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avcodec.h
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1 /*
2  * copyright (c) 2001 Fabrice Bellard
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #ifndef AVCODEC_AVCODEC_H
22 #define AVCODEC_AVCODEC_H
23 
24 /**
25  * @file
26  * @ingroup libavc
27  * Libavcodec external API header
28  */
29 
30 #include <errno.h>
31 #include "libavutil/samplefmt.h"
32 #include "libavutil/avutil.h"
33 #include "libavutil/buffer.h"
34 #include "libavutil/cpu.h"
36 #include "libavutil/dict.h"
37 #include "libavutil/frame.h"
38 #include "libavutil/log.h"
39 #include "libavutil/pixfmt.h"
40 #include "libavutil/rational.h"
41 
42 #include "libavcodec/version.h"
43 /**
44  * @defgroup libavc Encoding/Decoding Library
45  * @{
46  *
47  * @defgroup lavc_decoding Decoding
48  * @{
49  * @}
50  *
51  * @defgroup lavc_encoding Encoding
52  * @{
53  * @}
54  *
55  * @defgroup lavc_codec Codecs
56  * @{
57  * @defgroup lavc_codec_native Native Codecs
58  * @{
59  * @}
60  * @defgroup lavc_codec_wrappers External library wrappers
61  * @{
62  * @}
63  * @defgroup lavc_codec_hwaccel Hardware Accelerators bridge
64  * @{
65  * @}
66  * @}
67  * @defgroup lavc_internal Internal
68  * @{
69  * @}
70  * @}
71  *
72  */
73 
74 /**
75  * @defgroup lavc_core Core functions/structures.
76  * @ingroup libavc
77  *
78  * Basic definitions, functions for querying libavcodec capabilities,
79  * allocating core structures, etc.
80  * @{
81  */
82 
83 
84 /**
85  * Identify the syntax and semantics of the bitstream.
86  * The principle is roughly:
87  * Two decoders with the same ID can decode the same streams.
88  * Two encoders with the same ID can encode compatible streams.
89  * There may be slight deviations from the principle due to implementation
90  * details.
91  *
92  * If you add a codec ID to this list, add it so that
93  * 1. no value of a existing codec ID changes (that would break ABI),
94  * 2. Give it a value which when taken as ASCII is recognized uniquely by a human as this specific codec.
95  * This ensures that 2 forks can independently add AVCodecIDs without producing conflicts.
96  *
97  * After adding new codec IDs, do not forget to add an entry to the codec
98  * descriptor list and bump libavcodec minor version.
99  */
100 enum AVCodecID {
102 
103  /* video codecs */
105  AV_CODEC_ID_MPEG2VIDEO, ///< preferred ID for MPEG-1/2 video decoding
276 
277  AV_CODEC_ID_BRENDER_PIX= MKBETAG('B','P','I','X'),
278  AV_CODEC_ID_Y41P = MKBETAG('Y','4','1','P'),
279  AV_CODEC_ID_ESCAPE130 = MKBETAG('E','1','3','0'),
280  AV_CODEC_ID_EXR = MKBETAG('0','E','X','R'),
281  AV_CODEC_ID_AVRP = MKBETAG('A','V','R','P'),
282 
283  AV_CODEC_ID_012V = MKBETAG('0','1','2','V'),
284  AV_CODEC_ID_G2M = MKBETAG( 0 ,'G','2','M'),
285  AV_CODEC_ID_AVUI = MKBETAG('A','V','U','I'),
286  AV_CODEC_ID_AYUV = MKBETAG('A','Y','U','V'),
287  AV_CODEC_ID_TARGA_Y216 = MKBETAG('T','2','1','6'),
288  AV_CODEC_ID_V308 = MKBETAG('V','3','0','8'),
289  AV_CODEC_ID_V408 = MKBETAG('V','4','0','8'),
290  AV_CODEC_ID_YUV4 = MKBETAG('Y','U','V','4'),
291  AV_CODEC_ID_SANM = MKBETAG('S','A','N','M'),
292  AV_CODEC_ID_PAF_VIDEO = MKBETAG('P','A','F','V'),
293  AV_CODEC_ID_AVRN = MKBETAG('A','V','R','n'),
294  AV_CODEC_ID_CPIA = MKBETAG('C','P','I','A'),
295  AV_CODEC_ID_XFACE = MKBETAG('X','F','A','C'),
296  AV_CODEC_ID_SGIRLE = MKBETAG('S','G','I','R'),
297  AV_CODEC_ID_MVC1 = MKBETAG('M','V','C','1'),
298  AV_CODEC_ID_MVC2 = MKBETAG('M','V','C','2'),
299  AV_CODEC_ID_SNOW = MKBETAG('S','N','O','W'),
300  AV_CODEC_ID_WEBP = MKBETAG('W','E','B','P'),
301  AV_CODEC_ID_SMVJPEG = MKBETAG('S','M','V','J'),
302 
303  /* various PCM "codecs" */
304  AV_CODEC_ID_FIRST_AUDIO = 0x10000, ///< A dummy id pointing at the start of audio codecs
336 
337  /* various ADPCM codecs */
368  AV_CODEC_ID_VIMA = MKBETAG('V','I','M','A'),
369  AV_CODEC_ID_ADPCM_AFC = MKBETAG('A','F','C',' '),
370  AV_CODEC_ID_ADPCM_IMA_OKI = MKBETAG('O','K','I',' '),
371  AV_CODEC_ID_ADPCM_DTK = MKBETAG('D','T','K',' '),
372  AV_CODEC_ID_ADPCM_IMA_RAD = MKBETAG('R','A','D',' '),
373 
374  /* AMR */
377 
378  /* RealAudio codecs*/
381 
382  /* various DPCM codecs */
387 
388  /* audio codecs */
389  AV_CODEC_ID_MP2 = 0x15000,
390  AV_CODEC_ID_MP3, ///< preferred ID for decoding MPEG audio layer 1, 2 or 3
407  AV_CODEC_ID_GSM, ///< as in Berlin toast format
419  AV_CODEC_ID_GSM_MS, /* as found in WAV */
453  AV_CODEC_ID_FFWAVESYNTH = MKBETAG('F','F','W','S'),
454  AV_CODEC_ID_SONIC = MKBETAG('S','O','N','C'),
455  AV_CODEC_ID_SONIC_LS = MKBETAG('S','O','N','L'),
456  AV_CODEC_ID_PAF_AUDIO = MKBETAG('P','A','F','A'),
457  AV_CODEC_ID_OPUS = MKBETAG('O','P','U','S'),
458  AV_CODEC_ID_TAK = MKBETAG('t','B','a','K'),
459  AV_CODEC_ID_EVRC = MKBETAG('s','e','v','c'),
460  AV_CODEC_ID_SMV = MKBETAG('s','s','m','v'),
461 
462  /* subtitle codecs */
463  AV_CODEC_ID_FIRST_SUBTITLE = 0x17000, ///< A dummy ID pointing at the start of subtitle codecs.
466  AV_CODEC_ID_TEXT, ///< raw UTF-8 text
473  AV_CODEC_ID_MICRODVD = MKBETAG('m','D','V','D'),
474  AV_CODEC_ID_EIA_608 = MKBETAG('c','6','0','8'),
475  AV_CODEC_ID_JACOSUB = MKBETAG('J','S','U','B'),
476  AV_CODEC_ID_SAMI = MKBETAG('S','A','M','I'),
477  AV_CODEC_ID_REALTEXT = MKBETAG('R','T','X','T'),
478  AV_CODEC_ID_SUBVIEWER1 = MKBETAG('S','b','V','1'),
479  AV_CODEC_ID_SUBVIEWER = MKBETAG('S','u','b','V'),
480  AV_CODEC_ID_SUBRIP = MKBETAG('S','R','i','p'),
481  AV_CODEC_ID_WEBVTT = MKBETAG('W','V','T','T'),
482  AV_CODEC_ID_MPL2 = MKBETAG('M','P','L','2'),
483  AV_CODEC_ID_VPLAYER = MKBETAG('V','P','l','r'),
484  AV_CODEC_ID_PJS = MKBETAG('P','h','J','S'),
485  AV_CODEC_ID_ASS = MKBETAG('A','S','S',' '), ///< ASS as defined in Matroska
486 
487  /* other specific kind of codecs (generally used for attachments) */
488  AV_CODEC_ID_FIRST_UNKNOWN = 0x18000, ///< A dummy ID pointing at the start of various fake codecs.
489  AV_CODEC_ID_TTF = 0x18000,
490  AV_CODEC_ID_BINTEXT = MKBETAG('B','T','X','T'),
491  AV_CODEC_ID_XBIN = MKBETAG('X','B','I','N'),
492  AV_CODEC_ID_IDF = MKBETAG( 0 ,'I','D','F'),
493  AV_CODEC_ID_OTF = MKBETAG( 0 ,'O','T','F'),
494  AV_CODEC_ID_SMPTE_KLV = MKBETAG('K','L','V','A'),
495  AV_CODEC_ID_DVD_NAV = MKBETAG('D','N','A','V'),
496 
497 
498  AV_CODEC_ID_PROBE = 0x19000, ///< codec_id is not known (like AV_CODEC_ID_NONE) but lavf should attempt to identify it
499 
500  AV_CODEC_ID_MPEG2TS = 0x20000, /**< _FAKE_ codec to indicate a raw MPEG-2 TS
501  * stream (only used by libavformat) */
502  AV_CODEC_ID_MPEG4SYSTEMS = 0x20001, /**< _FAKE_ codec to indicate a MPEG-4 Systems
503  * stream (only used by libavformat) */
504  AV_CODEC_ID_FFMETADATA = 0x21000, ///< Dummy codec for streams containing only metadata information.
505 
506 #if FF_API_CODEC_ID
507 #include "old_codec_ids.h"
508 #endif
509 };
510 
511 /**
512  * This struct describes the properties of a single codec described by an
513  * AVCodecID.
514  * @see avcodec_get_descriptor()
515  */
516 typedef struct AVCodecDescriptor {
517  enum AVCodecID id;
519  /**
520  * Name of the codec described by this descriptor. It is non-empty and
521  * unique for each codec descriptor. It should contain alphanumeric
522  * characters and '_' only.
523  */
524  const char *name;
525  /**
526  * A more descriptive name for this codec. May be NULL.
527  */
528  const char *long_name;
529  /**
530  * Codec properties, a combination of AV_CODEC_PROP_* flags.
531  */
532  int props;
534 
535 /**
536  * Codec uses only intra compression.
537  * Video codecs only.
538  */
539 #define AV_CODEC_PROP_INTRA_ONLY (1 << 0)
540 /**
541  * Codec supports lossy compression. Audio and video codecs only.
542  * @note a codec may support both lossy and lossless
543  * compression modes
544  */
545 #define AV_CODEC_PROP_LOSSY (1 << 1)
546 /**
547  * Codec supports lossless compression. Audio and video codecs only.
548  */
549 #define AV_CODEC_PROP_LOSSLESS (1 << 2)
550 /**
551  * Subtitle codec is bitmap based
552  * Decoded AVSubtitle data can be read from the AVSubtitleRect->pict field.
553  */
554 #define AV_CODEC_PROP_BITMAP_SUB (1 << 16)
555 /**
556  * Subtitle codec is text based.
557  * Decoded AVSubtitle data can be read from the AVSubtitleRect->ass field.
558  */
559 #define AV_CODEC_PROP_TEXT_SUB (1 << 17)
560 
561 /**
562  * @ingroup lavc_decoding
563  * Required number of additionally allocated bytes at the end of the input bitstream for decoding.
564  * This is mainly needed because some optimized bitstream readers read
565  * 32 or 64 bit at once and could read over the end.<br>
566  * Note: If the first 23 bits of the additional bytes are not 0, then damaged
567  * MPEG bitstreams could cause overread and segfault.
568  */
569 #define FF_INPUT_BUFFER_PADDING_SIZE 16
570 
571 /**
572  * @ingroup lavc_encoding
573  * minimum encoding buffer size
574  * Used to avoid some checks during header writing.
575  */
576 #define FF_MIN_BUFFER_SIZE 16384
577 
578 
579 /**
580  * @ingroup lavc_encoding
581  * motion estimation type.
582  */
584  ME_ZERO = 1, ///< no search, that is use 0,0 vector whenever one is needed
588  ME_EPZS, ///< enhanced predictive zonal search
589  ME_X1, ///< reserved for experiments
590  ME_HEX, ///< hexagon based search
591  ME_UMH, ///< uneven multi-hexagon search
592  ME_TESA, ///< transformed exhaustive search algorithm
593  ME_ITER=50, ///< iterative search
594 };
595 
596 /**
597  * @ingroup lavc_decoding
598  */
600  /* We leave some space between them for extensions (drop some
601  * keyframes for intra-only or drop just some bidir frames). */
602  AVDISCARD_NONE =-16, ///< discard nothing
603  AVDISCARD_DEFAULT = 0, ///< discard useless packets like 0 size packets in avi
604  AVDISCARD_NONREF = 8, ///< discard all non reference
605  AVDISCARD_BIDIR = 16, ///< discard all bidirectional frames
606  AVDISCARD_NONKEY = 32, ///< discard all frames except keyframes
607  AVDISCARD_ALL = 48, ///< discard all
608 };
609 
611  AVCOL_PRI_BT709 = 1, ///< also ITU-R BT1361 / IEC 61966-2-4 / SMPTE RP177 Annex B
614  AVCOL_PRI_BT470BG = 5, ///< also ITU-R BT601-6 625 / ITU-R BT1358 625 / ITU-R BT1700 625 PAL & SECAM
615  AVCOL_PRI_SMPTE170M = 6, ///< also ITU-R BT601-6 525 / ITU-R BT1358 525 / ITU-R BT1700 NTSC
616  AVCOL_PRI_SMPTE240M = 7, ///< functionally identical to above
618  AVCOL_PRI_NB , ///< Not part of ABI
619 };
620 
622  AVCOL_TRC_BT709 = 1, ///< also ITU-R BT1361
624  AVCOL_TRC_GAMMA22 = 4, ///< also ITU-R BT470M / ITU-R BT1700 625 PAL & SECAM
625  AVCOL_TRC_GAMMA28 = 5, ///< also ITU-R BT470BG
627  AVCOL_TRC_NB , ///< Not part of ABI
628 };
629 
632  AVCOL_SPC_BT709 = 1, ///< also ITU-R BT1361 / IEC 61966-2-4 xvYCC709 / SMPTE RP177 Annex B
635  AVCOL_SPC_BT470BG = 5, ///< also ITU-R BT601-6 625 / ITU-R BT1358 625 / ITU-R BT1700 625 PAL & SECAM / IEC 61966-2-4 xvYCC601
636  AVCOL_SPC_SMPTE170M = 6, ///< also ITU-R BT601-6 525 / ITU-R BT1358 525 / ITU-R BT1700 NTSC / functionally identical to above
638  AVCOL_SPC_YCOCG = 8, ///< Used by Dirac / VC-2 and H.264 FRext, see ITU-T SG16
639  AVCOL_SPC_NB , ///< Not part of ABI
640 };
641 #define AVCOL_SPC_YCGCO AVCOL_SPC_YCOCG
642 
645  AVCOL_RANGE_MPEG = 1, ///< the normal 219*2^(n-8) "MPEG" YUV ranges
646  AVCOL_RANGE_JPEG = 2, ///< the normal 2^n-1 "JPEG" YUV ranges
647  AVCOL_RANGE_NB , ///< Not part of ABI
648 };
649 
650 /**
651  * X X 3 4 X X are luma samples,
652  * 1 2 1-6 are possible chroma positions
653  * X X 5 6 X 0 is undefined/unknown position
654  */
657  AVCHROMA_LOC_LEFT = 1, ///< mpeg2/4, h264 default
658  AVCHROMA_LOC_CENTER = 2, ///< mpeg1, jpeg, h263
659  AVCHROMA_LOC_TOPLEFT = 3, ///< DV
663  AVCHROMA_LOC_NB , ///< Not part of ABI
664 };
665 
676  AV_AUDIO_SERVICE_TYPE_NB , ///< Not part of ABI
677 };
678 
679 /**
680  * @ingroup lavc_encoding
681  */
682 typedef struct RcOverride{
685  int qscale; // If this is 0 then quality_factor will be used instead.
687 } RcOverride;
688 
689 #define FF_MAX_B_FRAMES 16
690 
691 /* encoding support
692  These flags can be passed in AVCodecContext.flags before initialization.
693  Note: Not everything is supported yet.
694 */
695 
696 /**
697  * Allow decoders to produce frames with data planes that are not aligned
698  * to CPU requirements (e.g. due to cropping).
699  */
700 #define CODEC_FLAG_UNALIGNED 0x0001
701 #define CODEC_FLAG_QSCALE 0x0002 ///< Use fixed qscale.
702 #define CODEC_FLAG_4MV 0x0004 ///< 4 MV per MB allowed / advanced prediction for H.263.
703 #define CODEC_FLAG_QPEL 0x0010 ///< Use qpel MC.
704 #define CODEC_FLAG_GMC 0x0020 ///< Use GMC.
705 #define CODEC_FLAG_MV0 0x0040 ///< Always try a MB with MV=<0,0>.
706 /**
707  * The parent program guarantees that the input for B-frames containing
708  * streams is not written to for at least s->max_b_frames+1 frames, if
709  * this is not set the input will be copied.
710  */
711 #define CODEC_FLAG_INPUT_PRESERVED 0x0100
712 #define CODEC_FLAG_PASS1 0x0200 ///< Use internal 2pass ratecontrol in first pass mode.
713 #define CODEC_FLAG_PASS2 0x0400 ///< Use internal 2pass ratecontrol in second pass mode.
714 #define CODEC_FLAG_GRAY 0x2000 ///< Only decode/encode grayscale.
715 #define CODEC_FLAG_EMU_EDGE 0x4000 ///< Don't draw edges.
716 #define CODEC_FLAG_PSNR 0x8000 ///< error[?] variables will be set during encoding.
717 #define CODEC_FLAG_TRUNCATED 0x00010000 /** Input bitstream might be truncated at a random
718  location instead of only at frame boundaries. */
719 #define CODEC_FLAG_NORMALIZE_AQP 0x00020000 ///< Normalize adaptive quantization.
720 #define CODEC_FLAG_INTERLACED_DCT 0x00040000 ///< Use interlaced DCT.
721 #define CODEC_FLAG_LOW_DELAY 0x00080000 ///< Force low delay.
722 #define CODEC_FLAG_GLOBAL_HEADER 0x00400000 ///< Place global headers in extradata instead of every keyframe.
723 #define CODEC_FLAG_BITEXACT 0x00800000 ///< Use only bitexact stuff (except (I)DCT).
724 /* Fx : Flag for h263+ extra options */
725 #define CODEC_FLAG_AC_PRED 0x01000000 ///< H.263 advanced intra coding / MPEG-4 AC prediction
726 #define CODEC_FLAG_LOOP_FILTER 0x00000800 ///< loop filter
727 #define CODEC_FLAG_INTERLACED_ME 0x20000000 ///< interlaced motion estimation
728 #define CODEC_FLAG_CLOSED_GOP 0x80000000
729 #define CODEC_FLAG2_FAST 0x00000001 ///< Allow non spec compliant speedup tricks.
730 #define CODEC_FLAG2_NO_OUTPUT 0x00000004 ///< Skip bitstream encoding.
731 #define CODEC_FLAG2_LOCAL_HEADER 0x00000008 ///< Place global headers at every keyframe instead of in extradata.
732 #define CODEC_FLAG2_DROP_FRAME_TIMECODE 0x00002000 ///< timecode is in drop frame format. DEPRECATED!!!!
733 #define CODEC_FLAG2_IGNORE_CROP 0x00010000 ///< Discard cropping information from SPS.
735 #define CODEC_FLAG2_CHUNKS 0x00008000 ///< Input bitstream might be truncated at a packet boundaries instead of only at frame boundaries.
736 #define CODEC_FLAG2_SHOW_ALL 0x00400000 ///< Show all frames before the first keyframe
737 
738 /* Unsupported options :
739  * Syntax Arithmetic coding (SAC)
740  * Reference Picture Selection
741  * Independent Segment Decoding */
742 /* /Fx */
743 /* codec capabilities */
745 #define CODEC_CAP_DRAW_HORIZ_BAND 0x0001 ///< Decoder can use draw_horiz_band callback.
746 /**
747  * Codec uses get_buffer() for allocating buffers and supports custom allocators.
748  * If not set, it might not use get_buffer() at all or use operations that
749  * assume the buffer was allocated by avcodec_default_get_buffer.
750  */
751 #define CODEC_CAP_DR1 0x0002
752 #define CODEC_CAP_TRUNCATED 0x0008
753 /* Codec can export data for HW decoding (XvMC). */
754 #define CODEC_CAP_HWACCEL 0x0010
755 /**
756  * Encoder or decoder requires flushing with NULL input at the end in order to
757  * give the complete and correct output.
758  *
759  * NOTE: If this flag is not set, the codec is guaranteed to never be fed with
760  * with NULL data. The user can still send NULL data to the public encode
761  * or decode function, but libavcodec will not pass it along to the codec
762  * unless this flag is set.
