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avcodec.h
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1 /*
2  * copyright (c) 2001 Fabrice Bellard
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #ifndef AVCODEC_AVCODEC_H
22 #define AVCODEC_AVCODEC_H
23 
24 /**
25  * @file
26  * @ingroup libavc
27  * Libavcodec external API header
28  */
29 
30 #include <errno.h>
31 #include "libavutil/samplefmt.h"
32 #include "libavutil/attributes.h"
33 #include "libavutil/avutil.h"
34 #include "libavutil/buffer.h"
35 #include "libavutil/cpu.h"
37 #include "libavutil/dict.h"
38 #include "libavutil/frame.h"
39 #include "libavutil/log.h"
40 #include "libavutil/pixfmt.h"
41 #include "libavutil/rational.h"
42 
43 #include "version.h"
44 
45 /**
46  * @defgroup libavc Encoding/Decoding Library
47  * @{
48  *
49  * @defgroup lavc_decoding Decoding
50  * @{
51  * @}
52  *
53  * @defgroup lavc_encoding Encoding
54  * @{
55  * @}
56  *
57  * @defgroup lavc_codec Codecs
58  * @{
59  * @defgroup lavc_codec_native Native Codecs
60  * @{
61  * @}
62  * @defgroup lavc_codec_wrappers External library wrappers
63  * @{
64  * @}
65  * @defgroup lavc_codec_hwaccel Hardware Accelerators bridge
66  * @{
67  * @}
68  * @}
69  * @defgroup lavc_internal Internal
70  * @{
71  * @}
72  * @}
73  *
74  */
75 
76 /**
77  * @defgroup lavc_core Core functions/structures.
78  * @ingroup libavc
79  *
80  * Basic definitions, functions for querying libavcodec capabilities,
81  * allocating core structures, etc.
82  * @{
83  */
84 
85 
86 /**
87  * Identify the syntax and semantics of the bitstream.
88  * The principle is roughly:
89  * Two decoders with the same ID can decode the same streams.
90  * Two encoders with the same ID can encode compatible streams.
91  * There may be slight deviations from the principle due to implementation
92  * details.
93  *
94  * If you add a codec ID to this list, add it so that
95  * 1. no value of a existing codec ID changes (that would break ABI),
96  * 2. Give it a value which when taken as ASCII is recognized uniquely by a human as this specific codec.
97  * This ensures that 2 forks can independently add AVCodecIDs without producing conflicts.
98  *
99  * After adding new codec IDs, do not forget to add an entry to the codec
100  * descriptor list and bump libavcodec minor version.
101  */
102 enum AVCodecID {
104 
105  /* video codecs */
107  AV_CODEC_ID_MPEG2VIDEO, ///< preferred ID for MPEG-1/2 video decoding
108 #if FF_API_XVMC
109  AV_CODEC_ID_MPEG2VIDEO_XVMC,
110 #endif /* FF_API_XVMC */
298 
299  AV_CODEC_ID_BRENDER_PIX= MKBETAG('B','P','I','X'),
300  AV_CODEC_ID_Y41P = MKBETAG('Y','4','1','P'),
301  AV_CODEC_ID_ESCAPE130 = MKBETAG('E','1','3','0'),
302  AV_CODEC_ID_EXR = MKBETAG('0','E','X','R'),
303  AV_CODEC_ID_AVRP = MKBETAG('A','V','R','P'),
304 
305  AV_CODEC_ID_012V = MKBETAG('0','1','2','V'),
306  AV_CODEC_ID_G2M = MKBETAG( 0 ,'G','2','M'),
307  AV_CODEC_ID_AVUI = MKBETAG('A','V','U','I'),
308  AV_CODEC_ID_AYUV = MKBETAG('A','Y','U','V'),
309  AV_CODEC_ID_TARGA_Y216 = MKBETAG('T','2','1','6'),
310  AV_CODEC_ID_V308 = MKBETAG('V','3','0','8'),
311  AV_CODEC_ID_V408 = MKBETAG('V','4','0','8'),
312  AV_CODEC_ID_YUV4 = MKBETAG('Y','U','V','4'),
313  AV_CODEC_ID_SANM = MKBETAG('S','A','N','M'),
314  AV_CODEC_ID_PAF_VIDEO = MKBETAG('P','A','F','V'),
315  AV_CODEC_ID_AVRN = MKBETAG('A','V','R','n'),
316  AV_CODEC_ID_CPIA = MKBETAG('C','P','I','A'),
317  AV_CODEC_ID_XFACE = MKBETAG('X','F','A','C'),
318  AV_CODEC_ID_SGIRLE = MKBETAG('S','G','I','R'),
319  AV_CODEC_ID_MVC1 = MKBETAG('M','V','C','1'),
320  AV_CODEC_ID_MVC2 = MKBETAG('M','V','C','2'),
321  AV_CODEC_ID_SNOW = MKBETAG('S','N','O','W'),
322  AV_CODEC_ID_WEBP = MKBETAG('W','E','B','P'),
323  AV_CODEC_ID_SMVJPEG = MKBETAG('S','M','V','J'),
324  AV_CODEC_ID_HEVC = MKBETAG('H','2','6','5'),
325 #define AV_CODEC_ID_H265 AV_CODEC_ID_HEVC
326  AV_CODEC_ID_VP7 = MKBETAG('V','P','7','0'),
327  AV_CODEC_ID_APNG = MKBETAG('A','P','N','G'),
328 
329  /* various PCM "codecs" */
330  AV_CODEC_ID_FIRST_AUDIO = 0x10000, ///< A dummy id pointing at the start of audio codecs
365 
366  /* various ADPCM codecs */
398  AV_CODEC_ID_ADPCM_VIMA = MKBETAG('V','I','M','A'),
399 #if FF_API_VIMA_DECODER
400  AV_CODEC_ID_VIMA = MKBETAG('V','I','M','A'),
401 #endif
402  AV_CODEC_ID_ADPCM_AFC = MKBETAG('A','F','C',' '),
403  AV_CODEC_ID_ADPCM_IMA_OKI = MKBETAG('O','K','I',' '),
404  AV_CODEC_ID_ADPCM_DTK = MKBETAG('D','T','K',' '),
405  AV_CODEC_ID_ADPCM_IMA_RAD = MKBETAG('R','A','D',' '),
406  AV_CODEC_ID_ADPCM_G726LE = MKBETAG('6','2','7','G'),
407  AV_CODEC_ID_ADPCM_THP_LE = MKBETAG('T','H','P','L'),
408 
409  /* AMR */
412 
413  /* RealAudio codecs*/
416 
417  /* various DPCM codecs */
422 
423  /* audio codecs */
424  AV_CODEC_ID_MP2 = 0x15000,
425  AV_CODEC_ID_MP3, ///< preferred ID for decoding MPEG audio layer 1, 2 or 3
442  AV_CODEC_ID_GSM, ///< as in Berlin toast format
454  AV_CODEC_ID_GSM_MS, /* as found in WAV */
456 #if FF_API_VOXWARE
458 #endif
494  AV_CODEC_ID_FFWAVESYNTH = MKBETAG('F','F','W','S'),
495  AV_CODEC_ID_SONIC = MKBETAG('S','O','N','C'),
496  AV_CODEC_ID_SONIC_LS = MKBETAG('S','O','N','L'),
497  AV_CODEC_ID_PAF_AUDIO = MKBETAG('P','A','F','A'),
498  AV_CODEC_ID_OPUS = MKBETAG('O','P','U','S'),
499  AV_CODEC_ID_TAK = MKBETAG('t','B','a','K'),
500  AV_CODEC_ID_EVRC = MKBETAG('s','e','v','c'),
501  AV_CODEC_ID_SMV = MKBETAG('s','s','m','v'),
502  AV_CODEC_ID_DSD_LSBF = MKBETAG('D','S','D','L'),
503  AV_CODEC_ID_DSD_MSBF = MKBETAG('D','S','D','M'),
506  AV_CODEC_ID_4GV = MKBETAG('s','4','g','v'),
507 
508  /* subtitle codecs */
509  AV_CODEC_ID_FIRST_SUBTITLE = 0x17000, ///< A dummy ID pointing at the start of subtitle codecs.
512  AV_CODEC_ID_TEXT, ///< raw UTF-8 text
519  AV_CODEC_ID_MICRODVD = MKBETAG('m','D','V','D'),
520  AV_CODEC_ID_EIA_608 = MKBETAG('c','6','0','8'),
521  AV_CODEC_ID_JACOSUB = MKBETAG('J','S','U','B'),
522  AV_CODEC_ID_SAMI = MKBETAG('S','A','M','I'),
523  AV_CODEC_ID_REALTEXT = MKBETAG('R','T','X','T'),
524  AV_CODEC_ID_STL = MKBETAG('S','p','T','L'),
525  AV_CODEC_ID_SUBVIEWER1 = MKBETAG('S','b','V','1'),
526  AV_CODEC_ID_SUBVIEWER = MKBETAG('S','u','b','V'),
527  AV_CODEC_ID_SUBRIP = MKBETAG('S','R','i','p'),
528  AV_CODEC_ID_WEBVTT = MKBETAG('W','V','T','T'),
529  AV_CODEC_ID_MPL2 = MKBETAG('M','P','L','2'),
530  AV_CODEC_ID_VPLAYER = MKBETAG('V','P','l','r'),
531  AV_CODEC_ID_PJS = MKBETAG('P','h','J','S'),
532  AV_CODEC_ID_ASS = MKBETAG('A','S','S',' '), ///< ASS as defined in Matroska
534 
535  /* other specific kind of codecs (generally used for attachments) */
536  AV_CODEC_ID_FIRST_UNKNOWN = 0x18000, ///< A dummy ID pointing at the start of various fake codecs.
537  AV_CODEC_ID_TTF = 0x18000,
538  AV_CODEC_ID_BINTEXT = MKBETAG('B','T','X','T'),
539  AV_CODEC_ID_XBIN = MKBETAG('X','B','I','N'),
540  AV_CODEC_ID_IDF = MKBETAG( 0 ,'I','D','F'),
541  AV_CODEC_ID_OTF = MKBETAG( 0 ,'O','T','F'),
542  AV_CODEC_ID_SMPTE_KLV = MKBETAG('K','L','V','A'),
543  AV_CODEC_ID_DVD_NAV = MKBETAG('D','N','A','V'),
544  AV_CODEC_ID_TIMED_ID3 = MKBETAG('T','I','D','3'),
545  AV_CODEC_ID_BIN_DATA = MKBETAG('D','A','T','A'),
546 
547 
548  AV_CODEC_ID_PROBE = 0x19000, ///< codec_id is not known (like AV_CODEC_ID_NONE) but lavf should attempt to identify it
549 
550  AV_CODEC_ID_MPEG2TS = 0x20000, /**< _FAKE_ codec to indicate a raw MPEG-2 TS
551  * stream (only used by libavformat) */
552  AV_CODEC_ID_MPEG4SYSTEMS = 0x20001, /**< _FAKE_ codec to indicate a MPEG-4 Systems
553  * stream (only used by libavformat) */
554  AV_CODEC_ID_FFMETADATA = 0x21000, ///< Dummy codec for streams containing only metadata information.
555 
556 #if FF_API_CODEC_ID
557 #include "old_codec_ids.h"
558 #endif
559 };
560 
561 /**
562  * This struct describes the properties of a single codec described by an
563  * AVCodecID.
564  * @see avcodec_descriptor_get()
565  */
566 typedef struct AVCodecDescriptor {
567  enum AVCodecID id;
569  /**
570  * Name of the codec described by this descriptor. It is non-empty and
571  * unique for each codec descriptor. It should contain alphanumeric
572  * characters and '_' only.
573  */
574  const char *name;
575  /**
576  * A more descriptive name for this codec. May be NULL.
577  */
578  const char *long_name;
579  /**
580  * Codec properties, a combination of AV_CODEC_PROP_* flags.
581  */
582  int props;
583 
584  /**
585  * MIME type(s) associated with the codec.
586  * May be NULL; if not, a NULL-terminated array of MIME types.
587  * The first item is always non-NULL and is the preferred MIME type.
588  */
589  const char *const *mime_types;
592 /**
593  * Codec uses only intra compression.
594  * Video codecs only.
595  */
596 #define AV_CODEC_PROP_INTRA_ONLY (1 << 0)
597 /**
598  * Codec supports lossy compression. Audio and video codecs only.
599  * @note a codec may support both lossy and lossless
600  * compression modes
601  */
602 #define AV_CODEC_PROP_LOSSY (1 << 1)
603 /**
604  * Codec supports lossless compression. Audio and video codecs only.
605  */
606 #define AV_CODEC_PROP_LOSSLESS (1 << 2)
607 /**
608  * Codec supports frame reordering. That is, the coded order (the order in which
609  * the encoded packets are output by the encoders / stored / input to the
610  * decoders) may be different from the presentation order of the corresponding
611  * frames.
612  *
613  * For codecs that do not have this property set, PTS and DTS should always be
614  * equal.
615  */
616 #define AV_CODEC_PROP_REORDER (1 << 3)
617 /**
618  * Subtitle codec is bitmap based
619  * Decoded AVSubtitle data can be read from the AVSubtitleRect->pict field.
620  */
621 #define AV_CODEC_PROP_BITMAP_SUB (1 << 16)
622 /**
623  * Subtitle codec is text based.
624  * Decoded AVSubtitle data can be read from the AVSubtitleRect->ass field.
625  */
626 #define AV_CODEC_PROP_TEXT_SUB (1 << 17)
628 /**
629  * @ingroup lavc_decoding
630  * Required number of additionally allocated bytes at the end of the input bitstream for decoding.
631  * This is mainly needed because some optimized bitstream readers read
632  * 32 or 64 bit at once and could read over the end.<br>
633  * Note: If the first 23 bits of the additional bytes are not 0, then damaged
634  * MPEG bitstreams could cause overread and segfault.
635  */
636 #define AV_INPUT_BUFFER_PADDING_SIZE 32
638 /**
639  * @ingroup lavc_encoding
640  * minimum encoding buffer size
641  * Used to avoid some checks during header writing.
642  */
643 #define AV_INPUT_BUFFER_MIN_SIZE 16384
645 #if FF_API_WITHOUT_PREFIX
646 /**
647  * @deprecated use AV_INPUT_BUFFER_PADDING_SIZE instead
648  */
649 #define FF_INPUT_BUFFER_PADDING_SIZE 32
651 /**
652  * @deprecated use AV_INPUT_BUFFER_MIN_SIZE instead
653  */
654 #define FF_MIN_BUFFER_SIZE 16384
655 #endif /* FF_API_WITHOUT_PREFIX */
657 /**
658  * @ingroup lavc_encoding
659  * motion estimation type.
660  * @deprecated use codec private option instead
661  */
662 #if FF_API_MOTION_EST
664  ME_ZERO = 1, ///< no search, that is use 0,0 vector whenever one is needed
668  ME_EPZS, ///< enhanced predictive zonal search
669  ME_X1, ///< reserved for experiments
670  ME_HEX, ///< hexagon based search
671  ME_UMH, ///< uneven multi-hexagon search
672  ME_TESA, ///< transformed exhaustive search algorithm
673  ME_ITER=50, ///< iterative search
674 };
675 #endif
677 /**
678  * @ingroup lavc_decoding
679  */
681  /* We leave some space between them for extensions (drop some
682  * keyframes for intra-only or drop just some bidir frames). */
683  AVDISCARD_NONE =-16, ///< discard nothing
684  AVDISCARD_DEFAULT = 0, ///< discard useless packets like 0 size packets in avi
685  AVDISCARD_NONREF = 8, ///< discard all non reference
686  AVDISCARD_BIDIR = 16, ///< discard all bidirectional frames
687  AVDISCARD_NONINTRA= 24, ///< discard all non intra frames
688  AVDISCARD_NONKEY = 32, ///< discard all frames except keyframes
689  AVDISCARD_ALL = 48, ///< discard all
690 };
702  AV_AUDIO_SERVICE_TYPE_NB , ///< Not part of ABI
703 };
705 /**
706  * @ingroup lavc_encoding
707  */
708 typedef struct RcOverride{
711  int qscale; // If this is 0 then quality_factor will be used instead.
715 #if FF_API_MAX_BFRAMES
716 /**
717  * @deprecated there is no libavcodec-wide limit on the number of B-frames
718  */
719 #define FF_MAX_B_FRAMES 16
720 #endif
722 /* encoding support
723  These flags can be passed in AVCodecContext.flags before initialization.
724  Note: Not everything is supported yet.
725 */
727 /**
728  * Allow decoders to produce frames with data planes that are not aligned
729  * to CPU requirements (e.g. due to cropping).
730  */
731 #define AV_CODEC_FLAG_UNALIGNED (1 << 0)
732 /**
733  * Use fixed qscale.
734  */
735 #define AV_CODEC_FLAG_QSCALE (1 << 1)
736 /**
737  * 4 MV per MB allowed / advanced prediction for H.263.
738  */
739 #define AV_CODEC_FLAG_4MV (1 << 2)
740 /**
741  * Output even those frames that might be corrupted.
742  */
743 #define AV_CODEC_FLAG_OUTPUT_CORRUPT (1 << 3)
744 /**
745  * Use qpel MC.
746  */
747 #define AV_CODEC_FLAG_QPEL (1 << 4)
748 /**
749  * Use internal 2pass ratecontrol in first pass mode.
750  */
751 #define AV_CODEC_FLAG_PASS1 (1 << 9)
752 /**
753  * Use internal 2pass ratecontrol in second pass mode.
754  */
755 #define AV_CODEC_FLAG_PASS2 (1 << 10)
756 /**
757  * loop filter.
758  */
759 #define AV_CODEC_FLAG_LOOP_FILTER (1 << 11)
760 /**
761  * Only decode/encode grayscale.
762  */
763 #define AV_CODEC_FLAG_GRAY (1 << 13)
764 /**
765  * error[?] variables will be set during encoding.
766  */
767 #define AV_CODEC_FLAG_PSNR (1 << 15)
768 /**
769  * Input bitstream might be truncated at a random location
770  * instead of only at frame boundaries.
771  */
772 #define AV_CODEC_FLAG_TRUNCATED (1 << 16)
773 /**
774  * Use interlaced DCT.
775  */
776 #define AV_CODEC_FLAG_INTERLACED_DCT (1 << 18)
777 /**
778  * Force low delay.
779  */
780 #define AV_CODEC_FLAG_LOW_DELAY (1 << 19)
781 /**
782  * Place global headers in extradata instead of every keyframe.
783  */
784 #define AV_CODEC_FLAG_GLOBAL_HEADER (1 << 22)
785 /**
786  * Use only bitexact stuff (except (I)DCT).
787  */
788 #define AV_CODEC_FLAG_BITEXACT (1 << 23)
789 /* Fx : Flag for h263+ extra options */
790 /**
791  * H.263 advanced intra coding / MPEG-4 AC prediction
792  */
793 #define AV_CODEC_FLAG_AC_PRED (1 << 24)
794 /**
795  * interlaced motion estimation
796  */
797 #define AV_CODEC_FLAG_INTERLACED_ME (1 << 29)
798 /**
799  * Allow non spec compliant speedup tricks.
800  */
801 #define AV_CODEC_FLAG_CLOSED_GOP (1U << 31)
803 #define AV_CODEC_FLAG2_FAST (1 << 0)
804 /**
805  * Skip bitstream encoding.
806  */
807 #define AV_CODEC_FLAG2_NO_OUTPUT (1 << 2)
808 /**
809  * Place global headers at every keyframe instead of in extradata.
810  */
811 #define AV_CODEC_FLAG2_LOCAL_HEADER (1 << 3)
813 /**
814  * timecode is in drop frame format. DEPRECATED!!!!
815  */
816 #define AV_CODEC_FLAG2_DROP_FRAME_TIMECODE (1 << 13)
818 /**
819  * Input bitstream might be truncated at a packet boundaries
820  * instead of only at frame boundaries.
821  */
822 #define AV_CODEC_FLAG2_CHUNKS (1 << 15)
823 /**
824  * Discard cropping information from SPS.
825  */
826 #define AV_CODEC_FLAG2_IGNORE_CROP (1 << 16)
828 /**
829  * Show all frames before the first keyframe
830  */
831 #define AV_CODEC_FLAG2_SHOW_ALL (1 << 22)
832 /**
833  * Export motion vectors through frame side data
834  */
835 #define AV_CODEC_FLAG2_EXPORT_MVS (1 << 28)
836 /**
837  * Do not skip samples and export skip information as frame side data
838  */
839 #define AV_CODEC_FLAG2_SKIP_MANUAL (1 << 29)
841 /* Unsupported options :
842  * Syntax Arithmetic coding (SAC)
843  * Reference Picture Selection
844  * Independent Segment Decoding */
845 /* /Fx */
846 /* codec capabilities */
848 /**
849  * Decoder can use draw_horiz_band callback.
