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
30 #include "libavutil/samplefmt.h"
31 #include "libavutil/avutil.h"
32 #include "libavutil/cpu.h"
33 #include "libavutil/dict.h"
34 #include "libavutil/log.h"
35 #include "libavutil/pixfmt.h"
36 #include "libavutil/rational.h"
38 #include "libavcodec/version.h"
40 * @defgroup libavc Encoding/Decoding Library
43 * @defgroup lavc_decoding Decoding
47 * @defgroup lavc_encoding Encoding
51 * @defgroup lavc_codec Codecs
53 * @defgroup lavc_codec_native Native Codecs
56 * @defgroup lavc_codec_wrappers External library wrappers
59 * @defgroup lavc_codec_hwaccel Hardware Accelerators bridge
63 * @defgroup lavc_internal Internal
71 * @defgroup lavc_core Core functions/structures.
74 * Basic definitions, functions for querying libavcodec capabilities,
75 * allocating core structures, etc.
81 * Identify the syntax and semantics of the bitstream.
82 * The principle is roughly:
83 * Two decoders with the same ID can decode the same streams.
84 * Two encoders with the same ID can encode compatible streams.
85 * There may be slight deviations from the principle due to implementation
88 * If you add a codec ID to this list, add it so that
89 * 1. no value of a existing codec ID changes (that would break ABI),
90 * 2. it is as close as possible to similar codecs.
92 * After adding new codec IDs, do not forget to add an entry to the codec
93 * descriptor list and bump libavcodec minor version.
99 AV_CODEC_ID_MPEG1VIDEO,
100 AV_CODEC_ID_MPEG2VIDEO, ///< preferred ID for MPEG-1/2 video decoding
101 AV_CODEC_ID_MPEG2VIDEO_XVMC,
112 AV_CODEC_ID_RAWVIDEO,
113 AV_CODEC_ID_MSMPEG4V1,
114 AV_CODEC_ID_MSMPEG4V2,
115 AV_CODEC_ID_MSMPEG4V3,
138 AV_CODEC_ID_INTERPLAY_VIDEO,
145 AV_CODEC_ID_MSVIDEO1,
150 AV_CODEC_ID_TRUEMOTION1,
151 AV_CODEC_ID_VMDVIDEO,
177 AV_CODEC_ID_TRUEMOTION2,
183 AV_CODEC_ID_SMACKVIDEO,
188 AV_CODEC_ID_JPEG2000,
194 AV_CODEC_ID_DSICINVIDEO,
195 AV_CODEC_ID_TIERTEXSEQVIDEO,
203 AV_CODEC_ID_BETHSOFTVID,
215 AV_CODEC_ID_ESCAPE124,
219 AV_CODEC_ID_MOTIONPIXELS,
231 AV_CODEC_ID_FLASHSV2,
232 AV_CODEC_ID_CDGRAPHICS,
235 AV_CODEC_ID_BINKVIDEO,
236 AV_CODEC_ID_IFF_ILBM,
237 AV_CODEC_ID_IFF_BYTERUN1,
243 AV_CODEC_ID_A64_MULTI,
244 AV_CODEC_ID_A64_MULTI5,
247 AV_CODEC_ID_LAGARITH,
251 AV_CODEC_ID_WMV3IMAGE,
252 AV_CODEC_ID_VC1IMAGE,
254 AV_CODEC_ID_BMV_VIDEO,
261 AV_CODEC_ID_ZEROCODEC,
269 /* various PCM "codecs" */
270 AV_CODEC_ID_FIRST_AUDIO = 0x10000, ///< A dummy id pointing at the start of audio codecs
271 AV_CODEC_ID_PCM_S16LE = 0x10000,
272 AV_CODEC_ID_PCM_S16BE,
273 AV_CODEC_ID_PCM_U16LE,
274 AV_CODEC_ID_PCM_U16BE,
277 AV_CODEC_ID_PCM_MULAW,
278 AV_CODEC_ID_PCM_ALAW,
279 AV_CODEC_ID_PCM_S32LE,
280 AV_CODEC_ID_PCM_S32BE,
281 AV_CODEC_ID_PCM_U32LE,
282 AV_CODEC_ID_PCM_U32BE,
283 AV_CODEC_ID_PCM_S24LE,
284 AV_CODEC_ID_PCM_S24BE,
285 AV_CODEC_ID_PCM_U24LE,
286 AV_CODEC_ID_PCM_U24BE,
287 AV_CODEC_ID_PCM_S24DAUD,
288 AV_CODEC_ID_PCM_ZORK,
289 AV_CODEC_ID_PCM_S16LE_PLANAR,
291 AV_CODEC_ID_PCM_F32BE,
292 AV_CODEC_ID_PCM_F32LE,
293 AV_CODEC_ID_PCM_F64BE,
294 AV_CODEC_ID_PCM_F64LE,
295 AV_CODEC_ID_PCM_BLURAY,
298 AV_CODEC_ID_PCM_S8_PLANAR,
300 /* various ADPCM codecs */
301 AV_CODEC_ID_ADPCM_IMA_QT = 0x11000,
302 AV_CODEC_ID_ADPCM_IMA_WAV,
303 AV_CODEC_ID_ADPCM_IMA_DK3,
304 AV_CODEC_ID_ADPCM_IMA_DK4,
305 AV_CODEC_ID_ADPCM_IMA_WS,
306 AV_CODEC_ID_ADPCM_IMA_SMJPEG,
307 AV_CODEC_ID_ADPCM_MS,
308 AV_CODEC_ID_ADPCM_4XM,
309 AV_CODEC_ID_ADPCM_XA,
310 AV_CODEC_ID_ADPCM_ADX,
311 AV_CODEC_ID_ADPCM_EA,
312 AV_CODEC_ID_ADPCM_G726,
313 AV_CODEC_ID_ADPCM_CT,
314 AV_CODEC_ID_ADPCM_SWF,
315 AV_CODEC_ID_ADPCM_YAMAHA,
316 AV_CODEC_ID_ADPCM_SBPRO_4,
317 AV_CODEC_ID_ADPCM_SBPRO_3,
318 AV_CODEC_ID_ADPCM_SBPRO_2,
319 AV_CODEC_ID_ADPCM_THP,
320 AV_CODEC_ID_ADPCM_IMA_AMV,
321 AV_CODEC_ID_ADPCM_EA_R1,
322 AV_CODEC_ID_ADPCM_EA_R3,
323 AV_CODEC_ID_ADPCM_EA_R2,
324 AV_CODEC_ID_ADPCM_IMA_EA_SEAD,
325 AV_CODEC_ID_ADPCM_IMA_EA_EACS,
326 AV_CODEC_ID_ADPCM_EA_XAS,
327 AV_CODEC_ID_ADPCM_EA_MAXIS_XA,
328 AV_CODEC_ID_ADPCM_IMA_ISS,
329 AV_CODEC_ID_ADPCM_G722,
330 AV_CODEC_ID_ADPCM_IMA_APC,
333 AV_CODEC_ID_AMR_NB = 0x12000,
336 /* RealAudio codecs*/
337 AV_CODEC_ID_RA_144 = 0x13000,
340 /* various DPCM codecs */
341 AV_CODEC_ID_ROQ_DPCM = 0x14000,
342 AV_CODEC_ID_INTERPLAY_DPCM,
343 AV_CODEC_ID_XAN_DPCM,
344 AV_CODEC_ID_SOL_DPCM,
347 AV_CODEC_ID_MP2 = 0x15000,
348 AV_CODEC_ID_MP3, ///< preferred ID for decoding MPEG audio layer 1, 2 or 3
358 AV_CODEC_ID_VMDAUDIO,
364 AV_CODEC_ID_WESTWOOD_SND1,
365 AV_CODEC_ID_GSM, ///< as in Berlin toast format
368 AV_CODEC_ID_TRUESPEECH,
370 AV_CODEC_ID_SMACKAUDIO,
373 AV_CODEC_ID_DSICINAUDIO,
375 AV_CODEC_ID_MUSEPACK7,
377 AV_CODEC_ID_GSM_MS, /* as found in WAV */
381 AV_CODEC_ID_NELLYMOSER,
382 AV_CODEC_ID_MUSEPACK8,
384 AV_CODEC_ID_WMAVOICE,
386 AV_CODEC_ID_WMALOSSLESS,
395 AV_CODEC_ID_BINKAUDIO_RDFT,
396 AV_CODEC_ID_BINKAUDIO_DCT,
397 AV_CODEC_ID_AAC_LATM,
402 AV_CODEC_ID_8SVX_EXP,
403 AV_CODEC_ID_8SVX_FIB,
404 AV_CODEC_ID_BMV_AUDIO,
409 AV_CODEC_ID_COMFORT_NOISE,
412 /* subtitle codecs */
413 AV_CODEC_ID_FIRST_SUBTITLE = 0x17000, ///< A dummy ID pointing at the start of subtitle codecs.
414 AV_CODEC_ID_DVD_SUBTITLE = 0x17000,
415 AV_CODEC_ID_DVB_SUBTITLE,
416 AV_CODEC_ID_TEXT, ///< raw UTF-8 text
419 AV_CODEC_ID_MOV_TEXT,
420 AV_CODEC_ID_HDMV_PGS_SUBTITLE,
421 AV_CODEC_ID_DVB_TELETEXT,
424 /* other specific kind of codecs (generally used for attachments) */
425 AV_CODEC_ID_FIRST_UNKNOWN = 0x18000, ///< A dummy ID pointing at the start of various fake codecs.
426 AV_CODEC_ID_TTF = 0x18000,
428 AV_CODEC_ID_PROBE = 0x19000, ///< codec_id is not known (like AV_CODEC_ID_NONE) but lavf should attempt to identify it
430 AV_CODEC_ID_MPEG2TS = 0x20000, /**< _FAKE_ codec to indicate a raw MPEG-2 TS
431 * stream (only used by libavformat) */
432 AV_CODEC_ID_MPEG4SYSTEMS = 0x20001, /**< _FAKE_ codec to indicate a MPEG-4 Systems
433 * stream (only used by libavformat) */
434 AV_CODEC_ID_FFMETADATA = 0x21000, ///< Dummy codec for streams containing only metadata information.
437 #include "old_codec_ids.h"
442 #define CodecID AVCodecID
446 * This struct describes the properties of a single codec described by an
448 * @see avcodec_get_descriptor()
450 typedef struct AVCodecDescriptor {
452 enum AVMediaType type;
454 * Name of the codec described by this descriptor. It is non-empty and
455 * unique for each codec descriptor. It should contain alphanumeric
456 * characters and '_' only.
460 * A more descriptive name for this codec. May be NULL.
462 const char *long_name;
464 * Codec properties, a combination of AV_CODEC_PROP_* flags.
470 * Codec uses only intra compression.
473 #define AV_CODEC_PROP_INTRA_ONLY (1 << 0)
475 * Codec supports lossy compression. Audio and video codecs only.
476 * @note a codec may support both lossy and lossless
479 #define AV_CODEC_PROP_LOSSY (1 << 1)
481 * Codec supports lossless compression. Audio and video codecs only.
483 #define AV_CODEC_PROP_LOSSLESS (1 << 2)
485 #if FF_API_OLD_DECODE_AUDIO
487 #define AVCODEC_MAX_AUDIO_FRAME_SIZE 192000 // 1 second of 48khz 32bit audio
491 * @ingroup lavc_decoding
492 * Required number of additionally allocated bytes at the end of the input bitstream for decoding.
493 * This is mainly needed because some optimized bitstream readers read
494 * 32 or 64 bit at once and could read over the end.<br>
495 * Note: If the first 23 bits of the additional bytes are not 0, then damaged
496 * MPEG bitstreams could cause overread and segfault.
498 #define FF_INPUT_BUFFER_PADDING_SIZE 8
501 * @ingroup lavc_encoding
502 * minimum encoding buffer size
503 * Used to avoid some checks during header writing.
505 #define FF_MIN_BUFFER_SIZE 16384
509 * @ingroup lavc_encoding
510 * motion estimation type.
513 ME_ZERO = 1, ///< no search, that is use 0,0 vector whenever one is needed
517 ME_EPZS, ///< enhanced predictive zonal search
518 ME_X1, ///< reserved for experiments
519 ME_HEX, ///< hexagon based search
520 ME_UMH, ///< uneven multi-hexagon search
521 ME_ITER, ///< iterative search
522 ME_TESA, ///< transformed exhaustive search algorithm
526 * @ingroup lavc_decoding
529 /* We leave some space between them for extensions (drop some
530 * keyframes for intra-only or drop just some bidir frames). */
531 AVDISCARD_NONE =-16, ///< discard nothing
532 AVDISCARD_DEFAULT = 0, ///< discard useless packets like 0 size packets in avi
533 AVDISCARD_NONREF = 8, ///< discard all non reference
534 AVDISCARD_BIDIR = 16, ///< discard all bidirectional frames
535 AVDISCARD_NONKEY = 32, ///< discard all frames except keyframes
536 AVDISCARD_ALL = 48, ///< discard all
539 enum AVColorPrimaries{
540 AVCOL_PRI_BT709 = 1, ///< also ITU-R BT1361 / IEC 61966-2-4 / SMPTE RP177 Annex B
541 AVCOL_PRI_UNSPECIFIED = 2,
542 AVCOL_PRI_BT470M = 4,
543 AVCOL_PRI_BT470BG = 5, ///< also ITU-R BT601-6 625 / ITU-R BT1358 625 / ITU-R BT1700 625 PAL & SECAM
544 AVCOL_PRI_SMPTE170M = 6, ///< also ITU-R BT601-6 525 / ITU-R BT1358 525 / ITU-R BT1700 NTSC
545 AVCOL_PRI_SMPTE240M = 7, ///< functionally identical to above
547 AVCOL_PRI_NB , ///< Not part of ABI
550 enum AVColorTransferCharacteristic{
551 AVCOL_TRC_BT709 = 1, ///< also ITU-R BT1361
552 AVCOL_TRC_UNSPECIFIED = 2,
553 AVCOL_TRC_GAMMA22 = 4, ///< also ITU-R BT470M / ITU-R BT1700 625 PAL & SECAM
554 AVCOL_TRC_GAMMA28 = 5, ///< also ITU-R BT470BG
555 AVCOL_TRC_SMPTE240M = 7,
556 AVCOL_TRC_NB , ///< Not part of ABI
561 AVCOL_SPC_BT709 = 1, ///< also ITU-R BT1361 / IEC 61966-2-4 xvYCC709 / SMPTE RP177 Annex B
562 AVCOL_SPC_UNSPECIFIED = 2,
564 AVCOL_SPC_BT470BG = 5, ///< also ITU-R BT601-6 625 / ITU-R BT1358 625 / ITU-R BT1700 625 PAL & SECAM / IEC 61966-2-4 xvYCC601
565 AVCOL_SPC_SMPTE170M = 6, ///< also ITU-R BT601-6 525 / ITU-R BT1358 525 / ITU-R BT1700 NTSC / functionally identical to above
566 AVCOL_SPC_SMPTE240M = 7,
567 AVCOL_SPC_YCOCG = 8, ///< Used by Dirac / VC-2 and H.264 FRext, see ITU-T SG16
568 AVCOL_SPC_NB , ///< Not part of ABI
572 AVCOL_RANGE_UNSPECIFIED = 0,
573 AVCOL_RANGE_MPEG = 1, ///< the normal 219*2^(n-8) "MPEG" YUV ranges
574 AVCOL_RANGE_JPEG = 2, ///< the normal 2^n-1 "JPEG" YUV ranges
575 AVCOL_RANGE_NB , ///< Not part of ABI
579 * X X 3 4 X X are luma samples,
580 * 1 2 1-6 are possible chroma positions
581 * X X 5 6 X 0 is undefined/unknown position
583 enum AVChromaLocation{
584 AVCHROMA_LOC_UNSPECIFIED = 0,
585 AVCHROMA_LOC_LEFT = 1, ///< mpeg2/4, h264 default
586 AVCHROMA_LOC_CENTER = 2, ///< mpeg1, jpeg, h263
587 AVCHROMA_LOC_TOPLEFT = 3, ///< DV
588 AVCHROMA_LOC_TOP = 4,
589 AVCHROMA_LOC_BOTTOMLEFT = 5,
590 AVCHROMA_LOC_BOTTOM = 6,
591 AVCHROMA_LOC_NB , ///< Not part of ABI
594 enum AVAudioServiceType {
595 AV_AUDIO_SERVICE_TYPE_MAIN = 0,
596 AV_AUDIO_SERVICE_TYPE_EFFECTS = 1,
597 AV_AUDIO_SERVICE_TYPE_VISUALLY_IMPAIRED = 2,
598 AV_AUDIO_SERVICE_TYPE_HEARING_IMPAIRED = 3,
599 AV_AUDIO_SERVICE_TYPE_DIALOGUE = 4,
600 AV_AUDIO_SERVICE_TYPE_COMMENTARY = 5,
601 AV_AUDIO_SERVICE_TYPE_EMERGENCY = 6,
602 AV_AUDIO_SERVICE_TYPE_VOICE_OVER = 7,
603 AV_AUDIO_SERVICE_TYPE_KARAOKE = 8,
604 AV_AUDIO_SERVICE_TYPE_NB , ///< Not part of ABI
608 * @ingroup lavc_encoding
610 typedef struct RcOverride{
613 int qscale; // If this is 0 then quality_factor will be used instead.
614 float quality_factor;
617 #define FF_MAX_B_FRAMES 16
620 These flags can be passed in AVCodecContext.flags before initialization.
621 Note: Not everything is supported yet.
624 #define CODEC_FLAG_QSCALE 0x0002 ///< Use fixed qscale.
625 #define CODEC_FLAG_4MV 0x0004 ///< 4 MV per MB allowed / advanced prediction for H.263.
626 #define CODEC_FLAG_QPEL 0x0010 ///< Use qpel MC.
627 #define CODEC_FLAG_GMC 0x0020 ///< Use GMC.
628 #define CODEC_FLAG_MV0 0x0040 ///< Always try a MB with MV=<0,0>.
630 * The parent program guarantees that the input for B-frames containing
631 * streams is not written to for at least s->max_b_frames+1 frames, if
632 * this is not set the input will be copied.
634 #define CODEC_FLAG_INPUT_PRESERVED 0x0100
635 #define CODEC_FLAG_PASS1 0x0200 ///< Use internal 2pass ratecontrol in first pass mode.
