endif
4679 
4681 
4682 /**
4683  * Pack a dictionary for use in side_data.
4684  *
4685  * @param dict The dictionary to pack.
4686  * @param size pointer to store the size of the returned data
4687  * @return pointer to data if successful, NULL otherwise
4688  */
4690 /**
4691  * Unpack a dictionary from side_data.
4692  *
4693  * @param data data from side_data
4694  * @param size size of the data
4695  * @param dict the metadata storage dictionary
4696  * @return 0 on success, < 0 on failure
4697  */
4698 int av_packet_unpack_dictionary(const uint8_t *data, int size, AVDictionary **dict);
4699 
4700 
4701 /**
4702  * Convenience function to free all the side data stored.
4703  * All the other fields stay untouched.
4704  *
4705  * @param pkt packet
4706  */
4708 
4709 /**
4710  * Setup a new reference to the data described by a given packet
4711  *
4712  * If src is reference-counted, setup dst as a new reference to the
4713  * buffer in src. Otherwise allocate a new buffer in dst and copy the
4714  * data from src into it.
4715  *
4716  * All the other fields are copied from src.
4717  *
4718  * @see av_packet_unref
4719  *
4720  * @param dst Destination packet
4721  * @param src Source packet
4722  *
4723  * @return 0 on success, a negative AVERROR on error.
4724  */
4725 int av_packet_ref(AVPacket *dst, const AVPacket *src);
4726 
4727 /**
4728  * Wipe the packet.
4729  *
4730  * Unreference the buffer referenced by the packet and reset the
4731  * remaining packet fields to their default values.
4732  *
4733  * @param pkt The packet to be unreferenced.
4734  */
4736 
4737 /**
4738  * Move every field in src to dst and reset src.
4739  *
4740  * @see av_packet_unref
4741  *
4742  * @param src Source packet, will be reset
4743  * @param dst Destination packet
4744  */
4746 
4747 /**
4748  * Copy only "properties" fields from src to dst.
4749  *
4750  * Properties for the purpose of this function are all the fields
4751  * beside those related to the packet data (buf, data, size)
4752  *
4753  * @param dst Destination packet
4754  * @param src Source packet
4755  *
4756  * @return 0 on success AVERROR on failure.
4757  */
4758 int av_packet_copy_props(AVPacket *dst, const AVPacket *src);
4759 
4760 /**
4761  * Convert valid timing fields (timestamps / durations) in a packet from one
4762  * timebase to another. Timestamps with unknown values (AV_NOPTS_VALUE) will be
4763  * ignored.
4764  *
4765  * @param pkt packet on which the conversion will be performed
4766  * @param tb_src source timebase, in which the timing fields in pkt are
4767  * expressed
4768  * @param tb_dst destination timebase, to which the timing fields will be
4769  * converted
4770  */
4771 void av_packet_rescale_ts(AVPacket *pkt, AVRational tb_src, AVRational tb_dst);
4772 
4773 /**
4774  * @}
4775  */
4776 
4777 /**
4778  * @addtogroup lavc_decoding
4779  * @{
4780  */
4781 
4782 /**
4783  * Find a registered decoder with a matching codec ID.
4784  *
4785  * @param id AVCodecID of the requested decoder
4786  * @return A decoder if one was found, NULL otherwise.
4787  */
4789 
4790 /**
4791  * Find a registered decoder with the specified name.
4792  *
4793  * @param name name of the requested decoder
4794  * @return A decoder if one was found, NULL otherwise.
4795  */
4797 
4798 /**
4799  * The default callback for AVCodecContext.get_buffer2(). It is made public so
4800  * it can be called by custom get_buffer2() implementations for decoders without
4801  * AV_CODEC_CAP_DR1 set.
4802  */
4804 
4805 #if FF_API_EMU_EDGE
4806 /**
4807  * Return the amount of padding in pixels which the get_buffer callback must
4808  * provide around the edge of the image for codecs which do not have the
4809  * CODEC_FLAG_EMU_EDGE flag.
4810  *
4811  * @return Required padding in pixels.
