FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
avcodec.h
Go to the documentation of this file.
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 #if FF_API_FAST_MALLOC
46 // to provide fast_*alloc
47 #include "libavutil/mem.h"
48 #endif
49 
50 /**
51  * @defgroup libavc Encoding/Decoding Library
52  * @{
53  *
54  * @defgroup lavc_decoding Decoding
55  * @{
56  * @}
57  *
58  * @defgroup lavc_encoding Encoding
59  * @{
60  * @}
61  *
62  * @defgroup lavc_codec Codecs
63  * @{
64  * @defgroup lavc_codec_native Native Codecs
65  * @{
66  * @}
67  * @defgroup lavc_codec_wrappers External library wrappers
68  * @{
69  * @}
70  * @defgroup lavc_codec_hwaccel Hardware Accelerators bridge
71  * @{
72  * @}
73  * @}
74  * @defgroup lavc_internal Internal
75  * @{
76  * @}
77  * @}
78  *
79  */
80 
81 /**
82  * @defgroup lavc_core Core functions/structures.
83  * @ingroup libavc
84  *
85  * Basic definitions, functions for querying libavcodec capabilities,
86  * allocating core structures, etc.
87  * @{
88  */
89 
90 
91 /**
92  * Identify the syntax and semantics of the bitstream.
93  * The principle is roughly:
94  * Two decoders with the same ID can decode the same streams.
95  * Two encoders with the same ID can encode compatible streams.
96  * There may be slight deviations from the principle due to implementation
97  * details.
98  *
99  * If you add a codec ID to this list, add it so that
100  * 1. no value of a existing codec ID changes (that would break ABI),
101  * 2. Give it a value which when taken as ASCII is recognized uniquely by a human as this specific codec.
102  * This ensures that 2 forks can independently add AVCodecIDs without producing conflicts.
103  *
104  * After adding new codec IDs, do not forget to add an entry to the codec
105  * descriptor list and bump libavcodec minor version.
106  */
107 enum AVCodecID {
109 
110  /* video codecs */
112  AV_CODEC_ID_MPEG2VIDEO, ///< preferred ID for MPEG-1/2 video decoding
113 #if FF_API_XVMC
114  AV_CODEC_ID_MPEG2VIDEO_XVMC,
115 #endif /* FF_API_XVMC */
298 
299  AV_CODEC_ID_BRENDER_PIX= MKBETAG('B','P','I','X'),
300  AV_CODEC_ID_Y41P = MKBETAG('Y','4','1','P'),
301  AV_CODEC_ID_ESCAPE130 = MKBETAG('E','1','3','0'),
302  AV_CODEC_ID_EXR = MKBETAG('0','E','X','R'),
303  AV_CODEC_ID_AVRP = MKBETAG('A','V','R','P'),
304 
305  AV_CODEC_ID_012V = MKBETAG('0','1','2','V'),
306  AV_CODEC_ID_G2M = MKBETAG( 0 ,'G','2','M'),
307  AV_CODEC_ID_AVUI = MKBETAG('A','V','U','I'),
308  AV_CODEC_ID_AYUV = MKBETAG('A','Y','U','V'),
309  AV_CODEC_ID_TARGA_Y216 = MKBETAG('T','2','1','6'),
310  AV_CODEC_ID_V308 = MKBETAG('V','3','0','8'),
311  AV_CODEC_ID_V408 = MKBETAG('V','4','0','8'),
312  AV_CODEC_ID_YUV4 = MKBETAG('Y','U','V','4'),
313  AV_CODEC_ID_SANM = MKBETAG('S','A','N','M'),
314  AV_CODEC_ID_PAF_VIDEO = MKBETAG('P','A','F','V'),
315  AV_CODEC_ID_AVRN = MKBETAG('A','V','R','n'),
316  AV_CODEC_ID_CPIA = MKBETAG('C','P','I','A'),
317  AV_CODEC_ID_XFACE = MKBETAG('X','F','A','C'),
318  AV_CODEC_ID_SGIRLE = MKBETAG('S','G','I','R'),
319  AV_CODEC_ID_MVC1 = MKBETAG('M','V','C','1'),
320  AV_CODEC_ID_MVC2 = MKBETAG('M','V','C','2'),
321  AV_CODEC_ID_SNOW = MKBETAG('S','N','O','W'),
322  AV_CODEC_ID_WEBP = MKBETAG('W','E','B','P'),
323  AV_CODEC_ID_SMVJPEG = MKBETAG('S','M','V','J'),
324  AV_CODEC_ID_HEVC = MKBETAG('H','2','6','5'),
325 #define AV_CODEC_ID_H265 AV_CODEC_ID_HEVC
326  AV_CODEC_ID_VP7 = MKBETAG('V','P','7','0'),
327 
328  /* various PCM "codecs" */
329  AV_CODEC_ID_FIRST_AUDIO = 0x10000, ///< A dummy id pointing at the start of audio codecs
363 
364  /* various ADPCM codecs */
396  AV_CODEC_ID_ADPCM_VIMA = MKBETAG('V','I','M','A'),
397  AV_CODEC_ID_VIMA = MKBETAG('V','I','M','A'),
398  AV_CODEC_ID_ADPCM_AFC = MKBETAG('A','F','C',' '),
399  AV_CODEC_ID_ADPCM_IMA_OKI = MKBETAG('O','K','I',' '),
400  AV_CODEC_ID_ADPCM_DTK = MKBETAG('D','T','K',' '),
401  AV_CODEC_ID_ADPCM_IMA_RAD = MKBETAG('R','A','D',' '),
402  AV_CODEC_ID_ADPCM_G726LE = MKBETAG('6','2','7','G'),
403 
404  /* AMR */
407 
408  /* RealAudio codecs*/
411 
412  /* various DPCM codecs */
417 
418  /* audio codecs */
419  AV_CODEC_ID_MP2 = 0x15000,
420  AV_CODEC_ID_MP3, ///< preferred ID for decoding MPEG audio layer 1, 2 or 3
437  AV_CODEC_ID_GSM, ///< as in Berlin toast format
449  AV_CODEC_ID_GSM_MS, /* as found in WAV */
451 #if FF_API_VOXWARE
453 #endif
488  AV_CODEC_ID_FFWAVESYNTH = MKBETAG('F','F','W','S'),
489  AV_CODEC_ID_SONIC = MKBETAG('S','O','N','C'),
490  AV_CODEC_ID_SONIC_LS = MKBETAG('S','O','N','L'),
491  AV_CODEC_ID_PAF_AUDIO = MKBETAG('P','A','F','A'),
492  AV_CODEC_ID_OPUS = MKBETAG('O','P','U','S'),
493  AV_CODEC_ID_TAK = MKBETAG('t','B','a','K'),
494  AV_CODEC_ID_EVRC = MKBETAG('s','e','v','c'),
495  AV_CODEC_ID_SMV = MKBETAG('s','s','m','v'),
496  AV_CODEC_ID_DSD_LSBF = MKBETAG('D','S','D','L'),
497  AV_CODEC_ID_DSD_MSBF = MKBETAG('D','S','D','M'),
500 
501  /* subtitle codecs */
502  AV_CODEC_ID_FIRST_SUBTITLE = 0x17000, ///< A dummy ID pointing at the start of subtitle codecs.
505  AV_CODEC_ID_TEXT, ///< raw UTF-8 text
512  AV_CODEC_ID_MICRODVD = MKBETAG('m','D','V','D'),
513  AV_CODEC_ID_EIA_608 = MKBETAG('c','6','0','8'),
514  AV_CODEC_ID_JACOSUB = MKBETAG('J','S','U','B'),
515  AV_CODEC_ID_SAMI = MKBETAG('S','A','M','I'),
516  AV_CODEC_ID_REALTEXT = MKBETAG('R','T','X','T'),
517  AV_CODEC_ID_SUBVIEWER1 = MKBETAG('S','b','V','1'),
518  AV_CODEC_ID_SUBVIEWER = MKBETAG('S','u','b','V'),
519  AV_CODEC_ID_SUBRIP = MKBETAG('S','R','i','p'),
520  AV_CODEC_ID_WEBVTT = MKBETAG('W','V','T','T'),
521  AV_CODEC_ID_MPL2 = MKBETAG('M','P','L','2'),
522  AV_CODEC_ID_VPLAYER = MKBETAG('V','P','l','r'),
523  AV_CODEC_ID_PJS = MKBETAG('P','h','J','S'),
524  AV_CODEC_ID_ASS = MKBETAG('A','S','S',' '), ///< ASS as defined in Matroska
525 
526  /* other specific kind of codecs (generally used for attachments) */
527  AV_CODEC_ID_FIRST_UNKNOWN = 0x18000, ///< A dummy ID pointing at the start of various fake codecs.
528  AV_CODEC_ID_TTF = 0x18000,
529  AV_CODEC_ID_BINTEXT = MKBETAG('B','T','X','T'),
530  AV_CODEC_ID_XBIN = MKBETAG('X','B','I','N'),
531  AV_CODEC_ID_IDF = MKBETAG( 0 ,'I','D','F'),
532  AV_CODEC_ID_OTF = MKBETAG( 0 ,'O','T','F'),
533  AV_CODEC_ID_SMPTE_KLV = MKBETAG('K','L','V','A'),
534  AV_CODEC_ID_DVD_NAV = MKBETAG('D','N','A','V'),
535  AV_CODEC_ID_TIMED_ID3 = MKBETAG('T','I','D','3'),
536  AV_CODEC_ID_BIN_DATA = MKBETAG('D','A','T','A'),
537 
538 
539  AV_CODEC_ID_PROBE = 0x19000, ///< codec_id is not known (like AV_CODEC_ID_NONE) but lavf should attempt to identify it
540 
541  AV_CODEC_ID_MPEG2TS = 0x20000, /**< _FAKE_ codec to indicate a raw MPEG-2 TS
542  * stream (only used by libavformat) */
543  AV_CODEC_ID_MPEG4SYSTEMS = 0x20001, /**< _FAKE_ codec to indicate a MPEG-4 Systems
544  * stream (only used by libavformat) */
545  AV_CODEC_ID_FFMETADATA = 0x21000, ///< Dummy codec for streams containing only metadata information.
546 
547 #if FF_API_CODEC_ID
548 #include "old_codec_ids.h"
549 #endif
550 };
551 
552 /**
553  * This struct describes the properties of a single codec described by an
554  * AVCodecID.
555  * @see avcodec_get_descriptor()
556  */
557 typedef struct AVCodecDescriptor {
558  enum AVCodecID id;
560  /**
561  * Name of the codec described by this descriptor. It is non-empty and
562  * unique for each codec descriptor. It should contain alphanumeric
563  * characters and '_' only.
564  */
565  const char *name;
566  /**
567  * A more descriptive name for this codec. May be NULL.
568  */
569  const char *long_name;
570  /**
571  * Codec properties, a combination of AV_CODEC_PROP_* flags.
572  */
573  int props;
574 
575  /**
576  * MIME type(s) associated with the codec.
577  * May be NULL; if not, a NULL-terminated array of MIME types.
578  * The first item is always non-NULL and is the preferred MIME type.
579  */
580  const char *const *mime_types;
583 /**
584  * Codec uses only intra compression.
585  * Video codecs only.
586  */
587 #define AV_CODEC_PROP_INTRA_ONLY (1 << 0)
588 /**
589  * Codec supports lossy compression. Audio and video codecs only.
590  * @note a codec may support both lossy and lossless
591  * compression modes
592  */
593 #define AV_CODEC_PROP_LOSSY (1 << 1)
594 /**
595  * Codec supports lossless compression. Audio and video codecs only.
596  */
597 #define AV_CODEC_PROP_LOSSLESS (1 << 2)
598 /**
599  * Codec supports frame reordering. That is, the coded order (the order in which
600  * the encoded packets are output by the encoders / stored / input to the
601  * decoders) may be different from the presentation order of the corresponding
602  * frames.
603  *
604  * For codecs that do not have this property set, PTS and DTS should always be
605  * equal.
606  */
607 #define AV_CODEC_PROP_REORDER (1 << 3)
608 /**
609  * Subtitle codec is bitmap based
610  * Decoded AVSubtitle data can be read from the AVSubtitleRect->pict field.
611  */
612 #define AV_CODEC_PROP_BITMAP_SUB (1 << 16)
613 /**
614  * Subtitle codec is text based.
615  * Decoded AVSubtitle data can be read from the AVSubtitleRect->ass field.
616  */
617 #define AV_CODEC_PROP_TEXT_SUB (1 << 17)
619 /**
620  * @ingroup lavc_decoding
621  * Required number of additionally allocated bytes at the end of the input bitstream for decoding.
622  * This is mainly needed because some optimized bitstream readers read
623  * 32 or 64 bit at once and could read over the end.<br>
624  * Note: If the first 23 bits of the additional bytes are not 0, then damaged
625  * MPEG bitstreams could cause overread and segfault.
626  */
627 #define FF_INPUT_BUFFER_PADDING_SIZE 32
629 /**
630  * @ingroup lavc_encoding
631  * minimum encoding buffer size
632  * Used to avoid some checks during header writing.
633  */
634 #define FF_MIN_BUFFER_SIZE 16384
637 /**
638  * @ingroup lavc_encoding
639  * motion estimation type.
640  */
642  ME_ZERO = 1, ///< no search, that is use 0,0 vector whenever one is needed
646  ME_EPZS, ///< enhanced predictive zonal search
647  ME_X1, ///< reserved for experiments
648  ME_HEX, ///< hexagon based search
649  ME_UMH, ///< uneven multi-hexagon search
650  ME_TESA, ///< transformed exhaustive search algorithm
651  ME_ITER=50, ///< iterative search
652 };
654 /**
655  * @ingroup lavc_decoding
656  */
658  /* We leave some space between them for extensions (drop some
659  * keyframes for intra-only or drop just some bidir frames). */
660  AVDISCARD_NONE =-16, ///< discard nothing
661  AVDISCARD_DEFAULT = 0, ///< discard useless packets like 0 size packets in avi
662  AVDISCARD_NONREF = 8, ///< discard all non reference
663  AVDISCARD_BIDIR = 16, ///< discard all bidirectional frames
664  AVDISCARD_NONINTRA= 24, ///< discard all non intra frames
665  AVDISCARD_NONKEY = 32, ///< discard all frames except keyframes
666  AVDISCARD_ALL = 48, ///< discard all
667 };
679  AV_AUDIO_SERVICE_TYPE_NB , ///< Not part of ABI
680 };
682 /**
683  * @ingroup lavc_encoding
684  */
685 typedef struct RcOverride{
688  int qscale; // If this is 0 then quality_factor will be used instead.
692 #if FF_API_MAX_BFRAMES
693 /**
694  * @deprecated there is no libavcodec-wide limit on the number of B-frames
695  */
696 #define FF_MAX_B_FRAMES 16
697 #endif
699 /* encoding support
700  These flags can be passed in AVCodecContext.flags before initialization.
701  Note: Not everything is supported yet.
702 */
704 /**
705  * Allow decoders to produce frames with data planes that are not aligned
706  * to CPU requirements (e.g. due to cropping).
707  */
708 #define CODEC_FLAG_UNALIGNED 0x0001
709 #define CODEC_FLAG_QSCALE 0x0002 ///< Use fixed qscale.
710 #define CODEC_FLAG_4MV 0x0004 ///< 4 MV per MB allowed / advanced prediction for H.263.
711 #define CODEC_FLAG_OUTPUT_CORRUPT 0x0008 ///< Output even those frames that might be corrupted
712 #define CODEC_FLAG_QPEL 0x0010 ///< Use qpel MC.
713 #if FF_API_GMC
714 /**
715  * @deprecated use the "gmc" private option of the libxvid encoder
716  */
717 #define CODEC_FLAG_GMC 0x0020 ///< Use GMC.
718 #endif
719 #if FF_API_MV0
720 /**
721  * @deprecated use the flag "mv0" in the "mpv_flags" private option of the
722  * mpegvideo encoders
723  */
724 #define CODEC_FLAG_MV0 0x0040
725 #endif
726 #if FF_API_INPUT_PRESERVED
727 /**
728  * @deprecated passing reference-counted frames to the encoders replaces this
729  * flag
730  */
731 #define CODEC_FLAG_INPUT_PRESERVED 0x0100
732 #endif
733 #define CODEC_FLAG_PASS1 0x0200 ///< Use internal 2pass ratecontrol in first pass mode.
734 #define CODEC_FLAG_PASS2 0x0400 ///< Use internal 2pass ratecontrol in second pass mode.
735 #define CODEC_FLAG_GRAY 0x2000 ///< Only decode/encode grayscale.
736 #if FF_API_EMU_EDGE
737 /**
738  * @deprecated edges are not used/required anymore. I.e. this flag is now always
739  * set.
740  */
741 #define CODEC_FLAG_EMU_EDGE 0x4000
742 #endif
743 #define CODEC_FLAG_PSNR 0x8000 ///< error[?] variables will be set during encoding.
744 #define CODEC_FLAG_TRUNCATED 0x00010000 /** Input bitstream might be truncated at a random
745  location instead of only at frame boundaries. */
746 #if FF_API_NORMALIZE_AQP
747 /**
748  * @deprecated use the flag "naq" in the "mpv_flags" private option of the
749  * mpegvideo encoders
750  */
751 #define CODEC_FLAG_NORMALIZE_AQP 0x00020000
752 #endif
753 #define CODEC_FLAG_INTERLACED_DCT 0x00040000 ///< Use interlaced DCT.
754 #define CODEC_FLAG_LOW_DELAY 0x00080000 ///< Force low delay.
755 #define CODEC_FLAG_GLOBAL_HEADER 0x00400000 ///< Place global headers in extradata instead of every keyframe.
756 #define CODEC_FLAG_BITEXACT 0x00800000 ///< Use only bitexact stuff (except (I)DCT).
757 /* Fx : Flag for h263+ extra options */
758 #define CODEC_FLAG_AC_PRED 0x01000000 ///< H.263 advanced intra coding / MPEG-4 AC prediction
759 #define CODEC_FLAG_LOOP_FILTER 0x00000800 ///< loop filter
760 #define CODEC_FLAG_INTERLACED_ME 0x20000000 ///< interlaced motion estimation
761 #define CODEC_FLAG_CLOSED_GOP 0x80000000
762 #define CODEC_FLAG2_FAST 0x00000001 ///< Allow non spec compliant speedup tricks.
763 #define CODEC_FLAG2_NO_OUTPUT 0x00000004 ///< Skip bitstream encoding.
764 #define CODEC_FLAG2_LOCAL_HEADER 0x00000008 ///< Place global headers at every keyframe instead of in extradata.
765 #define CODEC_FLAG2_DROP_FRAME_TIMECODE 0x00002000 ///< timecode is in drop frame format. DEPRECATED!!!!
766 #define CODEC_FLAG2_IGNORE_CROP 0x00010000 ///< Discard cropping information from SPS.
768 #define CODEC_FLAG2_CHUNKS 0x00008000 ///< Input bitstream might be truncated at a packet boundaries instead of only at frame boundaries.
769 #define CODEC_FLAG2_SHOW_ALL 0x00400000 ///< Show all frames before the first keyframe
770 #define CODEC_FLAG2_EXPORT_MVS 0x10000000 ///< Export motion vectors through frame side data
772 /* Unsupported options :
773  * Syntax Arithmetic coding (SAC)
774  * Reference Picture Selection
775  * Independent Segment Decoding */
776 /* /Fx */
777 /* codec capabilities */
779 #define CODEC_CAP_DRAW_HORIZ_BAND 0x0001 ///< Decoder can use draw_horiz_band callback.
780 /**
781  * Codec uses get_buffer() for allocating buffers and supports custom allocators.
782  * If not set, it might not use get_buffer() at all or use operations that
783  * assume the buffer was allocated by avcodec_default_get_buffer.
784  */
785 #define CODEC_CAP_DR1 0x0002
786 #define CODEC_CAP_TRUNCATED 0x0008
787 #if FF_API_XVMC
788 /* Codec can export data for HW decoding. This flag indicates that
789  * the codec would call get_format() with list that might contain HW accelerated
790  * pixel formats (XvMC, VDPAU, VAAPI, etc). The application can pick any of them
791  * including raw image format.
792  * The application can use the passed context to determine bitstream version,
793  * chroma format, resolution etc.
794  */
795 #define CODEC_CAP_HWACCEL 0x0010
796 #endif /* FF_API_XVMC */
797 /**
798  * Encoder or decoder requires flushing with NULL input at the end in order to
799  * give the complete and correct output.
