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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 */
293 
294  AV_CODEC_ID_BRENDER_PIX= MKBETAG('B','P','I','X'),
295  AV_CODEC_ID_Y41P = MKBETAG('Y','4','1','P'),
296  AV_CODEC_ID_ESCAPE130 = MKBETAG('E','1','3','0'),
297  AV_CODEC_ID_EXR = MKBETAG('0','E','X','R'),
298  AV_CODEC_ID_AVRP = MKBETAG('A','V','R','P'),
299 
300  AV_CODEC_ID_012V = MKBETAG('0','1','2','V'),
301  AV_CODEC_ID_G2M = MKBETAG( 0 ,'G','2','M'),
302  AV_CODEC_ID_AVUI = MKBETAG('A','V','U','I'),
303  AV_CODEC_ID_AYUV = MKBETAG('A','Y','U','V'),
304  AV_CODEC_ID_TARGA_Y216 = MKBETAG('T','2','1','6'),
305  AV_CODEC_ID_V308 = MKBETAG('V','3','0','8'),
306  AV_CODEC_ID_V408 = MKBETAG('V','4','0','8'),
307  AV_CODEC_ID_YUV4 = MKBETAG('Y','U','V','4'),
308  AV_CODEC_ID_SANM = MKBETAG('S','A','N','M'),
309  AV_CODEC_ID_PAF_VIDEO = MKBETAG('P','A','F','V'),
310  AV_CODEC_ID_AVRN = MKBETAG('A','V','R','n'),
311  AV_CODEC_ID_CPIA = MKBETAG('C','P','I','A'),
312  AV_CODEC_ID_XFACE = MKBETAG('X','F','A','C'),
313  AV_CODEC_ID_SGIRLE = MKBETAG('S','G','I','R'),
314  AV_CODEC_ID_MVC1 = MKBETAG('M','V','C','1'),
315  AV_CODEC_ID_MVC2 = MKBETAG('M','V','C','2'),
316  AV_CODEC_ID_SNOW = MKBETAG('S','N','O','W'),
317  AV_CODEC_ID_WEBP = MKBETAG('W','E','B','P'),
318  AV_CODEC_ID_SMVJPEG = MKBETAG('S','M','V','J'),
319  AV_CODEC_ID_HEVC = MKBETAG('H','2','6','5'),
320 #define AV_CODEC_ID_H265 AV_CODEC_ID_HEVC
321  AV_CODEC_ID_VP7 = MKBETAG('V','P','7','0'),
322  AV_CODEC_ID_APNG = MKBETAG('A','P','N','G'),
323 
324  /* various PCM "codecs" */
325  AV_CODEC_ID_FIRST_AUDIO = 0x10000, ///< A dummy id pointing at the start of audio codecs
359 
360  /* various ADPCM codecs */
392  AV_CODEC_ID_ADPCM_VIMA = MKBETAG('V','I','M','A'),
393  AV_CODEC_ID_VIMA = MKBETAG('V','I','M','A'),
394  AV_CODEC_ID_ADPCM_AFC = MKBETAG('A','F','C',' '),
395  AV_CODEC_ID_ADPCM_IMA_OKI = MKBETAG('O','K','I',' '),
396  AV_CODEC_ID_ADPCM_DTK = MKBETAG('D','T','K',' '),
397  AV_CODEC_ID_ADPCM_IMA_RAD = MKBETAG('R','A','D',' '),
398  AV_CODEC_ID_ADPCM_G726LE = MKBETAG('6','2','7','G'),
399 
400  /* AMR */
403 
404  /* RealAudio codecs*/
407 
408  /* various DPCM codecs */
413 
414  /* audio codecs */
415  AV_CODEC_ID_MP2 = 0x15000,
416  AV_CODEC_ID_MP3, ///< preferred ID for decoding MPEG audio layer 1, 2 or 3
433  AV_CODEC_ID_GSM, ///< as in Berlin toast format
445  AV_CODEC_ID_GSM_MS, /* as found in WAV */
447 #if FF_API_VOXWARE
449 #endif
484  AV_CODEC_ID_FFWAVESYNTH = MKBETAG('F','F','W','S'),
485  AV_CODEC_ID_SONIC = MKBETAG('S','O','N','C'),
486  AV_CODEC_ID_SONIC_LS = MKBETAG('S','O','N','L'),
487  AV_CODEC_ID_PAF_AUDIO = MKBETAG('P','A','F','A'),
488  AV_CODEC_ID_OPUS = MKBETAG('O','P','U','S'),
489  AV_CODEC_ID_TAK = MKBETAG('t','B','a','K'),
490  AV_CODEC_ID_EVRC = MKBETAG('s','e','v','c'),
491  AV_CODEC_ID_SMV = MKBETAG('s','s','m','v'),
492  AV_CODEC_ID_DSD_LSBF = MKBETAG('D','S','D','L'),
493  AV_CODEC_ID_DSD_MSBF = MKBETAG('D','S','D','M'),
496 
497  /* subtitle codecs */
498  AV_CODEC_ID_FIRST_SUBTITLE = 0x17000, ///< A dummy ID pointing at the start of subtitle codecs.
501  AV_CODEC_ID_TEXT, ///< raw UTF-8 text
508  AV_CODEC_ID_MICRODVD = MKBETAG('m','D','V','D'),
509  AV_CODEC_ID_EIA_608 = MKBETAG('c','6','0','8'),
510  AV_CODEC_ID_JACOSUB = MKBETAG('J','S','U','B'),
511  AV_CODEC_ID_SAMI = MKBETAG('S','A','M','I'),
512  AV_CODEC_ID_REALTEXT = MKBETAG('R','T','X','T'),
513  AV_CODEC_ID_STL = MKBETAG('S','p','T','L'),
514  AV_CODEC_ID_SUBVIEWER1 = MKBETAG('S','b','V','1'),
515  AV_CODEC_ID_SUBVIEWER = MKBETAG('S','u','b','V'),
516  AV_CODEC_ID_SUBRIP = MKBETAG('S','R','i','p'),
517  AV_CODEC_ID_WEBVTT = MKBETAG('W','V','T','T'),
518  AV_CODEC_ID_MPL2 = MKBETAG('M','P','L','2'),
519  AV_CODEC_ID_VPLAYER = MKBETAG('V','P','l','r'),
520  AV_CODEC_ID_PJS = MKBETAG('P','h','J','S'),
521  AV_CODEC_ID_ASS = MKBETAG('A','S','S',' '), ///< ASS as defined in Matroska
522 
523  /* other specific kind of codecs (generally used for attachments) */
524  AV_CODEC_ID_FIRST_UNKNOWN = 0x18000, ///< A dummy ID pointing at the start of various fake codecs.
525  AV_CODEC_ID_TTF = 0x18000,
526  AV_CODEC_ID_BINTEXT = MKBETAG('B','T','X','T'),
527  AV_CODEC_ID_XBIN = MKBETAG('X','B','I','N'),
528  AV_CODEC_ID_IDF = MKBETAG( 0 ,'I','D','F'),
529  AV_CODEC_ID_OTF = MKBETAG( 0 ,'O','T','F'),
530  AV_CODEC_ID_SMPTE_KLV = MKBETAG('K','L','V','A'),
531  AV_CODEC_ID_DVD_NAV = MKBETAG('D','N','A','V'),
532  AV_CODEC_ID_TIMED_ID3 = MKBETAG('T','I','D','3'),
533  AV_CODEC_ID_BIN_DATA = MKBETAG('D','A','T','A'),
534 
535 
536  AV_CODEC_ID_PROBE = 0x19000, ///< codec_id is not known (like AV_CODEC_ID_NONE) but lavf should attempt to identify it
537 
538  AV_CODEC_ID_MPEG2TS = 0x20000, /**< _FAKE_ codec to indicate a raw MPEG-2 TS
539  * stream (only used by libavformat) */
540  AV_CODEC_ID_MPEG4SYSTEMS = 0x20001, /**< _FAKE_ codec to indicate a MPEG-4 Systems
541  * stream (only used by libavformat) */
542  AV_CODEC_ID_FFMETADATA = 0x21000, ///< Dummy codec for streams containing only metadata information.
543 
544 #if FF_API_CODEC_ID
545 #include "old_codec_ids.h"
546 #endif
547 };
548 
549 /**
550  * This struct describes the properties of a single codec described by an
551  * AVCodecID.
552  * @see avcodec_descriptor_get()
553  */
554 typedef struct AVCodecDescriptor {
555  enum AVCodecID id;
557  /**
558  * Name of the codec described by this descriptor. It is non-empty and
559  * unique for each codec descriptor. It should contain alphanumeric
560  * characters and '_' only.
561  */
562  const char *name;
563  /**
564  * A more descriptive name for this codec. May be NULL.
565  */
566  const char *long_name;
567  /**
568  * Codec properties, a combination of AV_CODEC_PROP_* flags.
569  */
570  int props;
571 
572  /**
573  * MIME type(s) associated with the codec.
574  * May be NULL; if not, a NULL-terminated array of MIME types.
575  * The first item is always non-NULL and is the preferred MIME type.
576  */
577  const char *const *mime_types;
580 /**
581  * Codec uses only intra compression.
582  * Video codecs only.
583  */
584 #define AV_CODEC_PROP_INTRA_ONLY (1 << 0)
585 /**
586  * Codec supports lossy compression. Audio and video codecs only.
587  * @note a codec may support both lossy and lossless
588  * compression modes
589  */
590 #define AV_CODEC_PROP_LOSSY (1 << 1)
591 /**
592  * Codec supports lossless compression. Audio and video codecs only.
593  */
594 #define AV_CODEC_PROP_LOSSLESS (1 << 2)
595 /**
596  * Codec supports frame reordering. That is, the coded order (the order in which
597  * the encoded packets are output by the encoders / stored / input to the
598  * decoders) may be different from the presentation order of the corresponding
599  * frames.
600  *
601  * For codecs that do not have this property set, PTS and DTS should always be
602  * equal.
603  */
604 #define AV_CODEC_PROP_REORDER (1 << 3)
605 /**
606  * Subtitle codec is bitmap based
607  * Decoded AVSubtitle data can be read from the AVSubtitleRect->pict field.
608  */
609 #define AV_CODEC_PROP_BITMAP_SUB (1 << 16)
610 /**
611  * Subtitle codec is text based.
612  * Decoded AVSubtitle data can be read from the AVSubtitleRect->ass field.
613  */
614 #define AV_CODEC_PROP_TEXT_SUB (1 << 17)
616 /**
617  * @ingroup lavc_decoding
618  * Required number of additionally allocated bytes at the end of the input bitstream for decoding.
619  * This is mainly needed because some optimized bitstream readers read
620  * 32 or 64 bit at once and could read over the end.<br>
621  * Note: If the first 23 bits of the additional bytes are not 0, then damaged
622  * MPEG bitstreams could cause overread and segfault.
623  */
624 #define FF_INPUT_BUFFER_PADDING_SIZE 32
626 /**
627  * @ingroup lavc_encoding
628  * minimum encoding buffer size
629  * Used to avoid some checks during header writing.
630  */
631 #define FF_MIN_BUFFER_SIZE 16384
634 /**
635  * @ingroup lavc_encoding
636  * motion estimation type.
637  */
639  ME_ZERO = 1, ///< no search, that is use 0,0 vector whenever one is needed
643  ME_EPZS, ///< enhanced predictive zonal search
644  ME_X1, ///< reserved for experiments
645  ME_HEX, ///< hexagon based search
646  ME_UMH, ///< uneven multi-hexagon search
647  ME_TESA, ///< transformed exhaustive search algorithm
648  ME_ITER=50, ///< iterative search
649 };
651 /**
652  * @ingroup lavc_decoding
653  */
655  /* We leave some space between them for extensions (drop some
656  * keyframes for intra-only or drop just some bidir frames). */
657  AVDISCARD_NONE =-16, ///< discard nothing
658  AVDISCARD_DEFAULT = 0, ///< discard useless packets like 0 size packets in avi
659  AVDISCARD_NONREF = 8, ///< discard all non reference
660  AVDISCARD_BIDIR = 16, ///< discard all bidirectional frames
661  AVDISCARD_NONINTRA= 24, ///< discard all non intra frames
662  AVDISCARD_NONKEY = 32, ///< discard all frames except keyframes
663  AVDISCARD_ALL = 48, ///< discard all
664 };
676  AV_AUDIO_SERVICE_TYPE_NB , ///< Not part of ABI
677 };
679 /**
680  * @ingroup lavc_encoding
681  */
682 typedef struct RcOverride{
685  int qscale; // If this is 0 then quality_factor will be used instead.
689 #if FF_API_MAX_BFRAMES
690 /**
691  * @deprecated there is no libavcodec-wide limit on the number of B-frames
692  */
693 #define FF_MAX_B_FRAMES 16
694 #endif
696 /* encoding support
697  These flags can be passed in AVCodecContext.flags before initialization.
698  Note: Not everything is supported yet.
699 */
701 /**
702  * Allow decoders to produce frames with data planes that are not aligned
703  * to CPU requirements (e.g. due to cropping).
704  */
705 #define CODEC_FLAG_UNALIGNED 0x0001
706 #define CODEC_FLAG_QSCALE 0x0002 ///< Use fixed qscale.
707 #define CODEC_FLAG_4MV 0x0004 ///< 4 MV per MB allowed / advanced prediction for H.263.
708 #define CODEC_FLAG_OUTPUT_CORRUPT 0x0008 ///< Output even those frames that might be corrupted
709 #define CODEC_FLAG_QPEL 0x0010 ///< Use qpel MC.
710 #if FF_API_GMC
711 /**
712  * @deprecated use the "gmc" private option of the libxvid encoder
713  */
714 #define CODEC_FLAG_GMC 0x0020 ///< Use GMC.
715 #endif
716 #if FF_API_MV0
717 /**
718  * @deprecated use the flag "mv0" in the "mpv_flags" private option of the
719  * mpegvideo encoders
720  */
721 #define CODEC_FLAG_MV0 0x0040
722 #endif
723 #if FF_API_INPUT_PRESERVED
724 /**
725  * @deprecated passing reference-counted frames to the encoders replaces this
726  * flag
727  */
728 #define CODEC_FLAG_INPUT_PRESERVED 0x0100
729 #endif
730 #define CODEC_FLAG_PASS1 0x0200 ///< Use internal 2pass ratecontrol in first pass mode.
731 #define CODEC_FLAG_PASS2 0x0400 ///< Use internal 2pass ratecontrol in second pass mode.
732 #define CODEC_FLAG_GRAY 0x2000 ///< Only decode/encode grayscale.
733 #if FF_API_EMU_EDGE
734 /**
735  * @deprecated edges are not used/required anymore. I.e. this flag is now always
736  * set.
737  */
738 #define CODEC_FLAG_EMU_EDGE 0x4000
739 #endif
740 #define CODEC_FLAG_PSNR 0x8000 ///< error[?] variables will be set during encoding.
741 #define CODEC_FLAG_TRUNCATED 0x00010000 /** Input bitstream might be truncated at a random
742  location instead of only at frame boundaries. */
743 #if FF_API_NORMALIZE_AQP
744 /**
745  * @deprecated use the flag "naq" in the "mpv_flags" private option of the
746  * mpegvideo encoders
747  */
748 #define CODEC_FLAG_NORMALIZE_AQP 0x00020000
749 #endif
750 #define CODEC_FLAG_INTERLACED_DCT 0x00040000 ///< Use interlaced DCT.
751 #define CODEC_FLAG_LOW_DELAY 0x00080000 ///< Force low delay.
752 #define CODEC_FLAG_GLOBAL_HEADER 0x00400000 ///< Place global headers in extradata instead of every keyframe.
753 #define CODEC_FLAG_BITEXACT 0x00800000 ///< Use only bitexact stuff (except (I)DCT).
754 /* Fx : Flag for h263+ extra options */
755 #define CODEC_FLAG_AC_PRED 0x01000000 ///< H.263 advanced intra coding / MPEG-4 AC prediction
756 #define CODEC_FLAG_LOOP_FILTER 0x00000800 ///< loop filter
757 #define CODEC_FLAG_INTERLACED_ME 0x20000000 ///< interlaced motion estimation
758 #define CODEC_FLAG_CLOSED_GOP 0x80000000
759 #define CODEC_FLAG2_FAST 0x00000001 ///< Allow non spec compliant speedup tricks.
760 #define CODEC_FLAG2_NO_OUTPUT 0x00000004 ///< Skip bitstream encoding.
761 #define CODEC_FLAG2_LOCAL_HEADER 0x00000008 ///< Place global headers at every keyframe instead of in extradata.
762 #define CODEC_FLAG2_DROP_FRAME_TIMECODE 0x00002000 ///< timecode is in drop frame format. DEPRECATED!!!!
763 #define CODEC_FLAG2_IGNORE_CROP 0x00010000 ///< Discard cropping information from SPS.
765 #define CODEC_FLAG2_CHUNKS 0x00008000 ///< Input bitstream might be truncated at a packet boundaries instead of only at frame boundaries.
766 #define CODEC_FLAG2_SHOW_ALL 0x00400000 ///< Show all frames before the first keyframe
767 #define CODEC_FLAG2_EXPORT_MVS 0x10000000 ///< Export motion vectors through frame side data
768 #define CODEC_FLAG2_SKIP_MANUAL 0x20000000 ///< Do not skip samples and export skip information as frame side data
770 /* Unsupported options :
771  * Syntax Arithmetic coding (SAC)
772  * Reference Picture Selection
773  * Independent Segment Decoding */
774 /* /Fx */
775 /* codec capabilities */
777 #define CODEC_CAP_DRAW_HORIZ_BAND 0x0001 ///< Decoder can use draw_horiz_band callback.
778 /**
779  * Codec uses get_buffer() for allocating buffers and supports custom allocators.
780  * If not set, it might not use get_buffer() at all or use operations that
781  * assume the buffer was allocated by avcodec_default_get_buffer.
782  */
783 #define CODEC_CAP_DR1 0x0002
784 #define CODEC_CAP_TRUNCATED 0x0008
785 #if FF_API_XVMC
786 /* Codec can export data for HW decoding. This flag indicates that
787  * the codec would call get_format() with list that might contain HW accelerated
788  * pixel formats (XvMC, VDPAU, VAAPI, etc). The application can pick any of them
789  * including raw image format.
790  * The application can use the passed context to determine bitstream version,
791  * chroma format, resolution etc.
792  */
793 #define CODEC_CAP_HWACCEL 0x0010
794 #endif /* FF_API_XVMC */
795 /**
796  * Encoder or decoder requires flushing with NULL input at the end in order to
797  * give the complete and correct output.
798  *
799  * NOTE: If this flag is not set, the codec is guaranteed to never be fed with
800  * with NULL data. The user can still send NULL data to the public encode
801  * or decode function, but libavcodec will not pass it along to the codec
802  * unless this flag is set.
803  *
804  * Decoders:
805  * The decoder has a non-zero delay and needs to be fed with avpkt->data=NULL,
806  * avpkt->size=0 at the end to get the delayed data until the decoder no longer
807  * returns frames.
808  *
809  * Encoders:
810  * The encoder needs to be fed with NULL data at the end of encoding until the
811  * encoder no longer returns data.
812  *
813  * NOTE: For encoders implementing the AVCodec.encode2() function, setting this
814  * flag also means that the encoder must set the pts and duration for
815  * each output packet. If this flag is not set, the pts and duration will
816  * be determined by libavcodec from the input frame.
817  */
818 #define CODEC_CAP_DELAY 0x0020
819 /**
820  * Codec can be fed a final frame with a smaller size.
821  * This can be used to prevent truncation of the last audio samples.
822  */
823 #define CODEC_CAP_SMALL_LAST_FRAME 0x0040
824 #if FF_API_CAP_VDPAU
825 /**
826  * Codec can export data for HW decoding (VDPAU).
827  */
828 #define CODEC_CAP_HWACCEL_VDPAU 0x0080
829 #endif
830 /**
831  * Codec can output multiple frames per AVPacket
832  * Normally demuxers return one frame at a time, demuxers which do not do
833  * are connected to a parser to split what they return into proper frames.
834  * This flag is reserved to the very rare category of codecs which have a
835  * bitstream that cannot be split into frames without timeconsuming
836  * operations like full decoding. Demuxers carring such bitstreams thus
837  * may return multiple frames in a packet. This has many disadvantages like
838  * prohibiting stream copy in many cases thus it should only be considered
839  * as a last resort.
