2 * copyright (c) 2001 Fabrice Bellard
4 * This file is part of Libav.
6 * Libav 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.
11 * Libav 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.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with Libav; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 #ifndef AVCODEC_AVCODEC_H
22 #define AVCODEC_AVCODEC_H
27 * Libavcodec external API header
31 #include "libavutil/samplefmt.h"
32 #include "libavutil/attributes.h"
33 #include "libavutil/avutil.h"
34 #include "libavutil/buffer.h"
35 #include "libavutil/cpu.h"
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"
44 #if FF_API_FAST_MALLOC
45 // to provide fast_*alloc
46 #include "libavutil/mem.h"
50 * @defgroup libavc Encoding/Decoding Library
53 * @defgroup lavc_decoding Decoding
57 * @defgroup lavc_encoding Encoding
61 * @defgroup lavc_codec Codecs
63 * @defgroup lavc_codec_native Native Codecs
66 * @defgroup lavc_codec_wrappers External library wrappers
69 * @defgroup lavc_codec_hwaccel Hardware Accelerators bridge
73 * @defgroup lavc_internal Internal
81 * @defgroup lavc_core Core functions/structures.
84 * Basic definitions, functions for querying libavcodec capabilities,
85 * allocating core structures, etc.
91 * Identify the syntax and semantics of the bitstream.
92 * The principle is roughly:
93 * Two decoders with the same ID can decode the same streams.
94 * Two encoders with the same ID can encode compatible streams.
95 * There may be slight deviations from the principle due to implementation
98 * If you add a codec ID to this list, add it so that
99 * 1. no value of a existing codec ID changes (that would break ABI),
100 * 2. it is as close as possible to similar codecs.
102 * After adding new codec IDs, do not forget to add an entry to the codec
103 * descriptor list and bump libavcodec minor version.
109 AV_CODEC_ID_MPEG1VIDEO,
110 AV_CODEC_ID_MPEG2VIDEO, ///< preferred ID for MPEG-1/2 video decoding
112 AV_CODEC_ID_MPEG2VIDEO_XVMC,
113 #endif /* FF_API_XVMC */
124 AV_CODEC_ID_RAWVIDEO,
125 AV_CODEC_ID_MSMPEG4V1,
126 AV_CODEC_ID_MSMPEG4V2,
127 AV_CODEC_ID_MSMPEG4V3,
150 AV_CODEC_ID_INTERPLAY_VIDEO,
157 AV_CODEC_ID_MSVIDEO1,
162 AV_CODEC_ID_TRUEMOTION1,
163 AV_CODEC_ID_VMDVIDEO,
188 AV_CODEC_ID_TRUEMOTION2,
194 AV_CODEC_ID_SMACKVIDEO,
199 AV_CODEC_ID_JPEG2000,
205 AV_CODEC_ID_DSICINVIDEO,
206 AV_CODEC_ID_TIERTEXSEQVIDEO,
214 AV_CODEC_ID_BETHSOFTVID,
226 AV_CODEC_ID_ESCAPE124,
230 AV_CODEC_ID_MOTIONPIXELS,
242 AV_CODEC_ID_FLASHSV2,
243 AV_CODEC_ID_CDGRAPHICS,
246 AV_CODEC_ID_BINKVIDEO,
247 AV_CODEC_ID_IFF_ILBM,
248 AV_CODEC_ID_IFF_BYTERUN1,
254 AV_CODEC_ID_A64_MULTI,
255 AV_CODEC_ID_A64_MULTI5,
258 AV_CODEC_ID_LAGARITH,
262 AV_CODEC_ID_WMV3IMAGE,
263 AV_CODEC_ID_VC1IMAGE,
265 AV_CODEC_ID_BMV_VIDEO,
272 AV_CODEC_ID_ZEROCODEC,
281 AV_CODEC_ID_ESCAPE130,
284 AV_CODEC_ID_HNM4_VIDEO,
287 AV_CODEC_ID_ALIAS_PIX,
288 AV_CODEC_ID_BRENDER_PIX,
289 AV_CODEC_ID_PAF_VIDEO,
302 /* various PCM "codecs" */
303 AV_CODEC_ID_FIRST_AUDIO = 0x10000, ///< A dummy id pointing at the start of audio codecs
304 AV_CODEC_ID_PCM_S16LE = 0x10000,
305 AV_CODEC_ID_PCM_S16BE,
306 AV_CODEC_ID_PCM_U16LE,
307 AV_CODEC_ID_PCM_U16BE,
310 AV_CODEC_ID_PCM_MULAW,
311 AV_CODEC_ID_PCM_ALAW,
312 AV_CODEC_ID_PCM_S32LE,
313 AV_CODEC_ID_PCM_S32BE,
314 AV_CODEC_ID_PCM_U32LE,
315 AV_CODEC_ID_PCM_U32BE,
316 AV_CODEC_ID_PCM_S24LE,
317 AV_CODEC_ID_PCM_S24BE,
318 AV_CODEC_ID_PCM_U24LE,
319 AV_CODEC_ID_PCM_U24BE,
320 AV_CODEC_ID_PCM_S24DAUD,
321 AV_CODEC_ID_PCM_ZORK,
322 AV_CODEC_ID_PCM_S16LE_PLANAR,
324 AV_CODEC_ID_PCM_F32BE,
325 AV_CODEC_ID_PCM_F32LE,
326 AV_CODEC_ID_PCM_F64BE,
327 AV_CODEC_ID_PCM_F64LE,
328 AV_CODEC_ID_PCM_BLURAY,
331 AV_CODEC_ID_PCM_S8_PLANAR,
332 AV_CODEC_ID_PCM_S24LE_PLANAR,
333 AV_CODEC_ID_PCM_S32LE_PLANAR,
334 AV_CODEC_ID_PCM_S16BE_PLANAR,
336 /* various ADPCM codecs */
337 AV_CODEC_ID_ADPCM_IMA_QT = 0x11000,
338 AV_CODEC_ID_ADPCM_IMA_WAV,
339 AV_CODEC_ID_ADPCM_IMA_DK3,
340 AV_CODEC_ID_ADPCM_IMA_DK4,
341 AV_CODEC_ID_ADPCM_IMA_WS,
342 AV_CODEC_ID_ADPCM_IMA_SMJPEG,
343 AV_CODEC_ID_ADPCM_MS,
344 AV_CODEC_ID_ADPCM_4XM,
345 AV_CODEC_ID_ADPCM_XA,
346 AV_CODEC_ID_ADPCM_ADX,
347 AV_CODEC_ID_ADPCM_EA,
348 AV_CODEC_ID_ADPCM_G726,
349 AV_CODEC_ID_ADPCM_CT,
350 AV_CODEC_ID_ADPCM_SWF,
351 AV_CODEC_ID_ADPCM_YAMAHA,
352 AV_CODEC_ID_ADPCM_SBPRO_4,
353 AV_CODEC_ID_ADPCM_SBPRO_3,
354 AV_CODEC_ID_ADPCM_SBPRO_2,
355 AV_CODEC_ID_ADPCM_THP,
356 AV_CODEC_ID_ADPCM_IMA_AMV,
357 AV_CODEC_ID_ADPCM_EA_R1,
358 AV_CODEC_ID_ADPCM_EA_R3,
359 AV_CODEC_ID_ADPCM_EA_R2,
360 AV_CODEC_ID_ADPCM_IMA_EA_SEAD,
361 AV_CODEC_ID_ADPCM_IMA_EA_EACS,
362 AV_CODEC_ID_ADPCM_EA_XAS,
363 AV_CODEC_ID_ADPCM_EA_MAXIS_XA,
364 AV_CODEC_ID_ADPCM_IMA_ISS,
365 AV_CODEC_ID_ADPCM_G722,
366 AV_CODEC_ID_ADPCM_IMA_APC,
367 AV_CODEC_ID_ADPCM_VIMA,
370 AV_CODEC_ID_AMR_NB = 0x12000,
373 /* RealAudio codecs*/
374 AV_CODEC_ID_RA_144 = 0x13000,
377 /* various DPCM codecs */
378 AV_CODEC_ID_ROQ_DPCM = 0x14000,
379 AV_CODEC_ID_INTERPLAY_DPCM,
380 AV_CODEC_ID_XAN_DPCM,
381 AV_CODEC_ID_SOL_DPCM,
384 AV_CODEC_ID_MP2 = 0x15000,
385 AV_CODEC_ID_MP3, ///< preferred ID for decoding MPEG audio layer 1, 2 or 3
395 AV_CODEC_ID_VMDAUDIO,
401 AV_CODEC_ID_WESTWOOD_SND1,
402 AV_CODEC_ID_GSM, ///< as in Berlin toast format
405 AV_CODEC_ID_TRUESPEECH,
407 AV_CODEC_ID_SMACKAUDIO,
410 AV_CODEC_ID_DSICINAUDIO,
412 AV_CODEC_ID_MUSEPACK7,
414 AV_CODEC_ID_GSM_MS, /* as found in WAV */
420 AV_CODEC_ID_NELLYMOSER,
421 AV_CODEC_ID_MUSEPACK8,
423 AV_CODEC_ID_WMAVOICE,
425 AV_CODEC_ID_WMALOSSLESS,
434 AV_CODEC_ID_BINKAUDIO_RDFT,
435 AV_CODEC_ID_BINKAUDIO_DCT,
436 AV_CODEC_ID_AAC_LATM,
441 AV_CODEC_ID_8SVX_EXP,
442 AV_CODEC_ID_8SVX_FIB,
443 AV_CODEC_ID_BMV_AUDIO,
448 AV_CODEC_ID_COMFORT_NOISE,
450 AV_CODEC_ID_METASOUND,
451 AV_CODEC_ID_PAF_AUDIO,
455 /* subtitle codecs */
456 AV_CODEC_ID_FIRST_SUBTITLE = 0x17000, ///< A dummy ID pointing at the start of subtitle codecs.
457 AV_CODEC_ID_DVD_SUBTITLE = 0x17000,
458 AV_CODEC_ID_DVB_SUBTITLE,
459 AV_CODEC_ID_TEXT, ///< raw UTF-8 text
462 AV_CODEC_ID_MOV_TEXT,
463 AV_CODEC_ID_HDMV_PGS_SUBTITLE,
464 AV_CODEC_ID_DVB_TELETEXT,
467 /* other specific kind of codecs (generally used for attachments) */
468 AV_CODEC_ID_FIRST_UNKNOWN = 0x18000, ///< A dummy ID pointing at the start of various fake codecs.
469 AV_CODEC_ID_TTF = 0x18000,
471 AV_CODEC_ID_PROBE = 0x19000, ///< codec_id is not known (like AV_CODEC_ID_NONE) but lavf should attempt to identify it
473 AV_CODEC_ID_MPEG2TS = 0x20000, /**< _FAKE_ codec to indicate a raw MPEG-2 TS
474 * stream (only used by libavformat) */
475 AV_CODEC_ID_MPEG4SYSTEMS = 0x20001, /**< _FAKE_ codec to indicate a MPEG-4 Systems
476 * stream (only used by libavformat) */
477 AV_CODEC_ID_FFMETADATA = 0x21000, ///< Dummy codec for streams containing only metadata information.
481 * This struct describes the properties of a single codec described by an
483 * @see avcodec_descriptor_get()
485 typedef struct AVCodecDescriptor {
487 enum AVMediaType type;
489 * Name of the codec described by this descriptor. It is non-empty and
490 * unique for each codec descriptor. It should contain alphanumeric
491 * characters and '_' only.
495 * A more descriptive name for this codec. May be NULL.
497 const char *long_name;
499 * Codec properties, a combination of AV_CODEC_PROP_* flags.
505 * Codec uses only intra compression.
508 #define AV_CODEC_PROP_INTRA_ONLY (1 << 0)
510 * Codec supports lossy compression. Audio and video codecs only.
511 * @note a codec may support both lossy and lossless
514 #define AV_CODEC_PROP_LOSSY (1 << 1)
516 * Codec supports lossless compression. Audio and video codecs only.
518 #define AV_CODEC_PROP_LOSSLESS (1 << 2)
520 * Codec supports frame reordering. That is, the coded order (the order in which
521 * the encoded packets are output by the encoders / stored / input to the
522 * decoders) may be different from the presentation order of the corresponding
525 * For codecs that do not have this property set, PTS and DTS should always be
528 #define AV_CODEC_PROP_REORDER (1 << 3)
531 * @ingroup lavc_decoding
532 * Required number of additionally allocated bytes at the end of the input bitstream for decoding.
533 * This is mainly needed because some optimized bitstream readers read
534 * 32 or 64 bit at once and could read over the end.<br>
535 * Note: If the first 23 bits of the additional bytes are not 0, then damaged
536 * MPEG bitstreams could cause overread and segfault.
538 #define FF_INPUT_BUFFER_PADDING_SIZE 8
541 * @ingroup lavc_encoding
542 * minimum encoding buffer size
543 * Used to avoid some checks during header writing.
545 #define FF_MIN_BUFFER_SIZE 16384
549 * @ingroup lavc_encoding
550 * motion estimation type.
551 * @deprecated use codec private option instead
553 #if FF_API_MOTION_EST
555 ME_ZERO = 1, ///< no search, that is use 0,0 vector whenever one is needed
559 ME_EPZS, ///< enhanced predictive zonal search
560 ME_X1, ///< reserved for experiments
561 ME_HEX, ///< hexagon based search
562 ME_UMH, ///< uneven multi-hexagon search
563 ME_TESA, ///< transformed exhaustive search algorithm
568 * @ingroup lavc_decoding
571 /* We leave some space between them for extensions (drop some
572 * keyframes for intra-only or drop just some bidir frames). */
573 AVDISCARD_NONE =-16, ///< discard nothing
574 AVDISCARD_DEFAULT = 0, ///< discard useless packets like 0 size packets in avi
575 AVDISCARD_NONREF = 8, ///< discard all non reference
576 AVDISCARD_BIDIR = 16, ///< discard all bidirectional frames
577 AVDISCARD_NONKEY = 32, ///< discard all frames except keyframes
578 AVDISCARD_ALL = 48, ///< discard all
581 enum AVAudioServiceType {
582 AV_AUDIO_SERVICE_TYPE_MAIN = 0,
583 AV_AUDIO_SERVICE_TYPE_EFFECTS = 1,
584 AV_AUDIO_SERVICE_TYPE_VISUALLY_IMPAIRED = 2,
585 AV_AUDIO_SERVICE_TYPE_HEARING_IMPAIRED = 3,
586 AV_AUDIO_SERVICE_TYPE_DIALOGUE = 4,
587 AV_AUDIO_SERVICE_TYPE_COMMENTARY = 5,
588 AV_AUDIO_SERVICE_TYPE_EMERGENCY = 6,
589 AV_AUDIO_SERVICE_TYPE_VOICE_OVER = 7,
590 AV_AUDIO_SERVICE_TYPE_KARAOKE = 8,
591 AV_AUDIO_SERVICE_TYPE_NB , ///< Not part of ABI
595 * @ingroup lavc_encoding
597 typedef struct RcOverride{
600 int qscale; // If this is 0 then quality_factor will be used instead.
601 float quality_factor;
604 #if FF_API_MAX_BFRAMES
606 * @deprecated there is no libavcodec-wide limit on the number of B-frames
608 #define FF_MAX_B_FRAMES 16
612 These flags can be passed in AVCodecContext.flags before initialization.
613 Note: Not everything is supported yet.
617 * Allow decoders to produce frames with data planes that are not aligned
618 * to CPU requirements (e.g. due to cropping).
620 #define AV_CODEC_FLAG_UNALIGNED (1 << 0)
624 #define AV_CODEC_FLAG_QSCALE (1 << 1)
626 * 4 MV per MB allowed / advanced prediction for H.263.
628 #define AV_CODEC_FLAG_4MV (1 << 2)
630 * Output even those frames that might be corrupted.
632 #define AV_CODEC_FLAG_OUTPUT_CORRUPT (1 << 3)
636 #define AV_CODEC_FLAG_QPEL (1 << 4)
638 * Use internal 2pass ratecontrol in first pass mode.
640 #define AV_CODEC_FLAG_PASS1 (1 << 9)
642 * Use internal 2pass ratecontrol in second pass mode.
644 #define AV_CODEC_FLAG_PASS2 (1 << 10)
648 #define AV_CODEC_FLAG_LOOP_FILTER (1 << 11)
650 * Only decode/encode grayscale.
652 #define AV_CODEC_FLAG_GRAY (1 << 13)
654 * error[?] variables will be set during encoding.
656 #define AV_CODEC_FLAG_PSNR (1 << 15)
658 * Input bitstream might be truncated at a random location
659 * instead of only at frame boundaries.
661 #define AV_CODEC_FLAG_TRUNCATED (1 << 16)
663 * Use interlaced DCT.
665 #define AV_CODEC_FLAG_INTERLACED_DCT (1 << 18)
669 #define AV_CODEC_FLAG_LOW_DELAY (1 << 19)
671 * Place global headers in extradata instead of every keyframe.
673 #define AV_CODEC_FLAG_GLOBAL_HEADER (1 << 22)
675 * Use only bitexact stuff (except (I)DCT).
677 #define AV_CODEC_FLAG_BITEXACT (1 << 23)
678 /* Fx : Flag for h263+ extra options */
680 * H.263 advanced intra coding / MPEG-4 AC prediction
682 #define AV_CODEC_FLAG_AC_PRED (1 << 24)
684 * interlaced motion estimation
686 #define AV_CODEC_FLAG_INTERLACED_ME (1 << 29)
688 * Allow non spec compliant speedup tricks.
690 #define AV_CODEC_FLAG_CLOSED_GOP (1 << 31)
692 #define AV_CODEC_FLAG2_FAST (1 << 0)
694 * Skip bitstream encoding.
696 #define AV_CODEC_FLAG2_NO_OUTPUT (1 << 2)
698 * Place global headers at every keyframe instead of in extradata.
700 #define AV_CODEC_FLAG2_LOCAL_HEADER (1 << 3)
702 * Input bitstream might be truncated at a packet boundaries
703 * instead of only at frame boundaries.
705 #define AV_CODEC_FLAG2_CHUNKS (1 << 15)
707 * Discard cropping information from SPS.