4812  *
4813  * @deprecated CODEC_FLAG_EMU_EDGE is deprecated, so this function is no longer
4814  * needed
4815  */
4817 unsigned avcodec_get_edge_width(void);
4818 #endif
4819 
4820 /**
4821  * Modify width and height values so that they will result in a memory
4822  * buffer that is acceptable for the codec if you do not use any horizontal
4823  * padding.
4824  *
4825  * May only be used if a codec with AV_CODEC_CAP_DR1 has been opened.
4826  */
4828 
4829 /**
4830  * Modify width and height values so that they will result in a memory
4831  * buffer that is acceptable for the codec if you also ensure that all
4832  * line sizes are a multiple of the respective linesize_align[i].
4833  *
4834  * May only be used if a codec with AV_CODEC_CAP_DR1 has been opened.
4835  */
4837  int linesize_align[AV_NUM_DATA_POINTERS]);
4838 
4839 /**
4840  * Converts AVChromaLocation to swscale x/y chroma position.
4841  *
4842  * The positions represent the chroma (0,0) position in a coordinates system
4843  * with luma (0,0) representing the origin and luma(1,1) representing 256,256
4844  *
4845  * @param xpos horizontal chroma sample position
4846  * @param ypos vertical chroma sample position
4847  */
4848 int avcodec_enum_to_chroma_pos(int *xpos, int *ypos, enum AVChromaLocation pos);
4849 
4850 /**
4851  * Converts swscale x/y chroma position to AVChromaLocation.
4852  *
4853  * The positions represent the chroma (0,0) position in a coordinates system
4854  * with luma (0,0) representing the origin and luma(1,1) representing 256,256
4855  *
4856  * @param xpos horizontal chroma sample position
4857  * @param ypos vertical chroma sample position
4858  */
4859 enum AVChromaLocation avcodec_chroma_pos_to_enum(int xpos, int ypos);
4860 
4861 /**
4862  * Decode the audio frame of size avpkt->size from avpkt->data into frame.
4863  *
4864  * Some decoders may support multiple frames in a single AVPacket. Such
4865  * decoders would then just decode the first frame and the return value would be
4866  * less than the packet size. In this case, avcodec_decode_audio4 has to be
4867  * called again with an AVPacket containing the remaining data in order to
4868  * decode the second frame, etc... Even if no frames are returned, the packet
4869  * needs to be fed to the decoder with remaining data until it is completely
4870  * consumed or an error occurs.
4871  *
4872  * Some decoders (those marked with AV_CODEC_CAP_DELAY) have a delay between input
4873  * and output. This means that for some packets they will not immediately
4874  * produce decoded output and need to be flushed at the end of decoding to get
4875  * all the decoded data. Flushing is done by calling this function with packets
4876  * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
4877  * returning samples. It is safe to flush even those decoders that are not
4878  * marked with AV_CODEC_CAP_DELAY, then no samples will be returned.
4879  *
4880  * @warning The input buffer, avpkt->data must be AV_INPUT_BUFFER_PADDING_SIZE
4881  * larger than the actual read bytes because some optimized bitstream
4882  * readers read 32 or 64 bits at once and could read over the end.
4883  *
4884  * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
4885  * before packets may be fed to the decoder.
4886  *
4887  * @param avctx the codec context
4888  * @param[out] frame The AVFrame in which to store decoded audio samples.
4889  * The decoder will allocate a buffer for the decoded frame by
4890  * calling the AVCodecContext.get_buffer2() callback.
4891  * When AVCodecContext.refcounted_frames is set to 1, the frame is
4892  * reference counted and the returned reference belongs to the
4893  * caller. The caller must release the frame using av_frame_unref()
4894  * when the frame is no longer needed. The caller may safely write
4895  * to the frame if av_frame_is_writable() returns 1.
4896  * When AVCodecContext.refcounted_frames is set to 0, the returned
4897  * reference belongs to the decoder and is valid only until the
4898  * next call to this function or until closing or flushing the
4899  * decoder. The caller may not write to it.
4900  * @param[out] got_frame_ptr Zero if no frame could be decoded, otherwise it is
4901  * non-zero. Note that this field being set to zero
4902  * does not mean that an error has occurred. For
4903  * decoders with AV_CODEC_CAP_DELAY set, no given decode
4904  * call is guaranteed to produce a frame.
