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avcodec.h
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1 /*
2  * copyright (c) 2001 Fabrice Bellard
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #ifndef AVCODEC_AVCODEC_H
22 #define AVCODEC_AVCODEC_H
23 
24 /**
25  * @file
26  * @ingroup libavc
27  * Libavcodec external API header
28  */
29 
30 #include <errno.h>
31 #include "libavutil/samplefmt.h"
32 #include "libavutil/attributes.h"
33 #include "libavutil/avutil.h"
34 #include "libavutil/buffer.h"
35 #include "libavutil/cpu.h"
37 #include "libavutil/dict.h"
38 #include "libavutil/frame.h"
39 #include "libavutil/log.h"
40 #include "libavutil/pixfmt.h"
41 #include "libavutil/rational.h"
42 
43 #include "version.h"
44 
45 #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  * Subtitle codec is bitmap based
600  * Decoded AVSubtitle data can be read from the AVSubtitleRect->pict field.
601  */
602 #define AV_CODEC_PROP_BITMAP_SUB (1 << 16)
603 /**
604  * Subtitle codec is text based.
605  * Decoded AVSubtitle data can be read from the AVSubtitleRect->ass field.
606  */
607 #define AV_CODEC_PROP_TEXT_SUB (1 << 17)
609 /**
610  * @ingroup lavc_decoding
611  * Required number of additionally allocated bytes at the end of the input bitstream for decoding.
612  * This is mainly needed because some optimized bitstream readers read
613  * 32 or 64 bit at once and could read over the end.<br>
614  * Note: If the first 23 bits of the additional bytes are not 0, then damaged
615  * MPEG bitstreams could cause overread and segfault.
616  */
617 #define FF_INPUT_BUFFER_PADDING_SIZE 32
619 /**
620  * @ingroup lavc_encoding
621  * minimum encoding buffer size
622  * Used to avoid some checks during header writing.
623  */
624 #define FF_MIN_BUFFER_SIZE 16384
627 /**
628  * @ingroup lavc_encoding
629  * motion estimation type.
630  */
632  ME_ZERO = 1, ///< no search, that is use 0,0 vector whenever one is needed
636  ME_EPZS, ///< enhanced predictive zonal search
637  ME_X1, ///< reserved for experiments
638  ME_HEX, ///< hexagon based search
639  ME_UMH, ///< uneven multi-hexagon search
640  ME_TESA, ///< transformed exhaustive search algorithm
641  ME_ITER=50, ///< iterative search
642 };
644 /**
645  * @ingroup lavc_decoding
646  */
648  /* We leave some space between them for extensions (drop some
649  * keyframes for intra-only or drop just some bidir frames). */
650  AVDISCARD_NONE =-16, ///< discard nothing
651  AVDISCARD_DEFAULT = 0, ///< discard useless packets like 0 size packets in avi
652  AVDISCARD_NONREF = 8, ///< discard all non reference
653  AVDISCARD_BIDIR = 16, ///< discard all bidirectional frames
654  AVDISCARD_NONINTRA= 24, ///< discard all non intra frames
655  AVDISCARD_NONKEY = 32, ///< discard all frames except keyframes
656  AVDISCARD_ALL = 48, ///< discard all
657 };
669  AV_AUDIO_SERVICE_TYPE_NB , ///< Not part of ABI
670 };
672 /**
673  * @ingroup lavc_encoding
674  */
675 typedef struct RcOverride{
678  int qscale; // If this is 0 then quality_factor will be used instead.
682 #if FF_API_MAX_BFRAMES
683 /**
684  * @deprecated there is no libavcodec-wide limit on the number of B-frames
685  */
686 #define FF_MAX_B_FRAMES 16
687 #endif
689 /* encoding support
690  These flags can be passed in AVCodecContext.flags before initialization.
691  Note: Not everything is supported yet.
692 */
694 /**
695  * Allow decoders to produce frames with data planes that are not aligned
696  * to CPU requirements (e.g. due to cropping).
697  */
698 #define CODEC_FLAG_UNALIGNED 0x0001
699 #define CODEC_FLAG_QSCALE 0x0002 ///< Use fixed qscale.
700 #define CODEC_FLAG_4MV 0x0004 ///< 4 MV per MB allowed / advanced prediction for H.263.
701 #define CODEC_FLAG_OUTPUT_CORRUPT 0x0008 ///< Output even those frames that might be corrupted
702 #define CODEC_FLAG_QPEL 0x0010 ///< Use qpel MC.
703 #if FF_API_GMC
704 /**
705  * @deprecated use the "gmc" private option of the libxvid encoder
706  */
707 #define CODEC_FLAG_GMC 0x0020 ///< Use GMC.
708 #endif
709 #if FF_API_MV0
710 /**
711  * @deprecated use the flag "mv0" in the "mpv_flags" private option of the
712  * mpegvideo encoders
713  */
714 #define CODEC_FLAG_MV0 0x0040
715 #endif
716 #if FF_API_INPUT_PRESERVED
717 /**
718  * @deprecated passing reference-counted frames to the encoders replaces this
719  * flag
720  */
721 #define CODEC_FLAG_INPUT_PRESERVED 0x0100
722 #endif
723 #define CODEC_FLAG_PASS1 0x0200 ///< Use internal 2pass ratecontrol in first pass mode.
724 #define CODEC_FLAG_PASS2 0x0400 ///< Use internal 2pass ratecontrol in second pass mode.
725 #define CODEC_FLAG_GRAY 0x2000 ///< Only decode/encode grayscale.
726 #if FF_API_EMU_EDGE
727 /**
728  * @deprecated edges are not used/required anymore. I.e. this flag is now always
729  * set.
730  */
731 #define CODEC_FLAG_EMU_EDGE 0x4000
732 #endif
733 #define CODEC_FLAG_PSNR 0x8000 ///< error[?] variables will be set during encoding.
734 #define CODEC_FLAG_TRUNCATED 0x00010000 /** Input bitstream might be truncated at a random
735  location instead of only at frame boundaries. */
736 #if FF_API_NORMALIZE_AQP
737 /**
738  * @deprecated use the flag "naq" in the "mpv_flags" private option of the
739  * mpegvideo encoders
740  */
741 #define CODEC_FLAG_NORMALIZE_AQP 0x00020000
742 #endif
743 #define CODEC_FLAG_INTERLACED_DCT 0x00040000 ///< Use interlaced DCT.
744 #define CODEC_FLAG_LOW_DELAY 0x00080000 ///< Force low delay.
745 #define CODEC_FLAG_GLOBAL_HEADER 0x00400000 ///< Place global headers in extradata instead of every keyframe.
746 #define CODEC_FLAG_BITEXACT 0x00800000 ///< Use only bitexact stuff (except (I)DCT).
747 /* Fx : Flag for h263+ extra options */
748 #define CODEC_FLAG_AC_PRED 0x01000000 ///< H.263 advanced intra coding / MPEG-4 AC prediction
749 #define CODEC_FLAG_LOOP_FILTER 0x00000800 ///< loop filter
750 #define CODEC_FLAG_INTERLACED_ME 0x20000000 ///< interlaced motion estimation
751 #define CODEC_FLAG_CLOSED_GOP 0x80000000
752 #define CODEC_FLAG2_FAST 0x00000001 ///< Allow non spec compliant speedup tricks.
753 #define CODEC_FLAG2_NO_OUTPUT 0x00000004 ///< Skip bitstream encoding.
754 #define CODEC_FLAG2_LOCAL_HEADER 0x00000008 ///< Place global headers at every keyframe instead of in extradata.
755 #define CODEC_FLAG2_DROP_FRAME_TIMECODE 0x00002000 ///< timecode is in drop frame format. DEPRECATED!!!!
756 #define CODEC_FLAG2_IGNORE_CROP 0x00010000 ///< Discard cropping information from SPS.
758 #define CODEC_FLAG2_CHUNKS 0x00008000 ///< Input bitstream might be truncated at a packet boundaries instead of only at frame boundaries.
759 #define CODEC_FLAG2_SHOW_ALL 0x00400000 ///< Show all frames before the first keyframe
761 /* Unsupported options :
762  * Syntax Arithmetic coding (SAC)
763  * Reference Picture Selection
764  * Independent Segment Decoding */
765 /* /Fx */
766 /* codec capabilities */
768 #define CODEC_CAP_DRAW_HORIZ_BAND 0x0001 ///< Decoder can use draw_horiz_band callback.
769 /**
770  * Codec uses get_buffer() for allocating buffers and supports custom allocators.
771  * If not set, it might not use get_buffer() at all or use operations that
772  * assume the buffer was allocated by avcodec_default_get_buffer.
773  */
774 #define CODEC_CAP_DR1 0x0002
775 #define CODEC_CAP_TRUNCATED 0x0008
776 #if FF_API_XVMC
777 /* Codec can export data for HW decoding. This flag indicates that
778  * the codec would call get_format() with list that might contain HW accelerated
779  * pixel formats (XvMC, VDPAU, VAAPI, etc). The application can pick any of them
780  * including raw image format.
781  * The application can use the passed context to determine bitstream version,
782  * chroma format, resolution etc.
783  */
784 #define CODEC_CAP_HWACCEL 0x0010
785 #endif /* FF_API_XVMC */
786 /**
787  * Encoder or decoder requires flushing with NULL input at the end in order to
788  * give the complete and correct output.
789  *
790  * NOTE: If this flag is not set, the codec is guaranteed to never be fed with
791  * with NULL data. The user can still send NULL data to the public encode
792  * or decode function, but libavcodec will not pass it along to the codec
793  * unless this flag is set.
794  *
795  * Decoders:
796  * The decoder has a non-zero delay and needs to be fed with avpkt->data=NULL,
797  * avpkt->size=0 at the end to get the delayed data until the decoder no longer
798  * returns frames.
799  *
800  * Encoders:
801  * The encoder needs to be fed with NULL data at the end of encoding until the
802  * encoder no longer returns data.
803  *
804  * NOTE: For encoders implementing the AVCodec.encode2() function, setting this
805  * flag also means that the encoder must set the pts and duration for
806  * each output packet. If this flag is not set, the pts and duration will
807  * be determined by libavcodec from the input frame.
808  */
809 #define CODEC_CAP_DELAY 0x0020
810 /**
811  * Codec can be fed a final frame with a smaller size.
812  * This can be used to prevent truncation of the last audio samples.
813  */
814 #define CODEC_CAP_SMALL_LAST_FRAME 0x0040
815 #if FF_API_CAP_VDPAU
816 /**
817  * Codec can export data for HW decoding (VDPAU).
818  */
819 #define CODEC_CAP_HWACCEL_VDPAU 0x0080
820 #endif
821 /**
822  * Codec can output multiple frames per AVPacket
823  * Normally demuxers return one frame at a time, demuxers which do not do
824  * are connected to a parser to split what they return into proper frames.
825  * This flag is reserved to the very rare category of codecs which have a
826  * bitstream that cannot be split into frames without timeconsuming
827  * operations like full decoding. Demuxers carring such bitstreams thus
828  * may return multiple frames in a packet. This has many disadvantages like
829  * prohibiting stream copy in many cases thus it should only be considered
830  * as a last resort.
831  */
832 #define CODEC_CAP_SUBFRAMES 0x0100
833 /**
834  * Codec is experimental and is thus avoided in favor of non experimental
835  * encoders
836  */
837 #define CODEC_CAP_EXPERIMENTAL 0x0200
838 /**
839  * Codec should fill in channel configuration and samplerate instead of container
840  */
841 #define CODEC_CAP_CHANNEL_CONF 0x0400
842 #if FF_API_NEG_LINESIZES
843 /**
844  * @deprecated no codecs use this capability
845  */
846 #define CODEC_CAP_NEG_LINESIZES 0x0800
847 #endif
848 /**
849  * Codec supports frame-level multithreading.
850  */
851 #define CODEC_CAP_FRAME_THREADS 0x1000
852 /**
853  * Codec supports slice-based (or partition-based) multithreading.
854  */
855 #define CODEC_CAP_SLICE_THREADS 0x2000
856 /**
857  * Codec supports changed parameters at any point.
858  */
859 #define CODEC_CAP_PARAM_CHANGE 0x4000
860 /**
861  * Codec supports avctx->thread_count == 0 (auto).
862  */
863 #define CODEC_CAP_AUTO_THREADS 0x8000
864 /**
865  * Audio encoder supports receiving a different number of samples in each call.
866  */
867 #define CODEC_CAP_VARIABLE_FRAME_SIZE 0x10000
868 /**
869  * Codec is intra only.
870  */
871 #define CODEC_CAP_INTRA_ONLY 0x40000000
872 /**
873  * Codec is lossless.
874  */
875 #define CODEC_CAP_LOSSLESS 0x80000000
877 #if FF_API_MB_TYPE
878 //The following defines may change, don't expect compatibility if you use them.
879 #define MB_TYPE_INTRA4x4 0x0001
880 #define MB_TYPE_INTRA16x16 0x0002 //FIXME H.264-specific
881 #define MB_TYPE_INTRA_PCM 0x0004 //FIXME H.264-specific
882 #define MB_TYPE_16x16 0x0008
883 #define MB_TYPE_16x8 0x0010
884 #define MB_TYPE_8x16 0x0020
885 #define MB_TYPE_8x8 0x0040
886 #define MB_TYPE_INTERLACED 0x0080
887 #define MB_TYPE_DIRECT2 0x0100 //FIXME
888 #define MB_TYPE_ACPRED 0x0200
889 #define MB_TYPE_GMC 0x0400
890 #define MB_TYPE_SKIP 0x0800
891 #define MB_TYPE_P0L0 0x1000
892 #define MB_TYPE_P1L0 0x2000
893 #define MB_TYPE_P0L1 0x4000
894 #define MB_TYPE_P1L1 0x8000
895 #define MB_TYPE_L0 (MB_TYPE_P0L0 | MB_TYPE_P1L0)
896 #define MB_TYPE_L1 (MB_TYPE_P0L1 | MB_TYPE_P1L1)
897 #define MB_TYPE_L0L1 (MB_TYPE_L0 | MB_TYPE_L1)
898 #define MB_TYPE_QUANT 0x00010000
899 #define MB_TYPE_CBP 0x00020000
900 //Note bits 24-31 are reserved for codec specific use (h264 ref0, mpeg1 0mv, ...)
901 #endif
903 /**
904  * Pan Scan area.
905  * This specifies the area which should be displayed.
906  * Note there may be multiple such areas for one frame.
907  */
908 typedef struct AVPanScan{
909  /**
910  * id
911  * - encoding: Set by user.
912  * - decoding: Set by libavcodec.
913  */
914  int id;
916  /**
917  * width and height in 1/16 pel
918  * - encoding: Set by user.
919  * - decoding: Set by libavcodec.
920  */
921  int width;
922  int height;
924  /**
925  * position of the top left corner in 1/16 pel for up to 3 fields/frames
926  * - encoding: Set by user.
927  * - decoding: Set by libavcodec.
928  */
929  int16_t position[3][2];
932 #if FF_API_QSCALE_TYPE
933 #define FF_QSCALE_TYPE_MPEG1 0
934 #define FF_QSCALE_TYPE_MPEG2 1
935 #define FF_QSCALE_TYPE_H264 2
936 #define FF_QSCALE_TYPE_VP56 3
937 #endif
938 
939 #if FF_API_GET_BUFFER
940 #define FF_BUFFER_TYPE_INTERNAL 1
941 #define FF_BUFFER_TYPE_USER 2 ///< direct rendering buffers (image is (de)allocated by user)
942 #define FF_BUFFER_TYPE_SHARED 4 ///< Buffer from somewhere else; don't deallocate image (data/base), all other tables are not shared.
943 #define FF_BUFFER_TYPE_COPY 8 ///< Just a (modified) copy of some other buffer, don't deallocate anything.
945 #define FF_BUFFER_HINTS_VALID 0x01 // Buffer hints value is meaningful (if 0 ignore).
946 #define FF_BUFFER_HINTS_READABLE 0x02 // Codec will read from buffer.
947 #define FF_BUFFER_HINTS_PRESERVE 0x04 // User must not alter buffer content.
948 #define FF_BUFFER_HINTS_REUSABLE 0x08 // Codec will reuse the buffer (update).
949 #endif
950 
951 /**
952  * The decoder will keep a reference to the frame and may reuse it later.
953  */
954 #define AV_GET_BUFFER_FLAG_REF (1 << 0)
955 
956 /**
957  * @defgroup lavc_packet AVPacket
958  *
959  * Types and functions for working with AVPacket.
960  * @{
961  */
965 
966  /**
967  * An AV_PKT_DATA_PARAM_CHANGE side data packet is laid out as follows:
968  * @code
969  * u32le param_flags
970  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT)
971  * s32le channel_count
972  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT)
973  * u64le channel_layout
974  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE)
975  * s32le sample_rate
976  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS)
977  * s32le width
978  * s32le height
979  * @endcode
980  */
982 
983  /**
984  * An AV_PKT_DATA_H263_MB_INFO side data packet contains a number of
985  * structures with info about macroblocks relevant to splitting the
986  * packet into smaller packets on macroblock edges (e.g. as for RFC 2190).
987  * That is, it does not necessarily contain info about all macroblocks,
988  * as long as the distance between macroblocks in the info is smaller
989  * than the target payload size.
990  * Each MB info structure is 12 bytes, and is laid out as follows:
991  * @code
992  * u32le bit offset from the start of the packet
993  * u8 current quantizer at the start of the macroblock
994  * u8 GOB number
995  * u16le macroblock address within the GOB
996  * u8 horizontal MV predictor
997  * u8 vertical MV predictor
998  * u8 horizontal MV predictor for block number 3
999  * u8 vertical MV predictor for block number 3
1000  * @endcode
1001  */
1003 
1004  /**
1005  * This side data should be associated with an audio stream and contains
1006  * ReplayGain information in form of the AVReplayGain struct.
1007  */
1009 
1010  /**
1011  * This side data contains a 3x3 transformation matrix describing an affine
1012  * transformation that needs to be applied to the decoded video frames for
1013  * correct presentation.
1014  *
1015  * See libavutil/display.h for a detailed description of the data.
1016  */
1018 
1019  /**
1020  * Recommmends skipping the specified number of samples
1021  * @code
1022  * u32le number of samples to skip from start of this packet
1023  * u32le number of samples to skip from end of this packet
1024  * u8 reason for start skip
1025  * u8 reason for end skip (0=padding silence, 1=convergence)
1026  * @endcode
1027  */
1029 
1030  /**
1031  * An AV_PKT_DATA_JP_DUALMONO side data packet indicates that
1032  * the packet may contain "dual mono" audio specific to Japanese DTV
1033  * and if it is true, recommends only the selected channel to be used.
1034  * @code
1035  * u8 selected channels (0=mail/left, 1=sub/right, 2=both)
1036  * @endcode
1037  */
1039 
1040  /**
1041  * A list of zero terminated key/value strings. There is no end marker for
1042  * the list, so it is required to rely on the side data size to stop.
1043  */
1045 
1046  /**
1047  * Subtitle event position
1048  * @code
1049  * u32le x1
1050  * u32le y1
1051  * u32le x2
1052  * u32le y2
1053  * @endcode
1054  */
1056 
1057  /**
1058  * Data found in BlockAdditional element of matroska container. There is
1059  * no end marker for the data, so it is required to rely on the side data
1060  * size to recognize the end. 8 byte id (as found in BlockAddId) followed
1061  * by data.