840  */
841 #define CODEC_CAP_SUBFRAMES 0x0100
842 /**
843  * Codec is experimental and is thus avoided in favor of non experimental
844  * encoders
845  */
846 #define CODEC_CAP_EXPERIMENTAL 0x0200
847 /**
848  * Codec should fill in channel configuration and samplerate instead of container
849  */
850 #define CODEC_CAP_CHANNEL_CONF 0x0400
851 #if FF_API_NEG_LINESIZES
852 /**
853  * @deprecated no codecs use this capability
854  */
855 #define CODEC_CAP_NEG_LINESIZES 0x0800
856 #endif
857 /**
858  * Codec supports frame-level multithreading.
859  */
860 #define CODEC_CAP_FRAME_THREADS 0x1000
861 /**
862  * Codec supports slice-based (or partition-based) multithreading.
863  */
864 #define CODEC_CAP_SLICE_THREADS 0x2000
865 /**
866  * Codec supports changed parameters at any point.
867  */
868 #define CODEC_CAP_PARAM_CHANGE 0x4000
869 /**
870  * Codec supports avctx->thread_count == 0 (auto).
871  */
872 #define CODEC_CAP_AUTO_THREADS 0x8000
873 /**
874  * Audio encoder supports receiving a different number of samples in each call.
875  */
876 #define CODEC_CAP_VARIABLE_FRAME_SIZE 0x10000
877 /**
878  * Codec is intra only.
879  */
880 #define CODEC_CAP_INTRA_ONLY 0x40000000
881 /**
882  * Codec is lossless.
883  */
884 #define CODEC_CAP_LOSSLESS 0x80000000
886 #if FF_API_MB_TYPE
887 //The following defines may change, don't expect compatibility if you use them.
888 #define MB_TYPE_INTRA4x4 0x0001
889 #define MB_TYPE_INTRA16x16 0x0002 //FIXME H.264-specific
890 #define MB_TYPE_INTRA_PCM 0x0004 //FIXME H.264-specific
891 #define MB_TYPE_16x16 0x0008
892 #define MB_TYPE_16x8 0x0010
893 #define MB_TYPE_8x16 0x0020
894 #define MB_TYPE_8x8 0x0040
895 #define MB_TYPE_INTERLACED 0x0080
896 #define MB_TYPE_DIRECT2 0x0100 //FIXME
897 #define MB_TYPE_ACPRED 0x0200
898 #define MB_TYPE_GMC 0x0400
899 #define MB_TYPE_SKIP 0x0800
900 #define MB_TYPE_P0L0 0x1000
901 #define MB_TYPE_P1L0 0x2000
902 #define MB_TYPE_P0L1 0x4000
903 #define MB_TYPE_P1L1 0x8000
904 #define MB_TYPE_L0 (MB_TYPE_P0L0 | MB_TYPE_P1L0)
905 #define MB_TYPE_L1 (MB_TYPE_P0L1 | MB_TYPE_P1L1)
906 #define MB_TYPE_L0L1 (MB_TYPE_L0 | MB_TYPE_L1)
907 #define MB_TYPE_QUANT 0x00010000
908 #define MB_TYPE_CBP 0x00020000
909 //Note bits 24-31 are reserved for codec specific use (h264 ref0, mpeg1 0mv, ...)
910 #endif
912 /**
913  * Pan Scan area.
914  * This specifies the area which should be displayed.
915  * Note there may be multiple such areas for one frame.
916  */
917 typedef struct AVPanScan{
918  /**
919  * id
920  * - encoding: Set by user.
921  * - decoding: Set by libavcodec.
922  */
923  int id;
925  /**
926  * width and height in 1/16 pel
927  * - encoding: Set by user.
928  * - decoding: Set by libavcodec.
929  */
930  int width;
931  int height;
933  /**
934  * position of the top left corner in 1/16 pel for up to 3 fields/frames
935  * - encoding: Set by user.
936  * - decoding: Set by libavcodec.
937  */
938  int16_t position[3][2];
939 }AVPanScan;
941 #if FF_API_QSCALE_TYPE
942 #define FF_QSCALE_TYPE_MPEG1 0
943 #define FF_QSCALE_TYPE_MPEG2 1
944 #define FF_QSCALE_TYPE_H264 2
945 #define FF_QSCALE_TYPE_VP56 3
946 #endif
947 
948 #if FF_API_GET_BUFFER
949 #define FF_BUFFER_TYPE_INTERNAL 1
950 #define FF_BUFFER_TYPE_USER 2 ///< direct rendering buffers (image is (de)allocated by user)
951 #define FF_BUFFER_TYPE_SHARED 4 ///< Buffer from somewhere else; don't deallocate image (data/base), all other tables are not shared.
952 #define FF_BUFFER_TYPE_COPY 8 ///< Just a (modified) copy of some other buffer, don't deallocate anything.
954 #define FF_BUFFER_HINTS_VALID 0x01 // Buffer hints value is meaningful (if 0 ignore).
955 #define FF_BUFFER_HINTS_READABLE 0x02 // Codec will read from buffer.
956 #define FF_BUFFER_HINTS_PRESERVE 0x04 // User must not alter buffer content.
957 #define FF_BUFFER_HINTS_REUSABLE 0x08 // Codec will reuse the buffer (update).
958 #endif
959 
960 /**
961  * The decoder will keep a reference to the frame and may reuse it later.
962  */
963 #define AV_GET_BUFFER_FLAG_REF (1 << 0)
964 
965 /**
966  * @defgroup lavc_packet AVPacket
967  *
968  * Types and functions for working with AVPacket.
969  * @{
970  */
974 
975  /**
976  * An AV_PKT_DATA_PARAM_CHANGE side data packet is laid out as follows:
977  * @code
978  * u32le param_flags
979  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT)
980  * s32le channel_count
981  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT)
982  * u64le channel_layout
983  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE)
984  * s32le sample_rate
985  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS)
986  * s32le width
987  * s32le height
988  * @endcode
989  */
991 
992  /**
993  * An AV_PKT_DATA_H263_MB_INFO side data packet contains a number of
994  * structures with info about macroblocks relevant to splitting the
995  * packet into smaller packets on macroblock edges (e.g. as for RFC 2190).
996  * That is, it does not necessarily contain info about all macroblocks,
997  * as long as the distance between macroblocks in the info is smaller
998  * than the target payload size.
999  * Each MB info structure is 12 bytes, and is laid out as follows:
1000  * @code
1001  * u32le bit offset from the start of the packet
1002  * u8 current quantizer at the start of the macroblock
1003  * u8 GOB number
1004  * u16le macroblock address within the GOB
1005  * u8 horizontal MV predictor
1006  * u8 vertical MV predictor
1007  * u8 horizontal MV predictor for block number 3
1008  * u8 vertical MV predictor for block number 3
1009  * @endcode
1010  */
1012 
1013  /**
1014  * This side data should be associated with an audio stream and contains
1015  * ReplayGain information in form of the AVReplayGain struct.
1016  */
1018 
1019  /**
1020  * This side data contains a 3x3 transformation matrix describing an affine
1021  * transformation that needs to be applied to the decoded video frames for
1022  * correct presentation.
1023  *
1024  * See libavutil/display.h for a detailed description of the data.
1025  */
1027 
1028  /**
1029  * This side data should be associated with a video stream and contains
1030  * Stereoscopic 3D information in form of the AVStereo3D struct.
1031  */
1033 
1034  /**
1035  * This side data should be associated with an audio stream and corresponds
1036  * to enum AVAudioServiceType.
1037  */
1039 
1040  /**
1041  * Recommmends skipping the specified number of samples
1042  * @code
1043  * u32le number of samples to skip from start of this packet
1044  * u32le number of samples to skip from end of this packet
1045  * u8 reason for start skip
1046  * u8 reason for end skip (0=padding silence, 1=convergence)
1047  * @endcode
1048  */
1050 
1051  /**
1052  * An AV_PKT_DATA_JP_DUALMONO side data packet indicates that
1053  * the packet may contain "dual mono" audio specific to Japanese DTV
1054  * and if it is true, recommends only the selected channel to be used.
1055  * @code
1056  * u8 selected channels (0=mail/left, 1=sub/right, 2=both)
1057  * @endcode
1058  */
1060 
1061  /**
1062  * A list of zero terminated key/value strings. There is no end marker for
1063  * the list, so it is required to rely on the side data size to stop.
1064  */
1066 
1067  /**
1068  * Subtitle event position
1069  * @code
1070  * u32le x1
1071  * u32le y1
1072  * u32le x2
1073  * u32le y2
1074  * @endcode
1075  */
1077 
1078  /**
1079  * Data found in BlockAdditional element of matroska container. There is
1080  * no end marker for the data, so it is required to rely on the side data
1081  * size to recognize the end. 8 byte id (as found in BlockAddId) followed
1082  * by data.
1083  */
1085 
1086  /**
1087  * The optional first identifier line of a WebVTT cue.
1088  */
1090 
1091  /**
1092  * The optional settings (rendering instructions) that immediately
1093  * follow the timestamp specifier of a WebVTT cue.
1094  */
1096 
1097  /**
1098  * A list of zero terminated key/value strings. There is no end marker for
1099  * the list, so it is required to rely on the side data size to stop. This
1100  * side data includes updated metadata which appeared in the stream.
1101  */
1103 };
1105 typedef struct AVPacketSideData {
1107  int size;
1110 
1111 /**
1112  * This structure stores compressed data. It is typically exported by demuxers
1113  * and then passed as input to decoders, or received as output from encoders and
1114  * then passed to muxers.
1115  *
1116  * For video, it should typically contain one compressed frame. For audio it may
1117  * contain several compressed frames.
1118  *
1119  * AVPacket is one of the few structs in FFmpeg, whose size is a part of public
1120  * ABI. Thus it may be allocated on stack and no new fields can be added to it
1121  * without libavcodec and libavformat major bump.
1122  *
1123  * The semantics of data ownership depends on the buf or destruct (deprecated)
1124  * fields. If either is set, the packet data is dynamically allocated and is
1125  * valid indefinitely until av_free_packet() is called (which in turn calls
1126  * av_buffer_unref()/the destruct callback to free the data). If neither is set,
1127  * the packet data is typically backed by some static buffer somewhere and is
1128  * only valid for a limited time (e.g. until the next read call when demuxing).
1129  *
1130  * The side data is always allocated with av_malloc() and is freed in
1131  * av_free_packet().
1132  */
1133 typedef struct AVPacket {
1134  /**
1135  * A reference to the reference-counted buffer where the packet data is
1136  * stored.
1137  * May be NULL, then the packet data is not reference-counted.
1138  */
1139  AVBufferRef *buf;
1140  /**
1141  * Presentation timestamp in AVStream->time_base units; the time at which
1142  * the decompressed packet will be presented to the user.
1143  * Can be AV_NOPTS_VALUE if it is not stored in the file.
1144  * pts MUST be larger or equal to dts as presentation cannot happen before
1145  * decompression, unless one wants to view hex dumps. Some formats misuse
1146  * the terms dts and pts/cts to mean something different. Such timestamps
1147  * must be converted to true pts/dts before they are stored in AVPacket.
1148  */
1149  int64_t pts;
1150  /**
1151  * Decompression timestamp in AVStream->time_base units; the time at which
1152  * the packet is decompressed.
1153  * Can be AV_NOPTS_VALUE if it is not stored in the file.
1154  */
1155  int64_t dts;
1157  int size;
1158  int stream_index;
1159  /**
1160  * A combination of AV_PKT_FLAG values
1161  */
1162  int flags;
1163  /**
1164  * Additional packet data that can be provided by the container.
1165  * Packet can contain several types of side information.
1166  */
1168  int side_data_elems;
1169 
1170  /**
1171  * Duration of this packet in AVStream->time_base units, 0 if unknown.
1172  * Equals next_pts - this_pts in presentation order.
1173  */
1174  int duration;
1175 #if FF_API_DESTRUCT_PACKET
1177  void (*destruct)(struct AVPacket *);
1179  void *priv;
1180 #endif
1181  int64_t pos; ///< byte position in stream, -1 if unknown
1182 
1183  /**
1184  * Time difference in AVStream->time_base units from the pts of this
1185  * packet to the point at which the output from the decoder has converged
1186  * independent from the availability of previous frames. That is, the
1187  * frames are virtually identical no matter if decoding started from
1188  * the very first frame or from this keyframe.
1189  * Is AV_NOPTS_VALUE if unknown.
1190  * This field is not the display duration of the current packet.
1191  * This field has no meaning if the packet does not have AV_PKT_FLAG_KEY
1192  * set.
1193  *
1194  * The purpose of this field is to allow seeking in streams that have no
1195  * keyframes in the conventional sense. It corresponds to the
1196  * recovery point SEI in H.264 and match_time_delta in NUT. It is also
1197  * essential for some types of subtitle streams to ensure that all
1198  * subtitles are correctly displayed after seeking.
1199  */
1200  int64_t convergence_duration;
1202 #define AV_PKT_FLAG_KEY 0x0001 ///< The packet contains a keyframe
1203 #define AV_PKT_FLAG_CORRUPT 0x0002 ///< The packet content is corrupted
1210 };
1211 /**
1212  * @}
1213  */
1214 
1215 struct AVCodecInternal;
1220  AV_FIELD_TT, //< Top coded_first, top displayed first
1221  AV_FIELD_BB, //< Bottom coded first, bottom displayed first
1222  AV_FIELD_TB, //< Top coded first, bottom displayed first
1223  AV_FIELD_BT, //< Bottom coded first, top displayed first
1224 };
1225 
1226 /**
1227  * main external API structure.
1228  * New fields can be added to the end with minor version bumps.
1229  * Removal, reordering and changes to existing fields require a major
1230  * version bump.
1231  * Please use AVOptions (av_opt* / av_set/get*()) to access these fields from user
1232  * applications.
1233  * sizeof(AVCodecContext) must not be used outside libav*.
1234  */
1235 typedef struct AVCodecContext {
1236  /**
1237  * information on struct for av_log
1238  * - set by avcodec_alloc_context3
1239  */
1241  int log_level_offset;
1243  enum AVMediaType codec_type; /* see AVMEDIA_TYPE_xxx */
1244  const struct AVCodec *codec;
1245 #if FF_API_CODEC_NAME
1246  /**
1247  * @deprecated this field is not used for anything in libavcodec
1248  */
1250  char codec_name[32];
1251 #endif
1252  enum AVCodecID codec_id; /* see AV_CODEC_ID_xxx */
1253 
1254  /**
1255  * fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
1256  * This is used to work around some encoder bugs.
1257  * A demuxer should set this to what is stored in the field used to identify the codec.
1258  * If there are multiple such fields in a container then the demuxer should choose the one
1259  * which maximizes the information about the used codec.
1260  * If the codec tag field in a container is larger than 32 bits then the demuxer should
1261  * remap the longer ID to 32 bits with a table or other structure. Alternatively a new
1262  * extra_codec_tag + size could be added but for this a clear advantage must be demonstrated
1263  * first.
1264  * - encoding: Set by user, if not then the default based on codec_id will be used.
1265  * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
1266  */
1267  unsigned int codec_tag;
1268 
1269 #if FF_API_STREAM_CODEC_TAG
1270  /**
1271  * @deprecated this field is unused
1272  */
1274  unsigned int stream_codec_tag;
1275 #endif
1277  void *priv_data;
1278 
1279  /**
1280  * Private context used for internal data.
1281  *
1282  * Unlike priv_data, this is not codec-specific. It is used in general
1283  * libavcodec functions.
1284  */
1285  struct AVCodecInternal *internal;
1286 
1287  /**
1288  * Private data of the user, can be used to carry app specific stuff.
1289  * - encoding: Set by user.
1290  * - decoding: Set by user.
1291  */
1292  void *opaque;
1293 
1294  /**
1295  * the average bitrate
1296  * - encoding: Set by user; unused for constant quantizer encoding.
1297  * - decoding: Set by libavcodec. 0 or some bitrate if this info is available in the stream.
1298  */
1299  int bit_rate;
1300 
1301  /**
1302  * number of bits the bitstream is allowed to diverge from the reference.
1303  * the reference can be CBR (for CBR pass1) or VBR (for pass2)
1304  * - encoding: Set by user; unused for constant quantizer encoding.
1305  * - decoding: unused
1306  */
1307  int bit_rate_tolerance;
1308 
1309  /**
1310  * Global quality for codecs which cannot change it per frame.
1311  * This should be proportional to MPEG-1/2/4 qscale.
1312  * - encoding: Set by user.
1313  * - decoding: unused
1314  */
1315  int global_quality;
1316 
1317  /**
1318  * - encoding: Set by user.
1319  * - decoding: unused
1320  */
1322 #define FF_COMPRESSION_DEFAULT -1
1323 
1324  /**
1325  * CODEC_FLAG_*.
1326  * - encoding: Set by user.
1327  * - decoding: Set by user.
1328  */
1329  int flags;
1330 
1331  /**
1332  * CODEC_FLAG2_*
1333  * - encoding: Set by user.
1334  * - decoding: Set by user.
1335  */
1336  int flags2;
1337 
1338  /**
1339  * some codecs need / can use extradata like Huffman tables.
1340  * mjpeg: Huffman tables
1341  * rv10: additional flags
1342  * mpeg4: global headers (they can be in the bitstream or here)
1343  * The allocated memory should be FF_INPUT_BUFFER_PADDING_SIZE bytes larger
1344  * than extradata_size to avoid problems if it is read with the bitstream reader.
1345  * The bytewise contents of extradata must not depend on the architecture or CPU endianness.
1346  * - encoding: Set/allocated/freed by libavcodec.
1347  * - decoding: Set/allocated/freed by user.
1348  */
1350  int extradata_size;
1351 
1352  /**
1353  * This is the fundamental unit of time (in seconds) in terms
1354  * of which frame timestamps are represented. For fixed-fps content,
1355  * timebase should be 1/framerate and timestamp increments should be
1356  * identically 1.
1357  * This often, but not always is the inverse of the frame rate or field rate
1358  * for video.
1359  * - encoding: MUST be set by user.
1360  * - decoding: the use of this field for decoding is deprecated.
1361  * Use framerate instead.
1362  */
1364 
1365  /**
1366  * For some codecs, the time base is closer to the field rate than the frame rate.
1367  * Most notably, H.264 and MPEG-2 specify time_base as half of frame duration
1368  * if no telecine is used ...
1369  *
1370  * Set to time_base ticks per frame. Default 1, e.g., H.264/MPEG-2 set it to 2.
1371  */
1372  int ticks_per_frame;
1373 
1374  /**
1375  * Codec delay.
1376  *
1377  * Encoding: Number of frames delay there will be from the encoder input to
1378  * the decoder output. (we assume the decoder matches the spec)
1379  * Decoding: Number of frames delay in addition to what a standard decoder
1380  * as specified in the spec would produce.
1381  *
1382  * Video:
1383  * Number of frames the decoded output will be delayed relative to the
1384  * encoded input.
1385  *
1386  * Audio:
1387  * For encoding, this field is unused (see initial_padding).
1388  *
1389  * For decoding, this is the number of samples the decoder needs to
1390  * output before the decoder's output is valid. When seeking, you should
1391  * start decoding this many samples prior to your desired seek point.
1392  *
1393  * - encoding: Set by libavcodec.
1394  * - decoding: Set by libavcodec.
1395  */
1396  int delay;
1397 
1398 
1399  /* video only */
1400  /**
1401  * picture width / height.
1402  * - encoding: MUST be set by user.
1403  * - decoding: May be set by the user before opening the decoder if known e.g.
1404  * from the container. Some decoders will require the dimensions
1405  * to be set by the caller. During decoding, the decoder may
1406  * overwrite those values as required.
1407  */
1408  int width, height;
1409 
1410  /**
1411  * Bitstream width / height, may be different from width/height e.g. when
1412  * the decoded frame is cropped before being output or lowres is enabled.
1413  * - encoding: unused
1414  * - decoding: May be set by the user before opening the decoder if known
1415  * e.g. from the container. During decoding, the decoder may
1416  * overwrite those values as required.
1417  */
1419 
1420 #if FF_API_ASPECT_EXTENDED
1421 #define FF_ASPECT_EXTENDED 15
1422 #endif
1423 
1424  /**
1425  * the number of pictures in a group of pictures, or 0 for intra_only
1426  * - encoding: Set by user.
