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avcodec.h
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1 /*
2  * copyright (c) 2001 Fabrice Bellard
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #ifndef AVCODEC_AVCODEC_H
22 #define AVCODEC_AVCODEC_H
23 
24 /**
25  * @file
26  * @ingroup libavc
27  * Libavcodec external API header
28  */
29 
30 #include <errno.h>
31 #include "libavutil/samplefmt.h"
32 #include "libavutil/attributes.h"
33 #include "libavutil/avutil.h"
34 #include "libavutil/buffer.h"
35 #include "libavutil/cpu.h"
37 #include "libavutil/dict.h"
38 #include "libavutil/frame.h"
39 #include "libavutil/hwcontext.h"
40 #include "libavutil/log.h"
41 #include "libavutil/pixfmt.h"
42 #include "libavutil/rational.h"
43 
44 #include "version.h"
45 
46 /**
47  * @defgroup libavc libavcodec
48  * Encoding/Decoding Library
49  *
50  * @{
51  *
52  * @defgroup lavc_decoding Decoding
53  * @{
54  * @}
55  *
56  * @defgroup lavc_encoding Encoding
57  * @{
58  * @}
59  *
60  * @defgroup lavc_codec Codecs
61  * @{
62  * @defgroup lavc_codec_native Native Codecs
63  * @{
64  * @}
65  * @defgroup lavc_codec_wrappers External library wrappers
66  * @{
67  * @}
68  * @defgroup lavc_codec_hwaccel Hardware Accelerators bridge
69  * @{
70  * @}
71  * @}
72  * @defgroup lavc_internal Internal
73  * @{
74  * @}
75  * @}
76  */
77 
78 /**
79  * @ingroup libavc
80  * @defgroup lavc_encdec send/receive encoding and decoding API overview
81  * @{
82  *
83  * The avcodec_send_packet()/avcodec_receive_frame()/avcodec_send_frame()/
84  * avcodec_receive_packet() functions provide an encode/decode API, which
85  * decouples input and output.
86  *
87  * The API is very similar for encoding/decoding and audio/video, and works as
88  * follows:
89  * - Set up and open the AVCodecContext as usual.
90  * - Send valid input:
91  * - For decoding, call avcodec_send_packet() to give the decoder raw
92  * compressed data in an AVPacket.
93  * - For encoding, call avcodec_send_frame() to give the encoder an AVFrame
94  * containing uncompressed audio or video.
95  * In both cases, it is recommended that AVPackets and AVFrames are
96  * refcounted, or libavcodec might have to copy the input data. (libavformat
97  * always returns refcounted AVPackets, and av_frame_get_buffer() allocates
98  * refcounted AVFrames.)
99  * - Receive output in a loop. Periodically call one of the avcodec_receive_*()
100  * functions and process their output:
101  * - For decoding, call avcodec_receive_frame(). On success, it will return
102  * an AVFrame containing uncompressed audio or video data.
103  * - For encoding, call avcodec_receive_packet(). On success, it will return
104  * an AVPacket with a compressed frame.
105  * Repeat this call until it returns AVERROR(EAGAIN) or an error. The
106  * AVERROR(EAGAIN) return value means that new input data is required to
107  * return new output. In this case, continue with sending input. For each
108  * input frame/packet, the codec will typically return 1 output frame/packet,
109  * but it can also be 0 or more than 1.
110  *
111  * At the beginning of decoding or encoding, the codec might accept multiple
112  * input frames/packets without returning a frame, until its internal buffers
113  * are filled. This situation is handled transparently if you follow the steps
114  * outlined above.
115  *
116  * In theory, sending input can result in EAGAIN - this should happen only if
117  * not all output was received. You can use this to structure alternative decode
118  * or encode loops other than the one suggested above. For example, you could
119  * try sending new input on each iteration, and try to receive output if that
120  * returns EAGAIN.
121  *
122  * End of stream situations. These require "flushing" (aka draining) the codec,
123  * as the codec might buffer multiple frames or packets internally for
124  * performance or out of necessity (consider B-frames).
125  * This is handled as follows:
126  * - Instead of valid input, send NULL to the avcodec_send_packet() (decoding)
127  * or avcodec_send_frame() (encoding) functions. This will enter draining
128  * mode.
129  * - Call avcodec_receive_frame() (decoding) or avcodec_receive_packet()
130  * (encoding) in a loop until AVERROR_EOF is returned. The functions will
131  * not return AVERROR(EAGAIN), unless you forgot to enter draining mode.
132  * - Before decoding can be resumed again, the codec has to be reset with
133  * avcodec_flush_buffers().
134  *
135  * Using the API as outlined above is highly recommended. But it is also
136  * possible to call functions outside of this rigid schema. For example, you can
137  * call avcodec_send_packet() repeatedly without calling
138  * avcodec_receive_frame(). In this case, avcodec_send_packet() will succeed
139  * until the codec's internal buffer has been filled up (which is typically of
140  * size 1 per output frame, after initial input), and then reject input with
141  * AVERROR(EAGAIN). Once it starts rejecting input, you have no choice but to
142  * read at least some output.
143  *
144  * Not all codecs will follow a rigid and predictable dataflow; the only
145  * guarantee is that an AVERROR(EAGAIN) return value on a send/receive call on
146  * one end implies that a receive/send call on the other end will succeed, or
147  * at least will not fail with AVERROR(EAGAIN). In general, no codec will
148  * permit unlimited buffering of input or output.
149  *
150  * This API replaces the following legacy functions:
151  * - avcodec_decode_video2() and avcodec_decode_audio4():
152  * Use avcodec_send_packet() to feed input to the decoder, then use
153  * avcodec_receive_frame() to receive decoded frames after each packet.
154  * Unlike with the old video decoding API, multiple frames might result from
155  * a packet. For audio, splitting the input packet into frames by partially
156  * decoding packets becomes transparent to the API user. You never need to
157  * feed an AVPacket to the API twice (unless it is rejected with AVERROR(EAGAIN) - then
158  * no data was read from the packet).
159  * Additionally, sending a flush/draining packet is required only once.
160  * - avcodec_encode_video2()/avcodec_encode_audio2():
161  * Use avcodec_send_frame() to feed input to the encoder, then use
162  * avcodec_receive_packet() to receive encoded packets.
163  * Providing user-allocated buffers for avcodec_receive_packet() is not
164  * possible.
165  * - The new API does not handle subtitles yet.
166  *
167  * Mixing new and old function calls on the same AVCodecContext is not allowed,
168  * and will result in undefined behavior.
169  *
170  * Some codecs might require using the new API; using the old API will return
171  * an error when calling it. All codecs support the new API.
172  *
173  * A codec is not allowed to return AVERROR(EAGAIN) for both sending and receiving. This
174  * would be an invalid state, which could put the codec user into an endless
175  * loop. The API has no concept of time either: it cannot happen that trying to
176  * do avcodec_send_packet() results in AVERROR(EAGAIN), but a repeated call 1 second
177  * later accepts the packet (with no other receive/flush API calls involved).
178  * The API is a strict state machine, and the passage of time is not supposed
179  * to influence it. Some timing-dependent behavior might still be deemed
180  * acceptable in certain cases. But it must never result in both send/receive
181  * returning EAGAIN at the same time at any point. It must also absolutely be
182  * avoided that the current state is "unstable" and can "flip-flop" between
183  * the send/receive APIs allowing progress. For example, it's not allowed that
184  * the codec randomly decides that it actually wants to consume a packet now
185  * instead of returning a frame, after it just returned AVERROR(EAGAIN) on an
186  * avcodec_send_packet() call.
187  * @}
188  */
189 
190 /**
191  * @defgroup lavc_core Core functions/structures.
192  * @ingroup libavc
193  *
194  * Basic definitions, functions for querying libavcodec capabilities,
195  * allocating core structures, etc.
196  * @{
197  */
198 
199 
200 /**
201  * Identify the syntax and semantics of the bitstream.
202  * The principle is roughly:
203  * Two decoders with the same ID can decode the same streams.
204  * Two encoders with the same ID can encode compatible streams.
205  * There may be slight deviations from the principle due to implementation
206  * details.
207  *
208  * If you add a codec ID to this list, add it so that
209  * 1. no value of an existing codec ID changes (that would break ABI),
210  * 2. it is as close as possible to similar codecs
211  *
212  * After adding new codec IDs, do not forget to add an entry to the codec
213  * descriptor list and bump libavcodec minor version.
214  */
215 enum AVCodecID {
217 
218  /* video codecs */
220  AV_CODEC_ID_MPEG2VIDEO, ///< preferred ID for MPEG-1/2 video decoding
355 #define AV_CODEC_ID_IFF_BYTERUN1 AV_CODEC_ID_IFF_ILBM
393 #define AV_CODEC_ID_H265 AV_CODEC_ID_HEVC
412 
449 
450  /* various PCM "codecs" */
451  AV_CODEC_ID_FIRST_AUDIO = 0x10000, ///< A dummy id pointing at the start of audio codecs
483 
488 
489  /* various ADPCM codecs */
521 
532 
533  /* AMR */
536 
537  /* RealAudio codecs*/
540 
541  /* various DPCM codecs */
546 
549 
550  /* audio codecs */
551  AV_CODEC_ID_MP2 = 0x15000,
552  AV_CODEC_ID_MP3, ///< preferred ID for decoding MPEG audio layer 1, 2 or 3
569  AV_CODEC_ID_GSM, ///< as in Berlin toast format
581  AV_CODEC_ID_GSM_MS, /* as found in WAV */
619 
640 
641  /* subtitle codecs */
642  AV_CODEC_ID_FIRST_SUBTITLE = 0x17000, ///< A dummy ID pointing at the start of subtitle codecs.
645  AV_CODEC_ID_TEXT, ///< raw UTF-8 text
652 
669 
670  /* other specific kind of codecs (generally used for attachments) */
671  AV_CODEC_ID_FIRST_UNKNOWN = 0x18000, ///< A dummy ID pointing at the start of various fake codecs.
672  AV_CODEC_ID_TTF = 0x18000,
673 
674  AV_CODEC_ID_SCTE_35, ///< Contain timestamp estimated through PCR of program stream.
683 
684 
685  AV_CODEC_ID_PROBE = 0x19000, ///< codec_id is not known (like AV_CODEC_ID_NONE) but lavf should attempt to identify it
686 
687  AV_CODEC_ID_MPEG2TS = 0x20000, /**< _FAKE_ codec to indicate a raw MPEG-2 TS
688  * stream (only used by libavformat) */
689  AV_CODEC_ID_MPEG4SYSTEMS = 0x20001, /**< _FAKE_ codec to indicate a MPEG-4 Systems
690  * stream (only used by libavformat) */
691  AV_CODEC_ID_FFMETADATA = 0x21000, ///< Dummy codec for streams containing only metadata information.
692  AV_CODEC_ID_WRAPPED_AVFRAME = 0x21001, ///< Passthrough codec, AVFrames wrapped in AVPacket
693 };
694 
695 /**
696  * This struct describes the properties of a single codec described by an
697  * AVCodecID.
698  * @see avcodec_descriptor_get()
699  */
700 typedef struct AVCodecDescriptor {
701  enum AVCodecID id;
703  /**
704  * Name of the codec described by this descriptor. It is non-empty and
705  * unique for each codec descriptor. It should contain alphanumeric
706  * characters and '_' only.
707  */
708  const char *name;
709  /**
710  * A more descriptive name for this codec. May be NULL.
711  */
712  const char *long_name;
713  /**
714  * Codec properties, a combination of AV_CODEC_PROP_* flags.
715  */
716  int props;
717  /**
718  * MIME type(s) associated with the codec.
719  * May be NULL; if not, a NULL-terminated array of MIME types.
720  * The first item is always non-NULL and is the preferred MIME type.
721  */
722  const char *const *mime_types;
723  /**
724  * If non-NULL, an array of profiles recognized for this codec.
725  * Terminated with FF_PROFILE_UNKNOWN.
726  */
727  const struct AVProfile *profiles;
729 
730 /**
731  * Codec uses only intra compression.
732  * Video and audio codecs only.
733  */
734 #define AV_CODEC_PROP_INTRA_ONLY (1 << 0)
735 /**
736  * Codec supports lossy compression. Audio and video codecs only.
737  * @note a codec may support both lossy and lossless
738  * compression modes
739  */
740 #define AV_CODEC_PROP_LOSSY (1 << 1)
741 /**
742  * Codec supports lossless compression. Audio and video codecs only.
743  */
744 #define AV_CODEC_PROP_LOSSLESS (1 << 2)
745 /**
746  * Codec supports frame reordering. That is, the coded order (the order in which
747  * the encoded packets are output by the encoders / stored / input to the
748  * decoders) may be different from the presentation order of the corresponding
749  * frames.
750  *
751  * For codecs that do not have this property set, PTS and DTS should always be
752  * equal.
753  */
754 #define AV_CODEC_PROP_REORDER (1 << 3)
755 /**
756  * Subtitle codec is bitmap based
757  * Decoded AVSubtitle data can be read from the AVSubtitleRect->pict field.
758  */
759 #define AV_CODEC_PROP_BITMAP_SUB (1 << 16)
760 /**
761  * Subtitle codec is text based.
762  * Decoded AVSubtitle data can be read from the AVSubtitleRect->ass field.
763  */
764 #define AV_CODEC_PROP_TEXT_SUB (1 << 17)
765 
766 /**
767  * @ingroup lavc_decoding
768  * Required number of additionally allocated bytes at the end of the input bitstream for decoding.
769  * This is mainly needed because some optimized bitstream readers read
770  * 32 or 64 bit at once and could read over the end.<br>
771  * Note: If the first 23 bits of the additional bytes are not 0, then damaged
772  * MPEG bitstreams could cause overread and segfault.
773  */
774 #define AV_INPUT_BUFFER_PADDING_SIZE 64
775 
776 /**
777  * @ingroup lavc_encoding
778  * minimum encoding buffer size
779  * Used to avoid some checks during header writing.
780  */
781 #define AV_INPUT_BUFFER_MIN_SIZE 16384
782 
783 /**
784  * @ingroup lavc_decoding
785  */
787  /* We leave some space between them for extensions (drop some
788  * keyframes for intra-only or drop just some bidir frames). */
789  AVDISCARD_NONE =-16, ///< discard nothing
790  AVDISCARD_DEFAULT = 0, ///< discard useless packets like 0 size packets in avi
791  AVDISCARD_NONREF = 8, ///< discard all non reference
792  AVDISCARD_BIDIR = 16, ///< discard all bidirectional frames
793  AVDISCARD_NONINTRA= 24, ///< discard all non intra frames
794  AVDISCARD_NONKEY = 32, ///< discard all frames except keyframes
795  AVDISCARD_ALL = 48, ///< discard all
796 };
797 
808  AV_AUDIO_SERVICE_TYPE_NB , ///< Not part of ABI
809 };
810 
811 /**
812  * @ingroup lavc_encoding
813  */
814 typedef struct RcOverride{
817  int qscale; // If this is 0 then quality_factor will be used instead.
819 } RcOverride;
820 
821 /* encoding support
822  These flags can be passed in AVCodecContext.flags before initialization.
823  Note: Not everything is supported yet.
824 */
825 
826 /**
827  * Allow decoders to produce frames with data planes that are not aligned
828  * to CPU requirements (e.g. due to cropping).
829  */
830 #define AV_CODEC_FLAG_UNALIGNED (1 << 0)
831 /**
832  * Use fixed qscale.
833  */
834 #define AV_CODEC_FLAG_QSCALE (1 << 1)
835 /**
836  * 4 MV per MB allowed / advanced prediction for H.263.
837  */
838 #define AV_CODEC_FLAG_4MV (1 << 2)
839 /**
840  * Output even those frames that might be corrupted.
841  */
842 #define AV_CODEC_FLAG_OUTPUT_CORRUPT (1 << 3)
843 /**
844  * Use qpel MC.
845  */
846 #define AV_CODEC_FLAG_QPEL (1 << 4)
847 /**
848  * Use internal 2pass ratecontrol in first pass mode.
849  */
850 #define AV_CODEC_FLAG_PASS1 (1 << 9)
851 /**
852  * Use internal 2pass ratecontrol in second pass mode.
853  */
854 #define AV_CODEC_FLAG_PASS2 (1 << 10)
855 /**
856  * loop filter.
857  */
858 #define AV_CODEC_FLAG_LOOP_FILTER (1 << 11)
859 /**
860  * Only decode/encode grayscale.
861  */
862 #define AV_CODEC_FLAG_GRAY (1 << 13)
863 /**
864  * error[?] variables will be set during encoding.
865  */
866 #define AV_CODEC_FLAG_PSNR (1 << 15)
867 /**
868  * Input bitstream might be truncated at a random location
869  * instead of only at frame boundaries.
870  */
871 #define AV_CODEC_FLAG_TRUNCATED (1 << 16)
872 /**
873  * Use interlaced DCT.
874  */
875 #define AV_CODEC_FLAG_INTERLACED_DCT (1 << 18)
876 /**
877  * Force low delay.
878  */
879 #define AV_CODEC_FLAG_LOW_DELAY (1 << 19)
880 /**
881  * Place global headers in extradata instead of every keyframe.
882  */
883 #define AV_CODEC_FLAG_GLOBAL_HEADER (1 << 22)
884 /**
885  * Use only bitexact stuff (except (I)DCT).
886  */
887 #define AV_CODEC_FLAG_BITEXACT (1 << 23)
888 /* Fx : Flag for H.263+ extra options */
889 /**
890  * H.263 advanced intra coding / MPEG-4 AC prediction
891  */
892 #define AV_CODEC_FLAG_AC_PRED (1 << 24)
893 /**
894  * interlaced motion estimation
895  */
896 #define AV_CODEC_FLAG_INTERLACED_ME (1 << 29)
897 #define AV_CODEC_FLAG_CLOSED_GOP (1U << 31)
898 
899 /**
900  * Allow non spec compliant speedup tricks.
901  */
902 #define AV_CODEC_FLAG2_FAST (1 << 0)
903 /**
904  * Skip bitstream encoding.
905  */
906 #define AV_CODEC_FLAG2_NO_OUTPUT (1 << 2)
907 /**
908  * Place global headers at every keyframe instead of in extradata.
909  */
910 #define AV_CODEC_FLAG2_LOCAL_HEADER (1 << 3)
911 
912 /**
913  * timecode is in drop frame format. DEPRECATED!!!!
914  */
915 #define AV_CODEC_FLAG2_DROP_FRAME_TIMECODE (1 << 13)
916 
917 /**
918  * Input bitstream might be truncated at a packet boundaries
919  * instead of only at frame boundaries.
920  */
921 #define AV_CODEC_FLAG2_CHUNKS (1 << 15)
922 /**
923  * Discard cropping information from SPS.
924  */
925 #define AV_CODEC_FLAG2_IGNORE_CROP (1 << 16)
926 
927 /**
928  * Show all frames before the first keyframe
929  */
930 #define AV_CODEC_FLAG2_SHOW_ALL (1 << 22)
931 /**
932  * Export motion vectors through frame side data
933  */
934 #define AV_CODEC_FLAG2_EXPORT_MVS (1 << 28)
935 /**
936  * Do not skip samples and export skip information as frame side data
937  */
938 #define AV_CODEC_FLAG2_SKIP_MANUAL (1 << 29)
939 /**
940  * Do not reset ASS ReadOrder field on flush (subtitles decoding)
941  */
942 #define AV_CODEC_FLAG2_RO_FLUSH_NOOP (1 << 30)
943 
944 /* Unsupported options :
945  * Syntax Arithmetic coding (SAC)
946  * Reference Picture Selection
947  * Independent Segment Decoding */
948 /* /Fx */
949 /* codec capabilities */
950 
951 /**
952  * Decoder can use draw_horiz_band callback.
953  */
954 #define AV_CODEC_CAP_DRAW_HORIZ_BAND (1 << 0)
955 /**
956  * Codec uses get_buffer() for allocating buffers and supports custom allocators.
957  * If not set, it might not use get_buffer() at all or use operations that
958  * assume the buffer was allocated by avcodec_default_get_buffer.
959  */
960 #define AV_CODEC_CAP_DR1 (1 << 1)
961 #define AV_CODEC_CAP_TRUNCATED (1 << 3)
962 /**
963  * Encoder or decoder requires flushing with NULL input at the end in order to
964  * give the complete and correct output.
965  *
966  * NOTE: If this flag is not set, the codec is guaranteed to never be fed with
967  * with NULL data. The user can still send NULL data to the public encode
968  * or decode function, but libavcodec will not pass it along to the codec
969  * unless this flag is set.
970  *
971  * Decoders:
972  * The decoder has a non-zero delay and needs to be fed with avpkt->data=NULL,
973  * avpkt->size=0 at the end to get the delayed data until the decoder no longer
974  * returns frames.
975  *
976  * Encoders:
977  * The encoder needs to be fed with NULL data at the end of encoding until the
978  * encoder no longer returns data.
979  *
980  * NOTE: For encoders implementing the AVCodec.encode2() function, setting this
981  * flag also means that the encoder must set the pts and duration for
982  * each output packet. If this flag is not set, the pts and duration will
983  * be determined by libavcodec from the input frame.
984  */
985 #define AV_CODEC_CAP_DELAY (1 << 5)
986 /**
987  * Codec can be fed a final frame with a smaller size.