1062  */
1064 
1065  /**
1066  * The optional first identifier line of a WebVTT cue.
1067  */
1069 
1070  /**
1071  * The optional settings (rendering instructions) that immediately
1072  * follow the timestamp specifier of a WebVTT cue.
1073  */
1075 
1076  /**
1077  * A list of zero terminated key/value strings. There is no end marker for
1078  * the list, so it is required to rely on the side data size to stop. This
1079  * side data includes updated metadata which appeared in the stream.
1080  */
1082 };
1084 typedef struct AVPacketSideData {
1086  int size;
1089 
1090 /**
1091  * This structure stores compressed data. It is typically exported by demuxers
1092  * and then passed as input to decoders, or received as output from encoders and
1093  * then passed to muxers.
1094  *
1095  * For video, it should typically contain one compressed frame. For audio it may
1096  * contain several compressed frames.
1097  *
1098  * AVPacket is one of the few structs in FFmpeg, whose size is a part of public
1099  * ABI. Thus it may be allocated on stack and no new fields can be added to it
1100  * without libavcodec and libavformat major bump.
1101  *
1102  * The semantics of data ownership depends on the buf or destruct (deprecated)
1103  * fields. If either is set, the packet data is dynamically allocated and is
1104  * valid indefinitely until av_free_packet() is called (which in turn calls
1105  * av_buffer_unref()/the destruct callback to free the data). If neither is set,
1106  * the packet data is typically backed by some static buffer somewhere and is
1107  * only valid for a limited time (e.g. until the next read call when demuxing).
1108  *
1109  * The side data is always allocated with av_malloc() and is freed in
1110  * av_free_packet().
1111  */
1112 typedef struct AVPacket {
1113  /**
1114  * A reference to the reference-counted buffer where the packet data is
1115  * stored.
1116  * May be NULL, then the packet data is not reference-counted.
1117  */
1118  AVBufferRef *buf;
1119  /**
1120  * Presentation timestamp in AVStream->time_base units; the time at which
1121  * the decompressed packet will be presented to the user.
1122  * Can be AV_NOPTS_VALUE if it is not stored in the file.
1123  * pts MUST be larger or equal to dts as presentation cannot happen before
1124  * decompression, unless one wants to view hex dumps. Some formats misuse
1125  * the terms dts and pts/cts to mean something different. Such timestamps
1126  * must be converted to true pts/dts before they are stored in AVPacket.
1127  */
1128  int64_t pts;
1129  /**
1130  * Decompression timestamp in AVStream->time_base units; the time at which
1131  * the packet is decompressed.
1132  * Can be AV_NOPTS_VALUE if it is not stored in the file.
1133  */
1134  int64_t dts;
1136  int size;
1137  int stream_index;
1138  /**
1139  * A combination of AV_PKT_FLAG values
1140  */
1141  int flags;
1142  /**
1143  * Additional packet data that can be provided by the container.
1144  * Packet can contain several types of side information.
1145  */
1147  int side_data_elems;
1148 
1149  /**
1150  * Duration of this packet in AVStream->time_base units, 0 if unknown.
1151  * Equals next_pts - this_pts in presentation order.
1152  */
1153  int duration;
1154 #if FF_API_DESTRUCT_PACKET
1156  void (*destruct)(struct AVPacket *);
1158  void *priv;
1159 #endif
1160  int64_t pos; ///< byte position in stream, -1 if unknown
1161 
1162  /**
1163  * Time difference in AVStream->time_base units from the pts of this
1164  * packet to the point at which the output from the decoder has converged
1165  * independent from the availability of previous frames. That is, the
1166  * frames are virtually identical no matter if decoding started from
1167  * the very first frame or from this keyframe.
1168  * Is AV_NOPTS_VALUE if unknown.
1169  * This field is not the display duration of the current packet.
1170  * This field has no meaning if the packet does not have AV_PKT_FLAG_KEY
1171  * set.
1172  *
1173  * The purpose of this field is to allow seeking in streams that have no
1174  * keyframes in the conventional sense. It corresponds to the
1175  * recovery point SEI in H.264 and match_time_delta in NUT. It is also
1176  * essential for some types of subtitle streams to ensure that all
1177  * subtitles are correctly displayed after seeking.
1178  */
1179  int64_t convergence_duration;
1181 #define AV_PKT_FLAG_KEY 0x0001 ///< The packet contains a keyframe
1182 #define AV_PKT_FLAG_CORRUPT 0x0002 ///< The packet content is corrupted
1189 };
1190 /**
1191  * @}
1192  */
1193 
1194 struct AVCodecInternal;
1199  AV_FIELD_TT, //< Top coded_first, top displayed first
1200  AV_FIELD_BB, //< Bottom coded first, bottom displayed first
1201  AV_FIELD_TB, //< Top coded first, bottom displayed first
1202  AV_FIELD_BT, //< Bottom coded first, top displayed first
1203 };
1204 
1205 /**
1206  * main external API structure.
1207  * New fields can be added to the end with minor version bumps.
1208  * Removal, reordering and changes to existing fields require a major
1209  * version bump.
1210  * Please use AVOptions (av_opt* / av_set/get*()) to access these fields from user
1211  * applications.
1212  * sizeof(AVCodecContext) must not be used outside libav*.
1213  */
1214 typedef struct AVCodecContext {
1215  /**
1216  * information on struct for av_log
1217  * - set by avcodec_alloc_context3
1218  */
1220  int log_level_offset;
1222  enum AVMediaType codec_type; /* see AVMEDIA_TYPE_xxx */
1223  const struct AVCodec *codec;
1224 #if FF_API_CODEC_NAME
1225  /**
1226  * @deprecated this field is not used for anything in libavcodec
1227  */
1229  char codec_name[32];
1230 #endif
1231  enum AVCodecID codec_id; /* see AV_CODEC_ID_xxx */
1232 
1233  /**
1234  * fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
1235  * This is used to work around some encoder bugs.
1236  * A demuxer should set this to what is stored in the field used to identify the codec.
1237  * If there are multiple such fields in a container then the demuxer should choose the one
1238  * which maximizes the information about the used codec.
1239  * If the codec tag field in a container is larger than 32 bits then the demuxer should
1240  * remap the longer ID to 32 bits with a table or other structure. Alternatively a new
1241  * extra_codec_tag + size could be added but for this a clear advantage must be demonstrated
1242  * first.
1243  * - encoding: Set by user, if not then the default based on codec_id will be used.
1244  * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
1245  */
1246  unsigned int codec_tag;
1247 
1248  /**
1249  * fourcc from the AVI stream header (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
1250  * This is used to work around some encoder bugs.
1251  * - encoding: unused
1252  * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
1253  */
1254  unsigned int stream_codec_tag;
1256  void *priv_data;
1257 
1258  /**
1259  * Private context used for internal data.
1260  *
1261  * Unlike priv_data, this is not codec-specific. It is used in general
1262  * libavcodec functions.
1263  */
1264  struct AVCodecInternal *internal;
1265 
1266  /**
1267  * Private data of the user, can be used to carry app specific stuff.
1268  * - encoding: Set by user.
1269  * - decoding: Set by user.
1270  */
1271  void *opaque;
1272 
1273  /**
1274  * the average bitrate
1275  * - encoding: Set by user; unused for constant quantizer encoding.
1276  * - decoding: Set by libavcodec. 0 or some bitrate if this info is available in the stream.
1277  */
1278  int bit_rate;
1279 
1280  /**
1281  * number of bits the bitstream is allowed to diverge from the reference.
1282  * the reference can be CBR (for CBR pass1) or VBR (for pass2)
1283  * - encoding: Set by user; unused for constant quantizer encoding.
1284  * - decoding: unused
1285  */
1286  int bit_rate_tolerance;
1287 
1288  /**
1289  * Global quality for codecs which cannot change it per frame.
1290  * This should be proportional to MPEG-1/2/4 qscale.
1291  * - encoding: Set by user.
1292  * - decoding: unused
1293  */
1294  int global_quality;
1295 
1296  /**
1297  * - encoding: Set by user.
1298  * - decoding: unused
1299  */
1301 #define FF_COMPRESSION_DEFAULT -1
1302 
1303  /**
1304  * CODEC_FLAG_*.
1305  * - encoding: Set by user.
1306  * - decoding: Set by user.
1307  */
1308  int flags;
1309 
1310  /**
1311  * CODEC_FLAG2_*
1312  * - encoding: Set by user.
1313  * - decoding: Set by user.
1314  */
1315  int flags2;
1316 
1317  /**
1318  * some codecs need / can use extradata like Huffman tables.
1319  * mjpeg: Huffman tables
1320  * rv10: additional flags
1321  * mpeg4: global headers (they can be in the bitstream or here)
1322  * The allocated memory should be FF_INPUT_BUFFER_PADDING_SIZE bytes larger
1323  * than extradata_size to avoid problems if it is read with the bitstream reader.
1324  * The bytewise contents of extradata must not depend on the architecture or CPU endianness.
1325  * - encoding: Set/allocated/freed by libavcodec.
1326  * - decoding: Set/allocated/freed by user.
1327  */
1329  int extradata_size;
1330 
1331  /**
1332  * This is the fundamental unit of time (in seconds) in terms
1333  * of which frame timestamps are represented. For fixed-fps content,
1334  * timebase should be 1/framerate and timestamp increments should be
1335  * identically 1.
1336  * - encoding: MUST be set by user.
1337  * - decoding: Set by libavcodec.
1338  */
1340 
1341  /**
1342  * For some codecs, the time base is closer to the field rate than the frame rate.
1343  * Most notably, H.264 and MPEG-2 specify time_base as half of frame duration
1344  * if no telecine is used ...
1345  *
1346  * Set to time_base ticks per frame. Default 1, e.g., H.264/MPEG-2 set it to 2.
1347  */
1348  int ticks_per_frame;
1349 
1350  /**
1351  * Codec delay.
1352  *
1353  * Encoding: Number of frames delay there will be from the encoder input to
1354  * the decoder output. (we assume the decoder matches the spec)
1355  * Decoding: Number of frames delay in addition to what a standard decoder
1356  * as specified in the spec would produce.
1357  *
1358  * Video:
1359  * Number of frames the decoded output will be delayed relative to the
1360  * encoded input.
1361  *
1362  * Audio:
1363  * For encoding, this is the number of "priming" samples added by the
1364  * encoder to the beginning of the stream. The decoded output will be
1365  * delayed by this many samples relative to the input to the encoder (or
1366  * more, if the decoder adds its own padding).
1367  * The timestamps on the output packets are adjusted by the encoder so
1368  * that they always refer to the first sample of the data actually
1369  * contained in the packet, including any added padding.
1370  * E.g. if the timebase is 1/samplerate and the timestamp of the first
1371  * input sample is 0, the timestamp of the first output packet will be
1372  * -delay.
1373  *
1374  * For decoding, this is the number of samples the decoder needs to
1375  * output before the decoder's output is valid. When seeking, you should
1376  * start decoding this many samples prior to your desired seek point.
1377  *
1378  * - encoding: Set by libavcodec.
1379  * - decoding: Set by libavcodec.
1380  */
1381  int delay;
1382 
1383 
1384  /* video only */
1385  /**
1386  * picture width / height.
1387  * - encoding: MUST be set by user.
1388  * - decoding: May be set by the user before opening the decoder if known e.g.
1389  * from the container. Some decoders will require the dimensions
1390  * to be set by the caller. During decoding, the decoder may
1391  * overwrite those values as required.
1392  */
1393  int width, height;
1394 
1395  /**
1396  * Bitstream width / height, may be different from width/height e.g. when
1397  * the decoded frame is cropped before being output or lowres is enabled.
1398  * - encoding: unused
1399  * - decoding: May be set by the user before opening the decoder if known
1400  * e.g. from the container. During decoding, the decoder may
1401  * overwrite those values as required.
1402  */
1404 
1405 #if FF_API_ASPECT_EXTENDED
1406 #define FF_ASPECT_EXTENDED 15
1407 #endif
1408 
1409  /**
1410  * the number of pictures in a group of pictures, or 0 for intra_only
1411  * - encoding: Set by user.
1412  * - decoding: unused
1413  */
1414  int gop_size;
1415 
1416  /**
1417  * Pixel format, see AV_PIX_FMT_xxx.
1418  * May be set by the demuxer if known from headers.
1419  * May be overridden by the decoder if it knows better.
1420  * - encoding: Set by user.
1421  * - decoding: Set by user if known, overridden by libavcodec if known
1422  */
1423  enum AVPixelFormat pix_fmt;
1424 
1425  /**
1426  * Motion estimation algorithm used for video coding.
1427  * 1 (zero), 2 (full), 3 (log), 4 (phods), 5 (epzs), 6 (x1), 7 (hex),
1428  * 8 (umh), 9 (iter), 10 (tesa) [7, 8, 10 are x264 specific, 9 is snow specific]
1429  * - encoding: MUST be set by user.
1430  * - decoding: unused
1431  */
1432  int me_method;
1433 
1434  /**
1435  * If non NULL, 'draw_horiz_band' is called by the libavcodec
1436  * decoder to draw a horizontal band. It improves cache usage. Not
1437  * all codecs can do that. You must check the codec capabilities
1438  * beforehand.
1439  * When multithreading is used, it may be called from multiple threads
1440  * at the same time; threads might draw different parts of the same AVFrame,
1441  * or multiple AVFrames, and there is no guarantee that slices will be drawn
1442  * in order.
1443  * The function is also used by hardware acceleration APIs.
1444  * It is called at least once during frame decoding to pass
1445  * the data needed for hardware render.
1446  * In that mode instead of pixel data, AVFrame points to
1447  * a structure specific to the acceleration API. The application
1448  * reads the structure and can change some fields to indicate progress
1449  * or mark state.
1450  * - encoding: unused
1451  * - decoding: Set by user.
1452  * @param height the height of the slice
1453  * @param y the y position of the slice
1454  * @param type 1->top field, 2->bottom field, 3->frame
1455  * @param offset offset into the AVFrame.data from which the slice should be read
1456  */
1457  void (*draw_horiz_band)(struct AVCodecContext *s,
1458  const AVFrame *src, int offset[AV_NUM_DATA_POINTERS],
1459  int y, int type, int height);
1460 
1461  /**
1462  * callback to negotiate the pixelFormat
1463  * @param fmt is the list of formats which are supported by the codec,
1464  * it is terminated by -1 as 0 is a valid format, the formats are ordered by quality.
1465  * The first is always the native one.
1466  * @return the chosen format
1467  * - encoding: unused
1468  * - decoding: Set by user, if not set the native format will be chosen.
1469  */
1470  enum AVPixelFormat (*get_format)(struct AVCodecContext *s, const enum AVPixelFormat * fmt);
1471 
1472  /**
1473  * maximum number of B-frames between non-B-frames
1474  * Note: The output will be delayed by max_b_frames+1 relative to the input.
1475  * - encoding: Set by user.
1476  * - decoding: unused
1477  */
1478  int max_b_frames;
1479 
1480  /**
1481  * qscale factor between IP and B-frames
1482  * If > 0 then the last P-frame quantizer will be used (q= lastp_q*factor+offset).
1483  * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1484  * - encoding: Set by user.
1485  * - decoding: unused
1486  */
1487  float b_quant_factor;
1488 
1489  /** obsolete FIXME remove */
1491 #define FF_RC_STRATEGY_XVID 1
1493  int b_frame_strategy;
1494 
1495  /**
1496  * qscale offset between IP and B-frames
1497  * - encoding: Set by user.
1498  * - decoding: unused
1499  */
1500  float b_quant_offset;
1501 
1502  /**
1503  * Size of the frame reordering buffer in the decoder.
1504  * For MPEG-2 it is 1 IPB or 0 low delay IP.
1505  * - encoding: Set by libavcodec.
1506  * - decoding: Set by libavcodec.
1507  */
1508  int has_b_frames;
1509 
1510  /**
1511  * 0-> h263 quant 1-> mpeg quant
1512  * - encoding: Set by user.
1513  * - decoding: unused
1514  */
1515  int mpeg_quant;
1516 
1517  /**
1518  * qscale factor between P and I-frames
1519  * If > 0 then the last p frame quantizer will be used (q= lastp_q*factor+offset).
1520  * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1521  * - encoding: Set by user.
1522  * - decoding: unused
1523  */
1524  float i_quant_factor;
1525 
1526  /**
1527  * qscale offset between P and I-frames
1528  * - encoding: Set by user.
1529  * - decoding: unused
1530  */
1531  float i_quant_offset;
1532 
1533  /**
1534  * luminance masking (0-> disabled)
1535  * - encoding: Set by user.
1536  * - decoding: unused
1537  */
1538  float lumi_masking;
1539 
1540  /**
1541  * temporary complexity masking (0-> disabled)
1542  * - encoding: Set by user.
1543  * - decoding: unused
1544  */
1545  float temporal_cplx_masking;
1546 
1547  /**
1548  * spatial complexity masking (0-> disabled)
1549  * - encoding: Set by user.
1550  * - decoding: unused
1551  */
1552  float spatial_cplx_masking;
1553 
1554  /**
1555  * p block masking (0-> disabled)
1556  * - encoding: Set by user.
1557  * - decoding: unused
1558  */
1559  float p_masking;
1560 
1561  /**
1562  * darkness masking (0-> disabled)
1563  * - encoding: Set by user.
1564  * - decoding: unused
1565  */
1566  float dark_masking;
1567 
1568  /**
1569  * slice count
1570  * - encoding: Set by libavcodec.
1571  * - decoding: Set by user (or 0).
1572  */
1573  int slice_count;
1574  /**
1575  * prediction method (needed for huffyuv)
1576  * - encoding: Set by user.
1577  * - decoding: unused
1578  */
1580 #define FF_PRED_LEFT 0
1581 #define FF_PRED_PLANE 1
1582 #define FF_PRED_MEDIAN 2
1583 
1584  /**
1585  * slice offsets in the frame in bytes
1586  * - encoding: Set/allocated by libavcodec.
1587  * - decoding: Set/allocated by user (or NULL).
1588  */
1589  int *slice_offset;
1590 
1591  /**
1592  * sample aspect ratio (0 if unknown)
1593  * That is the width of a pixel divided by the height of the pixel.
1594  * Numerator and denominator must be relatively prime and smaller than 256 for some video standards.
1595  * - encoding: Set by user.
1596  * - decoding: Set by libavcodec.
1597  */
1599 
1600  /**
1601  * motion estimation comparison function
1602  * - encoding: Set by user.
1603  * - decoding: unused
1604  */
1605  int me_cmp;
1606  /**
1607  * subpixel motion estimation comparison function
1608  * - encoding: Set by user.
1609  * - decoding: unused
1610  */
1611  int me_sub_cmp;
1612  /**
1613  * macroblock comparison function (not supported yet)
1614  * - encoding: Set by user.
1615  * - decoding: unused
1616  */
1617  int mb_cmp;
1618  /**
1619  * interlaced DCT comparison function
1620  * - encoding: Set by user.