1427  * - decoding: unused
1428  */
1429  int gop_size;
1430 
1431  /**
1432  * Pixel format, see AV_PIX_FMT_xxx.
1433  * May be set by the demuxer if known from headers.
1434  * May be overridden by the decoder if it knows better.
1435  * - encoding: Set by user.
1436  * - decoding: Set by user if known, overridden by libavcodec if known
1437  */
1438  enum AVPixelFormat pix_fmt;
1439 
1440  /**
1441  * Motion estimation algorithm used for video coding.
1442  * 1 (zero), 2 (full), 3 (log), 4 (phods), 5 (epzs), 6 (x1), 7 (hex),
1443  * 8 (umh), 9 (iter), 10 (tesa) [7, 8, 10 are x264 specific, 9 is snow specific]
1444  * - encoding: MUST be set by user.
1445  * - decoding: unused
1446  */
1447  int me_method;
1448 
1449  /**
1450  * If non NULL, 'draw_horiz_band' is called by the libavcodec
1451  * decoder to draw a horizontal band. It improves cache usage. Not
1452  * all codecs can do that. You must check the codec capabilities
1453  * beforehand.
1454  * When multithreading is used, it may be called from multiple threads
1455  * at the same time; threads might draw different parts of the same AVFrame,
1456  * or multiple AVFrames, and there is no guarantee that slices will be drawn
1457  * in order.
1458  * The function is also used by hardware acceleration APIs.
1459  * It is called at least once during frame decoding to pass
1460  * the data needed for hardware render.
1461  * In that mode instead of pixel data, AVFrame points to
1462  * a structure specific to the acceleration API. The application
1463  * reads the structure and can change some fields to indicate progress
1464  * or mark state.
1465  * - encoding: unused
1466  * - decoding: Set by user.
1467  * @param height the height of the slice
1468  * @param y the y position of the slice
1469  * @param type 1->top field, 2->bottom field, 3->frame
1470  * @param offset offset into the AVFrame.data from which the slice should be read
1471  */
1472  void (*draw_horiz_band)(struct AVCodecContext *s,
1473  const AVFrame *src, int offset[AV_NUM_DATA_POINTERS],
1474  int y, int type, int height);
1475 
1476  /**
1477  * callback to negotiate the pixelFormat
1478  * @param fmt is the list of formats which are supported by the codec,
1479  * it is terminated by -1 as 0 is a valid format, the formats are ordered by quality.
1480  * The first is always the native one.
1481  * @note The callback may be called again immediately if initialization for
1482  * the selected (hardware-accelerated) pixel format failed.
1483  * @warning Behavior is undefined if the callback returns a value not
1484  * in the fmt list of formats.
1485  * @return the chosen format
1486  * - encoding: unused
1487  * - decoding: Set by user, if not set the native format will be chosen.
1488  */
1489  enum AVPixelFormat (*get_format)(struct AVCodecContext *s, const enum AVPixelFormat * fmt);
1490 
1491  /**
1492  * maximum number of B-frames between non-B-frames
1493  * Note: The output will be delayed by max_b_frames+1 relative to the input.
1494  * - encoding: Set by user.
1495  * - decoding: unused
1496  */
1497  int max_b_frames;
1498 
1499  /**
1500  * qscale factor between IP and B-frames
1501  * If > 0 then the last P-frame quantizer will be used (q= lastp_q*factor+offset).
1502  * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1503  * - encoding: Set by user.
1504  * - decoding: unused
1505  */
1506  float b_quant_factor;
1507 
1508  /** obsolete FIXME remove */
1510 #define FF_RC_STRATEGY_XVID 1
1512  int b_frame_strategy;
1513 
1514  /**
1515  * qscale offset between IP and B-frames
1516  * - encoding: Set by user.
1517  * - decoding: unused
1518  */
1519  float b_quant_offset;
1520 
1521  /**
1522  * Size of the frame reordering buffer in the decoder.
1523  * For MPEG-2 it is 1 IPB or 0 low delay IP.
1524  * - encoding: Set by libavcodec.
1525  * - decoding: Set by libavcodec.
1526  */
1527  int has_b_frames;
1528 
1529  /**
1530  * 0-> h263 quant 1-> mpeg quant
1531  * - encoding: Set by user.
1532  * - decoding: unused
1533  */
1534  int mpeg_quant;
1535 
1536  /**
1537  * qscale factor between P and I-frames
1538  * If > 0 then the last p frame quantizer will be used (q= lastp_q*factor+offset).
1539  * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1540  * - encoding: Set by user.
1541  * - decoding: unused
1542  */
1543  float i_quant_factor;
1544 
1545  /**
1546  * qscale offset between P and I-frames
1547  * - encoding: Set by user.
1548  * - decoding: unused
1549  */
1550  float i_quant_offset;
1551 
1552  /**
1553  * luminance masking (0-> disabled)
1554  * - encoding: Set by user.
1555  * - decoding: unused
1556  */
1557  float lumi_masking;
1558 
1559  /**
1560  * temporary complexity masking (0-> disabled)
1561  * - encoding: Set by user.
1562  * - decoding: unused
1563  */
1564  float temporal_cplx_masking;
1565 
1566  /**
1567  * spatial complexity masking (0-> disabled)
1568  * - encoding: Set by user.
1569  * - decoding: unused
1570  */
1571  float spatial_cplx_masking;
1572 
1573  /**
1574  * p block masking (0-> disabled)
1575  * - encoding: Set by user.
1576  * - decoding: unused
1577  */
1578  float p_masking;
1579 
1580  /**
1581  * darkness masking (0-> disabled)
1582  * - encoding: Set by user.
1583  * - decoding: unused
1584  */
1585  float dark_masking;
1586 
1587  /**
1588  * slice count
1589  * - encoding: Set by libavcodec.
1590  * - decoding: Set by user (or 0).
1591  */
1592  int slice_count;
1593  /**
1594  * prediction method (needed for huffyuv)
1595  * - encoding: Set by user.
1596  * - decoding: unused
1597  */
1599 #define FF_PRED_LEFT 0
1600 #define FF_PRED_PLANE 1
1601 #define FF_PRED_MEDIAN 2
1602 
1603  /**
1604  * slice offsets in the frame in bytes
1605  * - encoding: Set/allocated by libavcodec.
1606  * - decoding: Set/allocated by user (or NULL).
1607  */
1608  int *slice_offset;
1609 
1610  /**
1611  * sample aspect ratio (0 if unknown)
1612  * That is the width of a pixel divided by the height of the pixel.
1613  * Numerator and denominator must be relatively prime and smaller than 256 for some video standards.
1614  * - encoding: Set by user.
1615  * - decoding: Set by libavcodec.
1616  */
1618 
1619  /**
1620  * motion estimation comparison function
1621  * - encoding: Set by user.
1622  * - decoding: unused
1623  */
1624  int me_cmp;
1625  /**
1626  * subpixel motion estimation comparison function
1627  * - encoding: Set by user.
1628  * - decoding: unused
1629  */
1630  int me_sub_cmp;
1631  /**
1632  * macroblock comparison function (not supported yet)
1633  * - encoding: Set by user.
1634  * - decoding: unused
1635  */
1636  int mb_cmp;
1637  /**
1638  * interlaced DCT comparison function
1639  * - encoding: Set by user.
1640  * - decoding: unused
1641  */
1643 #define FF_CMP_SAD 0
1644 #define FF_CMP_SSE 1
1645 #define FF_CMP_SATD 2
1646 #define FF_CMP_DCT 3
1647 #define FF_CMP_PSNR 4
1648 #define FF_CMP_BIT 5
1649 #define FF_CMP_RD 6
1650 #define FF_CMP_ZERO 7
1651 #define FF_CMP_VSAD 8
1652 #define FF_CMP_VSSE 9
1653 #define FF_CMP_NSSE 10
1654 #define FF_CMP_W53 11
1655 #define FF_CMP_W97 12
1656 #define FF_CMP_DCTMAX 13
1657 #define FF_CMP_DCT264 14
1658 #define FF_CMP_CHROMA 256
1659 
1660  /**
1661  * ME diamond size & shape
1662  * - encoding: Set by user.
1663  * - decoding: unused
1664  */
1665  int dia_size;
1666 
1667  /**
1668  * amount of previous MV predictors (2a+1 x 2a+1 square)
1669  * - encoding: Set by user.
1670  * - decoding: unused
1671  */
1673 
1674  /**
1675  * prepass for motion estimation
1676  * - encoding: Set by user.
1677  * - decoding: unused
1678  */
1679  int pre_me;
1680 
1681  /**
1682  * motion estimation prepass comparison function
1683  * - encoding: Set by user.
1684  * - decoding: unused
1685  */
1686  int me_pre_cmp;
1687 
1688  /**
1689  * ME prepass diamond size & shape
1690  * - encoding: Set by user.
1691  * - decoding: unused
1692  */
1693  int pre_dia_size;
1694 
1695  /**
1696  * subpel ME quality
1697  * - encoding: Set by user.
1698  * - decoding: unused
1699  */
1700  int me_subpel_quality;
1701 
1702 #if FF_API_AFD
1703  /**
1704  * DTG active format information (additional aspect ratio
1705  * information only used in DVB MPEG-2 transport streams)
1706  * 0 if not set.
1707  *
1708  * - encoding: unused
1709  * - decoding: Set by decoder.
1710  * @deprecated Deprecated in favor of AVSideData
1711  */
1713 #define FF_DTG_AFD_SAME 8
1714 #define FF_DTG_AFD_4_3 9
1715 #define FF_DTG_AFD_16_9 10
1716 #define FF_DTG_AFD_14_9 11
1717 #define FF_DTG_AFD_4_3_SP_14_9 13
1718 #define FF_DTG_AFD_16_9_SP_14_9 14
1719 #define FF_DTG_AFD_SP_4_3 15
1720 #endif /* FF_API_AFD */
1721 
1722  /**
1723  * maximum motion estimation search range in subpel units
1724  * If 0 then no limit.
1725  *
1726  * - encoding: Set by user.
1727  * - decoding: unused
1728  */
1729  int me_range;
1730 
1731  /**
1732  * intra quantizer bias
1733  * - encoding: Set by user.
1734  * - decoding: unused
1735  */
1737 #define FF_DEFAULT_QUANT_BIAS 999999
1738 
1739  /**
1740  * inter quantizer bias
1741  * - encoding: Set by user.
1742  * - decoding: unused
1743  */
1744  int inter_quant_bias;
1745 
1746  /**
1747  * slice flags
1748  * - encoding: unused
1749  * - decoding: Set by user.
1750  */
1752 #define SLICE_FLAG_CODED_ORDER 0x0001 ///< draw_horiz_band() is called in coded order instead of display
1753 #define SLICE_FLAG_ALLOW_FIELD 0x0002 ///< allow draw_horiz_band() with field slices (MPEG2 field pics)
1754 #define SLICE_FLAG_ALLOW_PLANE 0x0004 ///< allow draw_horiz_band() with 1 component at a time (SVQ1)
1755 
1756 #if FF_API_XVMC
1757  /**
1758  * XVideo Motion Acceleration
1759  * - encoding: forbidden
1760  * - decoding: set by decoder
1761  * @deprecated XvMC doesn't need it anymore.
1762  */
1763  attribute_deprecated int xvmc_acceleration;
1764 #endif /* FF_API_XVMC */
1765 
1766  /**
1767  * macroblock decision mode
1768  * - encoding: Set by user.
1769  * - decoding: unused
1770  */
1772 #define FF_MB_DECISION_SIMPLE 0 ///< uses mb_cmp
1773 #define FF_MB_DECISION_BITS 1 ///< chooses the one which needs the fewest bits
1774 #define FF_MB_DECISION_RD 2 ///< rate distortion
1775 
1776  /**
1777  * custom intra quantization matrix
1778  * - encoding: Set by user, can be NULL.
1779  * - decoding: Set by libavcodec.
1780  */
1781  uint16_t *intra_matrix;
1782 
1783  /**
1784  * custom inter quantization matrix
1785  * - encoding: Set by user, can be NULL.
1786  * - decoding: Set by libavcodec.
1787  */
1788  uint16_t *inter_matrix;
1789 
1790  /**
1791  * scene change detection threshold
1792  * 0 is default, larger means fewer detected scene changes.
1793  * - encoding: Set by user.
1794  * - decoding: unused
1795  */
1797 
1798  /**
1799  * noise reduction strength
1800  * - encoding: Set by user.
1801  * - decoding: unused
1802  */
1803  int noise_reduction;
1804 
1805 #if FF_API_MPV_OPT
1806  /**
1807  * @deprecated this field is unused
1808  */
1810  int me_threshold;
1811 
1812  /**
1813  * @deprecated this field is unused
1814  */
1816  int mb_threshold;
1817 #endif
1818 
1819  /**
1820  * precision of the intra DC coefficient - 8
1821  * - encoding: Set by user.
1822  * - decoding: unused
1823  */
1824  int intra_dc_precision;
1825 
1826  /**
1827  * Number of macroblock rows at the top which are skipped.
1828  * - encoding: unused
1829  * - decoding: Set by user.
1830  */
1831  int skip_top;
1832 
1833  /**
1834  * Number of macroblock rows at the bottom which are skipped.
1835  * - encoding: unused
1836  * - decoding: Set by user.
1837  */
1838  int skip_bottom;
1839 
1840 #if FF_API_MPV_OPT
1841  /**
1842  * @deprecated use encoder private options instead
1843  */
1845  float border_masking;
1846 #endif
1847 
1848  /**
1849  * minimum MB lagrange multipler
1850  * - encoding: Set by user.
1851  * - decoding: unused
1852  */
1853  int mb_lmin;
1854 
1855  /**
1856  * maximum MB lagrange multipler
1857  * - encoding: Set by user.
1858  * - decoding: unused
1859  */
1860  int mb_lmax;
1861 
1862  /**
1863  *
1864  * - encoding: Set by user.
1865  * - decoding: unused
1866  */
1868 
1869  /**
1870  *
1871  * - encoding: Set by user.
1872  * - decoding: unused
1873  */
1874  int bidir_refine;
1875 
1876  /**
1877  *
1878  * - encoding: Set by user.
1879  * - decoding: unused
1880  */
1881  int brd_scale;
1882 
1883  /**
1884  * minimum GOP size
1885  * - encoding: Set by user.
1886  * - decoding: unused
1887  */
1888  int keyint_min;
1889 
1890  /**
1891  * number of reference frames
1892  * - encoding: Set by user.
1893  * - decoding: Set by lavc.
1894  */
1895  int refs;
1896 
1897  /**
1898  * chroma qp offset from luma
1899  * - encoding: Set by user.
1900  * - decoding: unused
1901  */
1902  int chromaoffset;
1903 
1904 #if FF_API_UNUSED_MEMBERS
1905  /**
1906  * Multiplied by qscale for each frame and added to scene_change_score.
1907  * - encoding: Set by user.
1908  * - decoding: unused
1909  */
1911 #endif
1912 
1913  /**
1914  *
1915  * Note: Value depends upon the compare function used for fullpel ME.
1916  * - encoding: Set by user.
1917  * - decoding: unused
1918  */
1919  int mv0_threshold;
1920 
1921  /**
1922  * Adjust sensitivity of b_frame_strategy 1.
1923  * - encoding: Set by user.
1924  * - decoding: unused
1925  */
1926  int b_sensitivity;
1927 
1928  /**
1929  * Chromaticity coordinates of the source primaries.
1930  * - encoding: Set by user
1931  * - decoding: Set by libavcodec
1932  */
1934 
1935  /**
1936  * Color Transfer Characteristic.
1937  * - encoding: Set by user
1938  * - decoding: Set by libavcodec
1939  */
1941 
1942  /**
1943  * YUV colorspace type.
1944  * - encoding: Set by user
1945  * - decoding: Set by libavcodec
1946  */
1947  enum AVColorSpace colorspace;
1948 
1949  /**
1950  * MPEG vs JPEG YUV range.
1951  * - encoding: Set by user
1952  * - decoding: Set by libavcodec
1953  */
1955 
1956  /**
1957  * This defines the location of chroma samples.
1958  * - encoding: Set by user
1959  * - decoding: Set by libavcodec
1960  */
1962 
1963  /**
1964  * Number of slices.
1965  * Indicates number of picture subdivisions. Used for parallelized
1966  * decoding.
1967  * - encoding: Set by user
1968  * - decoding: unused
1969  */
1970  int slices;
1971 
1972  /** Field order
1973  * - encoding: set by libavcodec
1974  * - decoding: Set by user.
1975  */
1977 
1978  /* audio only */
1979  int sample_rate; ///< samples per second
1980  int channels; ///< number of audio channels
1981 
1982  /**
1983  * audio sample format
1984  * - encoding: Set by user.
1985  * - decoding: Set by libavcodec.
1986  */
1987  enum AVSampleFormat sample_fmt; ///< sample format
1988 
1989  /* The following data should not be initialized. */
1990  /**
1991  * Number of samples per channel in an audio frame.
1992  *
1993  * - encoding: set by libavcodec in avcodec_open2(). Each submitted frame
1994  * except the last must contain exactly frame_size samples per channel.
1995  * May be 0 when the codec has CODEC_CAP_VARIABLE_FRAME_SIZE set, then the
1996  * frame size is not restricted.
1997  * - decoding: may be set by some decoders to indicate constant frame size
1998  */
1999  int frame_size;
2000 
2001  /**
2002  * Frame counter, set by libavcodec.
2003  *
2004  * - decoding: total number of frames returned from the decoder so far.
2005  * - encoding: total number of frames passed to the encoder so far.
2006  *
2007  * @note the counter is not incremented if encoding/decoding resulted in
2008  * an error.
2009  */
2010  int frame_number;
2011 
2012  /**
2013  * number of bytes per packet if constant and known or 0
2014  * Used by some WAV based audio codecs.
2015  */
2016  int block_align;
2017 
2018  /**
2019  * Audio cutoff bandwidth (0 means "automatic")
2020  * - encoding: Set by user.
2021  * - decoding: unused
2022  */
2023  int cutoff;
2024 
2025 #if FF_API_REQUEST_CHANNELS
2026  /**
2027  * Decoder should decode to this many channels if it can (0 for default)
2028  * - encoding: unused
2029  * - decoding: Set by user.
2030  * @deprecated Deprecated in favor of request_channel_layout.
2031  */
2033 #endif
2034 
2035  /**
2036  * Audio channel layout.
2037  * - encoding: set by user.
2038  * - decoding: set by user, may be overwritten by libavcodec.
2039  */
2040  uint64_t channel_layout;
2041 
2042  /**
2043  * Request decoder to use this channel layout if it can (0 for default)
2044  * - encoding: unused
2045  * - decoding: Set by user.
2046  */
2047  uint64_t request_channel_layout;
2048 
2049  /**
2050  * Type of service that the audio stream conveys.
2051  * - encoding: Set by user.
2052  * - decoding: Set by libavcodec.
2053  */
2055 
2056  /**
2057  * desired sample format
2058  * - encoding: Not used.
2059  * - decoding: Set by user.
2060  * Decoder will decode to this format if it can.
2061  */
2063 
2064 #if FF_API_GET_BUFFER
2065  /**
2066  * Called at the beginning of each frame to get a buffer for it.
2067  *
2068  * The function will set AVFrame.data[], AVFrame.linesize[].
2069  * AVFrame.extended_data[] must also be set, but it should be the same as
2070  * AVFrame.data[] except for planar audio with more channels than can fit
2071  * in AVFrame.data[]. In that case, AVFrame.data[] shall still contain as
2072  * many data pointers as it can hold.
2073  *
2074  * if CODEC_CAP_DR1 is not set then get_buffer() must call
2075  * avcodec_default_get_buffer() instead of providing buffers allocated by
2076  * some other means.
2077  *
2078  * AVFrame.data[] should be 32- or 16-byte-aligned unless the CPU doesn't
2079  * need it. avcodec_default_get_buffer() aligns the output buffer properly,
2080  * but if get_buffer() is overridden then alignment considerations should
2081  * be taken into account.
2082  *
2083  * @see avcodec_default_get_buffer()
2084  *
2085  * Video:
2086  *
2087  * If pic.reference is set then the frame will be read later by libavcodec.
2088  * avcodec_align_dimensions2() should be used to find the required width and
2089  * height, as they normally need to be rounded up to the next multiple of 16.
