FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
avcodec.h
Go to the documentation of this file.
1 /*
2  * copyright (c) 2001 Fabrice Bellard
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #ifndef AVCODEC_AVCODEC_H
22 #define AVCODEC_AVCODEC_H
23 
24 /**
25  * @file
26  * @ingroup libavc
27  * Libavcodec external API header
28  */
29 
30 #include <errno.h>
31 #include "libavutil/samplefmt.h"
32 #include "libavutil/attributes.h"
33 #include "libavutil/avutil.h"
34 #include "libavutil/buffer.h"
35 #include "libavutil/cpu.h"
37 #include "libavutil/dict.h"
38 #include "libavutil/frame.h"
39 #include "libavutil/log.h"
40 #include "libavutil/pixfmt.h"
41 #include "libavutil/rational.h"
42 
43 #include "version.h"
44 
45 /**
46  * @defgroup libavc Encoding/Decoding Library
47  * @{
48  *
49  * @defgroup lavc_decoding Decoding
50  * @{
51  * @}
52  *
53  * @defgroup lavc_encoding Encoding
54  * @{
55  * @}
56  *
57  * @defgroup lavc_codec Codecs
58  * @{
59  * @defgroup lavc_codec_native Native Codecs
60  * @{
61  * @}
62  * @defgroup lavc_codec_wrappers External library wrappers
63  * @{
64  * @}
65  * @defgroup lavc_codec_hwaccel Hardware Accelerators bridge
66  * @{
67  * @}
68  * @}
69  * @defgroup lavc_internal Internal
70  * @{
71  * @}
72  * @}
73  *
74  */
75 
76 /**
77  * @defgroup lavc_core Core functions/structures.
78  * @ingroup libavc
79  *
80  * Basic definitions, functions for querying libavcodec capabilities,
81  * allocating core structures, etc.
82  * @{
83  */
84 
85 
86 /**
87  * Identify the syntax and semantics of the bitstream.
88  * The principle is roughly:
89  * Two decoders with the same ID can decode the same streams.
90  * Two encoders with the same ID can encode compatible streams.
91  * There may be slight deviations from the principle due to implementation
92  * details.
93  *
94  * If you add a codec ID to this list, add it so that
95  * 1. no value of a existing codec ID changes (that would break ABI),
96  * 2. Give it a value which when taken as ASCII is recognized uniquely by a human as this specific codec.
97  * This ensures that 2 forks can independently add AVCodecIDs without producing conflicts.
98  *
99  * After adding new codec IDs, do not forget to add an entry to the codec
100  * descriptor list and bump libavcodec minor version.
101  */
102 enum AVCodecID {
104 
105  /* video codecs */
107  AV_CODEC_ID_MPEG2VIDEO, ///< preferred ID for MPEG-1/2 video decoding
108 #if FF_API_XVMC
109  AV_CODEC_ID_MPEG2VIDEO_XVMC,
110 #endif /* FF_API_XVMC */
293 
294  AV_CODEC_ID_BRENDER_PIX= MKBETAG('B','P','I','X'),
295  AV_CODEC_ID_Y41P = MKBETAG('Y','4','1','P'),
296  AV_CODEC_ID_ESCAPE130 = MKBETAG('E','1','3','0'),
297  AV_CODEC_ID_EXR = MKBETAG('0','E','X','R'),
298  AV_CODEC_ID_AVRP = MKBETAG('A','V','R','P'),
299 
300  AV_CODEC_ID_012V = MKBETAG('0','1','2','V'),
301  AV_CODEC_ID_G2M = MKBETAG( 0 ,'G','2','M'),
302  AV_CODEC_ID_AVUI = MKBETAG('A','V','U','I'),
303  AV_CODEC_ID_AYUV = MKBETAG('A','Y','U','V'),
304  AV_CODEC_ID_TARGA_Y216 = MKBETAG('T','2','1','6'),
305  AV_CODEC_ID_V308 = MKBETAG('V','3','0','8'),
306  AV_CODEC_ID_V408 = MKBETAG('V','4','0','8'),
307  AV_CODEC_ID_YUV4 = MKBETAG('Y','U','V','4'),
308  AV_CODEC_ID_SANM = MKBETAG('S','A','N','M'),
309  AV_CODEC_ID_PAF_VIDEO = MKBETAG('P','A','F','V'),
310  AV_CODEC_ID_AVRN = MKBETAG('A','V','R','n'),
311  AV_CODEC_ID_CPIA = MKBETAG('C','P','I','A'),
312  AV_CODEC_ID_XFACE = MKBETAG('X','F','A','C'),
313  AV_CODEC_ID_SGIRLE = MKBETAG('S','G','I','R'),
314  AV_CODEC_ID_MVC1 = MKBETAG('M','V','C','1'),
315  AV_CODEC_ID_MVC2 = MKBETAG('M','V','C','2'),
316  AV_CODEC_ID_SNOW = MKBETAG('S','N','O','W'),
317  AV_CODEC_ID_WEBP = MKBETAG('W','E','B','P'),
318  AV_CODEC_ID_SMVJPEG = MKBETAG('S','M','V','J'),
319  AV_CODEC_ID_HEVC = MKBETAG('H','2','6','5'),
320 #define AV_CODEC_ID_H265 AV_CODEC_ID_HEVC
321  AV_CODEC_ID_VP7 = MKBETAG('V','P','7','0'),
322  AV_CODEC_ID_APNG = MKBETAG('A','P','N','G'),
323 
324  /* various PCM "codecs" */
325  AV_CODEC_ID_FIRST_AUDIO = 0x10000, ///< A dummy id pointing at the start of audio codecs
359 
360  /* various ADPCM codecs */
392  AV_CODEC_ID_ADPCM_VIMA = MKBETAG('V','I','M','A'),
393  AV_CODEC_ID_VIMA = MKBETAG('V','I','M','A'),
394  AV_CODEC_ID_ADPCM_AFC = MKBETAG('A','F','C',' '),
395  AV_CODEC_ID_ADPCM_IMA_OKI = MKBETAG('O','K','I',' '),
396  AV_CODEC_ID_ADPCM_DTK = MKBETAG('D','T','K',' '),
397  AV_CODEC_ID_ADPCM_IMA_RAD = MKBETAG('R','A','D',' '),
398  AV_CODEC_ID_ADPCM_G726LE = MKBETAG('6','2','7','G'),
399 
400  /* AMR */
403 
404  /* RealAudio codecs*/
407 
408  /* various DPCM codecs */
413 
414  /* audio codecs */
415  AV_CODEC_ID_MP2 = 0x15000,
416  AV_CODEC_ID_MP3, ///< preferred ID for decoding MPEG audio layer 1, 2 or 3
433  AV_CODEC_ID_GSM, ///< as in Berlin toast format
445  AV_CODEC_ID_GSM_MS, /* as found in WAV */
447 #if FF_API_VOXWARE
449 #endif
484  AV_CODEC_ID_FFWAVESYNTH = MKBETAG('F','F','W','S'),
485  AV_CODEC_ID_SONIC = MKBETAG('S','O','N','C'),
486  AV_CODEC_ID_SONIC_LS = MKBETAG('S','O','N','L'),
487  AV_CODEC_ID_PAF_AUDIO = MKBETAG('P','A','F','A'),
488  AV_CODEC_ID_OPUS = MKBETAG('O','P','U','S'),
489  AV_CODEC_ID_TAK = MKBETAG('t','B','a','K'),
490  AV_CODEC_ID_EVRC = MKBETAG('s','e','v','c'),
491  AV_CODEC_ID_SMV = MKBETAG('s','s','m','v'),
492  AV_CODEC_ID_DSD_LSBF = MKBETAG('D','S','D','L'),
493  AV_CODEC_ID_DSD_MSBF = MKBETAG('D','S','D','M'),
496 
497  /* subtitle codecs */
498  AV_CODEC_ID_FIRST_SUBTITLE = 0x17000, ///< A dummy ID pointing at the start of subtitle codecs.
501  AV_CODEC_ID_TEXT, ///< raw UTF-8 text
508  AV_CODEC_ID_MICRODVD = MKBETAG('m','D','V','D'),
509  AV_CODEC_ID_EIA_608 = MKBETAG('c','6','0','8'),
510  AV_CODEC_ID_JACOSUB = MKBETAG('J','S','U','B'),
511  AV_CODEC_ID_SAMI = MKBETAG('S','A','M','I'),
512  AV_CODEC_ID_REALTEXT = MKBETAG('R','T','X','T'),
513  AV_CODEC_ID_STL = MKBETAG('S','p','T','L'),
514  AV_CODEC_ID_SUBVIEWER1 = MKBETAG('S','b','V','1'),
515  AV_CODEC_ID_SUBVIEWER = MKBETAG('S','u','b','V'),
516  AV_CODEC_ID_SUBRIP = MKBETAG('S','R','i','p'),
517  AV_CODEC_ID_WEBVTT = MKBETAG('W','V','T','T'),
518  AV_CODEC_ID_MPL2 = MKBETAG('M','P','L','2'),
519  AV_CODEC_ID_VPLAYER = MKBETAG('V','P','l','r'),
520  AV_CODEC_ID_PJS = MKBETAG('P','h','J','S'),
521  AV_CODEC_ID_ASS = MKBETAG('A','S','S',' '), ///< ASS as defined in Matroska
522 
523  /* other specific kind of codecs (generally used for attachments) */
524  AV_CODEC_ID_FIRST_UNKNOWN = 0x18000, ///< A dummy ID pointing at the start of various fake codecs.
525  AV_CODEC_ID_TTF = 0x18000,
526  AV_CODEC_ID_BINTEXT = MKBETAG('B','T','X','T'),
527  AV_CODEC_ID_XBIN = MKBETAG('X','B','I','N'),
528  AV_CODEC_ID_IDF = MKBETAG( 0 ,'I','D','F'),
529  AV_CODEC_ID_OTF = MKBETAG( 0 ,'O','T','F'),
530  AV_CODEC_ID_SMPTE_KLV = MKBETAG('K','L','V','A'),
531  AV_CODEC_ID_DVD_NAV = MKBETAG('D','N','A','V'),
532  AV_CODEC_ID_TIMED_ID3 = MKBETAG('T','I','D','3'),
533  AV_CODEC_ID_BIN_DATA = MKBETAG('D','A','T','A'),
534 
535 
536  AV_CODEC_ID_PROBE = 0x19000, ///< codec_id is not known (like AV_CODEC_ID_NONE) but lavf should attempt to identify it
537 
538  AV_CODEC_ID_MPEG2TS = 0x20000, /**< _FAKE_ codec to indicate a raw MPEG-2 TS
539  * stream (only used by libavformat) */
540  AV_CODEC_ID_MPEG4SYSTEMS = 0x20001, /**< _FAKE_ codec to indicate a MPEG-4 Systems
541  * stream (only used by libavformat) */
542  AV_CODEC_ID_FFMETADATA = 0x21000, ///< Dummy codec for streams containing only metadata information.
543 
544 #if FF_API_CODEC_ID
545 #include "old_codec_ids.h"
546 #endif
547 };
548 
549 /**
550  * This struct describes the properties of a single codec described by an
551  * AVCodecID.
552  * @see avcodec_descriptor_get()
553  */
554 typedef struct AVCodecDescriptor {
555  enum AVCodecID id;
557  /**
558  * Name of the codec described by this descriptor. It is non-empty and
559  * unique for each codec descriptor. It should contain alphanumeric
560  * characters and '_' only.
561  */
562  const char *name;
563  /**
564  * A more descriptive name for this codec. May be NULL.
565  */
566  const char *long_name;
567  /**
568  * Codec properties, a combination of AV_CODEC_PROP_* flags.
569  */
570  int props;
571 
572  /**
573  * MIME type(s) associated with the codec.
574  * May be NULL; if not, a NULL-terminated array of MIME types.
575  * The first item is always non-NULL and is the preferred MIME type.
576  */
577  const char *const *mime_types;
580 /**
581  * Codec uses only intra compression.
582  * Video codecs only.
583  */
584 #define AV_CODEC_PROP_INTRA_ONLY (1 << 0)
585 /**
586  * Codec supports lossy compression. Audio and video codecs only.
587  * @note a codec may support both lossy and lossless
588  * compression modes
589  */
590 #define AV_CODEC_PROP_LOSSY (1 << 1)
591 /**
592  * Codec supports lossless compression. Audio and video codecs only.
593  */
594 #define AV_CODEC_PROP_LOSSLESS (1 << 2)
595 /**
596  * Codec supports frame reordering. That is, the coded order (the order in which
597  * the encoded packets are output by the encoders / stored / input to the
598  * decoders) may be different from the presentation order of the corresponding
599  * frames.
600  *
601  * For codecs that do not have this property set, PTS and DTS should always be
602  * equal.
603  */
604 #define AV_CODEC_PROP_REORDER (1 << 3)
605 /**
606  * Subtitle codec is bitmap based
607  * Decoded AVSubtitle data can be read from the AVSubtitleRect->pict field.
608  */
609 #define AV_CODEC_PROP_BITMAP_SUB (1 << 16)
610 /**
611  * Subtitle codec is text based.
612  * Decoded AVSubtitle data can be read from the AVSubtitleRect->ass field.
613  */
614 #define AV_CODEC_PROP_TEXT_SUB (1 << 17)
616 /**
617  * @ingroup lavc_decoding
618  * Required number of additionally allocated bytes at the end of the input bitstream for decoding.
619  * This is mainly needed because some optimized bitstream readers read
620  * 32 or 64 bit at once and could read over the end.<br>
621  * Note: If the first 23 bits of the additional bytes are not 0, then damaged
622  * MPEG bitstreams could cause overread and segfault.
623  */
624 #define FF_INPUT_BUFFER_PADDING_SIZE 32
626 /**
627  * @ingroup lavc_encoding
628  * minimum encoding buffer size
629  * Used to avoid some checks during header writing.
630  */
631 #define FF_MIN_BUFFER_SIZE 16384
634 /**
635  * @ingroup lavc_encoding
636  * motion estimation type.
637  */
639  ME_ZERO = 1, ///< no search, that is use 0,0 vector whenever one is needed
643  ME_EPZS, ///< enhanced predictive zonal search
644  ME_X1, ///< reserved for experiments
645  ME_HEX, ///< hexagon based search
646  ME_UMH, ///< uneven multi-hexagon search
647  ME_TESA, ///< transformed exhaustive search algorithm
648  ME_ITER=50, ///< iterative search
649 };
651 /**
652  * @ingroup lavc_decoding
653  */
655  /* We leave some space between them for extensions (drop some
656  * keyframes for intra-only or drop just some bidir frames). */
657  AVDISCARD_NONE =-16, ///< discard nothing
658  AVDISCARD_DEFAULT = 0, ///< discard useless packets like 0 size packets in avi
659  AVDISCARD_NONREF = 8, ///< discard all non reference
660  AVDISCARD_BIDIR = 16, ///< discard all bidirectional frames
661  AVDISCARD_NONINTRA= 24, ///< discard all non intra frames
662  AVDISCARD_NONKEY = 32, ///< discard all frames except keyframes
663  AVDISCARD_ALL = 48, ///< discard all
664 };
676  AV_AUDIO_SERVICE_TYPE_NB , ///< Not part of ABI
677 };
679 /**
680  * @ingroup lavc_encoding
681  */
682 typedef struct RcOverride{
685  int qscale; // If this is 0 then quality_factor will be used instead.
689 #if FF_API_MAX_BFRAMES
690 /**
691  * @deprecated there is no libavcodec-wide limit on the number of B-frames
692  */
693 #define FF_MAX_B_FRAMES 16
694 #endif
696 /* encoding support
697  These flags can be passed in AVCodecContext.flags before initialization.
698  Note: Not everything is supported yet.
699 */
701 /**
702  * Allow decoders to produce frames with data planes that are not aligned
703  * to CPU requirements (e.g. due to cropping).
704  */
705 #define CODEC_FLAG_UNALIGNED 0x0001
706 #define CODEC_FLAG_QSCALE 0x0002 ///< Use fixed qscale.
707 #define CODEC_FLAG_4MV 0x0004 ///< 4 MV per MB allowed / advanced prediction for H.263.
708 #define CODEC_FLAG_OUTPUT_CORRUPT 0x0008 ///< Output even those frames that might be corrupted
709 #define CODEC_FLAG_QPEL 0x0010 ///< Use qpel MC.
710 #if FF_API_GMC
711 /**
712  * @deprecated use the "gmc" private option of the libxvid encoder
713  */
714 #define CODEC_FLAG_GMC 0x0020 ///< Use GMC.
715 #endif
716 #if FF_API_MV0
717 /**
718  * @deprecated use the flag "mv0" in the "mpv_flags" private option of the
719  * mpegvideo encoders
720  */
721 #define CODEC_FLAG_MV0 0x0040
722 #endif
723 #if FF_API_INPUT_PRESERVED
724 /**
725  * @deprecated passing reference-counted frames to the encoders replaces this
726  * flag
727  */
728 #define CODEC_FLAG_INPUT_PRESERVED 0x0100
729 #endif
730 #define CODEC_FLAG_PASS1 0x0200 ///< Use internal 2pass ratecontrol in first pass mode.
731 #define CODEC_FLAG_PASS2 0x0400 ///< Use internal 2pass ratecontrol in second pass mode.
732 #define CODEC_FLAG_GRAY 0x2000 ///< Only decode/encode grayscale.
733 #if FF_API_EMU_EDGE
734 /**
735  * @deprecated edges are not used/required anymore. I.e. this flag is now always
736  * set.
737  */
738 #define CODEC_FLAG_EMU_EDGE 0x4000
739 #endif
740 #define CODEC_FLAG_PSNR 0x8000 ///< error[?] variables will be set during encoding.
741 #define CODEC_FLAG_TRUNCATED 0x00010000 /** Input bitstream might be truncated at a random
742  location instead of only at frame boundaries. */
743 #if FF_API_NORMALIZE_AQP
744 /**
745  * @deprecated use the flag "naq" in the "mpv_flags" private option of the
746  * mpegvideo encoders
747  */
748 #define CODEC_FLAG_NORMALIZE_AQP 0x00020000
749 #endif
750 #define CODEC_FLAG_INTERLACED_DCT 0x00040000 ///< Use interlaced DCT.
751 #define CODEC_FLAG_LOW_DELAY 0x00080000 ///< Force low delay.
752 #define CODEC_FLAG_GLOBAL_HEADER 0x00400000 ///< Place global headers in extradata instead of every keyframe.
753 #define CODEC_FLAG_BITEXACT 0x00800000 ///< Use only bitexact stuff (except (I)DCT).
754 /* Fx : Flag for h263+ extra options */
755 #define CODEC_FLAG_AC_PRED 0x01000000 ///< H.263 advanced intra coding / MPEG-4 AC prediction
756 #define CODEC_FLAG_LOOP_FILTER 0x00000800 ///< loop filter
757 #define CODEC_FLAG_INTERLACED_ME 0x20000000 ///< interlaced motion estimation
758 #define CODEC_FLAG_CLOSED_GOP 0x80000000
759 #define CODEC_FLAG2_FAST 0x00000001 ///< Allow non spec compliant speedup tricks.
760 #define CODEC_FLAG2_NO_OUTPUT 0x00000004 ///< Skip bitstream encoding.
761 #define CODEC_FLAG2_LOCAL_HEADER 0x00000008 ///< Place global headers at every keyframe instead of in extradata.
762 #define CODEC_FLAG2_DROP_FRAME_TIMECODE 0x00002000 ///< timecode is in drop frame format. DEPRECATED!!!!
763 #define CODEC_FLAG2_IGNORE_CROP 0x00010000 ///< Discard cropping information from SPS.
765 #define CODEC_FLAG2_CHUNKS 0x00008000 ///< Input bitstream might be truncated at a packet boundaries instead of only at frame boundaries.
766 #define CODEC_FLAG2_SHOW_ALL 0x00400000 ///< Show all frames before the first keyframe
767 #define CODEC_FLAG2_EXPORT_MVS 0x10000000 ///< Export motion vectors through frame side data
768 #define CODEC_FLAG2_SKIP_MANUAL 0x20000000 ///< Do not skip samples and export skip information as frame side data
770 /* Unsupported options :
771  * Syntax Arithmetic coding (SAC)
772  * Reference Picture Selection
773  * Independent Segment Decoding */
774 /* /Fx */
775 /* codec capabilities */
777 #define CODEC_CAP_DRAW_HORIZ_BAND 0x0001 ///< Decoder can use draw_horiz_band callback.
778 /**
779  * Codec uses get_buffer() for allocating buffers and supports custom allocators.