1621  * - decoding: unused
1622  */
1624 #define FF_CMP_SAD 0
1625 #define FF_CMP_SSE 1
1626 #define FF_CMP_SATD 2
1627 #define FF_CMP_DCT 3
1628 #define FF_CMP_PSNR 4
1629 #define FF_CMP_BIT 5
1630 #define FF_CMP_RD 6
1631 #define FF_CMP_ZERO 7
1632 #define FF_CMP_VSAD 8
1633 #define FF_CMP_VSSE 9
1634 #define FF_CMP_NSSE 10
1635 #define FF_CMP_W53 11
1636 #define FF_CMP_W97 12
1637 #define FF_CMP_DCTMAX 13
1638 #define FF_CMP_DCT264 14
1639 #define FF_CMP_CHROMA 256
1640 
1641  /**
1642  * ME diamond size & shape
1643  * - encoding: Set by user.
1644  * - decoding: unused
1645  */
1646  int dia_size;
1647 
1648  /**
1649  * amount of previous MV predictors (2a+1 x 2a+1 square)
1650  * - encoding: Set by user.
1651  * - decoding: unused
1652  */
1654 
1655  /**
1656  * prepass for motion estimation
1657  * - encoding: Set by user.
1658  * - decoding: unused
1659  */
1660  int pre_me;
1661 
1662  /**
1663  * motion estimation prepass comparison function
1664  * - encoding: Set by user.
1665  * - decoding: unused
1666  */
1667  int me_pre_cmp;
1668 
1669  /**
1670  * ME prepass diamond size & shape
1671  * - encoding: Set by user.
1672  * - decoding: unused
1673  */
1674  int pre_dia_size;
1675 
1676  /**
1677  * subpel ME quality
1678  * - encoding: Set by user.
1679  * - decoding: unused
1680  */
1681  int me_subpel_quality;
1682 
1683  /**
1684  * DTG active format information (additional aspect ratio
1685  * information only used in DVB MPEG-2 transport streams)
1686  * 0 if not set.
1687  *
1688  * - encoding: unused
1689  * - decoding: Set by decoder.
1690  */
1692 #define FF_DTG_AFD_SAME 8
1693 #define FF_DTG_AFD_4_3 9
1694 #define FF_DTG_AFD_16_9 10
1695 #define FF_DTG_AFD_14_9 11
1696 #define FF_DTG_AFD_4_3_SP_14_9 13
1697 #define FF_DTG_AFD_16_9_SP_14_9 14
1698 #define FF_DTG_AFD_SP_4_3 15
1699 
1700  /**
1701  * maximum motion estimation search range in subpel units
1702  * If 0 then no limit.
1703  *
1704  * - encoding: Set by user.
1705  * - decoding: unused
1706  */
1707  int me_range;
1708 
1709  /**
1710  * intra quantizer bias
1711  * - encoding: Set by user.
1712  * - decoding: unused
1713  */
1715 #define FF_DEFAULT_QUANT_BIAS 999999
1716 
1717  /**
1718  * inter quantizer bias
1719  * - encoding: Set by user.
1720  * - decoding: unused
1721  */
1722  int inter_quant_bias;
1723 
1724  /**
1725  * slice flags
1726  * - encoding: unused
1727  * - decoding: Set by user.
1728  */
1730 #define SLICE_FLAG_CODED_ORDER 0x0001 ///< draw_horiz_band() is called in coded order instead of display
1731 #define SLICE_FLAG_ALLOW_FIELD 0x0002 ///< allow draw_horiz_band() with field slices (MPEG2 field pics)
1732 #define SLICE_FLAG_ALLOW_PLANE 0x0004 ///< allow draw_horiz_band() with 1 component at a time (SVQ1)
1733 
1734 #if FF_API_XVMC
1735  /**
1736  * XVideo Motion Acceleration
1737  * - encoding: forbidden
1738  * - decoding: set by decoder
1739  * @deprecated XvMC doesn't need it anymore.
1740  */
1741  attribute_deprecated int xvmc_acceleration;
1742 #endif /* FF_API_XVMC */
1743 
1744  /**
1745  * macroblock decision mode
1746  * - encoding: Set by user.
1747  * - decoding: unused
1748  */
1750 #define FF_MB_DECISION_SIMPLE 0 ///< uses mb_cmp
1751 #define FF_MB_DECISION_BITS 1 ///< chooses the one which needs the fewest bits
1752 #define FF_MB_DECISION_RD 2 ///< rate distortion
1753 
1754  /**
1755  * custom intra quantization matrix
1756  * - encoding: Set by user, can be NULL.
1757  * - decoding: Set by libavcodec.
1758  */
1759  uint16_t *intra_matrix;
1760 
1761  /**
1762  * custom inter quantization matrix
1763  * - encoding: Set by user, can be NULL.
1764  * - decoding: Set by libavcodec.
1765  */
1766  uint16_t *inter_matrix;
1767 
1768  /**
1769  * scene change detection threshold
1770  * 0 is default, larger means fewer detected scene changes.
1771  * - encoding: Set by user.
1772  * - decoding: unused
1773  */
1775 
1776  /**
1777  * noise reduction strength
1778  * - encoding: Set by user.
1779  * - decoding: unused
1780  */
1781  int noise_reduction;
1782 
1783  /**
1784  * Motion estimation threshold below which no motion estimation is
1785  * performed, but instead the user specified motion vectors are used.
1786  *
1787  * - encoding: Set by user.
1788  * - decoding: unused
1789  */
1790  int me_threshold;
1791 
1792  /**
1793  * Macroblock threshold below which the user specified macroblock types will be used.
1794  * - encoding: Set by user.
1795  * - decoding: unused
1796  */
1797  int mb_threshold;
1798 
1799  /**
1800  * precision of the intra DC coefficient - 8
1801  * - encoding: Set by user.
1802  * - decoding: unused
1803  */
1804  int intra_dc_precision;
1805 
1806  /**
1807  * Number of macroblock rows at the top which are skipped.
1808  * - encoding: unused
1809  * - decoding: Set by user.
1810  */
1811  int skip_top;
1812 
1813  /**
1814  * Number of macroblock rows at the bottom which are skipped.
1815  * - encoding: unused
1816  * - decoding: Set by user.
1817  */
1818  int skip_bottom;
1819 
1820  /**
1821  * Border processing masking, raises the quantizer for mbs on the borders
1822  * of the picture.
1823  * - encoding: Set by user.
1824  * - decoding: unused
1825  */
1826  float border_masking;
1827 
1828  /**
1829  * minimum MB lagrange multipler
1830  * - encoding: Set by user.
1831  * - decoding: unused
1832  */
1833  int mb_lmin;
1834 
1835  /**
1836  * maximum MB lagrange multipler
1837  * - encoding: Set by user.
1838  * - decoding: unused
1839  */
1840  int mb_lmax;
1841 
1842  /**
1843  *
1844  * - encoding: Set by user.
1845  * - decoding: unused
1846  */
1848 
1849  /**
1850  *
1851  * - encoding: Set by user.
1852  * - decoding: unused
1853  */
1854  int bidir_refine;
1855 
1856  /**
1857  *
1858  * - encoding: Set by user.
1859  * - decoding: unused
1860  */
1861  int brd_scale;
1862 
1863  /**
1864  * minimum GOP size
1865  * - encoding: Set by user.
1866  * - decoding: unused
1867  */
1868  int keyint_min;
1869 
1870  /**
1871  * number of reference frames
1872  * - encoding: Set by user.
1873  * - decoding: Set by lavc.
1874  */
1875  int refs;
1876 
1877  /**
1878  * chroma qp offset from luma
1879  * - encoding: Set by user.
1880  * - decoding: unused
1881  */
1882  int chromaoffset;
1883 
1884  /**
1885  * Multiplied by qscale for each frame and added to scene_change_score.
1886  * - encoding: Set by user.
1887  * - decoding: unused
1888  */
1889  int scenechange_factor;
1890 
1891  /**
1892  *
1893  * Note: Value depends upon the compare function used for fullpel ME.
1894  * - encoding: Set by user.
1895  * - decoding: unused
1896  */
1897  int mv0_threshold;
1898 
1899  /**
1900  * Adjust sensitivity of b_frame_strategy 1.
1901  * - encoding: Set by user.
1902  * - decoding: unused
1903  */
1904  int b_sensitivity;
1905 
1906  /**
1907  * Chromaticity coordinates of the source primaries.
1908  * - encoding: Set by user
1909  * - decoding: Set by libavcodec
1910  */
1912 
1913  /**
1914  * Color Transfer Characteristic.
1915  * - encoding: Set by user
1916  * - decoding: Set by libavcodec
1917  */
1919 
1920  /**
1921  * YUV colorspace type.
1922  * - encoding: Set by user
1923  * - decoding: Set by libavcodec
1924  */
1925  enum AVColorSpace colorspace;
1926 
1927  /**
1928  * MPEG vs JPEG YUV range.
1929  * - encoding: Set by user
1930  * - decoding: Set by libavcodec
1931  */
1933 
1934  /**
1935  * This defines the location of chroma samples.
1936  * - encoding: Set by user
1937  * - decoding: Set by libavcodec
1938  */
1940 
1941  /**
1942  * Number of slices.
1943  * Indicates number of picture subdivisions. Used for parallelized
1944  * decoding.
1945  * - encoding: Set by user
1946  * - decoding: unused
1947  */
1948  int slices;
1949 
1950  /** Field order
1951  * - encoding: set by libavcodec
1952  * - decoding: Set by user.
1953  */
1955 
1956  /* audio only */
1957  int sample_rate; ///< samples per second
1958  int channels; ///< number of audio channels
1959 
1960  /**
1961  * audio sample format
1962  * - encoding: Set by user.
1963  * - decoding: Set by libavcodec.
1964  */
1965  enum AVSampleFormat sample_fmt; ///< sample format
1966 
1967  /* The following data should not be initialized. */
1968  /**
1969  * Number of samples per channel in an audio frame.
1970  *
1971  * - encoding: set by libavcodec in avcodec_open2(). Each submitted frame
1972  * except the last must contain exactly frame_size samples per channel.
1973  * May be 0 when the codec has CODEC_CAP_VARIABLE_FRAME_SIZE set, then the
1974  * frame size is not restricted.
1975  * - decoding: may be set by some decoders to indicate constant frame size
1976  */
1977  int frame_size;
1978 
1979  /**
1980  * Frame counter, set by libavcodec.
1981  *
1982  * - decoding: total number of frames returned from the decoder so far.
1983  * - encoding: total number of frames passed to the encoder so far.
1984  *
1985  * @note the counter is not incremented if encoding/decoding resulted in
1986  * an error.
1987  */
1988  int frame_number;
1989 
1990  /**
1991  * number of bytes per packet if constant and known or 0
1992  * Used by some WAV based audio codecs.
1993  */
1994  int block_align;
1995 
1996  /**
1997  * Audio cutoff bandwidth (0 means "automatic")
1998  * - encoding: Set by user.
1999  * - decoding: unused
2000  */
2001  int cutoff;
2002 
2003 #if FF_API_REQUEST_CHANNELS
2004  /**
2005  * Decoder should decode to this many channels if it can (0 for default)
2006  * - encoding: unused
2007  * - decoding: Set by user.
2008  * @deprecated Deprecated in favor of request_channel_layout.
2009  */
2011 #endif
2012 
2013  /**
2014  * Audio channel layout.
2015  * - encoding: set by user.
2016  * - decoding: set by user, may be overwritten by libavcodec.
2017  */
2018  uint64_t channel_layout;
2019 
2020  /**
2021  * Request decoder to use this channel layout if it can (0 for default)
2022  * - encoding: unused
2023  * - decoding: Set by user.
2024  */
2025  uint64_t request_channel_layout;
2026 
2027  /**
2028  * Type of service that the audio stream conveys.
2029  * - encoding: Set by user.
2030  * - decoding: Set by libavcodec.
2031  */
2033 
2034  /**
2035  * desired sample format
2036  * - encoding: Not used.
2037  * - decoding: Set by user.
2038  * Decoder will decode to this format if it can.
2039  */
2041 
2042 #if FF_API_GET_BUFFER
2043  /**
2044  * Called at the beginning of each frame to get a buffer for it.
2045  *
2046  * The function will set AVFrame.data[], AVFrame.linesize[].
2047  * AVFrame.extended_data[] must also be set, but it should be the same as
2048  * AVFrame.data[] except for planar audio with more channels than can fit
2049  * in AVFrame.data[]. In that case, AVFrame.data[] shall still contain as
2050  * many data pointers as it can hold.
2051  *
2052  * if CODEC_CAP_DR1 is not set then get_buffer() must call
2053  * avcodec_default_get_buffer() instead of providing buffers allocated by
2054  * some other means.
2055  *
2056  * AVFrame.data[] should be 32- or 16-byte-aligned unless the CPU doesn't
2057  * need it. avcodec_default_get_buffer() aligns the output buffer properly,
2058  * but if get_buffer() is overridden then alignment considerations should
2059  * be taken into account.
2060  *
2061  * @see avcodec_default_get_buffer()
2062  *
2063  * Video:
2064  *
2065  * If pic.reference is set then the frame will be read later by libavcodec.
2066  * avcodec_align_dimensions2() should be used to find the required width and
2067  * height, as they normally need to be rounded up to the next multiple of 16.
2068  *
2069  * If frame multithreading is used and thread_safe_callbacks is set,
2070  * it may be called from a different thread, but not from more than one at
2071  * once. Does not need to be reentrant.
2072  *
2073  * @see release_buffer(), reget_buffer()
2074  * @see avcodec_align_dimensions2()
2075  *
2076  * Audio:
2077  *
2078  * Decoders request a buffer of a particular size by setting
2079  * AVFrame.nb_samples prior to calling get_buffer(). The decoder may,
2080  * however, utilize only part of the buffer by setting AVFrame.nb_samples
2081  * to a smaller value in the output frame.
2082  *
2083  * Decoders cannot use the buffer after returning from
2084  * avcodec_decode_audio4(), so they will not call release_buffer(), as it
2085  * is assumed to be released immediately upon return. In some rare cases,
2086  * a decoder may need to call get_buffer() more than once in a single
2087  * call to avcodec_decode_audio4(). In that case, when get_buffer() is
2088  * called again after it has already been called once, the previously
2089  * acquired buffer is assumed to be released at that time and may not be
2090  * reused by the decoder.
2091  *
2092  * As a convenience, av_samples_get_buffer_size() and
2093  * av_samples_fill_arrays() in libavutil may be used by custom get_buffer()
2094  * functions to find the required data size and to fill data pointers and
2095  * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
2096  * since all planes must be the same size.
2097  *
2098  * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
2099  *
2100  * - encoding: unused
2101  * - decoding: Set by libavcodec, user can override.
2102  *
2103  * @deprecated use get_buffer2()
2104  */
2106  int (*get_buffer)(struct AVCodecContext *c, AVFrame *pic);
2107 
2108  /**
2109  * Called to release buffers which were allocated with get_buffer.
2110  * A released buffer can be reused in get_buffer().
2111  * pic.data[*] must be set to NULL.
2112  * May be called from a different thread if frame multithreading is used,
2113  * but not by more than one thread at once, so does not need to be reentrant.
2114  * - encoding: unused
2115  * - decoding: Set by libavcodec, user can override.
2116  *
2117  * @deprecated custom freeing callbacks should be set from get_buffer2()
2118  */
2120  void (*release_buffer)(struct AVCodecContext *c, AVFrame *pic);
2121 
2122  /**
2123  * Called at the beginning of a frame to get cr buffer for it.
2124  * Buffer type (size, hints) must be the same. libavcodec won't check it.
2125  * libavcodec will pass previous buffer in pic, function should return
2126  * same buffer or new buffer with old frame "painted" into it.
2127  * If pic.data[0] == NULL must behave like get_buffer().
2128  * if CODEC_CAP_DR1 is not set then reget_buffer() must call
2129  * avcodec_default_reget_buffer() instead of providing buffers allocated by
2130  * some other means.
2131  * - encoding: unused
2132  * - decoding: Set by libavcodec, user can override.
2133  */
2135  int (*reget_buffer)(struct AVCodecContext *c, AVFrame *pic);
2136 #endif
2137 
2138  /**
2139  * This callback is called at the beginning of each frame to get data
2140  * buffer(s) for it. There may be one contiguous buffer for all the data or
2141  * there may be a buffer per each data plane or anything in between. What
2142  * this means is, you may set however many entries in buf[] you feel necessary.
2143  * Each buffer must be reference-counted using the AVBuffer API (see description
2144  * of buf[] below).
2145  *
2146  * The following fields will be set in the frame before this callback is
2147  * called:
2148  * - format
2149  * - width, height (video only)
2150  * - sample_rate, channel_layout, nb_samples (audio only)
2151  * Their values may differ from the corresponding values in
2152  * AVCodecContext. This callback must use the frame values, not the codec
2153  * context values, to calculate the required buffer size.
2154  *
2155  * This callback must fill the following fields in the frame:
2156  * - data[]
2157  * - linesize[]
2158  * - extended_data:
2159  * * if the data is planar audio with more than 8 channels, then this
2160  * callback must allocate and fill extended_data to contain all pointers
2161  * to all data planes. data[] must hold as many pointers as it can.
2162  * extended_data must be allocated with av_malloc() and will be freed in
2163  * av_frame_unref().
2164  * * otherwise exended_data must point to data
2165  * - buf[] must contain one or more pointers to AVBufferRef structures. Each of
2166  * the frame's data and extended_data pointers must be contained in these. That
2167  * is, one AVBufferRef for each allocated chunk of memory, not necessarily one
2168  * AVBufferRef per data[] entry. See: av_buffer_create(), av_buffer_alloc(),
2169  * and av_buffer_ref().
2170  * - extended_buf and nb_extended_buf must be allocated with av_malloc() by
2171  * this callback and filled with the extra buffers if there are more
2172  * buffers than buf[] can hold. extended_buf will be freed in
2173  * av_frame_unref().
2174  *
2175  * If CODEC_CAP_DR1 is not set then get_buffer2() must call
2176  * avcodec_default_get_buffer2() instead of providing buffers allocated by
2177  * some other means.
2178  *
2179  * Each data plane must be aligned to the maximum required by the target
2180  * CPU.
2181  *
2182  * @see avcodec_default_get_buffer2()
2183  *
2184  * Video:
2185  *
2186  * If AV_GET_BUFFER_FLAG_REF is set in flags then the frame may be reused
2187  * (read and/or written to if it is writable) later by libavcodec.
2188  *
2189  * avcodec_align_dimensions2() should be used to find the required width and
2190  * height, as they normally need to be rounded up to the next multiple of 16.
2191  *
2192  * Some decoders do not support linesizes changing between frames.
2193  *
2194  * If frame multithreading is used and thread_safe_callbacks is set,
2195  * this callback may be called from a different thread, but not from more
2196  * than one at once. Does not need to be reentrant.
2197  *
2198  * @see avcodec_align_dimensions2()
2199  *
2200  * Audio:
2201  *
2202  * Decoders request a buffer of a particular size by setting
2203  * AVFrame.nb_samples prior to calling get_buffer2(). The decoder may,
2204  * however, utilize only part of the buffer by setting AVFrame.nb_samples
2205  * to a smaller value in the output frame.
2206  *
2207  * As a convenience, av_samples_get_buffer_size() and
2208  * av_samples_fill_arrays() in libavutil may be used by custom get_buffer2()
2209  * functions to find the required data size and to fill data pointers and
2210  * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
2211  * since all planes must be the same size.