763  *
764  * Decoders:
765  * The decoder has a non-zero delay and needs to be fed with avpkt->data=NULL,
766  * avpkt->size=0 at the end to get the delayed data until the decoder no longer
767  * returns frames.
768  *
769  * Encoders:
770  * The encoder needs to be fed with NULL data at the end of encoding until the
771  * encoder no longer returns data.
772  *
773  * NOTE: For encoders implementing the AVCodec.encode2() function, setting this
774  * flag also means that the encoder must set the pts and duration for
775  * each output packet. If this flag is not set, the pts and duration will
776  * be determined by libavcodec from the input frame.
777  */
778 #define CODEC_CAP_DELAY 0x0020
779 /**
780  * Codec can be fed a final frame with a smaller size.
781  * This can be used to prevent truncation of the last audio samples.
782  */
783 #define CODEC_CAP_SMALL_LAST_FRAME 0x0040
784 /**
785  * Codec can export data for HW decoding (VDPAU).
786  */
787 #define CODEC_CAP_HWACCEL_VDPAU 0x0080
788 /**
789  * Codec can output multiple frames per AVPacket
790  * Normally demuxers return one frame at a time, demuxers which do not do
791  * are connected to a parser to split what they return into proper frames.
792  * This flag is reserved to the very rare category of codecs which have a
793  * bitstream that cannot be split into frames without timeconsuming
794  * operations like full decoding. Demuxers carring such bitstreams thus
795  * may return multiple frames in a packet. This has many disadvantages like
796  * prohibiting stream copy in many cases thus it should only be considered
797  * as a last resort.
798  */
799 #define CODEC_CAP_SUBFRAMES 0x0100
800 /**
801  * Codec is experimental and is thus avoided in favor of non experimental
802  * encoders
803  */
804 #define CODEC_CAP_EXPERIMENTAL 0x0200
805 /**
806  * Codec should fill in channel configuration and samplerate instead of container
807  */
808 #define CODEC_CAP_CHANNEL_CONF 0x0400
809 
810 /**
811  * Codec is able to deal with negative linesizes
812  */
813 #define CODEC_CAP_NEG_LINESIZES 0x0800
814 
815 /**
816  * Codec supports frame-level multithreading.
817  */
818 #define CODEC_CAP_FRAME_THREADS 0x1000
819 /**
820  * Codec supports slice-based (or partition-based) multithreading.
821  */
822 #define CODEC_CAP_SLICE_THREADS 0x2000
823 /**
824  * Codec supports changed parameters at any point.
825  */
826 #define CODEC_CAP_PARAM_CHANGE 0x4000
827 /**
828  * Codec supports avctx->thread_count == 0 (auto).
829  */
830 #define CODEC_CAP_AUTO_THREADS 0x8000
831 /**
832  * Audio encoder supports receiving a different number of samples in each call.
833  */
834 #define CODEC_CAP_VARIABLE_FRAME_SIZE 0x10000
835 /**
836  * Codec is intra only.
837  */
838 #define CODEC_CAP_INTRA_ONLY 0x40000000
839 /**
840  * Codec is lossless.
841  */
842 #define CODEC_CAP_LOSSLESS 0x80000000
843 
844 //The following defines may change, don't expect compatibility if you use them.
845 #define MB_TYPE_INTRA4x4 0x0001
846 #define MB_TYPE_INTRA16x16 0x0002 //FIXME H.264-specific
847 #define MB_TYPE_INTRA_PCM 0x0004 //FIXME H.264-specific
848 #define MB_TYPE_16x16 0x0008
849 #define MB_TYPE_16x8 0x0010
850 #define MB_TYPE_8x16 0x0020
851 #define MB_TYPE_8x8 0x0040
852 #define MB_TYPE_INTERLACED 0x0080
853 #define MB_TYPE_DIRECT2 0x0100 //FIXME
854 #define MB_TYPE_ACPRED 0x0200
855 #define MB_TYPE_GMC 0x0400
856 #define MB_TYPE_SKIP 0x0800
857 #define MB_TYPE_P0L0 0x1000
858 #define MB_TYPE_P1L0 0x2000
859 #define MB_TYPE_P0L1 0x4000
860 #define MB_TYPE_P1L1 0x8000
861 #define MB_TYPE_L0 (MB_TYPE_P0L0 | MB_TYPE_P1L0)
862 #define MB_TYPE_L1 (MB_TYPE_P0L1 | MB_TYPE_P1L1)
863 #define MB_TYPE_L0L1 (MB_TYPE_L0 | MB_TYPE_L1)
864 #define MB_TYPE_QUANT 0x00010000
865 #define MB_TYPE_CBP 0x00020000
866 //Note bits 24-31 are reserved for codec specific use (h264 ref0, mpeg1 0mv, ...)
867 
868 /**
869  * Pan Scan area.
870  * This specifies the area which should be displayed.
871  * Note there may be multiple such areas for one frame.
872  */
873 typedef struct AVPanScan{
874  /**
875  * id
876  * - encoding: Set by user.
877  * - decoding: Set by libavcodec.
878  */
879  int id;
880 
881  /**
882  * width and height in 1/16 pel
883  * - encoding: Set by user.
884  * - decoding: Set by libavcodec.
885  */
886  int width;
887  int height;
888 
889  /**
890  * position of the top left corner in 1/16 pel for up to 3 fields/frames
891  * - encoding: Set by user.
892  * - decoding: Set by libavcodec.
893  */
894  int16_t position[3][2];
895 }AVPanScan;
897 #define FF_QSCALE_TYPE_MPEG1 0
898 #define FF_QSCALE_TYPE_MPEG2 1
899 #define FF_QSCALE_TYPE_H264 2
900 #define FF_QSCALE_TYPE_VP56 3
901 
902 #if FF_API_GET_BUFFER
903 #define FF_BUFFER_TYPE_INTERNAL 1
904 #define FF_BUFFER_TYPE_USER 2 ///< direct rendering buffers (image is (de)allocated by user)
905 #define FF_BUFFER_TYPE_SHARED 4 ///< Buffer from somewhere else; don't deallocate image (data/base), all other tables are not shared.
906 #define FF_BUFFER_TYPE_COPY 8 ///< Just a (modified) copy of some other buffer, don't deallocate anything.
907 
908 #define FF_BUFFER_HINTS_VALID 0x01 // Buffer hints value is meaningful (if 0 ignore).
909 #define FF_BUFFER_HINTS_READABLE 0x02 // Codec will read from buffer.
910 #define FF_BUFFER_HINTS_PRESERVE 0x04 // User must not alter buffer content.
911 #define FF_BUFFER_HINTS_REUSABLE 0x08 // Codec will reuse the buffer (update).
912 #endif
913 
914 /**
915  * The decoder will keep a reference to the frame and may reuse it later.
916  */
917 #define AV_GET_BUFFER_FLAG_REF (1 << 0)
918 
919 /**
920  * @defgroup lavc_packet AVPacket
921  *
922  * Types and functions for working with AVPacket.
923  * @{
924  */
928 
929  /**
930  * An AV_PKT_DATA_PARAM_CHANGE side data packet is laid out as follows:
931  * @code
932  * u32le param_flags
933  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT)
934  * s32le channel_count
935  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT)
936  * u64le channel_layout
937  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE)
938  * s32le sample_rate
939  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS)
940  * s32le width
941  * s32le height
942  * @endcode
943  */
945 
946  /**
947  * An AV_PKT_DATA_H263_MB_INFO side data packet contains a number of
948  * structures with info about macroblocks relevant to splitting the
949  * packet into smaller packets on macroblock edges (e.g. as for RFC 2190).
950  * That is, it does not necessarily contain info about all macroblocks,
951  * as long as the distance between macroblocks in the info is smaller
952  * than the target payload size.
953  * Each MB info structure is 12 bytes, and is laid out as follows:
954  * @code
955  * u32le bit offset from the start of the packet
956  * u8 current quantizer at the start of the macroblock
957  * u8 GOB number
958  * u16le macroblock address within the GOB
959  * u8 horizontal MV predictor
960  * u8 vertical MV predictor
961  * u8 horizontal MV predictor for block number 3
962  * u8 vertical MV predictor for block number 3
963  * @endcode
964  */
966 
967  /**
968  * Recommmends skipping the specified number of samples
969  * @code
970  * u32le number of samples to skip from start of this packet
971  * u32le number of samples to skip from end of this packet
972  * u8 reason for start skip
973  * u8 reason for end skip (0=padding silence, 1=convergence)
974  * @endcode
975  */
977 
978  /**
979  * An AV_PKT_DATA_JP_DUALMONO side data packet indicates that
980  * the packet may contain "dual mono" audio specific to Japanese DTV
981  * and if it is true, recommends only the selected channel to be used.
982  * @code
983  * u8 selected channels (0=mail/left, 1=sub/right, 2=both)
984  * @endcode
985  */
987 
988  /**
989  * A list of zero terminated key/value strings. There is no end marker for
990  * the list, so it is required to rely on the side data size to stop.
991  */
993 
994  /**
995  * Subtitle event position
996  * @code
997  * u32le x1
998  * u32le y1
999  * u32le x2
1000  * u32le y2
1001  * @endcode
1002  */
1004 
1005  /**
1006  * Data found in BlockAdditional element of matroska container. There is
1007  * no end marker for the data, so it is required to rely on the side data
1008  * size to recognize the end. 8 byte id (as found in BlockAddId) followed
1009  * by data.
1010  */
1012 
1013  /**
1014  * The optional first identifier line of a WebVTT cue.
1015  */
1017 
1018  /**
1019  * The optional settings (rendering instructions) that immediately
1020  * follow the timestamp specifier of a WebVTT cue.
1021  */
1023 };
1024 
1025 /**
1026  * This structure stores compressed data. It is typically exported by demuxers
1027  * and then passed as input to decoders, or received as output from encoders and
1028  * then passed to muxers.
1029  *
1030  * For video, it should typically contain one compressed frame. For audio it may
1031  * contain several compressed frames.
1032  *
1033  * AVPacket is one of the few structs in FFmpeg, whose size is a part of public
1034  * ABI. Thus it may be allocated on stack and no new fields can be added to it
1035  * without libavcodec and libavformat major bump.
1036  *
1037  * The semantics of data ownership depends on the buf or destruct (deprecated)
1038  * fields. If either is set, the packet data is dynamically allocated and is
1039  * valid indefinitely until av_free_packet() is called (which in turn calls
1040  * av_buffer_unref()/the destruct callback to free the data). If neither is set,
1041  * the packet data is typically backed by some static buffer somewhere and is
1042  * only valid for a limited time (e.g. until the next read call when demuxing).
1043  *
1044  * The side data is always allocated with av_malloc() and is freed in
1045  * av_free_packet().
1046  */
1047 typedef struct AVPacket {
1048  /**
1049  * A reference to the reference-counted buffer where the packet data is
1050  * stored.
1051  * May be NULL, then the packet data is not reference-counted.
1052  */
1053  AVBufferRef *buf;
1054  /**
1055  * Presentation timestamp in AVStream->time_base units; the time at which
1056  * the decompressed packet will be presented to the user.
1057  * Can be AV_NOPTS_VALUE if it is not stored in the file.
1058  * pts MUST be larger or equal to dts as presentation cannot happen before
1059  * decompression, unless one wants to view hex dumps. Some formats misuse
1060  * the terms dts and pts/cts to mean something different. Such timestamps
1061  * must be converted to true pts/dts before they are stored in AVPacket.
1062  */
1063  int64_t pts;
1064  /**
1065  * Decompression timestamp in AVStream->time_base units; the time at which
1066  * the packet is decompressed.
1067  * Can be AV_NOPTS_VALUE if it is not stored in the file.
1068  */
1069  int64_t dts;
1071  int size;
1072  int stream_index;
1073  /**
1074  * A combination of AV_PKT_FLAG values
1075  */
1076  int flags;
1077  /**
1078  * Additional packet data that can be provided by the container.
1079  * Packet can contain several types of side information.
1080  */
1081  struct {
1082  uint8_t *data;
1083  int size;
1086  int side_data_elems;
1087 
1088  /**
1089  * Duration of this packet in AVStream->time_base units, 0 if unknown.
1090  * Equals next_pts - this_pts in presentation order.
1091  */
1092  int duration;
1093 #if FF_API_DESTRUCT_PACKET
1095  void (*destruct)(struct AVPacket *);
1097  void *priv;
1098 #endif
1099  int64_t pos; ///< byte position in stream, -1 if unknown
1100 
1101  /**
1102  * Time difference in AVStream->time_base units from the pts of this
1103  * packet to the point at which the output from the decoder has converged
1104  * independent from the availability of previous frames. That is, the
1105  * frames are virtually identical no matter if decoding started from
1106  * the very first frame or from this keyframe.
1107  * Is AV_NOPTS_VALUE if unknown.
1108  * This field is not the display duration of the current packet.
1109  * This field has no meaning if the packet does not have AV_PKT_FLAG_KEY
1110  * set.
1111  *
1112  * The purpose of this field is to allow seeking in streams that have no
1113  * keyframes in the conventional sense. It corresponds to the
1114  * recovery point SEI in H.264 and match_time_delta in NUT. It is also
1115  * essential for some types of subtitle streams to ensure that all
1116  * subtitles are correctly displayed after seeking.
1117  */
1118  int64_t convergence_duration;
1120 #define AV_PKT_FLAG_KEY 0x0001 ///< The packet contains a keyframe
1121 #define AV_PKT_FLAG_CORRUPT 0x0002 ///< The packet content is corrupted
1128 };
1129 /**
1130  * @}
1131  */
1132 
1133 struct AVCodecInternal;
1138  AV_FIELD_TT, //< Top coded_first, top displayed first
1139  AV_FIELD_BB, //< Bottom coded first, bottom displayed first
1140  AV_FIELD_TB, //< Top coded first, bottom displayed first
1141  AV_FIELD_BT, //< Bottom coded first, top displayed first
1142 };
1143 
1144 /**
1145  * main external API structure.
1146  * New fields can be added to the end with minor version bumps.
1147  * Removal, reordering and changes to existing fields require a major
1148  * version bump.
1149  * Please use AVOptions (av_opt* / av_set/get*()) to access these fields from user
1150  * applications.
1151  * sizeof(AVCodecContext) must not be used outside libav*.
1152  */
1153 typedef struct AVCodecContext {
1154  /**
1155  * information on struct for av_log
1156  * - set by avcodec_alloc_context3
1157  */
1159  int log_level_offset;
1161  enum AVMediaType codec_type; /* see AVMEDIA_TYPE_xxx */
1162  const struct AVCodec *codec;
1163  char codec_name[32];
1164  enum AVCodecID codec_id; /* see AV_CODEC_ID_xxx */
1165 
1166  /**
1167  * fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
1168  * This is used to work around some encoder bugs.
1169  * A demuxer should set this to what is stored in the field used to identify the codec.
1170  * If there are multiple such fields in a container then the demuxer should choose the one
1171  * which maximizes the information about the used codec.
1172  * If the codec tag field in a container is larger than 32 bits then the demuxer should
1173  * remap the longer ID to 32 bits with a table or other structure. Alternatively a new
1174  * extra_codec_tag + size could be added but for this a clear advantage must be demonstrated
1175  * first.
1176  * - encoding: Set by user, if not then the default based on codec_id will be used.
1177  * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
1178  */
1179  unsigned int codec_tag;
1180 
1181  /**
1182  * fourcc from the AVI stream header (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
1183  * This is used to work around some encoder bugs.
1184  * - encoding: unused
1185  * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
1186  */
1187  unsigned int stream_codec_tag;
1189  void *priv_data;
1190 
1191  /**
1192  * Private context used for internal data.
1193  *
1194  * Unlike priv_data, this is not codec-specific. It is used in general
1195  * libavcodec functions.
1196  */
1197  struct AVCodecInternal *internal;
1198 
1199  /**
1200  * Private data of the user, can be used to carry app specific stuff.
1201  * - encoding: Set by user.
1202  * - decoding: Set by user.
1203  */
1204  void *opaque;
1205 
1206  /**
1207  * the average bitrate
1208  * - encoding: Set by user; unused for constant quantizer encoding.
1209  * - decoding: Set by libavcodec. 0 or some bitrate if this info is available in the stream.
1210  */
1211  int bit_rate;
1212 
1213  /**
1214  * number of bits the bitstream is allowed to diverge from the reference.
1215  * the reference can be CBR (for CBR pass1) or VBR (for pass2)
1216  * - encoding: Set by user; unused for constant quantizer encoding.
1217  * - decoding: unused
1218  */
1219  int bit_rate_tolerance;
1220 
1221  /**
1222  * Global quality for codecs which cannot change it per frame.
1223  * This should be proportional to MPEG-1/2/4 qscale.
1224  * - encoding: Set by user.
1225  * - decoding: unused
1226  */
1227  int global_quality;
1228 
1229  /**
1230  * - encoding: Set by user.
1231  * - decoding: unused
1232  */
1234 #define FF_COMPRESSION_DEFAULT -1
1235 
1236  /**
1237  * CODEC_FLAG_*.
1238  * - encoding: Set by user.
1239  * - decoding: Set by user.
1240  */
1241  int flags;
1242 
1243  /**
1244  * CODEC_FLAG2_*
1245  * - encoding: Set by user.
1246  * - decoding: Set by user.
1247  */
1248  int flags2;
1249 
1250  /**
1251  * some codecs need / can use extradata like Huffman tables.
1252  * mjpeg: Huffman tables
1253  * rv10: additional flags
1254  * mpeg4: global headers (they can be in the bitstream or here)
1255  * The allocated memory should be FF_INPUT_BUFFER_PADDING_SIZE bytes larger
1256  * than extradata_size to avoid problems if it is read with the bitstream reader.
1257  * The bytewise contents of extradata must not depend on the architecture or CPU endianness.
1258  * - encoding: Set/allocated/freed by libavcodec.
1259  * - decoding: Set/allocated/freed by user.
1260  */
1262  int extradata_size;
1263 
1264  /**
1265  * This is the fundamental unit of time (in seconds) in terms
1266  * of which frame timestamps are represented. For fixed-fps content,
1267  * timebase should be 1/framerate and timestamp increments should be
1268  * identically 1.
1269  * - encoding: MUST be set by user.
1270  * - decoding: Set by libavcodec.
1271  */
1273 
1274  /**
1275  * For some codecs, the time base is closer to the field rate than the frame rate.
1276  * Most notably, H.264 and MPEG-2 specify time_base as half of frame duration
1277  * if no telecine is used ...
1278  *
1279  * Set to time_base ticks per frame. Default 1, e.g., H.264/MPEG-2 set it to 2.
1280  */
1281  int ticks_per_frame;
1282 
1283  /**
1284  * Codec delay.
1285  *
1286  * Encoding: Number of frames delay there will be from the encoder input to
1287  * the decoder output. (we assume the decoder matches the spec)
1288  * Decoding: Number of frames delay in addition to what a standard decoder
1289  * as specified in the spec would produce.
1290  *
1291  * Video:
1292  * Number of frames the decoded output will be delayed relative to the
1293  * encoded input.
1294  *
1295  * Audio:
1296  * For encoding, this is the number of "priming" samples added to the
1297  * beginning of the stream. The decoded output will be delayed by this
1298  * many samples relative to the input to the encoder. Note that this
1299  * field is purely informational and does not directly affect the pts
1300  * output by the encoder, which should always be based on the actual
1301  * presentation time, including any delay.
1302  * For decoding, this is the number of samples the decoder needs to
1303  * output before the decoder's output is valid. When seeking, you should
1304  * start decoding this many samples prior to your desired seek point.
1305  *
1306  * - encoding: Set by libavcodec.
1307  * - decoding: Set by libavcodec.
1308  */
1309  int delay;
1310 
1311 
1312  /* video only */
1313  /**
1314  * picture width / height.
1315  * - encoding: MUST be set by user.
1316  * - decoding: May be set by the user before opening the decoder if known e.g.
1317  * from the container. Some decoders will require the dimensions
1318  * to be set by the caller. During decoding, the decoder may
1319  * overwrite those values as required.
1320  */
1321  int width, height;
1322 
1323  /**
1324  * Bitstream width / height, may be different from width/height e.g. when
1325  * the decoded frame is cropped before being output or lowres is enabled.
1326  * - encoding: unused
1327  * - decoding: May be set by the user before opening the decoder if known
1328  * e.g. from the container. During decoding, the decoder may
1329  * overwrite those values as required.
1330  */
1333 #define FF_ASPECT_EXTENDED 15
1334 
1335  /**
1336  * the number of pictures in a group of pictures, or 0 for intra_only
1337  * - encoding: Set by user.
1338  * - decoding: unused
1339  */
1340  int gop_size;
1341 
1342  /**
1343  * Pixel format, see AV_PIX_FMT_xxx.
1344  * May be set by the demuxer if known from headers.
1345  * May be overridden by the decoder if it knows better.
1346  * - encoding: Set by user.
1347  * - decoding: Set by user if known, overridden by libavcodec if known
1348  */
1349  enum AVPixelFormat pix_fmt;
1350 
1351  /**
1352  * Motion estimation algorithm used for video coding.