636 #define CODEC_FLAG_PASS2 0x0400 ///< Use internal 2pass ratecontrol in second pass mode.
637 #define CODEC_FLAG_GRAY 0x2000 ///< Only decode/encode grayscale.
638 #define CODEC_FLAG_EMU_EDGE 0x4000 ///< Don't draw edges.
639 #define CODEC_FLAG_PSNR 0x8000 ///< error[?] variables will be set during encoding.
640 #define CODEC_FLAG_TRUNCATED 0x00010000 /** Input bitstream might be truncated at a random
641 location instead of only at frame boundaries. */
642 #define CODEC_FLAG_NORMALIZE_AQP 0x00020000 ///< Normalize adaptive quantization.
643 #define CODEC_FLAG_INTERLACED_DCT 0x00040000 ///< Use interlaced DCT.
644 #define CODEC_FLAG_LOW_DELAY 0x00080000 ///< Force low delay.
645 #define CODEC_FLAG_GLOBAL_HEADER 0x00400000 ///< Place global headers in extradata instead of every keyframe.
646 #define CODEC_FLAG_BITEXACT 0x00800000 ///< Use only bitexact stuff (except (I)DCT).
647 /* Fx : Flag for h263+ extra options */
648 #define CODEC_FLAG_AC_PRED 0x01000000 ///< H.263 advanced intra coding / MPEG-4 AC prediction
649 #define CODEC_FLAG_LOOP_FILTER 0x00000800 ///< loop filter
650 #define CODEC_FLAG_INTERLACED_ME 0x20000000 ///< interlaced motion estimation
651 #define CODEC_FLAG_CLOSED_GOP 0x80000000
652 #define CODEC_FLAG2_FAST 0x00000001 ///< Allow non spec compliant speedup tricks.
653 #define CODEC_FLAG2_NO_OUTPUT 0x00000004 ///< Skip bitstream encoding.
654 #define CODEC_FLAG2_LOCAL_HEADER 0x00000008 ///< Place global headers at every keyframe instead of in extradata.
655 #if FF_API_MPV_GLOBAL_OPTS
656 #define CODEC_FLAG_CBP_RD 0x04000000 ///< Use rate distortion optimization for cbp.
657 #define CODEC_FLAG_QP_RD 0x08000000 ///< Use rate distortion optimization for qp selectioon.
658 #define CODEC_FLAG2_STRICT_GOP 0x00000002 ///< Strictly enforce GOP size.
659 #define CODEC_FLAG2_SKIP_RD 0x00004000 ///< RD optimal MB level residual skipping
661 #define CODEC_FLAG2_CHUNKS 0x00008000 ///< Input bitstream might be truncated at a packet boundaries instead of only at frame boundaries.
663 /* Unsupported options :
664 * Syntax Arithmetic coding (SAC)
665 * Reference Picture Selection
666 * Independent Segment Decoding */
668 /* codec capabilities */
670 #define CODEC_CAP_DRAW_HORIZ_BAND 0x0001 ///< Decoder can use draw_horiz_band callback.
672 * Codec uses get_buffer() for allocating buffers and supports custom allocators.
673 * If not set, it might not use get_buffer() at all or use operations that
674 * assume the buffer was allocated by avcodec_default_get_buffer.
676 #define CODEC_CAP_DR1 0x0002
677 #define CODEC_CAP_TRUNCATED 0x0008
678 /* Codec can export data for HW decoding (XvMC). */
679 #define CODEC_CAP_HWACCEL 0x0010
681 * Encoder or decoder requires flushing with NULL input at the end in order to
682 * give the complete and correct output.
684 * NOTE: If this flag is not set, the codec is guaranteed to never be fed with
685 * with NULL data. The user can still send NULL data to the public encode
686 * or decode function, but libavcodec will not pass it along to the codec
687 * unless this flag is set.
690 * The decoder has a non-zero delay and needs to be fed with avpkt->data=NULL,
691 * avpkt->size=0 at the end to get the delayed data until the decoder no longer
695 * The encoder needs to be fed with NULL data at the end of encoding until the
696 * encoder no longer returns data.
698 * NOTE: For encoders implementing the AVCodec.encode2() function, setting this
699 * flag also means that the encoder must set the pts and duration for
700 * each output packet. If this flag is not set, the pts and duration will
701 * be determined by libavcodec from the input frame.
703 #define CODEC_CAP_DELAY 0x0020
705 * Codec can be fed a final frame with a smaller size.
706 * This can be used to prevent truncation of the last audio samples.
708 #define CODEC_CAP_SMALL_LAST_FRAME 0x0040
710 * Codec can export data for HW decoding (VDPAU).
712 #define CODEC_CAP_HWACCEL_VDPAU 0x0080
714 * Codec can output multiple frames per AVPacket
715 * Normally demuxers return one frame at a time, demuxers which do not do
716 * are connected to a parser to split what they return into proper frames.
717 * This flag is reserved to the very rare category of codecs which have a
718 * bitstream that cannot be split into frames without timeconsuming
719 * operations like full decoding. Demuxers carring such bitstreams thus
720 * may return multiple frames in a packet. This has many disadvantages like
721 * prohibiting stream copy in many cases thus it should only be considered
724 #define CODEC_CAP_SUBFRAMES 0x0100
726 * Codec is experimental and is thus avoided in favor of non experimental
729 #define CODEC_CAP_EXPERIMENTAL 0x0200
731 * Codec should fill in channel configuration and samplerate instead of container
733 #define CODEC_CAP_CHANNEL_CONF 0x0400
735 * Codec is able to deal with negative linesizes
737 #define CODEC_CAP_NEG_LINESIZES 0x0800
739 * Codec supports frame-level multithreading.
741 #define CODEC_CAP_FRAME_THREADS 0x1000
743 * Codec supports slice-based (or partition-based) multithreading.
745 #define CODEC_CAP_SLICE_THREADS 0x2000
747 * Codec supports changed parameters at any point.
749 #define CODEC_CAP_PARAM_CHANGE 0x4000
751 * Codec supports avctx->thread_count == 0 (auto).
753 #define CODEC_CAP_AUTO_THREADS 0x8000
755 * Audio encoder supports receiving a different number of samples in each call.
757 #define CODEC_CAP_VARIABLE_FRAME_SIZE 0x10000
759 //The following defines may change, don't expect compatibility if you use them.
760 #define MB_TYPE_INTRA4x4 0x0001
761 #define MB_TYPE_INTRA16x16 0x0002 //FIXME H.264-specific
762 #define MB_TYPE_INTRA_PCM 0x0004 //FIXME H.264-specific
763 #define MB_TYPE_16x16 0x0008
764 #define MB_TYPE_16x8 0x0010
765 #define MB_TYPE_8x16 0x0020
766 #define MB_TYPE_8x8 0x0040
767 #define MB_TYPE_INTERLACED 0x0080
768 #define MB_TYPE_DIRECT2 0x0100 //FIXME
769 #define MB_TYPE_ACPRED 0x0200
770 #define MB_TYPE_GMC 0x0400
771 #define MB_TYPE_SKIP 0x0800
772 #define MB_TYPE_P0L0 0x1000
773 #define MB_TYPE_P1L0 0x2000
774 #define MB_TYPE_P0L1 0x4000
775 #define MB_TYPE_P1L1 0x8000
776 #define MB_TYPE_L0 (MB_TYPE_P0L0 | MB_TYPE_P1L0)
777 #define MB_TYPE_L1 (MB_TYPE_P0L1 | MB_TYPE_P1L1)
778 #define MB_TYPE_L0L1 (MB_TYPE_L0 | MB_TYPE_L1)
779 #define MB_TYPE_QUANT 0x00010000
780 #define MB_TYPE_CBP 0x00020000
781 //Note bits 24-31 are reserved for codec specific use (h264 ref0, mpeg1 0mv, ...)
785 * This specifies the area which should be displayed.
786 * Note there may be multiple such areas for one frame.
788 typedef struct AVPanScan{
791 * - encoding: Set by user.
792 * - decoding: Set by libavcodec.
797 * width and height in 1/16 pel
798 * - encoding: Set by user.
799 * - decoding: Set by libavcodec.
805 * position of the top left corner in 1/16 pel for up to 3 fields/frames
806 * - encoding: Set by user.
807 * - decoding: Set by libavcodec.
809 int16_t position[3][2];
812 #define FF_QSCALE_TYPE_MPEG1 0
813 #define FF_QSCALE_TYPE_MPEG2 1
814 #define FF_QSCALE_TYPE_H264 2
815 #define FF_QSCALE_TYPE_VP56 3
817 #define FF_BUFFER_TYPE_INTERNAL 1
818 #define FF_BUFFER_TYPE_USER 2 ///< direct rendering buffers (image is (de)allocated by user)
819 #define FF_BUFFER_TYPE_SHARED 4 ///< Buffer from somewhere else; don't deallocate image (data/base), all other tables are not shared.
820 #define FF_BUFFER_TYPE_COPY 8 ///< Just a (modified) copy of some other buffer, don't deallocate anything.
822 #define FF_BUFFER_HINTS_VALID 0x01 // Buffer hints value is meaningful (if 0 ignore).
823 #define FF_BUFFER_HINTS_READABLE 0x02 // Codec will read from buffer.
824 #define FF_BUFFER_HINTS_PRESERVE 0x04 // User must not alter buffer content.
825 #define FF_BUFFER_HINTS_REUSABLE 0x08 // Codec will reuse the buffer (update).
828 * @defgroup lavc_packet AVPacket
830 * Types and functions for working with AVPacket.
833 enum AVPacketSideDataType {
835 AV_PKT_DATA_NEW_EXTRADATA,
838 * An AV_PKT_DATA_PARAM_CHANGE side data packet is laid out as follows:
841 * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT)
842 * s32le channel_count
843 * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT)
844 * u64le channel_layout
845 * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE)
847 * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS)
852 AV_PKT_DATA_PARAM_CHANGE,
855 * An AV_PKT_DATA_H263_MB_INFO side data packet contains a number of
856 * structures with info about macroblocks relevant to splitting the
857 * packet into smaller packets on macroblock edges (e.g. as for RFC 2190).
858 * That is, it does not necessarily contain info about all macroblocks,
859 * as long as the distance between macroblocks in the info is smaller
860 * than the target payload size.
861 * Each MB info structure is 12 bytes, and is laid out as follows:
863 * u32le bit offset from the start of the packet
864 * u8 current quantizer at the start of the macroblock
866 * u16le macroblock address within the GOB
867 * u8 horizontal MV predictor
868 * u8 vertical MV predictor
869 * u8 horizontal MV predictor for block number 3
870 * u8 vertical MV predictor for block number 3
873 AV_PKT_DATA_H263_MB_INFO,
877 * This structure stores compressed data. It is typically exported by demuxers
878 * and then passed as input to decoders, or received as output from encoders and
879 * then passed to muxers.
881 * For video, it should typically contain one compressed frame. For audio it may
882 * contain several compressed frames.
884 * AVPacket is one of the few structs in Libav, whose size is a part of public
885 * ABI. Thus it may be allocated on stack and no new fields can be added to it
886 * without libavcodec and libavformat major bump.
888 * The semantics of data ownership depends on the destruct field.
889 * If it is set, the packet data is dynamically allocated and is valid
890 * indefinitely until av_free_packet() is called (which in turn calls the
891 * destruct callback to free the data). If destruct is not set, the packet data
892 * is typically backed by some static buffer somewhere and is only valid for a
893 * limited time (e.g. until the next read call when demuxing).
895 * The side data is always allocated with av_malloc() and is freed in
898 typedef struct AVPacket {
900 * Presentation timestamp in AVStream->time_base units; the time at which
901 * the decompressed packet will be presented to the user.
902 * Can be AV_NOPTS_VALUE if it is not stored in the file.
903 * pts MUST be larger or equal to dts as presentation cannot happen before
904 * decompression, unless one wants to view hex dumps. Some formats misuse
905 * the terms dts and pts/cts to mean something different. Such timestamps
906 * must be converted to true pts/dts before they are stored in AVPacket.
910 * Decompression timestamp in AVStream->time_base units; the time at which
911 * the packet is decompressed.
912 * Can be AV_NOPTS_VALUE if it is not stored in the file.
919 * A combination of AV_PKT_FLAG values
923 * Additional packet data that can be provided by the container.
924 * Packet can contain several types of side information.
929 enum AVPacketSideDataType type;
934 * Duration of this packet in AVStream->time_base units, 0 if unknown.
935 * Equals next_pts - this_pts in presentation order.
938 void (*destruct)(struct AVPacket *);
940 int64_t pos; ///< byte position in stream, -1 if unknown
943 * Time difference in AVStream->time_base units from the pts of this
944 * packet to the point at which the output from the decoder has converged
945 * independent from the availability of previous frames. That is, the
946 * frames are virtually identical no matter if decoding started from
947 * the very first frame or from this keyframe.
948 * Is AV_NOPTS_VALUE if unknown.
949 * This field is not the display duration of the current packet.
950 * This field has no meaning if the packet does not have AV_PKT_FLAG_KEY
953 * The purpose of this field is to allow seeking in streams that have no
954 * keyframes in the conventional sense. It corresponds to the
955 * recovery point SEI in H.264 and match_time_delta in NUT. It is also
956 * essential for some types of subtitle streams to ensure that all
957 * subtitles are correctly displayed after seeking.
959 int64_t convergence_duration;
961 #define AV_PKT_FLAG_KEY 0x0001 ///< The packet contains a keyframe
962 #define AV_PKT_FLAG_CORRUPT 0x0002 ///< The packet content is corrupted
964 enum AVSideDataParamChangeFlags {
965 AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT = 0x0001,
966 AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT = 0x0002,
967 AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE = 0x0004,
968 AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS = 0x0008,
975 * This structure describes decoded (raw) audio or video data.
977 * AVFrame must be allocated using avcodec_alloc_frame() and freed with
978 * avcodec_free_frame(). Note that this allocates only the AVFrame itself. The
979 * buffers for the data must be managed through other means.
981 * AVFrame is typically allocated once and then reused multiple times to hold
982 * different data (e.g. a single AVFrame to hold frames received from a
983 * decoder). In such a case, avcodec_get_frame_defaults() should be used to
984 * reset the frame to its original clean state before it is reused again.
986 * sizeof(AVFrame) is not a part of the public ABI, so new fields may be added
987 * to the end with a minor bump.
989 typedef struct AVFrame {
990 #define AV_NUM_DATA_POINTERS 8
992 * pointer to the picture/channel planes.
993 * This might be different from the first allocated byte
994 * - encoding: Set by user
995 * - decoding: set by AVCodecContext.get_buffer()
997 uint8_t *data[AV_NUM_DATA_POINTERS];
1000 * Size, in bytes, of the data for each picture/channel plane.
1002 * For audio, only linesize[0] may be set. For planar audio, each channel
1003 * plane must be the same size.
1005 * - encoding: Set by user
1006 * - decoding: set by AVCodecContext.get_buffer()
1008 int linesize[AV_NUM_DATA_POINTERS];
1011 * pointers to the data planes/channels.
1013 * For video, this should simply point to data[].
1015 * For planar audio, each channel has a separate data pointer, and
1016 * linesize[0] contains the size of each channel buffer.
1017 * For packed audio, there is just one data pointer, and linesize[0]
1018 * contains the total size of the buffer for all channels.
1020 * Note: Both data and extended_data will always be set by get_buffer(),
1021 * but for planar audio with more channels that can fit in data,
1022 * extended_data must be used by the decoder in order to access all
1025 * encoding: set by user
1026 * decoding: set by AVCodecContext.get_buffer()
1028 uint8_t **extended_data;
1031 * width and height of the video frame
1032 * - encoding: unused
1033 * - decoding: Read by user.
1038 * number of audio samples (per channel) described by this frame
1039 * - encoding: Set by user
1040 * - decoding: Set by libavcodec
1045 * format of the frame, -1 if unknown or unset
1046 * Values correspond to enum AVPixelFormat for video frames,
1047 * enum AVSampleFormat for audio)
1048 * - encoding: unused
1049 * - decoding: Read by user.
1054 * 1 -> keyframe, 0-> not
1055 * - encoding: Set by libavcodec.
1056 * - decoding: Set by libavcodec.
1061 * Picture type of the frame, see ?_TYPE below.
1062 * - encoding: Set by libavcodec. for coded_picture (and set by user for input).
1063 * - decoding: Set by libavcodec.
1065 enum AVPictureType pict_type;
1068 * pointer to the first allocated byte of the picture. Can be used in get_buffer/release_buffer.
1069 * This isn't used by libavcodec unless the default get/release_buffer() is used.
1073 uint8_t *base[AV_NUM_DATA_POINTERS];
1076 * sample aspect ratio for the video frame, 0/1 if unknown/unspecified
1077 * - encoding: unused
1078 * - decoding: Read by user.
1080 AVRational sample_aspect_ratio;
1083 * presentation timestamp in time_base units (time when frame should be shown to user)
1084 * If AV_NOPTS_VALUE then frame_rate = 1/time_base will be assumed.
1085 * - encoding: MUST be set by user.
1086 * - decoding: Set by libavcodec.
1091 * reordered pts from the last AVPacket that has been input into the decoder
1092 * - encoding: unused
1093 * - decoding: Read by user.
1098 * dts from the last AVPacket that has been input into the decoder
1099 * - encoding: unused
1100 * - decoding: Read by user.
1105 * picture number in bitstream order
1106 * - encoding: set by
1107 * - decoding: Set by libavcodec.
1109 int coded_picture_number;
1111 * picture number in display order
1112 * - encoding: set by
1113 * - decoding: Set by libavcodec.
1115 int display_picture_number;
1118 * quality (between 1 (good) and FF_LAMBDA_MAX (bad))
1119 * - encoding: Set by libavcodec. for coded_picture (and set by user for input).
1120 * - decoding: Set by libavcodec.
1125 * is this picture used as reference
1126 * The values for this are the same as the MpegEncContext.picture_structure
1127 * variable, that is 1->top field, 2->bottom field, 3->frame/both fields.
1128 * Set to 4 for delayed, non-reference frames.
1129 * - encoding: unused
1130 * - decoding: Set by libavcodec. (before get_buffer() call)).
1136 * - encoding: unused
1137 * - decoding: Set by libavcodec.