4905  * @param[in] avpkt The input AVPacket containing the input buffer.
4906  * At least avpkt->data and avpkt->size should be set. Some
4907  * decoders might also require additional fields to be set.
4908  * @return A negative error code is returned if an error occurred during
4909  * decoding, otherwise the number of bytes consumed from the input
4910  * AVPacket is returned.
4911  *
4912 * @deprecated Use avcodec_send_packet() and avcodec_receive_frame().
4913  */
4916  int *got_frame_ptr, const AVPacket *avpkt);
4917 
4918 /**
4919  * Decode the video frame of size avpkt->size from avpkt->data into picture.
4920  * Some decoders may support multiple frames in a single AVPacket, such
4921  * decoders would then just decode the first frame.
4922  *
4923  * @warning The input buffer must be AV_INPUT_BUFFER_PADDING_SIZE larger than
4924  * the actual read bytes because some optimized bitstream readers read 32 or 64
4925  * bits at once and could read over the end.
4926  *
4927  * @warning The end of the input buffer buf should be set to 0 to ensure that
4928  * no overreading happens for damaged MPEG streams.
4929  *
4930  * @note Codecs which have the AV_CODEC_CAP_DELAY capability set have a delay
4931  * between input and output, these need to be fed with avpkt->data=NULL,
4932  * avpkt->size=0 at the end to return the remaining frames.
4933  *
4934  * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
4935  * before packets may be fed to the decoder.
4936  *
4937  * @param avctx the codec context
4938  * @param[out] picture The AVFrame in which the decoded video frame will be stored.
4939  * Use av_frame_alloc() to get an AVFrame. The codec will
4940  * allocate memory for the actual bitmap by calling the
4941  * AVCodecContext.get_buffer2() callback.
4942  * When AVCodecContext.refcounted_frames is set to 1, the frame is
4943  * reference counted and the returned reference belongs to the
4944  * caller. The caller must release the frame using av_frame_unref()
4945  * when the frame is no longer needed. The caller may safely write
4946  * to the frame if av_frame_is_writable() returns 1.
4947  * When AVCodecContext.refcounted_frames is set to 0, the returned
4948  * reference belongs to the decoder and is valid only until the
4949  * next call to this function or until closing or flushing the
4950  * decoder. The caller may not write to it.
4951  *
4952  * @param[in] avpkt The input AVPacket containing the input buffer.
4953  * You can create such packet with av_init_packet() and by then setting
4954  * data and size, some decoders might in addition need other fields like
4955  * flags&AV_PKT_FLAG_KEY. All decoders are designed to use the least
4956  * fields possible.
4957  * @param[in,out] got_picture_ptr Zero if no frame could be decompressed, otherwise, it is nonzero.
4958  * @return On error a negative value is returned, otherwise the number of bytes
4959  * used or zero if no frame could be decompressed.
4960  *
4961  * @deprecated Use avcodec_send_packet() and avcodec_receive_frame().
4962  */
4964 int avcodec_decode_video2(AVCodecContext *avctx, AVFrame *picture,
4965  int *got_picture_ptr,
4966  const AVPacket *avpkt);
4967 
4968 /**
4969  * Decode a subtitle message.
4970  * Return a negative value on error, otherwise return the number of bytes used.
4971  * If no subtitle could be decompressed, got_sub_ptr is zero.
4972  * Otherwise, the subtitle is stored in *sub.
4973  * Note that AV_CODEC_CAP_DR1 is not available for subtitle codecs. This is for
4974  * simplicity, because the performance difference is expect to be negligible
4975  * and reusing a get_buffer written for video codecs would probably perform badly
4976  * due to a potentially very different allocation pattern.
4977  *
4978  * Some decoders (those marked with AV_CODEC_CAP_DELAY) have a delay between input
4979  * and output. This means that for some packets they will not immediately
4980  * produce decoded output and need to be flushed at the end of decoding to get
4981  * all the decoded data. Flushing is done by calling this function with packets
4982  * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
4983  * returning subtitles. It is safe to flush even those decoders that are not
4984  * marked with AV_CODEC_CAP_DELAY, then no subtitles will be returned.