1353  * 1 (zero), 2 (full), 3 (log), 4 (phods), 5 (epzs), 6 (x1), 7 (hex),
1354  * 8 (umh), 9 (iter), 10 (tesa) [7, 8, 10 are x264 specific, 9 is snow specific]
1355  * - encoding: MUST be set by user.
1356  * - decoding: unused
1357  */
1358  int me_method;
1359 
1360  /**
1361  * If non NULL, 'draw_horiz_band' is called by the libavcodec
1362  * decoder to draw a horizontal band. It improves cache usage. Not
1363  * all codecs can do that. You must check the codec capabilities
1364  * beforehand.
1365  * When multithreading is used, it may be called from multiple threads
1366  * at the same time; threads might draw different parts of the same AVFrame,
1367  * or multiple AVFrames, and there is no guarantee that slices will be drawn
1368  * in order.
1369  * The function is also used by hardware acceleration APIs.
1370  * It is called at least once during frame decoding to pass
1371  * the data needed for hardware render.
1372  * In that mode instead of pixel data, AVFrame points to
1373  * a structure specific to the acceleration API. The application
1374  * reads the structure and can change some fields to indicate progress
1375  * or mark state.
1376  * - encoding: unused
1377  * - decoding: Set by user.
1378  * @param height the height of the slice
1379  * @param y the y position of the slice
1380  * @param type 1->top field, 2->bottom field, 3->frame
1381  * @param offset offset into the AVFrame.data from which the slice should be read
1382  */
1383  void (*draw_horiz_band)(struct AVCodecContext *s,
1384  const AVFrame *src, int offset[AV_NUM_DATA_POINTERS],
1385  int y, int type, int height);
1386 
1387  /**
1388  * callback to negotiate the pixelFormat
1389  * @param fmt is the list of formats which are supported by the codec,
1390  * it is terminated by -1 as 0 is a valid format, the formats are ordered by quality.
1391  * The first is always the native one.
1392  * @return the chosen format
1393  * - encoding: unused
1394  * - decoding: Set by user, if not set the native format will be chosen.
1395  */
1396  enum AVPixelFormat (*get_format)(struct AVCodecContext *s, const enum AVPixelFormat * fmt);
1397 
1398  /**
1399  * maximum number of B-frames between non-B-frames
1400  * Note: The output will be delayed by max_b_frames+1 relative to the input.
1401  * - encoding: Set by user.
1402  * - decoding: unused
1403  */
1404  int max_b_frames;
1405 
1406  /**
1407  * qscale factor between IP and B-frames
1408  * If > 0 then the last P-frame quantizer will be used (q= lastp_q*factor+offset).
1409  * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1410  * - encoding: Set by user.
1411  * - decoding: unused
1412  */
1413  float b_quant_factor;
1414 
1415  /** obsolete FIXME remove */
1417 #define FF_RC_STRATEGY_XVID 1
1419  int b_frame_strategy;
1420 
1421  /**
1422  * qscale offset between IP and B-frames
1423  * - encoding: Set by user.
1424  * - decoding: unused
1425  */
1426  float b_quant_offset;
1427 
1428  /**
1429  * Size of the frame reordering buffer in the decoder.
1430  * For MPEG-2 it is 1 IPB or 0 low delay IP.
1431  * - encoding: Set by libavcodec.
1432  * - decoding: Set by libavcodec.
1433  */
1434  int has_b_frames;
1435 
1436  /**
1437  * 0-> h263 quant 1-> mpeg quant
1438  * - encoding: Set by user.
1439  * - decoding: unused
1440  */
1441  int mpeg_quant;
1442 
1443  /**
1444  * qscale factor between P and I-frames
1445  * If > 0 then the last p frame quantizer will be used (q= lastp_q*factor+offset).
1446  * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1447  * - encoding: Set by user.
1448  * - decoding: unused
1449  */
1450  float i_quant_factor;
1451 
1452  /**
1453  * qscale offset between P and I-frames
1454  * - encoding: Set by user.
1455  * - decoding: unused
1456  */
1457  float i_quant_offset;
1458 
1459  /**
1460  * luminance masking (0-> disabled)
1461  * - encoding: Set by user.
1462  * - decoding: unused
1463  */
1464  float lumi_masking;
1465 
1466  /**
1467  * temporary complexity masking (0-> disabled)
1468  * - encoding: Set by user.
1469  * - decoding: unused
1470  */
1471  float temporal_cplx_masking;
1472 
1473  /**
1474  * spatial complexity masking (0-> disabled)
1475  * - encoding: Set by user.
1476  * - decoding: unused
1477  */
1478  float spatial_cplx_masking;
1479 
1480  /**
1481  * p block masking (0-> disabled)
1482  * - encoding: Set by user.
1483  * - decoding: unused
1484  */
1485  float p_masking;
1486 
1487  /**
1488  * darkness masking (0-> disabled)
1489  * - encoding: Set by user.
1490  * - decoding: unused
1491  */
1492  float dark_masking;
1493 
1494  /**
1495  * slice count
1496  * - encoding: Set by libavcodec.
1497  * - decoding: Set by user (or 0).
1498  */
1499  int slice_count;
1500  /**
1501  * prediction method (needed for huffyuv)
1502  * - encoding: Set by user.
1503  * - decoding: unused
1504  */
1506 #define FF_PRED_LEFT 0
1507 #define FF_PRED_PLANE 1
1508 #define FF_PRED_MEDIAN 2
1509 
1510  /**
1511  * slice offsets in the frame in bytes
1512  * - encoding: Set/allocated by libavcodec.
1513  * - decoding: Set/allocated by user (or NULL).
1514  */
1515  int *slice_offset;
1516 
1517  /**
1518  * sample aspect ratio (0 if unknown)
1519  * That is the width of a pixel divided by the height of the pixel.
1520  * Numerator and denominator must be relatively prime and smaller than 256 for some video standards.
1521  * - encoding: Set by user.
1522  * - decoding: Set by libavcodec.
1523  */
1525 
1526  /**
1527  * motion estimation comparison function
1528  * - encoding: Set by user.
1529  * - decoding: unused
1530  */
1531  int me_cmp;
1532  /**
1533  * subpixel motion estimation comparison function
1534  * - encoding: Set by user.
1535  * - decoding: unused
1536  */
1537  int me_sub_cmp;
1538  /**
1539  * macroblock comparison function (not supported yet)
1540  * - encoding: Set by user.
1541  * - decoding: unused
1542  */
1543  int mb_cmp;
1544  /**
1545  * interlaced DCT comparison function
1546  * - encoding: Set by user.
1547  * - decoding: unused
1548  */
1550 #define FF_CMP_SAD 0
1551 #define FF_CMP_SSE 1
1552 #define FF_CMP_SATD 2
1553 #define FF_CMP_DCT 3
1554 #define FF_CMP_PSNR 4
1555 #define FF_CMP_BIT 5
1556 #define FF_CMP_RD 6
1557 #define FF_CMP_ZERO 7
1558 #define FF_CMP_VSAD 8
1559 #define FF_CMP_VSSE 9
1560 #define FF_CMP_NSSE 10
1561 #define FF_CMP_W53 11
1562 #define FF_CMP_W97 12
1563 #define FF_CMP_DCTMAX 13
1564 #define FF_CMP_DCT264 14
1565 #define FF_CMP_CHROMA 256
1566 
1567  /**
1568  * ME diamond size & shape
1569  * - encoding: Set by user.
1570  * - decoding: unused
1571  */
1572  int dia_size;
1573 
1574  /**
1575  * amount of previous MV predictors (2a+1 x 2a+1 square)
1576  * - encoding: Set by user.
1577  * - decoding: unused
1578  */
1580 
1581  /**
1582  * prepass for motion estimation
1583  * - encoding: Set by user.
1584  * - decoding: unused
1585  */
1586  int pre_me;
1587 
1588  /**
1589  * motion estimation prepass comparison function
1590  * - encoding: Set by user.
1591  * - decoding: unused
1592  */
1593  int me_pre_cmp;
1594 
1595  /**
1596  * ME prepass diamond size & shape
1597  * - encoding: Set by user.
1598  * - decoding: unused
1599  */
1600  int pre_dia_size;
1601 
1602  /**
1603  * subpel ME quality
1604  * - encoding: Set by user.
1605  * - decoding: unused
1606  */
1607  int me_subpel_quality;
1608 
1609  /**
1610  * DTG active format information (additional aspect ratio
1611  * information only used in DVB MPEG-2 transport streams)
1612  * 0 if not set.
1613  *
1614  * - encoding: unused
1615  * - decoding: Set by decoder.
1616  */
1618 #define FF_DTG_AFD_SAME 8
1619 #define FF_DTG_AFD_4_3 9
1620 #define FF_DTG_AFD_16_9 10
1621 #define FF_DTG_AFD_14_9 11
1622 #define FF_DTG_AFD_4_3_SP_14_9 13
1623 #define FF_DTG_AFD_16_9_SP_14_9 14
1624 #define FF_DTG_AFD_SP_4_3 15
1625 
1626  /**
1627  * maximum motion estimation search range in subpel units
1628  * If 0 then no limit.
1629  *
1630  * - encoding: Set by user.
1631  * - decoding: unused
1632  */
1633  int me_range;
1634 
1635  /**
1636  * intra quantizer bias
1637  * - encoding: Set by user.
1638  * - decoding: unused
1639  */
1641 #define FF_DEFAULT_QUANT_BIAS 999999
1642 
1643  /**
1644  * inter quantizer bias
1645  * - encoding: Set by user.
1646  * - decoding: unused
1647  */
1648  int inter_quant_bias;
1649 
1650  /**
1651  * slice flags
1652  * - encoding: unused
1653  * - decoding: Set by user.
1654  */
1656 #define SLICE_FLAG_CODED_ORDER 0x0001 ///< draw_horiz_band() is called in coded order instead of display
1657 #define SLICE_FLAG_ALLOW_FIELD 0x0002 ///< allow draw_horiz_band() with field slices (MPEG2 field pics)
1658 #define SLICE_FLAG_ALLOW_PLANE 0x0004 ///< allow draw_horiz_band() with 1 component at a time (SVQ1)
1659 
1660  /**
1661  * XVideo Motion Acceleration
1662  * - encoding: forbidden
1663  * - decoding: set by decoder
1664  */
1665  int xvmc_acceleration;
1666 
1667  /**
1668  * macroblock decision mode
1669  * - encoding: Set by user.
1670  * - decoding: unused
1671  */
1673 #define FF_MB_DECISION_SIMPLE 0 ///< uses mb_cmp
1674 #define FF_MB_DECISION_BITS 1 ///< chooses the one which needs the fewest bits
1675 #define FF_MB_DECISION_RD 2 ///< rate distortion
1676 
1677  /**
1678  * custom intra quantization matrix
1679  * - encoding: Set by user, can be NULL.
1680  * - decoding: Set by libavcodec.
1681  */
1682  uint16_t *intra_matrix;
1683 
1684  /**
1685  * custom inter quantization matrix
1686  * - encoding: Set by user, can be NULL.
1687  * - decoding: Set by libavcodec.
1688  */
1689  uint16_t *inter_matrix;
1690 
1691  /**
1692  * scene change detection threshold
1693  * 0 is default, larger means fewer detected scene changes.
1694  * - encoding: Set by user.
1695  * - decoding: unused
1696  */
1698 
1699  /**
1700  * noise reduction strength
1701  * - encoding: Set by user.
1702  * - decoding: unused
1703  */
1704  int noise_reduction;
1705 
1706  /**
1707  * Motion estimation threshold below which no motion estimation is
1708  * performed, but instead the user specified motion vectors are used.
1709  *
1710  * - encoding: Set by user.
1711  * - decoding: unused
1712  */
1713  int me_threshold;
1714 
1715  /**
1716  * Macroblock threshold below which the user specified macroblock types will be used.
1717  * - encoding: Set by user.
1718  * - decoding: unused
1719  */
1720  int mb_threshold;
1721 
1722  /**
1723  * precision of the intra DC coefficient - 8
1724  * - encoding: Set by user.
1725  * - decoding: unused
1726  */
1727  int intra_dc_precision;
1728 
1729  /**
1730  * Number of macroblock rows at the top which are skipped.
1731  * - encoding: unused
1732  * - decoding: Set by user.
1733  */
1734  int skip_top;
1735 
1736  /**
1737  * Number of macroblock rows at the bottom which are skipped.
1738  * - encoding: unused
1739  * - decoding: Set by user.
1740  */
1741  int skip_bottom;
1742 
1743  /**
1744  * Border processing masking, raises the quantizer for mbs on the borders
1745  * of the picture.
1746  * - encoding: Set by user.
1747  * - decoding: unused
1748  */
1749  float border_masking;
1750 
1751  /**
1752  * minimum MB lagrange multipler
1753  * - encoding: Set by user.
1754  * - decoding: unused
1755  */
1756  int mb_lmin;
1757 
1758  /**
1759  * maximum MB lagrange multipler
1760  * - encoding: Set by user.
1761  * - decoding: unused
1762  */
1763  int mb_lmax;
1764 
1765  /**
1766  *
1767  * - encoding: Set by user.
1768  * - decoding: unused
1769  */
1771 
1772  /**
1773  *
1774  * - encoding: Set by user.
1775  * - decoding: unused
1776  */
1777  int bidir_refine;
1778 
1779  /**
1780  *
1781  * - encoding: Set by user.
1782  * - decoding: unused
1783  */
1784  int brd_scale;
1785 
1786  /**
1787  * minimum GOP size
1788  * - encoding: Set by user.
1789  * - decoding: unused
1790  */
1791  int keyint_min;
1792 
1793  /**
1794  * number of reference frames
1795  * - encoding: Set by user.
1796  * - decoding: Set by lavc.
1797  */
1798  int refs;
1799 
1800  /**
1801  * chroma qp offset from luma
1802  * - encoding: Set by user.
1803  * - decoding: unused
1804  */
1805  int chromaoffset;
1806 
1807  /**
1808  * Multiplied by qscale for each frame and added to scene_change_score.
1809  * - encoding: Set by user.
1810  * - decoding: unused
1811  */
1812  int scenechange_factor;
1813 
1814  /**
1815  *
1816  * Note: Value depends upon the compare function used for fullpel ME.
1817  * - encoding: Set by user.
1818  * - decoding: unused
1819  */
1820  int mv0_threshold;
1821 
1822  /**
1823  * Adjust sensitivity of b_frame_strategy 1.
1824  * - encoding: Set by user.
1825  * - decoding: unused
1826  */
1827  int b_sensitivity;
1828 
1829  /**
1830  * Chromaticity coordinates of the source primaries.
1831  * - encoding: Set by user
1832  * - decoding: Set by libavcodec
1833  */
1835 
1836  /**
1837  * Color Transfer Characteristic.
1838  * - encoding: Set by user
1839  * - decoding: Set by libavcodec
1840  */
1842 
1843  /**
1844  * YUV colorspace type.
1845  * - encoding: Set by user
1846  * - decoding: Set by libavcodec
1847  */
1848  enum AVColorSpace colorspace;
1849 
1850  /**
1851  * MPEG vs JPEG YUV range.
1852  * - encoding: Set by user
1853  * - decoding: Set by libavcodec
1854  */
1856 
1857  /**
1858  * This defines the location of chroma samples.
1859  * - encoding: Set by user
1860  * - decoding: Set by libavcodec
1861  */
1863 
1864  /**
1865  * Number of slices.
1866  * Indicates number of picture subdivisions. Used for parallelized
1867  * decoding.
1868  * - encoding: Set by user
1869  * - decoding: unused
1870  */
1871  int slices;
1872 
1873  /** Field order
1874  * - encoding: set by libavcodec
1875  * - decoding: Set by user.
1876  */
1878 
1879  /* audio only */
1880  int sample_rate; ///< samples per second
1881  int channels; ///< number of audio channels
1882 
1883  /**
1884  * audio sample format
1885  * - encoding: Set by user.
1886  * - decoding: Set by libavcodec.
1887  */
1888  enum AVSampleFormat sample_fmt; ///< sample format
1889 
1890  /* The following data should not be initialized. */
1891  /**
1892  * Number of samples per channel in an audio frame.
1893  *
1894  * - encoding: set by libavcodec in avcodec_open2(). Each submitted frame
1895  * except the last must contain exactly frame_size samples per channel.
1896  * May be 0 when the codec has CODEC_CAP_VARIABLE_FRAME_SIZE set, then the
1897  * frame size is not restricted.
1898  * - decoding: may be set by some decoders to indicate constant frame size
1899  */
1900  int frame_size;
1901 
1902  /**
1903  * Frame counter, set by libavcodec.
1904  *
1905  * - decoding: total number of frames returned from the decoder so far.
1906  * - encoding: total number of frames passed to the encoder so far.
1907  *
1908  * @note the counter is not incremented if encoding/decoding resulted in
1909  * an error.
1910  */
1911  int frame_number;
1912 
1913  /**
1914  * number of bytes per packet if constant and known or 0
1915  * Used by some WAV based audio codecs.
1916  */
1917  int block_align;
1918 
1919  /**
1920  * Audio cutoff bandwidth (0 means "automatic")
1921  * - encoding: Set by user.
1922  * - decoding: unused
1923  */
1924  int cutoff;
1925 
1926 #if FF_API_REQUEST_CHANNELS
1927  /**
1928  * Decoder should decode to this many channels if it can (0 for default)
1929  * - encoding: unused
1930  * - decoding: Set by user.
1931  * @deprecated Deprecated in favor of request_channel_layout.
1932  */
1933  int request_channels;
1934 #endif
1935 
1936  /**
1937  * Audio channel layout.
1938  * - encoding: set by user.
1939  * - decoding: set by user, may be overwritten by libavcodec.
1940  */
1941  uint64_t channel_layout;
1942 
1943  /**
1944  * Request decoder to use this channel layout if it can (0 for default)
1945  * - encoding: unused
1946  * - decoding: Set by user.
1947  */
1948  uint64_t request_channel_layout;
1949 
1950  /**
1951  * Type of service that the audio stream conveys.
1952  * - encoding: Set by user.
1953  * - decoding: Set by libavcodec.
1954  */
1956 
1957  /**
1958  * desired sample format
1959  * - encoding: Not used.
1960  * - decoding: Set by user.
1961  * Decoder will decode to this format if it can.
1962  */
1964 
1965 #if FF_API_GET_BUFFER
1966  /**
1967  * Called at the beginning of each frame to get a buffer for it.
1968  *
1969  * The function will set AVFrame.data[], AVFrame.linesize[].
1970  * AVFrame.extended_data[] must also be set, but it should be the same as
1971  * AVFrame.data[] except for planar audio with more channels than can fit
1972  * in AVFrame.data[]. In that case, AVFrame.data[] shall still contain as
1973  * many data pointers as it can hold.
1974  *
1975  * if CODEC_CAP_DR1 is not set then get_buffer() must call
1976  * avcodec_default_get_buffer() instead of providing buffers allocated by
1977  * some other means.
1978  *
1979  * AVFrame.data[] should be 32- or 16-byte-aligned unless the CPU doesn't
1980  * need it. avcodec_default_get_buffer() aligns the output buffer properly,
1981  * but if get_buffer() is overridden then alignment considerations should
1982  * be taken into account.
1983  *
1984  * @see avcodec_default_get_buffer()
1985  *
1986  * Video:
1987  *
1988  * If pic.reference is set then the frame will be read later by libavcodec.
1989  * avcodec_align_dimensions2() should be used to find the required width and
1990  * height, as they normally need to be rounded up to the next multiple of 16.
1991  *
1992  * If frame multithreading is used and thread_safe_callbacks is set,
1993  * it may be called from a different thread, but not from more than one at
1994  * once. Does not need to be reentrant.
1995  *
1996  * @see release_buffer(), reget_buffer()
1997  * @see avcodec_align_dimensions2()
1998  *
1999  * Audio:
2000  *
2001  * Decoders request a buffer of a particular size by setting
2002  * AVFrame.nb_samples prior to calling get_buffer(). The decoder may,
2003  * however, utilize only part of the buffer by setting AVFrame.nb_samples
2004  * to a smaller value in the output frame.
2005  *
2006  * Decoders cannot use the buffer after returning from
2007  * avcodec_decode_audio4(), so they will not call release_buffer(), as it
2008  * is assumed to be released immediately upon return. In some rare cases,
2009  * a decoder may need to call get_buffer() more than once in a single
2010  * call to avcodec_decode_audio4(). In that case, when get_buffer() is
2011  * called again after it has already been called once, the previously
2012  * acquired buffer is assumed to be released at that time and may not be
2013  * reused by the decoder.
2014  *
2015  * As a convenience, av_samples_get_buffer_size() and
2016  * av_samples_fill_arrays() in libavutil may be used by custom get_buffer()
2017  * functions to find the required data size and to fill data pointers and
2018  * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
2019  * since all planes must be the same size.
2020  *
2021  * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
2022  *
2023  * - encoding: unused
2024  * - decoding: Set by libavcodec, user can override.
2025  *
2026  * @deprecated use get_buffer2()
2027  */
2029  int (*get_buffer)(struct AVCodecContext *c, AVFrame *pic);
2030 
2031  /**
2032  * Called to release buffers which were allocated with get_buffer.