2090  *
2091  * If frame multithreading is used and thread_safe_callbacks is set,
2092  * it may be called from a different thread, but not from more than one at
2093  * once. Does not need to be reentrant.
2094  *
2095  * @see release_buffer(), reget_buffer()
2096  * @see avcodec_align_dimensions2()
2097  *
2098  * Audio:
2099  *
2100  * Decoders request a buffer of a particular size by setting
2101  * AVFrame.nb_samples prior to calling get_buffer(). The decoder may,
2102  * however, utilize only part of the buffer by setting AVFrame.nb_samples
2103  * to a smaller value in the output frame.
2104  *
2105  * Decoders cannot use the buffer after returning from
2106  * avcodec_decode_audio4(), so they will not call release_buffer(), as it
2107  * is assumed to be released immediately upon return. In some rare cases,
2108  * a decoder may need to call get_buffer() more than once in a single
2109  * call to avcodec_decode_audio4(). In that case, when get_buffer() is
2110  * called again after it has already been called once, the previously
2111  * acquired buffer is assumed to be released at that time and may not be
2112  * reused by the decoder.
2113  *
2114  * As a convenience, av_samples_get_buffer_size() and
2115  * av_samples_fill_arrays() in libavutil may be used by custom get_buffer()
2116  * functions to find the required data size and to fill data pointers and
2117  * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
2118  * since all planes must be the same size.
2119  *
2120  * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
2121  *
2122  * - encoding: unused
2123  * - decoding: Set by libavcodec, user can override.
2124  *
2125  * @deprecated use get_buffer2()
2126  */
2128  int (*get_buffer)(struct AVCodecContext *c, AVFrame *pic);
2129 
2130  /**
2131  * Called to release buffers which were allocated with get_buffer.
2132  * A released buffer can be reused in get_buffer().
2133  * pic.data[*] must be set to NULL.
2134  * May be called from a different thread if frame multithreading is used,
2135  * but not by more than one thread at once, so does not need to be reentrant.
2136  * - encoding: unused
2137  * - decoding: Set by libavcodec, user can override.
2138  *
2139  * @deprecated custom freeing callbacks should be set from get_buffer2()
2140  */
2142  void (*release_buffer)(struct AVCodecContext *c, AVFrame *pic);
2143 
2144  /**
2145  * Called at the beginning of a frame to get cr buffer for it.
2146  * Buffer type (size, hints) must be the same. libavcodec won't check it.
2147  * libavcodec will pass previous buffer in pic, function should return
2148  * same buffer or new buffer with old frame "painted" into it.
2149  * If pic.data[0] == NULL must behave like get_buffer().
2150  * if CODEC_CAP_DR1 is not set then reget_buffer() must call
2151  * avcodec_default_reget_buffer() instead of providing buffers allocated by
2152  * some other means.
2153  * - encoding: unused
2154  * - decoding: Set by libavcodec, user can override.
2155  */
2157  int (*reget_buffer)(struct AVCodecContext *c, AVFrame *pic);
2158 #endif
2159 
2160  /**
2161  * This callback is called at the beginning of each frame to get data
2162  * buffer(s) for it. There may be one contiguous buffer for all the data or
2163  * there may be a buffer per each data plane or anything in between. What
2164  * this means is, you may set however many entries in buf[] you feel necessary.
2165  * Each buffer must be reference-counted using the AVBuffer API (see description
2166  * of buf[] below).
2167  *
2168  * The following fields will be set in the frame before this callback is
2169  * called:
2170  * - format
2171  * - width, height (video only)
2172  * - sample_rate, channel_layout, nb_samples (audio only)
2173  * Their values may differ from the corresponding values in
2174  * AVCodecContext. This callback must use the frame values, not the codec
2175  * context values, to calculate the required buffer size.
2176  *
2177  * This callback must fill the following fields in the frame:
2178  * - data[]
2179  * - linesize[]
2180  * - extended_data:
2181  * * if the data is planar audio with more than 8 channels, then this
2182  * callback must allocate and fill extended_data to contain all pointers
2183  * to all data planes. data[] must hold as many pointers as it can.
2184  * extended_data must be allocated with av_malloc() and will be freed in
2185  * av_frame_unref().
2186  * * otherwise exended_data must point to data
2187  * - buf[] must contain one or more pointers to AVBufferRef structures. Each of
2188  * the frame's data and extended_data pointers must be contained in these. That
2189  * is, one AVBufferRef for each allocated chunk of memory, not necessarily one
2190  * AVBufferRef per data[] entry. See: av_buffer_create(), av_buffer_alloc(),
2191  * and av_buffer_ref().
2192  * - extended_buf and nb_extended_buf must be allocated with av_malloc() by
2193  * this callback and filled with the extra buffers if there are more
2194  * buffers than buf[] can hold. extended_buf will be freed in
2195  * av_frame_unref().
2196  *
2197  * If CODEC_CAP_DR1 is not set then get_buffer2() must call
2198  * avcodec_default_get_buffer2() instead of providing buffers allocated by
2199  * some other means.
2200  *
2201  * Each data plane must be aligned to the maximum required by the target
2202  * CPU.
2203  *
2204  * @see avcodec_default_get_buffer2()
2205  *
2206  * Video:
2207  *
2208  * If AV_GET_BUFFER_FLAG_REF is set in flags then the frame may be reused
2209  * (read and/or written to if it is writable) later by libavcodec.
2210  *
2211  * avcodec_align_dimensions2() should be used to find the required width and
2212  * height, as they normally need to be rounded up to the next multiple of 16.
2213  *
2214  * Some decoders do not support linesizes changing between frames.
2215  *
2216  * If frame multithreading is used and thread_safe_callbacks is set,
2217  * this callback may be called from a different thread, but not from more
2218  * than one at once. Does not need to be reentrant.
2219  *
2220  * @see avcodec_align_dimensions2()
2221  *
2222  * Audio:
2223  *
2224  * Decoders request a buffer of a particular size by setting
2225  * AVFrame.nb_samples prior to calling get_buffer2(). The decoder may,
2226  * however, utilize only part of the buffer by setting AVFrame.nb_samples
2227  * to a smaller value in the output frame.
2228  *
2229  * As a convenience, av_samples_get_buffer_size() and
2230  * av_samples_fill_arrays() in libavutil may be used by custom get_buffer2()
2231  * functions to find the required data size and to fill data pointers and
2232  * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
2233  * since all planes must be the same size.
2234  *
2235  * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
2236  *
2237  * - encoding: unused
2238  * - decoding: Set by libavcodec, user can override.
2239  */
2240  int (*get_buffer2)(struct AVCodecContext *s, AVFrame *frame, int flags);
2241 
2242  /**
2243  * If non-zero, the decoded audio and video frames returned from
2244  * avcodec_decode_video2() and avcodec_decode_audio4() are reference-counted
2245  * and are valid indefinitely. The caller must free them with
2246  * av_frame_unref() when they are not needed anymore.
2247  * Otherwise, the decoded frames must not be freed by the caller and are
2248  * only valid until the next decode call.
2249  *
2250  * - encoding: unused
2251  * - decoding: set by the caller before avcodec_open2().
2252  */
2253  int refcounted_frames;
2254 
2255  /* - encoding parameters */
2256  float qcompress; ///< amount of qscale change between easy & hard scenes (0.0-1.0)
2257  float qblur; ///< amount of qscale smoothing over time (0.0-1.0)
2258 
2259  /**
2260  * minimum quantizer
2261  * - encoding: Set by user.
2262  * - decoding: unused
2263  */
2264  int qmin;
2265 
2266  /**
2267  * maximum quantizer
2268  * - encoding: Set by user.
2269  * - decoding: unused
2270  */
2271  int qmax;
2272 
2273  /**
2274  * maximum quantizer difference between frames
2275  * - encoding: Set by user.
2276  * - decoding: unused
2277  */
2278  int max_qdiff;
2279 
2280 #if FF_API_MPV_OPT
2281  /**
2282  * @deprecated use encoder private options instead
2283  */
2285  float rc_qsquish;
2286 
2288  float rc_qmod_amp;
2290  int rc_qmod_freq;
2291 #endif
2292 
2293  /**
2294  * decoder bitstream buffer size
2295  * - encoding: Set by user.
2296  * - decoding: unused
2297  */
2298  int rc_buffer_size;
2299 
2300  /**
2301  * ratecontrol override, see RcOverride
2302  * - encoding: Allocated/set/freed by user.
2303  * - decoding: unused
2304  */
2307 
2308 #if FF_API_MPV_OPT
2309  /**
2310  * @deprecated use encoder private options instead
2311  */
2313  const char *rc_eq;
2314 #endif
2315 
2316  /**
2317  * maximum bitrate
2318  * - encoding: Set by user.
2319  * - decoding: Set by libavcodec.
2320  */
2321  int rc_max_rate;
2322 
2323  /**
2324  * minimum bitrate
2325  * - encoding: Set by user.
2326  * - decoding: unused
2327  */
2328  int rc_min_rate;
2329 
2330 #if FF_API_MPV_OPT
2331  /**
2332  * @deprecated use encoder private options instead
2333  */
2335  float rc_buffer_aggressivity;
2336 
2338  float rc_initial_cplx;
2339 #endif
2340 
2341  /**
2342  * Ratecontrol attempt to use, at maximum, <value> of what can be used without an underflow.
2343  * - encoding: Set by user.
2344  * - decoding: unused.
2345  */
2347 
2348  /**
2349  * Ratecontrol attempt to use, at least, <value> times the amount needed to prevent a vbv overflow.
2350  * - encoding: Set by user.
2351  * - decoding: unused.
2352  */
2354 
2355  /**
2356  * Number of bits which should be loaded into the rc buffer before decoding starts.
2357  * - encoding: Set by user.
2358  * - decoding: unused
2359  */
2362 #define FF_CODER_TYPE_VLC 0
2363 #define FF_CODER_TYPE_AC 1
2364 #define FF_CODER_TYPE_RAW 2
2365 #define FF_CODER_TYPE_RLE 3
2366 #if FF_API_UNUSED_MEMBERS
2367 #define FF_CODER_TYPE_DEFLATE 4
2368 #endif /* FF_API_UNUSED_MEMBERS */
2369  /**
2370  * coder type
2371  * - encoding: Set by user.
2372  * - decoding: unused
2373  */
2374  int coder_type;
2375 
2376  /**
2377  * context model
2378  * - encoding: Set by user.
2379  * - decoding: unused
2380  */
2381  int context_model;
2382 
2383 #if FF_API_MPV_OPT
2384  /**
2385  * @deprecated use encoder private options instead
2386  */
2388  int lmin;
2389 
2390  /**
2391  * @deprecated use encoder private options instead
2392  */
2394  int lmax;
2395 #endif
2396 
2397  /**
2398  * frame skip threshold
2399  * - encoding: Set by user.
2400  * - decoding: unused
2401  */
2403 
2404  /**
2405  * frame skip factor
2406  * - encoding: Set by user.
2407  * - decoding: unused
2408  */
2409  int frame_skip_factor;
2410 
2411  /**
2412  * frame skip exponent
2413  * - encoding: Set by user.
2414  * - decoding: unused
2415  */
2416  int frame_skip_exp;
2417 
2418  /**
2419  * frame skip comparison function
2420  * - encoding: Set by user.
2421  * - decoding: unused
2422  */
2423  int frame_skip_cmp;
2424 
2425  /**
2426  * trellis RD quantization
2427  * - encoding: Set by user.
2428  * - decoding: unused
2429  */
2430  int trellis;
2431 
2432  /**
2433  * - encoding: Set by user.
2434  * - decoding: unused
2435  */
2437 
2438  /**
2439  * - encoding: Set by user.
2440  * - decoding: unused
2441  */
2443 
2444  /**
2445  * GOP timecode frame start number
2446  * - encoding: Set by user, in non drop frame format
2447  * - decoding: Set by libavcodec (timecode in the 25 bits format, -1 if unset)
2448  */
2449  int64_t timecode_frame_start;
2450 
2451  /* The RTP callback: This function is called */
2452  /* every time the encoder has a packet to send. */
2453  /* It depends on the encoder if the data starts */
2454  /* with a Start Code (it should). H.263 does. */
2455  /* mb_nb contains the number of macroblocks */
2456  /* encoded in the RTP payload. */
2457  void (*rtp_callback)(struct AVCodecContext *avctx, void *data, int size, int mb_nb);
2459  int rtp_payload_size; /* The size of the RTP payload: the coder will */
2460  /* do its best to deliver a chunk with size */
2461  /* below rtp_payload_size, the chunk will start */
2462  /* with a start code on some codecs like H.263. */
2463  /* This doesn't take account of any particular */
2464  /* headers inside the transmitted RTP payload. */
2465 
2466  /* statistics, used for 2-pass encoding */
2467  int mv_bits;
2471  int i_count;
2472  int p_count;
2474  int misc_bits;
2475 
2476  /**
2477  * number of bits used for the previously encoded frame
2478  * - encoding: Set by libavcodec.
2479  * - decoding: unused
2480  */
2481  int frame_bits;
2482 
2483  /**
2484  * pass1 encoding statistics output buffer
2485  * - encoding: Set by libavcodec.
2486  * - decoding: unused
2487  */
2488  char *stats_out;
2489 
2490  /**
2491  * pass2 encoding statistics input buffer
2492  * Concatenated stuff from stats_out of pass1 should be placed here.
2493  * - encoding: Allocated/set/freed by user.
2494  * - decoding: unused
2495  */
2496  char *stats_in;
2497 
2498  /**
2499  * Work around bugs in encoders which sometimes cannot be detected automatically.
2500  * - encoding: Set by user
2501  * - decoding: Set by user
2502  */
2504 #define FF_BUG_AUTODETECT 1 ///< autodetection
2505 #if FF_API_OLD_MSMPEG4
2506 #define FF_BUG_OLD_MSMPEG4 2
2507 #endif
2508 #define FF_BUG_XVID_ILACE 4
2509 #define FF_BUG_UMP4 8
2510 #define FF_BUG_NO_PADDING 16
2511 #define FF_BUG_AMV 32
2512 #if FF_API_AC_VLC
2513 #define FF_BUG_AC_VLC 0 ///< Will be removed, libavcodec can now handle these non-compliant files by default.
2514 #endif
2515 #define FF_BUG_QPEL_CHROMA 64
2516 #define FF_BUG_STD_QPEL 128
2517 #define FF_BUG_QPEL_CHROMA2 256
2518 #define FF_BUG_DIRECT_BLOCKSIZE 512
2519 #define FF_BUG_EDGE 1024
2520 #define FF_BUG_HPEL_CHROMA 2048
2521 #define FF_BUG_DC_CLIP 4096
2522 #define FF_BUG_MS 8192 ///< Work around various bugs in Microsoft's broken decoders.
2523 #define FF_BUG_TRUNCATED 16384
2524 
2525  /**
2526  * strictly follow the standard (MPEG4, ...).
2527  * - encoding: Set by user.
2528  * - decoding: Set by user.
2529  * Setting this to STRICT or higher means the encoder and decoder will
2530  * generally do stupid things, whereas setting it to unofficial or lower
2531  * will mean the encoder might produce output that is not supported by all
2532  * spec-compliant decoders. Decoders don't differentiate between normal,
2533  * unofficial and experimental (that is, they always try to decode things
2534  * when they can) unless they are explicitly asked to behave stupidly
2535  * (=strictly conform to the specs)
2536  */
2538 #define FF_COMPLIANCE_VERY_STRICT 2 ///< Strictly conform to an older more strict version of the spec or reference software.
2539 #define FF_COMPLIANCE_STRICT 1 ///< Strictly conform to all the things in the spec no matter what consequences.
2540 #define FF_COMPLIANCE_NORMAL 0
2541 #define FF_COMPLIANCE_UNOFFICIAL -1 ///< Allow unofficial extensions
2542 #define FF_COMPLIANCE_EXPERIMENTAL -2 ///< Allow nonstandardized experimental things.
2543 
2544  /**
2545  * error concealment flags
2546  * - encoding: unused
2547  * - decoding: Set by user.
2548  */
2550 #define FF_EC_GUESS_MVS 1
2551 #define FF_EC_DEBLOCK 2
2552 #define FF_EC_FAVOR_INTER 256
2553 
2554  /**
2555  * debug
2556  * - encoding: Set by user.
2557  * - decoding: Set by user.
2558  */
2559  int debug;
2560 #define FF_DEBUG_PICT_INFO 1
2561 #define FF_DEBUG_RC 2
2562 #define FF_DEBUG_BITSTREAM 4
2563 #define FF_DEBUG_MB_TYPE 8
2564 #define FF_DEBUG_QP 16
2565 #if FF_API_DEBUG_MV
2566 /**
2567  * @deprecated this option does nothing
2568  */
2569 #define FF_DEBUG_MV 32
2570 #endif
2571 #define FF_DEBUG_DCT_COEFF 0x00000040
2572 #define FF_DEBUG_SKIP 0x00000080
2573 #define FF_DEBUG_STARTCODE 0x00000100
2574 #if FF_API_UNUSED_MEMBERS
2575 #define FF_DEBUG_PTS 0x00000200
2576 #endif /* FF_API_UNUSED_MEMBERS */
2577 #define FF_DEBUG_ER 0x00000400
2578 #define FF_DEBUG_MMCO 0x00000800
2579 #define FF_DEBUG_BUGS 0x00001000
2580 #if FF_API_DEBUG_MV
2581 #define FF_DEBUG_VIS_QP 0x00002000 ///< only access through AVOptions from outside libavcodec
2582 #define FF_DEBUG_VIS_MB_TYPE 0x00004000 ///< only access through AVOptions from outside libavcodec
2583 #endif
2584 #define FF_DEBUG_BUFFERS 0x00008000
2585 #define FF_DEBUG_THREADS 0x00010000
2586 #define FF_DEBUG_NOMC 0x01000000
2587 
2588 #if FF_API_DEBUG_MV
2589  /**
2590  * debug
2591  * Code outside libavcodec should access this field using AVOptions
2592  * - encoding: Set by user.
2593  * - decoding: Set by user.
2594  */
2596 #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 //visualize forward predicted MVs of P frames
2597 #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 //visualize forward predicted MVs of B frames
2598 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
2599 #endif
2600 
2601  /**
2602  * Error recognition; may misdetect some more or less valid parts as errors.
2603  * - encoding: unused
2604  * - decoding: Set by user.
2605  */
2606  int err_recognition;
2607 
2608 /**
2609  * Verify checksums embedded in the bitstream (could be of either encoded or
2610  * decoded data, depending on the codec) and print an error message on mismatch.
2611  * If AV_EF_EXPLODE is also set, a mismatching checksum will result in the
2612  * decoder returning an error.
2613  */
2614 #define AV_EF_CRCCHECK (1<<0)
2615 #define AV_EF_BITSTREAM (1<<1) ///< detect bitstream specification deviations
2616 #define AV_EF_BUFFER (1<<2) ///< detect improper bitstream length
2617 #define AV_EF_EXPLODE (1<<3) ///< abort decoding on minor error detection
2619 #define AV_EF_IGNORE_ERR (1<<15) ///< ignore errors and continue
2620 #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
2621 #define AV_EF_COMPLIANT (1<<17) ///< consider all spec non compliances as errors
2622 #define AV_EF_AGGRESSIVE (1<<18) ///< consider things that a sane encoder should not do as an error
2623 
2624 
2625  /**
2626  * opaque 64bit number (generally a PTS) that will be reordered and
2627  * output in AVFrame.reordered_opaque
2628  * - encoding: unused
2629  * - decoding: Set by user.
2630  */
2631  int64_t reordered_opaque;
2632 
2633  /**
2634  * Hardware accelerator in use
2635  * - encoding: unused.
2636  * - decoding: Set by libavcodec
2637  */
2638  struct AVHWAccel *hwaccel;
2639 
2640  /**
2641  * Hardware accelerator context.
2642  * For some hardware accelerators, a global context needs to be
2643  * provided by the user. In that case, this holds display-dependent
2644  * data FFmpeg cannot instantiate itself. Please refer to the
2645  * FFmpeg HW accelerator documentation to know how to fill this
2646  * is. e.g. for VA API, this is a struct vaapi_context.
2647  * - encoding: unused
2648  * - decoding: Set by user
2649  */
2650  void *hwaccel_context;
2651 
2652  /**
2653  * error
2654  * - encoding: Set by libavcodec if flags&CODEC_FLAG_PSNR.