709 #define AV_CODEC_FLAG2_IGNORE_CROP (1 << 16)
711 /* Unsupported options :
712 * Syntax Arithmetic coding (SAC)
713 * Reference Picture Selection
714 * Independent Segment Decoding */
716 /* codec capabilities */
719 * Decoder can use draw_horiz_band callback.
721 #define AV_CODEC_CAP_DRAW_HORIZ_BAND (1 << 0)
723 * Codec uses get_buffer() for allocating buffers and supports custom allocators.
724 * If not set, it might not use get_buffer() at all or use operations that
725 * assume the buffer was allocated by avcodec_default_get_buffer.
727 #define AV_CODEC_CAP_DR1 (1 << 1)
728 #define AV_CODEC_CAP_TRUNCATED (1 << 3)
730 * Encoder or decoder requires flushing with NULL input at the end in order to
731 * give the complete and correct output.
733 * NOTE: If this flag is not set, the codec is guaranteed to never be fed with
734 * with NULL data. The user can still send NULL data to the public encode
735 * or decode function, but libavcodec will not pass it along to the codec
736 * unless this flag is set.
739 * The decoder has a non-zero delay and needs to be fed with avpkt->data=NULL,
740 * avpkt->size=0 at the end to get the delayed data until the decoder no longer
744 * The encoder needs to be fed with NULL data at the end of encoding until the
745 * encoder no longer returns data.
747 * NOTE: For encoders implementing the AVCodec.encode2() function, setting this
748 * flag also means that the encoder must set the pts and duration for
749 * each output packet. If this flag is not set, the pts and duration will
750 * be determined by libavcodec from the input frame.
752 #define AV_CODEC_CAP_DELAY (1 << 5)
754 * Codec can be fed a final frame with a smaller size.
755 * This can be used to prevent truncation of the last audio samples.
757 #define AV_CODEC_CAP_SMALL_LAST_FRAME (1 << 6)
759 * Codec can output multiple frames per AVPacket
760 * Normally demuxers return one frame at a time, demuxers which do not do
761 * are connected to a parser to split what they return into proper frames.
762 * This flag is reserved to the very rare category of codecs which have a
763 * bitstream that cannot be split into frames without timeconsuming
764 * operations like full decoding. Demuxers carring such bitstreams thus
765 * may return multiple frames in a packet. This has many disadvantages like
766 * prohibiting stream copy in many cases thus it should only be considered
769 #define AV_CODEC_CAP_SUBFRAMES (1 << 8)
771 * Codec is experimental and is thus avoided in favor of non experimental
774 #define AV_CODEC_CAP_EXPERIMENTAL (1 << 9)
776 * Codec should fill in channel configuration and samplerate instead of container
778 #define AV_CODEC_CAP_CHANNEL_CONF (1 << 10)
780 * Codec supports frame-level multithreading.
782 #define AV_CODEC_CAP_FRAME_THREADS (1 << 12)
784 * Codec supports slice-based (or partition-based) multithreading.
786 #define AV_CODEC_CAP_SLICE_THREADS (1 << 13)
788 * Codec supports changed parameters at any point.
790 #define AV_CODEC_CAP_PARAM_CHANGE (1 << 14)
792 * Codec supports avctx->thread_count == 0 (auto).
794 #define AV_CODEC_CAP_AUTO_THREADS (1 << 15)
796 * Audio encoder supports receiving a different number of samples in each call.
798 #define AV_CODEC_CAP_VARIABLE_FRAME_SIZE (1 << 16)
801 * Allow decoders to produce frames with data planes that are not aligned
802 * to CPU requirements (e.g. due to cropping).
804 #define CODEC_FLAG_UNALIGNED 0x0001
805 #define CODEC_FLAG_QSCALE 0x0002 ///< Use fixed qscale.
806 #define CODEC_FLAG_4MV 0x0004 ///< 4 MV per MB allowed / advanced prediction for H.263.
807 #define CODEC_FLAG_OUTPUT_CORRUPT 0x0008 ///< Output even those frames that might be corrupted
808 #define CODEC_FLAG_QPEL 0x0010 ///< Use qpel MC.
811 * @deprecated use the "gmc" private option of the libxvid encoder
813 #define CODEC_FLAG_GMC 0x0020 ///< Use GMC.
817 * @deprecated use the flag "mv0" in the "mpv_flags" private option of the
820 #define CODEC_FLAG_MV0 0x0040
822 #if FF_API_INPUT_PRESERVED
824 * @deprecated passing reference-counted frames to the encoders replaces this
827 #define CODEC_FLAG_INPUT_PRESERVED 0x0100
829 #define CODEC_FLAG_PASS1 0x0200 ///< Use internal 2pass ratecontrol in first pass mode.
830 #define CODEC_FLAG_PASS2 0x0400 ///< Use internal 2pass ratecontrol in second pass mode.
831 #define CODEC_FLAG_GRAY 0x2000 ///< Only decode/encode grayscale.
834 * @deprecated edges are not used/required anymore. I.e. this flag is now always
837 #define CODEC_FLAG_EMU_EDGE 0x4000
839 #define CODEC_FLAG_PSNR 0x8000 ///< error[?] variables will be set during encoding.
840 #define CODEC_FLAG_TRUNCATED 0x00010000 /** Input bitstream might be truncated at a random
841 location instead of only at frame boundaries. */
842 #if FF_API_NORMALIZE_AQP
844 * @deprecated use the flag "naq" in the "mpv_flags" private option of the
847 #define CODEC_FLAG_NORMALIZE_AQP 0x00020000
849 #define CODEC_FLAG_INTERLACED_DCT 0x00040000 ///< Use interlaced DCT.
850 #define CODEC_FLAG_LOW_DELAY 0x00080000 ///< Force low delay.
851 #define CODEC_FLAG_GLOBAL_HEADER 0x00400000 ///< Place global headers in extradata instead of every keyframe.
852 #define CODEC_FLAG_BITEXACT 0x00800000 ///< Use only bitexact stuff (except (I)DCT).
853 /* Fx : Flag for h263+ extra options */
854 #define CODEC_FLAG_AC_PRED 0x01000000 ///< H.263 advanced intra coding / MPEG-4 AC prediction
855 #define CODEC_FLAG_LOOP_FILTER 0x00000800 ///< loop filter
856 #define CODEC_FLAG_INTERLACED_ME 0x20000000 ///< interlaced motion estimation
857 #define CODEC_FLAG_CLOSED_GOP 0x80000000
858 #define CODEC_FLAG2_FAST 0x00000001 ///< Allow non spec compliant speedup tricks.
859 #define CODEC_FLAG2_NO_OUTPUT 0x00000004 ///< Skip bitstream encoding.
860 #define CODEC_FLAG2_LOCAL_HEADER 0x00000008 ///< Place global headers at every keyframe instead of in extradata.
861 #define CODEC_FLAG2_IGNORE_CROP 0x00010000 ///< Discard cropping information from SPS.
863 #define CODEC_FLAG2_CHUNKS 0x00008000 ///< Input bitstream might be truncated at a packet boundaries instead of only at frame boundaries.
865 /* Unsupported options :
866 * Syntax Arithmetic coding (SAC)
867 * Reference Picture Selection
868 * Independent Segment Decoding */
870 /* codec capabilities */
872 #define CODEC_CAP_DRAW_HORIZ_BAND 0x0001 ///< Decoder can use draw_horiz_band callback.
874 * Codec uses get_buffer() for allocating buffers and supports custom allocators.
875 * If not set, it might not use get_buffer() at all or use operations that
876 * assume the buffer was allocated by avcodec_default_get_buffer.
878 #define CODEC_CAP_DR1 0x0002
879 #define CODEC_CAP_TRUNCATED 0x0008
881 /* Codec can export data for HW decoding (XvMC). */
882 #define CODEC_CAP_HWACCEL 0x0010
883 #endif /* FF_API_XVMC */
885 * Encoder or decoder requires flushing with NULL input at the end in order to
886 * give the complete and correct output.
888 * NOTE: If this flag is not set, the codec is guaranteed to never be fed with
889 * with NULL data. The user can still send NULL data to the public encode
890 * or decode function, but libavcodec will not pass it along to the codec
891 * unless this flag is set.
894 * The decoder has a non-zero delay and needs to be fed with avpkt->data=NULL,
895 * avpkt->size=0 at the end to get the delayed data until the decoder no longer
899 * The encoder needs to be fed with NULL data at the end of encoding until the
900 * encoder no longer returns data.
902 * NOTE: For encoders implementing the AVCodec.encode2() function, setting this
903 * flag also means that the encoder must set the pts and duration for
904 * each output packet. If this flag is not set, the pts and duration will
905 * be determined by libavcodec from the input frame.
907 #define CODEC_CAP_DELAY 0x0020
909 * Codec can be fed a final frame with a smaller size.
910 * This can be used to prevent truncation of the last audio samples.
912 #define CODEC_CAP_SMALL_LAST_FRAME 0x0040
915 * Codec can export data for HW decoding (VDPAU).
917 #define CODEC_CAP_HWACCEL_VDPAU 0x0080
920 * Codec can output multiple frames per AVPacket
921 * Normally demuxers return one frame at a time, demuxers which do not do
922 * are connected to a parser to split what they return into proper frames.
923 * This flag is reserved to the very rare category of codecs which have a
924 * bitstream that cannot be split into frames without timeconsuming
925 * operations like full decoding. Demuxers carring such bitstreams thus
926 * may return multiple frames in a packet. This has many disadvantages like
927 * prohibiting stream copy in many cases thus it should only be considered
930 #define CODEC_CAP_SUBFRAMES 0x0100
932 * Codec is experimental and is thus avoided in favor of non experimental
935 #define CODEC_CAP_EXPERIMENTAL 0x0200
937 * Codec should fill in channel configuration and samplerate instead of container
939 #define CODEC_CAP_CHANNEL_CONF 0x0400
940 #if FF_API_NEG_LINESIZES
942 * @deprecated no codecs use this capability
944 #define CODEC_CAP_NEG_LINESIZES 0x0800
947 * Codec supports frame-level multithreading.
949 #define CODEC_CAP_FRAME_THREADS 0x1000
951 * Codec supports slice-based (or partition-based) multithreading.
953 #define CODEC_CAP_SLICE_THREADS 0x2000
955 * Codec supports changed parameters at any point.
957 #define CODEC_CAP_PARAM_CHANGE 0x4000
959 * Codec supports avctx->thread_count == 0 (auto).
961 #define CODEC_CAP_AUTO_THREADS 0x8000
963 * Audio encoder supports receiving a different number of samples in each call.
965 #define CODEC_CAP_VARIABLE_FRAME_SIZE 0x10000
968 //The following defines may change, don't expect compatibility if you use them.
969 #define MB_TYPE_INTRA4x4 0x0001
970 #define MB_TYPE_INTRA16x16 0x0002 //FIXME H.264-specific
971 #define MB_TYPE_INTRA_PCM 0x0004 //FIXME H.264-specific
972 #define MB_TYPE_16x16 0x0008
973 #define MB_TYPE_16x8 0x0010
974 #define MB_TYPE_8x16 0x0020
975 #define MB_TYPE_8x8 0x0040
976 #define MB_TYPE_INTERLACED 0x0080
977 #define MB_TYPE_DIRECT2 0x0100 //FIXME
978 #define MB_TYPE_ACPRED 0x0200
979 #define MB_TYPE_GMC 0x0400
980 #define MB_TYPE_SKIP 0x0800
981 #define MB_TYPE_P0L0 0x1000
982 #define MB_TYPE_P1L0 0x2000
983 #define MB_TYPE_P0L1 0x4000
984 #define MB_TYPE_P1L1 0x8000
985 #define MB_TYPE_L0 (MB_TYPE_P0L0 | MB_TYPE_P1L0)
986 #define MB_TYPE_L1 (MB_TYPE_P0L1 | MB_TYPE_P1L1)
987 #define MB_TYPE_L0L1 (MB_TYPE_L0 | MB_TYPE_L1)
988 #define MB_TYPE_QUANT 0x00010000
989 #define MB_TYPE_CBP 0x00020000
990 //Note bits 24-31 are reserved for codec specific use (h264 ref0, mpeg1 0mv, ...)
995 * This specifies the area which should be displayed.
996 * Note there may be multiple such areas for one frame.
998 typedef struct AVPanScan{
1001 * - encoding: Set by user.
1002 * - decoding: Set by libavcodec.
1007 * width and height in 1/16 pel
1008 * - encoding: Set by user.
1009 * - decoding: Set by libavcodec.
1015 * position of the top left corner in 1/16 pel for up to 3 fields/frames
1016 * - encoding: Set by user.
1017 * - decoding: Set by libavcodec.
1019 int16_t position[3][2];
1022 #if FF_API_QSCALE_TYPE
1023 #define FF_QSCALE_TYPE_MPEG1 0
1024 #define FF_QSCALE_TYPE_MPEG2 1
1025 #define FF_QSCALE_TYPE_H264 2
1026 #define FF_QSCALE_TYPE_VP56 3
1029 #if FF_API_GET_BUFFER
1030 #define FF_BUFFER_TYPE_INTERNAL 1
1031 #define FF_BUFFER_TYPE_USER 2 ///< direct rendering buffers (image is (de)allocated by user)
1032 #define FF_BUFFER_TYPE_SHARED 4 ///< Buffer from somewhere else; don't deallocate image (data/base), all other tables are not shared.
1033 #define FF_BUFFER_TYPE_COPY 8 ///< Just a (modified) copy of some other buffer, don't deallocate anything.
1035 #define FF_BUFFER_HINTS_VALID 0x01 // Buffer hints value is meaningful (if 0 ignore).
1036 #define FF_BUFFER_HINTS_READABLE 0x02 // Codec will read from buffer.
1037 #define FF_BUFFER_HINTS_PRESERVE 0x04 // User must not alter buffer content.
1038 #define FF_BUFFER_HINTS_REUSABLE 0x08 // Codec will reuse the buffer (update).
1042 * The decoder will keep a reference to the frame and may reuse it later.
1044 #define AV_GET_BUFFER_FLAG_REF (1 << 0)
1047 * @defgroup lavc_packet AVPacket
1049 * Types and functions for working with AVPacket.
1052 enum AVPacketSideDataType {
1053 AV_PKT_DATA_PALETTE,
1054 AV_PKT_DATA_NEW_EXTRADATA,
1057 * An AV_PKT_DATA_PARAM_CHANGE side data packet is laid out as follows:
1060 * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT)
1061 * s32le channel_count
1062 * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT)
1063 * u64le channel_layout
1064 * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE)
1066 * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS)
1071 AV_PKT_DATA_PARAM_CHANGE,
1074 * An AV_PKT_DATA_H263_MB_INFO side data packet contains a number of
1075 * structures with info about macroblocks relevant to splitting the
1076 * packet into smaller packets on macroblock edges (e.g. as for RFC 2190).
1077 * That is, it does not necessarily contain info about all macroblocks,
1078 * as long as the distance between macroblocks in the info is smaller
1079 * than the target payload size.
1080 * Each MB info structure is 12 bytes, and is laid out as follows:
1082 * u32le bit offset from the start of the packet
1083 * u8 current quantizer at the start of the macroblock
1085 * u16le macroblock address within the GOB
1086 * u8 horizontal MV predictor
1087 * u8 vertical MV predictor
1088 * u8 horizontal MV predictor for block number 3
1089 * u8 vertical MV predictor for block number 3
1092 AV_PKT_DATA_H263_MB_INFO,
1095 * This side data should be associated with an audio stream and contains
1096 * ReplayGain information in form of the AVReplayGain struct.
1098 AV_PKT_DATA_REPLAYGAIN,
1101 * This side data contains a 3x3 transformation matrix describing an affine
1102 * transformation that needs to be applied to the decoded video frames for
1103 * correct presentation.
1105 * See libavutil/display.h for a detailed description of the data.
1107 AV_PKT_DATA_DISPLAYMATRIX,
1110 * This side data should be associated with a video stream and contains
1111 * Stereoscopic 3D information in form of the AVStereo3D struct.
1113 AV_PKT_DATA_STEREO3D,
1116 * This side data should be associated with an audio stream and corresponds
1117 * to enum AVAudioServiceType.
1119 AV_PKT_DATA_AUDIO_SERVICE_TYPE,
1122 * This side data contains an integer value representing the quality
1123 * factor of the compressed frame. Allowed range is between 1 (good)
1124 * and FF_LAMBDA_MAX (bad).
1126 AV_PKT_DATA_QUALITY_FACTOR,
1129 typedef struct AVPacketSideData {
1132 enum AVPacketSideDataType type;
1136 * This structure stores compressed data. It is typically exported by demuxers
1137 * and then passed as input to decoders, or received as output from encoders and
1138 * then passed to muxers.
1140 * For video, it should typically contain one compressed frame. For audio it may
1141 * contain several compressed frames.
1143 * AVPacket is one of the few structs in Libav, whose size is a part of public
1144 * ABI. Thus it may be allocated on stack and no new fields can be added to it
1145 * without libavcodec and libavformat major bump.
1147 * The semantics of data ownership depends on the buf or destruct (deprecated)
1148 * fields. If either is set, the packet data is dynamically allocated and is
1149 * valid indefinitely until av_free_packet() is called (which in turn calls
1150 * av_buffer_unref()/the destruct callback to free the data). If neither is set,
1151 * the packet data is typically backed by some static buffer somewhere and is
1152 * only valid for a limited time (e.g. until the next read call when demuxing).
1154 * The side data is always allocated with av_malloc() and is freed in
1157 typedef struct AVPacket {
1159 * A reference to the reference-counted buffer where the packet data is
1161 * May be NULL, then the packet data is not reference-counted.
1165 * Presentation timestamp in AVStream->time_base units; the time at which
1166 * the decompressed packet will be presented to the user.
1167 * Can be AV_NOPTS_VALUE if it is not stored in the file.
1168 * pts MUST be larger or equal to dts as presentation cannot happen before
1169 * decompression, unless one wants to view hex dumps. Some formats misuse
1170 * the terms dts and pts/cts to mean something different. Such timestamps
1171 * must be converted to true pts/dts before they are stored in AVPacket.
1175 * Decompression timestamp in AVStream->time_base units; the time at which
1176 * the packet is decompressed.
1177 * Can be AV_NOPTS_VALUE if it is not stored in the file.
1184 * A combination of AV_PKT_FLAG values
1188 * Additional packet data that can be provided by the container.
