2 * copyright (c) 2001 Fabrice Bellard
4 * This file is part of FFmpeg.
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 #ifndef AVCODEC_AVCODEC_H
22 #define AVCODEC_AVCODEC_H
25 * @file libavcodec/avcodec.h
30 #include "libavutil/avutil.h"
32 #define LIBAVCODEC_VERSION_MAJOR 52
33 #define LIBAVCODEC_VERSION_MINOR 41
34 #define LIBAVCODEC_VERSION_MICRO 0
36 #define LIBAVCODEC_VERSION_INT AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
37 LIBAVCODEC_VERSION_MINOR, \
38 LIBAVCODEC_VERSION_MICRO)
39 #define LIBAVCODEC_VERSION AV_VERSION(LIBAVCODEC_VERSION_MAJOR, \
40 LIBAVCODEC_VERSION_MINOR, \
41 LIBAVCODEC_VERSION_MICRO)
42 #define LIBAVCODEC_BUILD LIBAVCODEC_VERSION_INT
44 #define LIBAVCODEC_IDENT "Lavc" AV_STRINGIFY(LIBAVCODEC_VERSION)
46 #define AV_NOPTS_VALUE INT64_C(0x8000000000000000)
47 #define AV_TIME_BASE 1000000
48 #define AV_TIME_BASE_Q (AVRational){1, AV_TIME_BASE}
51 * Identifies the syntax and semantics of the bitstream.
52 * The principle is roughly:
53 * Two decoders with the same ID can decode the same streams.
54 * Two encoders with the same ID can encode compatible streams.
55 * There may be slight deviations from the principle due to implementation
58 * If you add a codec ID to this list, add it so that
59 * 1. no value of a existing codec ID changes (that would break ABI),
60 * 2. it is as close as possible to similar codecs.
67 CODEC_ID_MPEG2VIDEO
, ///< preferred ID for MPEG-1/2 video decoding
68 CODEC_ID_MPEG2VIDEO_XVMC
,
105 CODEC_ID_INTERPLAY_VIDEO
,
117 CODEC_ID_TRUEMOTION1
,
145 CODEC_ID_TRUEMOTION2
,
162 CODEC_ID_DSICINVIDEO
,
163 CODEC_ID_TIERTEXSEQVIDEO
,
172 CODEC_ID_BETHSOFTVID
,
190 CODEC_ID_MOTIONPIXELS
,
203 /* various PCM "codecs" */
204 CODEC_ID_PCM_S16LE
= 0x10000,
220 CODEC_ID_PCM_S24DAUD
,
222 CODEC_ID_PCM_S16LE_PLANAR
,
230 /* various ADPCM codecs */
231 CODEC_ID_ADPCM_IMA_QT
= 0x11000,
232 CODEC_ID_ADPCM_IMA_WAV
,
233 CODEC_ID_ADPCM_IMA_DK3
,
234 CODEC_ID_ADPCM_IMA_DK4
,
235 CODEC_ID_ADPCM_IMA_WS
,
236 CODEC_ID_ADPCM_IMA_SMJPEG
,
245 CODEC_ID_ADPCM_YAMAHA
,
246 CODEC_ID_ADPCM_SBPRO_4
,
247 CODEC_ID_ADPCM_SBPRO_3
,
248 CODEC_ID_ADPCM_SBPRO_2
,
250 CODEC_ID_ADPCM_IMA_AMV
,
251 CODEC_ID_ADPCM_EA_R1
,
252 CODEC_ID_ADPCM_EA_R3
,
253 CODEC_ID_ADPCM_EA_R2
,
254 CODEC_ID_ADPCM_IMA_EA_SEAD
,
255 CODEC_ID_ADPCM_IMA_EA_EACS
,
256 CODEC_ID_ADPCM_EA_XAS
,
257 CODEC_ID_ADPCM_EA_MAXIS_XA
,
258 CODEC_ID_ADPCM_IMA_ISS
,
261 CODEC_ID_AMR_NB
= 0x12000,
264 /* RealAudio codecs*/
265 CODEC_ID_RA_144
= 0x13000,
268 /* various DPCM codecs */
269 CODEC_ID_ROQ_DPCM
= 0x14000,
270 CODEC_ID_INTERPLAY_DPCM
,
275 CODEC_ID_MP2
= 0x15000,
276 CODEC_ID_MP3
, ///< preferred ID for decoding MPEG audio layer 1, 2 or 3
294 CODEC_ID_WESTWOOD_SND1
,
295 CODEC_ID_GSM
, ///< as in Berlin toast format
303 CODEC_ID_DSICINAUDIO
,
307 CODEC_ID_GSM_MS
, /* as found in WAV */
316 CODEC_ID_WMALOSSLESS
,
326 /* subtitle codecs */
327 CODEC_ID_DVD_SUBTITLE
= 0x17000,
328 CODEC_ID_DVB_SUBTITLE
,
329 CODEC_ID_TEXT
, ///< raw UTF-8 text
333 CODEC_ID_HDMV_PGS_SUBTITLE
,
334 CODEC_ID_DVB_TELETEXT
,
336 /* other specific kind of codecs (generally used for attachments) */
337 CODEC_ID_TTF
= 0x18000,
339 CODEC_ID_PROBE
= 0x19000, ///< codec_id is not known (like CODEC_ID_NONE) but lavf should attempt to identify it
341 CODEC_ID_MPEG2TS
= 0x20000, /**< _FAKE_ codec to indicate a raw MPEG-2 TS
342 * stream (only used by libavformat) */
346 CODEC_TYPE_UNKNOWN
= -1,
351 CODEC_TYPE_ATTACHMENT
,
356 * all in native-endian format
359 SAMPLE_FMT_NONE
= -1,
360 SAMPLE_FMT_U8
, ///< unsigned 8 bits
361 SAMPLE_FMT_S16
, ///< signed 16 bits
362 SAMPLE_FMT_S32
, ///< signed 32 bits
363 SAMPLE_FMT_FLT
, ///< float
364 SAMPLE_FMT_DBL
, ///< double
365 SAMPLE_FMT_NB
///< Number of sample formats. DO NOT USE if dynamically linking to libavcodec
368 /* Audio channel masks */
369 #define CH_FRONT_LEFT 0x00000001
370 #define CH_FRONT_RIGHT 0x00000002
371 #define CH_FRONT_CENTER 0x00000004
372 #define CH_LOW_FREQUENCY 0x00000008
373 #define CH_BACK_LEFT 0x00000010
374 #define CH_BACK_RIGHT 0x00000020
375 #define CH_FRONT_LEFT_OF_CENTER 0x00000040
376 #define CH_FRONT_RIGHT_OF_CENTER 0x00000080
377 #define CH_BACK_CENTER 0x00000100
378 #define CH_SIDE_LEFT 0x00000200
379 #define CH_SIDE_RIGHT 0x00000400
380 #define CH_TOP_CENTER 0x00000800
381 #define CH_TOP_FRONT_LEFT 0x00001000
382 #define CH_TOP_FRONT_CENTER 0x00002000
383 #define CH_TOP_FRONT_RIGHT 0x00004000
384 #define CH_TOP_BACK_LEFT 0x00008000
385 #define CH_TOP_BACK_CENTER 0x00010000
386 #define CH_TOP_BACK_RIGHT 0x00020000
387 #define CH_STEREO_LEFT 0x20000000 ///< Stereo downmix.
388 #define CH_STEREO_RIGHT 0x40000000 ///< See CH_STEREO_LEFT.
390 /** Channel mask value used for AVCodecContext.request_channel_layout
391 to indicate that the user requests the channel order of the decoder output
392 to be the native codec channel order. */
393 #define CH_LAYOUT_NATIVE 0x8000000000000000LL
395 /* Audio channel convenience macros */
396 #define CH_LAYOUT_MONO (CH_FRONT_CENTER)
397 #define CH_LAYOUT_STEREO (CH_FRONT_LEFT|CH_FRONT_RIGHT)
398 #define CH_LAYOUT_2_1 (CH_LAYOUT_STEREO|CH_BACK_CENTER)
399 #define CH_LAYOUT_SURROUND (CH_LAYOUT_STEREO|CH_FRONT_CENTER)
400 #define CH_LAYOUT_4POINT0 (CH_LAYOUT_SURROUND|CH_BACK_CENTER)
401 #define CH_LAYOUT_2_2 (CH_LAYOUT_STEREO|CH_SIDE_LEFT|CH_SIDE_RIGHT)
402 #define CH_LAYOUT_QUAD (CH_LAYOUT_STEREO|CH_BACK_LEFT|CH_BACK_RIGHT)
403 #define CH_LAYOUT_5POINT0 (CH_LAYOUT_SURROUND|CH_SIDE_LEFT|CH_SIDE_RIGHT)
404 #define CH_LAYOUT_5POINT1 (CH_LAYOUT_5POINT0|CH_LOW_FREQUENCY)
405 #define CH_LAYOUT_5POINT0_BACK (CH_LAYOUT_SURROUND|CH_BACK_LEFT|CH_BACK_RIGHT)
406 #define CH_LAYOUT_5POINT1_BACK (CH_LAYOUT_5POINT0_BACK|CH_LOW_FREQUENCY)
407 #define CH_LAYOUT_7POINT0 (CH_LAYOUT_5POINT0|CH_BACK_LEFT|CH_BACK_RIGHT)
408 #define CH_LAYOUT_7POINT1 (CH_LAYOUT_5POINT1|CH_BACK_LEFT|CH_BACK_RIGHT)
409 #define CH_LAYOUT_7POINT1_WIDE (CH_LAYOUT_5POINT1_BACK|\
410 CH_FRONT_LEFT_OF_CENTER|CH_FRONT_RIGHT_OF_CENTER)
411 #define CH_LAYOUT_STEREO_DOWNMIX (CH_STEREO_LEFT|CH_STEREO_RIGHT)
414 #define AVCODEC_MAX_AUDIO_FRAME_SIZE 192000 // 1 second of 48khz 32bit audio
417 * Required number of additionally allocated bytes at the end of the input bitstream for decoding.
418 * This is mainly needed because some optimized bitstream readers read
419 * 32 or 64 bit at once and could read over the end.<br>
420 * Note: If the first 23 bits of the additional bytes are not 0, then damaged
421 * MPEG bitstreams could cause overread and segfault.
423 #define FF_INPUT_BUFFER_PADDING_SIZE 8
426 * minimum encoding buffer size
427 * Used to avoid some checks during header writing.
429 #define FF_MIN_BUFFER_SIZE 16384
433 * motion estimation type.
436 ME_ZERO
= 1, ///< no search, that is use 0,0 vector whenever one is needed
440 ME_EPZS
, ///< enhanced predictive zonal search
441 ME_X1
, ///< reserved for experiments
442 ME_HEX
, ///< hexagon based search
443 ME_UMH
, ///< uneven multi-hexagon search
444 ME_ITER
, ///< iterative search
445 ME_TESA
, ///< transformed exhaustive search algorithm
449 /* We leave some space between them for extensions (drop some
450 * keyframes for intra-only or drop just some bidir frames). */
451 AVDISCARD_NONE
=-16, ///< discard nothing
452 AVDISCARD_DEFAULT
= 0, ///< discard useless packets like 0 size packets in avi
453 AVDISCARD_NONREF
= 8, ///< discard all non reference
454 AVDISCARD_BIDIR
= 16, ///< discard all bidirectional frames
455 AVDISCARD_NONKEY
= 32, ///< discard all frames except keyframes
456 AVDISCARD_ALL
= 48, ///< discard all
459 enum AVColorPrimaries
{
460 AVCOL_PRI_BT709
=1, ///< also ITU-R BT1361 / IEC 61966-2-4 / SMPTE RP177 Annex B
461 AVCOL_PRI_UNSPECIFIED
=2,
463 AVCOL_PRI_BT470BG
=5, ///< also ITU-R BT601-6 625 / ITU-R BT1358 625 / ITU-R BT1700 625 PAL & SECAM
464 AVCOL_PRI_SMPTE170M
=6, ///< also ITU-R BT601-6 525 / ITU-R BT1358 525 / ITU-R BT1700 NTSC
465 AVCOL_PRI_SMPTE240M
=7, ///< functionally identical to above
467 AVCOL_PRI_NB
, ///< Not part of ABI
470 enum AVColorTransferCharacteristic
{
471 AVCOL_TRC_BT709
=1, ///< also ITU-R BT1361
472 AVCOL_TRC_UNSPECIFIED
=2,
473 AVCOL_TRC_GAMMA22
=4, ///< also ITU-R BT470M / ITU-R BT1700 625 PAL & SECAM
474 AVCOL_TRC_GAMMA28
=5, ///< also ITU-R BT470BG
475 AVCOL_TRC_NB
, ///< Not part of ABI
480 AVCOL_SPC_BT709
=1, ///< also ITU-R BT1361 / IEC 61966-2-4 xvYCC709 / SMPTE RP177 Annex B
481 AVCOL_SPC_UNSPECIFIED
=2,
483 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
484 AVCOL_SPC_SMPTE170M
=6, ///< also ITU-R BT601-6 525 / ITU-R BT1358 525 / ITU-R BT1700 NTSC / functionally identical to above
485 AVCOL_SPC_SMPTE240M
=7,
486 AVCOL_SPC_NB
, ///< Not part of ABI
490 AVCOL_RANGE_UNSPECIFIED
=0,
491 AVCOL_RANGE_MPEG
=1, ///< the normal 219*2^(n-8) "MPEG" YUV ranges
492 AVCOL_RANGE_JPEG
=2, ///< the normal 2^n-1 "JPEG" YUV ranges
493 AVCOL_RANGE_NB
, ///< Not part of ABI
497 * X X 3 4 X X are luma samples,
498 * 1 2 1-6 are possible chroma positions
499 * X X 5 6 X 0 is undefined/unknown position
501 enum AVChromaLocation
{
502 AVCHROMA_LOC_UNSPECIFIED
=0,
503 AVCHROMA_LOC_LEFT
=1, ///< mpeg2/4, h264 default
504 AVCHROMA_LOC_CENTER
=2, ///< mpeg1, jpeg, h263
505 AVCHROMA_LOC_TOPLEFT
=3, ///< DV
507 AVCHROMA_LOC_BOTTOMLEFT
=5,
508 AVCHROMA_LOC_BOTTOM
=6,
509 AVCHROMA_LOC_NB
, ///< Not part of ABI
512 typedef struct RcOverride
{
515 int qscale
; // If this is 0 then quality_factor will be used instead.
516 float quality_factor
;
519 #define FF_MAX_B_FRAMES 16
522 These flags can be passed in AVCodecContext.flags before initialization.
523 Note: Not everything is supported yet.
526 #define CODEC_FLAG_QSCALE 0x0002 ///< Use fixed qscale.
527 #define CODEC_FLAG_4MV 0x0004 ///< 4 MV per MB allowed / advanced prediction for H.263.
528 #define CODEC_FLAG_QPEL 0x0010 ///< Use qpel MC.
529 #define CODEC_FLAG_GMC 0x0020 ///< Use GMC.
530 #define CODEC_FLAG_MV0 0x0040 ///< Always try a MB with MV=<0,0>.
531 #define CODEC_FLAG_PART 0x0080 ///< Use data partitioning.
533 * The parent program guarantees that the input for B-frames containing
534 * streams is not written to for at least s->max_b_frames+1 frames, if
535 * this is not set the input will be copied.
537 #define CODEC_FLAG_INPUT_PRESERVED 0x0100
538 #define CODEC_FLAG_PASS1 0x0200 ///< Use internal 2pass ratecontrol in first pass mode.