4985  *
4986  * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
4987  * before packets may be fed to the decoder.
4988  *
4989  * @param avctx the codec context
4990  * @param[out] sub The Preallocated AVSubtitle in which the decoded subtitle will be stored,
4991  * must be freed with avsubtitle_free if *got_sub_ptr is set.
4992  * @param[in,out] got_sub_ptr Zero if no subtitle could be decompressed, otherwise, it is nonzero.
4993  * @param[in] avpkt The input AVPacket containing the input buffer.
4994  */
4996  int *got_sub_ptr,
4997  AVPacket *avpkt);
4998 
4999 /**
5000  * Supply raw packet data as input to a decoder.
5001  *
5002  * Internally, this call will copy relevant AVCodecContext fields, which can
5003  * influence decoding per-packet, and apply them when the packet is actually
5004  * decoded. (For example AVCodecContext.skip_frame, which might direct the
5005  * decoder to drop the frame contained by the packet sent with this function.)
5006  *
5007  * @warning The input buffer, avpkt->data must be AV_INPUT_BUFFER_PADDING_SIZE
5008  * larger than the actual read bytes because some optimized bitstream
5009  * readers read 32 or 64 bits at once and could read over the end.
5010  *
5011  * @warning Do not mix this API with the legacy API (like avcodec_decode_video2())
5012  * on the same AVCodecContext. It will return unexpected results now
5013  * or in future libavcodec versions.
5014  *
5015  * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
5016  * before packets may be fed to the decoder.
5017  *
5018  * @param avctx codec context
5019  * @param[in] avpkt The input AVPacket. Usually, this will be a single video
5020  * frame, or several complete audio frames.
5021  * Ownership of the packet remains with the caller, and the
5022  * decoder will not write to the packet. The decoder may create
5023  * a reference to the packet data (or copy it if the packet is
5024  * not reference-counted).
5025  * Unlike with older APIs, the packet is always fully consumed,
5026  * and if it contains multiple frames (e.g. some audio codecs),
5027  * will require you to call avcodec_receive_frame() multiple
5028  * times afterwards before you can send a new packet.
5029  * It can be NULL (or an AVPacket with data set to NULL and
5030  * size set to 0); in this case, it is considered a flush
5031  * packet, which signals the end of the stream. Sending the
5032  * first flush packet will return success. Subsequent ones are
5033  * unnecessary and will return AVERROR_EOF. If the decoder
5034  * still has frames buffered, it will return them after sending
5035  * a flush packet.
5036  *
5037  * @return 0 on success, otherwise negative error code:
5038  * AVERROR(EAGAIN): input is not accepted in the current state - user
5039  * must read output with avcodec_receive_frame() (once
5040  * all output is read, the packet should be resent, and
5041  * the call will not fail with EAGAIN).
5042  * AVERROR_EOF: the decoder has been flushed, and no new packets can
5043  * be sent to it (also returned if more than 1 flush
5044  * packet is sent)
5045  * AVERROR(EINVAL): codec not opened, it is an encoder, or requires flush
5046  * AVERROR(ENOMEM): failed to add packet to internal queue, or similar
5047  * other errors: legitimate decoding errors
5048  */
5049 int avcodec_send_packet(AVCodecContext *avctx, const AVPacket *avpkt);
5050 
5051 /**
5052  * Return decoded output data from a decoder.
5053  *
5054  * @param avctx codec context
5055  * @param frame This will be set to a reference-counted video or audio
5056  * frame (depending on the decoder type) allocated by the
5057  * decoder. Note that the function will always call
5058  * av_frame_unref(frame) before doing anything else.
5059  *
5060  * @return
5061  * 0: success, a frame was returned
5062  * AVERROR(EAGAIN): output is not available in this state - user must try
5063  * to send new input
5064  * AVERROR_EOF: the decoder has been fully flushed, and there will be
5065  * no more output frames
5066  * AVERROR(EINVAL): codec not opened, or it is an encoder
5067  * other negative values: legitimate decoding errors
5068  */
5070 
5071 /**
5072  * Supply a raw video or audio frame to the encoder. Use avcodec_receive_packet()
5073  * to retrieve buffered output packets.