1189 * Packet can contain several types of side information.
1191 AVPacketSideData *side_data;
1192 int side_data_elems;
1195 * Duration of this packet in AVStream->time_base units, 0 if unknown.
1196 * Equals next_pts - this_pts in presentation order.
1199 #if FF_API_DESTRUCT_PACKET
1200 attribute_deprecated
1201 void (*destruct)(struct AVPacket *);
1202 attribute_deprecated
1205 int64_t pos; ///< byte position in stream, -1 if unknown
1208 * Time difference in AVStream->time_base units from the pts of this
1209 * packet to the point at which the output from the decoder has converged
1210 * independent from the availability of previous frames. That is, the
1211 * frames are virtually identical no matter if decoding started from
1212 * the very first frame or from this keyframe.
1213 * Is AV_NOPTS_VALUE if unknown.
1214 * This field is not the display duration of the current packet.
1215 * This field has no meaning if the packet does not have AV_PKT_FLAG_KEY
1218 * The purpose of this field is to allow seeking in streams that have no
1219 * keyframes in the conventional sense. It corresponds to the
1220 * recovery point SEI in H.264 and match_time_delta in NUT. It is also
1221 * essential for some types of subtitle streams to ensure that all
1222 * subtitles are correctly displayed after seeking.
1224 int64_t convergence_duration;
1226 #define AV_PKT_FLAG_KEY 0x0001 ///< The packet contains a keyframe
1227 #define AV_PKT_FLAG_CORRUPT 0x0002 ///< The packet content is corrupted
1229 enum AVSideDataParamChangeFlags {
1230 AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT = 0x0001,
1231 AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT = 0x0002,
1232 AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE = 0x0004,
1233 AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS = 0x0008,
1239 struct AVCodecInternal;
1243 AV_FIELD_PROGRESSIVE,
1244 AV_FIELD_TT, //< Top coded_first, top displayed first
1245 AV_FIELD_BB, //< Bottom coded first, bottom displayed first
1246 AV_FIELD_TB, //< Top coded first, bottom displayed first
1247 AV_FIELD_BT, //< Bottom coded first, top displayed first
1251 * main external API structure.
1252 * New fields can be added to the end with minor version bumps.
1253 * Removal, reordering and changes to existing fields require a major
1255 * sizeof(AVCodecContext) must not be used outside libav*.
1257 typedef struct AVCodecContext {
1259 * information on struct for av_log
1260 * - set by avcodec_alloc_context3
1262 const AVClass *av_class;
1263 int log_level_offset;
1265 enum AVMediaType codec_type; /* see AVMEDIA_TYPE_xxx */
1266 const struct AVCodec *codec;
1267 #if FF_API_CODEC_NAME
1269 * @deprecated this field is not used for anything in libavcodec
1271 attribute_deprecated
1272 char codec_name[32];
1274 enum AVCodecID codec_id; /* see AV_CODEC_ID_xxx */
1277 * fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
1278 * This is used to work around some encoder bugs.
1279 * A demuxer should set this to what is stored in the field used to identify the codec.
1280 * If there are multiple such fields in a container then the demuxer should choose the one
1281 * which maximizes the information about the used codec.
1282 * If the codec tag field in a container is larger than 32 bits then the demuxer should
1283 * remap the longer ID to 32 bits with a table or other structure. Alternatively a new
1284 * extra_codec_tag + size could be added but for this a clear advantage must be demonstrated
1286 * - encoding: Set by user, if not then the default based on codec_id will be used.
1287 * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
1289 unsigned int codec_tag;
1291 #if FF_API_STREAM_CODEC_TAG
1293 * @deprecated this field is unused
1295 attribute_deprecated
1296 unsigned int stream_codec_tag;
1302 * Private context used for internal data.
1304 * Unlike priv_data, this is not codec-specific. It is used in general
1305 * libavcodec functions.
1307 struct AVCodecInternal *internal;
1310 * Private data of the user, can be used to carry app specific stuff.
1311 * - encoding: Set by user.
1312 * - decoding: Set by user.
1317 * the average bitrate
1318 * - encoding: Set by user; unused for constant quantizer encoding.
1319 * - decoding: Set by libavcodec. 0 or some bitrate if this info is available in the stream.
1324 * number of bits the bitstream is allowed to diverge from the reference.
1325 * the reference can be CBR (for CBR pass1) or VBR (for pass2)
1326 * - encoding: Set by user; unused for constant quantizer encoding.
1327 * - decoding: unused
1329 int bit_rate_tolerance;
1332 * Global quality for codecs which cannot change it per frame.
1333 * This should be proportional to MPEG-1/2/4 qscale.
1334 * - encoding: Set by user.
1335 * - decoding: unused
1340 * - encoding: Set by user.
1341 * - decoding: unused
1343 int compression_level;
1344 #define FF_COMPRESSION_DEFAULT -1
1348 * - encoding: Set by user.
1349 * - decoding: Set by user.
1355 * - encoding: Set by user.
1356 * - decoding: Set by user.
1361 * some codecs need / can use extradata like Huffman tables.
1362 * mjpeg: Huffman tables
1363 * rv10: additional flags
1364 * mpeg4: global headers (they can be in the bitstream or here)
1365 * The allocated memory should be FF_INPUT_BUFFER_PADDING_SIZE bytes larger
1366 * than extradata_size to avoid prolems if it is read with the bitstream reader.
1367 * The bytewise contents of extradata must not depend on the architecture or CPU endianness.
1368 * - encoding: Set/allocated/freed by libavcodec.
1369 * - decoding: Set/allocated/freed by user.
1375 * This is the fundamental unit of time (in seconds) in terms
1376 * of which frame timestamps are represented. For fixed-fps content,
1377 * timebase should be 1/framerate and timestamp increments should be
1379 * - encoding: MUST be set by user.
1380 * - decoding: the use of this field for decoding is deprecated.
1381 * Use framerate instead.
1383 AVRational time_base;
1386 * For some codecs, the time base is closer to the field rate than the frame rate.
1387 * Most notably, H.264 and MPEG-2 specify time_base as half of frame duration
1388 * if no telecine is used ...
1390 * Set to time_base ticks per frame. Default 1, e.g., H.264/MPEG-2 set it to 2.
1392 int ticks_per_frame;
1398 * Number of frames the decoded output will be delayed relative to the
1402 * For encoding, this field is unused (see initial_padding).
1404 * For decoding, this is the number of samples the decoder needs to
1405 * output before the decoder's output is valid. When seeking, you should
1406 * start decoding this many samples prior to your desired seek point.
1408 * - encoding: Set by libavcodec.
1409 * - decoding: Set by libavcodec.
1416 * picture width / height.
1418 * @note Those fields may not match the values of the last
1419 * AVFrame outputted by avcodec_decode_video2 due frame
1422 * - encoding: MUST be set by user.
1423 * - decoding: May be set by the user before opening the decoder if known e.g.
1424 * from the container. Some decoders will require the dimensions
1425 * to be set by the caller. During decoding, the decoder may
1426 * overwrite those values as required while parsing the data.
1431 * Bitstream width / height, may be different from width/height e.g. when
1432 * the decoded frame is cropped before being output.
1434 * @note Those field may not match the value of the last
1435 * AVFrame outputted by avcodec_decode_video2 due frame
1438 * - encoding: unused
1439 * - decoding: May be set by the user before opening the decoder if known
1440 * e.g. from the container. During decoding, the decoder may
1441 * overwrite those values as required while parsing the data.
1443 int coded_width, coded_height;
1445 #if FF_API_ASPECT_EXTENDED
1446 #define FF_ASPECT_EXTENDED 15
1450 * the number of pictures in a group of pictures, or 0 for intra_only
1451 * - encoding: Set by user.
1452 * - decoding: unused
1457 * Pixel format, see AV_PIX_FMT_xxx.
1458 * May be set by the demuxer if known from headers.
1459 * May be overriden by the decoder if it knows better.
1461 * @note This field may not match the value of the last
1462 * AVFrame outputted by avcodec_decode_video2 due frame
1465 * - encoding: Set by user.
1466 * - decoding: Set by user if known, overridden by libavcodec while
1469 enum AVPixelFormat pix_fmt;
1471 #if FF_API_MOTION_EST
1473 * This option does nothing
1474 * @deprecated use codec private options instead
1476 attribute_deprecated int me_method;
1480 * If non NULL, 'draw_horiz_band' is called by the libavcodec
1481 * decoder to draw a horizontal band. It improves cache usage. Not
1482 * all codecs can do that. You must check the codec capabilities
1484 * When multithreading is used, it may be called from multiple threads
1485 * at the same time; threads might draw different parts of the same AVFrame,
1486 * or multiple AVFrames, and there is no guarantee that slices will be drawn
1488 * The function is also used by hardware acceleration APIs.
1489 * It is called at least once during frame decoding to pass
1490 * the data needed for hardware render.
1491 * In that mode instead of pixel data, AVFrame points to
1492 * a structure specific to the acceleration API. The application
1493 * reads the structure and can change some fields to indicate progress
1495 * - encoding: unused
1496 * - decoding: Set by user.
1497 * @param height the height of the slice
1498 * @param y the y position of the slice
1499 * @param type 1->top field, 2->bottom field, 3->frame
1500 * @param offset offset into the AVFrame.data from which the slice should be read
1502 void (*draw_horiz_band)(struct AVCodecContext *s,
1503 const AVFrame *src, int offset[AV_NUM_DATA_POINTERS],
1504 int y, int type, int height);
1507 * callback to negotiate the pixelFormat
1508 * @param fmt is the list of formats which are supported by the codec,
1509 * it is terminated by -1 as 0 is a valid format, the formats are ordered by quality.
1510 * The first is always the native one.
1511 * @note The callback may be called again immediately if initialization for
1512 * the selected (hardware-accelerated) pixel format failed.
1513 * @warning Behavior is undefined if the callback returns a value not
1514 * in the fmt list of formats.
1515 * @return the chosen format
1516 * - encoding: unused
1517 * - decoding: Set by user, if not set the native format will be chosen.
1519 enum AVPixelFormat (*get_format)(struct AVCodecContext *s, const enum AVPixelFormat * fmt);
1522 * maximum number of B-frames between non-B-frames
1523 * Note: The output will be delayed by max_b_frames+1 relative to the input.
1524 * - encoding: Set by user.
1525 * - decoding: unused
1530 * qscale factor between IP and B-frames
1531 * If > 0 then the last P-frame quantizer will be used (q= lastp_q*factor+offset).
1532 * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1533 * - encoding: Set by user.
1534 * - decoding: unused
1536 float b_quant_factor;
1538 #if FF_API_RC_STRATEGY
1539 /** @deprecated use codec private option instead */
1540 attribute_deprecated int rc_strategy;
1541 #define FF_RC_STRATEGY_XVID 1
1544 int b_frame_strategy;
1547 * qscale offset between IP and B-frames
1548 * - encoding: Set by user.
1549 * - decoding: unused
1551 float b_quant_offset;
1554 * Size of the frame reordering buffer in the decoder.
1555 * For MPEG-2 it is 1 IPB or 0 low delay IP.
1556 * - encoding: Set by libavcodec.
1557 * - decoding: Set by libavcodec.
1562 * 0-> h263 quant 1-> mpeg quant
1563 * - encoding: Set by user.
1564 * - decoding: unused
1569 * qscale factor between P and I-frames
1570 * If > 0 then the last p frame quantizer will be used (q= lastp_q*factor+offset).
1571 * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1572 * - encoding: Set by user.
1573 * - decoding: unused
1575 float i_quant_factor;
1578 * qscale offset between P and I-frames
1579 * - encoding: Set by user.
1580 * - decoding: unused
1582 float i_quant_offset;
1585 * luminance masking (0-> disabled)
1586 * - encoding: Set by user.
1587 * - decoding: unused
1592 * temporary complexity masking (0-> disabled)
1593 * - encoding: Set by user.
1594 * - decoding: unused
1596 float temporal_cplx_masking;
1599 * spatial complexity masking (0-> disabled)
1600 * - encoding: Set by user.
1601 * - decoding: unused
1603 float spatial_cplx_masking;
1606 * p block masking (0-> disabled)
1607 * - encoding: Set by user.
1608 * - decoding: unused
1613 * darkness masking (0-> disabled)
1614 * - encoding: Set by user.
1615 * - decoding: unused
1621 * - encoding: Set by libavcodec.
1622 * - decoding: Set by user (or 0).
1626 * prediction method (needed for huffyuv)
1627 * - encoding: Set by user.
1628 * - decoding: unused
1630 int prediction_method;
1631 #define FF_PRED_LEFT 0
1632 #define FF_PRED_PLANE 1
1633 #define FF_PRED_MEDIAN 2
1636 * slice offsets in the frame in bytes
1637 * - encoding: Set/allocated by libavcodec.
1638 * - decoding: Set/allocated by user (or NULL).
1643 * sample aspect ratio (0 if unknown)
1644 * That is the width of a pixel divided by the height of the pixel.
1645 * Numerator and denominator must be relatively prime and smaller than 256 for some video standards.
1646 * - encoding: Set by user.
1647 * - decoding: Set by libavcodec.
1649 AVRational sample_aspect_ratio;
1652 * motion estimation comparison function
1653 * - encoding: Set by user.
1654 * - decoding: unused
1658 * subpixel motion estimation comparison function
1659 * - encoding: Set by user.
1660 * - decoding: unused
1664 * macroblock comparison function (not supported yet)
1665 * - encoding: Set by user.
1666 * - decoding: unused
1670 * interlaced DCT comparison function
1671 * - encoding: Set by user.
1672 * - decoding: unused
1675 #define FF_CMP_SAD 0
1676 #define FF_CMP_SSE 1
1677 #define FF_CMP_SATD 2
1678 #define FF_CMP_DCT 3
1679 #define FF_CMP_PSNR 4
1680 #define FF_CMP_BIT 5
1682 #define FF_CMP_ZERO 7
1683 #define FF_CMP_VSAD 8
1684 #define FF_CMP_VSSE 9
1685 #define FF_CMP_NSSE 10
1686 #define FF_CMP_DCTMAX 13
1687 #define FF_CMP_DCT264 14
1688 #define FF_CMP_CHROMA 256
1691 * ME diamond size & shape
1692 * - encoding: Set by user.
1693 * - decoding: unused
1698 * amount of previous MV predictors (2a+1 x 2a+1 square)
1699 * - encoding: Set by user.
1700 * - decoding: unused
1702 int last_predictor_count;
1705 * prepass for motion estimation
1706 * - encoding: Set by user.
1707 * - decoding: unused
1712 * motion estimation prepass comparison function
1713 * - encoding: Set by user.
1714 * - decoding: unused
1719 * ME prepass diamond size & shape
1720 * - encoding: Set by user.
1721 * - decoding: unused
1727 * - encoding: Set by user.
1728 * - decoding: unused
1730 int me_subpel_quality;
1734 * DTG active format information (additional aspect ratio
1735 * information only used in DVB MPEG-2 transport streams)
1738 * - encoding: unused
1739 * - decoding: Set by decoder.
1740 * @deprecated Deprecated in favor of AVSideData
1742 attribute_deprecated int dtg_active_format;
1743 #define FF_DTG_AFD_SAME 8
1744 #define FF_DTG_AFD_4_3 9
1745 #define FF_DTG_AFD_16_9 10
1746 #define FF_DTG_AFD_14_9 11
1747 #define FF_DTG_AFD_4_3_SP_14_9 13
1748 #define FF_DTG_AFD_16_9_SP_14_9 14
1749 #define FF_DTG_AFD_SP_4_3 15
1750 #endif /* FF_API_AFD */
1753 * maximum motion estimation search range in subpel units
1754 * If 0 then no limit.
1756 * - encoding: Set by user.
1757 * - decoding: unused
1761 #if FF_API_QUANT_BIAS
1763 * @deprecated use encoder private option instead
1765 attribute_deprecated int intra_quant_bias;
1766 #define FF_DEFAULT_QUANT_BIAS 999999
1769 * @deprecated use encoder private option instead
1771 attribute_deprecated int inter_quant_bias;
1776 * - encoding: unused
1777 * - decoding: Set by user.
1780 #define SLICE_FLAG_CODED_ORDER 0x0001 ///< draw_horiz_band() is called in coded order instead of display
1781 #define SLICE_FLAG_ALLOW_FIELD 0x0002 ///< allow draw_horiz_band() with field slices (MPEG2 field pics)
1782 #define SLICE_FLAG_ALLOW_PLANE 0x0004 ///< allow draw_horiz_band() with 1 component at a time (SVQ1)
1786 * XVideo Motion Acceleration
1787 * - encoding: forbidden
1788 * - decoding: set by decoder
1789 * @deprecated XvMC support is slated for removal.
1791 attribute_deprecated int xvmc_acceleration;
1792 #endif /* FF_API_XVMC */
1795 * macroblock decision mode
1796 * - encoding: Set by user.
1797 * - decoding: unused
1800 #define FF_MB_DECISION_SIMPLE 0 ///< uses mb_cmp
1801 #define FF_MB_DECISION_BITS 1 ///< chooses the one which needs the fewest bits
1802 #define FF_MB_DECISION_RD 2 ///< rate distortion
1805 * custom intra quantization matrix
1806 * - encoding: Set by user, can be NULL.
1807 * - decoding: Set by libavcodec.
1809 uint16_t *intra_matrix;
1812 * custom inter quantization matrix
1813 * - encoding: Set by user, can be NULL.
1814 * - decoding: Set by libavcodec.
1816 uint16_t *inter_matrix;
1819 * scene change detection threshold
1820 * 0 is default, larger means fewer detected scene changes.
1821 * - encoding: Set by user.
1822 * - decoding: unused
1824 int scenechange_threshold;
1827 * noise reduction strength
1828 * - encoding: Set by user.
1829 * - decoding: unused
1831 int noise_reduction;
1835 * @deprecated this field is unused
1837 attribute_deprecated
1841 * @deprecated this field is unused
1843 attribute_deprecated
1848 * precision of the intra DC coefficient - 8
1849 * - encoding: Set by user.
1850 * - decoding: unused
1852 int intra_dc_precision;
1855 * Number of macroblock rows at the top which are skipped.
1856 * - encoding: unused
1857 * - decoding: Set by user.
1862 * Number of macroblock rows at the bottom which are skipped.