539 #define CODEC_FLAG_PASS2 0x0400 ///< Use internal 2pass ratecontrol in second pass mode.
540 #define CODEC_FLAG_EXTERN_HUFF 0x1000 ///< Use external Huffman table (for MJPEG).
541 #define CODEC_FLAG_GRAY 0x2000 ///< Only decode/encode grayscale.
542 #define CODEC_FLAG_EMU_EDGE 0x4000 ///< Don't draw edges.
543 #define CODEC_FLAG_PSNR 0x8000 ///< error[?] variables will be set during encoding.
544 #define CODEC_FLAG_TRUNCATED 0x00010000 /** Input bitstream might be truncated at a random
545 location instead of only at frame boundaries. */
546 #define CODEC_FLAG_NORMALIZE_AQP 0x00020000 ///< Normalize adaptive quantization.
547 #define CODEC_FLAG_INTERLACED_DCT 0x00040000 ///< Use interlaced DCT.
548 #define CODEC_FLAG_LOW_DELAY 0x00080000 ///< Force low delay.
549 #define CODEC_FLAG_ALT_SCAN 0x00100000 ///< Use alternate scan.
550 #define CODEC_FLAG_GLOBAL_HEADER 0x00400000 ///< Place global headers in extradata instead of every keyframe.
551 #define CODEC_FLAG_BITEXACT 0x00800000 ///< Use only bitexact stuff (except (I)DCT).
552 /* Fx : Flag for h263+ extra options */
553 #define CODEC_FLAG_AC_PRED 0x01000000 ///< H.263 advanced intra coding / MPEG-4 AC prediction
554 #define CODEC_FLAG_H263P_UMV 0x02000000 ///< unlimited motion vector
555 #define CODEC_FLAG_CBP_RD 0x04000000 ///< Use rate distortion optimization for cbp.
556 #define CODEC_FLAG_QP_RD 0x08000000 ///< Use rate distortion optimization for qp selectioon.
557 #define CODEC_FLAG_H263P_AIV 0x00000008 ///< H.263 alternative inter VLC
558 #define CODEC_FLAG_OBMC 0x00000001 ///< OBMC
559 #define CODEC_FLAG_LOOP_FILTER 0x00000800 ///< loop filter
560 #define CODEC_FLAG_H263P_SLICE_STRUCT 0x10000000
561 #define CODEC_FLAG_INTERLACED_ME 0x20000000 ///< interlaced motion estimation
562 #define CODEC_FLAG_SVCD_SCAN_OFFSET 0x40000000 ///< Will reserve space for SVCD scan offset user data.
563 #define CODEC_FLAG_CLOSED_GOP 0x80000000
564 #define CODEC_FLAG2_FAST 0x00000001 ///< Allow non spec compliant speedup tricks.
565 #define CODEC_FLAG2_STRICT_GOP 0x00000002 ///< Strictly enforce GOP size.
566 #define CODEC_FLAG2_NO_OUTPUT 0x00000004 ///< Skip bitstream encoding.
567 #define CODEC_FLAG2_LOCAL_HEADER 0x00000008 ///< Place global headers at every keyframe instead of in extradata.
568 #define CODEC_FLAG2_BPYRAMID 0x00000010 ///< H.264 allow B-frames to be used as references.
569 #define CODEC_FLAG2_WPRED 0x00000020 ///< H.264 weighted biprediction for B-frames
570 #define CODEC_FLAG2_MIXED_REFS 0x00000040 ///< H.264 one reference per partition, as opposed to one reference per macroblock
571 #define CODEC_FLAG2_8X8DCT 0x00000080 ///< H.264 high profile 8x8 transform
572 #define CODEC_FLAG2_FASTPSKIP 0x00000100 ///< H.264 fast pskip
573 #define CODEC_FLAG2_AUD 0x00000200 ///< H.264 access unit delimiters
574 #define CODEC_FLAG2_BRDO 0x00000400 ///< B-frame rate-distortion optimization
575 #define CODEC_FLAG2_INTRA_VLC 0x00000800 ///< Use MPEG-2 intra VLC table.
576 #define CODEC_FLAG2_MEMC_ONLY 0x00001000 ///< Only do ME/MC (I frames -> ref, P frame -> ME+MC).
577 #define CODEC_FLAG2_DROP_FRAME_TIMECODE 0x00002000 ///< timecode is in drop frame format.
578 #define CODEC_FLAG2_SKIP_RD 0x00004000 ///< RD optimal MB level residual skipping
579 #define CODEC_FLAG2_CHUNKS 0x00008000 ///< Input bitstream might be truncated at a packet boundaries instead of only at frame boundaries.
580 #define CODEC_FLAG2_NON_LINEAR_QUANT 0x00010000 ///< Use MPEG-2 nonlinear quantizer.
581 #define CODEC_FLAG2_BIT_RESERVOIR 0x00020000 ///< Use a bit reservoir when encoding if possible
583 /* Unsupported options :
584 * Syntax Arithmetic coding (SAC)
585 * Reference Picture Selection
586 * Independent Segment Decoding */
588 /* codec capabilities */
590 #define CODEC_CAP_DRAW_HORIZ_BAND 0x0001 ///< Decoder can use draw_horiz_band callback.
592 * Codec uses get_buffer() for allocating buffers.
593 * direct rendering method 1
595 #define CODEC_CAP_DR1 0x0002
596 /* If 'parse_only' field is true, then avcodec_parse_frame() can be used. */
597 #define CODEC_CAP_PARSE_ONLY 0x0004
598 #define CODEC_CAP_TRUNCATED 0x0008
599 /* Codec can export data for HW decoding (XvMC). */
600 #define CODEC_CAP_HWACCEL 0x0010
602 * Codec has a nonzero delay and needs to be fed with NULL at the end to get the delayed data.
603 * If this is not set, the codec is guaranteed to never be fed with NULL data.
605 #define CODEC_CAP_DELAY 0x0020
607 * Codec can be fed a final frame with a smaller size.
608 * This can be used to prevent truncation of the last audio samples.
610 #define CODEC_CAP_SMALL_LAST_FRAME 0x0040
612 * Codec can export data for HW decoding (VDPAU).
614 #define CODEC_CAP_HWACCEL_VDPAU 0x0080
616 * Codec can output multiple frames per AVPacket
618 #define CODEC_CAP_SUBFRAMES 0x0100
620 //The following defines may change, don't expect compatibility if you use them.
621 #define MB_TYPE_INTRA4x4 0x0001
622 #define MB_TYPE_INTRA16x16 0x0002 //FIXME H.264-specific
623 #define MB_TYPE_INTRA_PCM 0x0004 //FIXME H.264-specific
624 #define MB_TYPE_16x16 0x0008
625 #define MB_TYPE_16x8 0x0010
626 #define MB_TYPE_8x16 0x0020
627 #define MB_TYPE_8x8 0x0040
628 #define MB_TYPE_INTERLACED 0x0080
629 #define MB_TYPE_DIRECT2 0x0100 //FIXME
630 #define MB_TYPE_ACPRED 0x0200
631 #define MB_TYPE_GMC 0x0400
632 #define MB_TYPE_SKIP 0x0800
633 #define MB_TYPE_P0L0 0x1000
634 #define MB_TYPE_P1L0 0x2000
635 #define MB_TYPE_P0L1 0x4000
636 #define MB_TYPE_P1L1 0x8000
637 #define MB_TYPE_L0 (MB_TYPE_P0L0 | MB_TYPE_P1L0)
638 #define MB_TYPE_L1 (MB_TYPE_P0L1 | MB_TYPE_P1L1)
639 #define MB_TYPE_L0L1 (MB_TYPE_L0 | MB_TYPE_L1)
640 #define MB_TYPE_QUANT 0x00010000
641 #define MB_TYPE_CBP 0x00020000
642 //Note bits 24-31 are reserved for codec specific use (h264 ref0, mpeg1 0mv, ...)
646 * This specifies the area which should be displayed.
647 * Note there may be multiple such areas for one frame.
649 typedef struct AVPanScan
{
652 * - encoding: Set by user.
653 * - decoding: Set by libavcodec.
658 * width and height in 1/16 pel
659 * - encoding: Set by user.
660 * - decoding: Set by libavcodec.
666 * position of the top left corner in 1/16 pel for up to 3 fields/frames
667 * - encoding: Set by user.
668 * - decoding: Set by libavcodec.
670 int16_t position
[3][2];
673 #define FF_COMMON_FRAME \
675 * pointer to the picture planes.\
676 * This might be different from the first allocated byte\
683 * pointer to the first allocated byte of the picture. Can be used in get_buffer/release_buffer.\
684 * This isn't used by libavcodec unless the default get/release_buffer() is used.\
690 * 1 -> keyframe, 0-> not\
691 * - encoding: Set by libavcodec.\
692 * - decoding: Set by libavcodec.\
697 * Picture type of the frame, see ?_TYPE below.\
698 * - encoding: Set by libavcodec. for coded_picture (and set by user for input).\
699 * - decoding: Set by libavcodec.\
704 * presentation timestamp in time_base units (time when frame should be shown to user)\
705 * If AV_NOPTS_VALUE then frame_rate = 1/time_base will be assumed.\
706 * - encoding: MUST be set by user.\
707 * - decoding: Set by libavcodec.\
712 * picture number in bitstream order\
713 * - encoding: set by\
714 * - decoding: Set by libavcodec.\
716 int coded_picture_number;\
718 * picture number in display order\
719 * - encoding: set by\
720 * - decoding: Set by libavcodec.\
722 int display_picture_number;\
725 * quality (between 1 (good) and FF_LAMBDA_MAX (bad)) \
726 * - encoding: Set by libavcodec. for coded_picture (and set by user for input).\
727 * - decoding: Set by libavcodec.\
732 * buffer age (1->was last buffer and dint change, 2->..., ...).\
733 * Set to INT_MAX if the buffer has not been used yet.\
734 * - encoding: unused\
735 * - decoding: MUST be set by get_buffer().\
740 * is this picture used as reference\
741 * The values for this are the same as the MpegEncContext.picture_structure\
742 * variable, that is 1->top field, 2->bottom field, 3->frame/both fields.\
743 * Set to 4 for delayed, non-reference frames.\
744 * - encoding: unused\
745 * - decoding: Set by libavcodec. (before get_buffer() call)).\
751 * - encoding: unused\
752 * - decoding: Set by libavcodec.\
754 int8_t *qscale_table;\
757 * - encoding: unused\
758 * - decoding: Set by libavcodec.\
763 * mbskip_table[mb]>=1 if MB didn't change\
764 * stride= mb_width = (width+15)>>4\
765 * - encoding: unused\
766 * - decoding: Set by libavcodec.\
768 uint8_t *mbskip_table;\
771 * motion vector table\
774 * int mv_sample_log2= 4 - motion_subsample_log2;\
775 * int mb_width= (width+15)>>4;\
776 * int mv_stride= (mb_width << mv_sample_log2) + 1;\
777 * motion_val[direction][x + y*mv_stride][0->mv_x, 1->mv_y];\
779 * - encoding: Set by user.\
780 * - decoding: Set by libavcodec.\
782 int16_t (*motion_val[2])[2];\
785 * macroblock type table\
786 * mb_type_base + mb_width + 2\
787 * - encoding: Set by user.\
788 * - decoding: Set by libavcodec.\
793 * log2 of the size of the block which a single vector in motion_val represents: \
794 * (4->16x16, 3->8x8, 2-> 4x4, 1-> 2x2)\
795 * - encoding: unused\
796 * - decoding: Set by libavcodec.\
798 uint8_t motion_subsample_log2;\
801 * for some private data of the user\
802 * - encoding: unused\
803 * - decoding: Set by user.\
809 * - encoding: Set by libavcodec. if flags&CODEC_FLAG_PSNR.\
810 * - decoding: unused\
815 * type of the buffer (to keep track of who has to deallocate data[*])\
816 * - encoding: Set by the one who allocates it.\
817 * - decoding: Set by the one who allocates it.\
818 * Note: User allocated (direct rendering) & internal buffers cannot coexist currently.\
823 * When decoding, this signals how much the picture must be delayed.\
824 * extra_delay = repeat_pict / (2*fps)\
825 * - encoding: unused\
826 * - decoding: Set by libavcodec.\
836 * The content of the picture is interlaced.\
837 * - encoding: Set by user.\
838 * - decoding: Set by libavcodec. (default 0)\
840 int interlaced_frame;\
843 * If the content is interlaced, is top field displayed first.\
844 * - encoding: Set by user.\
845 * - decoding: Set by libavcodec.\
847 int top_field_first;\
851 * - encoding: Set by user.\
852 * - decoding: Set by libavcodec.\
854 AVPanScan *pan_scan;\
857 * Tell user application that palette has changed from previous frame.\
858 * - encoding: ??? (no palette-enabled encoder yet)\
859 * - decoding: Set by libavcodec. (default 0).\
861 int palette_has_changed;\
864 * codec suggestion on buffer type if != 0\
865 * - encoding: unused\
866 * - decoding: Set by libavcodec. (before get_buffer() call)).\
872 * - encoding: unused\
873 * - decoding: Set by libavcodec.\
878 * motion referece frame index\
879 * - encoding: Set by user.\
880 * - decoding: Set by libavcodec.\
882 int8_t *ref_index[2];\
885 * reordered opaque 64bit number (generally a PTS) from AVCodecContext.reordered_opaque\
886 * output in AVFrame.reordered_opaque\
887 * - encoding: unused\
888 * - decoding: Read by user.\
890 int64_t reordered_opaque;\
893 * hardware accelerator private data (FFmpeg allocated)\
894 * - encoding: unused\
895 * - decoding: Set by libavcodec\
897 void *hwaccel_picture_private;\
900 #define FF_QSCALE_TYPE_MPEG1 0
901 #define FF_QSCALE_TYPE_MPEG2 1
902 #define FF_QSCALE_TYPE_H264 2
904 #define FF_BUFFER_TYPE_INTERNAL 1
905 #define FF_BUFFER_TYPE_USER 2 ///< direct rendering buffers (image is (de)allocated by user)
906 #define FF_BUFFER_TYPE_SHARED 4 ///< Buffer from somewhere else; don't deallocate image (data/base), all other tables are not shared.
907 #define FF_BUFFER_TYPE_COPY 8 ///< Just a (modified) copy of some other buffer, don't deallocate anything.
910 #define FF_I_TYPE 1 ///< Intra
911 #define FF_P_TYPE 2 ///< Predicted
912 #define FF_B_TYPE 3 ///< Bi-dir predicted
913 #define FF_S_TYPE 4 ///< S(GMC)-VOP MPEG4
914 #define FF_SI_TYPE 5 ///< Switching Intra
915 #define FF_SP_TYPE 6 ///< Switching Predicted
918 #define FF_BUFFER_HINTS_VALID 0x01 // Buffer hints value is meaningful (if 0 ignore).
919 #define FF_BUFFER_HINTS_READABLE 0x02 // Codec will read from buffer.
920 #define FF_BUFFER_HINTS_PRESERVE 0x04 // User must not alter buffer content.
921 #define FF_BUFFER_HINTS_REUSABLE 0x08 // Codec will reuse the buffer (update).
923 typedef struct AVPacket
{
925 * Presentation timestamp in AVStream->time_base units; the time at which
926 * the decompressed packet will be presented to the user.
927 * Can be AV_NOPTS_VALUE if it is not stored in the file.