2033  * A released buffer can be reused in get_buffer().
2034  * pic.data[*] must be set to NULL.
2035  * May be called from a different thread if frame multithreading is used,
2036  * but not by more than one thread at once, so does not need to be reentrant.
2037  * - encoding: unused
2038  * - decoding: Set by libavcodec, user can override.
2039  *
2040  * @deprecated custom freeing callbacks should be set from get_buffer2()
2041  */
2043  void (*release_buffer)(struct AVCodecContext *c, AVFrame *pic);
2044 
2045  /**
2046  * Called at the beginning of a frame to get cr buffer for it.
2047  * Buffer type (size, hints) must be the same. libavcodec won't check it.
2048  * libavcodec will pass previous buffer in pic, function should return
2049  * same buffer or new buffer with old frame "painted" into it.
2050  * If pic.data[0] == NULL must behave like get_buffer().
2051  * if CODEC_CAP_DR1 is not set then reget_buffer() must call
2052  * avcodec_default_reget_buffer() instead of providing buffers allocated by
2053  * some other means.
2054  * - encoding: unused
2055  * - decoding: Set by libavcodec, user can override.
2056  */
2058  int (*reget_buffer)(struct AVCodecContext *c, AVFrame *pic);
2059 #endif
2060 
2061  /**
2062  * This callback is called at the beginning of each frame to get data
2063  * buffer(s) for it. There may be one contiguous buffer for all the data or
2064  * there may be a buffer per each data plane or anything in between. What
2065  * this means is, you may set however many entries in buf[] you feel necessary.
2066  * Each buffer must be reference-counted using the AVBuffer API (see description
2067  * of buf[] below).
2068  *
2069  * The following fields will be set in the frame before this callback is
2070  * called:
2071  * - format
2072  * - width, height (video only)
2073  * - sample_rate, channel_layout, nb_samples (audio only)
2074  * Their values may differ from the corresponding values in
2075  * AVCodecContext. This callback must use the frame values, not the codec
2076  * context values, to calculate the required buffer size.
2077  *
2078  * This callback must fill the following fields in the frame:
2079  * - data[]
2080  * - linesize[]
2081  * - extended_data:
2082  * * if the data is planar audio with more than 8 channels, then this
2083  * callback must allocate and fill extended_data to contain all pointers
2084  * to all data planes. data[] must hold as many pointers as it can.
2085  * extended_data must be allocated with av_malloc() and will be freed in
2086  * av_frame_unref().
2087  * * otherwise exended_data must point to data
2088  * - buf[] must contain one or more pointers to AVBufferRef structures. Each of
2089  * the frame's data and extended_data pointers must be contained in these. That
2090  * is, one AVBufferRef for each allocated chunk of memory, not necessarily one
2091  * AVBufferRef per data[] entry. See: av_buffer_create(), av_buffer_alloc(),
2092  * and av_buffer_ref().
2093  * - extended_buf and nb_extended_buf must be allocated with av_malloc() by
2094  * this callback and filled with the extra buffers if there are more
2095  * buffers than buf[] can hold. extended_buf will be freed in
2096  * av_frame_unref().
2097  *
2098  * If CODEC_CAP_DR1 is not set then get_buffer2() must call
2099  * avcodec_default_get_buffer2() instead of providing buffers allocated by
2100  * some other means.
2101  *
2102  * Each data plane must be aligned to the maximum required by the target
2103  * CPU.
2104  *
2105  * @see avcodec_default_get_buffer2()
2106  *
2107  * Video:
2108  *
2109  * If AV_GET_BUFFER_FLAG_REF is set in flags then the frame may be reused
2110  * (read and/or written to if it is writable) later by libavcodec.
2111  *
2112  * If CODEC_FLAG_EMU_EDGE is not set in s->flags, the buffer must contain an
2113  * edge of the size returned by avcodec_get_edge_width() on all sides.
2114  *
2115  * avcodec_align_dimensions2() should be used to find the required width and
2116  * height, as they normally need to be rounded up to the next multiple of 16.
2117  *
2118  * If frame multithreading is used and thread_safe_callbacks is set,
2119  * this callback may be called from a different thread, but not from more
2120  * than one at once. Does not need to be reentrant.
2121  *
2122  * @see avcodec_align_dimensions2()
2123  *
2124  * Audio:
2125  *
2126  * Decoders request a buffer of a particular size by setting
2127  * AVFrame.nb_samples prior to calling get_buffer2(). The decoder may,
2128  * however, utilize only part of the buffer by setting AVFrame.nb_samples
2129  * to a smaller value in the output frame.
2130  *
2131  * As a convenience, av_samples_get_buffer_size() and
2132  * av_samples_fill_arrays() in libavutil may be used by custom get_buffer2()
2133  * functions to find the required data size and to fill data pointers and
2134  * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
2135  * since all planes must be the same size.
2136  *
2137  * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
2138  *
2139  * - encoding: unused
2140  * - decoding: Set by libavcodec, user can override.
2141  */
2142  int (*get_buffer2)(struct AVCodecContext *s, AVFrame *frame, int flags);
2143 
2144  /**
2145  * If non-zero, the decoded audio and video frames returned from
2146  * avcodec_decode_video2() and avcodec_decode_audio4() are reference-counted
2147  * and are valid indefinitely. The caller must free them with
2148  * av_frame_unref() when they are not needed anymore.
2149  * Otherwise, the decoded frames must not be freed by the caller and are
2150  * only valid until the next decode call.
2151  *
2152  * - encoding: unused
2153  * - decoding: set by the caller before avcodec_open2().
2154  */
2155  int refcounted_frames;
2156 
2157  /* - encoding parameters */
2158  float qcompress; ///< amount of qscale change between easy & hard scenes (0.0-1.0)
2159  float qblur; ///< amount of qscale smoothing over time (0.0-1.0)
2160 
2161  /**
2162  * minimum quantizer
2163  * - encoding: Set by user.
2164  * - decoding: unused
2165  */
2166  int qmin;
2167 
2168  /**
2169  * maximum quantizer
2170  * - encoding: Set by user.
2171  * - decoding: unused
2172  */
2173  int qmax;
2174 
2175  /**
2176  * maximum quantizer difference between frames
2177  * - encoding: Set by user.
2178  * - decoding: unused
2179  */
2180  int max_qdiff;
2181 
2182  /**
2183  * ratecontrol qmin qmax limiting method
2184  * 0-> clipping, 1-> use a nice continuous function to limit qscale wthin qmin/qmax.
2185  * - encoding: Set by user.
2186  * - decoding: unused
2187  */
2188  float rc_qsquish;
2191  int rc_qmod_freq;
2192 
2193  /**
2194  * decoder bitstream buffer size
2195  * - encoding: Set by user.
2196  * - decoding: unused
2197  */
2198  int rc_buffer_size;
2199 
2200  /**
2201  * ratecontrol override, see RcOverride
2202  * - encoding: Allocated/set/freed by user.
2203  * - decoding: unused
2204  */
2207 
2208  /**
2209  * rate control equation
2210  * - encoding: Set by user
2211  * - decoding: unused
2212  */
2213  const char *rc_eq;
2214 
2215  /**
2216  * maximum bitrate
2217  * - encoding: Set by user.
2218  * - decoding: unused
2219  */
2220  int rc_max_rate;
2221 
2222  /**
2223  * minimum bitrate
2224  * - encoding: Set by user.
2225  * - decoding: unused
2226  */
2227  int rc_min_rate;
2229  float rc_buffer_aggressivity;
2230 
2231  /**
2232  * initial complexity for pass1 ratecontrol
2233  * - encoding: Set by user.
2234  * - decoding: unused
2235  */
2236  float rc_initial_cplx;
2237 
2238  /**
2239  * Ratecontrol attempt to use, at maximum, <value> of what can be used without an underflow.
2240  * - encoding: Set by user.
2241  * - decoding: unused.
2242  */
2244 
2245  /**
2246  * Ratecontrol attempt to use, at least, <value> times the amount needed to prevent a vbv overflow.
2247  * - encoding: Set by user.
2248  * - decoding: unused.
2249  */
2251 
2252  /**
2253  * Number of bits which should be loaded into the rc buffer before decoding starts.
2254  * - encoding: Set by user.
2255  * - decoding: unused
2256  */
2259 #define FF_CODER_TYPE_VLC 0
2260 #define FF_CODER_TYPE_AC 1
2261 #define FF_CODER_TYPE_RAW 2
2262 #define FF_CODER_TYPE_RLE 3
2263 #define FF_CODER_TYPE_DEFLATE 4
2264  /**
2265  * coder type
2266  * - encoding: Set by user.
2267  * - decoding: unused
2268  */
2269  int coder_type;
2270 
2271  /**
2272  * context model
2273  * - encoding: Set by user.
2274  * - decoding: unused
2275  */
2276  int context_model;
2277 
2278  /**
2279  * minimum Lagrange multipler
2280  * - encoding: Set by user.
2281  * - decoding: unused
2282  */
2283  int lmin;
2284 
2285  /**
2286  * maximum Lagrange multipler
2287  * - encoding: Set by user.
2288  * - decoding: unused
2289  */
2290  int lmax;
2291 
2292  /**
2293  * frame skip threshold
2294  * - encoding: Set by user.
2295  * - decoding: unused
2296  */
2298 
2299  /**
2300  * frame skip factor
2301  * - encoding: Set by user.
2302  * - decoding: unused
2303  */
2304  int frame_skip_factor;
2305 
2306  /**
2307  * frame skip exponent
2308  * - encoding: Set by user.
2309  * - decoding: unused
2310  */
2311  int frame_skip_exp;
2312 
2313  /**
2314  * frame skip comparison function
2315  * - encoding: Set by user.
2316  * - decoding: unused
2317  */
2318  int frame_skip_cmp;
2319 
2320  /**
2321  * trellis RD quantization
2322  * - encoding: Set by user.
2323  * - decoding: unused
2324  */
2325  int trellis;
2326 
2327  /**
2328  * - encoding: Set by user.
2329  * - decoding: unused
2330  */
2332 
2333  /**
2334  * - encoding: Set by user.
2335  * - decoding: unused
2336  */
2338 
2339  /**
2340  * GOP timecode frame start number
2341  * - encoding: Set by user, in non drop frame format
2342  * - decoding: Set by libavcodec (timecode in the 25 bits format, -1 if unset)
2343  */
2344  int64_t timecode_frame_start;
2345 
2346  /* The RTP callback: This function is called */
2347  /* every time the encoder has a packet to send. */
2348  /* It depends on the encoder if the data starts */
2349  /* with a Start Code (it should). H.263 does. */
2350  /* mb_nb contains the number of macroblocks */
2351  /* encoded in the RTP payload. */
2352  void (*rtp_callback)(struct AVCodecContext *avctx, void *data, int size, int mb_nb);
2354  int rtp_payload_size; /* The size of the RTP payload: the coder will */
2355  /* do its best to deliver a chunk with size */
2356  /* below rtp_payload_size, the chunk will start */
2357  /* with a start code on some codecs like H.263. */
2358  /* This doesn't take account of any particular */
2359  /* headers inside the transmitted RTP payload. */
2360 
2361  /* statistics, used for 2-pass encoding */
2362  int mv_bits;
2366  int i_count;
2367  int p_count;
2369  int misc_bits;
2370 
2371  /**
2372  * number of bits used for the previously encoded frame
2373  * - encoding: Set by libavcodec.
2374  * - decoding: unused
2375  */
2376  int frame_bits;
2377 
2378  /**
2379  * pass1 encoding statistics output buffer
2380  * - encoding: Set by libavcodec.
2381  * - decoding: unused
2382  */
2383  char *stats_out;
2384 
2385  /**
2386  * pass2 encoding statistics input buffer
2387  * Concatenated stuff from stats_out of pass1 should be placed here.
2388  * - encoding: Allocated/set/freed by user.
2389  * - decoding: unused
2390  */
2391  char *stats_in;
2392 
2393  /**
2394  * Work around bugs in encoders which sometimes cannot be detected automatically.
2395  * - encoding: Set by user
2396  * - decoding: Set by user
2397  */
2399 #define FF_BUG_AUTODETECT 1 ///< autodetection
2400 #define FF_BUG_OLD_MSMPEG4 2
2401 #define FF_BUG_XVID_ILACE 4
2402 #define FF_BUG_UMP4 8
2403 #define FF_BUG_NO_PADDING 16
2404 #define FF_BUG_AMV 32
2405 #define FF_BUG_AC_VLC 0 ///< Will be removed, libavcodec can now handle these non-compliant files by default.
2406 #define FF_BUG_QPEL_CHROMA 64
2407 #define FF_BUG_STD_QPEL 128
2408 #define FF_BUG_QPEL_CHROMA2 256
2409 #define FF_BUG_DIRECT_BLOCKSIZE 512
2410 #define FF_BUG_EDGE 1024
2411 #define FF_BUG_HPEL_CHROMA 2048
2412 #define FF_BUG_DC_CLIP 4096
2413 #define FF_BUG_MS 8192 ///< Work around various bugs in Microsoft's broken decoders.
2414 #define FF_BUG_TRUNCATED 16384
2415 
2416  /**
2417  * strictly follow the standard (MPEG4, ...).
2418  * - encoding: Set by user.
2419  * - decoding: Set by user.
2420  * Setting this to STRICT or higher means the encoder and decoder will
2421  * generally do stupid things, whereas setting it to unofficial or lower
2422  * will mean the encoder might produce output that is not supported by all
2423  * spec-compliant decoders. Decoders don't differentiate between normal,
2424  * unofficial and experimental (that is, they always try to decode things
2425  * when they can) unless they are explicitly asked to behave stupidly
2426  * (=strictly conform to the specs)
2427  */
2429 #define FF_COMPLIANCE_VERY_STRICT 2 ///< Strictly conform to an older more strict version of the spec or reference software.
2430 #define FF_COMPLIANCE_STRICT 1 ///< Strictly conform to all the things in the spec no matter what consequences.
2431 #define FF_COMPLIANCE_NORMAL 0
2432 #define FF_COMPLIANCE_UNOFFICIAL -1 ///< Allow unofficial extensions
2433 #define FF_COMPLIANCE_EXPERIMENTAL -2 ///< Allow nonstandardized experimental things.
2434 
2435  /**
2436  * error concealment flags
2437  * - encoding: unused
2438  * - decoding: Set by user.
2439  */
2441 #define FF_EC_GUESS_MVS 1
2442 #define FF_EC_DEBLOCK 2
2443 
2444  /**
2445  * debug
2446  * - encoding: Set by user.
2447  * - decoding: Set by user.
2448  */
2449  int debug;
2450 #define FF_DEBUG_PICT_INFO 1
2451 #define FF_DEBUG_RC 2
2452 #define FF_DEBUG_BITSTREAM 4
2453 #define FF_DEBUG_MB_TYPE 8
2454 #define FF_DEBUG_QP 16
2455 #define FF_DEBUG_MV 32
2456 #define FF_DEBUG_DCT_COEFF 0x00000040
2457 #define FF_DEBUG_SKIP 0x00000080
2458 #define FF_DEBUG_STARTCODE 0x00000100
2459 #define FF_DEBUG_PTS 0x00000200
2460 #define FF_DEBUG_ER 0x00000400
2461 #define FF_DEBUG_MMCO 0x00000800
2462 #define FF_DEBUG_BUGS 0x00001000
2463 #define FF_DEBUG_VIS_QP 0x00002000
2464 #define FF_DEBUG_VIS_MB_TYPE 0x00004000
2465 #define FF_DEBUG_BUFFERS 0x00008000
2466 #define FF_DEBUG_THREADS 0x00010000
2467 
2468  /**
2469  * debug
2470  * - encoding: Set by user.
2471  * - decoding: Set by user.
2472  */
2474 #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 //visualize forward predicted MVs of P frames
2475 #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 //visualize forward predicted MVs of B frames
2476 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
2477 
2478  /**
2479  * Error recognition; may misdetect some more or less valid parts as errors.
2480  * - encoding: unused
2481  * - decoding: Set by user.
2482  */
2484 #define AV_EF_CRCCHECK (1<<0)
2485 #define AV_EF_BITSTREAM (1<<1)
2486 #define AV_EF_BUFFER (1<<2)
2487 #define AV_EF_EXPLODE (1<<3)
2489 #define AV_EF_CAREFUL (1<<16)
2490 #define AV_EF_COMPLIANT (1<<17)
2491 #define AV_EF_AGGRESSIVE (1<<18)
2492 
2493 
2494  /**
2495  * opaque 64bit number (generally a PTS) that will be reordered and
2496  * output in AVFrame.reordered_opaque
2497  * @deprecated in favor of pkt_pts
2498  * - encoding: unused
2499  * - decoding: Set by user.
2500  */
2501  int64_t reordered_opaque;
2502 
2503  /**
2504  * Hardware accelerator in use
2505  * - encoding: unused.
2506  * - decoding: Set by libavcodec
2507  */
2508  struct AVHWAccel *hwaccel;
2509 
2510  /**
2511  * Hardware accelerator context.
2512  * For some hardware accelerators, a global context needs to be
2513  * provided by the user. In that case, this holds display-dependent
2514  * data FFmpeg cannot instantiate itself. Please refer to the
2515  * FFmpeg HW accelerator documentation to know how to fill this
2516  * is. e.g. for VA API, this is a struct vaapi_context.
2517  * - encoding: unused
2518  * - decoding: Set by user
2519  */
2520  void *hwaccel_context;
2521 
2522  /**
2523  * error
2524  * - encoding: Set by libavcodec if flags&CODEC_FLAG_PSNR.
2525  * - decoding: unused
2526  */
2527  uint64_t error[AV_NUM_DATA_POINTERS];
2528 
2529  /**
2530  * DCT algorithm, see FF_DCT_* below
2531  * - encoding: Set by user.
2532  * - decoding: unused
2533  */
2535 #define FF_DCT_AUTO 0
2536 #define FF_DCT_FASTINT 1
2537 #define FF_DCT_INT 2
2538 #define FF_DCT_MMX 3
2539 #define FF_DCT_ALTIVEC 5
2540 #define FF_DCT_FAAN 6
2541 
2542  /**
2543  * IDCT algorithm, see FF_IDCT_* below.
2544  * - encoding: Set by user.
2545  * - decoding: Set by user.
2546  */
2548 #define FF_IDCT_AUTO 0
2549 #define FF_IDCT_INT 1
2550 #define FF_IDCT_SIMPLE 2
2551 #define FF_IDCT_SIMPLEMMX 3
2552 #define FF_IDCT_ARM 7
2553 #define FF_IDCT_ALTIVEC 8
2554 #define FF_IDCT_SH4 9
2555 #define FF_IDCT_SIMPLEARM 10
2556 #define FF_IDCT_IPP 13
2557 #define FF_IDCT_XVIDMMX 14
2558 #define FF_IDCT_SIMPLEARMV5TE 16
2559 #define FF_IDCT_SIMPLEARMV6 17
2560 #define FF_IDCT_SIMPLEVIS 18
2561 #define FF_IDCT_FAAN 20
2562 #define FF_IDCT_SIMPLENEON 22
2563 #define FF_IDCT_SIMPLEALPHA 23
2564 
2565  /**
2566  * bits per sample/pixel from the demuxer (needed for huffyuv).
2567  * - encoding: Set by libavcodec.
2568  * - decoding: Set by user.
2569  */
2571 
2572  /**
2573  * Bits per sample/pixel of internal libavcodec pixel/sample format.
2574  * - encoding: set by user.
2575  * - decoding: set by libavcodec.
2576  */
2577  int bits_per_raw_sample;
2578 
2579 #if FF_API_LOWRES
2580  /**
2581  * low resolution decoding, 1-> 1/2 size, 2->1/4 size
2582  * - encoding: unused
2583  * - decoding: Set by user.
2584  * Code outside libavcodec should access this field using:
2585  * av_codec_{get,set}_lowres(avctx)
2586  */
2587  int lowres;
2588 #endif
2589 
2590  /**
2591  * the picture in the bitstream
2592  * - encoding: Set by libavcodec.
2593  * - decoding: Set by libavcodec.
2594  */
2596 
2597  /**
2598  * thread count
2599  * is used to decide how many independent tasks should be passed to execute()
2600  * - encoding: Set by user.
2601  * - decoding: Set by user.
2602  */
2603  int thread_count;
2604 
2605  /**
2606  * Which multithreading methods to use.
2607  * Use of FF_THREAD_FRAME will increase decoding delay by one frame per thread,
2608  * so clients which cannot provide future frames should not use it.
2609  *
2610  * - encoding: Set by user, otherwise the default is used.
2611  * - decoding: Set by user, otherwise the default is used.
2612  */
2614 #define FF_THREAD_FRAME 1 ///< Decode more than one frame at once
2615 #define FF_THREAD_SLICE 2 ///< Decode more than one part of a single frame at once
2616 
2617  /**
2618  * Which multithreading methods are in use by the codec.
2619  * - encoding: Set by libavcodec.
2620  * - decoding: Set by libavcodec.
2621  */
2622  int active_thread_type;
2623 
2624  /**
2625  * Set by the client if its custom get_buffer() callback can be called
2626  * synchronously from another thread, which allows faster multithreaded decoding.