1863 * - encoding: unused
1864 * - decoding: Set by user.
1870 * @deprecated use encoder private options instead
1872 attribute_deprecated
1873 float border_masking;
1877 * minimum MB lagrange multipler
1878 * - encoding: Set by user.
1879 * - decoding: unused
1884 * maximum MB lagrange multipler
1885 * - encoding: Set by user.
1886 * - decoding: unused
1892 * - encoding: Set by user.
1893 * - decoding: unused
1895 int me_penalty_compensation;
1899 * - encoding: Set by user.
1900 * - decoding: unused
1906 * - encoding: Set by user.
1907 * - decoding: unused
1913 * - encoding: Set by user.
1914 * - decoding: unused
1919 * number of reference frames
1920 * - encoding: Set by user.
1921 * - decoding: Set by lavc.
1926 * chroma qp offset from luma
1927 * - encoding: Set by user.
1928 * - decoding: unused
1932 #if FF_API_UNUSED_MEMBERS
1934 * Multiplied by qscale for each frame and added to scene_change_score.
1935 * - encoding: Set by user.
1936 * - decoding: unused
1938 attribute_deprecated int scenechange_factor;
1943 * Note: Value depends upon the compare function used for fullpel ME.
1944 * - encoding: Set by user.
1945 * - decoding: unused
1950 * Adjust sensitivity of b_frame_strategy 1.
1951 * - encoding: Set by user.
1952 * - decoding: unused
1957 * Chromaticity coordinates of the source primaries.
1958 * - encoding: Set by user
1959 * - decoding: Set by libavcodec
1961 enum AVColorPrimaries color_primaries;
1964 * Color Transfer Characteristic.
1965 * - encoding: Set by user
1966 * - decoding: Set by libavcodec
1968 enum AVColorTransferCharacteristic color_trc;
1971 * YUV colorspace type.
1972 * - encoding: Set by user
1973 * - decoding: Set by libavcodec
1975 enum AVColorSpace colorspace;
1978 * MPEG vs JPEG YUV range.
1979 * - encoding: Set by user
1980 * - decoding: Set by libavcodec
1982 enum AVColorRange color_range;
1985 * This defines the location of chroma samples.
1986 * - encoding: Set by user
1987 * - decoding: Set by libavcodec
1989 enum AVChromaLocation chroma_sample_location;
1993 * Indicates number of picture subdivisions. Used for parallelized
1995 * - encoding: Set by user
1996 * - decoding: unused
2001 * - encoding: set by libavcodec
2002 * - decoding: Set by libavcodec
2004 enum AVFieldOrder field_order;
2007 int sample_rate; ///< samples per second
2008 int channels; ///< number of audio channels
2011 * audio sample format
2012 * - encoding: Set by user.
2013 * - decoding: Set by libavcodec.
2015 enum AVSampleFormat sample_fmt; ///< sample format
2017 /* The following data should not be initialized. */
2019 * Number of samples per channel in an audio frame.
2021 * - encoding: set by libavcodec in avcodec_open2(). Each submitted frame
2022 * except the last must contain exactly frame_size samples per channel.
2023 * May be 0 when the codec has AV_CODEC_CAP_VARIABLE_FRAME_SIZE set, then the
2024 * frame size is not restricted.
2025 * - decoding: may be set by some decoders to indicate constant frame size
2030 * Frame counter, set by libavcodec.
2032 * - decoding: total number of frames returned from the decoder so far.
2033 * - encoding: total number of frames passed to the encoder so far.
2035 * @note the counter is not incremented if encoding/decoding resulted in
2041 * number of bytes per packet if constant and known or 0
2042 * Used by some WAV based audio codecs.
2047 * Audio cutoff bandwidth (0 means "automatic")
2048 * - encoding: Set by user.
2049 * - decoding: unused
2053 #if FF_API_REQUEST_CHANNELS
2055 * Decoder should decode to this many channels if it can (0 for default)
2056 * - encoding: unused
2057 * - decoding: Set by user.
2058 * @deprecated Deprecated in favor of request_channel_layout.
2060 attribute_deprecated int request_channels;
2064 * Audio channel layout.
2065 * - encoding: set by user.
2066 * - decoding: set by libavcodec.
2068 uint64_t channel_layout;
2071 * Request decoder to use this channel layout if it can (0 for default)
2072 * - encoding: unused
2073 * - decoding: Set by user.
2075 uint64_t request_channel_layout;
2078 * Type of service that the audio stream conveys.
2079 * - encoding: Set by user.
2080 * - decoding: Set by libavcodec.
2082 enum AVAudioServiceType audio_service_type;
2085 * Used to request a sample format from the decoder.
2086 * - encoding: unused.
2087 * - decoding: Set by user.
2089 enum AVSampleFormat request_sample_fmt;
2091 #if FF_API_GET_BUFFER
2093 * Called at the beginning of each frame to get a buffer for it.
2095 * The function will set AVFrame.data[], AVFrame.linesize[].
2096 * AVFrame.extended_data[] must also be set, but it should be the same as
2097 * AVFrame.data[] except for planar audio with more channels than can fit
2098 * in AVFrame.data[]. In that case, AVFrame.data[] shall still contain as
2099 * many data pointers as it can hold.
2101 * if CODEC_CAP_DR1 is not set then get_buffer() must call
2102 * avcodec_default_get_buffer() instead of providing buffers allocated by
2105 * AVFrame.data[] should be 32- or 16-byte-aligned unless the CPU doesn't
2106 * need it. avcodec_default_get_buffer() aligns the output buffer properly,
2107 * but if get_buffer() is overridden then alignment considerations should
2108 * be taken into account.
2110 * @see avcodec_default_get_buffer()
2114 * If pic.reference is set then the frame will be read later by libavcodec.
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.
2118 * If frame multithreading is used and thread_safe_callbacks is set,
2119 * it may be called from a different thread, but not from more than one at
2120 * once. Does not need to be reentrant.
2122 * @see release_buffer(), reget_buffer()
2123 * @see avcodec_align_dimensions2()
2127 * Decoders request a buffer of a particular size by setting
2128 * AVFrame.nb_samples prior to calling get_buffer(). The decoder may,
2129 * however, utilize only part of the buffer by setting AVFrame.nb_samples
2130 * to a smaller value in the output frame.
2132 * Decoders cannot use the buffer after returning from
2133 * avcodec_decode_audio4(), so they will not call release_buffer(), as it
2134 * is assumed to be released immediately upon return. In some rare cases,
2135 * a decoder may need to call get_buffer() more than once in a single
2136 * call to avcodec_decode_audio4(). In that case, when get_buffer() is
2137 * called again after it has already been called once, the previously
2138 * acquired buffer is assumed to be released at that time and may not be
2139 * reused by the decoder.
2141 * As a convenience, av_samples_get_buffer_size() and
2142 * av_samples_fill_arrays() in libavutil may be used by custom get_buffer()
2143 * functions to find the required data size and to fill data pointers and
2144 * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
2145 * since all planes must be the same size.
2147 * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
2149 * - encoding: unused
2150 * - decoding: Set by libavcodec, user can override.
2152 * @deprecated use get_buffer2()
2154 attribute_deprecated
2155 int (*get_buffer)(struct AVCodecContext *c, AVFrame *pic);
2158 * Called to release buffers which were allocated with get_buffer.
2159 * A released buffer can be reused in get_buffer().
2160 * pic.data[*] must be set to NULL.
2161 * May be called from a different thread if frame multithreading is used,
2162 * but not by more than one thread at once, so does not need to be reentrant.
2163 * - encoding: unused
2164 * - decoding: Set by libavcodec, user can override.
2166 * @deprecated custom freeing callbacks should be set from get_buffer2()
2168 attribute_deprecated
2169 void (*release_buffer)(struct AVCodecContext *c, AVFrame *pic);
2172 * Called at the beginning of a frame to get cr buffer for it.
2173 * Buffer type (size, hints) must be the same. libavcodec won't check it.
2174 * libavcodec will pass previous buffer in pic, function should return
2175 * same buffer or new buffer with old frame "painted" into it.
2176 * If pic.data[0] == NULL must behave like get_buffer().
2177 * if CODEC_CAP_DR1 is not set then reget_buffer() must call
2178 * avcodec_default_reget_buffer() instead of providing buffers allocated by
2180 * - encoding: unused
2181 * - decoding: Set by libavcodec, user can override.
2183 attribute_deprecated
2184 int (*reget_buffer)(struct AVCodecContext *c, AVFrame *pic);
2188 * This callback is called at the beginning of each frame to get data
2189 * buffer(s) for it. There may be one contiguous buffer for all the data or
2190 * there may be a buffer per each data plane or anything in between. What
2191 * this means is, you may set however many entries in buf[] you feel necessary.
2192 * Each buffer must be reference-counted using the AVBuffer API (see description
2195 * The following fields will be set in the frame before this callback is
2198 * - width, height (video only)
2199 * - sample_rate, channel_layout, nb_samples (audio only)
2200 * Their values may differ from the corresponding values in
2201 * AVCodecContext. This callback must use the frame values, not the codec
2202 * context values, to calculate the required buffer size.
2204 * This callback must fill the following fields in the frame:
2208 * * if the data is planar audio with more than 8 channels, then this
2209 * callback must allocate and fill extended_data to contain all pointers
2210 * to all data planes. data[] must hold as many pointers as it can.
2211 * extended_data must be allocated with av_malloc() and will be freed in
2213 * * otherwise exended_data must point to data
2214 * - buf[] must contain one or more pointers to AVBufferRef structures. Each of
2215 * the frame's data and extended_data pointers must be contained in these. That
2216 * is, one AVBufferRef for each allocated chunk of memory, not necessarily one
2217 * AVBufferRef per data[] entry. See: av_buffer_create(), av_buffer_alloc(),
2218 * and av_buffer_ref().
2219 * - extended_buf and nb_extended_buf must be allocated with av_malloc() by
2220 * this callback and filled with the extra buffers if there are more
2221 * buffers than buf[] can hold. extended_buf will be freed in
2224 * If AV_CODEC_CAP_DR1 is not set then get_buffer2() must call
2225 * avcodec_default_get_buffer2() instead of providing buffers allocated by
2228 * Each data plane must be aligned to the maximum required by the target
2231 * @see avcodec_default_get_buffer2()
2235 * If AV_GET_BUFFER_FLAG_REF is set in flags then the frame may be reused
2236 * (read and/or written to if it is writable) later by libavcodec.
2238 * avcodec_align_dimensions2() should be used to find the required width and
2239 * height, as they normally need to be rounded up to the next multiple of 16.
2241 * If frame multithreading is used and thread_safe_callbacks is set,
2242 * this callback may be called from a different thread, but not from more
2243 * than one at once. Does not need to be reentrant.
2245 * @see avcodec_align_dimensions2()
2249 * Decoders request a buffer of a particular size by setting
2250 * AVFrame.nb_samples prior to calling get_buffer2(). The decoder may,
2251 * however, utilize only part of the buffer by setting AVFrame.nb_samples
2252 * to a smaller value in the output frame.
2254 * As a convenience, av_samples_get_buffer_size() and
2255 * av_samples_fill_arrays() in libavutil may be used by custom get_buffer2()
2256 * functions to find the required data size and to fill data pointers and
2257 * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
2258 * since all planes must be the same size.
2260 * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
2262 * - encoding: unused
2263 * - decoding: Set by libavcodec, user can override.
2265 int (*get_buffer2)(struct AVCodecContext *s, AVFrame *frame, int flags);
2268 * If non-zero, the decoded audio and video frames returned from
2269 * avcodec_decode_video2() and avcodec_decode_audio4() are reference-counted
2270 * and are valid indefinitely. The caller must free them with
2271 * av_frame_unref() when they are not needed anymore.
2272 * Otherwise, the decoded frames must not be freed by the caller and are
2273 * only valid until the next decode call.
2275 * - encoding: unused
2276 * - decoding: set by the caller before avcodec_open2().
2278 int refcounted_frames;
2280 /* - encoding parameters */
2281 float qcompress; ///< amount of qscale change between easy & hard scenes (0.0-1.0)
2282 float qblur; ///< amount of qscale smoothing over time (0.0-1.0)
2286 * - encoding: Set by user.
2287 * - decoding: unused
2293 * - encoding: Set by user.
2294 * - decoding: unused
2299 * maximum quantizer difference between frames
2300 * - encoding: Set by user.
2301 * - decoding: unused
2307 * @deprecated use encoder private options instead
2309 attribute_deprecated
2312 attribute_deprecated
2314 attribute_deprecated
2319 * decoder bitstream buffer size
2320 * - encoding: Set by user.
2321 * - decoding: unused
2326 * ratecontrol override, see RcOverride
2327 * - encoding: Allocated/set/freed by user.
2328 * - decoding: unused
2330 int rc_override_count;
2331 RcOverride *rc_override;
2335 * @deprecated use encoder private options instead
2337 attribute_deprecated
2343 * - encoding: Set by user.
2344 * - decoding: unused
2350 * - encoding: Set by user.
2351 * - decoding: unused
2357 * @deprecated use encoder private options instead
2359 attribute_deprecated
2360 float rc_buffer_aggressivity;
2362 attribute_deprecated
2363 float rc_initial_cplx;
2367 * Ratecontrol attempt to use, at maximum, <value> of what can be used without an underflow.
2368 * - encoding: Set by user.
2369 * - decoding: unused.
2371 float rc_max_available_vbv_use;
2374 * Ratecontrol attempt to use, at least, <value> times the amount needed to prevent a vbv overflow.
2375 * - encoding: Set by user.
2376 * - decoding: unused.
2378 float rc_min_vbv_overflow_use;
2381 * Number of bits which should be loaded into the rc buffer before decoding starts.
2382 * - encoding: Set by user.
2383 * - decoding: unused
2385 int rc_initial_buffer_occupancy;
2387 #define FF_CODER_TYPE_VLC 0
2388 #define FF_CODER_TYPE_AC 1
2389 #define FF_CODER_TYPE_RAW 2
2390 #define FF_CODER_TYPE_RLE 3
2391 #if FF_API_UNUSED_MEMBERS
2392 #define FF_CODER_TYPE_DEFLATE 4
2393 #endif /* FF_API_UNUSED_MEMBERS */
2396 * - encoding: Set by user.
2397 * - decoding: unused
2403 * - encoding: Set by user.
2404 * - decoding: unused
2410 * @deprecated use encoder private options instead
2412 attribute_deprecated
2416 * @deprecated use encoder private options instead
2418 attribute_deprecated
2423 * frame skip threshold
2424 * - encoding: Set by user.
2425 * - decoding: unused
2427 int frame_skip_threshold;
2431 * - encoding: Set by user.
2432 * - decoding: unused
2434 int frame_skip_factor;
2437 * frame skip exponent
2438 * - encoding: Set by user.
2439 * - decoding: unused
2444 * frame skip comparison function
2445 * - encoding: Set by user.
2446 * - decoding: unused
2451 * trellis RD quantization
2452 * - encoding: Set by user.
2453 * - decoding: unused
2458 * - encoding: Set by user.
2459 * - decoding: unused
2461 int min_prediction_order;
2464 * - encoding: Set by user.
2465 * - decoding: unused
2467 int max_prediction_order;
2470 * GOP timecode frame start number, in non drop frame format
2471 * - encoding: Set by user.
2472 * - decoding: unused
2474 int64_t timecode_frame_start;
2476 /* The RTP callback: This function is called */
2477 /* every time the encoder has a packet to send. */
2478 /* It depends on the encoder if the data starts */
2479 /* with a Start Code (it should). H.263 does. */
2480 /* mb_nb contains the number of macroblocks */
2481 /* encoded in the RTP payload. */
2482 void (*rtp_callback)(struct AVCodecContext *avctx, void *data, int size, int mb_nb);
2484 int rtp_payload_size; /* The size of the RTP payload: the coder will */
2485 /* do its best to deliver a chunk with size */
2486 /* below rtp_payload_size, the chunk will start */
2487 /* with a start code on some codecs like H.263. */
2488 /* This doesn't take account of any particular */
2489 /* headers inside the transmitted RTP payload. */
2491 /* statistics, used for 2-pass encoding */
2502 * number of bits used for the previously encoded frame
2503 * - encoding: Set by libavcodec.
2504 * - decoding: unused
2509 * pass1 encoding statistics output buffer
2510 * - encoding: Set by libavcodec.
2511 * - decoding: unused
2516 * pass2 encoding statistics input buffer
2517 * Concatenated stuff from stats_out of pass1 should be placed here.
2518 * - encoding: Allocated/set/freed by user.
2519 * - decoding: unused
2524 * Work around bugs in encoders which sometimes cannot be detected automatically.
2525 * - encoding: Set by user
2526 * - decoding: Set by user
2528 int workaround_bugs;
2529 #define FF_BUG_AUTODETECT 1 ///< autodetection
2530 #if FF_API_OLD_MSMPEG4
2531 #define FF_BUG_OLD_MSMPEG4 2
2533 #define FF_BUG_XVID_ILACE 4
2534 #define FF_BUG_UMP4 8
2535 #define FF_BUG_NO_PADDING 16
2536 #define FF_BUG_AMV 32
2538 #define FF_BUG_AC_VLC 0 ///< Will be removed, libavcodec can now handle these non-compliant files by default.
2540 #define FF_BUG_QPEL_CHROMA 64
2541 #define FF_BUG_STD_QPEL 128
2542 #define FF_BUG_QPEL_CHROMA2 256
2543 #define FF_BUG_DIRECT_BLOCKSIZE 512
2544 #define FF_BUG_EDGE 1024
2545 #define FF_BUG_HPEL_CHROMA 2048
2546 #define FF_BUG_DC_CLIP 4096
2547 #define FF_BUG_MS 8192 ///< Work around various bugs in Microsoft's broken decoders.
2548 #define FF_BUG_TRUNCATED 16384
2551 * strictly follow the standard (MPEG4, ...).
2552 * - encoding: Set by user.
2553 * - decoding: Set by user.
2554 * Setting this to STRICT or higher means the encoder and decoder will
2555 * generally do stupid things, whereas setting it to unofficial or lower
2556 * will mean the encoder might produce output that is not supported by all
2557 * spec-compliant decoders. Decoders don't differentiate between normal,
2558 * unofficial and experimental (that is, they always try to decode things
2559 * when they can) unless they are explicitly asked to behave stupidly
2560 * (=strictly conform to the specs)
2562 int strict_std_compliance;
2563 #define FF_COMPLIANCE_VERY_STRICT 2 ///< Strictly conform to an older more strict version of the spec or reference software.