850  */
851 #define AV_CODEC_CAP_DRAW_HORIZ_BAND (1 << 0)
852 /**
853  * Codec uses get_buffer() for allocating buffers and supports custom allocators.
854  * If not set, it might not use get_buffer() at all or use operations that
855  * assume the buffer was allocated by avcodec_default_get_buffer.
856  */
857 #define AV_CODEC_CAP_DR1 (1 << 1)
858 #define AV_CODEC_CAP_TRUNCATED (1 << 3)
859 /**
860  * Encoder or decoder requires flushing with NULL input at the end in order to
861  * give the complete and correct output.
862  *
863  * NOTE: If this flag is not set, the codec is guaranteed to never be fed with
864  * with NULL data. The user can still send NULL data to the public encode
865  * or decode function, but libavcodec will not pass it along to the codec
866  * unless this flag is set.
867  *
868  * Decoders:
869  * The decoder has a non-zero delay and needs to be fed with avpkt->data=NULL,
870  * avpkt->size=0 at the end to get the delayed data until the decoder no longer
871  * returns frames.
872  *
873  * Encoders:
874  * The encoder needs to be fed with NULL data at the end of encoding until the
875  * encoder no longer returns data.
876  *
877  * NOTE: For encoders implementing the AVCodec.encode2() function, setting this
878  * flag also means that the encoder must set the pts and duration for
879  * each output packet. If this flag is not set, the pts and duration will
880  * be determined by libavcodec from the input frame.
881  */
882 #define AV_CODEC_CAP_DELAY (1 << 5)
883 /**
884  * Codec can be fed a final frame with a smaller size.
885  * This can be used to prevent truncation of the last audio samples.
886  */
887 #define AV_CODEC_CAP_SMALL_LAST_FRAME (1 << 6)
889 #if FF_API_CAP_VDPAU
890 /**
891  * Codec can export data for HW decoding (VDPAU).
892  */
893 #define AV_CODEC_CAP_HWACCEL_VDPAU (1 << 7)
894 #endif
896 /**
897  * Codec can output multiple frames per AVPacket
898  * Normally demuxers return one frame at a time, demuxers which do not do
899  * are connected to a parser to split what they return into proper frames.
900  * This flag is reserved to the very rare category of codecs which have a
901  * bitstream that cannot be split into frames without timeconsuming
902  * operations like full decoding. Demuxers carring such bitstreams thus
903  * may return multiple frames in a packet. This has many disadvantages like
904  * prohibiting stream copy in many cases thus it should only be considered
905  * as a last resort.
906  */
907 #define AV_CODEC_CAP_SUBFRAMES (1 << 8)
908 /**
909  * Codec is experimental and is thus avoided in favor of non experimental
910  * encoders
911  */
912 #define AV_CODEC_CAP_EXPERIMENTAL (1 << 9)
913 /**
914  * Codec should fill in channel configuration and samplerate instead of container
915  */
916 #define AV_CODEC_CAP_CHANNEL_CONF (1 << 10)
917 /**
918  * Codec supports frame-level multithreading.
919  */
920 #define AV_CODEC_CAP_FRAME_THREADS (1 << 12)
921 /**
922  * Codec supports slice-based (or partition-based) multithreading.
923  */
924 #define AV_CODEC_CAP_SLICE_THREADS (1 << 13)
925 /**
926  * Codec supports changed parameters at any point.
927  */
928 #define AV_CODEC_CAP_PARAM_CHANGE (1 << 14)
929 /**
930  * Codec supports avctx->thread_count == 0 (auto).
931  */
932 #define AV_CODEC_CAP_AUTO_THREADS (1 << 15)
933 /**
934  * Audio encoder supports receiving a different number of samples in each call.
935  */
936 #define AV_CODEC_CAP_VARIABLE_FRAME_SIZE (1 << 16)
937 /**
938  * Codec is intra only.
939  */
940 #define AV_CODEC_CAP_INTRA_ONLY 0x40000000
941 /**
942  * Codec is lossless.
943  */
944 #define AV_CODEC_CAP_LOSSLESS 0x80000000
945 
947 #if FF_API_WITHOUT_PREFIX
948 /**
949  * Allow decoders to produce frames with data planes that are not aligned
950  * to CPU requirements (e.g. due to cropping).
951  */
952 #define CODEC_FLAG_UNALIGNED AV_CODEC_FLAG_UNALIGNED
953 #define CODEC_FLAG_QSCALE AV_CODEC_FLAG_QSCALE
954 #define CODEC_FLAG_4MV AV_CODEC_FLAG_4MV
955 #define CODEC_FLAG_OUTPUT_CORRUPT AV_CODEC_FLAG_OUTPUT_CORRUPT
956 #define CODEC_FLAG_QPEL AV_CODEC_FLAG_QPEL
957 #if FF_API_GMC
958 /**
959  * @deprecated use the "gmc" private option of the libxvid encoder
960  */
961 #define CODEC_FLAG_GMC 0x0020 ///< Use GMC.
962 #endif
963 #if FF_API_MV0
964 /**
965  * @deprecated use the flag "mv0" in the "mpv_flags" private option of the
966  * mpegvideo encoders
967  */
968 #define CODEC_FLAG_MV0 0x0040
969 #endif
970 #if FF_API_INPUT_PRESERVED
971 /**
972  * @deprecated passing reference-counted frames to the encoders replaces this
973  * flag
974  */
975 #define CODEC_FLAG_INPUT_PRESERVED 0x0100
976 #endif
977 #define CODEC_FLAG_PASS1 AV_CODEC_FLAG_PASS1
978 #define CODEC_FLAG_PASS2 AV_CODEC_FLAG_PASS2
979 #define CODEC_FLAG_GRAY AV_CODEC_FLAG_GRAY
980 #if FF_API_EMU_EDGE
981 /**
982  * @deprecated edges are not used/required anymore. I.e. this flag is now always
983  * set.
984  */
985 #define CODEC_FLAG_EMU_EDGE 0x4000
986 #endif
987 #define CODEC_FLAG_PSNR AV_CODEC_FLAG_PSNR
988 #define CODEC_FLAG_TRUNCATED AV_CODEC_FLAG_TRUNCATED
989 
990 #if FF_API_NORMALIZE_AQP
991 /**
992  * @deprecated use the flag "naq" in the "mpv_flags" private option of the
993  * mpegvideo encoders
994  */
995 #define CODEC_FLAG_NORMALIZE_AQP 0x00020000
996 #endif
997 #define CODEC_FLAG_INTERLACED_DCT AV_CODEC_FLAG_INTERLACED_DCT
998 #define CODEC_FLAG_LOW_DELAY AV_CODEC_FLAG_LOW_DELAY
999 #define CODEC_FLAG_GLOBAL_HEADER AV_CODEC_FLAG_GLOBAL_HEADER
1000 #define CODEC_FLAG_BITEXACT AV_CODEC_FLAG_BITEXACT
1001 #define CODEC_FLAG_AC_PRED AV_CODEC_FLAG_AC_PRED
1002 #define CODEC_FLAG_LOOP_FILTER AV_CODEC_FLAG_LOOP_FILTER
1003 #define CODEC_FLAG_INTERLACED_ME AV_CODEC_FLAG_INTERLACED_ME
1004 #define CODEC_FLAG_CLOSED_GOP AV_CODEC_FLAG_CLOSED_GOP
1005 #define CODEC_FLAG2_FAST AV_CODEC_FLAG2_FAST
1006 #define CODEC_FLAG2_NO_OUTPUT AV_CODEC_FLAG2_NO_OUTPUT
1007 #define CODEC_FLAG2_LOCAL_HEADER AV_CODEC_FLAG2_LOCAL_HEADER
1008 #define CODEC_FLAG2_DROP_FRAME_TIMECODE AV_CODEC_FLAG2_DROP_FRAME_TIMECODE
1009 #define CODEC_FLAG2_IGNORE_CROP AV_CODEC_FLAG2_IGNORE_CROP
1010 
1011 #define CODEC_FLAG2_CHUNKS AV_CODEC_FLAG2_CHUNKS
1012 #define CODEC_FLAG2_SHOW_ALL AV_CODEC_FLAG2_SHOW_ALL
1013 #define CODEC_FLAG2_EXPORT_MVS AV_CODEC_FLAG2_EXPORT_MVS
1014 #define CODEC_FLAG2_SKIP_MANUAL AV_CODEC_FLAG2_SKIP_MANUAL
1015 
1016 /* Unsupported options :
1017  * Syntax Arithmetic coding (SAC)
1018  * Reference Picture Selection
1019  * Independent Segment Decoding */
1020 /* /Fx */
1021 /* codec capabilities */
1022 
1023 #define CODEC_CAP_DRAW_HORIZ_BAND AV_CODEC_CAP_DRAW_HORIZ_BAND ///< Decoder can use draw_horiz_band callback.
1024 /**
1025  * Codec uses get_buffer() for allocating buffers and supports custom allocators.
1026  * If not set, it might not use get_buffer() at all or use operations that
1027  * assume the buffer was allocated by avcodec_default_get_buffer.
1028  */
1029 #define CODEC_CAP_DR1 AV_CODEC_CAP_DR1
1030 #define CODEC_CAP_TRUNCATED AV_CODEC_CAP_TRUNCATED
1031 #if FF_API_XVMC
1032 /* Codec can export data for HW decoding. This flag indicates that
1033  * the codec would call get_format() with list that might contain HW accelerated
1034  * pixel formats (XvMC, VDPAU, VAAPI, etc). The application can pick any of them
1035  * including raw image format.
1036  * The application can use the passed context to determine bitstream version,
1037  * chroma format, resolution etc.
1038  */
1039 #define CODEC_CAP_HWACCEL 0x0010
1040 #endif /* FF_API_XVMC */
1041 /**
1042  * Encoder or decoder requires flushing with NULL input at the end in order to
1043  * give the complete and correct output.
1044  *
1045  * NOTE: If this flag is not set, the codec is guaranteed to never be fed with
1046  * with NULL data. The user can still send NULL data to the public encode
1047  * or decode function, but libavcodec will not pass it along to the codec
1048  * unless this flag is set.
1049  *
1050  * Decoders:
1051  * The decoder has a non-zero delay and needs to be fed with avpkt->data=NULL,
1052  * avpkt->size=0 at the end to get the delayed data until the decoder no longer
1053  * returns frames.
1054  *
1055  * Encoders:
1056  * The encoder needs to be fed with NULL data at the end of encoding until the
1057  * encoder no longer returns data.
1058  *
1059  * NOTE: For encoders implementing the AVCodec.encode2() function, setting this
1060  * flag also means that the encoder must set the pts and duration for
1061  * each output packet. If this flag is not set, the pts and duration will
1062  * be determined by libavcodec from the input frame.
1063  */
1064 #define CODEC_CAP_DELAY AV_CODEC_CAP_DELAY
1065 /**
1066  * Codec can be fed a final frame with a smaller size.
1067  * This can be used to prevent truncation of the last audio samples.
1068  */
1069 #define CODEC_CAP_SMALL_LAST_FRAME AV_CODEC_CAP_SMALL_LAST_FRAME
1070 #if FF_API_CAP_VDPAU
1071 /**
1072  * Codec can export data for HW decoding (VDPAU).
1073  */
1074 #define CODEC_CAP_HWACCEL_VDPAU AV_CODEC_CAP_HWACCEL_VDPAU
1075 #endif
1076 /**
1077  * Codec can output multiple frames per AVPacket
1078  * Normally demuxers return one frame at a time, demuxers which do not do
1079  * are connected to a parser to split what they return into proper frames.
1080  * This flag is reserved to the very rare category of codecs which have a
1081  * bitstream that cannot be split into frames without timeconsuming
1082  * operations like full decoding. Demuxers carring such bitstreams thus
1083  * may return multiple frames in a packet. This has many disadvantages like
1084  * prohibiting stream copy in many cases thus it should only be considered
1085  * as a last resort.
1086  */
1087 #define CODEC_CAP_SUBFRAMES AV_CODEC_CAP_SUBFRAMES
1088 /**
1089  * Codec is experimental and is thus avoided in favor of non experimental
1090  * encoders
1091  */
1092 #define CODEC_CAP_EXPERIMENTAL AV_CODEC_CAP_EXPERIMENTAL
1093 /**
1094  * Codec should fill in channel configuration and samplerate instead of container
1095  */
1096 #define CODEC_CAP_CHANNEL_CONF AV_CODEC_CAP_CHANNEL_CONF
1097 #if FF_API_NEG_LINESIZES
1098 /**
1099  * @deprecated no codecs use this capability
1100  */
1101 #define CODEC_CAP_NEG_LINESIZES 0x0800
1102 #endif
1103 /**
1104  * Codec supports frame-level multithreading.
1105  */
1106 #define CODEC_CAP_FRAME_THREADS AV_CODEC_CAP_FRAME_THREADS
1107 /**
1108  * Codec supports slice-based (or partition-based) multithreading.
1109  */
1110 #define CODEC_CAP_SLICE_THREADS AV_CODEC_CAP_SLICE_THREADS
1111 /**
1112  * Codec supports changed parameters at any point.
1113  */
1114 #define CODEC_CAP_PARAM_CHANGE AV_CODEC_CAP_PARAM_CHANGE
1115 /**
1116  * Codec supports avctx->thread_count == 0 (auto).
1117  */
1118 #define CODEC_CAP_AUTO_THREADS AV_CODEC_CAP_AUTO_THREADS
1119 /**
1120  * Audio encoder supports receiving a different number of samples in each call.
1121  */
1122 #define CODEC_CAP_VARIABLE_FRAME_SIZE AV_CODEC_CAP_VARIABLE_FRAME_SIZE
1123 /**
1124  * Codec is intra only.
1125  */
1126 #define CODEC_CAP_INTRA_ONLY AV_CODEC_CAP_INTRA_ONLY
1127 /**
1128  * Codec is lossless.
1129  */
1130 #define CODEC_CAP_LOSSLESS AV_CODEC_CAP_LOSSLESS
1131 
1132 /**
1133  * HWAccel is experimental and is thus avoided in favor of non experimental
1134  * codecs
1135  */
1136 #define HWACCEL_CODEC_CAP_EXPERIMENTAL 0x0200
1137 #endif /* FF_API_WITHOUT_PREFIX */
1138 
1139 #if FF_API_MB_TYPE
1140 //The following defines may change, don't expect compatibility if you use them.
1141 #define MB_TYPE_INTRA4x4 0x0001
1142 #define MB_TYPE_INTRA16x16 0x0002 //FIXME H.264-specific
1143 #define MB_TYPE_INTRA_PCM 0x0004 //FIXME H.264-specific
1144 #define MB_TYPE_16x16 0x0008
1145 #define MB_TYPE_16x8 0x0010
1146 #define MB_TYPE_8x16 0x0020
1147 #define MB_TYPE_8x8 0x0040
1148 #define MB_TYPE_INTERLACED 0x0080
1149 #define MB_TYPE_DIRECT2 0x0100 //FIXME
1150 #define MB_TYPE_ACPRED 0x0200
1151 #define MB_TYPE_GMC 0x0400
1152 #define MB_TYPE_SKIP 0x0800
1153 #define MB_TYPE_P0L0 0x1000
1154 #define MB_TYPE_P1L0 0x2000
1155 #define MB_TYPE_P0L1 0x4000
1156 #define MB_TYPE_P1L1 0x8000
1157 #define MB_TYPE_L0 (MB_TYPE_P0L0 | MB_TYPE_P1L0)
1158 #define MB_TYPE_L1 (MB_TYPE_P0L1 | MB_TYPE_P1L1)
1159 #define MB_TYPE_L0L1 (MB_TYPE_L0 | MB_TYPE_L1)
1160 #define MB_TYPE_QUANT 0x00010000
1161 #define MB_TYPE_CBP 0x00020000
1162 //Note bits 24-31 are reserved for codec specific use (h264 ref0, mpeg1 0mv, ...)
1163 #endif
1164 
1165 /**
1166  * Pan Scan area.
1167  * This specifies the area which should be displayed.
1168  * Note there may be multiple such areas for one frame.
1169  */
1170 typedef struct AVPanScan{
1171  /**
1172  * id
1173  * - encoding: Set by user.
1174  * - decoding: Set by libavcodec.
1175  */
1176  int id;
1177 
1178  /**
1179  * width and height in 1/16 pel
1180  * - encoding: Set by user.
1181  * - decoding: Set by libavcodec.
1182  */
1183  int width;
1184  int height;
1185 
1186  /**
1187  * position of the top left corner in 1/16 pel for up to 3 fields/frames
1188  * - encoding: Set by user.
1189  * - decoding: Set by libavcodec.
1190  */
1191  int16_t position[3][2];
1192 }AVPanScan;
1193 
1194 #if FF_API_QSCALE_TYPE
1195 #define FF_QSCALE_TYPE_MPEG1 0
1196 #define FF_QSCALE_TYPE_MPEG2 1
1197 #define FF_QSCALE_TYPE_H264 2
1198 #define FF_QSCALE_TYPE_VP56 3
1199 #endif
1200 
1201 #if FF_API_GET_BUFFER
1202 #define FF_BUFFER_TYPE_INTERNAL 1
1203 #define FF_BUFFER_TYPE_USER 2 ///< direct rendering buffers (image is (de)allocated by user)
1204 #define FF_BUFFER_TYPE_SHARED 4 ///< Buffer from somewhere else; don't deallocate image (data/base), all other tables are not shared.
1205 #define FF_BUFFER_TYPE_COPY 8 ///< Just a (modified) copy of some other buffer, don't deallocate anything.
1206 
1207 #define FF_BUFFER_HINTS_VALID 0x01 // Buffer hints value is meaningful (if 0 ignore).
1208 #define FF_BUFFER_HINTS_READABLE 0x02 // Codec will read from buffer.
1209 #define FF_BUFFER_HINTS_PRESERVE 0x04 // User must not alter buffer content.
1210 #define FF_BUFFER_HINTS_REUSABLE 0x08 // Codec will reuse the buffer (update).
1211 #endif
1212 
1213 /**
1214  * The decoder will keep a reference to the frame and may reuse it later.
1215  */
1216 #define AV_GET_BUFFER_FLAG_REF (1 << 0)
1217 
1218 /**
1219  * @defgroup lavc_packet AVPacket
1220  *
1221  * Types and functions for working with AVPacket.
1222  * @{
1223  */
1227 
1228  /**
1229  * An AV_PKT_DATA_PARAM_CHANGE side data packet is laid out as follows:
1230  * @code
1231  * u32le param_flags
1232  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT)
1233  * s32le channel_count
1234  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT)
1235  * u64le channel_layout
1236  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE)
1237  * s32le sample_rate
1238  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS)
1239  * s32le width
1240  * s32le height
1241  * @endcode
1242  */
1244 
1245  /**
1246  * An AV_PKT_DATA_H263_MB_INFO side data packet contains a number of
1247  * structures with info about macroblocks relevant to splitting the
1248  * packet into smaller packets on macroblock edges (e.g. as for RFC 2190).
1249  * That is, it does not necessarily contain info about all macroblocks,
1250  * as long as the distance between macroblocks in the info is smaller
1251  * than the target payload size.
1252  * Each MB info structure is 12 bytes, and is laid out as follows:
1253  * @code
1254  * u32le bit offset from the start of the packet
1255  * u8 current quantizer at the start of the macroblock
1256  * u8 GOB number
1257  * u16le macroblock address within the GOB
1258  * u8 horizontal MV predictor
1259  * u8 vertical MV predictor
1260  * u8 horizontal MV predictor for block number 3
1261  * u8 vertical MV predictor for block number 3
1262  * @endcode
1263  */
1265 
1266  /**
1267  * This side data should be associated with an audio stream and contains
1268  * ReplayGain information in form of the AVReplayGain struct.
1269  */
1271 
1272  /**
1273  * This side data contains a 3x3 transformation matrix describing an affine
1274  * transformation that needs to be applied to the decoded video frames for
1275  * correct presentation.
1276  *
1277  * See libavutil/display.h for a detailed description of the data.
1278  */
1280 
1281  /**
1282  * This side data should be associated with a video stream and contains
1283  * Stereoscopic 3D information in form of the AVStereo3D struct.
1284  */
1286 
1287  /**
1288  * This side data should be associated with an audio stream and corresponds
1289  * to enum AVAudioServiceType.
1290  */
1292 
1293  /**
1294  * This side data contains quality related information from the encoder.
1295  * @code
1296  * u32le quality factor of the compressed frame. Allowed range is between 1 (good) and FF_LAMBDA_MAX (bad).
1297  * u8 picture type
1298  * u8 error count
1299  * u16 reserved
1300  * u64le[error count] sum of squared differences between encoder in and output
1301  * @endcode
1302  */
1304 
1305  /**
1306  * Recommmends skipping the specified number of samples
1307  * @code
1308  * u32le number of samples to skip from start of this packet
1309  * u32le number of samples to skip from end of this packet
1310  * u8 reason for start skip
1311  * u8 reason for end skip (0=padding silence, 1=convergence)
1312  * @endcode
1313  */
1315 
1316  /**
1317  * An AV_PKT_DATA_JP_DUALMONO side data packet indicates that
1318  * the packet may contain "dual mono" audio specific to Japanese DTV
1319  * and if it is true, recommends only the selected channel to be used.