800  *
801  * NOTE: If this flag is not set, the codec is guaranteed to never be fed with
802  * with NULL data. The user can still send NULL data to the public encode
803  * or decode function, but libavcodec will not pass it along to the codec
804  * unless this flag is set.
805  *
806  * Decoders:
807  * The decoder has a non-zero delay and needs to be fed with avpkt->data=NULL,
808  * avpkt->size=0 at the end to get the delayed data until the decoder no longer
809  * returns frames.
810  *
811  * Encoders:
812  * The encoder needs to be fed with NULL data at the end of encoding until the
813  * encoder no longer returns data.
814  *
815  * NOTE: For encoders implementing the AVCodec.encode2() function, setting this
816  * flag also means that the encoder must set the pts and duration for
817  * each output packet. If this flag is not set, the pts and duration will
818  * be determined by libavcodec from the input frame.
819  */
820 #define CODEC_CAP_DELAY 0x0020
821 /**
822  * Codec can be fed a final frame with a smaller size.
823  * This can be used to prevent truncation of the last audio samples.
824  */
825 #define CODEC_CAP_SMALL_LAST_FRAME 0x0040
826 #if FF_API_CAP_VDPAU
827 /**
828  * Codec can export data for HW decoding (VDPAU).
829  */
830 #define CODEC_CAP_HWACCEL_VDPAU 0x0080
831 #endif
832 /**
833  * Codec can output multiple frames per AVPacket
834  * Normally demuxers return one frame at a time, demuxers which do not do
835  * are connected to a parser to split what they return into proper frames.
836  * This flag is reserved to the very rare category of codecs which have a
837  * bitstream that cannot be split into frames without timeconsuming
838  * operations like full decoding. Demuxers carring such bitstreams thus
839  * may return multiple frames in a packet. This has many disadvantages like
840  * prohibiting stream copy in many cases thus it should only be considered
841  * as a last resort.
842  */
843 #define CODEC_CAP_SUBFRAMES 0x0100
844 /**
845  * Codec is experimental and is thus avoided in favor of non experimental
846  * encoders
847  */
848 #define CODEC_CAP_EXPERIMENTAL 0x0200
849 /**
850  * Codec should fill in channel configuration and samplerate instead of container
851  */
852 #define CODEC_CAP_CHANNEL_CONF 0x0400
853 #if FF_API_NEG_LINESIZES
854 /**
855  * @deprecated no codecs use this capability
856  */
857 #define CODEC_CAP_NEG_LINESIZES 0x0800
858 #endif
859 /**
860  * Codec supports frame-level multithreading.
861  */
862 #define CODEC_CAP_FRAME_THREADS 0x1000
863 /**
864  * Codec supports slice-based (or partition-based) multithreading.
865  */
866 #define CODEC_CAP_SLICE_THREADS 0x2000
867 /**
868  * Codec supports changed parameters at any point.
869  */
870 #define CODEC_CAP_PARAM_CHANGE 0x4000
871 /**
872  * Codec supports avctx->thread_count == 0 (auto).
873  */
874 #define CODEC_CAP_AUTO_THREADS 0x8000
875 /**
876  * Audio encoder supports receiving a different number of samples in each call.
877  */
878 #define CODEC_CAP_VARIABLE_FRAME_SIZE 0x10000
879 /**
880  * Codec is intra only.
881  */
882 #define CODEC_CAP_INTRA_ONLY 0x40000000
883 /**
884  * Codec is lossless.
885  */
886 #define CODEC_CAP_LOSSLESS 0x80000000
888 #if FF_API_MB_TYPE
889 //The following defines may change, don't expect compatibility if you use them.
890 #define MB_TYPE_INTRA4x4 0x0001
891 #define MB_TYPE_INTRA16x16 0x0002 //FIXME H.264-specific
892 #define MB_TYPE_INTRA_PCM 0x0004 //FIXME H.264-specific
893 #define MB_TYPE_16x16 0x0008
894 #define MB_TYPE_16x8 0x0010
895 #define MB_TYPE_8x16 0x0020
896 #define MB_TYPE_8x8 0x0040
897 #define MB_TYPE_INTERLACED 0x0080
898 #define MB_TYPE_DIRECT2 0x0100 //FIXME
899 #define MB_TYPE_ACPRED 0x0200
900 #define MB_TYPE_GMC 0x0400
901 #define MB_TYPE_SKIP 0x0800
902 #define MB_TYPE_P0L0 0x1000
903 #define MB_TYPE_P1L0 0x2000
904 #define MB_TYPE_P0L1 0x4000
905 #define MB_TYPE_P1L1 0x8000
906 #define MB_TYPE_L0 (MB_TYPE_P0L0 | MB_TYPE_P1L0)
907 #define MB_TYPE_L1 (MB_TYPE_P0L1 | MB_TYPE_P1L1)
908 #define MB_TYPE_L0L1 (MB_TYPE_L0 | MB_TYPE_L1)
909 #define MB_TYPE_QUANT 0x00010000
910 #define MB_TYPE_CBP 0x00020000
911 //Note bits 24-31 are reserved for codec specific use (h264 ref0, mpeg1 0mv, ...)
912 #endif
914 /**
915  * Pan Scan area.
916  * This specifies the area which should be displayed.
917  * Note there may be multiple such areas for one frame.
918  */
919 typedef struct AVPanScan{
920  /**
921  * id
922  * - encoding: Set by user.
923  * - decoding: Set by libavcodec.
924  */
925  int id;
927  /**
928  * width and height in 1/16 pel
929  * - encoding: Set by user.
930  * - decoding: Set by libavcodec.
931  */
932  int width;
933  int height;
935  /**
936  * position of the top left corner in 1/16 pel for up to 3 fields/frames
937  * - encoding: Set by user.
938  * - decoding: Set by libavcodec.
939  */
940  int16_t position[3][2];
942 
943 #if FF_API_QSCALE_TYPE
944 #define FF_QSCALE_TYPE_MPEG1 0
945 #define FF_QSCALE_TYPE_MPEG2 1
946 #define FF_QSCALE_TYPE_H264 2
947 #define FF_QSCALE_TYPE_VP56 3
948 #endif
949 
950 #if FF_API_GET_BUFFER
951 #define FF_BUFFER_TYPE_INTERNAL 1
952 #define FF_BUFFER_TYPE_USER 2 ///< direct rendering buffers (image is (de)allocated by user)
953 #define FF_BUFFER_TYPE_SHARED 4 ///< Buffer from somewhere else; don't deallocate image (data/base), all other tables are not shared.
954 #define FF_BUFFER_TYPE_COPY 8 ///< Just a (modified) copy of some other buffer, don't deallocate anything.
956 #define FF_BUFFER_HINTS_VALID 0x01 // Buffer hints value is meaningful (if 0 ignore).
957 #define FF_BUFFER_HINTS_READABLE 0x02 // Codec will read from buffer.
958 #define FF_BUFFER_HINTS_PRESERVE 0x04 // User must not alter buffer content.
959 #define FF_BUFFER_HINTS_REUSABLE 0x08 // Codec will reuse the buffer (update).
960 #endif
961 
962 /**
963  * The decoder will keep a reference to the frame and may reuse it later.
964  */
965 #define AV_GET_BUFFER_FLAG_REF (1 << 0)
966 
967 /**
968  * @defgroup lavc_packet AVPacket
969  *
970  * Types and functions for working with AVPacket.
971  * @{
972  */
976 
977  /**
978  * An AV_PKT_DATA_PARAM_CHANGE side data packet is laid out as follows:
979  * @code
980  * u32le param_flags
981  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT)
982  * s32le channel_count
983  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT)
984  * u64le channel_layout
985  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE)
986  * s32le sample_rate
987  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS)
988  * s32le width
989  * s32le height
990  * @endcode
991  */
993 
994  /**
995  * An AV_PKT_DATA_H263_MB_INFO side data packet contains a number of
996  * structures with info about macroblocks relevant to splitting the
997  * packet into smaller packets on macroblock edges (e.g. as for RFC 2190).
998  * That is, it does not necessarily contain info about all macroblocks,
999  * as long as the distance between macroblocks in the info is smaller
1000  * than the target payload size.
1001  * Each MB info structure is 12 bytes, and is laid out as follows:
1002  * @code
1003  * u32le bit offset from the start of the packet
1004  * u8 current quantizer at the start of the macroblock
1005  * u8 GOB number
1006  * u16le macroblock address within the GOB
1007  * u8 horizontal MV predictor
1008  * u8 vertical MV predictor
1009  * u8 horizontal MV predictor for block number 3
1010  * u8 vertical MV predictor for block number 3
1011  * @endcode
1012  */
1014 
1015  /**
1016  * This side data should be associated with an audio stream and contains
1017  * ReplayGain information in form of the AVReplayGain struct.
1018  */
1020 
1021  /**
1022  * This side data contains a 3x3 transformation matrix describing an affine
1023  * transformation that needs to be applied to the decoded video frames for
1024  * correct presentation.
1025  *
1026  * See libavutil/display.h for a detailed description of the data.
1027  */
1029 
1030  /**
1031  * Recommmends skipping the specified number of samples
1032  * @code
1033  * u32le number of samples to skip from start of this packet
1034  * u32le number of samples to skip from end of this packet
1035  * u8 reason for start skip
1036  * u8 reason for end skip (0=padding silence, 1=convergence)
1037  * @endcode
1038  */
1040 
1041  /**
1042  * An AV_PKT_DATA_JP_DUALMONO side data packet indicates that
1043  * the packet may contain "dual mono" audio specific to Japanese DTV
1044  * and if it is true, recommends only the selected channel to be used.
1045  * @code
1046  * u8 selected channels (0=mail/left, 1=sub/right, 2=both)
1047  * @endcode
1048  */
1050 
1051  /**
1052  * A list of zero terminated key/value strings. There is no end marker for
1053  * the list, so it is required to rely on the side data size to stop.
1054  */
1056 
1057  /**
1058  * Subtitle event position
1059  * @code
1060  * u32le x1
1061  * u32le y1
1062  * u32le x2
1063  * u32le y2
1064  * @endcode
1065  */
1067 
1068  /**
1069  * Data found in BlockAdditional element of matroska container. There is
1070  * no end marker for the data, so it is required to rely on the side data
1071  * size to recognize the end. 8 byte id (as found in BlockAddId) followed
1072  * by data.
1073  */
1075 
1076  /**
1077  * The optional first identifier line of a WebVTT cue.
1078  */
1080 
1081  /**
1082  * The optional settings (rendering instructions) that immediately
1083  * follow the timestamp specifier of a WebVTT cue.
1084  */
1086 
1087  /**
1088  * A list of zero terminated key/value strings. There is no end marker for
1089  * the list, so it is required to rely on the side data size to stop. This
1090  * side data includes updated metadata which appeared in the stream.
1091  */
1093 };
1095 typedef struct AVPacketSideData {
1097  int size;
1100 
1101 /**
1102  * This structure stores compressed data. It is typically exported by demuxers
1103  * and then passed as input to decoders, or received as output from encoders and
1104  * then passed to muxers.
1105  *
1106  * For video, it should typically contain one compressed frame. For audio it may
1107  * contain several compressed frames.
1108  *
1109  * AVPacket is one of the few structs in FFmpeg, whose size is a part of public
1110  * ABI. Thus it may be allocated on stack and no new fields can be added to it
1111  * without libavcodec and libavformat major bump.
1112  *
1113  * The semantics of data ownership depends on the buf or destruct (deprecated)
1114  * fields. If either is set, the packet data is dynamically allocated and is
1115  * valid indefinitely until av_free_packet() is called (which in turn calls
1116  * av_buffer_unref()/the destruct callback to free the data). If neither is set,
1117  * the packet data is typically backed by some static buffer somewhere and is
1118  * only valid for a limited time (e.g. until the next read call when demuxing).
1119  *
1120  * The side data is always allocated with av_malloc() and is freed in
1121  * av_free_packet().
1122  */
1123 typedef struct AVPacket {
1124  /**
1125  * A reference to the reference-counted buffer where the packet data is
1126  * stored.
1127  * May be NULL, then the packet data is not reference-counted.
1128  */
1129  AVBufferRef *buf;
1130  /**
1131  * Presentation timestamp in AVStream->time_base units; the time at which
1132  * the decompressed packet will be presented to the user.
1133  * Can be AV_NOPTS_VALUE if it is not stored in the file.
1134  * pts MUST be larger or equal to dts as presentation cannot happen before
1135  * decompression, unless one wants to view hex dumps. Some formats misuse
1136  * the terms dts and pts/cts to mean something different. Such timestamps
1137  * must be converted to true pts/dts before they are stored in AVPacket.
1138  */
1139  int64_t pts;
1140  /**
1141  * Decompression timestamp in AVStream->time_base units; the time at which
1142  * the packet is decompressed.
1143  * Can be AV_NOPTS_VALUE if it is not stored in the file.
1144  */
1145  int64_t dts;
1147  int size;
1148  int stream_index;
1149  /**
1150  * A combination of AV_PKT_FLAG values
1151  */
1152  int flags;
1153  /**
1154  * Additional packet data that can be provided by the container.
1155  * Packet can contain several types of side information.
1156  */
1158  int side_data_elems;
1159 
1160  /**
1161  * Duration of this packet in AVStream->time_base units, 0 if unknown.
1162  * Equals next_pts - this_pts in presentation order.
1163  */
1164  int duration;
1165 #if FF_API_DESTRUCT_PACKET
1167  void (*destruct)(struct AVPacket *);
1169  void *priv;
1170 #endif
1171  int64_t pos; ///< byte position in stream, -1 if unknown
1172 
1173  /**
1174  * Time difference in AVStream->time_base units from the pts of this
1175  * packet to the point at which the output from the decoder has converged
1176  * independent from the availability of previous frames. That is, the
1177  * frames are virtually identical no matter if decoding started from
1178  * the very first frame or from this keyframe.
1179  * Is AV_NOPTS_VALUE if unknown.
1180  * This field is not the display duration of the current packet.
1181  * This field has no meaning if the packet does not have AV_PKT_FLAG_KEY
1182  * set.
1183  *
1184  * The purpose of this field is to allow seeking in streams that have no
1185  * keyframes in the conventional sense. It corresponds to the
1186  * recovery point SEI in H.264 and match_time_delta in NUT. It is also
1187  * essential for some types of subtitle streams to ensure that all
1188  * subtitles are correctly displayed after seeking.
1189  */
1190  int64_t convergence_duration;
1192 #define AV_PKT_FLAG_KEY 0x0001 ///< The packet contains a keyframe
1193 #define AV_PKT_FLAG_CORRUPT 0x0002 ///< The packet content is corrupted
1200 };
1201 /**
1202  * @}
1203  */
1204 
1205 struct AVCodecInternal;
1210  AV_FIELD_TT, //< Top coded_first, top displayed first
1211  AV_FIELD_BB, //< Bottom coded first, bottom displayed first
1212  AV_FIELD_TB, //< Top coded first, bottom displayed first
1213  AV_FIELD_BT, //< Bottom coded first, top displayed first
1214 };
1215 
1216 /**
1217  * main external API structure.
1218  * New fields can be added to the end with minor version bumps.
1219  * Removal, reordering and changes to existing fields require a major
1220  * version bump.
1221  * Please use AVOptions (av_opt* / av_set/get*()) to access these fields from user
1222  * applications.
1223  * sizeof(AVCodecContext) must not be used outside libav*.
1224  */
1225 typedef struct AVCodecContext {
1226  /**
1227  * information on struct for av_log
1228  * - set by avcodec_alloc_context3
1229  */
1231  int log_level_offset;
1233  enum AVMediaType codec_type; /* see AVMEDIA_TYPE_xxx */
1234  const struct AVCodec *codec;
1235 #if FF_API_CODEC_NAME
1236  /**
1237  * @deprecated this field is not used for anything in libavcodec
1238  */
1240  char codec_name[32];
1241 #endif
1242  enum AVCodecID codec_id; /* see AV_CODEC_ID_xxx */
1243 
1244  /**
1245  * fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
1246  * This is used to work around some encoder bugs.
1247  * A demuxer should set this to what is stored in the field used to identify the codec.
1248  * If there are multiple such fields in a container then the demuxer should choose the one
1249  * which maximizes the information about the used codec.
1250  * If the codec tag field in a container is larger than 32 bits then the demuxer should
1251  * remap the longer ID to 32 bits with a table or other structure. Alternatively a new
1252  * extra_codec_tag + size could be added but for this a clear advantage must be demonstrated
1253  * first.
1254  * - encoding: Set by user, if not then the default based on codec_id will be used.
1255  * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
1256  */
1257  unsigned int codec_tag;
1258 
1259  /**
1260  * fourcc from the AVI stream header (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
1261  * This is used to work around some encoder bugs.
1262  * - encoding: unused
1263  * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
1264  */
1265  unsigned int stream_codec_tag;
1267  void *priv_data;
1268 
1269  /**
1270  * Private context used for internal data.
1271  *
1272  * Unlike priv_data, this is not codec-specific. It is used in general
1273  * libavcodec functions.
1274  */
1275  struct AVCodecInternal *internal;
1276 
1277  /**
1278  * Private data of the user, can be used to carry app specific stuff.
1279  * - encoding: Set by user.
1280  * - decoding: Set by user.
1281  */
1282  void *opaque;
1283 
1284  /**
1285  * the average bitrate
1286  * - encoding: Set by user; unused for constant quantizer encoding.
1287  * - decoding: Set by libavcodec. 0 or some bitrate if this info is available in the stream.
1288  */
1289  int bit_rate;
1290 
1291  /**
1292  * number of bits the bitstream is allowed to diverge from the reference.
1293  * the reference can be CBR (for CBR pass1) or VBR (for pass2)
1294  * - encoding: Set by user; unused for constant quantizer encoding.
1295  * - decoding: unused
1296  */
1297  int bit_rate_tolerance;
1298 
1299  /**
1300  * Global quality for codecs which cannot change it per frame.
1301  * This should be proportional to MPEG-1/2/4 qscale.
1302  * - encoding: Set by user.
1303  * - decoding: unused
1304  */
1305  int global_quality;
1306 
1307  /**
1308  * - encoding: Set by user.
1309  * - decoding: unused
1310  */
1312 #define FF_COMPRESSION_DEFAULT -1
1313 
1314  /**
1315  * CODEC_FLAG_*.
1316  * - encoding: Set by user.
1317  * - decoding: Set by user.
1318  */
1319  int flags;
1320 
1321  /**
1322  * CODEC_FLAG2_*
1323  * - encoding: Set by user.
1324  * - decoding: Set by user.
1325  */
1326  int flags2;
1327 
1328  /**
1329  * some codecs need / can use extradata like Huffman tables.
1330  * mjpeg: Huffman tables
1331  * rv10: additional flags
1332  * mpeg4: global headers (they can be in the bitstream or here)
1333  * The allocated memory should be FF_INPUT_BUFFER_PADDING_SIZE bytes larger
1334  * than extradata_size to avoid problems if it is read with the bitstream reader.
1335  * The bytewise contents of extradata must not depend on the architecture or CPU endianness.
1336  * - encoding: Set/allocated/freed by libavcodec.
1337  * - decoding: Set/allocated/freed by user.
1338  */
1340  int extradata_size;
1341 
1342  /**
1343  * This is the fundamental unit of time (in seconds) in terms
1344  * of which frame timestamps are represented. For fixed-fps content,
1345  * timebase should be 1/framerate and timestamp increments should be
1346  * identically 1.
1347  * - encoding: MUST be set by user.
1348  * - decoding: Set by libavcodec.
1349  */
1351 
1352  /**
1353  * For some codecs, the time base is closer to the field rate than the frame rate.
1354  * Most notably, H.264 and MPEG-2 specify time_base as half of frame duration
1355  * if no telecine is used ...
1356  *
1357  * Set to time_base ticks per frame. Default 1, e.g., H.264/MPEG-2 set it to 2.
1358  */
1359  int ticks_per_frame;
1360 
1361  /**
1362  * Codec delay.
1363  *
1364  * Encoding: Number of frames delay there will be from the encoder input to
1365  * the decoder output. (we assume the decoder matches the spec)
1366  * Decoding: Number of frames delay in addition to what a standard decoder
1367  * as specified in the spec would produce.
1368  *
1369  * Video:
1370  * Number of frames the decoded output will be delayed relative to the
1371  * encoded input.
1372  *
1373  * Audio:
1374  * For encoding, this is the number of "priming" samples added by the
1375  * encoder to the beginning of the stream. The decoded output will be
1376  * delayed by this many samples relative to the input to the encoder (or
1377  * more, if the decoder adds its own padding).