2564 #define FF_COMPLIANCE_STRICT 1 ///< Strictly conform to all the things in the spec no matter what consequences.
2565 #define FF_COMPLIANCE_NORMAL 0
2566 #define FF_COMPLIANCE_UNOFFICIAL -1 ///< Allow unofficial extensions
2567 #define FF_COMPLIANCE_EXPERIMENTAL -2 ///< Allow nonstandardized experimental things.
2570 * error concealment flags
2571 * - encoding: unused
2572 * - decoding: Set by user.
2574 int error_concealment;
2575 #define FF_EC_GUESS_MVS 1
2576 #define FF_EC_DEBLOCK 2
2580 * - encoding: Set by user.
2581 * - decoding: Set by user.
2584 #define FF_DEBUG_PICT_INFO 1
2585 #define FF_DEBUG_RC 2
2586 #define FF_DEBUG_BITSTREAM 4
2587 #define FF_DEBUG_MB_TYPE 8
2588 #define FF_DEBUG_QP 16
2591 * @deprecated this option does nothing
2593 #define FF_DEBUG_MV 32
2595 #define FF_DEBUG_DCT_COEFF 0x00000040
2596 #define FF_DEBUG_SKIP 0x00000080
2597 #define FF_DEBUG_STARTCODE 0x00000100
2598 #if FF_API_UNUSED_MEMBERS
2599 #define FF_DEBUG_PTS 0x00000200
2600 #endif /* FF_API_UNUSED_MEMBERS */
2601 #define FF_DEBUG_ER 0x00000400
2602 #define FF_DEBUG_MMCO 0x00000800
2603 #define FF_DEBUG_BUGS 0x00001000
2605 #define FF_DEBUG_VIS_QP 0x00002000
2606 #define FF_DEBUG_VIS_MB_TYPE 0x00004000
2608 #define FF_DEBUG_BUFFERS 0x00008000
2609 #define FF_DEBUG_THREADS 0x00010000
2613 * @deprecated this option does not have any effect
2615 attribute_deprecated
2617 #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 //visualize forward predicted MVs of P frames
2618 #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 //visualize forward predicted MVs of B frames
2619 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
2623 * Error recognition; may misdetect some more or less valid parts as errors.
2624 * - encoding: unused
2625 * - decoding: Set by user.
2627 int err_recognition;
2630 * Verify checksums embedded in the bitstream (could be of either encoded or
2631 * decoded data, depending on the codec) and print an error message on mismatch.
2632 * If AV_EF_EXPLODE is also set, a mismatching checksum will result in the
2633 * decoder returning an error.
2635 #define AV_EF_CRCCHECK (1<<0)
2636 #define AV_EF_BITSTREAM (1<<1)
2637 #define AV_EF_BUFFER (1<<2)
2638 #define AV_EF_EXPLODE (1<<3)
2641 * opaque 64bit number (generally a PTS) that will be reordered and
2642 * output in AVFrame.reordered_opaque
2643 * - encoding: unused
2644 * - decoding: Set by user.
2646 int64_t reordered_opaque;
2649 * Hardware accelerator in use
2650 * - encoding: unused.
2651 * - decoding: Set by libavcodec
2653 struct AVHWAccel *hwaccel;
2656 * Hardware accelerator context.
2657 * For some hardware accelerators, a global context needs to be
2658 * provided by the user. In that case, this holds display-dependent
2659 * data Libav cannot instantiate itself. Please refer to the
2660 * Libav HW accelerator documentation to know how to fill this
2661 * is. e.g. for VA API, this is a struct vaapi_context.
2662 * - encoding: unused
2663 * - decoding: Set by user
2665 void *hwaccel_context;
2669 * - encoding: Set by libavcodec if flags & AV_CODEC_FLAG_PSNR.
2670 * - decoding: unused
2672 uint64_t error[AV_NUM_DATA_POINTERS];
2675 * DCT algorithm, see FF_DCT_* below
2676 * - encoding: Set by user.
2677 * - decoding: unused
2680 #define FF_DCT_AUTO 0
2681 #define FF_DCT_FASTINT 1
2682 #if FF_API_UNUSED_MEMBERS
2683 #define FF_DCT_INT 2
2684 #endif /* FF_API_UNUSED_MEMBERS */
2685 #define FF_DCT_MMX 3
2686 #define FF_DCT_ALTIVEC 5
2687 #define FF_DCT_FAAN 6
2690 * IDCT algorithm, see FF_IDCT_* below.
2691 * - encoding: Set by user.
2692 * - decoding: Set by user.
2695 #define FF_IDCT_AUTO 0
2696 #define FF_IDCT_INT 1
2697 #define FF_IDCT_SIMPLE 2
2698 #define FF_IDCT_SIMPLEMMX 3
2699 #define FF_IDCT_ARM 7
2700 #define FF_IDCT_ALTIVEC 8
2702 #define FF_IDCT_SH4 9
2704 #define FF_IDCT_SIMPLEARM 10
2705 #if FF_API_UNUSED_MEMBERS
2706 #define FF_IDCT_IPP 13
2707 #endif /* FF_API_UNUSED_MEMBERS */
2708 #define FF_IDCT_XVID 14
2709 #if FF_API_IDCT_XVIDMMX
2710 #define FF_IDCT_XVIDMMX 14
2711 #endif /* FF_API_IDCT_XVIDMMX */
2712 #define FF_IDCT_SIMPLEARMV5TE 16
2713 #define FF_IDCT_SIMPLEARMV6 17
2714 #if FF_API_ARCH_SPARC
2715 #define FF_IDCT_SIMPLEVIS 18
2717 #define FF_IDCT_FAAN 20
2718 #define FF_IDCT_SIMPLENEON 22
2719 #if FF_API_ARCH_ALPHA
2720 #define FF_IDCT_SIMPLEALPHA 23
2724 * bits per sample/pixel from the demuxer (needed for huffyuv).
2725 * - encoding: Set by libavcodec.
2726 * - decoding: Set by user.
2728 int bits_per_coded_sample;
2731 * Bits per sample/pixel of internal libavcodec pixel/sample format.
2732 * - encoding: set by user.
2733 * - decoding: set by libavcodec.
2735 int bits_per_raw_sample;
2739 * low resolution decoding, 1-> 1/2 size, 2->1/4 size
2740 * - encoding: unused
2741 * - decoding: Set by user.
2743 * @deprecated use decoder private options instead
2745 attribute_deprecated int lowres;
2748 #if FF_API_CODED_FRAME
2750 * the picture in the bitstream
2751 * - encoding: Set by libavcodec.
2752 * - decoding: unused
2754 * @deprecated use the quality factor packet side data instead
2756 attribute_deprecated AVFrame *coded_frame;
2761 * is used to decide how many independent tasks should be passed to execute()
2762 * - encoding: Set by user.
2763 * - decoding: Set by user.
2768 * Which multithreading methods to use.
2769 * Use of FF_THREAD_FRAME will increase decoding delay by one frame per thread,
2770 * so clients which cannot provide future frames should not use it.
2772 * - encoding: Set by user, otherwise the default is used.
2773 * - decoding: Set by user, otherwise the default is used.
2776 #define FF_THREAD_FRAME 1 ///< Decode more than one frame at once
2777 #define FF_THREAD_SLICE 2 ///< Decode more than one part of a single frame at once
2780 * Which multithreading methods are in use by the codec.
2781 * - encoding: Set by libavcodec.
2782 * - decoding: Set by libavcodec.
2784 int active_thread_type;
2787 * Set by the client if its custom get_buffer() callback can be called
2788 * synchronously from another thread, which allows faster multithreaded decoding.
2789 * draw_horiz_band() will be called from other threads regardless of this setting.
2790 * Ignored if the default get_buffer() is used.
2791 * - encoding: Set by user.
2792 * - decoding: Set by user.
2794 int thread_safe_callbacks;
2797 * The codec may call this to execute several independent things.
2798 * It will return only after finishing all tasks.
2799 * The user may replace this with some multithreaded implementation,
2800 * the default implementation will execute the parts serially.
2801 * @param count the number of things to execute
2802 * - encoding: Set by libavcodec, user can override.
2803 * - decoding: Set by libavcodec, user can override.
2805 int (*execute)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size);
2808 * The codec may call this to execute several independent things.
2809 * It will return only after finishing all tasks.
2810 * The user may replace this with some multithreaded implementation,
2811 * the default implementation will execute the parts serially.
2812 * Also see avcodec_thread_init and e.g. the --enable-pthread configure option.
2813 * @param c context passed also to func
2814 * @param count the number of things to execute
2815 * @param arg2 argument passed unchanged to func
2816 * @param ret return values of executed functions, must have space for "count" values. May be NULL.
2817 * @param func function that will be called count times, with jobnr from 0 to count-1.
2818 * threadnr will be in the range 0 to c->thread_count-1 < MAX_THREADS and so that no
2819 * two instances of func executing at the same time will have the same threadnr.
2820 * @return always 0 currently, but code should handle a future improvement where when any call to func
2821 * returns < 0 no further calls to func may be done and < 0 is returned.
2822 * - encoding: Set by libavcodec, user can override.
2823 * - decoding: Set by libavcodec, user can override.
2825 int (*execute2)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count);
2827 #if FF_API_THREAD_OPAQUE
2829 * @deprecated this field should not be used from outside of lavc
2831 attribute_deprecated
2832 void *thread_opaque;
2836 * noise vs. sse weight for the nsse comparsion function
2837 * - encoding: Set by user.
2838 * - decoding: unused
2844 * - encoding: Set by user.
2845 * - decoding: Set by libavcodec.
2848 #define FF_PROFILE_UNKNOWN -99
2849 #define FF_PROFILE_RESERVED -100
2851 #define FF_PROFILE_AAC_MAIN 0
2852 #define FF_PROFILE_AAC_LOW 1
2853 #define FF_PROFILE_AAC_SSR 2
2854 #define FF_PROFILE_AAC_LTP 3
2855 #define FF_PROFILE_AAC_HE 4
2856 #define FF_PROFILE_AAC_HE_V2 28
2857 #define FF_PROFILE_AAC_LD 22
2858 #define FF_PROFILE_AAC_ELD 38
2859 #define FF_PROFILE_MPEG2_AAC_LOW 128
2860 #define FF_PROFILE_MPEG2_AAC_HE 131
2862 #define FF_PROFILE_DTS 20
2863 #define FF_PROFILE_DTS_ES 30
2864 #define FF_PROFILE_DTS_96_24 40
2865 #define FF_PROFILE_DTS_HD_HRA 50
2866 #define FF_PROFILE_DTS_HD_MA 60
2867 #define FF_PROFILE_DTS_EXPRESS 70
2869 #define FF_PROFILE_MPEG2_422 0
2870 #define FF_PROFILE_MPEG2_HIGH 1
2871 #define FF_PROFILE_MPEG2_SS 2
2872 #define FF_PROFILE_MPEG2_SNR_SCALABLE 3
2873 #define FF_PROFILE_MPEG2_MAIN 4
2874 #define FF_PROFILE_MPEG2_SIMPLE 5
2876 #define FF_PROFILE_H264_CONSTRAINED (1<<9) // 8+1; constraint_set1_flag
2877 #define FF_PROFILE_H264_INTRA (1<<11) // 8+3; constraint_set3_flag
2879 #define FF_PROFILE_H264_BASELINE 66
2880 #define FF_PROFILE_H264_CONSTRAINED_BASELINE (66|FF_PROFILE_H264_CONSTRAINED)
2881 #define FF_PROFILE_H264_MAIN 77
2882 #define FF_PROFILE_H264_EXTENDED 88
2883 #define FF_PROFILE_H264_HIGH 100
2884 #define FF_PROFILE_H264_HIGH_10 110
2885 #define FF_PROFILE_H264_HIGH_10_INTRA (110|FF_PROFILE_H264_INTRA)
2886 #define FF_PROFILE_H264_HIGH_422 122
2887 #define FF_PROFILE_H264_HIGH_422_INTRA (122|FF_PROFILE_H264_INTRA)
2888 #define FF_PROFILE_H264_HIGH_444 144
2889 #define FF_PROFILE_H264_HIGH_444_PREDICTIVE 244
2890 #define FF_PROFILE_H264_HIGH_444_INTRA (244|FF_PROFILE_H264_INTRA)
2891 #define FF_PROFILE_H264_CAVLC_444 44
2893 #define FF_PROFILE_VC1_SIMPLE 0
2894 #define FF_PROFILE_VC1_MAIN 1
2895 #define FF_PROFILE_VC1_COMPLEX 2
2896 #define FF_PROFILE_VC1_ADVANCED 3
2898 #define FF_PROFILE_MPEG4_SIMPLE 0
2899 #define FF_PROFILE_MPEG4_SIMPLE_SCALABLE 1
2900 #define FF_PROFILE_MPEG4_CORE 2
2901 #define FF_PROFILE_MPEG4_MAIN 3
2902 #define FF_PROFILE_MPEG4_N_BIT 4
2903 #define FF_PROFILE_MPEG4_SCALABLE_TEXTURE 5
2904 #define FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION 6
2905 #define FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE 7
2906 #define FF_PROFILE_MPEG4_HYBRID 8
2907 #define FF_PROFILE_MPEG4_ADVANCED_REAL_TIME 9
2908 #define FF_PROFILE_MPEG4_CORE_SCALABLE 10
2909 #define FF_PROFILE_MPEG4_ADVANCED_CODING 11
2910 #define FF_PROFILE_MPEG4_ADVANCED_CORE 12
2911 #define FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE 13
2912 #define FF_PROFILE_MPEG4_SIMPLE_STUDIO 14
2913 #define FF_PROFILE_MPEG4_ADVANCED_SIMPLE 15
2915 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_0 0
2916 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_1 1
2917 #define FF_PROFILE_JPEG2000_CSTREAM_NO_RESTRICTION 2
2918 #define FF_PROFILE_JPEG2000_DCINEMA_2K 3
2919 #define FF_PROFILE_JPEG2000_DCINEMA_4K 4
2921 #define FF_PROFILE_VP9_0 0
2922 #define FF_PROFILE_VP9_1 1
2923 #define FF_PROFILE_VP9_2 2
2924 #define FF_PROFILE_VP9_3 3
2926 #define FF_PROFILE_HEVC_MAIN 1
2927 #define FF_PROFILE_HEVC_MAIN_10 2
2928 #define FF_PROFILE_HEVC_MAIN_STILL_PICTURE 3
2932 * - encoding: Set by user.
2933 * - decoding: Set by libavcodec.
2936 #define FF_LEVEL_UNKNOWN -99
2940 * - encoding: unused
2941 * - decoding: Set by user.
2943 enum AVDiscard skip_loop_filter;
2947 * - encoding: unused
2948 * - decoding: Set by user.
2950 enum AVDiscard skip_idct;
2954 * - encoding: unused
2955 * - decoding: Set by user.
2957 enum AVDiscard skip_frame;
2960 * Header containing style information for text subtitles.
2961 * For SUBTITLE_ASS subtitle type, it should contain the whole ASS
2962 * [Script Info] and [V4+ Styles] section, plus the [Events] line and
2963 * the Format line following. It shouldn't include any Dialogue line.
2964 * - encoding: Set/allocated/freed by user (before avcodec_open2())
2965 * - decoding: Set/allocated/freed by libavcodec (by avcodec_open2())
2967 uint8_t *subtitle_header;
2968 int subtitle_header_size;
2970 #if FF_API_ERROR_RATE
2972 * @deprecated use the 'error_rate' private AVOption of the mpegvideo
2975 attribute_deprecated
2979 #if FF_API_CODEC_PKT
2981 * @deprecated this field is not supposed to be accessed from outside lavc
2983 attribute_deprecated
2988 * VBV delay coded in the last frame (in periods of a 27 MHz clock).
2989 * Used for compliant TS muxing.
2990 * - encoding: Set by libavcodec.
2991 * - decoding: unused.
2996 * Encoding only. Allow encoders to output packets that do not contain any
2997 * encoded data, only side data.
2999 * Some encoders need to output such packets, e.g. to update some stream
3000 * parameters at the end of encoding.
3002 * All callers are strongly recommended to set this option to 1 and update
3003 * their code to deal with such packets, since this behaviour may become
3004 * always enabled in the future (then this option will be deprecated and
3005 * later removed). To avoid ABI issues when this happens, the callers should
3006 * use AVOptions to set this field.
3008 int side_data_only_packets;
3011 * Audio only. The number of "priming" samples (padding) inserted by the
3012 * encoder at the beginning of the audio. I.e. this number of leading
3013 * decoded samples must be discarded by the caller to get the original audio
3014 * without leading padding.
3016 * - decoding: unused
3017 * - encoding: Set by libavcodec. The timestamps on the output packets are
3018 * adjusted by the encoder so that they always refer to the
3019 * first sample of the data actually contained in the packet,
3020 * including any added padding. E.g. if the timebase is
3021 * 1/samplerate and the timestamp of the first input sample is
3022 * 0, the timestamp of the first output packet will be
3025 int initial_padding;
3028 * - decoding: For codecs that store a framerate value in the compressed
3029 * bitstream, the decoder may export it here. { 0, 1} when
3031 * - encoding: unused
3033 AVRational framerate;
3036 * Nominal unaccelerated pixel format, see AV_PIX_FMT_xxx.
3037 * - encoding: unused.
3038 * - decoding: Set by libavcodec before calling get_format()
3040 enum AVPixelFormat sw_pix_fmt;
3046 typedef struct AVProfile {
3048 const char *name; ///< short name for the profile
3051 typedef struct AVCodecDefault AVCodecDefault;
3058 typedef struct AVCodec {
3060 * Name of the codec implementation.
3061 * The name is globally unique among encoders and among decoders (but an
3062 * encoder and a decoder can share the same name).
3063 * This is the primary way to find a codec from the user perspective.
3067 * Descriptive name for the codec, meant to be more human readable than name.
3068 * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
3070 const char *long_name;
3071 enum AVMediaType type;
3074 * Codec capabilities.