5074  *
5075  * @param avctx codec context
5076  * @param[in] frame AVFrame containing the raw audio or video frame to be encoded.
5077  * Ownership of the frame remains with the caller, and the
5078  * encoder will not write to the frame. The encoder may create
5079  * a reference to the frame data (or copy it if the frame is
5080  * not reference-counted).
5081  * It can be NULL, in which case it is considered a flush
5082  * packet. This signals the end of the stream. If the encoder
5083  * still has packets buffered, it will return them after this
5084  * call. Once flushing mode has been entered, additional flush
5085  * packets are ignored, and sending frames will return
5086  * AVERROR_EOF.
5087  *
5088  * For audio:
5089  * If AV_CODEC_CAP_VARIABLE_FRAME_SIZE is set, then each frame
5090  * can have any number of samples.
5091  * If it is not set, frame->nb_samples must be equal to
5092  * avctx->frame_size for all frames except the last.
5093  * The final frame may be smaller than avctx->frame_size.
5094  * @return 0 on success, otherwise negative error code:
5095  * AVERROR(EAGAIN): input is not accepted in the current state - user
5096  * must read output with avcodec_receive_packet() (once
5097  * all output is read, the packet should be resent, and
5098  * the call will not fail with EAGAIN).
5099  * AVERROR_EOF: the encoder has been flushed, and no new frames can
5100  * be sent to it
5101  * AVERROR(EINVAL): codec not opened, refcounted_frames not set, it is a
5102  * decoder, or requires flush
5103  * AVERROR(ENOMEM): failed to add packet to internal queue, or similar
5104  * other errors: legitimate decoding errors
5105  */
5106 int avcodec_send_frame(AVCodecContext *avctx, const AVFrame *frame);
5107 
5108 /**
5109  * Read encoded data from the encoder.
5110  *
5111  * @param avctx codec context
5112  * @param avpkt This will be set to a reference-counted packet allocated by the
5113  * encoder. Note that the function will always call
5114  * av_frame_unref(frame) before doing anything else.
5115  * @return 0 on success, otherwise negative error code:
5116  * AVERROR(EAGAIN): output is not available in the current state - user
5117  * must try to send input
5118  * AVERROR_EOF: the encoder has been fully flushed, and there will be
5119  * no more output packets
5120  * AVERROR(EINVAL): codec not opened, or it is an encoder
5121  * other errors: legitimate decoding errors
5122  */
5123 int avcodec_receive_packet(AVCodecContext *avctx, AVPacket *avpkt);
5124 
5125 
5126 /**
5127  * @defgroup lavc_parsing Frame parsing
5128  * @{
5129  */
5130 
5133  AV_PICTURE_STRUCTURE_TOP_FIELD, //< coded as top field
5134  AV_PICTURE_STRUCTURE_BOTTOM_FIELD, //< coded as bottom field
5135  AV_PICTURE_STRUCTURE_FRAME, //< coded as frame
5136 };
5137 
5138 typedef struct AVCodecParserContext {
5139  void *priv_data;
5141  int64_t frame_offset; /* offset of the current frame */
5142  int64_t cur_offset; /* current offset
5143  (incremented by each av_parser_parse()) */
5144  int64_t next_frame_offset; /* offset of the next frame */
5145  /* video info */
5146  int pict_type; /* XXX: Put it back in AVCodecContext. */
5147  /**
5148  * This field is used for proper frame duration computation in lavf.
5149  * It signals, how much longer the frame duration of the current frame
5150  * is compared to normal frame duration.
5151  *
5152  * frame_duration = (1 + repeat_pict) * time_base
5153  *
5154  * It is used by codecs like H.264 to display telecined material.