2655  * - decoding: unused
2656  */
2657  uint64_t error[AV_NUM_DATA_POINTERS];
2658 
2659  /**
2660  * DCT algorithm, see FF_DCT_* below
2661  * - encoding: Set by user.
2662  * - decoding: unused
2663  */
2665 #define FF_DCT_AUTO 0
2666 #define FF_DCT_FASTINT 1
2667 #if FF_API_UNUSED_MEMBERS
2668 #define FF_DCT_INT 2
2669 #endif /* FF_API_UNUSED_MEMBERS */
2670 #define FF_DCT_MMX 3
2671 #define FF_DCT_ALTIVEC 5
2672 #define FF_DCT_FAAN 6
2673 
2674  /**
2675  * IDCT algorithm, see FF_IDCT_* below.
2676  * - encoding: Set by user.
2677  * - decoding: Set by user.
2678  */
2680 #define FF_IDCT_AUTO 0
2681 #define FF_IDCT_INT 1
2682 #define FF_IDCT_SIMPLE 2
2683 #define FF_IDCT_SIMPLEMMX 3
2684 #define FF_IDCT_ARM 7
2685 #define FF_IDCT_ALTIVEC 8
2686 #if FF_API_ARCH_SH4
2687 #define FF_IDCT_SH4 9
2688 #endif
2689 #define FF_IDCT_SIMPLEARM 10
2690 #if FF_API_UNUSED_MEMBERS
2691 #define FF_IDCT_IPP 13
2692 #endif /* FF_API_UNUSED_MEMBERS */
2693 #define FF_IDCT_XVID 14
2694 #if FF_API_IDCT_XVIDMMX
2695 #define FF_IDCT_XVIDMMX 14
2696 #endif /* FF_API_IDCT_XVIDMMX */
2697 #define FF_IDCT_SIMPLEARMV5TE 16
2698 #define FF_IDCT_SIMPLEARMV6 17
2699 #if FF_API_ARCH_SPARC
2700 #define FF_IDCT_SIMPLEVIS 18
2701 #endif
2702 #define FF_IDCT_FAAN 20
2703 #define FF_IDCT_SIMPLENEON 22
2704 #if FF_API_ARCH_ALPHA
2705 #define FF_IDCT_SIMPLEALPHA 23
2706 #endif
2707 #define FF_IDCT_SIMPLEAUTO 128
2708 
2709  /**
2710  * bits per sample/pixel from the demuxer (needed for huffyuv).
2711  * - encoding: Set by libavcodec.
2712  * - decoding: Set by user.
2713  */
2715 
2716  /**
2717  * Bits per sample/pixel of internal libavcodec pixel/sample format.
2718  * - encoding: set by user.
2719  * - decoding: set by libavcodec.
2720  */
2721  int bits_per_raw_sample;
2722 
2723 #if FF_API_LOWRES
2724  /**
2725  * low resolution decoding, 1-> 1/2 size, 2->1/4 size
2726  * - encoding: unused
2727  * - decoding: Set by user.
2728  * Code outside libavcodec should access this field using:
2729  * av_codec_{get,set}_lowres(avctx)
2730  */
2731  int lowres;
2732 #endif
2733 
2734  /**
2735  * the picture in the bitstream
2736  * - encoding: Set by libavcodec.
2737  * - decoding: unused
2738  */
2740 
2741  /**
2742  * thread count
2743  * is used to decide how many independent tasks should be passed to execute()
2744  * - encoding: Set by user.
2745  * - decoding: Set by user.
2746  */
2747  int thread_count;
2748 
2749  /**
2750  * Which multithreading methods to use.
2751  * Use of FF_THREAD_FRAME will increase decoding delay by one frame per thread,
2752  * so clients which cannot provide future frames should not use it.
2753  *
2754  * - encoding: Set by user, otherwise the default is used.
2755  * - decoding: Set by user, otherwise the default is used.
2756  */
2758 #define FF_THREAD_FRAME 1 ///< Decode more than one frame at once
2759 #define FF_THREAD_SLICE 2 ///< Decode more than one part of a single frame at once
2760 
2761  /**
2762  * Which multithreading methods are in use by the codec.
2763  * - encoding: Set by libavcodec.
2764  * - decoding: Set by libavcodec.
2765  */
2766  int active_thread_type;
2767 
2768  /**
2769  * Set by the client if its custom get_buffer() callback can be called
2770  * synchronously from another thread, which allows faster multithreaded decoding.
2771  * draw_horiz_band() will be called from other threads regardless of this setting.
2772  * Ignored if the default get_buffer() is used.
2773  * - encoding: Set by user.
2774  * - decoding: Set by user.
2775  */
2777 
2778  /**
2779  * The codec may call this to execute several independent things.
2780  * It will return only after finishing all tasks.
2781  * The user may replace this with some multithreaded implementation,
2782  * the default implementation will execute the parts serially.
2783  * @param count the number of things to execute
2784  * - encoding: Set by libavcodec, user can override.
2785  * - decoding: Set by libavcodec, user can override.
2786  */
2787  int (*execute)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size);
2788 
2789  /**
2790  * The codec may call this to execute several independent things.
2791  * It will return only after finishing all tasks.
2792  * The user may replace this with some multithreaded implementation,
2793  * the default implementation will execute the parts serially.
2794  * Also see avcodec_thread_init and e.g. the --enable-pthread configure option.
2795  * @param c context passed also to func
2796  * @param count the number of things to execute
2797  * @param arg2 argument passed unchanged to func
2798  * @param ret return values of executed functions, must have space for "count" values. May be NULL.
2799  * @param func function that will be called count times, with jobnr from 0 to count-1.
2800  * threadnr will be in the range 0 to c->thread_count-1 < MAX_THREADS and so that no
2801  * two instances of func executing at the same time will have the same threadnr.
2802  * @return always 0 currently, but code should handle a future improvement where when any call to func
2803  * returns < 0 no further calls to func may be done and < 0 is returned.
2804  * - encoding: Set by libavcodec, user can override.
2805  * - decoding: Set by libavcodec, user can override.
2806  */
2807  int (*execute2)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count);
2808 
2809 #if FF_API_THREAD_OPAQUE
2810  /**
2811  * @deprecated this field should not be used from outside of lavc
2812  */
2814  void *thread_opaque;
2815 #endif
2816 
2817  /**
2818  * noise vs. sse weight for the nsse comparison function
2819  * - encoding: Set by user.
2820  * - decoding: unused
2821  */
2822  int nsse_weight;
2823 
2824  /**
2825  * profile
2826  * - encoding: Set by user.
2827  * - decoding: Set by libavcodec.
2828  */
2829  int profile;
2830 #define FF_PROFILE_UNKNOWN -99
2831 #define FF_PROFILE_RESERVED -100
2833 #define FF_PROFILE_AAC_MAIN 0
2834 #define FF_PROFILE_AAC_LOW 1
2835 #define FF_PROFILE_AAC_SSR 2
2836 #define FF_PROFILE_AAC_LTP 3
2837 #define FF_PROFILE_AAC_HE 4
2838 #define FF_PROFILE_AAC_HE_V2 28
2839 #define FF_PROFILE_AAC_LD 22
2840 #define FF_PROFILE_AAC_ELD 38
2841 #define FF_PROFILE_MPEG2_AAC_LOW 128
2842 #define FF_PROFILE_MPEG2_AAC_HE 131
2844 #define FF_PROFILE_DTS 20
2845 #define FF_PROFILE_DTS_ES 30
2846 #define FF_PROFILE_DTS_96_24 40
2847 #define FF_PROFILE_DTS_HD_HRA 50
2848 #define FF_PROFILE_DTS_HD_MA 60
2850 #define FF_PROFILE_MPEG2_422 0
2851 #define FF_PROFILE_MPEG2_HIGH 1
2852 #define FF_PROFILE_MPEG2_SS 2
2853 #define FF_PROFILE_MPEG2_SNR_SCALABLE 3
2854 #define FF_PROFILE_MPEG2_MAIN 4
2855 #define FF_PROFILE_MPEG2_SIMPLE 5
2857 #define FF_PROFILE_H264_CONSTRAINED (1<<9) // 8+1; constraint_set1_flag
2858 #define FF_PROFILE_H264_INTRA (1<<11) // 8+3; constraint_set3_flag
2860 #define FF_PROFILE_H264_BASELINE 66
2861 #define FF_PROFILE_H264_CONSTRAINED_BASELINE (66|FF_PROFILE_H264_CONSTRAINED)
2862 #define FF_PROFILE_H264_MAIN 77
2863 #define FF_PROFILE_H264_EXTENDED 88
2864 #define FF_PROFILE_H264_HIGH 100
2865 #define FF_PROFILE_H264_HIGH_10 110
2866 #define FF_PROFILE_H264_HIGH_10_INTRA (110|FF_PROFILE_H264_INTRA)
2867 #define FF_PROFILE_H264_HIGH_422 122
2868 #define FF_PROFILE_H264_HIGH_422_INTRA (122|FF_PROFILE_H264_INTRA)
2869 #define FF_PROFILE_H264_HIGH_444 144
2870 #define FF_PROFILE_H264_HIGH_444_PREDICTIVE 244
2871 #define FF_PROFILE_H264_HIGH_444_INTRA (244|FF_PROFILE_H264_INTRA)
2872 #define FF_PROFILE_H264_CAVLC_444 44
2874 #define FF_PROFILE_VC1_SIMPLE 0
2875 #define FF_PROFILE_VC1_MAIN 1
2876 #define FF_PROFILE_VC1_COMPLEX 2
2877 #define FF_PROFILE_VC1_ADVANCED 3
2879 #define FF_PROFILE_MPEG4_SIMPLE 0
2880 #define FF_PROFILE_MPEG4_SIMPLE_SCALABLE 1
2881 #define FF_PROFILE_MPEG4_CORE 2
2882 #define FF_PROFILE_MPEG4_MAIN 3
2883 #define FF_PROFILE_MPEG4_N_BIT 4
2884 #define FF_PROFILE_MPEG4_SCALABLE_TEXTURE 5
2885 #define FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION 6
2886 #define FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE 7
2887 #define FF_PROFILE_MPEG4_HYBRID 8
2888 #define FF_PROFILE_MPEG4_ADVANCED_REAL_TIME 9
2889 #define FF_PROFILE_MPEG4_CORE_SCALABLE 10
2890 #define FF_PROFILE_MPEG4_ADVANCED_CODING 11
2891 #define FF_PROFILE_MPEG4_ADVANCED_CORE 12
2892 #define FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE 13
2893 #define FF_PROFILE_MPEG4_SIMPLE_STUDIO 14
2894 #define FF_PROFILE_MPEG4_ADVANCED_SIMPLE 15
2896 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_0 0
2897 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_1 1
2898 #define FF_PROFILE_JPEG2000_CSTREAM_NO_RESTRICTION 2
2899 #define FF_PROFILE_JPEG2000_DCINEMA_2K 3
2900 #define FF_PROFILE_JPEG2000_DCINEMA_4K 4
2901 
2903 #define FF_PROFILE_HEVC_MAIN 1
2904 #define FF_PROFILE_HEVC_MAIN_10 2
2905 #define FF_PROFILE_HEVC_MAIN_STILL_PICTURE 3
2906 #define FF_PROFILE_HEVC_REXT 4
2907 
2908  /**
2909  * level
2910  * - encoding: Set by user.
2911  * - decoding: Set by libavcodec.
2912  */
2913  int level;
2914 #define FF_LEVEL_UNKNOWN -99
2915 
2916  /**
2917  * Skip loop filtering for selected frames.
2918  * - encoding: unused
2919  * - decoding: Set by user.
2920  */
2922 
2923  /**
2924  * Skip IDCT/dequantization for selected frames.
2925  * - encoding: unused
2926  * - decoding: Set by user.
2927  */
2928  enum AVDiscard skip_idct;
2929 
2930  /**
2931  * Skip decoding for selected frames.
2932  * - encoding: unused
2933  * - decoding: Set by user.
2934  */
2935  enum AVDiscard skip_frame;
2936 
2937  /**
2938  * Header containing style information for text subtitles.
2939  * For SUBTITLE_ASS subtitle type, it should contain the whole ASS
2940  * [Script Info] and [V4+ Styles] section, plus the [Events] line and
2941  * the Format line following. It shouldn't include any Dialogue line.
2942  * - encoding: Set/allocated/freed by user (before avcodec_open2())
2943  * - decoding: Set/allocated/freed by libavcodec (by avcodec_open2())
2944  */
2947 
2948 #if FF_API_ERROR_RATE
2949  /**
2950  * @deprecated use the 'error_rate' private AVOption of the mpegvideo
2951  * encoders
2952  */
2954  int error_rate;
2955 #endif
2956 
2957 #if FF_API_CODEC_PKT
2958  /**
2959  * @deprecated this field is not supposed to be accessed from outside lavc
2960  */
2962  AVPacket *pkt;
2963 #endif
2964 
2965  /**
2966  * VBV delay coded in the last frame (in periods of a 27 MHz clock).
2967  * Used for compliant TS muxing.
2968  * - encoding: Set by libavcodec.
2969  * - decoding: unused.
2970  */
2971  uint64_t vbv_delay;
2972 
2973  /**
2974  * Encoding only. Allow encoders to output packets that do not contain any
2975  * encoded data, only side data.
2976  *
2977  * Some encoders need to output such packets, e.g. to update some stream
2978  * parameters at the end of encoding.
2979  *
2980  * All callers are strongly recommended to set this option to 1 and update
2981  * their code to deal with such packets, since this behaviour may become
2982  * always enabled in the future (then this option will be deprecated and
2983  * later removed). To avoid ABI issues when this happens, the callers should
2984  * use AVOptions to set this field.
2985  */
2987 
2988  /**
2989  * Audio only. The number of "priming" samples (padding) inserted by the
2990  * encoder at the beginning of the audio. I.e. this number of leading
2991  * decoded samples must be discarded by the caller to get the original audio
2992  * without leading padding.
2993  *
2994  * - decoding: unused
2995  * - encoding: Set by libavcodec. The timestamps on the output packets are
2996  * adjusted by the encoder so that they always refer to the
2997  * first sample of the data actually contained in the packet,
2998  * including any added padding. E.g. if the timebase is
2999  * 1/samplerate and the timestamp of the first input sample is
3000  * 0, the timestamp of the first output packet will be
3001  * -initial_padding.
3002  */
3003  int initial_padding;
3004 
3005  /**
3006  * - decoding: For codecs that store a framerate value in the compressed
3007  * bitstream, the decoder may export it here. { 0, 1} when
3008  * unknown.
3009  * - encoding: unused
3010  */
3012 
3013  /**
3014  * Nominal unaccelerated pixel format, see AV_PIX_FMT_xxx.
3015  * - encoding: unused.
3016  * - decoding: Set by libavcodec before calling get_format()
3017  */
3019 
3020  /**
3021  * Timebase in which pkt_dts/pts and AVPacket.dts/pts are.
3022  * Code outside libavcodec should access this field using:
3023  * av_codec_{get,set}_pkt_timebase(avctx)
3024  * - encoding unused.
3025  * - decoding set by user.
3026  */
3028 
3029  /**
3030  * AVCodecDescriptor
3031  * Code outside libavcodec should access this field using:
3032  * av_codec_{get,set}_codec_descriptor(avctx)
3033  * - encoding: unused.
3034  * - decoding: set by libavcodec.
3035  */
3037 
3038 #if !FF_API_LOWRES
3039  /**
3040  * low resolution decoding, 1-> 1/2 size, 2->1/4 size
3041  * - encoding: unused
3042  * - decoding: Set by user.
3043  * Code outside libavcodec should access this field using:
3044  * av_codec_{get,set}_lowres(avctx)
3045  */
3046  int lowres;
3047 #endif
3048 
3049  /**
3050  * Current statistics for PTS correction.
3051  * - decoding: maintained and used by libavcodec, not intended to be used by user apps
3052  * - encoding: unused
3053  */
3054  int64_t pts_correction_num_faulty_pts; /// Number of incorrect PTS values so far
3055  int64_t pts_correction_num_faulty_dts; /// Number of incorrect DTS values so far
3056  int64_t pts_correction_last_pts; /// PTS of the last frame
3057  int64_t pts_correction_last_dts; /// DTS of the last frame
3058 
3059  /**
3060  * Character encoding of the input subtitles file.
3061  * - decoding: set by user
3062  * - encoding: unused
3063  */
3064  char *sub_charenc;
3065 
3066  /**
3067  * Subtitles character encoding mode. Formats or codecs might be adjusting
3068  * this setting (if they are doing the conversion themselves for instance).
3069  * - decoding: set by libavcodec
3070  * - encoding: unused
3071  */
3073 #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)
3074 #define FF_SUB_CHARENC_MODE_AUTOMATIC 0 ///< libavcodec will select the mode itself
3075 #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
3076 
3077  /**
3078  * Skip processing alpha if supported by codec.
3079  * Note that if the format uses pre-multiplied alpha (common with VP6,
3080  * and recommended due to better video quality/compression)
3081  * the image will look as if alpha-blended onto a black background.
3082  * However for formats that do not use pre-multiplied alpha
3083  * there might be serious artefacts (though e.g. libswscale currently
3084  * assumes pre-multiplied alpha anyway).
3085  * Code outside libavcodec should access this field using AVOptions
3086  *
3087  * - decoding: set by user
3088  * - encoding: unused
3089  */
3090  int skip_alpha;
3091 
3092  /**
3093  * Number of samples to skip after a discontinuity
3094  * - decoding: unused
3095  * - encoding: set by libavcodec
3096  */
3097  int seek_preroll;
3098 
3099 #if !FF_API_DEBUG_MV
3100  /**
3101  * debug motion vectors
3102  * Code outside libavcodec should access this field using AVOptions
3103  * - encoding: Set by user.
3104  * - decoding: Set by user.
3105  */
3106  int debug_mv;
3107 #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 //visualize forward predicted MVs of P frames
3108 #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 //visualize forward predicted MVs of B frames
3109 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
3110 #endif
3111 
3112  /**
3113  * custom intra quantization matrix
3114  * Code outside libavcodec should access this field using av_codec_g/set_chroma_intra_matrix()
3115  * - encoding: Set by user, can be NULL.
3116  * - decoding: unused.
3117  */
3118  uint16_t *chroma_intra_matrix;
3119 
3120  /**
3121  * dump format separator.
3122  * can be ", " or "\n " or anything else
3123  * Code outside libavcodec should access this field using AVOptions
3124  * (NO direct access).
3125  * - encoding: Set by user.
3126  * - decoding: Set by user.
3127  */
3129 
3130  /**
3131  * ',' separated list of allowed decoders.
3132  * If NULL then all are allowed
3133  * - encoding: unused
3134  * - decoding: set by user through AVOPtions (NO direct access)
3135  */
3136  char *codec_whitelist;
3137 } AVCodecContext;
3138 
3141 
3144 
3145 int av_codec_get_lowres(const AVCodecContext *avctx);
3146 void av_codec_set_lowres(AVCodecContext *avctx, int val);
3147 
3148 int av_codec_get_seek_preroll(const AVCodecContext *avctx);
3149 void av_codec_set_seek_preroll(AVCodecContext *avctx, int val);
3150 
3151 uint16_t *av_codec_get_chroma_intra_matrix(const AVCodecContext *avctx);
3152 void av_codec_set_chroma_intra_matrix(AVCodecContext *avctx, uint16_t *val);
3153 
3154 /**
3155  * AVProfile.
3156  */
3157 typedef struct AVProfile {
3158  int profile;
3159  const char *name; ///< short name for the profile
3160 } AVProfile;
3161 
3162 typedef struct AVCodecDefault AVCodecDefault;
3163 
3164 struct AVSubtitle;
3165 
3166 /**
3167  * AVCodec.
3168  */
3169 typedef struct AVCodec {
3170  /**
3171  * Name of the codec implementation.
3172  * The name is globally unique among encoders and among decoders (but an
3173  * encoder and a decoder can share the same name).
3174  * This is the primary way to find a codec from the user perspective.
3175  */
3176  const char *name;
3177  /**
3178  * Descriptive name for the codec, meant to be more human readable than name.
3179  * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
3180  */
3181  const char *long_name;
3183  enum AVCodecID id;
3184  /**
3185  * Codec capabilities.
