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avcodec.h
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1 /*
2  * copyright (c) 2001 Fabrice Bellard
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #ifndef AVCODEC_AVCODEC_H
22 #define AVCODEC_AVCODEC_H
23 
24 /**
25  * @file
26  * @ingroup libavc
27  * Libavcodec external API header
28  */
29 
30 #include <errno.h>
31 #include "libavutil/samplefmt.h"
32 #include "libavutil/attributes.h"
33 #include "libavutil/avutil.h"
34 #include "libavutil/buffer.h"
35 #include "libavutil/cpu.h"
37 #include "libavutil/dict.h"
38 #include "libavutil/frame.h"
39 #include "libavutil/log.h"
40 #include "libavutil/pixfmt.h"
41 #include "libavutil/rational.h"
42 
43 #include "version.h"
44 
45 /**
46  * @defgroup libavc Encoding/Decoding Library
47  * @{
48  *
49  * @defgroup lavc_decoding Decoding
50  * @{
51  * @}
52  *
53  * @defgroup lavc_encoding Encoding
54  * @{
55  * @}
56  *
57  * @defgroup lavc_codec Codecs
58  * @{
59  * @defgroup lavc_codec_native Native Codecs
60  * @{
61  * @}
62  * @defgroup lavc_codec_wrappers External library wrappers
63  * @{
64  * @}
65  * @defgroup lavc_codec_hwaccel Hardware Accelerators bridge
66  * @{
67  * @}
68  * @}
69  * @defgroup lavc_internal Internal
70  * @{
71  * @}
72  * @}
73  *
74  */
75 
76 /**
77  * @defgroup lavc_core Core functions/structures.
78  * @ingroup libavc
79  *
80  * Basic definitions, functions for querying libavcodec capabilities,
81  * allocating core structures, etc.
82  * @{
83  */
84 
85 
86 /**
87  * Identify the syntax and semantics of the bitstream.
88  * The principle is roughly:
89  * Two decoders with the same ID can decode the same streams.
90  * Two encoders with the same ID can encode compatible streams.
91  * There may be slight deviations from the principle due to implementation
92  * details.
93  *
94  * If you add a codec ID to this list, add it so that
95  * 1. no value of a existing codec ID changes (that would break ABI),
96  * 2. Give it a value which when taken as ASCII is recognized uniquely by a human as this specific codec.
97  * This ensures that 2 forks can independently add AVCodecIDs without producing conflicts.
98  *
99  * After adding new codec IDs, do not forget to add an entry to the codec
100  * descriptor list and bump libavcodec minor version.
101  */
102 enum AVCodecID {
104 
105  /* video codecs */
107  AV_CODEC_ID_MPEG2VIDEO, ///< preferred ID for MPEG-1/2 video decoding
108 #if FF_API_XVMC
109  AV_CODEC_ID_MPEG2VIDEO_XVMC,
110 #endif /* FF_API_XVMC */
293 
294  AV_CODEC_ID_BRENDER_PIX= MKBETAG('B','P','I','X'),
295  AV_CODEC_ID_Y41P = MKBETAG('Y','4','1','P'),
296  AV_CODEC_ID_ESCAPE130 = MKBETAG('E','1','3','0'),
297  AV_CODEC_ID_EXR = MKBETAG('0','E','X','R'),
298  AV_CODEC_ID_AVRP = MKBETAG('A','V','R','P'),
299 
300  AV_CODEC_ID_012V = MKBETAG('0','1','2','V'),
301  AV_CODEC_ID_G2M = MKBETAG( 0 ,'G','2','M'),
302  AV_CODEC_ID_AVUI = MKBETAG('A','V','U','I'),
303  AV_CODEC_ID_AYUV = MKBETAG('A','Y','U','V'),
304  AV_CODEC_ID_TARGA_Y216 = MKBETAG('T','2','1','6'),
305  AV_CODEC_ID_V308 = MKBETAG('V','3','0','8'),
306  AV_CODEC_ID_V408 = MKBETAG('V','4','0','8'),
307  AV_CODEC_ID_YUV4 = MKBETAG('Y','U','V','4'),
308  AV_CODEC_ID_SANM = MKBETAG('S','A','N','M'),
309  AV_CODEC_ID_PAF_VIDEO = MKBETAG('P','A','F','V'),
310  AV_CODEC_ID_AVRN = MKBETAG('A','V','R','n'),
311  AV_CODEC_ID_CPIA = MKBETAG('C','P','I','A'),
312  AV_CODEC_ID_XFACE = MKBETAG('X','F','A','C'),
313  AV_CODEC_ID_SGIRLE = MKBETAG('S','G','I','R'),
314  AV_CODEC_ID_MVC1 = MKBETAG('M','V','C','1'),
315  AV_CODEC_ID_MVC2 = MKBETAG('M','V','C','2'),
316  AV_CODEC_ID_SNOW = MKBETAG('S','N','O','W'),
317  AV_CODEC_ID_WEBP = MKBETAG('W','E','B','P'),
318  AV_CODEC_ID_SMVJPEG = MKBETAG('S','M','V','J'),
319  AV_CODEC_ID_HEVC = MKBETAG('H','2','6','5'),
320 #define AV_CODEC_ID_H265 AV_CODEC_ID_HEVC
321  AV_CODEC_ID_VP7 = MKBETAG('V','P','7','0'),
322 
323  /* various PCM "codecs" */
324  AV_CODEC_ID_FIRST_AUDIO = 0x10000, ///< A dummy id pointing at the start of audio codecs
358 
359  /* various ADPCM codecs */
391  AV_CODEC_ID_ADPCM_VIMA = MKBETAG('V','I','M','A'),
392  AV_CODEC_ID_VIMA = MKBETAG('V','I','M','A'),
393  AV_CODEC_ID_ADPCM_AFC = MKBETAG('A','F','C',' '),
394  AV_CODEC_ID_ADPCM_IMA_OKI = MKBETAG('O','K','I',' '),
395  AV_CODEC_ID_ADPCM_DTK = MKBETAG('D','T','K',' '),
396  AV_CODEC_ID_ADPCM_IMA_RAD = MKBETAG('R','A','D',' '),
397  AV_CODEC_ID_ADPCM_G726LE = MKBETAG('6','2','7','G'),
398 
399  /* AMR */
402 
403  /* RealAudio codecs*/
406 
407  /* various DPCM codecs */
412 
413  /* audio codecs */
414  AV_CODEC_ID_MP2 = 0x15000,
415  AV_CODEC_ID_MP3, ///< preferred ID for decoding MPEG audio layer 1, 2 or 3
432  AV_CODEC_ID_GSM, ///< as in Berlin toast format
444  AV_CODEC_ID_GSM_MS, /* as found in WAV */
446 #if FF_API_VOXWARE
448 #endif
483  AV_CODEC_ID_FFWAVESYNTH = MKBETAG('F','F','W','S'),
484  AV_CODEC_ID_SONIC = MKBETAG('S','O','N','C'),
485  AV_CODEC_ID_SONIC_LS = MKBETAG('S','O','N','L'),
486  AV_CODEC_ID_PAF_AUDIO = MKBETAG('P','A','F','A'),
487  AV_CODEC_ID_OPUS = MKBETAG('O','P','U','S'),
488  AV_CODEC_ID_TAK = MKBETAG('t','B','a','K'),
489  AV_CODEC_ID_EVRC = MKBETAG('s','e','v','c'),
490  AV_CODEC_ID_SMV = MKBETAG('s','s','m','v'),
491  AV_CODEC_ID_DSD_LSBF = MKBETAG('D','S','D','L'),
492  AV_CODEC_ID_DSD_MSBF = MKBETAG('D','S','D','M'),
495 
496  /* subtitle codecs */
497  AV_CODEC_ID_FIRST_SUBTITLE = 0x17000, ///< A dummy ID pointing at the start of subtitle codecs.
500  AV_CODEC_ID_TEXT, ///< raw UTF-8 text
507  AV_CODEC_ID_MICRODVD = MKBETAG('m','D','V','D'),
508  AV_CODEC_ID_EIA_608 = MKBETAG('c','6','0','8'),
509  AV_CODEC_ID_JACOSUB = MKBETAG('J','S','U','B'),
510  AV_CODEC_ID_SAMI = MKBETAG('S','A','M','I'),
511  AV_CODEC_ID_REALTEXT = MKBETAG('R','T','X','T'),
512  AV_CODEC_ID_STL = MKBETAG('S','p','T','L'),
513  AV_CODEC_ID_SUBVIEWER1 = MKBETAG('S','b','V','1'),
514  AV_CODEC_ID_SUBVIEWER = MKBETAG('S','u','b','V'),
515  AV_CODEC_ID_SUBRIP = MKBETAG('S','R','i','p'),
516  AV_CODEC_ID_WEBVTT = MKBETAG('W','V','T','T'),
517  AV_CODEC_ID_MPL2 = MKBETAG('M','P','L','2'),
518  AV_CODEC_ID_VPLAYER = MKBETAG('V','P','l','r'),
519  AV_CODEC_ID_PJS = MKBETAG('P','h','J','S'),
520  AV_CODEC_ID_ASS = MKBETAG('A','S','S',' '), ///< ASS as defined in Matroska
521 
522  /* other specific kind of codecs (generally used for attachments) */
523  AV_CODEC_ID_FIRST_UNKNOWN = 0x18000, ///< A dummy ID pointing at the start of various fake codecs.
524  AV_CODEC_ID_TTF = 0x18000,
525  AV_CODEC_ID_BINTEXT = MKBETAG('B','T','X','T'),
526  AV_CODEC_ID_XBIN = MKBETAG('X','B','I','N'),
527  AV_CODEC_ID_IDF = MKBETAG( 0 ,'I','D','F'),
528  AV_CODEC_ID_OTF = MKBETAG( 0 ,'O','T','F'),
529  AV_CODEC_ID_SMPTE_KLV = MKBETAG('K','L','V','A'),
530  AV_CODEC_ID_DVD_NAV = MKBETAG('D','N','A','V'),
531  AV_CODEC_ID_TIMED_ID3 = MKBETAG('T','I','D','3'),
532  AV_CODEC_ID_BIN_DATA = MKBETAG('D','A','T','A'),
533 
534 
535  AV_CODEC_ID_PROBE = 0x19000, ///< codec_id is not known (like AV_CODEC_ID_NONE) but lavf should attempt to identify it
536 
537  AV_CODEC_ID_MPEG2TS = 0x20000, /**< _FAKE_ codec to indicate a raw MPEG-2 TS
538  * stream (only used by libavformat) */
539  AV_CODEC_ID_MPEG4SYSTEMS = 0x20001, /**< _FAKE_ codec to indicate a MPEG-4 Systems
540  * stream (only used by libavformat) */
541  AV_CODEC_ID_FFMETADATA = 0x21000, ///< Dummy codec for streams containing only metadata information.
542 
543 #if FF_API_CODEC_ID
544 #include "old_codec_ids.h"
545 #endif
546 };
547 
548 /**
549  * This struct describes the properties of a single codec described by an
550  * AVCodecID.
551  * @see avcodec_descriptor_get()
552  */
553 typedef struct AVCodecDescriptor {
554  enum AVCodecID id;
556  /**
557  * Name of the codec described by this descriptor. It is non-empty and
558  * unique for each codec descriptor. It should contain alphanumeric
559  * characters and '_' only.
560  */
561  const char *name;
562  /**
563  * A more descriptive name for this codec. May be NULL.
564  */
565  const char *long_name;
566  /**
567  * Codec properties, a combination of AV_CODEC_PROP_* flags.
568  */
569  int props;
570 
571  /**
572  * MIME type(s) associated with the codec.
573  * May be NULL; if not, a NULL-terminated array of MIME types.
574  * The first item is always non-NULL and is the preferred MIME type.
575  */
576  const char *const *mime_types;
579 /**
580  * Codec uses only intra compression.
581  * Video codecs only.
582  */
583 #define AV_CODEC_PROP_INTRA_ONLY (1 << 0)
584 /**
585  * Codec supports lossy compression. Audio and video codecs only.
586  * @note a codec may support both lossy and lossless
587  * compression modes
588  */
589 #define AV_CODEC_PROP_LOSSY (1 << 1)
590 /**
591  * Codec supports lossless compression. Audio and video codecs only.
592  */
593 #define AV_CODEC_PROP_LOSSLESS (1 << 2)
594 /**
595  * Codec supports frame reordering. That is, the coded order (the order in which
596  * the encoded packets are output by the encoders / stored / input to the
597  * decoders) may be different from the presentation order of the corresponding
598  * frames.
599  *
600  * For codecs that do not have this property set, PTS and DTS should always be
601  * equal.
602  */
603 #define AV_CODEC_PROP_REORDER (1 << 3)
604 /**
605  * Subtitle codec is bitmap based
606  * Decoded AVSubtitle data can be read from the AVSubtitleRect->pict field.
607  */
608 #define AV_CODEC_PROP_BITMAP_SUB (1 << 16)
609 /**
610  * Subtitle codec is text based.
611  * Decoded AVSubtitle data can be read from the AVSubtitleRect->ass field.
612  */
613 #define AV_CODEC_PROP_TEXT_SUB (1 << 17)
615 /**
616  * @ingroup lavc_decoding
617  * Required number of additionally allocated bytes at the end of the input bitstream for decoding.
618  * This is mainly needed because some optimized bitstream readers read
619  * 32 or 64 bit at once and could read over the end.<br>
620  * Note: If the first 23 bits of the additional bytes are not 0, then damaged
621  * MPEG bitstreams could cause overread and segfault.
622  */
623 #define FF_INPUT_BUFFER_PADDING_SIZE 32
625 /**
626  * @ingroup lavc_encoding
627  * minimum encoding buffer size
628  * Used to avoid some checks during header writing.
629  */
630 #define FF_MIN_BUFFER_SIZE 16384
633 /**
634  * @ingroup lavc_encoding
635  * motion estimation type.
636  */
638  ME_ZERO = 1, ///< no search, that is use 0,0 vector whenever one is needed
642  ME_EPZS, ///< enhanced predictive zonal search
643  ME_X1, ///< reserved for experiments
644  ME_HEX, ///< hexagon based search
645  ME_UMH, ///< uneven multi-hexagon search
646  ME_TESA, ///< transformed exhaustive search algorithm
647  ME_ITER=50, ///< iterative search
648 };
650 /**
651  * @ingroup lavc_decoding
652  */
654  /* We leave some space between them for extensions (drop some
655  * keyframes for intra-only or drop just some bidir frames). */
656  AVDISCARD_NONE =-16, ///< discard nothing
657  AVDISCARD_DEFAULT = 0, ///< discard useless packets like 0 size packets in avi
658  AVDISCARD_NONREF = 8, ///< discard all non reference
659  AVDISCARD_BIDIR = 16, ///< discard all bidirectional frames
660  AVDISCARD_NONINTRA= 24, ///< discard all non intra frames
661  AVDISCARD_NONKEY = 32, ///< discard all frames except keyframes
662  AVDISCARD_ALL = 48, ///< discard all
663 };
675  AV_AUDIO_SERVICE_TYPE_NB , ///< Not part of ABI
676 };
678 /**
679  * @ingroup lavc_encoding
680  */
681 typedef struct RcOverride{
684  int qscale; // If this is 0 then quality_factor will be used instead.
688 #if FF_API_MAX_BFRAMES
689 /**
690  * @deprecated there is no libavcodec-wide limit on the number of B-frames
691  */
692 #define FF_MAX_B_FRAMES 16
693 #endif
695 /* encoding support
696  These flags can be passed in AVCodecContext.flags before initialization.
697  Note: Not everything is supported yet.
698 */
700 /**
701  * Allow decoders to produce frames with data planes that are not aligned
702  * to CPU requirements (e.g. due to cropping).
703  */
704 #define CODEC_FLAG_UNALIGNED 0x0001
705 #define CODEC_FLAG_QSCALE 0x0002 ///< Use fixed qscale.
706 #define CODEC_FLAG_4MV 0x0004 ///< 4 MV per MB allowed / advanced prediction for H.263.
707 #define CODEC_FLAG_OUTPUT_CORRUPT 0x0008 ///< Output even those frames that might be corrupted
708 #define CODEC_FLAG_QPEL 0x0010 ///< Use qpel MC.
709 #if FF_API_GMC
710 /**
711  * @deprecated use the "gmc" private option of the libxvid encoder
712  */
713 #define CODEC_FLAG_GMC 0x0020 ///< Use GMC.
714 #endif
715 #if FF_API_MV0
716 /**
717  * @deprecated use the flag "mv0" in the "mpv_flags" private option of the
718  * mpegvideo encoders
719  */
720 #define CODEC_FLAG_MV0 0x0040
721 #endif
722 #if FF_API_INPUT_PRESERVED
723 /**
724  * @deprecated passing reference-counted frames to the encoders replaces this
725  * flag
726  */
727 #define CODEC_FLAG_INPUT_PRESERVED 0x0100
728 #endif
729 #define CODEC_FLAG_PASS1 0x0200 ///< Use internal 2pass ratecontrol in first pass mode.
730 #define CODEC_FLAG_PASS2 0x0400 ///< Use internal 2pass ratecontrol in second pass mode.
731 #define CODEC_FLAG_GRAY 0x2000 ///< Only decode/encode grayscale.
732 #if FF_API_EMU_EDGE
733 /**
734  * @deprecated edges are not used/required anymore. I.e. this flag is now always
735  * set.
736  */
737 #define CODEC_FLAG_EMU_EDGE 0x4000
738 #endif
739 #define CODEC_FLAG_PSNR 0x8000 ///< error[?] variables will be set during encoding.
740 #define CODEC_FLAG_TRUNCATED 0x00010000 /** Input bitstream might be truncated at a random
741  location instead of only at frame boundaries. */
742 #if FF_API_NORMALIZE_AQP
743 /**
744  * @deprecated use the flag "naq" in the "mpv_flags" private option of the
745  * mpegvideo encoders
746  */
747 #define CODEC_FLAG_NORMALIZE_AQP 0x00020000
748 #endif
749 #define CODEC_FLAG_INTERLACED_DCT 0x00040000 ///< Use interlaced DCT.
750 #define CODEC_FLAG_LOW_DELAY 0x00080000 ///< Force low delay.
751 #define CODEC_FLAG_GLOBAL_HEADER 0x00400000 ///< Place global headers in extradata instead of every keyframe.
752 #define CODEC_FLAG_BITEXACT 0x00800000 ///< Use only bitexact stuff (except (I)DCT).
753 /* Fx : Flag for h263+ extra options */
754 #define CODEC_FLAG_AC_PRED 0x01000000 ///< H.263 advanced intra coding / MPEG-4 AC prediction
755 #define CODEC_FLAG_LOOP_FILTER 0x00000800 ///< loop filter
756 #define CODEC_FLAG_INTERLACED_ME 0x20000000 ///< interlaced motion estimation
757 #define CODEC_FLAG_CLOSED_GOP 0x80000000
758 #define CODEC_FLAG2_FAST 0x00000001 ///< Allow non spec compliant speedup tricks.
759 #define CODEC_FLAG2_NO_OUTPUT 0x00000004 ///< Skip bitstream encoding.
760 #define CODEC_FLAG2_LOCAL_HEADER 0x00000008 ///< Place global headers at every keyframe instead of in extradata.
761 #define CODEC_FLAG2_DROP_FRAME_TIMECODE 0x00002000 ///< timecode is in drop frame format. DEPRECATED!!!!
762 #define CODEC_FLAG2_IGNORE_CROP 0x00010000 ///< Discard cropping information from SPS.
764 #define CODEC_FLAG2_CHUNKS 0x00008000 ///< Input bitstream might be truncated at a packet boundaries instead of only at frame boundaries.
765 #define CODEC_FLAG2_SHOW_ALL 0x00400000 ///< Show all frames before the first keyframe
766 #define CODEC_FLAG2_EXPORT_MVS 0x10000000 ///< Export motion vectors through frame side data
767 #define CODEC_FLAG2_SKIP_MANUAL 0x20000000 ///< Do not skip samples and export skip information as frame side data
769 /* Unsupported options :
770  * Syntax Arithmetic coding (SAC)
771  * Reference Picture Selection
772  * Independent Segment Decoding */
773 /* /Fx */
774 /* codec capabilities */
776 #define CODEC_CAP_DRAW_HORIZ_BAND 0x0001 ///< Decoder can use draw_horiz_band callback.
777 /**
778  * Codec uses get_buffer() for allocating buffers and supports custom allocators.
779  * If not set, it might not use get_buffer() at all or use operations that
780  * assume the buffer was allocated by avcodec_default_get_buffer.