1139 int8_t *qscale_table;
1142 * - encoding: unused
1143 * - decoding: Set by libavcodec.
1153 * mbskip_table[mb]>=1 if MB didn't change
1154 * stride= mb_width = (width+15)>>4
1155 * - encoding: unused
1156 * - decoding: Set by libavcodec.
1158 uint8_t *mbskip_table;
1161 * motion vector table
1164 * int mv_sample_log2= 4 - motion_subsample_log2;
1165 * int mb_width= (width+15)>>4;
1166 * int mv_stride= (mb_width << mv_sample_log2) + 1;
1167 * motion_val[direction][x + y*mv_stride][0->mv_x, 1->mv_y];
1169 * - encoding: Set by user.
1170 * - decoding: Set by libavcodec.
1172 int16_t (*motion_val[2])[2];
1175 * macroblock type table
1176 * mb_type_base + mb_width + 2
1177 * - encoding: Set by user.
1178 * - decoding: Set by libavcodec.
1184 * - encoding: unused
1185 * - decoding: Set by libavcodec.
1190 * motion reference frame index
1191 * the order in which these are stored can depend on the codec.
1192 * - encoding: Set by user.
1193 * - decoding: Set by libavcodec.
1195 int8_t *ref_index[2];
1198 * for some private data of the user
1199 * - encoding: unused
1200 * - decoding: Set by user.
1206 * - encoding: Set by libavcodec. if flags&CODEC_FLAG_PSNR.
1207 * - decoding: unused
1209 uint64_t error[AV_NUM_DATA_POINTERS];
1212 * type of the buffer (to keep track of who has to deallocate data[*])
1213 * - encoding: Set by the one who allocates it.
1214 * - decoding: Set by the one who allocates it.
1215 * Note: User allocated (direct rendering) & internal buffers cannot coexist currently.
1220 * When decoding, this signals how much the picture must be delayed.
1221 * extra_delay = repeat_pict / (2*fps)
1222 * - encoding: unused
1223 * - decoding: Set by libavcodec.
1228 * The content of the picture is interlaced.
1229 * - encoding: Set by user.
1230 * - decoding: Set by libavcodec. (default 0)
1232 int interlaced_frame;
1235 * If the content is interlaced, is top field displayed first.
1236 * - encoding: Set by user.
1237 * - decoding: Set by libavcodec.
1239 int top_field_first;
1242 * Tell user application that palette has changed from previous frame.
1243 * - encoding: ??? (no palette-enabled encoder yet)
1244 * - decoding: Set by libavcodec. (default 0).
1246 int palette_has_changed;
1249 * codec suggestion on buffer type if != 0
1250 * - encoding: unused
1251 * - decoding: Set by libavcodec. (before get_buffer() call)).
1257 * - encoding: Set by user.
1258 * - decoding: Set by libavcodec.
1260 AVPanScan *pan_scan;
1263 * reordered opaque 64bit (generally an integer or a double precision float
1264 * PTS but can be anything).
1265 * The user sets AVCodecContext.reordered_opaque to represent the input at
1267 * the decoder reorders values as needed and sets AVFrame.reordered_opaque
1268 * to exactly one of the values provided by the user through AVCodecContext.reordered_opaque
1269 * @deprecated in favor of pkt_pts
1270 * - encoding: unused
1271 * - decoding: Read by user.
1273 int64_t reordered_opaque;
1276 * hardware accelerator private data (Libav-allocated)
1277 * - encoding: unused
1278 * - decoding: Set by libavcodec
1280 void *hwaccel_picture_private;
1283 * the AVCodecContext which ff_thread_get_buffer() was last called on
1284 * - encoding: Set by libavcodec.
1285 * - decoding: Set by libavcodec.
1287 struct AVCodecContext *owner;
1290 * used by multithreading to store frame-specific info
1291 * - encoding: Set by libavcodec.
1292 * - decoding: Set by libavcodec.
1294 void *thread_opaque;
1297 * log2 of the size of the block which a single vector in motion_val represents:
1298 * (4->16x16, 3->8x8, 2-> 4x4, 1-> 2x2)
1299 * - encoding: unused
1300 * - decoding: Set by libavcodec.
1302 uint8_t motion_subsample_log2;
1305 * Sample rate of the audio data.
1307 * - encoding: unused
1308 * - decoding: set by get_buffer()
1313 * Channel layout of the audio data.
1315 * - encoding: unused
1316 * - decoding: set by get_buffer()
1318 uint64_t channel_layout;
1321 struct AVCodecInternal;
1325 AV_FIELD_PROGRESSIVE,
1326 AV_FIELD_TT, //< Top coded_first, top displayed first
1327 AV_FIELD_BB, //< Bottom coded first, bottom displayed first
1328 AV_FIELD_TB, //< Top coded first, bottom displayed first
1329 AV_FIELD_BT, //< Bottom coded first, top displayed first
1333 * main external API structure.
1334 * New fields can be added to the end with minor version bumps.
1335 * Removal, reordering and changes to existing fields require a major
1337 * sizeof(AVCodecContext) must not be used outside libav*.
1339 typedef struct AVCodecContext {
1341 * information on struct for av_log
1342 * - set by avcodec_alloc_context3
1344 const AVClass *av_class;
1345 int log_level_offset;
1347 enum AVMediaType codec_type; /* see AVMEDIA_TYPE_xxx */
1348 const struct AVCodec *codec;
1349 char codec_name[32];
1350 enum AVCodecID codec_id; /* see AV_CODEC_ID_xxx */
1353 * fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
1354 * This is used to work around some encoder bugs.
1355 * A demuxer should set this to what is stored in the field used to identify the codec.
1356 * If there are multiple such fields in a container then the demuxer should choose the one
1357 * which maximizes the information about the used codec.
1358 * If the codec tag field in a container is larger than 32 bits then the demuxer should
1359 * remap the longer ID to 32 bits with a table or other structure. Alternatively a new
1360 * extra_codec_tag + size could be added but for this a clear advantage must be demonstrated
1362 * - encoding: Set by user, if not then the default based on codec_id will be used.
1363 * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
1365 unsigned int codec_tag;
1368 * fourcc from the AVI stream header (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
1369 * This is used to work around some encoder bugs.
1370 * - encoding: unused
1371 * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
1373 unsigned int stream_codec_tag;
1377 * @deprecated this field is unused
1379 attribute_deprecated int sub_id;
1385 * Private context used for internal data.
1387 * Unlike priv_data, this is not codec-specific. It is used in general
1388 * libavcodec functions.
1390 struct AVCodecInternal *internal;
1393 * Private data of the user, can be used to carry app specific stuff.
1394 * - encoding: Set by user.
1395 * - decoding: Set by user.
1400 * the average bitrate
1401 * - encoding: Set by user; unused for constant quantizer encoding.
1402 * - decoding: Set by libavcodec. 0 or some bitrate if this info is available in the stream.
1407 * number of bits the bitstream is allowed to diverge from the reference.
1408 * the reference can be CBR (for CBR pass1) or VBR (for pass2)
1409 * - encoding: Set by user; unused for constant quantizer encoding.
1410 * - decoding: unused
1412 int bit_rate_tolerance;
1415 * Global quality for codecs which cannot change it per frame.
1416 * This should be proportional to MPEG-1/2/4 qscale.
1417 * - encoding: Set by user.
1418 * - decoding: unused
1423 * - encoding: Set by user.
1424 * - decoding: unused
1426 int compression_level;
1427 #define FF_COMPRESSION_DEFAULT -1
1431 * - encoding: Set by user.
1432 * - decoding: Set by user.
1438 * - encoding: Set by user.
1439 * - decoding: Set by user.
1444 * some codecs need / can use extradata like Huffman tables.
1445 * mjpeg: Huffman tables
1446 * rv10: additional flags
1447 * mpeg4: global headers (they can be in the bitstream or here)
1448 * The allocated memory should be FF_INPUT_BUFFER_PADDING_SIZE bytes larger
1449 * than extradata_size to avoid prolems if it is read with the bitstream reader.
1450 * The bytewise contents of extradata must not depend on the architecture or CPU endianness.
1451 * - encoding: Set/allocated/freed by libavcodec.
1452 * - decoding: Set/allocated/freed by user.
1458 * This is the fundamental unit of time (in seconds) in terms
1459 * of which frame timestamps are represented. For fixed-fps content,
1460 * timebase should be 1/framerate and timestamp increments should be
1462 * - encoding: MUST be set by user.
1463 * - decoding: Set by libavcodec.
1465 AVRational time_base;
1468 * For some codecs, the time base is closer to the field rate than the frame rate.
1469 * Most notably, H.264 and MPEG-2 specify time_base as half of frame duration
1470 * if no telecine is used ...
1472 * Set to time_base ticks per frame. Default 1, e.g., H.264/MPEG-2 set it to 2.
1474 int ticks_per_frame;
1480 * Number of frames the decoded output will be delayed relative to the
1484 * For encoding, this is the number of "priming" samples added to the
1485 * beginning of the stream. The decoded output will be delayed by this
1486 * many samples relative to the input to the encoder. Note that this
1487 * field is purely informational and does not directly affect the pts
1488 * output by the encoder, which should always be based on the actual
1489 * presentation time, including any delay.
1490 * For decoding, this is the number of samples the decoder needs to
1491 * output before the decoder's output is valid. When seeking, you should
1492 * start decoding this many samples prior to your desired seek point.
1494 * - encoding: Set by libavcodec.
1495 * - decoding: Set by libavcodec.
1502 * picture width / height.
1503 * - encoding: MUST be set by user.
1504 * - decoding: Set by libavcodec.
1505 * Note: For compatibility it is possible to set this instead of
1506 * coded_width/height before decoding.
1511 * Bitstream width / height, may be different from width/height.
1512 * - encoding: unused
1513 * - decoding: Set by user before init if known. Codec should override / dynamically change if needed.
1515 int coded_width, coded_height;
1517 #define FF_ASPECT_EXTENDED 15
1520 * the number of pictures in a group of pictures, or 0 for intra_only
1521 * - encoding: Set by user.
1522 * - decoding: unused
1527 * Pixel format, see AV_PIX_FMT_xxx.
1528 * May be set by the demuxer if known from headers.
1529 * May be overriden by the decoder if it knows better.
1530 * - encoding: Set by user.
1531 * - decoding: Set by user if known, overridden by libavcodec if known
1533 enum AVPixelFormat pix_fmt;
1536 * Motion estimation algorithm used for video coding.
1537 * 1 (zero), 2 (full), 3 (log), 4 (phods), 5 (epzs), 6 (x1), 7 (hex),
1538 * 8 (umh), 9 (iter), 10 (tesa) [7, 8, 10 are x264 specific, 9 is snow specific]
1539 * - encoding: MUST be set by user.
1540 * - decoding: unused
1545 * If non NULL, 'draw_horiz_band' is called by the libavcodec
1546 * decoder to draw a horizontal band. It improves cache usage. Not
1547 * all codecs can do that. You must check the codec capabilities
1549 * When multithreading is used, it may be called from multiple threads
1550 * at the same time; threads might draw different parts of the same AVFrame,
1551 * or multiple AVFrames, and there is no guarantee that slices will be drawn
1553 * The function is also used by hardware acceleration APIs.
1554 * It is called at least once during frame decoding to pass
1555 * the data needed for hardware render.
1556 * In that mode instead of pixel data, AVFrame points to
1557 * a structure specific to the acceleration API. The application
1558 * reads the structure and can change some fields to indicate progress
1560 * - encoding: unused
1561 * - decoding: Set by user.
1562 * @param height the height of the slice
1563 * @param y the y position of the slice
1564 * @param type 1->top field, 2->bottom field, 3->frame
1565 * @param offset offset into the AVFrame.data from which the slice should be read
1567 void (*draw_horiz_band)(struct AVCodecContext *s,
1568 const AVFrame *src, int offset[AV_NUM_DATA_POINTERS],
1569 int y, int type, int height);
1572 * callback to negotiate the pixelFormat
1573 * @param fmt is the list of formats which are supported by the codec,
1574 * it is terminated by -1 as 0 is a valid format, the formats are ordered by quality.
1575 * The first is always the native one.
1576 * @return the chosen format
1577 * - encoding: unused
1578 * - decoding: Set by user, if not set the native format will be chosen.
1580 enum AVPixelFormat (*get_format)(struct AVCodecContext *s, const enum AVPixelFormat * fmt);
1583 * maximum number of B-frames between non-B-frames
1584 * Note: The output will be delayed by max_b_frames+1 relative to the input.
1585 * - encoding: Set by user.
1586 * - decoding: unused
1591 * qscale factor between IP and B-frames
1592 * If > 0 then the last P-frame quantizer will be used (q= lastp_q*factor+offset).
1593 * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1594 * - encoding: Set by user.
1595 * - decoding: unused
1597 float b_quant_factor;
1599 /** obsolete FIXME remove */
1601 #define FF_RC_STRATEGY_XVID 1
1603 int b_frame_strategy;
1605 #if FF_API_MPV_GLOBAL_OPTS
1607 * luma single coefficient elimination threshold
1608 * - encoding: Set by user.
1609 * - decoding: unused
1611 attribute_deprecated int luma_elim_threshold;
1614 * chroma single coeff elimination threshold
1615 * - encoding: Set by user.
1616 * - decoding: unused
1618 attribute_deprecated int chroma_elim_threshold;
1622 * qscale offset between IP and B-frames
1623 * - encoding: Set by user.
1624 * - decoding: unused
1626 float b_quant_offset;
1629 * Size of the frame reordering buffer in the decoder.
1630 * For MPEG-2 it is 1 IPB or 0 low delay IP.
1631 * - encoding: Set by libavcodec.
1632 * - decoding: Set by libavcodec.
1637 * 0-> h263 quant 1-> mpeg quant
1638 * - encoding: Set by user.
1639 * - decoding: unused
1644 * qscale factor between P and I-frames
1645 * If > 0 then the last p frame quantizer will be used (q= lastp_q*factor+offset).
1646 * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1647 * - encoding: Set by user.
1648 * - decoding: unused
1650 float i_quant_factor;
1653 * qscale offset between P and I-frames
1654 * - encoding: Set by user.
1655 * - decoding: unused
1657 float i_quant_offset;
1660 * luminance masking (0-> disabled)
1661 * - encoding: Set by user.
1662 * - decoding: unused
1667 * temporary complexity masking (0-> disabled)
1668 * - encoding: Set by user.
1669 * - decoding: unused
1671 float temporal_cplx_masking;
1674 * spatial complexity masking (0-> disabled)
1675 * - encoding: Set by user.
1676 * - decoding: unused
1678 float spatial_cplx_masking;
1681 * p block masking (0-> disabled)
1682 * - encoding: Set by user.
1683 * - decoding: unused
1688 * darkness masking (0-> disabled)
1689 * - encoding: Set by user.
1690 * - decoding: unused
1696 * - encoding: Set by libavcodec.
1697 * - decoding: Set by user (or 0).
1701 * prediction method (needed for huffyuv)
1702 * - encoding: Set by user.
1703 * - decoding: unused
1705 int prediction_method;
1706 #define FF_PRED_LEFT 0
1707 #define FF_PRED_PLANE 1
1708 #define FF_PRED_MEDIAN 2
1711 * slice offsets in the frame in bytes
1712 * - encoding: Set/allocated by libavcodec.
1713 * - decoding: Set/allocated by user (or NULL).
1718 * sample aspect ratio (0 if unknown)
1719 * That is the width of a pixel divided by the height of the pixel.
1720 * Numerator and denominator must be relatively prime and smaller than 256 for some video standards.
1721 * - encoding: Set by user.
1722 * - decoding: Set by libavcodec.
1724 AVRational sample_aspect_ratio;
1727 * motion estimation comparison function
1728 * - encoding: Set by user.
1729 * - decoding: unused
1733 * subpixel motion estimation comparison function
1734 * - encoding: Set by user.
1735 * - decoding: unused
1739 * macroblock comparison function (not supported yet)
1740 * - encoding: Set by user.
1741 * - decoding: unused
1745 * interlaced DCT comparison function
1746 * - encoding: Set by user.
1747 * - decoding: unused
1750 #define FF_CMP_SAD 0
1751 #define FF_CMP_SSE 1
1752 #define FF_CMP_SATD 2
1753 #define FF_CMP_DCT 3
1754 #define FF_CMP_PSNR 4
1755 #define FF_CMP_BIT 5
1757 #define FF_CMP_ZERO 7
1758 #define FF_CMP_VSAD 8
1759 #define FF_CMP_VSSE 9
1760 #define FF_CMP_NSSE 10
1761 #define FF_CMP_W53 11
1762 #define FF_CMP_W97 12
1763 #define FF_CMP_DCTMAX 13
1764 #define FF_CMP_DCT264 14
1765 #define FF_CMP_CHROMA 256
1768 * ME diamond size & shape
1769 * - encoding: Set by user.
1770 * - decoding: unused
1775 * amount of previous MV predictors (2a+1 x 2a+1 square)
1776 * - encoding: Set by user.
1777 * - decoding: unused
1779 int last_predictor_count;
1782 * prepass for motion estimation
1783 * - encoding: Set by user.
1784 * - decoding: unused
1789 * motion estimation prepass comparison function
1790 * - encoding: Set by user.
1791 * - decoding: unused
1796 * ME prepass diamond size & shape
1797 * - encoding: Set by user.
1798 * - decoding: unused
1804 * - encoding: Set by user.
1805 * - decoding: unused
1807 int me_subpel_quality;
1810 * DTG active format information (additional aspect ratio
1811 * information only used in DVB MPEG-2 transport streams)
1814 * - encoding: unused
1815 * - decoding: Set by decoder.
1817 int dtg_active_format;
1818 #define FF_DTG_AFD_SAME 8
1819 #define FF_DTG_AFD_4_3 9
1820 #define FF_DTG_AFD_16_9 10
1821 #define FF_DTG_AFD_14_9 11
1822 #define FF_DTG_AFD_4_3_SP_14_9 13
1823 #define FF_DTG_AFD_16_9_SP_14_9 14
1824 #define FF_DTG_AFD_SP_4_3 15
1827 * maximum motion estimation search range in subpel units
1828 * If 0 then no limit.
1830 * - encoding: Set by user.
1831 * - decoding: unused
1836 * intra quantizer bias
1837 * - encoding: Set by user.