988  * This can be used to prevent truncation of the last audio samples.
989  */
990 #define AV_CODEC_CAP_SMALL_LAST_FRAME (1 << 6)
991 
992 /**
993  * Codec can output multiple frames per AVPacket
994  * Normally demuxers return one frame at a time, demuxers which do not do
995  * are connected to a parser to split what they return into proper frames.
996  * This flag is reserved to the very rare category of codecs which have a
997  * bitstream that cannot be split into frames without timeconsuming
998  * operations like full decoding. Demuxers carrying such bitstreams thus
999  * may return multiple frames in a packet. This has many disadvantages like
1000  * prohibiting stream copy in many cases thus it should only be considered
1001  * as a last resort.
1002  */
1003 #define AV_CODEC_CAP_SUBFRAMES (1 << 8)
1004 /**
1005  * Codec is experimental and is thus avoided in favor of non experimental
1006  * encoders
1007  */
1008 #define AV_CODEC_CAP_EXPERIMENTAL (1 << 9)
1009 /**
1010  * Codec should fill in channel configuration and samplerate instead of container
1011  */
1012 #define AV_CODEC_CAP_CHANNEL_CONF (1 << 10)
1013 /**
1014  * Codec supports frame-level multithreading.
1015  */
1016 #define AV_CODEC_CAP_FRAME_THREADS (1 << 12)
1017 /**
1018  * Codec supports slice-based (or partition-based) multithreading.
1019  */
1020 #define AV_CODEC_CAP_SLICE_THREADS (1 << 13)
1021 /**
1022  * Codec supports changed parameters at any point.
1023  */
1024 #define AV_CODEC_CAP_PARAM_CHANGE (1 << 14)
1025 /**
1026  * Codec supports avctx->thread_count == 0 (auto).
1027  */
1028 #define AV_CODEC_CAP_AUTO_THREADS (1 << 15)
1029 /**
1030  * Audio encoder supports receiving a different number of samples in each call.
1031  */
1032 #define AV_CODEC_CAP_VARIABLE_FRAME_SIZE (1 << 16)
1033 /**
1034  * Decoder is not a preferred choice for probing.
1035  * This indicates that the decoder is not a good choice for probing.
1036  * It could for example be an expensive to spin up hardware decoder,
1037  * or it could simply not provide a lot of useful information about
1038  * the stream.
1039  * A decoder marked with this flag should only be used as last resort
1040  * choice for probing.
1041  */
1042 #define AV_CODEC_CAP_AVOID_PROBING (1 << 17)
1043 /**
1044  * Codec is intra only.
1045  */
1046 #define AV_CODEC_CAP_INTRA_ONLY 0x40000000
1047 /**
1048  * Codec is lossless.
1049  */
1050 #define AV_CODEC_CAP_LOSSLESS 0x80000000
1051 
1052 /**
1053  * Codec is backed by a hardware implementation. Typically used to
1054  * identify a non-hwaccel hardware decoder. For information about hwaccels, use
1055  * avcodec_get_hw_config() instead.
1056  */
1057 #define AV_CODEC_CAP_HARDWARE (1 << 18)
1058 
1059 /**
1060  * Codec is potentially backed by a hardware implementation, but not
1061  * necessarily. This is used instead of AV_CODEC_CAP_HARDWARE, if the
1062  * implementation provides some sort of internal fallback.
1063  */
1064 #define AV_CODEC_CAP_HYBRID (1 << 19)
1065 
1066 /**
1067  * Pan Scan area.
1068  * This specifies the area which should be displayed.
1069  * Note there may be multiple such areas for one frame.
1070  */
1071 typedef struct AVPanScan {
1072  /**
1073  * id
1074  * - encoding: Set by user.
1075  * - decoding: Set by libavcodec.
1076  */
1077  int id;
1078 
1079  /**
1080  * width and height in 1/16 pel
1081  * - encoding: Set by user.
1082  * - decoding: Set by libavcodec.
1083  */
1084  int width;
1085  int height;
1086 
1087  /**
1088  * position of the top left corner in 1/16 pel for up to 3 fields/frames
1089  * - encoding: Set by user.
1090  * - decoding: Set by libavcodec.
1091  */
1092  int16_t position[3][2];
1093 } AVPanScan;
1094 
1095 /**
1096  * This structure describes the bitrate properties of an encoded bitstream. It
1097  * roughly corresponds to a subset the VBV parameters for MPEG-2 or HRD
1098  * parameters for H.264/HEVC.
1099  */
1100 typedef struct AVCPBProperties {
1101  /**
1102  * Maximum bitrate of the stream, in bits per second.
1103  * Zero if unknown or unspecified.
1104  */
1106  /**
1107  * Minimum bitrate of the stream, in bits per second.
1108  * Zero if unknown or unspecified.
1109  */
1111  /**
1112  * Average bitrate of the stream, in bits per second.
1113  * Zero if unknown or unspecified.
1114  */
1116 
1117  /**
1118  * The size of the buffer to which the ratecontrol is applied, in bits.
1119  * Zero if unknown or unspecified.
1120  */
1122 
1123  /**
1124  * The delay between the time the packet this structure is associated with
1125  * is received and the time when it should be decoded, in periods of a 27MHz
1126  * clock.
1127  *
1128  * UINT64_MAX when unknown or unspecified.
1129  */
1130  uint64_t vbv_delay;
1131 } AVCPBProperties;
1132 
1133 /**
1134  * The decoder will keep a reference to the frame and may reuse it later.
1135  */
1136 #define AV_GET_BUFFER_FLAG_REF (1 << 0)
1137 
1138 /**
1139  * @defgroup lavc_packet AVPacket
1140  *
1141  * Types and functions for working with AVPacket.
1142  * @{
1143  */
1145  /**
1146  * An AV_PKT_DATA_PALETTE side data packet contains exactly AVPALETTE_SIZE
1147  * bytes worth of palette. This side data signals that a new palette is
1148  * present.
1149  */
1151 
1152  /**
1153  * The AV_PKT_DATA_NEW_EXTRADATA is used to notify the codec or the format
1154  * that the extradata buffer was changed and the receiving side should
1155  * act upon it appropriately. The new extradata is embedded in the side
1156  * data buffer and should be immediately used for processing the current
1157  * frame or packet.
1158  */
1160 
1161  /**
1162  * An AV_PKT_DATA_PARAM_CHANGE side data packet is laid out as follows:
1163  * @code
1164  * u32le param_flags
1165  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT)
1166  * s32le channel_count
1167  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT)
1168  * u64le channel_layout
1169  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE)
1170  * s32le sample_rate
1171  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS)
1172  * s32le width
1173  * s32le height
1174  * @endcode
1175  */
1177 
1178  /**
1179  * An AV_PKT_DATA_H263_MB_INFO side data packet contains a number of
1180  * structures with info about macroblocks relevant to splitting the
1181  * packet into smaller packets on macroblock edges (e.g. as for RFC 2190).
1182  * That is, it does not necessarily contain info about all macroblocks,
1183  * as long as the distance between macroblocks in the info is smaller
1184  * than the target payload size.
1185  * Each MB info structure is 12 bytes, and is laid out as follows:
1186  * @code
1187  * u32le bit offset from the start of the packet
1188  * u8 current quantizer at the start of the macroblock
1189  * u8 GOB number
1190  * u16le macroblock address within the GOB
1191  * u8 horizontal MV predictor
1192  * u8 vertical MV predictor
1193  * u8 horizontal MV predictor for block number 3
1194  * u8 vertical MV predictor for block number 3
1195  * @endcode
1196  */
1198 
1199  /**
1200  * This side data should be associated with an audio stream and contains
1201  * ReplayGain information in form of the AVReplayGain struct.
1202  */
1204 
1205  /**
1206  * This side data contains a 3x3 transformation matrix describing an affine
1207  * transformation that needs to be applied to the decoded video frames for
1208  * correct presentation.
1209  *
1210  * See libavutil/display.h for a detailed description of the data.
1211  */
1213 
1214  /**
1215  * This side data should be associated with a video stream and contains
1216  * Stereoscopic 3D information in form of the AVStereo3D struct.
1217  */
1219 
1220  /**
1221  * This side data should be associated with an audio stream and corresponds
1222  * to enum AVAudioServiceType.
1223  */
1225 
1226  /**
1227  * This side data contains quality related information from the encoder.
1228  * @code
1229  * u32le quality factor of the compressed frame. Allowed range is between 1 (good) and FF_LAMBDA_MAX (bad).
1230  * u8 picture type
1231  * u8 error count
1232  * u16 reserved
1233  * u64le[error count] sum of squared differences between encoder in and output
1234  * @endcode
1235  */
1237 
1238  /**
1239  * This side data contains an integer value representing the stream index
1240  * of a "fallback" track. A fallback track indicates an alternate
1241  * track to use when the current track can not be decoded for some reason.
1242  * e.g. no decoder available for codec.
1243  */
1245 
1246  /**
1247  * This side data corresponds to the AVCPBProperties struct.
1248  */
1250 
1251  /**
1252  * Recommmends skipping the specified number of samples
1253  * @code
1254  * u32le number of samples to skip from start of this packet
1255  * u32le number of samples to skip from end of this packet
1256  * u8 reason for start skip
1257  * u8 reason for end skip (0=padding silence, 1=convergence)
1258  * @endcode
1259  */
1261 
1262  /**
1263  * An AV_PKT_DATA_JP_DUALMONO side data packet indicates that
1264  * the packet may contain "dual mono" audio specific to Japanese DTV
1265  * and if it is true, recommends only the selected channel to be used.
1266  * @code
1267  * u8 selected channels (0=mail/left, 1=sub/right, 2=both)
1268  * @endcode
1269  */
1271 
1272  /**
1273  * A list of zero terminated key/value strings. There is no end marker for
1274  * the list, so it is required to rely on the side data size to stop.
1275  */
1277 
1278  /**
1279  * Subtitle event position
1280  * @code
1281  * u32le x1
1282  * u32le y1
1283  * u32le x2
1284  * u32le y2
1285  * @endcode
1286  */
1288 
1289  /**
1290  * Data found in BlockAdditional element of matroska container. There is
1291  * no end marker for the data, so it is required to rely on the side data
1292  * size to recognize the end. 8 byte id (as found in BlockAddId) followed
1293  * by data.
1294  */
1296 
1297  /**
1298  * The optional first identifier line of a WebVTT cue.
1299  */
1301 
1302  /**
1303  * The optional settings (rendering instructions) that immediately
1304  * follow the timestamp specifier of a WebVTT cue.
1305  */
1307 
1308  /**
1309  * A list of zero terminated key/value strings. There is no end marker for
1310  * the list, so it is required to rely on the side data size to stop. This
1311  * side data includes updated metadata which appeared in the stream.
1312  */
1314 
1315  /**
1316  * MPEGTS stream ID, this is required to pass the stream ID
1317  * information from the demuxer to the corresponding muxer.
1318  */
1320 
1321  /**
1322  * Mastering display metadata (based on SMPTE-2086:2014). This metadata
1323  * should be associated with a video stream and contains data in the form
1324  * of the AVMasteringDisplayMetadata struct.
1325  */
1327 
1328  /**
1329  * This side data should be associated with a video stream and corresponds
1330  * to the AVSphericalMapping structure.
1331  */
1333 
1334  /**
1335  * Content light level (based on CTA-861.3). This metadata should be
1336  * associated with a video stream and contains data in the form of the
1337  * AVContentLightMetadata struct.
1338  */
1340 
1341  /**
1342  * ATSC A53 Part 4 Closed Captions. This metadata should be associated with
1343  * a video stream. A53 CC bitstream is stored as uint8_t in AVPacketSideData.data.
1344  * The number of bytes of CC data is AVPacketSideData.size.
1345  */
1347 
1348  /**
1349  * This side data is encryption initialization data.
1350  * The format is not part of ABI, use av_encryption_init_info_* methods to
1351  * access.
1352  */
1354 
1355  /**
1356  * This side data contains encryption info for how to decrypt the packet.
1357  * The format is not part of ABI, use av_encryption_info_* methods to access.
1358  */
1360 
1361  /**
1362  * The number of side data types.
1363  * This is not part of the public API/ABI in the sense that it may
1364  * change when new side data types are added.
1365  * This must stay the last enum value.
1366  * If its value becomes huge, some code using it
1367  * needs to be updated as it assumes it to be smaller than other limits.
1368  */
1370 };
1371 
1372 #define AV_PKT_DATA_QUALITY_FACTOR AV_PKT_DATA_QUALITY_STATS //DEPRECATED
1373 
1374 typedef struct AVPacketSideData {
1376  int size;
1379 
1380 /**
1381  * This structure stores compressed data. It is typically exported by demuxers
1382  * and then passed as input to decoders, or received as output from encoders and
1383  * then passed to muxers.
1384  *
1385  * For video, it should typically contain one compressed frame. For audio it may
1386  * contain several compressed frames. Encoders are allowed to output empty
1387  * packets, with no compressed data, containing only side data
1388  * (e.g. to update some stream parameters at the end of encoding).
1389  *
1390  * AVPacket is one of the few structs in FFmpeg, whose size is a part of public
1391  * ABI. Thus it may be allocated on stack and no new fields can be added to it
1392  * without libavcodec and libavformat major bump.
1393  *
1394  * The semantics of data ownership depends on the buf field.
1395  * If it is set, the packet data is dynamically allocated and is
1396  * valid indefinitely until a call to av_packet_unref() reduces the
1397  * reference count to 0.
1398  *
1399  * If the buf field is not set av_packet_ref() would make a copy instead
1400  * of increasing the reference count.
1401  *
1402  * The side data is always allocated with av_malloc(), copied by
1403  * av_packet_ref() and freed by av_packet_unref().
1404  *
1405  * @see av_packet_ref
1406  * @see av_packet_unref
1407  */
1408 typedef struct AVPacket {
1409  /**
1410  * A reference to the reference-counted buffer where the packet data is
1411  * stored.
1412  * May be NULL, then the packet data is not reference-counted.
1413  */
1415  /**
1416  * Presentation timestamp in AVStream->time_base units; the time at which
1417  * the decompressed packet will be presented to the user.
1418  * Can be AV_NOPTS_VALUE if it is not stored in the file.
1419  * pts MUST be larger or equal to dts as presentation cannot happen before
1420  * decompression, unless one wants to view hex dumps. Some formats misuse
1421  * the terms dts and pts/cts to mean something different. Such timestamps
1422  * must be converted to true pts/dts before they are stored in AVPacket.
1423  */
1424  int64_t pts;
1425  /**
1426  * Decompression timestamp in AVStream->time_base units; the time at which
1427  * the packet is decompressed.
1428  * Can be AV_NOPTS_VALUE if it is not stored in the file.
1429  */
1430  int64_t dts;
1432  int size;
1434  /**
1435  * A combination of AV_PKT_FLAG values
1436  */
1437  int flags;
1438  /**
1439  * Additional packet data that can be provided by the container.
1440  * Packet can contain several types of side information.
1441  */
1444 
1445  /**
1446  * Duration of this packet in AVStream->time_base units, 0 if unknown.
1447  * Equals next_pts - this_pts in presentation order.
1448  */
1449  int64_t duration;
1450 
1451  int64_t pos; ///< byte position in stream, -1 if unknown
1452 
1453 #if FF_API_CONVERGENCE_DURATION
1454  /**
1455  * @deprecated Same as the duration field, but as int64_t. This was required
1456  * for Matroska subtitles, whose duration values could overflow when the
1457  * duration field was still an int.
1458  */
1461 #endif
1462 } AVPacket;
1463 #define AV_PKT_FLAG_KEY 0x0001 ///< The packet contains a keyframe
1464 #define AV_PKT_FLAG_CORRUPT 0x0002 ///< The packet content is corrupted
1465 /**
1466  * Flag is used to discard packets which are required to maintain valid
1467  * decoder state but are not required for output and should be dropped
1468  * after decoding.
1469  **/
1470 #define AV_PKT_FLAG_DISCARD 0x0004
1471 /**
1472  * The packet comes from a trusted source.
1473  *
1474  * Otherwise-unsafe constructs such as arbitrary pointers to data
1475  * outside the packet may be followed.
1476  */
1477 #define AV_PKT_FLAG_TRUSTED 0x0008
1478 /**
1479  * Flag is used to indicate packets that contain frames that can
1480  * be discarded by the decoder. I.e. Non-reference frames.
1481  */
1482 #define AV_PKT_FLAG_DISPOSABLE 0x0010
1483 
1484 
1490 };
1491 /**
1492  * @}
1493  */
1494 
1495 struct AVCodecInternal;
1496 
1500  AV_FIELD_TT, //< Top coded_first, top displayed first
1501  AV_FIELD_BB, //< Bottom coded first, bottom displayed first
1502  AV_FIELD_TB, //< Top coded first, bottom displayed first
1503  AV_FIELD_BT, //< Bottom coded first, top displayed first
1504 };
1505 
1506 /**
1507  * main external API structure.
1508  * New fields can be added to the end with minor version bumps.
1509  * Removal, reordering and changes to existing fields require a major
1510  * version bump.
1511  * You can use AVOptions (av_opt* / av_set/get*()) to access these fields from user
1512  * applications.
1513  * The name string for AVOptions options matches the associated command line
1514  * parameter name and can be found in libavcodec/options_table.h
1515  * The AVOption/command line parameter names differ in some cases from the C
1516  * structure field names for historic reasons or brevity.
1517  * sizeof(AVCodecContext) must not be used outside libav*.
1518  */
1519 typedef struct AVCodecContext {
1520  /**
1521  * information on struct for av_log
1522  * - set by avcodec_alloc_context3
1523  */
1526 
1527  enum AVMediaType codec_type; /* see AVMEDIA_TYPE_xxx */
1528  const struct AVCodec *codec;
1529  enum AVCodecID codec_id; /* see AV_CODEC_ID_xxx */
1530 
1531  /**
1532  * fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
1533  * This is used to work around some encoder bugs.
1534  * A demuxer should set this to what is stored in the field used to identify the codec.
1535  * If there are multiple such fields in a container then the demuxer should choose the one
1536  * which maximizes the information about the used codec.
1537  * If the codec tag field in a container is larger than 32 bits then the demuxer should
1538  * remap the longer ID to 32 bits with a table or other structure. Alternatively a new
1539  * extra_codec_tag + size could be added but for this a clear advantage must be demonstrated
1540  * first.
1541  * - encoding: Set by user, if not then the default based on codec_id will be used.
1542  * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
1543  */
1544  unsigned int codec_tag;
1545 
1546  void *priv_data;
1547 
1548  /**
1549  * Private context used for internal data.
1550  *
1551  * Unlike priv_data, this is not codec-specific. It is used in general
1552  * libavcodec functions.
1553  */
1554  struct AVCodecInternal *internal;
1555 
1556  /**
1557  * Private data of the user, can be used to carry app specific stuff.
1558  * - encoding: Set by user.
1559  * - decoding: Set by user.
1560  */
1561  void *opaque;
1562 
1563  /**
1564  * the average bitrate
1565  * - encoding: Set by user; unused for constant quantizer encoding.
1566  * - decoding: Set by user, may be overwritten by libavcodec
1567  * if this info is available in the stream
1568  */
1569  int64_t bit_rate;
1570 
1571  /**
1572  * number of bits the bitstream is allowed to diverge from the reference.
1573  * the reference can be CBR (for CBR pass1) or VBR (for pass2)
1574  * - encoding: Set by user; unused for constant quantizer encoding.
1575  * - decoding: unused
1576  */
1578 
1579  /**
1580  * Global quality for codecs which cannot change it per frame.
1581  * This should be proportional to MPEG-1/2/4 qscale.
1582  * - encoding: Set by user.
1583  * - decoding: unused
1584  */
1586 
1587  /**
1588  * - encoding: Set by user.
1589  * - decoding: unused
1590  */
1592 #define FF_COMPRESSION_DEFAULT -1
1593 
1594  /**
1595  * AV_CODEC_FLAG_*.
1596  * - encoding: Set by user.
1597  * - decoding: Set by user.
1598  */
1599  int flags;
1600 
1601  /**
1602  * AV_CODEC_FLAG2_*
1603  * - encoding: Set by user.
1604  * - decoding: Set by user.
1605  */
1606  int flags2;
1607 
1608  /**
1609  * some codecs need / can use extradata like Huffman tables.
1610  * MJPEG: Huffman tables
1611  * rv10: additional flags
1612  * MPEG-4: global headers (they can be in the bitstream or here)
1613  * The allocated memory should be AV_INPUT_BUFFER_PADDING_SIZE bytes larger
1614  * than extradata_size to avoid problems if it is read with the bitstream reader.
1615  * The bytewise contents of extradata must not depend on the architecture or CPU endianness.
1616  * - encoding: Set/allocated/freed by libavcodec.
1617  * - decoding: Set/allocated/freed by user.
1618  */
1621 
1622  /**
1623  * This is the fundamental unit of time (in seconds) in terms
1624  * of which frame timestamps are represented. For fixed-fps content,
1625  * timebase should be 1/framerate and timestamp increments should be
1626  * identically 1.
1627  * This often, but not always is the inverse of the frame rate or field rate
1628  * for video. 1/time_base is not the average frame rate if the frame rate is not
1629  * constant.