781  */
782 #define CODEC_CAP_DR1 0x0002
783 #define CODEC_CAP_TRUNCATED 0x0008
784 #if FF_API_XVMC
785 /* Codec can export data for HW decoding. This flag indicates that
786  * the codec would call get_format() with list that might contain HW accelerated
787  * pixel formats (XvMC, VDPAU, VAAPI, etc). The application can pick any of them
788  * including raw image format.
789  * The application can use the passed context to determine bitstream version,
790  * chroma format, resolution etc.
791  */
792 #define CODEC_CAP_HWACCEL 0x0010
793 #endif /* FF_API_XVMC */
794 /**
795  * Encoder or decoder requires flushing with NULL input at the end in order to
796  * give the complete and correct output.
797  *
798  * NOTE: If this flag is not set, the codec is guaranteed to never be fed with
799  * with NULL data. The user can still send NULL data to the public encode
800  * or decode function, but libavcodec will not pass it along to the codec
801  * unless this flag is set.
802  *
803  * Decoders:
804  * The decoder has a non-zero delay and needs to be fed with avpkt->data=NULL,
805  * avpkt->size=0 at the end to get the delayed data until the decoder no longer
806  * returns frames.
807  *
808  * Encoders:
809  * The encoder needs to be fed with NULL data at the end of encoding until the
810  * encoder no longer returns data.
811  *
812  * NOTE: For encoders implementing the AVCodec.encode2() function, setting this
813  * flag also means that the encoder must set the pts and duration for
814  * each output packet. If this flag is not set, the pts and duration will
815  * be determined by libavcodec from the input frame.
816  */
817 #define CODEC_CAP_DELAY 0x0020
818 /**
819  * Codec can be fed a final frame with a smaller size.
820  * This can be used to prevent truncation of the last audio samples.
821  */
822 #define CODEC_CAP_SMALL_LAST_FRAME 0x0040
823 #if FF_API_CAP_VDPAU
824 /**
825  * Codec can export data for HW decoding (VDPAU).
826  */
827 #define CODEC_CAP_HWACCEL_VDPAU 0x0080
828 #endif
829 /**
830  * Codec can output multiple frames per AVPacket
831  * Normally demuxers return one frame at a time, demuxers which do not do
832  * are connected to a parser to split what they return into proper frames.
833  * This flag is reserved to the very rare category of codecs which have a
834  * bitstream that cannot be split into frames without timeconsuming
835  * operations like full decoding. Demuxers carring such bitstreams thus
836  * may return multiple frames in a packet. This has many disadvantages like
837  * prohibiting stream copy in many cases thus it should only be considered
838  * as a last resort.
839  */
840 #define CODEC_CAP_SUBFRAMES 0x0100
841 /**
842  * Codec is experimental and is thus avoided in favor of non experimental
843  * encoders
844  */
845 #define CODEC_CAP_EXPERIMENTAL 0x0200
846 /**
847  * Codec should fill in channel configuration and samplerate instead of container
848  */
849 #define CODEC_CAP_CHANNEL_CONF 0x0400
850 #if FF_API_NEG_LINESIZES
851 /**
852  * @deprecated no codecs use this capability
853  */
854 #define CODEC_CAP_NEG_LINESIZES 0x0800
855 #endif
856 /**
857  * Codec supports frame-level multithreading.
858  */
859 #define CODEC_CAP_FRAME_THREADS 0x1000
860 /**
861  * Codec supports slice-based (or partition-based) multithreading.
862  */
863 #define CODEC_CAP_SLICE_THREADS 0x2000
864 /**
865  * Codec supports changed parameters at any point.
866  */
867 #define CODEC_CAP_PARAM_CHANGE 0x4000
868 /**
869  * Codec supports avctx->thread_count == 0 (auto).
870  */
871 #define CODEC_CAP_AUTO_THREADS 0x8000
872 /**
873  * Audio encoder supports receiving a different number of samples in each call.
874  */
875 #define CODEC_CAP_VARIABLE_FRAME_SIZE 0x10000
876 /**
877  * Codec is intra only.
878  */
879 #define CODEC_CAP_INTRA_ONLY 0x40000000
880 /**
881  * Codec is lossless.
882  */
883 #define CODEC_CAP_LOSSLESS 0x80000000
885 #if FF_API_MB_TYPE
886 //The following defines may change, don't expect compatibility if you use them.
887 #define MB_TYPE_INTRA4x4 0x0001
888 #define MB_TYPE_INTRA16x16 0x0002 //FIXME H.264-specific
889 #define MB_TYPE_INTRA_PCM 0x0004 //FIXME H.264-specific
890 #define MB_TYPE_16x16 0x0008
891 #define MB_TYPE_16x8 0x0010
892 #define MB_TYPE_8x16 0x0020
893 #define MB_TYPE_8x8 0x0040
894 #define MB_TYPE_INTERLACED 0x0080
895 #define MB_TYPE_DIRECT2 0x0100 //FIXME
896 #define MB_TYPE_ACPRED 0x0200
897 #define MB_TYPE_GMC 0x0400
898 #define MB_TYPE_SKIP 0x0800
899 #define MB_TYPE_P0L0 0x1000
900 #define MB_TYPE_P1L0 0x2000
901 #define MB_TYPE_P0L1 0x4000
902 #define MB_TYPE_P1L1 0x8000
903 #define MB_TYPE_L0 (MB_TYPE_P0L0 | MB_TYPE_P1L0)
904 #define MB_TYPE_L1 (MB_TYPE_P0L1 | MB_TYPE_P1L1)
905 #define MB_TYPE_L0L1 (MB_TYPE_L0 | MB_TYPE_L1)
906 #define MB_TYPE_QUANT 0x00010000
907 #define MB_TYPE_CBP 0x00020000
908 //Note bits 24-31 are reserved for codec specific use (h264 ref0, mpeg1 0mv, ...)
909 #endif
911 /**
912  * Pan Scan area.
913  * This specifies the area which should be displayed.
914  * Note there may be multiple such areas for one frame.
915  */
916 typedef struct AVPanScan{
917  /**
918  * id
919  * - encoding: Set by user.
920  * - decoding: Set by libavcodec.
921  */
922  int id;
924  /**
925  * width and height in 1/16 pel
926  * - encoding: Set by user.
927  * - decoding: Set by libavcodec.
928  */
929  int width;
930  int height;
932  /**
933  * position of the top left corner in 1/16 pel for up to 3 fields/frames
934  * - encoding: Set by user.
935  * - decoding: Set by libavcodec.
936  */
937  int16_t position[3][2];
938 }AVPanScan;
940 #if FF_API_QSCALE_TYPE
941 #define FF_QSCALE_TYPE_MPEG1 0
942 #define FF_QSCALE_TYPE_MPEG2 1
943 #define FF_QSCALE_TYPE_H264 2
944 #define FF_QSCALE_TYPE_VP56 3
945 #endif
946 
947 #if FF_API_GET_BUFFER
948 #define FF_BUFFER_TYPE_INTERNAL 1
949 #define FF_BUFFER_TYPE_USER 2 ///< direct rendering buffers (image is (de)allocated by user)
950 #define FF_BUFFER_TYPE_SHARED 4 ///< Buffer from somewhere else; don't deallocate image (data/base), all other tables are not shared.
951 #define FF_BUFFER_TYPE_COPY 8 ///< Just a (modified) copy of some other buffer, don't deallocate anything.
953 #define FF_BUFFER_HINTS_VALID 0x01 // Buffer hints value is meaningful (if 0 ignore).
954 #define FF_BUFFER_HINTS_READABLE 0x02 // Codec will read from buffer.
955 #define FF_BUFFER_HINTS_PRESERVE 0x04 // User must not alter buffer content.
956 #define FF_BUFFER_HINTS_REUSABLE 0x08 // Codec will reuse the buffer (update).
957 #endif
958 
959 /**
960  * The decoder will keep a reference to the frame and may reuse it later.
961  */
962 #define AV_GET_BUFFER_FLAG_REF (1 << 0)
963 
964 /**
965  * @defgroup lavc_packet AVPacket
966  *
967  * Types and functions for working with AVPacket.
968  * @{
969  */
973 
974  /**
975  * An AV_PKT_DATA_PARAM_CHANGE side data packet is laid out as follows:
976  * @code
977  * u32le param_flags
978  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT)
979  * s32le channel_count
980  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT)
981  * u64le channel_layout
982  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE)
983  * s32le sample_rate
984  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS)
985  * s32le width
986  * s32le height
987  * @endcode
988  */
990 
991  /**
992  * An AV_PKT_DATA_H263_MB_INFO side data packet contains a number of
993  * structures with info about macroblocks relevant to splitting the
994  * packet into smaller packets on macroblock edges (e.g. as for RFC 2190).
995  * That is, it does not necessarily contain info about all macroblocks,
996  * as long as the distance between macroblocks in the info is smaller
997  * than the target payload size.
998  * Each MB info structure is 12 bytes, and is laid out as follows:
999  * @code
1000  * u32le bit offset from the start of the packet
1001  * u8 current quantizer at the start of the macroblock
1002  * u8 GOB number
1003  * u16le macroblock address within the GOB
1004  * u8 horizontal MV predictor
1005  * u8 vertical MV predictor
1006  * u8 horizontal MV predictor for block number 3
1007  * u8 vertical MV predictor for block number 3
1008  * @endcode
1009  */
1011 
1012  /**
1013  * This side data should be associated with an audio stream and contains
1014  * ReplayGain information in form of the AVReplayGain struct.
1015  */
1017 
1018  /**
1019  * This side data contains a 3x3 transformation matrix describing an affine
1020  * transformation that needs to be applied to the decoded video frames for
1021  * correct presentation.
1022  *
1023  * See libavutil/display.h for a detailed description of the data.
1024  */
1026 
1027  /**
1028  * This side data should be associated with a video stream and contains
1029  * Stereoscopic 3D information in form of the AVStereo3D struct.
1030  */
1032 
1033  /**
1034  * Recommmends skipping the specified number of samples
1035  * @code
1036  * u32le number of samples to skip from start of this packet
1037  * u32le number of samples to skip from end of this packet
1038  * u8 reason for start skip
1039  * u8 reason for end skip (0=padding silence, 1=convergence)
1040  * @endcode
1041  */
1043 
1044  /**
1045  * An AV_PKT_DATA_JP_DUALMONO side data packet indicates that
1046  * the packet may contain "dual mono" audio specific to Japanese DTV
1047  * and if it is true, recommends only the selected channel to be used.
1048  * @code
1049  * u8 selected channels (0=mail/left, 1=sub/right, 2=both)
1050  * @endcode
1051  */
1053 
1054  /**
1055  * A list of zero terminated key/value strings. There is no end marker for
1056  * the list, so it is required to rely on the side data size to stop.
1057  */
1059 
1060  /**
1061  * Subtitle event position
1062  * @code
1063  * u32le x1
1064  * u32le y1
1065  * u32le x2
1066  * u32le y2
1067  * @endcode
1068  */
1070 
1071  /**
1072  * Data found in BlockAdditional element of matroska container. There is
1073  * no end marker for the data, so it is required to rely on the side data
1074  * size to recognize the end. 8 byte id (as found in BlockAddId) followed
1075  * by data.
1076  */
1078 
1079  /**
1080  * The optional first identifier line of a WebVTT cue.
1081  */
1083 
1084  /**
1085  * The optional settings (rendering instructions) that immediately
1086  * follow the timestamp specifier of a WebVTT cue.
1087  */
1089 
1090  /**
1091  * A list of zero terminated key/value strings. There is no end marker for
1092  * the list, so it is required to rely on the side data size to stop. This
1093  * side data includes updated metadata which appeared in the stream.
1094  */
1096 };
1098 typedef struct AVPacketSideData {
1100  int size;
1103 
1104 /**
1105  * This structure stores compressed data. It is typically exported by demuxers
1106  * and then passed as input to decoders, or received as output from encoders and
1107  * then passed to muxers.
1108  *
1109  * For video, it should typically contain one compressed frame. For audio it may
1110  * contain several compressed frames.
1111  *
1112  * AVPacket is one of the few structs in FFmpeg, whose size is a part of public
1113  * ABI. Thus it may be allocated on stack and no new fields can be added to it
1114  * without libavcodec and libavformat major bump.
1115  *
1116  * The semantics of data ownership depends on the buf or destruct (deprecated)
1117  * fields. If either is set, the packet data is dynamically allocated and is
1118  * valid indefinitely until av_free_packet() is called (which in turn calls
1119  * av_buffer_unref()/the destruct callback to free the data). If neither is set,
1120  * the packet data is typically backed by some static buffer somewhere and is
1121  * only valid for a limited time (e.g. until the next read call when demuxing).
1122  *
1123  * The side data is always allocated with av_malloc() and is freed in
1124  * av_free_packet().
1125  */
1126 typedef struct AVPacket {
1127  /**
1128  * A reference to the reference-counted buffer where the packet data is
1129  * stored.
1130  * May be NULL, then the packet data is not reference-counted.
1131  */
1132  AVBufferRef *buf;
1133  /**
1134  * Presentation timestamp in AVStream->time_base units; the time at which
1135  * the decompressed packet will be presented to the user.
1136  * Can be AV_NOPTS_VALUE if it is not stored in the file.
1137  * pts MUST be larger or equal to dts as presentation cannot happen before
1138  * decompression, unless one wants to view hex dumps. Some formats misuse
1139  * the terms dts and pts/cts to mean something different. Such timestamps
1140  * must be converted to true pts/dts before they are stored in AVPacket.
1141  */
1142  int64_t pts;
1143  /**
1144  * Decompression timestamp in AVStream->time_base units; the time at which
1145  * the packet is decompressed.
1146  * Can be AV_NOPTS_VALUE if it is not stored in the file.
1147  */
1148  int64_t dts;
1150  int size;
1151  int stream_index;
1152  /**
1153  * A combination of AV_PKT_FLAG values
1154  */
1155  int flags;
1156  /**
1157  * Additional packet data that can be provided by the container.
1158  * Packet can contain several types of side information.
1159  */
1161  int side_data_elems;
1162 
1163  /**
1164  * Duration of this packet in AVStream->time_base units, 0 if unknown.
1165  * Equals next_pts - this_pts in presentation order.
1166  */
1167  int duration;
1168 #if FF_API_DESTRUCT_PACKET
1170  void (*destruct)(struct AVPacket *);
1172  void *priv;
1173 #endif
1174  int64_t pos; ///< byte position in stream, -1 if unknown
1175 
1176  /**
1177  * Time difference in AVStream->time_base units from the pts of this
1178  * packet to the point at which the output from the decoder has converged
1179  * independent from the availability of previous frames. That is, the
1180  * frames are virtually identical no matter if decoding started from
1181  * the very first frame or from this keyframe.
1182  * Is AV_NOPTS_VALUE if unknown.
1183  * This field is not the display duration of the current packet.
1184  * This field has no meaning if the packet does not have AV_PKT_FLAG_KEY
1185  * set.
1186  *
1187  * The purpose of this field is to allow seeking in streams that have no
1188  * keyframes in the conventional sense. It corresponds to the
1189  * recovery point SEI in H.264 and match_time_delta in NUT. It is also
1190  * essential for some types of subtitle streams to ensure that all
1191  * subtitles are correctly displayed after seeking.
1192  */
1193  int64_t convergence_duration;
1195 #define AV_PKT_FLAG_KEY 0x0001 ///< The packet contains a keyframe
1196 #define AV_PKT_FLAG_CORRUPT 0x0002 ///< The packet content is corrupted
1203 };
1204 /**
1205  * @}
1206  */
1207 
1208 struct AVCodecInternal;
1213  AV_FIELD_TT, //< Top coded_first, top displayed first
1214  AV_FIELD_BB, //< Bottom coded first, bottom displayed first
1215  AV_FIELD_TB, //< Top coded first, bottom displayed first
1216  AV_FIELD_BT, //< Bottom coded first, top displayed first
1217 };
1218 
1219 /**
1220  * main external API structure.
1221  * New fields can be added to the end with minor version bumps.
1222  * Removal, reordering and changes to existing fields require a major
1223  * version bump.
1224  * Please use AVOptions (av_opt* / av_set/get*()) to access these fields from user
1225  * applications.
1226  * sizeof(AVCodecContext) must not be used outside libav*.
1227  */
1228 typedef struct AVCodecContext {
1229  /**
1230  * information on struct for av_log
1231  * - set by avcodec_alloc_context3
1232  */
1234  int log_level_offset;
1236  enum AVMediaType codec_type; /* see AVMEDIA_TYPE_xxx */
1237  const struct AVCodec *codec;
1238 #if FF_API_CODEC_NAME
1239  /**
1240  * @deprecated this field is not used for anything in libavcodec
1241  */
1243  char codec_name[32];
1244 #endif
1245  enum AVCodecID codec_id; /* see AV_CODEC_ID_xxx */
1246 
1247  /**
1248  * fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
1249  * This is used to work around some encoder bugs.
1250  * A demuxer should set this to what is stored in the field used to identify the codec.
1251  * If there are multiple such fields in a container then the demuxer should choose the one
1252  * which maximizes the information about the used codec.
1253  * If the codec tag field in a container is larger than 32 bits then the demuxer should
1254  * remap the longer ID to 32 bits with a table or other structure. Alternatively a new
1255  * extra_codec_tag + size could be added but for this a clear advantage must be demonstrated
1256  * first.
1257  * - encoding: Set by user, if not then the default based on codec_id will be used.
1258  * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
1259  */
1260  unsigned int codec_tag;
1261 
1262  /**
1263  * fourcc from the AVI stream header (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
1264  * This is used to work around some encoder bugs.
1265  * - encoding: unused
1266  * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
1267  */
1268  unsigned int stream_codec_tag;
1270  void *priv_data;
1271 
1272  /**
1273  * Private context used for internal data.
1274  *
1275  * Unlike priv_data, this is not codec-specific. It is used in general
1276  * libavcodec functions.
1277  */
1278  struct AVCodecInternal *internal;
1279 
1280  /**
1281  * Private data of the user, can be used to carry app specific stuff.
1282  * - encoding: Set by user.
1283  * - decoding: Set by user.
1284  */
1285  void *opaque;
1286 
1287  /**
1288  * the average bitrate
1289  * - encoding: Set by user; unused for constant quantizer encoding.
1290  * - decoding: Set by libavcodec. 0 or some bitrate if this info is available in the stream.
1291  */
1292  int bit_rate;
1293 
1294  /**
1295  * number of bits the bitstream is allowed to diverge from the reference.
1296  * the reference can be CBR (for CBR pass1) or VBR (for pass2)
1297  * - encoding: Set by user; unused for constant quantizer encoding.
1298  * - decoding: unused
1299  */
1300  int bit_rate_tolerance;
1301 
1302  /**
1303  * Global quality for codecs which cannot change it per frame.
1304  * This should be proportional to MPEG-1/2/4 qscale.
1305  * - encoding: Set by user.
1306  * - decoding: unused
1307  */
1308  int global_quality;
1309 
1310  /**
1311  * - encoding: Set by user.
1312  * - decoding: unused
1313  */
1315 #define FF_COMPRESSION_DEFAULT -1
1316 
1317  /**
1318  * CODEC_FLAG_*.
1319  * - encoding: Set by user.
1320  * - decoding: Set by user.
1321  */
1322  int flags;
1323 
1324  /**
1325  * CODEC_FLAG2_*
1326  * - encoding: Set by user.
1327  * - decoding: Set by user.
1328  */
1329  int flags2;
1330 
1331  /**
1332  * some codecs need / can use extradata like Huffman tables.
1333  * mjpeg: Huffman tables
1334  * rv10: additional flags
1335  * mpeg4: global headers (they can be in the bitstream or here)
1336  * The allocated memory should be FF_INPUT_BUFFER_PADDING_SIZE bytes larger
1337  * than extradata_size to avoid problems if it is read with the bitstream reader.
1338  * The bytewise contents of extradata must not depend on the architecture or CPU endianness.
1339  * - encoding: Set/allocated/freed by libavcodec.
1340  * - decoding: Set/allocated/freed by user.
1341  */
1343  int extradata_size;
1344 
1345  /**
1346  * This is the fundamental unit of time (in seconds) in terms
1347  * of which frame timestamps are represented. For fixed-fps content,
1348  * timebase should be 1/framerate and timestamp increments should be
1349  * identically 1.
1350  * This often, but not always is the inverse of the frame rate or field rate
1351  * for video.
1352  * - encoding: MUST be set by user.
1353  * - decoding: the use of this field for decoding is deprecated.
1354  * Use framerate instead.
1355  */
1357 
1358  /**
1359  * For some codecs, the time base is closer to the field rate than the frame rate.