1378  * The timestamps on the output packets are adjusted by the encoder so
1379  * that they always refer to the first sample of the data actually
1380  * contained in the packet, including any added padding.
1381  * E.g. if the timebase is 1/samplerate and the timestamp of the first
1382  * input sample is 0, the timestamp of the first output packet will be
1383  * -delay.
1384  *
1385  * For decoding, this is the number of samples the decoder needs to
1386  * output before the decoder's output is valid. When seeking, you should
1387  * start decoding this many samples prior to your desired seek point.
1388  *
1389  * - encoding: Set by libavcodec.
1390  * - decoding: Set by libavcodec.
1391  */
1392  int delay;
1393 
1394 
1395  /* video only */
1396  /**
1397  * picture width / height.
1398  * - encoding: MUST be set by user.
1399  * - decoding: May be set by the user before opening the decoder if known e.g.
1400  * from the container. Some decoders will require the dimensions
1401  * to be set by the caller. During decoding, the decoder may
1402  * overwrite those values as required.
1403  */
1404  int width, height;
1405 
1406  /**
1407  * Bitstream width / height, may be different from width/height e.g. when
1408  * the decoded frame is cropped before being output or lowres is enabled.
1409  * - encoding: unused
1410  * - decoding: May be set by the user before opening the decoder if known
1411  * e.g. from the container. During decoding, the decoder may
1412  * overwrite those values as required.
1413  */
1415 
1416 #if FF_API_ASPECT_EXTENDED
1417 #define FF_ASPECT_EXTENDED 15
1418 #endif
1419 
1420  /**
1421  * the number of pictures in a group of pictures, or 0 for intra_only
1422  * - encoding: Set by user.
1423  * - decoding: unused
1424  */
1425  int gop_size;
1426 
1427  /**
1428  * Pixel format, see AV_PIX_FMT_xxx.
1429  * May be set by the demuxer if known from headers.
1430  * May be overridden by the decoder if it knows better.
1431  * - encoding: Set by user.
1432  * - decoding: Set by user if known, overridden by libavcodec if known
1433  */
1434  enum AVPixelFormat pix_fmt;
1435 
1436  /**
1437  * Motion estimation algorithm used for video coding.
1438  * 1 (zero), 2 (full), 3 (log), 4 (phods), 5 (epzs), 6 (x1), 7 (hex),
1439  * 8 (umh), 9 (iter), 10 (tesa) [7, 8, 10 are x264 specific, 9 is snow specific]
1440  * - encoding: MUST be set by user.
1441  * - decoding: unused
1442  */
1443  int me_method;
1444 
1445  /**
1446  * If non NULL, 'draw_horiz_band' is called by the libavcodec
1447  * decoder to draw a horizontal band. It improves cache usage. Not
1448  * all codecs can do that. You must check the codec capabilities
1449  * beforehand.
1450  * When multithreading is used, it may be called from multiple threads
1451  * at the same time; threads might draw different parts of the same AVFrame,
1452  * or multiple AVFrames, and there is no guarantee that slices will be drawn
1453  * in order.
1454  * The function is also used by hardware acceleration APIs.
1455  * It is called at least once during frame decoding to pass
1456  * the data needed for hardware render.
1457  * In that mode instead of pixel data, AVFrame points to
1458  * a structure specific to the acceleration API. The application
1459  * reads the structure and can change some fields to indicate progress
1460  * or mark state.
1461  * - encoding: unused
1462  * - decoding: Set by user.
1463  * @param height the height of the slice
1464  * @param y the y position of the slice
1465  * @param type 1->top field, 2->bottom field, 3->frame
1466  * @param offset offset into the AVFrame.data from which the slice should be read
1467  */
1468  void (*draw_horiz_band)(struct AVCodecContext *s,
1469  const AVFrame *src, int offset[AV_NUM_DATA_POINTERS],
1470  int y, int type, int height);
1471 
1472  /**
1473  * callback to negotiate the pixelFormat
1474  * @param fmt is the list of formats which are supported by the codec,
1475  * it is terminated by -1 as 0 is a valid format, the formats are ordered by quality.
1476  * The first is always the native one.
1477  * @return the chosen format
1478  * - encoding: unused
1479  * - decoding: Set by user, if not set the native format will be chosen.
1480  */
1481  enum AVPixelFormat (*get_format)(struct AVCodecContext *s, const enum AVPixelFormat * fmt);
1482 
1483  /**
1484  * maximum number of B-frames between non-B-frames
1485  * Note: The output will be delayed by max_b_frames+1 relative to the input.
1486  * - encoding: Set by user.
1487  * - decoding: unused
1488  */
1489  int max_b_frames;
1490 
1491  /**
1492  * qscale factor between IP and B-frames
1493  * If > 0 then the last P-frame quantizer will be used (q= lastp_q*factor+offset).
1494  * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1495  * - encoding: Set by user.
1496  * - decoding: unused
1497  */
1498  float b_quant_factor;
1499 
1500  /** obsolete FIXME remove */
1502 #define FF_RC_STRATEGY_XVID 1
1504  int b_frame_strategy;
1505 
1506  /**
1507  * qscale offset between IP and B-frames
1508  * - encoding: Set by user.
1509  * - decoding: unused
1510  */
1511  float b_quant_offset;
1512 
1513  /**
1514  * Size of the frame reordering buffer in the decoder.
1515  * For MPEG-2 it is 1 IPB or 0 low delay IP.
1516  * - encoding: Set by libavcodec.
1517  * - decoding: Set by libavcodec.
1518  */
1519  int has_b_frames;
1520 
1521  /**
1522  * 0-> h263 quant 1-> mpeg quant
1523  * - encoding: Set by user.
1524  * - decoding: unused
1525  */
1526  int mpeg_quant;
1527 
1528  /**
1529  * qscale factor between P and I-frames
1530  * If > 0 then the last p frame quantizer will be used (q= lastp_q*factor+offset).
1531  * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1532  * - encoding: Set by user.
1533  * - decoding: unused
1534  */
1535  float i_quant_factor;
1536 
1537  /**
1538  * qscale offset between P and I-frames
1539  * - encoding: Set by user.
1540  * - decoding: unused
1541  */
1542  float i_quant_offset;
1543 
1544  /**
1545  * luminance masking (0-> disabled)
1546  * - encoding: Set by user.
1547  * - decoding: unused
1548  */
1549  float lumi_masking;
1550 
1551  /**
1552  * temporary complexity masking (0-> disabled)
1553  * - encoding: Set by user.
1554  * - decoding: unused
1555  */
1556  float temporal_cplx_masking;
1557 
1558  /**
1559  * spatial complexity masking (0-> disabled)
1560  * - encoding: Set by user.
1561  * - decoding: unused
1562  */
1563  float spatial_cplx_masking;
1564 
1565  /**
1566  * p block masking (0-> disabled)
1567  * - encoding: Set by user.
1568  * - decoding: unused
1569  */
1570  float p_masking;
1571 
1572  /**
1573  * darkness masking (0-> disabled)
1574  * - encoding: Set by user.
1575  * - decoding: unused
1576  */
1577  float dark_masking;
1578 
1579  /**
1580  * slice count
1581  * - encoding: Set by libavcodec.
1582  * - decoding: Set by user (or 0).
1583  */
1584  int slice_count;
1585  /**
1586  * prediction method (needed for huffyuv)
1587  * - encoding: Set by user.
1588  * - decoding: unused
1589  */
1591 #define FF_PRED_LEFT 0
1592 #define FF_PRED_PLANE 1
1593 #define FF_PRED_MEDIAN 2
1594 
1595  /**
1596  * slice offsets in the frame in bytes
1597  * - encoding: Set/allocated by libavcodec.
1598  * - decoding: Set/allocated by user (or NULL).
1599  */
1600  int *slice_offset;
1601 
1602  /**
1603  * sample aspect ratio (0 if unknown)
1604  * That is the width of a pixel divided by the height of the pixel.
1605  * Numerator and denominator must be relatively prime and smaller than 256 for some video standards.
1606  * - encoding: Set by user.
1607  * - decoding: Set by libavcodec.
1608  */
1610 
1611  /**
1612  * motion estimation comparison function
1613  * - encoding: Set by user.
1614  * - decoding: unused
1615  */
1616  int me_cmp;
1617  /**
1618  * subpixel motion estimation comparison function
1619  * - encoding: Set by user.
1620  * - decoding: unused
1621  */
1622  int me_sub_cmp;
1623  /**
1624  * macroblock comparison function (not supported yet)
1625  * - encoding: Set by user.
1626  * - decoding: unused
1627  */
1628  int mb_cmp;
1629  /**
1630  * interlaced DCT comparison function
1631  * - encoding: Set by user.
1632  * - decoding: unused
1633  */
1635 #define FF_CMP_SAD 0
1636 #define FF_CMP_SSE 1
1637 #define FF_CMP_SATD 2
1638 #define FF_CMP_DCT 3
1639 #define FF_CMP_PSNR 4
1640 #define FF_CMP_BIT 5
1641 #define FF_CMP_RD 6
1642 #define FF_CMP_ZERO 7
1643 #define FF_CMP_VSAD 8
1644 #define FF_CMP_VSSE 9
1645 #define FF_CMP_NSSE 10
1646 #define FF_CMP_W53 11
1647 #define FF_CMP_W97 12
1648 #define FF_CMP_DCTMAX 13
1649 #define FF_CMP_DCT264 14
1650 #define FF_CMP_CHROMA 256
1651 
1652  /**
1653  * ME diamond size & shape
1654  * - encoding: Set by user.
1655  * - decoding: unused
1656  */
1657  int dia_size;
1658 
1659  /**
1660  * amount of previous MV predictors (2a+1 x 2a+1 square)
1661  * - encoding: Set by user.
1662  * - decoding: unused
1663  */
1665 
1666  /**
1667  * prepass for motion estimation
1668  * - encoding: Set by user.
1669  * - decoding: unused
1670  */
1671  int pre_me;
1672 
1673  /**
1674  * motion estimation prepass comparison function
1675  * - encoding: Set by user.
1676  * - decoding: unused
1677  */
1678  int me_pre_cmp;
1679 
1680  /**
1681  * ME prepass diamond size & shape
1682  * - encoding: Set by user.
1683  * - decoding: unused
1684  */
1685  int pre_dia_size;
1686 
1687  /**
1688  * subpel ME quality
1689  * - encoding: Set by user.
1690  * - decoding: unused
1691  */
1692  int me_subpel_quality;
1693 
1694 #if FF_API_AFD
1695  /**
1696  * DTG active format information (additional aspect ratio
1697  * information only used in DVB MPEG-2 transport streams)
1698  * 0 if not set.
1699  *
1700  * - encoding: unused
1701  * - decoding: Set by decoder.
1702  * @deprecated Deprecated in favor of AVSideData
1703  */
1705 #define FF_DTG_AFD_SAME 8
1706 #define FF_DTG_AFD_4_3 9
1707 #define FF_DTG_AFD_16_9 10
1708 #define FF_DTG_AFD_14_9 11
1709 #define FF_DTG_AFD_4_3_SP_14_9 13
1710 #define FF_DTG_AFD_16_9_SP_14_9 14
1711 #define FF_DTG_AFD_SP_4_3 15
1712 #endif /* FF_API_AFD */
1713 
1714  /**
1715  * maximum motion estimation search range in subpel units
1716  * If 0 then no limit.
1717  *
1718  * - encoding: Set by user.
1719  * - decoding: unused
1720  */
1721  int me_range;
1722 
1723  /**
1724  * intra quantizer bias
1725  * - encoding: Set by user.
1726  * - decoding: unused
1727  */
1729 #define FF_DEFAULT_QUANT_BIAS 999999
1730 
1731  /**
1732  * inter quantizer bias
1733  * - encoding: Set by user.
1734  * - decoding: unused
1735  */
1736  int inter_quant_bias;
1737 
1738  /**
1739  * slice flags
1740  * - encoding: unused
1741  * - decoding: Set by user.
1742  */
1744 #define SLICE_FLAG_CODED_ORDER 0x0001 ///< draw_horiz_band() is called in coded order instead of display
1745 #define SLICE_FLAG_ALLOW_FIELD 0x0002 ///< allow draw_horiz_band() with field slices (MPEG2 field pics)
1746 #define SLICE_FLAG_ALLOW_PLANE 0x0004 ///< allow draw_horiz_band() with 1 component at a time (SVQ1)
1747 
1748 #if FF_API_XVMC
1749  /**
1750  * XVideo Motion Acceleration
1751  * - encoding: forbidden
1752  * - decoding: set by decoder
1753  * @deprecated XvMC doesn't need it anymore.
1754  */
1755  attribute_deprecated int xvmc_acceleration;
1756 #endif /* FF_API_XVMC */
1757 
1758  /**
1759  * macroblock decision mode
1760  * - encoding: Set by user.
1761  * - decoding: unused
1762  */
1764 #define FF_MB_DECISION_SIMPLE 0 ///< uses mb_cmp
1765 #define FF_MB_DECISION_BITS 1 ///< chooses the one which needs the fewest bits
1766 #define FF_MB_DECISION_RD 2 ///< rate distortion
1767 
1768  /**
1769  * custom intra quantization matrix
1770  * - encoding: Set by user, can be NULL.
1771  * - decoding: Set by libavcodec.
1772  */
1773  uint16_t *intra_matrix;
1774 
1775  /**
1776  * custom inter quantization matrix
1777  * - encoding: Set by user, can be NULL.
1778  * - decoding: Set by libavcodec.
1779  */
1780  uint16_t *inter_matrix;
1781 
1782  /**
1783  * scene change detection threshold
1784  * 0 is default, larger means fewer detected scene changes.
1785  * - encoding: Set by user.
1786  * - decoding: unused
1787  */
1789 
1790  /**
1791  * noise reduction strength
1792  * - encoding: Set by user.
1793  * - decoding: unused
1794  */
1795  int noise_reduction;
1796 
1797  /**
1798  * Motion estimation threshold below which no motion estimation is
1799  * performed, but instead the user specified motion vectors are used.
1800  *
1801  * - encoding: Set by user.
1802  * - decoding: unused
1803  */
1804  int me_threshold;
1805 
1806  /**
1807  * Macroblock threshold below which the user specified macroblock types will be used.
1808  * - encoding: Set by user.
1809  * - decoding: unused
1810  */
1811  int mb_threshold;
1812 
1813  /**
1814  * precision of the intra DC coefficient - 8
1815  * - encoding: Set by user.
1816  * - decoding: unused
1817  */
1818  int intra_dc_precision;
1819 
1820  /**
1821  * Number of macroblock rows at the top which are skipped.
1822  * - encoding: unused
1823  * - decoding: Set by user.
1824  */
1825  int skip_top;
1826 
1827  /**
1828  * Number of macroblock rows at the bottom which are skipped.
1829  * - encoding: unused
1830  * - decoding: Set by user.
1831  */
1832  int skip_bottom;
1833 
1834  /**
1835  * Border processing masking, raises the quantizer for mbs on the borders
1836  * of the picture.
1837  * - encoding: Set by user.
1838  * - decoding: unused
1839  */
1840  float border_masking;
1841 
1842  /**
1843  * minimum MB lagrange multipler
1844  * - encoding: Set by user.
1845  * - decoding: unused
1846  */
1847  int mb_lmin;
1848 
1849  /**
1850  * maximum MB lagrange multipler
1851  * - encoding: Set by user.
1852  * - decoding: unused
1853  */
1854  int mb_lmax;
1855 
1856  /**
1857  *
1858  * - encoding: Set by user.
1859  * - decoding: unused
1860  */
1862 
1863  /**
1864  *
1865  * - encoding: Set by user.
1866  * - decoding: unused
1867  */
1868  int bidir_refine;
1869 
1870  /**
1871  *
1872  * - encoding: Set by user.
1873  * - decoding: unused
1874  */
1875  int brd_scale;
1876 
1877  /**
1878  * minimum GOP size
1879  * - encoding: Set by user.
1880  * - decoding: unused
1881  */
1882  int keyint_min;
1883 
1884  /**
1885  * number of reference frames
1886  * - encoding: Set by user.
1887  * - decoding: Set by lavc.
1888  */
1889  int refs;
1890 
1891  /**
1892  * chroma qp offset from luma
1893  * - encoding: Set by user.
1894  * - decoding: unused
1895  */
1896  int chromaoffset;
1897 
1898 #if FF_API_UNUSED_MEMBERS
1899  /**
1900  * Multiplied by qscale for each frame and added to scene_change_score.
1901  * - encoding: Set by user.
1902  * - decoding: unused
1903  */
1905 #endif
1906 
1907  /**
1908  *
1909  * Note: Value depends upon the compare function used for fullpel ME.
1910  * - encoding: Set by user.
1911  * - decoding: unused
1912  */
1913  int mv0_threshold;
1914 
1915  /**
1916  * Adjust sensitivity of b_frame_strategy 1.
1917  * - encoding: Set by user.
1918  * - decoding: unused
1919  */
1920  int b_sensitivity;
1921 
1922  /**
1923  * Chromaticity coordinates of the source primaries.
1924  * - encoding: Set by user
1925  * - decoding: Set by libavcodec
1926  */
1928 
1929  /**
1930  * Color Transfer Characteristic.
1931  * - encoding: Set by user
1932  * - decoding: Set by libavcodec
1933  */
1935 
1936  /**
1937  * YUV colorspace type.
1938  * - encoding: Set by user
1939  * - decoding: Set by libavcodec
1940  */
1941  enum AVColorSpace colorspace;
1942 
1943  /**
1944  * MPEG vs JPEG YUV range.
1945  * - encoding: Set by user
1946  * - decoding: Set by libavcodec
1947  */
1949 
1950  /**
1951  * This defines the location of chroma samples.
1952  * - encoding: Set by user
1953  * - decoding: Set by libavcodec
1954  */
1956 
1957  /**
1958  * Number of slices.
1959  * Indicates number of picture subdivisions. Used for parallelized
1960  * decoding.
1961  * - encoding: Set by user
1962  * - decoding: unused
1963  */
1964  int slices;
1965 
1966  /** Field order
1967  * - encoding: set by libavcodec
1968  * - decoding: Set by user.
1969  */
1971 
1972  /* audio only */
1973  int sample_rate; ///< samples per second
1974  int channels; ///< number of audio channels
1975 
1976  /**
1977  * audio sample format
1978  * - encoding: Set by user.
1979  * - decoding: Set by libavcodec.
1980  */
1981  enum AVSampleFormat sample_fmt; ///< sample format
1982 
1983  /* The following data should not be initialized. */
1984  /**
1985  * Number of samples per channel in an audio frame.
1986  *
1987  * - encoding: set by libavcodec in avcodec_open2(). Each submitted frame
1988  * except the last must contain exactly frame_size samples per channel.
1989  * May be 0 when the codec has CODEC_CAP_VARIABLE_FRAME_SIZE set, then the
1990  * frame size is not restricted.
1991  * - decoding: may be set by some decoders to indicate constant frame size
1992  */
1993  int frame_size;
1994 
1995  /**
1996  * Frame counter, set by libavcodec.
1997  *
1998  * - decoding: total number of frames returned from the decoder so far.
1999  * - encoding: total number of frames passed to the encoder so far.
2000  *
2001  * @note the counter is not incremented if encoding/decoding resulted in
2002  * an error.
2003  */
2004  int frame_number;
2005 
2006  /**
2007  * number of bytes per packet if constant and known or 0
2008  * Used by some WAV based audio codecs.
2009  */
2010  int block_align;
2011 
2012  /**
2013  * Audio cutoff bandwidth (0 means "automatic")
2014  * - encoding: Set by user.
2015  * - decoding: unused
2016  */
2017  int cutoff;
2018 
2019 #if FF_API_REQUEST_CHANNELS
2020  /**
2021  * Decoder should decode to this many channels if it can (0 for default)
2022  * - encoding: unused
2023  * - decoding: Set by user.
2024  * @deprecated Deprecated in favor of request_channel_layout.
2025  */
2027 #endif
2028 
2029  /**
2030  * Audio channel layout.
2031  * - encoding: set by user.
2032  * - decoding: set by user, may be overwritten by libavcodec.
2033  */
2034  uint64_t channel_layout;
2035 
2036  /**
2037  * Request decoder to use this channel layout if it can (0 for default)
2038  * - encoding: unused
2039  * - decoding: Set by user.
2040  */
2041  uint64_t request_channel_layout;
2042 
2043  /**
2044  * Type of service that the audio stream conveys.
2045  * - encoding: Set by user.