780  * If not set, it might not use get_buffer() at all or use operations that
781  * assume the buffer was allocated by avcodec_default_get_buffer.
782  */
783 #define CODEC_CAP_DR1 0x0002
784 #define CODEC_CAP_TRUNCATED 0x0008
785 #if FF_API_XVMC
786 /* Codec can export data for HW decoding. This flag indicates that
787  * the codec would call get_format() with list that might contain HW accelerated
788  * pixel formats (XvMC, VDPAU, VAAPI, etc). The application can pick any of them
789  * including raw image format.
790  * The application can use the passed context to determine bitstream version,
791  * chroma format, resolution etc.
792  */
793 #define CODEC_CAP_HWACCEL 0x0010
794 #endif /* FF_API_XVMC */
795 /**
796  * Encoder or decoder requires flushing with NULL input at the end in order to
797  * give the complete and correct output.
798  *
799  * NOTE: If this flag is not set, the codec is guaranteed to never be fed with
800  * with NULL data. The user can still send NULL data to the public encode
801  * or decode function, but libavcodec will not pass it along to the codec
802  * unless this flag is set.
803  *
804  * Decoders:
805  * The decoder has a non-zero delay and needs to be fed with avpkt->data=NULL,
806  * avpkt->size=0 at the end to get the delayed data until the decoder no longer
807  * returns frames.
808  *
809  * Encoders:
810  * The encoder needs to be fed with NULL data at the end of encoding until the
811  * encoder no longer returns data.
812  *
813  * NOTE: For encoders implementing the AVCodec.encode2() function, setting this
814  * flag also means that the encoder must set the pts and duration for
815  * each output packet. If this flag is not set, the pts and duration will
816  * be determined by libavcodec from the input frame.
817  */
818 #define CODEC_CAP_DELAY 0x0020
819 /**
820  * Codec can be fed a final frame with a smaller size.
821  * This can be used to prevent truncation of the last audio samples.
822  */
823 #define CODEC_CAP_SMALL_LAST_FRAME 0x0040
824 #if FF_API_CAP_VDPAU
825 /**
826  * Codec can export data for HW decoding (VDPAU).
827  */
828 #define CODEC_CAP_HWACCEL_VDPAU 0x0080
829 #endif
830 /**
831  * Codec can output multiple frames per AVPacket
832  * Normally demuxers return one frame at a time, demuxers which do not do
833  * are connected to a parser to split what they return into proper frames.
834  * This flag is reserved to the very rare category of codecs which have a
835  * bitstream that cannot be split into frames without timeconsuming
836  * operations like full decoding. Demuxers carring such bitstreams thus
837  * may return multiple frames in a packet. This has many disadvantages like
838  * prohibiting stream copy in many cases thus it should only be considered
839  * as a last resort.
840  */
841 #define CODEC_CAP_SUBFRAMES 0x0100
842 /**
843  * Codec is experimental and is thus avoided in favor of non experimental
844  * encoders
845  */
846 #define CODEC_CAP_EXPERIMENTAL 0x0200
847 /**
848  * Codec should fill in channel configuration and samplerate instead of container
849  */
850 #define CODEC_CAP_CHANNEL_CONF 0x0400
851 #if FF_API_NEG_LINESIZES
852 /**
853  * @deprecated no codecs use this capability
854  */
855 #define CODEC_CAP_NEG_LINESIZES 0x0800
856 #endif
857 /**
858  * Codec supports frame-level multithreading.
859  */
860 #define CODEC_CAP_FRAME_THREADS 0x1000
861 /**
862  * Codec supports slice-based (or partition-based) multithreading.
863  */
864 #define CODEC_CAP_SLICE_THREADS 0x2000
865 /**
866  * Codec supports changed parameters at any point.
867  */
868 #define CODEC_CAP_PARAM_CHANGE 0x4000
869 /**
870  * Codec supports avctx->thread_count == 0 (auto).
871  */
872 #define CODEC_CAP_AUTO_THREADS 0x8000
873 /**
874  * Audio encoder supports receiving a different number of samples in each call.
875  */
876 #define CODEC_CAP_VARIABLE_FRAME_SIZE 0x10000
877 /**
878  * Codec is intra only.
879  */
880 #define CODEC_CAP_INTRA_ONLY 0x40000000
881 /**
882  * Codec is lossless.
883  */
884 #define CODEC_CAP_LOSSLESS 0x80000000
886 #if FF_API_MB_TYPE
887 //The following defines may change, don't expect compatibility if you use them.
888 #define MB_TYPE_INTRA4x4 0x0001
889 #define MB_TYPE_INTRA16x16 0x0002 //FIXME H.264-specific
890 #define MB_TYPE_INTRA_PCM 0x0004 //FIXME H.264-specific
891 #define MB_TYPE_16x16 0x0008
892 #define MB_TYPE_16x8 0x0010
893 #define MB_TYPE_8x16 0x0020
894 #define MB_TYPE_8x8 0x0040
895 #define MB_TYPE_INTERLACED 0x0080
896 #define MB_TYPE_DIRECT2 0x0100 //FIXME
897 #define MB_TYPE_ACPRED 0x0200
898 #define MB_TYPE_GMC 0x0400
899 #define MB_TYPE_SKIP 0x0800
900 #define MB_TYPE_P0L0 0x1000
901 #define MB_TYPE_P1L0 0x2000
902 #define MB_TYPE_P0L1 0x4000
903 #define MB_TYPE_P1L1 0x8000
904 #define MB_TYPE_L0 (MB_TYPE_P0L0 | MB_TYPE_P1L0)
905 #define MB_TYPE_L1 (MB_TYPE_P0L1 | MB_TYPE_P1L1)
906 #define MB_TYPE_L0L1 (MB_TYPE_L0 | MB_TYPE_L1)
907 #define MB_TYPE_QUANT 0x00010000
908 #define MB_TYPE_CBP 0x00020000
909 //Note bits 24-31 are reserved for codec specific use (h264 ref0, mpeg1 0mv, ...)
910 #endif
912 /**
913  * Pan Scan area.
914  * This specifies the area which should be displayed.
915  * Note there may be multiple such areas for one frame.
916  */
917 typedef struct AVPanScan{
918  /**
919  * id
920  * - encoding: Set by user.
921  * - decoding: Set by libavcodec.
922  */
923  int id;
925  /**
926  * width and height in 1/16 pel
927  * - encoding: Set by user.
928  * - decoding: Set by libavcodec.
929  */
930  int width;
931  int height;
933  /**
934  * position of the top left corner in 1/16 pel for up to 3 fields/frames
935  * - encoding: Set by user.
936  * - decoding: Set by libavcodec.
937  */
938  int16_t position[3][2];
939 }AVPanScan;
941 #if FF_API_QSCALE_TYPE
942 #define FF_QSCALE_TYPE_MPEG1 0
943 #define FF_QSCALE_TYPE_MPEG2 1
944 #define FF_QSCALE_TYPE_H264 2
945 #define FF_QSCALE_TYPE_VP56 3
946 #endif
947 
948 #if FF_API_GET_BUFFER
949 #define FF_BUFFER_TYPE_INTERNAL 1
950 #define FF_BUFFER_TYPE_USER 2 ///< direct rendering buffers (image is (de)allocated by user)
951 #define FF_BUFFER_TYPE_SHARED 4 ///< Buffer from somewhere else; don't deallocate image (data/base), all other tables are not shared.
952 #define FF_BUFFER_TYPE_COPY 8 ///< Just a (modified) copy of some other buffer, don't deallocate anything.
954 #define FF_BUFFER_HINTS_VALID 0x01 // Buffer hints value is meaningful (if 0 ignore).
955 #define FF_BUFFER_HINTS_READABLE 0x02 // Codec will read from buffer.
956 #define FF_BUFFER_HINTS_PRESERVE 0x04 // User must not alter buffer content.
957 #define FF_BUFFER_HINTS_REUSABLE 0x08 // Codec will reuse the buffer (update).
958 #endif
959 
960 /**
961  * The decoder will keep a reference to the frame and may reuse it later.
962  */
963 #define AV_GET_BUFFER_FLAG_REF (1 << 0)
964 
965 /**
966  * @defgroup lavc_packet AVPacket
967  *
968  * Types and functions for working with AVPacket.
969  * @{
970  */
974 
975  /**
976  * An AV_PKT_DATA_PARAM_CHANGE side data packet is laid out as follows:
977  * @code
978  * u32le param_flags
979  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT)
980  * s32le channel_count
981  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT)
982  * u64le channel_layout
983  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE)
984  * s32le sample_rate
985  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS)
986  * s32le width
987  * s32le height
988  * @endcode
989  */
991 
992  /**
993  * An AV_PKT_DATA_H263_MB_INFO side data packet contains a number of
994  * structures with info about macroblocks relevant to splitting the
995  * packet into smaller packets on macroblock edges (e.g. as for RFC 2190).
996  * That is, it does not necessarily contain info about all macroblocks,
997  * as long as the distance between macroblocks in the info is smaller
998  * than the target payload size.
999  * Each MB info structure is 12 bytes, and is laid out as follows:
1000  * @code
1001  * u32le bit offset from the start of the packet
1002  * u8 current quantizer at the start of the macroblock
1003  * u8 GOB number
1004  * u16le macroblock address within the GOB
1005  * u8 horizontal MV predictor
1006  * u8 vertical MV predictor
1007  * u8 horizontal MV predictor for block number 3
1008  * u8 vertical MV predictor for block number 3
1009  * @endcode
1010  */
1012 
1013  /**
1014  * This side data should be associated with an audio stream and contains
1015  * ReplayGain information in form of the AVReplayGain struct.
1016  */
1018 
1019  /**
1020  * This side data contains a 3x3 transformation matrix describing an affine
1021  * transformation that needs to be applied to the decoded video frames for
1022  * correct presentation.
1023  *
1024  * See libavutil/display.h for a detailed description of the data.
1025  */
1027 
1028  /**
1029  * This side data should be associated with a video stream and contains
1030  * Stereoscopic 3D information in form of the AVStereo3D struct.
1031  */
1033 
1034  /**
1035  * Recommmends skipping the specified number of samples
1036  * @code
1037  * u32le number of samples to skip from start of this packet
1038  * u32le number of samples to skip from end of this packet
1039  * u8 reason for start skip
1040  * u8 reason for end skip (0=padding silence, 1=convergence)
1041  * @endcode
1042  */
1044 
1045  /**
1046  * An AV_PKT_DATA_JP_DUALMONO side data packet indicates that
1047  * the packet may contain "dual mono" audio specific to Japanese DTV
1048  * and if it is true, recommends only the selected channel to be used.
1049  * @code
1050  * u8 selected channels (0=mail/left, 1=sub/right, 2=both)
1051  * @endcode
1052  */
1054 
1055  /**
1056  * A list of zero terminated key/value strings. There is no end marker for
1057  * the list, so it is required to rely on the side data size to stop.
1058  */
1060 
1061  /**
1062  * Subtitle event position
1063  * @code
1064  * u32le x1
1065  * u32le y1
1066  * u32le x2
1067  * u32le y2
1068  * @endcode
1069  */
1071 
1072  /**
1073  * Data found in BlockAdditional element of matroska container. There is
1074  * no end marker for the data, so it is required to rely on the side data
1075  * size to recognize the end. 8 byte id (as found in BlockAddId) followed
1076  * by data.
1077  */
1079 
1080  /**
1081  * The optional first identifier line of a WebVTT cue.
1082  */
1084 
1085  /**
1086  * The optional settings (rendering instructions) that immediately
1087  * follow the timestamp specifier of a WebVTT cue.
1088  */
1090 
1091  /**
1092  * A list of zero terminated key/value strings. There is no end marker for
1093  * the list, so it is required to rely on the side data size to stop. This
1094  * side data includes updated metadata which appeared in the stream.
1095  */
1097 };
1099 typedef struct AVPacketSideData {
1101  int size;
1104 
1105 /**
1106  * This structure stores compressed data. It is typically exported by demuxers
1107  * and then passed as input to decoders, or received as output from encoders and
1108  * then passed to muxers.
1109  *
1110  * For video, it should typically contain one compressed frame. For audio it may
1111  * contain several compressed frames.
1112  *
1113  * AVPacket is one of the few structs in FFmpeg, whose size is a part of public
1114  * ABI. Thus it may be allocated on stack and no new fields can be added to it
1115  * without libavcodec and libavformat major bump.
1116  *
1117  * The semantics of data ownership depends on the buf or destruct (deprecated)
1118  * fields. If either is set, the packet data is dynamically allocated and is
1119  * valid indefinitely until av_free_packet() is called (which in turn calls
1120  * av_buffer_unref()/the destruct callback to free the data). If neither is set,
1121  * the packet data is typically backed by some static buffer somewhere and is
1122  * only valid for a limited time (e.g. until the next read call when demuxing).
1123  *
1124  * The side data is always allocated with av_malloc() and is freed in
1125  * av_free_packet().
1126  */
1127 typedef struct AVPacket {
1128  /**
1129  * A reference to the reference-counted buffer where the packet data is
1130  * stored.
1131  * May be NULL, then the packet data is not reference-counted.
1132  */
1133  AVBufferRef *buf;
1134  /**
1135  * Presentation timestamp in AVStream->time_base units; the time at which
1136  * the decompressed packet will be presented to the user.
1137  * Can be AV_NOPTS_VALUE if it is not stored in the file.
1138  * pts MUST be larger or equal to dts as presentation cannot happen before
1139  * decompression, unless one wants to view hex dumps. Some formats misuse
1140  * the terms dts and pts/cts to mean something different. Such timestamps
1141  * must be converted to true pts/dts before they are stored in AVPacket.
1142  */
1143  int64_t pts;
1144  /**
1145  * Decompression timestamp in AVStream->time_base units; the time at which
1146  * the packet is decompressed.
1147  * Can be AV_NOPTS_VALUE if it is not stored in the file.
1148  */
1149  int64_t dts;
1151  int size;
1152  int stream_index;
1153  /**
1154  * A combination of AV_PKT_FLAG values
1155  */
1156  int flags;
1157  /**
1158  * Additional packet data that can be provided by the container.
1159  * Packet can contain several types of side information.
1160  */
1162  int side_data_elems;
1163 
1164  /**
1165  * Duration of this packet in AVStream->time_base units, 0 if unknown.
1166  * Equals next_pts - this_pts in presentation order.
1167  */
1168  int duration;
1169 #if FF_API_DESTRUCT_PACKET
1171  void (*destruct)(struct AVPacket *);
1173  void *priv;
1174 #endif
1175  int64_t pos; ///< byte position in stream, -1 if unknown
1176 
1177  /**
1178  * Time difference in AVStream->time_base units from the pts of this
1179  * packet to the point at which the output from the decoder has converged
1180  * independent from the availability of previous frames. That is, the
1181  * frames are virtually identical no matter if decoding started from
1182  * the very first frame or from this keyframe.
1183  * Is AV_NOPTS_VALUE if unknown.
1184  * This field is not the display duration of the current packet.
1185  * This field has no meaning if the packet does not have AV_PKT_FLAG_KEY
1186  * set.
1187  *
1188  * The purpose of this field is to allow seeking in streams that have no
1189  * keyframes in the conventional sense. It corresponds to the
1190  * recovery point SEI in H.264 and match_time_delta in NUT. It is also
1191  * essential for some types of subtitle streams to ensure that all
1192  * subtitles are correctly displayed after seeking.
1193  */
1194  int64_t convergence_duration;
1196 #define AV_PKT_FLAG_KEY 0x0001 ///< The packet contains a keyframe
1197 #define AV_PKT_FLAG_CORRUPT 0x0002 ///< The packet content is corrupted
1204 };
1205 /**
1206  * @}
1207  */
1208 
1209 struct AVCodecInternal;
1214  AV_FIELD_TT, //< Top coded_first, top displayed first
1215  AV_FIELD_BB, //< Bottom coded first, bottom displayed first
1216  AV_FIELD_TB, //< Top coded first, bottom displayed first
1217  AV_FIELD_BT, //< Bottom coded first, top displayed first
1218 };
1219 
1220 /**
1221  * main external API structure.
1222  * New fields can be added to the end with minor version bumps.
1223  * Removal, reordering and changes to existing fields require a major
1224  * version bump.
1225  * Please use AVOptions (av_opt* / av_set/get*()) to access these fields from user
1226  * applications.
1227  * sizeof(AVCodecContext) must not be used outside libav*.
1228  */
1229 typedef struct AVCodecContext {
1230  /**
1231  * information on struct for av_log
1232  * - set by avcodec_alloc_context3
1233  */
1235  int log_level_offset;
1237  enum AVMediaType codec_type; /* see AVMEDIA_TYPE_xxx */
1238  const struct AVCodec *codec;
1239 #if FF_API_CODEC_NAME
1240  /**
1241  * @deprecated this field is not used for anything in libavcodec
1242  */
1244  char codec_name[32];
1245 #endif
1246  enum AVCodecID codec_id; /* see AV_CODEC_ID_xxx */
1247 
1248  /**
1249  * fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
1250  * This is used to work around some encoder bugs.
1251  * A demuxer should set this to what is stored in the field used to identify the codec.
1252  * If there are multiple such fields in a container then the demuxer should choose the one
1253  * which maximizes the information about the used codec.
1254  * If the codec tag field in a container is larger than 32 bits then the demuxer should
1255  * remap the longer ID to 32 bits with a table or other structure. Alternatively a new
1256  * extra_codec_tag + size could be added but for this a clear advantage must be demonstrated
1257  * first.
1258  * - encoding: Set by user, if not then the default based on codec_id will be used.
1259  * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
1260  */
1261  unsigned int codec_tag;
1262 
1263  /**
1264  * fourcc from the AVI stream header (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
1265  * This is used to work around some encoder bugs.
1266  * - encoding: unused
1267  * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
1268  */
1269  unsigned int stream_codec_tag;
1271  void *priv_data;
1272 
1273  /**
1274  * Private context used for internal data.
1275  *
1276  * Unlike priv_data, this is not codec-specific. It is used in general
1277  * libavcodec functions.
1278  */
1279  struct AVCodecInternal *internal;
1280 
1281  /**
1282  * Private data of the user, can be used to carry app specific stuff.
1283  * - encoding: Set by user.
1284  * - decoding: Set by user.
1285  */
1286  void *opaque;
1287 
1288  /**
1289  * the average bitrate
1290  * - encoding: Set by user; unused for constant quantizer encoding.
1291  * - decoding: Set by libavcodec. 0 or some bitrate if this info is available in the stream.
1292  */
1293  int bit_rate;
1294 
1295  /**
1296  * number of bits the bitstream is allowed to diverge from the reference.
1297  * the reference can be CBR (for CBR pass1) or VBR (for pass2)
1298  * - encoding: Set by user; unused for constant quantizer encoding.
1299  * - decoding: unused
1300  */
1301  int bit_rate_tolerance;
1302 
1303  /**
1304  * Global quality for codecs which cannot change it per frame.
1305  * This should be proportional to MPEG-1/2/4 qscale.
1306  * - encoding: Set by user.
1307  * - decoding: unused
1308  */
1309  int global_quality;
1310 
1311  /**
1312  * - encoding: Set by user.
1313  * - decoding: unused
1314  */
1316 #define FF_COMPRESSION_DEFAULT -1
1317 
1318  /**
1319  * CODEC_FLAG_*.
1320  * - encoding: Set by user.
1321  * - decoding: Set by user.
1322  */
1323  int flags;
1324 
1325  /**
1326  * CODEC_FLAG2_*
1327  * - encoding: Set by user.
1328  * - decoding: Set by user.
1329  */
1330  int flags2;
1331 
1332  /**
1333  * some codecs need / can use extradata like Huffman tables.
1334  * mjpeg: Huffman tables
1335  * rv10: additional flags
1336  * mpeg4: global headers (they can be in the bitstream or here)
1337  * The allocated memory should be FF_INPUT_BUFFER_PADDING_SIZE bytes larger
1338  * than extradata_size to avoid problems if it is read with the bitstream reader.
1339  * The bytewise contents of extradata must not depend on the architecture or CPU endianness.
1340  * - encoding: Set/allocated/freed by libavcodec.
1341  * - decoding: Set/allocated/freed by user.
1342  */
1344  int extradata_size;
1345 
1346  /**
1347  * This is the fundamental unit of time (in seconds) in terms
1348  * of which frame timestamps are represented. For fixed-fps content,
1349  * timebase should be 1/framerate and timestamp increments should be
1350  * identically 1.