3186  * see CODEC_CAP_*
3187  */
3189  const AVRational *supported_framerates; ///< array of supported framerates, or NULL if any, array is terminated by {0,0}
3190  const enum AVPixelFormat *pix_fmts; ///< array of supported pixel formats, or NULL if unknown, array is terminated by -1
3191  const int *supported_samplerates; ///< array of supported audio samplerates, or NULL if unknown, array is terminated by 0
3192  const enum AVSampleFormat *sample_fmts; ///< array of supported sample formats, or NULL if unknown, array is terminated by -1
3193  const uint64_t *channel_layouts; ///< array of support channel layouts, or NULL if unknown. array is terminated by 0
3194 #if FF_API_LOWRES
3195  uint8_t max_lowres; ///< maximum value for lowres supported by the decoder, no direct access, use av_codec_get_max_lowres()
3196 #endif
3197  const AVClass *priv_class; ///< AVClass for the private context
3198  const AVProfile *profiles; ///< array of recognized profiles, or NULL if unknown, array is terminated by {FF_PROFILE_UNKNOWN}
3199 
3200  /*****************************************************************
3201  * No fields below this line are part of the public API. They
3202  * may not be used outside of libavcodec and can be changed and
3203  * removed at will.
3204  * New public fields should be added right above.
3205  *****************************************************************
3206  */
3208  struct AVCodec *next;
3209  /**
3210  * @name Frame-level threading support functions
3211  * @{
3212  */
3213  /**
3214  * If defined, called on thread contexts when they are created.
3215  * If the codec allocates writable tables in init(), re-allocate them here.
3216  * priv_data will be set to a copy of the original.
3217  */
3218  int (*init_thread_copy)(AVCodecContext *);
3219  /**
3220  * Copy necessary context variables from a previous thread context to the current one.
3221  * If not defined, the next thread will start automatically; otherwise, the codec
3222  * must call ff_thread_finish_setup().
3223  *
3224  * dst and src will (rarely) point to the same context, in which case memcpy should be skipped.
3225  */
3227  /** @} */
3228 
3229  /**
3230  * Private codec-specific defaults.
3231  */
3232  const AVCodecDefault *defaults;
3233 
3234  /**
3235  * Initialize codec static data, called from avcodec_register().
3236  */
3237  void (*init_static_data)(struct AVCodec *codec);
3240  int (*encode_sub)(AVCodecContext *, uint8_t *buf, int buf_size,
3241  const struct AVSubtitle *sub);
3242  /**
3243  * Encode data to an AVPacket.
3244  *
3245  * @param avctx codec context
3246  * @param avpkt output AVPacket (may contain a user-provided buffer)
3247  * @param[in] frame AVFrame containing the raw data to be encoded
3248  * @param[out] got_packet_ptr encoder sets to 0 or 1 to indicate that a
3249  * non-empty packet was returned in avpkt.
3250  * @return 0 on success, negative error code on failure
3251  */
3252  int (*encode2)(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame,
3253  int *got_packet_ptr);
3254  int (*decode)(AVCodecContext *, void *outdata, int *outdata_size, AVPacket *avpkt);
3255  int (*close)(AVCodecContext *);
3256  /**
3257  * Flush buffers.
3258  * Will be called when seeking
3259  */
3260  void (*flush)(AVCodecContext *);
3261 } AVCodec;
3262 
3263 int av_codec_get_max_lowres(const AVCodec *codec);
3264 
3265 struct MpegEncContext;
3266 
3267 /**
3268  * @defgroup lavc_hwaccel AVHWAccel
3269  * @{
3270  */
3271 typedef struct AVHWAccel {
3272  /**
3273  * Name of the hardware accelerated codec.
3274  * The name is globally unique among encoders and among decoders (but an
3275  * encoder and a decoder can share the same name).
3276  */
3277  const char *name;
3278 
3279  /**
3280  * Type of codec implemented by the hardware accelerator.
3281  *
3282  * See AVMEDIA_TYPE_xxx
3283  */
3284  enum AVMediaType type;
3285 
3286  /**
3287  * Codec implemented by the hardware accelerator.
3288  *
3289  * See AV_CODEC_ID_xxx
3290  */
3291  enum AVCodecID id;
3292 
3293  /**
3294  * Supported pixel format.
3295  *
3296  * Only hardware accelerated formats are supported here.
3297  */
3298  enum AVPixelFormat pix_fmt;
3299 
3300  /**
3301  * Hardware accelerated codec capabilities.
3302  * see FF_HWACCEL_CODEC_CAP_*
3303  */
3304  int capabilities;
3305 
3306  /*****************************************************************
3307  * No fields below this line are part of the public API. They
3308  * may not be used outside of libavcodec and can be changed and
3309  * removed at will.
3310  * New public fields should be added right above.
3311  *****************************************************************
3312  */
3313  struct AVHWAccel *next;
3314 
3315  /**
3316  * Allocate a custom buffer
3317  */
3318  int (*alloc_frame)(AVCodecContext *avctx, AVFrame *frame);
3319 
3320  /**
3321  * Called at the beginning of each frame or field picture.
3322  *
3323  * Meaningful frame information (codec specific) is guaranteed to
3324  * be parsed at this point. This function is mandatory.
3325  *
3326  * Note that buf can be NULL along with buf_size set to 0.
3327  * Otherwise, this means the whole frame is available at this point.
3328  *
3329  * @param avctx the codec context
3330  * @param buf the frame data buffer base
3331  * @param buf_size the size of the frame in bytes
3332  * @return zero if successful, a negative value otherwise
3333  */
3334  int (*start_frame)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3335 
3336  /**
3337  * Callback for each slice.
3338  *
3339  * Meaningful slice information (codec specific) is guaranteed to
3340  * be parsed at this point. This function is mandatory.
3341  * The only exception is XvMC, that works on MB level.
3342  *
3343  * @param avctx the codec context
3344  * @param buf the slice data buffer base
3345  * @param buf_size the size of the slice in bytes
3346  * @return zero if successful, a negative value otherwise
3347  */
3348  int (*decode_slice)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3349 
3350  /**
3351  * Called at the end of each frame or field picture.
3352  *
3353  * The whole picture is parsed at this point and can now be sent
3354  * to the hardware accelerator. This function is mandatory.
3355  *
3356  * @param avctx the codec context
3357  * @return zero if successful, a negative value otherwise
3358  */
3359  int (*end_frame)(AVCodecContext *avctx);
3360 
3361  /**
3362  * Size of per-frame hardware accelerator private data.
3363  *
3364  * Private data is allocated with av_mallocz() before
3365  * AVCodecContext.get_buffer() and deallocated after
3366  * AVCodecContext.release_buffer().
3367  */
3369 
3370  /**
3371  * Called for every Macroblock in a slice.
3372  *
3373  * XvMC uses it to replace the ff_mpv_decode_mb().
3374  * Instead of decoding to raw picture, MB parameters are
3375  * stored in an array provided by the video driver.
3376  *
3377  * @param s the mpeg context
3378  */
3379  void (*decode_mb)(struct MpegEncContext *s);
3380 
3381  /**
3382  * Initialize the hwaccel private data.
3383  *
3384  * This will be called from ff_get_format(), after hwaccel and
3385  * hwaccel_context are set and the hwaccel private data in AVCodecInternal
3386  * is allocated.
3387  */
3388  int (*init)(AVCodecContext *avctx);
3389 
3390  /**
3391  * Uninitialize the hwaccel private data.
3392  *
3393  * This will be called from get_format() or avcodec_close(), after hwaccel
3394  * and hwaccel_context are already uninitialized.
3395  */
3396  int (*uninit)(AVCodecContext *avctx);
3397 
3398  /**
3399  * Size of the private data to allocate in
3400  * AVCodecInternal.hwaccel_priv_data.
3401  */
3402  int priv_data_size;
3403 } AVHWAccel;
3404 
3405 /**
3406  * Hardware acceleration should be used for decoding even if the codec level
3407  * used is unknown or higher than the maximum supported level reported by the
3408  * hardware driver.
3409  */
3410 #define AV_HWACCEL_FLAG_IGNORE_LEVEL (1 << 0)
3411 
3412 /**
3413  * Hardware acceleration can output YUV pixel formats with a different chroma
3414  * sampling than 4:2:0 and/or other than 8 bits per component.
3415  */
3416 #define AV_HWACCEL_FLAG_ALLOW_HIGH_DEPTH (1 << 1)
3417 
3418 /**
3419  * @}
3420  */
3421 
3422 /**
3423  * @defgroup lavc_picture AVPicture
3424  *
3425  * Functions for working with AVPicture
3426  * @{
3427  */
3428 
3429 /**
3430  * Picture data structure.
3431  *
3432  * Up to four components can be stored into it, the last component is
3433  * alpha.
3434  */
3435 typedef struct AVPicture {
3436  uint8_t *data[AV_NUM_DATA_POINTERS]; ///< pointers to the image data planes
3437  int linesize[AV_NUM_DATA_POINTERS]; ///< number of bytes per line
3438 } AVPicture;
3439 
3440 /**
3441  * @}
3442  */
3445  SUBTITLE_NONE,
3447  SUBTITLE_BITMAP, ///< A bitmap, pict will be set
3448 
3449  /**
3450  * Plain text, the text field must be set by the decoder and is
3451  * authoritative. ass and pict fields may contain approximations.
3452  */
3453  SUBTITLE_TEXT,
3454 
3455  /**
3456  * Formatted text, the ass field must be set by the decoder and is
3457  * authoritative. pict and text fields may contain approximations.
3458  */
3459  SUBTITLE_ASS,
3460 };
3462 #define AV_SUBTITLE_FLAG_FORCED 0x00000001
3464 typedef struct AVSubtitleRect {
3465  int x; ///< top left corner of pict, undefined when pict is not set
3466  int y; ///< top left corner of pict, undefined when pict is not set
3467  int w; ///< width of pict, undefined when pict is not set
3468  int h; ///< height of pict, undefined when pict is not set
3469  int nb_colors; ///< number of colors in pict, undefined when pict is not set
3470 
3471  /**
3472  * data+linesize for the bitmap of this subtitle.
3473  * can be set for text/ass as well once they are rendered
3474  */
3476  enum AVSubtitleType type;
3478  char *text; ///< 0 terminated plain UTF-8 text
3479 
3480  /**
3481  * 0 terminated ASS/SSA compatible event line.
3482  * The presentation of this is unaffected by the other values in this
3483  * struct.
3484  */
3485  char *ass;
3487  int flags;
3488 } AVSubtitleRect;
3490 typedef struct AVSubtitle {
3491  uint16_t format; /* 0 = graphics */
3492  uint32_t start_display_time; /* relative to packet pts, in ms */
3493  uint32_t end_display_time; /* relative to packet pts, in ms */
3494  unsigned num_rects;
3496  int64_t pts; ///< Same as packet pts, in AV_TIME_BASE
3497 } AVSubtitle;
3498 
3499 /**
3500  * If c is NULL, returns the first registered codec,
3501  * if c is non-NULL, returns the next registered codec after c,
3502  * or NULL if c is the last one.
3503  */
3504 AVCodec *av_codec_next(const AVCodec *c);
3505 
3506 /**
3507  * Return the LIBAVCODEC_VERSION_INT constant.
3508  */
3509 unsigned avcodec_version(void);
3510 
3511 /**
3512  * Return the libavcodec build-time configuration.
3513  */
3514 const char *avcodec_configuration(void);
3515 
3516 /**
3517  * Return the libavcodec license.
3518  */
3519 const char *avcodec_license(void);
3520 
3521 /**
3522  * Register the codec codec and initialize libavcodec.
3523  *
3524  * @warning either this function or avcodec_register_all() must be called
3525  * before any other libavcodec functions.
3526  *
3527  * @see avcodec_register_all()
3528  */
3529 void avcodec_register(AVCodec *codec);
3530 
3531 /**
3532  * Register all the codecs, parsers and bitstream filters which were enabled at
3533  * configuration time. If you do not call this function you can select exactly
3534  * which formats you want to support, by using the individual registration
3535  * functions.
3536  *
3537  * @see avcodec_register
3538  * @see av_register_codec_parser
3539  * @see av_register_bitstream_filter
3540  */
3541 void avcodec_register_all(void);
3542 
3543 /**
3544  * Allocate an AVCodecContext and set its fields to default values. The
3545  * resulting struct should be freed with avcodec_free_context().
3546  *
3547  * @param codec if non-NULL, allocate private data and initialize defaults
3548  * for the given codec. It is illegal to then call avcodec_open2()
3549  * with a different codec.
3550  * If NULL, then the codec-specific defaults won't be initialized,
3551  * which may result in suboptimal default settings (this is
3552  * important mainly for encoders, e.g. libx264).
3553  *
3554  * @return An AVCodecContext filled with default values or NULL on failure.
3555  * @see avcodec_get_context_defaults
3556  */
3558 
3559 /**
3560  * Free the codec context and everything associated with it and write NULL to
3561  * the provided pointer.
3562  */
3563 void avcodec_free_context(AVCodecContext **avctx);
3564 
3565 /**
3566  * Set the fields of the given AVCodecContext to default values corresponding
3567  * to the given codec (defaults may be codec-dependent).
3568  *
3569  * Do not call this function if a non-NULL codec has been passed
3570  * to avcodec_alloc_context3() that allocated this AVCodecContext.
3571  * If codec is non-NULL, it is illegal to call avcodec_open2() with a
3572  * different codec on this AVCodecContext.
3573  */
3575 
3576 /**
3577  * Get the AVClass for AVCodecContext. It can be used in combination with
3578  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
3579  *
3580  * @see av_opt_find().
3581  */
3582 const AVClass *avcodec_get_class(void);
3583 
3584 /**
3585  * Get the AVClass for AVFrame. It can be used in combination with
3586  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
3587  *
3588  * @see av_opt_find().
3589  */
3590 const AVClass *avcodec_get_frame_class(void);
3591 
3592 /**
3593  * Get the AVClass for AVSubtitleRect. It can be used in combination with
3594  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
3595  *
3596  * @see av_opt_find().
3597  */
3599 
3600 /**
3601  * Copy the settings of the source AVCodecContext into the destination
3602  * AVCodecContext. The resulting destination codec context will be
3603  * unopened, i.e. you are required to call avcodec_open2() before you
3604  * can use this AVCodecContext to decode/encode video/audio data.
3605  *
3606  * @param dest target codec context, should be initialized with
3607  * avcodec_alloc_context3(NULL), but otherwise uninitialized
3608  * @param src source codec context
3609  * @return AVERROR() on error (e.g. memory allocation error), 0 on success
3610  */
3612 
3613 #if FF_API_AVFRAME_LAVC
3614 /**
3615  * @deprecated use av_frame_alloc()
3616  */
3618 AVFrame *avcodec_alloc_frame(void);
3619 
3620 /**
3621  * Set the fields of the given AVFrame to default values.
3622  *
3623  * @param frame The AVFrame of which the fields should be set to default values.
3624  *
3625  * @deprecated use av_frame_unref()
3626  */
3628 void avcodec_get_frame_defaults(AVFrame *frame);
3629 
3630 /**
3631  * Free the frame and any dynamically allocated objects in it,
3632  * e.g. extended_data.
3633  *
3634  * @param frame frame to be freed. The pointer will be set to NULL.
3635  *
3636  * @warning this function does NOT free the data buffers themselves
3637  * (it does not know how, since they might have been allocated with
3638  * a custom get_buffer()).
3639  *
3640  * @deprecated use av_frame_free()
3641  */
3643 void avcodec_free_frame(AVFrame **frame);
3644 #endif
3645 
3646 /**
3647  * Initialize the AVCodecContext to use the given AVCodec. Prior to using this
3648  * function the context has to be allocated with avcodec_alloc_context3().
3649  *
3650  * The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(),
3651  * avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for
3652  * retrieving a codec.
3653  *
3654  * @warning This function is not thread safe!
3655  *
3656  * @code
3657  * avcodec_register_all();
3658  * av_dict_set(&opts, "b", "2.5M", 0);
3659  * codec = avcodec_find_decoder(AV_CODEC_ID_H264);
3660  * if (!codec)
3661  * exit(1);
3662  *
3663  * context = avcodec_alloc_context3(codec);
3664  *
3665  * if (avcodec_open2(context, codec, opts) < 0)
3666  * exit(1);
3667  * @endcode
3668  *
3669  * @param avctx The context to initialize.
3670  * @param codec The codec to open this context for. If a non-NULL codec has been
3671  * previously passed to avcodec_alloc_context3() or
3672  * avcodec_get_context_defaults3() for this context, then this
3673  * parameter MUST be either NULL or equal to the previously passed
3674  * codec.
3675  * @param options A dictionary filled with AVCodecContext and codec-private options.
3676  * On return this object will be filled with options that were not found.
3677  *
3678  * @return zero on success, a negative value on error
3679  * @see avcodec_alloc_context3(), avcodec_find_decoder(), avcodec_find_encoder(),
3680  * av_dict_set(), av_opt_find().
3681  */
3682 int avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options);
3683 
3684 /**
3685  * Close a given AVCodecContext and free all the data associated with it
3686  * (but not the AVCodecContext itself).
3687  *
3688  * Calling this function on an AVCodecContext that hasn't been opened will free
3689  * the codec-specific data allocated in avcodec_alloc_context3() /
3690  * avcodec_get_context_defaults3() with a non-NULL codec. Subsequent calls will
3691  * do nothing.
3692  */
3693 int avcodec_close(AVCodecContext *avctx);
3694 
3695 /**
3696  * Free all allocated data in the given subtitle struct.
3697  *
3698  * @param sub AVSubtitle to free.
3699  */
3700 void avsubtitle_free(AVSubtitle *sub);
3701 
3702 /**
3703  * @}
3704  */
3705 
3706 /**
3707  * @addtogroup lavc_packet
3708  * @{
3709  */
3710 
3711 #if FF_API_DESTRUCT_PACKET
3712 /**
3713  * Default packet destructor.
3714  * @deprecated use the AVBuffer API instead
3715  */
3718 #endif
3719 
3720 /**
3721  * Initialize optional fields of a packet with default values.
3722  *
3723  * Note, this does not touch the data and size members, which have to be
3724  * initialized separately.
3725  *
3726  * @param pkt packet
3727  */
3728 void av_init_packet(AVPacket *pkt);
3729 
3730 /**
3731  * Allocate the payload of a packet and initialize its fields with
3732  * default values.
3733  *
3734  * @param pkt packet
3735  * @param size wanted payload size
3736  * @return 0 if OK, AVERROR_xxx otherwise
3737  */
3738 int av_new_packet(AVPacket *pkt, int size);
3739 
3740 /**
3741  * Reduce packet size, correctly zeroing padding
3742  *
3743  * @param pkt packet
3744  * @param size new size
3745  */
3746 void av_shrink_packet(AVPacket *pkt, int size);
3747 
3748 /**
3749  * Increase packet size, correctly zeroing padding
3750  *
3751  * @param pkt packet
3752  * @param grow_by number of bytes by which to increase the size of the packet
3753  */
3754 int av_grow_packet(AVPacket *pkt, int grow_by);
3755 
3756 /**
3757  * Initialize a reference-counted packet from av_malloc()ed data.
3758  *
3759  * @param pkt packet to be initialized. This function will set the data, size,
3760  * buf and destruct fields, all others are left untouched.
3761  * @param data Data allocated by av_malloc() to be used as packet data. If this
3762  * function returns successfully, the data is owned by the underlying AVBuffer.
3763  * The caller may not access the data through other means.
3764  * @param size size of data in bytes, without the padding. I.e. the full buffer
3765  * size is assumed to be size + FF_INPUT_BUFFER_PADDING_SIZE.
3766  *
3767  * @return 0 on success, a negative AVERROR on error
3768  */
3770 
3771 /**
3772  * @warning This is a hack - the packet memory allocation stuff is broken. The
3773  * packet is allocated if it was not really allocated.
3774  */
3775 int av_dup_packet(AVPacket *pkt);
3776 
3777 /**
3778  * Copy packet, including contents
3779  *
3780  * @return 0 on success, negative AVERROR on fail
3781  */
3782 int av_copy_packet(AVPacket *dst, const AVPacket *src);
3783 
3784 /**
3785  * Copy packet side data
3786  *
3787  * @return 0 on success, negative AVERROR on fail
3788  */
3789 int av_copy_packet_side_data(AVPacket *dst, const AVPacket *src);
3790 
3791 /**
3792  * Free a packet.