928 * pts MUST be larger or equal to dts as presentation cannot happen before
929 * decompression, unless one wants to view hex dumps. Some formats misuse
930 * the terms dts and pts/cts to mean something different. Such timestamps
931 * must be converted to true pts/dts before they are stored in AVPacket.
935 * Decompression timestamp in AVStream->time_base units; the time at which
936 * the packet is decompressed.
937 * Can be AV_NOPTS_VALUE if it is not stored in the file.
945 * Duration of this packet in AVStream->time_base units, 0 if unknown.
946 * Equals next_pts - this_pts in presentation order.
949 void (*destruct
)(struct AVPacket
*);
951 int64_t pos
; ///< byte position in stream, -1 if unknown
954 * Time difference in AVStream->time_base units from the pts of this
955 * packet to the point at which the output from the decoder has converged
956 * independent from the availability of previous frames. That is, the
957 * frames are virtually identical no matter if decoding started from
958 * the very first frame or from this keyframe.
959 * Is AV_NOPTS_VALUE if unknown.
960 * This field is not the display duration of the current packet.
962 * The purpose of this field is to allow seeking in streams that have no
963 * keyframes in the conventional sense. It corresponds to the
964 * recovery point SEI in H.264 and match_time_delta in NUT. It is also
965 * essential for some types of subtitle streams to ensure that all
966 * subtitles are correctly displayed after seeking.
968 int64_t convergence_duration
;
970 #define AV_PKT_FLAG_KEY 0x0001
971 #if LIBAVCODEC_VERSION_MAJOR < 53
972 #define PKT_FLAG_KEY AV_PKT_FLAG_KEY
977 * New fields can be added to the end of FF_COMMON_FRAME with minor version
979 * Removal, reordering and changes to existing fields require a major
980 * version bump. No fields should be added into AVFrame before or after
982 * sizeof(AVFrame) must not be used outside libav*.
984 typedef struct AVFrame
{
989 * main external API structure.
990 * New fields can be added to the end with minor version bumps.
991 * Removal, reordering and changes to existing fields require a major
993 * sizeof(AVCodecContext) must not be used outside libav*.
995 typedef struct AVCodecContext
{
997 * information on struct for av_log
998 * - set by avcodec_alloc_context
1000 const AVClass
*av_class
;
1002 * the average bitrate
1003 * - encoding: Set by user; unused for constant quantizer encoding.
1004 * - decoding: Set by libavcodec. 0 or some bitrate if this info is available in the stream.
1009 * number of bits the bitstream is allowed to diverge from the reference.
1010 * the reference can be CBR (for CBR pass1) or VBR (for pass2)
1011 * - encoding: Set by user; unused for constant quantizer encoding.
1012 * - decoding: unused
1014 int bit_rate_tolerance
;
1018 * - encoding: Set by user.
1019 * - decoding: Set by user.
1024 * Some codecs need additional format info. It is stored here.
1025 * If any muxer uses this then ALL demuxers/parsers AND encoders for the
1026 * specific codec MUST set it correctly otherwise stream copy breaks.
1027 * In general use of this field by muxers is not recommanded.
1028 * - encoding: Set by libavcodec.
1029 * - decoding: Set by libavcodec. (FIXME: Is this OK?)
1034 * Motion estimation algorithm used for video coding.
1035 * 1 (zero), 2 (full), 3 (log), 4 (phods), 5 (epzs), 6 (x1), 7 (hex),
1036 * 8 (umh), 9 (iter), 10 (tesa) [7, 8, 10 are x264 specific, 9 is snow specific]
1037 * - encoding: MUST be set by user.
1038 * - decoding: unused
1043 * some codecs need / can use extradata like Huffman tables.
1044 * mjpeg: Huffman tables
1045 * rv10: additional flags
1046 * mpeg4: global headers (they can be in the bitstream or here)
1047 * The allocated memory should be FF_INPUT_BUFFER_PADDING_SIZE bytes larger
1048 * than extradata_size to avoid prolems if it is read with the bitstream reader.
1049 * The bytewise contents of extradata must not depend on the architecture or CPU endianness.
1050 * - encoding: Set/allocated/freed by libavcodec.
1051 * - decoding: Set/allocated/freed by user.
1057 * This is the fundamental unit of time (in seconds) in terms
1058 * of which frame timestamps are represented. For fixed-fps content,
1059 * timebase should be 1/framerate and timestamp increments should be
1061 * - encoding: MUST be set by user.
1062 * - decoding: Set by libavcodec.
1064 AVRational time_base
;
1068 * picture width / height.
1069 * - encoding: MUST be set by user.
1070 * - decoding: Set by libavcodec.
1071 * Note: For compatibility it is possible to set this instead of
1072 * coded_width/height before decoding.
1076 #define FF_ASPECT_EXTENDED 15
1079 * the number of pictures in a group of pictures, or 0 for intra_only
1080 * - encoding: Set by user.
1081 * - decoding: unused
1086 * Pixel format, see PIX_FMT_xxx.
1087 * - encoding: Set by user.
1088 * - decoding: Set by libavcodec.
1090 enum PixelFormat pix_fmt
;
1093 * Frame rate emulation. If not zero, the lower layer (i.e. format handler)
1094 * has to read frames at native frame rate.
1095 * - encoding: Set by user.
1096 * - decoding: unused
1101 * If non NULL, 'draw_horiz_band' is called by the libavcodec
1102 * decoder to draw a horizontal band. It improves cache usage. Not
1103 * all codecs can do that. You must check the codec capabilities
1105 * The function is also used by hardware acceleration APIs.
1106 * It is called at least once during frame decoding to pass
1107 * the data needed for hardware render.
1108 * In that mode instead of pixel data, AVFrame points to
1109 * a structure specific to the acceleration API. The application
1110 * reads the structure and can change some fields to indicate progress
1112 * - encoding: unused
1113 * - decoding: Set by user.
1114 * @param height the height of the slice
1115 * @param y the y position of the slice
1116 * @param type 1->top field, 2->bottom field, 3->frame
1117 * @param offset offset into the AVFrame.data from which the slice should be read
1119 void (*draw_horiz_band
)(struct AVCodecContext
*s
,
1120 const AVFrame
*src
, int offset
[4],
1121 int y
, int type
, int height
);
1124 int sample_rate
; ///< samples per second
1125 int channels
; ///< number of audio channels
1128 * audio sample format
1129 * - encoding: Set by user.
1130 * - decoding: Set by libavcodec.
1132 enum SampleFormat sample_fmt
; ///< sample format
1134 /* The following data should not be initialized. */
1136 * Samples per packet, initialized when calling 'init'.
1139 int frame_number
; ///< audio or video frame number
1140 #if LIBAVCODEC_VERSION_MAJOR < 53
1141 int real_pict_num
; ///< Returns the real picture number of previous encoded frame.
1145 * Number of frames the decoded output will be delayed relative to
1146 * the encoded input.
1147 * - encoding: Set by libavcodec.
1148 * - decoding: unused
1152 /* - encoding parameters */
1153 float qcompress
; ///< amount of qscale change between easy & hard scenes (0.0-1.0)
1154 float qblur
; ///< amount of qscale smoothing over time (0.0-1.0)
1158 * - encoding: Set by user.
1159 * - decoding: unused
1165 * - encoding: Set by user.
1166 * - decoding: unused
1171 * maximum quantizer difference between frames
1172 * - encoding: Set by user.
1173 * - decoding: unused
1178 * maximum number of B-frames between non-B-frames
1179 * Note: The output will be delayed by max_b_frames+1 relative to the input.
1180 * - encoding: Set by user.
1181 * - decoding: unused
1186 * qscale factor between IP and B-frames
1187 * If > 0 then the last P-frame quantizer will be used (q= lastp_q*factor+offset).
1188 * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1189 * - encoding: Set by user.
1190 * - decoding: unused
1192 float b_quant_factor
;
1194 /** obsolete FIXME remove */
1196 #define FF_RC_STRATEGY_XVID 1
1198 int b_frame_strategy
;
1202 * - encoding: unused
1203 * - decoding: Set by user. 1-> Skip B-frames, 2-> Skip IDCT/dequant too, 5-> Skip everything except header
1204 * @deprecated Deprecated in favor of skip_idct and skip_frame.
1208 struct AVCodec
*codec
;
1212 int rtp_payload_size
; /* The size of the RTP payload: the coder will */
1213 /* do its best to deliver a chunk with size */
1214 /* below rtp_payload_size, the chunk will start */
1215 /* with a start code on some codecs like H.263. */
1216 /* This doesn't take account of any particular */
1217 /* headers inside the transmitted RTP payload. */
1220 /* The RTP callback: This function is called */
1221 /* every time the encoder has a packet to send. */
1222 /* It depends on the encoder if the data starts */
1223 /* with a Start Code (it should). H.263 does. */
1224 /* mb_nb contains the number of macroblocks */
1225 /* encoded in the RTP payload. */
1226 void (*rtp_callback
)(struct AVCodecContext
*avctx
, void *data
, int size
, int mb_nb
);
1228 /* statistics, used for 2-pass encoding */
1239 * number of bits used for the previously encoded frame
1240 * - encoding: Set by libavcodec.
1241 * - decoding: unused
1246 * Private data of the user, can be used to carry app specific stuff.
1247 * - encoding: Set by user.
1248 * - decoding: Set by user.
1252 char codec_name
[32];
1253 enum CodecType codec_type
; /* see CODEC_TYPE_xxx */
1254 enum CodecID codec_id
; /* see CODEC_ID_xxx */
1257 * fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
1258 * This is used to work around some encoder bugs.
1259 * A demuxer should set this to what is stored in the field used to identify the codec.
1260 * If there are multiple such fields in a container then the demuxer should choose the one
1261 * which maximizes the information about the used codec.
1262 * If the codec tag field in a container is larger then 32 bits then the demuxer should
1263 * remap the longer ID to 32 bits with a table or other structure. Alternatively a new
1264 * extra_codec_tag + size could be added but for this a clear advantage must be demonstrated
1266 * - encoding: Set by user, if not then the default based on codec_id will be used.
1267 * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
1269 unsigned int codec_tag
;
1272 * Work around bugs in encoders which sometimes cannot be detected automatically.
1273 * - encoding: Set by user
1274 * - decoding: Set by user
1276 int workaround_bugs
;
1277 #define FF_BUG_AUTODETECT 1 ///< autodetection
1278 #define FF_BUG_OLD_MSMPEG4 2
1279 #define FF_BUG_XVID_ILACE 4
1280 #define FF_BUG_UMP4 8
1281 #define FF_BUG_NO_PADDING 16
1282 #define FF_BUG_AMV 32
1283 #define FF_BUG_AC_VLC 0 ///< Will be removed, libavcodec can now handle these non-compliant files by default.
1284 #define FF_BUG_QPEL_CHROMA 64
1285 #define FF_BUG_STD_QPEL 128
1286 #define FF_BUG_QPEL_CHROMA2 256
1287 #define FF_BUG_DIRECT_BLOCKSIZE 512
1288 #define FF_BUG_EDGE 1024
1289 #define FF_BUG_HPEL_CHROMA 2048
1290 #define FF_BUG_DC_CLIP 4096
1291 #define FF_BUG_MS 8192 ///< Work around various bugs in Microsoft's broken decoders.
1292 //#define FF_BUG_FAKE_SCALABILITY 16 //Autodetection should work 100%.
1295 * luma single coefficient elimination threshold
1296 * - encoding: Set by user.
1297 * - decoding: unused
1299 int luma_elim_threshold
;
1302 * chroma single coeff elimination threshold
1303 * - encoding: Set by user.
1304 * - decoding: unused
1306 int chroma_elim_threshold
;
1309 * strictly follow the standard (MPEG4, ...).
1310 * - encoding: Set by user.
1311 * - decoding: Set by user.
1312 * Setting this to STRICT or higher means the encoder and decoder will
1313 * generally do stupid things. While setting it to inofficial or lower
1314 * will mean the encoder might use things that are not supported by all
1315 * spec compliant decoders. Decoders make no difference between normal,
1316 * inofficial and experimental, that is they always try to decode things
1317 * when they can unless they are explicitly asked to behave stupid
1318 * (=strictly conform to the specs)
1320 int strict_std_compliance
;
1321 #define FF_COMPLIANCE_VERY_STRICT 2 ///< Strictly conform to a older more strict version of the spec or reference software.
1322 #define FF_COMPLIANCE_STRICT 1 ///< Strictly conform to all the things in the spec no matter what consequences.
1323 #define FF_COMPLIANCE_NORMAL 0
1324 #define FF_COMPLIANCE_INOFFICIAL -1 ///< Allow inofficial extensions.
1325 #define FF_COMPLIANCE_EXPERIMENTAL -2 ///< Allow nonstandardized experimental things.
1328 * qscale offset between IP and B-frames
1329 * - encoding: Set by user.
1330 * - decoding: unused
1332 float b_quant_offset
;
1335 * Error recognization; higher values will detect more errors but may
1336 * misdetect some more or less valid parts as errors.
1337 * - encoding: unused
1338 * - decoding: Set by user.
1340 int error_recognition
;
1341 #define FF_ER_CAREFUL 1
1342 #define FF_ER_COMPLIANT 2
1343 #define FF_ER_AGGRESSIVE 3
1344 #define FF_ER_VERY_AGGRESSIVE 4
1347 * Called at the beginning of each frame to get a buffer for it.
1348 * If pic.reference is set then the frame will be read later by libavcodec.
1349 * avcodec_align_dimensions() should be used to find the required width and
1350 * height, as they normally need to be rounded up to the next multiple of 16.
1351 * if CODEC_CAP_DR1 is not set then get_buffer() must call
1352 * avcodec_default_get_buffer() instead of providing buffers allocated by
1354 * - encoding: unused
1355 * - decoding: Set by libavcodec., user can override.
1357 int (*get_buffer
)(struct AVCodecContext
*c
, AVFrame
*pic
);
1360 * Called to release buffers which were allocated with get_buffer.
1361 * A released buffer can be reused in get_buffer().
1362 * pic.data[*] must be set to NULL.
1363 * - encoding: unused
1364 * - decoding: Set by libavcodec., user can override.
1366 void (*release_buffer
)(struct AVCodecContext
*c
, AVFrame
*pic
);
1369 * Size of the frame reordering buffer in the decoder.
1370 * For MPEG-2 it is 1 IPB or 0 low delay IP.
1371 * - encoding: Set by libavcodec.
1372 * - decoding: Set by libavcodec.
1377 * number of bytes per packet if constant and known or 0
1378 * Used by some WAV based audio codecs.
1382 int parse_only
; /* - decoding only: If true, only parsing is done
1383 (function avcodec_parse_frame()). The frame
1384 data is returned. Only MPEG codecs support this now. */
1387 * 0-> h263 quant 1-> mpeg quant
1388 * - encoding: Set by user.
1389 * - decoding: unused
1394 * pass1 encoding statistics output buffer
1395 * - encoding: Set by libavcodec.
1396 * - decoding: unused
1401 * pass2 encoding statistics input buffer
1402 * Concatenated stuff from stats_out of pass1 should be placed here.
1403 * - encoding: Allocated/set/freed by user.
1404 * - decoding: unused
1409 * ratecontrol qmin qmax limiting method
1410 * 0-> clipping, 1-> use a nice continous function to limit qscale wthin qmin/qmax.
1411 * - encoding: Set by user.
1412 * - decoding: unused
1420 * ratecontrol override, see RcOverride
1421 * - encoding: Allocated/set/freed by user.