2046  * - decoding: Set by libavcodec.
2047  */
2049 
2050  /**
2051  * desired sample format
2052  * - encoding: Not used.
2053  * - decoding: Set by user.
2054  * Decoder will decode to this format if it can.
2055  */
2057 
2058 #if FF_API_GET_BUFFER
2059  /**
2060  * Called at the beginning of each frame to get a buffer for it.
2061  *
2062  * The function will set AVFrame.data[], AVFrame.linesize[].
2063  * AVFrame.extended_data[] must also be set, but it should be the same as
2064  * AVFrame.data[] except for planar audio with more channels than can fit
2065  * in AVFrame.data[]. In that case, AVFrame.data[] shall still contain as
2066  * many data pointers as it can hold.
2067  *
2068  * if CODEC_CAP_DR1 is not set then get_buffer() must call
2069  * avcodec_default_get_buffer() instead of providing buffers allocated by
2070  * some other means.
2071  *
2072  * AVFrame.data[] should be 32- or 16-byte-aligned unless the CPU doesn't
2073  * need it. avcodec_default_get_buffer() aligns the output buffer properly,
2074  * but if get_buffer() is overridden then alignment considerations should
2075  * be taken into account.
2076  *
2077  * @see avcodec_default_get_buffer()
2078  *
2079  * Video:
2080  *
2081  * If pic.reference is set then the frame will be read later by libavcodec.
2082  * avcodec_align_dimensions2() should be used to find the required width and
2083  * height, as they normally need to be rounded up to the next multiple of 16.
2084  *
2085  * If frame multithreading is used and thread_safe_callbacks is set,
2086  * it may be called from a different thread, but not from more than one at
2087  * once. Does not need to be reentrant.
2088  *
2089  * @see release_buffer(), reget_buffer()
2090  * @see avcodec_align_dimensions2()
2091  *
2092  * Audio:
2093  *
2094  * Decoders request a buffer of a particular size by setting
2095  * AVFrame.nb_samples prior to calling get_buffer(). The decoder may,
2096  * however, utilize only part of the buffer by setting AVFrame.nb_samples
2097  * to a smaller value in the output frame.
2098  *
2099  * Decoders cannot use the buffer after returning from
2100  * avcodec_decode_audio4(), so they will not call release_buffer(), as it
2101  * is assumed to be released immediately upon return. In some rare cases,
2102  * a decoder may need to call get_buffer() more than once in a single
2103  * call to avcodec_decode_audio4(). In that case, when get_buffer() is
2104  * called again after it has already been called once, the previously
2105  * acquired buffer is assumed to be released at that time and may not be
2106  * reused by the decoder.
2107  *
2108  * As a convenience, av_samples_get_buffer_size() and
2109  * av_samples_fill_arrays() in libavutil may be used by custom get_buffer()
2110  * functions to find the required data size and to fill data pointers and
2111  * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
2112  * since all planes must be the same size.
2113  *
2114  * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
2115  *
2116  * - encoding: unused
2117  * - decoding: Set by libavcodec, user can override.
2118  *
2119  * @deprecated use get_buffer2()
2120  */
2122  int (*get_buffer)(struct AVCodecContext *c, AVFrame *pic);
2123 
2124  /**
2125  * Called to release buffers which were allocated with get_buffer.
2126  * A released buffer can be reused in get_buffer().
2127  * pic.data[*] must be set to NULL.
2128  * May be called from a different thread if frame multithreading is used,
2129  * but not by more than one thread at once, so does not need to be reentrant.
2130  * - encoding: unused
2131  * - decoding: Set by libavcodec, user can override.
2132  *
2133  * @deprecated custom freeing callbacks should be set from get_buffer2()
2134  */
2136  void (*release_buffer)(struct AVCodecContext *c, AVFrame *pic);
2137 
2138  /**
2139  * Called at the beginning of a frame to get cr buffer for it.
2140  * Buffer type (size, hints) must be the same. libavcodec won't check it.
2141  * libavcodec will pass previous buffer in pic, function should return
2142  * same buffer or new buffer with old frame "painted" into it.
2143  * If pic.data[0] == NULL must behave like get_buffer().
2144  * if CODEC_CAP_DR1 is not set then reget_buffer() must call
2145  * avcodec_default_reget_buffer() instead of providing buffers allocated by
2146  * some other means.
2147  * - encoding: unused
2148  * - decoding: Set by libavcodec, user can override.
2149  */
2151  int (*reget_buffer)(struct AVCodecContext *c, AVFrame *pic);
2152 #endif
2153 
2154  /**
2155  * This callback is called at the beginning of each frame to get data
2156  * buffer(s) for it. There may be one contiguous buffer for all the data or
2157  * there may be a buffer per each data plane or anything in between. What
2158  * this means is, you may set however many entries in buf[] you feel necessary.
2159  * Each buffer must be reference-counted using the AVBuffer API (see description
2160  * of buf[] below).
2161  *
2162  * The following fields will be set in the frame before this callback is
2163  * called:
2164  * - format
2165  * - width, height (video only)
2166  * - sample_rate, channel_layout, nb_samples (audio only)
2167  * Their values may differ from the corresponding values in
2168  * AVCodecContext. This callback must use the frame values, not the codec
2169  * context values, to calculate the required buffer size.
2170  *
2171  * This callback must fill the following fields in the frame:
2172  * - data[]
2173  * - linesize[]
2174  * - extended_data:
2175  * * if the data is planar audio with more than 8 channels, then this
2176  * callback must allocate and fill extended_data to contain all pointers
2177  * to all data planes. data[] must hold as many pointers as it can.
2178  * extended_data must be allocated with av_malloc() and will be freed in
2179  * av_frame_unref().
2180  * * otherwise exended_data must point to data
2181  * - buf[] must contain one or more pointers to AVBufferRef structures. Each of
2182  * the frame's data and extended_data pointers must be contained in these. That
2183  * is, one AVBufferRef for each allocated chunk of memory, not necessarily one
2184  * AVBufferRef per data[] entry. See: av_buffer_create(), av_buffer_alloc(),
2185  * and av_buffer_ref().
2186  * - extended_buf and nb_extended_buf must be allocated with av_malloc() by
2187  * this callback and filled with the extra buffers if there are more
2188  * buffers than buf[] can hold. extended_buf will be freed in
2189  * av_frame_unref().
2190  *
2191  * If CODEC_CAP_DR1 is not set then get_buffer2() must call
2192  * avcodec_default_get_buffer2() instead of providing buffers allocated by
2193  * some other means.
2194  *
2195  * Each data plane must be aligned to the maximum required by the target
2196  * CPU.
2197  *
2198  * @see avcodec_default_get_buffer2()
2199  *
2200  * Video:
2201  *
2202  * If AV_GET_BUFFER_FLAG_REF is set in flags then the frame may be reused
2203  * (read and/or written to if it is writable) later by libavcodec.
2204  *
2205  * avcodec_align_dimensions2() should be used to find the required width and
2206  * height, as they normally need to be rounded up to the next multiple of 16.
2207  *
2208  * Some decoders do not support linesizes changing between frames.
2209  *
2210  * If frame multithreading is used and thread_safe_callbacks is set,
2211  * this callback may be called from a different thread, but not from more
2212  * than one at once. Does not need to be reentrant.
2213  *
2214  * @see avcodec_align_dimensions2()
2215  *
2216  * Audio:
2217  *
2218  * Decoders request a buffer of a particular size by setting
2219  * AVFrame.nb_samples prior to calling get_buffer2(). The decoder may,
2220  * however, utilize only part of the buffer by setting AVFrame.nb_samples
2221  * to a smaller value in the output frame.
2222  *
2223  * As a convenience, av_samples_get_buffer_size() and
2224  * av_samples_fill_arrays() in libavutil may be used by custom get_buffer2()
2225  * functions to find the required data size and to fill data pointers and
2226  * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
2227  * since all planes must be the same size.
2228  *
2229  * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
2230  *
2231  * - encoding: unused
2232  * - decoding: Set by libavcodec, user can override.
2233  */
2234  int (*get_buffer2)(struct AVCodecContext *s, AVFrame *frame, int flags);
2235 
2236  /**
2237  * If non-zero, the decoded audio and video frames returned from
2238  * avcodec_decode_video2() and avcodec_decode_audio4() are reference-counted
2239  * and are valid indefinitely. The caller must free them with
2240  * av_frame_unref() when they are not needed anymore.
2241  * Otherwise, the decoded frames must not be freed by the caller and are
2242  * only valid until the next decode call.
2243  *
2244  * - encoding: unused
2245  * - decoding: set by the caller before avcodec_open2().
2246  */
2247  int refcounted_frames;
2248 
2249  /* - encoding parameters */
2250  float qcompress; ///< amount of qscale change between easy & hard scenes (0.0-1.0)
2251  float qblur; ///< amount of qscale smoothing over time (0.0-1.0)
2252 
2253  /**
2254  * minimum quantizer
2255  * - encoding: Set by user.
2256  * - decoding: unused
2257  */
2258  int qmin;
2259 
2260  /**
2261  * maximum quantizer
2262  * - encoding: Set by user.
2263  * - decoding: unused
2264  */
2265  int qmax;
2266 
2267  /**
2268  * maximum quantizer difference between frames
2269  * - encoding: Set by user.
2270  * - decoding: unused
2271  */
2272  int max_qdiff;
2273 
2274  /**
2275  * ratecontrol qmin qmax limiting method
2276  * 0-> clipping, 1-> use a nice continuous function to limit qscale within qmin/qmax.
2277  * - encoding: Set by user.
2278  * - decoding: unused
2279  */
2280  float rc_qsquish;
2283  int rc_qmod_freq;
2284 
2285  /**
2286  * decoder bitstream buffer size
2287  * - encoding: Set by user.
2288  * - decoding: unused
2289  */
2290  int rc_buffer_size;
2291 
2292  /**
2293  * ratecontrol override, see RcOverride
2294  * - encoding: Allocated/set/freed by user.
2295  * - decoding: unused
2296  */
2299 
2300  /**
2301  * rate control equation
2302  * - encoding: Set by user
2303  * - decoding: unused
2304  */
2305  const char *rc_eq;
2306 
2307  /**
2308  * maximum bitrate
2309  * - encoding: Set by user.
2310  * - decoding: Set by libavcodec.
2311  */
2312  int rc_max_rate;
2313 
2314  /**
2315  * minimum bitrate
2316  * - encoding: Set by user.
2317  * - decoding: unused
2318  */
2319  int rc_min_rate;
2321  float rc_buffer_aggressivity;
2322 
2323  /**
2324  * initial complexity for pass1 ratecontrol
2325  * - encoding: Set by user.
2326  * - decoding: unused
2327  */
2328  float rc_initial_cplx;
2329 
2330  /**
2331  * Ratecontrol attempt to use, at maximum, <value> of what can be used without an underflow.
2332  * - encoding: Set by user.
2333  * - decoding: unused.
2334  */
2336 
2337  /**
2338  * Ratecontrol attempt to use, at least, <value> times the amount needed to prevent a vbv overflow.
2339  * - encoding: Set by user.
2340  * - decoding: unused.
2341  */
2343 
2344  /**
2345  * Number of bits which should be loaded into the rc buffer before decoding starts.
2346  * - encoding: Set by user.
2347  * - decoding: unused
2348  */
2351 #define FF_CODER_TYPE_VLC 0
2352 #define FF_CODER_TYPE_AC 1
2353 #define FF_CODER_TYPE_RAW 2
2354 #define FF_CODER_TYPE_RLE 3
2355 #if FF_API_UNUSED_MEMBERS
2356 #define FF_CODER_TYPE_DEFLATE 4
2357 #endif /* FF_API_UNUSED_MEMBERS */
2358  /**
2359  * coder type
2360  * - encoding: Set by user.
2361  * - decoding: unused
2362  */
2363  int coder_type;
2364 
2365  /**
2366  * context model
2367  * - encoding: Set by user.
2368  * - decoding: unused
2369  */
2370  int context_model;
2371 
2372  /**
2373  * minimum Lagrange multiplier
2374  * - encoding: Set by user.
2375  * - decoding: unused
2376  */
2377  int lmin;
2378 
2379  /**
2380  * maximum Lagrange multiplier
2381  * - encoding: Set by user.
2382  * - decoding: unused
2383  */
2384  int lmax;
2385 
2386  /**
2387  * frame skip threshold
2388  * - encoding: Set by user.
2389  * - decoding: unused
2390  */
2392 
2393  /**
2394  * frame skip factor
2395  * - encoding: Set by user.
2396  * - decoding: unused
2397  */
2398  int frame_skip_factor;
2399 
2400  /**
2401  * frame skip exponent
2402  * - encoding: Set by user.
2403  * - decoding: unused
2404  */
2405  int frame_skip_exp;
2406 
2407  /**
2408  * frame skip comparison function
2409  * - encoding: Set by user.
2410  * - decoding: unused
2411  */
2412  int frame_skip_cmp;
2413 
2414  /**
2415  * trellis RD quantization
2416  * - encoding: Set by user.
2417  * - decoding: unused
2418  */
2419  int trellis;
2420 
2421  /**
2422  * - encoding: Set by user.
2423  * - decoding: unused
2424  */
2426 
2427  /**
2428  * - encoding: Set by user.
2429  * - decoding: unused
2430  */
2432 
2433  /**
2434  * GOP timecode frame start number
2435  * - encoding: Set by user, in non drop frame format
2436  * - decoding: Set by libavcodec (timecode in the 25 bits format, -1 if unset)
2437  */
2438  int64_t timecode_frame_start;
2439 
2440  /* The RTP callback: This function is called */
2441  /* every time the encoder has a packet to send. */
2442  /* It depends on the encoder if the data starts */
2443  /* with a Start Code (it should). H.263 does. */
2444  /* mb_nb contains the number of macroblocks */
2445  /* encoded in the RTP payload. */
2446  void (*rtp_callback)(struct AVCodecContext *avctx, void *data, int size, int mb_nb);
2448  int rtp_payload_size; /* The size of the RTP payload: the coder will */
2449  /* do its best to deliver a chunk with size */
2450  /* below rtp_payload_size, the chunk will start */
2451  /* with a start code on some codecs like H.263. */
2452  /* This doesn't take account of any particular */
2453  /* headers inside the transmitted RTP payload. */
2454 
2455  /* statistics, used for 2-pass encoding */
2456  int mv_bits;
2460  int i_count;
2461  int p_count;
2463  int misc_bits;
2464 
2465  /**
2466  * number of bits used for the previously encoded frame
2467  * - encoding: Set by libavcodec.
2468  * - decoding: unused
2469  */
2470  int frame_bits;
2471 
2472  /**
2473  * pass1 encoding statistics output buffer
2474  * - encoding: Set by libavcodec.
2475  * - decoding: unused
2476  */
2477  char *stats_out;
2478 
2479  /**
2480  * pass2 encoding statistics input buffer
2481  * Concatenated stuff from stats_out of pass1 should be placed here.
2482  * - encoding: Allocated/set/freed by user.
2483  * - decoding: unused
2484  */
2485  char *stats_in;
2486 
2487  /**
2488  * Work around bugs in encoders which sometimes cannot be detected automatically.
2489  * - encoding: Set by user
2490  * - decoding: Set by user
2491  */
2493 #define FF_BUG_AUTODETECT 1 ///< autodetection
2494 #if FF_API_OLD_MSMPEG4
2495 #define FF_BUG_OLD_MSMPEG4 2
2496 #endif
2497 #define FF_BUG_XVID_ILACE 4
2498 #define FF_BUG_UMP4 8
2499 #define FF_BUG_NO_PADDING 16
2500 #define FF_BUG_AMV 32
2501 #if FF_API_AC_VLC
2502 #define FF_BUG_AC_VLC 0 ///< Will be removed, libavcodec can now handle these non-compliant files by default.
2503 #endif
2504 #define FF_BUG_QPEL_CHROMA 64
2505 #define FF_BUG_STD_QPEL 128
2506 #define FF_BUG_QPEL_CHROMA2 256
2507 #define FF_BUG_DIRECT_BLOCKSIZE 512
2508 #define FF_BUG_EDGE 1024
2509 #define FF_BUG_HPEL_CHROMA 2048
2510 #define FF_BUG_DC_CLIP 4096
2511 #define FF_BUG_MS 8192 ///< Work around various bugs in Microsoft's broken decoders.
2512 #define FF_BUG_TRUNCATED 16384
2513 
2514  /**
2515  * strictly follow the standard (MPEG4, ...).
2516  * - encoding: Set by user.
2517  * - decoding: Set by user.
2518  * Setting this to STRICT or higher means the encoder and decoder will
2519  * generally do stupid things, whereas setting it to unofficial or lower
2520  * will mean the encoder might produce output that is not supported by all
2521  * spec-compliant decoders. Decoders don't differentiate between normal,
2522  * unofficial and experimental (that is, they always try to decode things
2523  * when they can) unless they are explicitly asked to behave stupidly
2524  * (=strictly conform to the specs)
2525  */
2527 #define FF_COMPLIANCE_VERY_STRICT 2 ///< Strictly conform to an older more strict version of the spec or reference software.
2528 #define FF_COMPLIANCE_STRICT 1 ///< Strictly conform to all the things in the spec no matter what consequences.
2529 #define FF_COMPLIANCE_NORMAL 0
2530 #define FF_COMPLIANCE_UNOFFICIAL -1 ///< Allow unofficial extensions
2531 #define FF_COMPLIANCE_EXPERIMENTAL -2 ///< Allow nonstandardized experimental things.
2532 
2533  /**
2534  * error concealment flags
2535  * - encoding: unused
2536  * - decoding: Set by user.
2537  */
2539 #define FF_EC_GUESS_MVS 1
2540 #define FF_EC_DEBLOCK 2
2541 #define FF_EC_FAVOR_INTER 256
2542 
2543  /**
2544  * debug
2545  * - encoding: Set by user.
2546  * - decoding: Set by user.
2547  */
2548  int debug;
2549 #define FF_DEBUG_PICT_INFO 1
2550 #define FF_DEBUG_RC 2
2551 #define FF_DEBUG_BITSTREAM 4
2552 #define FF_DEBUG_MB_TYPE 8
2553 #define FF_DEBUG_QP 16
2554 #if FF_API_DEBUG_MV
2555 /**
2556  * @deprecated this option does nothing
2557  */
2558 #define FF_DEBUG_MV 32
2559 #endif
2560 #define FF_DEBUG_DCT_COEFF 0x00000040
2561 #define FF_DEBUG_SKIP 0x00000080
2562 #define FF_DEBUG_STARTCODE 0x00000100
2563 #if FF_API_UNUSED_MEMBERS
2564 #define FF_DEBUG_PTS 0x00000200
2565 #endif /* FF_API_UNUSED_MEMBERS */
2566 #define FF_DEBUG_ER 0x00000400
2567 #define FF_DEBUG_MMCO 0x00000800
2568 #define FF_DEBUG_BUGS 0x00001000
2569 #if FF_API_DEBUG_MV
2570 #define FF_DEBUG_VIS_QP 0x00002000 ///< only access through AVOptions from outside libavcodec
2571 #define FF_DEBUG_VIS_MB_TYPE 0x00004000 ///< only access through AVOptions from outside libavcodec
2572 #endif
2573 #define FF_DEBUG_BUFFERS 0x00008000
2574 #define FF_DEBUG_THREADS 0x00010000
2575 #define FF_DEBUG_NOMC 0x01000000
2576 
2577 #if FF_API_DEBUG_MV
2578  /**
2579  * debug
2580  * Code outside libavcodec should access this field using AVOptions
2581  * - encoding: Set by user.
2582  * - decoding: Set by user.
2583  */
2585 #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 //visualize forward predicted MVs of P frames
2586 #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 //visualize forward predicted MVs of B frames
2587 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
2588 #endif
2589 
2590  /**
2591  * Error recognition; may misdetect some more or less valid parts as errors.
2592  * - encoding: unused
2593  * - decoding: Set by user.
2594  */
2595  int err_recognition;
2596 
2597 /**
2598  * Verify checksums embedded in the bitstream (could be of either encoded or
2599  * decoded data, depending on the codec) and print an error message on mismatch.
2600  * If AV_EF_EXPLODE is also set, a mismatching checksum will result in the
2601  * decoder returning an error.