1320  * @code
1321  * u8 selected channels (0=mail/left, 1=sub/right, 2=both)
1322  * @endcode
1323  */
1325 
1326  /**
1327  * A list of zero terminated key/value strings. There is no end marker for
1328  * the list, so it is required to rely on the side data size to stop.
1329  */
1331 
1332  /**
1333  * Subtitle event position
1334  * @code
1335  * u32le x1
1336  * u32le y1
1337  * u32le x2
1338  * u32le y2
1339  * @endcode
1340  */
1342 
1343  /**
1344  * Data found in BlockAdditional element of matroska container. There is
1345  * no end marker for the data, so it is required to rely on the side data
1346  * size to recognize the end. 8 byte id (as found in BlockAddId) followed
1347  * by data.
1348  */
1350 
1351  /**
1352  * The optional first identifier line of a WebVTT cue.
1353  */
1355 
1356  /**
1357  * The optional settings (rendering instructions) that immediately
1358  * follow the timestamp specifier of a WebVTT cue.
1359  */
1361 
1362  /**
1363  * A list of zero terminated key/value strings. There is no end marker for
1364  * the list, so it is required to rely on the side data size to stop. This
1365  * side data includes updated metadata which appeared in the stream.
1366  */
1368 };
1369 
1370 #define AV_PKT_DATA_QUALITY_FACTOR AV_PKT_DATA_QUALITY_STATS //DEPRECATED
1371 
1372 typedef struct AVPacketSideData {
1374  int size;
1377 
1378 /**
1379  * This structure stores compressed data. It is typically exported by demuxers
1380  * and then passed as input to decoders, or received as output from encoders and
1381  * then passed to muxers.
1382  *
1383  * For video, it should typically contain one compressed frame. For audio it may
1384  * contain several compressed frames.
1385  *
1386  * AVPacket is one of the few structs in FFmpeg, whose size is a part of public
1387  * ABI. Thus it may be allocated on stack and no new fields can be added to it
1388  * without libavcodec and libavformat major bump.
1389  *
1390  * The semantics of data ownership depends on the buf or destruct (deprecated)
1391  * fields. If either is set, the packet data is dynamically allocated and is
1392  * valid indefinitely until av_free_packet() is called (which in turn calls
1393  * av_buffer_unref()/the destruct callback to free the data). If neither is set,
1394  * the packet data is typically backed by some static buffer somewhere and is
1395  * only valid for a limited time (e.g. until the next read call when demuxing).
1396  *
1397  * The side data is always allocated with av_malloc() and is freed in
1398  * av_free_packet().
1399  */
1400 typedef struct AVPacket {
1401  /**
1402  * A reference to the reference-counted buffer where the packet data is
1403  * stored.
1404  * May be NULL, then the packet data is not reference-counted.
1405  */
1407  /**
1408  * Presentation timestamp in AVStream->time_base units; the time at which
1409  * the decompressed packet will be presented to the user.
1410  * Can be AV_NOPTS_VALUE if it is not stored in the file.
1411  * pts MUST be larger or equal to dts as presentation cannot happen before
1412  * decompression, unless one wants to view hex dumps. Some formats misuse
1413  * the terms dts and pts/cts to mean something different. Such timestamps
1414  * must be converted to true pts/dts before they are stored in AVPacket.
1415  */
1416  int64_t pts;
1417  /**
1418  * Decompression timestamp in AVStream->time_base units; the time at which
1419  * the packet is decompressed.
1420  * Can be AV_NOPTS_VALUE if it is not stored in the file.
1421  */
1422  int64_t dts;
1424  int size;
1426  /**
1427  * A combination of AV_PKT_FLAG values
1428  */
1429  int flags;
1430  /**
1431  * Additional packet data that can be provided by the container.
1432  * Packet can contain several types of side information.
1433  */
1436 
1437  /**
1438  * Duration of this packet in AVStream->time_base units, 0 if unknown.
1439  * Equals next_pts - this_pts in presentation order.
1440  */
1442 #if FF_API_DESTRUCT_PACKET
1444  void (*destruct)(struct AVPacket *);
1446  void *priv;
1447 #endif
1448  int64_t pos; ///< byte position in stream, -1 if unknown
1449 
1450  /**
1451  * Time difference in AVStream->time_base units from the pts of this
1452  * packet to the point at which the output from the decoder has converged
1453  * independent from the availability of previous frames. That is, the
1454  * frames are virtually identical no matter if decoding started from
1455  * the very first frame or from this keyframe.
1456  * Is AV_NOPTS_VALUE if unknown.
1457  * This field is not the display duration of the current packet.
1458  * This field has no meaning if the packet does not have AV_PKT_FLAG_KEY
1459  * set.
1460  *
1461  * The purpose of this field is to allow seeking in streams that have no
1462  * keyframes in the conventional sense. It corresponds to the
1463  * recovery point SEI in H.264 and match_time_delta in NUT. It is also
1464  * essential for some types of subtitle streams to ensure that all
1465  * subtitles are correctly displayed after seeking.
1466  */
1468 } AVPacket;
1469 #define AV_PKT_FLAG_KEY 0x0001 ///< The packet contains a keyframe
1470 #define AV_PKT_FLAG_CORRUPT 0x0002 ///< The packet content is corrupted
1471 
1477 };
1478 /**
1479  * @}
1480  */
1481 
1482 struct AVCodecInternal;
1483 
1487  AV_FIELD_TT, //< Top coded_first, top displayed first
1488  AV_FIELD_BB, //< Bottom coded first, bottom displayed first
1489  AV_FIELD_TB, //< Top coded first, bottom displayed first
1490  AV_FIELD_BT, //< Bottom coded first, top displayed first
1491 };
1492 
1493 /**
1494  * main external API structure.
1495  * New fields can be added to the end with minor version bumps.
1496  * Removal, reordering and changes to existing fields require a major
1497  * version bump.
1498  * Please use AVOptions (av_opt* / av_set/get*()) to access these fields from user
1499  * applications.
1500  * sizeof(AVCodecContext) must not be used outside libav*.
1501  */
1502 typedef struct AVCodecContext {
1503  /**
1504  * information on struct for av_log
1505  * - set by avcodec_alloc_context3
1506  */
1509 
1510  enum AVMediaType codec_type; /* see AVMEDIA_TYPE_xxx */
1511  const struct AVCodec *codec;
1512 #if FF_API_CODEC_NAME
1513  /**
1514  * @deprecated this field is not used for anything in libavcodec
1515  */
1517  char codec_name[32];
1518 #endif
1519  enum AVCodecID codec_id; /* see AV_CODEC_ID_xxx */
1520 
1521  /**
1522  * fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
1523  * This is used to work around some encoder bugs.
1524  * A demuxer should set this to what is stored in the field used to identify the codec.
1525  * If there are multiple such fields in a container then the demuxer should choose the one
1526  * which maximizes the information about the used codec.
1527  * If the codec tag field in a container is larger than 32 bits then the demuxer should
1528  * remap the longer ID to 32 bits with a table or other structure. Alternatively a new
1529  * extra_codec_tag + size could be added but for this a clear advantage must be demonstrated
1530  * first.
1531  * - encoding: Set by user, if not then the default based on codec_id will be used.
1532  * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
1533  */
1534  unsigned int codec_tag;
1535 
1536 #if FF_API_STREAM_CODEC_TAG
1537  /**
1538  * @deprecated this field is unused
1539  */
1541  unsigned int stream_codec_tag;
1542 #endif
1543 
1544  void *priv_data;
1545 
1546  /**
1547  * Private context used for internal data.
1548  *
1549  * Unlike priv_data, this is not codec-specific. It is used in general
1550  * libavcodec functions.
1551  */
1552  struct AVCodecInternal *internal;
1553 
1554  /**
1555  * Private data of the user, can be used to carry app specific stuff.
1556  * - encoding: Set by user.
1557  * - decoding: Set by user.
1558  */
1559  void *opaque;
1560 
1561  /**
1562  * the average bitrate
1563  * - encoding: Set by user; unused for constant quantizer encoding.
1564  * - decoding: Set by user, may be overwritten by libavcodec
1565  * if this info is available in the stream
1566  */
1568 
1569  /**
1570  * number of bits the bitstream is allowed to diverge from the reference.
1571  * the reference can be CBR (for CBR pass1) or VBR (for pass2)
1572  * - encoding: Set by user; unused for constant quantizer encoding.
1573  * - decoding: unused
1574  */
1576 
1577  /**
1578  * Global quality for codecs which cannot change it per frame.
1579  * This should be proportional to MPEG-1/2/4 qscale.
1580  * - encoding: Set by user.
1581  * - decoding: unused
1582  */
1584 
1585  /**
1586  * - encoding: Set by user.
1587  * - decoding: unused
1588  */
1590 #define FF_COMPRESSION_DEFAULT -1
1591 
1592  /**
1593  * AV_CODEC_FLAG_*.
1594  * - encoding: Set by user.
1595  * - decoding: Set by user.
1596  */
1597  int flags;
1598 
1599  /**
1600  * AV_CODEC_FLAG2_*
1601  * - encoding: Set by user.
1602  * - decoding: Set by user.
1603  */
1604  int flags2;
1605 
1606  /**
1607  * some codecs need / can use extradata like Huffman tables.
1608  * mjpeg: Huffman tables
1609  * rv10: additional flags
1610  * mpeg4: global headers (they can be in the bitstream or here)
1611  * The allocated memory should be AV_INPUT_BUFFER_PADDING_SIZE bytes larger
1612  * than extradata_size to avoid problems if it is read with the bitstream reader.
1613  * The bytewise contents of extradata must not depend on the architecture or CPU endianness.
1614  * - encoding: Set/allocated/freed by libavcodec.
1615  * - decoding: Set/allocated/freed by user.
1616  */
1619 
1620  /**
1621  * This is the fundamental unit of time (in seconds) in terms
1622  * of which frame timestamps are represented. For fixed-fps content,
1623  * timebase should be 1/framerate and timestamp increments should be
1624  * identically 1.
1625  * This often, but not always is the inverse of the frame rate or field rate
1626  * for video.
1627  * - encoding: MUST be set by user.
1628  * - decoding: the use of this field for decoding is deprecated.
1629  * Use framerate instead.
1630  */
1632 
1633  /**
1634  * For some codecs, the time base is closer to the field rate than the frame rate.
1635  * Most notably, H.264 and MPEG-2 specify time_base as half of frame duration
1636  * if no telecine is used ...
1637  *
1638  * Set to time_base ticks per frame. Default 1, e.g., H.264/MPEG-2 set it to 2.
1639  */
1641 
1642  /**
1643  * Codec delay.
1644  *
1645  * Encoding: Number of frames delay there will be from the encoder input to
1646  * the decoder output. (we assume the decoder matches the spec)
1647  * Decoding: Number of frames delay in addition to what a standard decoder
1648  * as specified in the spec would produce.
1649  *
1650  * Video:
1651  * Number of frames the decoded output will be delayed relative to the
1652  * encoded input.
1653  *
1654  * Audio:
1655  * For encoding, this field is unused (see initial_padding).
1656  *
1657  * For decoding, this is the number of samples the decoder needs to
1658  * output before the decoder's output is valid. When seeking, you should
1659  * start decoding this many samples prior to your desired seek point.
1660  *
1661  * - encoding: Set by libavcodec.
1662  * - decoding: Set by libavcodec.
1663  */
1664  int delay;
1665 
1666 
1667  /* video only */
1668  /**
1669  * picture width / height.
1670  *
1671  * @note Those fields may not match the values of the last
1672  * AVFrame outputted by avcodec_decode_video2 due frame
1673  * reordering.
1674  *
1675  * - encoding: MUST be set by user.
1676  * - decoding: May be set by the user before opening the decoder if known e.g.
1677  * from the container. Some decoders will require the dimensions
1678  * to be set by the caller. During decoding, the decoder may
1679  * overwrite those values as required while parsing the data.
1680  */
1682 
1683  /**
1684  * Bitstream width / height, may be different from width/height e.g. when
1685  * the decoded frame is cropped before being output or lowres is enabled.
1686  *
1687  * @note Those field may not match the value of the last
1688  * AVFrame outputted by avcodec_decode_video2 due frame
1689  * reordering.
1690  *
1691  * - encoding: unused
1692  * - decoding: May be set by the user before opening the decoder if known
1693  * e.g. from the container. During decoding, the decoder may
1694  * overwrite those values as required while parsing the data.
1695  */
1697 
1698 #if FF_API_ASPECT_EXTENDED
1699 #define FF_ASPECT_EXTENDED 15
1700 #endif
1701 
1702  /**
1703  * the number of pictures in a group of pictures, or 0 for intra_only
1704  * - encoding: Set by user.
1705  * - decoding: unused
1706  */
1708 
1709  /**
1710  * Pixel format, see AV_PIX_FMT_xxx.
1711  * May be set by the demuxer if known from headers.
1712  * May be overridden by the decoder if it knows better.
1713  *
1714  * @note This field may not match the value of the last
1715  * AVFrame outputted by avcodec_decode_video2 due frame
1716  * reordering.
1717  *
1718  * - encoding: Set by user.
1719  * - decoding: Set by user if known, overridden by libavcodec while
1720  * parsing the data.
1721  */
1723 
1724 #if FF_API_MOTION_EST
1725  /**
1726  * This option does nothing
1727  * @deprecated use codec private options instead
1728  */
1730 #endif
1731 
1732  /**
1733  * If non NULL, 'draw_horiz_band' is called by the libavcodec
1734  * decoder to draw a horizontal band. It improves cache usage. Not
1735  * all codecs can do that. You must check the codec capabilities
1736  * beforehand.
1737  * When multithreading is used, it may be called from multiple threads
1738  * at the same time; threads might draw different parts of the same AVFrame,
1739  * or multiple AVFrames, and there is no guarantee that slices will be drawn
1740  * in order.
1741  * The function is also used by hardware acceleration APIs.
1742  * It is called at least once during frame decoding to pass
1743  * the data needed for hardware render.
1744  * In that mode instead of pixel data, AVFrame points to
1745  * a structure specific to the acceleration API. The application
1746  * reads the structure and can change some fields to indicate progress
1747  * or mark state.
1748  * - encoding: unused
1749  * - decoding: Set by user.
1750  * @param height the height of the slice
1751  * @param y the y position of the slice
1752  * @param type 1->top field, 2->bottom field, 3->frame
1753  * @param offset offset into the AVFrame.data from which the slice should be read
1754  */
1756  const AVFrame *src, int offset[AV_NUM_DATA_POINTERS],
1757  int y, int type, int height);
1758 
1759  /**
1760  * callback to negotiate the pixelFormat
1761  * @param fmt is the list of formats which are supported by the codec,
1762  * it is terminated by -1 as 0 is a valid format, the formats are ordered by quality.
1763  * The first is always the native one.
1764  * @note The callback may be called again immediately if initialization for
1765  * the selected (hardware-accelerated) pixel format failed.
1766  * @warning Behavior is undefined if the callback returns a value not
1767  * in the fmt list of formats.
1768  * @return the chosen format
1769  * - encoding: unused
1770  * - decoding: Set by user, if not set the native format will be chosen.
1771  */
1772  enum AVPixelFormat (*get_format)(struct AVCodecContext *s, const enum AVPixelFormat * fmt);
1773 
1774  /**
1775  * maximum number of B-frames between non-B-frames
1776  * Note: The output will be delayed by max_b_frames+1 relative to the input.
1777  * - encoding: Set by user.
1778  * - decoding: unused
1779  */
1781 
1782  /**
1783  * qscale factor between IP and B-frames
1784  * If > 0 then the last P-frame quantizer will be used (q= lastp_q*factor+offset).
1785  * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1786  * - encoding: Set by user.
1787  * - decoding: unused
1788  */
1790 
1791 #if FF_API_RC_STRATEGY
1792  /** @deprecated use codec private option instead */
1794 #define FF_RC_STRATEGY_XVID 1
1795 #endif
1796 
1798 
1799  /**
1800  * qscale offset between IP and B-frames
1801  * - encoding: Set by user.
1802  * - decoding: unused
1803  */
1805 
1806  /**
1807  * Size of the frame reordering buffer in the decoder.
1808  * For MPEG-2 it is 1 IPB or 0 low delay IP.
1809  * - encoding: Set by libavcodec.
1810  * - decoding: Set by libavcodec.
1811  */
1813 
1814  /**
1815  * 0-> h263 quant 1-> mpeg quant
1816  * - encoding: Set by user.
1817  * - decoding: unused
1818  */
1820 
1821  /**
1822  * qscale factor between P and I-frames
1823  * If > 0 then the last p frame quantizer will be used (q= lastp_q*factor+offset).
1824  * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1825  * - encoding: Set by user.
1826  * - decoding: unused
1827  */
1829 
1830  /**
1831  * qscale offset between P and I-frames
1832  * - encoding: Set by user.
1833  * - decoding: unused
1834  */
1836 
1837  /**
1838  * luminance masking (0-> disabled)
1839  * - encoding: Set by user.
1840  * - decoding: unused
1841  */
1843 
1844  /**
1845  * temporary complexity masking (0-> disabled)
1846  * - encoding: Set by user.
1847  * - decoding: unused
1848  */
1850 
1851  /**
1852  * spatial complexity masking (0-> disabled)
1853  * - encoding: Set by user.
1854  * - decoding: unused
1855  */
1857 
1858  /**
1859  * p block masking (0-> disabled)
1860  * - encoding: Set by user.
1861  * - decoding: unused
1862  */
1863  float p_masking;
1864 
1865  /**
1866  * darkness masking (0-> disabled)
1867  * - encoding: Set by user.
1868  * - decoding: unused
1869  */
1871 
1872  /**
1873  * slice count
1874  * - encoding: Set by libavcodec.
1875  * - decoding: Set by user (or 0).
1876  */
1878  /**
1879  * prediction method (needed for huffyuv)
1880  * - encoding: Set by user.
1881  * - decoding: unused
1882  */
1884 #define FF_PRED_LEFT 0
1885 #define FF_PRED_PLANE 1
1886 #define FF_PRED_MEDIAN 2
1887 
1888  /**
1889  * slice offsets in the frame in bytes
1890  * - encoding: Set/allocated by libavcodec.
1891  * - decoding: Set/allocated by user (or NULL).
1892  */
1894 
1895  /**
1896  * sample aspect ratio (0 if unknown)
1897  * That is the width of a pixel divided by the height of the pixel.
1898  * Numerator and denominator must be relatively prime and smaller than 256 for some video standards.
1899  * - encoding: Set by user.
1900  * - decoding: Set by libavcodec.
1901  */
1903 
1904  /**
1905  * motion estimation comparison function
1906  * - encoding: Set by user.
1907  * - decoding: unused
1908  */
1909  int me_cmp;
1910  /**
1911  * subpixel motion estimation comparison function
1912  * - encoding: Set by user.
1913  * - decoding: unused
1914  */
1916  /**
1917  * macroblock comparison function (not supported yet)
1918  * - encoding: Set by user.
1919  * - decoding: unused
1920  */
1921  int mb_cmp;
1922  /**
1923  * interlaced DCT comparison function
1924  * - encoding: Set by user.
1925  * - decoding: unused
1926  */
1928 #define FF_CMP_SAD 0
1929 #define FF_CMP_SSE 1
1930 #define FF_CMP_SATD 2
1931 #define FF_CMP_DCT 3
1932 #define FF_CMP_PSNR 4
1933 #define FF_CMP_BIT 5
1934 #define FF_CMP_RD 6
1935 #define FF_CMP_ZERO 7
1936 #define FF_CMP_VSAD 8
1937 #define FF_CMP_VSSE 9
1938 #define FF_CMP_NSSE 10
1939 #define FF_CMP_W53 11
1940 #define FF_CMP_W97 12
1941 #define FF_CMP_DCTMAX 13
1942 #define FF_CMP_DCT264 14
1943 #define FF_CMP_CHROMA 256
1944 
1945  /**
1946  * ME diamond size & shape
1947  * - encoding: Set by user.
1948  * - decoding: unused
1949  */
1951 
1952  /**
1953  * amount of previous MV predictors (2a+1 x 2a+1 square)
1954  * - encoding: Set by user.
1955  * - decoding: unused
1956  */
1958 
1959  /**
1960  * prepass for motion estimation
1961  * - encoding: Set by user.
1962  * - decoding: unused
1963  */
1964  int pre_me;
1965 
1966  /**
1967  * motion estimation prepass comparison function
1968  * - encoding: Set by user.
1969  * - decoding: unused
1970  */
1972 
1973  /**
1974  * ME prepass diamond size & shape
1975  * - encoding: Set by user.
1976  * - decoding: unused
1977  */
1979 
1980  /**
1981  * subpel ME quality
1982  * - encoding: Set by user.