1422 * - decoding: unused
1424 RcOverride
*rc_override
;
1425 int rc_override_count
;
1428 * rate control equation
1429 * - encoding: Set by user
1430 * - decoding: unused
1436 * - encoding: Set by user.
1437 * - decoding: unused
1443 * - encoding: Set by user.
1444 * - decoding: unused
1449 * decoder bitstream buffer size
1450 * - encoding: Set by user.
1451 * - decoding: unused
1454 float rc_buffer_aggressivity
;
1457 * qscale factor between P and I-frames
1458 * If > 0 then the last p frame quantizer will be used (q= lastp_q*factor+offset).
1459 * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1460 * - encoding: Set by user.
1461 * - decoding: unused
1463 float i_quant_factor
;
1466 * qscale offset between P and I-frames
1467 * - encoding: Set by user.
1468 * - decoding: unused
1470 float i_quant_offset
;
1473 * initial complexity for pass1 ratecontrol
1474 * - encoding: Set by user.
1475 * - decoding: unused
1477 float rc_initial_cplx
;
1480 * DCT algorithm, see FF_DCT_* below
1481 * - encoding: Set by user.
1482 * - decoding: unused
1485 #define FF_DCT_AUTO 0
1486 #define FF_DCT_FASTINT 1
1487 #define FF_DCT_INT 2
1488 #define FF_DCT_MMX 3
1489 #define FF_DCT_MLIB 4
1490 #define FF_DCT_ALTIVEC 5
1491 #define FF_DCT_FAAN 6
1494 * luminance masking (0-> disabled)
1495 * - encoding: Set by user.
1496 * - decoding: unused
1501 * temporary complexity masking (0-> disabled)
1502 * - encoding: Set by user.
1503 * - decoding: unused
1505 float temporal_cplx_masking
;
1508 * spatial complexity masking (0-> disabled)
1509 * - encoding: Set by user.
1510 * - decoding: unused
1512 float spatial_cplx_masking
;
1515 * p block masking (0-> disabled)
1516 * - encoding: Set by user.
1517 * - decoding: unused
1522 * darkness masking (0-> disabled)
1523 * - encoding: Set by user.
1524 * - decoding: unused
1529 * IDCT algorithm, see FF_IDCT_* below.
1530 * - encoding: Set by user.
1531 * - decoding: Set by user.
1534 #define FF_IDCT_AUTO 0
1535 #define FF_IDCT_INT 1
1536 #define FF_IDCT_SIMPLE 2
1537 #define FF_IDCT_SIMPLEMMX 3
1538 #define FF_IDCT_LIBMPEG2MMX 4
1539 #define FF_IDCT_PS2 5
1540 #define FF_IDCT_MLIB 6
1541 #define FF_IDCT_ARM 7
1542 #define FF_IDCT_ALTIVEC 8
1543 #define FF_IDCT_SH4 9
1544 #define FF_IDCT_SIMPLEARM 10
1545 #define FF_IDCT_H264 11
1546 #define FF_IDCT_VP3 12
1547 #define FF_IDCT_IPP 13
1548 #define FF_IDCT_XVIDMMX 14
1549 #define FF_IDCT_CAVS 15
1550 #define FF_IDCT_SIMPLEARMV5TE 16
1551 #define FF_IDCT_SIMPLEARMV6 17
1552 #define FF_IDCT_SIMPLEVIS 18
1553 #define FF_IDCT_WMV2 19
1554 #define FF_IDCT_FAAN 20
1555 #define FF_IDCT_EA 21
1556 #define FF_IDCT_SIMPLENEON 22
1557 #define FF_IDCT_SIMPLEALPHA 23
1561 * - encoding: Set by libavcodec.
1562 * - decoding: Set by user (or 0).
1566 * slice offsets in the frame in bytes
1567 * - encoding: Set/allocated by libavcodec.
1568 * - decoding: Set/allocated by user (or NULL).
1573 * error concealment flags
1574 * - encoding: unused
1575 * - decoding: Set by user.
1577 int error_concealment
;
1578 #define FF_EC_GUESS_MVS 1
1579 #define FF_EC_DEBLOCK 2
1582 * dsp_mask could be add used to disable unwanted CPU features
1583 * CPU features (i.e. MMX, SSE. ...)
1585 * With the FORCE flag you may instead enable given CPU features.
1586 * (Dangerous: Usable in case of misdetection, improper usage however will
1587 * result into program crash.)
1590 #define FF_MM_FORCE 0x80000000 /* Force usage of selected flags (OR) */
1591 /* lower 16 bits - CPU features */
1592 #define FF_MM_MMX 0x0001 ///< standard MMX
1593 #define FF_MM_3DNOW 0x0004 ///< AMD 3DNOW
1594 #if LIBAVCODEC_VERSION_MAJOR < 53
1595 #define FF_MM_MMXEXT 0x0002 ///< SSE integer functions or AMD MMX ext
1597 #define FF_MM_MMX2 0x0002 ///< SSE integer functions or AMD MMX ext
1598 #define FF_MM_SSE 0x0008 ///< SSE functions
1599 #define FF_MM_SSE2 0x0010 ///< PIV SSE2 functions
1600 #define FF_MM_3DNOWEXT 0x0020 ///< AMD 3DNowExt
1601 #define FF_MM_SSE3 0x0040 ///< Prescott SSE3 functions
1602 #define FF_MM_SSSE3 0x0080 ///< Conroe SSSE3 functions
1603 #define FF_MM_SSE4 0x0100 ///< Penryn SSE4.1 functions
1604 #define FF_MM_SSE42 0x0200 ///< Nehalem SSE4.2 functions
1605 #define FF_MM_IWMMXT 0x0100 ///< XScale IWMMXT
1606 #define FF_MM_ALTIVEC 0x0001 ///< standard AltiVec
1609 * bits per sample/pixel from the demuxer (needed for huffyuv).
1610 * - encoding: Set by libavcodec.
1611 * - decoding: Set by user.
1613 int bits_per_coded_sample
;
1616 * prediction method (needed for huffyuv)
1617 * - encoding: Set by user.
1618 * - decoding: unused
1620 int prediction_method
;
1621 #define FF_PRED_LEFT 0
1622 #define FF_PRED_PLANE 1
1623 #define FF_PRED_MEDIAN 2
1626 * sample aspect ratio (0 if unknown)
1627 * That is the width of a pixel divided by the height of the pixel.
1628 * Numerator and denominator must be relatively prime and smaller than 256 for some video standards.
1629 * - encoding: Set by user.
1630 * - decoding: Set by libavcodec.
1632 AVRational sample_aspect_ratio
;
1635 * the picture in the bitstream
1636 * - encoding: Set by libavcodec.
1637 * - decoding: Set by libavcodec.
1639 AVFrame
*coded_frame
;
1643 * - encoding: Set by user.
1644 * - decoding: Set by user.
1647 #define FF_DEBUG_PICT_INFO 1
1648 #define FF_DEBUG_RC 2
1649 #define FF_DEBUG_BITSTREAM 4
1650 #define FF_DEBUG_MB_TYPE 8
1651 #define FF_DEBUG_QP 16
1652 #define FF_DEBUG_MV 32
1653 #define FF_DEBUG_DCT_COEFF 0x00000040
1654 #define FF_DEBUG_SKIP 0x00000080
1655 #define FF_DEBUG_STARTCODE 0x00000100
1656 #define FF_DEBUG_PTS 0x00000200
1657 #define FF_DEBUG_ER 0x00000400
1658 #define FF_DEBUG_MMCO 0x00000800
1659 #define FF_DEBUG_BUGS 0x00001000
1660 #define FF_DEBUG_VIS_QP 0x00002000
1661 #define FF_DEBUG_VIS_MB_TYPE 0x00004000
1662 #define FF_DEBUG_BUFFERS 0x00008000
1666 * - encoding: Set by user.
1667 * - decoding: Set by user.
1670 #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 //visualize forward predicted MVs of P frames
1671 #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 //visualize forward predicted MVs of B frames
1672 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
1676 * - encoding: Set by libavcodec if flags&CODEC_FLAG_PSNR.
1677 * - decoding: unused
1682 * minimum MB quantizer
1683 * - encoding: unused
1684 * - decoding: unused
1689 * maximum MB quantizer
1690 * - encoding: unused
1691 * - decoding: unused
1696 * motion estimation comparison function
1697 * - encoding: Set by user.
1698 * - decoding: unused
1702 * subpixel motion estimation comparison function
1703 * - encoding: Set by user.
1704 * - decoding: unused
1708 * macroblock comparison function (not supported yet)
1709 * - encoding: Set by user.
1710 * - decoding: unused
1714 * interlaced DCT comparison function
1715 * - encoding: Set by user.
1716 * - decoding: unused
1719 #define FF_CMP_SAD 0
1720 #define FF_CMP_SSE 1
1721 #define FF_CMP_SATD 2
1722 #define FF_CMP_DCT 3
1723 #define FF_CMP_PSNR 4
1724 #define FF_CMP_BIT 5
1726 #define FF_CMP_ZERO 7
1727 #define FF_CMP_VSAD 8
1728 #define FF_CMP_VSSE 9
1729 #define FF_CMP_NSSE 10
1730 #define FF_CMP_W53 11
1731 #define FF_CMP_W97 12
1732 #define FF_CMP_DCTMAX 13
1733 #define FF_CMP_DCT264 14
1734 #define FF_CMP_CHROMA 256
1737 * ME diamond size & shape
1738 * - encoding: Set by user.
1739 * - decoding: unused
1744 * amount of previous MV predictors (2a+1 x 2a+1 square)
1745 * - encoding: Set by user.
1746 * - decoding: unused
1748 int last_predictor_count
;
1751 * prepass for motion estimation
1752 * - encoding: Set by user.
1753 * - decoding: unused
1758 * motion estimation prepass comparison function
1759 * - encoding: Set by user.
1760 * - decoding: unused
1765 * ME prepass diamond size & shape
1766 * - encoding: Set by user.
1767 * - decoding: unused
1773 * - encoding: Set by user.
1774 * - decoding: unused
1776 int me_subpel_quality
;
1779 * callback to negotiate the pixelFormat
1780 * @param fmt is the list of formats which are supported by the codec,
1781 * it is terminated by -1 as 0 is a valid format, the formats are ordered by quality.
1782 * The first is always the native one.
1783 * @return the chosen format
1784 * - encoding: unused
1785 * - decoding: Set by user, if not set the native format will be chosen.
1787 enum PixelFormat (*get_format
)(struct AVCodecContext
*s
, const enum PixelFormat
* fmt
);
1790 * DTG active format information (additional aspect ratio
1791 * information only used in DVB MPEG-2 transport streams)
1794 * - encoding: unused
1795 * - decoding: Set by decoder.
1797 int dtg_active_format
;
1798 #define FF_DTG_AFD_SAME 8
1799 #define FF_DTG_AFD_4_3 9
1800 #define FF_DTG_AFD_16_9 10
1801 #define FF_DTG_AFD_14_9 11
1802 #define FF_DTG_AFD_4_3_SP_14_9 13
1803 #define FF_DTG_AFD_16_9_SP_14_9 14
1804 #define FF_DTG_AFD_SP_4_3 15
1807 * maximum motion estimation search range in subpel units
1808 * If 0 then no limit.
1810 * - encoding: Set by user.
1811 * - decoding: unused
1816 * intra quantizer bias
1817 * - encoding: Set by user.
1818 * - decoding: unused
1820 int intra_quant_bias
;
1821 #define FF_DEFAULT_QUANT_BIAS 999999
1824 * inter quantizer bias
1825 * - encoding: Set by user.
1826 * - decoding: unused
1828 int inter_quant_bias
;
1832 * - encoding: unused
1833 * - decoding: Which clrtable should be used for 8bit RGB images.
1834 * Tables have to be stored somewhere. FIXME
1839 * internal_buffer count
1840 * Don't touch, used by libavcodec default_get_buffer().
1842 int internal_buffer_count
;
1846 * Don't touch, used by libavcodec default_get_buffer().
1848 void *internal_buffer
;
1850 #define FF_LAMBDA_SHIFT 7
1851 #define FF_LAMBDA_SCALE (1<<FF_LAMBDA_SHIFT)
1852 #define FF_QP2LAMBDA 118 ///< factor to convert from H.263 QP to lambda
1853 #define FF_LAMBDA_MAX (256*128-1)
1855 #define FF_QUALITY_SCALE FF_LAMBDA_SCALE //FIXME maybe remove
1857 * Global quality for codecs which cannot change it per frame.
1858 * This should be proportional to MPEG-1/2/4 qscale.
1859 * - encoding: Set by user.
1860 * - decoding: unused
1864 #define FF_CODER_TYPE_VLC 0
1865 #define FF_CODER_TYPE_AC 1
1866 #define FF_CODER_TYPE_RAW 2
1867 #define FF_CODER_TYPE_RLE 3
1868 #define FF_CODER_TYPE_DEFLATE 4
1871 * - encoding: Set by user.
1872 * - decoding: unused
1878 * - encoding: Set by user.
1879 * - decoding: unused
1885 * - encoding: unused
1886 * - decoding: Set by user.
1888 uint8_t * (*realloc
)(struct AVCodecContext
*s
, uint8_t *buf
, int buf_size
);
1893 * - encoding: unused
1894 * - decoding: Set by user.
1897 #define SLICE_FLAG_CODED_ORDER 0x0001 ///< draw_horiz_band() is called in coded order instead of display
1898 #define SLICE_FLAG_ALLOW_FIELD 0x0002 ///< allow draw_horiz_band() with field slices (MPEG2 field pics)
1899 #define SLICE_FLAG_ALLOW_PLANE 0x0004 ///< allow draw_horiz_band() with 1 component at a time (SVQ1)
1902 * XVideo Motion Acceleration
1903 * - encoding: forbidden
1904 * - decoding: set by decoder
1906 int xvmc_acceleration
;
1909 * macroblock decision mode
1910 * - encoding: Set by user.
1911 * - decoding: unused
1914 #define FF_MB_DECISION_SIMPLE 0 ///< uses mb_cmp
1915 #define FF_MB_DECISION_BITS 1 ///< chooses the one which needs the fewest bits
1916 #define FF_MB_DECISION_RD 2 ///< rate distortion
1919 * custom intra quantization matrix
1920 * - encoding: Set by user, can be NULL.
1921 * - decoding: Set by libavcodec.
1923 uint16_t *intra_matrix
;
1926 * custom inter quantization matrix
1927 * - encoding: Set by user, can be NULL.
1928 * - decoding: Set by libavcodec.
1930 uint16_t *inter_matrix
;
1933 * fourcc from the AVI stream header (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
1934 * This is used to work around some encoder bugs.
1935 * - encoding: unused
1936 * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
1938 unsigned int stream_codec_tag
;
1941 * scene change detection threshold
1942 * 0 is default, larger means fewer detected scene changes.
1943 * - encoding: Set by user.
1944 * - decoding: unused
1946 int scenechange_threshold
;
1949 * minimum Lagrange multipler
1950 * - encoding: Set by user.
1951 * - decoding: unused
1956 * maximum Lagrange multipler
1957 * - encoding: Set by user.
1958 * - decoding: unused
1963 * palette control structure
1964 * - encoding: ??? (no palette-enabled encoder yet)
1965 * - decoding: Set by user.
1967 struct AVPaletteControl
*palctrl
;
1970 * noise reduction strength
1971 * - encoding: Set by user.