2212  *
2213  * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
2214  *
2215  * - encoding: unused
2216  * - decoding: Set by libavcodec, user can override.
2217  */
2218  int (*get_buffer2)(struct AVCodecContext *s, AVFrame *frame, int flags);
2219 
2220  /**
2221  * If non-zero, the decoded audio and video frames returned from
2222  * avcodec_decode_video2() and avcodec_decode_audio4() are reference-counted
2223  * and are valid indefinitely. The caller must free them with
2224  * av_frame_unref() when they are not needed anymore.
2225  * Otherwise, the decoded frames must not be freed by the caller and are
2226  * only valid until the next decode call.
2227  *
2228  * - encoding: unused
2229  * - decoding: set by the caller before avcodec_open2().
2230  */
2231  int refcounted_frames;
2232 
2233  /* - encoding parameters */
2234  float qcompress; ///< amount of qscale change between easy & hard scenes (0.0-1.0)
2235  float qblur; ///< amount of qscale smoothing over time (0.0-1.0)
2236 
2237  /**
2238  * minimum quantizer
2239  * - encoding: Set by user.
2240  * - decoding: unused
2241  */
2242  int qmin;
2243 
2244  /**
2245  * maximum quantizer
2246  * - encoding: Set by user.
2247  * - decoding: unused
2248  */
2249  int qmax;
2250 
2251  /**
2252  * maximum quantizer difference between frames
2253  * - encoding: Set by user.
2254  * - decoding: unused
2255  */
2256  int max_qdiff;
2257 
2258  /**
2259  * ratecontrol qmin qmax limiting method
2260  * 0-> clipping, 1-> use a nice continuous function to limit qscale within qmin/qmax.
2261  * - encoding: Set by user.
2262  * - decoding: unused
2263  */
2264  float rc_qsquish;
2267  int rc_qmod_freq;
2268 
2269  /**
2270  * decoder bitstream buffer size
2271  * - encoding: Set by user.
2272  * - decoding: unused
2273  */
2274  int rc_buffer_size;
2275 
2276  /**
2277  * ratecontrol override, see RcOverride
2278  * - encoding: Allocated/set/freed by user.
2279  * - decoding: unused
2280  */
2283 
2284  /**
2285  * rate control equation
2286  * - encoding: Set by user
2287  * - decoding: unused
2288  */
2289  const char *rc_eq;
2290 
2291  /**
2292  * maximum bitrate
2293  * - encoding: Set by user.
2294  * - decoding: Set by libavcodec.
2295  */
2296  int rc_max_rate;
2297 
2298  /**
2299  * minimum bitrate
2300  * - encoding: Set by user.
2301  * - decoding: unused
2302  */
2303  int rc_min_rate;
2305  float rc_buffer_aggressivity;
2306 
2307  /**
2308  * initial complexity for pass1 ratecontrol
2309  * - encoding: Set by user.
2310  * - decoding: unused
2311  */
2312  float rc_initial_cplx;
2313 
2314  /**
2315  * Ratecontrol attempt to use, at maximum, <value> of what can be used without an underflow.
2316  * - encoding: Set by user.
2317  * - decoding: unused.
2318  */
2320 
2321  /**
2322  * Ratecontrol attempt to use, at least, <value> times the amount needed to prevent a vbv overflow.
2323  * - encoding: Set by user.
2324  * - decoding: unused.
2325  */
2327 
2328  /**
2329  * Number of bits which should be loaded into the rc buffer before decoding starts.
2330  * - encoding: Set by user.
2331  * - decoding: unused
2332  */
2335 #define FF_CODER_TYPE_VLC 0
2336 #define FF_CODER_TYPE_AC 1
2337 #define FF_CODER_TYPE_RAW 2
2338 #define FF_CODER_TYPE_RLE 3
2339 #define FF_CODER_TYPE_DEFLATE 4
2340  /**
2341  * coder type
2342  * - encoding: Set by user.
2343  * - decoding: unused
2344  */
2345  int coder_type;
2346 
2347  /**
2348  * context model
2349  * - encoding: Set by user.
2350  * - decoding: unused
2351  */
2352  int context_model;
2353 
2354  /**
2355  * minimum Lagrange multiplier
2356  * - encoding: Set by user.
2357  * - decoding: unused
2358  */
2359  int lmin;
2360 
2361  /**
2362  * maximum Lagrange multiplier
2363  * - encoding: Set by user.
2364  * - decoding: unused
2365  */
2366  int lmax;
2367 
2368  /**
2369  * frame skip threshold
2370  * - encoding: Set by user.
2371  * - decoding: unused
2372  */
2374 
2375  /**
2376  * frame skip factor
2377  * - encoding: Set by user.
2378  * - decoding: unused
2379  */
2380  int frame_skip_factor;
2381 
2382  /**
2383  * frame skip exponent
2384  * - encoding: Set by user.
2385  * - decoding: unused
2386  */
2387  int frame_skip_exp;
2388 
2389  /**
2390  * frame skip comparison function
2391  * - encoding: Set by user.
2392  * - decoding: unused
2393  */
2394  int frame_skip_cmp;
2395 
2396  /**
2397  * trellis RD quantization
2398  * - encoding: Set by user.
2399  * - decoding: unused
2400  */
2401  int trellis;
2402 
2403  /**
2404  * - encoding: Set by user.
2405  * - decoding: unused
2406  */
2408 
2409  /**
2410  * - encoding: Set by user.
2411  * - decoding: unused
2412  */
2414 
2415  /**
2416  * GOP timecode frame start number
2417  * - encoding: Set by user, in non drop frame format
2418  * - decoding: Set by libavcodec (timecode in the 25 bits format, -1 if unset)
2419  */
2420  int64_t timecode_frame_start;
2421 
2422  /* The RTP callback: This function is called */
2423  /* every time the encoder has a packet to send. */
2424  /* It depends on the encoder if the data starts */
2425  /* with a Start Code (it should). H.263 does. */
2426  /* mb_nb contains the number of macroblocks */
2427  /* encoded in the RTP payload. */
2428  void (*rtp_callback)(struct AVCodecContext *avctx, void *data, int size, int mb_nb);
2430  int rtp_payload_size; /* The size of the RTP payload: the coder will */
2431  /* do its best to deliver a chunk with size */
2432  /* below rtp_payload_size, the chunk will start */
2433  /* with a start code on some codecs like H.263. */
2434  /* This doesn't take account of any particular */
2435  /* headers inside the transmitted RTP payload. */
2436 
2437  /* statistics, used for 2-pass encoding */
2438  int mv_bits;
2442  int i_count;
2443  int p_count;
2445  int misc_bits;
2446 
2447  /**
2448  * number of bits used for the previously encoded frame
2449  * - encoding: Set by libavcodec.
2450  * - decoding: unused
2451  */
2452  int frame_bits;
2453 
2454  /**
2455  * pass1 encoding statistics output buffer
2456  * - encoding: Set by libavcodec.
2457  * - decoding: unused
2458  */
2459  char *stats_out;
2460 
2461  /**
2462  * pass2 encoding statistics input buffer
2463  * Concatenated stuff from stats_out of pass1 should be placed here.
2464  * - encoding: Allocated/set/freed by user.
2465  * - decoding: unused
2466  */
2467  char *stats_in;
2468 
2469  /**
2470  * Work around bugs in encoders which sometimes cannot be detected automatically.
2471  * - encoding: Set by user
2472  * - decoding: Set by user
2473  */
2475 #define FF_BUG_AUTODETECT 1 ///< autodetection
2476 #if FF_API_OLD_MSMPEG4
2477 #define FF_BUG_OLD_MSMPEG4 2
2478 #endif
2479 #define FF_BUG_XVID_ILACE 4
2480 #define FF_BUG_UMP4 8
2481 #define FF_BUG_NO_PADDING 16
2482 #define FF_BUG_AMV 32
2483 #if FF_API_AC_VLC
2484 #define FF_BUG_AC_VLC 0 ///< Will be removed, libavcodec can now handle these non-compliant files by default.
2485 #endif
2486 #define FF_BUG_QPEL_CHROMA 64
2487 #define FF_BUG_STD_QPEL 128
2488 #define FF_BUG_QPEL_CHROMA2 256
2489 #define FF_BUG_DIRECT_BLOCKSIZE 512
2490 #define FF_BUG_EDGE 1024
2491 #define FF_BUG_HPEL_CHROMA 2048
2492 #define FF_BUG_DC_CLIP 4096
2493 #define FF_BUG_MS 8192 ///< Work around various bugs in Microsoft's broken decoders.
2494 #define FF_BUG_TRUNCATED 16384
2495 
2496  /**
2497  * strictly follow the standard (MPEG4, ...).
2498  * - encoding: Set by user.
2499  * - decoding: Set by user.
2500  * Setting this to STRICT or higher means the encoder and decoder will
2501  * generally do stupid things, whereas setting it to unofficial or lower
2502  * will mean the encoder might produce output that is not supported by all
2503  * spec-compliant decoders. Decoders don't differentiate between normal,
2504  * unofficial and experimental (that is, they always try to decode things
2505  * when they can) unless they are explicitly asked to behave stupidly
2506  * (=strictly conform to the specs)
2507  */
2509 #define FF_COMPLIANCE_VERY_STRICT 2 ///< Strictly conform to an older more strict version of the spec or reference software.
2510 #define FF_COMPLIANCE_STRICT 1 ///< Strictly conform to all the things in the spec no matter what consequences.
2511 #define FF_COMPLIANCE_NORMAL 0
2512 #define FF_COMPLIANCE_UNOFFICIAL -1 ///< Allow unofficial extensions
2513 #define FF_COMPLIANCE_EXPERIMENTAL -2 ///< Allow nonstandardized experimental things.
2514 
2515  /**
2516  * error concealment flags
2517  * - encoding: unused
2518  * - decoding: Set by user.
2519  */
2521 #define FF_EC_GUESS_MVS 1
2522 #define FF_EC_DEBLOCK 2
2523 #define FF_EC_FAVOR_INTER 256
2524 
2525  /**
2526  * debug
2527  * - encoding: Set by user.
2528  * - decoding: Set by user.
2529  */
2530  int debug;
2531 #define FF_DEBUG_PICT_INFO 1
2532 #define FF_DEBUG_RC 2
2533 #define FF_DEBUG_BITSTREAM 4
2534 #define FF_DEBUG_MB_TYPE 8
2535 #define FF_DEBUG_QP 16
2536 #if FF_API_DEBUG_MV
2537 /**
2538  * @deprecated this option does nothing
2539  */
2540 #define FF_DEBUG_MV 32
2541 #endif
2542 #define FF_DEBUG_DCT_COEFF 0x00000040
2543 #define FF_DEBUG_SKIP 0x00000080
2544 #define FF_DEBUG_STARTCODE 0x00000100
2545 #define FF_DEBUG_PTS 0x00000200
2546 #define FF_DEBUG_ER 0x00000400
2547 #define FF_DEBUG_MMCO 0x00000800
2548 #define FF_DEBUG_BUGS 0x00001000
2549 #if FF_API_DEBUG_MV
2550 #define FF_DEBUG_VIS_QP 0x00002000 ///< only access through AVOptions from outside libavcodec
2551 #define FF_DEBUG_VIS_MB_TYPE 0x00004000 ///< only access through AVOptions from outside libavcodec
2552 #endif
2553 #define FF_DEBUG_BUFFERS 0x00008000
2554 #define FF_DEBUG_THREADS 0x00010000
2555 #define FF_DEBUG_NOMC 0x01000000
2556 
2557 #if FF_API_DEBUG_MV
2558  /**
2559  * debug
2560  * Code outside libavcodec should access this field using AVOptions
2561  * - encoding: Set by user.
2562  * - decoding: Set by user.
2563  */
2565 #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 //visualize forward predicted MVs of P frames
2566 #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 //visualize forward predicted MVs of B frames
2567 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
2568 #endif
2569 
2570  /**
2571  * Error recognition; may misdetect some more or less valid parts as errors.
2572  * - encoding: unused
2573  * - decoding: Set by user.
2574  */
2575  int err_recognition;
2576 
2577 /**
2578  * Verify checksums embedded in the bitstream (could be of either encoded or
2579  * decoded data, depending on the codec) and print an error message on mismatch.
2580  * If AV_EF_EXPLODE is also set, a mismatching checksum will result in the
2581  * decoder returning an error.
2582  */
2583 #define AV_EF_CRCCHECK (1<<0)
2584 #define AV_EF_BITSTREAM (1<<1) ///< detect bitstream specification deviations
2585 #define AV_EF_BUFFER (1<<2) ///< detect improper bitstream length
2586 #define AV_EF_EXPLODE (1<<3) ///< abort decoding on minor error detection
2588 #define AV_EF_IGNORE_ERR (1<<15) ///< ignore errors and continue
2589 #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
2590 #define AV_EF_COMPLIANT (1<<17) ///< consider all spec non compliances as errors
2591 #define AV_EF_AGGRESSIVE (1<<18) ///< consider things that a sane encoder should not do as an error
2592 
2593 
2594  /**
2595  * opaque 64bit number (generally a PTS) that will be reordered and
2596  * output in AVFrame.reordered_opaque
2597  * @deprecated in favor of pkt_pts
2598  * - encoding: unused
2599  * - decoding: Set by user.
2600  */
2601  int64_t reordered_opaque;
2602 
2603  /**
2604  * Hardware accelerator in use
2605  * - encoding: unused.
2606  * - decoding: Set by libavcodec
2607  */
2608  struct AVHWAccel *hwaccel;
2609 
2610  /**
2611  * Hardware accelerator context.
2612  * For some hardware accelerators, a global context needs to be
2613  * provided by the user. In that case, this holds display-dependent
2614  * data FFmpeg cannot instantiate itself. Please refer to the
2615  * FFmpeg HW accelerator documentation to know how to fill this
2616  * is. e.g. for VA API, this is a struct vaapi_context.
2617  * - encoding: unused
2618  * - decoding: Set by user
2619  */
2620  void *hwaccel_context;
2621 
2622  /**
2623  * error
2624  * - encoding: Set by libavcodec if flags&CODEC_FLAG_PSNR.
2625  * - decoding: unused
2626  */
2627  uint64_t error[AV_NUM_DATA_POINTERS];
2628 
2629  /**
2630  * DCT algorithm, see FF_DCT_* below
2631  * - encoding: Set by user.
2632  * - decoding: unused
2633  */
2635 #define FF_DCT_AUTO 0
2636 #define FF_DCT_FASTINT 1
2637 #define FF_DCT_INT 2
2638 #define FF_DCT_MMX 3
2639 #define FF_DCT_ALTIVEC 5
2640 #define FF_DCT_FAAN 6
2641 
2642  /**
2643  * IDCT algorithm, see FF_IDCT_* below.
2644  * - encoding: Set by user.
2645  * - decoding: Set by user.
2646  */
2648 #define FF_IDCT_AUTO 0
2649 #define FF_IDCT_INT 1
2650 #define FF_IDCT_SIMPLE 2
2651 #define FF_IDCT_SIMPLEMMX 3
2652 #define FF_IDCT_ARM 7
2653 #define FF_IDCT_ALTIVEC 8
2654 #if FF_API_ARCH_SH4
2655 #define FF_IDCT_SH4 9
2656 #endif
2657 #define FF_IDCT_SIMPLEARM 10
2658 #define FF_IDCT_IPP 13
2659 #define FF_IDCT_XVIDMMX 14
2660 #define FF_IDCT_SIMPLEARMV5TE 16
2661 #define FF_IDCT_SIMPLEARMV6 17
2662 #if FF_API_ARCH_SPARC
2663 #define FF_IDCT_SIMPLEVIS 18
2664 #endif
2665 #define FF_IDCT_FAAN 20
2666 #define FF_IDCT_SIMPLENEON 22
2667 #if FF_API_ARCH_ALPHA
2668 #define FF_IDCT_SIMPLEALPHA 23
2669 #endif
2670 #define FF_IDCT_SIMPLEAUTO 128
2671 
2672  /**
2673  * bits per sample/pixel from the demuxer (needed for huffyuv).
2674  * - encoding: Set by libavcodec.
2675  * - decoding: Set by user.
2676  */
2678 
2679  /**
2680  * Bits per sample/pixel of internal libavcodec pixel/sample format.
2681  * - encoding: set by user.
2682  * - decoding: set by libavcodec.
2683  */
2684  int bits_per_raw_sample;
2685 
2686 #if FF_API_LOWRES
2687  /**
2688  * low resolution decoding, 1-> 1/2 size, 2->1/4 size
2689  * - encoding: unused
2690  * - decoding: Set by user.
2691  * Code outside libavcodec should access this field using:
2692  * av_codec_{get,set}_lowres(avctx)
2693  */
2694  int lowres;
2695 #endif
2696 
2697  /**
2698  * the picture in the bitstream
2699  * - encoding: Set by libavcodec.
2700  * - decoding: unused
2701  */
2703 
2704  /**
2705  * thread count
2706  * is used to decide how many independent tasks should be passed to execute()
2707  * - encoding: Set by user.
2708  * - decoding: Set by user.
2709  */
2710  int thread_count;
2711 
2712  /**
2713  * Which multithreading methods to use.
2714  * Use of FF_THREAD_FRAME will increase decoding delay by one frame per thread,
2715  * so clients which cannot provide future frames should not use it.
2716  *
2717  * - encoding: Set by user, otherwise the default is used.
2718  * - decoding: Set by user, otherwise the default is used.
2719  */
2721 #define FF_THREAD_FRAME 1 ///< Decode more than one frame at once
2722 #define FF_THREAD_SLICE 2 ///< Decode more than one part of a single frame at once
2723 
2724  /**
2725  * Which multithreading methods are in use by the codec.
2726  * - encoding: Set by libavcodec.
2727  * - decoding: Set by libavcodec.
2728  */
2729  int active_thread_type;
2730 
2731  /**
2732  * Set by the client if its custom get_buffer() callback can be called
2733  * synchronously from another thread, which allows faster multithreaded decoding.
2734  * draw_horiz_band() will be called from other threads regardless of this setting.
2735  * Ignored if the default get_buffer() is used.
2736  * - encoding: Set by user.
2737  * - decoding: Set by user.
2738  */
2740 
2741  /**
2742  * The codec may call this to execute several independent things.
2743  * It will return only after finishing all tasks.
2744  * The user may replace this with some multithreaded implementation,
2745  * the default implementation will execute the parts serially.
2746  * @param count the number of things to execute
2747  * - encoding: Set by libavcodec, user can override.
2748  * - decoding: Set by libavcodec, user can override.
2749  */
2750  int (*execute)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size);
2751 
2752  /**
2753  * The codec may call this to execute several independent things.
2754  * It will return only after finishing all tasks.
2755  * The user may replace this with some multithreaded implementation,
2756  * the default implementation will execute the parts serially.
2757  * Also see avcodec_thread_init and e.g. the --enable-pthread configure option.
2758  * @param c context passed also to func
2759  * @param count the number of things to execute
2760  * @param arg2 argument passed unchanged to func
2761  * @param ret return values of executed functions, must have space for "count" values. May be NULL.
2762  * @param func function that will be called count times, with jobnr from 0 to count-1.