2602  */
2603 #define AV_EF_CRCCHECK (1<<0)
2604 #define AV_EF_BITSTREAM (1<<1) ///< detect bitstream specification deviations
2605 #define AV_EF_BUFFER (1<<2) ///< detect improper bitstream length
2606 #define AV_EF_EXPLODE (1<<3) ///< abort decoding on minor error detection
2608 #define AV_EF_IGNORE_ERR (1<<15) ///< ignore errors and continue
2609 #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
2610 #define AV_EF_COMPLIANT (1<<17) ///< consider all spec non compliances as errors
2611 #define AV_EF_AGGRESSIVE (1<<18) ///< consider things that a sane encoder should not do as an error
2612 
2613 
2614  /**
2615  * opaque 64bit number (generally a PTS) that will be reordered and
2616  * output in AVFrame.reordered_opaque
2617  * - encoding: unused
2618  * - decoding: Set by user.
2619  */
2620  int64_t reordered_opaque;
2621 
2622  /**
2623  * Hardware accelerator in use
2624  * - encoding: unused.
2625  * - decoding: Set by libavcodec
2626  */
2627  struct AVHWAccel *hwaccel;
2628 
2629  /**
2630  * Hardware accelerator context.
2631  * For some hardware accelerators, a global context needs to be
2632  * provided by the user. In that case, this holds display-dependent
2633  * data FFmpeg cannot instantiate itself. Please refer to the
2634  * FFmpeg HW accelerator documentation to know how to fill this
2635  * is. e.g. for VA API, this is a struct vaapi_context.
2636  * - encoding: unused
2637  * - decoding: Set by user
2638  */
2639  void *hwaccel_context;
2640 
2641  /**
2642  * error
2643  * - encoding: Set by libavcodec if flags&CODEC_FLAG_PSNR.
2644  * - decoding: unused
2645  */
2646  uint64_t error[AV_NUM_DATA_POINTERS];
2647 
2648  /**
2649  * DCT algorithm, see FF_DCT_* below
2650  * - encoding: Set by user.
2651  * - decoding: unused
2652  */
2654 #define FF_DCT_AUTO 0
2655 #define FF_DCT_FASTINT 1
2656 #if FF_API_UNUSED_MEMBERS
2657 #define FF_DCT_INT 2
2658 #endif /* FF_API_UNUSED_MEMBERS */
2659 #define FF_DCT_MMX 3
2660 #define FF_DCT_ALTIVEC 5
2661 #define FF_DCT_FAAN 6
2662 
2663  /**
2664  * IDCT algorithm, see FF_IDCT_* below.
2665  * - encoding: Set by user.
2666  * - decoding: Set by user.
2667  */
2669 #define FF_IDCT_AUTO 0
2670 #define FF_IDCT_INT 1
2671 #define FF_IDCT_SIMPLE 2
2672 #define FF_IDCT_SIMPLEMMX 3
2673 #define FF_IDCT_ARM 7
2674 #define FF_IDCT_ALTIVEC 8
2675 #if FF_API_ARCH_SH4
2676 #define FF_IDCT_SH4 9
2677 #endif
2678 #define FF_IDCT_SIMPLEARM 10
2679 #if FF_API_UNUSED_MEMBERS
2680 #define FF_IDCT_IPP 13
2681 #endif /* FF_API_UNUSED_MEMBERS */
2682 #define FF_IDCT_XVID 14
2683 #if FF_API_IDCT_XVIDMMX
2684 #define FF_IDCT_XVIDMMX 14
2685 #endif /* FF_API_IDCT_XVIDMMX */
2686 #define FF_IDCT_SIMPLEARMV5TE 16
2687 #define FF_IDCT_SIMPLEARMV6 17
2688 #if FF_API_ARCH_SPARC
2689 #define FF_IDCT_SIMPLEVIS 18
2690 #endif
2691 #define FF_IDCT_FAAN 20
2692 #define FF_IDCT_SIMPLENEON 22
2693 #if FF_API_ARCH_ALPHA
2694 #define FF_IDCT_SIMPLEALPHA 23
2695 #endif
2696 #define FF_IDCT_SIMPLEAUTO 128
2697 
2698  /**
2699  * bits per sample/pixel from the demuxer (needed for huffyuv).
2700  * - encoding: Set by libavcodec.
2701  * - decoding: Set by user.
2702  */
2704 
2705  /**
2706  * Bits per sample/pixel of internal libavcodec pixel/sample format.
2707  * - encoding: set by user.
2708  * - decoding: set by libavcodec.
2709  */
2710  int bits_per_raw_sample;
2711 
2712 #if FF_API_LOWRES
2713  /**
2714  * low resolution decoding, 1-> 1/2 size, 2->1/4 size
2715  * - encoding: unused
2716  * - decoding: Set by user.
2717  * Code outside libavcodec should access this field using:
2718  * av_codec_{get,set}_lowres(avctx)
2719  */
2720  int lowres;
2721 #endif
2722 
2723  /**
2724  * the picture in the bitstream
2725  * - encoding: Set by libavcodec.
2726  * - decoding: unused
2727  */
2729 
2730  /**
2731  * thread count
2732  * is used to decide how many independent tasks should be passed to execute()
2733  * - encoding: Set by user.
2734  * - decoding: Set by user.
2735  */
2736  int thread_count;
2737 
2738  /**
2739  * Which multithreading methods to use.
2740  * Use of FF_THREAD_FRAME will increase decoding delay by one frame per thread,
2741  * so clients which cannot provide future frames should not use it.
2742  *
2743  * - encoding: Set by user, otherwise the default is used.
2744  * - decoding: Set by user, otherwise the default is used.
2745  */
2747 #define FF_THREAD_FRAME 1 ///< Decode more than one frame at once
2748 #define FF_THREAD_SLICE 2 ///< Decode more than one part of a single frame at once
2749 
2750  /**
2751  * Which multithreading methods are in use by the codec.
2752  * - encoding: Set by libavcodec.
2753  * - decoding: Set by libavcodec.
2754  */
2755  int active_thread_type;
2756 
2757  /**
2758  * Set by the client if its custom get_buffer() callback can be called
2759  * synchronously from another thread, which allows faster multithreaded decoding.
2760  * draw_horiz_band() will be called from other threads regardless of this setting.
2761  * Ignored if the default get_buffer() is used.
2762  * - encoding: Set by user.
2763  * - decoding: Set by user.
2764  */
2766 
2767  /**
2768  * The codec may call this to execute several independent things.
2769  * It will return only after finishing all tasks.
2770  * The user may replace this with some multithreaded implementation,
2771  * the default implementation will execute the parts serially.
2772  * @param count the number of things to execute
2773  * - encoding: Set by libavcodec, user can override.
2774  * - decoding: Set by libavcodec, user can override.
2775  */
2776  int (*execute)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size);
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  * Also see avcodec_thread_init and e.g. the --enable-pthread configure option.
2784  * @param c context passed also to func
2785  * @param count the number of things to execute
2786  * @param arg2 argument passed unchanged to func
2787  * @param ret return values of executed functions, must have space for "count" values. May be NULL.
2788  * @param func function that will be called count times, with jobnr from 0 to count-1.
2789  * threadnr will be in the range 0 to c->thread_count-1 < MAX_THREADS and so that no
2790  * two instances of func executing at the same time will have the same threadnr.
2791  * @return always 0 currently, but code should handle a future improvement where when any call to func
2792  * returns < 0 no further calls to func may be done and < 0 is returned.
2793  * - encoding: Set by libavcodec, user can override.
2794  * - decoding: Set by libavcodec, user can override.
2795  */
2796  int (*execute2)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count);
2797 
2798 #if FF_API_THREAD_OPAQUE
2799  /**
2800  * @deprecated this field should not be used from outside of lavc
2801  */
2803  void *thread_opaque;
2804 #endif
2805 
2806  /**
2807  * noise vs. sse weight for the nsse comparison function
2808  * - encoding: Set by user.
2809  * - decoding: unused
2810  */
2811  int nsse_weight;
2812 
2813  /**
2814  * profile
2815  * - encoding: Set by user.
2816  * - decoding: Set by libavcodec.
2817  */
2818  int profile;
2819 #define FF_PROFILE_UNKNOWN -99
2820 #define FF_PROFILE_RESERVED -100
2822 #define FF_PROFILE_AAC_MAIN 0
2823 #define FF_PROFILE_AAC_LOW 1
2824 #define FF_PROFILE_AAC_SSR 2
2825 #define FF_PROFILE_AAC_LTP 3
2826 #define FF_PROFILE_AAC_HE 4
2827 #define FF_PROFILE_AAC_HE_V2 28
2828 #define FF_PROFILE_AAC_LD 22
2829 #define FF_PROFILE_AAC_ELD 38
2830 #define FF_PROFILE_MPEG2_AAC_LOW 128
2831 #define FF_PROFILE_MPEG2_AAC_HE 131
2833 #define FF_PROFILE_DTS 20
2834 #define FF_PROFILE_DTS_ES 30
2835 #define FF_PROFILE_DTS_96_24 40
2836 #define FF_PROFILE_DTS_HD_HRA 50
2837 #define FF_PROFILE_DTS_HD_MA 60
2839 #define FF_PROFILE_MPEG2_422 0
2840 #define FF_PROFILE_MPEG2_HIGH 1
2841 #define FF_PROFILE_MPEG2_SS 2
2842 #define FF_PROFILE_MPEG2_SNR_SCALABLE 3
2843 #define FF_PROFILE_MPEG2_MAIN 4
2844 #define FF_PROFILE_MPEG2_SIMPLE 5
2846 #define FF_PROFILE_H264_CONSTRAINED (1<<9) // 8+1; constraint_set1_flag
2847 #define FF_PROFILE_H264_INTRA (1<<11) // 8+3; constraint_set3_flag
2849 #define FF_PROFILE_H264_BASELINE 66
2850 #define FF_PROFILE_H264_CONSTRAINED_BASELINE (66|FF_PROFILE_H264_CONSTRAINED)
2851 #define FF_PROFILE_H264_MAIN 77
2852 #define FF_PROFILE_H264_EXTENDED 88
2853 #define FF_PROFILE_H264_HIGH 100
2854 #define FF_PROFILE_H264_HIGH_10 110
2855 #define FF_PROFILE_H264_HIGH_10_INTRA (110|FF_PROFILE_H264_INTRA)
2856 #define FF_PROFILE_H264_HIGH_422 122
2857 #define FF_PROFILE_H264_HIGH_422_INTRA (122|FF_PROFILE_H264_INTRA)
2858 #define FF_PROFILE_H264_HIGH_444 144
2859 #define FF_PROFILE_H264_HIGH_444_PREDICTIVE 244
2860 #define FF_PROFILE_H264_HIGH_444_INTRA (244|FF_PROFILE_H264_INTRA)
2861 #define FF_PROFILE_H264_CAVLC_444 44
2863 #define FF_PROFILE_VC1_SIMPLE 0
2864 #define FF_PROFILE_VC1_MAIN 1
2865 #define FF_PROFILE_VC1_COMPLEX 2
2866 #define FF_PROFILE_VC1_ADVANCED 3
2868 #define FF_PROFILE_MPEG4_SIMPLE 0
2869 #define FF_PROFILE_MPEG4_SIMPLE_SCALABLE 1
2870 #define FF_PROFILE_MPEG4_CORE 2
2871 #define FF_PROFILE_MPEG4_MAIN 3
2872 #define FF_PROFILE_MPEG4_N_BIT 4
2873 #define FF_PROFILE_MPEG4_SCALABLE_TEXTURE 5
2874 #define FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION 6
2875 #define FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE 7
2876 #define FF_PROFILE_MPEG4_HYBRID 8
2877 #define FF_PROFILE_MPEG4_ADVANCED_REAL_TIME 9
2878 #define FF_PROFILE_MPEG4_CORE_SCALABLE 10
2879 #define FF_PROFILE_MPEG4_ADVANCED_CODING 11
2880 #define FF_PROFILE_MPEG4_ADVANCED_CORE 12
2881 #define FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE 13
2882 #define FF_PROFILE_MPEG4_SIMPLE_STUDIO 14
2883 #define FF_PROFILE_MPEG4_ADVANCED_SIMPLE 15
2885 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_0 0
2886 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_1 1
2887 #define FF_PROFILE_JPEG2000_CSTREAM_NO_RESTRICTION 2
2888 #define FF_PROFILE_JPEG2000_DCINEMA_2K 3
2889 #define FF_PROFILE_JPEG2000_DCINEMA_4K 4
2890 
2892 #define FF_PROFILE_HEVC_MAIN 1
2893 #define FF_PROFILE_HEVC_MAIN_10 2
2894 #define FF_PROFILE_HEVC_MAIN_STILL_PICTURE 3
2895 #define FF_PROFILE_HEVC_REXT 4
2896 
2897  /**
2898  * level
2899  * - encoding: Set by user.
2900  * - decoding: Set by libavcodec.
2901  */
2902  int level;
2903 #define FF_LEVEL_UNKNOWN -99
2904 
2905  /**
2906  * Skip loop filtering for selected frames.
2907  * - encoding: unused
2908  * - decoding: Set by user.
2909  */
2911 
2912  /**
2913  * Skip IDCT/dequantization for selected frames.
2914  * - encoding: unused
2915  * - decoding: Set by user.
2916  */
2917  enum AVDiscard skip_idct;
2918 
2919  /**
2920  * Skip decoding for selected frames.
2921  * - encoding: unused
2922  * - decoding: Set by user.
2923  */
2924  enum AVDiscard skip_frame;
2925 
2926  /**
2927  * Header containing style information for text subtitles.
2928  * For SUBTITLE_ASS subtitle type, it should contain the whole ASS
2929  * [Script Info] and [V4+ Styles] section, plus the [Events] line and
2930  * the Format line following. It shouldn't include any Dialogue line.
2931  * - encoding: Set/allocated/freed by user (before avcodec_open2())
2932  * - decoding: Set/allocated/freed by libavcodec (by avcodec_open2())
2933  */
2936 
2937 #if FF_API_ERROR_RATE
2938  /**
2939  * @deprecated use the 'error_rate' private AVOption of the mpegvideo
2940  * encoders
2941  */
2943  int error_rate;
2944 #endif
2945 
2946 #if FF_API_CODEC_PKT
2947  /**
2948  * @deprecated this field is not supposed to be accessed from outside lavc
2949  */
2951  AVPacket *pkt;
2952 #endif
2953 
2954  /**
2955  * VBV delay coded in the last frame (in periods of a 27 MHz clock).
2956  * Used for compliant TS muxing.
2957  * - encoding: Set by libavcodec.
2958  * - decoding: unused.
2959  */
2960  uint64_t vbv_delay;
2961 
2962  /**
2963  * Encoding only. Allow encoders to output packets that do not contain any
2964  * encoded data, only side data.
2965  *
2966  * Some encoders need to output such packets, e.g. to update some stream
2967  * parameters at the end of encoding.
2968  *
2969  * All callers are strongly recommended to set this option to 1 and update
2970  * their code to deal with such packets, since this behaviour may become
2971  * always enabled in the future (then this option will be deprecated and
2972  * later removed). To avoid ABI issues when this happens, the callers should
2973  * use AVOptions to set this field.
2974  */
2976 
2977  /**
2978  * Timebase in which pkt_dts/pts and AVPacket.dts/pts are.
2979  * Code outside libavcodec should access this field using:
2980  * av_codec_{get,set}_pkt_timebase(avctx)
2981  * - encoding unused.
2982  * - decoding set by user.
2983  */
2985 
2986  /**
2987  * AVCodecDescriptor
2988  * Code outside libavcodec should access this field using:
2989  * av_codec_{get,set}_codec_descriptor(avctx)
2990  * - encoding: unused.
2991  * - decoding: set by libavcodec.
2992  */
2994 
2995 #if !FF_API_LOWRES
2996  /**
2997  * low resolution decoding, 1-> 1/2 size, 2->1/4 size
2998  * - encoding: unused
2999  * - decoding: Set by user.
3000  * Code outside libavcodec should access this field using:
3001  * av_codec_{get,set}_lowres(avctx)
3002  */
3003  int lowres;
3004 #endif
3005 
3006  /**
3007  * Current statistics for PTS correction.
3008  * - decoding: maintained and used by libavcodec, not intended to be used by user apps
3009  * - encoding: unused
3010  */
3011  int64_t pts_correction_num_faulty_pts; /// Number of incorrect PTS values so far
3012  int64_t pts_correction_num_faulty_dts; /// Number of incorrect DTS values so far
3013  int64_t pts_correction_last_pts; /// PTS of the last frame
3014  int64_t pts_correction_last_dts; /// DTS of the last frame
3015 
3016  /**
3017  * Character encoding of the input subtitles file.
3018  * - decoding: set by user
3019  * - encoding: unused
3020  */
3021  char *sub_charenc;
3022 
3023  /**
3024  * Subtitles character encoding mode. Formats or codecs might be adjusting
3025  * this setting (if they are doing the conversion themselves for instance).
3026  * - decoding: set by libavcodec
3027  * - encoding: unused
3028  */
3030 #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)
3031 #define FF_SUB_CHARENC_MODE_AUTOMATIC 0 ///< libavcodec will select the mode itself
3032 #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
3033 
3034  /**
3035  * Skip processing alpha if supported by codec.
3036  * Note that if the format uses pre-multiplied alpha (common with VP6,
3037  * and recommended due to better video quality/compression)
3038  * the image will look as if alpha-blended onto a black background.
3039  * However for formats that do not use pre-multiplied alpha
3040  * there might be serious artefacts (though e.g. libswscale currently
3041  * assumes pre-multiplied alpha anyway).
3042  * Code outside libavcodec should access this field using AVOptions
3043  *
3044  * - decoding: set by user
3045  * - encoding: unused
3046  */
3047  int skip_alpha;
3048 
3049  /**
3050  * Number of samples to skip after a discontinuity
3051  * - decoding: unused
3052  * - encoding: set by libavcodec
3053  */
3054  int seek_preroll;
3055 
3056 #if !FF_API_DEBUG_MV
3057  /**
3058  * debug motion vectors
3059  * Code outside libavcodec should access this field using AVOptions
3060  * - encoding: Set by user.
3061  * - decoding: Set by user.
3062  */
3063  int debug_mv;
3064 #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 //visualize forward predicted MVs of P frames
3065 #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 //visualize forward predicted MVs of B frames
3066 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
3067 #endif
3068 
3069  /**
3070  * custom intra quantization matrix
3071  * Code outside libavcodec should access this field using av_codec_g/set_chroma_intra_matrix()
3072  * - encoding: Set by user, can be NULL.
3073  * - decoding: unused.
3074  */
3075  uint16_t *chroma_intra_matrix;
3076 } AVCodecContext;
3077 
3080 
3083 
3084 int av_codec_get_lowres(const AVCodecContext *avctx);
3085 void av_codec_set_lowres(AVCodecContext *avctx, int val);
3086 
3087 int av_codec_get_seek_preroll(const AVCodecContext *avctx);
3088 void av_codec_set_seek_preroll(AVCodecContext *avctx, int val);
3089 
3090 uint16_t *av_codec_get_chroma_intra_matrix(const AVCodecContext *avctx);
3091 void av_codec_set_chroma_intra_matrix(AVCodecContext *avctx, uint16_t *val);
3092 
3093 /**
3094  * AVProfile.
3095  */
3096 typedef struct AVProfile {
3097  int profile;
3098  const char *name; ///< short name for the profile
3099 } AVProfile;
3100 
3101 typedef struct AVCodecDefault AVCodecDefault;
3102 
3103 struct AVSubtitle;
3104 
3105 /**
3106  * AVCodec.
3107  */
3108 typedef struct AVCodec {
3109  /**
3110  * Name of the codec implementation.
3111  * The name is globally unique among encoders and among decoders (but an
3112  * encoder and a decoder can share the same name).
3113  * This is the primary way to find a codec from the user perspective.
3114  */
3115  const char *name;
3116  /**
3117  * Descriptive name for the codec, meant to be more human readable than name.
3118  * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
3119  */
3120  const char *long_name;
3122  enum AVCodecID id;
3123  /**
3124  * Codec capabilities.
3125  * see CODEC_CAP_*
3126  */
3128  const AVRational *supported_framerates; ///< array of supported framerates, or NULL if any, array is terminated by {0,0}
3129  const enum AVPixelFormat *pix_fmts; ///< array of supported pixel formats, or NULL if unknown, array is terminated by -1
3130  const int *supported_samplerates; ///< array of supported audio samplerates, or NULL if unknown, array is terminated by 0
3131  const enum AVSampleFormat *sample_fmts; ///< array of supported sample formats, or NULL if unknown, array is terminated by -1
3132  const uint64_t *channel_layouts; ///< array of support channel layouts, or NULL if unknown. array is terminated by 0
3133 #if FF_API_LOWRES
3134  uint8_t max_lowres; ///< maximum value for lowres supported by the decoder, no direct access, use av_codec_get_max_lowres()
3135 #endif
3136  const AVClass *priv_class; ///< AVClass for the private context
3137  const AVProfile *profiles; ///< array of recognized profiles, or NULL if unknown, array is terminated by {FF_PROFILE_UNKNOWN}
3138 
3139  /*****************************************************************
3140  * No fields below this line are part of the public API. They
3141  * may not be used outside of libavcodec and can be changed and
3142  * removed at will.