2627  * draw_horiz_band() will be called from other threads regardless of this setting.
2628  * Ignored if the default get_buffer() is used.
2629  * - encoding: Set by user.
2630  * - decoding: Set by user.
2631  */
2633 
2634  /**
2635  * The codec may call this to execute several independent things.
2636  * It will return only after finishing all tasks.
2637  * The user may replace this with some multithreaded implementation,
2638  * the default implementation will execute the parts serially.
2639  * @param count the number of things to execute
2640  * - encoding: Set by libavcodec, user can override.
2641  * - decoding: Set by libavcodec, user can override.
2642  */
2643  int (*execute)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size);
2644 
2645  /**
2646  * The codec may call this to execute several independent things.
2647  * It will return only after finishing all tasks.
2648  * The user may replace this with some multithreaded implementation,
2649  * the default implementation will execute the parts serially.
2650  * Also see avcodec_thread_init and e.g. the --enable-pthread configure option.
2651  * @param c context passed also to func
2652  * @param count the number of things to execute
2653  * @param arg2 argument passed unchanged to func
2654  * @param ret return values of executed functions, must have space for "count" values. May be NULL.
2655  * @param func function that will be called count times, with jobnr from 0 to count-1.
2656  * threadnr will be in the range 0 to c->thread_count-1 < MAX_THREADS and so that no
2657  * two instances of func executing at the same time will have the same threadnr.
2658  * @return always 0 currently, but code should handle a future improvement where when any call to func
2659  * returns < 0 no further calls to func may be done and < 0 is returned.
2660  * - encoding: Set by libavcodec, user can override.
2661  * - decoding: Set by libavcodec, user can override.
2662  */
2663  int (*execute2)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count);
2664 
2665  /**
2666  * thread opaque
2667  * Can be used by execute() to store some per AVCodecContext stuff.
2668  * - encoding: set by execute()
2669  * - decoding: set by execute()
2670  */
2671  void *thread_opaque;
2672 
2673  /**
2674  * noise vs. sse weight for the nsse comparsion function
2675  * - encoding: Set by user.
2676  * - decoding: unused
2677  */
2678  int nsse_weight;
2679 
2680  /**
2681  * profile
2682  * - encoding: Set by user.
2683  * - decoding: Set by libavcodec.
2684  */
2685  int profile;
2686 #define FF_PROFILE_UNKNOWN -99
2687 #define FF_PROFILE_RESERVED -100
2689 #define FF_PROFILE_AAC_MAIN 0
2690 #define FF_PROFILE_AAC_LOW 1
2691 #define FF_PROFILE_AAC_SSR 2
2692 #define FF_PROFILE_AAC_LTP 3
2693 #define FF_PROFILE_AAC_HE 4
2694 #define FF_PROFILE_AAC_HE_V2 28
2695 #define FF_PROFILE_AAC_LD 22
2696 #define FF_PROFILE_AAC_ELD 38
2697 #define FF_PROFILE_MPEG2_AAC_LOW 128
2698 #define FF_PROFILE_MPEG2_AAC_HE 131
2700 #define FF_PROFILE_DTS 20
2701 #define FF_PROFILE_DTS_ES 30
2702 #define FF_PROFILE_DTS_96_24 40
2703 #define FF_PROFILE_DTS_HD_HRA 50
2704 #define FF_PROFILE_DTS_HD_MA 60
2706 #define FF_PROFILE_MPEG2_422 0
2707 #define FF_PROFILE_MPEG2_HIGH 1
2708 #define FF_PROFILE_MPEG2_SS 2
2709 #define FF_PROFILE_MPEG2_SNR_SCALABLE 3
2710 #define FF_PROFILE_MPEG2_MAIN 4
2711 #define FF_PROFILE_MPEG2_SIMPLE 5
2713 #define FF_PROFILE_H264_CONSTRAINED (1<<9) // 8+1; constraint_set1_flag
2714 #define FF_PROFILE_H264_INTRA (1<<11) // 8+3; constraint_set3_flag
2716 #define FF_PROFILE_H264_BASELINE 66
2717 #define FF_PROFILE_H264_CONSTRAINED_BASELINE (66|FF_PROFILE_H264_CONSTRAINED)
2718 #define FF_PROFILE_H264_MAIN 77
2719 #define FF_PROFILE_H264_EXTENDED 88
2720 #define FF_PROFILE_H264_HIGH 100
2721 #define FF_PROFILE_H264_HIGH_10 110
2722 #define FF_PROFILE_H264_HIGH_10_INTRA (110|FF_PROFILE_H264_INTRA)
2723 #define FF_PROFILE_H264_HIGH_422 122
2724 #define FF_PROFILE_H264_HIGH_422_INTRA (122|FF_PROFILE_H264_INTRA)
2725 #define FF_PROFILE_H264_HIGH_444 144
2726 #define FF_PROFILE_H264_HIGH_444_PREDICTIVE 244
2727 #define FF_PROFILE_H264_HIGH_444_INTRA (244|FF_PROFILE_H264_INTRA)
2728 #define FF_PROFILE_H264_CAVLC_444 44
2730 #define FF_PROFILE_VC1_SIMPLE 0
2731 #define FF_PROFILE_VC1_MAIN 1
2732 #define FF_PROFILE_VC1_COMPLEX 2
2733 #define FF_PROFILE_VC1_ADVANCED 3
2735 #define FF_PROFILE_MPEG4_SIMPLE 0
2736 #define FF_PROFILE_MPEG4_SIMPLE_SCALABLE 1
2737 #define FF_PROFILE_MPEG4_CORE 2
2738 #define FF_PROFILE_MPEG4_MAIN 3
2739 #define FF_PROFILE_MPEG4_N_BIT 4
2740 #define FF_PROFILE_MPEG4_SCALABLE_TEXTURE 5
2741 #define FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION 6
2742 #define FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE 7
2743 #define FF_PROFILE_MPEG4_HYBRID 8
2744 #define FF_PROFILE_MPEG4_ADVANCED_REAL_TIME 9
2745 #define FF_PROFILE_MPEG4_CORE_SCALABLE 10
2746 #define FF_PROFILE_MPEG4_ADVANCED_CODING 11
2747 #define FF_PROFILE_MPEG4_ADVANCED_CORE 12
2748 #define FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE 13
2749 #define FF_PROFILE_MPEG4_SIMPLE_STUDIO 14
2750 #define FF_PROFILE_MPEG4_ADVANCED_SIMPLE 15
2752 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_0 0
2753 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_1 1
2754 #define FF_PROFILE_JPEG2000_CSTREAM_NO_RESTRICTION 2
2755 #define FF_PROFILE_JPEG2000_DCINEMA_2K 3
2756 #define FF_PROFILE_JPEG2000_DCINEMA_4K 4
2757 
2758  /**
2759  * level
2760  * - encoding: Set by user.
2761  * - decoding: Set by libavcodec.
2762  */
2763  int level;
2764 #define FF_LEVEL_UNKNOWN -99
2765 
2766  /**
2767  * Skip loop filtering for selected frames.
2768  * - encoding: unused
2769  * - decoding: Set by user.
2770  */
2772 
2773  /**
2774  * Skip IDCT/dequantization for selected frames.
2775  * - encoding: unused
2776  * - decoding: Set by user.
2777  */
2778  enum AVDiscard skip_idct;
2779 
2780  /**
2781  * Skip decoding for selected frames.
2782  * - encoding: unused
2783  * - decoding: Set by user.
2784  */
2785  enum AVDiscard skip_frame;
2786 
2787  /**
2788  * Header containing style information for text subtitles.
2789  * For SUBTITLE_ASS subtitle type, it should contain the whole ASS
2790  * [Script Info] and [V4+ Styles] section, plus the [Events] line and
2791  * the Format line following. It shouldn't include any Dialogue line.
2792  * - encoding: Set/allocated/freed by user (before avcodec_open2())
2793  * - decoding: Set/allocated/freed by libavcodec (by avcodec_open2())
2794  */
2797 
2798  /**
2799  * Simulates errors in the bitstream to test error concealment.
2800  * - encoding: Set by user.
2801  * - decoding: unused
2802  */
2803  int error_rate;
2804 
2805  /**
2806  * Current packet as passed into the decoder, to avoid having
2807  * to pass the packet into every function. Currently only valid
2808  * inside lavc and get/release_buffer callbacks.
2809  * - decoding: set by avcodec_decode_*, read by get_buffer() for setting pkt_pts
2810  * - encoding: unused
2811  */
2812  AVPacket *pkt;
2813 
2814  /**
2815  * VBV delay coded in the last frame (in periods of a 27 MHz clock).
2816  * Used for compliant TS muxing.
2817  * - encoding: Set by libavcodec.
2818  * - decoding: unused.
2819  */
2820  uint64_t vbv_delay;
2821 
2822  /**
2823  * Timebase in which pkt_dts/pts and AVPacket.dts/pts are.
2824  * Code outside libavcodec should access this field using:
2825  * av_codec_{get,set}_pkt_timebase(avctx)
2826  * - encoding unused.
2827  * - decoding set by user.
2828  */
2830 
2831  /**
2832  * AVCodecDescriptor
2833  * Code outside libavcodec should access this field using:
2834  * av_codec_{get,set}_codec_descriptor(avctx)
2835  * - encoding: unused.
2836  * - decoding: set by libavcodec.
2837  */
2839 
2840 #if !FF_API_LOWRES
2841  /**
2842  * low resolution decoding, 1-> 1/2 size, 2->1/4 size
2843  * - encoding: unused
2844  * - decoding: Set by user.
2845  * Code outside libavcodec should access this field using:
2846  * av_codec_{get,set}_lowres(avctx)
2847  */
2848  int lowres;
2849 #endif
2850 
2851  /**
2852  * Current statistics for PTS correction.
2853  * - decoding: maintained and used by libavcodec, not intended to be used by user apps
2854  * - encoding: unused
2855  */
2856  int64_t pts_correction_num_faulty_pts; /// Number of incorrect PTS values so far
2857  int64_t pts_correction_num_faulty_dts; /// Number of incorrect DTS values so far
2858  int64_t pts_correction_last_pts; /// PTS of the last frame
2859  int64_t pts_correction_last_dts; /// DTS of the last frame
2860 
2861  /**
2862  * Character encoding of the input subtitles file.
2863  * - decoding: set by user
2864  * - encoding: unused
2865  */
2866  char *sub_charenc;
2867 
2868  /**
2869  * Subtitles character encoding mode. Formats or codecs might be adjusting
2870  * this setting (if they are doing the conversion themselves for instance).
2871  * - decoding: set by libavcodec
2872  * - encoding: unused
2873  */
2875 #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)
2876 #define FF_SUB_CHARENC_MODE_AUTOMATIC 0 ///< libavcodec will select the mode itself
2877 #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
2878 
2879 } AVCodecContext;
2880 
2883 
2886 
2887 int av_codec_get_lowres(const AVCodecContext *avctx);
2888 void av_codec_set_lowres(AVCodecContext *avctx, int val);
2889 
2890 /**
2891  * AVProfile.
2892  */
2893 typedef struct AVProfile {
2894  int profile;
2895  const char *name; ///< short name for the profile
2896 } AVProfile;
2897 
2898 typedef struct AVCodecDefault AVCodecDefault;
2899 
2900 struct AVSubtitle;
2901 
2902 /**
2903  * AVCodec.
2904  */
2905 typedef struct AVCodec {
2906  /**
2907  * Name of the codec implementation.
2908  * The name is globally unique among encoders and among decoders (but an
2909  * encoder and a decoder can share the same name).
2910  * This is the primary way to find a codec from the user perspective.
2911  */
2912  const char *name;
2913  /**
2914  * Descriptive name for the codec, meant to be more human readable than name.
2915  * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
2916  */
2917  const char *long_name;
2919  enum AVCodecID id;
2920  /**
2921  * Codec capabilities.
2922  * see CODEC_CAP_*
2923  */
2925  const AVRational *supported_framerates; ///< array of supported framerates, or NULL if any, array is terminated by {0,0}
2926  const enum AVPixelFormat *pix_fmts; ///< array of supported pixel formats, or NULL if unknown, array is terminated by -1
2927  const int *supported_samplerates; ///< array of supported audio samplerates, or NULL if unknown, array is terminated by 0
2928  const enum AVSampleFormat *sample_fmts; ///< array of supported sample formats, or NULL if unknown, array is terminated by -1
2929  const uint64_t *channel_layouts; ///< array of support channel layouts, or NULL if unknown. array is terminated by 0
2930  uint8_t max_lowres; ///< maximum value for lowres supported by the decoder
2931  const AVClass *priv_class; ///< AVClass for the private context
2932  const AVProfile *profiles; ///< array of recognized profiles, or NULL if unknown, array is terminated by {FF_PROFILE_UNKNOWN}
2933 
2934  /*****************************************************************
2935  * No fields below this line are part of the public API. They
2936  * may not be used outside of libavcodec and can be changed and
2937  * removed at will.
2938  * New public fields should be added right above.
2939  *****************************************************************
2940  */
2942  struct AVCodec *next;
2943  /**
2944  * @name Frame-level threading support functions
2945  * @{
2946  */
2947  /**
2948  * If defined, called on thread contexts when they are created.
2949  * If the codec allocates writable tables in init(), re-allocate them here.
2950  * priv_data will be set to a copy of the original.
2951  */
2952  int (*init_thread_copy)(AVCodecContext *);
2953  /**
2954  * Copy necessary context variables from a previous thread context to the current one.
2955  * If not defined, the next thread will start automatically; otherwise, the codec
2956  * must call ff_thread_finish_setup().
2957  *
2958  * dst and src will (rarely) point to the same context, in which case memcpy should be skipped.
2959  */
2961  /** @} */
2962 
2963  /**
2964  * Private codec-specific defaults.
2965  */
2966  const AVCodecDefault *defaults;
2967 
2968  /**
2969  * Initialize codec static data, called from avcodec_register().
2970  */
2971  void (*init_static_data)(struct AVCodec *codec);
2974  int (*encode_sub)(AVCodecContext *, uint8_t *buf, int buf_size,
2975  const struct AVSubtitle *sub);
2976  /**
2977  * Encode data to an AVPacket.
2978  *
2979  * @param avctx codec context
2980  * @param avpkt output AVPacket (may contain a user-provided buffer)
2981  * @param[in] frame AVFrame containing the raw data to be encoded
2982  * @param[out] got_packet_ptr encoder sets to 0 or 1 to indicate that a
2983  * non-empty packet was returned in avpkt.
2984  * @return 0 on success, negative error code on failure
2985  */
2986  int (*encode2)(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame,
2987  int *got_packet_ptr);
2988  int (*decode)(AVCodecContext *, void *outdata, int *outdata_size, AVPacket *avpkt);
2989  int (*close)(AVCodecContext *);
2990  /**
2991  * Flush buffers.
2992  * Will be called when seeking
2993  */
2994  void (*flush)(AVCodecContext *);
2995 } AVCodec;
2996 
2997 /**
2998  * AVHWAccel.
2999  */
3000 typedef struct AVHWAccel {
3001  /**
3002  * Name of the hardware accelerated codec.
3003  * The name is globally unique among encoders and among decoders (but an
3004  * encoder and a decoder can share the same name).
3005  */
3006  const char *name;
3007 
3008  /**
3009  * Type of codec implemented by the hardware accelerator.
3010  *
3011  * See AVMEDIA_TYPE_xxx
3012  */
3013  enum AVMediaType type;
3014 
3015  /**
3016  * Codec implemented by the hardware accelerator.
3017  *
3018  * See AV_CODEC_ID_xxx
3019  */
3020  enum AVCodecID id;
3021 
3022  /**
3023  * Supported pixel format.
3024  *
3025  * Only hardware accelerated formats are supported here.
3026  */
3027  enum AVPixelFormat pix_fmt;
3028 
3029  /**
3030  * Hardware accelerated codec capabilities.
3031  * see FF_HWACCEL_CODEC_CAP_*
3032  */
3033  int capabilities;
3035  struct AVHWAccel *next;
3036 
3037  /**
3038  * Called at the beginning of each frame or field picture.
3039  *
3040  * Meaningful frame information (codec specific) is guaranteed to
3041  * be parsed at this point. This function is mandatory.
3042  *
3043  * Note that buf can be NULL along with buf_size set to 0.
3044  * Otherwise, this means the whole frame is available at this point.
3045  *
3046  * @param avctx the codec context
3047  * @param buf the frame data buffer base
3048  * @param buf_size the size of the frame in bytes
3049  * @return zero if successful, a negative value otherwise
3050  */
3051  int (*start_frame)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3052 
3053  /**
3054  * Callback for each slice.
3055  *
3056  * Meaningful slice information (codec specific) is guaranteed to
3057  * be parsed at this point. This function is mandatory.
3058  *
3059  * @param avctx the codec context
3060  * @param buf the slice data buffer base
3061  * @param buf_size the size of the slice in bytes
3062  * @return zero if successful, a negative value otherwise
3063  */
3064  int (*decode_slice)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3065 
3066  /**
3067  * Called at the end of each frame or field picture.
3068  *
3069  * The whole picture is parsed at this point and can now be sent
3070  * to the hardware accelerator. This function is mandatory.
3071  *
3072  * @param avctx the codec context
3073  * @return zero if successful, a negative value otherwise
3074  */
3075  int (*end_frame)(AVCodecContext *avctx);
3076 
3077  /**
3078  * Size of HW accelerator private data.
3079  *
3080  * Private data is allocated with av_mallocz() before
3081  * AVCodecContext.get_buffer() and deallocated after
3082  * AVCodecContext.release_buffer().
3083  */
3084  int priv_data_size;
3085 } AVHWAccel;
3086 
3087 /**
3088  * @defgroup lavc_picture AVPicture
3089  *
3090  * Functions for working with AVPicture
3091  * @{
3092  */
3093 
3094 /**
3095  * four components are given, that's all.
3096  * the last component is alpha
3097  */
3098 typedef struct AVPicture {
3100  int linesize[AV_NUM_DATA_POINTERS]; ///< number of bytes per line
3101 } AVPicture;
3102 
3103 /**
3104  * @}
3105  */
3108  SUBTITLE_NONE,
3110  SUBTITLE_BITMAP, ///< A bitmap, pict will be set
3111 
3112  /**
3113  * Plain text, the text field must be set by the decoder and is
3114  * authoritative. ass and pict fields may contain approximations.
3115  */
3116  SUBTITLE_TEXT,
3117 
3118  /**
3119  * Formatted text, the ass field must be set by the decoder and is
3120  * authoritative. pict and text fields may contain approximations.
3121  */
3122  SUBTITLE_ASS,
3123 };
3125 #define AV_SUBTITLE_FLAG_FORCED 0x00000001
3127 typedef struct AVSubtitleRect {
3128  int x; ///< top left corner of pict, undefined when pict is not set
3129  int y; ///< top left corner of pict, undefined when pict is not set
3130  int w; ///< width of pict, undefined when pict is not set
3131  int h; ///< height of pict, undefined when pict is not set
3132  int nb_colors; ///< number of colors in pict, undefined when pict is not set
3133 
3134  /**
3135  * data+linesize for the bitmap of this subtitle.
3136  * can be set for text/ass as well once they where rendered
3137  */
3139  enum AVSubtitleType type;
3141  char *text; ///< 0 terminated plain UTF-8 text
3142 
3143  /**
3144  * 0 terminated ASS/SSA compatible event line.
3145  * The presentation of this is unaffected by the other values in this
3146  * struct.
3147  */
3148  char *ass;
3150  int flags;
3151 } AVSubtitleRect;
3153 typedef struct AVSubtitle {
3154  uint16_t format; /* 0 = graphics */
3155  uint32_t start_display_time; /* relative to packet pts, in ms */
3156  uint32_t end_display_time; /* relative to packet pts, in ms */
3157  unsigned num_rects;
3159  int64_t pts; ///< Same as packet pts, in AV_TIME_BASE
3160 } AVSubtitle;
3161 
3162 /**
3163  * If c is NULL, returns the first registered codec,
3164  * if c is non-NULL, returns the next registered codec after c,
3165  * or NULL if c is the last one.
3166  */
3167 AVCodec *av_codec_next(const AVCodec *c);
3168 
3169 /**
3170  * Return the LIBAVCODEC_VERSION_INT constant.
3171  */
3172 unsigned avcodec_version(void);
3173 
3174 /**
3175  * Return the libavcodec build-time configuration.
3176  */
3177 const char *avcodec_configuration(void);
3178 
3179 /**
3180  * Return the libavcodec license.
3181  */
3182 const char *avcodec_license(void);
3183 
3184 /**
3185  * Register the codec codec and initialize libavcodec.
3186  *
3187  * @warning either this function or avcodec_register_all() must be called
3188  * before any other libavcodec functions.
3189  *
3190  * @see avcodec_register_all()
3191  */
3192 void avcodec_register(AVCodec *codec);
3193 
3194 /**
3195  * Register all the codecs, parsers and bitstream filters which were enabled at
3196  * configuration time. If you do not call this function you can select exactly
3197  * which formats you want to support, by using the individual registration
3198  * functions.