1351  * This often, but not always is the inverse of the frame rate or field rate
1352  * for video.
1353  * - encoding: MUST be set by user.
1354  * - decoding: the use of this field for decoding is deprecated.
1355  * Use framerate instead.
1356  */
1358 
1359  /**
1360  * For some codecs, the time base is closer to the field rate than the frame rate.
1361  * Most notably, H.264 and MPEG-2 specify time_base as half of frame duration
1362  * if no telecine is used ...
1363  *
1364  * Set to time_base ticks per frame. Default 1, e.g., H.264/MPEG-2 set it to 2.
1365  */
1366  int ticks_per_frame;
1367 
1368  /**
1369  * Codec delay.
1370  *
1371  * Encoding: Number of frames delay there will be from the encoder input to
1372  * the decoder output. (we assume the decoder matches the spec)
1373  * Decoding: Number of frames delay in addition to what a standard decoder
1374  * as specified in the spec would produce.
1375  *
1376  * Video:
1377  * Number of frames the decoded output will be delayed relative to the
1378  * encoded input.
1379  *
1380  * Audio:
1381  * For encoding, this field is unused (see initial_padding).
1382  *
1383  * For decoding, this is the number of samples the decoder needs to
1384  * output before the decoder's output is valid. When seeking, you should
1385  * start decoding this many samples prior to your desired seek point.
1386  *
1387  * - encoding: Set by libavcodec.
1388  * - decoding: Set by libavcodec.
1389  */
1390  int delay;
1391 
1392 
1393  /* video only */
1394  /**
1395  * picture width / height.
1396  * - encoding: MUST be set by user.
1397  * - decoding: May be set by the user before opening the decoder if known e.g.
1398  * from the container. Some decoders will require the dimensions
1399  * to be set by the caller. During decoding, the decoder may
1400  * overwrite those values as required.
1401  */
1402  int width, height;
1403 
1404  /**
1405  * Bitstream width / height, may be different from width/height e.g. when
1406  * the decoded frame is cropped before being output or lowres is enabled.
1407  * - encoding: unused
1408  * - decoding: May be set by the user before opening the decoder if known
1409  * e.g. from the container. During decoding, the decoder may
1410  * overwrite those values as required.
1411  */
1413 
1414 #if FF_API_ASPECT_EXTENDED
1415 #define FF_ASPECT_EXTENDED 15
1416 #endif
1417 
1418  /**
1419  * the number of pictures in a group of pictures, or 0 for intra_only
1420  * - encoding: Set by user.
1421  * - decoding: unused
1422  */
1423  int gop_size;
1424 
1425  /**
1426  * Pixel format, see AV_PIX_FMT_xxx.
1427  * May be set by the demuxer if known from headers.
1428  * May be overridden by the decoder if it knows better.
1429  * - encoding: Set by user.
1430  * - decoding: Set by user if known, overridden by libavcodec if known
1431  */
1432  enum AVPixelFormat pix_fmt;
1433 
1434  /**
1435  * Motion estimation algorithm used for video coding.
1436  * 1 (zero), 2 (full), 3 (log), 4 (phods), 5 (epzs), 6 (x1), 7 (hex),
1437  * 8 (umh), 9 (iter), 10 (tesa) [7, 8, 10 are x264 specific, 9 is snow specific]
1438  * - encoding: MUST be set by user.
1439  * - decoding: unused
1440  */
1441  int me_method;
1442 
1443  /**
1444  * If non NULL, 'draw_horiz_band' is called by the libavcodec
1445  * decoder to draw a horizontal band. It improves cache usage. Not
1446  * all codecs can do that. You must check the codec capabilities
1447  * beforehand.
1448  * When multithreading is used, it may be called from multiple threads
1449  * at the same time; threads might draw different parts of the same AVFrame,
1450  * or multiple AVFrames, and there is no guarantee that slices will be drawn
1451  * in order.
1452  * The function is also used by hardware acceleration APIs.
1453  * It is called at least once during frame decoding to pass
1454  * the data needed for hardware render.
1455  * In that mode instead of pixel data, AVFrame points to
1456  * a structure specific to the acceleration API. The application
1457  * reads the structure and can change some fields to indicate progress
1458  * or mark state.
1459  * - encoding: unused
1460  * - decoding: Set by user.
1461  * @param height the height of the slice
1462  * @param y the y position of the slice
1463  * @param type 1->top field, 2->bottom field, 3->frame
1464  * @param offset offset into the AVFrame.data from which the slice should be read
1465  */
1466  void (*draw_horiz_band)(struct AVCodecContext *s,
1467  const AVFrame *src, int offset[AV_NUM_DATA_POINTERS],
1468  int y, int type, int height);
1469 
1470  /**
1471  * callback to negotiate the pixelFormat
1472  * @param fmt is the list of formats which are supported by the codec,
1473  * it is terminated by -1 as 0 is a valid format, the formats are ordered by quality.
1474  * The first is always the native one.
1475  * @note The callback may be called again immediately if initialization for
1476  * the selected (hardware-accelerated) pixel format failed.
1477  * @warning Behavior is undefined if the callback returns a value not
1478  * in the fmt list of formats.
1479  * @return the chosen format
1480  * - encoding: unused
1481  * - decoding: Set by user, if not set the native format will be chosen.
1482  */
1483  enum AVPixelFormat (*get_format)(struct AVCodecContext *s, const enum AVPixelFormat * fmt);
1484 
1485  /**
1486  * maximum number of B-frames between non-B-frames
1487  * Note: The output will be delayed by max_b_frames+1 relative to the input.
1488  * - encoding: Set by user.
1489  * - decoding: unused
1490  */
1491  int max_b_frames;
1492 
1493  /**
1494  * qscale factor between IP and B-frames
1495  * If > 0 then the last P-frame quantizer will be used (q= lastp_q*factor+offset).
1496  * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1497  * - encoding: Set by user.
1498  * - decoding: unused
1499  */
1500  float b_quant_factor;
1501 
1502  /** obsolete FIXME remove */
1504 #define FF_RC_STRATEGY_XVID 1
1506  int b_frame_strategy;
1507 
1508  /**
1509  * qscale offset between IP and B-frames
1510  * - encoding: Set by user.
1511  * - decoding: unused
1512  */
1513  float b_quant_offset;
1514 
1515  /**
1516  * Size of the frame reordering buffer in the decoder.
1517  * For MPEG-2 it is 1 IPB or 0 low delay IP.
1518  * - encoding: Set by libavcodec.
1519  * - decoding: Set by libavcodec.
1520  */
1521  int has_b_frames;
1522 
1523  /**
1524  * 0-> h263 quant 1-> mpeg quant
1525  * - encoding: Set by user.
1526  * - decoding: unused
1527  */
1528  int mpeg_quant;
1529 
1530  /**
1531  * qscale factor between P and I-frames
1532  * If > 0 then the last p frame quantizer will be used (q= lastp_q*factor+offset).
1533  * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1534  * - encoding: Set by user.
1535  * - decoding: unused
1536  */
1537  float i_quant_factor;
1538 
1539  /**
1540  * qscale offset between P and I-frames
1541  * - encoding: Set by user.
1542  * - decoding: unused
1543  */
1544  float i_quant_offset;
1545 
1546  /**
1547  * luminance masking (0-> disabled)
1548  * - encoding: Set by user.
1549  * - decoding: unused
1550  */
1551  float lumi_masking;
1552 
1553  /**
1554  * temporary complexity masking (0-> disabled)
1555  * - encoding: Set by user.
1556  * - decoding: unused
1557  */
1558  float temporal_cplx_masking;
1559 
1560  /**
1561  * spatial complexity masking (0-> disabled)
1562  * - encoding: Set by user.
1563  * - decoding: unused
1564  */
1565  float spatial_cplx_masking;
1566 
1567  /**
1568  * p block masking (0-> disabled)
1569  * - encoding: Set by user.
1570  * - decoding: unused
1571  */
1572  float p_masking;
1573 
1574  /**
1575  * darkness masking (0-> disabled)
1576  * - encoding: Set by user.
1577  * - decoding: unused
1578  */
1579  float dark_masking;
1580 
1581  /**
1582  * slice count
1583  * - encoding: Set by libavcodec.
1584  * - decoding: Set by user (or 0).
1585  */
1586  int slice_count;
1587  /**
1588  * prediction method (needed for huffyuv)
1589  * - encoding: Set by user.
1590  * - decoding: unused
1591  */
1593 #define FF_PRED_LEFT 0
1594 #define FF_PRED_PLANE 1
1595 #define FF_PRED_MEDIAN 2
1596 
1597  /**
1598  * slice offsets in the frame in bytes
1599  * - encoding: Set/allocated by libavcodec.
1600  * - decoding: Set/allocated by user (or NULL).
1601  */
1602  int *slice_offset;
1603 
1604  /**
1605  * sample aspect ratio (0 if unknown)
1606  * That is the width of a pixel divided by the height of the pixel.
1607  * Numerator and denominator must be relatively prime and smaller than 256 for some video standards.
1608  * - encoding: Set by user.
1609  * - decoding: Set by libavcodec.
1610  */
1612 
1613  /**
1614  * motion estimation comparison function
1615  * - encoding: Set by user.
1616  * - decoding: unused
1617  */
1618  int me_cmp;
1619  /**
1620  * subpixel motion estimation comparison function
1621  * - encoding: Set by user.
1622  * - decoding: unused
1623  */
1624  int me_sub_cmp;
1625  /**
1626  * macroblock comparison function (not supported yet)
1627  * - encoding: Set by user.
1628  * - decoding: unused
1629  */
1630  int mb_cmp;
1631  /**
1632  * interlaced DCT comparison function
1633  * - encoding: Set by user.
1634  * - decoding: unused
1635  */
1637 #define FF_CMP_SAD 0
1638 #define FF_CMP_SSE 1
1639 #define FF_CMP_SATD 2
1640 #define FF_CMP_DCT 3
1641 #define FF_CMP_PSNR 4
1642 #define FF_CMP_BIT 5
1643 #define FF_CMP_RD 6
1644 #define FF_CMP_ZERO 7
1645 #define FF_CMP_VSAD 8
1646 #define FF_CMP_VSSE 9
1647 #define FF_CMP_NSSE 10
1648 #define FF_CMP_W53 11
1649 #define FF_CMP_W97 12
1650 #define FF_CMP_DCTMAX 13
1651 #define FF_CMP_DCT264 14
1652 #define FF_CMP_CHROMA 256
1653 
1654  /**
1655  * ME diamond size & shape
1656  * - encoding: Set by user.
1657  * - decoding: unused
1658  */
1659  int dia_size;
1660 
1661  /**
1662  * amount of previous MV predictors (2a+1 x 2a+1 square)
1663  * - encoding: Set by user.
1664  * - decoding: unused
1665  */
1667 
1668  /**
1669  * prepass for motion estimation
1670  * - encoding: Set by user.
1671  * - decoding: unused
1672  */
1673  int pre_me;
1674 
1675  /**
1676  * motion estimation prepass comparison function
1677  * - encoding: Set by user.
1678  * - decoding: unused
1679  */
1680  int me_pre_cmp;
1681 
1682  /**
1683  * ME prepass diamond size & shape
1684  * - encoding: Set by user.
1685  * - decoding: unused
1686  */
1687  int pre_dia_size;
1688 
1689  /**
1690  * subpel ME quality
1691  * - encoding: Set by user.
1692  * - decoding: unused
1693  */
1694  int me_subpel_quality;
1695 
1696 #if FF_API_AFD
1697  /**
1698  * DTG active format information (additional aspect ratio
1699  * information only used in DVB MPEG-2 transport streams)
1700  * 0 if not set.
1701  *
1702  * - encoding: unused
1703  * - decoding: Set by decoder.
1704  * @deprecated Deprecated in favor of AVSideData
1705  */
1707 #define FF_DTG_AFD_SAME 8
1708 #define FF_DTG_AFD_4_3 9
1709 #define FF_DTG_AFD_16_9 10
1710 #define FF_DTG_AFD_14_9 11
1711 #define FF_DTG_AFD_4_3_SP_14_9 13
1712 #define FF_DTG_AFD_16_9_SP_14_9 14
1713 #define FF_DTG_AFD_SP_4_3 15
1714 #endif /* FF_API_AFD */
1715 
1716  /**
1717  * maximum motion estimation search range in subpel units
1718  * If 0 then no limit.
1719  *
1720  * - encoding: Set by user.
1721  * - decoding: unused
1722  */
1723  int me_range;
1724 
1725  /**
1726  * intra quantizer bias
1727  * - encoding: Set by user.
1728  * - decoding: unused
1729  */
1731 #define FF_DEFAULT_QUANT_BIAS 999999
1732 
1733  /**
1734  * inter quantizer bias
1735  * - encoding: Set by user.
1736  * - decoding: unused
1737  */
1738  int inter_quant_bias;
1739 
1740  /**
1741  * slice flags
1742  * - encoding: unused
1743  * - decoding: Set by user.
1744  */
1746 #define SLICE_FLAG_CODED_ORDER 0x0001 ///< draw_horiz_band() is called in coded order instead of display
1747 #define SLICE_FLAG_ALLOW_FIELD 0x0002 ///< allow draw_horiz_band() with field slices (MPEG2 field pics)
1748 #define SLICE_FLAG_ALLOW_PLANE 0x0004 ///< allow draw_horiz_band() with 1 component at a time (SVQ1)
1749 
1750 #if FF_API_XVMC
1751  /**
1752  * XVideo Motion Acceleration
1753  * - encoding: forbidden
1754  * - decoding: set by decoder
1755  * @deprecated XvMC doesn't need it anymore.
1756  */
1757  attribute_deprecated int xvmc_acceleration;
1758 #endif /* FF_API_XVMC */
1759 
1760  /**
1761  * macroblock decision mode
1762  * - encoding: Set by user.
1763  * - decoding: unused
1764  */
1766 #define FF_MB_DECISION_SIMPLE 0 ///< uses mb_cmp
1767 #define FF_MB_DECISION_BITS 1 ///< chooses the one which needs the fewest bits
1768 #define FF_MB_DECISION_RD 2 ///< rate distortion
1769 
1770  /**
1771  * custom intra quantization matrix
1772  * - encoding: Set by user, can be NULL.
1773  * - decoding: Set by libavcodec.
1774  */
1775  uint16_t *intra_matrix;
1776 
1777  /**
1778  * custom inter quantization matrix
1779  * - encoding: Set by user, can be NULL.
1780  * - decoding: Set by libavcodec.
1781  */
1782  uint16_t *inter_matrix;
1783 
1784  /**
1785  * scene change detection threshold
1786  * 0 is default, larger means fewer detected scene changes.
1787  * - encoding: Set by user.
1788  * - decoding: unused
1789  */
1791 
1792  /**
1793  * noise reduction strength
1794  * - encoding: Set by user.
1795  * - decoding: unused
1796  */
1797  int noise_reduction;
1798 
1799 #if FF_API_MPV_OPT
1800  /**
1801  * @deprecated this field is unused
1802  */
1804  int me_threshold;
1805 
1806  /**
1807  * @deprecated this field is unused
1808  */
1810  int mb_threshold;
1811 #endif
1812 
1813  /**
1814  * precision of the intra DC coefficient - 8
1815  * - encoding: Set by user.
1816  * - decoding: unused
1817  */
1818  int intra_dc_precision;
1819 
1820  /**
1821  * Number of macroblock rows at the top which are skipped.
1822  * - encoding: unused
1823  * - decoding: Set by user.
1824  */
1825  int skip_top;
1826 
1827  /**
1828  * Number of macroblock rows at the bottom which are skipped.
1829  * - encoding: unused
1830  * - decoding: Set by user.
1831  */
1832  int skip_bottom;
1833 
1834 #if FF_API_MPV_OPT
1835  /**
1836  * @deprecated use encoder private options instead
1837  */
1839  float border_masking;
1840 #endif
1841 
1842  /**
1843  * minimum MB lagrange multipler
1844  * - encoding: Set by user.
1845  * - decoding: unused
1846  */
1847  int mb_lmin;
1848 
1849  /**
1850  * maximum MB lagrange multipler
1851  * - encoding: Set by user.
1852  * - decoding: unused
1853  */
1854  int mb_lmax;
1855 
1856  /**
1857  *
1858  * - encoding: Set by user.
1859  * - decoding: unused
1860  */
1862 
1863  /**
1864  *
1865  * - encoding: Set by user.
1866  * - decoding: unused
1867  */
1868  int bidir_refine;
1869 
1870  /**
1871  *
1872  * - encoding: Set by user.
1873  * - decoding: unused
1874  */
1875  int brd_scale;
1876 
1877  /**
1878  * minimum GOP size
1879  * - encoding: Set by user.
1880  * - decoding: unused
1881  */
1882  int keyint_min;
1883 
1884  /**
1885  * number of reference frames
1886  * - encoding: Set by user.
1887  * - decoding: Set by lavc.
1888  */
1889  int refs;
1890 
1891  /**
1892  * chroma qp offset from luma
1893  * - encoding: Set by user.
1894  * - decoding: unused
1895  */
1896  int chromaoffset;
1897 
1898 #if FF_API_UNUSED_MEMBERS
1899  /**
1900  * Multiplied by qscale for each frame and added to scene_change_score.
1901  * - encoding: Set by user.
1902  * - decoding: unused
1903  */
1905 #endif
1906 
1907  /**
1908  *
1909  * Note: Value depends upon the compare function used for fullpel ME.
1910  * - encoding: Set by user.
1911  * - decoding: unused
1912  */
1913  int mv0_threshold;
1914 
1915  /**
1916  * Adjust sensitivity of b_frame_strategy 1.
1917  * - encoding: Set by user.
1918  * - decoding: unused
1919  */
1920  int b_sensitivity;
1921 
1922  /**
1923  * Chromaticity coordinates of the source primaries.
1924  * - encoding: Set by user
1925  * - decoding: Set by libavcodec
1926  */
1928 
1929  /**
1930  * Color Transfer Characteristic.
1931  * - encoding: Set by user
1932  * - decoding: Set by libavcodec
1933  */
1935 
1936  /**
1937  * YUV colorspace type.
1938  * - encoding: Set by user
1939  * - decoding: Set by libavcodec
1940  */
1941  enum AVColorSpace colorspace;
1942 
1943  /**
1944  * MPEG vs JPEG YUV range.
1945  * - encoding: Set by user
1946  * - decoding: Set by libavcodec
1947  */
1949 
1950  /**
1951  * This defines the location of chroma samples.
1952  * - encoding: Set by user
1953  * - decoding: Set by libavcodec
1954  */
1956 
1957  /**
1958  * Number of slices.
1959  * Indicates number of picture subdivisions. Used for parallelized
1960  * decoding.
1961  * - encoding: Set by user
1962  * - decoding: unused
1963  */
1964  int slices;
1965 
1966  /** Field order
1967  * - encoding: set by libavcodec
1968  * - decoding: Set by user.
1969  */
1971 
1972  /* audio only */
1973  int sample_rate; ///< samples per second
1974  int channels; ///< number of audio channels
1975 
1976  /**
1977  * audio sample format
1978  * - encoding: Set by user.
1979  * - decoding: Set by libavcodec.
1980  */
1981  enum AVSampleFormat sample_fmt; ///< sample format
1982 
1983  /* The following data should not be initialized. */
1984  /**
1985  * Number of samples per channel in an audio frame.
1986  *
1987  * - encoding: set by libavcodec in avcodec_open2(). Each submitted frame
1988  * except the last must contain exactly frame_size samples per channel.
1989  * May be 0 when the codec has CODEC_CAP_VARIABLE_FRAME_SIZE set, then the
1990  * frame size is not restricted.
1991  * - decoding: may be set by some decoders to indicate constant frame size
1992  */
1993  int frame_size;
1994 
1995  /**
1996  * Frame counter, set by libavcodec.
1997  *
1998  * - decoding: total number of frames returned from the decoder so far.
1999  * - encoding: total number of frames passed to the encoder so far.
2000  *
2001  * @note the counter is not incremented if encoding/decoding resulted in
2002  * an error.
2003  */
2004  int frame_number;
2005 
2006  /**
2007  * number of bytes per packet if constant and known or 0
2008  * Used by some WAV based audio codecs.
2009  */
2010  int block_align;
2011 
2012  /**
2013  * Audio cutoff bandwidth (0 means "automatic")
2014  * - encoding: Set by user.
2015  * - decoding: unused
2016  */
2017  int cutoff;
2018 
2019 #if FF_API_REQUEST_CHANNELS
2020  /**
2021  * Decoder should decode to this many channels if it can (0 for default)
2022  * - encoding: unused
2023  * - decoding: Set by user.