1360  * Most notably, H.264 and MPEG-2 specify time_base as half of frame duration
1361  * if no telecine is used ...
1362  *
1363  * Set to time_base ticks per frame. Default 1, e.g., H.264/MPEG-2 set it to 2.
1364  */
1365  int ticks_per_frame;
1366 
1367  /**
1368  * Codec delay.
1369  *
1370  * Encoding: Number of frames delay there will be from the encoder input to
1371  * the decoder output. (we assume the decoder matches the spec)
1372  * Decoding: Number of frames delay in addition to what a standard decoder
1373  * as specified in the spec would produce.
1374  *
1375  * Video:
1376  * Number of frames the decoded output will be delayed relative to the
1377  * encoded input.
1378  *
1379  * Audio:
1380  * For encoding, this field is unused (see initial_padding).
1381  *
1382  * For decoding, this is the number of samples the decoder needs to
1383  * output before the decoder's output is valid. When seeking, you should
1384  * start decoding this many samples prior to your desired seek point.
1385  *
1386  * - encoding: Set by libavcodec.
1387  * - decoding: Set by libavcodec.
1388  */
1389  int delay;
1390 
1391 
1392  /* video only */
1393  /**
1394  * picture width / height.
1395  * - encoding: MUST be set by user.
1396  * - decoding: May be set by the user before opening the decoder if known e.g.
1397  * from the container. Some decoders will require the dimensions
1398  * to be set by the caller. During decoding, the decoder may
1399  * overwrite those values as required.
1400  */
1401  int width, height;
1402 
1403  /**
1404  * Bitstream width / height, may be different from width/height e.g. when
1405  * the decoded frame is cropped before being output or lowres is enabled.
1406  * - encoding: unused
1407  * - decoding: May be set by the user before opening the decoder if known
1408  * e.g. from the container. During decoding, the decoder may
1409  * overwrite those values as required.
1410  */
1412 
1413 #if FF_API_ASPECT_EXTENDED
1414 #define FF_ASPECT_EXTENDED 15
1415 #endif
1416 
1417  /**
1418  * the number of pictures in a group of pictures, or 0 for intra_only
1419  * - encoding: Set by user.
1420  * - decoding: unused
1421  */
1422  int gop_size;
1423 
1424  /**
1425  * Pixel format, see AV_PIX_FMT_xxx.
1426  * May be set by the demuxer if known from headers.
1427  * May be overridden by the decoder if it knows better.
1428  * - encoding: Set by user.
1429  * - decoding: Set by user if known, overridden by libavcodec if known
1430  */
1431  enum AVPixelFormat pix_fmt;
1432 
1433  /**
1434  * Motion estimation algorithm used for video coding.
1435  * 1 (zero), 2 (full), 3 (log), 4 (phods), 5 (epzs), 6 (x1), 7 (hex),
1436  * 8 (umh), 9 (iter), 10 (tesa) [7, 8, 10 are x264 specific, 9 is snow specific]
1437  * - encoding: MUST be set by user.
1438  * - decoding: unused
1439  */
1440  int me_method;
1441 
1442  /**
1443  * If non NULL, 'draw_horiz_band' is called by the libavcodec
1444  * decoder to draw a horizontal band. It improves cache usage. Not
1445  * all codecs can do that. You must check the codec capabilities
1446  * beforehand.
1447  * When multithreading is used, it may be called from multiple threads
1448  * at the same time; threads might draw different parts of the same AVFrame,
1449  * or multiple AVFrames, and there is no guarantee that slices will be drawn
1450  * in order.
1451  * The function is also used by hardware acceleration APIs.
1452  * It is called at least once during frame decoding to pass
1453  * the data needed for hardware render.
1454  * In that mode instead of pixel data, AVFrame points to
1455  * a structure specific to the acceleration API. The application
1456  * reads the structure and can change some fields to indicate progress
1457  * or mark state.
1458  * - encoding: unused
1459  * - decoding: Set by user.
1460  * @param height the height of the slice
1461  * @param y the y position of the slice
1462  * @param type 1->top field, 2->bottom field, 3->frame
1463  * @param offset offset into the AVFrame.data from which the slice should be read
1464  */
1465  void (*draw_horiz_band)(struct AVCodecContext *s,
1466  const AVFrame *src, int offset[AV_NUM_DATA_POINTERS],
1467  int y, int type, int height);
1468 
1469  /**
1470  * callback to negotiate the pixelFormat
1471  * @param fmt is the list of formats which are supported by the codec,
1472  * it is terminated by -1 as 0 is a valid format, the formats are ordered by quality.
1473  * The first is always the native one.
1474  * @note The callback may be called again immediately if initialization for
1475  * the selected (hardware-accelerated) pixel format failed.
1476  * @warning Behavior is undefined if the callback returns a value not
1477  * in the fmt list of formats.
1478  * @return the chosen format
1479  * - encoding: unused
1480  * - decoding: Set by user, if not set the native format will be chosen.
1481  */
1482  enum AVPixelFormat (*get_format)(struct AVCodecContext *s, const enum AVPixelFormat * fmt);
1483 
1484  /**
1485  * maximum number of B-frames between non-B-frames
1486  * Note: The output will be delayed by max_b_frames+1 relative to the input.
1487  * - encoding: Set by user.
1488  * - decoding: unused
1489  */
1490  int max_b_frames;
1491 
1492  /**
1493  * qscale factor between IP and B-frames
1494  * If > 0 then the last P-frame quantizer will be used (q= lastp_q*factor+offset).
1495  * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1496  * - encoding: Set by user.
1497  * - decoding: unused
1498  */
1499  float b_quant_factor;
1500 
1501  /** obsolete FIXME remove */
1503 #define FF_RC_STRATEGY_XVID 1
1505  int b_frame_strategy;
1506 
1507  /**
1508  * qscale offset between IP and B-frames
1509  * - encoding: Set by user.
1510  * - decoding: unused
1511  */
1512  float b_quant_offset;
1513 
1514  /**
1515  * Size of the frame reordering buffer in the decoder.
1516  * For MPEG-2 it is 1 IPB or 0 low delay IP.
1517  * - encoding: Set by libavcodec.
1518  * - decoding: Set by libavcodec.
1519  */
1520  int has_b_frames;
1521 
1522  /**
1523  * 0-> h263 quant 1-> mpeg quant
1524  * - encoding: Set by user.
1525  * - decoding: unused
1526  */
1527  int mpeg_quant;
1528 
1529  /**
1530  * qscale factor between P and I-frames
1531  * If > 0 then the last p frame quantizer will be used (q= lastp_q*factor+offset).
1532  * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1533  * - encoding: Set by user.
1534  * - decoding: unused
1535  */
1536  float i_quant_factor;
1537 
1538  /**
1539  * qscale offset between P and I-frames
1540  * - encoding: Set by user.
1541  * - decoding: unused
1542  */
1543  float i_quant_offset;
1544 
1545  /**
1546  * luminance masking (0-> disabled)
1547  * - encoding: Set by user.
1548  * - decoding: unused
1549  */
1550  float lumi_masking;
1551 
1552  /**
1553  * temporary complexity masking (0-> disabled)
1554  * - encoding: Set by user.
1555  * - decoding: unused
1556  */
1557  float temporal_cplx_masking;
1558 
1559  /**
1560  * spatial complexity masking (0-> disabled)
1561  * - encoding: Set by user.
1562  * - decoding: unused
1563  */
1564  float spatial_cplx_masking;
1565 
1566  /**
1567  * p block masking (0-> disabled)
1568  * - encoding: Set by user.
1569  * - decoding: unused
1570  */
1571  float p_masking;
1572 
1573  /**
1574  * darkness masking (0-> disabled)
1575  * - encoding: Set by user.
1576  * - decoding: unused
1577  */
1578  float dark_masking;
1579 
1580  /**
1581  * slice count
1582  * - encoding: Set by libavcodec.
1583  * - decoding: Set by user (or 0).
1584  */
1585  int slice_count;
1586  /**
1587  * prediction method (needed for huffyuv)
1588  * - encoding: Set by user.
1589  * - decoding: unused
1590  */
1592 #define FF_PRED_LEFT 0
1593 #define FF_PRED_PLANE 1
1594 #define FF_PRED_MEDIAN 2
1595 
1596  /**
1597  * slice offsets in the frame in bytes
1598  * - encoding: Set/allocated by libavcodec.
1599  * - decoding: Set/allocated by user (or NULL).
1600  */
1601  int *slice_offset;
1602 
1603  /**
1604  * sample aspect ratio (0 if unknown)
1605  * That is the width of a pixel divided by the height of the pixel.
1606  * Numerator and denominator must be relatively prime and smaller than 256 for some video standards.
1607  * - encoding: Set by user.
1608  * - decoding: Set by libavcodec.
1609  */
1611 
1612  /**
1613  * motion estimation comparison function
1614  * - encoding: Set by user.
1615  * - decoding: unused
1616  */
1617  int me_cmp;
1618  /**
1619  * subpixel motion estimation comparison function
1620  * - encoding: Set by user.
1621  * - decoding: unused
1622  */
1623  int me_sub_cmp;
1624  /**
1625  * macroblock comparison function (not supported yet)
1626  * - encoding: Set by user.
1627  * - decoding: unused
1628  */
1629  int mb_cmp;
1630  /**
1631  * interlaced DCT comparison function
1632  * - encoding: Set by user.
1633  * - decoding: unused
1634  */
1636 #define FF_CMP_SAD 0
1637 #define FF_CMP_SSE 1
1638 #define FF_CMP_SATD 2
1639 #define FF_CMP_DCT 3
1640 #define FF_CMP_PSNR 4
1641 #define FF_CMP_BIT 5
1642 #define FF_CMP_RD 6
1643 #define FF_CMP_ZERO 7
1644 #define FF_CMP_VSAD 8
1645 #define FF_CMP_VSSE 9
1646 #define FF_CMP_NSSE 10
1647 #define FF_CMP_W53 11
1648 #define FF_CMP_W97 12
1649 #define FF_CMP_DCTMAX 13
1650 #define FF_CMP_DCT264 14
1651 #define FF_CMP_CHROMA 256
1652 
1653  /**
1654  * ME diamond size & shape
1655  * - encoding: Set by user.
1656  * - decoding: unused
1657  */
1658  int dia_size;
1659 
1660  /**
1661  * amount of previous MV predictors (2a+1 x 2a+1 square)
1662  * - encoding: Set by user.
1663  * - decoding: unused
1664  */
1666 
1667  /**
1668  * prepass for motion estimation
1669  * - encoding: Set by user.
1670  * - decoding: unused
1671  */
1672  int pre_me;
1673 
1674  /**
1675  * motion estimation prepass comparison function
1676  * - encoding: Set by user.
1677  * - decoding: unused
1678  */
1679  int me_pre_cmp;
1680 
1681  /**
1682  * ME prepass diamond size & shape
1683  * - encoding: Set by user.
1684  * - decoding: unused
1685  */
1686  int pre_dia_size;
1687 
1688  /**
1689  * subpel ME quality
1690  * - encoding: Set by user.
1691  * - decoding: unused
1692  */
1693  int me_subpel_quality;
1694 
1695 #if FF_API_AFD
1696  /**
1697  * DTG active format information (additional aspect ratio
1698  * information only used in DVB MPEG-2 transport streams)
1699  * 0 if not set.
1700  *
1701  * - encoding: unused
1702  * - decoding: Set by decoder.
1703  * @deprecated Deprecated in favor of AVSideData
1704  */
1706 #define FF_DTG_AFD_SAME 8
1707 #define FF_DTG_AFD_4_3 9
1708 #define FF_DTG_AFD_16_9 10
1709 #define FF_DTG_AFD_14_9 11
1710 #define FF_DTG_AFD_4_3_SP_14_9 13
1711 #define FF_DTG_AFD_16_9_SP_14_9 14
1712 #define FF_DTG_AFD_SP_4_3 15
1713 #endif /* FF_API_AFD */
1714 
1715  /**
1716  * maximum motion estimation search range in subpel units
1717  * If 0 then no limit.
1718  *
1719  * - encoding: Set by user.
1720  * - decoding: unused
1721  */
1722  int me_range;
1723 
1724  /**
1725  * intra quantizer bias
1726  * - encoding: Set by user.
1727  * - decoding: unused
1728  */
1730 #define FF_DEFAULT_QUANT_BIAS 999999
1731 
1732  /**
1733  * inter quantizer bias
1734  * - encoding: Set by user.
1735  * - decoding: unused
1736  */
1737  int inter_quant_bias;
1738 
1739  /**
1740  * slice flags
1741  * - encoding: unused
1742  * - decoding: Set by user.
1743  */
1745 #define SLICE_FLAG_CODED_ORDER 0x0001 ///< draw_horiz_band() is called in coded order instead of display
1746 #define SLICE_FLAG_ALLOW_FIELD 0x0002 ///< allow draw_horiz_band() with field slices (MPEG2 field pics)
1747 #define SLICE_FLAG_ALLOW_PLANE 0x0004 ///< allow draw_horiz_band() with 1 component at a time (SVQ1)
1748 
1749 #if FF_API_XVMC
1750  /**
1751  * XVideo Motion Acceleration
1752  * - encoding: forbidden
1753  * - decoding: set by decoder
1754  * @deprecated XvMC doesn't need it anymore.
1755  */
1756  attribute_deprecated int xvmc_acceleration;
1757 #endif /* FF_API_XVMC */
1758 
1759  /**
1760  * macroblock decision mode
1761  * - encoding: Set by user.
1762  * - decoding: unused
1763  */
1765 #define FF_MB_DECISION_SIMPLE 0 ///< uses mb_cmp
1766 #define FF_MB_DECISION_BITS 1 ///< chooses the one which needs the fewest bits
1767 #define FF_MB_DECISION_RD 2 ///< rate distortion
1768 
1769  /**
1770  * custom intra quantization matrix
1771  * - encoding: Set by user, can be NULL.
1772  * - decoding: Set by libavcodec.
1773  */
1774  uint16_t *intra_matrix;
1775 
1776  /**
1777  * custom inter quantization matrix
1778  * - encoding: Set by user, can be NULL.
1779  * - decoding: Set by libavcodec.
1780  */
1781  uint16_t *inter_matrix;
1782 
1783  /**
1784  * scene change detection threshold
1785  * 0 is default, larger means fewer detected scene changes.
1786  * - encoding: Set by user.
1787  * - decoding: unused
1788  */
1790 
1791  /**
1792  * noise reduction strength
1793  * - encoding: Set by user.
1794  * - decoding: unused
1795  */
1796  int noise_reduction;
1797 
1798 #if FF_API_MPV_OPT
1799  /**
1800  * @deprecated this field is unused
1801  */
1803  int me_threshold;
1804 
1805  /**
1806  * @deprecated this field is unused
1807  */
1809  int mb_threshold;
1810 #endif
1811 
1812  /**
1813  * precision of the intra DC coefficient - 8
1814  * - encoding: Set by user.
1815  * - decoding: unused
1816  */
1817  int intra_dc_precision;
1818 
1819  /**
1820  * Number of macroblock rows at the top which are skipped.
1821  * - encoding: unused
1822  * - decoding: Set by user.
1823  */
1824  int skip_top;
1825 
1826  /**
1827  * Number of macroblock rows at the bottom which are skipped.
1828  * - encoding: unused
1829  * - decoding: Set by user.
1830  */
1831  int skip_bottom;
1832 
1833 #if FF_API_MPV_OPT
1834  /**
1835  * @deprecated use encoder private options instead
1836  */
1838  float border_masking;
1839 #endif
1840 
1841  /**
1842  * minimum MB lagrange multipler
1843  * - encoding: Set by user.
1844  * - decoding: unused
1845  */
1846  int mb_lmin;
1847 
1848  /**
1849  * maximum MB lagrange multipler
1850  * - encoding: Set by user.
1851  * - decoding: unused
1852  */
1853  int mb_lmax;
1854 
1855  /**
1856  *
1857  * - encoding: Set by user.
1858  * - decoding: unused
1859  */
1861 
1862  /**
1863  *
1864  * - encoding: Set by user.
1865  * - decoding: unused
1866  */
1867  int bidir_refine;
1868 
1869  /**
1870  *
1871  * - encoding: Set by user.
1872  * - decoding: unused
1873  */
1874  int brd_scale;
1875 
1876  /**
1877  * minimum GOP size
1878  * - encoding: Set by user.
1879  * - decoding: unused
1880  */
1881  int keyint_min;
1882 
1883  /**
1884  * number of reference frames
1885  * - encoding: Set by user.
1886  * - decoding: Set by lavc.
1887  */
1888  int refs;
1889 
1890  /**
1891  * chroma qp offset from luma
1892  * - encoding: Set by user.
1893  * - decoding: unused
1894  */
1895  int chromaoffset;
1896 
1897 #if FF_API_UNUSED_MEMBERS
1898  /**
1899  * Multiplied by qscale for each frame and added to scene_change_score.
1900  * - encoding: Set by user.
1901  * - decoding: unused
1902  */
1904 #endif
1905 
1906  /**
1907  *
1908  * Note: Value depends upon the compare function used for fullpel ME.
1909  * - encoding: Set by user.
1910  * - decoding: unused
1911  */
1912  int mv0_threshold;
1913 
1914  /**
1915  * Adjust sensitivity of b_frame_strategy 1.
1916  * - encoding: Set by user.
1917  * - decoding: unused
1918  */
1919  int b_sensitivity;
1920 
1921  /**
1922  * Chromaticity coordinates of the source primaries.
1923  * - encoding: Set by user
1924  * - decoding: Set by libavcodec
1925  */
1927 
1928  /**
1929  * Color Transfer Characteristic.
1930  * - encoding: Set by user
1931  * - decoding: Set by libavcodec
1932  */
1934 
1935  /**
1936  * YUV colorspace type.
1937  * - encoding: Set by user
1938  * - decoding: Set by libavcodec
1939  */
1940  enum AVColorSpace colorspace;
1941 
1942  /**
1943  * MPEG vs JPEG YUV range.
1944  * - encoding: Set by user
1945  * - decoding: Set by libavcodec
1946  */
1948 
1949  /**
1950  * This defines the location of chroma samples.
1951  * - encoding: Set by user
1952  * - decoding: Set by libavcodec
1953  */
1955 
1956  /**
1957  * Number of slices.
1958  * Indicates number of picture subdivisions. Used for parallelized
1959  * decoding.
1960  * - encoding: Set by user
1961  * - decoding: unused
1962  */
1963  int slices;
1964 
1965  /** Field order
1966  * - encoding: set by libavcodec
1967  * - decoding: Set by user.
1968  */
1970 
1971  /* audio only */
1972  int sample_rate; ///< samples per second
1973  int channels; ///< number of audio channels
1974 
1975  /**
1976  * audio sample format
1977  * - encoding: Set by user.
1978  * - decoding: Set by libavcodec.
1979  */
1980  enum AVSampleFormat sample_fmt; ///< sample format
1981 
1982  /* The following data should not be initialized. */
1983  /**
1984  * Number of samples per channel in an audio frame.
1985  *
1986  * - encoding: set by libavcodec in avcodec_open2(). Each submitted frame
1987  * except the last must contain exactly frame_size samples per channel.
1988  * May be 0 when the codec has CODEC_CAP_VARIABLE_FRAME_SIZE set, then the
1989  * frame size is not restricted.
1990  * - decoding: may be set by some decoders to indicate constant frame size
1991  */
1992  int frame_size;
1993 
1994  /**
1995  * Frame counter, set by libavcodec.
1996  *
1997  * - decoding: total number of frames returned from the decoder so far.
1998  * - encoding: total number of frames passed to the encoder so far.
1999  *
2000  * @note the counter is not incremented if encoding/decoding resulted in
2001  * an error.
2002  */
2003  int frame_number;
2004 
2005  /**
2006  * number of bytes per packet if constant and known or 0
2007  * Used by some WAV based audio codecs.
2008  */
2009  int block_align;
2010 
2011  /**
2012  * Audio cutoff bandwidth (0 means "automatic")
2013  * - encoding: Set by user.
2014  * - decoding: unused
2015  */
2016  int cutoff;
2017 
2018 #if FF_API_REQUEST_CHANNELS
2019  /**
2020  * Decoder should decode to this many channels if it can (0 for default)
2021  * - encoding: unused
2022  * - decoding: Set by user.
2023  * @deprecated Deprecated in favor of request_channel_layout.
2024  */
2026 #endif
2027 
2028  /**
2029  * Audio channel layout.
2030  * - encoding: set by user.
2031  * - decoding: set by user, may be overwritten by libavcodec.