1630  *
1631  * Like containers, elementary streams also can store timestamps, 1/time_base
1632  * is the unit in which these timestamps are specified.
1633  * As example of such codec time base see ISO/IEC 14496-2:2001(E)
1634  * vop_time_increment_resolution and fixed_vop_rate
1635  * (fixed_vop_rate == 0 implies that it is different from the framerate)
1636  *
1637  * - encoding: MUST be set by user.
1638  * - decoding: the use of this field for decoding is deprecated.
1639  * Use framerate instead.
1640  */
1642 
1643  /**
1644  * For some codecs, the time base is closer to the field rate than the frame rate.
1645  * Most notably, H.264 and MPEG-2 specify time_base as half of frame duration
1646  * if no telecine is used ...
1647  *
1648  * Set to time_base ticks per frame. Default 1, e.g., H.264/MPEG-2 set it to 2.
1649  */
1651 
1652  /**
1653  * Codec delay.
1654  *
1655  * Encoding: Number of frames delay there will be from the encoder input to
1656  * the decoder output. (we assume the decoder matches the spec)
1657  * Decoding: Number of frames delay in addition to what a standard decoder
1658  * as specified in the spec would produce.
1659  *
1660  * Video:
1661  * Number of frames the decoded output will be delayed relative to the
1662  * encoded input.
1663  *
1664  * Audio:
1665  * For encoding, this field is unused (see initial_padding).
1666  *
1667  * For decoding, this is the number of samples the decoder needs to
1668  * output before the decoder's output is valid. When seeking, you should
1669  * start decoding this many samples prior to your desired seek point.
1670  *
1671  * - encoding: Set by libavcodec.
1672  * - decoding: Set by libavcodec.
1673  */
1674  int delay;
1675 
1676 
1677  /* video only */
1678  /**
1679  * picture width / height.
1680  *
1681  * @note Those fields may not match the values of the last
1682  * AVFrame output by avcodec_decode_video2 due frame
1683  * reordering.
1684  *
1685  * - encoding: MUST be set by user.
1686  * - decoding: May be set by the user before opening the decoder if known e.g.
1687  * from the container. Some decoders will require the dimensions
1688  * to be set by the caller. During decoding, the decoder may
1689  * overwrite those values as required while parsing the data.
1690  */
1692 
1693  /**
1694  * Bitstream width / height, may be different from width/height e.g. when
1695  * the decoded frame is cropped before being output or lowres is enabled.
1696  *
1697  * @note Those field may not match the value of the last
1698  * AVFrame output by avcodec_receive_frame() due frame
1699  * reordering.
1700  *
1701  * - encoding: unused
1702  * - decoding: May be set by the user before opening the decoder if known
1703  * e.g. from the container. During decoding, the decoder may
1704  * overwrite those values as required while parsing the data.
1705  */
1707 
1708  /**
1709  * the number of pictures in a group of pictures, or 0 for intra_only
1710  * - encoding: Set by user.
1711  * - decoding: unused
1712  */
1714 
1715  /**
1716  * Pixel format, see AV_PIX_FMT_xxx.
1717  * May be set by the demuxer if known from headers.
1718  * May be overridden by the decoder if it knows better.
1719  *
1720  * @note This field may not match the value of the last
1721  * AVFrame output by avcodec_receive_frame() due frame
1722  * reordering.
1723  *
1724  * - encoding: Set by user.
1725  * - decoding: Set by user if known, overridden by libavcodec while
1726  * parsing the data.
1727  */
1729 
1730  /**
1731  * If non NULL, 'draw_horiz_band' is called by the libavcodec
1732  * decoder to draw a horizontal band. It improves cache usage. Not
1733  * all codecs can do that. You must check the codec capabilities
1734  * beforehand.
1735  * When multithreading is used, it may be called from multiple threads
1736  * at the same time; threads might draw different parts of the same AVFrame,
1737  * or multiple AVFrames, and there is no guarantee that slices will be drawn
1738  * in order.
1739  * The function is also used by hardware acceleration APIs.
1740  * It is called at least once during frame decoding to pass
1741  * the data needed for hardware render.
1742  * In that mode instead of pixel data, AVFrame points to
1743  * a structure specific to the acceleration API. The application
1744  * reads the structure and can change some fields to indicate progress
1745  * or mark state.
1746  * - encoding: unused
1747  * - decoding: Set by user.
1748  * @param height the height of the slice
1749  * @param y the y position of the slice
1750  * @param type 1->top field, 2->bottom field, 3->frame
1751  * @param offset offset into the AVFrame.data from which the slice should be read
1752  */
1754  const AVFrame *src, int offset[AV_NUM_DATA_POINTERS],
1755  int y, int type, int height);
1756 
1757  /**
1758  * callback to negotiate the pixelFormat
1759  * @param fmt is the list of formats which are supported by the codec,
1760  * it is terminated by -1 as 0 is a valid format, the formats are ordered by quality.
1761  * The first is always the native one.
1762  * @note The callback may be called again immediately if initialization for
1763  * the selected (hardware-accelerated) pixel format failed.
1764  * @warning Behavior is undefined if the callback returns a value not
1765  * in the fmt list of formats.
1766  * @return the chosen format
1767  * - encoding: unused
1768  * - decoding: Set by user, if not set the native format will be chosen.
1769  */
1770  enum AVPixelFormat (*get_format)(struct AVCodecContext *s, const enum AVPixelFormat * fmt);
1771 
1772  /**
1773  * maximum number of B-frames between non-B-frames
1774  * Note: The output will be delayed by max_b_frames+1 relative to the input.
1775  * - encoding: Set by user.
1776  * - decoding: unused
1777  */
1779 
1780  /**
1781  * qscale factor between IP and B-frames
1782  * If > 0 then the last P-frame quantizer will be used (q= lastp_q*factor+offset).
1783  * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1784  * - encoding: Set by user.
1785  * - decoding: unused
1786  */
1788 
1789 #if FF_API_PRIVATE_OPT
1790  /** @deprecated use encoder private options instead */
1793 #endif
1794 
1795  /**
1796  * qscale offset between IP and B-frames
1797  * - encoding: Set by user.
1798  * - decoding: unused
1799  */
1801 
1802  /**
1803  * Size of the frame reordering buffer in the decoder.
1804  * For MPEG-2 it is 1 IPB or 0 low delay IP.
1805  * - encoding: Set by libavcodec.
1806  * - decoding: Set by libavcodec.
1807  */
1809 
1810 #if FF_API_PRIVATE_OPT
1811  /** @deprecated use encoder private options instead */
1814 #endif
1815 
1816  /**
1817  * qscale factor between P- and I-frames
1818  * If > 0 then the last P-frame quantizer will be used (q = lastp_q * factor + offset).
1819  * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1820  * - encoding: Set by user.
1821  * - decoding: unused
1822  */
1824 
1825  /**
1826  * qscale offset between P and I-frames
1827  * - encoding: Set by user.
1828  * - decoding: unused
1829  */
1831 
1832  /**
1833  * luminance masking (0-> disabled)
1834  * - encoding: Set by user.
1835  * - decoding: unused
1836  */
1838 
1839  /**
1840  * temporary complexity masking (0-> disabled)
1841  * - encoding: Set by user.
1842  * - decoding: unused
1843  */
1845 
1846  /**
1847  * spatial complexity masking (0-> disabled)
1848  * - encoding: Set by user.
1849  * - decoding: unused
1850  */
1852 
1853  /**
1854  * p block masking (0-> disabled)
1855  * - encoding: Set by user.
1856  * - decoding: unused
1857  */
1858  float p_masking;
1859 
1860  /**
1861  * darkness masking (0-> disabled)
1862  * - encoding: Set by user.
1863  * - decoding: unused
1864  */
1866 
1867  /**
1868  * slice count
1869  * - encoding: Set by libavcodec.
1870  * - decoding: Set by user (or 0).
1871  */
1873 
1874 #if FF_API_PRIVATE_OPT
1875  /** @deprecated use encoder private options instead */
1878 #define FF_PRED_LEFT 0
1879 #define FF_PRED_PLANE 1
1880 #define FF_PRED_MEDIAN 2
1881 #endif
1882 
1883  /**
1884  * slice offsets in the frame in bytes
1885  * - encoding: Set/allocated by libavcodec.
1886  * - decoding: Set/allocated by user (or NULL).
1887  */
1889 
1890  /**
1891  * sample aspect ratio (0 if unknown)
1892  * That is the width of a pixel divided by the height of the pixel.
1893  * Numerator and denominator must be relatively prime and smaller than 256 for some video standards.
1894  * - encoding: Set by user.
1895  * - decoding: Set by libavcodec.
1896  */
1898 
1899  /**
1900  * motion estimation comparison function
1901  * - encoding: Set by user.
1902  * - decoding: unused
1903  */
1904  int me_cmp;
1905  /**
1906  * subpixel motion estimation comparison function
1907  * - encoding: Set by user.
1908  * - decoding: unused
1909  */
1911  /**
1912  * macroblock comparison function (not supported yet)
1913  * - encoding: Set by user.
1914  * - decoding: unused
1915  */
1916  int mb_cmp;
1917  /**
1918  * interlaced DCT comparison function
1919  * - encoding: Set by user.
1920  * - decoding: unused
1921  */
1923 #define FF_CMP_SAD 0
1924 #define FF_CMP_SSE 1
1925 #define FF_CMP_SATD 2
1926 #define FF_CMP_DCT 3
1927 #define FF_CMP_PSNR 4
1928 #define FF_CMP_BIT 5
1929 #define FF_CMP_RD 6
1930 #define FF_CMP_ZERO 7
1931 #define FF_CMP_VSAD 8
1932 #define FF_CMP_VSSE 9
1933 #define FF_CMP_NSSE 10
1934 #define FF_CMP_W53 11
1935 #define FF_CMP_W97 12
1936 #define FF_CMP_DCTMAX 13
1937 #define FF_CMP_DCT264 14
1938 #define FF_CMP_MEDIAN_SAD 15
1939 #define FF_CMP_CHROMA 256
1940 
1941  /**
1942  * ME diamond size & shape
1943  * - encoding: Set by user.
1944  * - decoding: unused
1945  */
1947 
1948  /**
1949  * amount of previous MV predictors (2a+1 x 2a+1 square)
1950  * - encoding: Set by user.
1951  * - decoding: unused
1952  */
1954 
1955 #if FF_API_PRIVATE_OPT
1956  /** @deprecated use encoder private options instead */
1958  int pre_me;
1959 #endif
1960 
1961  /**
1962  * motion estimation prepass comparison function
1963  * - encoding: Set by user.
1964  * - decoding: unused
1965  */
1967 
1968  /**
1969  * ME prepass diamond size & shape
1970  * - encoding: Set by user.
1971  * - decoding: unused
1972  */
1974 
1975  /**
1976  * subpel ME quality
1977  * - encoding: Set by user.
1978  * - decoding: unused
1979  */
1981 
1982  /**
1983  * maximum motion estimation search range in subpel units
1984  * If 0 then no limit.
1985  *
1986  * - encoding: Set by user.
1987  * - decoding: unused
1988  */
1990 
1991  /**
1992  * slice flags
1993  * - encoding: unused
1994  * - decoding: Set by user.
1995  */
1997 #define SLICE_FLAG_CODED_ORDER 0x0001 ///< draw_horiz_band() is called in coded order instead of display
1998 #define SLICE_FLAG_ALLOW_FIELD 0x0002 ///< allow draw_horiz_band() with field slices (MPEG-2 field pics)
1999 #define SLICE_FLAG_ALLOW_PLANE 0x0004 ///< allow draw_horiz_band() with 1 component at a time (SVQ1)
2000 
2001  /**
2002  * macroblock decision mode
2003  * - encoding: Set by user.
2004  * - decoding: unused
2005  */
2007 #define FF_MB_DECISION_SIMPLE 0 ///< uses mb_cmp
2008 #define FF_MB_DECISION_BITS 1 ///< chooses the one which needs the fewest bits
2009 #define FF_MB_DECISION_RD 2 ///< rate distortion
2010 
2011  /**
2012  * custom intra quantization matrix
2013  * - encoding: Set by user, can be NULL.
2014  * - decoding: Set by libavcodec.
2015  */
2016  uint16_t *intra_matrix;
2017 
2018  /**
2019  * custom inter quantization matrix
2020  * - encoding: Set by user, can be NULL.
2021  * - decoding: Set by libavcodec.
2022  */
2023  uint16_t *inter_matrix;
2024 
2025 #if FF_API_PRIVATE_OPT
2026  /** @deprecated use encoder private options instead */
2029 
2030  /** @deprecated use encoder private options instead */
2033 #endif
2034 
2035  /**
2036  * precision of the intra DC coefficient - 8
2037  * - encoding: Set by user.
2038  * - decoding: Set by libavcodec
2039  */
2041 
2042  /**
2043  * Number of macroblock rows at the top which are skipped.
2044  * - encoding: unused
2045  * - decoding: Set by user.
2046  */
2048 
2049  /**
2050  * Number of macroblock rows at the bottom which are skipped.
2051  * - encoding: unused
2052  * - decoding: Set by user.
2053  */
2055 
2056  /**
2057  * minimum MB Lagrange multiplier
2058  * - encoding: Set by user.
2059  * - decoding: unused
2060  */
2061  int mb_lmin;
2062 
2063  /**
2064  * maximum MB Lagrange multiplier
2065  * - encoding: Set by user.
2066  * - decoding: unused
2067  */
2068  int mb_lmax;
2069 
2070 #if FF_API_PRIVATE_OPT
2071  /**
2072  * @deprecated use encoder private options instead
2073  */
2076 #endif
2077 
2078  /**
2079  * - encoding: Set by user.
2080  * - decoding: unused
2081  */
2083 
2084 #if FF_API_PRIVATE_OPT
2085  /** @deprecated use encoder private options instead */
2088 #endif
2089 
2090  /**
2091  * minimum GOP size
2092  * - encoding: Set by user.
2093  * - decoding: unused
2094  */
2096 
2097  /**
2098  * number of reference frames
2099  * - encoding: Set by user.
2100  * - decoding: Set by lavc.
2101  */
2102  int refs;
2103 
2104 #if FF_API_PRIVATE_OPT
2105  /** @deprecated use encoder private options instead */
2108 #endif
2109 
2110  /**
2111  * Note: Value depends upon the compare function used for fullpel ME.
2112  * - encoding: Set by user.
2113  * - decoding: unused
2114  */
2116 
2117 #if FF_API_PRIVATE_OPT
2118  /** @deprecated use encoder private options instead */
2121 #endif
2122 
2123  /**
2124  * Chromaticity coordinates of the source primaries.
2125  * - encoding: Set by user
2126  * - decoding: Set by libavcodec
2127  */
2129 
2130  /**
2131  * Color Transfer Characteristic.
2132  * - encoding: Set by user
2133  * - decoding: Set by libavcodec
2134  */
2136 
2137  /**
2138  * YUV colorspace type.
2139  * - encoding: Set by user
2140  * - decoding: Set by libavcodec
2141  */
2143 
2144  /**
2145  * MPEG vs JPEG YUV range.
2146  * - encoding: Set by user
2147  * - decoding: Set by libavcodec
2148  */
2150 
2151  /**
2152  * This defines the location of chroma samples.
2153  * - encoding: Set by user
2154  * - decoding: Set by libavcodec
2155  */
2157 
2158  /**
2159  * Number of slices.
2160  * Indicates number of picture subdivisions. Used for parallelized
2161  * decoding.
2162  * - encoding: Set by user
2163  * - decoding: unused
2164  */
2165  int slices;
2166 
2167  /** Field order
2168  * - encoding: set by libavcodec
2169  * - decoding: Set by user.
2170  */
2172 
2173  /* audio only */
2174  int sample_rate; ///< samples per second
2175  int channels; ///< number of audio channels
2176 
2177  /**
2178  * audio sample format
2179  * - encoding: Set by user.
2180  * - decoding: Set by libavcodec.
2181  */
2182  enum AVSampleFormat sample_fmt; ///< sample format
2183 
2184  /* The following data should not be initialized. */
2185  /**
2186  * Number of samples per channel in an audio frame.
2187  *
2188  * - encoding: set by libavcodec in avcodec_open2(). Each submitted frame
2189  * except the last must contain exactly frame_size samples per channel.
2190  * May be 0 when the codec has AV_CODEC_CAP_VARIABLE_FRAME_SIZE set, then the
2191  * frame size is not restricted.
2192  * - decoding: may be set by some decoders to indicate constant frame size
2193  */
2195 
2196  /**
2197  * Frame counter, set by libavcodec.
2198  *
2199  * - decoding: total number of frames returned from the decoder so far.
2200  * - encoding: total number of frames passed to the encoder so far.
2201  *
2202  * @note the counter is not incremented if encoding/decoding resulted in
2203  * an error.
2204  */
2206 
2207  /**
2208  * number of bytes per packet if constant and known or 0
2209  * Used by some WAV based audio codecs.
2210  */
2212 
2213  /**
2214  * Audio cutoff bandwidth (0 means "automatic")
2215  * - encoding: Set by user.
2216  * - decoding: unused
2217  */
2218  int cutoff;
2219 
2220  /**
2221  * Audio channel layout.
2222  * - encoding: set by user.
2223  * - decoding: set by user, may be overwritten by libavcodec.
2224  */
2225  uint64_t channel_layout;
2226 
2227  /**
2228  * Request decoder to use this channel layout if it can (0 for default)
2229  * - encoding: unused
2230  * - decoding: Set by user.
2231  */
2233 
2234  /**
2235  * Type of service that the audio stream conveys.
2236  * - encoding: Set by user.
2237  * - decoding: Set by libavcodec.
2238  */
2240 
2241  /**
2242  * desired sample format
2243  * - encoding: Not used.
2244  * - decoding: Set by user.
2245  * Decoder will decode to this format if it can.
2246  */
2248 
2249  /**
2250  * This callback is called at the beginning of each frame to get data
2251  * buffer(s) for it. There may be one contiguous buffer for all the data or
2252  * there may be a buffer per each data plane or anything in between. What
2253  * this means is, you may set however many entries in buf[] you feel necessary.
2254  * Each buffer must be reference-counted using the AVBuffer API (see description
2255  * of buf[] below).
2256  *
2257  * The following fields will be set in the frame before this callback is
2258  * called:
2259  * - format
2260  * - width, height (video only)
2261  * - sample_rate, channel_layout, nb_samples (audio only)
2262  * Their values may differ from the corresponding values in
2263  * AVCodecContext. This callback must use the frame values, not the codec
2264  * context values, to calculate the required buffer size.
2265  *
2266  * This callback must fill the following fields in the frame:
2267  * - data[]
2268  * - linesize[]
2269  * - extended_data:
2270  * * if the data is planar audio with more than 8 channels, then this
2271  * callback must allocate and fill extended_data to contain all pointers
2272  * to all data planes. data[] must hold as many pointers as it can.
2273  * extended_data must be allocated with av_malloc() and will be freed in
2274  * av_frame_unref().
2275  * * otherwise extended_data must point to data
2276  * - buf[] must contain one or more pointers to AVBufferRef structures. Each of
2277  * the frame's data and extended_data pointers must be contained in these. That
2278  * is, one AVBufferRef for each allocated chunk of memory, not necessarily one
2279  * AVBufferRef per data[] entry. See: av_buffer_create(), av_buffer_alloc(),
2280  * and av_buffer_ref().
2281  * - extended_buf and nb_extended_buf must be allocated with av_malloc() by
2282  * this callback and filled with the extra buffers if there are more
2283  * buffers than buf[] can hold. extended_buf will be freed in
2284  * av_frame_unref().
2285  *
2286  * If AV_CODEC_CAP_DR1 is not set then get_buffer2() must call
2287  * avcodec_default_get_buffer2() instead of providing buffers allocated by
2288  * some other means.
2289  *
2290  * Each data plane must be aligned to the maximum required by the target
2291  * CPU.
2292  *
2293  * @see avcodec_default_get_buffer2()
2294  *
2295  * Video:
2296  *
2297  * If AV_GET_BUFFER_FLAG_REF is set in flags then the frame may be reused
2298  * (read and/or written to if it is writable) later by libavcodec.
2299  *
2300  * avcodec_align_dimensions2() should be used to find the required width and
2301  * height, as they normally need to be rounded up to the next multiple of 16.
2302  *
2303  * Some decoders do not support linesizes changing between frames.
2304  *
2305  * If frame multithreading is used and thread_safe_callbacks is set,
2306  * this callback may be called from a different thread, but not from more
2307  * than one at once. Does not need to be reentrant.
2308  *
2309  * @see avcodec_align_dimensions2()
2310  *
2311  * Audio:
2312  *
2313  * Decoders request a buffer of a particular size by setting
2314  * AVFrame.nb_samples prior to calling get_buffer2(). The decoder may,
2315  * however, utilize only part of the buffer by setting AVFrame.nb_samples
2316  * to a smaller value in the output frame.
2317  *
2318  * As a convenience, av_samples_get_buffer_size() and
2319  * av_samples_fill_arrays() in libavutil may be used by custom get_buffer2()
2320  * functions to find the required data size and to fill data pointers and
2321  * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
2322  * since all planes must be the same size.
2323  *
2324  * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
2325  *
2326  * - encoding: unused
2327  * - decoding: Set by libavcodec, user can override.