3075 * see AV_CODEC_CAP_*
3078 const AVRational *supported_framerates; ///< array of supported framerates, or NULL if any, array is terminated by {0,0}
3079 const enum AVPixelFormat *pix_fmts; ///< array of supported pixel formats, or NULL if unknown, array is terminated by -1
3080 const int *supported_samplerates; ///< array of supported audio samplerates, or NULL if unknown, array is terminated by 0
3081 const enum AVSampleFormat *sample_fmts; ///< array of supported sample formats, or NULL if unknown, array is terminated by -1
3082 const uint64_t *channel_layouts; ///< array of support channel layouts, or NULL if unknown. array is terminated by 0
3084 attribute_deprecated uint8_t max_lowres; ///< maximum value for lowres supported by the decoder
3086 const AVClass *priv_class; ///< AVClass for the private context
3087 const AVProfile *profiles; ///< array of recognized profiles, or NULL if unknown, array is terminated by {FF_PROFILE_UNKNOWN}
3089 /*****************************************************************
3090 * No fields below this line are part of the public API. They
3091 * may not be used outside of libavcodec and can be changed and
3093 * New public fields should be added right above.
3094 *****************************************************************
3097 struct AVCodec *next;
3099 * @name Frame-level threading support functions
3103 * If defined, called on thread contexts when they are created.
3104 * If the codec allocates writable tables in init(), re-allocate them here.
3105 * priv_data will be set to a copy of the original.
3107 int (*init_thread_copy)(AVCodecContext *);
3109 * Copy necessary context variables from a previous thread context to the current one.
3110 * If not defined, the next thread will start automatically; otherwise, the codec
3111 * must call ff_thread_finish_setup().
3113 * dst and src will (rarely) point to the same context, in which case memcpy should be skipped.
3115 int (*update_thread_context)(AVCodecContext *dst, const AVCodecContext *src);
3119 * Private codec-specific defaults.
3121 const AVCodecDefault *defaults;
3124 * Initialize codec static data, called from avcodec_register().
3126 void (*init_static_data)(struct AVCodec *codec);
3128 int (*init)(AVCodecContext *);
3129 int (*encode_sub)(AVCodecContext *, uint8_t *buf, int buf_size,
3130 const struct AVSubtitle *sub);
3132 * Encode data to an AVPacket.
3134 * @param avctx codec context
3135 * @param avpkt output AVPacket (may contain a user-provided buffer)
3136 * @param[in] frame AVFrame containing the raw data to be encoded
3137 * @param[out] got_packet_ptr encoder sets to 0 or 1 to indicate that a
3138 * non-empty packet was returned in avpkt.
3139 * @return 0 on success, negative error code on failure
3141 int (*encode2)(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame,
3142 int *got_packet_ptr);
3143 int (*decode)(AVCodecContext *, void *outdata, int *outdata_size, AVPacket *avpkt);
3144 int (*close)(AVCodecContext *);
3147 * Will be called when seeking
3149 void (*flush)(AVCodecContext *);
3151 * Internal codec capabilities.
3152 * See FF_CODEC_CAP_* in internal.h
3158 * @defgroup lavc_hwaccel AVHWAccel
3161 typedef struct AVHWAccel {
3163 * Name of the hardware accelerated codec.
3164 * The name is globally unique among encoders and among decoders (but an
3165 * encoder and a decoder can share the same name).
3170 * Type of codec implemented by the hardware accelerator.
3172 * See AVMEDIA_TYPE_xxx
3174 enum AVMediaType type;
3177 * Codec implemented by the hardware accelerator.
3179 * See AV_CODEC_ID_xxx
3184 * Supported pixel format.
3186 * Only hardware accelerated formats are supported here.
3188 enum AVPixelFormat pix_fmt;
3191 * Hardware accelerated codec capabilities.
3192 * see FF_HWACCEL_CODEC_CAP_*
3196 /*****************************************************************
3197 * No fields below this line are part of the public API. They
3198 * may not be used outside of libavcodec and can be changed and
3200 * New public fields should be added right above.
3201 *****************************************************************
3203 struct AVHWAccel *next;
3206 * Allocate a custom buffer
3208 int (*alloc_frame)(AVCodecContext *avctx, AVFrame *frame);
3211 * Called at the beginning of each frame or field picture.
3213 * Meaningful frame information (codec specific) is guaranteed to
3214 * be parsed at this point. This function is mandatory.
3216 * Note that buf can be NULL along with buf_size set to 0.
3217 * Otherwise, this means the whole frame is available at this point.
3219 * @param avctx the codec context
3220 * @param buf the frame data buffer base
3221 * @param buf_size the size of the frame in bytes
3222 * @return zero if successful, a negative value otherwise
3224 int (*start_frame)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3227 * Callback for each slice.
3229 * Meaningful slice information (codec specific) is guaranteed to
3230 * be parsed at this point. This function is mandatory.
3232 * @param avctx the codec context
3233 * @param buf the slice data buffer base
3234 * @param buf_size the size of the slice in bytes
3235 * @return zero if successful, a negative value otherwise
3237 int (*decode_slice)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3240 * Called at the end of each frame or field picture.
3242 * The whole picture is parsed at this point and can now be sent
3243 * to the hardware accelerator. This function is mandatory.
3245 * @param avctx the codec context
3246 * @return zero if successful, a negative value otherwise
3248 int (*end_frame)(AVCodecContext *avctx);
3251 * Size of per-frame hardware accelerator private data.
3253 * Private data is allocated with av_mallocz() before
3254 * AVCodecContext.get_buffer() and deallocated after
3255 * AVCodecContext.release_buffer().
3257 int frame_priv_data_size;
3260 * Initialize the hwaccel private data.
3262 * This will be called from ff_get_format(), after hwaccel and
3263 * hwaccel_context are set and the hwaccel private data in AVCodecInternal
3266 int (*init)(AVCodecContext *avctx);
3269 * Uninitialize the hwaccel private data.
3271 * This will be called from get_format() or avcodec_close(), after hwaccel
3272 * and hwaccel_context are already uninitialized.
3274 int (*uninit)(AVCodecContext *avctx);
3277 * Size of the private data to allocate in
3278 * AVCodecInternal.hwaccel_priv_data.
3284 * Hardware acceleration should be used for decoding even if the codec level
3285 * used is unknown or higher than the maximum supported level reported by the
3288 #define AV_HWACCEL_FLAG_IGNORE_LEVEL (1 << 0)
3291 * Hardware acceleration can output YUV pixel formats with a different chroma
3292 * sampling than 4:2:0 and/or other than 8 bits per component.
3294 #define AV_HWACCEL_FLAG_ALLOW_HIGH_DEPTH (1 << 1)
3301 * @defgroup lavc_picture AVPicture
3303 * Functions for working with AVPicture
3308 * four components are given, that's all.
3309 * the last component is alpha
3311 typedef struct AVPicture {
3312 uint8_t *data[AV_NUM_DATA_POINTERS];
3313 int linesize[AV_NUM_DATA_POINTERS]; ///< number of bytes per line
3320 #define AVPALETTE_SIZE 1024
3321 #define AVPALETTE_COUNT 256
3323 enum AVSubtitleType {
3326 SUBTITLE_BITMAP, ///< A bitmap, pict will be set
3329 * Plain text, the text field must be set by the decoder and is
3330 * authoritative. ass and pict fields may contain approximations.
3335 * Formatted text, the ass field must be set by the decoder and is
3336 * authoritative. pict and text fields may contain approximations.
3341 #define AV_SUBTITLE_FLAG_FORCED 0x00000001
3343 typedef struct AVSubtitleRect {
3344 int x; ///< top left corner of pict, undefined when pict is not set
3345 int y; ///< top left corner of pict, undefined when pict is not set
3346 int w; ///< width of pict, undefined when pict is not set
3347 int h; ///< height of pict, undefined when pict is not set
3348 int nb_colors; ///< number of colors in pict, undefined when pict is not set
3351 * data+linesize for the bitmap of this subtitle.
3352 * can be set for text/ass as well once they where rendered
3355 enum AVSubtitleType type;
3357 char *text; ///< 0 terminated plain UTF-8 text
3360 * 0 terminated ASS/SSA compatible event line.
3361 * The pressentation of this is unaffected by the other values in this
3368 typedef struct AVSubtitle {
3369 uint16_t format; /* 0 = graphics */
3370 uint32_t start_display_time; /* relative to packet pts, in ms */
3371 uint32_t end_display_time; /* relative to packet pts, in ms */
3373 AVSubtitleRect **rects;
3374 int64_t pts; ///< Same as packet pts, in AV_TIME_BASE
3378 * If c is NULL, returns the first registered codec,
3379 * if c is non-NULL, returns the next registered codec after c,
3380 * or NULL if c is the last one.
3382 AVCodec *av_codec_next(const AVCodec *c);
3385 * Return the LIBAVCODEC_VERSION_INT constant.
3387 unsigned avcodec_version(void);
3390 * Return the libavcodec build-time configuration.
3392 const char *avcodec_configuration(void);
3395 * Return the libavcodec license.
3397 const char *avcodec_license(void);
3400 * Register the codec codec and initialize libavcodec.
3402 * @warning either this function or avcodec_register_all() must be called
3403 * before any other libavcodec functions.
3405 * @see avcodec_register_all()
3407 void avcodec_register(AVCodec *codec);
3410 * Register all the codecs, parsers and bitstream filters which were enabled at
3411 * configuration time. If you do not call this function you can select exactly
3412 * which formats you want to support, by using the individual registration
3415 * @see avcodec_register
3416 * @see av_register_codec_parser
3417 * @see av_register_bitstream_filter
3419 void avcodec_register_all(void);
3422 * Allocate an AVCodecContext and set its fields to default values. The
3423 * resulting struct should be freed with avcodec_free_context().
3425 * @param codec if non-NULL, allocate private data and initialize defaults
3426 * for the given codec. It is illegal to then call avcodec_open2()
3427 * with a different codec.
3428 * If NULL, then the codec-specific defaults won't be initialized,
3429 * which may result in suboptimal default settings (this is
3430 * important mainly for encoders, e.g. libx264).
3432 * @return An AVCodecContext filled with default values or NULL on failure.
3433 * @see avcodec_get_context_defaults
3435 AVCodecContext *avcodec_alloc_context3(const AVCodec *codec);
3438 * Free the codec context and everything associated with it and write NULL to
3439 * the provided pointer.
3441 void avcodec_free_context(AVCodecContext **avctx);
3444 * Set the fields of the given AVCodecContext to default values corresponding
3445 * to the given codec (defaults may be codec-dependent).
3447 * Do not call this function if a non-NULL codec has been passed
3448 * to avcodec_alloc_context3() that allocated this AVCodecContext.
3449 * If codec is non-NULL, it is illegal to call avcodec_open2() with a
3450 * different codec on this AVCodecContext.
3452 int avcodec_get_context_defaults3(AVCodecContext *s, const AVCodec *codec);
3455 * Get the AVClass for AVCodecContext. It can be used in combination with
3456 * AV_OPT_SEARCH_FAKE_OBJ for examining options.
3458 * @see av_opt_find().
3460 const AVClass *avcodec_get_class(void);
3463 * Copy the settings of the source AVCodecContext into the destination
3464 * AVCodecContext. The resulting destination codec context will be
3465 * unopened, i.e. you are required to call avcodec_open2() before you
3466 * can use this AVCodecContext to decode/encode video/audio data.
3468 * @param dest target codec context, should be initialized with
3469 * avcodec_alloc_context3(), but otherwise uninitialized
3470 * @param src source codec context
3471 * @return AVERROR() on error (e.g. memory allocation error), 0 on success
3473 int avcodec_copy_context(AVCodecContext *dest, const AVCodecContext *src);
3475 #if FF_API_AVFRAME_LAVC
3477 * @deprecated use av_frame_alloc()
3479 attribute_deprecated
3480 AVFrame *avcodec_alloc_frame(void);
3483 * Set the fields of the given AVFrame to default values.
3485 * @param frame The AVFrame of which the fields should be set to default values.
3487 * @deprecated use av_frame_unref()
3489 attribute_deprecated
3490 void avcodec_get_frame_defaults(AVFrame *frame);
3493 * Free the frame and any dynamically allocated objects in it,
3494 * e.g. extended_data.
3496 * @param frame frame to be freed. The pointer will be set to NULL.
3498 * @warning this function does NOT free the data buffers themselves
3499 * (it does not know how, since they might have been allocated with
3500 * a custom get_buffer()).
3502 * @deprecated use av_frame_free()
3504 attribute_deprecated
3505 void avcodec_free_frame(AVFrame **frame);
3509 * Initialize the AVCodecContext to use the given AVCodec. Prior to using this
3510 * function the context has to be allocated with avcodec_alloc_context3().
3512 * The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(),
3513 * avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for
3514 * retrieving a codec.
3516 * @warning This function is not thread safe!
3518 * @note Always call this function before using decoding routines (such as
3519 * @ref avcodec_decode_video2()).
3522 * avcodec_register_all();
3523 * av_dict_set(&opts, "b", "2.5M", 0);
3524 * codec = avcodec_find_decoder(AV_CODEC_ID_H264);
3528 * context = avcodec_alloc_context3(codec);
3530 * if (avcodec_open2(context, codec, opts) < 0)
3534 * @param avctx The context to initialize.
3535 * @param codec The codec to open this context for. If a non-NULL codec has been
3536 * previously passed to avcodec_alloc_context3() or
3537 * avcodec_get_context_defaults3() for this context, then this
3538 * parameter MUST be either NULL or equal to the previously passed
3540 * @param options A dictionary filled with AVCodecContext and codec-private options.
3541 * On return this object will be filled with options that were not found.
3543 * @return zero on success, a negative value on error
3544 * @see avcodec_alloc_context3(), avcodec_find_decoder(), avcodec_find_encoder(),
3545 * av_dict_set(), av_opt_find().
3547 int avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options);
3550 * Close a given AVCodecContext and free all the data associated with it
3551 * (but not the AVCodecContext itself).
3553 * Calling this function on an AVCodecContext that hasn't been opened will free
3554 * the codec-specific data allocated in avcodec_alloc_context3() /
3555 * avcodec_get_context_defaults3() with a non-NULL codec. Subsequent calls will
3558 int avcodec_close(AVCodecContext *avctx);
3561 * Free all allocated data in the given subtitle struct.
3563 * @param sub AVSubtitle to free.
3565 void avsubtitle_free(AVSubtitle *sub);
3572 * @addtogroup lavc_packet
3576 #if FF_API_DESTRUCT_PACKET
3578 * Default packet destructor.
3579 * @deprecated use the AVBuffer API instead
3581 attribute_deprecated
3582 void av_destruct_packet(AVPacket *pkt);
3586 * Initialize optional fields of a packet with default values.
3588 * Note, this does not touch the data and size members, which have to be
3589 * initialized separately.
3593 void av_init_packet(AVPacket *pkt);
3596 * Allocate the payload of a packet and initialize its fields with
3600 * @param size wanted payload size
3601 * @return 0 if OK, AVERROR_xxx otherwise
3603 int av_new_packet(AVPacket *pkt, int size);
3606 * Reduce packet size, correctly zeroing padding
3609 * @param size new size
3611 void av_shrink_packet(AVPacket *pkt, int size);
3614 * Increase packet size, correctly zeroing padding
3617 * @param grow_by number of bytes by which to increase the size of the packet
3619 int av_grow_packet(AVPacket *pkt, int grow_by);
3622 * Initialize a reference-counted packet from av_malloc()ed data.
3624 * @param pkt packet to be initialized. This function will set the data, size,
3625 * buf and destruct fields, all others are left untouched.
3626 * @param data Data allocated by av_malloc() to be used as packet data. If this
3627 * function returns successfully, the data is owned by the underlying AVBuffer.
3628 * The caller may not access the data through other means.
3629 * @param size size of data in bytes, without the padding. I.e. the full buffer
3630 * size is assumed to be size + FF_INPUT_BUFFER_PADDING_SIZE.
3632 * @return 0 on success, a negative AVERROR on error
3634 int av_packet_from_data(AVPacket *pkt, uint8_t *data, int size);
3637 * @warning This is a hack - the packet memory allocation stuff is broken. The
3638 * packet is allocated if it was not really allocated.
3640 int av_dup_packet(AVPacket *pkt);
3645 * @param pkt packet to free
3647 void av_free_packet(AVPacket *pkt);
3650 * Allocate new information of a packet.
3653 * @param type side information type
3654 * @param size side information size
3655 * @return pointer to fresh allocated data or NULL otherwise
3657 uint8_t* av_packet_new_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
3661 * Shrink the already allocated side data buffer
3664 * @param type side information type
3665 * @param size new side information size
3666 * @return 0 on success, < 0 on failure
3668 int av_packet_shrink_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
3672 * Get side information from packet.
3675 * @param type desired side information type
3676 * @param size pointer for side information size to store (optional)
3677 * @return pointer to data if present or NULL otherwise
3679 uint8_t* av_packet_get_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
3683 * Convenience function to free all the side data stored.
3684 * All the other fields stay untouched.
3688 void av_packet_free_side_data(AVPacket *pkt);
3691 * Setup a new reference to the data described by a given packet
3693 * If src is reference-counted, setup dst as a new reference to the
3694 * buffer in src. Otherwise allocate a new buffer in dst and copy the
3695 * data from src into it.
3697 * All the other fields are copied from src.
3699 * @see av_packet_unref
3701 * @param dst Destination packet
3702 * @param src Source packet
3704 * @return 0 on success, a negative AVERROR on error.
3706 int av_packet_ref(AVPacket *dst, AVPacket *src);
3711 * Unreference the buffer referenced by the packet and reset the
3712 * remaining packet fields to their default values.
3714 * @param pkt The packet to be unreferenced.
3716 void av_packet_unref(AVPacket *pkt);
3719 * Move every field in src to dst and reset src.
3721 * @see av_packet_unref
3723 * @param src Source packet, will be reset
3724 * @param dst Destination packet
3726 void av_packet_move_ref(AVPacket *dst, AVPacket *src);
3729 * Copy only "properties" fields from src to dst.
3731 * Properties for the purpose of this function are all the fields
3732 * beside those related to the packet data (buf, data, size)
3734 * @param dst Destination packet
3735 * @param src Source packet
3737 * @return 0 on success AVERROR on failure.