1972 * - decoding: unused
1974 int noise_reduction
;
1977 * Called at the beginning of a frame to get cr buffer for it.
1978 * Buffer type (size, hints) must be the same. libavcodec won't check it.
1979 * libavcodec will pass previous buffer in pic, function should return
1980 * same buffer or new buffer with old frame "painted" into it.
1981 * If pic.data[0] == NULL must behave like get_buffer().
1982 * if CODEC_CAP_DR1 is not set then reget_buffer() must call
1983 * avcodec_default_reget_buffer() instead of providing buffers allocated by
1985 * - encoding: unused
1986 * - decoding: Set by libavcodec., user can override
1988 int (*reget_buffer
)(struct AVCodecContext
*c
, AVFrame
*pic
);
1991 * Number of bits which should be loaded into the rc buffer before decoding starts.
1992 * - encoding: Set by user.
1993 * - decoding: unused
1995 int rc_initial_buffer_occupancy
;
1999 * - encoding: Set by user.
2000 * - decoding: unused
2002 int inter_threshold
;
2006 * - encoding: Set by user.
2007 * - decoding: Set by user.
2012 * Simulates errors in the bitstream to test error concealment.
2013 * - encoding: Set by user.
2014 * - decoding: unused
2019 * MP3 antialias algorithm, see FF_AA_* below.
2020 * - encoding: unused
2021 * - decoding: Set by user.
2024 #define FF_AA_AUTO 0
2025 #define FF_AA_FASTINT 1 //not implemented yet
2027 #define FF_AA_FLOAT 3
2029 * quantizer noise shaping
2030 * - encoding: Set by user.
2031 * - decoding: unused
2033 int quantizer_noise_shaping
;
2037 * is used to decide how many independent tasks should be passed to execute()
2038 * - encoding: Set by user.
2039 * - decoding: Set by user.
2044 * The codec may call this to execute several independent things.
2045 * It will return only after finishing all tasks.
2046 * The user may replace this with some multithreaded implementation,
2047 * the default implementation will execute the parts serially.
2048 * @param count the number of things to execute
2049 * - encoding: Set by libavcodec, user can override.
2050 * - decoding: Set by libavcodec, user can override.
2052 int (*execute
)(struct AVCodecContext
*c
, int (*func
)(struct AVCodecContext
*c2
, void *arg
), void *arg2
, int *ret
, int count
, int size
);
2056 * Can be used by execute() to store some per AVCodecContext stuff.
2057 * - encoding: set by execute()
2058 * - decoding: set by execute()
2060 void *thread_opaque
;
2063 * Motion estimation threshold below which no motion estimation is
2064 * performed, but instead the user specified motion vectors are used.
2066 * - encoding: Set by user.
2067 * - decoding: unused
2072 * Macroblock threshold below which the user specified macroblock types will be used.
2073 * - encoding: Set by user.
2074 * - decoding: unused
2079 * precision of the intra DC coefficient - 8
2080 * - encoding: Set by user.
2081 * - decoding: unused
2083 int intra_dc_precision
;
2086 * noise vs. sse weight for the nsse comparsion function
2087 * - encoding: Set by user.
2088 * - decoding: unused
2093 * Number of macroblock rows at the top which are skipped.
2094 * - encoding: unused
2095 * - decoding: Set by user.
2100 * Number of macroblock rows at the bottom which are skipped.
2101 * - encoding: unused
2102 * - decoding: Set by user.
2108 * - encoding: Set by user.
2109 * - decoding: Set by libavcodec.
2112 #define FF_PROFILE_UNKNOWN -99
2113 #define FF_PROFILE_AAC_MAIN 0
2114 #define FF_PROFILE_AAC_LOW 1
2115 #define FF_PROFILE_AAC_SSR 2
2116 #define FF_PROFILE_AAC_LTP 3
2120 * - encoding: Set by user.
2121 * - decoding: Set by libavcodec.
2124 #define FF_LEVEL_UNKNOWN -99
2127 * low resolution decoding, 1-> 1/2 size, 2->1/4 size
2128 * - encoding: unused
2129 * - decoding: Set by user.
2134 * Bitstream width / height, may be different from width/height if lowres
2135 * or other things are used.
2136 * - encoding: unused
2137 * - decoding: Set by user before init if known. Codec should override / dynamically change if needed.
2139 int coded_width
, coded_height
;
2142 * frame skip threshold
2143 * - encoding: Set by user.
2144 * - decoding: unused
2146 int frame_skip_threshold
;
2150 * - encoding: Set by user.
2151 * - decoding: unused
2153 int frame_skip_factor
;
2156 * frame skip exponent
2157 * - encoding: Set by user.
2158 * - decoding: unused
2163 * frame skip comparison function
2164 * - encoding: Set by user.
2165 * - decoding: unused
2170 * Border processing masking, raises the quantizer for mbs on the borders
2172 * - encoding: Set by user.
2173 * - decoding: unused
2175 float border_masking
;
2178 * minimum MB lagrange multipler
2179 * - encoding: Set by user.
2180 * - decoding: unused
2185 * maximum MB lagrange multipler
2186 * - encoding: Set by user.
2187 * - decoding: unused
2193 * - encoding: Set by user.
2194 * - decoding: unused
2196 int me_penalty_compensation
;
2200 * - encoding: unused
2201 * - decoding: Set by user.
2203 enum AVDiscard skip_loop_filter
;
2207 * - encoding: unused
2208 * - decoding: Set by user.
2210 enum AVDiscard skip_idct
;
2214 * - encoding: unused
2215 * - decoding: Set by user.
2217 enum AVDiscard skip_frame
;
2221 * - encoding: Set by user.
2222 * - decoding: unused
2228 * - encoding: Set by user.
2229 * - decoding: unused
2234 * constant rate factor - quality-based VBR - values ~correspond to qps
2235 * - encoding: Set by user.
2236 * - decoding: unused
2241 * constant quantization parameter rate control method
2242 * - encoding: Set by user.
2243 * - decoding: unused
2249 * - encoding: Set by user.
2250 * - decoding: unused
2255 * number of reference frames
2256 * - encoding: Set by user.
2257 * - decoding: Set by lavc.
2262 * chroma qp offset from luma
2263 * - encoding: Set by user.
2264 * - decoding: unused
2269 * Influences how often B-frames are used.
2270 * - encoding: Set by user.
2271 * - decoding: unused
2276 * trellis RD quantization
2277 * - encoding: Set by user.
2278 * - decoding: unused
2283 * Reduce fluctuations in qp (before curve compression).
2284 * - encoding: Set by user.
2285 * - decoding: unused
2287 float complexityblur
;
2290 * in-loop deblocking filter alphac0 parameter
2291 * alpha is in the range -6...6
2292 * - encoding: Set by user.
2293 * - decoding: unused
2298 * in-loop deblocking filter beta parameter
2299 * beta is in the range -6...6
2300 * - encoding: Set by user.
2301 * - decoding: unused
2306 * macroblock subpartition sizes to consider - p8x8, p4x4, b8x8, i8x8, i4x4
2307 * - encoding: Set by user.
2308 * - decoding: unused
2311 #define X264_PART_I4X4 0x001 /* Analyze i4x4 */
2312 #define X264_PART_I8X8 0x002 /* Analyze i8x8 (requires 8x8 transform) */
2313 #define X264_PART_P8X8 0x010 /* Analyze p16x8, p8x16 and p8x8 */
2314 #define X264_PART_P4X4 0x020 /* Analyze p8x4, p4x8, p4x4 */
2315 #define X264_PART_B8X8 0x100 /* Analyze b16x8, b8x16 and b8x8 */
2318 * direct MV prediction mode - 0 (none), 1 (spatial), 2 (temporal), 3 (auto)
2319 * - encoding: Set by user.
2320 * - decoding: unused
2325 * Audio cutoff bandwidth (0 means "automatic")
2326 * - encoding: Set by user.
2327 * - decoding: unused
2332 * Multiplied by qscale for each frame and added to scene_change_score.
2333 * - encoding: Set by user.
2334 * - decoding: unused
2336 int scenechange_factor
;
2340 * Note: Value depends upon the compare function used for fullpel ME.
2341 * - encoding: Set by user.
2342 * - decoding: unused
2347 * Adjusts sensitivity of b_frame_strategy 1.
2348 * - encoding: Set by user.
2349 * - decoding: unused
2354 * - encoding: Set by user.
2355 * - decoding: unused
2357 int compression_level
;
2358 #define FF_COMPRESSION_DEFAULT -1
2361 * Sets whether to use LPC mode - used by FLAC encoder.
2362 * - encoding: Set by user.
2363 * - decoding: unused
2368 * LPC coefficient precision - used by FLAC encoder
2369 * - encoding: Set by user.
2370 * - decoding: unused
2372 int lpc_coeff_precision
;
2375 * - encoding: Set by user.
2376 * - decoding: unused
2378 int min_prediction_order
;
2381 * - encoding: Set by user.
2382 * - decoding: unused
2384 int max_prediction_order
;
2387 * search method for selecting prediction order
2388 * - encoding: Set by user.
2389 * - decoding: unused
2391 int prediction_order_method
;
2394 * - encoding: Set by user.
2395 * - decoding: unused
2397 int min_partition_order
;
2400 * - encoding: Set by user.
2401 * - decoding: unused
2403 int max_partition_order
;
2406 * GOP timecode frame start number, in non drop frame format
2407 * - encoding: Set by user.
2408 * - decoding: unused
2410 int64_t timecode_frame_start
;
2412 #if LIBAVCODEC_VERSION_MAJOR < 53
2414 * Decoder should decode to this many channels if it can (0 for default)
2415 * - encoding: unused
2416 * - decoding: Set by user.
2417 * @deprecated Deprecated in favor of request_channel_layout.
2419 int request_channels
;
2423 * Percentage of dynamic range compression to be applied by the decoder.
2424 * The default value is 1.0, corresponding to full compression.
2425 * - encoding: unused
2426 * - decoding: Set by user.
2431 * opaque 64bit number (generally a PTS) that will be reordered and
2432 * output in AVFrame.reordered_opaque
2433 * - encoding: unused
2434 * - decoding: Set by user.
2436 int64_t reordered_opaque
;
2439 * Bits per sample/pixel of internal libavcodec pixel/sample format.
2440 * This field is applicable only when sample_fmt is SAMPLE_FMT_S32.
2441 * - encoding: set by user.
2442 * - decoding: set by libavcodec.
2444 int bits_per_raw_sample
;
2447 * Audio channel layout.
2448 * - encoding: set by user.
2449 * - decoding: set by libavcodec.
2451 int64_t channel_layout
;
2454 * Request decoder to use this channel layout if it can (0 for default)
2455 * - encoding: unused
2456 * - decoding: Set by user.
2458 int64_t request_channel_layout
;
2461 * Ratecontrol attempt to use, at maximum, <value> of what can be used without an underflow.
2462 * - encoding: Set by user.
2463 * - decoding: unused.
2465 float rc_max_available_vbv_use
;
2468 * Ratecontrol attempt to use, at least, <value> times the amount needed to prevent a vbv overflow.
2469 * - encoding: Set by user.
2470 * - decoding: unused.
2472 float rc_min_vbv_overflow_use
;
2475 * Hardware accelerator in use
2476 * - encoding: unused.
2477 * - decoding: Set by libavcodec
2479 struct AVHWAccel
*hwaccel
;
2482 * For some codecs, the time base is closer to the field rate than the frame rate.
2483 * Most notably, H.264 and MPEG-2 specify time_base as half of frame duration
2484 * if no telecine is used ...
2486 * Set to time_base ticks per frame. Default 1, e.g., H.264/MPEG-2 set it to 2.
2488 int ticks_per_frame
;
2491 * Hardware accelerator context.
2492 * For some hardware accelerators, a global context needs to be
2493 * provided by the user. In that case, this holds display-dependent
2494 * data FFmpeg cannot instantiate itself. Please refer to the
2495 * FFmpeg HW accelerator documentation to know how to fill this
2496 * is. e.g. for VA API, this is a struct vaapi_context.
2497 * - encoding: unused
2498 * - decoding: Set by user
2500 void *hwaccel_context
;
2503 * Chromaticity coordinates of the source primaries.
2504 * - encoding: Set by user
2505 * - decoding: Set by libavcodec
2507 enum AVColorPrimaries color_primaries
;
2510 * Color Transfer Characteristic.
2511 * - encoding: Set by user
2512 * - decoding: Set by libavcodec
2514 enum AVColorTransferCharacteristic color_trc
;
2517 * YUV colorspace type.
2518 * - encoding: Set by user
2519 * - decoding: Set by libavcodec
2521 enum AVColorSpace colorspace
;
2524 * MPEG vs JPEG YUV range.
2525 * - encoding: Set by user
2526 * - decoding: Set by libavcodec
2528 enum AVColorRange color_range
;
2531 * This defines the location of chroma samples.
2532 * - encoding: Set by user
2533 * - decoding: Set by libavcodec
2535 enum AVChromaLocation chroma_sample_location
;
2538 * The codec may call this to execute several independent things.
2539 * It will return only after finishing all tasks.
2540 * The user may replace this with some multithreaded implementation,
2541 * the default implementation will execute the parts serially.
2542 * Also see avcodec_thread_init and e.g. the --enable-pthread configure option.
2543 * @param c context passed also to func
2544 * @param count the number of things to execute
2545 * @param arg2 argument passed unchanged to func
2546 * @param ret return values of executed functions, must have space for "count" values. May be NULL.
2547 * @param func function that will be called count times, with jobnr from 0 to count-1.
2548 * threadnr will be in the range 0 to c->thread_count-1 < MAX_THREADS and so that no
2549 * two instances of func executing at the same time will have the same threadnr.
2550 * @return always 0 currently, but code should handle a future improvement where when any call to func
2551 * returns < 0 no further calls to func may be done and < 0 is returned.
2552 * - encoding: Set by libavcodec, user can override.
2553 * - decoding: Set by libavcodec, user can override.
2555 int (*execute2
)(struct AVCodecContext
*c
, int (*func
)(struct AVCodecContext
*c2
, void *arg
, int jobnr
, int threadnr
), void *arg2
, int *ret
, int count
);
2561 typedef struct AVCodec
{
2563 * Name of the codec implementation.
2564 * The name is globally unique among encoders and among decoders (but an
2565 * encoder and a decoder can share the same name).
2566 * This is the primary way to find a codec from the user perspective.
2569 enum CodecType type
;
2572 int (*init
)(AVCodecContext
*);
2573 int (*encode
)(AVCodecContext
*, uint8_t *buf
, int buf_size
, void *data
);
2574 int (*close
)(AVCodecContext
*);
2575 int (*decode
)(AVCodecContext
*, void *outdata
, int *outdata_size
, AVPacket
*avpkt
);
2577 * Codec capabilities.
2581 struct AVCodec
*next
;
2584 * Will be called when seeking
2586 void (*flush
)(AVCodecContext
*);
2587 const AVRational
*supported_framerates
; ///< array of supported framerates, or NULL if any, array is terminated by {0,0}
2588 const enum PixelFormat
*pix_fmts
; ///< array of supported pixel formats, or NULL if unknown, array is terminated by -1
2590 * Descriptive name for the codec, meant to be more human readable than name.
2591 * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
2593 const char *long_name
;
2594 const int *supported_samplerates
; ///< array of supported audio samplerates, or NULL if unknown, array is terminated by 0
2595 const enum SampleFormat
*sample_fmts
; ///< array of supported sample formats, or NULL if unknown, array is terminated by -1
2596 const int64_t *channel_layouts
; ///< array of support channel layouts, or NULL if unknown. array is terminated by 0
2602 typedef struct AVHWAccel
{
2604 * Name of the hardware accelerated codec.