2328  */
2330 
2331  /**
2332  * If non-zero, the decoded audio and video frames returned from
2333  * avcodec_decode_video2() and avcodec_decode_audio4() are reference-counted
2334  * and are valid indefinitely. The caller must free them with
2335  * av_frame_unref() when they are not needed anymore.
2336  * Otherwise, the decoded frames must not be freed by the caller and are
2337  * only valid until the next decode call.
2338  *
2339  * This is always automatically enabled if avcodec_receive_frame() is used.
2340  *
2341  * - encoding: unused
2342  * - decoding: set by the caller before avcodec_open2().
2343  */
2346 
2347  /* - encoding parameters */
2348  float qcompress; ///< amount of qscale change between easy & hard scenes (0.0-1.0)
2349  float qblur; ///< amount of qscale smoothing over time (0.0-1.0)
2350 
2351  /**
2352  * minimum quantizer
2353  * - encoding: Set by user.
2354  * - decoding: unused
2355  */
2356  int qmin;
2357 
2358  /**
2359  * maximum quantizer
2360  * - encoding: Set by user.
2361  * - decoding: unused
2362  */
2363  int qmax;
2364 
2365  /**
2366  * maximum quantizer difference between frames
2367  * - encoding: Set by user.
2368  * - decoding: unused
2369  */
2371 
2372  /**
2373  * decoder bitstream buffer size
2374  * - encoding: Set by user.
2375  * - decoding: unused
2376  */
2378 
2379  /**
2380  * ratecontrol override, see RcOverride
2381  * - encoding: Allocated/set/freed by user.
2382  * - decoding: unused
2383  */
2386 
2387  /**
2388  * maximum bitrate
2389  * - encoding: Set by user.
2390  * - decoding: Set by user, may be overwritten by libavcodec.
2391  */
2392  int64_t rc_max_rate;
2393 
2394  /**
2395  * minimum bitrate
2396  * - encoding: Set by user.
2397  * - decoding: unused
2398  */
2399  int64_t rc_min_rate;
2400 
2401  /**
2402  * Ratecontrol attempt to use, at maximum, <value> of what can be used without an underflow.
2403  * - encoding: Set by user.
2404  * - decoding: unused.
2405  */
2407 
2408  /**
2409  * Ratecontrol attempt to use, at least, <value> times the amount needed to prevent a vbv overflow.
2410  * - encoding: Set by user.
2411  * - decoding: unused.
2412  */
2414 
2415  /**
2416  * Number of bits which should be loaded into the rc buffer before decoding starts.
2417  * - encoding: Set by user.
2418  * - decoding: unused
2419  */
2421 
2422 #if FF_API_CODER_TYPE
2423 #define FF_CODER_TYPE_VLC 0
2424 #define FF_CODER_TYPE_AC 1
2425 #define FF_CODER_TYPE_RAW 2
2426 #define FF_CODER_TYPE_RLE 3
2427  /**
2428  * @deprecated use encoder private options instead
2429  */
2432 #endif /* FF_API_CODER_TYPE */
2433 
2434 #if FF_API_PRIVATE_OPT
2435  /** @deprecated use encoder private options instead */
2438 #endif
2439 
2440 #if FF_API_PRIVATE_OPT
2441  /** @deprecated use encoder private options instead */
2444 
2445  /** @deprecated use encoder private options instead */
2448 
2449  /** @deprecated use encoder private options instead */
2452 
2453  /** @deprecated use encoder private options instead */
2456 #endif /* FF_API_PRIVATE_OPT */
2457 
2458  /**
2459  * trellis RD quantization
2460  * - encoding: Set by user.
2461  * - decoding: unused
2462  */
2463  int trellis;
2464 
2465 #if FF_API_PRIVATE_OPT
2466  /** @deprecated use encoder private options instead */
2469 
2470  /** @deprecated use encoder private options instead */
2473 
2474  /** @deprecated use encoder private options instead */
2477 #endif
2478 
2479 #if FF_API_RTP_CALLBACK
2480  /**
2481  * @deprecated unused
2482  */
2483  /* The RTP callback: This function is called */
2484  /* every time the encoder has a packet to send. */
2485  /* It depends on the encoder if the data starts */
2486  /* with a Start Code (it should). H.263 does. */
2487  /* mb_nb contains the number of macroblocks */
2488  /* encoded in the RTP payload. */
2490  void (*rtp_callback)(struct AVCodecContext *avctx, void *data, int size, int mb_nb);
2491 #endif
2492 
2493 #if FF_API_PRIVATE_OPT
2494  /** @deprecated use encoder private options instead */
2496  int rtp_payload_size; /* The size of the RTP payload: the coder will */
2497  /* do its best to deliver a chunk with size */
2498  /* below rtp_payload_size, the chunk will start */
2499  /* with a start code on some codecs like H.263. */
2500  /* This doesn't take account of any particular */
2501  /* headers inside the transmitted RTP payload. */
2502 #endif
2503 
2504 #if FF_API_STAT_BITS
2505  /* statistics, used for 2-pass encoding */
2507  int mv_bits;
2515  int i_count;
2517  int p_count;
2522 
2523  /** @deprecated this field is unused */
2526 #endif
2527 
2528  /**
2529  * pass1 encoding statistics output buffer
2530  * - encoding: Set by libavcodec.
2531  * - decoding: unused
2532  */
2533  char *stats_out;
2534 
2535  /**
2536  * pass2 encoding statistics input buffer
2537  * Concatenated stuff from stats_out of pass1 should be placed here.
2538  * - encoding: Allocated/set/freed by user.
2539  * - decoding: unused
2540  */
2541  char *stats_in;
2542 
2543  /**
2544  * Work around bugs in encoders which sometimes cannot be detected automatically.
2545  * - encoding: Set by user
2546  * - decoding: Set by user
2547  */
2549 #define FF_BUG_AUTODETECT 1 ///< autodetection
2550 #define FF_BUG_XVID_ILACE 4
2551 #define FF_BUG_UMP4 8
2552 #define FF_BUG_NO_PADDING 16
2553 #define FF_BUG_AMV 32
2554 #define FF_BUG_QPEL_CHROMA 64
2555 #define FF_BUG_STD_QPEL 128
2556 #define FF_BUG_QPEL_CHROMA2 256
2557 #define FF_BUG_DIRECT_BLOCKSIZE 512
2558 #define FF_BUG_EDGE 1024
2559 #define FF_BUG_HPEL_CHROMA 2048
2560 #define FF_BUG_DC_CLIP 4096
2561 #define FF_BUG_MS 8192 ///< Work around various bugs in Microsoft's broken decoders.
2562 #define FF_BUG_TRUNCATED 16384
2563 #define FF_BUG_IEDGE 32768
2564 
2565  /**
2566  * strictly follow the standard (MPEG-4, ...).
2567  * - encoding: Set by user.
2568  * - decoding: Set by user.
2569  * Setting this to STRICT or higher means the encoder and decoder will
2570  * generally do stupid things, whereas setting it to unofficial or lower
2571  * will mean the encoder might produce output that is not supported by all
2572  * spec-compliant decoders. Decoders don't differentiate between normal,
2573  * unofficial and experimental (that is, they always try to decode things
2574  * when they can) unless they are explicitly asked to behave stupidly
2575  * (=strictly conform to the specs)
2576  */
2578 #define FF_COMPLIANCE_VERY_STRICT 2 ///< Strictly conform to an older more strict version of the spec or reference software.
2579 #define FF_COMPLIANCE_STRICT 1 ///< Strictly conform to all the things in the spec no matter what consequences.
2580 #define FF_COMPLIANCE_NORMAL 0
2581 #define FF_COMPLIANCE_UNOFFICIAL -1 ///< Allow unofficial extensions
2582 #define FF_COMPLIANCE_EXPERIMENTAL -2 ///< Allow nonstandardized experimental things.
2583 
2584  /**
2585  * error concealment flags
2586  * - encoding: unused
2587  * - decoding: Set by user.
2588  */
2590 #define FF_EC_GUESS_MVS 1
2591 #define FF_EC_DEBLOCK 2
2592 #define FF_EC_FAVOR_INTER 256
2593 
2594  /**
2595  * debug
2596  * - encoding: Set by user.
2597  * - decoding: Set by user.
2598  */
2599  int debug;
2600 #define FF_DEBUG_PICT_INFO 1
2601 #define FF_DEBUG_RC 2
2602 #define FF_DEBUG_BITSTREAM 4
2603 #define FF_DEBUG_MB_TYPE 8
2604 #define FF_DEBUG_QP 16
2605 #if FF_API_DEBUG_MV
2606 /**
2607  * @deprecated this option does nothing
2608  */
2609 #define FF_DEBUG_MV 32
2610 #endif
2611 #define FF_DEBUG_DCT_COEFF 0x00000040
2612 #define FF_DEBUG_SKIP 0x00000080
2613 #define FF_DEBUG_STARTCODE 0x00000100
2614 #define FF_DEBUG_ER 0x00000400
2615 #define FF_DEBUG_MMCO 0x00000800
2616 #define FF_DEBUG_BUGS 0x00001000
2617 #if FF_API_DEBUG_MV
2618 #define FF_DEBUG_VIS_QP 0x00002000
2619 #define FF_DEBUG_VIS_MB_TYPE 0x00004000
2620 #endif
2621 #define FF_DEBUG_BUFFERS 0x00008000
2622 #define FF_DEBUG_THREADS 0x00010000
2623 #define FF_DEBUG_GREEN_MD 0x00800000
2624 #define FF_DEBUG_NOMC 0x01000000
2625 
2626 #if FF_API_DEBUG_MV
2627  /**
2628  * debug
2629  * - encoding: Set by user.
2630  * - decoding: Set by user.
2631  */
2632  int debug_mv;
2633 #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 // visualize forward predicted MVs of P-frames
2634 #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 // visualize forward predicted MVs of B-frames
2635 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 // visualize backward predicted MVs of B-frames
2636 #endif
2637 
2638  /**
2639  * Error recognition; may misdetect some more or less valid parts as errors.
2640  * - encoding: unused
2641  * - decoding: Set by user.
2642  */
2644 
2645 /**
2646  * Verify checksums embedded in the bitstream (could be of either encoded or
2647  * decoded data, depending on the codec) and print an error message on mismatch.
2648  * If AV_EF_EXPLODE is also set, a mismatching checksum will result in the
2649  * decoder returning an error.
2650  */
2651 #define AV_EF_CRCCHECK (1<<0)
2652 #define AV_EF_BITSTREAM (1<<1) ///< detect bitstream specification deviations
2653 #define AV_EF_BUFFER (1<<2) ///< detect improper bitstream length
2654 #define AV_EF_EXPLODE (1<<3) ///< abort decoding on minor error detection
2655 
2656 #define AV_EF_IGNORE_ERR (1<<15) ///< ignore errors and continue
2657 #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
2658 #define AV_EF_COMPLIANT (1<<17) ///< consider all spec non compliances as errors
2659 #define AV_EF_AGGRESSIVE (1<<18) ///< consider things that a sane encoder should not do as an error
2660 
2661 
2662  /**
2663  * opaque 64-bit number (generally a PTS) that will be reordered and
2664  * output in AVFrame.reordered_opaque
2665  * - encoding: unused
2666  * - decoding: Set by user.
2667  */
2669 
2670  /**
2671  * Hardware accelerator in use
2672  * - encoding: unused.
2673  * - decoding: Set by libavcodec
2674  */
2675  const struct AVHWAccel *hwaccel;
2676 
2677  /**
2678  * Hardware accelerator context.
2679  * For some hardware accelerators, a global context needs to be
2680  * provided by the user. In that case, this holds display-dependent
2681  * data FFmpeg cannot instantiate itself. Please refer to the
2682  * FFmpeg HW accelerator documentation to know how to fill this
2683  * is. e.g. for VA API, this is a struct vaapi_context.
2684  * - encoding: unused
2685  * - decoding: Set by user
2686  */
2688 
2689  /**
2690  * error
2691  * - encoding: Set by libavcodec if flags & AV_CODEC_FLAG_PSNR.
2692  * - decoding: unused
2693  */
2695 
2696  /**
2697  * DCT algorithm, see FF_DCT_* below
2698  * - encoding: Set by user.
2699  * - decoding: unused
2700  */
2702 #define FF_DCT_AUTO 0
2703 #define FF_DCT_FASTINT 1
2704 #define FF_DCT_INT 2
2705 #define FF_DCT_MMX 3
2706 #define FF_DCT_ALTIVEC 5
2707 #define FF_DCT_FAAN 6
2708 
2709  /**
2710  * IDCT algorithm, see FF_IDCT_* below.
2711  * - encoding: Set by user.
2712  * - decoding: Set by user.
2713  */
2715 #define FF_IDCT_AUTO 0
2716 #define FF_IDCT_INT 1
2717 #define FF_IDCT_SIMPLE 2
2718 #define FF_IDCT_SIMPLEMMX 3
2719 #define FF_IDCT_ARM 7
2720 #define FF_IDCT_ALTIVEC 8
2721 #define FF_IDCT_SIMPLEARM 10
2722 #define FF_IDCT_XVID 14
2723 #define FF_IDCT_SIMPLEARMV5TE 16
2724 #define FF_IDCT_SIMPLEARMV6 17
2725 #define FF_IDCT_FAAN 20
2726 #define FF_IDCT_SIMPLENEON 22
2727 #define FF_IDCT_NONE 24 /* Used by XvMC to extract IDCT coefficients with FF_IDCT_PERM_NONE */
2728 #define FF_IDCT_SIMPLEAUTO 128
2729 
2730  /**
2731  * bits per sample/pixel from the demuxer (needed for huffyuv).
2732  * - encoding: Set by libavcodec.
2733  * - decoding: Set by user.
2734  */
2736 
2737  /**
2738  * Bits per sample/pixel of internal libavcodec pixel/sample format.
2739  * - encoding: set by user.
2740  * - decoding: set by libavcodec.
2741  */
2743 
2744 #if FF_API_LOWRES
2745  /**
2746  * low resolution decoding, 1-> 1/2 size, 2->1/4 size
2747  * - encoding: unused
2748  * - decoding: Set by user.
2749  */
2750  int lowres;
2751 #endif
2752 
2753 #if FF_API_CODED_FRAME
2754  /**
2755  * the picture in the bitstream
2756  * - encoding: Set by libavcodec.
2757  * - decoding: unused
2758  *
2759  * @deprecated use the quality factor packet side data instead
2760  */
2762 #endif
2763 
2764  /**
2765  * thread count
2766  * is used to decide how many independent tasks should be passed to execute()
2767  * - encoding: Set by user.
2768  * - decoding: Set by user.
2769  */
2771 
2772  /**
2773  * Which multithreading methods to use.
2774  * Use of FF_THREAD_FRAME will increase decoding delay by one frame per thread,
2775  * so clients which cannot provide future frames should not use it.
2776  *
2777  * - encoding: Set by user, otherwise the default is used.
2778  * - decoding: Set by user, otherwise the default is used.
2779  */
2781 #define FF_THREAD_FRAME 1 ///< Decode more than one frame at once
2782 #define FF_THREAD_SLICE 2 ///< Decode more than one part of a single frame at once
2783 
2784  /**
2785  * Which multithreading methods are in use by the codec.
2786  * - encoding: Set by libavcodec.
2787  * - decoding: Set by libavcodec.
2788  */
2790 
2791  /**
2792  * Set by the client if its custom get_buffer() callback can be called
2793  * synchronously from another thread, which allows faster multithreaded decoding.
2794  * draw_horiz_band() will be called from other threads regardless of this setting.
2795  * Ignored if the default get_buffer() is used.
2796  * - encoding: Set by user.
2797  * - decoding: Set by user.
2798  */
2800 
2801  /**
2802  * The codec may call this to execute several independent things.
2803  * It will return only after finishing all tasks.
2804  * The user may replace this with some multithreaded implementation,
2805  * the default implementation will execute the parts serially.
2806  * @param count the number of things to execute
2807  * - encoding: Set by libavcodec, user can override.
2808  * - decoding: Set by libavcodec, user can override.
2809  */
2810  int (*execute)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size);
2811 
2812  /**
2813  * The codec may call this to execute several independent things.
2814  * It will return only after finishing all tasks.
2815  * The user may replace this with some multithreaded implementation,
2816  * the default implementation will execute the parts serially.
2817  * Also see avcodec_thread_init and e.g. the --enable-pthread configure option.
2818  * @param c context passed also to func
2819  * @param count the number of things to execute
2820  * @param arg2 argument passed unchanged to func
2821  * @param ret return values of executed functions, must have space for "count" values. May be NULL.
2822  * @param func function that will be called count times, with jobnr from 0 to count-1.
2823  * threadnr will be in the range 0 to c->thread_count-1 < MAX_THREADS and so that no
2824  * two instances of func executing at the same time will have the same threadnr.
2825  * @return always 0 currently, but code should handle a future improvement where when any call to func
2826  * returns < 0 no further calls to func may be done and < 0 is returned.
2827  * - encoding: Set by libavcodec, user can override.
2828  * - decoding: Set by libavcodec, user can override.
2829  */
2830  int (*execute2)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count);
2831 
2832  /**
2833  * noise vs. sse weight for the nsse comparison function
2834  * - encoding: Set by user.
2835  * - decoding: unused
2836  */
2838 
2839  /**
2840  * profile
2841  * - encoding: Set by user.
2842  * - decoding: Set by libavcodec.
2843  */
2844  int profile;
2845 #define FF_PROFILE_UNKNOWN -99
2846 #define FF_PROFILE_RESERVED -100
2847 
2848 #define FF_PROFILE_AAC_MAIN 0
2849 #define FF_PROFILE_AAC_LOW 1
2850 #define FF_PROFILE_AAC_SSR 2
2851 #define FF_PROFILE_AAC_LTP 3
2852 #define FF_PROFILE_AAC_HE 4
2853 #define FF_PROFILE_AAC_HE_V2 28
2854 #define FF_PROFILE_AAC_LD 22
2855 #define FF_PROFILE_AAC_ELD 38
2856 #define FF_PROFILE_MPEG2_AAC_LOW 128
2857 #define FF_PROFILE_MPEG2_AAC_HE 131
2858 
2859 #define FF_PROFILE_DNXHD 0
2860 #define FF_PROFILE_DNXHR_LB 1
2861 #define FF_PROFILE_DNXHR_SQ 2
2862 #define FF_PROFILE_DNXHR_HQ 3
2863 #define FF_PROFILE_DNXHR_HQX 4
2864 #define FF_PROFILE_DNXHR_444 5
2865 
2866 #define FF_PROFILE_DTS 20
2867 #define FF_PROFILE_DTS_ES 30
2868 #define FF_PROFILE_DTS_96_24 40
2869 #define FF_PROFILE_DTS_HD_HRA 50
2870 #define FF_PROFILE_DTS_HD_MA 60
2871 #define FF_PROFILE_DTS_EXPRESS 70
2872 
2873 #define FF_PROFILE_MPEG2_422 0
2874 #define FF_PROFILE_MPEG2_HIGH 1
2875 #define FF_PROFILE_MPEG2_SS 2
2876 #define FF_PROFILE_MPEG2_SNR_SCALABLE 3
2877 #define FF_PROFILE_MPEG2_MAIN 4
2878 #define FF_PROFILE_MPEG2_SIMPLE 5
2879 
2880 #define FF_PROFILE_H264_CONSTRAINED (1<<9) // 8+1; constraint_set1_flag
2881 #define FF_PROFILE_H264_INTRA (1<<11) // 8+3; constraint_set3_flag
2882 
2883 #define FF_PROFILE_H264_BASELINE 66
2884 #define FF_PROFILE_H264_CONSTRAINED_BASELINE (66|FF_PROFILE_H264_CONSTRAINED)
2885 #define FF_PROFILE_H264_MAIN 77
2886 #define FF_PROFILE_H264_EXTENDED 88
2887 #define FF_PROFILE_H264_HIGH 100
2888 #define FF_PROFILE_H264_HIGH_10 110
2889 #define FF_PROFILE_H264_HIGH_10_INTRA (110|FF_PROFILE_H264_INTRA)
2890 #define FF_PROFILE_H264_MULTIVIEW_HIGH 118
2891 #define FF_PROFILE_H264_HIGH_422 122
2892 #define FF_PROFILE_H264_HIGH_422_INTRA (122|FF_PROFILE_H264_INTRA)
2893 #define FF_PROFILE_H264_STEREO_HIGH 128
2894 #define FF_PROFILE_H264_HIGH_444 144
2895 #define FF_PROFILE_H264_HIGH_444_PREDICTIVE 244
2896 #define FF_PROFILE_H264_HIGH_444_INTRA (244|FF_PROFILE_H264_INTRA)
2897 #define FF_PROFILE_H264_CAVLC_444 44
2898 
2899 #define FF_PROFILE_VC1_SIMPLE 0
2900 #define FF_PROFILE_VC1_MAIN 1
2901 #define FF_PROFILE_VC1_COMPLEX 2
2902 #define FF_PROFILE_VC1_ADVANCED 3
2903 
2904 #define FF_PROFILE_MPEG4_SIMPLE 0
2905 #define FF_PROFILE_MPEG4_SIMPLE_SCALABLE 1
2906 #define FF_PROFILE_MPEG4_CORE 2
2907 #define FF_PROFILE_MPEG4_MAIN 3
2908 #define FF_PROFILE_MPEG4_N_BIT 4
2909 #define FF_PROFILE_MPEG4_SCALABLE_TEXTURE 5
2910 #define FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION 6
2911 #define FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE 7
2912 #define FF_PROFILE_MPEG4_HYBRID 8
2913 #define FF_PROFILE_MPEG4_ADVANCED_REAL_TIME 9
2914 #define FF_PROFILE_MPEG4_CORE_SCALABLE 10
2915 #define FF_PROFILE_MPEG4_ADVANCED_CODING 11
2916 #define FF_PROFILE_MPEG4_ADVANCED_CORE 12
2917 #define FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE 13
2918 #define FF_PROFILE_MPEG4_SIMPLE_STUDIO 14
2919 #define FF_PROFILE_MPEG4_ADVANCED_SIMPLE 15
2920 
2921 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_0 1
2922 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_1 2
2923 #define FF_PROFILE_JPEG2000_CSTREAM_NO_RESTRICTION 32768
2924 #define FF_PROFILE_JPEG2000_DCINEMA_2K 3
2925 #define FF_PROFILE_JPEG2000_DCINEMA_4K 4
2926 
2927 #define FF_PROFILE_VP9_0 0
2928 #define FF_PROFILE_VP9_1 1
2929 #define FF_PROFILE_VP9_2 2
2930 #define FF_PROFILE_VP9_3 3
2931 
2932 #define FF_PROFILE_HEVC_MAIN 1
2933 #define FF_PROFILE_HEVC_MAIN_10 2
2934 #define FF_PROFILE_HEVC_MAIN_STILL_PICTURE 3
2935 #define FF_PROFILE_HEVC_REXT 4
2936 
2937 #define FF_PROFILE_AV1_MAIN 0
2938 #define FF_PROFILE_AV1_HIGH 1
2939 #define FF_PROFILE_AV1_PROFESSIONAL 2
2940 
2941 #define FF_PROFILE_MJPEG_HUFFMAN_BASELINE_DCT 0xc0
2942 #define FF_PROFILE_MJPEG_HUFFMAN_EXTENDED_SEQUENTIAL_DCT 0xc1
2943 #define FF_PROFILE_MJPEG_HUFFMAN_PROGRESSIVE_DCT 0xc2
2944 #define FF_PROFILE_MJPEG_HUFFMAN_LOSSLESS 0xc3
2945 #define FF_PROFILE_MJPEG_JPEG_LS 0xf7
2946 
2947 #define FF_PROFILE_SBC_MSBC 1
2948 
2949  /**
2950  * level
2951  * - encoding: Set by user.