3740 int av_packet_copy_props(AVPacket *dst, const AVPacket *src);
3743 * Convert valid timing fields (timestamps / durations) in a packet from one
3744 * timebase to another. Timestamps with unknown values (AV_NOPTS_VALUE) will be
3747 * @param pkt packet on which the conversion will be performed
3748 * @param tb_src source timebase, in which the timing fields in pkt are
3750 * @param tb_dst destination timebase, to which the timing fields will be
3753 void av_packet_rescale_ts(AVPacket *pkt, AVRational tb_src, AVRational tb_dst);
3760 * @addtogroup lavc_decoding
3765 * Find a registered decoder with a matching codec ID.
3767 * @param id AVCodecID of the requested decoder
3768 * @return A decoder if one was found, NULL otherwise.
3770 AVCodec *avcodec_find_decoder(enum AVCodecID id);
3773 * Find a registered decoder with the specified name.
3775 * @param name name of the requested decoder
3776 * @return A decoder if one was found, NULL otherwise.
3778 AVCodec *avcodec_find_decoder_by_name(const char *name);
3780 #if FF_API_GET_BUFFER
3781 attribute_deprecated int avcodec_default_get_buffer(AVCodecContext *s, AVFrame *pic);
3782 attribute_deprecated void avcodec_default_release_buffer(AVCodecContext *s, AVFrame *pic);
3783 attribute_deprecated int avcodec_default_reget_buffer(AVCodecContext *s, AVFrame *pic);
3787 * The default callback for AVCodecContext.get_buffer2(). It is made public so
3788 * it can be called by custom get_buffer2() implementations for decoders without
3789 * AV_CODEC_CAP_DR1 set.
3791 int avcodec_default_get_buffer2(AVCodecContext *s, AVFrame *frame, int flags);
3795 * Return the amount of padding in pixels which the get_buffer callback must
3796 * provide around the edge of the image for codecs which do not have the
3797 * CODEC_FLAG_EMU_EDGE flag.
3799 * @return Required padding in pixels.
3801 * @deprecated CODEC_FLAG_EMU_EDGE is deprecated, so this function is no longer
3804 attribute_deprecated
3805 unsigned avcodec_get_edge_width(void);
3809 * Modify width and height values so that they will result in a memory
3810 * buffer that is acceptable for the codec if you do not use any horizontal
3813 * May only be used if a codec with AV_CODEC_CAP_DR1 has been opened.
3815 void avcodec_align_dimensions(AVCodecContext *s, int *width, int *height);
3818 * Modify width and height values so that they will result in a memory
3819 * buffer that is acceptable for the codec if you also ensure that all
3820 * line sizes are a multiple of the respective linesize_align[i].
3822 * May only be used if a codec with AV_CODEC_CAP_DR1 has been opened.
3824 void avcodec_align_dimensions2(AVCodecContext *s, int *width, int *height,
3825 int linesize_align[AV_NUM_DATA_POINTERS]);
3828 * Decode the audio frame of size avpkt->size from avpkt->data into frame.
3830 * Some decoders may support multiple frames in a single AVPacket. Such
3831 * decoders would then just decode the first frame and the return value would be
3832 * less than the packet size. In this case, avcodec_decode_audio4 has to be
3833 * called again with an AVPacket containing the remaining data in order to
3834 * decode the second frame, etc... Even if no frames are returned, the packet
3835 * needs to be fed to the decoder with remaining data until it is completely
3836 * consumed or an error occurs.
3838 * Some decoders (those marked with AV_CODEC_CAP_DELAY) have a delay between input
3839 * and output. This means that for some packets they will not immediately
3840 * produce decoded output and need to be flushed at the end of decoding to get
3841 * all the decoded data. Flushing is done by calling this function with packets
3842 * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
3843 * returning samples. It is safe to flush even those decoders that are not
3844 * marked with AV_CODEC_CAP_DELAY, then no samples will be returned.
3846 * @warning The input buffer, avpkt->data must be FF_INPUT_BUFFER_PADDING_SIZE
3847 * larger than the actual read bytes because some optimized bitstream
3848 * readers read 32 or 64 bits at once and could read over the end.
3850 * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
3851 * before packets may be fed to the decoder.
3853 * @param avctx the codec context
3854 * @param[out] frame The AVFrame in which to store decoded audio samples.
3855 * The decoder will allocate a buffer for the decoded frame by
3856 * calling the AVCodecContext.get_buffer2() callback.
3857 * When AVCodecContext.refcounted_frames is set to 1, the frame is
3858 * reference counted and the returned reference belongs to the
3859 * caller. The caller must release the frame using av_frame_unref()
3860 * when the frame is no longer needed. The caller may safely write
3861 * to the frame if av_frame_is_writable() returns 1.
3862 * When AVCodecContext.refcounted_frames is set to 0, the returned
3863 * reference belongs to the decoder and is valid only until the
3864 * next call to this function or until closing or flushing the
3865 * decoder. The caller may not write to it.
3866 * @param[out] got_frame_ptr Zero if no frame could be decoded, otherwise it is
3867 * non-zero. Note that this field being set to zero
3868 * does not mean that an error has occurred. For
3869 * decoders with AV_CODEC_CAP_DELAY set, no given decode
3870 * call is guaranteed to produce a frame.
3871 * @param[in] avpkt The input AVPacket containing the input buffer.
3872 * At least avpkt->data and avpkt->size should be set. Some
3873 * decoders might also require additional fields to be set.
3874 * @return A negative error code is returned if an error occurred during
3875 * decoding, otherwise the number of bytes consumed from the input
3876 * AVPacket is returned.
3878 int avcodec_decode_audio4(AVCodecContext *avctx, AVFrame *frame,
3879 int *got_frame_ptr, AVPacket *avpkt);
3882 * Decode the video frame of size avpkt->size from avpkt->data into picture.
3883 * Some decoders may support multiple frames in a single AVPacket, such
3884 * decoders would then just decode the first frame.
3886 * @warning The input buffer must be FF_INPUT_BUFFER_PADDING_SIZE larger than
3887 * the actual read bytes because some optimized bitstream readers read 32 or 64
3888 * bits at once and could read over the end.
3890 * @warning The end of the input buffer buf should be set to 0 to ensure that
3891 * no overreading happens for damaged MPEG streams.
3893 * @note Codecs which have the AV_CODEC_CAP_DELAY capability set have a delay
3894 * between input and output, these need to be fed with avpkt->data=NULL,
3895 * avpkt->size=0 at the end to return the remaining frames.
3897 * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
3898 * before packets may be fed to the decoder.
3900 * @param avctx the codec context
3901 * @param[out] picture The AVFrame in which the decoded video frame will be stored.
3902 * Use av_frame_alloc() to get an AVFrame. The codec will
3903 * allocate memory for the actual bitmap by calling the
3904 * AVCodecContext.get_buffer2() callback.
3905 * When AVCodecContext.refcounted_frames is set to 1, the frame is
3906 * reference counted and the returned reference belongs to the
3907 * caller. The caller must release the frame using av_frame_unref()
3908 * when the frame is no longer needed. The caller may safely write
3909 * to the frame if av_frame_is_writable() returns 1.
3910 * When AVCodecContext.refcounted_frames is set to 0, the returned
3911 * reference belongs to the decoder and is valid only until the
3912 * next call to this function or until closing or flushing the
3913 * decoder. The caller may not write to it.
3915 * @param[in] avpkt The input AVpacket containing the input buffer.
3916 * You can create such packet with av_init_packet() and by then setting
3917 * data and size, some decoders might in addition need other fields like
3918 * flags&AV_PKT_FLAG_KEY. All decoders are designed to use the least
3920 * @param[in,out] got_picture_ptr Zero if no frame could be decompressed, otherwise, it is nonzero.
3921 * @return On error a negative value is returned, otherwise the number of bytes
3922 * used or zero if no frame could be decompressed.
3924 int avcodec_decode_video2(AVCodecContext *avctx, AVFrame *picture,
3925 int *got_picture_ptr,
3929 * Decode a subtitle message.
3930 * Return a negative value on error, otherwise return the number of bytes used.
3931 * If no subtitle could be decompressed, got_sub_ptr is zero.
3932 * Otherwise, the subtitle is stored in *sub.
3933 * Note that AV_CODEC_CAP_DR1 is not available for subtitle codecs. This is for
3934 * simplicity, because the performance difference is expect to be negligible
3935 * and reusing a get_buffer written for video codecs would probably perform badly
3936 * due to a potentially very different allocation pattern.
3938 * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
3939 * before packets may be fed to the decoder.
3941 * @param avctx the codec context
3942 * @param[out] sub The AVSubtitle in which the decoded subtitle will be stored, must be
3943 freed with avsubtitle_free if *got_sub_ptr is set.
3944 * @param[in,out] got_sub_ptr Zero if no subtitle could be decompressed, otherwise, it is nonzero.
3945 * @param[in] avpkt The input AVPacket containing the input buffer.
3947 int avcodec_decode_subtitle2(AVCodecContext *avctx, AVSubtitle *sub,
3952 * @defgroup lavc_parsing Frame parsing
3956 enum AVPictureStructure {
3957 AV_PICTURE_STRUCTURE_UNKNOWN, //< unknown
3958 AV_PICTURE_STRUCTURE_TOP_FIELD, //< coded as top field
3959 AV_PICTURE_STRUCTURE_BOTTOM_FIELD, //< coded as bottom field
3960 AV_PICTURE_STRUCTURE_FRAME, //< coded as frame
3963 typedef struct AVCodecParserContext {
3965 struct AVCodecParser *parser;
3966 int64_t frame_offset; /* offset of the current frame */
3967 int64_t cur_offset; /* current offset
3968 (incremented by each av_parser_parse()) */
3969 int64_t next_frame_offset; /* offset of the next frame */
3971 int pict_type; /* XXX: Put it back in AVCodecContext. */
3973 * This field is used for proper frame duration computation in lavf.
3974 * It signals, how much longer the frame duration of the current frame
3975 * is compared to normal frame duration.
3977 * frame_duration = (1 + repeat_pict) * time_base
3979 * It is used by codecs like H.264 to display telecined material.
3981 int repeat_pict; /* XXX: Put it back in AVCodecContext. */
3982 int64_t pts; /* pts of the current frame */
3983 int64_t dts; /* dts of the current frame */
3988 int fetch_timestamp;
3990 #define AV_PARSER_PTS_NB 4
3991 int cur_frame_start_index;
3992 int64_t cur_frame_offset[AV_PARSER_PTS_NB];
3993 int64_t cur_frame_pts[AV_PARSER_PTS_NB];
3994 int64_t cur_frame_dts[AV_PARSER_PTS_NB];
3997 #define PARSER_FLAG_COMPLETE_FRAMES 0x0001
3998 #define PARSER_FLAG_ONCE 0x0002
3999 /// Set if the parser has a valid file offset
4000 #define PARSER_FLAG_FETCHED_OFFSET 0x0004
4002 int64_t offset; ///< byte offset from starting packet start
4003 int64_t cur_frame_end[AV_PARSER_PTS_NB];
4006 * Set by parser to 1 for key frames and 0 for non-key frames.
4007 * It is initialized to -1, so if the parser doesn't set this flag,
4008 * old-style fallback using AV_PICTURE_TYPE_I picture type as key frames
4014 * Time difference in stream time base units from the pts of this
4015 * packet to the point at which the output from the decoder has converged
4016 * independent from the availability of previous frames. That is, the
4017 * frames are virtually identical no matter if decoding started from
4018 * the very first frame or from this keyframe.
4019 * Is AV_NOPTS_VALUE if unknown.
4020 * This field is not the display duration of the current frame.
4021 * This field has no meaning if the packet does not have AV_PKT_FLAG_KEY
4024 * The purpose of this field is to allow seeking in streams that have no
4025 * keyframes in the conventional sense. It corresponds to the
4026 * recovery point SEI in H.264 and match_time_delta in NUT. It is also
4027 * essential for some types of subtitle streams to ensure that all
4028 * subtitles are correctly displayed after seeking.
4030 int64_t convergence_duration;
4032 // Timestamp generation support:
4034 * Synchronization point for start of timestamp generation.
4036 * Set to >0 for sync point, 0 for no sync point and <0 for undefined
4039 * For example, this corresponds to presence of H.264 buffering period
4045 * Offset of the current timestamp against last timestamp sync point in
4046 * units of AVCodecContext.time_base.
4048 * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
4049 * contain a valid timestamp offset.
4051 * Note that the timestamp of sync point has usually a nonzero
4052 * dts_ref_dts_delta, which refers to the previous sync point. Offset of
4053 * the next frame after timestamp sync point will be usually 1.
4055 * For example, this corresponds to H.264 cpb_removal_delay.
4057 int dts_ref_dts_delta;
4060 * Presentation delay of current frame in units of AVCodecContext.time_base.
4062 * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
4063 * contain valid non-negative timestamp delta (presentation time of a frame
4064 * must not lie in the past).
4066 * This delay represents the difference between decoding and presentation
4067 * time of the frame.
4069 * For example, this corresponds to H.264 dpb_output_delay.
4074 * Position of the packet in file.
4076 * Analogous to cur_frame_pts/dts
4078 int64_t cur_frame_pos[AV_PARSER_PTS_NB];
4081 * Byte position of currently parsed frame in stream.
4086 * Previous frame byte position.
4091 * Duration of the current frame.
4092 * For audio, this is in units of 1 / AVCodecContext.sample_rate.
4093 * For all other types, this is in units of AVCodecContext.time_base.
4097 enum AVFieldOrder field_order;
4100 * Indicate whether a picture is coded as a frame, top field or bottom field.
4102 * For example, H.264 field_pic_flag equal to 0 corresponds to
4103 * AV_PICTURE_STRUCTURE_FRAME. An H.264 picture with field_pic_flag
4104 * equal to 1 and bottom_field_flag equal to 0 corresponds to
4105 * AV_PICTURE_STRUCTURE_TOP_FIELD.
4107 enum AVPictureStructure picture_structure;
4110 * Picture number incremented in presentation or output order.
4111 * This field may be reinitialized at the first picture of a new sequence.
4113 * For example, this corresponds to H.264 PicOrderCnt.
4115 int output_picture_number;
4118 * Dimensions of the decoded video intended for presentation.
4124 * Dimensions of the coded video.
4130 * The format of the coded data, corresponds to enum AVPixelFormat for video
4131 * and for enum AVSampleFormat for audio.
4133 * Note that a decoder can have considerable freedom in how exactly it
4134 * decodes the data, so the format reported here might be different from the
4135 * one returned by a decoder.
4138 } AVCodecParserContext;
4140 typedef struct AVCodecParser {
4141 int codec_ids[5]; /* several codec IDs are permitted */
4143 int (*parser_init)(AVCodecParserContext *s);
4144 /* This callback never returns an error, a negative value means that
4145 * the frame start was in a previous packet. */
4146 int (*parser_parse)(AVCodecParserContext *s,
4147 AVCodecContext *avctx,
4148 const uint8_t **poutbuf, int *poutbuf_size,
4149 const uint8_t *buf, int buf_size);
4150 void (*parser_close)(AVCodecParserContext *s);
4151 int (*split)(AVCodecContext *avctx, const uint8_t *buf, int buf_size);
4152 struct AVCodecParser *next;
4155 AVCodecParser *av_parser_next(const AVCodecParser *c);
4157 void av_register_codec_parser(AVCodecParser *parser);
4158 AVCodecParserContext *av_parser_init(int codec_id);
4163 * @param s parser context.
4164 * @param avctx codec context.
4165 * @param poutbuf set to pointer to parsed buffer or NULL if not yet finished.
4166 * @param poutbuf_size set to size of parsed buffer or zero if not yet finished.
4167 * @param buf input buffer.
4168 * @param buf_size input length, to signal EOF, this should be 0 (so that the last frame can be output).
4169 * @param pts input presentation timestamp.
4170 * @param dts input decoding timestamp.
4171 * @param pos input byte position in stream.
4172 * @return the number of bytes of the input bitstream used.
4177 * len = av_parser_parse2(myparser, AVCodecContext, &data, &size,
4184 * decode_frame(data, size);
4188 int av_parser_parse2(AVCodecParserContext *s,
4189 AVCodecContext *avctx,
4190 uint8_t **poutbuf, int *poutbuf_size,
4191 const uint8_t *buf, int buf_size,
4192 int64_t pts, int64_t dts,
4196 * @return 0 if the output buffer is a subset of the input, 1 if it is allocated and must be freed
4197 * @deprecated use AVBitstreamFilter
4199 int av_parser_change(AVCodecParserContext *s,
4200 AVCodecContext *avctx,
4201 uint8_t **poutbuf, int *poutbuf_size,
4202 const uint8_t *buf, int buf_size, int keyframe);
4203 void av_parser_close(AVCodecParserContext *s);
4211 * @addtogroup lavc_encoding
4216 * Find a registered encoder with a matching codec ID.
4218 * @param id AVCodecID of the requested encoder
4219 * @return An encoder if one was found, NULL otherwise.
4221 AVCodec *avcodec_find_encoder(enum AVCodecID id);
4224 * Find a registered encoder with the specified name.
4226 * @param name name of the requested encoder
4227 * @return An encoder if one was found, NULL otherwise.
4229 AVCodec *avcodec_find_encoder_by_name(const char *name);
4232 * Encode a frame of audio.
4234 * Takes input samples from frame and writes the next output packet, if
4235 * available, to avpkt. The output packet does not necessarily contain data for
4236 * the most recent frame, as encoders can delay, split, and combine input frames
4237 * internally as needed.
4239 * @param avctx codec context
4240 * @param avpkt output AVPacket.
4241 * The user can supply an output buffer by setting
4242 * avpkt->data and avpkt->size prior to calling the
4243 * function, but if the size of the user-provided data is not
4244 * large enough, encoding will fail. All other AVPacket fields
4245 * will be reset by the encoder using av_init_packet(). If
4246 * avpkt->data is NULL, the encoder will allocate it.
4247 * The encoder will set avpkt->size to the size of the
4250 * If this function fails or produces no output, avpkt will be
4251 * freed using av_free_packet() (i.e. avpkt->destruct will be
4252 * called to free the user supplied buffer).
4253 * @param[in] frame AVFrame containing the raw audio data to be encoded.
4254 * May be NULL when flushing an encoder that has the
4255 * AV_CODEC_CAP_DELAY capability set.