2032  */
2033  uint64_t channel_layout;
2034 
2035  /**
2036  * Request decoder to use this channel layout if it can (0 for default)
2037  * - encoding: unused
2038  * - decoding: Set by user.
2039  */
2040  uint64_t request_channel_layout;
2041 
2042  /**
2043  * Type of service that the audio stream conveys.
2044  * - encoding: Set by user.
2045  * - decoding: Set by libavcodec.
2046  */
2048 
2049  /**
2050  * desired sample format
2051  * - encoding: Not used.
2052  * - decoding: Set by user.
2053  * Decoder will decode to this format if it can.
2054  */
2056 
2057 #if FF_API_GET_BUFFER
2058  /**
2059  * Called at the beginning of each frame to get a buffer for it.
2060  *
2061  * The function will set AVFrame.data[], AVFrame.linesize[].
2062  * AVFrame.extended_data[] must also be set, but it should be the same as
2063  * AVFrame.data[] except for planar audio with more channels than can fit
2064  * in AVFrame.data[]. In that case, AVFrame.data[] shall still contain as
2065  * many data pointers as it can hold.
2066  *
2067  * if CODEC_CAP_DR1 is not set then get_buffer() must call
2068  * avcodec_default_get_buffer() instead of providing buffers allocated by
2069  * some other means.
2070  *
2071  * AVFrame.data[] should be 32- or 16-byte-aligned unless the CPU doesn't
2072  * need it. avcodec_default_get_buffer() aligns the output buffer properly,
2073  * but if get_buffer() is overridden then alignment considerations should
2074  * be taken into account.
2075  *
2076  * @see avcodec_default_get_buffer()
2077  *
2078  * Video:
2079  *
2080  * If pic.reference is set then the frame will be read later by libavcodec.
2081  * avcodec_align_dimensions2() should be used to find the required width and
2082  * height, as they normally need to be rounded up to the next multiple of 16.
2083  *
2084  * If frame multithreading is used and thread_safe_callbacks is set,
2085  * it may be called from a different thread, but not from more than one at
2086  * once. Does not need to be reentrant.
2087  *
2088  * @see release_buffer(), reget_buffer()
2089  * @see avcodec_align_dimensions2()
2090  *
2091  * Audio:
2092  *
2093  * Decoders request a buffer of a particular size by setting
2094  * AVFrame.nb_samples prior to calling get_buffer(). The decoder may,
2095  * however, utilize only part of the buffer by setting AVFrame.nb_samples
2096  * to a smaller value in the output frame.
2097  *
2098  * Decoders cannot use the buffer after returning from
2099  * avcodec_decode_audio4(), so they will not call release_buffer(), as it
2100  * is assumed to be released immediately upon return. In some rare cases,
2101  * a decoder may need to call get_buffer() more than once in a single
2102  * call to avcodec_decode_audio4(). In that case, when get_buffer() is
2103  * called again after it has already been called once, the previously
2104  * acquired buffer is assumed to be released at that time and may not be
2105  * reused by the decoder.
2106  *
2107  * As a convenience, av_samples_get_buffer_size() and
2108  * av_samples_fill_arrays() in libavutil may be used by custom get_buffer()
2109  * functions to find the required data size and to fill data pointers and
2110  * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
2111  * since all planes must be the same size.
2112  *
2113  * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
2114  *
2115  * - encoding: unused
2116  * - decoding: Set by libavcodec, user can override.
2117  *
2118  * @deprecated use get_buffer2()
2119  */
2121  int (*get_buffer)(struct AVCodecContext *c, AVFrame *pic);
2122 
2123  /**
2124  * Called to release buffers which were allocated with get_buffer.
2125  * A released buffer can be reused in get_buffer().
2126  * pic.data[*] must be set to NULL.
2127  * May be called from a different thread if frame multithreading is used,
2128  * but not by more than one thread at once, so does not need to be reentrant.
2129  * - encoding: unused
2130  * - decoding: Set by libavcodec, user can override.
2131  *
2132  * @deprecated custom freeing callbacks should be set from get_buffer2()
2133  */
2135  void (*release_buffer)(struct AVCodecContext *c, AVFrame *pic);
2136 
2137  /**
2138  * Called at the beginning of a frame to get cr buffer for it.
2139  * Buffer type (size, hints) must be the same. libavcodec won't check it.
2140  * libavcodec will pass previous buffer in pic, function should return
2141  * same buffer or new buffer with old frame "painted" into it.
2142  * If pic.data[0] == NULL must behave like get_buffer().
2143  * if CODEC_CAP_DR1 is not set then reget_buffer() must call
2144  * avcodec_default_reget_buffer() instead of providing buffers allocated by
2145  * some other means.
2146  * - encoding: unused
2147  * - decoding: Set by libavcodec, user can override.
2148  */
2150  int (*reget_buffer)(struct AVCodecContext *c, AVFrame *pic);
2151 #endif
2152 
2153  /**
2154  * This callback is called at the beginning of each frame to get data
2155  * buffer(s) for it. There may be one contiguous buffer for all the data or
2156  * there may be a buffer per each data plane or anything in between. What
2157  * this means is, you may set however many entries in buf[] you feel necessary.
2158  * Each buffer must be reference-counted using the AVBuffer API (see description
2159  * of buf[] below).
2160  *
2161  * The following fields will be set in the frame before this callback is
2162  * called:
2163  * - format
2164  * - width, height (video only)
2165  * - sample_rate, channel_layout, nb_samples (audio only)
2166  * Their values may differ from the corresponding values in
2167  * AVCodecContext. This callback must use the frame values, not the codec
2168  * context values, to calculate the required buffer size.
2169  *
2170  * This callback must fill the following fields in the frame:
2171  * - data[]
2172  * - linesize[]
2173  * - extended_data:
2174  * * if the data is planar audio with more than 8 channels, then this
2175  * callback must allocate and fill extended_data to contain all pointers
2176  * to all data planes. data[] must hold as many pointers as it can.
2177  * extended_data must be allocated with av_malloc() and will be freed in
2178  * av_frame_unref().
2179  * * otherwise exended_data must point to data
2180  * - buf[] must contain one or more pointers to AVBufferRef structures. Each of
2181  * the frame's data and extended_data pointers must be contained in these. That
2182  * is, one AVBufferRef for each allocated chunk of memory, not necessarily one
2183  * AVBufferRef per data[] entry. See: av_buffer_create(), av_buffer_alloc(),
2184  * and av_buffer_ref().
2185  * - extended_buf and nb_extended_buf must be allocated with av_malloc() by
2186  * this callback and filled with the extra buffers if there are more
2187  * buffers than buf[] can hold. extended_buf will be freed in
2188  * av_frame_unref().
2189  *
2190  * If CODEC_CAP_DR1 is not set then get_buffer2() must call
2191  * avcodec_default_get_buffer2() instead of providing buffers allocated by
2192  * some other means.
2193  *
2194  * Each data plane must be aligned to the maximum required by the target
2195  * CPU.
2196  *
2197  * @see avcodec_default_get_buffer2()
2198  *
2199  * Video:
2200  *
2201  * If AV_GET_BUFFER_FLAG_REF is set in flags then the frame may be reused
2202  * (read and/or written to if it is writable) later by libavcodec.
2203  *
2204  * avcodec_align_dimensions2() should be used to find the required width and
2205  * height, as they normally need to be rounded up to the next multiple of 16.
2206  *
2207  * Some decoders do not support linesizes changing between frames.
2208  *
2209  * If frame multithreading is used and thread_safe_callbacks is set,
2210  * this callback may be called from a different thread, but not from more
2211  * than one at once. Does not need to be reentrant.
2212  *
2213  * @see avcodec_align_dimensions2()
2214  *
2215  * Audio:
2216  *
2217  * Decoders request a buffer of a particular size by setting
2218  * AVFrame.nb_samples prior to calling get_buffer2(). The decoder may,
2219  * however, utilize only part of the buffer by setting AVFrame.nb_samples
2220  * to a smaller value in the output frame.
2221  *
2222  * As a convenience, av_samples_get_buffer_size() and
2223  * av_samples_fill_arrays() in libavutil may be used by custom get_buffer2()
2224  * functions to find the required data size and to fill data pointers and
2225  * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
2226  * since all planes must be the same size.
2227  *
2228  * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
2229  *
2230  * - encoding: unused
2231  * - decoding: Set by libavcodec, user can override.
2232  */
2233  int (*get_buffer2)(struct AVCodecContext *s, AVFrame *frame, int flags);
2234 
2235  /**
2236  * If non-zero, the decoded audio and video frames returned from
2237  * avcodec_decode_video2() and avcodec_decode_audio4() are reference-counted
2238  * and are valid indefinitely. The caller must free them with
2239  * av_frame_unref() when they are not needed anymore.
2240  * Otherwise, the decoded frames must not be freed by the caller and are
2241  * only valid until the next decode call.
2242  *
2243  * - encoding: unused
2244  * - decoding: set by the caller before avcodec_open2().
2245  */
2246  int refcounted_frames;
2247 
2248  /* - encoding parameters */
2249  float qcompress; ///< amount of qscale change between easy & hard scenes (0.0-1.0)
2250  float qblur; ///< amount of qscale smoothing over time (0.0-1.0)
2251 
2252  /**
2253  * minimum quantizer
2254  * - encoding: Set by user.
2255  * - decoding: unused
2256  */
2257  int qmin;
2258 
2259  /**
2260  * maximum quantizer
2261  * - encoding: Set by user.
2262  * - decoding: unused
2263  */
2264  int qmax;
2265 
2266  /**
2267  * maximum quantizer difference between frames
2268  * - encoding: Set by user.
2269  * - decoding: unused
2270  */
2271  int max_qdiff;
2272 
2273 #if FF_API_MPV_OPT
2274  /**
2275  * @deprecated use encoder private options instead
2276  */
2278  float rc_qsquish;
2279 
2281  float rc_qmod_amp;
2283  int rc_qmod_freq;
2284 #endif
2285 
2286  /**
2287  * decoder bitstream buffer size
2288  * - encoding: Set by user.
2289  * - decoding: unused
2290  */
2291  int rc_buffer_size;
2292 
2293  /**
2294  * ratecontrol override, see RcOverride
2295  * - encoding: Allocated/set/freed by user.
2296  * - decoding: unused
2297  */
2300 
2301 #if FF_API_MPV_OPT
2302  /**
2303  * @deprecated use encoder private options instead
2304  */
2306  const char *rc_eq;
2307 #endif
2308 
2309  /**
2310  * maximum bitrate
2311  * - encoding: Set by user.
2312  * - decoding: Set by libavcodec.
2313  */
2314  int rc_max_rate;
2315 
2316  /**
2317  * minimum bitrate
2318  * - encoding: Set by user.
2319  * - decoding: unused
2320  */
2321  int rc_min_rate;
2322 
2323 #if FF_API_MPV_OPT
2324  /**
2325  * @deprecated use encoder private options instead
2326  */
2328  float rc_buffer_aggressivity;
2329 
2331  float rc_initial_cplx;
2332 #endif
2333 
2334  /**
2335  * Ratecontrol attempt to use, at maximum, <value> of what can be used without an underflow.
2336  * - encoding: Set by user.
2337  * - decoding: unused.
2338  */
2340 
2341  /**
2342  * Ratecontrol attempt to use, at least, <value> times the amount needed to prevent a vbv overflow.
2343  * - encoding: Set by user.
2344  * - decoding: unused.
2345  */
2347 
2348  /**
2349  * Number of bits which should be loaded into the rc buffer before decoding starts.
2350  * - encoding: Set by user.
2351  * - decoding: unused
2352  */
2355 #define FF_CODER_TYPE_VLC 0
2356 #define FF_CODER_TYPE_AC 1
2357 #define FF_CODER_TYPE_RAW 2
2358 #define FF_CODER_TYPE_RLE 3
2359 #if FF_API_UNUSED_MEMBERS
2360 #define FF_CODER_TYPE_DEFLATE 4
2361 #endif /* FF_API_UNUSED_MEMBERS */
2362  /**
2363  * coder type
2364  * - encoding: Set by user.
2365  * - decoding: unused
2366  */
2367  int coder_type;
2368 
2369  /**
2370  * context model
2371  * - encoding: Set by user.
2372  * - decoding: unused
2373  */
2374  int context_model;
2375 
2376 #if FF_API_MPV_OPT
2377  /**
2378  * @deprecated use encoder private options instead
2379  */
2381  int lmin;
2382 
2383  /**
2384  * @deprecated use encoder private options instead
2385  */
2387  int lmax;
2388 #endif
2389 
2390  /**
2391  * frame skip threshold
2392  * - encoding: Set by user.
2393  * - decoding: unused
2394  */
2396 
2397  /**
2398  * frame skip factor
2399  * - encoding: Set by user.
2400  * - decoding: unused
2401  */
2402  int frame_skip_factor;
2403 
2404  /**
2405  * frame skip exponent
2406  * - encoding: Set by user.
2407  * - decoding: unused
2408  */
2409  int frame_skip_exp;
2410 
2411  /**
2412  * frame skip comparison function
2413  * - encoding: Set by user.
2414  * - decoding: unused
2415  */
2416  int frame_skip_cmp;
2417 
2418  /**
2419  * trellis RD quantization
2420  * - encoding: Set by user.
2421  * - decoding: unused
2422  */
2423  int trellis;
2424 
2425  /**
2426  * - encoding: Set by user.
2427  * - decoding: unused
2428  */
2430 
2431  /**
2432  * - encoding: Set by user.
2433  * - decoding: unused
2434  */
2436 
2437  /**
2438  * GOP timecode frame start number
2439  * - encoding: Set by user, in non drop frame format
2440  * - decoding: Set by libavcodec (timecode in the 25 bits format, -1 if unset)
2441  */
2442  int64_t timecode_frame_start;
2443 
2444  /* The RTP callback: This function is called */
2445  /* every time the encoder has a packet to send. */
2446  /* It depends on the encoder if the data starts */
2447  /* with a Start Code (it should). H.263 does. */
2448  /* mb_nb contains the number of macroblocks */
2449  /* encoded in the RTP payload. */
2450  void (*rtp_callback)(struct AVCodecContext *avctx, void *data, int size, int mb_nb);
2452  int rtp_payload_size; /* The size of the RTP payload: the coder will */
2453  /* do its best to deliver a chunk with size */
2454  /* below rtp_payload_size, the chunk will start */
2455  /* with a start code on some codecs like H.263. */
2456  /* This doesn't take account of any particular */
2457  /* headers inside the transmitted RTP payload. */
2458 
2459  /* statistics, used for 2-pass encoding */
2460  int mv_bits;
2464  int i_count;
2465  int p_count;
2467  int misc_bits;
2468 
2469  /**
2470  * number of bits used for the previously encoded frame
2471  * - encoding: Set by libavcodec.
2472  * - decoding: unused
2473  */
2474  int frame_bits;
2475 
2476  /**
2477  * pass1 encoding statistics output buffer
2478  * - encoding: Set by libavcodec.
2479  * - decoding: unused
2480  */
2481  char *stats_out;
2482 
2483  /**
2484  * pass2 encoding statistics input buffer
2485  * Concatenated stuff from stats_out of pass1 should be placed here.
2486  * - encoding: Allocated/set/freed by user.
2487  * - decoding: unused
2488  */
2489  char *stats_in;
2490 
2491  /**
2492  * Work around bugs in encoders which sometimes cannot be detected automatically.
2493  * - encoding: Set by user
2494  * - decoding: Set by user
2495  */
2497 #define FF_BUG_AUTODETECT 1 ///< autodetection
2498 #if FF_API_OLD_MSMPEG4
2499 #define FF_BUG_OLD_MSMPEG4 2
2500 #endif
2501 #define FF_BUG_XVID_ILACE 4
2502 #define FF_BUG_UMP4 8
2503 #define FF_BUG_NO_PADDING 16
2504 #define FF_BUG_AMV 32
2505 #if FF_API_AC_VLC
2506 #define FF_BUG_AC_VLC 0 ///< Will be removed, libavcodec can now handle these non-compliant files by default.
2507 #endif
2508 #define FF_BUG_QPEL_CHROMA 64
2509 #define FF_BUG_STD_QPEL 128
2510 #define FF_BUG_QPEL_CHROMA2 256
2511 #define FF_BUG_DIRECT_BLOCKSIZE 512
2512 #define FF_BUG_EDGE 1024
2513 #define FF_BUG_HPEL_CHROMA 2048
2514 #define FF_BUG_DC_CLIP 4096
2515 #define FF_BUG_MS 8192 ///< Work around various bugs in Microsoft's broken decoders.
2516 #define FF_BUG_TRUNCATED 16384
2517 
2518  /**
2519  * strictly follow the standard (MPEG4, ...).
2520  * - encoding: Set by user.
2521  * - decoding: Set by user.
2522  * Setting this to STRICT or higher means the encoder and decoder will
2523  * generally do stupid things, whereas setting it to unofficial or lower
2524  * will mean the encoder might produce output that is not supported by all
2525  * spec-compliant decoders. Decoders don't differentiate between normal,
2526  * unofficial and experimental (that is, they always try to decode things
2527  * when they can) unless they are explicitly asked to behave stupidly
2528  * (=strictly conform to the specs)
2529  */
2531 #define FF_COMPLIANCE_VERY_STRICT 2 ///< Strictly conform to an older more strict version of the spec or reference software.
2532 #define FF_COMPLIANCE_STRICT 1 ///< Strictly conform to all the things in the spec no matter what consequences.
2533 #define FF_COMPLIANCE_NORMAL 0
2534 #define FF_COMPLIANCE_UNOFFICIAL -1 ///< Allow unofficial extensions
2535 #define FF_COMPLIANCE_EXPERIMENTAL -2 ///< Allow nonstandardized experimental things.
2536 
2537  /**
2538  * error concealment flags
2539  * - encoding: unused
2540  * - decoding: Set by user.
2541  */
2543 #define FF_EC_GUESS_MVS 1
2544 #define FF_EC_DEBLOCK 2
2545 #define FF_EC_FAVOR_INTER 256
2546 
2547  /**
2548  * debug
2549  * - encoding: Set by user.
2550  * - decoding: Set by user.
2551  */
2552  int debug;
2553 #define FF_DEBUG_PICT_INFO 1
2554 #define FF_DEBUG_RC 2
2555 #define FF_DEBUG_BITSTREAM 4
2556 #define FF_DEBUG_MB_TYPE 8
2557 #define FF_DEBUG_QP 16
2558 #if FF_API_DEBUG_MV
2559 /**
2560  * @deprecated this option does nothing
2561  */
2562 #define FF_DEBUG_MV 32
2563 #endif
2564 #define FF_DEBUG_DCT_COEFF 0x00000040
2565 #define FF_DEBUG_SKIP 0x00000080
2566 #define FF_DEBUG_STARTCODE 0x00000100
2567 #if FF_API_UNUSED_MEMBERS
2568 #define FF_DEBUG_PTS 0x00000200
2569 #endif /* FF_API_UNUSED_MEMBERS */
2570 #define FF_DEBUG_ER 0x00000400
2571 #define FF_DEBUG_MMCO 0x00000800
2572 #define FF_DEBUG_BUGS 0x00001000
2573 #if FF_API_DEBUG_MV
2574 #define FF_DEBUG_VIS_QP 0x00002000 ///< only access through AVOptions from outside libavcodec
2575 #define FF_DEBUG_VIS_MB_TYPE 0x00004000 ///< only access through AVOptions from outside libavcodec
2576 #endif
2577 #define FF_DEBUG_BUFFERS 0x00008000
2578 #define FF_DEBUG_THREADS 0x00010000
2579 #define FF_DEBUG_NOMC 0x01000000
2580 
2581 #if FF_API_DEBUG_MV
2582  /**
2583  * debug
2584  * Code outside libavcodec should access this field using AVOptions
2585  * - encoding: Set by user.
2586  * - decoding: Set by user.
2587  */
2589 #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 //visualize forward predicted MVs of P frames
2590 #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 //visualize forward predicted MVs of B frames
2591 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
2592 #endif
2593 
2594  /**
2595  * Error recognition; may misdetect some more or less valid parts as errors.
2596  * - encoding: unused
2597  * - decoding: Set by user.
2598  */
2599  int err_recognition;
2600 
2601 /**
2602  * Verify checksums embedded in the bitstream (could be of either encoded or
2603  * decoded data, depending on the codec) and print an error message on mismatch.
2604  * If AV_EF_EXPLODE is also set, a mismatching checksum will result in the
2605  * decoder returning an error.