2952  * - decoding: Set by libavcodec.
2953  */
2954  int level;
2955 #define FF_LEVEL_UNKNOWN -99
2956 
2957  /**
2958  * Skip loop filtering for selected frames.
2959  * - encoding: unused
2960  * - decoding: Set by user.
2961  */
2963 
2964  /**
2965  * Skip IDCT/dequantization for selected frames.
2966  * - encoding: unused
2967  * - decoding: Set by user.
2968  */
2970 
2971  /**
2972  * Skip decoding for selected frames.
2973  * - encoding: unused
2974  * - decoding: Set by user.
2975  */
2977 
2978  /**
2979  * Header containing style information for text subtitles.
2980  * For SUBTITLE_ASS subtitle type, it should contain the whole ASS
2981  * [Script Info] and [V4+ Styles] section, plus the [Events] line and
2982  * the Format line following. It shouldn't include any Dialogue line.
2983  * - encoding: Set/allocated/freed by user (before avcodec_open2())
2984  * - decoding: Set/allocated/freed by libavcodec (by avcodec_open2())
2985  */
2988 
2989 #if FF_API_VBV_DELAY
2990  /**
2991  * VBV delay coded in the last frame (in periods of a 27 MHz clock).
2992  * Used for compliant TS muxing.
2993  * - encoding: Set by libavcodec.
2994  * - decoding: unused.
2995  * @deprecated this value is now exported as a part of
2996  * AV_PKT_DATA_CPB_PROPERTIES packet side data
2997  */
2999  uint64_t vbv_delay;
3000 #endif
3001 
3002 #if FF_API_SIDEDATA_ONLY_PKT
3003  /**
3004  * Encoding only and set by default. Allow encoders to output packets
3005  * that do not contain any encoded data, only side data.
3006  *
3007  * Some encoders need to output such packets, e.g. to update some stream
3008  * parameters at the end of encoding.
3009  *
3010  * @deprecated this field disables the default behaviour and
3011  * it is kept only for compatibility.
3012  */
3015 #endif
3016 
3017  /**
3018  * Audio only. The number of "priming" samples (padding) inserted by the
3019  * encoder at the beginning of the audio. I.e. this number of leading
3020  * decoded samples must be discarded by the caller to get the original audio
3021  * without leading padding.
3022  *
3023  * - decoding: unused
3024  * - encoding: Set by libavcodec. The timestamps on the output packets are
3025  * adjusted by the encoder so that they always refer to the
3026  * first sample of the data actually contained in the packet,
3027  * including any added padding. E.g. if the timebase is
3028  * 1/samplerate and the timestamp of the first input sample is
3029  * 0, the timestamp of the first output packet will be
3030  * -initial_padding.
3031  */
3033 
3034  /**
3035  * - decoding: For codecs that store a framerate value in the compressed
3036  * bitstream, the decoder may export it here. { 0, 1} when
3037  * unknown.
3038  * - encoding: May be used to signal the framerate of CFR content to an
3039  * encoder.
3040  */
3042 
3043  /**
3044  * Nominal unaccelerated pixel format, see AV_PIX_FMT_xxx.
3045  * - encoding: unused.
3046  * - decoding: Set by libavcodec before calling get_format()
3047  */
3049 
3050  /**
3051  * Timebase in which pkt_dts/pts and AVPacket.dts/pts are.
3052  * - encoding unused.
3053  * - decoding set by user.
3054  */
3056 
3057  /**
3058  * AVCodecDescriptor
3059  * - encoding: unused.
3060  * - decoding: set by libavcodec.
3061  */
3063 
3064 #if !FF_API_LOWRES
3065  /**
3066  * low resolution decoding, 1-> 1/2 size, 2->1/4 size
3067  * - encoding: unused
3068  * - decoding: Set by user.
3069  */
3070  int lowres;
3071 #endif
3072 
3073  /**
3074  * Current statistics for PTS correction.
3075  * - decoding: maintained and used by libavcodec, not intended to be used by user apps
3076  * - encoding: unused
3077  */
3078  int64_t pts_correction_num_faulty_pts; /// Number of incorrect PTS values so far
3079  int64_t pts_correction_num_faulty_dts; /// Number of incorrect DTS values so far
3080  int64_t pts_correction_last_pts; /// PTS of the last frame
3081  int64_t pts_correction_last_dts; /// DTS of the last frame
3082 
3083  /**
3084  * Character encoding of the input subtitles file.
3085  * - decoding: set by user
3086  * - encoding: unused
3087  */
3089 
3090  /**
3091  * Subtitles character encoding mode. Formats or codecs might be adjusting
3092  * this setting (if they are doing the conversion themselves for instance).
3093  * - decoding: set by libavcodec
3094  * - encoding: unused
3095  */
3097 #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)
3098 #define FF_SUB_CHARENC_MODE_AUTOMATIC 0 ///< libavcodec will select the mode itself
3099 #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
3100 #define FF_SUB_CHARENC_MODE_IGNORE 2 ///< neither convert the subtitles, nor check them for valid UTF-8
3101 
3102  /**
3103  * Skip processing alpha if supported by codec.
3104  * Note that if the format uses pre-multiplied alpha (common with VP6,
3105  * and recommended due to better video quality/compression)
3106  * the image will look as if alpha-blended onto a black background.
3107  * However for formats that do not use pre-multiplied alpha
3108  * there might be serious artefacts (though e.g. libswscale currently
3109  * assumes pre-multiplied alpha anyway).
3110  *
3111  * - decoding: set by user
3112  * - encoding: unused
3113  */
3115 
3116  /**
3117  * Number of samples to skip after a discontinuity
3118  * - decoding: unused
3119  * - encoding: set by libavcodec
3120  */
3122 
3123 #if !FF_API_DEBUG_MV
3124  /**
3125  * debug motion vectors
3126  * - encoding: Set by user.
3127  * - decoding: Set by user.
3128  */
3130 #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 //visualize forward predicted MVs of P frames
3131 #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 //visualize forward predicted MVs of B frames
3132 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
3133 #endif
3134 
3135  /**
3136  * custom intra quantization matrix
3137  * - encoding: Set by user, can be NULL.
3138  * - decoding: unused.
3139  */
3141 
3142  /**
3143  * dump format separator.
3144  * can be ", " or "\n " or anything else
3145  * - encoding: Set by user.
3146  * - decoding: Set by user.
3147  */
3149 
3150  /**
3151  * ',' separated list of allowed decoders.
3152  * If NULL then all are allowed
3153  * - encoding: unused
3154  * - decoding: set by user
3155  */
3157 
3158  /**
3159  * Properties of the stream that gets decoded
3160  * - encoding: unused
3161  * - decoding: set by libavcodec
3162  */
3163  unsigned properties;
3164 #define FF_CODEC_PROPERTY_LOSSLESS 0x00000001
3165 #define FF_CODEC_PROPERTY_CLOSED_CAPTIONS 0x00000002
3166 
3167  /**
3168  * Additional data associated with the entire coded stream.
3169  *
3170  * - decoding: unused
3171  * - encoding: may be set by libavcodec after avcodec_open2().
3172  */
3175 
3176  /**
3177  * A reference to the AVHWFramesContext describing the input (for encoding)
3178  * or output (decoding) frames. The reference is set by the caller and
3179  * afterwards owned (and freed) by libavcodec - it should never be read by
3180  * the caller after being set.
3181  *
3182  * - decoding: This field should be set by the caller from the get_format()
3183  * callback. The previous reference (if any) will always be
3184  * unreffed by libavcodec before the get_format() call.
3185  *
3186  * If the default get_buffer2() is used with a hwaccel pixel
3187  * format, then this AVHWFramesContext will be used for
3188  * allocating the frame buffers.
3189  *
3190  * - encoding: For hardware encoders configured to use a hwaccel pixel
3191  * format, this field should be set by the caller to a reference
3192  * to the AVHWFramesContext describing input frames.
3193  * AVHWFramesContext.format must be equal to
3194  * AVCodecContext.pix_fmt.
3195  *
3196  * This field should be set before avcodec_open2() is called.
3197  */
3199 
3200  /**
3201  * Control the form of AVSubtitle.rects[N]->ass
3202  * - decoding: set by user
3203  * - encoding: unused
3204  */
3206 #define FF_SUB_TEXT_FMT_ASS 0
3207 #if FF_API_ASS_TIMING
3208 #define FF_SUB_TEXT_FMT_ASS_WITH_TIMINGS 1
3209 #endif
3210 
3211  /**
3212  * Audio only. The amount of padding (in samples) appended by the encoder to
3213  * the end of the audio. I.e. this number of decoded samples must be
3214  * discarded by the caller from the end of the stream to get the original
3215  * audio without any trailing padding.
3216  *
3217  * - decoding: unused
3218  * - encoding: unused
3219  */
3221 
3222  /**
3223  * The number of pixels per image to maximally accept.
3224  *
3225  * - decoding: set by user
3226  * - encoding: set by user
3227  */
3228  int64_t max_pixels;
3229 
3230  /**
3231  * A reference to the AVHWDeviceContext describing the device which will
3232  * be used by a hardware encoder/decoder. The reference is set by the
3233  * caller and afterwards owned (and freed) by libavcodec.
3234  *
3235  * This should be used if either the codec device does not require
3236  * hardware frames or any that are used are to be allocated internally by
3237  * libavcodec. If the user wishes to supply any of the frames used as
3238  * encoder input or decoder output then hw_frames_ctx should be used
3239  * instead. When hw_frames_ctx is set in get_format() for a decoder, this
3240  * field will be ignored while decoding the associated stream segment, but
3241  * may again be used on a following one after another get_format() call.
3242  *
3243  * For both encoders and decoders this field should be set before
3244  * avcodec_open2() is called and must not be written to thereafter.
3245  *
3246  * Note that some decoders may require this field to be set initially in
3247  * order to support hw_frames_ctx at all - in that case, all frames
3248  * contexts used must be created on the same device.
3249  */
3251 
3252  /**
3253  * Bit set of AV_HWACCEL_FLAG_* flags, which affect hardware accelerated
3254  * decoding (if active).
3255  * - encoding: unused
3256  * - decoding: Set by user (either before avcodec_open2(), or in the
3257  * AVCodecContext.get_format callback)
3258  */
3260 
3261  /**
3262  * Video decoding only. Certain video codecs support cropping, meaning that
3263  * only a sub-rectangle of the decoded frame is intended for display. This
3264  * option controls how cropping is handled by libavcodec.
3265  *
3266  * When set to 1 (the default), libavcodec will apply cropping internally.
3267  * I.e. it will modify the output frame width/height fields and offset the
3268  * data pointers (only by as much as possible while preserving alignment, or
3269  * by the full amount if the AV_CODEC_FLAG_UNALIGNED flag is set) so that
3270  * the frames output by the decoder refer only to the cropped area. The
3271  * crop_* fields of the output frames will be zero.
3272  *
3273  * When set to 0, the width/height fields of the output frames will be set
3274  * to the coded dimensions and the crop_* fields will describe the cropping
3275  * rectangle. Applying the cropping is left to the caller.
3276  *
3277  * @warning When hardware acceleration with opaque output frames is used,
3278  * libavcodec is unable to apply cropping from the top/left border.
3279  *
3280  * @note when this option is set to zero, the width/height fields of the
3281  * AVCodecContext and output AVFrames have different meanings. The codec
3282  * context fields store display dimensions (with the coded dimensions in
3283  * coded_width/height), while the frame fields store the coded dimensions
3284  * (with the display dimensions being determined by the crop_* fields).
3285  */
3287 
3288  /*
3289  * Video decoding only. Sets the number of extra hardware frames which
3290  * the decoder will allocate for use by the caller. This must be set
3291  * before avcodec_open2() is called.
3292  *
3293  * Some hardware decoders require all frames that they will use for
3294  * output to be defined in advance before decoding starts. For such
3295  * decoders, the hardware frame pool must therefore be of a fixed size.
3296  * The extra frames set here are on top of any number that the decoder
3297  * needs internally in order to operate normally (for example, frames
3298  * used as reference pictures).
3299  */
3301 } AVCodecContext;
3302 
3303 #if FF_API_CODEC_GET_SET
3304 /**
3305  * Accessors for some AVCodecContext fields. These used to be provided for ABI
3306  * compatibility, and do not need to be used anymore.
3307  */
3312 
3317 
3319 unsigned av_codec_get_codec_properties(const AVCodecContext *avctx);
3320 
3321 #if FF_API_LOWRES
3323 int av_codec_get_lowres(const AVCodecContext *avctx);
3325 void av_codec_set_lowres(AVCodecContext *avctx, int val);
3326 #endif
3327 
3329 int av_codec_get_seek_preroll(const AVCodecContext *avctx);
3331 void av_codec_set_seek_preroll(AVCodecContext *avctx, int val);
3332 
3334 uint16_t *av_codec_get_chroma_intra_matrix(const AVCodecContext *avctx);
3336 void av_codec_set_chroma_intra_matrix(AVCodecContext *avctx, uint16_t *val);
3337 #endif
3338 
3339 /**
3340  * AVProfile.
3341  */
3342 typedef struct AVProfile {
3343  int profile;
3344  const char *name; ///< short name for the profile
3345 } AVProfile;
3346 
3347 enum {
3348  /**
3349  * The codec supports this format via the hw_device_ctx interface.
3350  *
3351  * When selecting this format, AVCodecContext.hw_device_ctx should
3352  * have been set to a device of the specified type before calling
3353  * avcodec_open2().
3354  */
3356  /**
3357  * The codec supports this format via the hw_frames_ctx interface.
3358  *
3359  * When selecting this format for a decoder,
3360  * AVCodecContext.hw_frames_ctx should be set to a suitable frames
3361  * context inside the get_format() callback. The frames context
3362  * must have been created on a device of the specified type.
3363  */
3365  /**
3366  * The codec supports this format by some internal method.
3367  *
3368  * This format can be selected without any additional configuration -
3369  * no device or frames context is required.
3370  */
3372  /**
3373  * The codec supports this format by some ad-hoc method.
3374  *
3375  * Additional settings and/or function calls are required. See the
3376  * codec-specific documentation for details. (Methods requiring
3377  * this sort of configuration are deprecated and others should be
3378  * used in preference.)
3379  */
3381 };
3382 
3383 typedef struct AVCodecHWConfig {
3384  /**
3385  * A hardware pixel format which the codec can use.
3386  */
3388  /**
3389  * Bit set of AV_CODEC_HW_CONFIG_METHOD_* flags, describing the possible
3390  * setup methods which can be used with this configuration.
3391  */
3392  int methods;
3393  /**
3394  * The device type associated with the configuration.
3395  *
3396  * Must be set for AV_CODEC_HW_CONFIG_METHOD_HW_DEVICE_CTX and
3397  * AV_CODEC_HW_CONFIG_METHOD_HW_FRAMES_CTX, otherwise unused.
3398  */
3400 } AVCodecHWConfig;
3401 
3402 typedef struct AVCodecDefault AVCodecDefault;
3403 
3404 struct AVSubtitle;
3405 
3406 /**
3407  * AVCodec.
3408  */
3409 typedef struct AVCodec {
3410  /**
3411  * Name of the codec implementation.
3412  * The name is globally unique among encoders and among decoders (but an
3413  * encoder and a decoder can share the same name).
3414  * This is the primary way to find a codec from the user perspective.
3415  */
3416  const char *name;
3417  /**
3418  * Descriptive name for the codec, meant to be more human readable than name.
3419  * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
3420  */
3421  const char *long_name;
3424  /**
3425  * Codec capabilities.
3426  * see AV_CODEC_CAP_*
3427  */
3429  const AVRational *supported_framerates; ///< array of supported framerates, or NULL if any, array is terminated by {0,0}
3430  const enum AVPixelFormat *pix_fmts; ///< array of supported pixel formats, or NULL if unknown, array is terminated by -1
3431  const int *supported_samplerates; ///< array of supported audio samplerates, or NULL if unknown, array is terminated by 0
3432  const enum AVSampleFormat *sample_fmts; ///< array of supported sample formats, or NULL if unknown, array is terminated by -1
3433  const uint64_t *channel_layouts; ///< array of support channel layouts, or NULL if unknown. array is terminated by 0
3434  uint8_t max_lowres; ///< maximum value for lowres supported by the decoder
3435  const AVClass *priv_class; ///< AVClass for the private context
3436  const AVProfile *profiles; ///< array of recognized profiles, or NULL if unknown, array is terminated by {FF_PROFILE_UNKNOWN}
3437 
3438  /**
3439  * Group name of the codec implementation.
3440  * This is a short symbolic name of the wrapper backing this codec. A
3441  * wrapper uses some kind of external implementation for the codec, such
3442  * as an external library, or a codec implementation provided by the OS or
3443  * the hardware.
3444  * If this field is NULL, this is a builtin, libavcodec native codec.
3445  * If non-NULL, this will be the suffix in AVCodec.name in most cases
3446  * (usually AVCodec.name will be of the form "<codec_name>_<wrapper_name>").
3447  */
3448  const char *wrapper_name;
3449 
3450  /*****************************************************************
3451  * No fields below this line are part of the public API. They
3452  * may not be used outside of libavcodec and can be changed and
3453  * removed at will.
3454  * New public fields should be added right above.
3455  *****************************************************************
3456  */
3458  struct AVCodec *next;
3459  /**
3460  * @name Frame-level threading support functions
3461  * @{
3462  */
3463  /**
3464  * If defined, called on thread contexts when they are created.
3465  * If the codec allocates writable tables in init(), re-allocate them here.
3466  * priv_data will be set to a copy of the original.
3467  */
3469  /**
3470  * Copy necessary context variables from a previous thread context to the current one.
3471  * If not defined, the next thread will start automatically; otherwise, the codec
3472  * must call ff_thread_finish_setup().
3473  *
3474  * dst and src will (rarely) point to the same context, in which case memcpy should be skipped.
3475  */
3477  /** @} */
3478 
3479  /**
3480  * Private codec-specific defaults.
3481  */
3483 
3484  /**
3485  * Initialize codec static data, called from avcodec_register().
3486  *
3487  * This is not intended for time consuming operations as it is
3488  * run for every codec regardless of that codec being used.
3489  */
3490  void (*init_static_data)(struct AVCodec *codec);
3491 
3493  int (*encode_sub)(AVCodecContext *, uint8_t *buf, int buf_size,
3494  const struct AVSubtitle *sub);
3495  /**
3496  * Encode data to an AVPacket.
3497  *
3498  * @param avctx codec context
3499  * @param avpkt output AVPacket (may contain a user-provided buffer)
3500  * @param[in] frame AVFrame containing the raw data to be encoded
3501  * @param[out] got_packet_ptr encoder sets to 0 or 1 to indicate that a
3502  * non-empty packet was returned in avpkt.