3199  *
3200  * @see avcodec_register
3201  * @see av_register_codec_parser
3202  * @see av_register_bitstream_filter
3203  */
3204 void avcodec_register_all(void);
3205 
3206 
3207 #if FF_API_ALLOC_CONTEXT
3208 /**
3209  * Allocate an AVCodecContext and set its fields to default values. The
3210  * resulting struct can be deallocated by simply calling av_free().
3211  *
3212  * @return An AVCodecContext filled with default values or NULL on failure.
3213  * @see avcodec_get_context_defaults
3214  *
3215  * @deprecated use avcodec_alloc_context3()
3216  */
3218 AVCodecContext *avcodec_alloc_context(void);
3219 
3220 /** THIS FUNCTION IS NOT YET PART OF THE PUBLIC API!
3221  * we WILL change its arguments and name a few times! */
3223 AVCodecContext *avcodec_alloc_context2(enum AVMediaType);
3224 
3225 /**
3226  * Set the fields of the given AVCodecContext to default values.
3227  *
3228  * @param s The AVCodecContext of which the fields should be set to default values.
3229  * @deprecated use avcodec_get_context_defaults3
3230  */
3232 void avcodec_get_context_defaults(AVCodecContext *s);
3233 
3234 /** THIS FUNCTION IS NOT YET PART OF THE PUBLIC API!
3235  * we WILL change its arguments and name a few times! */
3237 void avcodec_get_context_defaults2(AVCodecContext *s, enum AVMediaType);
3238 #endif
3239 
3240 /**
3241  * Allocate an AVCodecContext and set its fields to default values. The
3242  * resulting struct can be deallocated by calling avcodec_close() on it followed
3243  * by av_free().
3244  *
3245  * @param codec if non-NULL, allocate private data and initialize defaults
3246  * for the given codec. It is illegal to then call avcodec_open2()
3247  * with a different codec.
3248  * If NULL, then the codec-specific defaults won't be initialized,
3249  * which may result in suboptimal default settings (this is
3250  * important mainly for encoders, e.g. libx264).
3251  *
3252  * @return An AVCodecContext filled with default values or NULL on failure.
3253  * @see avcodec_get_context_defaults
3254  */
3256 
3257 /**
3258  * Set the fields of the given AVCodecContext to default values corresponding
3259  * to the given codec (defaults may be codec-dependent).
3260  *
3261  * Do not call this function if a non-NULL codec has been passed
3262  * to avcodec_alloc_context3() that allocated this AVCodecContext.
3263  * If codec is non-NULL, it is illegal to call avcodec_open2() with a
3264  * different codec on this AVCodecContext.
3265  */
3267 
3268 /**
3269  * Get the AVClass for AVCodecContext. It can be used in combination with
3270  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
3271  *
3272  * @see av_opt_find().
3273  */
3274 const AVClass *avcodec_get_class(void);
3275 
3276 /**
3277  * Get the AVClass for AVFrame. It can be used in combination with
3278  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
3279  *
3280  * @see av_opt_find().
3281  */
3282 const AVClass *avcodec_get_frame_class(void);
3283 
3284 /**
3285  * Get the AVClass for AVSubtitleRect. It can be used in combination with
3286  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
3287  *
3288  * @see av_opt_find().
3289  */
3291 
3292 /**
3293  * Copy the settings of the source AVCodecContext into the destination
3294  * AVCodecContext. The resulting destination codec context will be
3295  * unopened, i.e. you are required to call avcodec_open2() before you
3296  * can use this AVCodecContext to decode/encode video/audio data.
3297  *
3298  * @param dest target codec context, should be initialized with
3299  * avcodec_alloc_context3(), but otherwise uninitialized
3300  * @param src source codec context
3301  * @return AVERROR() on error (e.g. memory allocation error), 0 on success
3302  */
3304 
3305 /**
3306  * Allocate an AVFrame and set its fields to default values. The resulting
3307  * struct must be freed using avcodec_free_frame().
3308  *
3309  * @return An AVFrame filled with default values or NULL on failure.
3310  * @see avcodec_get_frame_defaults
3311  */
3313 
3314 /**
3315  * Set the fields of the given AVFrame to default values.
3316  *
3317  * @param frame The AVFrame of which the fields should be set to default values.
3318  */
3320 
3321 /**
3322  * Free the frame and any dynamically allocated objects in it,
3323  * e.g. extended_data.
3324  *
3325  * @param frame frame to be freed. The pointer will be set to NULL.
3326  *
3327  * @warning this function does NOT free the data buffers themselves
3328  * (it does not know how, since they might have been allocated with
3329  * a custom get_buffer()).
3330  */
3332 
3333 #if FF_API_AVCODEC_OPEN
3334 /**
3335  * Initialize the AVCodecContext to use the given AVCodec. Prior to using this
3336  * function the context has to be allocated.
3337  *
3338  * The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(),
3339  * avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for
3340  * retrieving a codec.
3341  *
3342  * @warning This function is not thread safe!
3343  *
3344  * @code
3345  * avcodec_register_all();
3346  * codec = avcodec_find_decoder(AV_CODEC_ID_H264);
3347  * if (!codec)
3348  * exit(1);
3349  *
3350  * context = avcodec_alloc_context3(codec);
3351  *
3352  * if (avcodec_open(context, codec) < 0)
3353  * exit(1);
3354  * @endcode
3355  *
3356  * @param avctx The context which will be set up to use the given codec.
3357  * @param codec The codec to use within the context.
3358  * @return zero on success, a negative value on error
3359  * @see avcodec_alloc_context3, avcodec_find_decoder, avcodec_find_encoder, avcodec_close
3360  *
3361  * @deprecated use avcodec_open2
3362  */
3364 int avcodec_open(AVCodecContext *avctx, AVCodec *codec);
3365 #endif
3366 
3367 /**
3368  * Initialize the AVCodecContext to use the given AVCodec. Prior to using this
3369  * function the context has to be allocated with avcodec_alloc_context3().
3370  *
3371  * The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(),
3372  * avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for
3373  * retrieving a codec.
3374  *
3375  * @warning This function is not thread safe!
3376  *
3377  * @code
3378  * avcodec_register_all();
3379  * av_dict_set(&opts, "b", "2.5M", 0);
3380  * codec = avcodec_find_decoder(AV_CODEC_ID_H264);
3381  * if (!codec)
3382  * exit(1);
3383  *
3384  * context = avcodec_alloc_context3(codec);
3385  *
3386  * if (avcodec_open2(context, codec, opts) < 0)
3387  * exit(1);
3388  * @endcode
3389  *
3390  * @param avctx The context to initialize.
3391  * @param codec The codec to open this context for. If a non-NULL codec has been
3392  * previously passed to avcodec_alloc_context3() or
3393  * avcodec_get_context_defaults3() for this context, then this
3394  * parameter MUST be either NULL or equal to the previously passed
3395  * codec.
3396  * @param options A dictionary filled with AVCodecContext and codec-private options.
3397  * On return this object will be filled with options that were not found.
3398  *
3399  * @return zero on success, a negative value on error
3400  * @see avcodec_alloc_context3(), avcodec_find_decoder(), avcodec_find_encoder(),
3401  * av_dict_set(), av_opt_find().
3402  */
3403 int avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options);
3404 
3405 /**
3406  * Close a given AVCodecContext and free all the data associated with it
3407  * (but not the AVCodecContext itself).
3408  *
3409  * Calling this function on an AVCodecContext that hasn't been opened will free
3410  * the codec-specific data allocated in avcodec_alloc_context3() /
3411  * avcodec_get_context_defaults3() with a non-NULL codec. Subsequent calls will
3412  * do nothing.
3413  */
3414 int avcodec_close(AVCodecContext *avctx);
3415 
3416 /**
3417  * Free all allocated data in the given subtitle struct.
3418  *
3419  * @param sub AVSubtitle to free.
3420  */
3421 void avsubtitle_free(AVSubtitle *sub);
3422 
3423 /**
3424  * @}
3425  */
3426 
3427 /**
3428  * @addtogroup lavc_packet
3429  * @{
3430  */
3431 
3432 #if FF_API_DESTRUCT_PACKET
3433 /**
3434  * Default packet destructor.
3435  * @deprecated use the AVBuffer API instead
3436  */
3438 void av_destruct_packet(AVPacket *pkt);
3439 #endif
3440 
3441 /**
3442  * Initialize optional fields of a packet with default values.
3443  *
3444  * Note, this does not touch the data and size members, which have to be
3445  * initialized separately.
3446  *
3447  * @param pkt packet
3448  */
3449 void av_init_packet(AVPacket *pkt);
3450 
3451 /**
3452  * Allocate the payload of a packet and initialize its fields with
3453  * default values.
3454  *
3455  * @param pkt packet
3456  * @param size wanted payload size
3457  * @return 0 if OK, AVERROR_xxx otherwise
3458  */
3459 int av_new_packet(AVPacket *pkt, int size);
3460 
3461 /**
3462  * Reduce packet size, correctly zeroing padding
3463  *
3464  * @param pkt packet
3465  * @param size new size
3466  */
3467 void av_shrink_packet(AVPacket *pkt, int size);
3468 
3469 /**
3470  * Increase packet size, correctly zeroing padding
3471  *
3472  * @param pkt packet
3473  * @param grow_by number of bytes by which to increase the size of the packet
3474  */
3475 int av_grow_packet(AVPacket *pkt, int grow_by);
3476 
3477 /**
3478  * Initialize a reference-counted packet from av_malloc()ed data.
3479  *
3480  * @param pkt packet to be initialized. This function will set the data, size,
3481  * buf and destruct fields, all others are left untouched.
3482  * @param data Data allocated by av_malloc() to be used as packet data. If this
3483  * function returns successfully, the data is owned by the underlying AVBuffer.
3484  * The caller may not access the data through other means.
3485  * @param size size of data in bytes, without the padding. I.e. the full buffer
3486  * size is assumed to be size + FF_INPUT_BUFFER_PADDING_SIZE.
3487  *
3488  * @return 0 on success, a negative AVERROR on error
3489  */
3491 
3492 /**
3493  * @warning This is a hack - the packet memory allocation stuff is broken. The
3494  * packet is allocated if it was not really allocated.
3495  */
3496 int av_dup_packet(AVPacket *pkt);
3497 
3498 /**
3499  * Copy packet, including contents
3500  *
3501  * @return 0 on success, negative AVERROR on fail
3502  */
3503 int av_copy_packet(AVPacket *dst, AVPacket *src);
3504 
3505 /**
3506  * Copy packet side data
3507  *
3508  * @return 0 on success, negative AVERROR on fail
3509  */
3511 
3512 /**
3513  * Free a packet.
3514  *
3515  * @param pkt packet to free
3516  */
3517 void av_free_packet(AVPacket *pkt);
3518 
3519 /**
3520  * Allocate new information of a packet.
3521  *
3522  * @param pkt packet
3523  * @param type side information type
3524  * @param size side information size
3525  * @return pointer to fresh allocated data or NULL otherwise
3526  */
3528  int size);
3529 
3530 /**
3531  * Shrink the already allocated side data buffer
3532  *
3533  * @param pkt packet
3534  * @param type side information type
3535  * @param size new side information size
3536  * @return 0 on success, < 0 on failure
3537  */
3539  int size);
3540 
3541 /**
3542  * Get side information from packet.
3543  *
3544  * @param pkt packet
3545  * @param type desired side information type
3546  * @param size pointer for side information size to store (optional)
3547  * @return pointer to data if present or NULL otherwise
3548  */
3550  int *size);
3551 
3553 
3555 
3556 
3557 /**
3558  * @}
3559  */
3560 
3561 /**
3562  * @addtogroup lavc_decoding
3563  * @{
3564  */
3565 
3566 /**
3567  * Find a registered decoder with a matching codec ID.
3568  *
3569  * @param id AVCodecID of the requested decoder
3570  * @return A decoder if one was found, NULL otherwise.
3571  */
3573 
3574 /**
3575  * Find a registered decoder with the specified name.
3576  *
3577  * @param name name of the requested decoder
3578  * @return A decoder if one was found, NULL otherwise.
3579  */
3581 
3582 #if FF_API_GET_BUFFER
3583 attribute_deprecated int avcodec_default_get_buffer(AVCodecContext *s, AVFrame *pic);
3584 attribute_deprecated void avcodec_default_release_buffer(AVCodecContext *s, AVFrame *pic);
3585 attribute_deprecated int avcodec_default_reget_buffer(AVCodecContext *s, AVFrame *pic);
3586 #endif
3587 
3588 /**
3589  * The default callback for AVCodecContext.get_buffer2(). It is made public so
3590  * it can be called by custom get_buffer2() implementations for decoders without
3591  * CODEC_CAP_DR1 set.
3592  */
3594 
3595 /**
3596  * Return the amount of padding in pixels which the get_buffer callback must
3597  * provide around the edge of the image for codecs which do not have the
3598  * CODEC_FLAG_EMU_EDGE flag.
3599  *
3600  * @return Required padding in pixels.
3601  */
3602 unsigned avcodec_get_edge_width(void);
3603 
3604 /**
3605  * Modify width and height values so that they will result in a memory
3606  * buffer that is acceptable for the codec if you do not use any horizontal
3607  * padding.
3608  *
3609  * May only be used if a codec with CODEC_CAP_DR1 has been opened.
3610  * If CODEC_FLAG_EMU_EDGE is not set, the dimensions must have been increased
3611  * according to avcodec_get_edge_width() before.
3612  */
3614 
3615 /**
3616  * Modify width and height values so that they will result in a memory
3617  * buffer that is acceptable for the codec if you also ensure that all
3618  * line sizes are a multiple of the respective linesize_align[i].
3619  *
3620  * May only be used if a codec with CODEC_CAP_DR1 has been opened.
3621  * If CODEC_FLAG_EMU_EDGE is not set, the dimensions must have been increased
3622  * according to avcodec_get_edge_width() before.
3623  */
3625  int linesize_align[AV_NUM_DATA_POINTERS]);
3626 
3627 #if FF_API_OLD_DECODE_AUDIO
3628 /**
3629  * Wrapper function which calls avcodec_decode_audio4.
3630  *
3631  * @deprecated Use avcodec_decode_audio4 instead.
3632  *
3633  * Decode the audio frame of size avpkt->size from avpkt->data into samples.
3634  * Some decoders may support multiple frames in a single AVPacket, such
3635  * decoders would then just decode the first frame. In this case,
3636  * avcodec_decode_audio3 has to be called again with an AVPacket that contains
3637  * the remaining data in order to decode the second frame etc.
3638  * If no frame
3639  * could be outputted, frame_size_ptr is zero. Otherwise, it is the
3640  * decompressed frame size in bytes.
3641  *
3642  * @warning You must set frame_size_ptr to the allocated size of the
3643  * output buffer before calling avcodec_decode_audio3().
3644  *
3645  * @warning The input buffer must be FF_INPUT_BUFFER_PADDING_SIZE larger than
3646  * the actual read bytes because some optimized bitstream readers read 32 or 64
3647  * bits at once and could read over the end.
3648  *
3649  * @warning The end of the input buffer avpkt->data should be set to 0 to ensure that
3650  * no overreading happens for damaged MPEG streams.
3651  *
3652  * @warning You must not provide a custom get_buffer() when using
3653  * avcodec_decode_audio3(). Doing so will override it with
3654  * avcodec_default_get_buffer. Use avcodec_decode_audio4() instead,
3655  * which does allow the application to provide a custom get_buffer().
3656  *
3657  * @note You might have to align the input buffer avpkt->data and output buffer
3658  * samples. The alignment requirements depend on the CPU: On some CPUs it isn't
3659  * necessary at all, on others it won't work at all if not aligned and on others
3660  * it will work but it will have an impact on performance.
3661  *
3662  * In practice, avpkt->data should have 4 byte alignment at minimum and
3663  * samples should be 16 byte aligned unless the CPU doesn't need it
3664  * (AltiVec and SSE do).
3665  *
3666  * @note Codecs which have the CODEC_CAP_DELAY capability set have a delay
3667  * between input and output, these need to be fed with avpkt->data=NULL,
3668  * avpkt->size=0 at the end to return the remaining frames.
3669  *
3670  * @param avctx the codec context
3671  * @param[out] samples the output buffer, sample type in avctx->sample_fmt
3672  * If the sample format is planar, each channel plane will
3673  * be the same size, with no padding between channels.
3674  * @param[in,out] frame_size_ptr the output buffer size in bytes
3675  * @param[in] avpkt The input AVPacket containing the input buffer.
3676  * You can create such packet with av_init_packet() and by then setting
3677  * data and size, some decoders might in addition need other fields.
3678  * All decoders are designed to use the least fields possible though.
3679  * @return On error a negative value is returned, otherwise the number of bytes
3680  * used or zero if no frame data was decompressed (used) from the input AVPacket.
3681  */
3682 attribute_deprecated int avcodec_decode_audio3(AVCodecContext *avctx, int16_t *samples,
3683  int *frame_size_ptr,
3684  AVPacket *avpkt);
3685 #endif
3686 
3687 /**
3688  * Decode the audio frame of size avpkt->size from avpkt->data into frame.
3689  *
3690  * Some decoders may support multiple frames in a single AVPacket. Such
3691  * decoders would then just decode the first frame. In this case,
3692  * avcodec_decode_audio4 has to be called again with an AVPacket containing
3693  * the remaining data in order to decode the second frame, etc...
3694  * Even if no frames are returned, the packet needs to be fed to the decoder
3695  * with remaining data until it is completely consumed or an error occurs.
3696  *
3697  * @warning The input buffer, avpkt->data must be FF_INPUT_BUFFER_PADDING_SIZE
3698  * larger than the actual read bytes because some optimized bitstream
3699  * readers read 32 or 64 bits at once and could read over the end.
3700  *
3701  * @note You might have to align the input buffer. The alignment requirements
3702  * depend on the CPU and the decoder.
3703  *
3704  * @param avctx the codec context
3705  * @param[out] frame The AVFrame in which to store decoded audio samples.
3706  * The decoder will allocate a buffer for the decoded frame by
3707  * calling the AVCodecContext.get_buffer2() callback.
3708  * When AVCodecContext.refcounted_frames is set to 1, the frame is
3709  * reference counted and the returned reference belongs to the
3710  * caller. The caller must release the frame using av_frame_unref()
3711  * when the frame is no longer needed. The caller may safely write
3712  * to the frame if av_frame_is_writable() returns 1.
3713  * When AVCodecContext.refcounted_frames is set to 0, the returned
3714  * reference belongs to the decoder and is valid only until the
3715  * next call to this function or until closing the decoder.
3716  * The caller may not write to it.
3717  * @param[out] got_frame_ptr Zero if no frame could be decoded, otherwise it is
3718  * non-zero.
3719  * @param[in] avpkt The input AVPacket containing the input buffer.
3720  * At least avpkt->data and avpkt->size should be set. Some
3721  * decoders might also require additional fields to be set.
3722  * @return A negative error code is returned if an error occurred during
3723  * decoding, otherwise the number of bytes consumed from the input
3724  * AVPacket is returned.
3725  */
3727  int *got_frame_ptr, const AVPacket *avpkt);
3728 
3729 /**
3730  * Decode the video frame of size avpkt->size from avpkt->data into picture.
3731  * Some decoders may support multiple frames in a single AVPacket, such
3732  * decoders would then just decode the first frame.
3733  *
3734  * @warning The input buffer must be FF_INPUT_BUFFER_PADDING_SIZE larger than
3735  * the actual read bytes because some optimized bitstream readers read 32 or 64
3736  * bits at once and could read over the end.
3737  *
3738  * @warning The end of the input buffer buf should be set to 0 to ensure that
3739  * no overreading happens for damaged MPEG streams.
3740  *
3741  * @note You might have to align the input buffer avpkt->data.
3742  * The alignment requirements depend on the CPU: on some CPUs it isn't
3743  * necessary at all, on others it won't work at all if not aligned and on others
3744  * it will work but it will have an impact on performance.
3745  *
3746  * In practice, avpkt->data should have 4 byte alignment at minimum.
3747  *
3748  * @note Codecs which have the CODEC_CAP_DELAY capability set have a delay
3749  * between input and output, these need to be fed with avpkt->data=NULL,
3750  * avpkt->size=0 at the end to return the remaining frames.
3751  *
3752  * @param avctx the codec context
3753  * @param[out] picture The AVFrame in which the decoded video frame will be stored.
3754  * Use av_frame_alloc() to get an AVFrame. The codec will
3755  * allocate memory for the actual bitmap by calling the
3756  * AVCodecContext.get_buffer2() callback.
3757  * When AVCodecContext.refcounted_frames is set to 1, the frame is
3758  * reference counted and the returned reference belongs to the
3759  * caller. The caller must release the frame using av_frame_unref()
3760  * when the frame is no longer needed. The caller may safely write
3761  * to the frame if av_frame_is_writable() returns 1.
3762  * When AVCodecContext.refcounted_frames is set to 0, the returned
3763  * reference belongs to the decoder and is valid only until the
3764  * next call to this function or until closing the decoder. The
3765  * caller may not write to it.
3766  *
3767  * @param[in] avpkt The input AVpacket containing the input buffer.