2606  */
2607 #define AV_EF_CRCCHECK (1<<0)
2608 #define AV_EF_BITSTREAM (1<<1) ///< detect bitstream specification deviations
2609 #define AV_EF_BUFFER (1<<2) ///< detect improper bitstream length
2610 #define AV_EF_EXPLODE (1<<3) ///< abort decoding on minor error detection
2612 #define AV_EF_IGNORE_ERR (1<<15) ///< ignore errors and continue
2613 #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
2614 #define AV_EF_COMPLIANT (1<<17) ///< consider all spec non compliances as errors
2615 #define AV_EF_AGGRESSIVE (1<<18) ///< consider things that a sane encoder should not do as an error
2616 
2617 
2618  /**
2619  * opaque 64bit number (generally a PTS) that will be reordered and
2620  * output in AVFrame.reordered_opaque
2621  * - encoding: unused
2622  * - decoding: Set by user.
2623  */
2624  int64_t reordered_opaque;
2625 
2626  /**
2627  * Hardware accelerator in use
2628  * - encoding: unused.
2629  * - decoding: Set by libavcodec
2630  */
2631  struct AVHWAccel *hwaccel;
2632 
2633  /**
2634  * Hardware accelerator context.
2635  * For some hardware accelerators, a global context needs to be
2636  * provided by the user. In that case, this holds display-dependent
2637  * data FFmpeg cannot instantiate itself. Please refer to the
2638  * FFmpeg HW accelerator documentation to know how to fill this
2639  * is. e.g. for VA API, this is a struct vaapi_context.
2640  * - encoding: unused
2641  * - decoding: Set by user
2642  */
2643  void *hwaccel_context;
2644 
2645  /**
2646  * error
2647  * - encoding: Set by libavcodec if flags&CODEC_FLAG_PSNR.
2648  * - decoding: unused
2649  */
2650  uint64_t error[AV_NUM_DATA_POINTERS];
2651 
2652  /**
2653  * DCT algorithm, see FF_DCT_* below
2654  * - encoding: Set by user.
2655  * - decoding: unused
2656  */
2658 #define FF_DCT_AUTO 0
2659 #define FF_DCT_FASTINT 1
2660 #if FF_API_UNUSED_MEMBERS
2661 #define FF_DCT_INT 2
2662 #endif /* FF_API_UNUSED_MEMBERS */
2663 #define FF_DCT_MMX 3
2664 #define FF_DCT_ALTIVEC 5
2665 #define FF_DCT_FAAN 6
2666 
2667  /**
2668  * IDCT algorithm, see FF_IDCT_* below.
2669  * - encoding: Set by user.
2670  * - decoding: Set by user.
2671  */
2673 #define FF_IDCT_AUTO 0
2674 #define FF_IDCT_INT 1
2675 #define FF_IDCT_SIMPLE 2
2676 #define FF_IDCT_SIMPLEMMX 3
2677 #define FF_IDCT_ARM 7
2678 #define FF_IDCT_ALTIVEC 8
2679 #if FF_API_ARCH_SH4
2680 #define FF_IDCT_SH4 9
2681 #endif
2682 #define FF_IDCT_SIMPLEARM 10
2683 #if FF_API_UNUSED_MEMBERS
2684 #define FF_IDCT_IPP 13
2685 #endif /* FF_API_UNUSED_MEMBERS */
2686 #define FF_IDCT_XVID 14
2687 #if FF_API_IDCT_XVIDMMX
2688 #define FF_IDCT_XVIDMMX 14
2689 #endif /* FF_API_IDCT_XVIDMMX */
2690 #define FF_IDCT_SIMPLEARMV5TE 16
2691 #define FF_IDCT_SIMPLEARMV6 17
2692 #if FF_API_ARCH_SPARC
2693 #define FF_IDCT_SIMPLEVIS 18
2694 #endif
2695 #define FF_IDCT_FAAN 20
2696 #define FF_IDCT_SIMPLENEON 22
2697 #if FF_API_ARCH_ALPHA
2698 #define FF_IDCT_SIMPLEALPHA 23
2699 #endif
2700 #define FF_IDCT_SIMPLEAUTO 128
2701 
2702  /**
2703  * bits per sample/pixel from the demuxer (needed for huffyuv).
2704  * - encoding: Set by libavcodec.
2705  * - decoding: Set by user.
2706  */
2708 
2709  /**
2710  * Bits per sample/pixel of internal libavcodec pixel/sample format.
2711  * - encoding: set by user.
2712  * - decoding: set by libavcodec.
2713  */
2714  int bits_per_raw_sample;
2715 
2716 #if FF_API_LOWRES
2717  /**
2718  * low resolution decoding, 1-> 1/2 size, 2->1/4 size
2719  * - encoding: unused
2720  * - decoding: Set by user.
2721  * Code outside libavcodec should access this field using:
2722  * av_codec_{get,set}_lowres(avctx)
2723  */
2724  int lowres;
2725 #endif
2726 
2727  /**
2728  * the picture in the bitstream
2729  * - encoding: Set by libavcodec.
2730  * - decoding: unused
2731  */
2733 
2734  /**
2735  * thread count
2736  * is used to decide how many independent tasks should be passed to execute()
2737  * - encoding: Set by user.
2738  * - decoding: Set by user.
2739  */
2740  int thread_count;
2741 
2742  /**
2743  * Which multithreading methods to use.
2744  * Use of FF_THREAD_FRAME will increase decoding delay by one frame per thread,
2745  * so clients which cannot provide future frames should not use it.
2746  *
2747  * - encoding: Set by user, otherwise the default is used.
2748  * - decoding: Set by user, otherwise the default is used.
2749  */
2751 #define FF_THREAD_FRAME 1 ///< Decode more than one frame at once
2752 #define FF_THREAD_SLICE 2 ///< Decode more than one part of a single frame at once
2753 
2754  /**
2755  * Which multithreading methods are in use by the codec.
2756  * - encoding: Set by libavcodec.
2757  * - decoding: Set by libavcodec.
2758  */
2759  int active_thread_type;
2760 
2761  /**
2762  * Set by the client if its custom get_buffer() callback can be called
2763  * synchronously from another thread, which allows faster multithreaded decoding.
2764  * draw_horiz_band() will be called from other threads regardless of this setting.
2765  * Ignored if the default get_buffer() is used.
2766  * - encoding: Set by user.
2767  * - decoding: Set by user.
2768  */
2770 
2771  /**
2772  * The codec may call this to execute several independent things.
2773  * It will return only after finishing all tasks.
2774  * The user may replace this with some multithreaded implementation,
2775  * the default implementation will execute the parts serially.
2776  * @param count the number of things to execute
2777  * - encoding: Set by libavcodec, user can override.
2778  * - decoding: Set by libavcodec, user can override.
2779  */
2780  int (*execute)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size);
2781 
2782  /**
2783  * The codec may call this to execute several independent things.
2784  * It will return only after finishing all tasks.
2785  * The user may replace this with some multithreaded implementation,
2786  * the default implementation will execute the parts serially.
2787  * Also see avcodec_thread_init and e.g. the --enable-pthread configure option.
2788  * @param c context passed also to func
2789  * @param count the number of things to execute
2790  * @param arg2 argument passed unchanged to func
2791  * @param ret return values of executed functions, must have space for "count" values. May be NULL.
2792  * @param func function that will be called count times, with jobnr from 0 to count-1.
2793  * threadnr will be in the range 0 to c->thread_count-1 < MAX_THREADS and so that no
2794  * two instances of func executing at the same time will have the same threadnr.
2795  * @return always 0 currently, but code should handle a future improvement where when any call to func
2796  * returns < 0 no further calls to func may be done and < 0 is returned.
2797  * - encoding: Set by libavcodec, user can override.
2798  * - decoding: Set by libavcodec, user can override.
2799  */
2800  int (*execute2)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count);
2801 
2802 #if FF_API_THREAD_OPAQUE
2803  /**
2804  * @deprecated this field should not be used from outside of lavc
2805  */
2807  void *thread_opaque;
2808 #endif
2809 
2810  /**
2811  * noise vs. sse weight for the nsse comparison function
2812  * - encoding: Set by user.
2813  * - decoding: unused
2814  */
2815  int nsse_weight;
2816 
2817  /**
2818  * profile
2819  * - encoding: Set by user.
2820  * - decoding: Set by libavcodec.
2821  */
2822  int profile;
2823 #define FF_PROFILE_UNKNOWN -99
2824 #define FF_PROFILE_RESERVED -100
2826 #define FF_PROFILE_AAC_MAIN 0
2827 #define FF_PROFILE_AAC_LOW 1
2828 #define FF_PROFILE_AAC_SSR 2
2829 #define FF_PROFILE_AAC_LTP 3
2830 #define FF_PROFILE_AAC_HE 4
2831 #define FF_PROFILE_AAC_HE_V2 28
2832 #define FF_PROFILE_AAC_LD 22
2833 #define FF_PROFILE_AAC_ELD 38
2834 #define FF_PROFILE_MPEG2_AAC_LOW 128
2835 #define FF_PROFILE_MPEG2_AAC_HE 131
2837 #define FF_PROFILE_DTS 20
2838 #define FF_PROFILE_DTS_ES 30
2839 #define FF_PROFILE_DTS_96_24 40
2840 #define FF_PROFILE_DTS_HD_HRA 50
2841 #define FF_PROFILE_DTS_HD_MA 60
2843 #define FF_PROFILE_MPEG2_422 0
2844 #define FF_PROFILE_MPEG2_HIGH 1
2845 #define FF_PROFILE_MPEG2_SS 2
2846 #define FF_PROFILE_MPEG2_SNR_SCALABLE 3
2847 #define FF_PROFILE_MPEG2_MAIN 4
2848 #define FF_PROFILE_MPEG2_SIMPLE 5
2850 #define FF_PROFILE_H264_CONSTRAINED (1<<9) // 8+1; constraint_set1_flag
2851 #define FF_PROFILE_H264_INTRA (1<<11) // 8+3; constraint_set3_flag
2853 #define FF_PROFILE_H264_BASELINE 66
2854 #define FF_PROFILE_H264_CONSTRAINED_BASELINE (66|FF_PROFILE_H264_CONSTRAINED)
2855 #define FF_PROFILE_H264_MAIN 77
2856 #define FF_PROFILE_H264_EXTENDED 88
2857 #define FF_PROFILE_H264_HIGH 100
2858 #define FF_PROFILE_H264_HIGH_10 110
2859 #define FF_PROFILE_H264_HIGH_10_INTRA (110|FF_PROFILE_H264_INTRA)
2860 #define FF_PROFILE_H264_HIGH_422 122
2861 #define FF_PROFILE_H264_HIGH_422_INTRA (122|FF_PROFILE_H264_INTRA)
2862 #define FF_PROFILE_H264_HIGH_444 144
2863 #define FF_PROFILE_H264_HIGH_444_PREDICTIVE 244
2864 #define FF_PROFILE_H264_HIGH_444_INTRA (244|FF_PROFILE_H264_INTRA)
2865 #define FF_PROFILE_H264_CAVLC_444 44
2867 #define FF_PROFILE_VC1_SIMPLE 0
2868 #define FF_PROFILE_VC1_MAIN 1
2869 #define FF_PROFILE_VC1_COMPLEX 2
2870 #define FF_PROFILE_VC1_ADVANCED 3
2872 #define FF_PROFILE_MPEG4_SIMPLE 0
2873 #define FF_PROFILE_MPEG4_SIMPLE_SCALABLE 1
2874 #define FF_PROFILE_MPEG4_CORE 2
2875 #define FF_PROFILE_MPEG4_MAIN 3
2876 #define FF_PROFILE_MPEG4_N_BIT 4
2877 #define FF_PROFILE_MPEG4_SCALABLE_TEXTURE 5
2878 #define FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION 6
2879 #define FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE 7
2880 #define FF_PROFILE_MPEG4_HYBRID 8
2881 #define FF_PROFILE_MPEG4_ADVANCED_REAL_TIME 9
2882 #define FF_PROFILE_MPEG4_CORE_SCALABLE 10
2883 #define FF_PROFILE_MPEG4_ADVANCED_CODING 11
2884 #define FF_PROFILE_MPEG4_ADVANCED_CORE 12
2885 #define FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE 13
2886 #define FF_PROFILE_MPEG4_SIMPLE_STUDIO 14
2887 #define FF_PROFILE_MPEG4_ADVANCED_SIMPLE 15
2889 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_0 0
2890 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_1 1
2891 #define FF_PROFILE_JPEG2000_CSTREAM_NO_RESTRICTION 2
2892 #define FF_PROFILE_JPEG2000_DCINEMA_2K 3
2893 #define FF_PROFILE_JPEG2000_DCINEMA_4K 4
2894 
2896 #define FF_PROFILE_HEVC_MAIN 1
2897 #define FF_PROFILE_HEVC_MAIN_10 2
2898 #define FF_PROFILE_HEVC_MAIN_STILL_PICTURE 3
2899 #define FF_PROFILE_HEVC_REXT 4
2900 
2901  /**
2902  * level
2903  * - encoding: Set by user.
2904  * - decoding: Set by libavcodec.
2905  */
2906  int level;
2907 #define FF_LEVEL_UNKNOWN -99
2908 
2909  /**
2910  * Skip loop filtering for selected frames.
2911  * - encoding: unused
2912  * - decoding: Set by user.
2913  */
2915 
2916  /**
2917  * Skip IDCT/dequantization for selected frames.
2918  * - encoding: unused
2919  * - decoding: Set by user.
2920  */
2921  enum AVDiscard skip_idct;
2922 
2923  /**
2924  * Skip decoding for selected frames.
2925  * - encoding: unused
2926  * - decoding: Set by user.
2927  */
2928  enum AVDiscard skip_frame;
2929 
2930  /**
2931  * Header containing style information for text subtitles.
2932  * For SUBTITLE_ASS subtitle type, it should contain the whole ASS
2933  * [Script Info] and [V4+ Styles] section, plus the [Events] line and
2934  * the Format line following. It shouldn't include any Dialogue line.
2935  * - encoding: Set/allocated/freed by user (before avcodec_open2())
2936  * - decoding: Set/allocated/freed by libavcodec (by avcodec_open2())
2937  */
2940 
2941 #if FF_API_ERROR_RATE
2942  /**
2943  * @deprecated use the 'error_rate' private AVOption of the mpegvideo
2944  * encoders
2945  */
2947  int error_rate;
2948 #endif
2949 
2950 #if FF_API_CODEC_PKT
2951  /**
2952  * @deprecated this field is not supposed to be accessed from outside lavc
2953  */
2955  AVPacket *pkt;
2956 #endif
2957 
2958  /**
2959  * VBV delay coded in the last frame (in periods of a 27 MHz clock).
2960  * Used for compliant TS muxing.
2961  * - encoding: Set by libavcodec.
2962  * - decoding: unused.
2963  */
2964  uint64_t vbv_delay;
2965 
2966  /**
2967  * Encoding only. Allow encoders to output packets that do not contain any
2968  * encoded data, only side data.
2969  *
2970  * Some encoders need to output such packets, e.g. to update some stream
2971  * parameters at the end of encoding.
2972  *
2973  * All callers are strongly recommended to set this option to 1 and update
2974  * their code to deal with such packets, since this behaviour may become
2975  * always enabled in the future (then this option will be deprecated and
2976  * later removed). To avoid ABI issues when this happens, the callers should
2977  * use AVOptions to set this field.
2978  */
2980 
2981  /**
2982  * Audio only. The number of "priming" samples (padding) inserted by the
2983  * encoder at the beginning of the audio. I.e. this number of leading
2984  * decoded samples must be discarded by the caller to get the original audio
2985  * without leading padding.
2986  *
2987  * - decoding: unused
2988  * - encoding: Set by libavcodec. The timestamps on the output packets are
2989  * adjusted by the encoder so that they always refer to the
2990  * first sample of the data actually contained in the packet,
2991  * including any added padding. E.g. if the timebase is
2992  * 1/samplerate and the timestamp of the first input sample is
2993  * 0, the timestamp of the first output packet will be
2994  * -initial_padding.
2995  */
2996  int initial_padding;
2997 
2998  /**
2999  * - decoding: For codecs that store a framerate value in the compressed
3000  * bitstream, the decoder may export it here. { 0, 1} when
3001  * unknown.
3002  * - encoding: unused
3003  */
3005 
3006  /**
3007  * Timebase in which pkt_dts/pts and AVPacket.dts/pts are.
3008  * Code outside libavcodec should access this field using:
3009  * av_codec_{get,set}_pkt_timebase(avctx)
3010  * - encoding unused.
3011  * - decoding set by user.
3012  */
3014 
3015  /**
3016  * AVCodecDescriptor
3017  * Code outside libavcodec should access this field using:
3018  * av_codec_{get,set}_codec_descriptor(avctx)
3019  * - encoding: unused.
3020  * - decoding: set by libavcodec.
3021  */
3023 
3024 #if !FF_API_LOWRES
3025  /**
3026  * low resolution decoding, 1-> 1/2 size, 2->1/4 size
3027  * - encoding: unused
3028  * - decoding: Set by user.
3029  * Code outside libavcodec should access this field using:
3030  * av_codec_{get,set}_lowres(avctx)
3031  */
3032  int lowres;
3033 #endif
3034 
3035  /**
3036  * Current statistics for PTS correction.
3037  * - decoding: maintained and used by libavcodec, not intended to be used by user apps
3038  * - encoding: unused
3039  */
3040  int64_t pts_correction_num_faulty_pts; /// Number of incorrect PTS values so far
3041  int64_t pts_correction_num_faulty_dts; /// Number of incorrect DTS values so far
3042  int64_t pts_correction_last_pts; /// PTS of the last frame
3043  int64_t pts_correction_last_dts; /// DTS of the last frame
3044 
3045  /**
3046  * Character encoding of the input subtitles file.
3047  * - decoding: set by user
3048  * - encoding: unused
3049  */
3050  char *sub_charenc;
3051 
3052  /**
3053  * Subtitles character encoding mode. Formats or codecs might be adjusting
3054  * this setting (if they are doing the conversion themselves for instance).
3055  * - decoding: set by libavcodec
3056  * - encoding: unused
3057  */
3059 #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)
3060 #define FF_SUB_CHARENC_MODE_AUTOMATIC 0 ///< libavcodec will select the mode itself
3061 #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
3062 
3063  /**
3064  * Skip processing alpha if supported by codec.
3065  * Note that if the format uses pre-multiplied alpha (common with VP6,
3066  * and recommended due to better video quality/compression)
3067  * the image will look as if alpha-blended onto a black background.
3068  * However for formats that do not use pre-multiplied alpha
3069  * there might be serious artefacts (though e.g. libswscale currently
3070  * assumes pre-multiplied alpha anyway).
3071  * Code outside libavcodec should access this field using AVOptions
3072  *
3073  * - decoding: set by user
3074  * - encoding: unused
3075  */
3076  int skip_alpha;
3077 
3078  /**
3079  * Number of samples to skip after a discontinuity
3080  * - decoding: unused
3081  * - encoding: set by libavcodec
3082  */
3083  int seek_preroll;
3084 
3085 #if !FF_API_DEBUG_MV
3086  /**
3087  * debug motion vectors
3088  * Code outside libavcodec should access this field using AVOptions
3089  * - encoding: Set by user.
3090  * - decoding: Set by user.
3091  */
3092  int debug_mv;
3093 #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 //visualize forward predicted MVs of P frames
3094 #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 //visualize forward predicted MVs of B frames
3095 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
3096 #endif
3097 
3098  /**
3099  * custom intra quantization matrix
3100  * Code outside libavcodec should access this field using av_codec_g/set_chroma_intra_matrix()
3101  * - encoding: Set by user, can be NULL.
3102  * - decoding: unused.
3103  */
3104  uint16_t *chroma_intra_matrix;
3105 
3106  /**
3107  * dump format separator.
3108  * can be ", " or "\n " or anything else
3109  * Code outside libavcodec should access this field using AVOptions
3110  * (NO direct access).
3111  * - encoding: Set by user.
3112  * - decoding: Set by user.
3113  */
3115 
3116  /**
3117  * ',' seperated list of allowed decoders.
3118  * If NULL then all are allowed
3119  * - encoding: unused
3120  * - decoding: set by user through AVOPtions (NO direct access)
3121  */
3122  char *codec_whitelist;
3123 } AVCodecContext;
3124 
3127 
3130 
3131 int av_codec_get_lowres(const AVCodecContext *avctx);
3132 void av_codec_set_lowres(AVCodecContext *avctx, int val);
3133 
3134 int av_codec_get_seek_preroll(const AVCodecContext *avctx);
3135 void av_codec_set_seek_preroll(AVCodecContext *avctx, int val);
3136 
3137 uint16_t *av_codec_get_chroma_intra_matrix(const AVCodecContext *avctx);
3138 void av_codec_set_chroma_intra_matrix(AVCodecContext *avctx, uint16_t *val);
3139 
3140 /**
3141  * AVProfile.