2024  * @deprecated Deprecated in favor of request_channel_layout.
2025  */
2027 #endif
2028 
2029  /**
2030  * Audio channel layout.
2031  * - encoding: set by user.
2032  * - decoding: set by user, may be overwritten by libavcodec.
2033  */
2034  uint64_t channel_layout;
2035 
2036  /**
2037  * Request decoder to use this channel layout if it can (0 for default)
2038  * - encoding: unused
2039  * - decoding: Set by user.
2040  */
2041  uint64_t request_channel_layout;
2042 
2043  /**
2044  * Type of service that the audio stream conveys.
2045  * - encoding: Set by user.
2046  * - decoding: Set by libavcodec.
2047  */
2049 
2050  /**
2051  * desired sample format
2052  * - encoding: Not used.
2053  * - decoding: Set by user.
2054  * Decoder will decode to this format if it can.
2055  */
2057 
2058 #if FF_API_GET_BUFFER
2059  /**
2060  * Called at the beginning of each frame to get a buffer for it.
2061  *
2062  * The function will set AVFrame.data[], AVFrame.linesize[].
2063  * AVFrame.extended_data[] must also be set, but it should be the same as
2064  * AVFrame.data[] except for planar audio with more channels than can fit
2065  * in AVFrame.data[]. In that case, AVFrame.data[] shall still contain as
2066  * many data pointers as it can hold.
2067  *
2068  * if CODEC_CAP_DR1 is not set then get_buffer() must call
2069  * avcodec_default_get_buffer() instead of providing buffers allocated by
2070  * some other means.
2071  *
2072  * AVFrame.data[] should be 32- or 16-byte-aligned unless the CPU doesn't
2073  * need it. avcodec_default_get_buffer() aligns the output buffer properly,
2074  * but if get_buffer() is overridden then alignment considerations should
2075  * be taken into account.
2076  *
2077  * @see avcodec_default_get_buffer()
2078  *
2079  * Video:
2080  *
2081  * If pic.reference is set then the frame will be read later by libavcodec.
2082  * avcodec_align_dimensions2() should be used to find the required width and
2083  * height, as they normally need to be rounded up to the next multiple of 16.
2084  *
2085  * If frame multithreading is used and thread_safe_callbacks is set,
2086  * it may be called from a different thread, but not from more than one at
2087  * once. Does not need to be reentrant.
2088  *
2089  * @see release_buffer(), reget_buffer()
2090  * @see avcodec_align_dimensions2()
2091  *
2092  * Audio:
2093  *
2094  * Decoders request a buffer of a particular size by setting
2095  * AVFrame.nb_samples prior to calling get_buffer(). The decoder may,
2096  * however, utilize only part of the buffer by setting AVFrame.nb_samples
2097  * to a smaller value in the output frame.
2098  *
2099  * Decoders cannot use the buffer after returning from
2100  * avcodec_decode_audio4(), so they will not call release_buffer(), as it
2101  * is assumed to be released immediately upon return. In some rare cases,
2102  * a decoder may need to call get_buffer() more than once in a single
2103  * call to avcodec_decode_audio4(). In that case, when get_buffer() is
2104  * called again after it has already been called once, the previously
2105  * acquired buffer is assumed to be released at that time and may not be
2106  * reused by the decoder.
2107  *
2108  * As a convenience, av_samples_get_buffer_size() and
2109  * av_samples_fill_arrays() in libavutil may be used by custom get_buffer()
2110  * functions to find the required data size and to fill data pointers and
2111  * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
2112  * since all planes must be the same size.
2113  *
2114  * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
2115  *
2116  * - encoding: unused
2117  * - decoding: Set by libavcodec, user can override.
2118  *
2119  * @deprecated use get_buffer2()
2120  */
2122  int (*get_buffer)(struct AVCodecContext *c, AVFrame *pic);
2123 
2124  /**
2125  * Called to release buffers which were allocated with get_buffer.
2126  * A released buffer can be reused in get_buffer().
2127  * pic.data[*] must be set to NULL.
2128  * May be called from a different thread if frame multithreading is used,
2129  * but not by more than one thread at once, so does not need to be reentrant.
2130  * - encoding: unused
2131  * - decoding: Set by libavcodec, user can override.
2132  *
2133  * @deprecated custom freeing callbacks should be set from get_buffer2()
2134  */
2136  void (*release_buffer)(struct AVCodecContext *c, AVFrame *pic);
2137 
2138  /**
2139  * Called at the beginning of a frame to get cr buffer for it.
2140  * Buffer type (size, hints) must be the same. libavcodec won't check it.
2141  * libavcodec will pass previous buffer in pic, function should return
2142  * same buffer or new buffer with old frame "painted" into it.
2143  * If pic.data[0] == NULL must behave like get_buffer().
2144  * if CODEC_CAP_DR1 is not set then reget_buffer() must call
2145  * avcodec_default_reget_buffer() instead of providing buffers allocated by
2146  * some other means.
2147  * - encoding: unused
2148  * - decoding: Set by libavcodec, user can override.
2149  */
2151  int (*reget_buffer)(struct AVCodecContext *c, AVFrame *pic);
2152 #endif
2153 
2154  /**
2155  * This callback is called at the beginning of each frame to get data
2156  * buffer(s) for it. There may be one contiguous buffer for all the data or
2157  * there may be a buffer per each data plane or anything in between. What
2158  * this means is, you may set however many entries in buf[] you feel necessary.
2159  * Each buffer must be reference-counted using the AVBuffer API (see description
2160  * of buf[] below).
2161  *
2162  * The following fields will be set in the frame before this callback is
2163  * called:
2164  * - format
2165  * - width, height (video only)
2166  * - sample_rate, channel_layout, nb_samples (audio only)
2167  * Their values may differ from the corresponding values in
2168  * AVCodecContext. This callback must use the frame values, not the codec
2169  * context values, to calculate the required buffer size.
2170  *
2171  * This callback must fill the following fields in the frame:
2172  * - data[]
2173  * - linesize[]
2174  * - extended_data:
2175  * * if the data is planar audio with more than 8 channels, then this
2176  * callback must allocate and fill extended_data to contain all pointers
2177  * to all data planes. data[] must hold as many pointers as it can.
2178  * extended_data must be allocated with av_malloc() and will be freed in
2179  * av_frame_unref().
2180  * * otherwise exended_data must point to data
2181  * - buf[] must contain one or more pointers to AVBufferRef structures. Each of
2182  * the frame's data and extended_data pointers must be contained in these. That
2183  * is, one AVBufferRef for each allocated chunk of memory, not necessarily one
2184  * AVBufferRef per data[] entry. See: av_buffer_create(), av_buffer_alloc(),
2185  * and av_buffer_ref().
2186  * - extended_buf and nb_extended_buf must be allocated with av_malloc() by
2187  * this callback and filled with the extra buffers if there are more
2188  * buffers than buf[] can hold. extended_buf will be freed in
2189  * av_frame_unref().
2190  *
2191  * If CODEC_CAP_DR1 is not set then get_buffer2() must call
2192  * avcodec_default_get_buffer2() instead of providing buffers allocated by
2193  * some other means.
2194  *
2195  * Each data plane must be aligned to the maximum required by the target
2196  * CPU.
2197  *
2198  * @see avcodec_default_get_buffer2()
2199  *
2200  * Video:
2201  *
2202  * If AV_GET_BUFFER_FLAG_REF is set in flags then the frame may be reused
2203  * (read and/or written to if it is writable) later by libavcodec.
2204  *
2205  * avcodec_align_dimensions2() should be used to find the required width and
2206  * height, as they normally need to be rounded up to the next multiple of 16.
2207  *
2208  * Some decoders do not support linesizes changing between frames.
2209  *
2210  * If frame multithreading is used and thread_safe_callbacks is set,
2211  * this callback may be called from a different thread, but not from more
2212  * than one at once. Does not need to be reentrant.
2213  *
2214  * @see avcodec_align_dimensions2()
2215  *
2216  * Audio:
2217  *
2218  * Decoders request a buffer of a particular size by setting
2219  * AVFrame.nb_samples prior to calling get_buffer2(). The decoder may,
2220  * however, utilize only part of the buffer by setting AVFrame.nb_samples
2221  * to a smaller value in the output frame.
2222  *
2223  * As a convenience, av_samples_get_buffer_size() and
2224  * av_samples_fill_arrays() in libavutil may be used by custom get_buffer2()
2225  * functions to find the required data size and to fill data pointers and
2226  * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
2227  * since all planes must be the same size.
2228  *
2229  * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
2230  *
2231  * - encoding: unused
2232  * - decoding: Set by libavcodec, user can override.
2233  */
2234  int (*get_buffer2)(struct AVCodecContext *s, AVFrame *frame, int flags);
2235 
2236  /**
2237  * If non-zero, the decoded audio and video frames returned from
2238  * avcodec_decode_video2() and avcodec_decode_audio4() are reference-counted
2239  * and are valid indefinitely. The caller must free them with
2240  * av_frame_unref() when they are not needed anymore.
2241  * Otherwise, the decoded frames must not be freed by the caller and are
2242  * only valid until the next decode call.
2243  *
2244  * - encoding: unused
2245  * - decoding: set by the caller before avcodec_open2().
2246  */
2247  int refcounted_frames;
2248 
2249  /* - encoding parameters */
2250  float qcompress; ///< amount of qscale change between easy & hard scenes (0.0-1.0)
2251  float qblur; ///< amount of qscale smoothing over time (0.0-1.0)
2252 
2253  /**
2254  * minimum quantizer
2255  * - encoding: Set by user.
2256  * - decoding: unused
2257  */
2258  int qmin;
2259 
2260  /**
2261  * maximum quantizer
2262  * - encoding: Set by user.
2263  * - decoding: unused
2264  */
2265  int qmax;
2266 
2267  /**
2268  * maximum quantizer difference between frames
2269  * - encoding: Set by user.
2270  * - decoding: unused
2271  */
2272  int max_qdiff;
2273 
2274 #if FF_API_MPV_OPT
2275  /**
2276  * @deprecated use encoder private options instead
2277  */
2279  float rc_qsquish;
2280 
2282  float rc_qmod_amp;
2284  int rc_qmod_freq;
2285 #endif
2286 
2287  /**
2288  * decoder bitstream buffer size
2289  * - encoding: Set by user.
2290  * - decoding: unused
2291  */
2292  int rc_buffer_size;
2293 
2294  /**
2295  * ratecontrol override, see RcOverride
2296  * - encoding: Allocated/set/freed by user.
2297  * - decoding: unused
2298  */
2301 
2302 #if FF_API_MPV_OPT
2303  /**
2304  * @deprecated use encoder private options instead
2305  */
2307  const char *rc_eq;
2308 #endif
2309 
2310  /**
2311  * maximum bitrate
2312  * - encoding: Set by user.
2313  * - decoding: Set by libavcodec.
2314  */
2315  int rc_max_rate;
2316 
2317  /**
2318  * minimum bitrate
2319  * - encoding: Set by user.
2320  * - decoding: unused
2321  */
2322  int rc_min_rate;
2323 
2324 #if FF_API_MPV_OPT
2325  /**
2326  * @deprecated use encoder private options instead
2327  */
2329  float rc_buffer_aggressivity;
2330 
2332  float rc_initial_cplx;
2333 #endif
2334 
2335  /**
2336  * Ratecontrol attempt to use, at maximum, <value> of what can be used without an underflow.
2337  * - encoding: Set by user.
2338  * - decoding: unused.
2339  */
2341 
2342  /**
2343  * Ratecontrol attempt to use, at least, <value> times the amount needed to prevent a vbv overflow.
2344  * - encoding: Set by user.
2345  * - decoding: unused.
2346  */
2348 
2349  /**
2350  * Number of bits which should be loaded into the rc buffer before decoding starts.
2351  * - encoding: Set by user.
2352  * - decoding: unused
2353  */
2356 #define FF_CODER_TYPE_VLC 0
2357 #define FF_CODER_TYPE_AC 1
2358 #define FF_CODER_TYPE_RAW 2
2359 #define FF_CODER_TYPE_RLE 3
2360 #if FF_API_UNUSED_MEMBERS
2361 #define FF_CODER_TYPE_DEFLATE 4
2362 #endif /* FF_API_UNUSED_MEMBERS */
2363  /**
2364  * coder type
2365  * - encoding: Set by user.
2366  * - decoding: unused
2367  */
2368  int coder_type;
2369 
2370  /**
2371  * context model
2372  * - encoding: Set by user.
2373  * - decoding: unused
2374  */
2375  int context_model;
2376 
2377 #if FF_API_MPV_OPT
2378  /**
2379  * @deprecated use encoder private options instead
2380  */
2382  int lmin;
2383 
2384  /**
2385  * @deprecated use encoder private options instead
2386  */
2388  int lmax;
2389 #endif
2390 
2391  /**
2392  * frame skip threshold
2393  * - encoding: Set by user.
2394  * - decoding: unused
2395  */
2397 
2398  /**
2399  * frame skip factor
2400  * - encoding: Set by user.
2401  * - decoding: unused
2402  */
2403  int frame_skip_factor;
2404 
2405  /**
2406  * frame skip exponent
2407  * - encoding: Set by user.
2408  * - decoding: unused
2409  */
2410  int frame_skip_exp;
2411 
2412  /**
2413  * frame skip comparison function
2414  * - encoding: Set by user.
2415  * - decoding: unused
2416  */
2417  int frame_skip_cmp;
2418 
2419  /**
2420  * trellis RD quantization
2421  * - encoding: Set by user.
2422  * - decoding: unused
2423  */
2424  int trellis;
2425 
2426  /**
2427  * - encoding: Set by user.
2428  * - decoding: unused
2429  */
2431 
2432  /**
2433  * - encoding: Set by user.
2434  * - decoding: unused
2435  */
2437 
2438  /**
2439  * GOP timecode frame start number
2440  * - encoding: Set by user, in non drop frame format
2441  * - decoding: Set by libavcodec (timecode in the 25 bits format, -1 if unset)
2442  */
2443  int64_t timecode_frame_start;
2444 
2445  /* The RTP callback: This function is called */
2446  /* every time the encoder has a packet to send. */
2447  /* It depends on the encoder if the data starts */
2448  /* with a Start Code (it should). H.263 does. */
2449  /* mb_nb contains the number of macroblocks */
2450  /* encoded in the RTP payload. */
2451  void (*rtp_callback)(struct AVCodecContext *avctx, void *data, int size, int mb_nb);
2453  int rtp_payload_size; /* The size of the RTP payload: the coder will */
2454  /* do its best to deliver a chunk with size */
2455  /* below rtp_payload_size, the chunk will start */
2456  /* with a start code on some codecs like H.263. */
2457  /* This doesn't take account of any particular */
2458  /* headers inside the transmitted RTP payload. */
2459 
2460  /* statistics, used for 2-pass encoding */
2461  int mv_bits;
2465  int i_count;
2466  int p_count;
2468  int misc_bits;
2469 
2470  /**
2471  * number of bits used for the previously encoded frame
2472  * - encoding: Set by libavcodec.
2473  * - decoding: unused
2474  */
2475  int frame_bits;
2476 
2477  /**
2478  * pass1 encoding statistics output buffer
2479  * - encoding: Set by libavcodec.
2480  * - decoding: unused
2481  */
2482  char *stats_out;
2483 
2484  /**
2485  * pass2 encoding statistics input buffer
2486  * Concatenated stuff from stats_out of pass1 should be placed here.
2487  * - encoding: Allocated/set/freed by user.
2488  * - decoding: unused
2489  */
2490  char *stats_in;
2491 
2492  /**
2493  * Work around bugs in encoders which sometimes cannot be detected automatically.
2494  * - encoding: Set by user
2495  * - decoding: Set by user
2496  */
2498 #define FF_BUG_AUTODETECT 1 ///< autodetection
2499 #if FF_API_OLD_MSMPEG4
2500 #define FF_BUG_OLD_MSMPEG4 2
2501 #endif
2502 #define FF_BUG_XVID_ILACE 4
2503 #define FF_BUG_UMP4 8
2504 #define FF_BUG_NO_PADDING 16
2505 #define FF_BUG_AMV 32
2506 #if FF_API_AC_VLC
2507 #define FF_BUG_AC_VLC 0 ///< Will be removed, libavcodec can now handle these non-compliant files by default.
2508 #endif
2509 #define FF_BUG_QPEL_CHROMA 64
2510 #define FF_BUG_STD_QPEL 128
2511 #define FF_BUG_QPEL_CHROMA2 256
2512 #define FF_BUG_DIRECT_BLOCKSIZE 512
2513 #define FF_BUG_EDGE 1024
2514 #define FF_BUG_HPEL_CHROMA 2048
2515 #define FF_BUG_DC_CLIP 4096
2516 #define FF_BUG_MS 8192 ///< Work around various bugs in Microsoft's broken decoders.
2517 #define FF_BUG_TRUNCATED 16384
2518 
2519  /**
2520  * strictly follow the standard (MPEG4, ...).
2521  * - encoding: Set by user.
2522  * - decoding: Set by user.
2523  * Setting this to STRICT or higher means the encoder and decoder will
2524  * generally do stupid things, whereas setting it to unofficial or lower
2525  * will mean the encoder might produce output that is not supported by all
2526  * spec-compliant decoders. Decoders don't differentiate between normal,
2527  * unofficial and experimental (that is, they always try to decode things
2528  * when they can) unless they are explicitly asked to behave stupidly
2529  * (=strictly conform to the specs)
2530  */
2532 #define FF_COMPLIANCE_VERY_STRICT 2 ///< Strictly conform to an older more strict version of the spec or reference software.
2533 #define FF_COMPLIANCE_STRICT 1 ///< Strictly conform to all the things in the spec no matter what consequences.
2534 #define FF_COMPLIANCE_NORMAL 0
2535 #define FF_COMPLIANCE_UNOFFICIAL -1 ///< Allow unofficial extensions
2536 #define FF_COMPLIANCE_EXPERIMENTAL -2 ///< Allow nonstandardized experimental things.
2537 
2538  /**
2539  * error concealment flags
2540  * - encoding: unused
2541  * - decoding: Set by user.
2542  */
2544 #define FF_EC_GUESS_MVS 1
2545 #define FF_EC_DEBLOCK 2
2546 #define FF_EC_FAVOR_INTER 256
2547 
2548  /**
2549  * debug
2550  * - encoding: Set by user.
2551  * - decoding: Set by user.
2552  */
2553  int debug;
2554 #define FF_DEBUG_PICT_INFO 1
2555 #define FF_DEBUG_RC 2
2556 #define FF_DEBUG_BITSTREAM 4
2557 #define FF_DEBUG_MB_TYPE 8
2558 #define FF_DEBUG_QP 16
2559 #if FF_API_DEBUG_MV
2560 /**
2561  * @deprecated this option does nothing
2562  */
2563 #define FF_DEBUG_MV 32
2564 #endif
2565 #define FF_DEBUG_DCT_COEFF 0x00000040
2566 #define FF_DEBUG_SKIP 0x00000080
2567 #define FF_DEBUG_STARTCODE 0x00000100
2568 #if FF_API_UNUSED_MEMBERS
2569 #define FF_DEBUG_PTS 0x00000200
2570 #endif /* FF_API_UNUSED_MEMBERS */
2571 #define FF_DEBUG_ER 0x00000400
2572 #define FF_DEBUG_MMCO 0x00000800
2573 #define FF_DEBUG_BUGS 0x00001000
2574 #if FF_API_DEBUG_MV
2575 #define FF_DEBUG_VIS_QP 0x00002000 ///< only access through AVOptions from outside libavcodec
2576 #define FF_DEBUG_VIS_MB_TYPE 0x00004000 ///< only access through AVOptions from outside libavcodec
2577 #endif
2578 #define FF_DEBUG_BUFFERS 0x00008000
2579 #define FF_DEBUG_THREADS 0x00010000
2580 #define FF_DEBUG_NOMC 0x01000000
2581 
2582 #if FF_API_DEBUG_MV
2583  /**
2584  * debug
2585  * Code outside libavcodec should access this field using AVOptions
2586  * - encoding: Set by user.
2587  * - decoding: Set by user.
2588  */
2590 #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 //visualize forward predicted MVs of P frames
2591 #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 //visualize forward predicted MVs of B frames
2592 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
2593 #endif
2594 
2595  /**
2596  * Error recognition; may misdetect some more or less valid parts as errors.
2597  * - encoding: unused
2598  * - decoding: Set by user.