2605 * The name is globally unique among encoders and among decoders (but an
2606 * encoder and a decoder can share the same name).
2611 * Type of codec implemented by the hardware accelerator.
2613 * See CODEC_TYPE_xxx
2615 enum CodecType type
;
2618 * Codec implemented by the hardware accelerator.
2625 * Supported pixel format.
2627 * Only hardware accelerated formats are supported here.
2629 enum PixelFormat pix_fmt
;
2632 * Hardware accelerated codec capabilities.
2633 * see FF_HWACCEL_CODEC_CAP_*
2637 struct AVHWAccel
*next
;
2640 * Called at the beginning of each frame or field picture.
2642 * Meaningful frame information (codec specific) is guaranteed to
2643 * be parsed at this point. This function is mandatory.
2645 * Note that buf can be NULL along with buf_size set to 0.
2646 * Otherwise, this means the whole frame is available at this point.
2648 * @param avctx the codec context
2649 * @param buf the frame data buffer base
2650 * @param buf_size the size of the frame in bytes
2651 * @return zero if successful, a negative value otherwise
2653 int (*start_frame
)(AVCodecContext
*avctx
, const uint8_t *buf
, uint32_t buf_size
);
2656 * Callback for each slice.
2658 * Meaningful slice information (codec specific) is guaranteed to
2659 * be parsed at this point. This function is mandatory.
2661 * @param avctx the codec context
2662 * @param buf the slice data buffer base
2663 * @param buf_size the size of the slice in bytes
2664 * @return zero if successful, a negative value otherwise
2666 int (*decode_slice
)(AVCodecContext
*avctx
, const uint8_t *buf
, uint32_t buf_size
);
2669 * Called at the end of each frame or field picture.
2671 * The whole picture is parsed at this point and can now be sent
2672 * to the hardware accelerator. This function is mandatory.
2674 * @param avctx the codec context
2675 * @return zero if successful, a negative value otherwise
2677 int (*end_frame
)(AVCodecContext
*avctx
);
2680 * Size of HW accelerator private data.
2682 * Private data is allocated with av_mallocz() before
2683 * AVCodecContext.get_buffer() and deallocated after
2684 * AVCodecContext.release_buffer().
2690 * four components are given, that's all.
2691 * the last component is alpha
2693 typedef struct AVPicture
{
2695 int linesize
[4]; ///< number of bytes per line
2698 #if LIBAVCODEC_VERSION_MAJOR < 53
2701 * This structure defines a method for communicating palette changes
2702 * between and demuxer and a decoder.
2704 * @deprecated Use AVPacket to send palette changes instead.
2705 * This is totally broken.
2707 #define AVPALETTE_SIZE 1024
2708 #define AVPALETTE_COUNT 256
2709 typedef struct AVPaletteControl
{
2711 /* Demuxer sets this to 1 to indicate the palette has changed;
2712 * decoder resets to 0. */
2713 int palette_changed
;
2715 /* 4-byte ARGB palette entries, stored in native byte order; note that
2716 * the individual palette components should be on a 8-bit scale; if
2717 * the palette data comes from an IBM VGA native format, the component
2718 * data is probably 6 bits in size and needs to be scaled. */
2719 unsigned int palette
[AVPALETTE_COUNT
];
2721 } AVPaletteControl attribute_deprecated
;
2724 enum AVSubtitleType
{
2727 SUBTITLE_BITMAP
, ///< A bitmap, pict will be set
2730 * Plain text, the text field must be set by the decoder and is
2731 * authoritative. ass and pict fields may contain approximations.
2736 * Formatted text, the ass field must be set by the decoder and is
2737 * authoritative. pict and text fields may contain approximations.
2742 typedef struct AVSubtitleRect
{
2743 int x
; ///< top left corner of pict, undefined when pict is not set
2744 int y
; ///< top left corner of pict, undefined when pict is not set
2745 int w
; ///< width of pict, undefined when pict is not set
2746 int h
; ///< height of pict, undefined when pict is not set
2747 int nb_colors
; ///< number of colors in pict, undefined when pict is not set
2750 * data+linesize for the bitmap of this subtitle.
2751 * can be set for text/ass as well once they where rendered
2754 enum AVSubtitleType type
;
2756 char *text
; ///< 0 terminated plain UTF-8 text
2759 * 0 terminated ASS/SSA compatible event line.
2760 * The pressentation of this is unaffected by the other values in this
2766 typedef struct AVSubtitle
{
2767 uint16_t format
; /* 0 = graphics */
2768 uint32_t start_display_time
; /* relative to packet pts, in ms */
2769 uint32_t end_display_time
; /* relative to packet pts, in ms */
2771 AVSubtitleRect
**rects
;
2772 int64_t pts
; ///< Same as packet pts, in AV_TIME_BASE
2775 /* packet functions */
2778 * @deprecated use NULL instead
2780 attribute_deprecated
void av_destruct_packet_nofree(AVPacket
*pkt
);
2783 * Default packet destructor.
2785 void av_destruct_packet(AVPacket
*pkt
);
2788 * Initialize optional fields of a packet with default values.
2792 void av_init_packet(AVPacket
*pkt
);
2795 * Allocate the payload of a packet and initialize its fields with
2799 * @param size wanted payload size
2800 * @return 0 if OK, AVERROR_xxx otherwise
2802 int av_new_packet(AVPacket
*pkt
, int size
);
2805 * Reduce packet size, correctly zeroing padding
2808 * @param size new size
2810 void av_shrink_packet(AVPacket
*pkt
, int size
);
2813 * @warning This is a hack - the packet memory allocation stuff is broken. The
2814 * packet is allocated if it was not really allocated.
2816 int av_dup_packet(AVPacket
*pkt
);
2821 * @param pkt packet to free
2823 void av_free_packet(AVPacket
*pkt
);
2827 struct ReSampleContext
;
2828 struct AVResampleContext
;
2830 typedef struct ReSampleContext ReSampleContext
;
2832 #if LIBAVCODEC_VERSION_MAJOR < 53
2834 * @deprecated Use av_audio_resample_init() instead.
2836 attribute_deprecated ReSampleContext
*audio_resample_init(int output_channels
, int input_channels
,
2837 int output_rate
, int input_rate
);
2840 * Initializes audio resampling context
2842 * @param output_channels number of output channels
2843 * @param input_channels number of input channels
2844 * @param output_rate output sample rate
2845 * @param input_rate input sample rate
2846 * @param sample_fmt_out requested output sample format
2847 * @param sample_fmt_in input sample format
2848 * @param filter_length length of each FIR filter in the filterbank relative to the cutoff freq
2849 * @param log2_phase_count log2 of the number of entries in the polyphase filterbank
2850 * @param linear If 1 then the used FIR filter will be linearly interpolated
2851 between the 2 closest, if 0 the closest will be used
2852 * @param cutoff cutoff frequency, 1.0 corresponds to half the output sampling rate
2853 * @return allocated ReSampleContext, NULL if error occured
2855 ReSampleContext
*av_audio_resample_init(int output_channels
, int input_channels
,
2856 int output_rate
, int input_rate
,
2857 enum SampleFormat sample_fmt_out
,
2858 enum SampleFormat sample_fmt_in
,
2859 int filter_length
, int log2_phase_count
,
2860 int linear
, double cutoff
);
2862 int audio_resample(ReSampleContext
*s
, short *output
, short *input
, int nb_samples
);
2863 void audio_resample_close(ReSampleContext
*s
);
2867 * Initializes an audio resampler.
2868 * Note, if either rate is not an integer then simply scale both rates up so they are.
2869 * @param filter_length length of each FIR filter in the filterbank relative to the cutoff freq
2870 * @param log2_phase_count log2 of the number of entries in the polyphase filterbank
2871 * @param linear If 1 then the used FIR filter will be linearly interpolated
2872 between the 2 closest, if 0 the closest will be used
2873 * @param cutoff cutoff frequency, 1.0 corresponds to half the output sampling rate
2875 struct AVResampleContext
*av_resample_init(int out_rate
, int in_rate
, int filter_length
, int log2_phase_count
, int linear
, double cutoff
);
2879 * @param src an array of unconsumed samples
2880 * @param consumed the number of samples of src which have been consumed are returned here
2881 * @param src_size the number of unconsumed samples available
2882 * @param dst_size the amount of space in samples available in dst
2883 * @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.
2884 * @return the number of samples written in dst or -1 if an error occurred
2886 int av_resample(struct AVResampleContext
*c
, short *dst
, short *src
, int *consumed
, int src_size
, int dst_size
, int update_ctx
);
2890 * Compensates samplerate/timestamp drift. The compensation is done by changing
2891 * the resampler parameters, so no audible clicks or similar distortions occur
2892 * @param compensation_distance distance in output samples over which the compensation should be performed
2893 * @param sample_delta number of output samples which should be output less
2895 * example: av_resample_compensate(c, 10, 500)
2896 * here instead of 510 samples only 500 samples would be output
2898 * note, due to rounding the actual compensation might be slightly different,
2899 * especially if the compensation_distance is large and the in_rate used during init is small
2901 void av_resample_compensate(struct AVResampleContext
*c
, int sample_delta
, int compensation_distance
);
2902 void av_resample_close(struct AVResampleContext
*c
);
2905 * Allocate memory for a picture. Call avpicture_free to free it.
2907 * @param picture the picture to be filled in
2908 * @param pix_fmt the format of the picture
2909 * @param width the width of the picture
2910 * @param height the height of the picture
2911 * @return zero if successful, a negative value if not
2913 int avpicture_alloc(AVPicture
*picture
, enum PixelFormat pix_fmt
, int width
, int height
);
2916 * Free a picture previously allocated by avpicture_alloc().
2918 * @param picture the AVPicture to be freed
2920 void avpicture_free(AVPicture
*picture
);
2923 * Fill in the AVPicture fields.
2924 * The fields of the given AVPicture are filled in by using the 'ptr' address
2925 * which points to the image data buffer. Depending on the specified picture
2926 * format, one or multiple image data pointers and line sizes will be set.
2927 * If a planar format is specified, several pointers will be set pointing to
2928 * the different picture planes and the line sizes of the different planes
2929 * will be stored in the lines_sizes array.
2930 * Call with ptr == NULL to get the required size for the ptr buffer.
2932 * @param picture AVPicture whose fields are to be filled in
2933 * @param ptr Buffer which will contain or contains the actual image data
2934 * @param pix_fmt The format in which the picture data is stored.
2935 * @param width the width of the image in pixels
2936 * @param height the height of the image in pixels
2937 * @return size of the image data in bytes
2939 int avpicture_fill(AVPicture
*picture
, uint8_t *ptr
,
2940 enum PixelFormat pix_fmt
, int width
, int height
);
2941 int avpicture_layout(const AVPicture
* src
, enum PixelFormat pix_fmt
, int width
, int height
,
2942 unsigned char *dest
, int dest_size
);
2945 * Calculate the size in bytes that a picture of the given width and height
2946 * would occupy if stored in the given picture format.
2947 * Note that this returns the size of a compact representation as generated
2948 * by avpicture_layout, which can be smaller than the size required for e.g.
2951 * @param pix_fmt the given picture format
2952 * @param width the width of the image
2953 * @param height the height of the image
2954 * @return Image data size in bytes or -1 on error (e.g. too large dimensions).
2956 int avpicture_get_size(enum PixelFormat pix_fmt
, int width
, int height
);
2957 void avcodec_get_chroma_sub_sample(enum PixelFormat pix_fmt
, int *h_shift
, int *v_shift
);
2958 const char *avcodec_get_pix_fmt_name(enum PixelFormat pix_fmt
);
2959 void avcodec_set_dimensions(AVCodecContext
*s
, int width
, int height
);
2962 * Returns the pixel format corresponding to the name name.
2964 * If there is no pixel format with name name, then looks for a
2965 * pixel format with the name corresponding to the native endian
2967 * For example in a little-endian system, first looks for "gray16",
2968 * then for "gray16le".
2970 * Finally if no pixel format has been found, returns PIX_FMT_NONE.
2972 enum PixelFormat
avcodec_get_pix_fmt(const char* name
);
2973 unsigned int avcodec_pix_fmt_to_codec_tag(enum PixelFormat p
);
2975 #define FF_LOSS_RESOLUTION 0x0001 /**< loss due to resolution change */
2976 #define FF_LOSS_DEPTH 0x0002 /**< loss due to color depth change */
2977 #define FF_LOSS_COLORSPACE 0x0004 /**< loss due to color space conversion */
2978 #define FF_LOSS_ALPHA 0x0008 /**< loss of alpha bits */
2979 #define FF_LOSS_COLORQUANT 0x0010 /**< loss due to color quantization */
2980 #define FF_LOSS_CHROMA 0x0020 /**< loss of chroma (e.g. RGB to gray conversion) */
2983 * Computes what kind of losses will occur when converting from one specific
2984 * pixel format to another.
2985 * When converting from one pixel format to another, information loss may occur.
2986 * For example, when converting from RGB24 to GRAY, the color information will
2987 * be lost. Similarly, other losses occur when converting from some formats to
2988 * other formats. These losses can involve loss of chroma, but also loss of
2989 * resolution, loss of color depth, loss due to the color space conversion, loss
2990 * of the alpha bits or loss due to color quantization.
2991 * avcodec_get_fix_fmt_loss() informs you about the various types of losses
2992 * which will occur when converting from one pixel format to another.
2994 * @param[in] dst_pix_fmt destination pixel format
2995 * @param[in] src_pix_fmt source pixel format
2996 * @param[in] has_alpha Whether the source pixel format alpha channel is used.
2997 * @return Combination of flags informing you what kind of losses will occur.
2999 int avcodec_get_pix_fmt_loss(enum PixelFormat dst_pix_fmt
, enum PixelFormat src_pix_fmt
,
3003 * Finds the best pixel format to convert to given a certain source pixel
3004 * format. When converting from one pixel format to another, information loss
3005 * may occur. For example, when converting from RGB24 to GRAY, the color
3006 * information will be lost. Similarly, other losses occur when converting from
3007 * some formats to other formats. avcodec_find_best_pix_fmt() searches which of
3008 * the given pixel formats should be used to suffer the least amount of loss.
3009 * The pixel formats from which it chooses one, are determined by the
3010 * pix_fmt_mask parameter.
3013 * src_pix_fmt = PIX_FMT_YUV420P;
3014 * pix_fmt_mask = (1 << PIX_FMT_YUV422P) || (1 << PIX_FMT_RGB24);
3015 * dst_pix_fmt = avcodec_find_best_pix_fmt(pix_fmt_mask, src_pix_fmt, alpha, &loss);
3018 * @param[in] pix_fmt_mask bitmask determining which pixel format to choose from
3019 * @param[in] src_pix_fmt source pixel format
3020 * @param[in] has_alpha Whether the source pixel format alpha channel is used.
3021 * @param[out] loss_ptr Combination of flags informing you what kind of losses will occur.
3022 * @return The best pixel format to convert to or -1 if none was found.
3024 enum PixelFormat
avcodec_find_best_pix_fmt(int64_t pix_fmt_mask
, enum PixelFormat src_pix_fmt
,
3025 int has_alpha
, int *loss_ptr
);
3029 * Print in buf the string corresponding to the pixel format with
3030 * number pix_fmt, or an header if pix_fmt is negative.