3768  * You can create such packet with av_init_packet() and by then setting
3769  * data and size, some decoders might in addition need other fields like
3770  * flags&AV_PKT_FLAG_KEY. All decoders are designed to use the least
3771  * fields possible.
3772  * @param[in,out] got_picture_ptr Zero if no frame could be decompressed, otherwise, it is nonzero.
3773  * @return On error a negative value is returned, otherwise the number of bytes
3774  * used or zero if no frame could be decompressed.
3775  */
3776 int avcodec_decode_video2(AVCodecContext *avctx, AVFrame *picture,
3777  int *got_picture_ptr,
3778  const AVPacket *avpkt);
3779 
3780 /**
3781  * Decode a subtitle message.
3782  * Return a negative value on error, otherwise return the number of bytes used.
3783  * If no subtitle could be decompressed, got_sub_ptr is zero.
3784  * Otherwise, the subtitle is stored in *sub.
3785  * Note that CODEC_CAP_DR1 is not available for subtitle codecs. This is for
3786  * simplicity, because the performance difference is expect to be negligible
3787  * and reusing a get_buffer written for video codecs would probably perform badly
3788  * due to a potentially very different allocation pattern.
3789  *
3790  * @param avctx the codec context
3791  * @param[out] sub The AVSubtitle in which the decoded subtitle will be stored, must be
3792  freed with avsubtitle_free if *got_sub_ptr is set.
3793  * @param[in,out] got_sub_ptr Zero if no subtitle could be decompressed, otherwise, it is nonzero.
3794  * @param[in] avpkt The input AVPacket containing the input buffer.
3795  */
3797  int *got_sub_ptr,
3798  AVPacket *avpkt);
3799 
3800 /**
3801  * @defgroup lavc_parsing Frame parsing
3802  * @{
3803  */
3807  AV_PICTURE_STRUCTURE_TOP_FIELD, //< coded as top field
3808  AV_PICTURE_STRUCTURE_BOTTOM_FIELD, //< coded as bottom field
3809  AV_PICTURE_STRUCTURE_FRAME, //< coded as frame
3810 };
3812 typedef struct AVCodecParserContext {
3813  void *priv_data;
3815  int64_t frame_offset; /* offset of the current frame */
3816  int64_t cur_offset; /* current offset
3817  (incremented by each av_parser_parse()) */
3818  int64_t next_frame_offset; /* offset of the next frame */
3819  /* video info */
3820  int pict_type; /* XXX: Put it back in AVCodecContext. */
3821  /**
3822  * This field is used for proper frame duration computation in lavf.
3823  * It signals, how much longer the frame duration of the current frame
3824  * is compared to normal frame duration.
3825  *
3826  * frame_duration = (1 + repeat_pict) * time_base
3827  *
3828  * It is used by codecs like H.264 to display telecined material.
3829  */
3830  int repeat_pict; /* XXX: Put it back in AVCodecContext. */
3831  int64_t pts; /* pts of the current frame */
3832  int64_t dts; /* dts of the current frame */
3833 
3834  /* private data */
3835  int64_t last_pts;
3836  int64_t last_dts;
3837  int fetch_timestamp;
3839 #define AV_PARSER_PTS_NB 4
3845  int flags;
3846 #define PARSER_FLAG_COMPLETE_FRAMES 0x0001
3847 #define PARSER_FLAG_ONCE 0x0002
3848 /// Set if the parser has a valid file offset
3849 #define PARSER_FLAG_FETCHED_OFFSET 0x0004
3850 #define PARSER_FLAG_USE_CODEC_TS 0x1000
3852  int64_t offset; ///< byte offset from starting packet start
3854 
3855  /**
3856  * Set by parser to 1 for key frames and 0 for non-key frames.
3857  * It is initialized to -1, so if the parser doesn't set this flag,
3858  * old-style fallback using AV_PICTURE_TYPE_I picture type as key frames
3859  * will be used.
3860  */
3861  int key_frame;
3862 
3863  /**
3864  * Time difference in stream time base units from the pts of this
3865  * packet to the point at which the output from the decoder has converged
3866  * independent from the availability of previous frames. That is, the
3867  * frames are virtually identical no matter if decoding started from
3868  * the very first frame or from this keyframe.
3869  * Is AV_NOPTS_VALUE if unknown.
3870  * This field is not the display duration of the current frame.
3871  * This field has no meaning if the packet does not have AV_PKT_FLAG_KEY
3872  * set.
3873  *
3874  * The purpose of this field is to allow seeking in streams that have no
3875  * keyframes in the conventional sense. It corresponds to the
3876  * recovery point SEI in H.264 and match_time_delta in NUT. It is also
3877  * essential for some types of subtitle streams to ensure that all
3878  * subtitles are correctly displayed after seeking.
3879  */
3880  int64_t convergence_duration;
3881 
3882  // Timestamp generation support:
3883  /**
3884  * Synchronization point for start of timestamp generation.
3885  *
3886  * Set to >0 for sync point, 0 for no sync point and <0 for undefined
3887  * (default).
3888  *
3889  * For example, this corresponds to presence of H.264 buffering period
3890  * SEI message.
3891  */
3892  int dts_sync_point;
3893 
3894  /**
3895  * Offset of the current timestamp against last timestamp sync point in
3896  * units of AVCodecContext.time_base.
3897  *
3898  * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
3899  * contain a valid timestamp offset.
3900  *
3901  * Note that the timestamp of sync point has usually a nonzero
3902  * dts_ref_dts_delta, which refers to the previous sync point. Offset of
3903  * the next frame after timestamp sync point will be usually 1.
3904  *
3905  * For example, this corresponds to H.264 cpb_removal_delay.
3906  */
3907  int dts_ref_dts_delta;
3908 
3909  /**
3910  * Presentation delay of current frame in units of AVCodecContext.time_base.
3911  *
3912  * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
3913  * contain valid non-negative timestamp delta (presentation time of a frame
3914  * must not lie in the past).
3915  *
3916  * This delay represents the difference between decoding and presentation
3917  * time of the frame.
3918  *
3919  * For example, this corresponds to H.264 dpb_output_delay.
3920  */
3921  int pts_dts_delta;
3922 
3923  /**
3924  * Position of the packet in file.
3925  *
3926  * Analogous to cur_frame_pts/dts
3927  */
3929 
3930  /**
3931  * Byte position of currently parsed frame in stream.
3932  */
3933  int64_t pos;
3934 
3935  /**
3936  * Previous frame byte position.
3937  */
3938  int64_t last_pos;
3939 
3940  /**
3941  * Duration of the current frame.
3942  * For audio, this is in units of 1 / AVCodecContext.sample_rate.
3943  * For all other types, this is in units of AVCodecContext.time_base.
3944  */
3945  int duration;
3948 
3949  /**
3950  * Indicate whether a picture is coded as a frame, top field or bottom field.
3951  *
3952  * For example, H.264 field_pic_flag equal to 0 corresponds to
3953  * AV_PICTURE_STRUCTURE_FRAME. An H.264 picture with field_pic_flag
3954  * equal to 1 and bottom_field_flag equal to 0 corresponds to
3955  * AV_PICTURE_STRUCTURE_TOP_FIELD.
3956  */
3960 typedef struct AVCodecParser {
3961  int codec_ids[5]; /* several codec IDs are permitted */
3965  AVCodecContext *avctx,
3966  const uint8_t **poutbuf, int *poutbuf_size,
3967  const uint8_t *buf, int buf_size);
3969  int (*split)(AVCodecContext *avctx, const uint8_t *buf, int buf_size);
3970  struct AVCodecParser *next;
3971 } AVCodecParser;
3972 
3974 
3977 
3978 /**
3979  * Parse a packet.
3980  *
3981  * @param s parser context.
3982  * @param avctx codec context.
3983  * @param poutbuf set to pointer to parsed buffer or NULL if not yet finished.
3984  * @param poutbuf_size set to size of parsed buffer or zero if not yet finished.
3985  * @param buf input buffer.
3986  * @param buf_size input length, to signal EOF, this should be 0 (so that the last frame can be output).
3987  * @param pts input presentation timestamp.
3988  * @param dts input decoding timestamp.
3989  * @param pos input byte position in stream.
3990  * @return the number of bytes of the input bitstream used.
3991  *
3992  * Example:
3993  * @code
3994  * while(in_len){
3995  * len = av_parser_parse2(myparser, AVCodecContext, &data, &size,
3996  * in_data, in_len,
3997  * pts, dts, pos);
3998  * in_data += len;
3999  * in_len -= len;
4000  *
4001  * if(size)
4002  * decode_frame(data, size);
4003  * }
4004  * @endcode
4005  */
4007  AVCodecContext *avctx,
4008  uint8_t **poutbuf, int *poutbuf_size,
4009  const uint8_t *buf, int buf_size,
4010  int64_t pts, int64_t dts,
4011  int64_t pos);
4012 
4013 /**
4014  * @return 0 if the output buffer is a subset of the input, 1 if it is allocated and must be freed
4015  * @deprecated use AVBitStreamFilter
4016  */
4018  AVCodecContext *avctx,
4019  uint8_t **poutbuf, int *poutbuf_size,
4020  const uint8_t *buf, int buf_size, int keyframe);
4022 
4023 /**
4024  * @}
4025  * @}
4026  */
4027 
4028 /**
4029  * @addtogroup lavc_encoding
4030  * @{
4031  */
4032 
4033 /**
4034  * Find a registered encoder with a matching codec ID.
4035  *
4036  * @param id AVCodecID of the requested encoder
4037  * @return An encoder if one was found, NULL otherwise.
4038  */
4040 
4041 /**
4042  * Find a registered encoder with the specified name.
4043  *
4044  * @param name name of the requested encoder
4045  * @return An encoder if one was found, NULL otherwise.
4046  */
4048 
4049 #if FF_API_OLD_ENCODE_AUDIO
4050 /**
4051  * Encode an audio frame from samples into buf.
4052  *
4053  * @deprecated Use avcodec_encode_audio2 instead.
4054  *
4055  * @note The output buffer should be at least FF_MIN_BUFFER_SIZE bytes large.
4056  * However, for codecs with avctx->frame_size equal to 0 (e.g. PCM) the user
4057  * will know how much space is needed because it depends on the value passed
4058  * in buf_size as described below. In that case a lower value can be used.
4059  *
4060  * @param avctx the codec context
4061  * @param[out] buf the output buffer
4062  * @param[in] buf_size the output buffer size
4063  * @param[in] samples the input buffer containing the samples
4064  * The number of samples read from this buffer is frame_size*channels,
4065  * both of which are defined in avctx.
4066  * For codecs which have avctx->frame_size equal to 0 (e.g. PCM) the number of
4067  * samples read from samples is equal to:
4068  * buf_size * 8 / (avctx->channels * av_get_bits_per_sample(avctx->codec_id))
4069  * This also implies that av_get_bits_per_sample() must not return 0 for these
4070  * codecs.
4071  * @return On error a negative value is returned, on success zero or the number
4072  * of bytes used to encode the data read from the input buffer.
4073  */
4074 int attribute_deprecated avcodec_encode_audio(AVCodecContext *avctx,
4075  uint8_t *buf, int buf_size,
4076  const short *samples);
4077 #endif
4078 
4079 /**
4080  * Encode a frame of audio.
4081  *
4082  * Takes input samples from frame and writes the next output packet, if
4083  * available, to avpkt. The output packet does not necessarily contain data for
4084  * the most recent frame, as encoders can delay, split, and combine input frames
4085  * internally as needed.
4086  *
4087  * @param avctx codec context
4088  * @param avpkt output AVPacket.
4089  * The user can supply an output buffer by setting
4090  * avpkt->data and avpkt->size prior to calling the
4091  * function, but if the size of the user-provided data is not
4092  * large enough, encoding will fail. If avpkt->data and
4093  * avpkt->size are set, avpkt->destruct must also be set. All
4094  * other AVPacket fields will be reset by the encoder using
4095  * av_init_packet(). If avpkt->data is NULL, the encoder will
4096  * allocate it. The encoder will set avpkt->size to the size
4097  * of the output packet.
4098  *
4099  * If this function fails or produces no output, avpkt will be
4100  * freed using av_free_packet() (i.e. avpkt->destruct will be
4101  * called to free the user supplied buffer).
4102  * @param[in] frame AVFrame containing the raw audio data to be encoded.
4103  * May be NULL when flushing an encoder that has the
4104  * CODEC_CAP_DELAY capability set.
4105  * If CODEC_CAP_VARIABLE_FRAME_SIZE is set, then each frame
4106  * can have any number of samples.
4107  * If it is not set, frame->nb_samples must be equal to
4108  * avctx->frame_size for all frames except the last.
4109  * The final frame may be smaller than avctx->frame_size.
4110  * @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
4111  * output packet is non-empty, and to 0 if it is
4112  * empty. If the function returns an error, the
4113  * packet can be assumed to be invalid, and the
4114  * value of got_packet_ptr is undefined and should
4115  * not be used.
4116  * @return 0 on success, negative error code on failure
4117  */
4118 int avcodec_encode_audio2(AVCodecContext *avctx, AVPacket *avpkt,
4119  const AVFrame *frame, int *got_packet_ptr);
4120 
4121 #if FF_API_OLD_ENCODE_VIDEO
4122 /**
4123  * @deprecated use avcodec_encode_video2() instead.
4124  *
4125  * Encode a video frame from pict into buf.
4126  * The input picture should be
4127  * stored using a specific format, namely avctx.pix_fmt.
4128  *
4129  * @param avctx the codec context
4130  * @param[out] buf the output buffer for the bitstream of encoded frame
4131  * @param[in] buf_size the size of the output buffer in bytes
4132  * @param[in] pict the input picture to encode
4133  * @return On error a negative value is returned, on success zero or the number
4134  * of bytes used from the output buffer.
4135  */
4137 int avcodec_encode_video(AVCodecContext *avctx, uint8_t *buf, int buf_size,
4138  const AVFrame *pict);
4139 #endif
4140 
4141 /**
4142  * Encode a frame of video.
4143  *
4144  * Takes input raw video data from frame and writes the next output packet, if
4145  * available, to avpkt. The output packet does not necessarily contain data for
4146  * the most recent frame, as encoders can delay and reorder input frames
4147  * internally as needed.
4148  *
4149  * @param avctx codec context
4150  * @param avpkt output AVPacket.
4151  * The user can supply an output buffer by setting
4152  * avpkt->data and avpkt->size prior to calling the
4153  * function, but if the size of the user-provided data is not
4154  * large enough, encoding will fail. All other AVPacket fields
4155  * will be reset by the encoder using av_init_packet(). If
4156  * avpkt->data is NULL, the encoder will allocate it.
4157  * The encoder will set avpkt->size to the size of the
4158  * output packet. The returned data (if any) belongs to the
4159  * caller, he is responsible for freeing it.
4160  *
4161  * If this function fails or produces no output, avpkt will be
4162  * freed using av_free_packet() (i.e. avpkt->destruct will be
4163  * called to free the user supplied buffer).
4164  * @param[in] frame AVFrame containing the raw video data to be encoded.
4165  * May be NULL when flushing an encoder that has the
4166  * CODEC_CAP_DELAY capability set.
4167  * @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
4168  * output packet is non-empty, and to 0 if it is
4169  * empty. If the function returns an error, the
4170  * packet can be assumed to be invalid, and the
4171  * value of got_packet_ptr is undefined and should
4172  * not be used.
4173  * @return 0 on success, negative error code on failure
4174  */
4175 int avcodec_encode_video2(AVCodecContext *avctx, AVPacket *avpkt,
4176  const AVFrame *frame, int *got_packet_ptr);
4177 
4178 int avcodec_encode_subtitle(AVCodecContext *avctx, uint8_t *buf, int buf_size,
4179  const AVSubtitle *sub);
4180 
4181 
4182 /**
4183  * @}
4184  */
4185 
4186 #if FF_API_AVCODEC_RESAMPLE
4187 /**
4188  * @defgroup lavc_resample Audio resampling
4189  * @ingroup libavc
4190  * @deprecated use libswresample instead
4191  *
4192  * @{
4193  */
4194 struct ReSampleContext;
4195 struct AVResampleContext;
4196 
4197 typedef struct ReSampleContext ReSampleContext;
4198 
4199 /**
4200  * Initialize audio resampling context.
4201  *
4202  * @param output_channels number of output channels
4203  * @param input_channels number of input channels
4204  * @param output_rate output sample rate
4205  * @param input_rate input sample rate
4206  * @param sample_fmt_out requested output sample format
4207  * @param sample_fmt_in input sample format
4208  * @param filter_length length of each FIR filter in the filterbank relative to the cutoff frequency
4209  * @param log2_phase_count log2 of the number of entries in the polyphase filterbank
4210  * @param linear if 1 then the used FIR filter will be linearly interpolated
4211  between the 2 closest, if 0 the closest will be used
4212  * @param cutoff cutoff frequency, 1.0 corresponds to half the output sampling rate
4213  * @return allocated ReSampleContext, NULL if error occurred
4214  */
4216 ReSampleContext *av_audio_resample_init(int output_channels, int input_channels,
4217  int output_rate, int input_rate,
4218  enum AVSampleFormat sample_fmt_out,
4219  enum AVSampleFormat sample_fmt_in,
4220  int filter_length, int log2_phase_count,
4221  int linear, double cutoff);
4222 
4224 int audio_resample(ReSampleContext *s, short *output, short *input, int nb_samples);
4225 
4226 /**
4227  * Free resample context.
4228  *
4229  * @param s a non-NULL pointer to a resample context previously
4230  * created with av_audio_resample_init()
4231  */
4233 void audio_resample_close(ReSampleContext *s);
4234 
4235 
4236 /**
4237  * Initialize an audio resampler.
4238  * Note, if either rate is not an integer then simply scale both rates up so they are.
4239  * @param filter_length length of each FIR filter in the filterbank relative to the cutoff freq
4240  * @param log2_phase_count log2 of the number of entries in the polyphase filterbank
4241  * @param linear If 1 then the used FIR filter will be linearly interpolated
4242  between the 2 closest, if 0 the closest will be used
4243  * @param cutoff cutoff frequency, 1.0 corresponds to half the output sampling rate
4244  */
4246 struct AVResampleContext *av_resample_init(int out_rate, int in_rate, int filter_length, int log2_phase_count, int linear, double cutoff);
4247 
4248 /**
4249  * Resample an array of samples using a previously configured context.
4250  * @param src an array of unconsumed samples
4251  * @param consumed the number of samples of src which have been consumed are returned here
4252  * @param src_size the number of unconsumed samples available
4253  * @param dst_size the amount of space in samples available in dst
4254  * @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.
4255  * @return the number of samples written in dst or -1 if an error occurred
4256  */
4258 int av_resample(struct AVResampleContext *c, short *dst, short *src, int *consumed, int src_size, int dst_size, int update_ctx);
4259 
4260 
4261 /**
4262  * Compensate samplerate/timestamp drift. The compensation is done by changing
4263  * the resampler parameters, so no audible clicks or similar distortions occur
4264  * @param compensation_distance distance in output samples over which the compensation should be performed
4265  * @param sample_delta number of output samples which should be output less
4266  *
4267  * example: av_resample_compensate(c, 10, 500)
4268  * here instead of 510 samples only 500 samples would be output
4269  *
4270  * note, due to rounding the actual compensation might be slightly different,
4271  * especially if the compensation_distance is large and the in_rate used during init is small
4272  */
4274 void av_resample_compensate(struct AVResampleContext *c, int sample_delta, int compensation_distance);
4276 void av_resample_close(struct AVResampleContext *c);
4277 
4278 /**
4279  * @}
4280  */
4281 #endif
4282 
4283 /**
4284  * @addtogroup lavc_picture
4285  * @{
4286  */
4287 
4288 /**
4289  * Allocate memory for a picture. Call avpicture_free() to free it.
4290  *
4291  * @see avpicture_fill()
4292  *
4293  * @param picture the picture to be filled in
4294  * @param pix_fmt the format of the picture
4295  * @param width the width of the picture
4296  * @param height the height of the picture
4297  * @return zero if successful, a negative value if not
4298  */
4299 int avpicture_alloc(AVPicture *picture, enum AVPixelFormat pix_fmt, int width, int height);
4300 
4301 /**
4302  * Free a picture previously allocated by avpicture_alloc().
4303  * The data buffer used by the AVPicture is freed, but the AVPicture structure
4304  * itself is not.
4305  *
4306  * @param picture the AVPicture to be freed
4307  */
4308 void avpicture_free(AVPicture *picture);
4309 
4310 /**
4311  * Fill in the AVPicture fields, always assume a linesize alignment of
4312  * 1.
4313  *
4314  * @see av_image_fill_arrays()
4315  */
4316 int avpicture_fill(AVPicture *picture, const uint8_t *ptr,
4317  enum AVPixelFormat pix_fmt, int width, int height);
4318 
4319 /**
4320  * Copy pixel data from an AVPicture into a buffer, always assume a
4321  * linesize alignment of 1.
4322  *
4323  * @see av_image_copy_to_buffer()
4324  */
4326  int width, int height,
4327  unsigned char *dest, int dest_size);
4328 
4329 /**
4330  * Calculate the size in bytes that a picture of the given width and height
4331  * would occupy if stored in the given picture format.