2599  */
2600  int err_recognition;
2601 
2602 /**
2603  * Verify checksums embedded in the bitstream (could be of either encoded or
2604  * decoded data, depending on the codec) and print an error message on mismatch.
2605  * If AV_EF_EXPLODE is also set, a mismatching checksum will result in the
2606  * decoder returning an error.
2607  */
2608 #define AV_EF_CRCCHECK (1<<0)
2609 #define AV_EF_BITSTREAM (1<<1) ///< detect bitstream specification deviations
2610 #define AV_EF_BUFFER (1<<2) ///< detect improper bitstream length
2611 #define AV_EF_EXPLODE (1<<3) ///< abort decoding on minor error detection
2613 #define AV_EF_IGNORE_ERR (1<<15) ///< ignore errors and continue
2614 #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
2615 #define AV_EF_COMPLIANT (1<<17) ///< consider all spec non compliances as errors
2616 #define AV_EF_AGGRESSIVE (1<<18) ///< consider things that a sane encoder should not do as an error
2617 
2618 
2619  /**
2620  * opaque 64bit number (generally a PTS) that will be reordered and
2621  * output in AVFrame.reordered_opaque
2622  * - encoding: unused
2623  * - decoding: Set by user.
2624  */
2625  int64_t reordered_opaque;
2626 
2627  /**
2628  * Hardware accelerator in use
2629  * - encoding: unused.
2630  * - decoding: Set by libavcodec
2631  */
2632  struct AVHWAccel *hwaccel;
2633 
2634  /**
2635  * Hardware accelerator context.
2636  * For some hardware accelerators, a global context needs to be
2637  * provided by the user. In that case, this holds display-dependent
2638  * data FFmpeg cannot instantiate itself. Please refer to the
2639  * FFmpeg HW accelerator documentation to know how to fill this
2640  * is. e.g. for VA API, this is a struct vaapi_context.
2641  * - encoding: unused
2642  * - decoding: Set by user
2643  */
2644  void *hwaccel_context;
2645 
2646  /**
2647  * error
2648  * - encoding: Set by libavcodec if flags&CODEC_FLAG_PSNR.
2649  * - decoding: unused
2650  */
2651  uint64_t error[AV_NUM_DATA_POINTERS];
2652 
2653  /**
2654  * DCT algorithm, see FF_DCT_* below
2655  * - encoding: Set by user.
2656  * - decoding: unused
2657  */
2659 #define FF_DCT_AUTO 0
2660 #define FF_DCT_FASTINT 1
2661 #if FF_API_UNUSED_MEMBERS
2662 #define FF_DCT_INT 2
2663 #endif /* FF_API_UNUSED_MEMBERS */
2664 #define FF_DCT_MMX 3
2665 #define FF_DCT_ALTIVEC 5
2666 #define FF_DCT_FAAN 6
2667 
2668  /**
2669  * IDCT algorithm, see FF_IDCT_* below.
2670  * - encoding: Set by user.
2671  * - decoding: Set by user.
2672  */
2674 #define FF_IDCT_AUTO 0
2675 #define FF_IDCT_INT 1
2676 #define FF_IDCT_SIMPLE 2
2677 #define FF_IDCT_SIMPLEMMX 3
2678 #define FF_IDCT_ARM 7
2679 #define FF_IDCT_ALTIVEC 8
2680 #if FF_API_ARCH_SH4
2681 #define FF_IDCT_SH4 9
2682 #endif
2683 #define FF_IDCT_SIMPLEARM 10
2684 #if FF_API_UNUSED_MEMBERS
2685 #define FF_IDCT_IPP 13
2686 #endif /* FF_API_UNUSED_MEMBERS */
2687 #define FF_IDCT_XVID 14
2688 #if FF_API_IDCT_XVIDMMX
2689 #define FF_IDCT_XVIDMMX 14
2690 #endif /* FF_API_IDCT_XVIDMMX */
2691 #define FF_IDCT_SIMPLEARMV5TE 16
2692 #define FF_IDCT_SIMPLEARMV6 17
2693 #if FF_API_ARCH_SPARC
2694 #define FF_IDCT_SIMPLEVIS 18
2695 #endif
2696 #define FF_IDCT_FAAN 20
2697 #define FF_IDCT_SIMPLENEON 22
2698 #if FF_API_ARCH_ALPHA
2699 #define FF_IDCT_SIMPLEALPHA 23
2700 #endif
2701 #define FF_IDCT_SIMPLEAUTO 128
2702 
2703  /**
2704  * bits per sample/pixel from the demuxer (needed for huffyuv).
2705  * - encoding: Set by libavcodec.
2706  * - decoding: Set by user.
2707  */
2709 
2710  /**
2711  * Bits per sample/pixel of internal libavcodec pixel/sample format.
2712  * - encoding: set by user.
2713  * - decoding: set by libavcodec.
2714  */
2715  int bits_per_raw_sample;
2716 
2717 #if FF_API_LOWRES
2718  /**
2719  * low resolution decoding, 1-> 1/2 size, 2->1/4 size
2720  * - encoding: unused
2721  * - decoding: Set by user.
2722  * Code outside libavcodec should access this field using:
2723  * av_codec_{get,set}_lowres(avctx)
2724  */
2725  int lowres;
2726 #endif
2727 
2728  /**
2729  * the picture in the bitstream
2730  * - encoding: Set by libavcodec.
2731  * - decoding: unused
2732  */
2734 
2735  /**
2736  * thread count
2737  * is used to decide how many independent tasks should be passed to execute()
2738  * - encoding: Set by user.
2739  * - decoding: Set by user.
2740  */
2741  int thread_count;
2742 
2743  /**
2744  * Which multithreading methods to use.
2745  * Use of FF_THREAD_FRAME will increase decoding delay by one frame per thread,
2746  * so clients which cannot provide future frames should not use it.
2747  *
2748  * - encoding: Set by user, otherwise the default is used.
2749  * - decoding: Set by user, otherwise the default is used.
2750  */
2752 #define FF_THREAD_FRAME 1 ///< Decode more than one frame at once
2753 #define FF_THREAD_SLICE 2 ///< Decode more than one part of a single frame at once
2754 
2755  /**
2756  * Which multithreading methods are in use by the codec.
2757  * - encoding: Set by libavcodec.
2758  * - decoding: Set by libavcodec.
2759  */
2760  int active_thread_type;
2761 
2762  /**
2763  * Set by the client if its custom get_buffer() callback can be called
2764  * synchronously from another thread, which allows faster multithreaded decoding.
2765  * draw_horiz_band() will be called from other threads regardless of this setting.
2766  * Ignored if the default get_buffer() is used.
2767  * - encoding: Set by user.
2768  * - decoding: Set by user.
2769  */
2771 
2772  /**
2773  * The codec may call this to execute several independent things.
2774  * It will return only after finishing all tasks.
2775  * The user may replace this with some multithreaded implementation,
2776  * the default implementation will execute the parts serially.
2777  * @param count the number of things to execute
2778  * - encoding: Set by libavcodec, user can override.
2779  * - decoding: Set by libavcodec, user can override.
2780  */
2781  int (*execute)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size);
2782 
2783  /**
2784  * The codec may call this to execute several independent things.
2785  * It will return only after finishing all tasks.
2786  * The user may replace this with some multithreaded implementation,
2787  * the default implementation will execute the parts serially.
2788  * Also see avcodec_thread_init and e.g. the --enable-pthread configure option.
2789  * @param c context passed also to func
2790  * @param count the number of things to execute
2791  * @param arg2 argument passed unchanged to func
2792  * @param ret return values of executed functions, must have space for "count" values. May be NULL.
2793  * @param func function that will be called count times, with jobnr from 0 to count-1.
2794  * threadnr will be in the range 0 to c->thread_count-1 < MAX_THREADS and so that no
2795  * two instances of func executing at the same time will have the same threadnr.
2796  * @return always 0 currently, but code should handle a future improvement where when any call to func
2797  * returns < 0 no further calls to func may be done and < 0 is returned.
2798  * - encoding: Set by libavcodec, user can override.
2799  * - decoding: Set by libavcodec, user can override.
2800  */
2801  int (*execute2)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count);
2802 
2803 #if FF_API_THREAD_OPAQUE
2804  /**
2805  * @deprecated this field should not be used from outside of lavc
2806  */
2808  void *thread_opaque;
2809 #endif
2810 
2811  /**
2812  * noise vs. sse weight for the nsse comparison function
2813  * - encoding: Set by user.
2814  * - decoding: unused
2815  */
2816  int nsse_weight;
2817 
2818  /**
2819  * profile
2820  * - encoding: Set by user.
2821  * - decoding: Set by libavcodec.
2822  */
2823  int profile;
2824 #define FF_PROFILE_UNKNOWN -99
2825 #define FF_PROFILE_RESERVED -100
2827 #define FF_PROFILE_AAC_MAIN 0
2828 #define FF_PROFILE_AAC_LOW 1
2829 #define FF_PROFILE_AAC_SSR 2
2830 #define FF_PROFILE_AAC_LTP 3
2831 #define FF_PROFILE_AAC_HE 4
2832 #define FF_PROFILE_AAC_HE_V2 28
2833 #define FF_PROFILE_AAC_LD 22
2834 #define FF_PROFILE_AAC_ELD 38
2835 #define FF_PROFILE_MPEG2_AAC_LOW 128
2836 #define FF_PROFILE_MPEG2_AAC_HE 131
2838 #define FF_PROFILE_DTS 20
2839 #define FF_PROFILE_DTS_ES 30
2840 #define FF_PROFILE_DTS_96_24 40
2841 #define FF_PROFILE_DTS_HD_HRA 50
2842 #define FF_PROFILE_DTS_HD_MA 60
2844 #define FF_PROFILE_MPEG2_422 0
2845 #define FF_PROFILE_MPEG2_HIGH 1
2846 #define FF_PROFILE_MPEG2_SS 2
2847 #define FF_PROFILE_MPEG2_SNR_SCALABLE 3
2848 #define FF_PROFILE_MPEG2_MAIN 4
2849 #define FF_PROFILE_MPEG2_SIMPLE 5
2851 #define FF_PROFILE_H264_CONSTRAINED (1<<9) // 8+1; constraint_set1_flag
2852 #define FF_PROFILE_H264_INTRA (1<<11) // 8+3; constraint_set3_flag
2854 #define FF_PROFILE_H264_BASELINE 66
2855 #define FF_PROFILE_H264_CONSTRAINED_BASELINE (66|FF_PROFILE_H264_CONSTRAINED)
2856 #define FF_PROFILE_H264_MAIN 77
2857 #define FF_PROFILE_H264_EXTENDED 88
2858 #define FF_PROFILE_H264_HIGH 100
2859 #define FF_PROFILE_H264_HIGH_10 110
2860 #define FF_PROFILE_H264_HIGH_10_INTRA (110|FF_PROFILE_H264_INTRA)
2861 #define FF_PROFILE_H264_HIGH_422 122
2862 #define FF_PROFILE_H264_HIGH_422_INTRA (122|FF_PROFILE_H264_INTRA)
2863 #define FF_PROFILE_H264_HIGH_444 144
2864 #define FF_PROFILE_H264_HIGH_444_PREDICTIVE 244
2865 #define FF_PROFILE_H264_HIGH_444_INTRA (244|FF_PROFILE_H264_INTRA)
2866 #define FF_PROFILE_H264_CAVLC_444 44
2868 #define FF_PROFILE_VC1_SIMPLE 0
2869 #define FF_PROFILE_VC1_MAIN 1
2870 #define FF_PROFILE_VC1_COMPLEX 2
2871 #define FF_PROFILE_VC1_ADVANCED 3
2873 #define FF_PROFILE_MPEG4_SIMPLE 0
2874 #define FF_PROFILE_MPEG4_SIMPLE_SCALABLE 1
2875 #define FF_PROFILE_MPEG4_CORE 2
2876 #define FF_PROFILE_MPEG4_MAIN 3
2877 #define FF_PROFILE_MPEG4_N_BIT 4
2878 #define FF_PROFILE_MPEG4_SCALABLE_TEXTURE 5
2879 #define FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION 6
2880 #define FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE 7
2881 #define FF_PROFILE_MPEG4_HYBRID 8
2882 #define FF_PROFILE_MPEG4_ADVANCED_REAL_TIME 9
2883 #define FF_PROFILE_MPEG4_CORE_SCALABLE 10
2884 #define FF_PROFILE_MPEG4_ADVANCED_CODING 11
2885 #define FF_PROFILE_MPEG4_ADVANCED_CORE 12
2886 #define FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE 13
2887 #define FF_PROFILE_MPEG4_SIMPLE_STUDIO 14
2888 #define FF_PROFILE_MPEG4_ADVANCED_SIMPLE 15
2890 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_0 0
2891 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_1 1
2892 #define FF_PROFILE_JPEG2000_CSTREAM_NO_RESTRICTION 2
2893 #define FF_PROFILE_JPEG2000_DCINEMA_2K 3
2894 #define FF_PROFILE_JPEG2000_DCINEMA_4K 4
2895 
2897 #define FF_PROFILE_HEVC_MAIN 1
2898 #define FF_PROFILE_HEVC_MAIN_10 2
2899 #define FF_PROFILE_HEVC_MAIN_STILL_PICTURE 3
2900 #define FF_PROFILE_HEVC_REXT 4
2901 
2902  /**
2903  * level
2904  * - encoding: Set by user.
2905  * - decoding: Set by libavcodec.
2906  */
2907  int level;
2908 #define FF_LEVEL_UNKNOWN -99
2909 
2910  /**
2911  * Skip loop filtering for selected frames.
2912  * - encoding: unused
2913  * - decoding: Set by user.
2914  */
2916 
2917  /**
2918  * Skip IDCT/dequantization for selected frames.
2919  * - encoding: unused
2920  * - decoding: Set by user.
2921  */
2922  enum AVDiscard skip_idct;
2923 
2924  /**
2925  * Skip decoding for selected frames.
2926  * - encoding: unused
2927  * - decoding: Set by user.
2928  */
2929  enum AVDiscard skip_frame;
2930 
2931  /**
2932  * Header containing style information for text subtitles.
2933  * For SUBTITLE_ASS subtitle type, it should contain the whole ASS
2934  * [Script Info] and [V4+ Styles] section, plus the [Events] line and
2935  * the Format line following. It shouldn't include any Dialogue line.
2936  * - encoding: Set/allocated/freed by user (before avcodec_open2())
2937  * - decoding: Set/allocated/freed by libavcodec (by avcodec_open2())
2938  */
2941 
2942 #if FF_API_ERROR_RATE
2943  /**
2944  * @deprecated use the 'error_rate' private AVOption of the mpegvideo
2945  * encoders
2946  */
2948  int error_rate;
2949 #endif
2950 
2951 #if FF_API_CODEC_PKT
2952  /**
2953  * @deprecated this field is not supposed to be accessed from outside lavc
2954  */
2956  AVPacket *pkt;
2957 #endif
2958 
2959  /**
2960  * VBV delay coded in the last frame (in periods of a 27 MHz clock).
2961  * Used for compliant TS muxing.
2962  * - encoding: Set by libavcodec.
2963  * - decoding: unused.
2964  */
2965  uint64_t vbv_delay;
2966 
2967  /**
2968  * Encoding only. Allow encoders to output packets that do not contain any
2969  * encoded data, only side data.
2970  *
2971  * Some encoders need to output such packets, e.g. to update some stream
2972  * parameters at the end of encoding.
2973  *
2974  * All callers are strongly recommended to set this option to 1 and update
2975  * their code to deal with such packets, since this behaviour may become
2976  * always enabled in the future (then this option will be deprecated and
2977  * later removed). To avoid ABI issues when this happens, the callers should
2978  * use AVOptions to set this field.
2979  */
2981 
2982  /**
2983  * Audio only. The number of "priming" samples (padding) inserted by the
2984  * encoder at the beginning of the audio. I.e. this number of leading
2985  * decoded samples must be discarded by the caller to get the original audio
2986  * without leading padding.
2987  *
2988  * - decoding: unused
2989  * - encoding: Set by libavcodec. The timestamps on the output packets are
2990  * adjusted by the encoder so that they always refer to the
2991  * first sample of the data actually contained in the packet,
2992  * including any added padding. E.g. if the timebase is
2993  * 1/samplerate and the timestamp of the first input sample is
2994  * 0, the timestamp of the first output packet will be
2995  * -initial_padding.
2996  */
2997  int initial_padding;
2998 
2999  /**
3000  * - decoding: For codecs that store a framerate value in the compressed
3001  * bitstream, the decoder may export it here. { 0, 1} when
3002  * unknown.
3003  * - encoding: unused
3004  */
3006 
3007  /**
3008  * Timebase in which pkt_dts/pts and AVPacket.dts/pts are.
3009  * Code outside libavcodec should access this field using:
3010  * av_codec_{get,set}_pkt_timebase(avctx)
3011  * - encoding unused.
3012  * - decoding set by user.
3013  */
3015 
3016  /**
3017  * AVCodecDescriptor
3018  * Code outside libavcodec should access this field using:
3019  * av_codec_{get,set}_codec_descriptor(avctx)
3020  * - encoding: unused.
3021  * - decoding: set by libavcodec.
3022  */
3024 
3025 #if !FF_API_LOWRES
3026  /**
3027  * low resolution decoding, 1-> 1/2 size, 2->1/4 size
3028  * - encoding: unused
3029  * - decoding: Set by user.
3030  * Code outside libavcodec should access this field using:
3031  * av_codec_{get,set}_lowres(avctx)
3032  */
3033  int lowres;
3034 #endif
3035 
3036  /**
3037  * Current statistics for PTS correction.
3038  * - decoding: maintained and used by libavcodec, not intended to be used by user apps
3039  * - encoding: unused
3040  */
3041  int64_t pts_correction_num_faulty_pts; /// Number of incorrect PTS values so far
3042  int64_t pts_correction_num_faulty_dts; /// Number of incorrect DTS values so far
3043  int64_t pts_correction_last_pts; /// PTS of the last frame
3044  int64_t pts_correction_last_dts; /// DTS of the last frame
3045 
3046  /**
3047  * Character encoding of the input subtitles file.
3048  * - decoding: set by user
3049  * - encoding: unused
3050  */
3051  char *sub_charenc;
3052 
3053  /**
3054  * Subtitles character encoding mode. Formats or codecs might be adjusting
3055  * this setting (if they are doing the conversion themselves for instance).
3056  * - decoding: set by libavcodec
3057  * - encoding: unused
3058  */
3060 #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)
3061 #define FF_SUB_CHARENC_MODE_AUTOMATIC 0 ///< libavcodec will select the mode itself
3062 #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
3063 
3064  /**
3065  * Skip processing alpha if supported by codec.
3066  * Note that if the format uses pre-multiplied alpha (common with VP6,
3067  * and recommended due to better video quality/compression)
3068  * the image will look as if alpha-blended onto a black background.
3069  * However for formats that do not use pre-multiplied alpha
3070  * there might be serious artefacts (though e.g. libswscale currently
3071  * assumes pre-multiplied alpha anyway).
3072  * Code outside libavcodec should access this field using AVOptions
3073  *
3074  * - decoding: set by user
3075  * - encoding: unused
3076  */
3077  int skip_alpha;
3078 
3079  /**
3080  * Number of samples to skip after a discontinuity
3081  * - decoding: unused
3082  * - encoding: set by libavcodec
3083  */
3084  int seek_preroll;
3085 
3086 #if !FF_API_DEBUG_MV
3087  /**
3088  * debug motion vectors
3089  * Code outside libavcodec should access this field using AVOptions
3090  * - encoding: Set by user.
3091  * - decoding: Set by user.
3092  */
3093  int debug_mv;
3094 #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 //visualize forward predicted MVs of P frames
3095 #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 //visualize forward predicted MVs of B frames
3096 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
3097 #endif
3098 
3099  /**
3100  * custom intra quantization matrix
3101  * Code outside libavcodec should access this field using av_codec_g/set_chroma_intra_matrix()
3102  * - encoding: Set by user, can be NULL.
3103  * - decoding: unused.
3104  */
3105  uint16_t *chroma_intra_matrix;
3106 
3107  /**
3108  * dump format separator.
3109  * can be ", " or "\n " or anything else
3110  * Code outside libavcodec should access this field using AVOptions
3111  * (NO direct access).
3112  * - encoding: Set by user.
3113  * - decoding: Set by user.
3114  */
3116 
3117  /**
3118  * ',' seperated list of allowed decoders.