3793  *
3794  * @param pkt packet to free
3795  */
3796 void av_free_packet(AVPacket *pkt);
3797 
3798 /**
3799  * Allocate new information of a packet.
3800  *
3801  * @param pkt packet
3802  * @param type side information type
3803  * @param size side information size
3804  * @return pointer to fresh allocated data or NULL otherwise
3805  */
3807  int size);
3808 
3809 /**
3810  * Shrink the already allocated side data buffer
3811  *
3812  * @param pkt packet
3813  * @param type side information type
3814  * @param size new side information size
3815  * @return 0 on success, < 0 on failure
3816  */
3818  int size);
3819 
3820 /**
3821  * Get side information from packet.
3822  *
3823  * @param pkt packet
3824  * @param type desired side information type
3825  * @param size pointer for side information size to store (optional)
3826  * @return pointer to data if present or NULL otherwise
3827  */
3829  int *size);
3830 
3832 
3834 
3835 /**
3836  * Pack a dictionary for use in side_data.
3837  *
3838  * @param dict The dictionary to pack.
3839  * @param size pointer to store the size of the returned data
3840  * @return pointer to data if successful, NULL otherwise
3841  */
3843 /**
3844  * Unpack a dictionary from side_data.
3845  *
3846  * @param data data from side_data
3847  * @param size size of the data
3848  * @param dict the metadata storage dictionary
3849  * @return 0 on success, < 0 on failure
3850  */
3851 int av_packet_unpack_dictionary(const uint8_t *data, int size, AVDictionary **dict);
3852 
3853 
3854 /**
3855  * Convenience function to free all the side data stored.
3856  * All the other fields stay untouched.
3857  *
3858  * @param pkt packet
3859  */
3861 
3862 /**
3863  * Setup a new reference to the data described by a given packet
3864  *
3865  * If src is reference-counted, setup dst as a new reference to the
3866  * buffer in src. Otherwise allocate a new buffer in dst and copy the
3867  * data from src into it.
3868  *
3869  * All the other fields are copied from src.
3870  *
3871  * @see av_packet_unref
3872  *
3873  * @param dst Destination packet
3874  * @param src Source packet
3875  *
3876  * @return 0 on success, a negative AVERROR on error.
3877  */
3878 int av_packet_ref(AVPacket *dst, const AVPacket *src);
3879 
3880 /**
3881  * Wipe the packet.
3882  *
3883  * Unreference the buffer referenced by the packet and reset the
3884  * remaining packet fields to their default values.
3885  *
3886  * @param pkt The packet to be unreferenced.
3887  */
3889 
3890 /**
3891  * Move every field in src to dst and reset src.
3892  *
3893  * @see av_packet_unref
3894  *
3895  * @param src Source packet, will be reset
3896  * @param dst Destination packet
3897  */
3899 
3900 /**
3901  * Copy only "properties" fields from src to dst.
3902  *
3903  * Properties for the purpose of this function are all the fields
3904  * beside those related to the packet data (buf, data, size)
3905  *
3906  * @param dst Destination packet
3907  * @param src Source packet
3908  *
3909  * @return 0 on success AVERROR on failure.
3910  *
3911  */
3912 int av_packet_copy_props(AVPacket *dst, const AVPacket *src);
3913 
3914 /**
3915  * Convert valid timing fields (timestamps / durations) in a packet from one
3916  * timebase to another. Timestamps with unknown values (AV_NOPTS_VALUE) will be
3917  * ignored.
3918  *
3919  * @param pkt packet on which the conversion will be performed
3920  * @param tb_src source timebase, in which the timing fields in pkt are
3921  * expressed
3922  * @param tb_dst destination timebase, to which the timing fields will be
3923  * converted
3924  */
3925 void av_packet_rescale_ts(AVPacket *pkt, AVRational tb_src, AVRational tb_dst);
3926 
3927 /**
3928  * @}
3929  */
3930 
3931 /**
3932  * @addtogroup lavc_decoding
3933  * @{
3934  */
3935 
3936 /**
3937  * Find a registered decoder with a matching codec ID.
3938  *
3939  * @param id AVCodecID of the requested decoder
3940  * @return A decoder if one was found, NULL otherwise.
3941  */
3943 
3944 /**
3945  * Find a registered decoder with the specified name.
3946  *
3947  * @param name name of the requested decoder
3948  * @return A decoder if one was found, NULL otherwise.
3949  */
3951 
3952 #if FF_API_GET_BUFFER
3956 #endif
3957 
3958 /**
3959  * The default callback for AVCodecContext.get_buffer2(). It is made public so
3960  * it can be called by custom get_buffer2() implementations for decoders without
3961  * CODEC_CAP_DR1 set.
3962  */
3964 
3965 #if FF_API_EMU_EDGE
3966 /**
3967  * Return the amount of padding in pixels which the get_buffer callback must
3968  * provide around the edge of the image for codecs which do not have the
3969  * CODEC_FLAG_EMU_EDGE flag.
3970  *
3971  * @return Required padding in pixels.
3972  *
3973  * @deprecated CODEC_FLAG_EMU_EDGE is deprecated, so this function is no longer
3974  * needed
3975  */
3977 unsigned avcodec_get_edge_width(void);
3978 #endif
3979 
3980 /**
3981  * Modify width and height values so that they will result in a memory
3982  * buffer that is acceptable for the codec if you do not use any horizontal
3983  * padding.
3984  *
3985  * May only be used if a codec with CODEC_CAP_DR1 has been opened.
3986  */
3988 
3989 /**
3990  * Modify width and height values so that they will result in a memory
3991  * buffer that is acceptable for the codec if you also ensure that all
3992  * line sizes are a multiple of the respective linesize_align[i].
3993  *
3994  * May only be used if a codec with CODEC_CAP_DR1 has been opened.
3995  */
3997  int linesize_align[AV_NUM_DATA_POINTERS]);
3998 
3999 /**
4000  * Converts AVChromaLocation to swscale x/y chroma position.
4001  *
4002  * The positions represent the chroma (0,0) position in a coordinates system
4003  * with luma (0,0) representing the origin and luma(1,1) representing 256,256
4004  *
4005  * @param xpos horizontal chroma sample position
4006  * @param ypos vertical chroma sample position
4007  */
4008 int avcodec_enum_to_chroma_pos(int *xpos, int *ypos, enum AVChromaLocation pos);
4009 
4010 /**
4011  * Converts swscale x/y chroma position to AVChromaLocation.
4012  *
4013  * The positions represent the chroma (0,0) position in a coordinates system
4014  * with luma (0,0) representing the origin and luma(1,1) representing 256,256
4015  *
4016  * @param xpos horizontal chroma sample position
4017  * @param ypos vertical chroma sample position
4018  */
4019 enum AVChromaLocation avcodec_chroma_pos_to_enum(int xpos, int ypos);
4020 
4021 #if FF_API_OLD_DECODE_AUDIO
4022 /**
4023  * Wrapper function which calls avcodec_decode_audio4.
4024  *
4025  * @deprecated Use avcodec_decode_audio4 instead.
4026  *
4027  * Decode the audio frame of size avpkt->size from avpkt->data into samples.
4028  * Some decoders may support multiple frames in a single AVPacket, such
4029  * decoders would then just decode the first frame. In this case,
4030  * avcodec_decode_audio3 has to be called again with an AVPacket that contains
4031  * the remaining data in order to decode the second frame etc.
4032  * If no frame
4033  * could be outputted, frame_size_ptr is zero. Otherwise, it is the
4034  * decompressed frame size in bytes.
4035  *
4036  * @warning You must set frame_size_ptr to the allocated size of the
4037  * output buffer before calling avcodec_decode_audio3().
4038  *
4039  * @warning The input buffer must be FF_INPUT_BUFFER_PADDING_SIZE larger than
4040  * the actual read bytes because some optimized bitstream readers read 32 or 64
4041  * bits at once and could read over the end.
4042  *
4043  * @warning The end of the input buffer avpkt->data should be set to 0 to ensure that
4044  * no overreading happens for damaged MPEG streams.
4045  *
4046  * @warning You must not provide a custom get_buffer() when using
4047  * avcodec_decode_audio3(). Doing so will override it with
4048  * avcodec_default_get_buffer. Use avcodec_decode_audio4() instead,
4049  * which does allow the application to provide a custom get_buffer().
4050  *
4051  * @note You might have to align the input buffer avpkt->data and output buffer
4052  * samples. The alignment requirements depend on the CPU: On some CPUs it isn't
4053  * necessary at all, on others it won't work at all if not aligned and on others
4054  * it will work but it will have an impact on performance.
4055  *
4056  * In practice, avpkt->data should have 4 byte alignment at minimum and
4057  * samples should be 16 byte aligned unless the CPU doesn't need it
4058  * (AltiVec and SSE do).
4059  *
4060  * @note Codecs which have the CODEC_CAP_DELAY capability set have a delay
4061  * between input and output, these need to be fed with avpkt->data=NULL,
4062  * avpkt->size=0 at the end to return the remaining frames.
4063  *
4064  * @param avctx the codec context
4065  * @param[out] samples the output buffer, sample type in avctx->sample_fmt
4066  * If the sample format is planar, each channel plane will
4067  * be the same size, with no padding between channels.
4068  * @param[in,out] frame_size_ptr the output buffer size in bytes
4069  * @param[in] avpkt The input AVPacket containing the input buffer.
4070  * You can create such packet with av_init_packet() and by then setting
4071  * data and size, some decoders might in addition need other fields.
4072  * All decoders are designed to use the least fields possible though.
4073  * @return On error a negative value is returned, otherwise the number of bytes
4074  * used or zero if no frame data was decompressed (used) from the input AVPacket.
4075  */
4076 attribute_deprecated int avcodec_decode_audio3(AVCodecContext *avctx, int16_t *samples,
4077  int *frame_size_ptr,
4078  AVPacket *avpkt);
4079 #endif
4080 
4081 /**
4082  * Decode the audio frame of size avpkt->size from avpkt->data into frame.
4083  *
4084  * Some decoders may support multiple frames in a single AVPacket. Such
4085  * decoders would then just decode the first frame and the return value would be
4086  * less than the packet size. In this case, avcodec_decode_audio4 has to be
4087  * called again with an AVPacket containing the remaining data in order to
4088  * decode the second frame, etc... Even if no frames are returned, the packet
4089  * needs to be fed to the decoder with remaining data until it is completely
4090  * consumed or an error occurs.
4091  *
4092  * Some decoders (those marked with CODEC_CAP_DELAY) have a delay between input
4093  * and output. This means that for some packets they will not immediately
4094  * produce decoded output and need to be flushed at the end of decoding to get
4095  * all the decoded data. Flushing is done by calling this function with packets
4096  * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
4097  * returning samples. It is safe to flush even those decoders that are not
4098  * marked with CODEC_CAP_DELAY, then no samples will be returned.
4099  *
4100  * @warning The input buffer, avpkt->data must be FF_INPUT_BUFFER_PADDING_SIZE
4101  * larger than the actual read bytes because some optimized bitstream
4102  * readers read 32 or 64 bits at once and could read over the end.
4103  *
4104  * @param avctx the codec context
4105  * @param[out] frame The AVFrame in which to store decoded audio samples.
4106  * The decoder will allocate a buffer for the decoded frame by
4107  * calling the AVCodecContext.get_buffer2() callback.
4108  * When AVCodecContext.refcounted_frames is set to 1, the frame is
4109  * reference counted and the returned reference belongs to the
4110  * caller. The caller must release the frame using av_frame_unref()
4111  * when the frame is no longer needed. The caller may safely write
4112  * to the frame if av_frame_is_writable() returns 1.
4113  * When AVCodecContext.refcounted_frames is set to 0, the returned
4114  * reference belongs to the decoder and is valid only until the
4115  * next call to this function or until closing or flushing the
4116  * decoder. The caller may not write to it.
4117  * @param[out] got_frame_ptr Zero if no frame could be decoded, otherwise it is
4118  * non-zero. Note that this field being set to zero
4119  * does not mean that an error has occurred. For
4120  * decoders with CODEC_CAP_DELAY set, no given decode
4121  * call is guaranteed to produce a frame.
4122  * @param[in] avpkt The input AVPacket containing the input buffer.
4123  * At least avpkt->data and avpkt->size should be set. Some
4124  * decoders might also require additional fields to be set.
4125  * @return A negative error code is returned if an error occurred during
4126  * decoding, otherwise the number of bytes consumed from the input
4127  * AVPacket is returned.
4128  */
4130  int *got_frame_ptr, const AVPacket *avpkt);
4131 
4132 /**
4133  * Decode the video frame of size avpkt->size from avpkt->data into picture.
4134  * Some decoders may support multiple frames in a single AVPacket, such
4135  * decoders would then just decode the first frame.
4136  *
4137  * @warning The input buffer must be FF_INPUT_BUFFER_PADDING_SIZE larger than
4138  * the actual read bytes because some optimized bitstream readers read 32 or 64
4139  * bits at once and could read over the end.
4140  *
4141  * @warning The end of the input buffer buf should be set to 0 to ensure that
4142  * no overreading happens for damaged MPEG streams.
4143  *
4144  * @note Codecs which have the CODEC_CAP_DELAY capability set have a delay
4145  * between input and output, these need to be fed with avpkt->data=NULL,
4146  * avpkt->size=0 at the end to return the remaining frames.
4147  *
4148  * @param avctx the codec context
4149  * @param[out] picture The AVFrame in which the decoded video frame will be stored.
4150  * Use av_frame_alloc() to get an AVFrame. The codec will
4151  * allocate memory for the actual bitmap by calling the
4152  * AVCodecContext.get_buffer2() callback.
4153  * When AVCodecContext.refcounted_frames is set to 1, the frame is
4154  * reference counted and the returned reference belongs to the
4155  * caller. The caller must release the frame using av_frame_unref()
4156  * when the frame is no longer needed. The caller may safely write
4157  * to the frame if av_frame_is_writable() returns 1.
4158  * When AVCodecContext.refcounted_frames is set to 0, the returned
4159  * reference belongs to the decoder and is valid only until the
4160  * next call to this function or until closing or flushing the
4161  * decoder. The caller may not write to it.
4162  *
4163  * @param[in] avpkt The input AVPacket containing the input buffer.
4164  * You can create such packet with av_init_packet() and by then setting
4165  * data and size, some decoders might in addition need other fields like
4166  * flags&AV_PKT_FLAG_KEY. All decoders are designed to use the least
4167  * fields possible.
4168  * @param[in,out] got_picture_ptr Zero if no frame could be decompressed, otherwise, it is nonzero.
4169  * @return On error a negative value is returned, otherwise the number of bytes
4170  * used or zero if no frame could be decompressed.
4171  */
4172 int avcodec_decode_video2(AVCodecContext *avctx, AVFrame *picture,
4173  int *got_picture_ptr,
4174  const AVPacket *avpkt);
4175 
4176 /**
4177  * Decode a subtitle message.
4178  * Return a negative value on error, otherwise return the number of bytes used.
4179  * If no subtitle could be decompressed, got_sub_ptr is zero.
4180  * Otherwise, the subtitle is stored in *sub.
4181  * Note that CODEC_CAP_DR1 is not available for subtitle codecs. This is for
4182  * simplicity, because the performance difference is expect to be negligible
4183  * and reusing a get_buffer written for video codecs would probably perform badly
4184  * due to a potentially very different allocation pattern.
4185  *
4186  * Some decoders (those marked with CODEC_CAP_DELAY) have a delay between input
4187  * and output. This means that for some packets they will not immediately
4188  * produce decoded output and need to be flushed at the end of decoding to get
4189  * all the decoded data. Flushing is done by calling this function with packets
4190  * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
4191  * returning subtitles. It is safe to flush even those decoders that are not
4192  * marked with CODEC_CAP_DELAY, then no subtitles will be returned.
4193  *
4194  * @param avctx the codec context
4195  * @param[out] sub The Preallocated AVSubtitle in which the decoded subtitle will be stored,
4196  * must be freed with avsubtitle_free if *got_sub_ptr is set.
4197  * @param[in,out] got_sub_ptr Zero if no subtitle could be decompressed, otherwise, it is nonzero.
4198  * @param[in] avpkt The input AVPacket containing the input buffer.
4199  */
4201  int *got_sub_ptr,
4202  AVPacket *avpkt);
4203 
4204 /**
4205  * @defgroup lavc_parsing Frame parsing
4206  * @{
4207  */
4211  AV_PICTURE_STRUCTURE_TOP_FIELD, //< coded as top field
4212  AV_PICTURE_STRUCTURE_BOTTOM_FIELD, //< coded as bottom field
4213  AV_PICTURE_STRUCTURE_FRAME, //< coded as frame
4214 };
4216 typedef struct AVCodecParserContext {
4217  void *priv_data;
4219  int64_t frame_offset; /* offset of the current frame */
4220  int64_t cur_offset; /* current offset
4221  (incremented by each av_parser_parse()) */
4222  int64_t next_frame_offset; /* offset of the next frame */
4223  /* video info */
4224  int pict_type; /* XXX: Put it back in AVCodecContext. */
4225  /**
4226  * This field is used for proper frame duration computation in lavf.
4227  * It signals, how much longer the frame duration of the current frame
4228  * is compared to normal frame duration.
4229  *
4230  * frame_duration = (1 + repeat_pict) * time_base
4231  *
4232  * It is used by codecs like H.264 to display telecined material.
4233  */
4234  int repeat_pict; /* XXX: Put it back in AVCodecContext. */
4235  int64_t pts; /* pts of the current frame */
4236  int64_t dts; /* dts of the current frame */
4237 
4238  /* private data */
4239  int64_t last_pts;
4240  int64_t last_dts;
4241  int fetch_timestamp;
4243 #define AV_PARSER_PTS_NB 4
4249  int flags;
4250 #define PARSER_FLAG_COMPLETE_FRAMES 0x0001
4251 #define PARSER_FLAG_ONCE 0x0002
4252 /// Set if the parser has a valid file offset
4253 #define PARSER_FLAG_FETCHED_OFFSET 0x0004
4254 #define PARSER_FLAG_USE_CODEC_TS 0x1000
4256  int64_t offset; ///< byte offset from starting packet start
4258 
4259  /**
4260  * Set by parser to 1 for key frames and 0 for non-key frames.
4261  * It is initialized to -1, so if the parser doesn't set this flag,
4262  * old-style fallback using AV_PICTURE_TYPE_I picture type as key frames
4263  * will be used.
4264  */
4265  int key_frame;
4266 
4267  /**
4268  * Time difference in stream time base units from the pts of this
4269  * packet to the point at which the output from the decoder has converged
4270  * independent from the availability of previous frames. That is, the
4271  * frames are virtually identical no matter if decoding started from
4272  * the very first frame or from this keyframe.
4273  * Is AV_NOPTS_VALUE if unknown.
4274  * This field is not the display duration of the current frame.
4275  * This field has no meaning if the packet does not have AV_PKT_FLAG_KEY
4276  * set.
4277  *
4278  * The purpose of this field is to allow seeking in streams that have no
4279  * keyframes in the conventional sense. It corresponds to the
4280  * recovery point SEI in H.264 and match_time_delta in NUT. It is also
4281  * essential for some types of subtitle streams to ensure that all
4282  * subtitles are correctly displayed after seeking.
4283  */
4284  int64_t convergence_duration;
4285 
4286  // Timestamp generation support:
4287  /**
4288  * Synchronization point for start of timestamp generation.
4289  *
4290  * Set to >0 for sync point, 0 for no sync point and <0 for undefined
4291  * (default).
4292  *
4293  * For example, this corresponds to presence of H.264 buffering period
4294  * SEI message.
4295  */
4296  int dts_sync_point;
4297 
4298  /**
4299  * Offset of the current timestamp against last timestamp sync point in
4300  * units of AVCodecContext.time_base.
4301  *
4302  * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
4303  * contain a valid timestamp offset.
4304  *
4305  * Note that the timestamp of sync point has usually a nonzero
4306  * dts_ref_dts_delta, which refers to the previous sync point. Offset of
4307  * the next frame after timestamp sync point will be usually 1.
4308  *
4309  * For example, this corresponds to H.264 cpb_removal_delay.
4310  */
4311  int dts_ref_dts_delta;
4312 
4313  /**
4314  * Presentation delay of current frame in units of AVCodecContext.time_base.