3503  * @return 0 on success, negative error code on failure
3504  */
3505  int (*encode2)(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame,
3506  int *got_packet_ptr);
3507  int (*decode)(AVCodecContext *, void *outdata, int *outdata_size, AVPacket *avpkt);
3509  /**
3510  * Encode API with decoupled packet/frame dataflow. The API is the
3511  * same as the avcodec_ prefixed APIs (avcodec_send_frame() etc.), except
3512  * that:
3513  * - never called if the codec is closed or the wrong type,
3514  * - if AV_CODEC_CAP_DELAY is not set, drain frames are never sent,
3515  * - only one drain frame is ever passed down,
3516  */
3519 
3520  /**
3521  * Decode API with decoupled packet/frame dataflow. This function is called
3522  * to get one output frame. It should call ff_decode_get_packet() to obtain
3523  * input data.
3524  */
3526  /**
3527  * Flush buffers.
3528  * Will be called when seeking
3529  */
3531  /**
3532  * Internal codec capabilities.
3533  * See FF_CODEC_CAP_* in internal.h
3534  */
3536 
3537  /**
3538  * Decoding only, a comma-separated list of bitstream filters to apply to
3539  * packets before decoding.
3540  */
3541  const char *bsfs;
3542 
3543  /**
3544  * Array of pointers to hardware configurations supported by the codec,
3545  * or NULL if no hardware supported. The array is terminated by a NULL
3546  * pointer.
3547  *
3548  * The user can only access this field via avcodec_get_hw_config().
3549  */
3551 } AVCodec;
3552 
3553 #if FF_API_CODEC_GET_SET
3555 int av_codec_get_max_lowres(const AVCodec *codec);
3556 #endif
3557 
3558 struct MpegEncContext;
3559 
3560 /**
3561  * Retrieve supported hardware configurations for a codec.
3562  *
3563  * Values of index from zero to some maximum return the indexed configuration
3564  * descriptor; all other values return NULL. If the codec does not support
3565  * any hardware configurations then it will always return NULL.
3566  */
3567 const AVCodecHWConfig *avcodec_get_hw_config(const AVCodec *codec, int index);
3568 
3569 /**
3570  * @defgroup lavc_hwaccel AVHWAccel
3571  *
3572  * @note Nothing in this structure should be accessed by the user. At some
3573  * point in future it will not be externally visible at all.
3574  *
3575  * @{
3576  */
3577 typedef struct AVHWAccel {
3578  /**
3579  * Name of the hardware accelerated codec.
3580  * The name is globally unique among encoders and among decoders (but an
3581  * encoder and a decoder can share the same name).
3582  */
3583  const char *name;
3584 
3585  /**
3586  * Type of codec implemented by the hardware accelerator.
3587  *
3588  * See AVMEDIA_TYPE_xxx
3589  */
3591 
3592  /**
3593  * Codec implemented by the hardware accelerator.
3594  *
3595  * See AV_CODEC_ID_xxx
3596  */
3598 
3599  /**
3600  * Supported pixel format.
3601  *
3602  * Only hardware accelerated formats are supported here.
3603  */
3605 
3606  /**
3607  * Hardware accelerated codec capabilities.
3608  * see AV_HWACCEL_CODEC_CAP_*
3609  */
3611 
3612  /*****************************************************************
3613  * No fields below this line are part of the public API. They
3614  * may not be used outside of libavcodec and can be changed and
3615  * removed at will.
3616  * New public fields should be added right above.
3617  *****************************************************************
3618  */
3619 
3620  /**
3621  * Allocate a custom buffer
3622  */
3624 
3625  /**
3626  * Called at the beginning of each frame or field picture.
3627  *
3628  * Meaningful frame information (codec specific) is guaranteed to
3629  * be parsed at this point. This function is mandatory.
3630  *
3631  * Note that buf can be NULL along with buf_size set to 0.
3632  * Otherwise, this means the whole frame is available at this point.
3633  *
3634  * @param avctx the codec context
3635  * @param buf the frame data buffer base
3636  * @param buf_size the size of the frame in bytes
3637  * @return zero if successful, a negative value otherwise
3638  */
3639  int (*start_frame)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3640 
3641  /**
3642  * Callback for parameter data (SPS/PPS/VPS etc).
3643  *
3644  * Useful for hardware decoders which keep persistent state about the
3645  * video parameters, and need to receive any changes to update that state.
3646  *
3647  * @param avctx the codec context
3648  * @param type the nal unit type
3649  * @param buf the nal unit data buffer
3650  * @param buf_size the size of the nal unit in bytes
3651  * @return zero if successful, a negative value otherwise
3652  */
3653  int (*decode_params)(AVCodecContext *avctx, int type, const uint8_t *buf, uint32_t buf_size);
3654 
3655  /**
3656  * Callback for each slice.
3657  *
3658  * Meaningful slice information (codec specific) is guaranteed to
3659  * be parsed at this point. This function is mandatory.
3660  * The only exception is XvMC, that works on MB level.
3661  *
3662  * @param avctx the codec context
3663  * @param buf the slice data buffer base
3664  * @param buf_size the size of the slice in bytes
3665  * @return zero if successful, a negative value otherwise
3666  */
3667  int (*decode_slice)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3668 
3669  /**
3670  * Called at the end of each frame or field picture.
3671  *
3672  * The whole picture is parsed at this point and can now be sent
3673  * to the hardware accelerator. This function is mandatory.
3674  *
3675  * @param avctx the codec context
3676  * @return zero if successful, a negative value otherwise
3677  */
3679 
3680  /**
3681  * Size of per-frame hardware accelerator private data.
3682  *
3683  * Private data is allocated with av_mallocz() before
3684  * AVCodecContext.get_buffer() and deallocated after
3685  * AVCodecContext.release_buffer().
3686  */
3688 
3689  /**
3690  * Called for every Macroblock in a slice.
3691  *
3692  * XvMC uses it to replace the ff_mpv_reconstruct_mb().
3693  * Instead of decoding to raw picture, MB parameters are
3694  * stored in an array provided by the video driver.
3695  *
3696  * @param s the mpeg context
3697  */
3699 
3700  /**
3701  * Initialize the hwaccel private data.
3702  *
3703  * This will be called from ff_get_format(), after hwaccel and
3704  * hwaccel_context are set and the hwaccel private data in AVCodecInternal
3705  * is allocated.
3706  */
3708 
3709  /**
3710  * Uninitialize the hwaccel private data.
3711  *
3712  * This will be called from get_format() or avcodec_close(), after hwaccel
3713  * and hwaccel_context are already uninitialized.
3714  */
3716 
3717  /**
3718  * Size of the private data to allocate in
3719  * AVCodecInternal.hwaccel_priv_data.
3720  */
3722 
3723  /**
3724  * Internal hwaccel capabilities.
3725  */
3727 
3728  /**
3729  * Fill the given hw_frames context with current codec parameters. Called
3730  * from get_format. Refer to avcodec_get_hw_frames_parameters() for
3731  * details.
3732  *
3733  * This CAN be called before AVHWAccel.init is called, and you must assume
3734  * that avctx->hwaccel_priv_data is invalid.
3735  */
3737 } AVHWAccel;
3738 
3739 /**
3740  * HWAccel is experimental and is thus avoided in favor of non experimental
3741  * codecs
3742  */
3743 #define AV_HWACCEL_CODEC_CAP_EXPERIMENTAL 0x0200
3744 
3745 /**
3746  * Hardware acceleration should be used for decoding even if the codec level
3747  * used is unknown or higher than the maximum supported level reported by the
3748  * hardware driver.
3749  *
3750  * It's generally a good idea to pass this flag unless you have a specific
3751  * reason not to, as hardware tends to under-report supported levels.
3752  */
3753 #define AV_HWACCEL_FLAG_IGNORE_LEVEL (1 << 0)
3754 
3755 /**
3756  * Hardware acceleration can output YUV pixel formats with a different chroma
3757  * sampling than 4:2:0 and/or other than 8 bits per component.
3758  */
3759 #define AV_HWACCEL_FLAG_ALLOW_HIGH_DEPTH (1 << 1)
3760 
3761 /**
3762  * Hardware acceleration should still be attempted for decoding when the
3763  * codec profile does not match the reported capabilities of the hardware.
3764  *
3765  * For example, this can be used to try to decode baseline profile H.264
3766  * streams in hardware - it will often succeed, because many streams marked
3767  * as baseline profile actually conform to constrained baseline profile.
3768  *
3769  * @warning If the stream is actually not supported then the behaviour is
3770  * undefined, and may include returning entirely incorrect output
3771  * while indicating success.
3772  */
3773 #define AV_HWACCEL_FLAG_ALLOW_PROFILE_MISMATCH (1 << 2)
3774 
3775 /**
3776  * @}
3777  */
3778 
3779 #if FF_API_AVPICTURE
3780 /**
3781  * @defgroup lavc_picture AVPicture
3782  *
3783  * Functions for working with AVPicture
3784  * @{
3785  */
3786 
3787 /**
3788  * Picture data structure.
3789  *
3790  * Up to four components can be stored into it, the last component is
3791  * alpha.
3792  * @deprecated use AVFrame or imgutils functions instead
3793  */
3794 typedef struct AVPicture {
3796  uint8_t *data[AV_NUM_DATA_POINTERS]; ///< pointers to the image data planes
3798  int linesize[AV_NUM_DATA_POINTERS]; ///< number of bytes per line
3799 } AVPicture;
3800 
3801 /**
3802  * @}
3803  */
3804 #endif
3805 
3808 
3809  SUBTITLE_BITMAP, ///< A bitmap, pict will be set
3810 
3811  /**
3812  * Plain text, the text field must be set by the decoder and is
3813  * authoritative. ass and pict fields may contain approximations.
3814  */
3816 
3817  /**
3818  * Formatted text, the ass field must be set by the decoder and is
3819  * authoritative. pict and text fields may contain approximations.
3820  */
3822 };
3823 
3824 #define AV_SUBTITLE_FLAG_FORCED 0x00000001
3825 
3826 typedef struct AVSubtitleRect {
3827  int x; ///< top left corner of pict, undefined when pict is not set
3828  int y; ///< top left corner of pict, undefined when pict is not set
3829  int w; ///< width of pict, undefined when pict is not set
3830  int h; ///< height of pict, undefined when pict is not set
3831  int nb_colors; ///< number of colors in pict, undefined when pict is not set
3832 
3833 #if FF_API_AVPICTURE
3834  /**
3835  * @deprecated unused
3836  */
3839 #endif
3840  /**
3841  * data+linesize for the bitmap of this subtitle.
3842  * Can be set for text/ass as well once they are rendered.
3843  */
3845  int linesize[4];
3846 
3848 
3849  char *text; ///< 0 terminated plain UTF-8 text
3850 
3851  /**
3852  * 0 terminated ASS/SSA compatible event line.
3853  * The presentation of this is unaffected by the other values in this
3854  * struct.
3855  */
3856  char *ass;
3857 
3858  int flags;
3859 } AVSubtitleRect;
3860 
3861 typedef struct AVSubtitle {
3862  uint16_t format; /* 0 = graphics */
3863  uint32_t start_display_time; /* relative to packet pts, in ms */
3864  uint32_t end_display_time; /* relative to packet pts, in ms */
3865  unsigned num_rects;
3867  int64_t pts; ///< Same as packet pts, in AV_TIME_BASE
3868 } AVSubtitle;
3869 
3870 /**
3871  * This struct describes the properties of an encoded stream.
3872  *
3873  * sizeof(AVCodecParameters) is not a part of the public ABI, this struct must
3874  * be allocated with avcodec_parameters_alloc() and freed with
3875  * avcodec_parameters_free().
3876  */
3877 typedef struct AVCodecParameters {
3878  /**
3879  * General type of the encoded data.
3880  */
3882  /**
3883  * Specific type of the encoded data (the codec used).
3884  */
3886  /**
3887  * Additional information about the codec (corresponds to the AVI FOURCC).
3888  */
3889  uint32_t codec_tag;
3890 
3891  /**
3892  * Extra binary data needed for initializing the decoder, codec-dependent.
3893  *
3894  * Must be allocated with av_malloc() and will be freed by
3895  * avcodec_parameters_free(). The allocated size of extradata must be at
3896  * least extradata_size + AV_INPUT_BUFFER_PADDING_SIZE, with the padding
3897  * bytes zeroed.
3898  */
3900  /**
3901  * Size of the extradata content in bytes.
3902  */
3904 
3905  /**
3906  * - video: the pixel format, the value corresponds to enum AVPixelFormat.
3907  * - audio: the sample format, the value corresponds to enum AVSampleFormat.
3908  */
3909  int format;
3910 
3911  /**
3912  * The average bitrate of the encoded data (in bits per second).
3913  */
3914  int64_t bit_rate;
3915 
3916  /**
3917  * The number of bits per sample in the codedwords.
3918  *
3919  * This is basically the bitrate per sample. It is mandatory for a bunch of
3920  * formats to actually decode them. It's the number of bits for one sample in
3921  * the actual coded bitstream.
3922  *
3923  * This could be for example 4 for ADPCM
3924  * For PCM formats this matches bits_per_raw_sample
3925  * Can be 0
3926  */
3928 
3929  /**
3930  * This is the number of valid bits in each output sample. If the
3931  * sample format has more bits, the least significant bits are additional
3932  * padding bits, which are always 0. Use right shifts to reduce the sample
3933  * to its actual size. For example, audio formats with 24 bit samples will
3934  * have bits_per_raw_sample set to 24, and format set to AV_SAMPLE_FMT_S32.
3935  * To get the original sample use "(int32_t)sample >> 8"."
3936  *
3937  * For ADPCM this might be 12 or 16 or similar
3938  * Can be 0
3939  */
3941 
3942  /**
3943  * Codec-specific bitstream restrictions that the stream conforms to.
3944  */
3945  int profile;
3946  int level;
3947 
3948  /**
3949  * Video only. The dimensions of the video frame in pixels.
3950  */
3951  int width;
3952  int height;
3953 
3954  /**
3955  * Video only. The aspect ratio (width / height) which a single pixel
3956  * should have when displayed.
3957  *
3958  * When the aspect ratio is unknown / undefined, the numerator should be
3959  * set to 0 (the denominator may have any value).
3960  */
3962 
3963  /**
3964  * Video only. The order of the fields in interlaced video.
3965  */
3967 
3968  /**
3969  * Video only. Additional colorspace characteristics.
3970  */
3976 
3977  /**
3978  * Video only. Number of delayed frames.
3979  */
3981 
3982  /**
3983  * Audio only. The channel layout bitmask. May be 0 if the channel layout is
3984  * unknown or unspecified, otherwise the number of bits set must be equal to
3985  * the channels field.
3986  */
3987  uint64_t channel_layout;
3988  /**
3989  * Audio only. The number of audio channels.
3990  */
3992  /**
3993  * Audio only. The number of audio samples per second.
3994  */
3996  /**
3997  * Audio only. The number of bytes per coded audio frame, required by some
3998  * formats.
3999  *
4000  * Corresponds to nBlockAlign in WAVEFORMATEX.
4001  */
4003  /**
4004  * Audio only. Audio frame size, if known. Required by some formats to be static.
4005  */
4007 
4008  /**
4009  * Audio only. The amount of padding (in samples) inserted by the encoder at
4010  * the beginning of the audio. I.e. this number of leading decoded samples
4011  * must be discarded by the caller to get the original audio without leading
4012  * padding.
4013  */
4015  /**
4016  * Audio only. The amount of padding (in samples) appended by the encoder to
4017  * the end of the audio. I.e. this number of decoded samples must be
4018  * discarded by the caller from the end of the stream to get the original
4019  * audio without any trailing padding.
4020  */
4022  /**
4023  * Audio only. Number of samples to skip after a discontinuity.
4024  */
4027 
4028 /**
4029  * Iterate over all registered codecs.
4030  *
4031  * @param opaque a pointer where libavcodec will store the iteration state. Must
4032  * point to NULL to start the iteration.
4033  *
4034  * @return the next registered codec or NULL when the iteration is
4035  * finished
4036  */
4037 const AVCodec *av_codec_iterate(void **opaque);
4038 
4039 #if FF_API_NEXT
4040 /**
4041  * If c is NULL, returns the first registered codec,
4042  * if c is non-NULL, returns the next registered codec after c,
4043  * or NULL if c is the last one.
4044  */
4046 AVCodec *av_codec_next(const AVCodec *c);
4047 #endif
4048 
4049 /**
4050  * Return the LIBAVCODEC_VERSION_INT constant.
4051  */
4052 unsigned avcodec_version(void);
4053 
4054 /**
4055  * Return the libavcodec build-time configuration.
4056  */
4057 const char *avcodec_configuration(void);
4058 
4059 /**
4060  * Return the libavcodec license.
4061  */
4062 const char *avcodec_license(void);
4063 
4064 #if FF_API_NEXT
4065 /**
4066  * Register the codec codec and initialize libavcodec.
4067  *
4068  * @warning either this function or avcodec_register_all() must be called
4069  * before any other libavcodec functions.
4070  *
4071  * @see avcodec_register_all()
4072  */
4074 void avcodec_register(AVCodec *codec);
4075 
4076 /**
4077  * Register all the codecs, parsers and bitstream filters which were enabled at
4078  * configuration time. If you do not call this function you can select exactly
4079  * which formats you want to support, by using the individual registration
4080  * functions.
4081  *
4082  * @see avcodec_register
4083  * @see av_register_codec_parser
4084  * @see av_register_bitstream_filter
4085  */
4087 void avcodec_register_all(void);
4088 #endif
4089 
4090 /**
4091  * Allocate an AVCodecContext and set its fields to default values. The
4092  * resulting struct should be freed with avcodec_free_context().
4093  *
4094  * @param codec if non-NULL, allocate private data and initialize defaults
4095  * for the given codec. It is illegal to then call avcodec_open2()
4096  * with a different codec.
4097  * If NULL, then the codec-specific defaults won't be initialized,
4098  * which may result in suboptimal default settings (this is
4099  * important mainly for encoders, e.g. libx264).
4100  *
4101  * @return An AVCodecContext filled with default values or NULL on failure.
4102  */
4104 
4105 /**
4106  * Free the codec context and everything associated with it and write NULL to
4107  * the provided pointer.
4108  */
4109 void avcodec_free_context(AVCodecContext **avctx);
4110 
4111 #if FF_API_GET_CONTEXT_DEFAULTS
4112 /**
4113  * @deprecated This function should not be used, as closing and opening a codec
4114  * context multiple time is not supported. A new codec context should be
4115  * allocated for each new use.
4116  */
4118 #endif
4119 
4120 /**
4121  * Get the AVClass for AVCodecContext. It can be used in combination with
4122  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
4123  *
4124  * @see av_opt_find().
4125  */
4126 const AVClass *avcodec_get_class(void);
4127 
4128 #if FF_API_COPY_CONTEXT
4129 /**
4130  * Get the AVClass for AVFrame. It can be used in combination with
4131  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
4132  *
4133  * @see av_opt_find().
4134  */
4135 const AVClass *avcodec_get_frame_class(void);
4136 
4137 /**
4138  * Get the AVClass for AVSubtitleRect. It can be used in combination with
4139  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
4140  *
4141  * @see av_opt_find().
4142  */
4144 
4145 /**
4146  * Copy the settings of the source AVCodecContext into the destination
4147  * AVCodecContext. The resulting destination codec context will be
4148  * unopened, i.e. you are required to call avcodec_open2() before you
4149  * can use this AVCodecContext to decode/encode video/audio data.
4150  *
4151  * @param dest target codec context, should be initialized with
4152  * avcodec_alloc_context3(NULL), but otherwise uninitialized
4153  * @param src source codec context
4154  * @return AVERROR() on error (e.g. memory allocation error), 0 on success
4155  *
4156  * @deprecated The semantics of this function are ill-defined and it should not
4157  * be used. If you need to transfer the stream parameters from one codec context
4158  * to another, use an intermediate AVCodecParameters instance and the
4159  * avcodec_parameters_from_context() / avcodec_parameters_to_context()
4160  * functions.
4161  */
4164 #endif
4165 
4166 /**
4167  * Allocate a new AVCodecParameters and set its fields to default values
4168  * (unknown/invalid/0). The returned struct must be freed with
4169  * avcodec_parameters_free().
4170  */
4172 
4173 /**
4174  * Free an AVCodecParameters instance and everything associated with it and
4175  * write NULL to the supplied pointer.
4176  */
4178 
4179 /**
4180  * Copy the contents of src to dst. Any allocated fields in dst are freed and
4181  * replaced with newly allocated duplicates of the corresponding fields in src.
4182  *
4183  * @return >= 0 on success, a negative AVERROR code on failure.
4184  */
4186 
4187 /**
4188  * Fill the parameters struct based on the values from the supplied codec
4189  * context. Any allocated fields in par are freed and replaced with duplicates
4190  * of the corresponding fields in codec.
4191  *
4192  * @return >= 0 on success, a negative AVERROR code on failure
4193  */
4195  const AVCodecContext *codec);
4196 
4197 /**
4198  * Fill the codec context based on the values from the supplied codec
4199  * parameters. Any allocated fields in codec that have a corresponding field in
4200  * par are freed and replaced with duplicates of the corresponding field in par.