1983  * - decoding: unused
1984  */
1986 
1987 #if FF_API_AFD
1988  /**
1989  * DTG active format information (additional aspect ratio
1990  * information only used in DVB MPEG-2 transport streams)
1991  * 0 if not set.
1992  *
1993  * - encoding: unused
1994  * - decoding: Set by decoder.
1995  * @deprecated Deprecated in favor of AVSideData
1996  */
1998 #define FF_DTG_AFD_SAME 8
1999 #define FF_DTG_AFD_4_3 9
2000 #define FF_DTG_AFD_16_9 10
2001 #define FF_DTG_AFD_14_9 11
2002 #define FF_DTG_AFD_4_3_SP_14_9 13
2003 #define FF_DTG_AFD_16_9_SP_14_9 14
2004 #define FF_DTG_AFD_SP_4_3 15
2005 #endif /* FF_API_AFD */
2006 
2007  /**
2008  * maximum motion estimation search range in subpel units
2009  * If 0 then no limit.
2010  *
2011  * - encoding: Set by user.
2012  * - decoding: unused
2013  */
2015 
2016 #if FF_API_QUANT_BIAS
2017  /**
2018  * @deprecated use encoder private option instead
2019  */
2021 #define FF_DEFAULT_QUANT_BIAS 999999
2022 
2023  /**
2024  * @deprecated use encoder private option instead
2025  */
2027 #endif
2028 
2029  /**
2030  * slice flags
2031  * - encoding: unused
2032  * - decoding: Set by user.
2033  */
2035 #define SLICE_FLAG_CODED_ORDER 0x0001 ///< draw_horiz_band() is called in coded order instead of display
2036 #define SLICE_FLAG_ALLOW_FIELD 0x0002 ///< allow draw_horiz_band() with field slices (MPEG2 field pics)
2037 #define SLICE_FLAG_ALLOW_PLANE 0x0004 ///< allow draw_horiz_band() with 1 component at a time (SVQ1)
2038 
2039 #if FF_API_XVMC
2040  /**
2041  * XVideo Motion Acceleration
2042  * - encoding: forbidden
2043  * - decoding: set by decoder
2044  * @deprecated XvMC doesn't need it anymore.
2045  */
2046  attribute_deprecated int xvmc_acceleration;
2047 #endif /* FF_API_XVMC */
2048 
2049  /**
2050  * macroblock decision mode
2051  * - encoding: Set by user.
2052  * - decoding: unused
2053  */
2055 #define FF_MB_DECISION_SIMPLE 0 ///< uses mb_cmp
2056 #define FF_MB_DECISION_BITS 1 ///< chooses the one which needs the fewest bits
2057 #define FF_MB_DECISION_RD 2 ///< rate distortion
2058 
2059  /**
2060  * custom intra quantization matrix
2061  * - encoding: Set by user, can be NULL.
2062  * - decoding: Set by libavcodec.
2063  */
2064  uint16_t *intra_matrix;
2065 
2066  /**
2067  * custom inter quantization matrix
2068  * - encoding: Set by user, can be NULL.
2069  * - decoding: Set by libavcodec.
2070  */
2071  uint16_t *inter_matrix;
2072 
2073  /**
2074  * scene change detection threshold
2075  * 0 is default, larger means fewer detected scene changes.
2076  * - encoding: Set by user.
2077  * - decoding: unused
2078  */
2080 
2081  /**
2082  * noise reduction strength
2083  * - encoding: Set by user.
2084  * - decoding: unused
2085  */
2087 
2088 #if FF_API_MPV_OPT
2089  /**
2090  * @deprecated this field is unused
2091  */
2094 
2095  /**
2096  * @deprecated this field is unused
2097  */
2100 #endif
2101 
2102  /**
2103  * precision of the intra DC coefficient - 8
2104  * - encoding: Set by user.
2105  * - decoding: Set by libavcodec
2106  */
2108 
2109  /**
2110  * Number of macroblock rows at the top which are skipped.
2111  * - encoding: unused
2112  * - decoding: Set by user.
2113  */
2115 
2116  /**
2117  * Number of macroblock rows at the bottom which are skipped.
2118  * - encoding: unused
2119  * - decoding: Set by user.
2120  */
2122 
2123 #if FF_API_MPV_OPT
2124  /**
2125  * @deprecated use encoder private options instead
2126  */
2129 #endif
2130 
2131  /**
2132  * minimum MB lagrange multipler
2133  * - encoding: Set by user.
2134  * - decoding: unused
2135  */
2136  int mb_lmin;
2137 
2138  /**
2139  * maximum MB lagrange multipler
2140  * - encoding: Set by user.
2141  * - decoding: unused
2142  */
2143  int mb_lmax;
2144 
2145  /**
2146  *
2147  * - encoding: Set by user.
2148  * - decoding: unused
2149  */
2151 
2152  /**
2153  *
2154  * - encoding: Set by user.
2155  * - decoding: unused
2156  */
2158 
2159  /**
2160  *
2161  * - encoding: Set by user.
2162  * - decoding: unused
2163  */
2165 
2166  /**
2167  * minimum GOP size
2168  * - encoding: Set by user.
2169  * - decoding: unused
2170  */
2172 
2173  /**
2174  * number of reference frames
2175  * - encoding: Set by user.
2176  * - decoding: Set by lavc.
2177  */
2178  int refs;
2179 
2180  /**
2181  * chroma qp offset from luma
2182  * - encoding: Set by user.
2183  * - decoding: unused
2184  */
2186 
2187 #if FF_API_UNUSED_MEMBERS
2188  /**
2189  * Multiplied by qscale for each frame and added to scene_change_score.
2190  * - encoding: Set by user.
2191  * - decoding: unused
2192  */
2194 #endif
2195 
2196  /**
2197  *
2198  * Note: Value depends upon the compare function used for fullpel ME.
2199  * - encoding: Set by user.
2200  * - decoding: unused
2201  */
2203 
2204  /**
2205  * Adjust sensitivity of b_frame_strategy 1.
2206  * - encoding: Set by user.
2207  * - decoding: unused
2208  */
2210 
2211  /**
2212  * Chromaticity coordinates of the source primaries.
2213  * - encoding: Set by user
2214  * - decoding: Set by libavcodec
2215  */
2217 
2218  /**
2219  * Color Transfer Characteristic.
2220  * - encoding: Set by user
2221  * - decoding: Set by libavcodec
2222  */
2224 
2225  /**
2226  * YUV colorspace type.
2227  * - encoding: Set by user
2228  * - decoding: Set by libavcodec
2229  */
2231 
2232  /**
2233  * MPEG vs JPEG YUV range.
2234  * - encoding: Set by user
2235  * - decoding: Set by libavcodec
2236  */
2238 
2239  /**
2240  * This defines the location of chroma samples.
2241  * - encoding: Set by user
2242  * - decoding: Set by libavcodec
2243  */
2245 
2246  /**
2247  * Number of slices.
2248  * Indicates number of picture subdivisions. Used for parallelized
2249  * decoding.
2250  * - encoding: Set by user
2251  * - decoding: unused
2252  */
2253  int slices;
2254 
2255  /** Field order
2256  * - encoding: set by libavcodec
2257  * - decoding: Set by user.
2258  */
2260 
2261  /* audio only */
2262  int sample_rate; ///< samples per second
2263  int channels; ///< number of audio channels
2264 
2265  /**
2266  * audio sample format
2267  * - encoding: Set by user.
2268  * - decoding: Set by libavcodec.
2269  */
2270  enum AVSampleFormat sample_fmt; ///< sample format
2271 
2272  /* The following data should not be initialized. */
2273  /**
2274  * Number of samples per channel in an audio frame.
2275  *
2276  * - encoding: set by libavcodec in avcodec_open2(). Each submitted frame
2277  * except the last must contain exactly frame_size samples per channel.
2278  * May be 0 when the codec has AV_CODEC_CAP_VARIABLE_FRAME_SIZE set, then the
2279  * frame size is not restricted.
2280  * - decoding: may be set by some decoders to indicate constant frame size
2281  */
2283 
2284  /**
2285  * Frame counter, set by libavcodec.
2286  *
2287  * - decoding: total number of frames returned from the decoder so far.
2288  * - encoding: total number of frames passed to the encoder so far.
2289  *
2290  * @note the counter is not incremented if encoding/decoding resulted in
2291  * an error.
2292  */
2294 
2295  /**
2296  * number of bytes per packet if constant and known or 0
2297  * Used by some WAV based audio codecs.
2298  */
2300 
2301  /**
2302  * Audio cutoff bandwidth (0 means "automatic")
2303  * - encoding: Set by user.
2304  * - decoding: unused
2305  */
2306  int cutoff;
2307 
2308 #if FF_API_REQUEST_CHANNELS
2309  /**
2310  * Decoder should decode to this many channels if it can (0 for default)
2311  * - encoding: unused
2312  * - decoding: Set by user.
2313  * @deprecated Deprecated in favor of request_channel_layout.
2314  */
2316 #endif
2317 
2318  /**
2319  * Audio channel layout.
2320  * - encoding: set by user.
2321  * - decoding: set by user, may be overwritten by libavcodec.
2322  */
2323  uint64_t channel_layout;
2324 
2325  /**
2326  * Request decoder to use this channel layout if it can (0 for default)
2327  * - encoding: unused
2328  * - decoding: Set by user.
2329  */
2331 
2332  /**
2333  * Type of service that the audio stream conveys.
2334  * - encoding: Set by user.
2335  * - decoding: Set by libavcodec.
2336  */
2338 
2339  /**
2340  * desired sample format
2341  * - encoding: Not used.
2342  * - decoding: Set by user.
2343  * Decoder will decode to this format if it can.
2344  */
2346 
2347 #if FF_API_GET_BUFFER
2348  /**
2349  * Called at the beginning of each frame to get a buffer for it.
2350  *
2351  * The function will set AVFrame.data[], AVFrame.linesize[].
2352  * AVFrame.extended_data[] must also be set, but it should be the same as
2353  * AVFrame.data[] except for planar audio with more channels than can fit
2354  * in AVFrame.data[]. In that case, AVFrame.data[] shall still contain as
2355  * many data pointers as it can hold.
2356  *
2357  * if CODEC_CAP_DR1 is not set then get_buffer() must call
2358  * avcodec_default_get_buffer() instead of providing buffers allocated by
2359  * some other means.
2360  *
2361  * AVFrame.data[] should be 32- or 16-byte-aligned unless the CPU doesn't
2362  * need it. avcodec_default_get_buffer() aligns the output buffer properly,
2363  * but if get_buffer() is overridden then alignment considerations should
2364  * be taken into account.
2365  *
2366  * @see avcodec_default_get_buffer()
2367  *
2368  * Video:
2369  *
2370  * If pic.reference is set then the frame will be read later by libavcodec.
2371  * avcodec_align_dimensions2() should be used to find the required width and
2372  * height, as they normally need to be rounded up to the next multiple of 16.
2373  *
2374  * If frame multithreading is used and thread_safe_callbacks is set,
2375  * it may be called from a different thread, but not from more than one at
2376  * once. Does not need to be reentrant.
2377  *
2378  * @see release_buffer(), reget_buffer()
2379  * @see avcodec_align_dimensions2()
2380  *
2381  * Audio:
2382  *
2383  * Decoders request a buffer of a particular size by setting
2384  * AVFrame.nb_samples prior to calling get_buffer(). The decoder may,
2385  * however, utilize only part of the buffer by setting AVFrame.nb_samples
2386  * to a smaller value in the output frame.
2387  *
2388  * Decoders cannot use the buffer after returning from
2389  * avcodec_decode_audio4(), so they will not call release_buffer(), as it
2390  * is assumed to be released immediately upon return. In some rare cases,
2391  * a decoder may need to call get_buffer() more than once in a single
2392  * call to avcodec_decode_audio4(). In that case, when get_buffer() is
2393  * called again after it has already been called once, the previously
2394  * acquired buffer is assumed to be released at that time and may not be
2395  * reused by the decoder.
2396  *
2397  * As a convenience, av_samples_get_buffer_size() and
2398  * av_samples_fill_arrays() in libavutil may be used by custom get_buffer()
2399  * functions to find the required data size and to fill data pointers and
2400  * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
2401  * since all planes must be the same size.
2402  *
2403  * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
2404  *
2405  * - encoding: unused
2406  * - decoding: Set by libavcodec, user can override.
2407  *
2408  * @deprecated use get_buffer2()
2409  */
2411  int (*get_buffer)(struct AVCodecContext *c, AVFrame *pic);
2412 
2413  /**
2414  * Called to release buffers which were allocated with get_buffer.
2415  * A released buffer can be reused in get_buffer().
2416  * pic.data[*] must be set to NULL.
2417  * May be called from a different thread if frame multithreading is used,
2418  * but not by more than one thread at once, so does not need to be reentrant.
2419  * - encoding: unused
2420  * - decoding: Set by libavcodec, user can override.
2421  *
2422  * @deprecated custom freeing callbacks should be set from get_buffer2()
2423  */
2426 
2427  /**
2428  * Called at the beginning of a frame to get cr buffer for it.
2429  * Buffer type (size, hints) must be the same. libavcodec won't check it.
2430  * libavcodec will pass previous buffer in pic, function should return
2431  * same buffer or new buffer with old frame "painted" into it.
2432  * If pic.data[0] == NULL must behave like get_buffer().
2433  * if CODEC_CAP_DR1 is not set then reget_buffer() must call
2434  * avcodec_default_reget_buffer() instead of providing buffers allocated by
2435  * some other means.
2436  * - encoding: unused
2437  * - decoding: Set by libavcodec, user can override.
2438  */
2440  int (*reget_buffer)(struct AVCodecContext *c, AVFrame *pic);
2441 #endif
2442 
2443  /**
2444  * This callback is called at the beginning of each frame to get data
2445  * buffer(s) for it. There may be one contiguous buffer for all the data or
2446  * there may be a buffer per each data plane or anything in between. What
2447  * this means is, you may set however many entries in buf[] you feel necessary.
2448  * Each buffer must be reference-counted using the AVBuffer API (see description
2449  * of buf[] below).
2450  *
2451  * The following fields will be set in the frame before this callback is
2452  * called:
2453  * - format
2454  * - width, height (video only)
2455  * - sample_rate, channel_layout, nb_samples (audio only)
2456  * Their values may differ from the corresponding values in
2457  * AVCodecContext. This callback must use the frame values, not the codec
2458  * context values, to calculate the required buffer size.
2459  *
2460  * This callback must fill the following fields in the frame:
2461  * - data[]
2462  * - linesize[]
2463  * - extended_data:
2464  * * if the data is planar audio with more than 8 channels, then this
2465  * callback must allocate and fill extended_data to contain all pointers
2466  * to all data planes. data[] must hold as many pointers as it can.
2467  * extended_data must be allocated with av_malloc() and will be freed in
2468  * av_frame_unref().
2469  * * otherwise exended_data must point to data
2470  * - buf[] must contain one or more pointers to AVBufferRef structures. Each of
2471  * the frame's data and extended_data pointers must be contained in these. That
2472  * is, one AVBufferRef for each allocated chunk of memory, not necessarily one
2473  * AVBufferRef per data[] entry. See: av_buffer_create(), av_buffer_alloc(),
2474  * and av_buffer_ref().
2475  * - extended_buf and nb_extended_buf must be allocated with av_malloc() by
2476  * this callback and filled with the extra buffers if there are more
2477  * buffers than buf[] can hold. extended_buf will be freed in
2478  * av_frame_unref().
2479  *
2480  * If AV_CODEC_CAP_DR1 is not set then get_buffer2() must call
2481  * avcodec_default_get_buffer2() instead of providing buffers allocated by
2482  * some other means.
2483  *
2484  * Each data plane must be aligned to the maximum required by the target
2485  * CPU.
2486  *
2487  * @see avcodec_default_get_buffer2()
2488  *
2489  * Video:
2490  *
2491  * If AV_GET_BUFFER_FLAG_REF is set in flags then the frame may be reused
2492  * (read and/or written to if it is writable) later by libavcodec.
2493  *
2494  * avcodec_align_dimensions2() should be used to find the required width and
2495  * height, as they normally need to be rounded up to the next multiple of 16.
2496  *
2497  * Some decoders do not support linesizes changing between frames.
2498  *
2499  * If frame multithreading is used and thread_safe_callbacks is set,
2500  * this callback may be called from a different thread, but not from more
2501  * than one at once. Does not need to be reentrant.
2502  *
2503  * @see avcodec_align_dimensions2()
2504  *
2505  * Audio:
2506  *
2507  * Decoders request a buffer of a particular size by setting
2508  * AVFrame.nb_samples prior to calling get_buffer2(). The decoder may,
2509  * however, utilize only part of the buffer by setting AVFrame.nb_samples
2510  * to a smaller value in the output frame.
2511  *
2512  * As a convenience, av_samples_get_buffer_size() and
2513  * av_samples_fill_arrays() in libavutil may be used by custom get_buffer2()
2514  * functions to find the required data size and to fill data pointers and
2515  * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
2516  * since all planes must be the same size.
2517  *
2518  * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
2519  *
2520  * - encoding: unused
2521  * - decoding: Set by libavcodec, user can override.
2522  */
2523  int (*get_buffer2)(struct AVCodecContext *s, AVFrame *frame, int flags);
2524 
2525  /**
2526  * If non-zero, the decoded audio and video frames returned from
2527  * avcodec_decode_video2() and avcodec_decode_audio4() are reference-counted
2528  * and are valid indefinitely. The caller must free them with
2529  * av_frame_unref() when they are not needed anymore.
2530  * Otherwise, the decoded frames must not be freed by the caller and are
2531  * only valid until the next decode call.
2532  *
2533  * - encoding: unused
2534  * - decoding: set by the caller before avcodec_open2().
2535  */
2537 
2538  /* - encoding parameters */
2539  float qcompress; ///< amount of qscale change between easy & hard scenes (0.0-1.0)
2540  float qblur; ///< amount of qscale smoothing over time (0.0-1.0)
2541 
2542  /**
2543  * minimum quantizer
2544  * - encoding: Set by user.
2545  * - decoding: unused
2546  */
2547  int qmin;
2548 
2549  /**
2550  * maximum quantizer
2551  * - encoding: Set by user.
2552  * - decoding: unused
2553  */
2554  int qmax;
2555 
2556  /**
2557  * maximum quantizer difference between frames
2558  * - encoding: Set by user.
2559  * - decoding: unused
2560  */
2562 
2563 #if FF_API_MPV_OPT
2564  /**
2565  * @deprecated use encoder private options instead
2566  */
2568  float rc_qsquish;
2569 
2574 #endif
2575 
2576  /**
2577  * decoder bitstream buffer size
2578  * - encoding: Set by user.
2579  * - decoding: unused
2580  */
2582 
2583  /**
2584  * ratecontrol override, see RcOverride
2585  * - encoding: Allocated/set/freed by user.
2586  * - decoding: unused
2587  */
2590 
2591 #if FF_API_MPV_OPT
2592  /**
2593  * @deprecated use encoder private options instead
2594  */
2596  const char *rc_eq;
2597 #endif
2598 
2599  /**
2600  * maximum bitrate
2601  * - encoding: Set by user.
2602  * - decoding: Set by user, may be overwritten by libavcodec.
2603  */
2605 
2606  /**
2607  * minimum bitrate
2608  * - encoding: Set by user.
2609  * - decoding: unused
2610  */
2612 
2613 #if FF_API_MPV_OPT
2614  /**
2615  * @deprecated use encoder private options instead
2616  */
2619 
2622 #endif
2623 
2624  /**
2625  * Ratecontrol attempt to use, at maximum, <value> of what can be used without an underflow.
2626  * - encoding: Set by user.
2627  * - decoding: unused.
2628  */
2630 
2631  /**
2632  * Ratecontrol attempt to use, at least, <value> times the amount needed to prevent a vbv overflow.
2633  * - encoding: Set by user.
2634  * - decoding: unused.
2635  */
2637 
2638  /**
2639  * Number of bits which should be loaded into the rc buffer before decoding starts.
2640  * - encoding: Set by user.
2641  * - decoding: unused
2642  */
2644 
2645 #define FF_CODER_TYPE_VLC 0
2646 #define FF_CODER_TYPE_AC 1
2647 #define FF_CODER_TYPE_RAW 2
2648 #define FF_CODER_TYPE_RLE 3
2649 #if FF_API_UNUSED_MEMBERS
2650 #define FF_CODER_TYPE_DEFLATE 4
2651 #endif /* FF_API_UNUSED_MEMBERS */
2652  /**
2653  * coder type
2654  * - encoding: Set by user.
2655  * - decoding: unused
2656  */
2658 
2659  /**
2660  * context model
2661  * - encoding: Set by user.