3119  * If NULL then all are allowed
3120  * - encoding: unused
3121  * - decoding: set by user through AVOPtions (NO direct access)
3122  */
3123  char *codec_whitelist;
3124 } AVCodecContext;
3125 
3128 
3131 
3132 int av_codec_get_lowres(const AVCodecContext *avctx);
3133 void av_codec_set_lowres(AVCodecContext *avctx, int val);
3134 
3135 int av_codec_get_seek_preroll(const AVCodecContext *avctx);
3136 void av_codec_set_seek_preroll(AVCodecContext *avctx, int val);
3137 
3138 uint16_t *av_codec_get_chroma_intra_matrix(const AVCodecContext *avctx);
3139 void av_codec_set_chroma_intra_matrix(AVCodecContext *avctx, uint16_t *val);
3140 
3141 /**
3142  * AVProfile.
3143  */
3144 typedef struct AVProfile {
3145  int profile;
3146  const char *name; ///< short name for the profile
3147 } AVProfile;
3148 
3149 typedef struct AVCodecDefault AVCodecDefault;
3150 
3151 struct AVSubtitle;
3152 
3153 /**
3154  * AVCodec.
3155  */
3156 typedef struct AVCodec {
3157  /**
3158  * Name of the codec implementation.
3159  * The name is globally unique among encoders and among decoders (but an
3160  * encoder and a decoder can share the same name).
3161  * This is the primary way to find a codec from the user perspective.
3162  */
3163  const char *name;
3164  /**
3165  * Descriptive name for the codec, meant to be more human readable than name.
3166  * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
3167  */
3168  const char *long_name;
3170  enum AVCodecID id;
3171  /**
3172  * Codec capabilities.
3173  * see CODEC_CAP_*
3174  */
3176  const AVRational *supported_framerates; ///< array of supported framerates, or NULL if any, array is terminated by {0,0}
3177  const enum AVPixelFormat *pix_fmts; ///< array of supported pixel formats, or NULL if unknown, array is terminated by -1
3178  const int *supported_samplerates; ///< array of supported audio samplerates, or NULL if unknown, array is terminated by 0
3179  const enum AVSampleFormat *sample_fmts; ///< array of supported sample formats, or NULL if unknown, array is terminated by -1
3180  const uint64_t *channel_layouts; ///< array of support channel layouts, or NULL if unknown. array is terminated by 0
3181 #if FF_API_LOWRES
3182  uint8_t max_lowres; ///< maximum value for lowres supported by the decoder, no direct access, use av_codec_get_max_lowres()
3183 #endif
3184  const AVClass *priv_class; ///< AVClass for the private context
3185  const AVProfile *profiles; ///< array of recognized profiles, or NULL if unknown, array is terminated by {FF_PROFILE_UNKNOWN}
3186 
3187  /*****************************************************************
3188  * No fields below this line are part of the public API. They
3189  * may not be used outside of libavcodec and can be changed and
3190  * removed at will.
3191  * New public fields should be added right above.
3192  *****************************************************************
3193  */
3195  struct AVCodec *next;
3196  /**
3197  * @name Frame-level threading support functions
3198  * @{
3199  */
3200  /**
3201  * If defined, called on thread contexts when they are created.
3202  * If the codec allocates writable tables in init(), re-allocate them here.
3203  * priv_data will be set to a copy of the original.
3204  */
3205  int (*init_thread_copy)(AVCodecContext *);
3206  /**
3207  * Copy necessary context variables from a previous thread context to the current one.
3208  * If not defined, the next thread will start automatically; otherwise, the codec
3209  * must call ff_thread_finish_setup().
3210  *
3211  * dst and src will (rarely) point to the same context, in which case memcpy should be skipped.
3212  */
3214  /** @} */
3215 
3216  /**
3217  * Private codec-specific defaults.
3218  */
3219  const AVCodecDefault *defaults;
3220 
3221  /**
3222  * Initialize codec static data, called from avcodec_register().
3223  */
3224  void (*init_static_data)(struct AVCodec *codec);
3227  int (*encode_sub)(AVCodecContext *, uint8_t *buf, int buf_size,
3228  const struct AVSubtitle *sub);
3229  /**
3230  * Encode data to an AVPacket.
3231  *
3232  * @param avctx codec context
3233  * @param avpkt output AVPacket (may contain a user-provided buffer)
3234  * @param[in] frame AVFrame containing the raw data to be encoded
3235  * @param[out] got_packet_ptr encoder sets to 0 or 1 to indicate that a
3236  * non-empty packet was returned in avpkt.
3237  * @return 0 on success, negative error code on failure
3238  */
3239  int (*encode2)(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame,
3240  int *got_packet_ptr);
3241  int (*decode)(AVCodecContext *, void *outdata, int *outdata_size, AVPacket *avpkt);
3242  int (*close)(AVCodecContext *);
3243  /**
3244  * Flush buffers.
3245  * Will be called when seeking
3246  */
3247  void (*flush)(AVCodecContext *);
3248 } AVCodec;
3249 
3250 int av_codec_get_max_lowres(const AVCodec *codec);
3251 
3252 struct MpegEncContext;
3253 
3254 /**
3255  * @defgroup lavc_hwaccel AVHWAccel
3256  * @{
3257  */
3258 typedef struct AVHWAccel {
3259  /**
3260  * Name of the hardware accelerated codec.
3261  * The name is globally unique among encoders and among decoders (but an
3262  * encoder and a decoder can share the same name).
3263  */
3264  const char *name;
3265 
3266  /**
3267  * Type of codec implemented by the hardware accelerator.
3268  *
3269  * See AVMEDIA_TYPE_xxx
3270  */
3271  enum AVMediaType type;
3272 
3273  /**
3274  * Codec implemented by the hardware accelerator.
3275  *
3276  * See AV_CODEC_ID_xxx
3277  */
3278  enum AVCodecID id;
3279 
3280  /**
3281  * Supported pixel format.
3282  *
3283  * Only hardware accelerated formats are supported here.
3284  */
3285  enum AVPixelFormat pix_fmt;
3286 
3287  /**
3288  * Hardware accelerated codec capabilities.
3289  * see FF_HWACCEL_CODEC_CAP_*
3290  */
3291  int capabilities;
3292 
3293  /*****************************************************************
3294  * No fields below this line are part of the public API. They
3295  * may not be used outside of libavcodec and can be changed and
3296  * removed at will.
3297  * New public fields should be added right above.
3298  *****************************************************************
3299  */
3300  struct AVHWAccel *next;
3301 
3302  /**
3303  * Allocate a custom buffer
3304  */
3305  int (*alloc_frame)(AVCodecContext *avctx, AVFrame *frame);
3306 
3307  /**
3308  * Called at the beginning of each frame or field picture.
3309  *
3310  * Meaningful frame information (codec specific) is guaranteed to
3311  * be parsed at this point. This function is mandatory.
3312  *
3313  * Note that buf can be NULL along with buf_size set to 0.
3314  * Otherwise, this means the whole frame is available at this point.
3315  *
3316  * @param avctx the codec context
3317  * @param buf the frame data buffer base
3318  * @param buf_size the size of the frame in bytes
3319  * @return zero if successful, a negative value otherwise
3320  */
3321  int (*start_frame)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3322 
3323  /**
3324  * Callback for each slice.
3325  *
3326  * Meaningful slice information (codec specific) is guaranteed to
3327  * be parsed at this point. This function is mandatory.
3328  * The only exception is XvMC, that works on MB level.
3329  *
3330  * @param avctx the codec context
3331  * @param buf the slice data buffer base
3332  * @param buf_size the size of the slice in bytes
3333  * @return zero if successful, a negative value otherwise
3334  */
3335  int (*decode_slice)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3336 
3337  /**
3338  * Called at the end of each frame or field picture.
3339  *
3340  * The whole picture is parsed at this point and can now be sent
3341  * to the hardware accelerator. This function is mandatory.
3342  *
3343  * @param avctx the codec context
3344  * @return zero if successful, a negative value otherwise
3345  */
3346  int (*end_frame)(AVCodecContext *avctx);
3347 
3348  /**
3349  * Size of per-frame hardware accelerator private data.
3350  *
3351  * Private data is allocated with av_mallocz() before
3352  * AVCodecContext.get_buffer() and deallocated after
3353  * AVCodecContext.release_buffer().
3354  */
3356 
3357  /**
3358  * Called for every Macroblock in a slice.
3359  *
3360  * XvMC uses it to replace the ff_mpv_decode_mb().
3361  * Instead of decoding to raw picture, MB parameters are
3362  * stored in an array provided by the video driver.
3363  *
3364  * @param s the mpeg context
3365  */
3366  void (*decode_mb)(struct MpegEncContext *s);
3367 
3368  /**
3369  * Initialize the hwaccel private data.
3370  *
3371  * This will be called from ff_get_format(), after hwaccel and
3372  * hwaccel_context are set and the hwaccel private data in AVCodecInternal
3373  * is allocated.
3374  */
3375  int (*init)(AVCodecContext *avctx);
3376 
3377  /**
3378  * Uninitialize the hwaccel private data.
3379  *
3380  * This will be called from get_format() or avcodec_close(), after hwaccel
3381  * and hwaccel_context are already uninitialized.
3382  */
3383  int (*uninit)(AVCodecContext *avctx);
3384 
3385  /**
3386  * Size of the private data to allocate in
3387  * AVCodecInternal.hwaccel_priv_data.
3388  */
3389  int priv_data_size;
3390 } AVHWAccel;
3391 
3392 /**
3393  * Hardware acceleration should be used for decoding even if the codec level
3394  * used is unknown or higher than the maximum supported level reported by the
3395  * hardware driver.
3396  */
3397 #define AV_HWACCEL_FLAG_IGNORE_LEVEL (1 << 0)
3398 
3399 /**
3400  * @}
3401  */
3402 
3403 /**
3404  * @defgroup lavc_picture AVPicture
3405  *
3406  * Functions for working with AVPicture
3407  * @{
3408  */
3409 
3410 /**
3411  * Picture data structure.
3412  *
3413  * Up to four components can be stored into it, the last component is
3414  * alpha.
3415  */
3416 typedef struct AVPicture {
3417  uint8_t *data[AV_NUM_DATA_POINTERS]; ///< pointers to the image data planes
3418  int linesize[AV_NUM_DATA_POINTERS]; ///< number of bytes per line
3419 } AVPicture;
3420 
3421 /**
3422  * @}
3423  */
3426  SUBTITLE_NONE,
3428  SUBTITLE_BITMAP, ///< A bitmap, pict will be set
3429 
3430  /**
3431  * Plain text, the text field must be set by the decoder and is
3432  * authoritative. ass and pict fields may contain approximations.
3433  */
3434  SUBTITLE_TEXT,
3435 
3436  /**
3437  * Formatted text, the ass field must be set by the decoder and is
3438  * authoritative. pict and text fields may contain approximations.
3439  */
3440  SUBTITLE_ASS,
3441 };
3443 #define AV_SUBTITLE_FLAG_FORCED 0x00000001
3445 typedef struct AVSubtitleRect {
3446  int x; ///< top left corner of pict, undefined when pict is not set
3447  int y; ///< top left corner of pict, undefined when pict is not set
3448  int w; ///< width of pict, undefined when pict is not set
3449  int h; ///< height of pict, undefined when pict is not set
3450  int nb_colors; ///< number of colors in pict, undefined when pict is not set
3451 
3452  /**
3453  * data+linesize for the bitmap of this subtitle.
3454  * can be set for text/ass as well once they where rendered
3455  */
3457  enum AVSubtitleType type;
3459  char *text; ///< 0 terminated plain UTF-8 text
3460 
3461  /**
3462  * 0 terminated ASS/SSA compatible event line.
3463  * The presentation of this is unaffected by the other values in this
3464  * struct.
3465  */
3466  char *ass;
3468  int flags;
3469 } AVSubtitleRect;
3471 typedef struct AVSubtitle {
3472  uint16_t format; /* 0 = graphics */
3473  uint32_t start_display_time; /* relative to packet pts, in ms */
3474  uint32_t end_display_time; /* relative to packet pts, in ms */
3475  unsigned num_rects;
3477  int64_t pts; ///< Same as packet pts, in AV_TIME_BASE
3478 } AVSubtitle;
3479 
3480 /**
3481  * If c is NULL, returns the first registered codec,
3482  * if c is non-NULL, returns the next registered codec after c,
3483  * or NULL if c is the last one.
3484  */
3485 AVCodec *av_codec_next(const AVCodec *c);
3486 
3487 /**
3488  * Return the LIBAVCODEC_VERSION_INT constant.
3489  */
3490 unsigned avcodec_version(void);
3491 
3492 /**
3493  * Return the libavcodec build-time configuration.
3494  */
3495 const char *avcodec_configuration(void);
3496 
3497 /**
3498  * Return the libavcodec license.
3499  */
3500 const char *avcodec_license(void);
3501 
3502 /**
3503  * Register the codec codec and initialize libavcodec.
3504  *
3505  * @warning either this function or avcodec_register_all() must be called
3506  * before any other libavcodec functions.
3507  *
3508  * @see avcodec_register_all()
3509  */
3510 void avcodec_register(AVCodec *codec);
3511 
3512 /**
3513  * Register all the codecs, parsers and bitstream filters which were enabled at
3514  * configuration time. If you do not call this function you can select exactly
3515  * which formats you want to support, by using the individual registration
3516  * functions.
3517  *
3518  * @see avcodec_register
3519  * @see av_register_codec_parser
3520  * @see av_register_bitstream_filter
3521  */
3522 void avcodec_register_all(void);
3523 
3524 /**
3525  * Allocate an AVCodecContext and set its fields to default values. The
3526  * resulting struct should be freed with avcodec_free_context().
3527  *
3528  * @param codec if non-NULL, allocate private data and initialize defaults
3529  * for the given codec. It is illegal to then call avcodec_open2()
3530  * with a different codec.
3531  * If NULL, then the codec-specific defaults won't be initialized,
3532  * which may result in suboptimal default settings (this is
3533  * important mainly for encoders, e.g. libx264).
3534  *
3535  * @return An AVCodecContext filled with default values or NULL on failure.
3536  * @see avcodec_get_context_defaults
3537  */
3539 
3540 /**
3541  * Free the codec context and everything associated with it and write NULL to
3542  * the provided pointer.
3543  */
3544 void avcodec_free_context(AVCodecContext **avctx);
3545 
3546 /**
3547  * Set the fields of the given AVCodecContext to default values corresponding
3548  * to the given codec (defaults may be codec-dependent).
3549  *
3550  * Do not call this function if a non-NULL codec has been passed
3551  * to avcodec_alloc_context3() that allocated this AVCodecContext.
3552  * If codec is non-NULL, it is illegal to call avcodec_open2() with a
3553  * different codec on this AVCodecContext.
3554  */
3556 
3557 /**
3558  * Get the AVClass for AVCodecContext. It can be used in combination with
3559  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
3560  *
3561  * @see av_opt_find().
3562  */
3563 const AVClass *avcodec_get_class(void);
3564 
3565 /**
3566  * Get the AVClass for AVFrame. It can be used in combination with
3567  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
3568  *
3569  * @see av_opt_find().
3570  */
3571 const AVClass *avcodec_get_frame_class(void);
3572 
3573 /**
3574  * Get the AVClass for AVSubtitleRect. It can be used in combination with
3575  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
3576  *
3577  * @see av_opt_find().
3578  */
3580 
3581 /**
3582  * Copy the settings of the source AVCodecContext into the destination
3583  * AVCodecContext. The resulting destination codec context will be
3584  * unopened, i.e. you are required to call avcodec_open2() before you
3585  * can use this AVCodecContext to decode/encode video/audio data.
3586  *
3587  * @param dest target codec context, should be initialized with
3588  * avcodec_alloc_context3(NULL), but otherwise uninitialized
3589  * @param src source codec context
3590  * @return AVERROR() on error (e.g. memory allocation error), 0 on success
3591  */
3593 
3594 #if FF_API_AVFRAME_LAVC
3595 /**
3596  * @deprecated use av_frame_alloc()
3597  */
3599 AVFrame *avcodec_alloc_frame(void);
3600 
3601 /**
3602  * Set the fields of the given AVFrame to default values.
3603  *
3604  * @param frame The AVFrame of which the fields should be set to default values.
3605  *
3606  * @deprecated use av_frame_unref()
3607  */
3609 void avcodec_get_frame_defaults(AVFrame *frame);
3610 
3611 /**
3612  * Free the frame and any dynamically allocated objects in it,
3613  * e.g. extended_data.
3614  *
3615  * @param frame frame to be freed. The pointer will be set to NULL.
3616  *
3617  * @warning this function does NOT free the data buffers themselves
3618  * (it does not know how, since they might have been allocated with
3619  * a custom get_buffer()).
3620  *
3621  * @deprecated use av_frame_free()
3622  */
3624 void avcodec_free_frame(AVFrame **frame);
3625 #endif
3626 
3627 /**
3628  * Initialize the AVCodecContext to use the given AVCodec. Prior to using this
3629  * function the context has to be allocated with avcodec_alloc_context3().
3630  *
3631  * The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(),
3632  * avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for
3633  * retrieving a codec.
3634  *
3635  * @warning This function is not thread safe!
3636  *
3637  * @code
3638  * avcodec_register_all();
3639  * av_dict_set(&opts, "b", "2.5M", 0);
3640  * codec = avcodec_find_decoder(AV_CODEC_ID_H264);
3641  * if (!codec)
3642  * exit(1);
3643  *
3644  * context = avcodec_alloc_context3(codec);
3645  *
3646  * if (avcodec_open2(context, codec, opts) < 0)
3647  * exit(1);
3648  * @endcode
3649  *
3650  * @param avctx The context to initialize.
3651  * @param codec The codec to open this context for. If a non-NULL codec has been
3652  * previously passed to avcodec_alloc_context3() or
3653  * avcodec_get_context_defaults3() for this context, then this
3654  * parameter MUST be either NULL or equal to the previously passed
3655  * codec.
3656  * @param options A dictionary filled with AVCodecContext and codec-private options.
3657  * On return this object will be filled with options that were not found.
3658  *
3659  * @return zero on success, a negative value on error
3660  * @see avcodec_alloc_context3(), avcodec_find_decoder(), avcodec_find_encoder(),
3661  * av_dict_set(), av_opt_find().
3662  */
3663 int avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options);
3664 
3665 /**
3666  * Close a given AVCodecContext and free all the data associated with it
3667  * (but not the AVCodecContext itself).
3668  *
3669  * Calling this function on an AVCodecContext that hasn't been opened will free
3670  * the codec-specific data allocated in avcodec_alloc_context3() /
3671  * avcodec_get_context_defaults3() with a non-NULL codec. Subsequent calls will
3672  * do nothing.
3673  */
3674 int avcodec_close(AVCodecContext *avctx);
3675 
3676 /**
3677  * Free all allocated data in the given subtitle struct.
3678  *
3679  * @param sub AVSubtitle to free.
3680  */
3681 void avsubtitle_free(AVSubtitle *sub);
3682 
3683 /**
3684  * @}
3685  */
3686 
3687 /**
3688  * @addtogroup lavc_packet
3689  * @{
3690  */
3691 
3692 #if FF_API_DESTRUCT_PACKET
3693 /**
3694  * Default packet destructor.
3695  * @deprecated use the AVBuffer API instead
3696  */
3699 #endif
3700 
3701 /**
3702  * Initialize optional fields of a packet with default values.
3703  *
3704  * Note, this does not touch the data and size members, which have to be
3705  * initialized separately.
3706  *
3707  * @param pkt packet
3708  */
3709 void av_init_packet(AVPacket *pkt);
3710 
3711 /**
3712  * Allocate the payload of a packet and initialize its fields with
3713  * default values.
3714  *
3715  * @param pkt packet
3716  * @param size wanted payload size
3717  * @return 0 if OK, AVERROR_xxx otherwise
3718  */
3719 int av_new_packet(AVPacket *pkt, int size);
3720 
3721 /**
3722  * Reduce packet size, correctly zeroing padding
3723  *
3724  * @param pkt packet
3725  * @param size new size
3726  */
3727 void av_shrink_packet(AVPacket *pkt, int size);
3728 
3729 /**
3730  * Increase packet size, correctly zeroing padding
3731  *
3732  * @param pkt packet
3733  * @param grow_by number of bytes by which to increase the size of the packet
3734  */
3735 int av_grow_packet(AVPacket *pkt, int grow_by);
3736 
3737 /**
3738  * Initialize a reference-counted packet from av_malloc()ed data.
3739  *
3740  * @param pkt packet to be initialized. This function will set the data, size,
3741  * buf and destruct fields, all others are left untouched.