4201  * Fields in codec that do not have a counterpart in par are not touched.
4202  *
4203  * @return >= 0 on success, a negative AVERROR code on failure.
4204  */
4206  const AVCodecParameters *par);
4207 
4208 /**
4209  * Initialize the AVCodecContext to use the given AVCodec. Prior to using this
4210  * function the context has to be allocated with avcodec_alloc_context3().
4211  *
4212  * The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(),
4213  * avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for
4214  * retrieving a codec.
4215  *
4216  * @warning This function is not thread safe!
4217  *
4218  * @note Always call this function before using decoding routines (such as
4219  * @ref avcodec_receive_frame()).
4220  *
4221  * @code
4222  * avcodec_register_all();
4223  * av_dict_set(&opts, "b", "2.5M", 0);
4224  * codec = avcodec_find_decoder(AV_CODEC_ID_H264);
4225  * if (!codec)
4226  * exit(1);
4227  *
4228  * context = avcodec_alloc_context3(codec);
4229  *
4230  * if (avcodec_open2(context, codec, opts) < 0)
4231  * exit(1);
4232  * @endcode
4233  *
4234  * @param avctx The context to initialize.
4235  * @param codec The codec to open this context for. If a non-NULL codec has been
4236  * previously passed to avcodec_alloc_context3() or
4237  * for this context, then this parameter MUST be either NULL or
4238  * equal to the previously passed codec.
4239  * @param options A dictionary filled with AVCodecContext and codec-private options.
4240  * On return this object will be filled with options that were not found.
4241  *
4242  * @return zero on success, a negative value on error
4243  * @see avcodec_alloc_context3(), avcodec_find_decoder(), avcodec_find_encoder(),
4244  * av_dict_set(), av_opt_find().
4245  */
4246 int avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options);
4247 
4248 /**
4249  * Close a given AVCodecContext and free all the data associated with it
4250  * (but not the AVCodecContext itself).
4251  *
4252  * Calling this function on an AVCodecContext that hasn't been opened will free
4253  * the codec-specific data allocated in avcodec_alloc_context3() with a non-NULL
4254  * codec. Subsequent calls will do nothing.
4255  *
4256  * @note Do not use this function. Use avcodec_free_context() to destroy a
4257  * codec context (either open or closed). Opening and closing a codec context
4258  * multiple times is not supported anymore -- use multiple codec contexts
4259  * instead.
4260  */
4261 int avcodec_close(AVCodecContext *avctx);
4262 
4263 /**
4264  * Free all allocated data in the given subtitle struct.
4265  *
4266  * @param sub AVSubtitle to free.
4267  */
4268 void avsubtitle_free(AVSubtitle *sub);
4269 
4270 /**
4271  * @}
4272  */
4273 
4274 /**
4275  * @addtogroup lavc_packet
4276  * @{
4277  */
4278 
4279 /**
4280  * Allocate an AVPacket and set its fields to default values. The resulting
4281  * struct must be freed using av_packet_free().
4282  *
4283  * @return An AVPacket filled with default values or NULL on failure.
4284  *
4285  * @note this only allocates the AVPacket itself, not the data buffers. Those
4286  * must be allocated through other means such as av_new_packet.
4287  *
4288  * @see av_new_packet
4289  */
4290 AVPacket *av_packet_alloc(void);
4291 
4292 /**
4293  * Create a new packet that references the same data as src.
4294  *
4295  * This is a shortcut for av_packet_alloc()+av_packet_ref().
4296  *
4297  * @return newly created AVPacket on success, NULL on error.
4298  *
4299  * @see av_packet_alloc
4300  * @see av_packet_ref
4301  */
4303 
4304 /**
4305  * Free the packet, if the packet is reference counted, it will be
4306  * unreferenced first.
4307  *
4308  * @param pkt packet to be freed. The pointer will be set to NULL.
4309  * @note passing NULL is a no-op.
4310  */
4311 void av_packet_free(AVPacket **pkt);
4312 
4313 /**
4314  * Initialize optional fields of a packet with default values.
4315  *
4316  * Note, this does not touch the data and size members, which have to be
4317  * initialized separately.
4318  *
4319  * @param pkt packet
4320  */
4321 void av_init_packet(AVPacket *pkt);
4322 
4323 /**
4324  * Allocate the payload of a packet and initialize its fields with
4325  * default values.
4326  *
4327  * @param pkt packet
4328  * @param size wanted payload size
4329  * @return 0 if OK, AVERROR_xxx otherwise
4330  */
4331 int av_new_packet(AVPacket *pkt, int size);
4332 
4333 /**
4334  * Reduce packet size, correctly zeroing padding
4335  *
4336  * @param pkt packet
4337  * @param size new size
4338  */
4339 void av_shrink_packet(AVPacket *pkt, int size);
4340 
4341 /**
4342  * Increase packet size, correctly zeroing padding
4343  *
4344  * @param pkt packet
4345  * @param grow_by number of bytes by which to increase the size of the packet
4346  */
4347 int av_grow_packet(AVPacket *pkt, int grow_by);
4348 
4349 /**
4350  * Initialize a reference-counted packet from av_malloc()ed data.
4351  *
4352  * @param pkt packet to be initialized. This function will set the data, size,
4353  * buf and destruct fields, all others are left untouched.
4354  * @param data Data allocated by av_malloc() to be used as packet data. If this
4355  * function returns successfully, the data is owned by the underlying AVBuffer.
4356  * The caller may not access the data through other means.
4357  * @param size size of data in bytes, without the padding. I.e. the full buffer
4358  * size is assumed to be size + AV_INPUT_BUFFER_PADDING_SIZE.
4359  *
4360  * @return 0 on success, a negative AVERROR on error
4361  */
4363 
4364 #if FF_API_AVPACKET_OLD_API
4365 /**
4366  * @warning This is a hack - the packet memory allocation stuff is broken. The
4367  * packet is allocated if it was not really allocated.
4368  *
4369  * @deprecated Use av_packet_ref or av_packet_make_refcounted
4370  */
4372 int av_dup_packet(AVPacket *pkt);
4373 /**
4374  * Copy packet, including contents
4375  *
4376  * @return 0 on success, negative AVERROR on fail
4377  *
4378  * @deprecated Use av_packet_ref
4379  */
4381 int av_copy_packet(AVPacket *dst, const AVPacket *src);
4382 
4383 /**
4384  * Copy packet side data
4385  *
4386  * @return 0 on success, negative AVERROR on fail
4387  *
4388  * @deprecated Use av_packet_copy_props
4389  */
4391 int av_copy_packet_side_data(AVPacket *dst, const AVPacket *src);
4392 
4393 /**
4394  * Free a packet.
4395  *
4396  * @deprecated Use av_packet_unref
4397  *
4398  * @param pkt packet to free
4399  */
4401 void av_free_packet(AVPacket *pkt);
4402 #endif
4403 /**
4404  * Allocate new information of a packet.
4405  *
4406  * @param pkt packet
4407  * @param type side information type
4408  * @param size side information size
4409  * @return pointer to fresh allocated data or NULL otherwise
4410  */
4412  int size);
4413 
4414 /**
4415  * Wrap an existing array as a packet side data.
4416  *
4417  * @param pkt packet
4418  * @param type side information type
4419  * @param data the side data array. It must be allocated with the av_malloc()
4420  * family of functions. The ownership of the data is transferred to
4421  * pkt.
4422  * @param size side information size
4423  * @return a non-negative number on success, a negative AVERROR code on
4424  * failure. On failure, the packet is unchanged and the data remains
4425  * owned by the caller.
4426  */
4428  uint8_t *data, size_t size);
4429 
4430 /**
4431  * Shrink the already allocated side data buffer
4432  *
4433  * @param pkt packet
4434  * @param type side information type
4435  * @param size new side information size
4436  * @return 0 on success, < 0 on failure
4437  */
4439  int size);
4440 
4441 /**
4442  * Get side information from packet.
4443  *
4444  * @param pkt packet
4445  * @param type desired side information type
4446  * @param size pointer for side information size to store (optional)
4447  * @return pointer to data if present or NULL otherwise
4448  */
4450  int *size);
4451 
4452 #if FF_API_MERGE_SD_API
4455 
4458 #endif
4459 
4461 
4462 /**
4463  * Pack a dictionary for use in side_data.
4464  *
4465  * @param dict The dictionary to pack.
4466  * @param size pointer to store the size of the returned data
4467  * @return pointer to data if successful, NULL otherwise
4468  */
4470 /**
4471  * Unpack a dictionary from side_data.
4472  *
4473  * @param data data from side_data
4474  * @param size size of the data
4475  * @param dict the metadata storage dictionary
4476  * @return 0 on success, < 0 on failure
4477  */
4478 int av_packet_unpack_dictionary(const uint8_t *data, int size, AVDictionary **dict);
4479 
4480 
4481 /**
4482  * Convenience function to free all the side data stored.
4483  * All the other fields stay untouched.
4484  *
4485  * @param pkt packet
4486  */
4488 
4489 /**
4490  * Setup a new reference to the data described by a given packet
4491  *
4492  * If src is reference-counted, setup dst as a new reference to the
4493  * buffer in src. Otherwise allocate a new buffer in dst and copy the
4494  * data from src into it.
4495  *
4496  * All the other fields are copied from src.
4497  *
4498  * @see av_packet_unref
4499  *
4500  * @param dst Destination packet
4501  * @param src Source packet
4502  *
4503  * @return 0 on success, a negative AVERROR on error.
4504  */
4505 int av_packet_ref(AVPacket *dst, const AVPacket *src);
4506 
4507 /**
4508  * Wipe the packet.
4509  *
4510  * Unreference the buffer referenced by the packet and reset the
4511  * remaining packet fields to their default values.
4512  *
4513  * @param pkt The packet to be unreferenced.
4514  */
4516 
4517 /**
4518  * Move every field in src to dst and reset src.
4519  *
4520  * @see av_packet_unref
4521  *
4522  * @param src Source packet, will be reset
4523  * @param dst Destination packet
4524  */
4526 
4527 /**
4528  * Copy only "properties" fields from src to dst.
4529  *
4530  * Properties for the purpose of this function are all the fields
4531  * beside those related to the packet data (buf, data, size)
4532  *
4533  * @param dst Destination packet
4534  * @param src Source packet
4535  *
4536  * @return 0 on success AVERROR on failure.
4537  */
4538 int av_packet_copy_props(AVPacket *dst, const AVPacket *src);
4539 
4540 /**
4541  * Ensure the data described by a given packet is reference counted.
4542  *
4543  * @note This function does not ensure that the reference will be writable.
4544  * Use av_packet_make_writable instead for that purpose.
4545  *
4546  * @see av_packet_ref
4547  * @see av_packet_make_writable
4548  *
4549  * @param pkt packet whose data should be made reference counted.
4550  *
4551  * @return 0 on success, a negative AVERROR on error. On failure, the
4552  * packet is unchanged.
4553  */
4555 
4556 /**
4557  * Create a writable reference for the data described by a given packet,
4558  * avoiding data copy if possible.
4559  *
4560  * @param pkt Packet whose data should be made writable.
4561  *
4562  * @return 0 on success, a negative AVERROR on failure. On failure, the
4563  * packet is unchanged.
4564  */
4566 
4567 /**
4568  * Convert valid timing fields (timestamps / durations) in a packet from one
4569  * timebase to another. Timestamps with unknown values (AV_NOPTS_VALUE) will be
4570  * ignored.
4571  *
4572  * @param pkt packet on which the conversion will be performed
4573  * @param tb_src source timebase, in which the timing fields in pkt are
4574  * expressed
4575  * @param tb_dst destination timebase, to which the timing fields will be
4576  * converted
4577  */
4578 void av_packet_rescale_ts(AVPacket *pkt, AVRational tb_src, AVRational tb_dst);
4579 
4580 /**
4581  * @}
4582  */
4583 
4584 /**
4585  * @addtogroup lavc_decoding
4586  * @{
4587  */
4588 
4589 /**
4590  * Find a registered decoder with a matching codec ID.
4591  *
4592  * @param id AVCodecID of the requested decoder
4593  * @return A decoder if one was found, NULL otherwise.
4594  */
4596 
4597 /**
4598  * Find a registered decoder with the specified name.
4599  *
4600  * @param name name of the requested decoder
4601  * @return A decoder if one was found, NULL otherwise.
4602  */
4604 
4605 /**
4606  * The default callback for AVCodecContext.get_buffer2(). It is made public so
4607  * it can be called by custom get_buffer2() implementations for decoders without
4608  * AV_CODEC_CAP_DR1 set.
4609  */
4611 
4612 /**
4613  * Modify width and height values so that they will result in a memory
4614  * buffer that is acceptable for the codec if you do not use any horizontal
4615  * padding.
4616  *
4617  * May only be used if a codec with AV_CODEC_CAP_DR1 has been opened.
4618  */
4620 
4621 /**
4622  * Modify width and height values so that they will result in a memory
4623  * buffer that is acceptable for the codec if you also ensure that all
4624  * line sizes are a multiple of the respective linesize_align[i].
4625  *
4626  * May only be used if a codec with AV_CODEC_CAP_DR1 has been opened.
4627  */
4629  int linesize_align[AV_NUM_DATA_POINTERS]);
4630 
4631 /**
4632  * Converts AVChromaLocation to swscale x/y chroma position.
4633  *
4634  * The positions represent the chroma (0,0) position in a coordinates system
4635  * with luma (0,0) representing the origin and luma(1,1) representing 256,256
4636  *
4637  * @param xpos horizontal chroma sample position
4638  * @param ypos vertical chroma sample position
4639  */
4640 int avcodec_enum_to_chroma_pos(int *xpos, int *ypos, enum AVChromaLocation pos);
4641 
4642 /**
4643  * Converts swscale x/y chroma position to AVChromaLocation.
4644  *
4645  * The positions represent the chroma (0,0) position in a coordinates system
4646  * with luma (0,0) representing the origin and luma(1,1) representing 256,256
4647  *
4648  * @param xpos horizontal chroma sample position
4649  * @param ypos vertical chroma sample position
4650  */
4651 enum AVChromaLocation avcodec_chroma_pos_to_enum(int xpos, int ypos);
4652 
4653 /**
4654  * Decode the audio frame of size avpkt->size from avpkt->data into frame.
4655  *
4656  * Some decoders may support multiple frames in a single AVPacket. Such
4657  * decoders would then just decode the first frame and the return value would be
4658  * less than the packet size. In this case, avcodec_decode_audio4 has to be
4659  * called again with an AVPacket containing the remaining data in order to
4660  * decode the second frame, etc... Even if no frames are returned, the packet
4661  * needs to be fed to the decoder with remaining data until it is completely
4662  * consumed or an error occurs.
4663  *
4664  * Some decoders (those marked with AV_CODEC_CAP_DELAY) have a delay between input
4665  * and output. This means that for some packets they will not immediately
4666  * produce decoded output and need to be flushed at the end of decoding to get
4667  * all the decoded data. Flushing is done by calling this function with packets
4668  * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
4669  * returning samples. It is safe to flush even those decoders that are not
4670  * marked with AV_CODEC_CAP_DELAY, then no samples will be returned.
4671  *
4672  * @warning The input buffer, avpkt->data must be AV_INPUT_BUFFER_PADDING_SIZE
4673  * larger than the actual read bytes because some optimized bitstream
4674  * readers read 32 or 64 bits at once and could read over the end.
4675  *
4676  * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
4677  * before packets may be fed to the decoder.
4678  *
4679  * @param avctx the codec context
4680  * @param[out] frame The AVFrame in which to store decoded audio samples.
4681  * The decoder will allocate a buffer for the decoded frame by
4682  * calling the AVCodecContext.get_buffer2() callback.
4683  * When AVCodecContext.refcounted_frames is set to 1, the frame is
4684  * reference counted and the returned reference belongs to the
4685  * caller. The caller must release the frame using av_frame_unref()
4686  * when the frame is no longer needed. The caller may safely write
4687  * to the frame if av_frame_is_writable() returns 1.
4688  * When AVCodecContext.refcounted_frames is set to 0, the returned
4689  * reference belongs to the decoder and is valid only until the
4690  * next call to this function or until closing or flushing the
4691  * decoder. The caller may not write to it.
4692  * @param[out] got_frame_ptr Zero if no frame could be decoded, otherwise it is
4693  * non-zero. Note that this field being set to zero
4694  * does not mean that an error has occurred. For
4695  * decoders with AV_CODEC_CAP_DELAY set, no given decode
4696  * call is guaranteed to produce a frame.
4697  * @param[in] avpkt The input AVPacket containing the input buffer.
4698  * At least avpkt->data and avpkt->size should be set. Some
4699  * decoders might also require additional fields to be set.
4700  * @return A negative error code is returned if an error occurred during
4701  * decoding, otherwise the number of bytes consumed from the input
4702  * AVPacket is returned.
4703  *
4704 * @deprecated Use avcodec_send_packet() and avcodec_receive_frame().
4705  */
4708  int *got_frame_ptr, const AVPacket *avpkt);
4709 
4710 /**
4711  * Decode the video frame of size avpkt->size from avpkt->data into picture.
4712  * Some decoders may support multiple frames in a single AVPacket, such
4713  * decoders would then just decode the first frame.
4714  *
4715  * @warning The input buffer must be AV_INPUT_BUFFER_PADDING_SIZE larger than
4716  * the actual read bytes because some optimized bitstream readers read 32 or 64
4717  * bits at once and could read over the end.
4718  *
4719  * @warning The end of the input buffer buf should be set to 0 to ensure that
4720  * no overreading happens for damaged MPEG streams.
4721  *
4722  * @note Codecs which have the AV_CODEC_CAP_DELAY capability set have a delay
4723  * between input and output, these need to be fed with avpkt->data=NULL,
4724  * avpkt->size=0 at the end to return the remaining frames.
4725  *
4726  * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
4727  * before packets may be fed to the decoder.
4728  *
4729  * @param avctx the codec context
4730  * @param[out] picture The AVFrame in which the decoded video frame will be stored.
4731  * Use av_frame_alloc() to get an AVFrame. The codec will
4732  * allocate memory for the actual bitmap by calling the
4733  * AVCodecContext.get_buffer2() callback.
4734  * When AVCodecContext.refcounted_frames is set to 1, the frame is
4735  * reference counted and the returned reference belongs to the
4736  * caller. The caller must release the frame using av_frame_unref()
4737  * when the frame is no longer needed. The caller may safely write
4738  * to the frame if av_frame_is_writable() returns 1.
4739  * When AVCodecContext.refcounted_frames is set to 0, the returned
4740  * reference belongs to the decoder and is valid only until the
4741  * next call to this function or until closing or flushing the
4742  * decoder. The caller may not write to it.
4743  *
4744  * @param[in] avpkt The input AVPacket containing the input buffer.
4745  * You can create such packet with av_init_packet() and by then setting
4746  * data and size, some decoders might in addition need other fields like
4747  * flags&AV_PKT_FLAG_KEY. All decoders are designed to use the least
4748  * fields possible.
4749  * @param[in,out] got_picture_ptr Zero if no frame could be decompressed, otherwise, it is nonzero.
4750  * @return On error a negative value is returned, otherwise the number of bytes
4751  * used or zero if no frame could be decompressed.
4752  *
4753  * @deprecated Use avcodec_send_packet() and avcodec_receive_frame().
4754  */
4756 int avcodec_decode_video2(AVCodecContext *avctx, AVFrame *picture,
4757  int *got_picture_ptr,
4758  const AVPacket *avpkt);
4759 
4760 /**
4761  * Decode a subtitle message.
4762  * Return a negative value on error, otherwise return the number of bytes used.
4763  * If no subtitle could be decompressed, got_sub_ptr is zero.
4764  * Otherwise, the subtitle is stored in *sub.
4765  * Note that AV_CODEC_CAP_DR1 is not available for subtitle codecs. This is for
4766  * simplicity, because the performance difference is expect to be negligible
4767  * and reusing a get_buffer written for video codecs would probably perform badly
4768  * due to a potentially very different allocation pattern.
4769  *
4770  * Some decoders (those marked with AV_CODEC_CAP_DELAY) have a delay between input
4771  * and output. This means that for some packets they will not immediately
4772  * produce decoded output and need to be flushed at the end of decoding to get
4773  * all the decoded data. Flushing is done by calling this function with packets
4774  * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
4775  * returning subtitles. It is safe to flush even those decoders that are not
4776  * marked with AV_CODEC_CAP_DELAY, then no subtitles will be returned.
4777  *
4778  * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
4779  * before packets may be fed to the decoder.
4780  *
4781  * @param avctx the codec context
4782  * @param[out] sub The Preallocated AVSubtitle in which the decoded subtitle will be stored,
4783  * must be freed with avsubtitle_free if *got_sub_ptr is set.
4784  * @param[in,out] got_sub_ptr Zero if no subtitle could be decompressed, otherwise, it is nonzero.
4785  * @param[in] avpkt The input AVPacket containing the input buffer.
4786  */
4788  int *got_sub_ptr,
4789  AVPacket *avpkt);
4790 
4791 /**
4792  * Supply raw packet data as input to a decoder.