3032 * @param[in] buf the buffer where to write the string
3033 * @param[in] buf_size the size of buf
3034 * @param[in] pix_fmt the number of the pixel format to print the corresponding info string, or
3035 * a negative value to print the corresponding header.
3036 * Meaningful values for obtaining a pixel format info vary from 0 to PIX_FMT_NB -1.
3038 void avcodec_pix_fmt_string (char *buf
, int buf_size
, enum PixelFormat pix_fmt
);
3040 #define FF_ALPHA_TRANSP 0x0001 /* image has some totally transparent pixels */
3041 #define FF_ALPHA_SEMI_TRANSP 0x0002 /* image has some transparent pixels */
3044 * Tell if an image really has transparent alpha values.
3045 * @return ored mask of FF_ALPHA_xxx constants
3047 int img_get_alpha_info(const AVPicture
*src
,
3048 enum PixelFormat pix_fmt
, int width
, int height
);
3050 /* deinterlace a picture */
3051 /* deinterlace - if not supported return -1 */
3052 int avpicture_deinterlace(AVPicture
*dst
, const AVPicture
*src
,
3053 enum PixelFormat pix_fmt
, int width
, int height
);
3055 /* external high level API */
3058 * If c is NULL, returns the first registered codec,
3059 * if c is non-NULL, returns the next registered codec after c,
3060 * or NULL if c is the last one.
3062 AVCodec
*av_codec_next(AVCodec
*c
);
3065 * Returns the LIBAVCODEC_VERSION_INT constant.
3067 unsigned avcodec_version(void);
3070 * Initializes libavcodec.
3072 * @warning This function must be called before any other libavcodec
3075 void avcodec_init(void);
3077 #if LIBAVCODEC_VERSION_MAJOR < 53
3079 * @deprecated Deprecated in favor of avcodec_register().
3081 attribute_deprecated
void register_avcodec(AVCodec
*codec
);
3085 * Register the codec codec and initialize libavcodec.
3087 * @see avcodec_init()
3089 void avcodec_register(AVCodec
*codec
);
3092 * Finds a registered encoder with a matching codec ID.
3094 * @param id CodecID of the requested encoder
3095 * @return An encoder if one was found, NULL otherwise.
3097 AVCodec
*avcodec_find_encoder(enum CodecID id
);
3100 * Finds a registered encoder with the specified name.
3102 * @param name name of the requested encoder
3103 * @return An encoder if one was found, NULL otherwise.
3105 AVCodec
*avcodec_find_encoder_by_name(const char *name
);
3108 * Finds a registered decoder with a matching codec ID.
3110 * @param id CodecID of the requested decoder
3111 * @return A decoder if one was found, NULL otherwise.
3113 AVCodec
*avcodec_find_decoder(enum CodecID id
);
3116 * Finds a registered decoder with the specified name.
3118 * @param name name of the requested decoder
3119 * @return A decoder if one was found, NULL otherwise.
3121 AVCodec
*avcodec_find_decoder_by_name(const char *name
);
3122 void avcodec_string(char *buf
, int buf_size
, AVCodecContext
*enc
, int encode
);
3125 * Sets the fields of the given AVCodecContext to default values.
3127 * @param s The AVCodecContext of which the fields should be set to default values.
3129 void avcodec_get_context_defaults(AVCodecContext
*s
);
3131 /** THIS FUNCTION IS NOT YET PART OF THE PUBLIC API!
3132 * we WILL change its arguments and name a few times! */
3133 void avcodec_get_context_defaults2(AVCodecContext
*s
, enum CodecType
);
3136 * Allocates an AVCodecContext and sets its fields to default values. The
3137 * resulting struct can be deallocated by simply calling av_free().
3139 * @return An AVCodecContext filled with default values or NULL on failure.
3140 * @see avcodec_get_context_defaults
3142 AVCodecContext
*avcodec_alloc_context(void);
3144 /** THIS FUNCTION IS NOT YET PART OF THE PUBLIC API!
3145 * we WILL change its arguments and name a few times! */
3146 AVCodecContext
*avcodec_alloc_context2(enum CodecType
);
3149 * Sets the fields of the given AVFrame to default values.
3151 * @param pic The AVFrame of which the fields should be set to default values.
3153 void avcodec_get_frame_defaults(AVFrame
*pic
);
3156 * Allocates an AVFrame and sets its fields to default values. The resulting
3157 * struct can be deallocated by simply calling av_free().
3159 * @return An AVFrame filled with default values or NULL on failure.
3160 * @see avcodec_get_frame_defaults
3162 AVFrame
*avcodec_alloc_frame(void);
3164 int avcodec_default_get_buffer(AVCodecContext
*s
, AVFrame
*pic
);
3165 void avcodec_default_release_buffer(AVCodecContext
*s
, AVFrame
*pic
);
3166 int avcodec_default_reget_buffer(AVCodecContext
*s
, AVFrame
*pic
);
3167 void avcodec_align_dimensions(AVCodecContext
*s
, int *width
, int *height
);
3170 * Checks if the given dimension of a picture is valid, meaning that all
3171 * bytes of the picture can be addressed with a signed int.
3173 * @param[in] w Width of the picture.
3174 * @param[in] h Height of the picture.
3175 * @return Zero if valid, a negative value if invalid.
3177 int avcodec_check_dimensions(void *av_log_ctx
, unsigned int w
, unsigned int h
);
3178 enum PixelFormat
avcodec_default_get_format(struct AVCodecContext
*s
, const enum PixelFormat
* fmt
);
3180 int avcodec_thread_init(AVCodecContext
*s
, int thread_count
);
3181 void avcodec_thread_free(AVCodecContext
*s
);
3182 int avcodec_thread_execute(AVCodecContext
*s
, int (*func
)(AVCodecContext
*c2
, void *arg2
),void *arg
, int *ret
, int count
, int size
);
3183 int avcodec_default_execute(AVCodecContext
*c
, int (*func
)(AVCodecContext
*c2
, void *arg2
),void *arg
, int *ret
, int count
, int size
);
3184 int avcodec_default_execute2(AVCodecContext
*c
, int (*func
)(AVCodecContext
*c2
, void *arg2
, int, int),void *arg
, int *ret
, int count
);
3185 //FIXME func typedef
3188 * Initializes the AVCodecContext to use the given AVCodec. Prior to using this
3189 * function the context has to be allocated.
3191 * The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(),
3192 * avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for
3193 * retrieving a codec.
3195 * @warning This function is not thread safe!
3198 * avcodec_register_all();
3199 * codec = avcodec_find_decoder(CODEC_ID_H264);
3203 * context = avcodec_alloc_context();
3205 * if (avcodec_open(context, codec) < 0)
3209 * @param avctx The context which will be set up to use the given codec.
3210 * @param codec The codec to use within the context.
3211 * @return zero on success, a negative value on error
3212 * @see avcodec_alloc_context, avcodec_find_decoder, avcodec_find_encoder
3214 int avcodec_open(AVCodecContext
*avctx
, AVCodec
*codec
);
3216 #if LIBAVCODEC_VERSION_MAJOR < 53
3218 * Decodes an audio frame from buf into samples.
3219 * Wrapper function which calls avcodec_decode_audio3.
3221 * @deprecated Use avcodec_decode_audio3 instead.
3222 * @param avctx the codec context
3223 * @param[out] samples the output buffer
3224 * @param[in,out] frame_size_ptr the output buffer size in bytes
3225 * @param[in] buf the input buffer
3226 * @param[in] buf_size the input buffer size in bytes
3227 * @return On error a negative value is returned, otherwise the number of bytes
3228 * used or zero if no frame could be decompressed.
3230 attribute_deprecated
int avcodec_decode_audio2(AVCodecContext
*avctx
, int16_t *samples
,
3231 int *frame_size_ptr
,
3232 const uint8_t *buf
, int buf_size
);
3236 * Decodes the audio frame of size avpkt->size from avpkt->data into samples.
3237 * Some decoders may support multiple frames in a single AVPacket, such
3238 * decoders would then just decode the first frame. In this case,
3239 * avcodec_decode_audio3 has to be called again with an AVPacket that contains
3240 * the remaining data in order to decode the second frame etc.
3242 * could be outputted, frame_size_ptr is zero. Otherwise, it is the
3243 * decompressed frame size in bytes.
3245 * @warning You must set frame_size_ptr to the allocated size of the
3246 * output buffer before calling avcodec_decode_audio3().
3248 * @warning The input buffer must be FF_INPUT_BUFFER_PADDING_SIZE larger than
3249 * the actual read bytes because some optimized bitstream readers read 32 or 64
3250 * bits at once and could read over the end.
3252 * @warning The end of the input buffer avpkt->data should be set to 0 to ensure that
3253 * no overreading happens for damaged MPEG streams.
3255 * @note You might have to align the input buffer avpkt->data and output buffer
3256 * samples. The alignment requirements depend on the CPU: On some CPUs it isn't
3257 * necessary at all, on others it won't work at all if not aligned and on others
3258 * it will work but it will have an impact on performance.
3260 * In practice, avpkt->data should have 4 byte alignment at minimum and
3261 * samples should be 16 byte aligned unless the CPU doesn't need it
3262 * (AltiVec and SSE do).
3264 * @param avctx the codec context
3265 * @param[out] samples the output buffer, sample type in avctx->sample_fmt
3266 * @param[in,out] frame_size_ptr the output buffer size in bytes
3267 * @param[in] avpkt The input AVPacket containing the input buffer.
3268 * You can create such packet with av_init_packet() and by then setting
3269 * data and size, some decoders might in addition need other fields.
3270 * All decoders are designed to use the least fields possible though.
3271 * @return On error a negative value is returned, otherwise the number of bytes
3272 * used or zero if no frame data was decompressed (used) from the input AVPacket.
3274 int avcodec_decode_audio3(AVCodecContext
*avctx
, int16_t *samples
,
3275 int *frame_size_ptr
,
3278 #if LIBAVCODEC_VERSION_MAJOR < 53
3280 * Decodes a video frame from buf into picture.
3281 * Wrapper function which calls avcodec_decode_video2.
3283 * @deprecated Use avcodec_decode_video2 instead.
3284 * @param avctx the codec context
3285 * @param[out] picture The AVFrame in which the decoded video frame will be stored.
3286 * @param[in] buf the input buffer
3287 * @param[in] buf_size the size of the input buffer in bytes
3288 * @param[in,out] got_picture_ptr Zero if no frame could be decompressed, otherwise, it is nonzero.
3289 * @return On error a negative value is returned, otherwise the number of bytes
3290 * used or zero if no frame could be decompressed.
3292 attribute_deprecated
int avcodec_decode_video(AVCodecContext
*avctx
, AVFrame
*picture
,
3293 int *got_picture_ptr
,
3294 const uint8_t *buf
, int buf_size
);
3298 * Decodes the video frame of size avpkt->size from avpkt->data into picture.
3299 * Some decoders may support multiple frames in a single AVPacket, such
3300 * decoders would then just decode the first frame.
3302 * @warning The input buffer must be FF_INPUT_BUFFER_PADDING_SIZE larger than
3303 * the actual read bytes because some optimized bitstream readers read 32 or 64
3304 * bits at once and could read over the end.
3306 * @warning The end of the input buffer buf should be set to 0 to ensure that
3307 * no overreading happens for damaged MPEG streams.
3309 * @note You might have to align the input buffer avpkt->data.
3310 * The alignment requirements depend on the CPU: on some CPUs it isn't
3311 * necessary at all, on others it won't work at all if not aligned and on others
3312 * it will work but it will have an impact on performance.
3314 * In practice, avpkt->data should have 4 byte alignment at minimum.
3316 * @note Some codecs have a delay between input and output, these need to be
3317 * feeded with avpkt->data=NULL, avpkt->size=0 at the end to return the remaining frames.
3319 * @param avctx the codec context
3320 * @param[out] picture The AVFrame in which the decoded video frame will be stored.
3321 * @param[in] avpkt The input AVpacket containing the input buffer.
3322 * You can create such packet with av_init_packet() and by then setting
3323 * data and size, some decoders might in addition need other fields like
3324 * flags&PKT_FLAG_KEY. All decoders are designed to use the least
3326 * @param[in,out] got_picture_ptr Zero if no frame could be decompressed, otherwise, it is nonzero.
3327 * @return On error a negative value is returned, otherwise the number of bytes
3328 * used or zero if no frame could be decompressed.
3330 int avcodec_decode_video2(AVCodecContext
*avctx
, AVFrame
*picture
,
3331 int *got_picture_ptr
,
3334 #if LIBAVCODEC_VERSION_MAJOR < 53
3335 /* Decode a subtitle message. Return -1 if error, otherwise return the
3336 * number of bytes used. If no subtitle could be decompressed,
3337 * got_sub_ptr is zero. Otherwise, the subtitle is stored in *sub. */
3338 attribute_deprecated
int avcodec_decode_subtitle(AVCodecContext
*avctx
, AVSubtitle
*sub
,
3340 const uint8_t *buf
, int buf_size
);
3344 * Decodes a subtitle message.
3345 * Returns a negative value on error, otherwise returns the number of bytes used.
3346 * If no subtitle could be decompressed, got_sub_ptr is zero.
3347 * Otherwise, the subtitle is stored in *sub.
3349 * @param avctx the codec context
3350 * @param[out] sub The AVSubtitle in which the decoded subtitle will be stored.
3351 * @param[in,out] got_sub_ptr Zero if no subtitle could be decompressed, otherwise, it is nonzero.
3352 * @param[in] avpkt The input AVPacket containing the input buffer.
3354 int avcodec_decode_subtitle2(AVCodecContext
*avctx
, AVSubtitle
*sub
,
3357 int avcodec_parse_frame(AVCodecContext
*avctx
, uint8_t **pdata
,
3359 uint8_t *buf
, int buf_size
);
3362 * Encodes an audio frame from samples into buf.
3364 * @note The output buffer should be at least FF_MIN_BUFFER_SIZE bytes large.
3365 * However, for PCM audio the user will know how much space is needed
3366 * because it depends on the value passed in buf_size as described
3367 * below. In that case a lower value can be used.
3369 * @param avctx the codec context
3370 * @param[out] buf the output buffer
3371 * @param[in] buf_size the output buffer size
3372 * @param[in] samples the input buffer containing the samples
3373 * The number of samples read from this buffer is frame_size*channels,
3374 * both of which are defined in avctx.
3375 * For PCM audio the number of samples read from samples is equal to
3376 * buf_size * input_sample_size / output_sample_size.
3377 * @return On error a negative value is returned, on success zero or the number
3378 * of bytes used to encode the data read from the input buffer.
3380 int avcodec_encode_audio(AVCodecContext
*avctx
, uint8_t *buf
, int buf_size
,
3381 const short *samples
);
3384 * Encodes a video frame from pict into buf.
3385 * The input picture should be
3386 * stored using a specific format, namely avctx.pix_fmt.
3388 * @param avctx the codec context
3389 * @param[out] buf the output buffer for the bitstream of encoded frame
3390 * @param[in] buf_size the size of the output buffer in bytes
3391 * @param[in] pict the input picture to encode
3392 * @return On error a negative value is returned, on success zero or the number
3393 * of bytes used from the output buffer.