2662  * - decoding: unused
2663  */
2665 
2666 #if FF_API_MPV_OPT
2667  /**
2668  * @deprecated use encoder private options instead
2669  */
2671  int lmin;
2672 
2673  /**
2674  * @deprecated use encoder private options instead
2675  */
2677  int lmax;
2678 #endif
2679 
2680  /**
2681  * frame skip threshold
2682  * - encoding: Set by user.
2683  * - decoding: unused
2684  */
2686 
2687  /**
2688  * frame skip factor
2689  * - encoding: Set by user.
2690  * - decoding: unused
2691  */
2693 
2694  /**
2695  * frame skip exponent
2696  * - encoding: Set by user.
2697  * - decoding: unused
2698  */
2700 
2701  /**
2702  * frame skip comparison function
2703  * - encoding: Set by user.
2704  * - decoding: unused
2705  */
2707 
2708  /**
2709  * trellis RD quantization
2710  * - encoding: Set by user.
2711  * - decoding: unused
2712  */
2713  int trellis;
2714 
2715  /**
2716  * - encoding: Set by user.
2717  * - decoding: unused
2718  */
2720 
2721  /**
2722  * - encoding: Set by user.
2723  * - decoding: unused
2724  */
2726 
2727  /**
2728  * GOP timecode frame start number
2729  * - encoding: Set by user, in non drop frame format
2730  * - decoding: Set by libavcodec (timecode in the 25 bits format, -1 if unset)
2731  */
2733 
2734  /* The RTP callback: This function is called */
2735  /* every time the encoder has a packet to send. */
2736  /* It depends on the encoder if the data starts */
2737  /* with a Start Code (it should). H.263 does. */
2738  /* mb_nb contains the number of macroblocks */
2739  /* encoded in the RTP payload. */
2740  void (*rtp_callback)(struct AVCodecContext *avctx, void *data, int size, int mb_nb);
2741 
2742  int rtp_payload_size; /* The size of the RTP payload: the coder will */
2743  /* do its best to deliver a chunk with size */
2744  /* below rtp_payload_size, the chunk will start */
2745  /* with a start code on some codecs like H.263. */
2746  /* This doesn't take account of any particular */
2747  /* headers inside the transmitted RTP payload. */
2748 
2749  /* statistics, used for 2-pass encoding */
2750  int mv_bits;
2754  int i_count;
2755  int p_count;
2758 
2759  /**
2760  * number of bits used for the previously encoded frame
2761  * - encoding: Set by libavcodec.
2762  * - decoding: unused
2763  */
2765 
2766  /**
2767  * pass1 encoding statistics output buffer
2768  * - encoding: Set by libavcodec.
2769  * - decoding: unused
2770  */
2771  char *stats_out;
2772 
2773  /**
2774  * pass2 encoding statistics input buffer
2775  * Concatenated stuff from stats_out of pass1 should be placed here.
2776  * - encoding: Allocated/set/freed by user.
2777  * - decoding: unused
2778  */
2779  char *stats_in;
2780 
2781  /**
2782  * Work around bugs in encoders which sometimes cannot be detected automatically.
2783  * - encoding: Set by user
2784  * - decoding: Set by user
2785  */
2787 #define FF_BUG_AUTODETECT 1 ///< autodetection
2788 #if FF_API_OLD_MSMPEG4
2789 #define FF_BUG_OLD_MSMPEG4 2
2790 #endif
2791 #define FF_BUG_XVID_ILACE 4
2792 #define FF_BUG_UMP4 8
2793 #define FF_BUG_NO_PADDING 16
2794 #define FF_BUG_AMV 32
2795 #if FF_API_AC_VLC
2796 #define FF_BUG_AC_VLC 0 ///< Will be removed, libavcodec can now handle these non-compliant files by default.
2797 #endif
2798 #define FF_BUG_QPEL_CHROMA 64
2799 #define FF_BUG_STD_QPEL 128
2800 #define FF_BUG_QPEL_CHROMA2 256
2801 #define FF_BUG_DIRECT_BLOCKSIZE 512
2802 #define FF_BUG_EDGE 1024
2803 #define FF_BUG_HPEL_CHROMA 2048
2804 #define FF_BUG_DC_CLIP 4096
2805 #define FF_BUG_MS 8192 ///< Work around various bugs in Microsoft's broken decoders.
2806 #define FF_BUG_TRUNCATED 16384
2807 
2808  /**
2809  * strictly follow the standard (MPEG4, ...).
2810  * - encoding: Set by user.
2811  * - decoding: Set by user.
2812  * Setting this to STRICT or higher means the encoder and decoder will
2813  * generally do stupid things, whereas setting it to unofficial or lower
2814  * will mean the encoder might produce output that is not supported by all
2815  * spec-compliant decoders. Decoders don't differentiate between normal,
2816  * unofficial and experimental (that is, they always try to decode things
2817  * when they can) unless they are explicitly asked to behave stupidly
2818  * (=strictly conform to the specs)
2819  */
2821 #define FF_COMPLIANCE_VERY_STRICT 2 ///< Strictly conform to an older more strict version of the spec or reference software.
2822 #define FF_COMPLIANCE_STRICT 1 ///< Strictly conform to all the things in the spec no matter what consequences.
2823 #define FF_COMPLIANCE_NORMAL 0
2824 #define FF_COMPLIANCE_UNOFFICIAL -1 ///< Allow unofficial extensions
2825 #define FF_COMPLIANCE_EXPERIMENTAL -2 ///< Allow nonstandardized experimental things.
2826 
2827  /**
2828  * error concealment flags
2829  * - encoding: unused
2830  * - decoding: Set by user.
2831  */
2833 #define FF_EC_GUESS_MVS 1
2834 #define FF_EC_DEBLOCK 2
2835 #define FF_EC_FAVOR_INTER 256
2836 
2837  /**
2838  * debug
2839  * - encoding: Set by user.
2840  * - decoding: Set by user.
2841  */
2842  int debug;
2843 #define FF_DEBUG_PICT_INFO 1
2844 #define FF_DEBUG_RC 2
2845 #define FF_DEBUG_BITSTREAM 4
2846 #define FF_DEBUG_MB_TYPE 8
2847 #define FF_DEBUG_QP 16
2848 #if FF_API_DEBUG_MV
2849 /**
2850  * @deprecated this option does nothing
2851  */
2852 #define FF_DEBUG_MV 32
2853 #endif
2854 #define FF_DEBUG_DCT_COEFF 0x00000040
2855 #define FF_DEBUG_SKIP 0x00000080
2856 #define FF_DEBUG_STARTCODE 0x00000100
2857 #if FF_API_UNUSED_MEMBERS
2858 #define FF_DEBUG_PTS 0x00000200
2859 #endif /* FF_API_UNUSED_MEMBERS */
2860 #define FF_DEBUG_ER 0x00000400
2861 #define FF_DEBUG_MMCO 0x00000800
2862 #define FF_DEBUG_BUGS 0x00001000
2863 #if FF_API_DEBUG_MV
2864 #define FF_DEBUG_VIS_QP 0x00002000 ///< only access through AVOptions from outside libavcodec
2865 #define FF_DEBUG_VIS_MB_TYPE 0x00004000 ///< only access through AVOptions from outside libavcodec
2866 #endif
2867 #define FF_DEBUG_BUFFERS 0x00008000
2868 #define FF_DEBUG_THREADS 0x00010000
2869 #define FF_DEBUG_GREEN_MD 0x00800000
2870 #define FF_DEBUG_NOMC 0x01000000
2871 
2872 #if FF_API_DEBUG_MV
2873  /**
2874  * debug
2875  * Code outside libavcodec should access this field using AVOptions
2876  * - encoding: Set by user.
2877  * - decoding: Set by user.
2878  */
2880 #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 //visualize forward predicted MVs of P frames
2881 #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 //visualize forward predicted MVs of B frames
2882 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
2883 #endif
2884 
2885  /**
2886  * Error recognition; may misdetect some more or less valid parts as errors.
2887  * - encoding: unused
2888  * - decoding: Set by user.
2889  */
2891 
2892 /**
2893  * Verify checksums embedded in the bitstream (could be of either encoded or
2894  * decoded data, depending on the codec) and print an error message on mismatch.
2895  * If AV_EF_EXPLODE is also set, a mismatching checksum will result in the
2896  * decoder returning an error.
2897  */
2898 #define AV_EF_CRCCHECK (1<<0)
2899 #define AV_EF_BITSTREAM (1<<1) ///< detect bitstream specification deviations
2900 #define AV_EF_BUFFER (1<<2) ///< detect improper bitstream length
2901 #define AV_EF_EXPLODE (1<<3) ///< abort decoding on minor error detection
2902 
2903 #define AV_EF_IGNORE_ERR (1<<15) ///< ignore errors and continue
2904 #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
2905 #define AV_EF_COMPLIANT (1<<17) ///< consider all spec non compliances as errors
2906 #define AV_EF_AGGRESSIVE (1<<18) ///< consider things that a sane encoder should not do as an error
2907 
2908 
2909  /**
2910  * opaque 64bit number (generally a PTS) that will be reordered and
2911  * output in AVFrame.reordered_opaque
2912  * - encoding: unused
2913  * - decoding: Set by user.
2914  */
2916 
2917  /**
2918  * Hardware accelerator in use
2919  * - encoding: unused.
2920  * - decoding: Set by libavcodec
2921  */
2923 
2924  /**
2925  * Hardware accelerator context.
2926  * For some hardware accelerators, a global context needs to be
2927  * provided by the user. In that case, this holds display-dependent
2928  * data FFmpeg cannot instantiate itself. Please refer to the
2929  * FFmpeg HW accelerator documentation to know how to fill this
2930  * is. e.g. for VA API, this is a struct vaapi_context.
2931  * - encoding: unused
2932  * - decoding: Set by user
2933  */
2935 
2936  /**
2937  * error
2938  * - encoding: Set by libavcodec if flags & AV_CODEC_FLAG_PSNR.
2939  * - decoding: unused
2940  */
2942 
2943  /**
2944  * DCT algorithm, see FF_DCT_* below
2945  * - encoding: Set by user.
2946  * - decoding: unused
2947  */
2949 #define FF_DCT_AUTO 0
2950 #define FF_DCT_FASTINT 1
2951 #define FF_DCT_INT 2
2952 #define FF_DCT_MMX 3
2953 #define FF_DCT_ALTIVEC 5
2954 #define FF_DCT_FAAN 6
2955 
2956  /**
2957  * IDCT algorithm, see FF_IDCT_* below.
2958  * - encoding: Set by user.
2959  * - decoding: Set by user.
2960  */
2962 #define FF_IDCT_AUTO 0
2963 #define FF_IDCT_INT 1
2964 #define FF_IDCT_SIMPLE 2
2965 #define FF_IDCT_SIMPLEMMX 3
2966 #define FF_IDCT_ARM 7
2967 #define FF_IDCT_ALTIVEC 8
2968 #if FF_API_ARCH_SH4
2969 #define FF_IDCT_SH4 9
2970 #endif
2971 #define FF_IDCT_SIMPLEARM 10
2972 #if FF_API_UNUSED_MEMBERS
2973 #define FF_IDCT_IPP 13
2974 #endif /* FF_API_UNUSED_MEMBERS */
2975 #define FF_IDCT_XVID 14
2976 #if FF_API_IDCT_XVIDMMX
2977 #define FF_IDCT_XVIDMMX 14
2978 #endif /* FF_API_IDCT_XVIDMMX */
2979 #define FF_IDCT_SIMPLEARMV5TE 16
2980 #define FF_IDCT_SIMPLEARMV6 17
2981 #if FF_API_ARCH_SPARC
2982 #define FF_IDCT_SIMPLEVIS 18
2983 #endif
2984 #define FF_IDCT_FAAN 20
2985 #define FF_IDCT_SIMPLENEON 22
2986 #if FF_API_ARCH_ALPHA
2987 #define FF_IDCT_SIMPLEALPHA 23
2988 #endif
2989 #define FF_IDCT_SIMPLEAUTO 128
2990 
2991  /**
2992  * bits per sample/pixel from the demuxer (needed for huffyuv).
2993  * - encoding: Set by libavcodec.
2994  * - decoding: Set by user.
2995  */
2997 
2998  /**
2999  * Bits per sample/pixel of internal libavcodec pixel/sample format.
3000  * - encoding: set by user.
3001  * - decoding: set by libavcodec.
3002  */
3004 
3005 #if FF_API_LOWRES
3006  /**
3007  * low resolution decoding, 1-> 1/2 size, 2->1/4 size
3008  * - encoding: unused
3009  * - decoding: Set by user.
3010  * Code outside libavcodec should access this field using:
3011  * av_codec_{get,set}_lowres(avctx)
3012  */
3013  int lowres;
3014 #endif
3015 
3016 #if FF_API_CODED_FRAME
3017  /**
3018  * the picture in the bitstream
3019  * - encoding: Set by libavcodec.
3020  * - decoding: unused
3021  *
3022  * @deprecated use the quality factor packet side data instead
3023  */
3025 #endif
3026 
3027  /**
3028  * thread count
3029  * is used to decide how many independent tasks should be passed to execute()
3030  * - encoding: Set by user.
3031  * - decoding: Set by user.
3032  */
3034 
3035  /**
3036  * Which multithreading methods to use.
3037  * Use of FF_THREAD_FRAME will increase decoding delay by one frame per thread,
3038  * so clients which cannot provide future frames should not use it.
3039  *
3040  * - encoding: Set by user, otherwise the default is used.
3041  * - decoding: Set by user, otherwise the default is used.
3042  */
3044 #define FF_THREAD_FRAME 1 ///< Decode more than one frame at once
3045 #define FF_THREAD_SLICE 2 ///< Decode more than one part of a single frame at once
3046 
3047  /**
3048  * Which multithreading methods are in use by the codec.
3049  * - encoding: Set by libavcodec.
3050  * - decoding: Set by libavcodec.
3051  */
3053 
3054  /**
3055  * Set by the client if its custom get_buffer() callback can be called
3056  * synchronously from another thread, which allows faster multithreaded decoding.
3057  * draw_horiz_band() will be called from other threads regardless of this setting.
3058  * Ignored if the default get_buffer() is used.
3059  * - encoding: Set by user.
3060  * - decoding: Set by user.
3061  */
3063 
3064  /**
3065  * The codec may call this to execute several independent things.
3066  * It will return only after finishing all tasks.
3067  * The user may replace this with some multithreaded implementation,
3068  * the default implementation will execute the parts serially.
3069  * @param count the number of things to execute
3070  * - encoding: Set by libavcodec, user can override.
3071  * - decoding: Set by libavcodec, user can override.
3072  */
3073  int (*execute)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size);
3074 
3075  /**
3076  * The codec may call this to execute several independent things.
3077  * It will return only after finishing all tasks.
3078  * The user may replace this with some multithreaded implementation,
3079  * the default implementation will execute the parts serially.
3080  * Also see avcodec_thread_init and e.g. the --enable-pthread configure option.
3081  * @param c context passed also to func
3082  * @param count the number of things to execute
3083  * @param arg2 argument passed unchanged to func
3084  * @param ret return values of executed functions, must have space for "count" values. May be NULL.
3085  * @param func function that will be called count times, with jobnr from 0 to count-1.
3086  * threadnr will be in the range 0 to c->thread_count-1 < MAX_THREADS and so that no
3087  * two instances of func executing at the same time will have the same threadnr.
3088  * @return always 0 currently, but code should handle a future improvement where when any call to func
3089  * returns < 0 no further calls to func may be done and < 0 is returned.
3090  * - encoding: Set by libavcodec, user can override.
3091  * - decoding: Set by libavcodec, user can override.
3092  */
3093  int (*execute2)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count);
3094 
3095 #if FF_API_THREAD_OPAQUE
3096  /**
3097  * @deprecated this field should not be used from outside of lavc
3098  */
3101 #endif
3102 
3103  /**
3104  * noise vs. sse weight for the nsse comparison function
3105  * - encoding: Set by user.
3106  * - decoding: unused
3107  */
3109 
3110  /**
3111  * profile
3112  * - encoding: Set by user.
3113  * - decoding: Set by libavcodec.
3114  */
3115  int profile;
3116 #define FF_PROFILE_UNKNOWN -99
3117 #define FF_PROFILE_RESERVED -100
3118 
3119 #define FF_PROFILE_AAC_MAIN 0
3120 #define FF_PROFILE_AAC_LOW 1
3121 #define FF_PROFILE_AAC_SSR 2
3122 #define FF_PROFILE_AAC_LTP 3
3123 #define FF_PROFILE_AAC_HE 4
3124 #define FF_PROFILE_AAC_HE_V2 28
3125 #define FF_PROFILE_AAC_LD 22
3126 #define FF_PROFILE_AAC_ELD 38
3127 #define FF_PROFILE_MPEG2_AAC_LOW 128
3128 #define FF_PROFILE_MPEG2_AAC_HE 131
3129 
3130 #define FF_PROFILE_DTS 20
3131 #define FF_PROFILE_DTS_ES 30
3132 #define FF_PROFILE_DTS_96_24 40
3133 #define FF_PROFILE_DTS_HD_HRA 50
3134 #define FF_PROFILE_DTS_HD_MA 60
3135 #define FF_PROFILE_DTS_EXPRESS 70
3136 
3137 #define FF_PROFILE_MPEG2_422 0
3138 #define FF_PROFILE_MPEG2_HIGH 1
3139 #define FF_PROFILE_MPEG2_SS 2
3140 #define FF_PROFILE_MPEG2_SNR_SCALABLE 3
3141 #define FF_PROFILE_MPEG2_MAIN 4
3142 #define FF_PROFILE_MPEG2_SIMPLE 5
3143 
3144 #define FF_PROFILE_H264_CONSTRAINED (1<<9) // 8+1; constraint_set1_flag
3145 #define FF_PROFILE_H264_INTRA (1<<11) // 8+3; constraint_set3_flag
3146 
3147 #define FF_PROFILE_H264_BASELINE 66
3148 #define FF_PROFILE_H264_CONSTRAINED_BASELINE (66|FF_PROFILE_H264_CONSTRAINED)
3149 #define FF_PROFILE_H264_MAIN 77
3150 #define FF_PROFILE_H264_EXTENDED 88
3151 #define FF_PROFILE_H264_HIGH 100
3152 #define FF_PROFILE_H264_HIGH_10 110
3153 #define FF_PROFILE_H264_HIGH_10_INTRA (110|FF_PROFILE_H264_INTRA)
3154 #define FF_PROFILE_H264_HIGH_422 122
3155 #define FF_PROFILE_H264_HIGH_422_INTRA (122|FF_PROFILE_H264_INTRA)
3156 #define FF_PROFILE_H264_HIGH_444 144
3157 #define FF_PROFILE_H264_HIGH_444_PREDICTIVE 244
3158 #define FF_PROFILE_H264_HIGH_444_INTRA (244|FF_PROFILE_H264_INTRA)
3159 #define FF_PROFILE_H264_CAVLC_444 44
3160 
3161 #define FF_PROFILE_VC1_SIMPLE 0
3162 #define FF_PROFILE_VC1_MAIN 1
3163 #define FF_PROFILE_VC1_COMPLEX 2
3164 #define FF_PROFILE_VC1_ADVANCED 3
3165 
3166 #define FF_PROFILE_MPEG4_SIMPLE 0
3167 #define FF_PROFILE_MPEG4_SIMPLE_SCALABLE 1
3168 #define FF_PROFILE_MPEG4_CORE 2
3169 #define FF_PROFILE_MPEG4_MAIN 3
3170 #define FF_PROFILE_MPEG4_N_BIT 4
3171 #define FF_PROFILE_MPEG4_SCALABLE_TEXTURE 5
3172 #define FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION 6
3173 #define FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE 7
3174 #define FF_PROFILE_MPEG4_HYBRID 8
3175 #define FF_PROFILE_MPEG4_ADVANCED_REAL_TIME 9
3176 #define FF_PROFILE_MPEG4_CORE_SCALABLE 10
3177 #define FF_PROFILE_MPEG4_ADVANCED_CODING 11
3178 #define FF_PROFILE_MPEG4_ADVANCED_CORE 12
3179 #define FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE 13
3180 #define FF_PROFILE_MPEG4_SIMPLE_STUDIO 14
3181 #define FF_PROFILE_MPEG4_ADVANCED_SIMPLE 15
3182 
3183 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_0 0
3184 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_1 1
3185 #define FF_PROFILE_JPEG2000_CSTREAM_NO_RESTRICTION 2
3186 #define FF_PROFILE_JPEG2000_DCINEMA_2K 3
3187 #define FF_PROFILE_JPEG2000_DCINEMA_4K 4
3188 
3189 #define FF_PROFILE_VP9_0 0
3190 #define FF_PROFILE_VP9_1 1
3191 #define FF_PROFILE_VP9_2 2
3192 #define FF_PROFILE_VP9_3 3
3193 
3194 #define FF_PROFILE_HEVC_MAIN 1
3195 #define FF_PROFILE_HEVC_MAIN_10 2
3196 #define FF_PROFILE_HEVC_MAIN_STILL_PICTURE 3
3197 #define FF_PROFILE_HEVC_REXT 4
3198 
3199  /**
3200  * level
3201  * - encoding: Set by user.