1838 * - decoding: unused
1840 int intra_quant_bias;
1841 #define FF_DEFAULT_QUANT_BIAS 999999
1844 * inter quantizer bias
1845 * - encoding: Set by user.
1846 * - decoding: unused
1848 int inter_quant_bias;
1850 #if FF_API_COLOR_TABLE_ID
1853 * - encoding: unused
1854 * - decoding: Which clrtable should be used for 8bit RGB images.
1855 * Tables have to be stored somewhere. FIXME
1857 attribute_deprecated int color_table_id;
1862 * - encoding: unused
1863 * - decoding: Set by user.
1866 #define SLICE_FLAG_CODED_ORDER 0x0001 ///< draw_horiz_band() is called in coded order instead of display
1867 #define SLICE_FLAG_ALLOW_FIELD 0x0002 ///< allow draw_horiz_band() with field slices (MPEG2 field pics)
1868 #define SLICE_FLAG_ALLOW_PLANE 0x0004 ///< allow draw_horiz_band() with 1 component at a time (SVQ1)
1871 * XVideo Motion Acceleration
1872 * - encoding: forbidden
1873 * - decoding: set by decoder
1875 int xvmc_acceleration;
1878 * macroblock decision mode
1879 * - encoding: Set by user.
1880 * - decoding: unused
1883 #define FF_MB_DECISION_SIMPLE 0 ///< uses mb_cmp
1884 #define FF_MB_DECISION_BITS 1 ///< chooses the one which needs the fewest bits
1885 #define FF_MB_DECISION_RD 2 ///< rate distortion
1888 * custom intra quantization matrix
1889 * - encoding: Set by user, can be NULL.
1890 * - decoding: Set by libavcodec.
1892 uint16_t *intra_matrix;
1895 * custom inter quantization matrix
1896 * - encoding: Set by user, can be NULL.
1897 * - decoding: Set by libavcodec.
1899 uint16_t *inter_matrix;
1902 * scene change detection threshold
1903 * 0 is default, larger means fewer detected scene changes.
1904 * - encoding: Set by user.
1905 * - decoding: unused
1907 int scenechange_threshold;
1910 * noise reduction strength
1911 * - encoding: Set by user.
1912 * - decoding: unused
1914 int noise_reduction;
1916 #if FF_API_INTER_THRESHOLD
1918 * @deprecated this field is unused
1920 attribute_deprecated int inter_threshold;
1923 #if FF_API_MPV_GLOBAL_OPTS
1925 * @deprecated use mpegvideo private options instead
1927 attribute_deprecated int quantizer_noise_shaping;
1931 * Motion estimation threshold below which no motion estimation is
1932 * performed, but instead the user specified motion vectors are used.
1934 * - encoding: Set by user.
1935 * - decoding: unused
1940 * Macroblock threshold below which the user specified macroblock types will be used.
1941 * - encoding: Set by user.
1942 * - decoding: unused
1947 * precision of the intra DC coefficient - 8
1948 * - encoding: Set by user.
1949 * - decoding: unused
1951 int intra_dc_precision;
1954 * Number of macroblock rows at the top which are skipped.
1955 * - encoding: unused
1956 * - decoding: Set by user.
1961 * Number of macroblock rows at the bottom which are skipped.
1962 * - encoding: unused
1963 * - decoding: Set by user.
1968 * Border processing masking, raises the quantizer for mbs on the borders
1970 * - encoding: Set by user.
1971 * - decoding: unused
1973 float border_masking;
1976 * minimum MB lagrange multipler
1977 * - encoding: Set by user.
1978 * - decoding: unused
1983 * maximum MB lagrange multipler
1984 * - encoding: Set by user.
1985 * - decoding: unused
1991 * - encoding: Set by user.
1992 * - decoding: unused
1994 int me_penalty_compensation;
1998 * - encoding: Set by user.
1999 * - decoding: unused
2005 * - encoding: Set by user.
2006 * - decoding: unused
2012 * - encoding: Set by user.
2013 * - decoding: unused
2018 * number of reference frames
2019 * - encoding: Set by user.
2020 * - decoding: Set by lavc.
2025 * chroma qp offset from luma
2026 * - encoding: Set by user.
2027 * - decoding: unused
2032 * Multiplied by qscale for each frame and added to scene_change_score.
2033 * - encoding: Set by user.
2034 * - decoding: unused
2036 int scenechange_factor;
2040 * Note: Value depends upon the compare function used for fullpel ME.
2041 * - encoding: Set by user.
2042 * - decoding: unused
2047 * Adjust sensitivity of b_frame_strategy 1.
2048 * - encoding: Set by user.
2049 * - decoding: unused
2054 * Chromaticity coordinates of the source primaries.
2055 * - encoding: Set by user
2056 * - decoding: Set by libavcodec
2058 enum AVColorPrimaries color_primaries;
2061 * Color Transfer Characteristic.
2062 * - encoding: Set by user
2063 * - decoding: Set by libavcodec
2065 enum AVColorTransferCharacteristic color_trc;
2068 * YUV colorspace type.
2069 * - encoding: Set by user
2070 * - decoding: Set by libavcodec
2072 enum AVColorSpace colorspace;
2075 * MPEG vs JPEG YUV range.
2076 * - encoding: Set by user
2077 * - decoding: Set by libavcodec
2079 enum AVColorRange color_range;
2082 * This defines the location of chroma samples.
2083 * - encoding: Set by user
2084 * - decoding: Set by libavcodec
2086 enum AVChromaLocation chroma_sample_location;
2090 * Indicates number of picture subdivisions. Used for parallelized
2092 * - encoding: Set by user
2093 * - decoding: unused
2098 * - encoding: set by libavcodec
2099 * - decoding: Set by libavcodec
2101 enum AVFieldOrder field_order;
2104 int sample_rate; ///< samples per second
2105 int channels; ///< number of audio channels
2108 * audio sample format
2109 * - encoding: Set by user.
2110 * - decoding: Set by libavcodec.
2112 enum AVSampleFormat sample_fmt; ///< sample format
2114 /* The following data should not be initialized. */
2116 * Number of samples per channel in an audio frame.
2118 * - encoding: set by libavcodec in avcodec_open2(). Each submitted frame
2119 * except the last must contain exactly frame_size samples per channel.
2120 * May be 0 when the codec has CODEC_CAP_VARIABLE_FRAME_SIZE set, then the
2121 * frame size is not restricted.
2122 * - decoding: may be set by some decoders to indicate constant frame size
2127 * Frame counter, set by libavcodec.
2129 * - decoding: total number of frames returned from the decoder so far.
2130 * - encoding: total number of frames passed to the encoder so far.
2132 * @note the counter is not incremented if encoding/decoding resulted in
2138 * number of bytes per packet if constant and known or 0
2139 * Used by some WAV based audio codecs.
2144 * Audio cutoff bandwidth (0 means "automatic")
2145 * - encoding: Set by user.
2146 * - decoding: unused
2150 #if FF_API_REQUEST_CHANNELS
2152 * Decoder should decode to this many channels if it can (0 for default)
2153 * - encoding: unused
2154 * - decoding: Set by user.
2155 * @deprecated Deprecated in favor of request_channel_layout.
2157 int request_channels;
2161 * Audio channel layout.
2162 * - encoding: set by user.
2163 * - decoding: set by libavcodec.
2165 uint64_t channel_layout;
2168 * Request decoder to use this channel layout if it can (0 for default)
2169 * - encoding: unused
2170 * - decoding: Set by user.
2172 uint64_t request_channel_layout;
2175 * Type of service that the audio stream conveys.
2176 * - encoding: Set by user.
2177 * - decoding: Set by libavcodec.
2179 enum AVAudioServiceType audio_service_type;
2182 * Used to request a sample format from the decoder.
2183 * - encoding: unused.
2184 * - decoding: Set by user.
2186 enum AVSampleFormat request_sample_fmt;
2189 * Called at the beginning of each frame to get a buffer for it.
2191 * The function will set AVFrame.data[], AVFrame.linesize[].
2192 * AVFrame.extended_data[] must also be set, but it should be the same as
2193 * AVFrame.data[] except for planar audio with more channels than can fit
2194 * in AVFrame.data[]. In that case, AVFrame.data[] shall still contain as
2195 * many data pointers as it can hold.
2197 * if CODEC_CAP_DR1 is not set then get_buffer() must call
2198 * avcodec_default_get_buffer() instead of providing buffers allocated by
2201 * AVFrame.data[] should be 32- or 16-byte-aligned unless the CPU doesn't
2202 * need it. avcodec_default_get_buffer() aligns the output buffer properly,
2203 * but if get_buffer() is overridden then alignment considerations should
2204 * be taken into account.
2206 * @see avcodec_default_get_buffer()
2210 * If pic.reference is set then the frame will be read later by libavcodec.
2211 * avcodec_align_dimensions2() should be used to find the required width and
2212 * height, as they normally need to be rounded up to the next multiple of 16.
2214 * If frame multithreading is used and thread_safe_callbacks is set,
2215 * it may be called from a different thread, but not from more than one at
2216 * once. Does not need to be reentrant.
2218 * @see release_buffer(), reget_buffer()
2219 * @see avcodec_align_dimensions2()
2223 * Decoders request a buffer of a particular size by setting
2224 * AVFrame.nb_samples prior to calling get_buffer(). The decoder may,
2225 * however, utilize only part of the buffer by setting AVFrame.nb_samples
2226 * to a smaller value in the output frame.
2228 * Decoders cannot use the buffer after returning from
2229 * avcodec_decode_audio4(), so they will not call release_buffer(), as it
2230 * is assumed to be released immediately upon return. In some rare cases,
2231 * a decoder may need to call get_buffer() more than once in a single
2232 * call to avcodec_decode_audio4(). In that case, when get_buffer() is
2233 * called again after it has already been called once, the previously
2234 * acquired buffer is assumed to be released at that time and may not be
2235 * reused by the decoder.
2237 * As a convenience, av_samples_get_buffer_size() and
2238 * av_samples_fill_arrays() in libavutil may be used by custom get_buffer()
2239 * functions to find the required data size and to fill data pointers and
2240 * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
2241 * since all planes must be the same size.
2243 * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
2245 * - encoding: unused
2246 * - decoding: Set by libavcodec, user can override.
2248 int (*get_buffer)(struct AVCodecContext *c, AVFrame *pic);
2251 * Called to release buffers which were allocated with get_buffer.
2252 * A released buffer can be reused in get_buffer().
2253 * pic.data[*] must be set to NULL.
2254 * May be called from a different thread if frame multithreading is used,
2255 * but not by more than one thread at once, so does not need to be reentrant.
2256 * - encoding: unused
2257 * - decoding: Set by libavcodec, user can override.
2259 void (*release_buffer)(struct AVCodecContext *c, AVFrame *pic);
2262 * Called at the beginning of a frame to get cr buffer for it.
2263 * Buffer type (size, hints) must be the same. libavcodec won't check it.
2264 * libavcodec will pass previous buffer in pic, function should return
2265 * same buffer or new buffer with old frame "painted" into it.
2266 * If pic.data[0] == NULL must behave like get_buffer().
2267 * if CODEC_CAP_DR1 is not set then reget_buffer() must call
2268 * avcodec_default_reget_buffer() instead of providing buffers allocated by
2270 * - encoding: unused
2271 * - decoding: Set by libavcodec, user can override.
2273 int (*reget_buffer)(struct AVCodecContext *c, AVFrame *pic);
2276 /* - encoding parameters */
2277 float qcompress; ///< amount of qscale change between easy & hard scenes (0.0-1.0)
2278 float qblur; ///< amount of qscale smoothing over time (0.0-1.0)
2282 * - encoding: Set by user.
2283 * - decoding: unused
2289 * - encoding: Set by user.
2290 * - decoding: unused
2295 * maximum quantizer difference between frames
2296 * - encoding: Set by user.
2297 * - decoding: unused
2302 * ratecontrol qmin qmax limiting method
2303 * 0-> clipping, 1-> use a nice continuous function to limit qscale wthin qmin/qmax.
2304 * - encoding: Set by user.
2305 * - decoding: unused
2313 * decoder bitstream buffer size
2314 * - encoding: Set by user.
2315 * - decoding: unused
2320 * ratecontrol override, see RcOverride
2321 * - encoding: Allocated/set/freed by user.
2322 * - decoding: unused
2324 int rc_override_count;
2325 RcOverride *rc_override;
2328 * rate control equation
2329 * - encoding: Set by user
2330 * - decoding: unused
2336 * - encoding: Set by user.
2337 * - decoding: unused
2343 * - encoding: Set by user.
2344 * - decoding: unused
2348 float rc_buffer_aggressivity;
2351 * initial complexity for pass1 ratecontrol
2352 * - encoding: Set by user.
2353 * - decoding: unused
2355 float rc_initial_cplx;
2358 * Ratecontrol attempt to use, at maximum, <value> of what can be used without an underflow.
2359 * - encoding: Set by user.
2360 * - decoding: unused.
2362 float rc_max_available_vbv_use;
2365 * Ratecontrol attempt to use, at least, <value> times the amount needed to prevent a vbv overflow.
2366 * - encoding: Set by user.
2367 * - decoding: unused.
2369 float rc_min_vbv_overflow_use;
2372 * Number of bits which should be loaded into the rc buffer before decoding starts.
2373 * - encoding: Set by user.
2374 * - decoding: unused
2376 int rc_initial_buffer_occupancy;
2378 #define FF_CODER_TYPE_VLC 0
2379 #define FF_CODER_TYPE_AC 1
2380 #define FF_CODER_TYPE_RAW 2
2381 #define FF_CODER_TYPE_RLE 3
2382 #define FF_CODER_TYPE_DEFLATE 4
2385 * - encoding: Set by user.
2386 * - decoding: unused
2392 * - encoding: Set by user.
2393 * - decoding: unused
2398 * minimum Lagrange multipler
2399 * - encoding: Set by user.
2400 * - decoding: unused
2405 * maximum Lagrange multipler
2406 * - encoding: Set by user.
2407 * - decoding: unused
2412 * frame skip threshold
2413 * - encoding: Set by user.
2414 * - decoding: unused
2416 int frame_skip_threshold;
2420 * - encoding: Set by user.
2421 * - decoding: unused
2423 int frame_skip_factor;
2426 * frame skip exponent
2427 * - encoding: Set by user.
2428 * - decoding: unused
2433 * frame skip comparison function
2434 * - encoding: Set by user.
2435 * - decoding: unused
2440 * trellis RD quantization
2441 * - encoding: Set by user.
2442 * - decoding: unused
2447 * - encoding: Set by user.
2448 * - decoding: unused
2450 int min_prediction_order;
2453 * - encoding: Set by user.
2454 * - decoding: unused
2456 int max_prediction_order;
2459 * GOP timecode frame start number, in non drop frame format
2460 * - encoding: Set by user.
2461 * - decoding: unused
2463 int64_t timecode_frame_start;
2465 /* The RTP callback: This function is called */
2466 /* every time the encoder has a packet to send. */
2467 /* It depends on the encoder if the data starts */
2468 /* with a Start Code (it should). H.263 does. */
2469 /* mb_nb contains the number of macroblocks */
2470 /* encoded in the RTP payload. */
2471 void (*rtp_callback)(struct AVCodecContext *avctx, void *data, int size, int mb_nb);
2473 int rtp_payload_size; /* The size of the RTP payload: the coder will */
2474 /* do its best to deliver a chunk with size */
2475 /* below rtp_payload_size, the chunk will start */
2476 /* with a start code on some codecs like H.263. */
2477 /* This doesn't take account of any particular */
2478 /* headers inside the transmitted RTP payload. */
2480 /* statistics, used for 2-pass encoding */
2491 * number of bits used for the previously encoded frame
2492 * - encoding: Set by libavcodec.
2493 * - decoding: unused
2498 * pass1 encoding statistics output buffer
2499 * - encoding: Set by libavcodec.
2500 * - decoding: unused
2505 * pass2 encoding statistics input buffer
2506 * Concatenated stuff from stats_out of pass1 should be placed here.
2507 * - encoding: Allocated/set/freed by user.
2508 * - decoding: unused
2513 * Work around bugs in encoders which sometimes cannot be detected automatically.
2514 * - encoding: Set by user
2515 * - decoding: Set by user
2517 int workaround_bugs;
2518 #define FF_BUG_AUTODETECT 1 ///< autodetection
2519 #define FF_BUG_OLD_MSMPEG4 2
2520 #define FF_BUG_XVID_ILACE 4
2521 #define FF_BUG_UMP4 8
2522 #define FF_BUG_NO_PADDING 16
2523 #define FF_BUG_AMV 32
2524 #define FF_BUG_AC_VLC 0 ///< Will be removed, libavcodec can now handle these non-compliant files by default.
2525 #define FF_BUG_QPEL_CHROMA 64
2526 #define FF_BUG_STD_QPEL 128
2527 #define FF_BUG_QPEL_CHROMA2 256
2528 #define FF_BUG_DIRECT_BLOCKSIZE 512
2529 #define FF_BUG_EDGE 1024
2530 #define FF_BUG_HPEL_CHROMA 2048
2531 #define FF_BUG_DC_CLIP 4096
2532 #define FF_BUG_MS 8192 ///< Work around various bugs in Microsoft's broken decoders.
2533 #define FF_BUG_TRUNCATED 16384
2536 * strictly follow the standard (MPEG4, ...).
2537 * - encoding: Set by user.
2538 * - decoding: Set by user.
2539 * Setting this to STRICT or higher means the encoder and decoder will
2540 * generally do stupid things, whereas setting it to unofficial or lower
2541 * will mean the encoder might produce output that is not supported by all
2542 * spec-compliant decoders. Decoders don't differentiate between normal,
2543 * unofficial and experimental (that is, they always try to decode things
2544 * when they can) unless they are explicitly asked to behave stupidly
2545 * (=strictly conform to the specs)
2547 int strict_std_compliance;
2548 #define FF_COMPLIANCE_VERY_STRICT 2 ///< Strictly conform to an older more strict version of the spec or reference software.
2549 #define FF_COMPLIANCE_STRICT 1 ///< Strictly conform to all the things in the spec no matter what consequences.