3395 int avcodec_encode_video(AVCodecContext
*avctx
, uint8_t *buf
, int buf_size
,
3396 const AVFrame
*pict
);
3397 int avcodec_encode_subtitle(AVCodecContext
*avctx
, uint8_t *buf
, int buf_size
,
3398 const AVSubtitle
*sub
);
3400 int avcodec_close(AVCodecContext
*avctx
);
3403 * Register all the codecs, parsers and bitstream filters which were enabled at
3404 * configuration time. If you do not call this function you can select exactly
3405 * which formats you want to support, by using the individual registration
3408 * @see avcodec_register
3409 * @see av_register_codec_parser
3410 * @see av_register_bitstream_filter
3412 void avcodec_register_all(void);
3415 * Flush buffers, should be called when seeking or when switching to a different stream.
3417 void avcodec_flush_buffers(AVCodecContext
*avctx
);
3419 void avcodec_default_free_buffers(AVCodecContext
*s
);
3421 /* misc useful functions */
3424 * Returns a single letter to describe the given picture type pict_type.
3426 * @param[in] pict_type the picture type
3427 * @return A single character representing the picture type.
3429 char av_get_pict_type_char(int pict_type
);
3432 * Returns codec bits per sample.
3434 * @param[in] codec_id the codec
3435 * @return Number of bits per sample or zero if unknown for the given codec.
3437 int av_get_bits_per_sample(enum CodecID codec_id
);
3440 * Returns sample format bits per sample.
3442 * @param[in] sample_fmt the sample format
3443 * @return Number of bits per sample or zero if unknown for the given sample format.
3445 int av_get_bits_per_sample_format(enum SampleFormat sample_fmt
);
3448 typedef struct AVCodecParserContext
{
3450 struct AVCodecParser
*parser
;
3451 int64_t frame_offset
; /* offset of the current frame */
3452 int64_t cur_offset
; /* current offset
3453 (incremented by each av_parser_parse()) */
3454 int64_t next_frame_offset
; /* offset of the next frame */
3456 int pict_type
; /* XXX: Put it back in AVCodecContext. */
3458 * This field is used for proper frame duration computation in lavf.
3459 * It signals, how much longer the frame duration of the current frame
3460 * is compared to normal frame duration.
3462 * frame_duration = (1 + repeat_pict) * time_base
3464 * It is used by codecs like H.264 to display telecined material.
3466 int repeat_pict
; /* XXX: Put it back in AVCodecContext. */
3467 int64_t pts
; /* pts of the current frame */
3468 int64_t dts
; /* dts of the current frame */
3473 int fetch_timestamp
;
3475 #define AV_PARSER_PTS_NB 4
3476 int cur_frame_start_index
;
3477 int64_t cur_frame_offset
[AV_PARSER_PTS_NB
];
3478 int64_t cur_frame_pts
[AV_PARSER_PTS_NB
];
3479 int64_t cur_frame_dts
[AV_PARSER_PTS_NB
];
3482 #define PARSER_FLAG_COMPLETE_FRAMES 0x0001
3484 int64_t offset
; ///< byte offset from starting packet start
3485 int64_t cur_frame_end
[AV_PARSER_PTS_NB
];
3488 * Set by parser to 1 for key frames and 0 for non-key frames.
3489 * It is initialized to -1, so if the parser doesn't set this flag,
3490 * old-style fallback using FF_I_TYPE picture type as key frames
3496 * Time difference in stream time base units from the pts of this
3497 * packet to the point at which the output from the decoder has converged
3498 * independent from the availability of previous frames. That is, the
3499 * frames are virtually identical no matter if decoding started from
3500 * the very first frame or from this keyframe.
3501 * Is AV_NOPTS_VALUE if unknown.
3502 * This field is not the display duration of the current frame.
3504 * The purpose of this field is to allow seeking in streams that have no
3505 * keyframes in the conventional sense. It corresponds to the
3506 * recovery point SEI in H.264 and match_time_delta in NUT. It is also
3507 * essential for some types of subtitle streams to ensure that all
3508 * subtitles are correctly displayed after seeking.
3510 int64_t convergence_duration
;
3512 // Timestamp generation support:
3514 * Synchronization point for start of timestamp generation.
3516 * Set to >0 for sync point, 0 for no sync point and <0 for undefined
3519 * For example, this corresponds to presence of H.264 buffering period
3525 * Offset of the current timestamp against last timestamp sync point in
3526 * units of AVCodecContext.time_base.
3528 * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
3529 * contain a valid timestamp offset.
3531 * Note that the timestamp of sync point has usually a nonzero
3532 * dts_ref_dts_delta, which refers to the previous sync point. Offset of
3533 * the next frame after timestamp sync point will be usually 1.
3535 * For example, this corresponds to H.264 cpb_removal_delay.
3537 int dts_ref_dts_delta
;
3540 * Presentation delay of current frame in units of AVCodecContext.time_base.
3542 * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
3543 * contain valid non-negative timestamp delta (presentation time of a frame
3544 * must not lie in the past).
3546 * This delay represents the difference between decoding and presentation
3547 * time of the frame.
3549 * For example, this corresponds to H.264 dpb_output_delay.
3554 * Position of the packet in file.
3556 * Analogous to cur_frame_pts/dts
3558 int64_t cur_frame_pos
[AV_PARSER_PTS_NB
];
3561 * Byte position of currently parsed frame in stream.
3566 * Previous frame byte position.
3569 } AVCodecParserContext
;
3571 typedef struct AVCodecParser
{
3572 int codec_ids
[5]; /* several codec IDs are permitted */
3574 int (*parser_init
)(AVCodecParserContext
*s
);
3575 int (*parser_parse
)(AVCodecParserContext
*s
,
3576 AVCodecContext
*avctx
,
3577 const uint8_t **poutbuf
, int *poutbuf_size
,
3578 const uint8_t *buf
, int buf_size
);
3579 void (*parser_close
)(AVCodecParserContext
*s
);
3580 int (*split
)(AVCodecContext
*avctx
, const uint8_t *buf
, int buf_size
);
3581 struct AVCodecParser
*next
;
3584 AVCodecParser
*av_parser_next(AVCodecParser
*c
);
3586 void av_register_codec_parser(AVCodecParser
*parser
);
3587 AVCodecParserContext
*av_parser_init(int codec_id
);
3589 #if LIBAVCODEC_VERSION_MAJOR < 53
3590 attribute_deprecated
3591 int av_parser_parse(AVCodecParserContext
*s
,
3592 AVCodecContext
*avctx
,
3593 uint8_t **poutbuf
, int *poutbuf_size
,
3594 const uint8_t *buf
, int buf_size
,
3595 int64_t pts
, int64_t dts
);
3601 * @param s parser context.
3602 * @param avctx codec context.
3603 * @param poutbuf set to pointer to parsed buffer or NULL if not yet finished.
3604 * @param poutbuf_size set to size of parsed buffer or zero if not yet finished.
3605 * @param buf input buffer.
3606 * @param buf_size input length, to signal EOF, this should be 0 (so that the last frame can be output).
3607 * @param pts input presentation timestamp.
3608 * @param dts input decoding timestamp.
3609 * @param pos input byte position in stream.
3610 * @return the number of bytes of the input bitstream used.
3615 * len = av_parser_parse2(myparser, AVCodecContext, &data, &size,
3622 * decode_frame(data, size);
3626 int av_parser_parse2(AVCodecParserContext
*s
,
3627 AVCodecContext
*avctx
,
3628 uint8_t **poutbuf
, int *poutbuf_size
,
3629 const uint8_t *buf
, int buf_size
,
3630 int64_t pts
, int64_t dts
,
3633 int av_parser_change(AVCodecParserContext
*s
,
3634 AVCodecContext
*avctx
,
3635 uint8_t **poutbuf
, int *poutbuf_size
,
3636 const uint8_t *buf
, int buf_size
, int keyframe
);
3637 void av_parser_close(AVCodecParserContext
*s
);
3640 typedef struct AVBitStreamFilterContext
{
3642 struct AVBitStreamFilter
*filter
;
3643 AVCodecParserContext
*parser
;
3644 struct AVBitStreamFilterContext
*next
;
3645 } AVBitStreamFilterContext
;
3648 typedef struct AVBitStreamFilter
{
3651 int (*filter
)(AVBitStreamFilterContext
*bsfc
,
3652 AVCodecContext
*avctx
, const char *args
,
3653 uint8_t **poutbuf
, int *poutbuf_size
,
3654 const uint8_t *buf
, int buf_size
, int keyframe
);
3655 void (*close
)(AVBitStreamFilterContext
*bsfc
);
3656 struct AVBitStreamFilter
*next
;
3657 } AVBitStreamFilter
;
3659 void av_register_bitstream_filter(AVBitStreamFilter
*bsf
);
3660 AVBitStreamFilterContext
*av_bitstream_filter_init(const char *name
);
3661 int av_bitstream_filter_filter(AVBitStreamFilterContext
*bsfc
,
3662 AVCodecContext
*avctx
, const char *args
,
3663 uint8_t **poutbuf
, int *poutbuf_size
,
3664 const uint8_t *buf
, int buf_size
, int keyframe
);
3665 void av_bitstream_filter_close(AVBitStreamFilterContext
*bsf
);
3667 AVBitStreamFilter
*av_bitstream_filter_next(AVBitStreamFilter
*f
);
3672 * Reallocates the given block if it is not large enough, otherwise it
3677 void *av_fast_realloc(void *ptr
, unsigned int *size
, unsigned int min_size
);
3680 * Allocates a buffer, reusing the given one if large enough.
3682 * Contrary to av_fast_realloc the current buffer contents might not be
3683 * preserved and on error the old buffer is freed, thus no special
3684 * handling to avoid memleaks is necessary.
3686 * @param ptr pointer to pointer to already allocated buffer, overwritten with pointer to new buffer
3687 * @param size size of the buffer *ptr points to
3688 * @param min_size minimum size of *ptr buffer after returning, *ptr will be NULL and
3689 * *size 0 if an error occurred.
3691 void av_fast_malloc(void *ptr
, unsigned int *size
, unsigned int min_size
);
3694 * Copy image 'src' to 'dst'.
3696 void av_picture_copy(AVPicture
*dst
, const AVPicture
*src
,
3697 enum PixelFormat pix_fmt
, int width
, int height
);
3700 * Crop image top and left side.
3702 int av_picture_crop(AVPicture
*dst
, const AVPicture
*src
,
3703 enum PixelFormat pix_fmt
, int top_band
, int left_band
);
3708 int av_picture_pad(AVPicture
*dst
, const AVPicture
*src
, int height
, int width
, enum PixelFormat pix_fmt
,
3709 int padtop
, int padbottom
, int padleft
, int padright
, int *color
);
3711 unsigned int av_xiphlacing(unsigned char *s
, unsigned int v
);
3714 * Parses str and put in width_ptr and height_ptr the detected values.
3716 * @return 0 in case of a successful parsing, a negative value otherwise
3717 * @param[in] str the string to parse: it has to be a string in the format
3718 * <width>x<height> or a valid video frame size abbreviation.
3719 * @param[in,out] width_ptr pointer to the variable which will contain the detected
3721 * @param[in,out] height_ptr pointer to the variable which will contain the detected
3722 * frame height value
3724 int av_parse_video_frame_size(int *width_ptr
, int *height_ptr
, const char *str
);
3727 * Parses str and put in frame_rate the detected values.
3729 * @return 0 in case of a successful parsing, a negative value otherwise
3730 * @param[in] str the string to parse: it has to be a string in the format
3731 * <frame_rate_num>/<frame_rate_den>, a float number or a valid video rate abbreviation
3732 * @param[in,out] frame_rate pointer to the AVRational which will contain the detected
3735 int av_parse_video_frame_rate(AVRational
*frame_rate
, const char *str
);
3737 /* error handling */
3739 #define AVERROR(e) (-(e)) /**< Returns a negative error code from a POSIX error code, to return from library functions. */
3740 #define AVUNERROR(e) (-(e)) /**< Returns a POSIX error code from a library function error return value. */
3742 /* Some platforms have E* and errno already negated. */
3743 #define AVERROR(e) (e)
3744 #define AVUNERROR(e) (e)
3746 #define AVERROR_UNKNOWN AVERROR(EINVAL) /**< unknown error */
3747 #define AVERROR_IO AVERROR(EIO) /**< I/O error */
3748 #define AVERROR_NUMEXPECTED AVERROR(EDOM) /**< Number syntax expected in filename. */
3749 #define AVERROR_INVALIDDATA AVERROR(EINVAL) /**< invalid data found */
3750 #define AVERROR_NOMEM AVERROR(ENOMEM) /**< not enough memory */
3751 #define AVERROR_NOFMT AVERROR(EILSEQ) /**< unknown format */
3752 #define AVERROR_NOTSUPP AVERROR(ENOSYS) /**< Operation not supported. */
3753 #define AVERROR_NOENT AVERROR(ENOENT) /**< No such file or directory. */
3754 #define AVERROR_EOF AVERROR(EPIPE) /**< End of file. */
3755 #define AVERROR_PATCHWELCOME -MKTAG('P','A','W','E') /**< Not yet implemented in FFmpeg. Patches welcome. */
3758 * Logs a generic warning message about a missing feature. This function is
3759 * intended to be used internally by FFmpeg (libavcodec, libavformat, etc.)
3760 * only, and would normally not be used by applications.
3761 * @param[in] avc a pointer to an arbitrary struct of which the first field is
3762 * a pointer to an AVClass struct
3763 * @param[in] feature string containing the name of the missing feature
3764 * @param[in] want_sample indicates if samples are wanted which exhibit this feature.
3765 * If want_sample is non-zero, additional verbage will be added to the log
3766 * message which tells the user how to report samples to the development
3769 void av_log_missing_feature(void *avc
, const char *feature
, int want_sample
);
3772 * Logs a generic warning message asking for a sample. This function is
3773 * intended to be used internally by FFmpeg (libavcodec, libavformat, etc.)
3774 * only, and would normally not be used by applications.
3775 * @param[in] avc a pointer to an arbitrary struct of which the first field is
3776 * a pointer to an AVClass struct
3777 * @param[in] msg string containing an optional message, or NULL if no message
3779 void av_log_ask_for_sample(void *avc
, const char *msg
);
3782 * Registers the hardware accelerator hwaccel.
3784 void av_register_hwaccel(AVHWAccel
*hwaccel
);
3787 * If hwaccel is NULL, returns the first registered hardware accelerator,
3788 * if hwaccel is non-NULL, returns the next registered hardware accelerator
3789 * after hwaccel, or NULL if hwaccel is the last one.
3791 AVHWAccel
*av_hwaccel_next(AVHWAccel
*hwaccel
);
3795 * Lock operation used by lockmgr
3798 AV_LOCK_CREATE
, ///< Create a mutex
3799 AV_LOCK_OBTAIN
, ///< Lock the mutex
3800 AV_LOCK_RELEASE
, ///< Unlock the mutex
3801 AV_LOCK_DESTROY
, ///< Free mutex resources
3805 * Register a user provided lock manager supporting the operations
3806 * specified by AVLockOp. mutex points to a (void *) where the
3807 * lockmgr should store/get a pointer to a user allocated mutex. It's
3808 * NULL upon AV_LOCK_CREATE and != NULL for all other ops.
3810 * @param cb User defined callback. Note: FFmpeg may invoke calls to this
3811 * callback during the call to av_lockmgr_register().
3812 * Thus, the application must be prepared to handle that.
3813 * If cb is set to NULL the lockmgr will be unregistered.
3814 * Also note that during unregistration the previously registered
3815 * lockmgr callback may also be invoked.
3817 int av_lockmgr_register(int (*cb
)(void **mutex
, enum AVLockOp op
));
3819 #endif /* AVCODEC_AVCODEC_H */