3143  * New public fields should be added right above.
3144  *****************************************************************
3145  */
3147  struct AVCodec *next;
3148  /**
3149  * @name Frame-level threading support functions
3150  * @{
3151  */
3152  /**
3153  * If defined, called on thread contexts when they are created.
3154  * If the codec allocates writable tables in init(), re-allocate them here.
3155  * priv_data will be set to a copy of the original.
3156  */
3157  int (*init_thread_copy)(AVCodecContext *);
3158  /**
3159  * Copy necessary context variables from a previous thread context to the current one.
3160  * If not defined, the next thread will start automatically; otherwise, the codec
3161  * must call ff_thread_finish_setup().
3162  *
3163  * dst and src will (rarely) point to the same context, in which case memcpy should be skipped.
3164  */
3166  /** @} */
3167 
3168  /**
3169  * Private codec-specific defaults.
3170  */
3171  const AVCodecDefault *defaults;
3172 
3173  /**
3174  * Initialize codec static data, called from avcodec_register().
3175  */
3176  void (*init_static_data)(struct AVCodec *codec);
3179  int (*encode_sub)(AVCodecContext *, uint8_t *buf, int buf_size,
3180  const struct AVSubtitle *sub);
3181  /**
3182  * Encode data to an AVPacket.
3183  *
3184  * @param avctx codec context
3185  * @param avpkt output AVPacket (may contain a user-provided buffer)
3186  * @param[in] frame AVFrame containing the raw data to be encoded
3187  * @param[out] got_packet_ptr encoder sets to 0 or 1 to indicate that a
3188  * non-empty packet was returned in avpkt.
3189  * @return 0 on success, negative error code on failure
3190  */
3191  int (*encode2)(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame,
3192  int *got_packet_ptr);
3193  int (*decode)(AVCodecContext *, void *outdata, int *outdata_size, AVPacket *avpkt);
3194  int (*close)(AVCodecContext *);
3195  /**
3196  * Flush buffers.
3197  * Will be called when seeking
3198  */
3199  void (*flush)(AVCodecContext *);
3200 } AVCodec;
3201 
3202 int av_codec_get_max_lowres(const AVCodec *codec);
3203 
3204 struct MpegEncContext;
3205 
3206 /**
3207  * AVHWAccel.
3208  */
3209 typedef struct AVHWAccel {
3210  /**
3211  * Name of the hardware accelerated codec.
3212  * The name is globally unique among encoders and among decoders (but an
3213  * encoder and a decoder can share the same name).
3214  */
3215  const char *name;
3216 
3217  /**
3218  * Type of codec implemented by the hardware accelerator.
3219  *
3220  * See AVMEDIA_TYPE_xxx
3221  */
3222  enum AVMediaType type;
3223 
3224  /**
3225  * Codec implemented by the hardware accelerator.
3226  *
3227  * See AV_CODEC_ID_xxx
3228  */
3229  enum AVCodecID id;
3230 
3231  /**
3232  * Supported pixel format.
3233  *
3234  * Only hardware accelerated formats are supported here.
3235  */
3236  enum AVPixelFormat pix_fmt;
3237 
3238  /**
3239  * Hardware accelerated codec capabilities.
3240  * see FF_HWACCEL_CODEC_CAP_*
3241  */
3242  int capabilities;
3243 
3244  /*****************************************************************
3245  * No fields below this line are part of the public API. They
3246  * may not be used outside of libavcodec and can be changed and
3247  * removed at will.
3248  * New public fields should be added right above.
3249  *****************************************************************
3250  */
3251  struct AVHWAccel *next;
3252 
3253  /**
3254  * Allocate a custom buffer
3255  */
3256  int (*alloc_frame)(AVCodecContext *avctx, AVFrame *frame);
3257 
3258  /**
3259  * Called at the beginning of each frame or field picture.
3260  *
3261  * Meaningful frame information (codec specific) is guaranteed to
3262  * be parsed at this point. This function is mandatory.
3263  *
3264  * Note that buf can be NULL along with buf_size set to 0.
3265  * Otherwise, this means the whole frame is available at this point.
3266  *
3267  * @param avctx the codec context
3268  * @param buf the frame data buffer base
3269  * @param buf_size the size of the frame in bytes
3270  * @return zero if successful, a negative value otherwise
3271  */
3272  int (*start_frame)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3273 
3274  /**
3275  * Callback for each slice.
3276  *
3277  * Meaningful slice information (codec specific) is guaranteed to
3278  * be parsed at this point. This function is mandatory.
3279  * The only exception is XvMC, that works on MB level.
3280  *
3281  * @param avctx the codec context
3282  * @param buf the slice data buffer base
3283  * @param buf_size the size of the slice in bytes
3284  * @return zero if successful, a negative value otherwise
3285  */
3286  int (*decode_slice)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3287 
3288  /**
3289  * Called at the end of each frame or field picture.
3290  *
3291  * The whole picture is parsed at this point and can now be sent
3292  * to the hardware accelerator. This function is mandatory.
3293  *
3294  * @param avctx the codec context
3295  * @return zero if successful, a negative value otherwise
3296  */
3297  int (*end_frame)(AVCodecContext *avctx);
3298 
3299  /**
3300  * Size of per-frame hardware accelerator private data.
3301  *
3302  * Private data is allocated with av_mallocz() before
3303  * AVCodecContext.get_buffer() and deallocated after
3304  * AVCodecContext.release_buffer().
3305  */
3307 
3308  /**
3309  * Called for every Macroblock in a slice.
3310  *
3311  * XvMC uses it to replace the ff_mpv_decode_mb().
3312  * Instead of decoding to raw picture, MB parameters are
3313  * stored in an array provided by the video driver.
3314  *
3315  * @param s the mpeg context
3316  */
3317  void (*decode_mb)(struct MpegEncContext *s);
3318 
3319  /**
3320  * Initialize the hwaccel private data.
3321  *
3322  * This will be called from ff_get_format(), after hwaccel and
3323  * hwaccel_context are set and the hwaccel private data in AVCodecInternal
3324  * is allocated.
3325  */
3326  int (*init)(AVCodecContext *avctx);
3327 
3328  /**
3329  * Uninitialize the hwaccel private data.
3330  *
3331  * This will be called from get_format() or avcodec_close(), after hwaccel
3332  * and hwaccel_context are already uninitialized.
3333  */
3334  int (*uninit)(AVCodecContext *avctx);
3335 
3336  /**
3337  * Size of the private data to allocate in
3338  * AVCodecInternal.hwaccel_priv_data.
3339  */
3340  int priv_data_size;
3341 } AVHWAccel;
3342 
3343 /**
3344  * @defgroup lavc_picture AVPicture
3345  *
3346  * Functions for working with AVPicture
3347  * @{
3348  */
3349 
3350 /**
3351  * Picture data structure.
3352  *
3353  * Up to four components can be stored into it, the last component is
3354  * alpha.
3355  */
3356 typedef struct AVPicture {
3357  uint8_t *data[AV_NUM_DATA_POINTERS]; ///< pointers to the image data planes
3358  int linesize[AV_NUM_DATA_POINTERS]; ///< number of bytes per line
3359 } AVPicture;
3360 
3361 /**
3362  * @}
3363  */
3366  SUBTITLE_NONE,
3368  SUBTITLE_BITMAP, ///< A bitmap, pict will be set
3369 
3370  /**
3371  * Plain text, the text field must be set by the decoder and is
3372  * authoritative. ass and pict fields may contain approximations.
3373  */
3374  SUBTITLE_TEXT,
3375 
3376  /**
3377  * Formatted text, the ass field must be set by the decoder and is
3378  * authoritative. pict and text fields may contain approximations.
3379  */
3380  SUBTITLE_ASS,
3381 };
3383 #define AV_SUBTITLE_FLAG_FORCED 0x00000001
3385 typedef struct AVSubtitleRect {
3386  int x; ///< top left corner of pict, undefined when pict is not set
3387  int y; ///< top left corner of pict, undefined when pict is not set
3388  int w; ///< width of pict, undefined when pict is not set
3389  int h; ///< height of pict, undefined when pict is not set
3390  int nb_colors; ///< number of colors in pict, undefined when pict is not set
3391 
3392  /**
3393  * data+linesize for the bitmap of this subtitle.
3394  * can be set for text/ass as well once they where rendered
3395  */
3397  enum AVSubtitleType type;
3399  char *text; ///< 0 terminated plain UTF-8 text
3400 
3401  /**
3402  * 0 terminated ASS/SSA compatible event line.
3403  * The presentation of this is unaffected by the other values in this
3404  * struct.
3405  */
3406  char *ass;
3408  int flags;
3409 } AVSubtitleRect;
3411 typedef struct AVSubtitle {
3412  uint16_t format; /* 0 = graphics */
3413  uint32_t start_display_time; /* relative to packet pts, in ms */
3414  uint32_t end_display_time; /* relative to packet pts, in ms */
3415  unsigned num_rects;
3417  int64_t pts; ///< Same as packet pts, in AV_TIME_BASE
3418 } AVSubtitle;
3419 
3420 /**
3421  * If c is NULL, returns the first registered codec,
3422  * if c is non-NULL, returns the next registered codec after c,
3423  * or NULL if c is the last one.
3424  */
3425 AVCodec *av_codec_next(const AVCodec *c);
3426 
3427 /**
3428  * Return the LIBAVCODEC_VERSION_INT constant.
3429  */
3430 unsigned avcodec_version(void);
3431 
3432 /**
3433  * Return the libavcodec build-time configuration.
3434  */
3435 const char *avcodec_configuration(void);
3436 
3437 /**
3438  * Return the libavcodec license.
3439  */
3440 const char *avcodec_license(void);
3441 
3442 /**
3443  * Register the codec codec and initialize libavcodec.
3444  *
3445  * @warning either this function or avcodec_register_all() must be called
3446  * before any other libavcodec functions.
3447  *
3448  * @see avcodec_register_all()
3449  */
3450 void avcodec_register(AVCodec *codec);
3451 
3452 /**
3453  * Register all the codecs, parsers and bitstream filters which were enabled at
3454  * configuration time. If you do not call this function you can select exactly
3455  * which formats you want to support, by using the individual registration
3456  * functions.
3457  *
3458  * @see avcodec_register
3459  * @see av_register_codec_parser
3460  * @see av_register_bitstream_filter
3461  */
3462 void avcodec_register_all(void);
3463 
3464 /**
3465  * Allocate an AVCodecContext and set its fields to default values. The
3466  * resulting struct should be freed with avcodec_free_context().
3467  *
3468  * @param codec if non-NULL, allocate private data and initialize defaults
3469  * for the given codec. It is illegal to then call avcodec_open2()
3470  * with a different codec.
3471  * If NULL, then the codec-specific defaults won't be initialized,
3472  * which may result in suboptimal default settings (this is
3473  * important mainly for encoders, e.g. libx264).
3474  *
3475  * @return An AVCodecContext filled with default values or NULL on failure.
3476  * @see avcodec_get_context_defaults
3477  */
3479 
3480 /**
3481  * Free the codec context and everything associated with it and write NULL to
3482  * the provided pointer.
3483  */
3484 void avcodec_free_context(AVCodecContext **avctx);
3485 
3486 /**
3487  * Set the fields of the given AVCodecContext to default values corresponding
3488  * to the given codec (defaults may be codec-dependent).
3489  *
3490  * Do not call this function if a non-NULL codec has been passed
3491  * to avcodec_alloc_context3() that allocated this AVCodecContext.
3492  * If codec is non-NULL, it is illegal to call avcodec_open2() with a
3493  * different codec on this AVCodecContext.
3494  */
3496 
3497 /**
3498  * Get the AVClass for AVCodecContext. It can be used in combination with
3499  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
3500  *
3501  * @see av_opt_find().
3502  */
3503 const AVClass *avcodec_get_class(void);
3504 
3505 /**
3506  * Get the AVClass for AVFrame. It can be used in combination with
3507  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
3508  *
3509  * @see av_opt_find().
3510  */
3511 const AVClass *avcodec_get_frame_class(void);
3512 
3513 /**
3514  * Get the AVClass for AVSubtitleRect. It can be used in combination with
3515  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
3516  *
3517  * @see av_opt_find().
3518  */
3520 
3521 /**
3522  * Copy the settings of the source AVCodecContext into the destination
3523  * AVCodecContext. The resulting destination codec context will be
3524  * unopened, i.e. you are required to call avcodec_open2() before you
3525  * can use this AVCodecContext to decode/encode video/audio data.
3526  *
3527  * @param dest target codec context, should be initialized with
3528  * avcodec_alloc_context3(NULL), but otherwise uninitialized
3529  * @param src source codec context
3530  * @return AVERROR() on error (e.g. memory allocation error), 0 on success
3531  */
3533 
3534 #if FF_API_AVFRAME_LAVC
3535 /**
3536  * @deprecated use av_frame_alloc()
3537  */
3539 AVFrame *avcodec_alloc_frame(void);
3540 
3541 /**
3542  * Set the fields of the given AVFrame to default values.
3543  *
3544  * @param frame The AVFrame of which the fields should be set to default values.
3545  *
3546  * @deprecated use av_frame_unref()
3547  */
3549 void avcodec_get_frame_defaults(AVFrame *frame);
3550 
3551 /**
3552  * Free the frame and any dynamically allocated objects in it,
3553  * e.g. extended_data.
3554  *
3555  * @param frame frame to be freed. The pointer will be set to NULL.
3556  *
3557  * @warning this function does NOT free the data buffers themselves
3558  * (it does not know how, since they might have been allocated with
3559  * a custom get_buffer()).
3560  *
3561  * @deprecated use av_frame_free()
3562  */
3564 void avcodec_free_frame(AVFrame **frame);
3565 #endif
3566 
3567 /**
3568  * Initialize the AVCodecContext to use the given AVCodec. Prior to using this
3569  * function the context has to be allocated with avcodec_alloc_context3().
3570  *
3571  * The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(),
3572  * avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for
3573  * retrieving a codec.
3574  *
3575  * @warning This function is not thread safe!
3576  *
3577  * @code
3578  * avcodec_register_all();
3579  * av_dict_set(&opts, "b", "2.5M", 0);
3580  * codec = avcodec_find_decoder(AV_CODEC_ID_H264);
3581  * if (!codec)
3582  * exit(1);
3583  *
3584  * context = avcodec_alloc_context3(codec);
3585  *
3586  * if (avcodec_open2(context, codec, opts) < 0)
3587  * exit(1);
3588  * @endcode
3589  *
3590  * @param avctx The context to initialize.
3591  * @param codec The codec to open this context for. If a non-NULL codec has been
3592  * previously passed to avcodec_alloc_context3() or
3593  * avcodec_get_context_defaults3() for this context, then this
3594  * parameter MUST be either NULL or equal to the previously passed
3595  * codec.
3596  * @param options A dictionary filled with AVCodecContext and codec-private options.
3597  * On return this object will be filled with options that were not found.
3598  *
3599  * @return zero on success, a negative value on error
3600  * @see avcodec_alloc_context3(), avcodec_find_decoder(), avcodec_find_encoder(),
3601  * av_dict_set(), av_opt_find().
3602  */
3603 int avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options);
3604 
3605 /**
3606  * Close a given AVCodecContext and free all the data associated with it
3607  * (but not the AVCodecContext itself).
3608  *
3609  * Calling this function on an AVCodecContext that hasn't been opened will free
3610  * the codec-specific data allocated in avcodec_alloc_context3() /
3611  * avcodec_get_context_defaults3() with a non-NULL codec. Subsequent calls will
3612  * do nothing.
3613  */
3614 int avcodec_close(AVCodecContext *avctx);
3615 
3616 /**
3617  * Free all allocated data in the given subtitle struct.
3618  *
3619  * @param sub AVSubtitle to free.
3620  */
3621 void avsubtitle_free(AVSubtitle *sub);
3622 
3623 /**
3624  * @}
3625  */
3626 
3627 /**
3628  * @addtogroup lavc_packet
3629  * @{
3630  */
3631 
3632 #if FF_API_DESTRUCT_PACKET
3633 /**
3634  * Default packet destructor.
3635  * @deprecated use the AVBuffer API instead
3636  */
3639 #endif
3640 
3641 /**
3642  * Initialize optional fields of a packet with default values.
3643  *
3644  * Note, this does not touch the data and size members, which have to be
3645  * initialized separately.
3646  *
3647  * @param pkt packet
3648  */
3649 void av_init_packet(AVPacket *pkt);
3650 
3651 /**
3652  * Allocate the payload of a packet and initialize its fields with
3653  * default values.
3654  *
3655  * @param pkt packet
3656  * @param size wanted payload size
3657  * @return 0 if OK, AVERROR_xxx otherwise
3658  */
3659 int av_new_packet(AVPacket *pkt, int size);
3660 
3661 /**
3662  * Reduce packet size, correctly zeroing padding
3663  *
3664  * @param pkt packet
3665  * @param size new size
3666  */
3667 void av_shrink_packet(AVPacket *pkt, int size);
3668 
3669 /**
3670  * Increase packet size, correctly zeroing padding
3671  *
3672  * @param pkt packet
3673  * @param grow_by number of bytes by which to increase the size of the packet
3674  */
3675 int av_grow_packet(AVPacket *pkt, int grow_by);
3676 
3677 /**
3678  * Initialize a reference-counted packet from av_malloc()ed data.
3679  *
3680  * @param pkt packet to be initialized. This function will set the data, size,
3681  * buf and destruct fields, all others are left untouched.
3682  * @param data Data allocated by av_malloc() to be used as packet data. If this
3683  * function returns successfully, the data is owned by the underlying AVBuffer.
3684  * The caller may not access the data through other means.
3685  * @param size size of data in bytes, without the padding. I.e. the full buffer
3686  * size is assumed to be size + FF_INPUT_BUFFER_PADDING_SIZE.
3687  *
3688  * @return 0 on success, a negative AVERROR on error
3689  */
3691 
3692 /**
3693  * @warning This is a hack - the packet memory allocation stuff is broken. The
3694  * packet is allocated if it was not really allocated.
3695  */
3696 int av_dup_packet(AVPacket *pkt);
3697 
3698 /**
3699  * Copy packet, including contents
3700  *
3701  * @return 0 on success, negative AVERROR on fail
3702  */
3703 int av_copy_packet(AVPacket *dst, const AVPacket *src);
3704 
3705 /**
3706  * Copy packet side data
3707  *
3708  * @return 0 on success, negative AVERROR on fail
3709  */
3710 int av_copy_packet_side_data(AVPacket *dst, const AVPacket *src);
3711 
3712 /**
3713  * Free a packet.
3714  *
3715  * @param pkt packet to free
3716  */
3717 void av_free_packet(AVPacket *pkt);
3718 
3719 /**
3720  * Allocate new information of a packet.
3721  *
3722  * @param pkt packet
3723  * @param type side information type
3724  * @param size side information size
3725  * @return pointer to fresh allocated data or NULL otherwise
3726  */
3728  int size);
3729 
3730 /**
3731  * Shrink the already allocated side data buffer
3732  *
3733  * @param pkt packet
3734  * @param type side information type
3735  * @param size new side information size
3736  * @return 0 on success, < 0 on failure
3737  */
3739  int size);
3740 
3741 /**
3742  * Get side information from packet.
3743  *
3744  * @param pkt packet
3745  * @param type desired side information type
3746  * @param size pointer for side information size to store (optional)
3747  * @return pointer to data if present or NULL otherwise
3748  */
3750  int *size);
3751 
3753 
3755 
3756 /**
3757  * Pack a dictionary for use in side_data.
3758  *
3759  * @param dict The dictionary to pack.
3760  * @param size pointer to store the size of the returned data
3761  * @return pointer to data if successful, NULL otherwise
3762  */
3764 /**
3765  * Unpack a dictionary from side_data.
3766  *
3767  * @param data data from side_data
3768  * @param size size of the data
3769  * @param dict the metadata storage dictionary
3770  * @return 0 on success, < 0 on failure
3771  */
3772 int av_packet_unpack_dictionary(const uint8_t *data, int size, AVDictionary **dict);
3773 
3774 
3775 /**
3776  * Convenience function to free all the side data stored.