2550 #define FF_COMPLIANCE_NORMAL 0
2551 #define FF_COMPLIANCE_UNOFFICIAL -1 ///< Allow unofficial extensions
2552 #define FF_COMPLIANCE_EXPERIMENTAL -2 ///< Allow nonstandardized experimental things.
2555 * error concealment flags
2556 * - encoding: unused
2557 * - decoding: Set by user.
2559 int error_concealment;
2560 #define FF_EC_GUESS_MVS 1
2561 #define FF_EC_DEBLOCK 2
2565 * - encoding: Set by user.
2566 * - decoding: Set by user.
2569 #define FF_DEBUG_PICT_INFO 1
2570 #define FF_DEBUG_RC 2
2571 #define FF_DEBUG_BITSTREAM 4
2572 #define FF_DEBUG_MB_TYPE 8
2573 #define FF_DEBUG_QP 16
2574 #define FF_DEBUG_MV 32
2575 #define FF_DEBUG_DCT_COEFF 0x00000040
2576 #define FF_DEBUG_SKIP 0x00000080
2577 #define FF_DEBUG_STARTCODE 0x00000100
2578 #define FF_DEBUG_PTS 0x00000200
2579 #define FF_DEBUG_ER 0x00000400
2580 #define FF_DEBUG_MMCO 0x00000800
2581 #define FF_DEBUG_BUGS 0x00001000
2582 #define FF_DEBUG_VIS_QP 0x00002000
2583 #define FF_DEBUG_VIS_MB_TYPE 0x00004000
2584 #define FF_DEBUG_BUFFERS 0x00008000
2585 #define FF_DEBUG_THREADS 0x00010000
2589 * - encoding: Set by user.
2590 * - decoding: Set by user.
2593 #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 //visualize forward predicted MVs of P frames
2594 #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 //visualize forward predicted MVs of B frames
2595 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
2598 * Error recognition; may misdetect some more or less valid parts as errors.
2599 * - encoding: unused
2600 * - decoding: Set by user.
2602 int err_recognition;
2603 #define AV_EF_CRCCHECK (1<<0)
2604 #define AV_EF_BITSTREAM (1<<1)
2605 #define AV_EF_BUFFER (1<<2)
2606 #define AV_EF_EXPLODE (1<<3)
2609 * opaque 64bit number (generally a PTS) that will be reordered and
2610 * output in AVFrame.reordered_opaque
2611 * @deprecated in favor of pkt_pts
2612 * - encoding: unused
2613 * - decoding: Set by user.
2615 int64_t reordered_opaque;
2618 * Hardware accelerator in use
2619 * - encoding: unused.
2620 * - decoding: Set by libavcodec
2622 struct AVHWAccel *hwaccel;
2625 * Hardware accelerator context.
2626 * For some hardware accelerators, a global context needs to be
2627 * provided by the user. In that case, this holds display-dependent
2628 * data Libav cannot instantiate itself. Please refer to the
2629 * Libav HW accelerator documentation to know how to fill this
2630 * is. e.g. for VA API, this is a struct vaapi_context.
2631 * - encoding: unused
2632 * - decoding: Set by user
2634 void *hwaccel_context;
2638 * - encoding: Set by libavcodec if flags&CODEC_FLAG_PSNR.
2639 * - decoding: unused
2641 uint64_t error[AV_NUM_DATA_POINTERS];
2644 * DCT algorithm, see FF_DCT_* below
2645 * - encoding: Set by user.
2646 * - decoding: unused
2649 #define FF_DCT_AUTO 0
2650 #define FF_DCT_FASTINT 1
2651 #define FF_DCT_INT 2
2652 #define FF_DCT_MMX 3
2653 #define FF_DCT_ALTIVEC 5
2654 #define FF_DCT_FAAN 6
2657 * IDCT algorithm, see FF_IDCT_* below.
2658 * - encoding: Set by user.
2659 * - decoding: Set by user.
2662 #define FF_IDCT_AUTO 0
2663 #define FF_IDCT_INT 1
2664 #define FF_IDCT_SIMPLE 2
2665 #define FF_IDCT_SIMPLEMMX 3
2667 #define FF_IDCT_LIBMPEG2MMX 4
2670 #define FF_IDCT_MMI 5
2672 #define FF_IDCT_ARM 7
2673 #define FF_IDCT_ALTIVEC 8
2674 #define FF_IDCT_SH4 9
2675 #define FF_IDCT_SIMPLEARM 10
2676 #define FF_IDCT_H264 11
2677 #define FF_IDCT_VP3 12
2678 #define FF_IDCT_IPP 13
2679 #define FF_IDCT_XVIDMMX 14
2680 #define FF_IDCT_CAVS 15
2681 #define FF_IDCT_SIMPLEARMV5TE 16
2682 #define FF_IDCT_SIMPLEARMV6 17
2683 #define FF_IDCT_SIMPLEVIS 18
2684 #define FF_IDCT_WMV2 19
2685 #define FF_IDCT_FAAN 20
2686 #define FF_IDCT_EA 21
2687 #define FF_IDCT_SIMPLENEON 22
2688 #define FF_IDCT_SIMPLEALPHA 23
2689 #define FF_IDCT_BINK 24
2694 * @deprecated use av_set_cpu_flags_mask() instead.
2696 attribute_deprecated unsigned dsp_mask;
2700 * bits per sample/pixel from the demuxer (needed for huffyuv).
2701 * - encoding: Set by libavcodec.
2702 * - decoding: Set by user.
2704 int bits_per_coded_sample;
2707 * Bits per sample/pixel of internal libavcodec pixel/sample format.
2708 * - encoding: set by user.
2709 * - decoding: set by libavcodec.
2711 int bits_per_raw_sample;
2714 * low resolution decoding, 1-> 1/2 size, 2->1/4 size
2715 * - encoding: unused
2716 * - decoding: Set by user.
2718 attribute_deprecated int lowres;
2721 * the picture in the bitstream
2722 * - encoding: Set by libavcodec.
2723 * - decoding: Set by libavcodec.
2725 AVFrame *coded_frame;
2729 * is used to decide how many independent tasks should be passed to execute()
2730 * - encoding: Set by user.
2731 * - decoding: Set by user.
2736 * Which multithreading methods to use.
2737 * Use of FF_THREAD_FRAME will increase decoding delay by one frame per thread,
2738 * so clients which cannot provide future frames should not use it.
2740 * - encoding: Set by user, otherwise the default is used.
2741 * - decoding: Set by user, otherwise the default is used.
2744 #define FF_THREAD_FRAME 1 ///< Decode more than one frame at once
2745 #define FF_THREAD_SLICE 2 ///< Decode more than one part of a single frame at once
2748 * Which multithreading methods are in use by the codec.
2749 * - encoding: Set by libavcodec.
2750 * - decoding: Set by libavcodec.
2752 int active_thread_type;
2755 * Set by the client if its custom get_buffer() callback can be called
2756 * synchronously from another thread, which allows faster multithreaded decoding.
2757 * draw_horiz_band() will be called from other threads regardless of this setting.
2758 * Ignored if the default get_buffer() is used.
2759 * - encoding: Set by user.
2760 * - decoding: Set by user.
2762 int thread_safe_callbacks;
2765 * The codec may call this to execute several independent things.
2766 * It will return only after finishing all tasks.
2767 * The user may replace this with some multithreaded implementation,
2768 * the default implementation will execute the parts serially.
2769 * @param count the number of things to execute
2770 * - encoding: Set by libavcodec, user can override.
2771 * - decoding: Set by libavcodec, user can override.
2773 int (*execute)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size);
2776 * The codec may call this to execute several independent things.
2777 * It will return only after finishing all tasks.
2778 * The user may replace this with some multithreaded implementation,
2779 * the default implementation will execute the parts serially.
2780 * Also see avcodec_thread_init and e.g. the --enable-pthread configure option.
2781 * @param c context passed also to func
2782 * @param count the number of things to execute
2783 * @param arg2 argument passed unchanged to func
2784 * @param ret return values of executed functions, must have space for "count" values. May be NULL.
2785 * @param func function that will be called count times, with jobnr from 0 to count-1.
2786 * threadnr will be in the range 0 to c->thread_count-1 < MAX_THREADS and so that no
2787 * two instances of func executing at the same time will have the same threadnr.
2788 * @return always 0 currently, but code should handle a future improvement where when any call to func
2789 * returns < 0 no further calls to func may be done and < 0 is returned.
2790 * - encoding: Set by libavcodec, user can override.
2791 * - decoding: Set by libavcodec, user can override.
2793 int (*execute2)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count);
2797 * Can be used by execute() to store some per AVCodecContext stuff.
2798 * - encoding: set by execute()
2799 * - decoding: set by execute()
2801 void *thread_opaque;
2804 * noise vs. sse weight for the nsse comparsion function
2805 * - encoding: Set by user.
2806 * - decoding: unused
2812 * - encoding: Set by user.
2813 * - decoding: Set by libavcodec.
2816 #define FF_PROFILE_UNKNOWN -99
2817 #define FF_PROFILE_RESERVED -100
2819 #define FF_PROFILE_AAC_MAIN 0
2820 #define FF_PROFILE_AAC_LOW 1
2821 #define FF_PROFILE_AAC_SSR 2
2822 #define FF_PROFILE_AAC_LTP 3
2823 #define FF_PROFILE_AAC_HE 4
2824 #define FF_PROFILE_AAC_HE_V2 28
2825 #define FF_PROFILE_AAC_LD 22
2826 #define FF_PROFILE_AAC_ELD 38
2828 #define FF_PROFILE_DTS 20
2829 #define FF_PROFILE_DTS_ES 30
2830 #define FF_PROFILE_DTS_96_24 40
2831 #define FF_PROFILE_DTS_HD_HRA 50
2832 #define FF_PROFILE_DTS_HD_MA 60
2834 #define FF_PROFILE_MPEG2_422 0
2835 #define FF_PROFILE_MPEG2_HIGH 1
2836 #define FF_PROFILE_MPEG2_SS 2
2837 #define FF_PROFILE_MPEG2_SNR_SCALABLE 3
2838 #define FF_PROFILE_MPEG2_MAIN 4
2839 #define FF_PROFILE_MPEG2_SIMPLE 5
2841 #define FF_PROFILE_H264_CONSTRAINED (1<<9) // 8+1; constraint_set1_flag
2842 #define FF_PROFILE_H264_INTRA (1<<11) // 8+3; constraint_set3_flag
2844 #define FF_PROFILE_H264_BASELINE 66
2845 #define FF_PROFILE_H264_CONSTRAINED_BASELINE (66|FF_PROFILE_H264_CONSTRAINED)
2846 #define FF_PROFILE_H264_MAIN 77
2847 #define FF_PROFILE_H264_EXTENDED 88
2848 #define FF_PROFILE_H264_HIGH 100
2849 #define FF_PROFILE_H264_HIGH_10 110
2850 #define FF_PROFILE_H264_HIGH_10_INTRA (110|FF_PROFILE_H264_INTRA)
2851 #define FF_PROFILE_H264_HIGH_422 122
2852 #define FF_PROFILE_H264_HIGH_422_INTRA (122|FF_PROFILE_H264_INTRA)
2853 #define FF_PROFILE_H264_HIGH_444 144
2854 #define FF_PROFILE_H264_HIGH_444_PREDICTIVE 244
2855 #define FF_PROFILE_H264_HIGH_444_INTRA (244|FF_PROFILE_H264_INTRA)
2856 #define FF_PROFILE_H264_CAVLC_444 44
2858 #define FF_PROFILE_VC1_SIMPLE 0
2859 #define FF_PROFILE_VC1_MAIN 1
2860 #define FF_PROFILE_VC1_COMPLEX 2
2861 #define FF_PROFILE_VC1_ADVANCED 3
2863 #define FF_PROFILE_MPEG4_SIMPLE 0
2864 #define FF_PROFILE_MPEG4_SIMPLE_SCALABLE 1
2865 #define FF_PROFILE_MPEG4_CORE 2
2866 #define FF_PROFILE_MPEG4_MAIN 3
2867 #define FF_PROFILE_MPEG4_N_BIT 4
2868 #define FF_PROFILE_MPEG4_SCALABLE_TEXTURE 5
2869 #define FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION 6
2870 #define FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE 7
2871 #define FF_PROFILE_MPEG4_HYBRID 8
2872 #define FF_PROFILE_MPEG4_ADVANCED_REAL_TIME 9
2873 #define FF_PROFILE_MPEG4_CORE_SCALABLE 10
2874 #define FF_PROFILE_MPEG4_ADVANCED_CODING 11
2875 #define FF_PROFILE_MPEG4_ADVANCED_CORE 12
2876 #define FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE 13
2877 #define FF_PROFILE_MPEG4_SIMPLE_STUDIO 14
2878 #define FF_PROFILE_MPEG4_ADVANCED_SIMPLE 15
2882 * - encoding: Set by user.
2883 * - decoding: Set by libavcodec.
2886 #define FF_LEVEL_UNKNOWN -99
2890 * - encoding: unused
2891 * - decoding: Set by user.
2893 enum AVDiscard skip_loop_filter;
2897 * - encoding: unused
2898 * - decoding: Set by user.
2900 enum AVDiscard skip_idct;
2904 * - encoding: unused
2905 * - decoding: Set by user.
2907 enum AVDiscard skip_frame;
2910 * Header containing style information for text subtitles.
2911 * For SUBTITLE_ASS subtitle type, it should contain the whole ASS
2912 * [Script Info] and [V4+ Styles] section, plus the [Events] line and
2913 * the Format line following. It shouldn't include any Dialogue line.
2914 * - encoding: Set/allocated/freed by user (before avcodec_open2())
2915 * - decoding: Set/allocated/freed by libavcodec (by avcodec_open2())
2917 uint8_t *subtitle_header;
2918 int subtitle_header_size;
2921 * Simulates errors in the bitstream to test error concealment.
2922 * - encoding: Set by user.
2923 * - decoding: unused
2928 * Current packet as passed into the decoder, to avoid having
2929 * to pass the packet into every function. Currently only valid
2930 * inside lavc and get/release_buffer callbacks.
2931 * - decoding: set by avcodec_decode_*, read by get_buffer() for setting pkt_pts
2932 * - encoding: unused
2937 * VBV delay coded in the last frame (in periods of a 27 MHz clock).
2938 * Used for compliant TS muxing.
2939 * - encoding: Set by libavcodec.
2940 * - decoding: unused.
2948 typedef struct AVProfile {
2950 const char *name; ///< short name for the profile
2953 typedef struct AVCodecDefault AVCodecDefault;
2960 typedef struct AVCodec {
2962 * Name of the codec implementation.
2963 * The name is globally unique among encoders and among decoders (but an
2964 * encoder and a decoder can share the same name).
2965 * This is the primary way to find a codec from the user perspective.
2969 * Descriptive name for the codec, meant to be more human readable than name.
2970 * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
2972 const char *long_name;
2973 enum AVMediaType type;
2976 * Codec capabilities.
2980 const AVRational *supported_framerates; ///< array of supported framerates, or NULL if any, array is terminated by {0,0}
2981 const enum AVPixelFormat *pix_fmts; ///< array of supported pixel formats, or NULL if unknown, array is terminated by -1
2982 const int *supported_samplerates; ///< array of supported audio samplerates, or NULL if unknown, array is terminated by 0
2983 const enum AVSampleFormat *sample_fmts; ///< array of supported sample formats, or NULL if unknown, array is terminated by -1
2984 const uint64_t *channel_layouts; ///< array of support channel layouts, or NULL if unknown. array is terminated by 0
2985 attribute_deprecated uint8_t max_lowres; ///< maximum value for lowres supported by the decoder
2986 const AVClass *priv_class; ///< AVClass for the private context
2987 const AVProfile *profiles; ///< array of recognized profiles, or NULL if unknown, array is terminated by {FF_PROFILE_UNKNOWN}
2989 /*****************************************************************
2990 * No fields below this line are part of the public API. They
2991 * may not be used outside of libavcodec and can be changed and
2993 * New public fields should be added right above.
2994 *****************************************************************
2997 struct AVCodec *next;
2999 * @name Frame-level threading support functions
3003 * If defined, called on thread contexts when they are created.
3004 * If the codec allocates writable tables in init(), re-allocate them here.
3005 * priv_data will be set to a copy of the original.
3007 int (*init_thread_copy)(AVCodecContext *);
3009 * Copy necessary context variables from a previous thread context to the current one.
3010 * If not defined, the next thread will start automatically; otherwise, the codec
3011 * must call ff_thread_finish_setup().
3013 * dst and src will (rarely) point to the same context, in which case memcpy should be skipped.
3015 int (*update_thread_context)(AVCodecContext *dst, const AVCodecContext *src);
3019 * Private codec-specific defaults.
3021 const AVCodecDefault *defaults;
3024 * Initialize codec static data, called from avcodec_register().
3026 void (*init_static_data)(struct AVCodec *codec);
3028 int (*init)(AVCodecContext *);
3029 int (*encode_sub)(AVCodecContext *, uint8_t *buf, int buf_size,
3030 const struct AVSubtitle *sub);
3032 * Encode data to an AVPacket.
3034 * @param avctx codec context
3035 * @param avpkt output AVPacket (may contain a user-provided buffer)
3036 * @param[in] frame AVFrame containing the raw data to be encoded
3037 * @param[out] got_packet_ptr encoder sets to 0 or 1 to indicate that a
3038 * non-empty packet was returned in avpkt.
3039 * @return 0 on success, negative error code on failure
3041 int (*encode2)(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame,
3042 int *got_packet_ptr);
3043 int (*decode)(AVCodecContext *, void *outdata, int *outdata_size, AVPacket *avpkt);
3044 int (*close)(AVCodecContext *);
3047 * Will be called when seeking
3049 void (*flush)(AVCodecContext *);
3055 typedef struct AVHWAccel {
3057 * Name of the hardware accelerated codec.
3058 * The name is globally unique among encoders and among decoders (but an
3059 * encoder and a decoder can share the same name).
3064 * Type of codec implemented by the hardware accelerator.
3066 * See AVMEDIA_TYPE_xxx
3068 enum AVMediaType type;
3071 * Codec implemented by the hardware accelerator.
3073 * See AV_CODEC_ID_xxx
3078 * Supported pixel format.
3080 * Only hardware accelerated formats are supported here.
3082 enum AVPixelFormat pix_fmt;
3085 * Hardware accelerated codec capabilities.