3142  */
3143 typedef struct AVProfile {
3144  int profile;
3145  const char *name; ///< short name for the profile
3146 } AVProfile;
3147 
3148 typedef struct AVCodecDefault AVCodecDefault;
3149 
3150 struct AVSubtitle;
3151 
3152 /**
3153  * AVCodec.
3154  */
3155 typedef struct AVCodec {
3156  /**
3157  * Name of the codec implementation.
3158  * The name is globally unique among encoders and among decoders (but an
3159  * encoder and a decoder can share the same name).
3160  * This is the primary way to find a codec from the user perspective.
3161  */
3162  const char *name;
3163  /**
3164  * Descriptive name for the codec, meant to be more human readable than name.
3165  * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
3166  */
3167  const char *long_name;
3169  enum AVCodecID id;
3170  /**
3171  * Codec capabilities.
3172  * see CODEC_CAP_*
3173  */
3175  const AVRational *supported_framerates; ///< array of supported framerates, or NULL if any, array is terminated by {0,0}
3176  const enum AVPixelFormat *pix_fmts; ///< array of supported pixel formats, or NULL if unknown, array is terminated by -1
3177  const int *supported_samplerates; ///< array of supported audio samplerates, or NULL if unknown, array is terminated by 0
3178  const enum AVSampleFormat *sample_fmts; ///< array of supported sample formats, or NULL if unknown, array is terminated by -1
3179  const uint64_t *channel_layouts; ///< array of support channel layouts, or NULL if unknown. array is terminated by 0
3180 #if FF_API_LOWRES
3181  uint8_t max_lowres; ///< maximum value for lowres supported by the decoder, no direct access, use av_codec_get_max_lowres()
3182 #endif
3183  const AVClass *priv_class; ///< AVClass for the private context
3184  const AVProfile *profiles; ///< array of recognized profiles, or NULL if unknown, array is terminated by {FF_PROFILE_UNKNOWN}
3185 
3186  /*****************************************************************
3187  * No fields below this line are part of the public API. They
3188  * may not be used outside of libavcodec and can be changed and
3189  * removed at will.
3190  * New public fields should be added right above.
3191  *****************************************************************
3192  */
3194  struct AVCodec *next;
3195  /**
3196  * @name Frame-level threading support functions
3197  * @{
3198  */
3199  /**
3200  * If defined, called on thread contexts when they are created.
3201  * If the codec allocates writable tables in init(), re-allocate them here.
3202  * priv_data will be set to a copy of the original.
3203  */
3204  int (*init_thread_copy)(AVCodecContext *);
3205  /**
3206  * Copy necessary context variables from a previous thread context to the current one.
3207  * If not defined, the next thread will start automatically; otherwise, the codec
3208  * must call ff_thread_finish_setup().
3209  *
3210  * dst and src will (rarely) point to the same context, in which case memcpy should be skipped.
3211  */
3213  /** @} */
3214 
3215  /**
3216  * Private codec-specific defaults.
3217  */
3218  const AVCodecDefault *defaults;
3219 
3220  /**
3221  * Initialize codec static data, called from avcodec_register().
3222  */
3223  void (*init_static_data)(struct AVCodec *codec);
3226  int (*encode_sub)(AVCodecContext *, uint8_t *buf, int buf_size,
3227  const struct AVSubtitle *sub);
3228  /**
3229  * Encode data to an AVPacket.
3230  *
3231  * @param avctx codec context
3232  * @param avpkt output AVPacket (may contain a user-provided buffer)
3233  * @param[in] frame AVFrame containing the raw data to be encoded
3234  * @param[out] got_packet_ptr encoder sets to 0 or 1 to indicate that a
3235  * non-empty packet was returned in avpkt.
3236  * @return 0 on success, negative error code on failure
3237  */
3238  int (*encode2)(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame,
3239  int *got_packet_ptr);
3240  int (*decode)(AVCodecContext *, void *outdata, int *outdata_size, AVPacket *avpkt);
3241  int (*close)(AVCodecContext *);
3242  /**
3243  * Flush buffers.
3244  * Will be called when seeking
3245  */
3246  void (*flush)(AVCodecContext *);
3247 } AVCodec;
3248 
3249 int av_codec_get_max_lowres(const AVCodec *codec);
3250 
3251 struct MpegEncContext;
3252 
3253 /**
3254  * @defgroup lavc_hwaccel AVHWAccel
3255  * @{
3256  */
3257 typedef struct AVHWAccel {
3258  /**
3259  * Name of the hardware accelerated codec.
3260  * The name is globally unique among encoders and among decoders (but an
3261  * encoder and a decoder can share the same name).
3262  */
3263  const char *name;
3264 
3265  /**
3266  * Type of codec implemented by the hardware accelerator.
3267  *
3268  * See AVMEDIA_TYPE_xxx
3269  */
3270  enum AVMediaType type;
3271 
3272  /**
3273  * Codec implemented by the hardware accelerator.
3274  *
3275  * See AV_CODEC_ID_xxx
3276  */
3277  enum AVCodecID id;
3278 
3279  /**
3280  * Supported pixel format.
3281  *
3282  * Only hardware accelerated formats are supported here.
3283  */
3284  enum AVPixelFormat pix_fmt;
3285 
3286  /**
3287  * Hardware accelerated codec capabilities.
3288  * see FF_HWACCEL_CODEC_CAP_*
3289  */
3290  int capabilities;
3291 
3292  /*****************************************************************
3293  * No fields below this line are part of the public API. They
3294  * may not be used outside of libavcodec and can be changed and
3295  * removed at will.
3296  * New public fields should be added right above.
3297  *****************************************************************
3298  */
3299  struct AVHWAccel *next;
3300 
3301  /**
3302  * Allocate a custom buffer
3303  */
3304  int (*alloc_frame)(AVCodecContext *avctx, AVFrame *frame);
3305 
3306  /**
3307  * Called at the beginning of each frame or field picture.
3308  *
3309  * Meaningful frame information (codec specific) is guaranteed to
3310  * be parsed at this point. This function is mandatory.
3311  *
3312  * Note that buf can be NULL along with buf_size set to 0.
3313  * Otherwise, this means the whole frame is available at this point.
3314  *
3315  * @param avctx the codec context
3316  * @param buf the frame data buffer base
3317  * @param buf_size the size of the frame in bytes
3318  * @return zero if successful, a negative value otherwise
3319  */
3320  int (*start_frame)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3321 
3322  /**
3323  * Callback for each slice.
3324  *
3325  * Meaningful slice information (codec specific) is guaranteed to
3326  * be parsed at this point. This function is mandatory.
3327  * The only exception is XvMC, that works on MB level.
3328  *
3329  * @param avctx the codec context
3330  * @param buf the slice data buffer base
3331  * @param buf_size the size of the slice in bytes
3332  * @return zero if successful, a negative value otherwise
3333  */
3334  int (*decode_slice)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3335 
3336  /**
3337  * Called at the end of each frame or field picture.
3338  *
3339  * The whole picture is parsed at this point and can now be sent
3340  * to the hardware accelerator. This function is mandatory.
3341  *
3342  * @param avctx the codec context
3343  * @return zero if successful, a negative value otherwise
3344  */
3345  int (*end_frame)(AVCodecContext *avctx);
3346 
3347  /**
3348  * Size of per-frame hardware accelerator private data.
3349  *
3350  * Private data is allocated with av_mallocz() before
3351  * AVCodecContext.get_buffer() and deallocated after
3352  * AVCodecContext.release_buffer().
3353  */
3355 
3356  /**
3357  * Called for every Macroblock in a slice.
3358  *
3359  * XvMC uses it to replace the ff_mpv_decode_mb().
3360  * Instead of decoding to raw picture, MB parameters are
3361  * stored in an array provided by the video driver.
3362  *
3363  * @param s the mpeg context
3364  */
3365  void (*decode_mb)(struct MpegEncContext *s);
3366 
3367  /**
3368  * Initialize the hwaccel private data.
3369  *
3370  * This will be called from ff_get_format(), after hwaccel and
3371  * hwaccel_context are set and the hwaccel private data in AVCodecInternal
3372  * is allocated.
3373  */
3374  int (*init)(AVCodecContext *avctx);
3375 
3376  /**
3377  * Uninitialize the hwaccel private data.
3378  *
3379  * This will be called from get_format() or avcodec_close(), after hwaccel
3380  * and hwaccel_context are already uninitialized.
3381  */
3382  int (*uninit)(AVCodecContext *avctx);
3383 
3384  /**
3385  * Size of the private data to allocate in
3386  * AVCodecInternal.hwaccel_priv_data.
3387  */
3388  int priv_data_size;
3389 } AVHWAccel;
3390 
3391 /**
3392  * Hardware acceleration should be used for decoding even if the codec level
3393  * used is unknown or higher than the maximum supported level reported by the
3394  * hardware driver.
3395  */
3396 #define AV_HWACCEL_FLAG_IGNORE_LEVEL (1 << 0)
3397 
3398 /**
3399  * @}
3400  */
3401 
3402 /**
3403  * @defgroup lavc_picture AVPicture
3404  *
3405  * Functions for working with AVPicture
3406  * @{
3407  */
3408 
3409 /**
3410  * Picture data structure.
3411  *
3412  * Up to four components can be stored into it, the last component is
3413  * alpha.
3414  */
3415 typedef struct AVPicture {
3416  uint8_t *data[AV_NUM_DATA_POINTERS]; ///< pointers to the image data planes
3417  int linesize[AV_NUM_DATA_POINTERS]; ///< number of bytes per line
3418 } AVPicture;
3419 
3420 /**
3421  * @}
3422  */
3425  SUBTITLE_NONE,
3427  SUBTITLE_BITMAP, ///< A bitmap, pict will be set
3428 
3429  /**
3430  * Plain text, the text field must be set by the decoder and is
3431  * authoritative. ass and pict fields may contain approximations.
3432  */
3433  SUBTITLE_TEXT,
3434 
3435  /**
3436  * Formatted text, the ass field must be set by the decoder and is
3437  * authoritative. pict and text fields may contain approximations.
3438  */
3439  SUBTITLE_ASS,
3440 };
3442 #define AV_SUBTITLE_FLAG_FORCED 0x00000001
3444 typedef struct AVSubtitleRect {
3445  int x; ///< top left corner of pict, undefined when pict is not set
3446  int y; ///< top left corner of pict, undefined when pict is not set
3447  int w; ///< width of pict, undefined when pict is not set
3448  int h; ///< height of pict, undefined when pict is not set
3449  int nb_colors; ///< number of colors in pict, undefined when pict is not set
3450 
3451  /**
3452  * data+linesize for the bitmap of this subtitle.
3453  * can be set for text/ass as well once they where rendered
3454  */
3456  enum AVSubtitleType type;
3458  char *text; ///< 0 terminated plain UTF-8 text
3459 
3460  /**
3461  * 0 terminated ASS/SSA compatible event line.
3462  * The presentation of this is unaffected by the other values in this
3463  * struct.
3464  */
3465  char *ass;
3467  int flags;
3468 } AVSubtitleRect;
3470 typedef struct AVSubtitle {
3471  uint16_t format; /* 0 = graphics */
3472  uint32_t start_display_time; /* relative to packet pts, in ms */
3473  uint32_t end_display_time; /* relative to packet pts, in ms */
3474  unsigned num_rects;
3476  int64_t pts; ///< Same as packet pts, in AV_TIME_BASE
3477 } AVSubtitle;
3478 
3479 /**
3480  * If c is NULL, returns the first registered codec,
3481  * if c is non-NULL, returns the next registered codec after c,
3482  * or NULL if c is the last one.
3483  */
3484 AVCodec *av_codec_next(const AVCodec *c);
3485 
3486 /**
3487  * Return the LIBAVCODEC_VERSION_INT constant.
3488  */
3489 unsigned avcodec_version(void);
3490 
3491 /**
3492  * Return the libavcodec build-time configuration.
3493  */
3494 const char *avcodec_configuration(void);
3495 
3496 /**
3497  * Return the libavcodec license.
3498  */
3499 const char *avcodec_license(void);
3500 
3501 /**
3502  * Register the codec codec and initialize libavcodec.
3503  *
3504  * @warning either this function or avcodec_register_all() must be called
3505  * before any other libavcodec functions.
3506  *
3507  * @see avcodec_register_all()
3508  */
3509 void avcodec_register(AVCodec *codec);
3510 
3511 /**
3512  * Register all the codecs, parsers and bitstream filters which were enabled at
3513  * configuration time. If you do not call this function you can select exactly
3514  * which formats you want to support, by using the individual registration
3515  * functions.
3516  *
3517  * @see avcodec_register
3518  * @see av_register_codec_parser
3519  * @see av_register_bitstream_filter
3520  */
3521 void avcodec_register_all(void);
3522 
3523 /**
3524  * Allocate an AVCodecContext and set its fields to default values. The
3525  * resulting struct should be freed with avcodec_free_context().
3526  *
3527  * @param codec if non-NULL, allocate private data and initialize defaults
3528  * for the given codec. It is illegal to then call avcodec_open2()
3529  * with a different codec.
3530  * If NULL, then the codec-specific defaults won't be initialized,
3531  * which may result in suboptimal default settings (this is
3532  * important mainly for encoders, e.g. libx264).
3533  *
3534  * @return An AVCodecContext filled with default values or NULL on failure.
3535  * @see avcodec_get_context_defaults
3536  */
3538 
3539 /**
3540  * Free the codec context and everything associated with it and write NULL to
3541  * the provided pointer.
3542  */
3543 void avcodec_free_context(AVCodecContext **avctx);
3544 
3545 /**
3546  * Set the fields of the given AVCodecContext to default values corresponding
3547  * to the given codec (defaults may be codec-dependent).
3548  *
3549  * Do not call this function if a non-NULL codec has been passed
3550  * to avcodec_alloc_context3() that allocated this AVCodecContext.
3551  * If codec is non-NULL, it is illegal to call avcodec_open2() with a
3552  * different codec on this AVCodecContext.
3553  */
3555 
3556 /**
3557  * Get the AVClass for AVCodecContext. It can be used in combination with
3558  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
3559  *
3560  * @see av_opt_find().
3561  */
3562 const AVClass *avcodec_get_class(void);
3563 
3564 /**
3565  * Get the AVClass for AVFrame. It can be used in combination with
3566  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
3567  *
3568  * @see av_opt_find().
3569  */
3570 const AVClass *avcodec_get_frame_class(void);
3571 
3572 /**
3573  * Get the AVClass for AVSubtitleRect. It can be used in combination with
3574  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
3575  *
3576  * @see av_opt_find().
3577  */
3579 
3580 /**
3581  * Copy the settings of the source AVCodecContext into the destination
3582  * AVCodecContext. The resulting destination codec context will be
3583  * unopened, i.e. you are required to call avcodec_open2() before you
3584  * can use this AVCodecContext to decode/encode video/audio data.
3585  *
3586  * @param dest target codec context, should be initialized with
3587  * avcodec_alloc_context3(NULL), but otherwise uninitialized
3588  * @param src source codec context
3589  * @return AVERROR() on error (e.g. memory allocation error), 0 on success
3590  */
3592 
3593 #if FF_API_AVFRAME_LAVC
3594 /**
3595  * @deprecated use av_frame_alloc()
3596  */
3598 AVFrame *avcodec_alloc_frame(void);
3599 
3600 /**
3601  * Set the fields of the given AVFrame to default values.
3602  *
3603  * @param frame The AVFrame of which the fields should be set to default values.
3604  *
3605  * @deprecated use av_frame_unref()
3606  */
3608 void avcodec_get_frame_defaults(AVFrame *frame);
3609 
3610 /**
3611  * Free the frame and any dynamically allocated objects in it,
3612  * e.g. extended_data.
3613  *
3614  * @param frame frame to be freed. The pointer will be set to NULL.
3615  *
3616  * @warning this function does NOT free the data buffers themselves
3617  * (it does not know how, since they might have been allocated with
3618  * a custom get_buffer()).
3619  *
3620  * @deprecated use av_frame_free()
3621  */
3623 void avcodec_free_frame(AVFrame **frame);
3624 #endif
3625 
3626 /**
3627  * Initialize the AVCodecContext to use the given AVCodec. Prior to using this
3628  * function the context has to be allocated with avcodec_alloc_context3().
3629  *
3630  * The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(),
3631  * avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for
3632  * retrieving a codec.
3633  *
3634  * @warning This function is not thread safe!
3635  *
3636  * @code
3637  * avcodec_register_all();
3638  * av_dict_set(&opts, "b", "2.5M", 0);
3639  * codec = avcodec_find_decoder(AV_CODEC_ID_H264);
3640  * if (!codec)
3641  * exit(1);
3642  *
3643  * context = avcodec_alloc_context3(codec);
3644  *
3645  * if (avcodec_open2(context, codec, opts) < 0)
3646  * exit(1);
3647  * @endcode
3648  *
3649  * @param avctx The context to initialize.
3650  * @param codec The codec to open this context for. If a non-NULL codec has been
3651  * previously passed to avcodec_alloc_context3() or
3652  * avcodec_get_context_defaults3() for this context, then this
3653  * parameter MUST be either NULL or equal to the previously passed
3654  * codec.
3655  * @param options A dictionary filled with AVCodecContext and codec-private options.
3656  * On return this object will be filled with options that were not found.
3657  *
3658  * @return zero on success, a negative value on error
3659  * @see avcodec_alloc_context3(), avcodec_find_decoder(), avcodec_find_encoder(),
3660  * av_dict_set(), av_opt_find().
3661  */
3662 int avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options);
3663 
3664 /**
3665  * Close a given AVCodecContext and free all the data associated with it
3666  * (but not the AVCodecContext itself).
3667  *
3668  * Calling this function on an AVCodecContext that hasn't been opened will free
3669  * the codec-specific data allocated in avcodec_alloc_context3() /
3670  * avcodec_get_context_defaults3() with a non-NULL codec. Subsequent calls will
3671  * do nothing.
3672  */
3673 int avcodec_close(AVCodecContext *avctx);
3674 
3675 /**
3676  * Free all allocated data in the given subtitle struct.
3677  *
3678  * @param sub AVSubtitle to free.
3679  */
3680 void avsubtitle_free(AVSubtitle *sub);
3681 
3682 /**
3683  * @}
3684  */
3685 
3686 /**
3687  * @addtogroup lavc_packet
3688  * @{
3689  */
3690 
3691 #if FF_API_DESTRUCT_PACKET
3692 /**
3693  * Default packet destructor.
3694  * @deprecated use the AVBuffer API instead
3695  */
3698 #endif
3699 
3700 /**
3701  * Initialize optional fields of a packet with default values.
3702  *
3703  * Note, this does not touch the data and size members, which have to be
3704  * initialized separately.
3705  *
3706  * @param pkt packet
3707  */
3708 void av_init_packet(AVPacket *pkt);
3709 
3710 /**
3711  * Allocate the payload of a packet and initialize its fields with
3712  * default values.
3713  *
3714  * @param pkt packet
3715  * @param size wanted payload size
3716  * @return 0 if OK, AVERROR_xxx otherwise
3717  */
3718 int av_new_packet(AVPacket *pkt, int size);
3719 
3720 /**
3721  * Reduce packet size, correctly zeroing padding
3722  *
3723  * @param pkt packet
3724  * @param size new size
3725  */
3726 void av_shrink_packet(AVPacket *pkt, int size);
3727 
3728 /**
3729  * Increase packet size, correctly zeroing padding
3730  *
3731  * @param pkt packet
3732  * @param grow_by number of bytes by which to increase the size of the packet
3733  */
3734 int av_grow_packet(AVPacket *pkt, int grow_by);
3735 
3736 /**
3737  * Initialize a reference-counted packet from av_malloc()ed data.
3738  *
3739  * @param pkt packet to be initialized. This function will set the data, size,
3740  * buf and destruct fields, all others are left untouched.
3741  * @param data Data allocated by av_malloc() to be used as packet data. If this
3742  * function returns successfully, the data is owned by the underlying AVBuffer.
3743  * The caller may not access the data through other means.
3744  * @param size size of data in bytes, without the padding. I.e. the full buffer
3745  * size is assumed to be size + FF_INPUT_BUFFER_PADDING_SIZE.
3746  *
3747  * @return 0 on success, a negative AVERROR on error
3748  */
3750 
3751 /**
3752  * @warning This is a hack - the packet memory allocation stuff is broken. The
3753  * packet is allocated if it was not really allocated.