4256 * If AV_CODEC_CAP_VARIABLE_FRAME_SIZE is set, then each frame
4257 * can have any number of samples.
4258 * If it is not set, frame->nb_samples must be equal to
4259 * avctx->frame_size for all frames except the last.
4260 * The final frame may be smaller than avctx->frame_size.
4261 * @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
4262 * output packet is non-empty, and to 0 if it is
4263 * empty. If the function returns an error, the
4264 * packet can be assumed to be invalid, and the
4265 * value of got_packet_ptr is undefined and should
4267 * @return 0 on success, negative error code on failure
4269 int avcodec_encode_audio2(AVCodecContext *avctx, AVPacket *avpkt,
4270 const AVFrame *frame, int *got_packet_ptr);
4273 * Encode a frame of video.
4275 * Takes input raw video data from frame and writes the next output packet, if
4276 * available, to avpkt. The output packet does not necessarily contain data for
4277 * the most recent frame, as encoders can delay and reorder input frames
4278 * internally as needed.
4280 * @param avctx codec context
4281 * @param avpkt output AVPacket.
4282 * The user can supply an output buffer by setting
4283 * avpkt->data and avpkt->size prior to calling the
4284 * function, but if the size of the user-provided data is not
4285 * large enough, encoding will fail. All other AVPacket fields
4286 * will be reset by the encoder using av_init_packet(). If
4287 * avpkt->data is NULL, the encoder will allocate it.
4288 * The encoder will set avpkt->size to the size of the
4289 * output packet. The returned data (if any) belongs to the
4290 * caller, he is responsible for freeing it.
4292 * If this function fails or produces no output, avpkt will be
4293 * freed using av_free_packet() (i.e. avpkt->destruct will be
4294 * called to free the user supplied buffer).
4295 * @param[in] frame AVFrame containing the raw video data to be encoded.
4296 * May be NULL when flushing an encoder that has the
4297 * AV_CODEC_CAP_DELAY capability set.
4298 * @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
4299 * output packet is non-empty, and to 0 if it is
4300 * empty. If the function returns an error, the
4301 * packet can be assumed to be invalid, and the
4302 * value of got_packet_ptr is undefined and should
4304 * @return 0 on success, negative error code on failure
4306 int avcodec_encode_video2(AVCodecContext *avctx, AVPacket *avpkt,
4307 const AVFrame *frame, int *got_packet_ptr);
4309 int avcodec_encode_subtitle(AVCodecContext *avctx, uint8_t *buf, int buf_size,
4310 const AVSubtitle *sub);
4318 * @addtogroup lavc_picture
4323 * Allocate memory for a picture. Call avpicture_free() to free it.
4325 * @see avpicture_fill()
4327 * @param picture the picture to be filled in
4328 * @param pix_fmt the format of the picture
4329 * @param width the width of the picture
4330 * @param height the height of the picture
4331 * @return zero if successful, a negative value if not
4333 int avpicture_alloc(AVPicture *picture, enum AVPixelFormat pix_fmt, int width, int height);
4336 * Free a picture previously allocated by avpicture_alloc().
4337 * The data buffer used by the AVPicture is freed, but the AVPicture structure
4340 * @param picture the AVPicture to be freed
4342 void avpicture_free(AVPicture *picture);
4345 * Fill in the AVPicture fields, always assume a linesize alignment of 1.
4347 * @see av_image_fill_arrays().
4349 int avpicture_fill(AVPicture *picture, uint8_t *ptr,
4350 enum AVPixelFormat pix_fmt, int width, int height);
4353 * Copy pixel data from an AVPicture into a buffer, always assume a
4354 * linesize alignment of 1.
4356 * @see av_image_copy_to_buffer().
4358 int avpicture_layout(const AVPicture* src, enum AVPixelFormat pix_fmt,
4359 int width, int height,
4360 unsigned char *dest, int dest_size);
4363 * Calculate the size in bytes that a picture of the given width and height
4364 * would occupy if stored in the given picture format.
4365 * Always assume a linesize alignment of 1.
4367 * @see av_image_get_buffer_size().
4369 int avpicture_get_size(enum AVPixelFormat pix_fmt, int width, int height);
4371 #if FF_API_DEINTERLACE
4373 * deinterlace - if not supported return -1
4375 * @deprecated - use yadif (in libavfilter) instead
4377 attribute_deprecated
4378 int avpicture_deinterlace(AVPicture *dst, const AVPicture *src,
4379 enum AVPixelFormat pix_fmt, int width, int height);
4382 * Copy image src to dst. Wraps av_picture_data_copy() above.
4384 void av_picture_copy(AVPicture *dst, const AVPicture *src,
4385 enum AVPixelFormat pix_fmt, int width, int height);
4388 * Crop image top and left side.
4390 int av_picture_crop(AVPicture *dst, const AVPicture *src,
4391 enum AVPixelFormat pix_fmt, int top_band, int left_band);
4396 int av_picture_pad(AVPicture *dst, const AVPicture *src, int height, int width, enum AVPixelFormat pix_fmt,
4397 int padtop, int padbottom, int padleft, int padright, int *color);
4404 * @defgroup lavc_misc Utility functions
4407 * Miscellaneous utility functions related to both encoding and decoding
4413 * @defgroup lavc_misc_pixfmt Pixel formats
4415 * Functions for working with pixel formats.
4420 * @deprecated Use av_pix_fmt_get_chroma_sub_sample
4423 void attribute_deprecated avcodec_get_chroma_sub_sample(enum AVPixelFormat pix_fmt, int *h_shift, int *v_shift);
4426 * Return a value representing the fourCC code associated to the
4427 * pixel format pix_fmt, or 0 if no associated fourCC code can be
4430 unsigned int avcodec_pix_fmt_to_codec_tag(enum AVPixelFormat pix_fmt);
4432 #define FF_LOSS_RESOLUTION 0x0001 /**< loss due to resolution change */
4433 #define FF_LOSS_DEPTH 0x0002 /**< loss due to color depth change */
4434 #define FF_LOSS_COLORSPACE 0x0004 /**< loss due to color space conversion */
4435 #define FF_LOSS_ALPHA 0x0008 /**< loss of alpha bits */
4436 #define FF_LOSS_COLORQUANT 0x0010 /**< loss due to color quantization */
4437 #define FF_LOSS_CHROMA 0x0020 /**< loss of chroma (e.g. RGB to gray conversion) */
4440 * Compute what kind of losses will occur when converting from one specific
4441 * pixel format to another.
4442 * When converting from one pixel format to another, information loss may occur.
4443 * For example, when converting from RGB24 to GRAY, the color information will
4444 * be lost. Similarly, other losses occur when converting from some formats to
4445 * other formats. These losses can involve loss of chroma, but also loss of
4446 * resolution, loss of color depth, loss due to the color space conversion, loss
4447 * of the alpha bits or loss due to color quantization.
4448 * avcodec_get_fix_fmt_loss() informs you about the various types of losses
4449 * which will occur when converting from one pixel format to another.
4451 * @param[in] dst_pix_fmt destination pixel format
4452 * @param[in] src_pix_fmt source pixel format
4453 * @param[in] has_alpha Whether the source pixel format alpha channel is used.
4454 * @return Combination of flags informing you what kind of losses will occur.
4456 int avcodec_get_pix_fmt_loss(enum AVPixelFormat dst_pix_fmt, enum AVPixelFormat src_pix_fmt,
4460 * Find the best pixel format to convert to given a certain source pixel
4461 * format. When converting from one pixel format to another, information loss
4462 * may occur. For example, when converting from RGB24 to GRAY, the color
4463 * information will be lost. Similarly, other losses occur when converting from
4464 * some formats to other formats. avcodec_find_best_pix_fmt2() searches which of
4465 * the given pixel formats should be used to suffer the least amount of loss.
4466 * The pixel formats from which it chooses one, are determined by the
4467 * pix_fmt_list parameter.
4470 * @param[in] pix_fmt_list AV_PIX_FMT_NONE terminated array of pixel formats to choose from
4471 * @param[in] src_pix_fmt source pixel format
4472 * @param[in] has_alpha Whether the source pixel format alpha channel is used.
4473 * @param[out] loss_ptr Combination of flags informing you what kind of losses will occur.
4474 * @return The best pixel format to convert to or -1 if none was found.
4476 enum AVPixelFormat avcodec_find_best_pix_fmt2(enum AVPixelFormat *pix_fmt_list,
4477 enum AVPixelFormat src_pix_fmt,
4478 int has_alpha, int *loss_ptr);
4480 enum AVPixelFormat avcodec_default_get_format(struct AVCodecContext *s, const enum AVPixelFormat * fmt);
4486 #if FF_API_SET_DIMENSIONS
4488 * @deprecated this function is not supposed to be used from outside of lavc
4490 attribute_deprecated
4491 void avcodec_set_dimensions(AVCodecContext *s, int width, int height);
4495 * Put a string representing the codec tag codec_tag in buf.
4497 * @param buf buffer to place codec tag in
4498 * @param buf_size size in bytes of buf
4499 * @param codec_tag codec tag to assign
4500 * @return the length of the string that would have been generated if
4501 * enough space had been available, excluding the trailing null
4503 size_t av_get_codec_tag_string(char *buf, size_t buf_size, unsigned int codec_tag);
4505 void avcodec_string(char *buf, int buf_size, AVCodecContext *enc, int encode);
4508 * Return a name for the specified profile, if available.
4510 * @param codec the codec that is searched for the given profile
4511 * @param profile the profile value for which a name is requested
4512 * @return A name for the profile if found, NULL otherwise.
4514 const char *av_get_profile_name(const AVCodec *codec, int profile);
4516 int avcodec_default_execute(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2),void *arg, int *ret, int count, int size);
4517 int avcodec_default_execute2(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2, int, int),void *arg, int *ret, int count);
4518 //FIXME func typedef
4521 * Fill audio frame data and linesize.
4522 * AVFrame extended_data channel pointers are allocated if necessary for
4525 * @param frame the AVFrame
4526 * frame->nb_samples must be set prior to calling the
4527 * function. This function fills in frame->data,
4528 * frame->extended_data, frame->linesize[0].
4529 * @param nb_channels channel count
4530 * @param sample_fmt sample format
4531 * @param buf buffer to use for frame data
4532 * @param buf_size size of buffer
4533 * @param align plane size sample alignment (0 = default)
4534 * @return 0 on success, negative error code on failure
4536 int avcodec_fill_audio_frame(AVFrame *frame, int nb_channels,
4537 enum AVSampleFormat sample_fmt, const uint8_t *buf,
4538 int buf_size, int align);
4541 * Reset the internal decoder state / flush internal buffers. Should be called
4542 * e.g. when seeking or when switching to a different stream.
4544 * @note when refcounted frames are not used (i.e. avctx->refcounted_frames is 0),
4545 * this invalidates the frames previously returned from the decoder. When
4546 * refcounted frames are used, the decoder just releases any references it might
4547 * keep internally, but the caller's reference remains valid.
4549 void avcodec_flush_buffers(AVCodecContext *avctx);
4552 * Return codec bits per sample.
4554 * @param[in] codec_id the codec
4555 * @return Number of bits per sample or zero if unknown for the given codec.
4557 int av_get_bits_per_sample(enum AVCodecID codec_id);
4560 * Return codec bits per sample.
4561 * Only return non-zero if the bits per sample is exactly correct, not an
4564 * @param[in] codec_id the codec
4565 * @return Number of bits per sample or zero if unknown for the given codec.
4567 int av_get_exact_bits_per_sample(enum AVCodecID codec_id);
4570 * Return audio frame duration.
4572 * @param avctx codec context
4573 * @param frame_bytes size of the frame, or 0 if unknown
4574 * @return frame duration, in samples, if known. 0 if not able to
4577 int av_get_audio_frame_duration(AVCodecContext *avctx, int frame_bytes);
4580 typedef struct AVBitStreamFilterContext {
4582 struct AVBitStreamFilter *filter;
4583 AVCodecParserContext *parser;
4584 struct AVBitStreamFilterContext *next;
4585 } AVBitStreamFilterContext;
4588 typedef struct AVBitStreamFilter {
4591 int (*filter)(AVBitStreamFilterContext *bsfc,
4592 AVCodecContext *avctx, const char *args,
4593 uint8_t **poutbuf, int *poutbuf_size,
4594 const uint8_t *buf, int buf_size, int keyframe);
4595 void (*close)(AVBitStreamFilterContext *bsfc);
4596 struct AVBitStreamFilter *next;
4597 } AVBitStreamFilter;
4599 void av_register_bitstream_filter(AVBitStreamFilter *bsf);
4600 AVBitStreamFilterContext *av_bitstream_filter_init(const char *name);
4601 int av_bitstream_filter_filter(AVBitStreamFilterContext *bsfc,
4602 AVCodecContext *avctx, const char *args,
4603 uint8_t **poutbuf, int *poutbuf_size,
4604 const uint8_t *buf, int buf_size, int keyframe);
4605 void av_bitstream_filter_close(AVBitStreamFilterContext *bsf);
4607 AVBitStreamFilter *av_bitstream_filter_next(const AVBitStreamFilter *f);
4612 * Allocate a buffer with padding, reusing the given one if large enough.
4614 * Same behaviour av_fast_malloc but the buffer has additional
4615 * FF_INPUT_PADDING_SIZE at the end which will always memset to 0.
4618 void av_fast_padded_malloc(void *ptr, unsigned int *size, size_t min_size);
4621 * Encode extradata length to a buffer. Used by xiph codecs.
4623 * @param s buffer to write to; must be at least (v/255+1) bytes long
4624 * @param v size of extradata in bytes
4625 * @return number of bytes written to the buffer.
4627 unsigned int av_xiphlacing(unsigned char *s, unsigned int v);
4629 #if FF_API_MISSING_SAMPLE
4631 * Log a generic warning message about a missing feature. This function is
4632 * intended to be used internally by Libav (libavcodec, libavformat, etc.)
4633 * only, and would normally not be used by applications.
4634 * @param[in] avc a pointer to an arbitrary struct of which the first field is
4635 * a pointer to an AVClass struct
4636 * @param[in] feature string containing the name of the missing feature
4637 * @param[in] want_sample indicates if samples are wanted which exhibit this feature.
4638 * If want_sample is non-zero, additional verbage will be added to the log
4639 * message which tells the user how to report samples to the development
4641 * @deprecated Use avpriv_report_missing_feature() instead.
4643 attribute_deprecated
4644 void av_log_missing_feature(void *avc, const char *feature, int want_sample);
4647 * Log a generic warning message asking for a sample. This function is
4648 * intended to be used internally by Libav (libavcodec, libavformat, etc.)
4649 * only, and would normally not be used by applications.
4650 * @param[in] avc a pointer to an arbitrary struct of which the first field is
4651 * a pointer to an AVClass struct
4652 * @param[in] msg string containing an optional message, or NULL if no message
4653 * @deprecated Use avpriv_request_sample() instead.
4655 attribute_deprecated
4656 void av_log_ask_for_sample(void *avc, const char *msg, ...) av_printf_format(2, 3);
4657 #endif /* FF_API_MISSING_SAMPLE */
4660 * Register the hardware accelerator hwaccel.
4662 void av_register_hwaccel(AVHWAccel *hwaccel);
4665 * If hwaccel is NULL, returns the first registered hardware accelerator,
4666 * if hwaccel is non-NULL, returns the next registered hardware accelerator
4667 * after hwaccel, or NULL if hwaccel is the last one.
4669 AVHWAccel *av_hwaccel_next(const AVHWAccel *hwaccel);
4673 * Lock operation used by lockmgr
4676 AV_LOCK_CREATE, ///< Create a mutex
4677 AV_LOCK_OBTAIN, ///< Lock the mutex
4678 AV_LOCK_RELEASE, ///< Unlock the mutex
4679 AV_LOCK_DESTROY, ///< Free mutex resources
4683 * Register a user provided lock manager supporting the operations
4684 * specified by AVLockOp. The "mutex" argument to the function points
4685 * to a (void *) where the lockmgr should store/get a pointer to a user
4686 * allocated mutex. It is NULL upon AV_LOCK_CREATE and equal to the
4687 * value left by the last call for all other ops. If the lock manager is
4688 * unable to perform the op then it should leave the mutex in the same
4689 * state as when it was called and return a non-zero value. However,
4690 * when called with AV_LOCK_DESTROY the mutex will always be assumed to
4691 * have been successfully destroyed. If av_lockmgr_register succeeds
4692 * it will return a non-negative value, if it fails it will return a
4693 * negative value and destroy all mutex and unregister all callbacks.
4694 * av_lockmgr_register is not thread-safe, it must be called from a
4695 * single thread before any calls which make use of locking are used.
4697 * @param cb User defined callback. av_lockmgr_register invokes calls
4698 * to this callback and the previously registered callback.
4699 * The callback will be used to create more than one mutex
4700 * each of which must be backed by its own underlying locking
4701 * mechanism (i.e. do not use a single static object to
4702 * implement your lock manager). If cb is set to NULL the
4703 * lockmgr will be unregistered.
4705 int av_lockmgr_register(int (*cb)(void **mutex, enum AVLockOp op));
4708 * Get the type of the given codec.
4710 enum AVMediaType avcodec_get_type(enum AVCodecID codec_id);
4713 * @return a positive value if s is open (i.e. avcodec_open2() was called on it
4714 * with no corresponding avcodec_close()), 0 otherwise.
4716 int avcodec_is_open(AVCodecContext *s);
4719 * @return a non-zero number if codec is an encoder, zero otherwise
4721 int av_codec_is_encoder(const AVCodec *codec);
4724 * @return a non-zero number if codec is a decoder, zero otherwise
4726 int av_codec_is_decoder(const AVCodec *codec);
4729 * @return descriptor for given codec ID or NULL if no descriptor exists.
4731 const AVCodecDescriptor *avcodec_descriptor_get(enum AVCodecID id);
4734 * Iterate over all codec descriptors known to libavcodec.
4736 * @param prev previous descriptor. NULL to get the first descriptor.
4738 * @return next descriptor or NULL after the last descriptor
4740 const AVCodecDescriptor *avcodec_descriptor_next(const AVCodecDescriptor *prev);
4743 * @return codec descriptor with the given name or NULL if no such descriptor
4746 const AVCodecDescriptor *avcodec_descriptor_get_by_name(const char *name);
4752 #endif /* AVCODEC_AVCODEC_H */