3086 * see FF_HWACCEL_CODEC_CAP_*
3090 struct AVHWAccel *next;
3093 * Called at the beginning of each frame or field picture.
3095 * Meaningful frame information (codec specific) is guaranteed to
3096 * be parsed at this point. This function is mandatory.
3098 * Note that buf can be NULL along with buf_size set to 0.
3099 * Otherwise, this means the whole frame is available at this point.
3101 * @param avctx the codec context
3102 * @param buf the frame data buffer base
3103 * @param buf_size the size of the frame in bytes
3104 * @return zero if successful, a negative value otherwise
3106 int (*start_frame)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3109 * Callback for each slice.
3111 * Meaningful slice information (codec specific) is guaranteed to
3112 * be parsed at this point. This function is mandatory.
3114 * @param avctx the codec context
3115 * @param buf the slice data buffer base
3116 * @param buf_size the size of the slice in bytes
3117 * @return zero if successful, a negative value otherwise
3119 int (*decode_slice)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3122 * Called at the end of each frame or field picture.
3124 * The whole picture is parsed at this point and can now be sent
3125 * to the hardware accelerator. This function is mandatory.
3127 * @param avctx the codec context
3128 * @return zero if successful, a negative value otherwise
3130 int (*end_frame)(AVCodecContext *avctx);
3133 * Size of HW accelerator private data.
3135 * Private data is allocated with av_mallocz() before
3136 * AVCodecContext.get_buffer() and deallocated after
3137 * AVCodecContext.release_buffer().
3143 * @defgroup lavc_picture AVPicture
3145 * Functions for working with AVPicture
3150 * four components are given, that's all.
3151 * the last component is alpha
3153 typedef struct AVPicture {
3154 uint8_t *data[AV_NUM_DATA_POINTERS];
3155 int linesize[AV_NUM_DATA_POINTERS]; ///< number of bytes per line
3162 #define AVPALETTE_SIZE 1024
3163 #define AVPALETTE_COUNT 256
3165 enum AVSubtitleType {
3168 SUBTITLE_BITMAP, ///< A bitmap, pict will be set
3171 * Plain text, the text field must be set by the decoder and is
3172 * authoritative. ass and pict fields may contain approximations.
3177 * Formatted text, the ass field must be set by the decoder and is
3178 * authoritative. pict and text fields may contain approximations.
3183 #define AV_SUBTITLE_FLAG_FORCED 0x00000001
3185 typedef struct AVSubtitleRect {
3186 int x; ///< top left corner of pict, undefined when pict is not set
3187 int y; ///< top left corner of pict, undefined when pict is not set
3188 int w; ///< width of pict, undefined when pict is not set
3189 int h; ///< height of pict, undefined when pict is not set
3190 int nb_colors; ///< number of colors in pict, undefined when pict is not set
3193 * data+linesize for the bitmap of this subtitle.
3194 * can be set for text/ass as well once they where rendered
3197 enum AVSubtitleType type;
3199 char *text; ///< 0 terminated plain UTF-8 text
3202 * 0 terminated ASS/SSA compatible event line.
3203 * The pressentation of this is unaffected by the other values in this
3210 typedef struct AVSubtitle {
3211 uint16_t format; /* 0 = graphics */
3212 uint32_t start_display_time; /* relative to packet pts, in ms */
3213 uint32_t end_display_time; /* relative to packet pts, in ms */
3215 AVSubtitleRect **rects;
3216 int64_t pts; ///< Same as packet pts, in AV_TIME_BASE
3220 * If c is NULL, returns the first registered codec,
3221 * if c is non-NULL, returns the next registered codec after c,
3222 * or NULL if c is the last one.
3224 AVCodec *av_codec_next(const AVCodec *c);
3227 * Return the LIBAVCODEC_VERSION_INT constant.
3229 unsigned avcodec_version(void);
3232 * Return the libavcodec build-time configuration.
3234 const char *avcodec_configuration(void);
3237 * Return the libavcodec license.
3239 const char *avcodec_license(void);
3242 * Register the codec codec and initialize libavcodec.
3244 * @warning either this function or avcodec_register_all() must be called
3245 * before any other libavcodec functions.
3247 * @see avcodec_register_all()
3249 void avcodec_register(AVCodec *codec);
3252 * Register all the codecs, parsers and bitstream filters which were enabled at
3253 * configuration time. If you do not call this function you can select exactly
3254 * which formats you want to support, by using the individual registration
3257 * @see avcodec_register
3258 * @see av_register_codec_parser
3259 * @see av_register_bitstream_filter
3261 void avcodec_register_all(void);
3264 * Allocate an AVCodecContext and set its fields to default values. The
3265 * resulting struct can be deallocated by calling avcodec_close() on it followed
3268 * @param codec if non-NULL, allocate private data and initialize defaults
3269 * for the given codec. It is illegal to then call avcodec_open2()
3270 * with a different codec.
3271 * If NULL, then the codec-specific defaults won't be initialized,
3272 * which may result in suboptimal default settings (this is
3273 * important mainly for encoders, e.g. libx264).
3275 * @return An AVCodecContext filled with default values or NULL on failure.
3276 * @see avcodec_get_context_defaults
3278 AVCodecContext *avcodec_alloc_context3(const AVCodec *codec);
3281 * Set the fields of the given AVCodecContext to default values corresponding
3282 * to the given codec (defaults may be codec-dependent).
3284 * Do not call this function if a non-NULL codec has been passed
3285 * to avcodec_alloc_context3() that allocated this AVCodecContext.
3286 * If codec is non-NULL, it is illegal to call avcodec_open2() with a
3287 * different codec on this AVCodecContext.
3289 int avcodec_get_context_defaults3(AVCodecContext *s, const AVCodec *codec);
3292 * Get the AVClass for AVCodecContext. It can be used in combination with
3293 * AV_OPT_SEARCH_FAKE_OBJ for examining options.
3295 * @see av_opt_find().
3297 const AVClass *avcodec_get_class(void);
3300 * Copy the settings of the source AVCodecContext into the destination
3301 * AVCodecContext. The resulting destination codec context will be
3302 * unopened, i.e. you are required to call avcodec_open2() before you
3303 * can use this AVCodecContext to decode/encode video/audio data.
3305 * @param dest target codec context, should be initialized with
3306 * avcodec_alloc_context3(), but otherwise uninitialized
3307 * @param src source codec context
3308 * @return AVERROR() on error (e.g. memory allocation error), 0 on success
3310 int avcodec_copy_context(AVCodecContext *dest, const AVCodecContext *src);
3313 * Allocate an AVFrame and set its fields to default values. The resulting
3314 * struct must be freed using avcodec_free_frame().
3316 * @return An AVFrame filled with default values or NULL on failure.
3317 * @see avcodec_get_frame_defaults
3319 AVFrame *avcodec_alloc_frame(void);
3322 * Set the fields of the given AVFrame to default values.
3324 * @param frame The AVFrame of which the fields should be set to default values.
3326 void avcodec_get_frame_defaults(AVFrame *frame);
3329 * Free the frame and any dynamically allocated objects in it,
3330 * e.g. extended_data.
3332 * @param frame frame to be freed. The pointer will be set to NULL.
3334 * @warning this function does NOT free the data buffers themselves
3335 * (it does not know how, since they might have been allocated with
3336 * a custom get_buffer()).
3338 void avcodec_free_frame(AVFrame **frame);
3341 * Initialize the AVCodecContext to use the given AVCodec. Prior to using this
3342 * function the context has to be allocated with avcodec_alloc_context3().
3344 * The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(),
3345 * avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for
3346 * retrieving a codec.
3348 * @warning This function is not thread safe!
3351 * avcodec_register_all();
3352 * av_dict_set(&opts, "b", "2.5M", 0);
3353 * codec = avcodec_find_decoder(AV_CODEC_ID_H264);
3357 * context = avcodec_alloc_context3(codec);
3359 * if (avcodec_open2(context, codec, opts) < 0)
3363 * @param avctx The context to initialize.
3364 * @param codec The codec to open this context for. If a non-NULL codec has been
3365 * previously passed to avcodec_alloc_context3() or
3366 * avcodec_get_context_defaults3() for this context, then this
3367 * parameter MUST be either NULL or equal to the previously passed
3369 * @param options A dictionary filled with AVCodecContext and codec-private options.
3370 * On return this object will be filled with options that were not found.
3372 * @return zero on success, a negative value on error
3373 * @see avcodec_alloc_context3(), avcodec_find_decoder(), avcodec_find_encoder(),
3374 * av_dict_set(), av_opt_find().
3376 int avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options);
3379 * Close a given AVCodecContext and free all the data associated with it
3380 * (but not the AVCodecContext itself).
3382 * Calling this function on an AVCodecContext that hasn't been opened will free
3383 * the codec-specific data allocated in avcodec_alloc_context3() /
3384 * avcodec_get_context_defaults3() with a non-NULL codec. Subsequent calls will
3387 int avcodec_close(AVCodecContext *avctx);
3390 * Free all allocated data in the given subtitle struct.
3392 * @param sub AVSubtitle to free.
3394 void avsubtitle_free(AVSubtitle *sub);
3401 * @addtogroup lavc_packet
3406 * Default packet destructor.
3408 void av_destruct_packet(AVPacket *pkt);
3411 * Initialize optional fields of a packet with default values.
3413 * Note, this does not touch the data and size members, which have to be
3414 * initialized separately.
3418 void av_init_packet(AVPacket *pkt);
3421 * Allocate the payload of a packet and initialize its fields with
3425 * @param size wanted payload size
3426 * @return 0 if OK, AVERROR_xxx otherwise
3428 int av_new_packet(AVPacket *pkt, int size);
3431 * Reduce packet size, correctly zeroing padding
3434 * @param size new size
3436 void av_shrink_packet(AVPacket *pkt, int size);
3439 * Increase packet size, correctly zeroing padding
3442 * @param grow_by number of bytes by which to increase the size of the packet
3444 int av_grow_packet(AVPacket *pkt, int grow_by);
3447 * @warning This is a hack - the packet memory allocation stuff is broken. The
3448 * packet is allocated if it was not really allocated.
3450 int av_dup_packet(AVPacket *pkt);
3455 * @param pkt packet to free
3457 void av_free_packet(AVPacket *pkt);
3460 * Allocate new information of a packet.
3463 * @param type side information type
3464 * @param size side information size
3465 * @return pointer to fresh allocated data or NULL otherwise
3467 uint8_t* av_packet_new_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
3471 * Shrink the already allocated side data buffer
3474 * @param type side information type
3475 * @param size new side information size
3476 * @return 0 on success, < 0 on failure
3478 int av_packet_shrink_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
3482 * Get side information from packet.
3485 * @param type desired side information type
3486 * @param size pointer for side information size to store (optional)
3487 * @return pointer to data if present or NULL otherwise
3489 uint8_t* av_packet_get_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
3497 * @addtogroup lavc_decoding
3502 * Find a registered decoder with a matching codec ID.
3504 * @param id AVCodecID of the requested decoder
3505 * @return A decoder if one was found, NULL otherwise.
3507 AVCodec *avcodec_find_decoder(enum AVCodecID id);
3510 * Find a registered decoder with the specified name.
3512 * @param name name of the requested decoder
3513 * @return A decoder if one was found, NULL otherwise.
3515 AVCodec *avcodec_find_decoder_by_name(const char *name);
3517 int avcodec_default_get_buffer(AVCodecContext *s, AVFrame *pic);
3518 void avcodec_default_release_buffer(AVCodecContext *s, AVFrame *pic);
3519 int avcodec_default_reget_buffer(AVCodecContext *s, AVFrame *pic);
3522 * Return the amount of padding in pixels which the get_buffer callback must
3523 * provide around the edge of the image for codecs which do not have the
3524 * CODEC_FLAG_EMU_EDGE flag.
3526 * @return Required padding in pixels.
3528 unsigned avcodec_get_edge_width(void);
3531 * Modify width and height values so that they will result in a memory
3532 * buffer that is acceptable for the codec if you do not use any horizontal
3535 * May only be used if a codec with CODEC_CAP_DR1 has been opened.
3536 * If CODEC_FLAG_EMU_EDGE is not set, the dimensions must have been increased
3537 * according to avcodec_get_edge_width() before.
3539 void avcodec_align_dimensions(AVCodecContext *s, int *width, int *height);
3542 * Modify width and height values so that they will result in a memory
3543 * buffer that is acceptable for the codec if you also ensure that all
3544 * line sizes are a multiple of the respective linesize_align[i].
3546 * May only be used if a codec with CODEC_CAP_DR1 has been opened.
3547 * If CODEC_FLAG_EMU_EDGE is not set, the dimensions must have been increased
3548 * according to avcodec_get_edge_width() before.
3550 void avcodec_align_dimensions2(AVCodecContext *s, int *width, int *height,
3551 int linesize_align[AV_NUM_DATA_POINTERS]);
3553 #if FF_API_OLD_DECODE_AUDIO
3555 * Wrapper function which calls avcodec_decode_audio4.
3557 * @deprecated Use avcodec_decode_audio4 instead.
3559 * Decode the audio frame of size avpkt->size from avpkt->data into samples.
3560 * Some decoders may support multiple frames in a single AVPacket, such
3561 * decoders would then just decode the first frame. In this case,
3562 * avcodec_decode_audio3 has to be called again with an AVPacket that contains
3563 * the remaining data in order to decode the second frame etc.
3565 * could be outputted, frame_size_ptr is zero. Otherwise, it is the
3566 * decompressed frame size in bytes.
3568 * @warning You must set frame_size_ptr to the allocated size of the
3569 * output buffer before calling avcodec_decode_audio3().
3571 * @warning The input buffer must be FF_INPUT_BUFFER_PADDING_SIZE larger than
3572 * the actual read bytes because some optimized bitstream readers read 32 or 64
3573 * bits at once and could read over the end.
3575 * @warning The end of the input buffer avpkt->data should be set to 0 to ensure that
3576 * no overreading happens for damaged MPEG streams.
3578 * @warning You must not provide a custom get_buffer() when using
3579 * avcodec_decode_audio3(). Doing so will override it with
3580 * avcodec_default_get_buffer. Use avcodec_decode_audio4() instead,
3581 * which does allow the application to provide a custom get_buffer().
3583 * @note You might have to align the input buffer avpkt->data and output buffer
3584 * samples. The alignment requirements depend on the CPU: On some CPUs it isn't
3585 * necessary at all, on others it won't work at all if not aligned and on others
3586 * it will work but it will have an impact on performance.
3588 * In practice, avpkt->data should have 4 byte alignment at minimum and
3589 * samples should be 16 byte aligned unless the CPU doesn't need it
3590 * (AltiVec and SSE do).
3592 * @note Codecs which have the CODEC_CAP_DELAY capability set have a delay
3593 * between input and output, these need to be fed with avpkt->data=NULL,
3594 * avpkt->size=0 at the end to return the remaining frames.
3596 * @param avctx the codec context
3597 * @param[out] samples the output buffer, sample type in avctx->sample_fmt
3598 * If the sample format is planar, each channel plane will
3599 * be the same size, with no padding between channels.
3600 * @param[in,out] frame_size_ptr the output buffer size in bytes
3601 * @param[in] avpkt The input AVPacket containing the input buffer.
3602 * You can create such packet with av_init_packet() and by then setting
3603 * data and size, some decoders might in addition need other fields.
3604 * All decoders are designed to use the least fields possible though.
3605 * @return On error a negative value is returned, otherwise the number of bytes
3606 * used or zero if no frame data was decompressed (used) from the input AVPacket.
3608 attribute_deprecated int avcodec_decode_audio3(AVCodecContext *avctx, int16_t *samples,
3609 int *frame_size_ptr,
3614 * Decode the audio frame of size avpkt->size from avpkt->data into frame.
3616 * Some decoders may support multiple frames in a single AVPacket. Such
3617 * decoders would then just decode the first frame. In this case,
3618 * avcodec_decode_audio4 has to be called again with an AVPacket containing
3619 * the remaining data in order to decode the second frame, etc...
3620 * Even if no frames are returned, the packet needs to be fed to the decoder
3621 * with remaining data until it is completely consumed or an error occurs.
3623 * @warning The input buffer, avpkt->data must be FF_INPUT_BUFFER_PADDING_SIZE
3624 * larger than the actual read bytes because some optimized bitstream
3625 * readers read 32 or 64 bits at once and could read over the end.
3627 * @note You might have to align the input buffer. The alignment requirements
3628 * depend on the CPU and the decoder.
3630 * @param avctx the codec context
3631 * @param[out] frame The AVFrame in which to store decoded audio samples.
3632 * Decoders request a buffer of a particular size by setting
3633 * AVFrame.nb_samples prior to calling get_buffer(). The
3634 * decoder may, however, only utilize part of the buffer by
3635 * setting AVFrame.nb_samples to a smaller value in the
3637 * @param[out] got_frame_ptr Zero if no frame could be decoded, otherwise it is
3639 * @param[in] avpkt The input AVPacket containing the input buffer.
3640 * At least avpkt->data and avpkt->size should be set. Some
3641 * decoders might also require additional fields to be set.
3642 * @return A negative error code is returned if an error occurred during
3643 * decoding, otherwise the number of bytes consumed from the input
3644 * AVPacket is returned.
3646 int avcodec_decode_audio4(AVCodecContext *avctx, AVFrame *frame,
3647 int *got_frame_ptr, AVPacket *avpkt);
3650 * Decode the video frame of size avpkt->size from avpkt->data into picture.
3651 * Some decoders may support multiple frames in a single AVPacket, such
3652 * decoders would then just decode the first frame.
3654 * @warning The input buffer must be FF_INPUT_BUFFER_PADDING_SIZE larger than
3655 * the actual read bytes because some optimized bitstream readers read 32 or 64
3656 * bits at once and could read over the end.
3658 * @warning The end of the input buffer buf should be set to 0 to ensure that
3659 * no overreading happens for damaged MPEG streams.
3661 * @note You might have to align the input buffer avpkt->data.
3662 * The alignment requirements depend on the CPU: on some CPUs it isn't
3663 * necessary at all, on others it won't work at all if not aligned and on others
3664 * it will work but it will have an impact on performance.
3666 * In practice, avpkt->data should have 4 byte alignment at minimum.
3668 * @note Codecs which have the CODEC_CAP_DELAY capability set have a delay
3669 * between input and output, these need to be fed with avpkt->data=NULL,
3670 * avpkt->size=0 at the end to return the remaining frames.