2763  * threadnr will be in the range 0 to c->thread_count-1 < MAX_THREADS and so that no
2764  * two instances of func executing at the same time will have the same threadnr.
2765  * @return always 0 currently, but code should handle a future improvement where when any call to func
2766  * returns < 0 no further calls to func may be done and < 0 is returned.
2767  * - encoding: Set by libavcodec, user can override.
2768  * - decoding: Set by libavcodec, user can override.
2769  */
2770  int (*execute2)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count);
2771 
2772 #if FF_API_THREAD_OPAQUE
2773  /**
2774  * @deprecated this field should not be used from outside of lavc
2775  */
2777  void *thread_opaque;
2778 #endif
2779 
2780  /**
2781  * noise vs. sse weight for the nsse comparison function
2782  * - encoding: Set by user.
2783  * - decoding: unused
2784  */
2785  int nsse_weight;
2786 
2787  /**
2788  * profile
2789  * - encoding: Set by user.
2790  * - decoding: Set by libavcodec.
2791  */
2792  int profile;
2793 #define FF_PROFILE_UNKNOWN -99
2794 #define FF_PROFILE_RESERVED -100
2796 #define FF_PROFILE_AAC_MAIN 0
2797 #define FF_PROFILE_AAC_LOW 1
2798 #define FF_PROFILE_AAC_SSR 2
2799 #define FF_PROFILE_AAC_LTP 3
2800 #define FF_PROFILE_AAC_HE 4
2801 #define FF_PROFILE_AAC_HE_V2 28
2802 #define FF_PROFILE_AAC_LD 22
2803 #define FF_PROFILE_AAC_ELD 38
2804 #define FF_PROFILE_MPEG2_AAC_LOW 128
2805 #define FF_PROFILE_MPEG2_AAC_HE 131
2807 #define FF_PROFILE_DTS 20
2808 #define FF_PROFILE_DTS_ES 30
2809 #define FF_PROFILE_DTS_96_24 40
2810 #define FF_PROFILE_DTS_HD_HRA 50
2811 #define FF_PROFILE_DTS_HD_MA 60
2813 #define FF_PROFILE_MPEG2_422 0
2814 #define FF_PROFILE_MPEG2_HIGH 1
2815 #define FF_PROFILE_MPEG2_SS 2
2816 #define FF_PROFILE_MPEG2_SNR_SCALABLE 3
2817 #define FF_PROFILE_MPEG2_MAIN 4
2818 #define FF_PROFILE_MPEG2_SIMPLE 5
2820 #define FF_PROFILE_H264_CONSTRAINED (1<<9) // 8+1; constraint_set1_flag
2821 #define FF_PROFILE_H264_INTRA (1<<11) // 8+3; constraint_set3_flag
2823 #define FF_PROFILE_H264_BASELINE 66
2824 #define FF_PROFILE_H264_CONSTRAINED_BASELINE (66|FF_PROFILE_H264_CONSTRAINED)
2825 #define FF_PROFILE_H264_MAIN 77
2826 #define FF_PROFILE_H264_EXTENDED 88
2827 #define FF_PROFILE_H264_HIGH 100
2828 #define FF_PROFILE_H264_HIGH_10 110
2829 #define FF_PROFILE_H264_HIGH_10_INTRA (110|FF_PROFILE_H264_INTRA)
2830 #define FF_PROFILE_H264_HIGH_422 122
2831 #define FF_PROFILE_H264_HIGH_422_INTRA (122|FF_PROFILE_H264_INTRA)
2832 #define FF_PROFILE_H264_HIGH_444 144
2833 #define FF_PROFILE_H264_HIGH_444_PREDICTIVE 244
2834 #define FF_PROFILE_H264_HIGH_444_INTRA (244|FF_PROFILE_H264_INTRA)
2835 #define FF_PROFILE_H264_CAVLC_444 44
2837 #define FF_PROFILE_VC1_SIMPLE 0
2838 #define FF_PROFILE_VC1_MAIN 1
2839 #define FF_PROFILE_VC1_COMPLEX 2
2840 #define FF_PROFILE_VC1_ADVANCED 3
2842 #define FF_PROFILE_MPEG4_SIMPLE 0
2843 #define FF_PROFILE_MPEG4_SIMPLE_SCALABLE 1
2844 #define FF_PROFILE_MPEG4_CORE 2
2845 #define FF_PROFILE_MPEG4_MAIN 3
2846 #define FF_PROFILE_MPEG4_N_BIT 4
2847 #define FF_PROFILE_MPEG4_SCALABLE_TEXTURE 5
2848 #define FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION 6
2849 #define FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE 7
2850 #define FF_PROFILE_MPEG4_HYBRID 8
2851 #define FF_PROFILE_MPEG4_ADVANCED_REAL_TIME 9
2852 #define FF_PROFILE_MPEG4_CORE_SCALABLE 10
2853 #define FF_PROFILE_MPEG4_ADVANCED_CODING 11
2854 #define FF_PROFILE_MPEG4_ADVANCED_CORE 12
2855 #define FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE 13
2856 #define FF_PROFILE_MPEG4_SIMPLE_STUDIO 14
2857 #define FF_PROFILE_MPEG4_ADVANCED_SIMPLE 15
2859 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_0 0
2860 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_1 1
2861 #define FF_PROFILE_JPEG2000_CSTREAM_NO_RESTRICTION 2
2862 #define FF_PROFILE_JPEG2000_DCINEMA_2K 3
2863 #define FF_PROFILE_JPEG2000_DCINEMA_4K 4
2864 
2866 #define FF_PROFILE_HEVC_MAIN 1
2867 #define FF_PROFILE_HEVC_MAIN_10 2
2868 #define FF_PROFILE_HEVC_MAIN_STILL_PICTURE 3
2869 #define FF_PROFILE_HEVC_REXT 4
2870 
2871  /**
2872  * level
2873  * - encoding: Set by user.
2874  * - decoding: Set by libavcodec.
2875  */
2876  int level;
2877 #define FF_LEVEL_UNKNOWN -99
2878 
2879  /**
2880  * Skip loop filtering for selected frames.
2881  * - encoding: unused
2882  * - decoding: Set by user.
2883  */
2885 
2886  /**
2887  * Skip IDCT/dequantization for selected frames.
2888  * - encoding: unused
2889  * - decoding: Set by user.
2890  */
2891  enum AVDiscard skip_idct;
2892 
2893  /**
2894  * Skip decoding for selected frames.
2895  * - encoding: unused
2896  * - decoding: Set by user.
2897  */
2898  enum AVDiscard skip_frame;
2899 
2900  /**
2901  * Header containing style information for text subtitles.
2902  * For SUBTITLE_ASS subtitle type, it should contain the whole ASS
2903  * [Script Info] and [V4+ Styles] section, plus the [Events] line and
2904  * the Format line following. It shouldn't include any Dialogue line.
2905  * - encoding: Set/allocated/freed by user (before avcodec_open2())
2906  * - decoding: Set/allocated/freed by libavcodec (by avcodec_open2())
2907  */
2910 
2911 #if FF_API_ERROR_RATE
2912  /**
2913  * @deprecated use the 'error_rate' private AVOption of the mpegvideo
2914  * encoders
2915  */
2917  int error_rate;
2918 #endif
2919 
2920 #if FF_API_CODEC_PKT
2921  /**
2922  * @deprecated this field is not supposed to be accessed from outside lavc
2923  */
2925  AVPacket *pkt;
2926 #endif
2927 
2928  /**
2929  * VBV delay coded in the last frame (in periods of a 27 MHz clock).
2930  * Used for compliant TS muxing.
2931  * - encoding: Set by libavcodec.
2932  * - decoding: unused.
2933  */
2934  uint64_t vbv_delay;
2935 
2936  /**
2937  * Encoding only. Allow encoders to output packets that do not contain any
2938  * encoded data, only side data.
2939  *
2940  * Some encoders need to output such packets, e.g. to update some stream
2941  * parameters at the end of encoding.
2942  *
2943  * All callers are strongly recommended to set this option to 1 and update
2944  * their code to deal with such packets, since this behaviour may become
2945  * always enabled in the future (then this option will be deprecated and
2946  * later removed). To avoid ABI issues when this happens, the callers should
2947  * use AVOptions to set this field.
2948  */
2950 
2951  /**
2952  * Timebase in which pkt_dts/pts and AVPacket.dts/pts are.
2953  * Code outside libavcodec should access this field using:
2954  * av_codec_{get,set}_pkt_timebase(avctx)
2955  * - encoding unused.
2956  * - decoding set by user.
2957  */
2959 
2960  /**
2961  * AVCodecDescriptor
2962  * Code outside libavcodec should access this field using:
2963  * av_codec_{get,set}_codec_descriptor(avctx)
2964  * - encoding: unused.
2965  * - decoding: set by libavcodec.
2966  */
2968 
2969 #if !FF_API_LOWRES
2970  /**
2971  * low resolution decoding, 1-> 1/2 size, 2->1/4 size
2972  * - encoding: unused
2973  * - decoding: Set by user.
2974  * Code outside libavcodec should access this field using:
2975  * av_codec_{get,set}_lowres(avctx)
2976  */
2977  int lowres;
2978 #endif
2979 
2980  /**
2981  * Current statistics for PTS correction.
2982  * - decoding: maintained and used by libavcodec, not intended to be used by user apps
2983  * - encoding: unused
2984  */
2985  int64_t pts_correction_num_faulty_pts; /// Number of incorrect PTS values so far
2986  int64_t pts_correction_num_faulty_dts; /// Number of incorrect DTS values so far
2987  int64_t pts_correction_last_pts; /// PTS of the last frame
2988  int64_t pts_correction_last_dts; /// DTS of the last frame
2989 
2990  /**
2991  * Character encoding of the input subtitles file.
2992  * - decoding: set by user
2993  * - encoding: unused
2994  */
2995  char *sub_charenc;
2996 
2997  /**
2998  * Subtitles character encoding mode. Formats or codecs might be adjusting
2999  * this setting (if they are doing the conversion themselves for instance).
3000  * - decoding: set by libavcodec
3001  * - encoding: unused
3002  */
3004 #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)
3005 #define FF_SUB_CHARENC_MODE_AUTOMATIC 0 ///< libavcodec will select the mode itself
3006 #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
3007 
3008  /**
3009  * Skip processing alpha if supported by codec.
3010  * Note that if the format uses pre-multiplied alpha (common with VP6,
3011  * and recommended due to better video quality/compression)
3012  * the image will look as if alpha-blended onto a black background.
3013  * However for formats that do not use pre-multiplied alpha
3014  * there might be serious artefacts (though e.g. libswscale currently
3015  * assumes pre-multiplied alpha anyway).
3016  * Code outside libavcodec should access this field using AVOptions
3017  *
3018  * - decoding: set by user
3019  * - encoding: unused
3020  */
3021  int skip_alpha;
3022 
3023  /**
3024  * Number of samples to skip after a discontinuity
3025  * - decoding: unused
3026  * - encoding: set by libavcodec
3027  */
3028  int seek_preroll;
3029 
3030 #if !FF_API_DEBUG_MV
3031  /**
3032  * debug motion vectors
3033  * Code outside libavcodec should access this field using AVOptions
3034  * - encoding: Set by user.
3035  * - decoding: Set by user.
3036  */
3037  int debug_mv;
3038 #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 //visualize forward predicted MVs of P frames
3039 #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 //visualize forward predicted MVs of B frames
3040 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
3041 #endif
3042 
3043  /**
3044  * custom intra quantization matrix
3045  * Code outside libavcodec should access this field using av_codec_g/set_chroma_intra_matrix()
3046  * - encoding: Set by user, can be NULL.
3047  * - decoding: unused.
3048  */
3049  uint16_t *chroma_intra_matrix;
3050 } AVCodecContext;
3051 
3054 
3057 
3058 int av_codec_get_lowres(const AVCodecContext *avctx);
3059 void av_codec_set_lowres(AVCodecContext *avctx, int val);
3060 
3061 int av_codec_get_seek_preroll(const AVCodecContext *avctx);
3062 void av_codec_set_seek_preroll(AVCodecContext *avctx, int val);
3063 
3064 uint16_t *av_codec_get_chroma_intra_matrix(const AVCodecContext *avctx);
3065 void av_codec_set_chroma_intra_matrix(AVCodecContext *avctx, uint16_t *val);
3066 
3067 /**
3068  * AVProfile.
3069  */
3070 typedef struct AVProfile {
3071  int profile;
3072  const char *name; ///< short name for the profile
3073 } AVProfile;
3074 
3075 typedef struct AVCodecDefault AVCodecDefault;
3076 
3077 struct AVSubtitle;
3078 
3079 /**
3080  * AVCodec.
3081  */
3082 typedef struct AVCodec {
3083  /**
3084  * Name of the codec implementation.
3085  * The name is globally unique among encoders and among decoders (but an
3086  * encoder and a decoder can share the same name).
3087  * This is the primary way to find a codec from the user perspective.
3088  */
3089  const char *name;
3090  /**
3091  * Descriptive name for the codec, meant to be more human readable than name.
3092  * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
3093  */
3094  const char *long_name;
3096  enum AVCodecID id;
3097  /**
3098  * Codec capabilities.
3099  * see CODEC_CAP_*
3100  */
3102  const AVRational *supported_framerates; ///< array of supported framerates, or NULL if any, array is terminated by {0,0}
3103  const enum AVPixelFormat *pix_fmts; ///< array of supported pixel formats, or NULL if unknown, array is terminated by -1
3104  const int *supported_samplerates; ///< array of supported audio samplerates, or NULL if unknown, array is terminated by 0
3105  const enum AVSampleFormat *sample_fmts; ///< array of supported sample formats, or NULL if unknown, array is terminated by -1
3106  const uint64_t *channel_layouts; ///< array of support channel layouts, or NULL if unknown. array is terminated by 0
3107 #if FF_API_LOWRES
3108  uint8_t max_lowres; ///< maximum value for lowres supported by the decoder, no direct access, use av_codec_get_max_lowres()
3109 #endif
3110  const AVClass *priv_class; ///< AVClass for the private context
3111  const AVProfile *profiles; ///< array of recognized profiles, or NULL if unknown, array is terminated by {FF_PROFILE_UNKNOWN}
3112 
3113  /*****************************************************************
3114  * No fields below this line are part of the public API. They
3115  * may not be used outside of libavcodec and can be changed and
3116  * removed at will.
3117  * New public fields should be added right above.
3118  *****************************************************************
3119  */
3121  struct AVCodec *next;
3122  /**
3123  * @name Frame-level threading support functions
3124  * @{
3125  */
3126  /**
3127  * If defined, called on thread contexts when they are created.
3128  * If the codec allocates writable tables in init(), re-allocate them here.
3129  * priv_data will be set to a copy of the original.
3130  */
3131  int (*init_thread_copy)(AVCodecContext *);
3132  /**
3133  * Copy necessary context variables from a previous thread context to the current one.
3134  * If not defined, the next thread will start automatically; otherwise, the codec
3135  * must call ff_thread_finish_setup().
3136  *
3137  * dst and src will (rarely) point to the same context, in which case memcpy should be skipped.
3138  */
3140  /** @} */
3141 
3142  /**
3143  * Private codec-specific defaults.
3144  */
3145  const AVCodecDefault *defaults;
3146 
3147  /**
3148  * Initialize codec static data, called from avcodec_register().
3149  */
3150  void (*init_static_data)(struct AVCodec *codec);
3153  int (*encode_sub)(AVCodecContext *, uint8_t *buf, int buf_size,
3154  const struct AVSubtitle *sub);
3155  /**
3156  * Encode data to an AVPacket.
3157  *
3158  * @param avctx codec context
3159  * @param avpkt output AVPacket (may contain a user-provided buffer)
3160  * @param[in] frame AVFrame containing the raw data to be encoded
3161  * @param[out] got_packet_ptr encoder sets to 0 or 1 to indicate that a
3162  * non-empty packet was returned in avpkt.
3163  * @return 0 on success, negative error code on failure
3164  */
3165  int (*encode2)(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame,
3166  int *got_packet_ptr);
3167  int (*decode)(AVCodecContext *, void *outdata, int *outdata_size, AVPacket *avpkt);
3168  int (*close)(AVCodecContext *);
3169  /**
3170  * Flush buffers.
3171  * Will be called when seeking
3172  */
3173  void (*flush)(AVCodecContext *);
3174 } AVCodec;
3175 
3176 int av_codec_get_max_lowres(const AVCodec *codec);
3177 
3178 struct MpegEncContext;
3179 
3180 /**
3181  * AVHWAccel.
3182  */
3183 typedef struct AVHWAccel {
3184  /**
3185  * Name of the hardware accelerated codec.
3186  * The name is globally unique among encoders and among decoders (but an
3187  * encoder and a decoder can share the same name).
3188  */
3189  const char *name;
3190 
3191  /**
3192  * Type of codec implemented by the hardware accelerator.
3193  *
3194  * See AVMEDIA_TYPE_xxx
3195  */
3196  enum AVMediaType type;
3197 
3198  /**
3199  * Codec implemented by the hardware accelerator.
3200  *
3201  * See AV_CODEC_ID_xxx
3202  */
3203  enum AVCodecID id;
3204 
3205  /**
3206  * Supported pixel format.
3207  *
3208  * Only hardware accelerated formats are supported here.
3209  */
3210  enum AVPixelFormat pix_fmt;
3211 
3212  /**
3213  * Hardware accelerated codec capabilities.
3214  * see FF_HWACCEL_CODEC_CAP_*
3215  */
3216  int capabilities;
3217 
3218  /*****************************************************************
3219  * No fields below this line are part of the public API. They
3220  * may not be used outside of libavcodec and can be changed and
3221  * removed at will.
3222  * New public fields should be added right above.
3223  *****************************************************************
3224  */
3225  struct AVHWAccel *next;
3226 
3227  /**
3228  * Allocate a custom buffer
3229  */
3230  int (*alloc_frame)(AVCodecContext *avctx, AVFrame *frame);
3231 
3232  /**
3233  * Called at the beginning of each frame or field picture.
3234  *
3235  * Meaningful frame information (codec specific) is guaranteed to
3236  * be parsed at this point. This function is mandatory.
3237  *
3238  * Note that buf can be NULL along with buf_size set to 0.
3239  * Otherwise, this means the whole frame is available at this point.
3240  *
3241  * @param avctx the codec context
3242  * @param buf the frame data buffer base
3243  * @param buf_size the size of the frame in bytes
3244  * @return zero if successful, a negative value otherwise
3245  */
3246  int (*start_frame)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3247 
3248  /**
3249  * Callback for each slice.
3250  *
3251  * Meaningful slice information (codec specific) is guaranteed to
3252  * be parsed at this point. This function is mandatory.
3253  * The only exception is XvMC, that works on MB level.
3254  *
3255  * @param avctx the codec context
3256  * @param buf the slice data buffer base
3257  * @param buf_size the size of the slice in bytes
3258  * @return zero if successful, a negative value otherwise
3259  */
3260  int (*decode_slice)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3261 
3262  /**
3263  * Called at the end of each frame or field picture.
3264  *
3265  * The whole picture is parsed at this point and can now be sent
3266  * to the hardware accelerator. This function is mandatory.
3267  *
3268  * @param avctx the codec context
3269  * @return zero if successful, a negative value otherwise
3270  */
3271  int (*end_frame)(AVCodecContext *avctx);
3272 
3273  /**
3274  * Size of per-frame hardware accelerator private data.