3754  */
3755 int av_dup_packet(AVPacket *pkt);
3756 
3757 /**
3758  * Copy packet, including contents
3759  *
3760  * @return 0 on success, negative AVERROR on fail
3761  */
3762 int av_copy_packet(AVPacket *dst, const AVPacket *src);
3763 
3764 /**
3765  * Copy packet side data
3766  *
3767  * @return 0 on success, negative AVERROR on fail
3768  */
3769 int av_copy_packet_side_data(AVPacket *dst, const AVPacket *src);
3770 
3771 /**
3772  * Free a packet.
3773  *
3774  * @param pkt packet to free
3775  */
3776 void av_free_packet(AVPacket *pkt);
3777 
3778 /**
3779  * Allocate new information of a packet.
3780  *
3781  * @param pkt packet
3782  * @param type side information type
3783  * @param size side information size
3784  * @return pointer to fresh allocated data or NULL otherwise
3785  */
3787  int size);
3788 
3789 /**
3790  * Shrink the already allocated side data buffer
3791  *
3792  * @param pkt packet
3793  * @param type side information type
3794  * @param size new side information size
3795  * @return 0 on success, < 0 on failure
3796  */
3798  int size);
3799 
3800 /**
3801  * Get side information from packet.
3802  *
3803  * @param pkt packet
3804  * @param type desired side information type
3805  * @param size pointer for side information size to store (optional)
3806  * @return pointer to data if present or NULL otherwise
3807  */
3809  int *size);
3810 
3812 
3814 
3815 /**
3816  * Pack a dictionary for use in side_data.
3817  *
3818  * @param dict The dictionary to pack.
3819  * @param size pointer to store the size of the returned data
3820  * @return pointer to data if successful, NULL otherwise
3821  */
3823 /**
3824  * Unpack a dictionary from side_data.
3825  *
3826  * @param data data from side_data
3827  * @param size size of the data
3828  * @param dict the metadata storage dictionary
3829  * @return 0 on success, < 0 on failure
3830  */
3831 int av_packet_unpack_dictionary(const uint8_t *data, int size, AVDictionary **dict);
3832 
3833 
3834 /**
3835  * Convenience function to free all the side data stored.
3836  * All the other fields stay untouched.
3837  *
3838  * @param pkt packet
3839  */
3841 
3842 /**
3843  * Setup a new reference to the data described by a given packet
3844  *
3845  * If src is reference-counted, setup dst as a new reference to the
3846  * buffer in src. Otherwise allocate a new buffer in dst and copy the
3847  * data from src into it.
3848  *
3849  * All the other fields are copied from src.
3850  *
3851  * @see av_packet_unref
3852  *
3853  * @param dst Destination packet
3854  * @param src Source packet
3855  *
3856  * @return 0 on success, a negative AVERROR on error.
3857  */
3858 int av_packet_ref(AVPacket *dst, const AVPacket *src);
3859 
3860 /**
3861  * Wipe the packet.
3862  *
3863  * Unreference the buffer referenced by the packet and reset the
3864  * remaining packet fields to their default values.
3865  *
3866  * @param pkt The packet to be unreferenced.
3867  */
3869 
3870 /**
3871  * Move every field in src to dst and reset src.
3872  *
3873  * @see av_packet_unref
3874  *
3875  * @param src Source packet, will be reset
3876  * @param dst Destination packet
3877  */
3879 
3880 /**
3881  * Copy only "properties" fields from src to dst.
3882  *
3883  * Properties for the purpose of this function are all the fields
3884  * beside those related to the packet data (buf, data, size)
3885  *
3886  * @param dst Destination packet
3887  * @param src Source packet
3888  *
3889  * @return 0 on success AVERROR on failure.
3890  *
3891  */
3892 int av_packet_copy_props(AVPacket *dst, const AVPacket *src);
3893 
3894 /**
3895  * Convert valid timing fields (timestamps / durations) in a packet from one
3896  * timebase to another. Timestamps with unknown values (AV_NOPTS_VALUE) will be
3897  * ignored.
3898  *
3899  * @param pkt packet on which the conversion will be performed
3900  * @param tb_src source timebase, in which the timing fields in pkt are
3901  * expressed
3902  * @param tb_dst destination timebase, to which the timing fields will be
3903  * converted
3904  */
3905 void av_packet_rescale_ts(AVPacket *pkt, AVRational tb_src, AVRational tb_dst);
3906 
3907 /**
3908  * @}
3909  */
3910 
3911 /**
3912  * @addtogroup lavc_decoding
3913  * @{
3914  */
3915 
3916 /**
3917  * Find a registered decoder with a matching codec ID.
3918  *
3919  * @param id AVCodecID of the requested decoder
3920  * @return A decoder if one was found, NULL otherwise.
3921  */
3923 
3924 /**
3925  * Find a registered decoder with the specified name.
3926  *
3927  * @param name name of the requested decoder
3928  * @return A decoder if one was found, NULL otherwise.
3929  */
3931 
3932 #if FF_API_GET_BUFFER
3936 #endif
3937 
3938 /**
3939  * The default callback for AVCodecContext.get_buffer2(). It is made public so
3940  * it can be called by custom get_buffer2() implementations for decoders without
3941  * CODEC_CAP_DR1 set.
3942  */
3944 
3945 #if FF_API_EMU_EDGE
3946 /**
3947  * Return the amount of padding in pixels which the get_buffer callback must
3948  * provide around the edge of the image for codecs which do not have the
3949  * CODEC_FLAG_EMU_EDGE flag.
3950  *
3951  * @return Required padding in pixels.
3952  *
3953  * @deprecated CODEC_FLAG_EMU_EDGE is deprecated, so this function is no longer
3954  * needed
3955  */
3957 unsigned avcodec_get_edge_width(void);
3958 #endif
3959 
3960 /**
3961  * Modify width and height values so that they will result in a memory
3962  * buffer that is acceptable for the codec if you do not use any horizontal
3963  * padding.
3964  *
3965  * May only be used if a codec with CODEC_CAP_DR1 has been opened.
3966  */
3968 
3969 /**
3970  * Modify width and height values so that they will result in a memory
3971  * buffer that is acceptable for the codec if you also ensure that all
3972  * line sizes are a multiple of the respective linesize_align[i].
3973  *
3974  * May only be used if a codec with CODEC_CAP_DR1 has been opened.
3975  */
3977  int linesize_align[AV_NUM_DATA_POINTERS]);
3978 
3979 /**
3980  * Converts AVChromaLocation to swscale x/y chroma position.
3981  *
3982  * The positions represent the chroma (0,0) position in a coordinates system
3983  * with luma (0,0) representing the origin and luma(1,1) representing 256,256
3984  *
3985  * @param xpos horizontal chroma sample position
3986  * @param ypos vertical chroma sample position
3987  */
3988 int avcodec_enum_to_chroma_pos(int *xpos, int *ypos, enum AVChromaLocation pos);
3989 
3990 /**
3991  * Converts swscale x/y chroma position to AVChromaLocation.
3992  *
3993  * The positions represent the chroma (0,0) position in a coordinates system
3994  * with luma (0,0) representing the origin and luma(1,1) representing 256,256
3995  *
3996  * @param xpos horizontal chroma sample position
3997  * @param ypos vertical chroma sample position
3998  */
3999 enum AVChromaLocation avcodec_chroma_pos_to_enum(int xpos, int ypos);
4000 
4001 #if FF_API_OLD_DECODE_AUDIO
4002 /**
4003  * Wrapper function which calls avcodec_decode_audio4.
4004  *
4005  * @deprecated Use avcodec_decode_audio4 instead.
4006  *
4007  * Decode the audio frame of size avpkt->size from avpkt->data into samples.
4008  * Some decoders may support multiple frames in a single AVPacket, such
4009  * decoders would then just decode the first frame. In this case,
4010  * avcodec_decode_audio3 has to be called again with an AVPacket that contains
4011  * the remaining data in order to decode the second frame etc.
4012  * If no frame
4013  * could be outputted, frame_size_ptr is zero. Otherwise, it is the
4014  * decompressed frame size in bytes.
4015  *
4016  * @warning You must set frame_size_ptr to the allocated size of the
4017  * output buffer before calling avcodec_decode_audio3().
4018  *
4019  * @warning The input buffer must be FF_INPUT_BUFFER_PADDING_SIZE larger than
4020  * the actual read bytes because some optimized bitstream readers read 32 or 64
4021  * bits at once and could read over the end.
4022  *
4023  * @warning The end of the input buffer avpkt->data should be set to 0 to ensure that
4024  * no overreading happens for damaged MPEG streams.
4025  *
4026  * @warning You must not provide a custom get_buffer() when using
4027  * avcodec_decode_audio3(). Doing so will override it with
4028  * avcodec_default_get_buffer. Use avcodec_decode_audio4() instead,
4029  * which does allow the application to provide a custom get_buffer().
4030  *
4031  * @note You might have to align the input buffer avpkt->data and output buffer
4032  * samples. The alignment requirements depend on the CPU: On some CPUs it isn't
4033  * necessary at all, on others it won't work at all if not aligned and on others
4034  * it will work but it will have an impact on performance.
4035  *
4036  * In practice, avpkt->data should have 4 byte alignment at minimum and
4037  * samples should be 16 byte aligned unless the CPU doesn't need it
4038  * (AltiVec and SSE do).
4039  *
4040  * @note Codecs which have the CODEC_CAP_DELAY capability set have a delay
4041  * between input and output, these need to be fed with avpkt->data=NULL,
4042  * avpkt->size=0 at the end to return the remaining frames.
4043  *
4044  * @param avctx the codec context
4045  * @param[out] samples the output buffer, sample type in avctx->sample_fmt
4046  * If the sample format is planar, each channel plane will
4047  * be the same size, with no padding between channels.
4048  * @param[in,out] frame_size_ptr the output buffer size in bytes
4049  * @param[in] avpkt The input AVPacket containing the input buffer.
4050  * You can create such packet with av_init_packet() and by then setting
4051  * data and size, some decoders might in addition need other fields.
4052  * All decoders are designed to use the least fields possible though.
4053  * @return On error a negative value is returned, otherwise the number of bytes
4054  * used or zero if no frame data was decompressed (used) from the input AVPacket.
4055  */
4056 attribute_deprecated int avcodec_decode_audio3(AVCodecContext *avctx, int16_t *samples,
4057  int *frame_size_ptr,
4058  AVPacket *avpkt);
4059 #endif
4060 
4061 /**
4062  * Decode the audio frame of size avpkt->size from avpkt->data into frame.
4063  *
4064  * Some decoders may support multiple frames in a single AVPacket. Such
4065  * decoders would then just decode the first frame and the return value would be
4066  * less than the packet size. In this case, avcodec_decode_audio4 has to be
4067  * called again with an AVPacket containing the remaining data in order to
4068  * decode the second frame, etc... Even if no frames are returned, the packet
4069  * needs to be fed to the decoder with remaining data until it is completely
4070  * consumed or an error occurs.
4071  *
4072  * Some decoders (those marked with CODEC_CAP_DELAY) have a delay between input
4073  * and output. This means that for some packets they will not immediately
4074  * produce decoded output and need to be flushed at the end of decoding to get
4075  * all the decoded data. Flushing is done by calling this function with packets
4076  * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
4077  * returning samples. It is safe to flush even those decoders that are not
4078  * marked with CODEC_CAP_DELAY, then no samples will be returned.
4079  *
4080  * @warning The input buffer, avpkt->data must be FF_INPUT_BUFFER_PADDING_SIZE
4081  * larger than the actual read bytes because some optimized bitstream
4082  * readers read 32 or 64 bits at once and could read over the end.
4083  *
4084  * @param avctx the codec context
4085  * @param[out] frame The AVFrame in which to store decoded audio samples.
4086  * The decoder will allocate a buffer for the decoded frame by
4087  * calling the AVCodecContext.get_buffer2() callback.
4088  * When AVCodecContext.refcounted_frames is set to 1, the frame is
4089  * reference counted and the returned reference belongs to the
4090  * caller. The caller must release the frame using av_frame_unref()
4091  * when the frame is no longer needed. The caller may safely write
4092  * to the frame if av_frame_is_writable() returns 1.
4093  * When AVCodecContext.refcounted_frames is set to 0, the returned
4094  * reference belongs to the decoder and is valid only until the
4095  * next call to this function or until closing or flushing the
4096  * decoder. The caller may not write to it.
4097  * @param[out] got_frame_ptr Zero if no frame could be decoded, otherwise it is
4098  * non-zero. Note that this field being set to zero
4099  * does not mean that an error has occurred. For
4100  * decoders with CODEC_CAP_DELAY set, no given decode
4101  * call is guaranteed to produce a frame.
4102  * @param[in] avpkt The input AVPacket containing the input buffer.
4103  * At least avpkt->data and avpkt->size should be set. Some
4104  * decoders might also require additional fields to be set.
4105  * @return A negative error code is returned if an error occurred during
4106  * decoding, otherwise the number of bytes consumed from the input
4107  * AVPacket is returned.
4108  */
4110  int *got_frame_ptr, const AVPacket *avpkt);
4111 
4112 /**
4113  * Decode the video frame of size avpkt->size from avpkt->data into picture.
4114  * Some decoders may support multiple frames in a single AVPacket, such
4115  * decoders would then just decode the first frame.
4116  *
4117  * @warning The input buffer must be FF_INPUT_BUFFER_PADDING_SIZE larger than
4118  * the actual read bytes because some optimized bitstream readers read 32 or 64
4119  * bits at once and could read over the end.
4120  *
4121  * @warning The end of the input buffer buf should be set to 0 to ensure that
4122  * no overreading happens for damaged MPEG streams.
4123  *
4124  * @note Codecs which have the CODEC_CAP_DELAY capability set have a delay
4125  * between input and output, these need to be fed with avpkt->data=NULL,
4126  * avpkt->size=0 at the end to return the remaining frames.
4127  *
4128  * @param avctx the codec context
4129  * @param[out] picture The AVFrame in which the decoded video frame will be stored.
4130  * Use av_frame_alloc() to get an AVFrame. The codec will
4131  * allocate memory for the actual bitmap by calling the
4132  * AVCodecContext.get_buffer2() callback.
4133  * When AVCodecContext.refcounted_frames is set to 1, the frame is
4134  * reference counted and the returned reference belongs to the
4135  * caller. The caller must release the frame using av_frame_unref()
4136  * when the frame is no longer needed. The caller may safely write
4137  * to the frame if av_frame_is_writable() returns 1.
4138  * When AVCodecContext.refcounted_frames is set to 0, the returned
4139  * reference belongs to the decoder and is valid only until the
4140  * next call to this function or until closing or flushing the
4141  * decoder. The caller may not write to it.
4142  *
4143  * @param[in] avpkt The input AVPacket containing the input buffer.
4144  * You can create such packet with av_init_packet() and by then setting
4145  * data and size, some decoders might in addition need other fields like
4146  * flags&AV_PKT_FLAG_KEY. All decoders are designed to use the least
4147  * fields possible.
4148  * @param[in,out] got_picture_ptr Zero if no frame could be decompressed, otherwise, it is nonzero.
4149  * @return On error a negative value is returned, otherwise the number of bytes
4150  * used or zero if no frame could be decompressed.
4151  */
4152 int avcodec_decode_video2(AVCodecContext *avctx, AVFrame *picture,
4153  int *got_picture_ptr,
4154  const AVPacket *avpkt);
4155 
4156 /**
4157  * Decode a subtitle message.
4158  * Return a negative value on error, otherwise return the number of bytes used.
4159  * If no subtitle could be decompressed, got_sub_ptr is zero.
4160  * Otherwise, the subtitle is stored in *sub.
4161  * Note that CODEC_CAP_DR1 is not available for subtitle codecs. This is for
4162  * simplicity, because the performance difference is expect to be negligible
4163  * and reusing a get_buffer written for video codecs would probably perform badly
4164  * due to a potentially very different allocation pattern.
4165  *
4166  * Some decoders (those marked with CODEC_CAP_DELAY) have a delay between input
4167  * and output. This means that for some packets they will not immediately
4168  * produce decoded output and need to be flushed at the end of decoding to get
4169  * all the decoded data. Flushing is done by calling this function with packets
4170  * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
4171  * returning subtitles. It is safe to flush even those decoders that are not
4172  * marked with CODEC_CAP_DELAY, then no subtitles will be returned.
4173  *
4174  * @param avctx the codec context
4175  * @param[out] sub The Preallocated AVSubtitle in which the decoded subtitle will be stored,
4176  * must be freed with avsubtitle_free if *got_sub_ptr is set.
4177  * @param[in,out] got_sub_ptr Zero if no subtitle could be decompressed, otherwise, it is nonzero.
4178  * @param[in] avpkt The input AVPacket containing the input buffer.
4179  */
4181  int *got_sub_ptr,
4182  AVPacket *avpkt);
4183 
4184 /**
4185  * @defgroup lavc_parsing Frame parsing
4186  * @{
4187  */
4191  AV_PICTURE_STRUCTURE_TOP_FIELD, //< coded as top field
4192  AV_PICTURE_STRUCTURE_BOTTOM_FIELD, //< coded as bottom field
4193  AV_PICTURE_STRUCTURE_FRAME, //< coded as frame
4194 };
4196 typedef struct AVCodecParserContext {
4197  void *priv_data;
4199  int64_t frame_offset; /* offset of the current frame */
4200  int64_t cur_offset; /* current offset
4201  (incremented by each av_parser_parse()) */
4202  int64_t next_frame_offset; /* offset of the next frame */
4203  /* video info */
4204  int pict_type; /* XXX: Put it back in AVCodecContext. */
4205  /**
4206  * This field is used for proper frame duration computation in lavf.
4207  * It signals, how much longer the frame duration of the current frame
4208  * is compared to normal frame duration.
4209  *
4210  * frame_duration = (1 + repeat_pict) * time_base
4211  *
4212  * It is used by codecs like H.264 to display telecined material.
4213  */
4214  int repeat_pict; /* XXX: Put it back in AVCodecContext. */
4215  int64_t pts; /* pts of the current frame */
4216  int64_t dts; /* dts of the current frame */
4217 
4218  /* private data */
4219  int64_t last_pts;
4220  int64_t last_dts;
4221  int fetch_timestamp;
4223 #define AV_PARSER_PTS_NB 4
4229  int flags;
4230 #define PARSER_FLAG_COMPLETE_FRAMES 0x0001
4231 #define PARSER_FLAG_ONCE 0x0002
4232 /// Set if the parser has a valid file offset
4233 #define PARSER_FLAG_FETCHED_OFFSET 0x0004
4234 #define PARSER_FLAG_USE_CODEC_TS 0x1000
4236  int64_t offset; ///< byte offset from starting packet start
4238 
4239  /**
4240  * Set by parser to 1 for key frames and 0 for non-key frames.
4241  * It is initialized to -1, so if the parser doesn't set this flag,
4242  * old-style fallback using AV_PICTURE_TYPE_I picture type as key frames
4243  * will be used.
4244  */
4245  int key_frame;
4246 
4247  /**
4248  * Time difference in stream time base units from the pts of this
4249  * packet to the point at which the output from the decoder has converged
4250  * independent from the availability of previous frames. That is, the
4251  * frames are virtually identical no matter if decoding started from
4252  * the very first frame or from this keyframe.
4253  * Is AV_NOPTS_VALUE if unknown.
4254  * This field is not the display duration of the current frame.
4255  * This field has no meaning if the packet does not have AV_PKT_FLAG_KEY
4256  * set.
4257  *
4258  * The purpose of this field is to allow seeking in streams that have no
4259  * keyframes in the conventional sense. It corresponds to the
4260  * recovery point SEI in H.264 and match_time_delta in NUT. It is also
4261  * essential for some types of subtitle streams to ensure that all
4262  * subtitles are correctly displayed after seeking.
4263  */
4264  int64_t convergence_duration;
4265 
4266  // Timestamp generation support:
4267  /**
4268  * Synchronization point for start of timestamp generation.
4269  *
4270  * Set to >0 for sync point, 0 for no sync point and <0 for undefined
4271  * (default).
4272  *
4273  * For example, this corresponds to presence of H.264 buffering period
4274  * SEI message.
4275  */
4276  int dts_sync_point;
4277 
4278  /**
4279  * Offset of the current timestamp against last timestamp sync point in
4280  * units of AVCodecContext.time_base.
4281  *
4282  * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
4283  * contain a valid timestamp offset.
4284  *
4285  * Note that the timestamp of sync point has usually a nonzero
4286  * dts_ref_dts_delta, which refers to the previous sync point. Offset of
4287  * the next frame after timestamp sync point will be usually 1.