3742  * @param data Data allocated by av_malloc() to be used as packet data. If this
3743  * function returns successfully, the data is owned by the underlying AVBuffer.
3744  * The caller may not access the data through other means.
3745  * @param size size of data in bytes, without the padding. I.e. the full buffer
3746  * size is assumed to be size + FF_INPUT_BUFFER_PADDING_SIZE.
3747  *
3748  * @return 0 on success, a negative AVERROR on error
3749  */
3751 
3752 /**
3753  * @warning This is a hack - the packet memory allocation stuff is broken. The
3754  * packet is allocated if it was not really allocated.
3755  */
3756 int av_dup_packet(AVPacket *pkt);
3757 
3758 /**
3759  * Copy packet, including contents
3760  *
3761  * @return 0 on success, negative AVERROR on fail
3762  */
3763 int av_copy_packet(AVPacket *dst, const AVPacket *src);
3764 
3765 /**
3766  * Copy packet side data
3767  *
3768  * @return 0 on success, negative AVERROR on fail
3769  */
3770 int av_copy_packet_side_data(AVPacket *dst, const AVPacket *src);
3771 
3772 /**
3773  * Free a packet.
3774  *
3775  * @param pkt packet to free
3776  */
3777 void av_free_packet(AVPacket *pkt);
3778 
3779 /**
3780  * Allocate new information of a packet.
3781  *
3782  * @param pkt packet
3783  * @param type side information type
3784  * @param size side information size
3785  * @return pointer to fresh allocated data or NULL otherwise
3786  */
3788  int size);
3789 
3790 /**
3791  * Shrink the already allocated side data buffer
3792  *
3793  * @param pkt packet
3794  * @param type side information type
3795  * @param size new side information size
3796  * @return 0 on success, < 0 on failure
3797  */
3799  int size);
3800 
3801 /**
3802  * Get side information from packet.
3803  *
3804  * @param pkt packet
3805  * @param type desired side information type
3806  * @param size pointer for side information size to store (optional)
3807  * @return pointer to data if present or NULL otherwise
3808  */
3810  int *size);
3811 
3813 
3815 
3816 /**
3817  * Pack a dictionary for use in side_data.
3818  *
3819  * @param dict The dictionary to pack.
3820  * @param size pointer to store the size of the returned data
3821  * @return pointer to data if successful, NULL otherwise
3822  */
3824 /**
3825  * Unpack a dictionary from side_data.
3826  *
3827  * @param data data from side_data
3828  * @param size size of the data
3829  * @param dict the metadata storage dictionary
3830  * @return 0 on success, < 0 on failure
3831  */
3832 int av_packet_unpack_dictionary(const uint8_t *data, int size, AVDictionary **dict);
3833 
3834 
3835 /**
3836  * Convenience function to free all the side data stored.
3837  * All the other fields stay untouched.
3838  *
3839  * @param pkt packet
3840  */
3842 
3843 /**
3844  * Setup a new reference to the data described by a given packet
3845  *
3846  * If src is reference-counted, setup dst as a new reference to the
3847  * buffer in src. Otherwise allocate a new buffer in dst and copy the
3848  * data from src into it.
3849  *
3850  * All the other fields are copied from src.
3851  *
3852  * @see av_packet_unref
3853  *
3854  * @param dst Destination packet
3855  * @param src Source packet
3856  *
3857  * @return 0 on success, a negative AVERROR on error.
3858  */
3859 int av_packet_ref(AVPacket *dst, const AVPacket *src);
3860 
3861 /**
3862  * Wipe the packet.
3863  *
3864  * Unreference the buffer referenced by the packet and reset the
3865  * remaining packet fields to their default values.
3866  *
3867  * @param pkt The packet to be unreferenced.
3868  */
3870 
3871 /**
3872  * Move every field in src to dst and reset src.
3873  *
3874  * @see av_packet_unref
3875  *
3876  * @param src Source packet, will be reset
3877  * @param dst Destination packet
3878  */
3880 
3881 /**
3882  * Copy only "properties" fields from src to dst.
3883  *
3884  * Properties for the purpose of this function are all the fields
3885  * beside those related to the packet data (buf, data, size)
3886  *
3887  * @param dst Destination packet
3888  * @param src Source packet
3889  *
3890  * @return 0 on success AVERROR on failure.
3891  *
3892  */
3893 int av_packet_copy_props(AVPacket *dst, const AVPacket *src);
3894 
3895 /**
3896  * Convert valid timing fields (timestamps / durations) in a packet from one
3897  * timebase to another. Timestamps with unknown values (AV_NOPTS_VALUE) will be
3898  * ignored.
3899  *
3900  * @param pkt packet on which the conversion will be performed
3901  * @param tb_src source timebase, in which the timing fields in pkt are
3902  * expressed
3903  * @param tb_dst destination timebase, to which the timing fields will be
3904  * converted
3905  */
3906 void av_packet_rescale_ts(AVPacket *pkt, AVRational tb_src, AVRational tb_dst);
3907 
3908 /**
3909  * @}
3910  */
3911 
3912 /**
3913  * @addtogroup lavc_decoding
3914  * @{
3915  */
3916 
3917 /**
3918  * Find a registered decoder with a matching codec ID.
3919  *
3920  * @param id AVCodecID of the requested decoder
3921  * @return A decoder if one was found, NULL otherwise.
3922  */
3924 
3925 /**
3926  * Find a registered decoder with the specified name.
3927  *
3928  * @param name name of the requested decoder
3929  * @return A decoder if one was found, NULL otherwise.
3930  */
3932 
3933 #if FF_API_GET_BUFFER
3937 #endif
3938 
3939 /**
3940  * The default callback for AVCodecContext.get_buffer2(). It is made public so
3941  * it can be called by custom get_buffer2() implementations for decoders without
3942  * CODEC_CAP_DR1 set.
3943  */
3945 
3946 #if FF_API_EMU_EDGE
3947 /**
3948  * Return the amount of padding in pixels which the get_buffer callback must
3949  * provide around the edge of the image for codecs which do not have the
3950  * CODEC_FLAG_EMU_EDGE flag.
3951  *
3952  * @return Required padding in pixels.
3953  *
3954  * @deprecated CODEC_FLAG_EMU_EDGE is deprecated, so this function is no longer
3955  * needed
3956  */
3958 unsigned avcodec_get_edge_width(void);
3959 #endif
3960 
3961 /**
3962  * Modify width and height values so that they will result in a memory
3963  * buffer that is acceptable for the codec if you do not use any horizontal
3964  * padding.
3965  *
3966  * May only be used if a codec with CODEC_CAP_DR1 has been opened.
3967  */
3969 
3970 /**
3971  * Modify width and height values so that they will result in a memory
3972  * buffer that is acceptable for the codec if you also ensure that all
3973  * line sizes are a multiple of the respective linesize_align[i].
3974  *
3975  * May only be used if a codec with CODEC_CAP_DR1 has been opened.
3976  */
3978  int linesize_align[AV_NUM_DATA_POINTERS]);
3979 
3980 /**
3981  * Converts AVChromaLocation to swscale x/y chroma position.
3982  *
3983  * The positions represent the chroma (0,0) position in a coordinates system
3984  * with luma (0,0) representing the origin and luma(1,1) representing 256,256
3985  *
3986  * @param xpos horizontal chroma sample position
3987  * @param ypos vertical chroma sample position
3988  */
3989 int avcodec_enum_to_chroma_pos(int *xpos, int *ypos, enum AVChromaLocation pos);
3990 
3991 /**
3992  * Converts swscale x/y chroma position to AVChromaLocation.
3993  *
3994  * The positions represent the chroma (0,0) position in a coordinates system
3995  * with luma (0,0) representing the origin and luma(1,1) representing 256,256
3996  *
3997  * @param xpos horizontal chroma sample position
3998  * @param ypos vertical chroma sample position
3999  */
4000 enum AVChromaLocation avcodec_chroma_pos_to_enum(int xpos, int ypos);
4001 
4002 #if FF_API_OLD_DECODE_AUDIO
4003 /**
4004  * Wrapper function which calls avcodec_decode_audio4.
4005  *
4006  * @deprecated Use avcodec_decode_audio4 instead.
4007  *
4008  * Decode the audio frame of size avpkt->size from avpkt->data into samples.
4009  * Some decoders may support multiple frames in a single AVPacket, such
4010  * decoders would then just decode the first frame. In this case,
4011  * avcodec_decode_audio3 has to be called again with an AVPacket that contains
4012  * the remaining data in order to decode the second frame etc.
4013  * If no frame
4014  * could be outputted, frame_size_ptr is zero. Otherwise, it is the
4015  * decompressed frame size in bytes.
4016  *
4017  * @warning You must set frame_size_ptr to the allocated size of the
4018  * output buffer before calling avcodec_decode_audio3().
4019  *
4020  * @warning The input buffer must be FF_INPUT_BUFFER_PADDING_SIZE larger than
4021  * the actual read bytes because some optimized bitstream readers read 32 or 64
4022  * bits at once and could read over the end.
4023  *
4024  * @warning The end of the input buffer avpkt->data should be set to 0 to ensure that
4025  * no overreading happens for damaged MPEG streams.
4026  *
4027  * @warning You must not provide a custom get_buffer() when using
4028  * avcodec_decode_audio3(). Doing so will override it with
4029  * avcodec_default_get_buffer. Use avcodec_decode_audio4() instead,
4030  * which does allow the application to provide a custom get_buffer().
4031  *
4032  * @note You might have to align the input buffer avpkt->data and output buffer
4033  * samples. The alignment requirements depend on the CPU: On some CPUs it isn't
4034  * necessary at all, on others it won't work at all if not aligned and on others
4035  * it will work but it will have an impact on performance.
4036  *
4037  * In practice, avpkt->data should have 4 byte alignment at minimum and
4038  * samples should be 16 byte aligned unless the CPU doesn't need it
4039  * (AltiVec and SSE do).
4040  *
4041  * @note Codecs which have the CODEC_CAP_DELAY capability set have a delay
4042  * between input and output, these need to be fed with avpkt->data=NULL,
4043  * avpkt->size=0 at the end to return the remaining frames.
4044  *
4045  * @param avctx the codec context
4046  * @param[out] samples the output buffer, sample type in avctx->sample_fmt
4047  * If the sample format is planar, each channel plane will
4048  * be the same size, with no padding between channels.
4049  * @param[in,out] frame_size_ptr the output buffer size in bytes
4050  * @param[in] avpkt The input AVPacket containing the input buffer.
4051  * You can create such packet with av_init_packet() and by then setting
4052  * data and size, some decoders might in addition need other fields.
4053  * All decoders are designed to use the least fields possible though.
4054  * @return On error a negative value is returned, otherwise the number of bytes
4055  * used or zero if no frame data was decompressed (used) from the input AVPacket.
4056  */
4057 attribute_deprecated int avcodec_decode_audio3(AVCodecContext *avctx, int16_t *samples,
4058  int *frame_size_ptr,
4059  AVPacket *avpkt);
4060 #endif
4061 
4062 /**
4063  * Decode the audio frame of size avpkt->size from avpkt->data into frame.
4064  *
4065  * Some decoders may support multiple frames in a single AVPacket. Such
4066  * decoders would then just decode the first frame and the return value would be
4067  * less than the packet size. In this case, avcodec_decode_audio4 has to be
4068  * called again with an AVPacket containing the remaining data in order to
4069  * decode the second frame, etc... Even if no frames are returned, the packet
4070  * needs to be fed to the decoder with remaining data until it is completely
4071  * consumed or an error occurs.
4072  *
4073  * Some decoders (those marked with CODEC_CAP_DELAY) have a delay between input
4074  * and output. This means that for some packets they will not immediately
4075  * produce decoded output and need to be flushed at the end of decoding to get
4076  * all the decoded data. Flushing is done by calling this function with packets
4077  * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
4078  * returning samples. It is safe to flush even those decoders that are not
4079  * marked with CODEC_CAP_DELAY, then no samples will be returned.
4080  *
4081  * @warning The input buffer, avpkt->data must be FF_INPUT_BUFFER_PADDING_SIZE
4082  * larger than the actual read bytes because some optimized bitstream
4083  * readers read 32 or 64 bits at once and could read over the end.
4084  *
4085  * @param avctx the codec context
4086  * @param[out] frame The AVFrame in which to store decoded audio samples.
4087  * The decoder will allocate a buffer for the decoded frame by
4088  * calling the AVCodecContext.get_buffer2() callback.
4089  * When AVCodecContext.refcounted_frames is set to 1, the frame is
4090  * reference counted and the returned reference belongs to the
4091  * caller. The caller must release the frame using av_frame_unref()
4092  * when the frame is no longer needed. The caller may safely write
4093  * to the frame if av_frame_is_writable() returns 1.
4094  * When AVCodecContext.refcounted_frames is set to 0, the returned
4095  * reference belongs to the decoder and is valid only until the
4096  * next call to this function or until closing or flushing the
4097  * decoder. The caller may not write to it.
4098  * @param[out] got_frame_ptr Zero if no frame could be decoded, otherwise it is
4099  * non-zero. Note that this field being set to zero
4100  * does not mean that an error has occurred. For
4101  * decoders with CODEC_CAP_DELAY set, no given decode
4102  * call is guaranteed to produce a frame.
4103  * @param[in] avpkt The input AVPacket containing the input buffer.
4104  * At least avpkt->data and avpkt->size should be set. Some
4105  * decoders might also require additional fields to be set.
4106  * @return A negative error code is returned if an error occurred during
4107  * decoding, otherwise the number of bytes consumed from the input
4108  * AVPacket is returned.
4109  */
4111  int *got_frame_ptr, const AVPacket *avpkt);
4112 
4113 /**
4114  * Decode the video frame of size avpkt->size from avpkt->data into picture.
4115  * Some decoders may support multiple frames in a single AVPacket, such
4116  * decoders would then just decode the first frame.
4117  *
4118  * @warning The input buffer must be FF_INPUT_BUFFER_PADDING_SIZE larger than
4119  * the actual read bytes because some optimized bitstream readers read 32 or 64
4120  * bits at once and could read over the end.
4121  *
4122  * @warning The end of the input buffer buf should be set to 0 to ensure that
4123  * no overreading happens for damaged MPEG streams.
4124  *
4125  * @note Codecs which have the CODEC_CAP_DELAY capability set have a delay
4126  * between input and output, these need to be fed with avpkt->data=NULL,
4127  * avpkt->size=0 at the end to return the remaining frames.
4128  *
4129  * @param avctx the codec context
4130  * @param[out] picture The AVFrame in which the decoded video frame will be stored.
4131  * Use av_frame_alloc() to get an AVFrame. The codec will
4132  * allocate memory for the actual bitmap by calling the
4133  * AVCodecContext.get_buffer2() callback.
4134  * When AVCodecContext.refcounted_frames is set to 1, the frame is
4135  * reference counted and the returned reference belongs to the
4136  * caller. The caller must release the frame using av_frame_unref()
4137  * when the frame is no longer needed. The caller may safely write
4138  * to the frame if av_frame_is_writable() returns 1.
4139  * When AVCodecContext.refcounted_frames is set to 0, the returned
4140  * reference belongs to the decoder and is valid only until the
4141  * next call to this function or until closing or flushing the
4142  * decoder. The caller may not write to it.
4143  *
4144  * @param[in] avpkt The input AVPacket containing the input buffer.
4145  * You can create such packet with av_init_packet() and by then setting
4146  * data and size, some decoders might in addition need other fields like
4147  * flags&AV_PKT_FLAG_KEY. All decoders are designed to use the least
4148  * fields possible.
4149  * @param[in,out] got_picture_ptr Zero if no frame could be decompressed, otherwise, it is nonzero.
4150  * @return On error a negative value is returned, otherwise the number of bytes
4151  * used or zero if no frame could be decompressed.
4152  */
4153 int avcodec_decode_video2(AVCodecContext *avctx, AVFrame *picture,
4154  int *got_picture_ptr,
4155  const AVPacket *avpkt);
4156 
4157 /**
4158  * Decode a subtitle message.
4159  * Return a negative value on error, otherwise return the number of bytes used.
4160  * If no subtitle could be decompressed, got_sub_ptr is zero.
4161  * Otherwise, the subtitle is stored in *sub.
4162  * Note that CODEC_CAP_DR1 is not available for subtitle codecs. This is for
4163  * simplicity, because the performance difference is expect to be negligible
4164  * and reusing a get_buffer written for video codecs would probably perform badly
4165  * due to a potentially very different allocation pattern.
4166  *
4167  * Some decoders (those marked with CODEC_CAP_DELAY) have a delay between input
4168  * and output. This means that for some packets they will not immediately
4169  * produce decoded output and need to be flushed at the end of decoding to get
4170  * all the decoded data. Flushing is done by calling this function with packets
4171  * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
4172  * returning subtitles. It is safe to flush even those decoders that are not
4173  * marked with CODEC_CAP_DELAY, then no subtitles will be returned.
4174  *
4175  * @param avctx the codec context
4176  * @param[out] sub The Preallocated AVSubtitle in which the decoded subtitle will be stored,
4177  * must be freed with avsubtitle_free if *got_sub_ptr is set.
4178  * @param[in,out] got_sub_ptr Zero if no subtitle could be decompressed, otherwise, it is nonzero.
4179  * @param[in] avpkt The input AVPacket containing the input buffer.
4180  */
4182  int *got_sub_ptr,
4183  AVPacket *avpkt);
4184 
4185 /**
4186  * @defgroup lavc_parsing Frame parsing
4187  * @{
4188  */
4192  AV_PICTURE_STRUCTURE_TOP_FIELD, //< coded as top field
4193  AV_PICTURE_STRUCTURE_BOTTOM_FIELD, //< coded as bottom field
4194  AV_PICTURE_STRUCTURE_FRAME, //< coded as frame
4195 };
4197 typedef struct AVCodecParserContext {
4198  void *priv_data;
4200  int64_t frame_offset; /* offset of the current frame */
4201  int64_t cur_offset; /* current offset
4202  (incremented by each av_parser_parse()) */
4203  int64_t next_frame_offset; /* offset of the next frame */
4204  /* video info */
4205  int pict_type; /* XXX: Put it back in AVCodecContext. */
4206  /**
4207  * This field is used for proper frame duration computation in lavf.
4208  * It signals, how much longer the frame duration of the current frame
4209  * is compared to normal frame duration.
4210  *
4211  * frame_duration = (1 + repeat_pict) * time_base
4212  *
4213  * It is used by codecs like H.264 to display telecined material.
4214  */
4215  int repeat_pict; /* XXX: Put it back in AVCodecContext. */
4216  int64_t pts; /* pts of the current frame */
4217  int64_t dts; /* dts of the current frame */
4218 
4219  /* private data */
4220  int64_t last_pts;
4221  int64_t last_dts;
4222  int fetch_timestamp;
4224 #define AV_PARSER_PTS_NB 4
4230  int flags;
4231 #define PARSER_FLAG_COMPLETE_FRAMES 0x0001
4232 #define PARSER_FLAG_ONCE 0x0002
4233 /// Set if the parser has a valid file offset
4234 #define PARSER_FLAG_FETCHED_OFFSET 0x0004
4235 #define PARSER_FLAG_USE_CODEC_TS 0x1000
4237  int64_t offset; ///< byte offset from starting packet start
4239 
4240  /**
4241  * Set by parser to 1 for key frames and 0 for non-key frames.
4242  * It is initialized to -1, so if the parser doesn't set this flag,
4243  * old-style fallback using AV_PICTURE_TYPE_I picture type as key frames
4244  * will be used.
4245  */
4246  int key_frame;
4247 
4248  /**
4249  * Time difference in stream time base units from the pts of this
4250  * packet to the point at which the output from the decoder has converged
4251  * independent from the availability of previous frames. That is, the
4252  * frames are virtually identical no matter if decoding started from
4253  * the very first frame or from this keyframe.
4254  * Is AV_NOPTS_VALUE if unknown.
4255  * This field is not the display duration of the current frame.
4256  * This field has no meaning if the packet does not have AV_PKT_FLAG_KEY
4257  * set.
4258  *
4259  * The purpose of this field is to allow seeking in streams that have no
4260  * keyframes in the conventional sense. It corresponds to the
4261  * recovery point SEI in H.264 and match_time_delta in NUT. It is also
4262  * essential for some types of subtitle streams to ensure that all
4263  * subtitles are correctly displayed after seeking.
4264  */
4265  int64_t convergence_duration;
4266 
4267  // Timestamp generation support:
4268  /**
4269  * Synchronization point for start of timestamp generation.