3672 * @param avctx the codec context
3673 * @param[out] picture The AVFrame in which the decoded video frame will be stored.
3674 * Use avcodec_alloc_frame to get an AVFrame, the codec will
3675 * allocate memory for the actual bitmap.
3676 * with default get/release_buffer(), the decoder frees/reuses the bitmap as it sees fit.
3677 * with overridden get/release_buffer() (needs CODEC_CAP_DR1) the user decides into what buffer the decoder
3678 * decodes and the decoder tells the user once it does not need the data anymore,
3679 * the user app can at this point free/reuse/keep the memory as it sees fit.
3681 * @param[in] avpkt The input AVpacket containing the input buffer.
3682 * You can create such packet with av_init_packet() and by then setting
3683 * data and size, some decoders might in addition need other fields like
3684 * flags&AV_PKT_FLAG_KEY. All decoders are designed to use the least
3686 * @param[in,out] got_picture_ptr Zero if no frame could be decompressed, otherwise, it is nonzero.
3687 * @return On error a negative value is returned, otherwise the number of bytes
3688 * used or zero if no frame could be decompressed.
3690 int avcodec_decode_video2(AVCodecContext *avctx, AVFrame *picture,
3691 int *got_picture_ptr,
3695 * Decode a subtitle message.
3696 * Return a negative value on error, otherwise return the number of bytes used.
3697 * If no subtitle could be decompressed, got_sub_ptr is zero.
3698 * Otherwise, the subtitle is stored in *sub.
3699 * Note that CODEC_CAP_DR1 is not available for subtitle codecs. This is for
3700 * simplicity, because the performance difference is expect to be negligible
3701 * and reusing a get_buffer written for video codecs would probably perform badly
3702 * due to a potentially very different allocation pattern.
3704 * @param avctx the codec context
3705 * @param[out] sub The AVSubtitle in which the decoded subtitle will be stored, must be
3706 freed with avsubtitle_free if *got_sub_ptr is set.
3707 * @param[in,out] got_sub_ptr Zero if no subtitle could be decompressed, otherwise, it is nonzero.
3708 * @param[in] avpkt The input AVPacket containing the input buffer.
3710 int avcodec_decode_subtitle2(AVCodecContext *avctx, AVSubtitle *sub,
3715 * @defgroup lavc_parsing Frame parsing
3719 typedef struct AVCodecParserContext {
3721 struct AVCodecParser *parser;
3722 int64_t frame_offset; /* offset of the current frame */
3723 int64_t cur_offset; /* current offset
3724 (incremented by each av_parser_parse()) */
3725 int64_t next_frame_offset; /* offset of the next frame */
3727 int pict_type; /* XXX: Put it back in AVCodecContext. */
3729 * This field is used for proper frame duration computation in lavf.
3730 * It signals, how much longer the frame duration of the current frame
3731 * is compared to normal frame duration.
3733 * frame_duration = (1 + repeat_pict) * time_base
3735 * It is used by codecs like H.264 to display telecined material.
3737 int repeat_pict; /* XXX: Put it back in AVCodecContext. */
3738 int64_t pts; /* pts of the current frame */
3739 int64_t dts; /* dts of the current frame */
3744 int fetch_timestamp;
3746 #define AV_PARSER_PTS_NB 4
3747 int cur_frame_start_index;
3748 int64_t cur_frame_offset[AV_PARSER_PTS_NB];
3749 int64_t cur_frame_pts[AV_PARSER_PTS_NB];
3750 int64_t cur_frame_dts[AV_PARSER_PTS_NB];
3753 #define PARSER_FLAG_COMPLETE_FRAMES 0x0001
3754 #define PARSER_FLAG_ONCE 0x0002
3755 /// Set if the parser has a valid file offset
3756 #define PARSER_FLAG_FETCHED_OFFSET 0x0004
3758 int64_t offset; ///< byte offset from starting packet start
3759 int64_t cur_frame_end[AV_PARSER_PTS_NB];
3762 * Set by parser to 1 for key frames and 0 for non-key frames.
3763 * It is initialized to -1, so if the parser doesn't set this flag,
3764 * old-style fallback using AV_PICTURE_TYPE_I picture type as key frames
3770 * Time difference in stream time base units from the pts of this
3771 * packet to the point at which the output from the decoder has converged
3772 * independent from the availability of previous frames. That is, the
3773 * frames are virtually identical no matter if decoding started from
3774 * the very first frame or from this keyframe.
3775 * Is AV_NOPTS_VALUE if unknown.
3776 * This field is not the display duration of the current frame.
3777 * This field has no meaning if the packet does not have AV_PKT_FLAG_KEY
3780 * The purpose of this field is to allow seeking in streams that have no
3781 * keyframes in the conventional sense. It corresponds to the
3782 * recovery point SEI in H.264 and match_time_delta in NUT. It is also
3783 * essential for some types of subtitle streams to ensure that all
3784 * subtitles are correctly displayed after seeking.
3786 int64_t convergence_duration;
3788 // Timestamp generation support:
3790 * Synchronization point for start of timestamp generation.
3792 * Set to >0 for sync point, 0 for no sync point and <0 for undefined
3795 * For example, this corresponds to presence of H.264 buffering period
3801 * Offset of the current timestamp against last timestamp sync point in
3802 * units of AVCodecContext.time_base.
3804 * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
3805 * contain a valid timestamp offset.
3807 * Note that the timestamp of sync point has usually a nonzero
3808 * dts_ref_dts_delta, which refers to the previous sync point. Offset of
3809 * the next frame after timestamp sync point will be usually 1.
3811 * For example, this corresponds to H.264 cpb_removal_delay.
3813 int dts_ref_dts_delta;
3816 * Presentation delay of current frame in units of AVCodecContext.time_base.
3818 * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
3819 * contain valid non-negative timestamp delta (presentation time of a frame
3820 * must not lie in the past).
3822 * This delay represents the difference between decoding and presentation
3823 * time of the frame.
3825 * For example, this corresponds to H.264 dpb_output_delay.
3830 * Position of the packet in file.
3832 * Analogous to cur_frame_pts/dts
3834 int64_t cur_frame_pos[AV_PARSER_PTS_NB];
3837 * Byte position of currently parsed frame in stream.
3842 * Previous frame byte position.
3847 * Duration of the current frame.
3848 * For audio, this is in units of 1 / AVCodecContext.sample_rate.
3849 * For all other types, this is in units of AVCodecContext.time_base.
3852 } AVCodecParserContext;
3854 typedef struct AVCodecParser {
3855 int codec_ids[5]; /* several codec IDs are permitted */
3857 int (*parser_init)(AVCodecParserContext *s);
3858 int (*parser_parse)(AVCodecParserContext *s,
3859 AVCodecContext *avctx,
3860 const uint8_t **poutbuf, int *poutbuf_size,
3861 const uint8_t *buf, int buf_size);
3862 void (*parser_close)(AVCodecParserContext *s);
3863 int (*split)(AVCodecContext *avctx, const uint8_t *buf, int buf_size);
3864 struct AVCodecParser *next;
3867 AVCodecParser *av_parser_next(AVCodecParser *c);
3869 void av_register_codec_parser(AVCodecParser *parser);
3870 AVCodecParserContext *av_parser_init(int codec_id);
3875 * @param s parser context.
3876 * @param avctx codec context.
3877 * @param poutbuf set to pointer to parsed buffer or NULL if not yet finished.
3878 * @param poutbuf_size set to size of parsed buffer or zero if not yet finished.
3879 * @param buf input buffer.
3880 * @param buf_size input length, to signal EOF, this should be 0 (so that the last frame can be output).
3881 * @param pts input presentation timestamp.
3882 * @param dts input decoding timestamp.
3883 * @param pos input byte position in stream.
3884 * @return the number of bytes of the input bitstream used.
3889 * len = av_parser_parse2(myparser, AVCodecContext, &data, &size,
3896 * decode_frame(data, size);
3900 int av_parser_parse2(AVCodecParserContext *s,
3901 AVCodecContext *avctx,
3902 uint8_t **poutbuf, int *poutbuf_size,
3903 const uint8_t *buf, int buf_size,
3904 int64_t pts, int64_t dts,
3908 * @return 0 if the output buffer is a subset of the input, 1 if it is allocated and must be freed
3909 * @deprecated use AVBitstreamFilter
3911 int av_parser_change(AVCodecParserContext *s,
3912 AVCodecContext *avctx,
3913 uint8_t **poutbuf, int *poutbuf_size,
3914 const uint8_t *buf, int buf_size, int keyframe);
3915 void av_parser_close(AVCodecParserContext *s);
3923 * @addtogroup lavc_encoding
3928 * Find a registered encoder with a matching codec ID.
3930 * @param id AVCodecID of the requested encoder
3931 * @return An encoder if one was found, NULL otherwise.
3933 AVCodec *avcodec_find_encoder(enum AVCodecID id);
3936 * Find a registered encoder with the specified name.
3938 * @param name name of the requested encoder
3939 * @return An encoder if one was found, NULL otherwise.
3941 AVCodec *avcodec_find_encoder_by_name(const char *name);
3943 #if FF_API_OLD_ENCODE_AUDIO
3945 * Encode an audio frame from samples into buf.
3947 * @deprecated Use avcodec_encode_audio2 instead.
3949 * @note The output buffer should be at least FF_MIN_BUFFER_SIZE bytes large.
3950 * However, for codecs with avctx->frame_size equal to 0 (e.g. PCM) the user
3951 * will know how much space is needed because it depends on the value passed
3952 * in buf_size as described below. In that case a lower value can be used.
3954 * @param avctx the codec context
3955 * @param[out] buf the output buffer
3956 * @param[in] buf_size the output buffer size
3957 * @param[in] samples the input buffer containing the samples
3958 * The number of samples read from this buffer is frame_size*channels,
3959 * both of which are defined in avctx.
3960 * For codecs which have avctx->frame_size equal to 0 (e.g. PCM) the number of
3961 * samples read from samples is equal to:
3962 * buf_size * 8 / (avctx->channels * av_get_bits_per_sample(avctx->codec_id))
3963 * This also implies that av_get_bits_per_sample() must not return 0 for these
3965 * @return On error a negative value is returned, on success zero or the number
3966 * of bytes used to encode the data read from the input buffer.
3968 int attribute_deprecated avcodec_encode_audio(AVCodecContext *avctx,
3969 uint8_t *buf, int buf_size,
3970 const short *samples);
3974 * Encode a frame of audio.
3976 * Takes input samples from frame and writes the next output packet, if
3977 * available, to avpkt. The output packet does not necessarily contain data for
3978 * the most recent frame, as encoders can delay, split, and combine input frames
3979 * internally as needed.
3981 * @param avctx codec context
3982 * @param avpkt output AVPacket.
3983 * The user can supply an output buffer by setting
3984 * avpkt->data and avpkt->size prior to calling the
3985 * function, but if the size of the user-provided data is not
3986 * large enough, encoding will fail. All other AVPacket fields
3987 * will be reset by the encoder using av_init_packet(). If
3988 * avpkt->data is NULL, the encoder will allocate it.
3989 * The encoder will set avpkt->size to the size of the
3992 * If this function fails or produces no output, avpkt will be
3993 * freed using av_free_packet() (i.e. avpkt->destruct will be
3994 * called to free the user supplied buffer).
3995 * @param[in] frame AVFrame containing the raw audio data to be encoded.
3996 * May be NULL when flushing an encoder that has the
3997 * CODEC_CAP_DELAY capability set.
3998 * If CODEC_CAP_VARIABLE_FRAME_SIZE is set, then each frame
3999 * can have any number of samples.
4000 * If it is not set, frame->nb_samples must be equal to
4001 * avctx->frame_size for all frames except the last.
4002 * The final frame may be smaller than avctx->frame_size.
4003 * @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
4004 * output packet is non-empty, and to 0 if it is
4005 * empty. If the function returns an error, the
4006 * packet can be assumed to be invalid, and the
4007 * value of got_packet_ptr is undefined and should
4009 * @return 0 on success, negative error code on failure
4011 int avcodec_encode_audio2(AVCodecContext *avctx, AVPacket *avpkt,
4012 const AVFrame *frame, int *got_packet_ptr);
4014 #if FF_API_OLD_ENCODE_VIDEO
4016 * @deprecated use avcodec_encode_video2() instead.
4018 * Encode a video frame from pict into buf.
4019 * The input picture should be
4020 * stored using a specific format, namely avctx.pix_fmt.
4022 * @param avctx the codec context
4023 * @param[out] buf the output buffer for the bitstream of encoded frame
4024 * @param[in] buf_size the size of the output buffer in bytes
4025 * @param[in] pict the input picture to encode
4026 * @return On error a negative value is returned, on success zero or the number
4027 * of bytes used from the output buffer.
4029 attribute_deprecated
4030 int avcodec_encode_video(AVCodecContext *avctx, uint8_t *buf, int buf_size,
4031 const AVFrame *pict);
4035 * Encode a frame of video.
4037 * Takes input raw video data from frame and writes the next output packet, if
4038 * available, to avpkt. The output packet does not necessarily contain data for
4039 * the most recent frame, as encoders can delay and reorder input frames
4040 * internally as needed.
4042 * @param avctx codec context
4043 * @param avpkt output AVPacket.
4044 * The user can supply an output buffer by setting
4045 * avpkt->data and avpkt->size prior to calling the
4046 * function, but if the size of the user-provided data is not
4047 * large enough, encoding will fail. All other AVPacket fields
4048 * will be reset by the encoder using av_init_packet(). If
4049 * avpkt->data is NULL, the encoder will allocate it.
4050 * The encoder will set avpkt->size to the size of the
4051 * output packet. The returned data (if any) belongs to the
4052 * caller, he is responsible for freeing it.
4054 * If this function fails or produces no output, avpkt will be
4055 * freed using av_free_packet() (i.e. avpkt->destruct will be
4056 * called to free the user supplied buffer).
4057 * @param[in] frame AVFrame containing the raw video data to be encoded.
4058 * May be NULL when flushing an encoder that has the
4059 * CODEC_CAP_DELAY capability set.
4060 * @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
4061 * output packet is non-empty, and to 0 if it is
4062 * empty. If the function returns an error, the
4063 * packet can be assumed to be invalid, and the
4064 * value of got_packet_ptr is undefined and should
4066 * @return 0 on success, negative error code on failure
4068 int avcodec_encode_video2(AVCodecContext *avctx, AVPacket *avpkt,
4069 const AVFrame *frame, int *got_packet_ptr);
4071 int avcodec_encode_subtitle(AVCodecContext *avctx, uint8_t *buf, int buf_size,
4072 const AVSubtitle *sub);
4079 #if FF_API_AVCODEC_RESAMPLE
4081 * @defgroup lavc_resample Audio resampling
4083 * @deprecated use libavresample instead
4087 struct ReSampleContext;
4088 struct AVResampleContext;
4090 typedef struct ReSampleContext ReSampleContext;
4093 * Initialize audio resampling context.
4095 * @param output_channels number of output channels
4096 * @param input_channels number of input channels
4097 * @param output_rate output sample rate
4098 * @param input_rate input sample rate
4099 * @param sample_fmt_out requested output sample format
4100 * @param sample_fmt_in input sample format
4101 * @param filter_length length of each FIR filter in the filterbank relative to the cutoff frequency
4102 * @param log2_phase_count log2 of the number of entries in the polyphase filterbank
4103 * @param linear if 1 then the used FIR filter will be linearly interpolated
4104 between the 2 closest, if 0 the closest will be used
4105 * @param cutoff cutoff frequency, 1.0 corresponds to half the output sampling rate
4106 * @return allocated ReSampleContext, NULL if error occurred
4108 attribute_deprecated
4109 ReSampleContext *av_audio_resample_init(int output_channels, int input_channels,
4110 int output_rate, int input_rate,
4111 enum AVSampleFormat sample_fmt_out,
4112 enum AVSampleFormat sample_fmt_in,
4113 int filter_length, int log2_phase_count,
4114 int linear, double cutoff);
4116 attribute_deprecated
4117 int audio_resample(ReSampleContext *s, short *output, short *input, int nb_samples);
4120 * Free resample context.
4122 * @param s a non-NULL pointer to a resample context previously
4123 * created with av_audio_resample_init()
4125 attribute_deprecated
4126 void audio_resample_close(ReSampleContext *s);
4130 * Initialize an audio resampler.
4131 * Note, if either rate is not an integer then simply scale both rates up so they are.
4132 * @param filter_length length of each FIR filter in the filterbank relative to the cutoff freq
4133 * @param log2_phase_count log2 of the number of entries in the polyphase filterbank
4134 * @param linear If 1 then the used FIR filter will be linearly interpolated
4135 between the 2 closest, if 0 the closest will be used
4136 * @param cutoff cutoff frequency, 1.0 corresponds to half the output sampling rate
4138 attribute_deprecated
4139 struct AVResampleContext *av_resample_init(int out_rate, int in_rate, int filter_length, int log2_phase_count, int linear, double cutoff);
4142 * Resample an array of samples using a previously configured context.
4143 * @param src an array of unconsumed samples
4144 * @param consumed the number of samples of src which have been consumed are returned here
4145 * @param src_size the number of unconsumed samples available
4146 * @param dst_size the amount of space in samples available in dst
4147 * @param update_ctx If this is 0 then the context will not be modified, that way several channels can be resampled with the same context.
4148 * @return the number of samples written in dst or -1 if an error occurred
4150 attribute_deprecated
4151 int av_resample(struct AVResampleContext *c, short *dst, short *src, int *consumed, int src_size, int dst_size, int update_ctx);
4155 * Compensate samplerate/timestamp drift. The compensation is done by changing
4156 * the resampler parameters, so no audible clicks or similar distortions occur
4157 * @param compensation_distance distance in output samples over which the compensation should be performed
4158 * @param sample_delta number of output samples which should be output less
4160 * example: av_resample_compensate(c, 10, 500)
4161 * here instead of 510 samples only 500 samples would be output
4163 * note, due to rounding the actual compensation might be slightly different,
4164 * especially if the compensation_distance is large and the in_rate used during init is small
4166 attribute_deprecated
4167 void av_resample_compensate(struct AVResampleContext *c, int sample_delta, int compensation_distance);
4168 attribute_deprecated
4169 void av_resample_close(struct AVResampleContext *c);
4177 * @addtogroup lavc_picture
4182 * Allocate memory for a picture. Call avpicture_free() to free it.