4288  *
4289  * For example, this corresponds to H.264 cpb_removal_delay.
4290  */
4291  int dts_ref_dts_delta;
4292 
4293  /**
4294  * Presentation delay of current frame in units of AVCodecContext.time_base.
4295  *
4296  * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
4297  * contain valid non-negative timestamp delta (presentation time of a frame
4298  * must not lie in the past).
4299  *
4300  * This delay represents the difference between decoding and presentation
4301  * time of the frame.
4302  *
4303  * For example, this corresponds to H.264 dpb_output_delay.
4304  */
4305  int pts_dts_delta;
4306 
4307  /**
4308  * Position of the packet in file.
4309  *
4310  * Analogous to cur_frame_pts/dts
4311  */
4313 
4314  /**
4315  * Byte position of currently parsed frame in stream.
4316  */
4317  int64_t pos;
4318 
4319  /**
4320  * Previous frame byte position.
4321  */
4322  int64_t last_pos;
4323 
4324  /**
4325  * Duration of the current frame.
4326  * For audio, this is in units of 1 / AVCodecContext.sample_rate.
4327  * For all other types, this is in units of AVCodecContext.time_base.
4328  */
4329  int duration;
4332 
4333  /**
4334  * Indicate whether a picture is coded as a frame, top field or bottom field.
4335  *
4336  * For example, H.264 field_pic_flag equal to 0 corresponds to
4337  * AV_PICTURE_STRUCTURE_FRAME. An H.264 picture with field_pic_flag
4338  * equal to 1 and bottom_field_flag equal to 0 corresponds to
4339  * AV_PICTURE_STRUCTURE_TOP_FIELD.
4340  */
4342 
4343  /**
4344  * Picture number incremented in presentation or output order.
4345  * This field may be reinitialized at the first picture of a new sequence.
4346  *
4347  * For example, this corresponds to H.264 PicOrderCnt.
4348  */
4352 typedef struct AVCodecParser {
4353  int codec_ids[5]; /* several codec IDs are permitted */
4357  AVCodecContext *avctx,
4358  const uint8_t **poutbuf, int *poutbuf_size,
4359  const uint8_t *buf, int buf_size);
4361  int (*split)(AVCodecContext *avctx, const uint8_t *buf, int buf_size);
4362  struct AVCodecParser *next;
4363 } AVCodecParser;
4364 
4366 
4369 
4370 /**
4371  * Parse a packet.
4372  *
4373  * @param s parser context.
4374  * @param avctx codec context.
4375  * @param poutbuf set to pointer to parsed buffer or NULL if not yet finished.
4376  * @param poutbuf_size set to size of parsed buffer or zero if not yet finished.
4377  * @param buf input buffer.
4378  * @param buf_size input length, to signal EOF, this should be 0 (so that the last frame can be output).
4379  * @param pts input presentation timestamp.
4380  * @param dts input decoding timestamp.
4381  * @param pos input byte position in stream.
4382  * @return the number of bytes of the input bitstream used.
4383  *
4384  * Example:
4385  * @code
4386  * while(in_len){
4387  * len = av_parser_parse2(myparser, AVCodecContext, &data, &size,
4388  * in_data, in_len,
4389  * pts, dts, pos);
4390  * in_data += len;
4391  * in_len -= len;
4392  *
4393  * if(size)
4394  * decode_frame(data, size);
4395  * }
4396  * @endcode
4397  */
4399  AVCodecContext *avctx,
4400  uint8_t **poutbuf, int *poutbuf_size,
4401  const uint8_t *buf, int buf_size,
4402  int64_t pts, int64_t dts,
4403  int64_t pos);
4404 
4405 /**
4406  * @return 0 if the output buffer is a subset of the input, 1 if it is allocated and must be freed
4407  * @deprecated use AVBitStreamFilter
4408  */
4410  AVCodecContext *avctx,
4411  uint8_t **poutbuf, int *poutbuf_size,
4412  const uint8_t *buf, int buf_size, int keyframe);
4414 
4415 /**
4416  * @}
4417  * @}
4418  */
4419 
4420 /**
4421  * @addtogroup lavc_encoding
4422  * @{
4423  */
4424 
4425 /**
4426  * Find a registered encoder with a matching codec ID.
4427  *
4428  * @param id AVCodecID of the requested encoder
4429  * @return An encoder if one was found, NULL otherwise.
4430  */
4432 
4433 /**
4434  * Find a registered encoder with the specified name.
4435  *
4436  * @param name name of the requested encoder
4437  * @return An encoder if one was found, NULL otherwise.
4438  */
4440 
4441 #if FF_API_OLD_ENCODE_AUDIO
4442 /**
4443  * Encode an audio frame from samples into buf.
4444  *
4445  * @deprecated Use avcodec_encode_audio2 instead.
4446  *
4447  * @note The output buffer should be at least FF_MIN_BUFFER_SIZE bytes large.
4448  * However, for codecs with avctx->frame_size equal to 0 (e.g. PCM) the user
4449  * will know how much space is needed because it depends on the value passed
4450  * in buf_size as described below. In that case a lower value can be used.
4451  *
4452  * @param avctx the codec context
4453  * @param[out] buf the output buffer
4454  * @param[in] buf_size the output buffer size
4455  * @param[in] samples the input buffer containing the samples
4456  * The number of samples read from this buffer is frame_size*channels,
4457  * both of which are defined in avctx.
4458  * For codecs which have avctx->frame_size equal to 0 (e.g. PCM) the number of
4459  * samples read from samples is equal to:
4460  * buf_size * 8 / (avctx->channels * av_get_bits_per_sample(avctx->codec_id))
4461  * This also implies that av_get_bits_per_sample() must not return 0 for these
4462  * codecs.
4463  * @return On error a negative value is returned, on success zero or the number
4464  * of bytes used to encode the data read from the input buffer.
4465  */
4467  uint8_t *buf, int buf_size,
4468  const short *samples);
4469 #endif
4470 
4471 /**
4472  * Encode a frame of audio.
4473  *
4474  * Takes input samples from frame and writes the next output packet, if
4475  * available, to avpkt. The output packet does not necessarily contain data for
4476  * the most recent frame, as encoders can delay, split, and combine input frames
4477  * internally as needed.
4478  *
4479  * @param avctx codec context
4480  * @param avpkt output AVPacket.
4481  * The user can supply an output buffer by setting
4482  * avpkt->data and avpkt->size prior to calling the
4483  * function, but if the size of the user-provided data is not
4484  * large enough, encoding will fail. If avpkt->data and
4485  * avpkt->size are set, avpkt->destruct must also be set. All
4486  * other AVPacket fields will be reset by the encoder using
4487  * av_init_packet(). If avpkt->data is NULL, the encoder will
4488  * allocate it. The encoder will set avpkt->size to the size
4489  * of the output packet.
4490  *
4491  * If this function fails or produces no output, avpkt will be
4492  * freed using av_free_packet() (i.e. avpkt->destruct will be
4493  * called to free the user supplied buffer).
4494  * @param[in] frame AVFrame containing the raw audio data to be encoded.
4495  * May be NULL when flushing an encoder that has the
4496  * CODEC_CAP_DELAY capability set.
4497  * If CODEC_CAP_VARIABLE_FRAME_SIZE is set, then each frame
4498  * can have any number of samples.
4499  * If it is not set, frame->nb_samples must be equal to
4500  * avctx->frame_size for all frames except the last.
4501  * The final frame may be smaller than avctx->frame_size.
4502  * @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
4503  * output packet is non-empty, and to 0 if it is
4504  * empty. If the function returns an error, the
4505  * packet can be assumed to be invalid, and the
4506  * value of got_packet_ptr is undefined and should
4507  * not be used.
4508  * @return 0 on success, negative error code on failure
4509  */
4510 int avcodec_encode_audio2(AVCodecContext *avctx, AVPacket *avpkt,
4511  const AVFrame *frame, int *got_packet_ptr);
4512 
4513 #if FF_API_OLD_ENCODE_VIDEO
4514 /**
4515  * @deprecated use avcodec_encode_video2() instead.
4516  *
4517  * Encode a video frame from pict into buf.
4518  * The input picture should be
4519  * stored using a specific format, namely avctx.pix_fmt.
4520  *
4521  * @param avctx the codec context
4522  * @param[out] buf the output buffer for the bitstream of encoded frame
4523  * @param[in] buf_size the size of the output buffer in bytes
4524  * @param[in] pict the input picture to encode
4525  * @return On error a negative value is returned, on success zero or the number
4526  * of bytes used from the output buffer.
4527  */
4529 int avcodec_encode_video(AVCodecContext *avctx, uint8_t *buf, int buf_size,
4530  const AVFrame *pict);
4531 #endif
4532 
4533 /**
4534  * Encode a frame of video.
4535  *
4536  * Takes input raw video data from frame and writes the next output packet, if
4537  * available, to avpkt. The output packet does not necessarily contain data for
4538  * the most recent frame, as encoders can delay and reorder input frames
4539  * internally as needed.
4540  *
4541  * @param avctx codec context
4542  * @param avpkt output AVPacket.
4543  * The user can supply an output buffer by setting
4544  * avpkt->data and avpkt->size prior to calling the
4545  * function, but if the size of the user-provided data is not
4546  * large enough, encoding will fail. All other AVPacket fields
4547  * will be reset by the encoder using av_init_packet(). If
4548  * avpkt->data is NULL, the encoder will allocate it.
4549  * The encoder will set avpkt->size to the size of the
4550  * output packet. The returned data (if any) belongs to the
4551  * caller, he is responsible for freeing it.
4552  *
4553  * If this function fails or produces no output, avpkt will be
4554  * freed using av_free_packet() (i.e. avpkt->destruct will be
4555  * called to free the user supplied buffer).
4556  * @param[in] frame AVFrame containing the raw video data to be encoded.
4557  * May be NULL when flushing an encoder that has the
4558  * CODEC_CAP_DELAY capability set.
4559  * @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
4560  * output packet is non-empty, and to 0 if it is
4561  * empty. If the function returns an error, the
4562  * packet can be assumed to be invalid, and the
4563  * value of got_packet_ptr is undefined and should
4564  * not be used.
4565  * @return 0 on success, negative error code on failure
4566  */
4567 int avcodec_encode_video2(AVCodecContext *avctx, AVPacket *avpkt,
4568  const AVFrame *frame, int *got_packet_ptr);
4569 
4570 int avcodec_encode_subtitle(AVCodecContext *avctx, uint8_t *buf, int buf_size,
4571  const AVSubtitle *sub);
4572 
4573 
4574 /**
4575  * @}
4576  */
4577 
4578 #if FF_API_AVCODEC_RESAMPLE
4579 /**
4580  * @defgroup lavc_resample Audio resampling
4581  * @ingroup libavc
4582  * @deprecated use libswresample instead
4583  *
4584  * @{
4585  */
4586 struct ReSampleContext;
4587 struct AVResampleContext;
4588 
4589 typedef struct ReSampleContext ReSampleContext;
4590 
4591 /**
4592  * Initialize audio resampling context.
4593  *
4594  * @param output_channels number of output channels
4595  * @param input_channels number of input channels
4596  * @param output_rate output sample rate
4597  * @param input_rate input sample rate
4598  * @param sample_fmt_out requested output sample format
4599  * @param sample_fmt_in input sample format
4600  * @param filter_length length of each FIR filter in the filterbank relative to the cutoff frequency
4601  * @param log2_phase_count log2 of the number of entries in the polyphase filterbank
4602  * @param linear if 1 then the used FIR filter will be linearly interpolated
4603  between the 2 closest, if 0 the closest will be used
4604  * @param cutoff cutoff frequency, 1.0 corresponds to half the output sampling rate
4605  * @return allocated ReSampleContext, NULL if error occurred
4606  */
4609  int output_rate, int input_rate,
4610  enum AVSampleFormat sample_fmt_out,
4611  enum AVSampleFormat sample_fmt_in,
4612  int filter_length, int log2_phase_count,
4613  int linear, double cutoff);
4614 
4616 int audio_resample(ReSampleContext *s, short *output, short *input, int nb_samples);
4617 
4618 /**
4619  * Free resample context.
4620  *
4621  * @param s a non-NULL pointer to a resample context previously
4622  * created with av_audio_resample_init()
4623  */
4626 
4627 
4628 /**
4629  * Initialize an audio resampler.
4630  * Note, if either rate is not an integer then simply scale both rates up so they are.
4631  * @param filter_length length of each FIR filter in the filterbank relative to the cutoff freq
4632  * @param log2_phase_count log2 of the number of entries in the polyphase filterbank
4633  * @param linear If 1 then the used FIR filter will be linearly interpolated
4634  between the 2 closest, if 0 the closest will be used
4635  * @param cutoff cutoff frequency, 1.0 corresponds to half the output sampling rate
4636  */
4638 struct AVResampleContext *av_resample_init(int out_rate, int in_rate, int filter_length, int log2_phase_count, int linear, double cutoff);
4639 
4640 /**
4641  * Resample an array of samples using a previously configured context.
4642  * @param src an array of unconsumed samples
4643  * @param consumed the number of samples of src which have been consumed are returned here
4644  * @param src_size the number of unconsumed samples available
4645  * @param dst_size the amount of space in samples available in dst
4646  * @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.
4647  * @return the number of samples written in dst or -1 if an error occurred
4648  */
4650 int av_resample(struct AVResampleContext *c, short *dst, short *src, int *consumed, int src_size, int dst_size, int update_ctx);
4651 
4652 
4653 /**
4654  * Compensate samplerate/timestamp drift. The compensation is done by changing
4655  * the resampler parameters, so no audible clicks or similar distortions occur
4656  * @param compensation_distance distance in output samples over which the compensation should be performed
4657  * @param sample_delta number of output samples which should be output less
4658  *
4659  * example: av_resample_compensate(c, 10, 500)
4660  * here instead of 510 samples only 500 samples would be output
4661  *
4662  * note, due to rounding the actual compensation might be slightly different,
4663  * especially if the compensation_distance is large and the in_rate used during init is small
4664  */
4666 void av_resample_compensate(struct AVResampleContext *c, int sample_delta, int compensation_distance);
4668 void av_resample_close(struct AVResampleContext *c);
4669 
4670 /**
4671  * @}
4672  */
4673 #endif
4674 
4675 /**
4676  * @addtogroup lavc_picture
4677  * @{
4678  */
4679 
4680 /**
4681  * Allocate memory for the pixels of a picture and setup the AVPicture
4682  * fields for it.
4683  *
4684  * Call avpicture_free() to free it.
4685  *
4686  * @param picture the picture structure to be filled in
4687  * @param pix_fmt the pixel format of the picture
4688  * @param width the width of the picture
4689  * @param height the height of the picture
4690  * @return zero if successful, a negative error code otherwise
4691  *
4692  * @see av_image_alloc(), avpicture_fill()
4693  */
4694 int avpicture_alloc(AVPicture *picture, enum AVPixelFormat pix_fmt, int width, int height);
4695 
4696 /**
4697  * Free a picture previously allocated by avpicture_alloc().
4698  * The data buffer used by the AVPicture is freed, but the AVPicture structure
4699  * itself is not.
4700  *
4701  * @param picture the AVPicture to be freed
4702  */
4703 void avpicture_free(AVPicture *picture);
4704 
4705 /**
4706  * Setup the picture fields based on the specified image parameters
4707  * and the provided image data buffer.
4708  *
4709  * The picture fields are filled in by using the image data buffer
4710  * pointed to by ptr.
4711  *
4712  * If ptr is NULL, the function will fill only the picture linesize
4713  * array and return the required size for the image buffer.
4714  *
4715  * To allocate an image buffer and fill the picture data in one call,
4716  * use avpicture_alloc().
4717  *
4718  * @param picture the picture to be filled in
4719  * @param ptr buffer where the image data is stored, or NULL
4720  * @param pix_fmt the pixel format of the image
4721  * @param width the width of the image in pixels
4722  * @param height the height of the image in pixels
4723  * @return the size in bytes required for src, a negative error code
4724  * in case of failure
4725  *
4726  * @see av_image_fill_arrays()
4727  */
4728 int avpicture_fill(AVPicture *picture, const uint8_t *ptr,
4729  enum AVPixelFormat pix_fmt, int width, int height);
4730 
4731 /**
4732  * Copy pixel data from an AVPicture into a buffer.
4733  *
4734  * avpicture_get_size() can be used to compute the required size for
4735  * the buffer to fill.
4736  *
4737  * @param src source picture with filled data
4738  * @param pix_fmt picture pixel format
4739  * @param width picture width
4740  * @param height picture height
4741  * @param dest destination buffer
4742  * @param dest_size destination buffer size in bytes
4743  * @return the number of bytes written to dest, or a negative value
4744  * (error code) on error, for example if the destination buffer is not
4745  * big enough
4746  *
4747  * @see av_image_copy_to_buffer()
4748  */
4750  int width, int height,
4751  unsigned char *dest, int dest_size);
4752 
4753 /**
4754  * Calculate the size in bytes that a picture of the given width and height
4755  * would occupy if stored in the given picture format.
4756  *
4757  * @param pix_fmt picture pixel format
4758  * @param width picture width
4759  * @param height picture height
4760  * @return the computed picture buffer size or a negative error code
4761  * in case of error
4762  *
4763  * @see av_image_get_buffer_size().
4764  */
4766 
4767 #if FF_API_DEINTERLACE
4768 /**
4769  * deinterlace - if not supported return -1
4770  *
4771  * @deprecated - use yadif (in libavfilter) instead
4772  */
4774 int avpicture_deinterlace(AVPicture *dst, const AVPicture *src,
4775  enum AVPixelFormat pix_fmt, int width, int height);
4776 #endif
4777 /**
4778  * Copy image src to dst. Wraps av_image_copy().
4779  */
4780 void av_picture_copy(AVPicture *dst, const AVPicture *src,
4781  enum AVPixelFormat pix_fmt, int width, int height);
4782 
4783 /**
4784  * Crop image top and left side.
4785  */
4786 int av_picture_crop(AVPicture *dst, const AVPicture *src,
4787  enum AVPixelFormat pix_fmt, int top_band, int left_band);
4788 
4789 /**
4790  * Pad image.
4791  */
4792 int av_picture_pad(AVPicture *dst, const AVPicture *src, int height, int width, enum AVPixelFormat pix_fmt,
4793  int padtop, int padbottom, int padleft, int padright, int *color);
4794 
4795 /**
4796  * @}
4797  */
4798 
4799 /**
4800  * @defgroup lavc_misc Utility functions
4801  * @ingroup libavc
4802  *
4803  * Miscellaneous utility functions related to both encoding and decoding
4804  * (or neither).
4805  * @{
4806  */
4807 
4808 /**
4809  * @defgroup lavc_misc_pixfmt Pixel formats
4810  *
4811  * Functions for working with pixel formats.
4812  * @{
4813  */
4814 
4815 /**
4816  * Utility function to access log2_chroma_w log2_chroma_h from
4817  * the pixel format AVPixFmtDescriptor.
4818  *
4819  * This function asserts that pix_fmt is valid. See av_pix_fmt_get_chroma_sub_sample
4820  * for one that returns a failure code and continues in case of invalid
4821  * pix_fmts.
4822  *
4823  * @param[in] pix_fmt the pixel format
4824  * @param[out] h_shift store log2_chroma_w
4825  * @param[out] v_shift store log2_chroma_h
4826  *
4827  * @see av_pix_fmt_get_chroma_sub_sample
4828  */
4829 
4830 void avcodec_get_chroma_sub_sample(enum AVPixelFormat pix_fmt, int *h_shift, int *v_shift);
4831 
4832 /**
4833  * Return a value representing the fourCC code associated to the
4834  * pixel format pix_fmt, or 0 if no associated fourCC code can be
4835  * found.
4836  */
4838 
4839 /**
4840  * @deprecated see av_get_pix_fmt_loss()
4841  */
4842 int avcodec_get_pix_fmt_loss(enum AVPixelFormat dst_pix_fmt, enum AVPixelFormat src_pix_fmt,
4843  int has_alpha);
4844 
4845 /**
4846  * Find the best pixel format to convert to given a certain source pixel
4847  * format. When converting from one pixel format to another, information loss
4848  * may occur. For example, when converting from RGB24 to GRAY, the color
4849  * information will be lost. Similarly, other losses occur when converting from
4850  * some formats to other formats. avcodec_find_best_pix_fmt_of_2() searches which of
4851  * the given pixel formats should be used to suffer the least amount of loss.
4852  * The pixel formats from which it chooses one, are determined by the
4853  * pix_fmt_list parameter.
4854  *
4855