4793  *
4794  * Internally, this call will copy relevant AVCodecContext fields, which can
4795  * influence decoding per-packet, and apply them when the packet is actually
4796  * decoded. (For example AVCodecContext.skip_frame, which might direct the
4797  * decoder to drop the frame contained by the packet sent with this function.)
4798  *
4799  * @warning The input buffer, avpkt->data must be AV_INPUT_BUFFER_PADDING_SIZE
4800  * larger than the actual read bytes because some optimized bitstream
4801  * readers read 32 or 64 bits at once and could read over the end.
4802  *
4803  * @warning Do not mix this API with the legacy API (like avcodec_decode_video2())
4804  * on the same AVCodecContext. It will return unexpected results now
4805  * or in future libavcodec versions.
4806  *
4807  * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
4808  * before packets may be fed to the decoder.
4809  *
4810  * @param avctx codec context
4811  * @param[in] avpkt The input AVPacket. Usually, this will be a single video
4812  * frame, or several complete audio frames.
4813  * Ownership of the packet remains with the caller, and the
4814  * decoder will not write to the packet. The decoder may create
4815  * a reference to the packet data (or copy it if the packet is
4816  * not reference-counted).
4817  * Unlike with older APIs, the packet is always fully consumed,
4818  * and if it contains multiple frames (e.g. some audio codecs),
4819  * will require you to call avcodec_receive_frame() multiple
4820  * times afterwards before you can send a new packet.
4821  * It can be NULL (or an AVPacket with data set to NULL and
4822  * size set to 0); in this case, it is considered a flush
4823  * packet, which signals the end of the stream. Sending the
4824  * first flush packet will return success. Subsequent ones are
4825  * unnecessary and will return AVERROR_EOF. If the decoder
4826  * still has frames buffered, it will return them after sending
4827  * a flush packet.
4828  *
4829  * @return 0 on success, otherwise negative error code:
4830  * AVERROR(EAGAIN): input is not accepted in the current state - user
4831  * must read output with avcodec_receive_frame() (once
4832  * all output is read, the packet should be resent, and
4833  * the call will not fail with EAGAIN).
4834  * AVERROR_EOF: the decoder has been flushed, and no new packets can
4835  * be sent to it (also returned if more than 1 flush
4836  * packet is sent)
4837  * AVERROR(EINVAL): codec not opened, it is an encoder, or requires flush
4838  * AVERROR(ENOMEM): failed to add packet to internal queue, or similar
4839  * other errors: legitimate decoding errors
4840  */
4841 int avcodec_send_packet(AVCodecContext *avctx, const AVPacket *avpkt);
4842 
4843 /**
4844  * Return decoded output data from a decoder.
4845  *
4846  * @param avctx codec context
4847  * @param frame This will be set to a reference-counted video or audio
4848  * frame (depending on the decoder type) allocated by the
4849  * decoder. Note that the function will always call
4850  * av_frame_unref(frame) before doing anything else.
4851  *
4852  * @return
4853  * 0: success, a frame was returned
4854  * AVERROR(EAGAIN): output is not available in this state - user must try
4855  * to send new input
4856  * AVERROR_EOF: the decoder has been fully flushed, and there will be
4857  * no more output frames
4858  * AVERROR(EINVAL): codec not opened, or it is an encoder
4859  * other negative values: legitimate decoding errors
4860  */
4862 
4863 /**
4864  * Supply a raw video or audio frame to the encoder. Use avcodec_receive_packet()
4865  * to retrieve buffered output packets.
4866  *
4867  * @param avctx codec context
4868  * @param[in] frame AVFrame containing the raw audio or video frame to be encoded.
4869  * Ownership of the frame remains with the caller, and the
4870  * encoder will not write to the frame. The encoder may create
4871  * a reference to the frame data (or copy it if the frame is
4872  * not reference-counted).
4873  * It can be NULL, in which case it is considered a flush
4874  * packet. This signals the end of the stream. If the encoder
4875  * still has packets buffered, it will return them after this
4876  * call. Once flushing mode has been entered, additional flush
4877  * packets are ignored, and sending frames will return
4878  * AVERROR_EOF.
4879  *
4880  * For audio:
4881  * If AV_CODEC_CAP_VARIABLE_FRAME_SIZE is set, then each frame
4882  * can have any number of samples.
4883  * If it is not set, frame->nb_samples must be equal to
4884  * avctx->frame_size for all frames except the last.
4885  * The final frame may be smaller than avctx->frame_size.
4886  * @return 0 on success, otherwise negative error code:
4887  * AVERROR(EAGAIN): input is not accepted in the current state - user
4888  * must read output with avcodec_receive_packet() (once
4889  * all output is read, the packet should be resent, and
4890  * the call will not fail with EAGAIN).
4891  * AVERROR_EOF: the encoder has been flushed, and no new frames can
4892  * be sent to it
4893  * AVERROR(EINVAL): codec not opened, refcounted_frames not set, it is a
4894  * decoder, or requires flush
4895  * AVERROR(ENOMEM): failed to add packet to internal queue, or similar
4896  * other errors: legitimate decoding errors
4897  */
4898 int avcodec_send_frame(AVCodecContext *avctx, const AVFrame *frame);
4899 
4900 /**
4901  * Read encoded data from the encoder.
4902  *
4903  * @param avctx codec context
4904  * @param avpkt This will be set to a reference-counted packet allocated by the
4905  * encoder. Note that the function will always call
4906  * av_frame_unref(frame) before doing anything else.
4907  * @return 0 on success, otherwise negative error code:
4908  * AVERROR(EAGAIN): output is not available in the current state - user
4909  * must try to send input
4910  * AVERROR_EOF: the encoder has been fully flushed, and there will be
4911  * no more output packets
4912  * AVERROR(EINVAL): codec not opened, or it is an encoder
4913  * other errors: legitimate decoding errors
4914  */
4915 int avcodec_receive_packet(AVCodecContext *avctx, AVPacket *avpkt);
4916 
4917 /**
4918  * Create and return a AVHWFramesContext with values adequate for hardware
4919  * decoding. This is meant to get called from the get_format callback, and is
4920  * a helper for preparing a AVHWFramesContext for AVCodecContext.hw_frames_ctx.
4921  * This API is for decoding with certain hardware acceleration modes/APIs only.
4922  *
4923  * The returned AVHWFramesContext is not initialized. The caller must do this
4924  * with av_hwframe_ctx_init().
4925  *
4926  * Calling this function is not a requirement, but makes it simpler to avoid
4927  * codec or hardware API specific details when manually allocating frames.
4928  *
4929  * Alternatively to this, an API user can set AVCodecContext.hw_device_ctx,
4930  * which sets up AVCodecContext.hw_frames_ctx fully automatically, and makes
4931  * it unnecessary to call this function or having to care about
4932  * AVHWFramesContext initialization at all.
4933  *
4934  * There are a number of requirements for calling this function:
4935  *
4936  * - It must be called from get_format with the same avctx parameter that was
4937  * passed to get_format. Calling it outside of get_format is not allowed, and
4938  * can trigger undefined behavior.
4939  * - The function is not always supported (see description of return values).
4940  * Even if this function returns successfully, hwaccel initialization could
4941  * fail later. (The degree to which implementations check whether the stream
4942  * is actually supported varies. Some do this check only after the user's
4943  * get_format callback returns.)
4944  * - The hw_pix_fmt must be one of the choices suggested by get_format. If the
4945  * user decides to use a AVHWFramesContext prepared with this API function,
4946  * the user must return the same hw_pix_fmt from get_format.
4947  * - The device_ref passed to this function must support the given hw_pix_fmt.
4948  * - After calling this API function, it is the user's responsibility to
4949  * initialize the AVHWFramesContext (returned by the out_frames_ref parameter),
4950  * and to set AVCodecContext.hw_frames_ctx to it. If done, this must be done
4951  * before returning from get_format (this is implied by the normal
4952  * AVCodecContext.hw_frames_ctx API rules).
4953  * - The AVHWFramesContext parameters may change every time time get_format is
4954  * called. Also, AVCodecContext.hw_frames_ctx is reset before get_format. So
4955  * you are inherently required to go through this process again on every
4956  * get_format call.
4957  * - It is perfectly possible to call this function without actually using
4958  * the resulting AVHWFramesContext. One use-case might be trying to reuse a
4959  * previously initialized AVHWFramesContext, and calling this API function
4960  * only to test whether the required frame parameters have changed.
4961  * - Fields that use dynamically allocated values of any kind must not be set
4962  * by the user unless setting them is explicitly allowed by the documentation.
4963  * If the user sets AVHWFramesContext.free and AVHWFramesContext.user_opaque,
4964  * the new free callback must call the potentially set previous free callback.
4965  * This API call may set any dynamically allocated fields, including the free
4966  * callback.
4967  *
4968  * The function will set at least the following fields on AVHWFramesContext
4969  * (potentially more, depending on hwaccel API):
4970  *
4971  * - All fields set by av_hwframe_ctx_alloc().
4972  * - Set the format field to hw_pix_fmt.
4973  * - Set the sw_format field to the most suited and most versatile format. (An
4974  * implication is that this will prefer generic formats over opaque formats
4975  * with arbitrary restrictions, if possible.)
4976  * - Set the width/height fields to the coded frame size, rounded up to the
4977  * API-specific minimum alignment.
4978  * - Only _if_ the hwaccel requires a pre-allocated pool: set the initial_pool_size
4979  * field to the number of maximum reference surfaces possible with the codec,
4980  * plus 1 surface for the user to work (meaning the user can safely reference
4981  * at most 1 decoded surface at a time), plus additional buffering introduced
4982  * by frame threading. If the hwaccel does not require pre-allocation, the
4983  * field is left to 0, and the decoder will allocate new surfaces on demand
4984  * during decoding.
4985  * - Possibly AVHWFramesContext.hwctx fields, depending on the underlying
4986  * hardware API.
4987  *
4988  * Essentially, out_frames_ref returns the same as av_hwframe_ctx_alloc(), but
4989  * with basic frame parameters set.
4990  *
4991  * The function is stateless, and does not change the AVCodecContext or the
4992  * device_ref AVHWDeviceContext.
4993  *
4994  * @param avctx The context which is currently calling get_format, and which
4995  * implicitly contains all state needed for filling the returned
4996  * AVHWFramesContext properly.
4997  * @param device_ref A reference to the AVHWDeviceContext describing the device
4998  * which will be used by the hardware decoder.
4999  * @param hw_pix_fmt The hwaccel format you are going to return from get_format.
5000  * @param out_frames_ref On success, set to a reference to an _uninitialized_
5001  * AVHWFramesContext, created from the given device_ref.
5002  * Fields will be set to values required for decoding.
5003  * Not changed if an error is returned.
5004  * @return zero on success, a negative value on error. The following error codes
5005  * have special semantics:
5006  * AVERROR(ENOENT): the decoder does not support this functionality. Setup
5007  * is always manual, or it is a decoder which does not
5008  * support setting AVCodecContext.hw_frames_ctx at all,
5009  * or it is a software format.
5010  * AVERROR(EINVAL): it is known that hardware decoding is not supported for
5011  * this configuration, or the device_ref is not supported
5012  * for the hwaccel referenced by hw_pix_fmt.
5013  */
5015  AVBufferRef *device_ref,
5017  AVBufferRef **out_frames_ref);
5018 
5019 
5020 
5021 /**
5022  * @defgroup lavc_parsing Frame parsing
5023  * @{
5024  */
5025 
5028  AV_PICTURE_STRUCTURE_TOP_FIELD, //< coded as top field
5029  AV_PICTURE_STRUCTURE_BOTTOM_FIELD, //< coded as bottom field
5030  AV_PICTURE_STRUCTURE_FRAME, //< coded as frame
5031 };
5032 
5033 typedef struct AVCodecParserContext {
5034  void *priv_data;
5036  int64_t frame_offset; /* offset of the current frame */
5037  int64_t cur_offset; /* current offset
5038  (incremented by each av_parser_parse()) */
5039  int64_t next_frame_offset; /* offset of the next frame */
5040  /* video info */
5041  int pict_type; /* XXX: Put it back in AVCodecContext. */
5042  /**
5043  * This field is used for proper frame duration computation in lavf.
5044  * It signals, how much longer the frame duration of the current frame
5045  * is compared to normal frame duration.
5046  *
5047  * frame_duration = (1 + repeat_pict) * time_base
5048  *
5049  * It is used by codecs like H.264 to display telecined material.
5050  */
5051  int repeat_pict; /* XXX: Put it back in AVCodecContext. */
5052  int64_t pts; /* pts of the current frame */
5053  int64_t dts; /* dts of the current frame */
5054 
5055  /* private data */
5056  int64_t last_pts;
5057  int64_t last_dts;
5059 
5060 #define AV_PARSER_PTS_NB 4
5065 
5066  int flags;
5067 #define PARSER_FLAG_COMPLETE_FRAMES 0x0001
5068 #define PARSER_FLAG_ONCE 0x0002
5069 /// Set if the parser has a valid file offset
5070 #define PARSER_FLAG_FETCHED_OFFSET 0x0004
5071 #define PARSER_FLAG_USE_CODEC_TS 0x1000
5072 
5073  int64_t offset; ///< byte offset from starting packet start
5075 
5076  /**
5077  * Set by parser to 1 for key frames and 0 for non-key frames.
5078  * It is initialized to -1, so if the parser doesn't set this flag,
5079  * old-style fallback using AV_PICTURE_TYPE_I picture type as key frames
5080  * will be used.
5081  */
5083 
5084 #if FF_API_CONVERGENCE_DURATION
5085  /**
5086  * @deprecated unused
5087  */
5090 #endif
5091 
5092  // Timestamp generation support:
5093  /**
5094  * Synchronization point for start of timestamp generation.
5095  *
5096  * Set to >0 for sync point, 0 for no sync point and <0 for undefined
5097  * (default).
5098  *
5099  * For example, this corresponds to presence of H.264 buffering period
5100  * SEI message.
5101  */
5103 
5104  /**
5105  * Offset of the current timestamp against last timestamp sync point in
5106  * units of AVCodecContext.time_base.
5107  *
5108  * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
5109  * contain a valid timestamp offset.
5110  *
5111  * Note that the timestamp of sync point has usually a nonzero
5112  * dts_ref_dts_delta, which refers to the previous sync point. Offset of
5113  * the next frame after timestamp sync point will be usually 1.
5114  *
5115  * For example, this corresponds to H.264 cpb_removal_delay.
5116  */
5118 
5119  /**
5120  * Presentation delay of current frame in units of AVCodecContext.time_base.
5121  *
5122  * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
5123  * contain valid non-negative timestamp delta (presentation time of a frame
5124  * must not lie in the past).
5125  *
5126  * This delay represents the difference between decoding and presentation
5127  * time of the frame.
5128  *
5129  * For example, this corresponds to H.264 dpb_output_delay.
5130  */
5132 
5133  /**
5134  * Position of the packet in file.
5135  *
5136  * Analogous to cur_frame_pts/dts
5137  */
5139 
5140  /**
5141  * Byte position of currently parsed frame in stream.
5142  */
5143  int64_t pos;
5144 
5145  /**
5146  * Previous frame byte position.
5147  */
5148  int64_t last_pos;
5149 
5150  /**
5151  * Duration of the current frame.
5152  * For audio, this is in units of 1 / AVCodecContext.sample_rate.
5153  * For all other types, this is in units of AVCodecContext.time_base.
5154  */
5156 
5158 
5159  /**
5160  * Indicate whether a picture is coded as a frame, top field or bottom field.
5161  *
5162  * For example, H.264 field_pic_flag equal to 0 corresponds to
5163  * AV_PICTURE_STRUCTURE_FRAME. An H.264 picture with field_pic_flag
5164  * equal to 1 and bottom_field_flag equal to 0 corresponds to
5165  * AV_PICTURE_STRUCTURE_TOP_FIELD.
5166  */
5168 
5169  /**
5170  * Picture number incremented in presentation or output order.
5171  * This field may be reinitialized at the first picture of a new sequence.
5172  *
5173  * For example, this corresponds to H.264 PicOrderCnt.
5174  */
5176 
5177  /**
5178  * Dimensions of the decoded video intended for presentation.
5179  */
5180  int width;
5181  int height;
5182 
5183  /**
5184  * Dimensions of the coded video.
5185  */
5188 
5189  /**
5190  * The format of the coded data, corresponds to enum AVPixelFormat for video
5191  * and for enum AVSampleFormat for audio.
5192  *
5193  * Note that a decoder can have considerable freedom in how exactly it
5194  * decodes the data, so the format reported here might be different from the
5195  * one returned by a decoder.
5196  */
5197  int format;
5199 
5200 typedef struct AVCodecParser {
5201  int codec_ids[5]; /* several codec IDs are permitted */
5204  /* This callback never returns an error, a negative value means that
5205  * the frame start was in a previous packet. */
5207  AVCodecContext *avctx,
5208  const uint8_t **poutbuf, int *poutbuf_size,
5209  const uint8_t *buf, int buf_size);
5211  int (*split)(AVCodecContext *avctx, const uint8_t *buf, int buf_size);
5213 } AVCodecParser;
5214 
5215 /**
5216  * Iterate over all registered codec parsers.
5217  *
5218  * @param opaque a pointer where libavcodec will store the iteration state. Must
5219  * point to NULL to start the iteration.
5220  *
5221  * @return the next registered codec parser or NULL when the iteration is
5222  * finished
5223  */
5224 const AVCodecParser *av_parser_iterate(void **opaque);
5225 
5228 
5232 
5233 /**
5234  * Parse a packet.
5235  *
5236  * @param s parser context.
5237  * @param avctx codec context.
5238  * @param poutbuf set to pointer to parsed buffer or NULL if not yet finished.
5239  * @param poutbuf_size set to size of parsed buffer or zero if not yet finished.
5240  * @param buf input buffer.
5241  * @param buf_size buffer size in bytes without the padding. I.e. the full buffer
5242  size is assumed to be buf_size + AV_INPUT_BUFFER_PADDING_SIZE.
5243  To signal EOF, this should be 0 (so that the last frame
5244  can be output).
5245  * @param pts input presentation timestamp.
5246  * @param dts input decoding timestamp.
5247  * @param pos input byte position in stream.
5248  * @return the number of bytes of the input bitstream used.
5249  *
5250  * Example:
5251  * @code
5252  * while(in_len){
5253  * len = av_parser_parse2(myparser, AVCodecContext, &data, &size,
5254  * in_data, in_len,
5255  * pts, dts, pos);
5256  * in_data += len;
5257  * in_len -= len;
5258  *
5259  * if(size)
5260  * decode_frame(data, size);
5261  * }
5262  * @endcode
5263  */
5265  AVCodecContext *avctx,
5266  uint8_t **poutbuf, int *poutbuf_size,
5267  const uint8_t *buf, int buf_size,
5268  int64_t pts, int64_t dts,
5269  int64_t pos);
5270 
5271 /**
5272  * @return 0 if the output buffer is a subset of the input, 1 if it is allocated and must be freed
5273  * @deprecated use AVBitStreamFilter
5274  */
5276  AVCodecContext *avctx,
5277  uint8_t **poutbuf, int *poutbuf_size,
5278  const uint8_t *buf, int buf_size, int keyframe);
5280 
5281 /**
5282  * @}
5283  * @}
5284  */
5285 
5286 /**
5287  * @addtogroup lavc_encoding
5288  * @{
5289  */
5290 
5291 /**
5292  * Find a registered encoder with a matching codec ID.
5293  *
5294  * @param id AVCodecID of the requested encoder
5295  * @return An encoder if one was found, NULL otherwise.
5296  */
5298 
5299 /**
5300  * Find a registered encoder with the specified name.
5301  *
5302  * @param name name of the requested encoder
5303  * @return An encoder if one was found, NULL otherwise.
5304  */
5306 
5307 /**
5308  * Encode a frame of audio.
5309  *
5310  * Takes input samples from frame and writes the next output packet, if
5311  * available, to avpkt. The output packet does not necessarily contain data for
5312  * the most recent frame, as encoders can delay, split, and combine input frames
5313  * internally as needed.
5314  *
5315  * @param avctx codec context
5316  * @param avpkt output AVPacket.
5317  * The user can supply an output buffer by setting
5318  * avpkt->data and avpkt->size prior to calling the
5319  * function, but if the size of the user-provided data is not
5320  * large enough, encoding will fail. If avpkt->data and
5321  * avpkt->size are set, avpkt->destruct must also be set. All
5322  * other AVPacket fields will be reset by the encoder using
5323  * av_init_packet(). If avpkt->data is NULL, the encoder will
5324  * allocate it. The encoder will set avpkt->size to the size
5325  * of the output packet.
5326  *
5327  * If this function fails or produces no output, avpkt will be
5328  * freed using av_packet_unref().
5329  * @param[in] frame AVFrame containing the raw audio data to be encoded.
5330  * May be NULL when flushing an encoder that has the
5331  * AV_CODEC_CAP_DELAY capability set.
5332  * If AV_CODEC_CAP_VARIABLE_FRAME_SIZE is set, then each frame
5333  * can have any number of samples.
5334  * If it is not set, frame->nb_samples must be equal to
5335  * avctx->frame_size for all frames except the last.
5336  * The final frame may be smaller than avctx->frame_size.
5337  * @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
5338  * output packet is non-empty, and to 0 if it is
5339  * empty. If the function returns an error, the
5340  * packet can be assum