3777  * All the other fields stay untouched.
3778  *
3779  * @param pkt packet
3780  */
3782 
3783 /**
3784  * Setup a new reference to the data described by a given packet
3785  *
3786  * If src is reference-counted, setup dst as a new reference to the
3787  * buffer in src. Otherwise allocate a new buffer in dst and copy the
3788  * data from src into it.
3789  *
3790  * All the other fields are copied from src.
3791  *
3792  * @see av_packet_unref
3793  *
3794  * @param dst Destination packet
3795  * @param src Source packet
3796  *
3797  * @return 0 on success, a negative AVERROR on error.
3798  */
3799 int av_packet_ref(AVPacket *dst, const AVPacket *src);
3800 
3801 /**
3802  * Wipe the packet.
3803  *
3804  * Unreference the buffer referenced by the packet and reset the
3805  * remaining packet fields to their default values.
3806  *
3807  * @param pkt The packet to be unreferenced.
3808  */
3810 
3811 /**
3812  * Move every field in src to dst and reset src.
3813  *
3814  * @see av_packet_unref
3815  *
3816  * @param src Source packet, will be reset
3817  * @param dst Destination packet
3818  */
3820 
3821 /**
3822  * Copy only "properties" fields from src to dst.
3823  *
3824  * Properties for the purpose of this function are all the fields
3825  * beside those related to the packet data (buf, data, size)
3826  *
3827  * @param dst Destination packet
3828  * @param src Source packet
3829  *
3830  * @return 0 on success AVERROR on failure.
3831  *
3832  */
3833 int av_packet_copy_props(AVPacket *dst, const AVPacket *src);
3834 
3835 /**
3836  * Convert valid timing fields (timestamps / durations) in a packet from one
3837  * timebase to another. Timestamps with unknown values (AV_NOPTS_VALUE) will be
3838  * ignored.
3839  *
3840  * @param pkt packet on which the conversion will be performed
3841  * @param tb_src source timebase, in which the timing fields in pkt are
3842  * expressed
3843  * @param tb_dst destination timebase, to which the timing fields will be
3844  * converted
3845  */
3846 void av_packet_rescale_ts(AVPacket *pkt, AVRational tb_src, AVRational tb_dst);
3847 
3848 /**
3849  * @}
3850  */
3851 
3852 /**
3853  * @addtogroup lavc_decoding
3854  * @{
3855  */
3856 
3857 /**
3858  * Find a registered decoder with a matching codec ID.
3859  *
3860  * @param id AVCodecID of the requested decoder
3861  * @return A decoder if one was found, NULL otherwise.
3862  */
3864 
3865 /**
3866  * Find a registered decoder with the specified name.
3867  *
3868  * @param name name of the requested decoder
3869  * @return A decoder if one was found, NULL otherwise.
3870  */
3872 
3873 #if FF_API_GET_BUFFER
3877 #endif
3878 
3879 /**
3880  * The default callback for AVCodecContext.get_buffer2(). It is made public so
3881  * it can be called by custom get_buffer2() implementations for decoders without
3882  * CODEC_CAP_DR1 set.
3883  */
3885 
3886 #if FF_API_EMU_EDGE
3887 /**
3888  * Return the amount of padding in pixels which the get_buffer callback must
3889  * provide around the edge of the image for codecs which do not have the
3890  * CODEC_FLAG_EMU_EDGE flag.
3891  *
3892  * @return Required padding in pixels.
3893  *
3894  * @deprecated CODEC_FLAG_EMU_EDGE is deprecated, so this function is no longer
3895  * needed
3896  */
3898 unsigned avcodec_get_edge_width(void);
3899 #endif
3900 
3901 /**
3902  * Modify width and height values so that they will result in a memory
3903  * buffer that is acceptable for the codec if you do not use any horizontal
3904  * padding.
3905  *
3906  * May only be used if a codec with CODEC_CAP_DR1 has been opened.
3907  */
3909 
3910 /**
3911  * Modify width and height values so that they will result in a memory
3912  * buffer that is acceptable for the codec if you also ensure that all
3913  * line sizes are a multiple of the respective linesize_align[i].
3914  *
3915  * May only be used if a codec with CODEC_CAP_DR1 has been opened.
3916  */
3918  int linesize_align[AV_NUM_DATA_POINTERS]);
3919 
3920 /**
3921  * Converts AVChromaLocation to swscale x/y chroma position.
3922  *
3923  * The positions represent the chroma (0,0) position in a coordinates system
3924  * with luma (0,0) representing the origin and luma(1,1) representing 256,256
3925  *
3926  * @param xpos horizontal chroma sample position
3927  * @param ypos vertical chroma sample position
3928  */
3929 int avcodec_enum_to_chroma_pos(int *xpos, int *ypos, enum AVChromaLocation pos);
3930 
3931 /**
3932  * Converts swscale x/y chroma position to AVChromaLocation.
3933  *
3934  * The positions represent the chroma (0,0) position in a coordinates system
3935  * with luma (0,0) representing the origin and luma(1,1) representing 256,256
3936  *
3937  * @param xpos horizontal chroma sample position
3938  * @param ypos vertical chroma sample position
3939  */
3940 enum AVChromaLocation avcodec_chroma_pos_to_enum(int xpos, int ypos);
3941 
3942 #if FF_API_OLD_DECODE_AUDIO
3943 /**
3944  * Wrapper function which calls avcodec_decode_audio4.
3945  *
3946  * @deprecated Use avcodec_decode_audio4 instead.
3947  *
3948  * Decode the audio frame of size avpkt->size from avpkt->data into samples.
3949  * Some decoders may support multiple frames in a single AVPacket, such
3950  * decoders would then just decode the first frame. In this case,
3951  * avcodec_decode_audio3 has to be called again with an AVPacket that contains
3952  * the remaining data in order to decode the second frame etc.
3953  * If no frame
3954  * could be outputted, frame_size_ptr is zero. Otherwise, it is the
3955  * decompressed frame size in bytes.
3956  *
3957  * @warning You must set frame_size_ptr to the allocated size of the
3958  * output buffer before calling avcodec_decode_audio3().
3959  *
3960  * @warning The input buffer must be FF_INPUT_BUFFER_PADDING_SIZE larger than
3961  * the actual read bytes because some optimized bitstream readers read 32 or 64
3962  * bits at once and could read over the end.
3963  *
3964  * @warning The end of the input buffer avpkt->data should be set to 0 to ensure that
3965  * no overreading happens for damaged MPEG streams.
3966  *
3967  * @warning You must not provide a custom get_buffer() when using
3968  * avcodec_decode_audio3(). Doing so will override it with
3969  * avcodec_default_get_buffer. Use avcodec_decode_audio4() instead,
3970  * which does allow the application to provide a custom get_buffer().
3971  *
3972  * @note You might have to align the input buffer avpkt->data and output buffer
3973  * samples. The alignment requirements depend on the CPU: On some CPUs it isn't
3974  * necessary at all, on others it won't work at all if not aligned and on others
3975  * it will work but it will have an impact on performance.
3976  *
3977  * In practice, avpkt->data should have 4 byte alignment at minimum and
3978  * samples should be 16 byte aligned unless the CPU doesn't need it
3979  * (AltiVec and SSE do).
3980  *
3981  * @note Codecs which have the CODEC_CAP_DELAY capability set have a delay
3982  * between input and output, these need to be fed with avpkt->data=NULL,
3983  * avpkt->size=0 at the end to return the remaining frames.
3984  *
3985  * @param avctx the codec context
3986  * @param[out] samples the output buffer, sample type in avctx->sample_fmt
3987  * If the sample format is planar, each channel plane will
3988  * be the same size, with no padding between channels.
3989  * @param[in,out] frame_size_ptr the output buffer size in bytes
3990  * @param[in] avpkt The input AVPacket containing the input buffer.
3991  * You can create such packet with av_init_packet() and by then setting
3992  * data and size, some decoders might in addition need other fields.
3993  * All decoders are designed to use the least fields possible though.
3994  * @return On error a negative value is returned, otherwise the number of bytes
3995  * used or zero if no frame data was decompressed (used) from the input AVPacket.
3996  */
3997 attribute_deprecated int avcodec_decode_audio3(AVCodecContext *avctx, int16_t *samples,
3998  int *frame_size_ptr,
3999  AVPacket *avpkt);
4000 #endif
4001 
4002 /**
4003  * Decode the audio frame of size avpkt->size from avpkt->data into frame.
4004  *
4005  * Some decoders may support multiple frames in a single AVPacket. Such
4006  * decoders would then just decode the first frame and the return value would be
4007  * less than the packet size. In this case, avcodec_decode_audio4 has to be
4008  * called again with an AVPacket containing the remaining data in order to
4009  * decode the second frame, etc... Even if no frames are returned, the packet
4010  * needs to be fed to the decoder with remaining data until it is completely
4011  * consumed or an error occurs.
4012  *
4013  * Some decoders (those marked with CODEC_CAP_DELAY) have a delay between input
4014  * and output. This means that for some packets they will not immediately
4015  * produce decoded output and need to be flushed at the end of decoding to get
4016  * all the decoded data. Flushing is done by calling this function with packets
4017  * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
4018  * returning samples. It is safe to flush even those decoders that are not
4019  * marked with CODEC_CAP_DELAY, then no samples will be returned.
4020  *
4021  * @warning The input buffer, avpkt->data must be FF_INPUT_BUFFER_PADDING_SIZE
4022  * larger than the actual read bytes because some optimized bitstream
4023  * readers read 32 or 64 bits at once and could read over the end.
4024  *
4025  * @param avctx the codec context
4026  * @param[out] frame The AVFrame in which to store decoded audio samples.
4027  * The decoder will allocate a buffer for the decoded frame by
4028  * calling the AVCodecContext.get_buffer2() callback.
4029  * When AVCodecContext.refcounted_frames is set to 1, the frame is
4030  * reference counted and the returned reference belongs to the
4031  * caller. The caller must release the frame using av_frame_unref()
4032  * when the frame is no longer needed. The caller may safely write
4033  * to the frame if av_frame_is_writable() returns 1.
4034  * When AVCodecContext.refcounted_frames is set to 0, the returned
4035  * reference belongs to the decoder and is valid only until the
4036  * next call to this function or until closing or flushing the
4037  * decoder. The caller may not write to it.
4038  * @param[out] got_frame_ptr Zero if no frame could be decoded, otherwise it is
4039  * non-zero. Note that this field being set to zero
4040  * does not mean that an error has occurred. For
4041  * decoders with CODEC_CAP_DELAY set, no given decode
4042  * call is guaranteed to produce a frame.
4043  * @param[in] avpkt The input AVPacket containing the input buffer.
4044  * At least avpkt->data and avpkt->size should be set. Some
4045  * decoders might also require additional fields to be set.
4046  * @return A negative error code is returned if an error occurred during
4047  * decoding, otherwise the number of bytes consumed from the input
4048  * AVPacket is returned.
4049  */
4051  int *got_frame_ptr, const AVPacket *avpkt);
4052 
4053 /**
4054  * Decode the video frame of size avpkt->size from avpkt->data into picture.
4055  * Some decoders may support multiple frames in a single AVPacket, such
4056  * decoders would then just decode the first frame.
4057  *
4058  * @warning The input buffer must be FF_INPUT_BUFFER_PADDING_SIZE larger than
4059  * the actual read bytes because some optimized bitstream readers read 32 or 64
4060  * bits at once and could read over the end.
4061  *
4062  * @warning The end of the input buffer buf should be set to 0 to ensure that
4063  * no overreading happens for damaged MPEG streams.
4064  *
4065  * @note Codecs which have the CODEC_CAP_DELAY capability set have a delay
4066  * between input and output, these need to be fed with avpkt->data=NULL,
4067  * avpkt->size=0 at the end to return the remaining frames.
4068  *
4069  * @param avctx the codec context
4070  * @param[out] picture The AVFrame in which the decoded video frame will be stored.
4071  * Use av_frame_alloc() to get an AVFrame. The codec will
4072  * allocate memory for the actual bitmap by calling the
4073  * AVCodecContext.get_buffer2() callback.
4074  * When AVCodecContext.refcounted_frames is set to 1, the frame is
4075  * reference counted and the returned reference belongs to the
4076  * caller. The caller must release the frame using av_frame_unref()
4077  * when the frame is no longer needed. The caller may safely write
4078  * to the frame if av_frame_is_writable() returns 1.
4079  * When AVCodecContext.refcounted_frames is set to 0, the returned
4080  * reference belongs to the decoder and is valid only until the
4081  * next call to this function or until closing or flushing the
4082  * decoder. The caller may not write to it.
4083  *
4084  * @param[in] avpkt The input AVPacket containing the input buffer.
4085  * You can create such packet with av_init_packet() and by then setting
4086  * data and size, some decoders might in addition need other fields like
4087  * flags&AV_PKT_FLAG_KEY. All decoders are designed to use the least
4088  * fields possible.
4089  * @param[in,out] got_picture_ptr Zero if no frame could be decompressed, otherwise, it is nonzero.
4090  * @return On error a negative value is returned, otherwise the number of bytes
4091  * used or zero if no frame could be decompressed.
4092  */
4093 int avcodec_decode_video2(AVCodecContext *avctx, AVFrame *picture,
4094  int *got_picture_ptr,
4095  const AVPacket *avpkt);
4096 
4097 /**
4098  * Decode a subtitle message.
4099  * Return a negative value on error, otherwise return the number of bytes used.
4100  * If no subtitle could be decompressed, got_sub_ptr is zero.
4101  * Otherwise, the subtitle is stored in *sub.
4102  * Note that CODEC_CAP_DR1 is not available for subtitle codecs. This is for
4103  * simplicity, because the performance difference is expect to be negligible
4104  * and reusing a get_buffer written for video codecs would probably perform badly
4105  * due to a potentially very different allocation pattern.
4106  *
4107  * Some decoders (those marked with CODEC_CAP_DELAY) have a delay between input
4108  * and output. This means that for some packets they will not immediately
4109  * produce decoded output and need to be flushed at the end of decoding to get
4110  * all the decoded data. Flushing is done by calling this function with packets
4111  * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
4112  * returning subtitles. It is safe to flush even those decoders that are not
4113  * marked with CODEC_CAP_DELAY, then no subtitles will be returned.
4114  *
4115  * @param avctx the codec context
4116  * @param[out] sub The Preallocated AVSubtitle in which the decoded subtitle will be stored,
4117  * must be freed with avsubtitle_free if *got_sub_ptr is set.
4118  * @param[in,out] got_sub_ptr Zero if no subtitle could be decompressed, otherwise, it is nonzero.
4119  * @param[in] avpkt The input AVPacket containing the input buffer.
4120  */
4122  int *got_sub_ptr,
4123  AVPacket *avpkt);
4124 
4125 /**
4126  * @defgroup lavc_parsing Frame parsing
4127  * @{
4128  */
4132  AV_PICTURE_STRUCTURE_TOP_FIELD, //< coded as top field
4133  AV_PICTURE_STRUCTURE_BOTTOM_FIELD, //< coded as bottom field
4134  AV_PICTURE_STRUCTURE_FRAME, //< coded as frame
4135 };
4137 typedef struct AVCodecParserContext {
4138  void *priv_data;
4140  int64_t frame_offset; /* offset of the current frame */
4141  int64_t cur_offset; /* current offset
4142  (incremented by each av_parser_parse()) */
4143  int64_t next_frame_offset; /* offset of the next frame */
4144  /* video info */
4145  int pict_type; /* XXX: Put it back in AVCodecContext. */
4146  /**
4147  * This field is used for proper frame duration computation in lavf.
4148  * It signals, how much longer the frame duration of the current frame
4149  * is compared to normal frame duration.
4150  *
4151  * frame_duration = (1 + repeat_pict) * time_base
4152  *
4153  * It is used by codecs like H.264 to display telecined material.
4154  */
4155  int repeat_pict; /* XXX: Put it back in AVCodecContext. */
4156  int64_t pts; /* pts of the current frame */
4157  int64_t dts; /* dts of the current frame */
4158 
4159  /* private data */
4160  int64_t last_pts;
4161  int64_t last_dts;
4162  int fetch_timestamp;
4164 #define AV_PARSER_PTS_NB 4
4170  int flags;
4171 #define PARSER_FLAG_COMPLETE_FRAMES 0x0001
4172 #define PARSER_FLAG_ONCE 0x0002
4173 /// Set if the parser has a valid file offset
4174 #define PARSER_FLAG_FETCHED_OFFSET 0x0004
4175 #define PARSER_FLAG_USE_CODEC_TS 0x1000
4177  int64_t offset; ///< byte offset from starting packet start
4179 
4180  /**
4181  * Set by parser to 1 for key frames and 0 for non-key frames.
4182  * It is initialized to -1, so if the parser doesn't set this flag,
4183  * old-style fallback using AV_PICTURE_TYPE_I picture type as key frames
4184  * will be used.
4185  */
4186  int key_frame;
4187 
4188  /**
4189  * Time difference in stream time base units from the pts of this
4190  * packet to the point at which the output from the decoder has converged
4191  * independent from the availability of previous frames. That is, the
4192  * frames are virtually identical no matter if decoding started from
4193  * the very first frame or from this keyframe.
4194  * Is AV_NOPTS_VALUE if unknown.
4195  * This field is not the display duration of the current frame.
4196  * This field has no meaning if the packet does not have AV_PKT_FLAG_KEY
4197  * set.
4198  *
4199  * The purpose of this field is to allow seeking in streams that have no
4200  * keyframes in the conventional sense. It corresponds to the
4201  * recovery point SEI in H.264 and match_time_delta in NUT. It is also
4202  * essential for some types of subtitle streams to ensure that all
4203  * subtitles are correctly displayed after seeking.
4204  */
4205  int64_t convergence_duration;
4206 
4207  // Timestamp generation support:
4208  /**
4209  * Synchronization point for start of timestamp generation.
4210  *
4211  * Set to >0 for sync point, 0 for no sync point and <0 for undefined
4212  * (default).
4213  *
4214  * For example, this corresponds to presence of H.264 buffering period
4215  * SEI message.
4216  */
4217  int dts_sync_point;
4218 
4219  /**
4220  * Offset of the current timestamp against last timestamp sync point in
4221  * units of AVCodecContext.time_base.
4222  *
4223  * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
4224  * contain a valid timestamp offset.
4225  *
4226  * Note that the timestamp of sync point has usually a nonzero
4227  * dts_ref_dts_delta, which refers to the previous sync point. Offset of
4228  * the next frame after timestamp sync point will be usually 1.
4229  *
4230  * For example, this corresponds to H.264 cpb_removal_delay.
4231  */
4232  int dts_ref_dts_delta;
4233 
4234  /**
4235  * Presentation delay of current frame in units of AVCodecContext.time_base.
4236  *
4237  * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
4238  * contain valid non-negative timestamp delta (presentation time of a frame
4239  * must not lie in the past).
4240  *
4241  * This delay represents the difference between decoding and presentation
4242  * time of the frame.
4243  *
4244  * For example, this corresponds to H.264 dpb_output_delay.
4245  */
4246  int pts_dts_delta;
4247 
4248  /**
4249  * Position of the packet in file.
4250  *
4251  * Analogous to cur_frame_pts/dts
4252  */
4254 
4255  /**
4256  * Byte position of currently parsed frame in stream.
4257  */
4258  int64_t pos;
4259 
4260  /**
4261  * Previous frame byte position.
4262  */
4263  int64_t last_pos;
4264 
4265  /**
4266  * Duration of the current frame.
4267  * For audio, this is in units of 1 / AVCodecContext.sample_rate.
4268  * For all other types, this is in units of AVCodecContext.time_base.
4269  */
4270  int duration;
4273 
4274  /**
4275  * Indicate whether a picture is coded as a frame, top field or bottom field.
4276  *
4277  * For example, H.264 field_pic_flag equal to 0 corresponds to
4278  * AV_PICTURE_STRUCTURE_FRAME. An H.264 picture with field_pic_flag
4279  * equal to 1 and bottom_field_flag equal to 0 corresponds to
4280  * AV_PICTURE_STRUCTURE_TOP_FIELD.
4281  */
4283 
4284  /**
4285  * Picture number incremented in presentation or output order.
4286  * This field may be reinitialized at the first picture of a new sequence.
4287  *
4288  * For example, this corresponds to H.264 PicOrderCnt.