3275  *
3276  * Private data is allocated with av_mallocz() before
3277  * AVCodecContext.get_buffer() and deallocated after
3278  * AVCodecContext.release_buffer().
3279  */
3281 
3282  /**
3283  * Called for every Macroblock in a slice.
3284  *
3285  * XvMC uses it to replace the ff_MPV_decode_mb().
3286  * Instead of decoding to raw picture, MB parameters are
3287  * stored in an array provided by the video driver.
3288  *
3289  * @param s the mpeg context
3290  */
3291  void (*decode_mb)(struct MpegEncContext *s);
3292 
3293  /**
3294  * Initialize the hwaccel private data.
3295  *
3296  * This will be called from ff_get_format(), after hwaccel and
3297  * hwaccel_context are set and the hwaccel private data in AVCodecInternal
3298  * is allocated.
3299  */
3300  int (*init)(AVCodecContext *avctx);
3301 
3302  /**
3303  * Uninitialize the hwaccel private data.
3304  *
3305  * This will be called from get_format() or avcodec_close(), after hwaccel
3306  * and hwaccel_context are already uninitialized.
3307  */
3308  int (*uninit)(AVCodecContext *avctx);
3309 
3310  /**
3311  * Size of the private data to allocate in
3312  * AVCodecInternal.hwaccel_priv_data.
3313  */
3314  int priv_data_size;
3315 } AVHWAccel;
3316 
3317 /**
3318  * @defgroup lavc_picture AVPicture
3319  *
3320  * Functions for working with AVPicture
3321  * @{
3322  */
3323 
3324 /**
3325  * Picture data structure.
3326  *
3327  * Up to four components can be stored into it, the last component is
3328  * alpha.
3329  */
3330 typedef struct AVPicture {
3331  uint8_t *data[AV_NUM_DATA_POINTERS]; ///< pointers to the image data planes
3332  int linesize[AV_NUM_DATA_POINTERS]; ///< number of bytes per line
3333 } AVPicture;
3334 
3335 /**
3336  * @}
3337  */
3340  SUBTITLE_NONE,
3342  SUBTITLE_BITMAP, ///< A bitmap, pict will be set
3343 
3344  /**
3345  * Plain text, the text field must be set by the decoder and is
3346  * authoritative. ass and pict fields may contain approximations.
3347  */
3348  SUBTITLE_TEXT,
3349 
3350  /**
3351  * Formatted text, the ass field must be set by the decoder and is
3352  * authoritative. pict and text fields may contain approximations.
3353  */
3354  SUBTITLE_ASS,
3355 };
3357 #define AV_SUBTITLE_FLAG_FORCED 0x00000001
3359 typedef struct AVSubtitleRect {
3360  int x; ///< top left corner of pict, undefined when pict is not set
3361  int y; ///< top left corner of pict, undefined when pict is not set
3362  int w; ///< width of pict, undefined when pict is not set
3363  int h; ///< height of pict, undefined when pict is not set
3364  int nb_colors; ///< number of colors in pict, undefined when pict is not set
3365 
3366  /**
3367  * data+linesize for the bitmap of this subtitle.
3368  * can be set for text/ass as well once they where rendered
3369  */
3371  enum AVSubtitleType type;
3373  char *text; ///< 0 terminated plain UTF-8 text
3374 
3375  /**
3376  * 0 terminated ASS/SSA compatible event line.
3377  * The presentation of this is unaffected by the other values in this
3378  * struct.
3379  */
3380  char *ass;
3382  int flags;
3383 } AVSubtitleRect;
3385 typedef struct AVSubtitle {
3386  uint16_t format; /* 0 = graphics */
3387  uint32_t start_display_time; /* relative to packet pts, in ms */
3388  uint32_t end_display_time; /* relative to packet pts, in ms */
3389  unsigned num_rects;
3391  int64_t pts; ///< Same as packet pts, in AV_TIME_BASE
3392 } AVSubtitle;
3393 
3394 /**
3395  * If c is NULL, returns the first registered codec,
3396  * if c is non-NULL, returns the next registered codec after c,
3397  * or NULL if c is the last one.
3398  */
3399 AVCodec *av_codec_next(const AVCodec *c);
3400 
3401 /**
3402  * Return the LIBAVCODEC_VERSION_INT constant.
3403  */
3404 unsigned avcodec_version(void);
3405 
3406 /**
3407  * Return the libavcodec build-time configuration.
3408  */
3409 const char *avcodec_configuration(void);
3410 
3411 /**
3412  * Return the libavcodec license.
3413  */
3414 const char *avcodec_license(void);
3415 
3416 /**
3417  * Register the codec codec and initialize libavcodec.
3418  *
3419  * @warning either this function or avcodec_register_all() must be called
3420  * before any other libavcodec functions.
3421  *
3422  * @see avcodec_register_all()
3423  */
3424 void avcodec_register(AVCodec *codec);
3425 
3426 /**
3427  * Register all the codecs, parsers and bitstream filters which were enabled at
3428  * configuration time. If you do not call this function you can select exactly
3429  * which formats you want to support, by using the individual registration
3430  * functions.
3431  *
3432  * @see avcodec_register
3433  * @see av_register_codec_parser
3434  * @see av_register_bitstream_filter
3435  */
3436 void avcodec_register_all(void);
3437 
3438 /**
3439  * Allocate an AVCodecContext and set its fields to default values. The
3440  * resulting struct should be freed with avcodec_free_context().
3441  *
3442  * @param codec if non-NULL, allocate private data and initialize defaults
3443  * for the given codec. It is illegal to then call avcodec_open2()
3444  * with a different codec.
3445  * If NULL, then the codec-specific defaults won't be initialized,
3446  * which may result in suboptimal default settings (this is
3447  * important mainly for encoders, e.g. libx264).
3448  *
3449  * @return An AVCodecContext filled with default values or NULL on failure.
3450  * @see avcodec_get_context_defaults
3451  */
3453 
3454 /**
3455  * Free the codec context and everything associated with it and write NULL to
3456  * the provided pointer.
3457  */
3458 void avcodec_free_context(AVCodecContext **avctx);
3459 
3460 /**
3461  * Set the fields of the given AVCodecContext to default values corresponding
3462  * to the given codec (defaults may be codec-dependent).
3463  *
3464  * Do not call this function if a non-NULL codec has been passed
3465  * to avcodec_alloc_context3() that allocated this AVCodecContext.
3466  * If codec is non-NULL, it is illegal to call avcodec_open2() with a
3467  * different codec on this AVCodecContext.
3468  */
3470 
3471 /**
3472  * Get the AVClass for AVCodecContext. It can be used in combination with
3473  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
3474  *
3475  * @see av_opt_find().
3476  */
3477 const AVClass *avcodec_get_class(void);
3478 
3479 /**
3480  * Get the AVClass for AVFrame. It can be used in combination with
3481  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
3482  *
3483  * @see av_opt_find().
3484  */
3485 const AVClass *avcodec_get_frame_class(void);
3486 
3487 /**
3488  * Get the AVClass for AVSubtitleRect. It can be used in combination with
3489  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
3490  *
3491  * @see av_opt_find().
3492  */
3494 
3495 /**
3496  * Copy the settings of the source AVCodecContext into the destination
3497  * AVCodecContext. The resulting destination codec context will be
3498  * unopened, i.e. you are required to call avcodec_open2() before you
3499  * can use this AVCodecContext to decode/encode video/audio data.
3500  *
3501  * @param dest target codec context, should be initialized with
3502  * avcodec_alloc_context3(NULL), but otherwise uninitialized
3503  * @param src source codec context
3504  * @return AVERROR() on error (e.g. memory allocation error), 0 on success
3505  */
3507 
3508 #if FF_API_AVFRAME_LAVC
3509 /**
3510  * @deprecated use av_frame_alloc()
3511  */
3513 AVFrame *avcodec_alloc_frame(void);
3514 
3515 /**
3516  * Set the fields of the given AVFrame to default values.
3517  *
3518  * @param frame The AVFrame of which the fields should be set to default values.
3519  *
3520  * @deprecated use av_frame_unref()
3521  */
3523 void avcodec_get_frame_defaults(AVFrame *frame);
3524 
3525 /**
3526  * Free the frame and any dynamically allocated objects in it,
3527  * e.g. extended_data.
3528  *
3529  * @param frame frame to be freed. The pointer will be set to NULL.
3530  *
3531  * @warning this function does NOT free the data buffers themselves
3532  * (it does not know how, since they might have been allocated with
3533  * a custom get_buffer()).
3534  *
3535  * @deprecated use av_frame_free()
3536  */
3538 void avcodec_free_frame(AVFrame **frame);
3539 #endif
3540 
3541 /**
3542  * Initialize the AVCodecContext to use the given AVCodec. Prior to using this
3543  * function the context has to be allocated with avcodec_alloc_context3().
3544  *
3545  * The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(),
3546  * avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for
3547  * retrieving a codec.
3548  *
3549  * @warning This function is not thread safe!
3550  *
3551  * @code
3552  * avcodec_register_all();
3553  * av_dict_set(&opts, "b", "2.5M", 0);
3554  * codec = avcodec_find_decoder(AV_CODEC_ID_H264);
3555  * if (!codec)
3556  * exit(1);
3557  *
3558  * context = avcodec_alloc_context3(codec);
3559  *
3560  * if (avcodec_open2(context, codec, opts) < 0)
3561  * exit(1);
3562  * @endcode
3563  *
3564  * @param avctx The context to initialize.
3565  * @param codec The codec to open this context for. If a non-NULL codec has been
3566  * previously passed to avcodec_alloc_context3() or
3567  * avcodec_get_context_defaults3() for this context, then this
3568  * parameter MUST be either NULL or equal to the previously passed
3569  * codec.
3570  * @param options A dictionary filled with AVCodecContext and codec-private options.
3571  * On return this object will be filled with options that were not found.
3572  *
3573  * @return zero on success, a negative value on error
3574  * @see avcodec_alloc_context3(), avcodec_find_decoder(), avcodec_find_encoder(),
3575  * av_dict_set(), av_opt_find().
3576  */
3577 int avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options);
3578 
3579 /**
3580  * Close a given AVCodecContext and free all the data associated with it
3581  * (but not the AVCodecContext itself).
3582  *
3583  * Calling this function on an AVCodecContext that hasn't been opened will free
3584  * the codec-specific data allocated in avcodec_alloc_context3() /
3585  * avcodec_get_context_defaults3() with a non-NULL codec. Subsequent calls will
3586  * do nothing.
3587  */
3588 int avcodec_close(AVCodecContext *avctx);
3589 
3590 /**
3591  * Free all allocated data in the given subtitle struct.
3592  *
3593  * @param sub AVSubtitle to free.
3594  */
3595 void avsubtitle_free(AVSubtitle *sub);
3596 
3597 /**
3598  * @}
3599  */
3600 
3601 /**
3602  * @addtogroup lavc_packet
3603  * @{
3604  */
3605 
3606 #if FF_API_DESTRUCT_PACKET
3607 /**
3608  * Default packet destructor.
3609  * @deprecated use the AVBuffer API instead
3610  */
3613 #endif
3614 
3615 /**
3616  * Initialize optional fields of a packet with default values.
3617  *
3618  * Note, this does not touch the data and size members, which have to be
3619  * initialized separately.
3620  *
3621  * @param pkt packet
3622  */
3623 void av_init_packet(AVPacket *pkt);
3624 
3625 /**
3626  * Allocate the payload of a packet and initialize its fields with
3627  * default values.
3628  *
3629  * @param pkt packet
3630  * @param size wanted payload size
3631  * @return 0 if OK, AVERROR_xxx otherwise
3632  */
3633 int av_new_packet(AVPacket *pkt, int size);
3634 
3635 /**
3636  * Reduce packet size, correctly zeroing padding
3637  *
3638  * @param pkt packet
3639  * @param size new size
3640  */
3641 void av_shrink_packet(AVPacket *pkt, int size);
3642 
3643 /**
3644  * Increase packet size, correctly zeroing padding
3645  *
3646  * @param pkt packet
3647  * @param grow_by number of bytes by which to increase the size of the packet
3648  */
3649 int av_grow_packet(AVPacket *pkt, int grow_by);
3650 
3651 /**
3652  * Initialize a reference-counted packet from av_malloc()ed data.
3653  *
3654  * @param pkt packet to be initialized. This function will set the data, size,
3655  * buf and destruct fields, all others are left untouched.
3656  * @param data Data allocated by av_malloc() to be used as packet data. If this
3657  * function returns successfully, the data is owned by the underlying AVBuffer.
3658  * The caller may not access the data through other means.
3659  * @param size size of data in bytes, without the padding. I.e. the full buffer
3660  * size is assumed to be size + FF_INPUT_BUFFER_PADDING_SIZE.
3661  *
3662  * @return 0 on success, a negative AVERROR on error
3663  */
3665 
3666 /**
3667  * @warning This is a hack - the packet memory allocation stuff is broken. The
3668  * packet is allocated if it was not really allocated.
3669  */
3670 int av_dup_packet(AVPacket *pkt);
3671 
3672 /**
3673  * Copy packet, including contents
3674  *
3675  * @return 0 on success, negative AVERROR on fail
3676  */
3677 int av_copy_packet(AVPacket *dst, const AVPacket *src);
3678 
3679 /**
3680  * Copy packet side data
3681  *
3682  * @return 0 on success, negative AVERROR on fail
3683  */
3684 int av_copy_packet_side_data(AVPacket *dst, const AVPacket *src);
3685 
3686 /**
3687  * Free a packet.
3688  *
3689  * @param pkt packet to free
3690  */
3691 void av_free_packet(AVPacket *pkt);
3692 
3693 /**
3694  * Allocate new information of a packet.
3695  *
3696  * @param pkt packet
3697  * @param type side information type
3698  * @param size side information size
3699  * @return pointer to fresh allocated data or NULL otherwise
3700  */
3702  int size);
3703 
3704 /**
3705  * Shrink the already allocated side data buffer
3706  *
3707  * @param pkt packet
3708  * @param type side information type
3709  * @param size new side information size
3710  * @return 0 on success, < 0 on failure
3711  */
3713  int size);
3714 
3715 /**
3716  * Get side information from packet.
3717  *
3718  * @param pkt packet
3719  * @param type desired side information type
3720  * @param size pointer for side information size to store (optional)
3721  * @return pointer to data if present or NULL otherwise
3722  */
3724  int *size);
3725 
3727 
3729 
3730 /**
3731  * Pack a dictionary for use in side_data.
3732  *
3733  * @param dict The dictionary to pack.
3734  * @param size pointer to store the size of the returned data
3735  * @return pointer to data if successful, NULL otherwise
3736  */
3738 /**
3739  * Unpack a dictionary from side_data.
3740  *
3741  * @param data data from side_data
3742  * @param size size of the data
3743  * @param dict the metadata storage dictionary
3744  * @return 0 on success, < 0 on failure
3745  */
3746 int av_packet_unpack_dictionary(const uint8_t *data, int size, AVDictionary **dict);
3747 
3748 
3749 /**
3750  * Convenience function to free all the side data stored.
3751  * All the other fields stay untouched.
3752  *
3753  * @param pkt packet
3754  */
3756 
3757 /**
3758  * Setup a new reference to the data described by a given packet
3759  *
3760  * If src is reference-counted, setup dst as a new reference to the
3761  * buffer in src. Otherwise allocate a new buffer in dst and copy the
3762  * data from src into it.
3763  *
3764  * All the other fields are copied from src.
3765  *
3766  * @see av_packet_unref
3767  *
3768  * @param dst Destination packet
3769  * @param src Source packet
3770  *
3771  * @return 0 on success, a negative AVERROR on error.
3772  */
3773 int av_packet_ref(AVPacket *dst, const AVPacket *src);
3774 
3775 /**
3776  * Wipe the packet.
3777  *
3778  * Unreference the buffer referenced by the packet and reset the
3779  * remaining packet fields to their default values.
3780  *
3781  * @param pkt The packet to be unreferenced.
3782  */
3784 
3785 /**
3786  * Move every field in src to dst and reset src.
3787  *
3788  * @see av_packet_unref
3789  *
3790  * @param src Source packet, will be reset
3791  * @param dst Destination packet
3792  */
3794 
3795 /**
3796  * Copy only "properties" fields from src to dst.
3797  *
3798  * Properties for the purpose of this function are all the fields
3799  * beside those related to the packet data (buf, data, size)
3800  *
3801  * @param dst Destination packet
3802  * @param src Source packet
3803  *
3804  * @return 0 on success AVERROR on failure.
3805  *
3806  */
3807 int av_packet_copy_props(AVPacket *dst, const AVPacket *src);
3808 
3809 /**
3810  * Convert valid timing fields (timestamps / durations) in a packet from one
3811  * timebase to another. Timestamps with unknown values (AV_NOPTS_VALUE) will be
3812  * ignored.
3813  *
3814  * @param pkt packet on which the conversion will be performed
3815  * @param tb_src source timebase, in which the timing fields in pkt are
3816  * expressed
3817  * @param tb_dst destination timebase, to which the timing fields will be
3818  * converted
3819  */
3820 void av_packet_rescale_ts(AVPacket *pkt, AVRational tb_src, AVRational tb_dst);
3821 
3822 /**
3823  * @}
3824  */
3825 
3826 /**
3827  * @addtogroup lavc_decoding
3828  * @{
3829  */
3830 
3831 /**
3832  * Find a registered decoder with a matching codec ID.
3833  *
3834  * @param id AVCodecID of the requested decoder
3835  * @return A decoder if one was found, NULL otherwise.
3836  */
3838 
3839 /**
3840  * Find a registered decoder with the specified name.
3841  *
3842  * @param name name of the requested decoder
3843  * @return A decoder if one was found, NULL otherwise.
3844  */
3846 
3847 #if FF_API_GET_BUFFER
3851 #endif
3852 
3853 /**
3854  * The default callback for AVCodecContext.get_buffer2(). It is made public so
3855  * it can be called by custom get_buffer2() implementations for decoders without
3856  * CODEC_CAP_DR1 set.
3857  */
3859 
3860 #if FF_API_EMU_EDGE
3861 /**
3862  * Return the amount of padding in pixels which the get_buffer callback must
3863  * provide around the edge of the image for codecs which do not have the
3864  * CODEC_FLAG_EMU_EDGE flag.
3865  *
3866  * @return Required padding in pixels.
3867  *
3868  * @deprecated CODEC_FLAG_EMU_EDGE is deprecated, so this function is no longer
3869  * needed
3870  */
3872 unsigned avcodec_get_edge_width(void);
3873 #endif
3874 
3875 /**
3876  * Modify width and height values so that they will result in a memory
3877  * buffer that is acceptable for the codec if you do not use any horizontal
3878  * padding.
3879  *
3880  * May only be used if a codec with CODEC_CAP_DR1 has been opened.
3881  */
3883 
3884 /**
3885  * Modify width and height values so that they will result in a memory
3886  * buffer that is acceptable for the codec if you also ensure that all
3887  * line sizes are a multiple of the respective linesize_align[i].
3888  *
3889  * May only be used if a codec with CODEC_CAP_DR1 has been opened.