4270  *
4271  * Set to >0 for sync point, 0 for no sync point and <0 for undefined
4272  * (default).
4273  *
4274  * For example, this corresponds to presence of H.264 buffering period
4275  * SEI message.
4276  */
4277  int dts_sync_point;
4278 
4279  /**
4280  * Offset of the current timestamp against last timestamp sync point in
4281  * units of AVCodecContext.time_base.
4282  *
4283  * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
4284  * contain a valid timestamp offset.
4285  *
4286  * Note that the timestamp of sync point has usually a nonzero
4287  * dts_ref_dts_delta, which refers to the previous sync point. Offset of
4288  * the next frame after timestamp sync point will be usually 1.
4289  *
4290  * For example, this corresponds to H.264 cpb_removal_delay.
4291  */
4292  int dts_ref_dts_delta;
4293 
4294  /**
4295  * Presentation delay of current frame in units of AVCodecContext.time_base.
4296  *
4297  * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
4298  * contain valid non-negative timestamp delta (presentation time of a frame
4299  * must not lie in the past).
4300  *
4301  * This delay represents the difference between decoding and presentation
4302  * time of the frame.
4303  *
4304  * For example, this corresponds to H.264 dpb_output_delay.
4305  */
4306  int pts_dts_delta;
4307 
4308  /**
4309  * Position of the packet in file.
4310  *
4311  * Analogous to cur_frame_pts/dts
4312  */
4314 
4315  /**
4316  * Byte position of currently parsed frame in stream.
4317  */
4318  int64_t pos;
4319 
4320  /**
4321  * Previous frame byte position.
4322  */
4323  int64_t last_pos;
4324 
4325  /**
4326  * Duration of the current frame.
4327  * For audio, this is in units of 1 / AVCodecContext.sample_rate.
4328  * For all other types, this is in units of AVCodecContext.time_base.
4329  */
4330  int duration;
4333 
4334  /**
4335  * Indicate whether a picture is coded as a frame, top field or bottom field.
4336  *
4337  * For example, H.264 field_pic_flag equal to 0 corresponds to
4338  * AV_PICTURE_STRUCTURE_FRAME. An H.264 picture with field_pic_flag
4339  * equal to 1 and bottom_field_flag equal to 0 corresponds to
4340  * AV_PICTURE_STRUCTURE_TOP_FIELD.
4341  */
4343 
4344  /**
4345  * Picture number incremented in presentation or output order.
4346  * This field may be reinitialized at the first picture of a new sequence.
4347  *
4348  * For example, this corresponds to H.264 PicOrderCnt.
4349  */
4353 typedef struct AVCodecParser {
4354  int codec_ids[5]; /* several codec IDs are permitted */
4358  AVCodecContext *avctx,
4359  const uint8_t **poutbuf, int *poutbuf_size,
4360  const uint8_t *buf, int buf_size);
4362  int (*split)(AVCodecContext *avctx, const uint8_t *buf, int buf_size);
4363  struct AVCodecParser *next;
4364 } AVCodecParser;
4365 
4367 
4370 
4371 /**
4372  * Parse a packet.
4373  *
4374  * @param s parser context.
4375  * @param avctx codec context.
4376  * @param poutbuf set to pointer to parsed buffer or NULL if not yet finished.
4377  * @param poutbuf_size set to size of parsed buffer or zero if not yet finished.
4378  * @param buf input buffer.
4379  * @param buf_size input length, to signal EOF, this should be 0 (so that the last frame can be output).
4380  * @param pts input presentation timestamp.
4381  * @param dts input decoding timestamp.
4382  * @param pos input byte position in stream.
4383  * @return the number of bytes of the input bitstream used.
4384  *
4385  * Example:
4386  * @code
4387  * while(in_len){
4388  * len = av_parser_parse2(myparser, AVCodecContext, &data, &size,
4389  * in_data, in_len,
4390  * pts, dts, pos);
4391  * in_data += len;
4392  * in_len -= len;
4393  *
4394  * if(size)
4395  * decode_frame(data, size);
4396  * }
4397  * @endcode
4398  */
4400  AVCodecContext *avctx,
4401  uint8_t **poutbuf, int *poutbuf_size,
4402  const uint8_t *buf, int buf_size,
4403  int64_t pts, int64_t dts,
4404  int64_t pos);
4405 
4406 /**
4407  * @return 0 if the output buffer is a subset of the input, 1 if it is allocated and must be freed
4408  * @deprecated use AVBitStreamFilter
4409  */
4411  AVCodecContext *avctx,
4412  uint8_t **poutbuf, int *poutbuf_size,
4413  const uint8_t *buf, int buf_size, int keyframe);
4415 
4416 /**
4417  * @}
4418  * @}
4419  */
4420 
4421 /**
4422  * @addtogroup lavc_encoding
4423  * @{
4424  */
4425 
4426 /**
4427  * Find a registered encoder with a matching codec ID.
4428  *
4429  * @param id AVCodecID of the requested encoder
4430  * @return An encoder if one was found, NULL otherwise.
4431  */
4433 
4434 /**
4435  * Find a registered encoder with the specified name.
4436  *
4437  * @param name name of the requested encoder
4438  * @return An encoder if one was found, NULL otherwise.
4439  */
4441 
4442 #if FF_API_OLD_ENCODE_AUDIO
4443 /**
4444  * Encode an audio frame from samples into buf.
4445  *
4446  * @deprecated Use avcodec_encode_audio2 instead.
4447  *
4448  * @note The output buffer should be at least FF_MIN_BUFFER_SIZE bytes large.
4449  * However, for codecs with avctx->frame_size equal to 0 (e.g. PCM) the user
4450  * will know how much space is needed because it depends on the value passed
4451  * in buf_size as described below. In that case a lower value can be used.
4452  *
4453  * @param avctx the codec context
4454  * @param[out] buf the output buffer
4455  * @param[in] buf_size the output buffer size
4456  * @param[in] samples the input buffer containing the samples
4457  * The number of samples read from this buffer is frame_size*channels,
4458  * both of which are defined in avctx.
4459  * For codecs which have avctx->frame_size equal to 0 (e.g. PCM) the number of
4460  * samples read from samples is equal to:
4461  * buf_size * 8 / (avctx->channels * av_get_bits_per_sample(avctx->codec_id))
4462  * This also implies that av_get_bits_per_sample() must not return 0 for these
4463  * codecs.
4464  * @return On error a negative value is returned, on success zero or the number
4465  * of bytes used to encode the data read from the input buffer.
4466  */
4468  uint8_t *buf, int buf_size,
4469  const short *samples);
4470 #endif
4471 
4472 /**
4473  * Encode a frame of audio.
4474  *
4475  * Takes input samples from frame and writes the next output packet, if
4476  * available, to avpkt. The output packet does not necessarily contain data for
4477  * the most recent frame, as encoders can delay, split, and combine input frames
4478  * internally as needed.
4479  *
4480  * @param avctx codec context
4481  * @param avpkt output AVPacket.
4482  * The user can supply an output buffer by setting
4483  * avpkt->data and avpkt->size prior to calling the
4484  * function, but if the size of the user-provided data is not
4485  * large enough, encoding will fail. If avpkt->data and
4486  * avpkt->size are set, avpkt->destruct must also be set. All
4487  * other AVPacket fields will be reset by the encoder using
4488  * av_init_packet(). If avpkt->data is NULL, the encoder will
4489  * allocate it. The encoder will set avpkt->size to the size
4490  * of the output packet.
4491  *
4492  * If this function fails or produces no output, avpkt will be
4493  * freed using av_free_packet() (i.e. avpkt->destruct will be
4494  * called to free the user supplied buffer).
4495  * @param[in] frame AVFrame containing the raw audio data to be encoded.
4496  * May be NULL when flushing an encoder that has the
4497  * CODEC_CAP_DELAY capability set.
4498  * If CODEC_CAP_VARIABLE_FRAME_SIZE is set, then each frame
4499  * can have any number of samples.
4500  * If it is not set, frame->nb_samples must be equal to
4501  * avctx->frame_size for all frames except the last.
4502  * The final frame may be smaller than avctx->frame_size.
4503  * @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
4504  * output packet is non-empty, and to 0 if it is
4505  * empty. If the function returns an error, the
4506  * packet can be assumed to be invalid, and the
4507  * value of got_packet_ptr is undefined and should
4508  * not be used.
4509  * @return 0 on success, negative error code on failure
4510  */
4511 int avcodec_encode_audio2(AVCodecContext *avctx, AVPacket *avpkt,
4512  const AVFrame *frame, int *got_packet_ptr);
4513 
4514 #if FF_API_OLD_ENCODE_VIDEO
4515 /**
4516  * @deprecated use avcodec_encode_video2() instead.
4517  *
4518  * Encode a video frame from pict into buf.
4519  * The input picture should be
4520  * stored using a specific format, namely avctx.pix_fmt.
4521  *
4522  * @param avctx the codec context
4523  * @param[out] buf the output buffer for the bitstream of encoded frame
4524  * @param[in] buf_size the size of the output buffer in bytes
4525  * @param[in] pict the input picture to encode
4526  * @return On error a negative value is returned, on success zero or the number
4527  * of bytes used from the output buffer.
4528  */
4530 int avcodec_encode_video(AVCodecContext *avctx, uint8_t *buf, int buf_size,
4531  const AVFrame *pict);
4532 #endif
4533 
4534 /**
4535  * Encode a frame of video.
4536  *
4537  * Takes input raw video data from frame and writes the next output packet, if
4538  * available, to avpkt. The output packet does not necessarily contain data for
4539  * the most recent frame, as encoders can delay and reorder input frames
4540  * internally as needed.
4541  *
4542  * @param avctx codec context
4543  * @param avpkt output AVPacket.
4544  * The user can supply an output buffer by setting
4545  * avpkt->data and avpkt->size prior to calling the
4546  * function, but if the size of the user-provided data is not
4547  * large enough, encoding will fail. All other AVPacket fields
4548  * will be reset by the encoder using av_init_packet(). If
4549  * avpkt->data is NULL, the encoder will allocate it.
4550  * The encoder will set avpkt->size to the size of the
4551  * output packet. The returned data (if any) belongs to the
4552  * caller, he is responsible for freeing it.
4553  *
4554  * If this function fails or produces no output, avpkt will be
4555  * freed using av_free_packet() (i.e. avpkt->destruct will be
4556  * called to free the user supplied buffer).
4557  * @param[in] frame AVFrame containing the raw video data to be encoded.
4558  * May be NULL when flushing an encoder that has the
4559  * CODEC_CAP_DELAY capability set.
4560  * @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
4561  * output packet is non-empty, and to 0 if it is
4562  * empty. If the function returns an error, the
4563  * packet can be assumed to be invalid, and the
4564  * value of got_packet_ptr is undefined and should
4565  * not be used.
4566  * @return 0 on success, negative error code on failure
4567  */
4568 int avcodec_encode_video2(AVCodecContext *avctx, AVPacket *avpkt,
4569  const AVFrame *frame, int *got_packet_ptr);
4570 
4571 int avcodec_encode_subtitle(AVCodecContext *avctx, uint8_t *buf, int buf_size,
4572  const AVSubtitle *sub);
4573 
4574 
4575 /**
4576  * @}
4577  */
4578 
4579 #if FF_API_AVCODEC_RESAMPLE
4580 /**
4581  * @defgroup lavc_resample Audio resampling
4582  * @ingroup libavc
4583  * @deprecated use libswresample instead
4584  *
4585  * @{
4586  */
4587 struct ReSampleContext;
4588 struct AVResampleContext;
4589 
4590 typedef struct ReSampleContext ReSampleContext;
4591 
4592 /**
4593  * Initialize audio resampling context.
4594  *
4595  * @param output_channels number of output channels
4596  * @param input_channels number of input channels
4597  * @param output_rate output sample rate
4598  * @param input_rate input sample rate
4599  * @param sample_fmt_out requested output sample format
4600  * @param sample_fmt_in input sample format
4601  * @param filter_length length of each FIR filter in the filterbank relative to the cutoff frequency
4602  * @param log2_phase_count log2 of the number of entries in the polyphase filterbank
4603  * @param linear if 1 then the used FIR filter will be linearly interpolated
4604  between the 2 closest, if 0 the closest will be used
4605  * @param cutoff cutoff frequency, 1.0 corresponds to half the output sampling rate
4606  * @return allocated ReSampleContext, NULL if error occurred
4607  */
4610  int output_rate, int input_rate,
4611  enum AVSampleFormat sample_fmt_out,
4612  enum AVSampleFormat sample_fmt_in,
4613  int filter_length, int log2_phase_count,
4614  int linear, double cutoff);
4615 
4617 int audio_resample(ReSampleContext *s, short *output, short *input, int nb_samples);
4618 
4619 /**
4620  * Free resample context.
4621  *
4622  * @param s a non-NULL pointer to a resample context previously
4623  * created with av_audio_resample_init()
4624  */
4627 
4628 
4629 /**
4630  * Initialize an audio resampler.
4631  * Note, if either rate is not an integer then simply scale both rates up so they are.
4632  * @param filter_length length of each FIR filter in the filterbank relative to the cutoff freq
4633  * @param log2_phase_count log2 of the number of entries in the polyphase filterbank
4634  * @param linear If 1 then the used FIR filter will be linearly interpolated
4635  between the 2 closest, if 0 the closest will be used
4636  * @param cutoff cutoff frequency, 1.0 corresponds to half the output sampling rate
4637  */
4639 struct AVResampleContext *av_resample_init(int out_rate, int in_rate, int filter_length, int log2_phase_count, int linear, double cutoff);
4640 
4641 /**
4642  * Resample an array of samples using a previously configured context.
4643  * @param src an array of unconsumed samples
4644  * @param consumed the number of samples of src which have been consumed are returned here
4645  * @param src_size the number of unconsumed samples available
4646  * @param dst_size the amount of space in samples available in dst
4647  * @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.
4648  * @return the number of samples written in dst or -1 if an error occurred
4649  */
4651 int av_resample(struct AVResampleContext *c, short *dst, short *src, int *consumed, int src_size, int dst_size, int update_ctx);
4652 
4653 
4654 /**
4655  * Compensate samplerate/timestamp drift. The compensation is done by changing
4656  * the resampler parameters, so no audible clicks or similar distortions occur
4657  * @param compensation_distance distance in output samples over which the compensation should be performed
4658  * @param sample_delta number of output samples which should be output less
4659  *
4660  * example: av_resample_compensate(c, 10, 500)
4661  * here instead of 510 samples only 500 samples would be output
4662  *
4663  * note, due to rounding the actual compensation might be slightly different,
4664  * especially if the compensation_distance is large and the in_rate used during init is small
4665  */
4667 void av_resample_compensate(struct AVResampleContext *c, int sample_delta, int compensation_distance);
4669 void av_resample_close(struct AVResampleContext *c);
4670 
4671 /**
4672  * @}
4673  */
4674 #endif
4675 
4676 /**
4677  * @addtogroup lavc_picture
4678  * @{
4679  */
4680 
4681 /**
4682  * Allocate memory for the pixels of a picture and setup the AVPicture
4683  * fields for it.
4684  *
4685  * Call avpicture_free() to free it.
4686  *
4687  * @param picture the picture structure to be filled in
4688  * @param pix_fmt the pixel format of the picture
4689  * @param width the width of the picture
4690  * @param height the height of the picture
4691  * @return zero if successful, a negative error code otherwise
4692  *
4693  * @see av_image_alloc(), avpicture_fill()
4694  */
4695 int avpicture_alloc(AVPicture *picture, enum AVPixelFormat pix_fmt, int width, int height);
4696 
4697 /**
4698  * Free a picture previously allocated by avpicture_alloc().
4699  * The data buffer used by the AVPicture is freed, but the AVPicture structure
4700  * itself is not.
4701  *
4702  * @param picture the AVPicture to be freed
4703  */
4704 void avpicture_free(AVPicture *picture);
4705 
4706 /**
4707  * Setup the picture fields based on the specified image parameters
4708  * and the provided image data buffer.
4709  *
4710  * The picture fields are filled in by using the image data buffer
4711  * pointed to by ptr.
4712  *
4713  * If ptr is NULL, the function will fill only the picture linesize
4714  * array and return the required size for the image buffer.
4715  *
4716  * To allocate an image buffer and fill the picture data in one call,
4717  * use avpicture_alloc().
4718  *
4719  * @param picture the picture to be filled in
4720  * @param ptr buffer where the image data is stored, or NULL
4721  * @param pix_fmt the pixel format of the image
4722  * @param width the width of the image in pixels
4723  * @param height the height of the image in pixels
4724  * @return the size in bytes required for src, a negative error code
4725  * in case of failure
4726  *
4727  * @see av_image_fill_arrays()
4728  */
4729 int avpicture_fill(AVPicture *picture, const uint8_t *ptr,
4730  enum AVPixelFormat pix_fmt, int width, int height);
4731 
4732 /**
4733  * Copy pixel data from an AVPicture into a buffer.
4734  *
4735  * avpicture_get_size() can be used to compute the required size for
4736  * the buffer to fill.
4737  *
4738  * @param src source picture with filled data
4739  * @param pix_fmt picture pixel format
4740  * @param width picture width
4741  * @param height picture height
4742  * @param dest destination buffer
4743  * @param dest_size destination buffer size in bytes
4744  * @return the number of bytes written to dest, or a negative value
4745  * (error code) on error, for example if the destination buffer is not
4746  * big enough
4747  *
4748  * @see av_image_copy_to_buffer()
4749  */
4751  int width, int height,
4752  unsigned char *dest, int dest_size);
4753 
4754 /**
4755  * Calculate the size in bytes that a picture of the given width and height
4756  * would occupy if stored in the given picture format.
4757  *
4758  * @param pix_fmt picture pixel format
4759  * @param width picture width
4760  * @param height picture height
4761  * @return the computed picture buffer size or a negative error code
4762  * in case of error
4763  *
4764  * @see av_image_get_buffer_size().
4765  */
4767 
4768 #if FF_API_DEINTERLACE
4769 /**
4770  * deinterlace - if not supported return -1
4771  *
4772  * @deprecated - use yadif (in libavfilter) instead
4773  */
4775 int avpicture_deinterlace(AVPicture *dst, const AVPicture *src,
4776  enum AVPixelFormat pix_fmt, int width, int height);
4777 #endif
4778 /**
4779  * Copy image src to dst. Wraps av_image_copy().
4780  */
4781 void av_picture_copy(AVPicture *dst, const AVPicture *src,
4782  enum AVPixelFormat pix_fmt, int width, int height);
4783 
4784 /**
4785  * Crop image top and left side.
4786  */
4787 int av_picture_crop(AVPicture *dst, const AVPicture *src,
4788  enum AVPixelFormat pix_fmt, int top_band, int left_band);
4789 
4790 /**
4791  * Pad image.
4792  */
4793 int av_picture_pad(AVPicture *dst, const AVPicture *src, int height, int width, enum AVPixelFormat pix_fmt,
4794  int padtop, int padbottom, int padleft, int padright, int *color);
4795 
4796 /**
4797  * @}
4798  */
4799 
4800 /**
4801  * @defgroup lavc_misc Utility functions
4802  * @ingroup libavc
4803  *
4804  * Miscellaneous utility functions related to both encoding and decoding
4805  * (or neither).
4806  * @{
4807  */
4808 
4809 /**
4810  * @defgroup lavc_misc_pixfmt Pixel formats
4811  *
4812  * Functions for working with pixel formats.
4813  * @{
4814  */
4815 
4816 /**
4817  * Utility function to access log2_chroma_w log2_chroma_h from
4818  * the pixel format AVPixFmtDescriptor.
4819  *
4820  * This function asserts that pix_fmt is valid. See av_pix_fmt_get_chroma_sub_sample
4821  * for one that returns a failure code and continues in case of invalid
4822  * pix_fmts.
4823  *
4824  * @param[in] pix_fmt the pixel format
4825  * @param[out] h_shift store log2_chroma_w
4826  * @param[out] v_shift store log2_chroma_h
4827  *
4828  * @see av_pix_fmt_get_chroma_sub_sample
4829  */
4830 
4831 void avcodec_get_chroma_sub_sample(enum AVPixelFormat pix_fmt, int *h_shift, int *v_shift);
4832 
4833 /**
4834  * Return a value representing the fourCC code associated to the
4835  * pixel format pix_fmt, or 0 if no associated fourCC code can be
4836  * found.
4837  */
4839 
4840 /**
4841  * @deprecated see av_get_pix_fmt_loss()
4842  */
4843