4289  */
4293 typedef struct AVCodecParser {
4294  int codec_ids[5]; /* several codec IDs are permitted */
4298  AVCodecContext *avctx,
4299  const uint8_t **poutbuf, int *poutbuf_size,
4300  const uint8_t *buf, int buf_size);
4302  int (*split)(AVCodecContext *avctx, const uint8_t *buf, int buf_size);
4303  struct AVCodecParser *next;
4304 } AVCodecParser;
4305 
4307 
4310 
4311 /**
4312  * Parse a packet.
4313  *
4314  * @param s parser context.
4315  * @param avctx codec context.
4316  * @param poutbuf set to pointer to parsed buffer or NULL if not yet finished.
4317  * @param poutbuf_size set to size of parsed buffer or zero if not yet finished.
4318  * @param buf input buffer.
4319  * @param buf_size input length, to signal EOF, this should be 0 (so that the last frame can be output).
4320  * @param pts input presentation timestamp.
4321  * @param dts input decoding timestamp.
4322  * @param pos input byte position in stream.
4323  * @return the number of bytes of the input bitstream used.
4324  *
4325  * Example:
4326  * @code
4327  * while(in_len){
4328  * len = av_parser_parse2(myparser, AVCodecContext, &data, &size,
4329  * in_data, in_len,
4330  * pts, dts, pos);
4331  * in_data += len;
4332  * in_len -= len;
4333  *
4334  * if(size)
4335  * decode_frame(data, size);
4336  * }
4337  * @endcode
4338  */
4340  AVCodecContext *avctx,
4341  uint8_t **poutbuf, int *poutbuf_size,
4342  const uint8_t *buf, int buf_size,
4343  int64_t pts, int64_t dts,
4344  int64_t pos);
4345 
4346 /**
4347  * @return 0 if the output buffer is a subset of the input, 1 if it is allocated and must be freed
4348  * @deprecated use AVBitStreamFilter
4349  */
4351  AVCodecContext *avctx,
4352  uint8_t **poutbuf, int *poutbuf_size,
4353  const uint8_t *buf, int buf_size, int keyframe);
4355 
4356 /**
4357  * @}
4358  * @}
4359  */
4360 
4361 /**
4362  * @addtogroup lavc_encoding
4363  * @{
4364  */
4365 
4366 /**
4367  * Find a registered encoder with a matching codec ID.
4368  *
4369  * @param id AVCodecID of the requested encoder
4370  * @return An encoder if one was found, NULL otherwise.
4371  */
4373 
4374 /**
4375  * Find a registered encoder with the specified name.
4376  *
4377  * @param name name of the requested encoder
4378  * @return An encoder if one was found, NULL otherwise.
4379  */
4381 
4382 #if FF_API_OLD_ENCODE_AUDIO
4383 /**
4384  * Encode an audio frame from samples into buf.
4385  *
4386  * @deprecated Use avcodec_encode_audio2 instead.
4387  *
4388  * @note The output buffer should be at least FF_MIN_BUFFER_SIZE bytes large.
4389  * However, for codecs with avctx->frame_size equal to 0 (e.g. PCM) the user
4390  * will know how much space is needed because it depends on the value passed
4391  * in buf_size as described below. In that case a lower value can be used.
4392  *
4393  * @param avctx the codec context
4394  * @param[out] buf the output buffer
4395  * @param[in] buf_size the output buffer size
4396  * @param[in] samples the input buffer containing the samples
4397  * The number of samples read from this buffer is frame_size*channels,
4398  * both of which are defined in avctx.
4399  * For codecs which have avctx->frame_size equal to 0 (e.g. PCM) the number of
4400  * samples read from samples is equal to:
4401  * buf_size * 8 / (avctx->channels * av_get_bits_per_sample(avctx->codec_id))
4402  * This also implies that av_get_bits_per_sample() must not return 0 for these
4403  * codecs.
4404  * @return On error a negative value is returned, on success zero or the number
4405  * of bytes used to encode the data read from the input buffer.
4406  */
4408  uint8_t *buf, int buf_size,
4409  const short *samples);
4410 #endif
4411 
4412 /**
4413  * Encode a frame of audio.
4414  *
4415  * Takes input samples from frame and writes the next output packet, if
4416  * available, to avpkt. The output packet does not necessarily contain data for
4417  * the most recent frame, as encoders can delay, split, and combine input frames
4418  * internally as needed.
4419  *
4420  * @param avctx codec context
4421  * @param avpkt output AVPacket.
4422  * The user can supply an output buffer by setting
4423  * avpkt->data and avpkt->size prior to calling the
4424  * function, but if the size of the user-provided data is not
4425  * large enough, encoding will fail. If avpkt->data and
4426  * avpkt->size are set, avpkt->destruct must also be set. All
4427  * other AVPacket fields will be reset by the encoder using
4428  * av_init_packet(). If avpkt->data is NULL, the encoder will
4429  * allocate it. The encoder will set avpkt->size to the size
4430  * of the output packet.
4431  *
4432  * If this function fails or produces no output, avpkt will be
4433  * freed using av_free_packet() (i.e. avpkt->destruct will be
4434  * called to free the user supplied buffer).
4435  * @param[in] frame AVFrame containing the raw audio data to be encoded.
4436  * May be NULL when flushing an encoder that has the
4437  * CODEC_CAP_DELAY capability set.
4438  * If CODEC_CAP_VARIABLE_FRAME_SIZE is set, then each frame
4439  * can have any number of samples.
4440  * If it is not set, frame->nb_samples must be equal to
4441  * avctx->frame_size for all frames except the last.
4442  * The final frame may be smaller than avctx->frame_size.
4443  * @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
4444  * output packet is non-empty, and to 0 if it is
4445  * empty. If the function returns an error, the
4446  * packet can be assumed to be invalid, and the
4447  * value of got_packet_ptr is undefined and should
4448  * not be used.
4449  * @return 0 on success, negative error code on failure
4450  */
4451 int avcodec_encode_audio2(AVCodecContext *avctx, AVPacket *avpkt,
4452  const AVFrame *frame, int *got_packet_ptr);
4453 
4454 #if FF_API_OLD_ENCODE_VIDEO
4455 /**
4456  * @deprecated use avcodec_encode_video2() instead.
4457  *
4458  * Encode a video frame from pict into buf.
4459  * The input picture should be
4460  * stored using a specific format, namely avctx.pix_fmt.
4461  *
4462  * @param avctx the codec context
4463  * @param[out] buf the output buffer for the bitstream of encoded frame
4464  * @param[in] buf_size the size of the output buffer in bytes
4465  * @param[in] pict the input picture to encode
4466  * @return On error a negative value is returned, on success zero or the number
4467  * of bytes used from the output buffer.
4468  */
4470 int avcodec_encode_video(AVCodecContext *avctx, uint8_t *buf, int buf_size,
4471  const AVFrame *pict);
4472 #endif
4473 
4474 /**
4475  * Encode a frame of video.
4476  *
4477  * Takes input raw video data from frame and writes the next output packet, if
4478  * available, to avpkt. The output packet does not necessarily contain data for
4479  * the most recent frame, as encoders can delay and reorder input frames
4480  * internally as needed.
4481  *
4482  * @param avctx codec context
4483  * @param avpkt output AVPacket.
4484  * The user can supply an output buffer by setting
4485  * avpkt->data and avpkt->size prior to calling the
4486  * function, but if the size of the user-provided data is not
4487  * large enough, encoding will fail. All other AVPacket fields
4488  * will be reset by the encoder using av_init_packet(). If
4489  * avpkt->data is NULL, the encoder will allocate it.
4490  * The encoder will set avpkt->size to the size of the
4491  * output packet. The returned data (if any) belongs to the
4492  * caller, he is responsible for freeing it.
4493  *
4494  * If this function fails or produces no output, avpkt will be
4495  * freed using av_free_packet() (i.e. avpkt->destruct will be
4496  * called to free the user supplied buffer).
4497  * @param[in] frame AVFrame containing the raw video data to be encoded.
4498  * May be NULL when flushing an encoder that has the
4499  * CODEC_CAP_DELAY capability set.
4500  * @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
4501  * output packet is non-empty, and to 0 if it is
4502  * empty. If the function returns an error, the
4503  * packet can be assumed to be invalid, and the
4504  * value of got_packet_ptr is undefined and should
4505  * not be used.
4506  * @return 0 on success, negative error code on failure
4507  */
4508 int avcodec_encode_video2(AVCodecContext *avctx, AVPacket *avpkt,
4509  const AVFrame *frame, int *got_packet_ptr);
4510 
4511 int avcodec_encode_subtitle(AVCodecContext *avctx, uint8_t *buf, int buf_size,
4512  const AVSubtitle *sub);
4513 
4514 
4515 /**
4516  * @}
4517  */
4518 
4519 #if FF_API_AVCODEC_RESAMPLE
4520 /**
4521  * @defgroup lavc_resample Audio resampling
4522  * @ingroup libavc
4523  * @deprecated use libswresample instead
4524  *
4525  * @{
4526  */
4527 struct ReSampleContext;
4528 struct AVResampleContext;
4529 
4530 typedef struct ReSampleContext ReSampleContext;
4531 
4532 /**
4533  * Initialize audio resampling context.
4534  *
4535  * @param output_channels number of output channels
4536  * @param input_channels number of input channels
4537  * @param output_rate output sample rate
4538  * @param input_rate input sample rate
4539  * @param sample_fmt_out requested output sample format
4540  * @param sample_fmt_in input sample format
4541  * @param filter_length length of each FIR filter in the filterbank relative to the cutoff frequency
4542  * @param log2_phase_count log2 of the number of entries in the polyphase filterbank
4543  * @param linear if 1 then the used FIR filter will be linearly interpolated
4544  between the 2 closest, if 0 the closest will be used
4545  * @param cutoff cutoff frequency, 1.0 corresponds to half the output sampling rate
4546  * @return allocated ReSampleContext, NULL if error occurred
4547  */
4550  int output_rate, int input_rate,
4551  enum AVSampleFormat sample_fmt_out,
4552  enum AVSampleFormat sample_fmt_in,
4553  int filter_length, int log2_phase_count,
4554  int linear, double cutoff);
4555 
4557 int audio_resample(ReSampleContext *s, short *output, short *input, int nb_samples);
4558 
4559 /**
4560  * Free resample context.
4561  *
4562  * @param s a non-NULL pointer to a resample context previously
4563  * created with av_audio_resample_init()
4564  */
4567 
4568 
4569 /**
4570  * Initialize an audio resampler.
4571  * Note, if either rate is not an integer then simply scale both rates up so they are.
4572  * @param filter_length length of each FIR filter in the filterbank relative to the cutoff freq
4573  * @param log2_phase_count log2 of the number of entries in the polyphase filterbank
4574  * @param linear If 1 then the used FIR filter will be linearly interpolated
4575  between the 2 closest, if 0 the closest will be used
4576  * @param cutoff cutoff frequency, 1.0 corresponds to half the output sampling rate
4577  */
4579 struct AVResampleContext *av_resample_init(int out_rate, int in_rate, int filter_length, int log2_phase_count, int linear, double cutoff);
4580 
4581 /**
4582  * Resample an array of samples using a previously configured context.
4583  * @param src an array of unconsumed samples
4584  * @param consumed the number of samples of src which have been consumed are returned here
4585  * @param src_size the number of unconsumed samples available
4586  * @param dst_size the amount of space in samples available in dst
4587  * @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.
4588  * @return the number of samples written in dst or -1 if an error occurred
4589  */
4591 int av_resample(struct AVResampleContext *c, short *dst, short *src, int *consumed, int src_size, int dst_size, int update_ctx);
4592 
4593 
4594 /**
4595  * Compensate samplerate/timestamp drift. The compensation is done by changing
4596  * the resampler parameters, so no audible clicks or similar distortions occur
4597  * @param compensation_distance distance in output samples over which the compensation should be performed
4598  * @param sample_delta number of output samples which should be output less
4599  *
4600  * example: av_resample_compensate(c, 10, 500)
4601  * here instead of 510 samples only 500 samples would be output
4602  *
4603  * note, due to rounding the actual compensation might be slightly different,
4604  * especially if the compensation_distance is large and the in_rate used during init is small
4605  */
4607 void av_resample_compensate(struct AVResampleContext *c, int sample_delta, int compensation_distance);
4609 void av_resample_close(struct AVResampleContext *c);
4610 
4611 /**
4612  * @}
4613  */
4614 #endif
4615 
4616 /**
4617  * @addtogroup lavc_picture
4618  * @{
4619  */
4620 
4621 /**
4622  * Allocate memory for the pixels of a picture and setup the AVPicture
4623  * fields for it.
4624  *
4625  * Call avpicture_free() to free it.
4626  *
4627  * @param picture the picture structure to be filled in
4628  * @param pix_fmt the pixel format of the picture
4629  * @param width the width of the picture
4630  * @param height the height of the picture
4631  * @return zero if successful, a negative error code otherwise
4632  *
4633  * @see av_image_alloc(), avpicture_fill()
4634  */
4635 int avpicture_alloc(AVPicture *picture, enum AVPixelFormat pix_fmt, int width, int height);
4636 
4637 /**
4638  * Free a picture previously allocated by avpicture_alloc().
4639  * The data buffer used by the AVPicture is freed, but the AVPicture structure
4640  * itself is not.
4641  *
4642  * @param picture the AVPicture to be freed
4643  */
4644 void avpicture_free(AVPicture *picture);
4645 
4646 /**
4647  * Setup the picture fields based on the specified image parameters
4648  * and the provided image data buffer.
4649  *
4650  * The picture fields are filled in by using the image data buffer
4651  * pointed to by ptr.
4652  *
4653  * If ptr is NULL, the function will fill only the picture linesize
4654  * array and return the required size for the image buffer.
4655  *
4656  * To allocate an image buffer and fill the picture data in one call,
4657  * use avpicture_alloc().
4658  *
4659  * @param picture the picture to be filled in
4660  * @param ptr buffer where the image data is stored, or NULL
4661  * @param pix_fmt the pixel format of the image
4662  * @param width the width of the image in pixels
4663  * @param height the height of the image in pixels
4664  * @return the size in bytes required for src, a negative error code
4665  * in case of failure
4666  *
4667  * @see av_image_fill_arrays()
4668  */
4669 int avpicture_fill(AVPicture *picture, const uint8_t *ptr,
4670  enum AVPixelFormat pix_fmt, int width, int height);
4671 
4672 /**
4673  * Copy pixel data from an AVPicture into a buffer.
4674  *
4675  * avpicture_get_size() can be used to compute the required size for
4676  * the buffer to fill.
4677  *
4678  * @param src source picture with filled data
4679  * @param pix_fmt picture pixel format
4680  * @param width picture width
4681  * @param height picture height
4682  * @param dest destination buffer
4683  * @param dest_size destination buffer size in bytes
4684  * @return the number of bytes written to dest, or a negative value
4685  * (error code) on error, for example if the destination buffer is not
4686  * big enough
4687  *
4688  * @see av_image_copy_to_buffer()
4689  */
4691  int width, int height,
4692  unsigned char *dest, int dest_size);
4693 
4694 /**
4695  * Calculate the size in bytes that a picture of the given width and height
4696  * would occupy if stored in the given picture format.
4697  *
4698  * @param pix_fmt picture pixel format
4699  * @param width picture width
4700  * @param height picture height
4701  * @return the computed picture buffer size or a negative error code
4702  * in case of error
4703  *
4704  * @see av_image_get_buffer_size().
4705  */
4707 
4708 #if FF_API_DEINTERLACE
4709 /**
4710  * deinterlace - if not supported return -1
4711  *
4712  * @deprecated - use yadif (in libavfilter) instead
4713  */
4715 int avpicture_deinterlace(AVPicture *dst, const AVPicture *src,
4716  enum AVPixelFormat pix_fmt, int width, int height);
4717 #endif
4718 /**
4719  * Copy image src to dst. Wraps av_image_copy().
4720  */
4721 void av_picture_copy(AVPicture *dst, const AVPicture *src,
4722  enum AVPixelFormat pix_fmt, int width, int height);
4723 
4724 /**
4725  * Crop image top and left side.
4726  */
4727 int av_picture_crop(AVPicture *dst, const AVPicture *src,
4728  enum AVPixelFormat pix_fmt, int top_band, int left_band);
4729 
4730 /**
4731  * Pad image.
4732  */
4733 int av_picture_pad(AVPicture *dst, const AVPicture *src, int height, int width, enum AVPixelFormat pix_fmt,
4734  int padtop, int padbottom, int padleft, int padright, int *color);
4735 
4736 /**
4737  * @}
4738  */
4739 
4740 /**
4741  * @defgroup lavc_misc Utility functions
4742  * @ingroup libavc
4743  *
4744  * Miscellaneous utility functions related to both encoding and decoding
4745  * (or neither).
4746  * @{
4747  */
4748 
4749 /**
4750  * @defgroup lavc_misc_pixfmt Pixel formats
4751  *
4752  * Functions for working with pixel formats.
4753  * @{
4754  */
4755 
4756 /**
4757  * Utility function to access log2_chroma_w log2_chroma_h from
4758  * the pixel format AVPixFmtDescriptor.
4759  *
4760  * This function asserts that pix_fmt is valid. See av_pix_fmt_get_chroma_sub_sample
4761  * for one that returns a failure code and continues in case of invalid
4762  * pix_fmts.
4763  *
4764  * @param[in] pix_fmt the pixel format
4765  * @param[out] h_shift store log2_chroma_w
4766  * @param[out] v_shift store log2_chroma_h
4767  *
4768  * @see av_pix_fmt_get_chroma_sub_sample
4769  */
4770 
4771 void avcodec_get_chroma_sub_sample(enum AVPixelFormat pix_fmt, int *h_shift, int *v_shift);
4772 
4773 /**
4774  * Return a value representing the fourCC code associated to the
4775  * pixel format pix_fmt, or 0 if no associated fourCC code can be
4776  * found.
4777  */
4779 
4780 /**
4781  * @deprecated see av_get_pix_fmt_loss()
4782  */
4783 int avcodec_get_pix_fmt_loss(enum AVPixelFormat dst_pix_fmt, enum AVPixelFormat src_pix_fmt,
4784  int has_alpha);
4785 
4786 /**
4787  * Find the best pixel format to convert to given a certain source pixel
4788  * format. When converting from one pixel format to another, information loss
4789  * may occur. For example, when converting from RGB24 to GRAY, the color
4790  * information will be lost. Similarly, other losses occur when converting from
4791  * some formats to other formats. avcodec_find_best_pix_fmt_of_2() searches which of
4792  * the given pixel formats should be used to suffer the least amount of loss.
4793  * The pixel formats from which it chooses one, are determined by the
4794  * pix_fmt_list parameter.
4795  *
4796  *
4797  * @param[in] pix_fmt_list AV_PIX_FMT_NONE terminated array of pixel formats to choose from
4798  * @param[in] src_pix_fmt source pixel format
4799  * @param[in] has_alpha Whether the source pixel format alpha channel is used.
4800  * @param[out] loss_ptr Combination of flags informing you what kind of losses will occur.
4801  * @return The best pixel format to convert to or -1 if none was found.
4802  */
4803 enum AVPixelFormat avcodec_find_best_pix_fmt_of_list(const enum AVPixelFormat *pix_fmt_list,
4804  enum AVPixelFormat src_pix_fmt,
4805  int has_alpha, int *loss_ptr);
4806 
4807 /**
4808  * @deprecated see av_find_best_pix_fmt_of_2()
4809  */
4810 enum AVPixelFormat avcodec_find_best_pix_fmt_of_2(enum AVPixelFormat dst_pix_fmt1, enum AVPixelFormat dst_pix_fmt2,
4811  enum AVPixelFormat src_pix_fmt, int has_alpha, int *loss_ptr);
4812 
4814 #if AV_HAVE_INCOMPATIBLE_LIBAV_ABI
4815 enum AVPixelFormat avcodec_find_best_pix_fmt2(const enum AVPixelFormat *pix_fmt_list,
4816  enum AVPixelFormat src_pix_fmt,
4817  int has_alpha, int *loss_ptr);
4818 #else
4819 enum AVPixelFormat avcodec_find_best_pix_fmt2(enum AVPixelFormat dst_pix_fmt1, enum AVPixelFormat dst_pix_fmt2,
4820  enum AVPixelFormat src_pix_fmt, int has_alpha, int *loss_ptr);
4821 #endif
4822 
4823 
4825 
4826 /**
4827  * @}
4828  */
4829 
4830 #if FF_API_SET_DIMENSIONS
4831 /**
4832  * @deprecated this function is not supposed to be used from outside of lavc
4833  */
4836 #endif
4837