3890  */
3892  int linesize_align[AV_NUM_DATA_POINTERS]);
3893 
3894 /**
3895  * Converts AVChromaLocation to swscale x/y chroma position.
3896  *
3897  * The positions represent the chroma (0,0) position in a coordinates system
3898  * with luma (0,0) representing the origin and luma(1,1) representing 256,256
3899  *
3900  * @param xpos horizontal chroma sample position
3901  * @param ypos vertical chroma sample position
3902  */
3903 int avcodec_enum_to_chroma_pos(int *xpos, int *ypos, enum AVChromaLocation pos);
3904 
3905 /**
3906  * Converts swscale x/y chroma position to AVChromaLocation.
3907  *
3908  * The positions represent the chroma (0,0) position in a coordinates system
3909  * with luma (0,0) representing the origin and luma(1,1) representing 256,256
3910  *
3911  * @param xpos horizontal chroma sample position
3912  * @param ypos vertical chroma sample position
3913  */
3914 enum AVChromaLocation avcodec_chroma_pos_to_enum(int xpos, int ypos);
3915 
3916 #if FF_API_OLD_DECODE_AUDIO
3917 /**
3918  * Wrapper function which calls avcodec_decode_audio4.
3919  *
3920  * @deprecated Use avcodec_decode_audio4 instead.
3921  *
3922  * Decode the audio frame of size avpkt->size from avpkt->data into samples.
3923  * Some decoders may support multiple frames in a single AVPacket, such
3924  * decoders would then just decode the first frame. In this case,
3925  * avcodec_decode_audio3 has to be called again with an AVPacket that contains
3926  * the remaining data in order to decode the second frame etc.
3927  * If no frame
3928  * could be outputted, frame_size_ptr is zero. Otherwise, it is the
3929  * decompressed frame size in bytes.
3930  *
3931  * @warning You must set frame_size_ptr to the allocated size of the
3932  * output buffer before calling avcodec_decode_audio3().
3933  *
3934  * @warning The input buffer must be FF_INPUT_BUFFER_PADDING_SIZE larger than
3935  * the actual read bytes because some optimized bitstream readers read 32 or 64
3936  * bits at once and could read over the end.
3937  *
3938  * @warning The end of the input buffer avpkt->data should be set to 0 to ensure that
3939  * no overreading happens for damaged MPEG streams.
3940  *
3941  * @warning You must not provide a custom get_buffer() when using
3942  * avcodec_decode_audio3(). Doing so will override it with
3943  * avcodec_default_get_buffer. Use avcodec_decode_audio4() instead,
3944  * which does allow the application to provide a custom get_buffer().
3945  *
3946  * @note You might have to align the input buffer avpkt->data and output buffer
3947  * samples. The alignment requirements depend on the CPU: On some CPUs it isn't
3948  * necessary at all, on others it won't work at all if not aligned and on others
3949  * it will work but it will have an impact on performance.
3950  *
3951  * In practice, avpkt->data should have 4 byte alignment at minimum and
3952  * samples should be 16 byte aligned unless the CPU doesn't need it
3953  * (AltiVec and SSE do).
3954  *
3955  * @note Codecs which have the CODEC_CAP_DELAY capability set have a delay
3956  * between input and output, these need to be fed with avpkt->data=NULL,
3957  * avpkt->size=0 at the end to return the remaining frames.
3958  *
3959  * @param avctx the codec context
3960  * @param[out] samples the output buffer, sample type in avctx->sample_fmt
3961  * If the sample format is planar, each channel plane will
3962  * be the same size, with no padding between channels.
3963  * @param[in,out] frame_size_ptr the output buffer size in bytes
3964  * @param[in] avpkt The input AVPacket containing the input buffer.
3965  * You can create such packet with av_init_packet() and by then setting
3966  * data and size, some decoders might in addition need other fields.
3967  * All decoders are designed to use the least fields possible though.
3968  * @return On error a negative value is returned, otherwise the number of bytes
3969  * used or zero if no frame data was decompressed (used) from the input AVPacket.
3970  */
3971 attribute_deprecated int avcodec_decode_audio3(AVCodecContext *avctx, int16_t *samples,
3972  int *frame_size_ptr,
3973  AVPacket *avpkt);
3974 #endif
3975 
3976 /**
3977  * Decode the audio frame of size avpkt->size from avpkt->data into frame.
3978  *
3979  * Some decoders may support multiple frames in a single AVPacket. Such
3980  * decoders would then just decode the first frame and the return value would be
3981  * less than the packet size. In this case, avcodec_decode_audio4 has to be
3982  * called again with an AVPacket containing the remaining data in order to
3983  * decode the second frame, etc... Even if no frames are returned, the packet
3984  * needs to be fed to the decoder with remaining data until it is completely
3985  * consumed or an error occurs.
3986  *
3987  * Some decoders (those marked with CODEC_CAP_DELAY) have a delay between input
3988  * and output. This means that for some packets they will not immediately
3989  * produce decoded output and need to be flushed at the end of decoding to get
3990  * all the decoded data. Flushing is done by calling this function with packets
3991  * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
3992  * returning samples. It is safe to flush even those decoders that are not
3993  * marked with CODEC_CAP_DELAY, then no samples will be returned.
3994  *
3995  * @warning The input buffer, avpkt->data must be FF_INPUT_BUFFER_PADDING_SIZE
3996  * larger than the actual read bytes because some optimized bitstream
3997  * readers read 32 or 64 bits at once and could read over the end.
3998  *
3999  * @param avctx the codec context
4000  * @param[out] frame The AVFrame in which to store decoded audio samples.
4001  * The decoder will allocate a buffer for the decoded frame by
4002  * calling the AVCodecContext.get_buffer2() callback.
4003  * When AVCodecContext.refcounted_frames is set to 1, the frame is
4004  * reference counted and the returned reference belongs to the
4005  * caller. The caller must release the frame using av_frame_unref()
4006  * when the frame is no longer needed. The caller may safely write
4007  * to the frame if av_frame_is_writable() returns 1.
4008  * When AVCodecContext.refcounted_frames is set to 0, the returned
4009  * reference belongs to the decoder and is valid only until the
4010  * next call to this function or until closing or flushing the
4011  * decoder. The caller may not write to it.
4012  * @param[out] got_frame_ptr Zero if no frame could be decoded, otherwise it is
4013  * non-zero. Note that this field being set to zero
4014  * does not mean that an error has occurred. For
4015  * decoders with CODEC_CAP_DELAY set, no given decode
4016  * call is guaranteed to produce a frame.
4017  * @param[in] avpkt The input AVPacket containing the input buffer.
4018  * At least avpkt->data and avpkt->size should be set. Some
4019  * decoders might also require additional fields to be set.
4020  * @return A negative error code is returned if an error occurred during
4021  * decoding, otherwise the number of bytes consumed from the input
4022  * AVPacket is returned.
4023  */
4025  int *got_frame_ptr, const AVPacket *avpkt);
4026 
4027 /**
4028  * Decode the video frame of size avpkt->size from avpkt->data into picture.
4029  * Some decoders may support multiple frames in a single AVPacket, such
4030  * decoders would then just decode the first frame.
4031  *
4032  * @warning The input buffer must be FF_INPUT_BUFFER_PADDING_SIZE larger than
4033  * the actual read bytes because some optimized bitstream readers read 32 or 64
4034  * bits at once and could read over the end.
4035  *
4036  * @warning The end of the input buffer buf should be set to 0 to ensure that
4037  * no overreading happens for damaged MPEG streams.
4038  *
4039  * @note Codecs which have the CODEC_CAP_DELAY capability set have a delay
4040  * between input and output, these need to be fed with avpkt->data=NULL,
4041  * avpkt->size=0 at the end to return the remaining frames.
4042  *
4043  * @param avctx the codec context
4044  * @param[out] picture The AVFrame in which the decoded video frame will be stored.
4045  * Use av_frame_alloc() to get an AVFrame. The codec will
4046  * allocate memory for the actual bitmap by calling the
4047  * AVCodecContext.get_buffer2() callback.
4048  * When AVCodecContext.refcounted_frames is set to 1, the frame is
4049  * reference counted and the returned reference belongs to the
4050  * caller. The caller must release the frame using av_frame_unref()
4051  * when the frame is no longer needed. The caller may safely write
4052  * to the frame if av_frame_is_writable() returns 1.
4053  * When AVCodecContext.refcounted_frames is set to 0, the returned
4054  * reference belongs to the decoder and is valid only until the
4055  * next call to this function or until closing or flushing the
4056  * decoder. The caller may not write to it.
4057  *
4058  * @param[in] avpkt The input AVPacket containing the input buffer.
4059  * You can create such packet with av_init_packet() and by then setting
4060  * data and size, some decoders might in addition need other fields like
4061  * flags&AV_PKT_FLAG_KEY. All decoders are designed to use the least
4062  * fields possible.
4063  * @param[in,out] got_picture_ptr Zero if no frame could be decompressed, otherwise, it is nonzero.
4064  * @return On error a negative value is returned, otherwise the number of bytes
4065  * used or zero if no frame could be decompressed.
4066  */
4067 int avcodec_decode_video2(AVCodecContext *avctx, AVFrame *picture,
4068  int *got_picture_ptr,
4069  const AVPacket *avpkt);
4070 
4071 /**
4072  * Decode a subtitle message.
4073  * Return a negative value on error, otherwise return the number of bytes used.
4074  * If no subtitle could be decompressed, got_sub_ptr is zero.
4075  * Otherwise, the subtitle is stored in *sub.
4076  * Note that CODEC_CAP_DR1 is not available for subtitle codecs. This is for
4077  * simplicity, because the performance difference is expect to be negligible
4078  * and reusing a get_buffer written for video codecs would probably perform badly
4079  * due to a potentially very different allocation pattern.
4080  *
4081  * Some decoders (those marked with CODEC_CAP_DELAY) have a delay between input
4082  * and output. This means that for some packets they will not immediately
4083  * produce decoded output and need to be flushed at the end of decoding to get
4084  * all the decoded data. Flushing is done by calling this function with packets
4085  * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
4086  * returning subtitles. It is safe to flush even those decoders that are not
4087  * marked with CODEC_CAP_DELAY, then no subtitles will be returned.
4088  *
4089  * @param avctx the codec context
4090  * @param[out] sub The Preallocated AVSubtitle in which the decoded subtitle will be stored,
4091  * must be freed with avsubtitle_free if *got_sub_ptr is set.
4092  * @param[in,out] got_sub_ptr Zero if no subtitle could be decompressed, otherwise, it is nonzero.
4093  * @param[in] avpkt The input AVPacket containing the input buffer.
4094  */
4096  int *got_sub_ptr,
4097  AVPacket *avpkt);
4098 
4099 /**
4100  * @defgroup lavc_parsing Frame parsing
4101  * @{
4102  */
4106  AV_PICTURE_STRUCTURE_TOP_FIELD, //< coded as top field
4107  AV_PICTURE_STRUCTURE_BOTTOM_FIELD, //< coded as bottom field
4108  AV_PICTURE_STRUCTURE_FRAME, //< coded as frame
4109 };
4111 typedef struct AVCodecParserContext {
4112  void *priv_data;
4114  int64_t frame_offset; /* offset of the current frame */
4115  int64_t cur_offset; /* current offset
4116  (incremented by each av_parser_parse()) */
4117  int64_t next_frame_offset; /* offset of the next frame */
4118  /* video info */
4119  int pict_type; /* XXX: Put it back in AVCodecContext. */
4120  /**
4121  * This field is used for proper frame duration computation in lavf.
4122  * It signals, how much longer the frame duration of the current frame
4123  * is compared to normal frame duration.
4124  *
4125  * frame_duration = (1 + repeat_pict) * time_base
4126  *
4127  * It is used by codecs like H.264 to display telecined material.
4128  */
4129  int repeat_pict; /* XXX: Put it back in AVCodecContext. */
4130  int64_t pts; /* pts of the current frame */
4131  int64_t dts; /* dts of the current frame */
4132 
4133  /* private data */
4134  int64_t last_pts;
4135  int64_t last_dts;
4136  int fetch_timestamp;
4138 #define AV_PARSER_PTS_NB 4
4144  int flags;
4145 #define PARSER_FLAG_COMPLETE_FRAMES 0x0001
4146 #define PARSER_FLAG_ONCE 0x0002
4147 /// Set if the parser has a valid file offset
4148 #define PARSER_FLAG_FETCHED_OFFSET 0x0004
4149 #define PARSER_FLAG_USE_CODEC_TS 0x1000
4151  int64_t offset; ///< byte offset from starting packet start
4153 
4154  /**
4155  * Set by parser to 1 for key frames and 0 for non-key frames.
4156  * It is initialized to -1, so if the parser doesn't set this flag,
4157  * old-style fallback using AV_PICTURE_TYPE_I picture type as key frames
4158  * will be used.
4159  */
4160  int key_frame;
4161 
4162  /**
4163  * Time difference in stream time base units from the pts of this
4164  * packet to the point at which the output from the decoder has converged
4165  * independent from the availability of previous frames. That is, the
4166  * frames are virtually identical no matter if decoding started from
4167  * the very first frame or from this keyframe.
4168  * Is AV_NOPTS_VALUE if unknown.
4169  * This field is not the display duration of the current frame.
4170  * This field has no meaning if the packet does not have AV_PKT_FLAG_KEY
4171  * set.
4172  *
4173  * The purpose of this field is to allow seeking in streams that have no
4174  * keyframes in the conventional sense. It corresponds to the
4175  * recovery point SEI in H.264 and match_time_delta in NUT. It is also
4176  * essential for some types of subtitle streams to ensure that all
4177  * subtitles are correctly displayed after seeking.
4178  */
4179  int64_t convergence_duration;
4180 
4181  // Timestamp generation support:
4182  /**
4183  * Synchronization point for start of timestamp generation.
4184  *
4185  * Set to >0 for sync point, 0 for no sync point and <0 for undefined
4186  * (default).
4187  *
4188  * For example, this corresponds to presence of H.264 buffering period
4189  * SEI message.
4190  */
4191  int dts_sync_point;
4192 
4193  /**
4194  * Offset of the current timestamp against last timestamp sync point in
4195  * units of AVCodecContext.time_base.
4196  *
4197  * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
4198  * contain a valid timestamp offset.
4199  *
4200  * Note that the timestamp of sync point has usually a nonzero
4201  * dts_ref_dts_delta, which refers to the previous sync point. Offset of
4202  * the next frame after timestamp sync point will be usually 1.
4203  *
4204  * For example, this corresponds to H.264 cpb_removal_delay.
4205  */
4206  int dts_ref_dts_delta;
4207 
4208  /**
4209  * Presentation delay of current frame in units of AVCodecContext.time_base.
4210  *
4211  * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
4212  * contain valid non-negative timestamp delta (presentation time of a frame
4213  * must not lie in the past).
4214  *
4215  * This delay represents the difference between decoding and presentation
4216  * time of the frame.
4217  *
4218  * For example, this corresponds to H.264 dpb_output_delay.
4219  */
4220  int pts_dts_delta;
4221 
4222  /**
4223  * Position of the packet in file.
4224  *
4225  * Analogous to cur_frame_pts/dts
4226  */
4228 
4229  /**
4230  * Byte position of currently parsed frame in stream.
4231  */
4232  int64_t pos;
4233 
4234  /**
4235  * Previous frame byte position.
4236  */
4237  int64_t last_pos;
4238 
4239  /**
4240  * Duration of the current frame.
4241  * For audio, this is in units of 1 / AVCodecContext.sample_rate.
4242  * For all other types, this is in units of AVCodecContext.time_base.
4243  */
4244  int duration;
4247 
4248  /**
4249  * Indicate whether a picture is coded as a frame, top field or bottom field.
4250  *
4251  * For example, H.264 field_pic_flag equal to 0 corresponds to
4252  * AV_PICTURE_STRUCTURE_FRAME. An H.264 picture with field_pic_flag
4253  * equal to 1 and bottom_field_flag equal to 0 corresponds to
4254  * AV_PICTURE_STRUCTURE_TOP_FIELD.
4255  */
4257 
4258  /**
4259  * Picture number incremented in presentation or output order.
4260  * This field may be reinitialized at the first picture of a new sequence.
4261  *
4262  * For example, this corresponds to H.264 PicOrderCnt.
4263  */
4267 typedef struct AVCodecParser {
4268  int codec_ids[5]; /* several codec IDs are permitted */
4272  AVCodecContext *avctx,
4273  const uint8_t **poutbuf, int *poutbuf_size,
4274  const uint8_t *buf, int buf_size);
4276  int (*split)(AVCodecContext *avctx, const uint8_t *buf, int buf_size);
4277  struct AVCodecParser *next;
4278 } AVCodecParser;
4279 
4281 
4284 
4285 /**
4286  * Parse a packet.
4287  *
4288  * @param s parser context.
4289  * @param avctx codec context.
4290  * @param poutbuf set to pointer to parsed buffer or NULL if not yet finished.
4291  * @param poutbuf_size set to size of parsed buffer or zero if not yet finished.
4292  * @param buf input buffer.
4293  * @param buf_size input length, to signal EOF, this should be 0 (so that the last frame can be output).
4294  * @param pts input presentation timestamp.
4295  * @param dts input decoding timestamp.
4296  * @param pos input byte position in stream.
4297  * @return the number of bytes of the input bitstream used.
4298  *
4299  * Example:
4300  * @code
4301  * while(in_len){
4302  * len = av_parser_parse2(myparser, AVCodecContext, &data, &size,
4303  * in_data, in_len,
4304  * pts, dts, pos);
4305  * in_data += len;
4306  * in_len -= len;
4307  *
4308  * if(size)
4309  * decode_frame(data, size);
4310  * }
4311  * @endcode
4312  */
4314  AVCodecContext *avctx,
4315  uint8_t **poutbuf, int *poutbuf_size,
4316  const uint8_t *buf, int buf_size,
4317  int64_t pts, int64_t dts,
4318  int64_t pos);
4319 
4320 /**
4321  * @return 0 if the output buffer is a subset of the input, 1 if it is allocated and must be freed
4322  * @deprecated use AVBitStreamFilter
4323  */
4325  AVCodecContext *avctx,
4326  uint8_t **poutbuf, int *poutbuf_size,
4327  const uint8_t *buf, int buf_size, int keyframe);
4329 
4330 /**
4331  * @}
4332  * @}
4333  */
4334 
4335 /**
4336  * @addtogroup lavc_encoding
4337  * @{
4338  */
4339 
4340 /**
4341  * Find a registered encoder with a matching codec ID.
4342  *
4343  * @param id AVCodecID of the requested encoder
4344  * @return An encoder if one was found, NULL otherwise.
4345  */
4347 
4348 /**
4349  * Find a registered encoder with the specified name.
4350  *
4351  * @param name name of the requested encoder
4352  * @return An encoder if one was found, NULL otherwise.
4353  */
4355 
4356 #if FF_API_OLD_ENCODE_AUDIO
4357 /**
4358  * Encode an audio frame from samples into buf.
4359  *
4360  * @deprecated Use avcodec_encode_audio2 instead.
4361  *
4362  * @note The output buffer should be at least FF_MIN_BUFFER_SIZE bytes large.
4363  * However, for codecs with avctx->frame_size equal to 0 (e.g. PCM) the user
4364  * will know how much space is needed because it depends on the value passed
4365  * in buf_size as described below. In that case a lower value can be used.