4184 * @see avpicture_fill()
4186 * @param picture the picture to be filled in
4187 * @param pix_fmt the format of the picture
4188 * @param width the width of the picture
4189 * @param height the height of the picture
4190 * @return zero if successful, a negative value if not
4192 int avpicture_alloc(AVPicture *picture, enum AVPixelFormat pix_fmt, int width, int height);
4195 * Free a picture previously allocated by avpicture_alloc().
4196 * The data buffer used by the AVPicture is freed, but the AVPicture structure
4199 * @param picture the AVPicture to be freed
4201 void avpicture_free(AVPicture *picture);
4204 * Fill in the AVPicture fields.
4205 * The fields of the given AVPicture are filled in by using the 'ptr' address
4206 * which points to the image data buffer. Depending on the specified picture
4207 * format, one or multiple image data pointers and line sizes will be set.
4208 * If a planar format is specified, several pointers will be set pointing to
4209 * the different picture planes and the line sizes of the different planes
4210 * will be stored in the lines_sizes array.
4211 * Call with ptr == NULL to get the required size for the ptr buffer.
4213 * To allocate the buffer and fill in the AVPicture fields in one call,
4214 * use avpicture_alloc().
4216 * @param picture AVPicture whose fields are to be filled in
4217 * @param ptr Buffer which will contain or contains the actual image data
4218 * @param pix_fmt The format in which the picture data is stored.
4219 * @param width the width of the image in pixels
4220 * @param height the height of the image in pixels
4221 * @return size of the image data in bytes
4223 int avpicture_fill(AVPicture *picture, uint8_t *ptr,
4224 enum AVPixelFormat pix_fmt, int width, int height);
4227 * Copy pixel data from an AVPicture into a buffer.
4228 * The data is stored compactly, without any gaps for alignment or padding
4229 * which may be applied by avpicture_fill().
4231 * @see avpicture_get_size()
4233 * @param[in] src AVPicture containing image data
4234 * @param[in] pix_fmt The format in which the picture data is stored.
4235 * @param[in] width the width of the image in pixels.
4236 * @param[in] height the height of the image in pixels.
4237 * @param[out] dest A buffer into which picture data will be copied.
4238 * @param[in] dest_size The size of 'dest'.
4239 * @return The number of bytes written to dest, or a negative value (error code) on error.
4241 int avpicture_layout(const AVPicture* src, enum AVPixelFormat pix_fmt,
4242 int width, int height,
4243 unsigned char *dest, int dest_size);
4246 * Calculate the size in bytes that a picture of the given width and height
4247 * would occupy if stored in the given picture format.
4248 * Note that this returns the size of a compact representation as generated
4249 * by avpicture_layout(), which can be smaller than the size required for e.g.
4252 * @param pix_fmt the given picture format
4253 * @param width the width of the image
4254 * @param height the height of the image
4255 * @return Image data size in bytes or -1 on error (e.g. too large dimensions).
4257 int avpicture_get_size(enum AVPixelFormat pix_fmt, int width, int height);
4260 * deinterlace - if not supported return -1
4262 int avpicture_deinterlace(AVPicture *dst, const AVPicture *src,
4263 enum AVPixelFormat pix_fmt, int width, int height);
4265 * Copy image src to dst. Wraps av_picture_data_copy() above.
4267 void av_picture_copy(AVPicture *dst, const AVPicture *src,
4268 enum AVPixelFormat pix_fmt, int width, int height);
4271 * Crop image top and left side.
4273 int av_picture_crop(AVPicture *dst, const AVPicture *src,
4274 enum AVPixelFormat pix_fmt, int top_band, int left_band);
4279 int av_picture_pad(AVPicture *dst, const AVPicture *src, int height, int width, enum AVPixelFormat pix_fmt,
4280 int padtop, int padbottom, int padleft, int padright, int *color);
4287 * @defgroup lavc_misc Utility functions
4290 * Miscellaneous utility functions related to both encoding and decoding
4296 * @defgroup lavc_misc_pixfmt Pixel formats
4298 * Functions for working with pixel formats.
4303 * @deprecated Use av_pix_fmt_get_chroma_sub_sample
4306 void attribute_deprecated avcodec_get_chroma_sub_sample(enum AVPixelFormat pix_fmt, int *h_shift, int *v_shift);
4309 * Return a value representing the fourCC code associated to the
4310 * pixel format pix_fmt, or 0 if no associated fourCC code can be
4313 unsigned int avcodec_pix_fmt_to_codec_tag(enum AVPixelFormat pix_fmt);
4315 #define FF_LOSS_RESOLUTION 0x0001 /**< loss due to resolution change */
4316 #define FF_LOSS_DEPTH 0x0002 /**< loss due to color depth change */
4317 #define FF_LOSS_COLORSPACE 0x0004 /**< loss due to color space conversion */
4318 #define FF_LOSS_ALPHA 0x0008 /**< loss of alpha bits */
4319 #define FF_LOSS_COLORQUANT 0x0010 /**< loss due to color quantization */
4320 #define FF_LOSS_CHROMA 0x0020 /**< loss of chroma (e.g. RGB to gray conversion) */
4323 * Compute what kind of losses will occur when converting from one specific
4324 * pixel format to another.
4325 * When converting from one pixel format to another, information loss may occur.
4326 * For example, when converting from RGB24 to GRAY, the color information will
4327 * be lost. Similarly, other losses occur when converting from some formats to
4328 * other formats. These losses can involve loss of chroma, but also loss of
4329 * resolution, loss of color depth, loss due to the color space conversion, loss
4330 * of the alpha bits or loss due to color quantization.
4331 * avcodec_get_fix_fmt_loss() informs you about the various types of losses
4332 * which will occur when converting from one pixel format to another.
4334 * @param[in] dst_pix_fmt destination pixel format
4335 * @param[in] src_pix_fmt source pixel format
4336 * @param[in] has_alpha Whether the source pixel format alpha channel is used.
4337 * @return Combination of flags informing you what kind of losses will occur.
4339 int avcodec_get_pix_fmt_loss(enum AVPixelFormat dst_pix_fmt, enum AVPixelFormat src_pix_fmt,
4342 #if FF_API_FIND_BEST_PIX_FMT
4344 * @deprecated use avcodec_find_best_pix_fmt2() instead.
4346 * Find the best pixel format to convert to given a certain source pixel
4347 * format. When converting from one pixel format to another, information loss
4348 * may occur. For example, when converting from RGB24 to GRAY, the color
4349 * information will be lost. Similarly, other losses occur when converting from
4350 * some formats to other formats. avcodec_find_best_pix_fmt() searches which of
4351 * the given pixel formats should be used to suffer the least amount of loss.
4352 * The pixel formats from which it chooses one, are determined by the
4353 * pix_fmt_mask parameter.
4356 * src_pix_fmt = AV_PIX_FMT_YUV420P;
4357 * pix_fmt_mask = (1 << AV_PIX_FMT_YUV422P) || (1 << AV_PIX_FMT_RGB24);
4358 * dst_pix_fmt = avcodec_find_best_pix_fmt(pix_fmt_mask, src_pix_fmt, alpha, &loss);
4361 * @param[in] pix_fmt_mask bitmask determining which pixel format to choose from
4362 * @param[in] src_pix_fmt source pixel format
4363 * @param[in] has_alpha Whether the source pixel format alpha channel is used.
4364 * @param[out] loss_ptr Combination of flags informing you what kind of losses will occur.
4365 * @return The best pixel format to convert to or -1 if none was found.
4367 attribute_deprecated
4368 enum AVPixelFormat avcodec_find_best_pix_fmt(int64_t pix_fmt_mask, enum AVPixelFormat src_pix_fmt,
4369 int has_alpha, int *loss_ptr);
4370 #endif /* FF_API_FIND_BEST_PIX_FMT */
4373 * Find the best pixel format to convert to given a certain source pixel
4374 * format. When converting from one pixel format to another, information loss
4375 * may occur. For example, when converting from RGB24 to GRAY, the color
4376 * information will be lost. Similarly, other losses occur when converting from
4377 * some formats to other formats. avcodec_find_best_pix_fmt2() searches which of
4378 * the given pixel formats should be used to suffer the least amount of loss.
4379 * The pixel formats from which it chooses one, are determined by the
4380 * pix_fmt_list parameter.
4383 * @param[in] pix_fmt_list AV_PIX_FMT_NONE terminated array of pixel formats to choose from
4384 * @param[in] src_pix_fmt source pixel format
4385 * @param[in] has_alpha Whether the source pixel format alpha channel is used.
4386 * @param[out] loss_ptr Combination of flags informing you what kind of losses will occur.
4387 * @return The best pixel format to convert to or -1 if none was found.
4389 enum AVPixelFormat avcodec_find_best_pix_fmt2(enum AVPixelFormat *pix_fmt_list,
4390 enum AVPixelFormat src_pix_fmt,
4391 int has_alpha, int *loss_ptr);
4393 enum AVPixelFormat avcodec_default_get_format(struct AVCodecContext *s, const enum AVPixelFormat * fmt);
4399 void avcodec_set_dimensions(AVCodecContext *s, int width, int height);
4402 * Put a string representing the codec tag codec_tag in buf.
4404 * @param buf_size size in bytes of buf
4405 * @return the length of the string that would have been generated if
4406 * enough space had been available, excluding the trailing null
4408 size_t av_get_codec_tag_string(char *buf, size_t buf_size, unsigned int codec_tag);
4410 void avcodec_string(char *buf, int buf_size, AVCodecContext *enc, int encode);
4413 * Return a name for the specified profile, if available.
4415 * @param codec the codec that is searched for the given profile
4416 * @param profile the profile value for which a name is requested
4417 * @return A name for the profile if found, NULL otherwise.
4419 const char *av_get_profile_name(const AVCodec *codec, int profile);
4421 int avcodec_default_execute(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2),void *arg, int *ret, int count, int size);
4422 int avcodec_default_execute2(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2, int, int),void *arg, int *ret, int count);
4423 //FIXME func typedef
4426 * Fill audio frame data and linesize.
4427 * AVFrame extended_data channel pointers are allocated if necessary for
4430 * @param frame the AVFrame
4431 * frame->nb_samples must be set prior to calling the
4432 * function. This function fills in frame->data,
4433 * frame->extended_data, frame->linesize[0].
4434 * @param nb_channels channel count
4435 * @param sample_fmt sample format
4436 * @param buf buffer to use for frame data
4437 * @param buf_size size of buffer
4438 * @param align plane size sample alignment (0 = default)
4439 * @return 0 on success, negative error code on failure
4441 int avcodec_fill_audio_frame(AVFrame *frame, int nb_channels,
4442 enum AVSampleFormat sample_fmt, const uint8_t *buf,
4443 int buf_size, int align);
4446 * Flush buffers, should be called when seeking or when switching to a different stream.
4448 void avcodec_flush_buffers(AVCodecContext *avctx);
4450 void avcodec_default_free_buffers(AVCodecContext *s);
4453 * Return codec bits per sample.
4455 * @param[in] codec_id the codec
4456 * @return Number of bits per sample or zero if unknown for the given codec.
4458 int av_get_bits_per_sample(enum AVCodecID codec_id);
4461 * Return codec bits per sample.
4462 * Only return non-zero if the bits per sample is exactly correct, not an
4465 * @param[in] codec_id the codec
4466 * @return Number of bits per sample or zero if unknown for the given codec.
4468 int av_get_exact_bits_per_sample(enum AVCodecID codec_id);
4471 * Return audio frame duration.
4473 * @param avctx codec context
4474 * @param frame_bytes size of the frame, or 0 if unknown
4475 * @return frame duration, in samples, if known. 0 if not able to
4478 int av_get_audio_frame_duration(AVCodecContext *avctx, int frame_bytes);
4481 typedef struct AVBitStreamFilterContext {
4483 struct AVBitStreamFilter *filter;
4484 AVCodecParserContext *parser;
4485 struct AVBitStreamFilterContext *next;
4486 } AVBitStreamFilterContext;
4489 typedef struct AVBitStreamFilter {
4492 int (*filter)(AVBitStreamFilterContext *bsfc,
4493 AVCodecContext *avctx, const char *args,
4494 uint8_t **poutbuf, int *poutbuf_size,
4495 const uint8_t *buf, int buf_size, int keyframe);
4496 void (*close)(AVBitStreamFilterContext *bsfc);
4497 struct AVBitStreamFilter *next;
4498 } AVBitStreamFilter;
4500 void av_register_bitstream_filter(AVBitStreamFilter *bsf);
4501 AVBitStreamFilterContext *av_bitstream_filter_init(const char *name);
4502 int av_bitstream_filter_filter(AVBitStreamFilterContext *bsfc,
4503 AVCodecContext *avctx, const char *args,
4504 uint8_t **poutbuf, int *poutbuf_size,
4505 const uint8_t *buf, int buf_size, int keyframe);
4506 void av_bitstream_filter_close(AVBitStreamFilterContext *bsf);
4508 AVBitStreamFilter *av_bitstream_filter_next(AVBitStreamFilter *f);
4513 * Reallocate the given block if it is not large enough, otherwise do nothing.
4517 void *av_fast_realloc(void *ptr, unsigned int *size, size_t min_size);
4520 * Allocate a buffer, reusing the given one if large enough.
4522 * Contrary to av_fast_realloc the current buffer contents might not be
4523 * preserved and on error the old buffer is freed, thus no special
4524 * handling to avoid memleaks is necessary.
4526 * @param ptr pointer to pointer to already allocated buffer, overwritten with pointer to new buffer
4527 * @param size size of the buffer *ptr points to
4528 * @param min_size minimum size of *ptr buffer after returning, *ptr will be NULL and
4529 * *size 0 if an error occurred.
4531 void av_fast_malloc(void *ptr, unsigned int *size, size_t min_size);
4534 * Allocate a buffer with padding, reusing the given one if large enough.
4536 * Same behaviour av_fast_malloc but the buffer has additional
4537 * FF_INPUT_PADDING_SIZE at the end which will always memset to 0.
4540 void av_fast_padded_malloc(void *ptr, unsigned int *size, size_t min_size);
4543 * Encode extradata length to a buffer. Used by xiph codecs.
4545 * @param s buffer to write to; must be at least (v/255+1) bytes long
4546 * @param v size of extradata in bytes
4547 * @return number of bytes written to the buffer.
4549 unsigned int av_xiphlacing(unsigned char *s, unsigned int v);
4552 * Log a generic warning message about a missing feature. This function is
4553 * intended to be used internally by Libav (libavcodec, libavformat, etc.)
4554 * only, and would normally not be used by applications.
4555 * @param[in] avc a pointer to an arbitrary struct of which the first field is
4556 * a pointer to an AVClass struct
4557 * @param[in] feature string containing the name of the missing feature
4558 * @param[in] want_sample indicates if samples are wanted which exhibit this feature.
4559 * If want_sample is non-zero, additional verbage will be added to the log
4560 * message which tells the user how to report samples to the development
4563 void av_log_missing_feature(void *avc, const char *feature, int want_sample);
4566 * Log a generic warning message asking for a sample. This function is
4567 * intended to be used internally by Libav (libavcodec, libavformat, etc.)
4568 * only, and would normally not be used by applications.
4569 * @param[in] avc a pointer to an arbitrary struct of which the first field is
4570 * a pointer to an AVClass struct
4571 * @param[in] msg string containing an optional message, or NULL if no message
4573 void av_log_ask_for_sample(void *avc, const char *msg, ...) av_printf_format(2, 3);
4576 * Register the hardware accelerator hwaccel.
4578 void av_register_hwaccel(AVHWAccel *hwaccel);
4581 * If hwaccel is NULL, returns the first registered hardware accelerator,
4582 * if hwaccel is non-NULL, returns the next registered hardware accelerator
4583 * after hwaccel, or NULL if hwaccel is the last one.
4585 AVHWAccel *av_hwaccel_next(AVHWAccel *hwaccel);
4589 * Lock operation used by lockmgr
4592 AV_LOCK_CREATE, ///< Create a mutex
4593 AV_LOCK_OBTAIN, ///< Lock the mutex
4594 AV_LOCK_RELEASE, ///< Unlock the mutex
4595 AV_LOCK_DESTROY, ///< Free mutex resources
4599 * Register a user provided lock manager supporting the operations
4600 * specified by AVLockOp. mutex points to a (void *) where the
4601 * lockmgr should store/get a pointer to a user allocated mutex. It's
4602 * NULL upon AV_LOCK_CREATE and != NULL for all other ops.
4604 * @param cb User defined callback. Note: Libav may invoke calls to this
4605 * callback during the call to av_lockmgr_register().
4606 * Thus, the application must be prepared to handle that.
4607 * If cb is set to NULL the lockmgr will be unregistered.
4608 * Also note that during unregistration the previously registered
4609 * lockmgr callback may also be invoked.
4611 int av_lockmgr_register(int (*cb)(void **mutex, enum AVLockOp op));
4614 * Get the type of the given codec.
4616 enum AVMediaType avcodec_get_type(enum AVCodecID codec_id);
4619 * @return a positive value if s is open (i.e. avcodec_open2() was called on it
4620 * with no corresponding avcodec_close()), 0 otherwise.
4622 int avcodec_is_open(AVCodecContext *s);
4625 * @return a non-zero number if codec is an encoder, zero otherwise
4627 int av_codec_is_encoder(const AVCodec *codec);
4630 * @return a non-zero number if codec is a decoder, zero otherwise
4632 int av_codec_is_decoder(const AVCodec *codec);
4635 * @return descriptor for given codec ID or NULL if no descriptor exists.
4637 const AVCodecDescriptor *avcodec_descriptor_get(enum AVCodecID id);
4640 * Iterate over all codec descriptors known to libavcodec.
4642 * @param prev previous descriptor. NULL to get the first descriptor.
4644 * @return next descriptor or NULL after the last descriptor
4646 const AVCodecDescriptor *avcodec_descriptor_next(const AVCodecDescriptor *prev);
4649 * @return codec descriptor with the given name or NULL if no such descriptor
4652 const AVCodecDescriptor *avcodec_descriptor_get_by_name(const char *name);
4658 #endif /* AVCODEC_AVCODEC_H */