3202  * - decoding: Set by libavcodec.
3203  */
3204  int level;
3205 #define FF_LEVEL_UNKNOWN -99
3206 
3207  /**
3208  * Skip loop filtering for selected frames.
3209  * - encoding: unused
3210  * - decoding: Set by user.
3211  */
3213 
3214  /**
3215  * Skip IDCT/dequantization for selected frames.
3216  * - encoding: unused
3217  * - decoding: Set by user.
3218  */
3220 
3221  /**
3222  * Skip decoding for selected frames.
3223  * - encoding: unused
3224  * - decoding: Set by user.
3225  */
3227 
3228  /**
3229  * Header containing style information for text subtitles.
3230  * For SUBTITLE_ASS subtitle type, it should contain the whole ASS
3231  * [Script Info] and [V4+ Styles] section, plus the [Events] line and
3232  * the Format line following. It shouldn't include any Dialogue line.
3233  * - encoding: Set/allocated/freed by user (before avcodec_open2())
3234  * - decoding: Set/allocated/freed by libavcodec (by avcodec_open2())
3235  */
3238 
3239 #if FF_API_ERROR_RATE
3240  /**
3241  * @deprecated use the 'error_rate' private AVOption of the mpegvideo
3242  * encoders
3243  */
3246 #endif
3247 
3248 #if FF_API_CODEC_PKT
3249  /**
3250  * @deprecated this field is not supposed to be accessed from outside lavc
3251  */
3254 #endif
3255 
3256  /**
3257  * VBV delay coded in the last frame (in periods of a 27 MHz clock).
3258  * Used for compliant TS muxing.
3259  * - encoding: Set by libavcodec.
3260  * - decoding: unused.
3261  */
3262  uint64_t vbv_delay;
3263 
3264  /**
3265  * Encoding only. Allow encoders to output packets that do not contain any
3266  * encoded data, only side data.
3267  *
3268  * Some encoders need to output such packets, e.g. to update some stream
3269  * parameters at the end of encoding.
3270  *
3271  * All callers are strongly recommended to set this option to 1 and update
3272  * their code to deal with such packets, since this behaviour may become
3273  * always enabled in the future (then this option will be deprecated and
3274  * later removed). To avoid ABI issues when this happens, the callers should
3275  * use AVOptions to set this field.
3276  */
3278 
3279  /**
3280  * Audio only. The number of "priming" samples (padding) inserted by the
3281  * encoder at the beginning of the audio. I.e. this number of leading
3282  * decoded samples must be discarded by the caller to get the original audio
3283  * without leading padding.
3284  *
3285  * - decoding: unused
3286  * - encoding: Set by libavcodec. The timestamps on the output packets are
3287  * adjusted by the encoder so that they always refer to the
3288  * first sample of the data actually contained in the packet,
3289  * including any added padding. E.g. if the timebase is
3290  * 1/samplerate and the timestamp of the first input sample is
3291  * 0, the timestamp of the first output packet will be
3292  * -initial_padding.
3293  */
3295 
3296  /**
3297  * - decoding: For codecs that store a framerate value in the compressed
3298  * bitstream, the decoder may export it here. { 0, 1} when
3299  * unknown.
3300  * - encoding: unused
3301  */
3303 
3304  /**
3305  * Nominal unaccelerated pixel format, see AV_PIX_FMT_xxx.
3306  * - encoding: unused.
3307  * - decoding: Set by libavcodec before calling get_format()
3308  */
3310 
3311  /**
3312  * Timebase in which pkt_dts/pts and AVPacket.dts/pts are.
3313  * Code outside libavcodec should access this field using:
3314  * av_codec_{get,set}_pkt_timebase(avctx)
3315  * - encoding unused.
3316  * - decoding set by user.
3317  */
3319 
3320  /**
3321  * AVCodecDescriptor
3322  * Code outside libavcodec should access this field using:
3323  * av_codec_{get,set}_codec_descriptor(avctx)
3324  * - encoding: unused.
3325  * - decoding: set by libavcodec.
3326  */
3328 
3329 #if !FF_API_LOWRES
3330  /**
3331  * low resolution decoding, 1-> 1/2 size, 2->1/4 size
3332  * - encoding: unused
3333  * - decoding: Set by user.
3334  * Code outside libavcodec should access this field using:
3335  * av_codec_{get,set}_lowres(avctx)
3336  */
3337  int lowres;
3338 #endif
3339 
3340  /**
3341  * Current statistics for PTS correction.
3342  * - decoding: maintained and used by libavcodec, not intended to be used by user apps
3343  * - encoding: unused
3344  */
3345  int64_t pts_correction_num_faulty_pts; /// Number of incorrect PTS values so far
3346  int64_t pts_correction_num_faulty_dts; /// Number of incorrect DTS values so far
3347  int64_t pts_correction_last_pts; /// PTS of the last frame
3348  int64_t pts_correction_last_dts; /// DTS of the last frame
3349 
3350  /**
3351  * Character encoding of the input subtitles file.
3352  * - decoding: set by user
3353  * - encoding: unused
3354  */
3356 
3357  /**
3358  * Subtitles character encoding mode. Formats or codecs might be adjusting
3359  * this setting (if they are doing the conversion themselves for instance).
3360  * - decoding: set by libavcodec
3361  * - encoding: unused
3362  */
3364 #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)
3365 #define FF_SUB_CHARENC_MODE_AUTOMATIC 0 ///< libavcodec will select the mode itself
3366 #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
3367 
3368  /**
3369  * Skip processing alpha if supported by codec.
3370  * Note that if the format uses pre-multiplied alpha (common with VP6,
3371  * and recommended due to better video quality/compression)
3372  * the image will look as if alpha-blended onto a black background.
3373  * However for formats that do not use pre-multiplied alpha
3374  * there might be serious artefacts (though e.g. libswscale currently
3375  * assumes pre-multiplied alpha anyway).
3376  * Code outside libavcodec should access this field using AVOptions
3377  *
3378  * - decoding: set by user
3379  * - encoding: unused
3380  */
3382 
3383  /**
3384  * Number of samples to skip after a discontinuity
3385  * - decoding: unused
3386  * - encoding: set by libavcodec
3387  */
3389 
3390 #if !FF_API_DEBUG_MV
3391  /**
3392  * debug motion vectors
3393  * Code outside libavcodec should access this field using AVOptions
3394  * - encoding: Set by user.
3395  * - decoding: Set by user.
3396  */
3397  int debug_mv;
3398 #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 //visualize forward predicted MVs of P frames
3399 #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 //visualize forward predicted MVs of B frames
3400 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
3401 #endif
3402 
3403  /**
3404  * custom intra quantization matrix
3405  * Code outside libavcodec should access this field using av_codec_g/set_chroma_intra_matrix()
3406  * - encoding: Set by user, can be NULL.
3407  * - decoding: unused.
3408  */
3410 
3411  /**
3412  * dump format separator.
3413  * can be ", " or "\n " or anything else
3414  * Code outside libavcodec should access this field using AVOptions
3415  * (NO direct access).
3416  * - encoding: Set by user.
3417  * - decoding: Set by user.
3418  */
3420 
3421  /**
3422  * ',' separated list of allowed decoders.
3423  * If NULL then all are allowed
3424  * - encoding: unused
3425  * - decoding: set by user through AVOPtions (NO direct access)
3426  */
3428 
3429  /*
3430  * Properties of the stream that gets decoded
3431  * To be accessed through av_codec_get_properties() (NO direct access)
3432  * - encoding: unused
3433  * - decoding: set by libavcodec
3434  */
3435  unsigned properties;
3436 #define FF_CODEC_PROPERTY_LOSSLESS 0x00000001
3437 #define FF_CODEC_PROPERTY_CLOSED_CAPTIONS 0x00000002
3438 } AVCodecContext;
3439 
3442 
3445 
3446 unsigned av_codec_get_codec_properties(const AVCodecContext *avctx);
3447 
3448 int av_codec_get_lowres(const AVCodecContext *avctx);
3449 void av_codec_set_lowres(AVCodecContext *avctx, int val);
3450 
3451 int av_codec_get_seek_preroll(const AVCodecContext *avctx);
3452 void av_codec_set_seek_preroll(AVCodecContext *avctx, int val);
3453 
3454 uint16_t *av_codec_get_chroma_intra_matrix(const AVCodecContext *avctx);
3455 void av_codec_set_chroma_intra_matrix(AVCodecContext *avctx, uint16_t *val);
3456 
3457 /**
3458  * AVProfile.
3459  */
3460 typedef struct AVProfile {
3461  int profile;
3462  const char *name; ///< short name for the profile
3463 } AVProfile;
3464 
3465 typedef struct AVCodecDefault AVCodecDefault;
3466 
3467 struct AVSubtitle;
3468 
3469 /**
3470  * AVCodec.
3471  */
3472 typedef struct AVCodec {
3473  /**
3474  * Name of the codec implementation.
3475  * The name is globally unique among encoders and among decoders (but an
3476  * encoder and a decoder can share the same name).
3477  * This is the primary way to find a codec from the user perspective.
3478  */
3479  const char *name;
3480  /**
3481  * Descriptive name for the codec, meant to be more human readable than name.
3482  * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
3483  */
3484  const char *long_name;
3487  /**
3488  * Codec capabilities.
3489  * see AV_CODEC_CAP_*
3490  */
3492  const AVRational *supported_framerates; ///< array of supported framerates, or NULL if any, array is terminated by {0,0}
3493  const enum AVPixelFormat *pix_fmts; ///< array of supported pixel formats, or NULL if unknown, array is terminated by -1
3494  const int *supported_samplerates; ///< array of supported audio samplerates, or NULL if unknown, array is terminated by 0
3495  const enum AVSampleFormat *sample_fmts; ///< array of supported sample formats, or NULL if unknown, array is terminated by -1
3496  const uint64_t *channel_layouts; ///< array of support channel layouts, or NULL if unknown. array is terminated by 0
3497  uint8_t max_lowres; ///< maximum value for lowres supported by the decoder, no direct access, use av_codec_get_max_lowres()
3498  const AVClass *priv_class; ///< AVClass for the private context
3499  const AVProfile *profiles; ///< array of recognized profiles, or NULL if unknown, array is terminated by {FF_PROFILE_UNKNOWN}
3500 
3501  /*****************************************************************
3502  * No fields below this line are part of the public API. They
3503  * may not be used outside of libavcodec and can be changed and
3504  * removed at will.
3505  * New public fields should be added right above.
3506  *****************************************************************
3507  */
3509  struct AVCodec *next;
3510  /**
3511  * @name Frame-level threading support functions
3512  * @{
3513  */
3514  /**
3515  * If defined, called on thread contexts when they are created.
3516  * If the codec allocates writable tables in init(), re-allocate them here.
3517  * priv_data will be set to a copy of the original.
3518  */
3520  /**
3521  * Copy necessary context variables from a previous thread context to the current one.
3522  * If not defined, the next thread will start automatically; otherwise, the codec
3523  * must call ff_thread_finish_setup().
3524  *
3525  * dst and src will (rarely) point to the same context, in which case memcpy should be skipped.
3526  */
3528  /** @} */
3529 
3530  /**
3531  * Private codec-specific defaults.
3532  */
3534 
3535  /**
3536  * Initialize codec static data, called from avcodec_register().
3537  */
3538  void (*init_static_data)(struct AVCodec *codec);
3539 
3541  int (*encode_sub)(AVCodecContext *, uint8_t *buf, int buf_size,
3542  const struct AVSubtitle *sub);
3543  /**
3544  * Encode data to an AVPacket.
3545  *
3546  * @param avctx codec context
3547  * @param avpkt output AVPacket (may contain a user-provided buffer)
3548  * @param[in] frame AVFrame containing the raw data to be encoded
3549  * @param[out] got_packet_ptr encoder sets to 0 or 1 to indicate that a
3550  * non-empty packet was returned in avpkt.
3551  * @return 0 on success, negative error code on failure
3552  */
3553  int (*encode2)(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame,
3554  int *got_packet_ptr);
3555  int (*decode)(AVCodecContext *, void *outdata, int *outdata_size, AVPacket *avpkt);
3557  /**
3558  * Flush buffers.
3559  * Will be called when seeking
3560  */
3562  /**
3563  * Internal codec capabilities.
3564  * See FF_CODEC_CAP_* in internal.h
3565  */
3567 } AVCodec;
3568 
3569 int av_codec_get_max_lowres(const AVCodec *codec);
3570 
3571 struct MpegEncContext;
3572 
3573 /**
3574  * @defgroup lavc_hwaccel AVHWAccel
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 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  struct AVHWAccel *next;
3620 
3621  /**
3622  * Allocate a custom buffer
3623  */
3625 
3626  /**
3627  * Called at the beginning of each frame or field picture.
3628  *
3629  * Meaningful frame information (codec specific) is guaranteed to
3630  * be parsed at this point. This function is mandatory.
3631  *
3632  * Note that buf can be NULL along with buf_size set to 0.
3633  * Otherwise, this means the whole frame is available at this point.
3634  *
3635  * @param avctx the codec context
3636  * @param buf the frame data buffer base
3637  * @param buf_size the size of the frame in bytes
3638  * @return zero if successful, a negative value otherwise
3639  */
3640  int (*start_frame)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3641 
3642  /**
3643  * Callback for each slice.
3644  *
3645  * Meaningful slice information (codec specific) is guaranteed to
3646  * be parsed at this point. This function is mandatory.
3647  * The only exception is XvMC, that works on MB level.
3648  *
3649  * @param avctx the codec context
3650  * @param buf the slice data buffer base
3651  * @param buf_size the size of the slice in bytes
3652  * @return zero if successful, a negative value otherwise
3653  */
3654  int (*decode_slice)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3655 
3656  /**
3657  * Called at the end of each frame or field picture.
3658  *
3659  * The whole picture is parsed at this point and can now be sent
3660  * to the hardware accelerator. This function is mandatory.
3661  *
3662  * @param avctx the codec context
3663  * @return zero if successful, a negative value otherwise
3664  */
3665  int (*end_frame)(AVCodecContext *avctx);
3666 
3667  /**
3668  * Size of per-frame hardware accelerator private data.
3669  *
3670  * Private data is allocated with av_mallocz() before
3671  * AVCodecContext.get_buffer() and deallocated after
3672  * AVCodecContext.release_buffer().
3673  */
3675 
3676  /**
3677  * Called for every Macroblock in a slice.
3678  *
3679  * XvMC uses it to replace the ff_mpv_decode_mb().
3680  * Instead of decoding to raw picture, MB parameters are
3681  * stored in an array provided by the video driver.
3682  *
3683  * @param s the mpeg context
3684  */
3686 
3687  /**
3688  * Initialize the hwaccel private data.
3689  *
3690  * This will be called from ff_get_format(), after hwaccel and
3691  * hwaccel_context are set and the hwaccel private data in AVCodecInternal
3692  * is allocated.
3693  */
3695 
3696  /**
3697  * Uninitialize the hwaccel private data.
3698  *
3699  * This will be called from get_format() or avcodec_close(), after hwaccel
3700  * and hwaccel_context are already uninitialized.
3701  */
3703 
3704  /**
3705  * Size of the private data to allocate in
3706  * AVCodecInternal.hwaccel_priv_data.
3707  */
3709 } AVHWAccel;
3710 
3711 /**
3712  * Hardware acceleration should be used for decoding even if the codec level
3713  * used is unknown or higher than the maximum supported level reported by the
3714  * hardware driver.
3715  *
3716  * It's generally a good idea to pass this flag unless you have a specific
3717  * reason not to, as hardware tends to under-report supported levels.
3718  */
3719 #define AV_HWACCEL_FLAG_IGNORE_LEVEL (1 << 0)
3720 
3721 /**
3722  * Hardware acceleration can output YUV pixel formats with a different chroma
3723  * sampling than 4:2:0 and/or other than 8 bits per component.
3724  */
3725 #define AV_HWACCEL_FLAG_ALLOW_HIGH_DEPTH (1 << 1)
3726 
3727 /**
3728  * @}
3729  */
3730 
3731 /**
3732  * @defgroup lavc_picture AVPicture
3733  *
3734  * Functions for working with AVPicture
3735  * @{
3736  */
3737 
3738 /**
3739  * Picture data structure.
3740  *
3741  * Up to four components can be stored into it, the last component is
3742  * alpha.
3743  */
3744 typedef struct AVPicture {
3745  uint8_t *data[AV_NUM_DATA_POINTERS]; ///< pointers to the image data planes
3746  int linesize[AV_NUM_DATA_POINTERS]; ///< number of bytes per line
3747 } AVPicture;
3748 
3749 /**
3750  * @}
3751  */
3752 
3755 
3756  SUBTITLE_BITMAP, ///< A bitmap, pict will be set
3757 
3758  /**
3759  * Plain text, the text field must be set by the decoder and is
3760  * authoritative. ass and pict fields may contain approximations.
3761  */
3763 
3764  /**
3765  * Formatted text, the ass field must be set by the decoder and is
3766  * authoritative. pict and text fields may contain approximations.
3767  */
3769 };
3770 
3771 #define AV_SUBTITLE_FLAG_FORCED 0x00000001
3772 
3773 typedef struct AVSubtitleRect {
3774  int x; ///< top left corner of pict, undefined when pict is not set
3775  int y; ///< top left corner of pict, undefined when pict is not set
3776  int w; ///< width of pict, undefined when pict is not set
3777  int h; ///< height of pict, undefined when pict is not set
3778  int nb_colors; ///< number of colors in pict, undefined when pict is not set
3779 
3780  /**
3781  * data+linesize for the bitmap of this subtitle.
3782  * can be set for text/ass as well once they are rendered
3783  */
3786 
3787  char *text; ///< 0 terminated plain UTF-8 text
3788 
3789  /**
3790  * 0 terminated ASS/SSA compatible event line.
3791  * The presentation of this is unaffected by the other values in this
3792  * struct.
3793  */
3794  char *ass;
3795 
3796  int flags;
3797 } AVSubtitleRect;
3798 
3799 typedef struct AVSubtitle {
3800  uint16_t format; /* 0 = graphics */
3801  uint32_t start_display_time; /* relative to packet pts, in ms */
3802  uint32_t end_display_time; /* relative to packet pts, in ms */
3803  unsigned num_rects;
3805  int64_t pts; ///< Same as packet pts, in AV_TIME_BASE
3806 } AVSubtitle;
3807 
3808 /**
3809  * If c is NULL, returns the first registered codec,
3810  * if c is non-NULL, returns the next registered codec after c,
3811  * or NULL if c is the last one.
3812  */
3813 AVCodec *av_codec_next(const AVCodec *c);
3814 
3815 /**
3816  * Return the LIBAVCODEC_VERSION_INT constant.
3817  */
3818 unsigned avcodec_version(void);
3819 
3820 /**
3821  * Return the libavcodec build-time configuration.
3822  */
3823 const char *avcodec_configuration(void);
3824 
3825 /**
3826  * Return the libavcodec license.
3827  */
3828 const char *avcodec_license(void);
3829 
3830 /**
3831  * Register the codec codec and initialize libavcodec.
3832  *
3833  * @warning either this function or avcodec_register_all() must be called
3834  * before any other libavcodec functions.
3835  *
3836  * @see avcodec_register_all()
3837  */
3838 void avcodec_register(AVCodec *codec);
3839 
3840 /**
3841  * Register all the codecs, parsers and bitstream filters which were enabled at
3842  * configuration time. If you do not call this function you can select exactly
3843  * which formats you want to support, by using the individual registration
3844  * functions.
3845  *
3846  * @see avcodec_register
3847  * @see av_register_codec_parser
3848  * @see av_register_bitstream_filter
3849  */
3850 void avcodec_register_all(void);
3851 
3852 /**
3853  * Allocate an AVCodecContext and set its fields to default values. The
3854  * resulting struct should be freed with avcodec_free_context().
3855  *
3856  * @param codec if non-NULL, allocate private data and initialize defaults
3857  * for the given codec. It is illegal to then call avcodec_open2()
3858  * with a different codec.
3859  * If NULL, then the codec-specific defaults won't be initialized,
3860  * which may result in suboptimal default settings (this is
3861  * important mainly for encoders, e.g. libx264).
3862  *
3863  * @return An AVCodecContext filled with default values or NULL on failure.
3864  * @see avcodec_get_context_defaults
3865  */
3867 
3868 /**
3869  * Free the codec context and everything associated with it and write NULL to
3870  * the provided pointer.
3871  */
3872 void avcodec_free_context(AVCodecContext **avctx);
3873 
3874 /**
3875  * Set the fields of the given AVCodecContext to default values corresponding
3876  * to the given codec (defaults may be codec-dependent).
3877  *
3878  * Do not call this function if a non-NULL codec has been passed
3879  * to avcodec_alloc_context3() that allocated this AVCodecContext.