4366  *
4367  * @param avctx the codec context
4368  * @param[out] buf the output buffer
4369  * @param[in] buf_size the output buffer size
4370  * @param[in] samples the input buffer containing the samples
4371  * The number of samples read from this buffer is frame_size*channels,
4372  * both of which are defined in avctx.
4373  * For codecs which have avctx->frame_size equal to 0 (e.g. PCM) the number of
4374  * samples read from samples is equal to:
4375  * buf_size * 8 / (avctx->channels * av_get_bits_per_sample(avctx->codec_id))
4376  * This also implies that av_get_bits_per_sample() must not return 0 for these
4377  * codecs.
4378  * @return On error a negative value is returned, on success zero or the number
4379  * of bytes used to encode the data read from the input buffer.
4380  */
4382  uint8_t *buf, int buf_size,
4383  const short *samples);
4384 #endif
4385 
4386 /**
4387  * Encode a frame of audio.
4388  *
4389  * Takes input samples from frame and writes the next output packet, if
4390  * available, to avpkt. The output packet does not necessarily contain data for
4391  * the most recent frame, as encoders can delay, split, and combine input frames
4392  * internally as needed.
4393  *
4394  * @param avctx codec context
4395  * @param avpkt output AVPacket.
4396  * The user can supply an output buffer by setting
4397  * avpkt->data and avpkt->size prior to calling the
4398  * function, but if the size of the user-provided data is not
4399  * large enough, encoding will fail. If avpkt->data and
4400  * avpkt->size are set, avpkt->destruct must also be set. All
4401  * other AVPacket fields will be reset by the encoder using
4402  * av_init_packet(). If avpkt->data is NULL, the encoder will
4403  * allocate it. The encoder will set avpkt->size to the size
4404  * of the output packet.
4405  *
4406  * If this function fails or produces no output, avpkt will be
4407  * freed using av_free_packet() (i.e. avpkt->destruct will be
4408  * called to free the user supplied buffer).
4409  * @param[in] frame AVFrame containing the raw audio data to be encoded.
4410  * May be NULL when flushing an encoder that has the
4411  * CODEC_CAP_DELAY capability set.
4412  * If CODEC_CAP_VARIABLE_FRAME_SIZE is set, then each frame
4413  * can have any number of samples.
4414  * If it is not set, frame->nb_samples must be equal to
4415  * avctx->frame_size for all frames except the last.
4416  * The final frame may be smaller than avctx->frame_size.
4417  * @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
4418  * output packet is non-empty, and to 0 if it is
4419  * empty. If the function returns an error, the
4420  * packet can be assumed to be invalid, and the
4421  * value of got_packet_ptr is undefined and should
4422  * not be used.
4423  * @return 0 on success, negative error code on failure
4424  */
4425 int avcodec_encode_audio2(AVCodecContext *avctx, AVPacket *avpkt,
4426  const AVFrame *frame, int *got_packet_ptr);
4427 
4428 #if FF_API_OLD_ENCODE_VIDEO
4429 /**
4430  * @deprecated use avcodec_encode_video2() instead.
4431  *
4432  * Encode a video frame from pict into buf.
4433  * The input picture should be
4434  * stored using a specific format, namely avctx.pix_fmt.
4435  *
4436  * @param avctx the codec context
4437  * @param[out] buf the output buffer for the bitstream of encoded frame
4438  * @param[in] buf_size the size of the output buffer in bytes
4439  * @param[in] pict the input picture to encode
4440  * @return On error a negative value is returned, on success zero or the number
4441  * of bytes used from the output buffer.
4442  */
4444 int avcodec_encode_video(AVCodecContext *avctx, uint8_t *buf, int buf_size,
4445  const AVFrame *pict);
4446 #endif
4447 
4448 /**
4449  * Encode a frame of video.
4450  *
4451  * Takes input raw video data from frame and writes the next output packet, if
4452  * available, to avpkt. The output packet does not necessarily contain data for
4453  * the most recent frame, as encoders can delay and reorder input frames
4454  * internally as needed.
4455  *
4456  * @param avctx codec context
4457  * @param avpkt output AVPacket.
4458  * The user can supply an output buffer by setting
4459  * avpkt->data and avpkt->size prior to calling the
4460  * function, but if the size of the user-provided data is not
4461  * large enough, encoding will fail. All other AVPacket fields
4462  * will be reset by the encoder using av_init_packet(). If
4463  * avpkt->data is NULL, the encoder will allocate it.
4464  * The encoder will set avpkt->size to the size of the
4465  * output packet. The returned data (if any) belongs to the
4466  * caller, he is responsible for freeing it.
4467  *
4468  * If this function fails or produces no output, avpkt will be
4469  * freed using av_free_packet() (i.e. avpkt->destruct will be
4470  * called to free the user supplied buffer).
4471  * @param[in] frame AVFrame containing the raw video data to be encoded.
4472  * May be NULL when flushing an encoder that has the
4473  * CODEC_CAP_DELAY capability set.
4474  * @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
4475  * output packet is non-empty, and to 0 if it is
4476  * empty. If the function returns an error, the
4477  * packet can be assumed to be invalid, and the
4478  * value of got_packet_ptr is undefined and should
4479  * not be used.
4480  * @return 0 on success, negative error code on failure
4481  */
4482 int avcodec_encode_video2(AVCodecContext *avctx, AVPacket *avpkt,
4483  const AVFrame *frame, int *got_packet_ptr);
4484 
4485 int avcodec_encode_subtitle(AVCodecContext *avctx, uint8_t *buf, int buf_size,
4486  const AVSubtitle *sub);
4487 
4488 
4489 /**
4490  * @}
4491  */
4492 
4493 #if FF_API_AVCODEC_RESAMPLE
4494 /**
4495  * @defgroup lavc_resample Audio resampling
4496  * @ingroup libavc
4497  * @deprecated use libswresample instead
4498  *
4499  * @{
4500  */
4501 struct ReSampleContext;
4502 struct AVResampleContext;
4503 
4504 typedef struct ReSampleContext ReSampleContext;
4505 
4506 /**
4507  * Initialize audio resampling context.
4508  *
4509  * @param output_channels number of output channels
4510  * @param input_channels number of input channels
4511  * @param output_rate output sample rate
4512  * @param input_rate input sample rate
4513  * @param sample_fmt_out requested output sample format
4514  * @param sample_fmt_in input sample format
4515  * @param filter_length length of each FIR filter in the filterbank relative to the cutoff frequency
4516  * @param log2_phase_count log2 of the number of entries in the polyphase filterbank
4517  * @param linear if 1 then the used FIR filter will be linearly interpolated
4518  between the 2 closest, if 0 the closest will be used
4519  * @param cutoff cutoff frequency, 1.0 corresponds to half the output sampling rate
4520  * @return allocated ReSampleContext, NULL if error occurred
4521  */
4524  int output_rate, int input_rate,
4525  enum AVSampleFormat sample_fmt_out,
4526  enum AVSampleFormat sample_fmt_in,
4527  int filter_length, int log2_phase_count,
4528  int linear, double cutoff);
4529 
4531 int audio_resample(ReSampleContext *s, short *output, short *input, int nb_samples);
4532 
4533 /**
4534  * Free resample context.
4535  *
4536  * @param s a non-NULL pointer to a resample context previously
4537  * created with av_audio_resample_init()
4538  */
4541 
4542 
4543 /**
4544  * Initialize an audio resampler.
4545  * Note, if either rate is not an integer then simply scale both rates up so they are.
4546  * @param filter_length length of each FIR filter in the filterbank relative to the cutoff freq
4547  * @param log2_phase_count log2 of the number of entries in the polyphase filterbank
4548  * @param linear If 1 then the used FIR filter will be linearly interpolated
4549  between the 2 closest, if 0 the closest will be used
4550  * @param cutoff cutoff frequency, 1.0 corresponds to half the output sampling rate
4551  */
4553 struct AVResampleContext *av_resample_init(int out_rate, int in_rate, int filter_length, int log2_phase_count, int linear, double cutoff);
4554 
4555 /**
4556  * Resample an array of samples using a previously configured context.
4557  * @param src an array of unconsumed samples
4558  * @param consumed the number of samples of src which have been consumed are returned here
4559  * @param src_size the number of unconsumed samples available
4560  * @param dst_size the amount of space in samples available in dst
4561  * @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.
4562  * @return the number of samples written in dst or -1 if an error occurred
4563  */
4565 int av_resample(struct AVResampleContext *c, short *dst, short *src, int *consumed, int src_size, int dst_size, int update_ctx);
4566 
4567 
4568 /**
4569  * Compensate samplerate/timestamp drift. The compensation is done by changing
4570  * the resampler parameters, so no audible clicks or similar distortions occur
4571  * @param compensation_distance distance in output samples over which the compensation should be performed
4572  * @param sample_delta number of output samples which should be output less
4573  *
4574  * example: av_resample_compensate(c, 10, 500)
4575  * here instead of 510 samples only 500 samples would be output
4576  *
4577  * note, due to rounding the actual compensation might be slightly different,
4578  * especially if the compensation_distance is large and the in_rate used during init is small
4579  */
4581 void av_resample_compensate(struct AVResampleContext *c, int sample_delta, int compensation_distance);
4583 void av_resample_close(struct AVResampleContext *c);
4584 
4585 /**
4586  * @}
4587  */
4588 #endif
4589 
4590 /**
4591  * @addtogroup lavc_picture
4592  * @{
4593  */
4594 
4595 /**
4596  * Allocate memory for the pixels of a picture and setup the AVPicture
4597  * fields for it.
4598  *
4599  * Call avpicture_free() to free it.
4600  *
4601  * @param picture the picture structure to be filled in
4602  * @param pix_fmt the pixel format of the picture
4603  * @param width the width of the picture
4604  * @param height the height of the picture
4605  * @return zero if successful, a negative error code otherwise
4606  *
4607  * @see av_image_alloc(), avpicture_fill()
4608  */
4609 int avpicture_alloc(AVPicture *picture, enum AVPixelFormat pix_fmt, int width, int height);
4610 
4611 /**
4612  * Free a picture previously allocated by avpicture_alloc().
4613  * The data buffer used by the AVPicture is freed, but the AVPicture structure
4614  * itself is not.
4615  *
4616  * @param picture the AVPicture to be freed
4617  */
4618 void avpicture_free(AVPicture *picture);
4619 
4620 /**
4621  * Setup the picture fields based on the specified image parameters
4622  * and the provided image data buffer.
4623  *
4624  * The picture fields are filled in by using the image data buffer
4625  * pointed to by ptr.
4626  *
4627  * If ptr is NULL, the function will fill only the picture linesize
4628  * array and return the required size for the image buffer.
4629  *
4630  * To allocate an image buffer and fill the picture data in one call,
4631  * use avpicture_alloc().
4632  *
4633  * @param picture the picture to be filled in
4634  * @param ptr buffer where the image data is stored, or NULL
4635  * @param pix_fmt the pixel format of the image
4636  * @param width the width of the image in pixels
4637  * @param height the height of the image in pixels
4638  * @return the size in bytes required for src, a negative error code
4639  * in case of failure
4640  *
4641  * @see av_image_fill_arrays()
4642  */
4643 int avpicture_fill(AVPicture *picture, const uint8_t *ptr,
4644  enum AVPixelFormat pix_fmt, int width, int height);
4645 
4646 /**
4647  * Copy pixel data from an AVPicture into a buffer.
4648  *
4649  * avpicture_get_size() can be used to compute the required size for
4650  * the buffer to fill.
4651  *
4652  * @param src source picture with filled data
4653  * @param pix_fmt picture pixel format
4654  * @param width picture width
4655  * @param height picture height
4656  * @param dest destination buffer
4657  * @param dest_size destination buffer size in bytes
4658  * @return the number of bytes written to dest, or a negative value
4659  * (error code) on error, for example if the destination buffer is not
4660  * big enough
4661  *
4662  * @see av_image_copy_to_buffer()
4663  */
4665  int width, int height,
4666  unsigned char *dest, int dest_size);
4667 
4668 /**
4669  * Calculate the size in bytes that a picture of the given width and height
4670  * would occupy if stored in the given picture format.
4671  *
4672  * @param pix_fmt picture pixel format
4673  * @param width picture width
4674  * @param height picture height
4675  * @return the computed picture buffer size or a negative error code
4676  * in case of error
4677  *
4678  * @see av_image_get_buffer_size().
4679  */
4681 
4682 #if FF_API_DEINTERLACE
4683 /**
4684  * deinterlace - if not supported return -1
4685  *
4686  * @deprecated - use yadif (in libavfilter) instead
4687  */
4689 int avpicture_deinterlace(AVPicture *dst, const AVPicture *src,
4690  enum AVPixelFormat pix_fmt, int width, int height);
4691 #endif
4692 /**
4693  * Copy image src to dst. Wraps av_image_copy().
4694  */
4695 void av_picture_copy(AVPicture *dst, const AVPicture *src,
4696  enum AVPixelFormat pix_fmt, int width, int height);
4697 
4698 /**
4699  * Crop image top and left side.
4700  */
4701 int av_picture_crop(AVPicture *dst, const AVPicture *src,
4702  enum AVPixelFormat pix_fmt, int top_band, int left_band);
4703 
4704 /**
4705  * Pad image.
4706  */
4707 int av_picture_pad(AVPicture *dst, const AVPicture *src, int height, int width, enum AVPixelFormat pix_fmt,
4708  int padtop, int padbottom, int padleft, int padright, int *color);
4709 
4710 /**
4711  * @}
4712  */
4713 
4714 /**
4715  * @defgroup lavc_misc Utility functions
4716  * @ingroup libavc
4717  *
4718  * Miscellaneous utility functions related to both encoding and decoding
4719  * (or neither).
4720  * @{
4721  */
4722 
4723 /**
4724  * @defgroup lavc_misc_pixfmt Pixel formats
4725  *
4726  * Functions for working with pixel formats.
4727  * @{
4728  */
4729 
4730 /**
4731  * Utility function to access log2_chroma_w log2_chroma_h from
4732  * the pixel format AVPixFmtDescriptor.
4733  *
4734  * This function asserts that pix_fmt is valid. See av_pix_fmt_get_chroma_sub_sample
4735  * for one that returns a failure code and continues in case of invalid
4736  * pix_fmts.
4737  *
4738  * @param[in] pix_fmt the pixel format
4739  * @param[out] h_shift store log2_chroma_w
4740  * @param[out] v_shift store log2_chroma_h
4741  *
4742  * @see av_pix_fmt_get_chroma_sub_sample
4743  */
4744 
4745 void avcodec_get_chroma_sub_sample(enum AVPixelFormat pix_fmt, int *h_shift, int *v_shift);
4746 
4747 /**
4748  * Return a value representing the fourCC code associated to the
4749  * pixel format pix_fmt, or 0 if no associated fourCC code can be
4750  * found.
4751  */
4753 
4754 /**
4755  * @deprecated see av_get_pix_fmt_loss()
4756  */
4757 int avcodec_get_pix_fmt_loss(enum AVPixelFormat dst_pix_fmt, enum AVPixelFormat src_pix_fmt,
4758  int has_alpha);
4759 
4760 /**
4761  * Find the best pixel format to convert to given a certain source pixel
4762  * format. When converting from one pixel format to another, information loss
4763  * may occur. For example, when converting from RGB24 to GRAY, the color
4764  * information will be lost. Similarly, other losses occur when converting from
4765  * some formats to other formats. avcodec_find_best_pix_fmt_of_2() searches which of
4766  * the given pixel formats should be used to suffer the least amount of loss.
4767  * The pixel formats from which it chooses one, are determined by the
4768  * pix_fmt_list parameter.
4769  *
4770  *
4771  * @param[in] pix_fmt_list AV_PIX_FMT_NONE terminated array of pixel formats to choose from
4772  * @param[in] src_pix_fmt source pixel format
4773  * @param[in] has_alpha Whether the source pixel format alpha channel is used.
4774  * @param[out] loss_ptr Combination of flags informing you what kind of losses will occur.
4775  * @return The best pixel format to convert to or -1 if none was found.
4776  */
4777 enum AVPixelFormat avcodec_find_best_pix_fmt_of_list(const enum AVPixelFormat *pix_fmt_list,
4778  enum AVPixelFormat src_pix_fmt,
4779  int has_alpha, int *loss_ptr);
4780 
4781 /**
4782  * @deprecated see av_find_best_pix_fmt_of_2()
4783  */
4784 enum AVPixelFormat avcodec_find_best_pix_fmt_of_2(enum AVPixelFormat dst_pix_fmt1, enum AVPixelFormat dst_pix_fmt2,
4785  enum AVPixelFormat src_pix_fmt, int has_alpha, int *loss_ptr);
4786 
4788 #if AV_HAVE_INCOMPATIBLE_LIBAV_ABI
4789 enum AVPixelFormat avcodec_find_best_pix_fmt2(const enum AVPixelFormat *pix_fmt_list,
4790  enum AVPixelFormat src_pix_fmt,
4791  int has_alpha, int *loss_ptr);
4792 #else
4793 enum AVPixelFormat avcodec_find_best_pix_fmt2(enum AVPixelFormat dst_pix_fmt1, enum AVPixelFormat dst_pix_fmt2,
4794  enum AVPixelFormat src_pix_fmt, int has_alpha, int *loss_ptr);
4795 #endif
4796 
4797 
4799 
4800 /**
4801  * @}
4802  */
4803 
4804 #if FF_API_SET_DIMENSIONS
4805 /**
4806  * @deprecated this function is not supposed to be used from outside of lavc
4807  */
4810 #endif
4811 
4812 /**
4813  * Put a string representing the codec tag codec_tag in buf.
4814  *
4815  * @param buf buffer to place codec tag in
4816  * @param buf_size size in bytes of buf
4817  * @param codec_tag codec tag to assign
4818  * @return the length of the string that would have been generated if
4819  * enough space had been available, excluding the trailing null
4820  */
4821 size_t av_get_codec_tag_string(char *buf, size_t buf_size, unsigned int codec_tag);
4822 
4823 void avcodec_string(char *buf, int buf_size, AVCodecContext *enc, int encode);
4824 
4825 /**
4826  * Return a name for the specified profile, if available.
4827  *
4828  * @param codec the codec that is searched for the given profile
4829  * @param profile the profile value for which a name is requested
4830  * @return A name for the profile if found, NULL otherwise.
4831  */
4832 const char *av_get_profile_name(const AVCodec *codec, int profile);
4833 
4834 int avcodec_default_execute(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2),void *arg, int *ret, int count, int size);
4835 int avcodec_default_execute2(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2, int, int),void *arg, int *ret, int count);
4836 //FIXME func typedef
4837 
4838 /**
4839  * Fill AVFrame audio data and linesize pointers.
4840  *
4841  * The buffer buf must be a preallocated buffer with a size big enough
4842  * to contain the specified samples amount. The filled AVFrame data
4843  * pointers will point to this buffer.
4844  *
4845  * AVFrame extended_data channel pointers are allocated if necessary for
4846  * planar audio.
4847  *
4848  * @param frame the AVFrame
4849  * frame->nb_samples must be set prior to calling the
4850  * function. This function fills in frame->data,
4851  * frame->extended_data, frame->linesize[0].
4852  * @param nb_channels channel count