5155  */
5156  int repeat_pict; /* XXX: Put it back in AVCodecContext. */
5157  int64_t pts; /* pts of the current frame */
5158  int64_t dts; /* dts of the current frame */
5159 
5160  /* private data */
5161  int64_t last_pts;
5162  int64_t last_dts;
5164 
5165 #define AV_PARSER_PTS_NB 4
5170 
5171  int flags;
5172 #define PARSER_FLAG_COMPLETE_FRAMES 0x0001
5173 #define PARSER_FLAG_ONCE 0x0002
5174 /// Set if the parser has a valid file offset
5175 #define PARSER_FLAG_FETCHED_OFFSET 0x0004
5176 #define PARSER_FLAG_USE_CODEC_TS 0x1000
5177 
5178  int64_t offset; ///< byte offset from starting packet start
5180 
5181  /**
5182  * Set by parser to 1 for key frames and 0 for non-key frames.
5183  * It is initialized to -1, so if the parser doesn't set this flag,
5184  * old-style fallback using AV_PICTURE_TYPE_I picture type as key frames
5185  * will be used.
5186  */
5188 
5189 #if FF_API_CONVERGENCE_DURATION
5190  /**
5191  * @deprecated unused
5192  */
5195 #endif
5196 
5197  // Timestamp generation support:
5198  /**
5199  * Synchronization point for start of timestamp generation.
5200  *
5201  * Set to >0 for sync point, 0 for no sync point and <0 for undefined
5202  * (default).
5203  *
5204  * For example, this corresponds to presence of H.264 buffering period
5205  * SEI message.
5206  */
5208 
5209  /**
5210  * Offset of the current timestamp against last timestamp sync point in
5211  * units of AVCodecContext.time_base.
5212  *
5213  * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
5214  * contain a valid timestamp offset.
5215  *
5216  * Note that the timestamp of sync point has usually a nonzero
5217  * dts_ref_dts_delta, which refers to the previous sync point. Offset of
5218  * the next frame after timestamp sync point will be usually 1.
5219  *
5220  * For example, this corresponds to H.264 cpb_removal_delay.
5221  */
5223 
5224  /**
5225  * Presentation delay of current frame in units of AVCodecContext.time_base.
5226  *
5227  * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
5228  * contain valid non-negative timestamp delta (presentation time of a frame
5229  * must not lie in the past).
5230  *
5231  * This delay represents the difference between decoding and presentation
5232  * time of the frame.
5233  *
5234  * For example, this corresponds to H.264 dpb_output_delay.
5235  */
5237 
5238  /**
5239  * Position of the packet in file.
5240  *
5241  * Analogous to cur_frame_pts/dts
5242  */
5244 
5245  /**
5246  * Byte position of currently parsed frame in stream.
5247  */
5248  int64_t pos;
5249 
5250  /**
5251  * Previous frame byte position.
5252  */
5253  int64_t last_pos;
5254 
5255  /**
5256  * Duration of the current frame.
5257  * For audio, this is in units of 1 / AVCodecContext.sample_rate.
5258  * For all other types, this is in units of AVCodecContext.time_base.
5259  */
5261 
5263 
5264  /**
5265  * Indicate whether a picture is coded as a frame, top field or bottom field.
5266  *
5267  * For example, H.264 field_pic_flag equal to 0 corresponds to
5268  * AV_PICTURE_STRUCTURE_FRAME. An H.264 picture with field_pic_flag
5269  * equal to 1 and bottom_field_flag equal to 0 corresponds to
5270  * AV_PICTURE_STRUCTURE_TOP_FIELD.
5271  */
5273 
5274  /**
5275  * Picture number incremented in presentation or output order.
5276  * This field may be reinitialized at the first picture of a new sequence.
5277  *
5278  * For example, this corresponds to H.264 PicOrderCnt.
5279  */
5281 
5282  /**
5283  * Dimensions of the decoded video intended for presentation.
5284  */
5285  int width;
5286  int height;
5287 
5288  /**
5289  * Dimensions of the coded video.
5290  */
5293 
5294  /**
5295  * The format of the coded data, corresponds to enum AVPixelFormat for video
5296  * and for enum AVSampleFormat for audio.
5297  *
5298  * Note that a decoder can have considerable freedom in how exactly it
5299  * decodes the data, so the format reported here might be different from the
5300  * one returned by a decoder.
5301  */
5302  int format;
5304 
5305 typedef struct AVCodecParser {
5306  int codec_ids[5]; /* several codec IDs are permitted */
5309  /* This callback never returns an error, a negative value means that
5310  * the frame start was in a previous packet. */