4315  *
4316  * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
4317  * contain valid non-negative timestamp delta (presentation time of a frame
4318  * must not lie in the past).
4319  *
4320  * This delay represents the difference between decoding and presentation
4321  * time of the frame.
4322  *
4323  * For example, this corresponds to H.264 dpb_output_delay.
4324  */
4325  int pts_dts_delta;
4326 
4327  /**
4328  * Position of the packet in file.
4329  *
4330  * Analogous to cur_frame_pts/dts
4331  */
4333 
4334  /**
4335  * Byte position of currently parsed frame in stream.
4336  */
4337  int64_t pos;
4338 
4339  /**
4340  * Previous frame byte position.
4341  */
4342  int64_t last_pos;
4343 
4344  /**
4345  * Duration of the current frame.
4346  * For audio, this is in units of 1 / AVCodecContext.sample_rate.
4347  * For all other types, this is in units of AVCodecContext.time_base.
4348  */
4349  int duration;
4352 
4353  /**
4354  * Indicate whether a picture is coded as a frame, top field or bottom field.
4355  *
4356  * For example, H.264 field_pic_flag equal to 0 corresponds to
4357  * AV_PICTURE_STRUCTURE_FRAME. An H.264 picture with field_pic_flag
4358  * equal to 1 and bottom_field_flag equal to 0 corresponds to
4359  * AV_PICTURE_STRUCTURE_TOP_FIELD.
4360  */
4362 
4363  /**
4364  * Picture number incremented in presentation or output order.
4365  * This field may be reinitialized at the first picture of a new sequence.
4366  *
4367  * For example, this corresponds to H.264 PicOrderCnt.
4368  */
4372 typedef struct AVCodecParser {
4373  int codec_ids[5]; /* several codec IDs are permitted */
4376  /* This callback never returns an error, a negative value means that
4377  * the frame start was in a previous packet. */
4379  AVCodecContext *avctx,
4380  const uint8_t **poutbuf, int *poutbuf_size,
4381  const uint8_t *buf, int buf_size);
4383  int (*split)(AVCodecContext *avctx, const uint8_t *buf, int buf_size);
4384  struct AVCodecParser *next;
4385 } AVCodecParser;
4386 
4388 
4391 
4392 /**
4393  * Parse a packet.
4394  *
4395  * @param s parser context.
4396  * @param avctx codec context.
4397  * @param poutbuf set to pointer to parsed buffer or NULL if not yet finished.
4398  * @param poutbuf_size set to size of parsed buffer or zero if not yet finished.
4399  * @param buf input buffer.
4400  * @param buf_size input length, to signal EOF, this should be 0 (so that the last frame can be output).
4401  * @param pts input presentation timestamp.
4402  * @param dts input decoding timestamp.
4403  * @param pos input byte position in stream.
4404  * @return the number of bytes of the input bitstream used.
4405  *
4406  * Example:
4407  * @code
4408  * while(in_len){
4409  * len = av_parser_parse2(myparser, AVCodecContext, &data, &size,
4410  * in_data, in_len,
4411  * pts, dts, pos);
4412  * in_data += len;
4413  * in_len -= len;
4414  *
4415  * if(size)
4416  * decode_frame(data, size);
4417  * }
4418  * @endcode
4419  */
4421  AVCodecContext *avctx,
4422  uint8_t **poutbuf, int *poutbuf_size,
4423  const uint8_t *buf, int buf_size,
4424  int64_t pts, int64_t dts,
4425  int64_t pos);
4426 
4427 /**
4428  * @return 0 if the output buffer is a subset of the input, 1 if it is allocated and must be freed
4429  * @deprecated use AVBitStreamFilter
4430  */
4432  AVCodecContext *avctx,
4433  uint8_t **poutbuf, int *poutbuf_size,
4434  const uint8_t *buf, int buf_size, int keyframe);
4436 
4437 /**
4438  * @}
4439  * @}
4440  */
4441 
4442 /**
4443  * @addtogroup lavc_encoding
4444  * @{
4445  */
4446 
4447 /**
4448  * Find a registered encoder with a matching codec ID.
4449  *
4450  * @param id AVCodecID of the requested encoder
4451  * @return An encoder if one was found, NULL otherwise.
4452  */
4454 
4455 /**
4456  * Find a registered encoder with the specified name.
4457  *
4458  * @param name name of the requested encoder
4459  * @return An encoder if one was found, NULL otherwise.
4460  */
4462 
4463 #if FF_API_OLD_ENCODE_AUDIO
4464 /**
4465  * Encode an audio frame from samples into buf.
4466  *
4467  * @deprecated Use avcodec_encode_audio2 instead.
4468  *
4469  * @note The output buffer should be at least FF_MIN_BUFFER_SIZE bytes large.
4470  * However, for codecs with avctx->frame_size equal to 0 (e.g. PCM) the user
4471  * will know how much space is needed because it depends on the value passed
4472  * in buf_size as described below. In that case a lower value can be used.
4473  *
4474  * @param avctx the codec context
4475  * @param[out] buf the output buffer
4476  * @param[in] buf_size the output buffer size
4477  * @param[in] samples the input buffer containing the samples
4478  * The number of samples read from this buffer is frame_size*channels,
4479  * both of which are defined in avctx.
4480  * For codecs which have avctx->frame_size equal to 0 (e.g. PCM) the number of
4481  * samples read from samples is equal to:
4482  * buf_size * 8 / (avctx->channels * av_get_bits_per_sample(avctx->codec_id))
4483  * This also implies that av_get_bits_per_sample() must not return 0 for these
4484  * codecs.
4485  * @return On error a negative value is returned, on success zero or the number
4486  * of bytes used to encode the data read from the input buffer.
4487  */
4489  uint8_t *buf, int buf_size,
4490  const short *samples);
4491 #endif
4492 
4493 /**
4494  * Encode a frame of audio.
4495  *
4496  * Takes input samples from frame and writes the next output packet, if
4497  * available, to avpkt. The output packet does not necessarily contain data for
4498  * the most recent frame, as encoders can delay, split, and combine input frames
4499  * internally as needed.
4500  *
4501  * @param avctx codec context
4502  * @param avpkt output AVPacket.
4503  * The user can supply an output buffer by setting
4504  * avpkt->data and avpkt->size prior to calling the
4505  * function, but if the size of the user-provided data is not
4506  * large enough, encoding will fail. If avpkt->data and
4507  * avpkt->size are set, avpkt->destruct must also be set. All
4508  * other AVPacket fields will be reset by the encoder using
4509  * av_init_packet(). If avpkt->data is NULL, the encoder will
4510  * allocate it. The encoder will set avpkt->size to the size
4511  * of the output packet.
4512  *
4513  * If this function fails or produces no output, avpkt will be
4514  * freed using av_free_packet() (i.e. avpkt->destruct will be
4515  * called to free the user supplied buffer).
4516  * @param[in] frame AVFrame containing the raw audio data to be encoded.
4517  * May be NULL when flushing an encoder that has the
4518  * CODEC_CAP_DELAY capability set.
4519  * If CODEC_CAP_VARIABLE_FRAME_SIZE is set, then each frame
4520  * can have any number of samples.
4521  * If it is not set, frame->nb_samples must be equal to
4522  * avctx->frame_size for all frames except the last.
4523  * The final frame may be smaller than avctx->frame_size.
4524  * @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
4525  * output packet is non-empty, and to 0 if it is
4526  * empty. If the function returns an error, the
4527  * packet can be assumed to be invalid, and the
4528  * value of got_packet_ptr is undefined and should
4529  * not be used.
4530  * @return 0 on success, negative error code on failure
4531  */
4532 int avcodec_encode_audio2(AVCodecContext *avctx, AVPacket *avpkt,
4533  const AVFrame *frame, int *got_packet_ptr);
4534 
4535 #if FF_API_OLD_ENCODE_VIDEO
4536 /**
4537  * @deprecated use avcodec_encode_video2() instead.
4538  *
4539  * Encode a video frame from pict into buf.
4540  * The input picture should be
4541  * stored using a specific format, namely avctx.pix_fmt.
4542  *
4543  * @param avctx the codec context
4544  * @param[out] buf the output buffer for the bitstream of encoded frame
4545  * @param[in] buf_size the size of the output buffer in bytes
4546  * @param[in] pict the input picture to encode
4547  * @return On error a negative value is returned, on success zero or the number
4548  * of bytes used from the output buffer.
4549  */
4551 int avcodec_encode_video(AVCodecContext *avctx, uint8_t *buf, int buf_size,
4552  const AVFrame *pict);
4553 #endif
4554 
4555 /**
4556  * Encode a frame of video.
4557  *
4558  * Takes input raw video data from frame and writes the next output packet, if
4559  * available, to avpkt. The output packet does not necessarily contain data for
4560  * the most recent frame, as encoders can delay and reorder input frames
4561  * internally as needed.
4562  *
4563  * @param avctx codec context
4564  * @param avpkt output AVPacket.
4565  * The user can supply an output buffer by setting
4566  * avpkt->data and avpkt->size prior to calling the
4567  * function, but if the size of the user-provided data is not
4568  * large enough, encoding will fail. All other AVPacket fields
4569  * will be reset by the encoder using av_init_packet(). If
4570  * avpkt->data is NULL, the encoder will allocate it.
4571  * The encoder will set avpkt->size to the size of the
4572  * output packet. The returned data (if any) belongs to the
4573  * caller, he is responsible for freeing it.
4574  *
4575  * If this function fails or produces no output, avpkt will be
4576  * freed using av_free_packet() (i.e. avpkt->destruct will be
4577  * called to free the user supplied buffer).
4578  * @param[in] frame AVFrame containing the raw video data to be encoded.
4579  * May be NULL when flushing an encoder that has the
4580  * CODEC_CAP_DELAY capability set.
4581  * @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
4582  * output packet is non-empty, and to 0 if it is
4583  * empty. If the function returns an error, the
4584  * packet can be assumed to be invalid, and the
4585  * value of got_packet_ptr is undefined and should
4586  * not be used.
4587  * @return 0 on success, negative error code on failure
4588  */
4589 int avcodec_encode_video2(AVCodecContext *avctx, AVPacket *avpkt,
4590  const AVFrame *frame, int *got_packet_ptr);
4591 
4592 int avcodec_encode_subtitle(AVCodecContext *avctx, uint8_t *buf, int buf_size,
4593  const AVSubtitle *sub);
4594 
4595 
4596 /**
4597  * @}
4598  */
4599 
4600 #if FF_API_AVCODEC_RESAMPLE
4601 /**
4602  * @defgroup lavc_resample Audio resampling
4603  * @ingroup libavc
4604  * @deprecated use libswresample instead
4605  *
4606  * @{
4607  */
4608 struct ReSampleContext;
4609 struct AVResampleContext;
4610 
4611 typedef struct ReSampleContext ReSampleContext;
4612 
4613 /**
4614  * Initialize audio resampling context.
4615  *
4616  * @param output_channels number of output channels
4617  * @param input_channels number of input channels
4618  * @param output_rate output sample rate
4619  * @param input_rate input sample rate
4620  * @param sample_fmt_out requested output sample format
4621  * @param sample_fmt_in input sample format
4622  * @param filter_length length of each FIR filter in the filterbank relative to the cutoff frequency
4623  * @param log2_phase_count log2 of the number of entries in the polyphase filterbank
4624  * @param linear if 1 then the used FIR filter will be linearly interpolated
4625  between the 2 closest, if 0 the closest will be used
4626  * @param cutoff cutoff frequency, 1.0 corresponds to half the output sampling rate
4627  * @return allocated ReSampleContext, NULL if error occurred
4628  */
4631  int output_rate, int input_rate,
4632  enum AVSampleFormat sample_fmt_out,
4633  enum AVSampleFormat sample_fmt_in,
4634  int filter_length, int log2_phase_count,
4635  int linear, double cutoff);
4636 
4638 int audio_resample(ReSampleContext *s, short *output, short *input, int nb_samples);
4639 
4640 /**
4641  * Free resample context.
4642  *
4643  * @param s a non-NULL pointer to a resample context previously
4644  * created with av_audio_resample_init()
4645  */
4648 
4649 
4650 /**
4651  * Initialize an audio resampler.
4652  * Note, if either rate is not an integer then simply scale both rates up so they are.
4653  * @param filter_length length of each FIR filter in the filterbank relative to the cutoff freq
4654  * @param log2_phase_count log2 of the number of entries in the polyphase filterbank
4655  * @param linear If 1 then the used FIR filter will be linearly interpolated
4656  between the 2 closest, if 0 the closest will be used
4657  * @param cutoff cutoff frequency, 1.0 corresponds to half the output sampling rate
4658  */
4660 struct AVResampleContext *av_resample_init(int out_rate, int in_rate, int filter_length, int log2_phase_count, int linear, double cutoff);
4661 
4662 /**
4663  * Resample an array of samples using a previously configured context.
4664  * @param src an array of unconsumed samples
4665  * @param consumed the number of samples of src which have been consumed are returned here
4666  * @param src_size the number of unconsumed samples available
4667  * @param dst_size the amount of space in samples available in dst
4668  * @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.
4669  * @return the number of samples written in dst or -1 if an error occurred
4670  */
4672 int av_resample(struct AVResampleContext *c, short *dst, short *src, int *consumed, int src_size, int dst_size, int update_ctx);
4673 
4674 
4675 /**
4676  * Compensate samplerate/timestamp drift. The compensation is done by changing
4677  * the resampler parameters, so no audible clicks or similar distortions occur
4678  * @param compensation_distance distance in output samples over which the compensation should be performed
4679  * @param sample_delta number of output samples which should be output less
4680  *
4681  * example: av_resample_compensate(c, 10, 500)
4682  * here instead of 510 samples only 500 samples would be output
4683  *
4684  * note, due to rounding the actual compensation might be slightly different,
4685  * especially if the compensation_distance is large and the in_rate used during init is small
4686  */
4688 void av_resample_compensate(struct AVResampleContext *c, int sample_delta, int compensation_distance);
4690 void av_resample_close(struct AVResampleContext *c);
4691 
4692 /**
4693  * @}
4694  */
4695 #endif
4696 
4697 /**
4698  * @addtogroup lavc_picture
4699  * @{
4700  */
4701 
4702 /**
4703  * Allocate memory for the pixels of a picture and setup the AVPicture
4704  * fields for it.
4705  *
4706  * Call avpicture_free() to free it.
4707  *
4708  * @param picture the picture structure to be filled in
4709  * @param pix_fmt the pixel format of the picture
4710  * @param width the width of the picture
4711  * @param height the height of the picture
4712  * @return zero if successful, a negative error code otherwise
4713  *
4714  * @see av_image_alloc(), avpicture_fill()
4715  */
4716 int avpicture_alloc(AVPicture *picture, enum AVPixelFormat pix_fmt, int width, int height);
4717 
4718 /**
4719  * Free a picture previously allocated by avpicture_alloc().
4720  * The data buffer used by the AVPicture is freed, but the AVPicture structure
4721  * itself is not.
4722  *
4723  * @param picture the AVPicture to be freed
4724  */
4725 void avpicture_free(AVPicture *picture);
4726 
4727 /**
4728  * Setup the picture fields based on the specified image parameters
4729  * and the provided image data buffer.
4730  *
4731  * The picture fields are filled in by using the image data buffer
4732  * pointed to by ptr.
4733  *
4734  * If ptr is NULL, the function will fill only the picture linesize
4735  * array and return the required size for the image buffer.
4736  *
4737  * To allocate an image buffer and fill the picture data in one call,
4738  * use avpicture_alloc().
4739  *
4740  * @param picture the picture to be filled in
4741  * @param ptr buffer where the image data is stored, or NULL
4742  * @param pix_fmt the pixel format of the image
4743  * @param width the width of the image in pixels
4744  * @param height the height of the image in pixels
4745  * @return the size in bytes required for src, a negative error code
4746  * in case of failure
4747  *
4748  * @see av_image_fill_arrays()
4749  */
4750 int avpicture_fill(AVPicture *picture, const uint8_t *ptr,
4751  enum AVPixelFormat pix_fmt, int width, int height);
4752 
4753 /**
4754  * Copy pixel data from an AVPicture into a buffer.
4755  *
4756  * avpicture_get_size() can be used to compute the required size for
4757  * the buffer to fill.
4758  *
4759  * @param src source picture with filled data
4760  * @param pix_fmt picture pixel format
4761  * @param width picture width
4762  * @param height picture height
4763  * @param dest destination buffer
4764  * @param dest_size destination buffer size in bytes
4765  * @return the number of bytes written to dest, or a negative value
4766  * (error code) on error, for example if the destination buffer is not
4767  * big enough
4768  *
4769  * @see av_image_copy_to_buffer()
4770  */
4772  int width, int height,
4773  unsigned char *dest, int dest_size);
4774 
4775 /**
4776  * Calculate the size in bytes that a picture of the given width and height
4777  * would occupy if stored in the given picture format.
4778  *
4779  * @param pix_fmt picture pixel format
4780  * @param width picture width
4781  * @param height picture height
4782  * @return the computed picture buffer size or a negative error code
4783  * in case of error
4784  *
4785  * @see av_image_get_buffer_size().
4786  */
4788 
4789 #if FF_API_DEINTERLACE
4790 /**
4791  * deinterlace - if not supported return -1
4792  *
4793  * @deprecated - use yadif (in libavfilter) instead
4794  */
4796 int avpicture_deinterlace(AVPicture *dst, const AVPicture *src,
4797  enum AVPixelFormat pix_fmt, int width, int height);
4798 #endif
4799 /**
4800  * Copy image src to dst. Wraps av_image_copy().
4801  */
4802 void av_picture_copy(AVPicture *dst, const AVPicture *src,
4803  enum AVPixelFormat pix_fmt, int width, int height);
4804 
4805 /**
4806  * Crop image top and left side.
4807  */
4808 int av_picture_crop(AVPicture *dst, const AVPicture *src,
4809  enum AVPixelFormat pix_fmt, int top_band, int left_band);
4810 
4811 /**
4812  * Pad image.
4813  */
4814 int av_picture_pad(AVPicture *dst, const AVPicture *src, int height, int width, enum AVPixelFormat pix_fmt,
4815  int padtop, int padbottom, int padleft, int padright, int *color);
4816 
4817 /**
4818  * @}
4819  */
4820 
4821 /**
4822  * @defgroup lavc_misc Utility functions
4823  * @ingroup libavc
4824  *
4825  * Miscellaneous utility functions related to both encoding and decoding
4826  * (or neither).
4827  * @{
4828  */
4829 
4830 /**
4831  * @defgroup lavc_misc_pixfmt Pixel formats
4832  *
4833  * Functions for working with pixel formats.
4834  * @{
4835  */
4836 
4837 /**
4838  * Utility function to access log2_chroma_w log2_chroma_h from
4839  * the pixel format AVPixFmtDescriptor.
4840  *
4841  * This function asserts that pix_fmt is valid. See av_pix_fmt_get_chroma_sub_sample
4842  * for one that returns a failure code and continues in case of invalid
4843  * pix_fmts.
4844  *
4845  * @param[in] pix_fmt the pixel format
4846  * @param[out] h_shift store log2_chroma_w
4847  * @param[out] v_shift store log2_chroma_h
4848  *
4849  * @see av_pix_fmt_get_chroma_sub_sample
4850  */
4851 
4852 void avcodec_get_chroma_sub_sample(enum AVPixelFormat pix_fmt, int *h_shift, int *v_shift);
4853 
4854 /**
4855  * Return a value representing the fourCC code associated to the
4856  * pixel format pix_fmt, or 0 if no associated fourCC code can be
4857  * found.
4858  */
4860 
4861 /**
4862  * @deprecated see av_get_pix_fmt_loss()
4863  */
4864 int avcodec_get_pix_fmt_loss(enum AVPixelFormat dst_pix_fmt, enum AVPixelFormat src_pix_fmt,
4865  int has_alpha);
4866 
4867 /**
4868  * Find the best pixel format to convert to given a certain source pixel
4869  * format. When converting from one pixel format to another, information loss
4870  * may occur. For example, when converting from RGB24 to GRAY, the color
4871  * information will be lost. Similarly, other losses occur when converting from
4872  * some formats to other formats. avcodec_find_best_pix_fmt_of_2() searches which of
4873  * the given pixel formats should be used to suffer the least amount of loss.
4874  * The