3880  * If codec is non-NULL, it is illegal to call avcodec_open2() with a
3881  * different codec on this AVCodecContext.
3882  */
3884 
3885 /**
3886  * Get the AVClass for AVCodecContext. It can be used in combination with
3887  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
3888  *
3889  * @see av_opt_find().
3890  */
3891 const AVClass *avcodec_get_class(void);
3892 
3893 /**
3894  * Get the AVClass for AVFrame. It can be used in combination with
3895  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
3896  *
3897  * @see av_opt_find().
3898  */
3899 const AVClass *avcodec_get_frame_class(void);
3900 
3901 /**
3902  * Get the AVClass for AVSubtitleRect. It can be used in combination with
3903  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
3904  *
3905  * @see av_opt_find().
3906  */
3908 
3909 /**
3910  * Copy the settings of the source AVCodecContext into the destination
3911  * AVCodecContext. The resulting destination codec context will be
3912  * unopened, i.e. you are required to call avcodec_open2() before you
3913  * can use this AVCodecContext to decode/encode video/audio data.
3914  *
3915  * @param dest target codec context, should be initialized with
3916  * avcodec_alloc_context3(NULL), but otherwise uninitialized
3917  * @param src source codec context
3918  * @return AVERROR() on error (e.g. memory allocation error), 0 on success
3919  */
3921 
3922 #if FF_API_AVFRAME_LAVC
3923 /**
3924  * @deprecated use av_frame_alloc()
3925  */
3928 
3929 /**
3930  * Set the fields of the given AVFrame to default values.
3931  *
3932  * @param frame The AVFrame of which the fields should be set to default values.
3933  *
3934  * @deprecated use av_frame_unref()
3935  */
3938 
3939 /**
3940  * Free the frame and any dynamically allocated objects in it,
3941  * e.g. extended_data.
3942  *
3943  * @param frame frame to be freed. The pointer will be set to NULL.
3944  *
3945  * @warning this function does NOT free the data buffers themselves
3946  * (it does not know how, since they might have been allocated with
3947  * a custom get_buffer()).
3948  *
3949  * @deprecated use av_frame_free()
3950  */
3953 #endif
3954 
3955 /**
3956  * Initialize the AVCodecContext to use the given AVCodec. Prior to using this
3957  * function the context has to be allocated with avcodec_alloc_context3().
3958  *
3959  * The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(),
3960  * avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for
3961  * retrieving a codec.
3962  *
3963  * @warning This function is not thread safe!
3964  *
3965  * @note Always call this function before using decoding routines (such as
3966  * @ref avcodec_decode_video2()).
3967  *
3968  * @code
3969  * avcodec_register_all();
3970  * av_dict_set(&opts, "b", "2.5M", 0);
3971  * codec = avcodec_find_decoder(AV_CODEC_ID_H264);
3972  * if (!codec)
3973  * exit(1);
3974  *
3975  * context = avcodec_alloc_context3(codec);
3976  *
3977  * if (avcodec_open2(context, codec, opts) < 0)
3978  * exit(1);
3979  * @endcode
3980  *
3981  * @param avctx The context to initialize.
3982  * @param codec The codec to open this context for. If a non-NULL codec has been
3983  * previously passed to avcodec_alloc_context3() or
3984  * avcodec_get_context_defaults3() for this context, then this
3985  * parameter MUST be either NULL or equal to the previously passed
3986  * codec.
3987  * @param options A dictionary filled with AVCodecContext and codec-private options.
3988  * On return this object will be filled with options that were not found.
3989  *
3990  * @return zero on success, a negative value on error
3991  * @see avcodec_alloc_context3(), avcodec_find_decoder(), avcodec_find_encoder(),
3992  * av_dict_set(), av_opt_find().
3993  */
3994 int avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options);
3995 
3996 /**
3997  * Close a given AVCodecContext and free all the data associated with it
3998  * (but not the AVCodecContext itself).
3999  *
4000  * Calling this function on an AVCodecContext that hasn't been opened will free
4001  * the codec-specific data allocated in avcodec_alloc_context3() /
4002  * avcodec_get_context_defaults3() with a non-NULL codec. Subsequent calls will
4003  * do nothing.
4004  */
4005 int avcodec_close(AVCodecContext *avctx);
4006 
4007 /**
4008  * Free all allocated data in the given subtitle struct.
4009  *
4010  * @param sub AVSubtitle to free.
4011  */
4012 void avsubtitle_free(AVSubtitle *sub);
4013 
4014 /**
4015  * @}
4016  */
4017 
4018 /**
4019  * @addtogroup lavc_packet
4020  * @{
4021  */
4022 
4023 #if FF_API_DESTRUCT_PACKET
4024 /**
4025  * Default packet destructor.
4026  * @deprecated use the AVBuffer API instead
4027  */
4030 #endif
4031 
4032 /**
4033  * Initialize optional fields of a packet with default values.
4034  *
4035  * Note, this does not touch the data and size members, which have to be
4036  * initialized separately.
4037  *
4038  * @param pkt packet
4039  */
4040 void av_init_packet(AVPacket *pkt);
4041 
4042 /**
4043  * Allocate the payload of a packet and initialize its fields with
4044  * default values.
4045  *
4046  * @param pkt packet
4047  * @param size wanted payload size
4048  * @return 0 if OK, AVERROR_xxx otherwise
4049  */
4050 int av_new_packet(AVPacket *pkt, int size);
4051 
4052 /**
4053  * Reduce packet size, correctly zeroing padding
4054  *
4055  * @param pkt packet
4056  * @param size new size
4057  */
4058 void av_shrink_packet(AVPacket *pkt, int size);
4059 
4060 /**
4061  * Increase packet size, correctly zeroing padding
4062  *
4063  * @param pkt packet
4064  * @param grow_by number of bytes by which to increase the size of the packet
4065  */
4066 int av_grow_packet(AVPacket *pkt, int grow_by);
4067 
4068 /**
4069  * Initialize a reference-counted packet from av_malloc()ed data.
4070  *
4071  * @param pkt packet to be initialized. This function will set the data, size,
4072  * buf and destruct fields, all others are left untouched.
4073  * @param data Data allocated by av_malloc() to be used as packet data. If this
4074  * function returns successfully, the data is owned by the underlying AVBuffer.
4075  * The caller may not access the data through other means.
4076  * @param size size of data in bytes, without the padding. I.e. the full buffer
4077  * size is assumed to be size + AV_INPUT_BUFFER_PADDING_SIZE.
4078  *
4079  * @return 0 on success, a negative AVERROR on error
4080  */
4082 
4083 /**
4084  * @warning This is a hack - the packet memory allocation stuff is broken. The
4085  * packet is allocated if it was not really allocated.
4086  */
4087 int av_dup_packet(AVPacket *pkt);
4088 
4089 /**
4090  * Copy packet, including contents
4091  *
4092  * @return 0 on success, negative AVERROR on fail
4093  */
4094 int av_copy_packet(AVPacket *dst, const AVPacket *src);
4095 
4096 /**
4097  * Copy packet side data
4098  *
4099  * @return 0 on success, negative AVERROR on fail
4100  */
4101 int av_copy_packet_side_data(AVPacket *dst, const AVPacket *src);
4102 
4103 /**
4104  * Free a packet.
4105  *
4106  * @param pkt packet to free
4107  */
4108 void av_free_packet(AVPacket *pkt);
4109 
4110 /**
4111  * Allocate new information of a packet.
4112  *
4113  * @param pkt packet
4114  * @param type side information type
4115  * @param size side information size
4116  * @return pointer to fresh allocated data or NULL otherwise
4117  */
4119  int size);
4120 
4121 /**
4122  * Shrink the already allocated side data buffer
4123  *
4124  * @param pkt packet
4125  * @param type side information type
4126  * @param size new side information size
4127  * @return 0 on success, < 0 on failure
4128  */
4130  int size);
4131 
4132 /**
4133  * Get side information from packet.
4134  *
4135  * @param pkt packet
4136  * @param type desired side information type
4137  * @param size pointer for side information size to store (optional)
4138  * @return pointer to data if present or NULL otherwise
4139  */
4141  int *size);
4142 
4144 
4146 
4148 
4149 /**
4150  * Pack a dictionary for use in side_data.
4151  *
4152  * @param dict The dictionary to pack.
4153  * @param size pointer to store the size of the returned data
4154  * @return pointer to data if successful, NULL otherwise
4155  */
4157 /**
4158  * Unpack a dictionary from side_data.
4159  *
4160  * @param data data from side_data
4161  * @param size size of the data
4162  * @param dict the metadata storage dictionary
4163  * @return 0 on success, < 0 on failure
4164  */
4165 int av_packet_unpack_dictionary(const uint8_t *data, int size, AVDictionary **dict);
4166 
4167 
4168 /**
4169  * Convenience function to free all the side data stored.
4170  * All the other fields stay untouched.
4171  *
4172  * @param pkt packet
4173  */
4175 
4176 /**
4177  * Setup a new reference to the data described by a given packet
4178  *
4179  * If src is reference-counted, setup dst as a new reference to the
4180  * buffer in src. Otherwise allocate a new buffer in dst and copy the
4181  * data from src into it.
4182  *
4183  * All the other fields are copied from src.
4184  *
4185  * @see av_packet_unref
4186  *
4187  * @param dst Destination packet
4188  * @param src Source packet
4189  *
4190  * @return 0 on success, a negative AVERROR on error.
4191  */
4192 int av_packet_ref(AVPacket *dst, const AVPacket *src);
4193 
4194 /**
4195  * Wipe the packet.
4196  *
4197  * Unreference the buffer referenced by the packet and reset the
4198  * remaining packet fields to their default values.
4199  *
4200  * @param pkt The packet to be unreferenced.
4201  */
4203 
4204 /**
4205  * Move every field in src to dst and reset src.
4206  *
4207  * @see av_packet_unref
4208  *
4209  * @param src Source packet, will be reset
4210  * @param dst Destination packet
4211  */
4213 
4214 /**
4215  * Copy only "properties" fields from src to dst.
4216  *
4217  * Properties for the purpose of this function are all the fields
4218  * beside those related to the packet data (buf, data, size)
4219  *
4220  * @param dst Destination packet
4221  * @param src Source packet
4222  *
4223  * @return 0 on success AVERROR on failure.
4224  *
4225  */
4226 int av_packet_copy_props(AVPacket *dst, const AVPacket *src);
4227 
4228 /**
4229  * Convert valid timing fields (timestamps / durations) in a packet from one
4230  * timebase to another. Timestamps with unknown values (AV_NOPTS_VALUE) will be
4231  * ignored.
4232  *
4233  * @param pkt packet on which the conversion will be performed
4234  * @param tb_src source timebase, in which the timing fields in pkt are
4235  * expressed
4236  * @param tb_dst destination timebase, to which the timing fields will be
4237  * converted
4238  */
4239 void av_packet_rescale_ts(AVPacket *pkt, AVRational tb_src, AVRational tb_dst);
4240 
4241 /**
4242  * @}
4243  */
4244 
4245 /**
4246  * @addtogroup lavc_decoding
4247  * @{
4248  */
4249 
4250 /**
4251  * Find a registered decoder with a matching codec ID.
4252  *
4253  * @param id AVCodecID of the requested decoder
4254  * @return A decoder if one was found, NULL otherwise.
4255  */
4257 
4258 /**
4259  * Find a registered decoder with the specified name.
4260  *
4261  * @param name name of the requested decoder
4262  * @return A decoder if one was found, NULL otherwise.
4263  */
4265 
4266 #if FF_API_GET_BUFFER
4270 #endif
4271 
4272 /**
4273  * The default callback for AVCodecContext.get_buffer2(). It is made public so
4274  * it can be called by custom get_buffer2() implementations for decoders without
4275  * AV_CODEC_CAP_DR1 set.
4276  */
4278 
4279 #if FF_API_EMU_EDGE
4280 /**
4281  * Return the amount of padding in pixels which the get_buffer callback must
4282  * provide around the edge of the image for codecs which do not have the
4283  * CODEC_FLAG_EMU_EDGE flag.
4284  *
4285  * @return Required padding in pixels.
4286  *
4287  * @deprecated CODEC_FLAG_EMU_EDGE is deprecated, so this function is no longer
4288  * needed
4289  */
4291 unsigned avcodec_get_edge_width(void);
4292 #endif
4293 
4294 /**
4295  * Modify width and height values so that they will result in a memory
4296  * buffer that is acceptable for the codec if you do not use any horizontal
4297  * padding.
4298  *
4299  * May only be used if a codec with AV_CODEC_CAP_DR1 has been opened.
4300  */
4302 
4303 /**
4304  * Modify width and height values so that they will result in a memory
4305  * buffer that is acceptable for the codec if you also ensure that all
4306  * line sizes are a multiple of the respective linesize_align[i].
4307  *
4308  * May only be used if a codec with AV_CODEC_CAP_DR1 has been opened.
4309  */
4311  int linesize_align[AV_NUM_DATA_POINTERS]);
4312 
4313 /**
4314  * Converts AVChromaLocation to swscale x/y chroma position.
4315  *
4316  * The positions represent the chroma (0,0) position in a coordinates system
4317  * with luma (0,0) representing the origin and luma(1,1) representing 256,256
4318  *
4319  * @param xpos horizontal chroma sample position
4320  * @param ypos vertical chroma sample position
4321  */
4322 int avcodec_enum_to_chroma_pos(int *xpos, int *ypos, enum AVChromaLocation pos);
4323 
4324 /**
4325  * Converts swscale x/y chroma position to AVChromaLocation.
4326  *
4327  * The positions represent the chroma (0,0) position in a coordinates system
4328  * with luma (0,0) representing the origin and luma(1,1) representing 256,256
4329  *
4330  * @param xpos horizontal chroma sample position
4331  * @param ypos vertical chroma sample position
4332  */
4333 enum AVChromaLocation avcodec_chroma_pos_to_enum(int xpos, int ypos);
4334 
4335 #if FF_API_OLD_DECODE_AUDIO
4336 /**
4337  * Wrapper function which calls avcodec_decode_audio4.
4338  *
4339  * @deprecated Use avcodec_decode_audio4 instead.
4340  *
4341  * Decode the audio frame of size avpkt->size from avpkt->data into samples.
4342  * Some decoders may support multiple frames in a single AVPacket, such
4343  * decoders would then just decode the first frame. In this case,
4344  * avcodec_decode_audio3 has to be called again with an AVPacket that contains
4345  * the remaining data in order to decode the second frame etc.
4346  * If no frame
4347  * could be outputted, frame_size_ptr is zero. Otherwise, it is the
4348  * decompressed frame size in bytes.
4349  *
4350  * @warning You must set frame_size_ptr to the allocated size of the
4351  * output buffer before calling avcodec_decode_audio3().
4352  *
4353  * @warning The input buffer must be FF_INPUT_BUFFER_PADDING_SIZE larger than
4354  * the actual read bytes because some optimized bitstream readers read 32 or 64
4355  * bits at once and could read over the end.
4356  *
4357  * @warning The end of the input buffer avpkt->data should be set to 0 to ensure that
4358  * no overreading happens for damaged MPEG streams.
4359  *
4360  * @warning You must not provide a custom get_buffer() when using
4361  * avcodec_decode_audio3(). Doing so will override it with
4362  * avcodec_default_get_buffer. Use avcodec_decode_audio4() instead,
4363  * which does allow the application to provide a custom get_buffer().
4364  *
4365  * @note You might have to align the input buffer avpkt->data and output buffer
4366  * samples. The alignment requirements depend on the CPU: On some CPUs it isn't
4367  * necessary at all, on others it won't work at all if not aligned and on others
4368  * it will work but it will have an impact on performance.
4369  *
4370  * In practice, avpkt->data should have 4 byte alignment at minimum and
4371  * samples should be 16 byte aligned unless the CPU doesn't need it
4372  * (AltiVec and SSE do).
4373  *
4374  * @note Codecs which have the CODEC_CAP_DELAY capability set have a delay
4375  * between input and output, these need to be fed with avpkt->data=NULL,
4376  * avpkt->size=0 at the end to return the remaining frames.
4377  *
4378  * @param avctx the codec context
4379  * @param[out] samples the output buffer, sample type in avctx->sample_fmt
4380  * If the sample format is planar, each channel plane will
4381  * be the same size, with no padding between channels.
4382  * @param[in,out] frame_size_ptr the output buffer size in bytes
4383  * @param[in] avpkt The input AVPacket containing the input buffer.
4384  * You can create such packet with av_init_packet() and by then setting
4385  * data and size, some decoders might in addition need other fields.
4386  * All decoders are designed to use the least fields possible though.
4387  * @return On error a negative value is returned, otherwise the number of bytes
4388  * used or zero if no frame data was decompressed (used) from the input AVPacket.
4389  */
4390 attribute_deprecated int avcodec_decode_audio3(AVCodecContext *avctx, int16_t *samples,
4391  int *frame_size_ptr,
4392  AVPacket *avpkt);
4393 #endif
4394 
4395 /**
4396  * Decode the audio frame of size avpkt->size from avpkt->data into frame.
4397  *
4398  * Some decoders may support multiple frames in a single AVPacket. Such
4399  * decoders would then just decode the first frame and the return value would be
4400  * less than the packet size. In this case, avcodec_decode_audio4 has to be
4401  * called again with an AVPacket containing the remaining data in order to
4402  * decode the second frame, etc... Even if no frames are returned, the packet
4403  * needs to be fed to the decoder with remaining data until it is completely
4404  * consumed or an error occurs.
4405  *
4406  * Some decoders (those marked with AV_CODEC_CAP_DELAY) have a delay between input
4407  * and output. This means that for some packets they will not immediately
4408  * produce decoded output and need to be flushed at the end of decoding to get
4409  * all the decoded data. Flushing is done by calling this function with packets
4410  * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
4411  * returning samples. It is safe to flush even those decoders that are not
4412  * marked with AV_CODEC_CAP_DELAY, then no samples will be returned.
4413  *
4414  * @warning The input buffer, avpkt->data must be AV_INPUT_BUFFER_PADDING_SIZE
4415  * larger than the actual read bytes because some optimized bitstream
4416  * readers read 32 or 64 bits at once and could read over the end.
4417  *
4418  * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
4419  * before packets may be fed to the decoder.
4420  *
4421  * @param avctx the codec context
4422  * @param[out] frame The AVFrame in which to store decoded audio samples.
4423  * The decoder will allocate a buffer for the decoded frame by
4424  * calling the AVCodecContext.get_buffer2() callback.
4425  * When AVCodecContext.refcounted_frames is set to 1, the frame is
4426  * reference counted and the returned reference belongs to the
4427  * caller. The caller must release the frame using av_frame_unref()
4428  * when the frame is no longer needed. The caller may safely write
4429  * to the frame if av_frame_is_writable() returns 1.
4430  * When AVCodecContext.refcounted_frames is set to 0, the returned
4431  * reference belongs to the decoder and is valid only until the
4432  * next call to this function or until closing or flushing the
4433  * decoder. The caller may not write to it.
4434  * @param[out] got_frame_ptr Zero if no frame could be decoded, otherwise it is
4435  * non-zero. Note that this field being set to zero
4436  * does not mean that an error has occurred. For
4437  * decoders with AV_CODEC_CAP_DELAY set, no given decode
4438  * call is guaranteed to produce a frame.
4439  * @param[in] avpkt The input AVPacket containing the input buffer.
4440  * At least avpkt->data and avpkt->size should be set. Some
4441  * decoders might also require additional fields to be set.
4442  * @return A negative error code is returned if an error occurred during
4443  * decoding, otherwise the number of bytes consumed from the input
4444  * AVPacket is returned.
4445  */
4447  int *got_frame_ptr, const AVPacket *avpkt);
4448 
4449 /**
4450  * Decode the video frame of size avpkt->size from avpkt->data into picture.
4451  * Some decoders may support multiple frames in a single AVPacket, such
4452  * decoders would then just decode the first frame.
4453  *
4454  * @warning The input buffer must be AV_INPUT_BUFFER_PADDING_SIZE larger than
4455  * the actual read bytes because some optimized bitstream readers read 32 or 64
4456  * bits at once and could read over the end.
4457  *
4458  * @warning The end of the input buffer buf should be set to 0 to ensure that
4459  * no overreading happens for damaged MPEG streams.
4460  *
4461  * @note Codecs which have the AV_CODEC_CAP_DELAY capability set have a delay
4462  * between input and output, these need to be fed with avpkt->data=NULL,
4463  * avpkt->size=0 at the end to return the remaining frames.
4464  *
4465  * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
4466  * before packets may be fed to the decoder.
4467  *
4468  * @param avctx the codec context
4469  * @param[out] picture The AVFrame in which the decoded video frame will be stored.
4470  * Use av_frame_alloc() to get an AVFrame. The codec will
4471  * allocate memory for the actual bitmap by calling the
4472  * AVCodecContext.get_buffer2() callback.