4332  * Always assume a linesize alignment of 1.
4333  *
4334  * @see av_image_get_buffer_size().
4335  */
4337 
4338 #if FF_API_DEINTERLACE
4339 /**
4340  * deinterlace - if not supported return -1
4341  *
4342  * @deprecated - use yadif (in libavfilter) instead
4343  */
4345 int avpicture_deinterlace(AVPicture *dst, const AVPicture *src,
4346  enum AVPixelFormat pix_fmt, int width, int height);
4347 #endif
4348 /**
4349  * Copy image src to dst. Wraps av_image_copy().
4350  */
4351 void av_picture_copy(AVPicture *dst, const AVPicture *src,
4352  enum AVPixelFormat pix_fmt, int width, int height);
4353 
4354 /**
4355  * Crop image top and left side.
4356  */
4357 int av_picture_crop(AVPicture *dst, const AVPicture *src,
4358  enum AVPixelFormat pix_fmt, int top_band, int left_band);
4359 
4360 /**
4361  * Pad image.
4362  */
4363 int av_picture_pad(AVPicture *dst, const AVPicture *src, int height, int width, enum AVPixelFormat pix_fmt,
4364  int padtop, int padbottom, int padleft, int padright, int *color);
4365 
4366 /**
4367  * @}
4368  */
4369 
4370 /**
4371  * @defgroup lavc_misc Utility functions
4372  * @ingroup libavc
4373  *
4374  * Miscellaneous utility functions related to both encoding and decoding
4375  * (or neither).
4376  * @{
4377  */
4378 
4379 /**
4380  * @defgroup lavc_misc_pixfmt Pixel formats
4381  *
4382  * Functions for working with pixel formats.
4383  * @{
4384  */
4385 
4386 /**
4387  * Utility function to access log2_chroma_w log2_chroma_h from
4388  * the pixel format AVPixFmtDescriptor.
4389  *
4390  * This function asserts that pix_fmt is valid. See av_pix_fmt_get_chroma_sub_sample
4391  * for one that returns a failure code and continues in case of invalid
4392  * pix_fmts.
4393  *
4394  * @param[in] pix_fmt the pixel format
4395  * @param[out] h_shift store log2_chroma_w
4396  * @param[out] v_shift store log2_chroma_h
4397  *
4398  * @see av_pix_fmt_get_chroma_sub_sample
4399  */
4400 
4401 void avcodec_get_chroma_sub_sample(enum AVPixelFormat pix_fmt, int *h_shift, int *v_shift);
4402 
4403 /**
4404  * Return a value representing the fourCC code associated to the
4405  * pixel format pix_fmt, or 0 if no associated fourCC code can be
4406  * found.
4407  */
4410 #define FF_LOSS_RESOLUTION 0x0001 /**< loss due to resolution change */
4411 #define FF_LOSS_DEPTH 0x0002 /**< loss due to color depth change */
4412 #define FF_LOSS_COLORSPACE 0x0004 /**< loss due to color space conversion */
4413 #define FF_LOSS_ALPHA 0x0008 /**< loss of alpha bits */
4414 #define FF_LOSS_COLORQUANT 0x0010 /**< loss due to color quantization */
4415 #define FF_LOSS_CHROMA 0x0020 /**< loss of chroma (e.g. RGB to gray conversion) */
4416 
4417 /**
4418  * Compute what kind of losses will occur when converting from one specific
4419  * pixel format to another.
4420  * When converting from one pixel format to another, information loss may occur.
4421  * For example, when converting from RGB24 to GRAY, the color information will
4422  * be lost. Similarly, other losses occur when converting from some formats to
4423  * other formats. These losses can involve loss of chroma, but also loss of
4424  * resolution, loss of color depth, loss due to the color space conversion, loss
4425  * of the alpha bits or loss due to color quantization.
4426  * avcodec_get_fix_fmt_loss() informs you about the various types of losses
4427  * which will occur when converting from one pixel format to another.
4428  *
4429  * @param[in] dst_pix_fmt destination pixel format
4430  * @param[in] src_pix_fmt source pixel format
4431  * @param[in] has_alpha Whether the source pixel format alpha channel is used.
4432  * @return Combination of flags informing you what kind of losses will occur
4433  * (maximum loss for an invalid dst_pix_fmt).
4434  */
4435 int avcodec_get_pix_fmt_loss(enum AVPixelFormat dst_pix_fmt, enum AVPixelFormat src_pix_fmt,
4436  int has_alpha);
4437 
4438 /**
4439  * Find the best pixel format to convert to given a certain source pixel
4440  * format. When converting from one pixel format to another, information loss
4441  * may occur. For example, when converting from RGB24 to GRAY, the color
4442  * information will be lost. Similarly, other losses occur when converting from
4443  * some formats to other formats. avcodec_find_best_pix_fmt_of_2() searches which of
4444  * the given pixel formats should be used to suffer the least amount of loss.
4445  * The pixel formats from which it chooses one, are determined by the
4446  * pix_fmt_list parameter.
4447  *
4448  *
4449  * @param[in] pix_fmt_list AV_PIX_FMT_NONE terminated array of pixel formats to choose from
4450  * @param[in] src_pix_fmt source pixel format
4451  * @param[in] has_alpha Whether the source pixel format alpha channel is used.
4452  * @param[out] loss_ptr Combination of flags informing you what kind of losses will occur.
4453  * @return The best pixel format to convert to or -1 if none was found.
4454  */
4456  enum AVPixelFormat src_pix_fmt,
4457  int has_alpha, int *loss_ptr);
4458 
4459 /**
4460  * Find the best pixel format to convert to given a certain source pixel
4461  * format and a selection of two destination pixel formats. When converting from
4462  * one pixel format to another, information loss may occur. For example, when converting
4463  * from RGB24 to GRAY, the color information will be lost. Similarly, other losses occur when
4464  * converting from some formats to other formats. avcodec_find_best_pix_fmt_of_2() selects which of
4465  * the given pixel formats should be used to suffer the least amount of loss.
4466  *
4467  * If one of the destination formats is AV_PIX_FMT_NONE the other pixel format (if valid) will be
4468  * returned.
4469  *
4470  * @code
4471  * src_pix_fmt = AV_PIX_FMT_YUV420P;
4472  * dst_pix_fmt1= AV_PIX_FMT_RGB24;
4473  * dst_pix_fmt2= AV_PIX_FMT_GRAY8;
4474  * dst_pix_fmt3= AV_PIX_FMT_RGB8;
4475  * loss= FF_LOSS_CHROMA; // don't care about chroma loss, so chroma loss will be ignored.
4476  * dst_pix_fmt = avcodec_find_best_pix_fmt_of_2(dst_pix_fmt1, dst_pix_fmt2, src_pix_fmt, alpha, &loss);
4477  * dst_pix_fmt = avcodec_find_best_pix_fmt_of_2(dst_pix_fmt, dst_pix_fmt3, src_pix_fmt, alpha, &loss);
4478  * @endcode
4479  *
4480  * @param[in] dst_pix_fmt1 One of the two destination pixel formats to choose from
4481  * @param[in] dst_pix_fmt2 The other of the two destination pixel formats to choose from
4482  * @param[in] src_pix_fmt Source pixel format
4483  * @param[in] has_alpha Whether the source pixel format alpha channel is used.
4484  * @param[in, out] loss_ptr Combination of loss flags. In: selects which of the losses to ignore, i.e.
4485  * NULL or value of zero means we care about all losses. Out: the loss
4486  * that occurs when converting from src to selected dst pixel format.
4487  * @return The best pixel format to convert to or -1 if none was found.
4488  */
4489 enum AVPixelFormat avcodec_find_best_pix_fmt_of_2(enum AVPixelFormat dst_pix_fmt1, enum AVPixelFormat dst_pix_fmt2,
4490  enum AVPixelFormat src_pix_fmt, int has_alpha, int *loss_ptr);
4491 
4493 #if AV_HAVE_INCOMPATIBLE_LIBAV_ABI
4495  enum AVPixelFormat src_pix_fmt,
4496  int has_alpha, int *loss_ptr);
4497 #else
4498 enum AVPixelFormat avcodec_find_best_pix_fmt2(enum AVPixelFormat dst_pix_fmt1, enum AVPixelFormat dst_pix_fmt2,
4499  enum AVPixelFormat src_pix_fmt, int has_alpha, int *loss_ptr);
4500 #endif
4501 
4502 
4504 
4505 /**
4506  * @}
4507  */
4508 
4510 
4511 /**
4512  * Put a string representing the codec tag codec_tag in buf.
4513  *
4514  * @param buf_size size in bytes of buf
4515  * @return the length of the string that would have been generated if
4516  * enough space had been available, excluding the trailing null
4517  */
4518 size_t av_get_codec_tag_string(char *buf, size_t buf_size, unsigned int codec_tag);
4519 
4520 void avcodec_string(char *buf, int buf_size, AVCodecContext *enc, int encode);
4521 
4522 /**
4523  * Return a name for the specified profile, if available.
4524  *
4525  * @param codec the codec that is searched for the given profile
4526  * @param profile the profile value for which a name is requested
4527  * @return A name for the profile if found, NULL otherwise.
4528  */
4529 const char *av_get_profile_name(const AVCodec *codec, int profile);
4530 
4531 int avcodec_default_execute(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2),void *arg, int *ret, int count, int size);
4532 int avcodec_default_execute2(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2, int, int),void *arg, int *ret, int count);
4533 //FIXME func typedef
4534 
4535 /**
4536  * Fill AVFrame audio data and linesize pointers.
4537  *
4538  * The buffer buf must be a preallocated buffer with a size big enough
4539  * to contain the specified samples amount. The filled AVFrame data
4540  * pointers will point to this buffer.
4541  *
4542  * AVFrame extended_data channel pointers are allocated if necessary for
4543  * planar audio.
4544  *
4545  * @param frame the AVFrame
4546  * frame->nb_samples must be set prior to calling the
4547  * function. This function fills in frame->data,
4548  * frame->extended_data, frame->linesize[0].
4549  * @param nb_channels channel count
4550  * @param sample_fmt sample format
4551  * @param buf buffer to use for frame data
4552  * @param buf_size size of buffer
4553  * @param align plane size sample alignment (0 = default)
4554  * @return >=0 on success, negative error code on failure
4555  * @todo return the size in bytes required to store the samples in
4556  * case of success, at the next libavutil bump
4557  */
4559  enum AVSampleFormat sample_fmt, const uint8_t *buf,
4560  int buf_size, int align);
4561 
4562 /**
4563  * Flush buffers, should be called when seeking or when switching to a different stream.
4564  */
4566 
4567 /**
4568  * Return codec bits per sample.
4569  *
4570  * @param[in] codec_id the codec
4571  * @return Number of bits per sample or zero if unknown for the given codec.
4572  */
4574 
4575 /**
4576  * Return the PCM codec associated with a sample format.
4577  * @param be endianness, 0 for little, 1 for big,
4578  * -1 (or anything else) for native
4579  * @return AV_CODEC_ID_PCM_* or AV_CODEC_ID_NONE
4580  */
4581 enum AVCodecID av_get_pcm_codec(enum AVSampleFormat fmt, int be);
4582 
4583 /**
4584  * Return codec bits per sample.
4585  * Only return non-zero if the bits per sample is exactly correct, not an
4586  * approximation.
4587  *
4588  * @param[in] codec_id the codec
4589  * @return Number of bits per sample or zero if unknown for the given codec.
4590  */
4592 
4593 /**
4594  * Return audio frame duration.
4595  *
4596  * @param avctx codec context
4597  * @param frame_bytes size of the frame, or 0 if unknown
4598  * @return frame duration, in samples, if known. 0 if not able to
4599  * determine.
4600  */
4601 int av_get_audio_frame_duration(AVCodecContext *avctx, int frame_bytes);
4602 
4605  void *priv_data;
4610 
4612 typedef struct AVBitStreamFilter {
4613  const char *name;
4615  int (*filter)(AVBitStreamFilterContext *bsfc,
4616  AVCodecContext *avctx, const char *args,
4617  uint8_t **poutbuf, int *poutbuf_size,
4618  const uint8_t *buf, int buf_size, int keyframe);
4620  struct AVBitStreamFilter *next;
4622 
4623 /**
4624  * Register a bitstream filter.
4625  *
4626  * The filter will be accessible to the application code through
4627  * av_bitstream_filter_next() or can be directly initialized with
4628  * av_bitstream_filter_init().
4629  *
4630  * @see avcodec_register_all()
4631  */
4633 
4634 /**
4635  * Create and initialize a bitstream filter context given a bitstream
4636  * filter name.
4637  *
4638  * The returned context must be freed with av_bitstream_filter_close().
4639  *
4640  * @param name the name of the bitstream filter
4641  * @return a bitstream filter context if a matching filter was found
4642  * and successfully initialized, NULL otherwise
4643  */
4645 
4646 /**
4647  * Filter bitstream.
4648  *
4649  * This function filters the buffer buf with size buf_size, and places the
4650  * filtered buffer in the buffer pointed to by poutbuf.
4651  *
4652  * The output buffer must be freed by the caller.
4653  *
4654  * @param bsfc bitstream filter context created by av_bitstream_filter_init()
4655  * @param avctx AVCodecContext accessed by the filter, may be NULL.
4656  * If specified, this must point to the encoder context of the
4657  * output stream the packet is sent to.
4658  * @param args arguments which specify the filter configuration, may be NULL
4659  * @param poutbuf pointer which is updated to point to the filtered buffer
4660  * @param poutbuf_size pointer which is updated to the filtered buffer size in bytes
4661  * @param buf buffer containing the data to filter
4662  * @param buf_size size in bytes of buf
4663  * @param keyframe set to non-zero if the buffer to filter corresponds to a key-frame packet data
4664  * @return >= 0 in case of success, or a negative error code in case of failure
4665  *
4666  * If the return value is positive, an output buffer is allocated and
4667  * is availble in *poutbuf, and is distinct from the input buffer.
4668  *
4669  * If the return value is 0, the output output buffer is not allocated
4670  * and the output buffer should be considered identical to the input
4671  * buffer, or in case *poutbuf was set it points to the input buffer
4672  * (not necessarily to its starting address).
4673  */
4675  AVCodecContext *avctx, const char *args,
4676  uint8_t **poutbuf, int *poutbuf_size,
4677  const uint8_t *buf, int buf_size, int keyframe);
4678 
4679 /**
4680  * Release bitstream filter context.
4681  *
4682  * @param bsf the bitstream filter context created with
4683  * av_bitstream_filter_init(), can be NULL
4684  */
4686 
4687 /**
4688  * If f is NULL, return the first registered bitstream filter,
4689  * if f is non-NULL, return the next registered bitstream filter
4690  * after f, or NULL if f is the last one.
4691  *
4692  * This function can be used to iterate over all registered bitstream
4693  * filters.
4694  */
4696 
4697 /* memory */
4698 
4699 /**
4700  * Reallocate the given block if it is not large enough, otherwise do nothing.
4701  *
4702  * @see av_realloc
4703  */
4704 void *av_fast_realloc(void *ptr, unsigned int *size, size_t min_size);
4705 
4706 /**
4707  * Allocate a buffer, reusing the given one if large enough.
4708  *
4709  * Contrary to av_fast_realloc the current buffer contents might not be
4710  * preserved and on error the old buffer is freed, thus no special
4711  * handling to avoid memleaks is necessary.
4712  *
4713  * @param ptr pointer to pointer to already allocated buffer, overwritten with pointer to new buffer
4714  * @param size size of the buffer *ptr points to
4715  * @param min_size minimum size of *ptr buffer after returning, *ptr will be NULL and
4716  * *size 0 if an error occurred.
4717  */
4718 void av_fast_malloc(void *ptr, unsigned int *size, size_t min_size);
4719 
4720 /**
4721  * Same behaviour av_fast_malloc but the buffer has additional
4722  * FF_INPUT_BUFFER_PADDING_SIZE at the end which will will always be 0.
4723  *
4724  * In addition the whole buffer will initially and after resizes
4725  * be 0-initialized so that no uninitialized data will ever appear.
4726  */
4727 void av_fast_padded_malloc(void *ptr, unsigned int *size, size_t min_size);
4728 
4729 /**
4730  * Same behaviour av_fast_padded_malloc except that buffer will always
4731  * be 0-initialized after call.
4732  */
4733 void av_fast_padded_mallocz(void *ptr, unsigned int *size, size_t min_size);
4734 
4735 /**
4736  * Encode extradata length to a buffer. Used by xiph codecs.
4737  *
4738  * @param s buffer to write to; must be at least (v/255+1) bytes long
4739  * @param v size of extradata in bytes
4740  * @return number of bytes written to the buffer.
4741  */
4742 unsigned int av_xiphlacing(unsigned char *s, unsigned int v);
4743 
4744 #if FF_API_MISSING_SAMPLE
4745 /**
4746  * Log a generic warning message about a missing feature. This function is
4747  * intended to be used internally by FFmpeg (libavcodec, libavformat, etc.)
4748  * only, and would normally not be used by applications.
4749  * @param[in] avc a pointer to an arbitrary struct of which the first field is
4750  * a pointer to an AVClass struct
4751  * @param[in] feature string containing the name of the missing feature
4752  * @param[in] want_sample indicates if samples are wanted which exhibit this feature.
4753  * If want_sample is non-zero, additional verbage will be added to the log
4754  * message which tells the user how to report samples to the development
4755  * mailing list.
4756  * @deprecated Use avpriv_report_missing_feature() instead.
4757  */
4759 void av_log_missing_feature(void *avc, const char *feature, int want_sample);
4760 
4761 /**
4762  * Log a generic warning message asking for a sample. This function is
4763  * intended to be used internally by FFmpeg (libavcodec, libavformat, etc.)
4764  * only, and would normally not be used by applications.
4765  * @param[in] avc a pointer to an arbitrary struct of which the first field is
4766  * a pointer to an AVClass struct
4767  * @param[in] msg string containing an optional message, or NULL if no message
4768  * @deprecated Use avpriv_request_sample() instead.
4769  */
4771 void av_log_ask_for_sample(void *avc, const char *msg, ...) av_printf_format(2, 3);
4772 #endif /* FF_API_MISSING_SAMPLE */
4773 
4774 /**
4775  * Register the hardware accelerator hwaccel.
4776  */
4777 void av_register_hwaccel(AVHWAccel *hwaccel);
4778 
4779 /**
4780  * If hwaccel is NULL, returns the first registered hardware accelerator,
4781  * if hwaccel is non-NULL, returns the next registered hardware accelerator
4782  * after hwaccel, or NULL if hwaccel is the last one.
4783  */
4785 
4786 
4787 /**
4788  * Lock operation used by lockmgr
4789  */
4790 enum AVLockOp {
4791  AV_LOCK_CREATE, ///< Create a mutex
4792  AV_LOCK_OBTAIN, ///< Lock the mutex
4793  AV_LOCK_RELEASE, ///< Unlock the mutex
4794  AV_LOCK_DESTROY, ///< Free mutex resources
4795 };
4796 
4797 /**
4798  * Register a user provided lock manager supporting the operations
4799  * specified by AVLockOp. mutex points to a (void *) where the
4800  * lockmgr should store/get a pointer to a user allocated mutex. It's
4801  * NULL upon AV_LOCK_CREATE and != NULL for all other ops.
4802  *
4803  * @param cb User defined callback. Note: FFmpeg may invoke calls to this
4804  * callback during the call to av_lockmgr_register().
4805  * Thus, the application must be prepared to handle that.
4806  * If cb is set to NULL the lockmgr will be unregistered.
4807  * Also note that during unregistration the previously registered
4808  * lockmgr callback may also be invoked.
4809  */
4810 int av_lockmgr_register(int (*cb)(void **mutex, enum AVLockOp op));
4811 
4812 /**
4813  * Get the type of the given codec.
4814  */
4816 
4817 /**
4818  * Get the name of a codec.
4819  * @return a static string identifying the codec; never NULL
4820  */
4821 const char *avcodec_get_name(enum AVCodecID id);
4822 
4823 /**
4824  * @return a positive value if s is open (i.e. avcodec_open2() was called on it
4825  * with no corresponding avcodec_close()), 0 otherwise.
4826  */
4828 
4829 /**
4830  * @return a non-zero number if codec is an encoder, zero otherwise
4831  */
4832 int av_codec_is_encoder(const AVCodec *codec);
4833 
4834 /**
4835  * @return a non-zero number if codec is a decoder, zero otherwise
4836  */
4837 int av_codec_is_decoder(const AVCodec *codec);
4838 
4839 /**
4840  * @return descriptor for given codec ID or NULL if no descriptor exists.
4841  */
4843 
4844 /**
4845  * Iterate over all codec descriptors known to libavcodec.
4846  *
4847  * @param prev previous descriptor. NULL to get the first descriptor.
4848  *
4849  * @return next descriptor or NULL after the last descriptor
4850  */
4852 
4853 /**
4854  * @return codec descriptor with the given name or NULL if no such descriptor
4855  * exists.
4856  */
4858 
4859 /**
4860  * @}
4861  */
4862 
4863 #endif /* AVCODEC_AVCODEC_H */