4473  * When AVCodecContext.refcounted_frames is set to 1, the frame is
4474  * reference counted and the returned reference belongs to the
4475  * caller. The caller must release the frame using av_frame_unref()
4476  * when the frame is no longer needed. The caller may safely write
4477  * to the frame if av_frame_is_writable() returns 1.
4478  * When AVCodecContext.refcounted_frames is set to 0, the returned
4479  * reference belongs to the decoder and is valid only until the
4480  * next call to this function or until closing or flushing the
4481  * decoder. The caller may not write to it.
4482  *
4483  * @param[in] avpkt The input AVPacket containing the input buffer.
4484  * You can create such packet with av_init_packet() and by then setting
4485  * data and size, some decoders might in addition need other fields like
4486  * flags&AV_PKT_FLAG_KEY. All decoders are designed to use the least
4487  * fields possible.
4488  * @param[in,out] got_picture_ptr Zero if no frame could be decompressed, otherwise, it is nonzero.
4489  * @return On error a negative value is returned, otherwise the number of bytes
4490  * used or zero if no frame could be decompressed.
4491  */
4492 int avcodec_decode_video2(AVCodecContext *avctx, AVFrame *picture,
4493  int *got_picture_ptr,
4494  const AVPacket *avpkt);
4495 
4496 /**
4497  * Decode a subtitle message.
4498  * Return a negative value on error, otherwise return the number of bytes used.
4499  * If no subtitle could be decompressed, got_sub_ptr is zero.
4500  * Otherwise, the subtitle is stored in *sub.
4501  * Note that AV_CODEC_CAP_DR1 is not available for subtitle codecs. This is for
4502  * simplicity, because the performance difference is expect to be negligible
4503  * and reusing a get_buffer written for video codecs would probably perform badly
4504  * due to a potentially very different allocation pattern.
4505  *
4506  * Some decoders (those marked with CODEC_CAP_DELAY) have a delay between input
4507  * and output. This means that for some packets they will not immediately
4508  * produce decoded output and need to be flushed at the end of decoding to get
4509  * all the decoded data. Flushing is done by calling this function with packets
4510  * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
4511  * returning subtitles. It is safe to flush even those decoders that are not
4512  * marked with CODEC_CAP_DELAY, then no subtitles will be returned.
4513  *
4514  * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
4515  * before packets may be fed to the decoder.
4516  *
4517  * @param avctx the codec context
4518  * @param[out] sub The Preallocated AVSubtitle in which the decoded subtitle will be stored,
4519  * must be freed with avsubtitle_free if *got_sub_ptr is set.
4520  * @param[in,out] got_sub_ptr Zero if no subtitle could be decompressed, otherwise, it is nonzero.
4521  * @param[in] avpkt The input AVPacket containing the input buffer.
4522  */
4524  int *got_sub_ptr,
4525  AVPacket *avpkt);
4526 
4527 /**
4528  * @defgroup lavc_parsing Frame parsing
4529  * @{
4530  */
4531 
4534  AV_PICTURE_STRUCTURE_TOP_FIELD, //< coded as top field
4535  AV_PICTURE_STRUCTURE_BOTTOM_FIELD, //< coded as bottom field
4536  AV_PICTURE_STRUCTURE_FRAME, //< coded as frame
4537 };
4538 
4539 typedef struct AVCodecParserContext {
4540  void *priv_data;
4542  int64_t frame_offset; /* offset of the current frame */
4543  int64_t cur_offset; /* current offset
4544  (incremented by each av_parser_parse()) */
4545  int64_t next_frame_offset; /* offset of the next frame */
4546  /* video info */
4547  int pict_type; /* XXX: Put it back in AVCodecContext. */
4548  /**
4549  * This field is used for proper frame duration computation in lavf.
4550  * It signals, how much longer the frame duration of the current frame
4551  * is compared to normal frame duration.
4552  *
4553  * frame_duration = (1 + repeat_pict) * time_base
4554  *
4555  * It is used by codecs like H.264 to display telecined material.
4556  */
4557  int repeat_pict; /* XXX: Put it back in AVCodecContext. */
4558  int64_t pts; /* pts of the current frame */
4559  int64_t dts; /* dts of the current frame */
4560 
4561  /* private data */
4562  int64_t last_pts;
4563  int64_t last_dts;
4565 
4566 #define AV_PARSER_PTS_NB 4
4571 
4572  int flags;
4573 #define PARSER_FLAG_COMPLETE_FRAMES 0x0001
4574 #define PARSER_FLAG_ONCE 0x0002
4575 /// Set if the parser has a valid file offset
4576 #define PARSER_FLAG_FETCHED_OFFSET 0x0004
4577 #define PARSER_FLAG_USE_CODEC_TS 0x1000
4578 
4579  int64_t offset; ///< byte offset from starting packet start
4581 
4582  /**
4583  * Set by parser to 1 for key frames and 0 for non-key frames.
4584  * It is initialized to -1, so if the parser doesn't set this flag,
4585  * old-style fallback using AV_PICTURE_TYPE_I picture type as key frames
4586  * will be used.
4587  */
4589 
4590  /**
4591  * Time difference in stream time base units from the pts of this
4592  * packet to the point at which the output from the decoder has converged
4593  * independent from the availability of previous frames. That is, the
4594  * frames are virtually identical no matter if decoding started from
4595  * the very first frame or from this keyframe.
4596  * Is AV_NOPTS_VALUE if unknown.
4597  * This field is not the display duration of the current frame.
4598  * This field has no meaning if the packet does not have AV_PKT_FLAG_KEY
4599  * set.
4600  *
4601  * The purpose of this field is to allow seeking in streams that have no
4602  * keyframes in the conventional sense. It corresponds to the
4603  * recovery point SEI in H.264 and match_time_delta in NUT. It is also
4604  * essential for some types of subtitle streams to ensure that all
4605  * subtitles are correctly displayed after seeking.
4606  */
4608 
4609  // Timestamp generation support:
4610  /**
4611  * Synchronization point for start of timestamp generation.
4612  *
4613  * Set to >0 for sync point, 0 for no sync point and <0 for undefined
4614  * (default).
4615  *
4616  * For example, this corresponds to presence of H.264 buffering period
4617  * SEI message.
4618  */
4620 
4621  /**
4622  * Offset of the current timestamp against last timestamp sync point in
4623  * units of AVCodecContext.time_base.
4624  *
4625  * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
4626  * contain a valid timestamp offset.
4627  *
4628  * Note that the timestamp of sync point has usually a nonzero
4629  * dts_ref_dts_delta, which refers to the previous sync point. Offset of
4630  * the next frame after timestamp sync point will be usually 1.
4631  *
4632  * For example, this corresponds to H.264 cpb_removal_delay.
4633  */
4635 
4636  /**
4637  * Presentation delay of current frame in units of AVCodecContext.time_base.
4638  *
4639  * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
4640  * contain valid non-negative timestamp delta (presentation time of a frame
4641  * must not lie in the past).
4642  *
4643  * This delay represents the difference between decoding and presentation
4644  * time of the frame.
4645  *
4646  * For example, this corresponds to H.264 dpb_output_delay.
4647  */
4649 
4650  /**
4651  * Position of the packet in file.
4652  *
4653  * Analogous to cur_frame_pts/dts
4654  */
4656 
4657  /**
4658  * Byte position of currently parsed frame in stream.
4659  */
4660  int64_t pos;
4661 
4662  /**
4663  * Previous frame byte position.
4664  */
4665  int64_t last_pos;
4666 
4667  /**
4668  * Duration of the current frame.
4669  * For audio, this is in units of 1 / AVCodecContext.sample_rate.
4670  * For all other types, this is in units of AVCodecContext.time_base.
4671  */
4673 
4675 
4676  /**
4677  * Indicate whether a picture is coded as a frame, top field or bottom field.
4678  *
4679  * For example, H.264 field_pic_flag equal to 0 corresponds to
4680  * AV_PICTURE_STRUCTURE_FRAME. An H.264 picture with field_pic_flag
4681  * equal to 1 and bottom_field_flag equal to 0 corresponds to
4682  * AV_PICTURE_STRUCTURE_TOP_FIELD.
4683  */
4685 
4686  /**
4687  * Picture number incremented in presentation or output order.
4688  * This field may be reinitialized at the first picture of a new sequence.
4689  *
4690  * For example, this corresponds to H.264 PicOrderCnt.
4691  */
4693 
4694  /**
4695  * Dimensions of the decoded video intended for presentation.
4696  */
4697  int width;
4698  int height;
4699 
4700  /**
4701  * Dimensions of the coded video.
4702  */
4705 
4706  /**
4707  * The format of the coded data, corresponds to enum AVPixelFormat for video
4708  * and for enum AVSampleFormat for audio.
4709  *
4710  * Note that a decoder can have considerable freedom in how exactly it
4711  * decodes the data, so the format reported here might be different from the
4712  * one returned by a decoder.
4713  */
4714  int format;
4716 
4717 typedef struct AVCodecParser {
4718  int codec_ids[5]; /* several codec IDs are permitted */
4721  /* This callback never returns an error, a negative value means that
4722  * the frame start was in a previous packet. */
4724  AVCodecContext *avctx,
4725  const uint8_t **poutbuf, int *poutbuf_size,
4726  const uint8_t *buf, int buf_size);
4728  int (*split)(AVCodecContext *avctx, const uint8_t *buf, int buf_size);
4730 } AVCodecParser;
4731 
4733 
4736 
4737 /**
4738  * Parse a packet.
4739  *
4740  * @param s parser context.
4741  * @param avctx codec context.
4742  * @param poutbuf set to pointer to parsed buffer or NULL if not yet finished.
4743  * @param poutbuf_size set to size of parsed buffer or zero if not yet finished.
4744  * @param buf input buffer.
4745  * @param buf_size input length, to signal EOF, this should be 0 (so that the last frame can be output).
4746  * @param pts input presentation timestamp.
4747  * @param dts input decoding timestamp.
4748  * @param pos input byte position in stream.
4749  * @return the number of bytes of the input bitstream used.
4750  *
4751  * Example:
4752  * @code
4753  * while(in_len){
4754  * len = av_parser_parse2(myparser, AVCodecContext, &data, &size,
4755  * in_data, in_len,
4756  * pts, dts, pos);
4757  * in_data += len;
4758  * in_len -= len;
4759  *
4760  * if(size)
4761  * decode_frame(data, size);
4762  * }
4763  * @endcode
4764  */
4766  AVCodecContext *avctx,
4767  uint8_t **poutbuf, int *poutbuf_size,
4768  const uint8_t *buf, int buf_size,
4769  int64_t pts, int64_t dts,
4770  int64_t pos);
4771 
4772 /**
4773  * @return 0 if the output buffer is a subset of the input, 1 if it is allocated and must be freed
4774  * @deprecated use AVBitStreamFilter
4775  */
4777  AVCodecContext *avctx,
4778  uint8_t **poutbuf, int *poutbuf_size,
4779  const uint8_t *buf, int buf_size, int keyframe);
4781 
4782 /**
4783  * @}
4784  * @}
4785  */
4786 
4787 /**
4788  * @addtogroup lavc_encoding
4789  * @{
4790  */
4791 
4792 /**
4793  * Find a registered encoder with a matching codec ID.
4794  *
4795  * @param id AVCodecID of the requested encoder
4796  * @return An encoder if one was found, NULL otherwise.
4797  */
4799 
4800 /**
4801  * Find a registered encoder with the specified name.
4802  *
4803  * @param name name of the requested encoder
4804  * @return An encoder if one was found, NULL otherwise.
4805  */
4807 
4808 #if FF_API_OLD_ENCODE_AUDIO
4809 /**
4810  * Encode an audio frame from samples into buf.
4811  *
4812  * @deprecated Use avcodec_encode_audio2 instead.
4813  *
4814  * @note The output buffer should be at least FF_MIN_BUFFER_SIZE bytes large.
4815  * However, for codecs with avctx->frame_size equal to 0 (e.g. PCM) the user
4816  * will know how much space is needed because it depends on the value passed
4817  * in buf_size as described below. In that case a lower value can be used.
4818  *
4819  * @param avctx the codec context
4820  * @param[out] buf the output buffer
4821  * @param[in] buf_size the output buffer size
4822  * @param[in] samples the input buffer containing the samples
4823  * The number of samples read from this buffer is frame_size*channels,
4824  * both of which are defined in avctx.
4825  * For codecs which have avctx->frame_size equal to 0 (e.g. PCM) the number of
4826  * samples read from samples is equal to:
4827  * buf_size * 8 / (avctx->channels * av_get_bits_per_sample(avctx->codec_id))
4828  * This also implies that av_get_bits_per_sample() must not return 0 for these
4829  * codecs.
4830  * @return On error a negative value is returned, on success zero or the number
4831  * of bytes used to encode the data read from the input buffer.
4832  */
4834  uint8_t *buf, int buf_size,
4835  const short *samples);
4836 #endif
4837 
4838 /**
4839  * Encode a frame of audio.
4840  *
4841  * Takes input samples from frame and writes the next output packet, if
4842  * available, to avpkt. The output packet does not necessarily contain data for
4843  * the most recent frame, as encoders can delay, split, and combine input frames
4844  * internally as needed.
4845  *
4846  * @param avctx codec context
4847  * @param avpkt output AVPacket.
4848  * The user can supply an output buffer by setting
4849  * avpkt->data and avpkt->size prior to calling the
4850  * function, but if the size of the user-provided data is not
4851  * large enough, encoding will fail. If avpkt->data and
4852  * avpkt->size are set, avpkt->destruct must also be set. All
4853  * other AVPacket fields will be reset by the encoder using
4854  * av_init_packet(). If avpkt->data is NULL, the encoder will
4855  * allocate it. The encoder will set avpkt->size to the size
4856  * of the output packet.
4857  *
4858  * If this function fails or produces no output, avpkt will be
4859  * freed using av_free_packet() (i.e. avpkt->destruct will be
4860  * called to free the user supplied buffer).
4861  * @param[in] frame AVFrame containing the raw audio data to be encoded.
4862  * May be NULL when flushing an encoder that has the
4863  * AV_CODEC_CAP_DELAY capability set.
4864  * If AV_CODEC_CAP_VARIABLE_FRAME_SIZE is set, then each frame
4865  * can have any number of samples.
4866  * If it is not set, frame->nb_samples must be equal to
4867  * avctx->frame_size for all frames except the last.
4868  * The final frame may be smaller than avctx->frame_size.
4869  * @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
4870  * output packet is non-empty, and to 0 if it is
4871  * empty. If the function returns an error, the
4872  * packet can be assumed to be invalid, and the
4873  * value of got_packet_ptr is undefined and should
4874  * not be used.
4875  * @return 0 on success, negative error code on failure
4876  */
4877 int avcodec_encode_audio2(AVCodecContext *avctx, AVPacket *avpkt,
4878  const AVFrame *frame, int *got_packet_ptr);
4879 
4880 #if FF_API_OLD_ENCODE_VIDEO
4881 /**
4882  * @deprecated use avcodec_encode_video2() instead.
4883  *
4884  * Encode a video frame from pict into buf.
4885  * The input picture should be
4886  * stored using a specific format, namely avctx.pix_fmt.
4887  *
4888  * @param avctx the codec context
4889  * @param[out] buf the output buffer for the bitstream of encoded frame
4890  * @param[in] buf_size the size of the output buffer in bytes
4891  * @param[in] pict the input picture to encode
4892  * @return On error a negative value is returned, on success zero or the number
4893  * of bytes used from the output buffer.
4894  */
4896 int avcodec_encode_video(AVCodecContext *avctx, uint8_t *buf, int buf_size,
4897  const AVFrame *pict);
4898 #endif
4899 
4900 /**
4901  * Encode a frame of video.
4902  *
4903  * Takes input raw video data from frame and writes the next output packet, if
4904  * available, to avpkt. The output packet does not necessarily contain data for
4905  * the most recent frame, as encoders can delay and reorder input frames
4906  * internally as needed.
4907  *
4908  * @param avctx codec context
4909  * @param avpkt output AVPacket.
4910  * The user can supply an output buffer by setting
4911  * avpkt->data and avpkt->size prior to calling the
4912  * function, but if the size of the user-provided data is not
4913  * large enough, encoding will fail. All other AVPacket fields
4914  * will be reset by the encoder using av_init_packet(). If
4915  * avpkt->data is NULL, the encoder will allocate it.
4916  * The encoder will set avpkt->size to the size of the
4917  * output packet. The returned data (if any) belongs to the
4918  * caller, he is responsible for freeing it.
4919  *
4920  * If this function fails or produces no output, avpkt will be
4921  * freed using av_free_packet() (i.e. avpkt->destruct will be
4922  * called to free the user supplied buffer).
4923  * @param[in] frame AVFrame containing the raw video data to be encoded.
4924  * May be NULL when flushing an encoder that has the
4925  * AV_CODEC_CAP_DELAY capability set.
4926  * @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
4927  * output packet is non-empty, and to 0 if it is
4928  * empty. If the function returns an error, the
4929  * packet can be assumed to be invalid, and the
4930  * value of got_packet_ptr is undefined and should
4931  * not be used.
4932  * @return 0 on success, negative error code on failure
4933  */
4934 int avcodec_encode_video2(AVCodecContext *avctx, AVPacket *avpkt,
4935  const AVFrame *frame, int *got_packet_ptr);
4936 
4937 int avcodec_encode_subtitle(AVCodecContext *avctx, uint8_t *buf, int buf_size,
4938  const AVSubtitle *sub);
4939 
4940 
4941 /**
4942  * @}
4943  */
4944 
4945 #if FF_API_AVCODEC_RESAMPLE
4946 /**
4947  * @defgroup lavc_resample Audio resampling
4948  * @ingroup libavc
4949  * @deprecated use libswresample instead
4950  *
4951  * @{
4952  */
4953 struct ReSampleContext;
4954 struct AVResampleContext;
4955 
4956 typedef struct ReSampleContext ReSampleContext;
4957 
4958 /**
4959  * Initialize audio resampling context.
4960  *
4961  * @param output_channels number of output channels
4962  * @param input_channels number of input channels
4963  * @param output_rate output sample rate
4964  * @param input_rate input sample rate
4965  * @param sample_fmt_out requested output sample format
4966  * @param sample_fmt_in input sample format
4967  * @param filter_length length of each FIR filter in the filterbank relative to the cutoff frequency
4968  * @param log2_phase_count log2 of the number of entries in the polyphase filterbank
4969  * @param linear if 1 then the used FIR filter will be linearly interpolated
4970  between the 2 closest, if 0 the closest will be used
4971  * @param cutoff cutoff frequency, 1.0 corresponds to half the output sampling rate
4972  * @return allocated ReSampleContext, NULL if error occurred
4973  */
4976  int output_rate, int input_rate,
4977  enum AVSampleFormat sample_fmt_out,
4978  enum AVSampleFormat sample_fmt_in,
4979  int filter_length, int log2_phase_count,
4980  int linear, double cutoff);
4981 
4983 int audio_resample(ReSampleContext *s, short *output, short *input, int nb_samples);
4984 
4985 /**
4986  * Free resample context.
4987  *
4988  * @param s a non-NULL pointer to a resample context previously
4989  * created with av_audio_resample_init()
4990  */
4993 
4994 
4995 /**
4996  * Initialize an audio resampler.
4997  * Note, if either rate is not an integer then simply scale both rates up so they are.
4998  * @param filter_length length of each FIR filter in the filterbank relative to the cutoff freq
4999  * @param log2_phase_count log2 of the number of entries in the polyphase filterbank
5000  * @param linear If 1 then the used FIR filter will be linearly interpolated
5001  between the 2 closest, if 0 the closest will be used
5002  * @param cutoff cutoff frequency, 1.0 corresponds to half the output sampling rate
5003  */
5005 struct AVResampleContext *av_resample_init(int out_rate, int in_rate, int filter_length, int log2_phase_count, int linear, double cutoff);
5006 
5007 /**
5008  * Resample an array of samples using a previously configured context.
5009  * @param src an array of unconsumed samples
5010  * @param consumed the number of samples of src which have been consumed are returned here
5011  * @param src_size the number of unconsumed samples available
5012  * @param dst_size the amount of space in samples available in dst
5013  * @param update_ctx If this is 0 then the context will not be modified, that way several channels can be resampled with the same context.
5014  * @return the number of samples written in dst or -1 if an error occurred
5015  */
5017 int av_resample(struct AVResampleContext *c, short *dst, short *src, int *consumed, int src_size, int dst_size, int update_ctx);
5018 
5019 
5020 /**
5021  * Compensate samplerate/timestamp drift. The compensation is done by changing
5022  * the resampler parameters, so no audible clicks or similar distortions occur
5023  * @param compensation_distance distance in output samples over which the compensation should be performed
5024  * @param sample_delta number of output samples which should be output less
5025  *
5026  * example: av_resample_compensate(c, 10, 500)
5027  * here instead of 510 samples only 500 samples would be output
5028  *
5029  * note, due to rounding the actual compensation might be slightly different,