lavc: fix mixing CODEC_ID/AV_CODEC_ID in C++ code.
[libav.git] / libavcodec / avcodec.h
1 /*
2 * copyright (c) 2001 Fabrice Bellard
3 *
4 * This file is part of Libav.
5 *
6 * Libav is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * Libav is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with Libav; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21 #ifndef AVCODEC_AVCODEC_H
22 #define AVCODEC_AVCODEC_H
23
24 /**
25 * @file
26 * external API header
27 */
28
29 #include <errno.h>
30 #include "libavutil/samplefmt.h"
31 #include "libavutil/avutil.h"
32 #include "libavutil/cpu.h"
33 #include "libavutil/dict.h"
34 #include "libavutil/log.h"
35 #include "libavutil/pixfmt.h"
36 #include "libavutil/rational.h"
37
38 #include "libavcodec/version.h"
39 /**
40 * @defgroup libavc Encoding/Decoding Library
41 * @{
42 *
43 * @defgroup lavc_decoding Decoding
44 * @{
45 * @}
46 *
47 * @defgroup lavc_encoding Encoding
48 * @{
49 * @}
50 *
51 * @defgroup lavc_codec Codecs
52 * @{
53 * @defgroup lavc_codec_native Native Codecs
54 * @{
55 * @}
56 * @defgroup lavc_codec_wrappers External library wrappers
57 * @{
58 * @}
59 * @defgroup lavc_codec_hwaccel Hardware Accelerators bridge
60 * @{
61 * @}
62 * @}
63 * @defgroup lavc_internal Internal
64 * @{
65 * @}
66 * @}
67 *
68 */
69
70 /**
71 * @defgroup lavc_core Core functions/structures.
72 * @ingroup libavc
73 *
74 * Basic definitions, functions for querying libavcodec capabilities,
75 * allocating core structures, etc.
76 * @{
77 */
78
79
80 /**
81 * Identify the syntax and semantics of the bitstream.
82 * The principle is roughly:
83 * Two decoders with the same ID can decode the same streams.
84 * Two encoders with the same ID can encode compatible streams.
85 * There may be slight deviations from the principle due to implementation
86 * details.
87 *
88 * If you add a codec ID to this list, add it so that
89 * 1. no value of a existing codec ID changes (that would break ABI),
90 * 2. it is as close as possible to similar codecs.
91 */
92 enum AVCodecID {
93 AV_CODEC_ID_NONE,
94
95 /* video codecs */
96 AV_CODEC_ID_MPEG1VIDEO,
97 AV_CODEC_ID_MPEG2VIDEO, ///< preferred ID for MPEG-1/2 video decoding
98 AV_CODEC_ID_MPEG2VIDEO_XVMC,
99 AV_CODEC_ID_H261,
100 AV_CODEC_ID_H263,
101 AV_CODEC_ID_RV10,
102 AV_CODEC_ID_RV20,
103 AV_CODEC_ID_MJPEG,
104 AV_CODEC_ID_MJPEGB,
105 AV_CODEC_ID_LJPEG,
106 AV_CODEC_ID_SP5X,
107 AV_CODEC_ID_JPEGLS,
108 AV_CODEC_ID_MPEG4,
109 AV_CODEC_ID_RAWVIDEO,
110 AV_CODEC_ID_MSMPEG4V1,
111 AV_CODEC_ID_MSMPEG4V2,
112 AV_CODEC_ID_MSMPEG4V3,
113 AV_CODEC_ID_WMV1,
114 AV_CODEC_ID_WMV2,
115 AV_CODEC_ID_H263P,
116 AV_CODEC_ID_H263I,
117 AV_CODEC_ID_FLV1,
118 AV_CODEC_ID_SVQ1,
119 AV_CODEC_ID_SVQ3,
120 AV_CODEC_ID_DVVIDEO,
121 AV_CODEC_ID_HUFFYUV,
122 AV_CODEC_ID_CYUV,
123 AV_CODEC_ID_H264,
124 AV_CODEC_ID_INDEO3,
125 AV_CODEC_ID_VP3,
126 AV_CODEC_ID_THEORA,
127 AV_CODEC_ID_ASV1,
128 AV_CODEC_ID_ASV2,
129 AV_CODEC_ID_FFV1,
130 AV_CODEC_ID_4XM,
131 AV_CODEC_ID_VCR1,
132 AV_CODEC_ID_CLJR,
133 AV_CODEC_ID_MDEC,
134 AV_CODEC_ID_ROQ,
135 AV_CODEC_ID_INTERPLAY_VIDEO,
136 AV_CODEC_ID_XAN_WC3,
137 AV_CODEC_ID_XAN_WC4,
138 AV_CODEC_ID_RPZA,
139 AV_CODEC_ID_CINEPAK,
140 AV_CODEC_ID_WS_VQA,
141 AV_CODEC_ID_MSRLE,
142 AV_CODEC_ID_MSVIDEO1,
143 AV_CODEC_ID_IDCIN,
144 AV_CODEC_ID_8BPS,
145 AV_CODEC_ID_SMC,
146 AV_CODEC_ID_FLIC,
147 AV_CODEC_ID_TRUEMOTION1,
148 AV_CODEC_ID_VMDVIDEO,
149 AV_CODEC_ID_MSZH,
150 AV_CODEC_ID_ZLIB,
151 AV_CODEC_ID_QTRLE,
152 AV_CODEC_ID_SNOW,
153 AV_CODEC_ID_TSCC,
154 AV_CODEC_ID_ULTI,
155 AV_CODEC_ID_QDRAW,
156 AV_CODEC_ID_VIXL,
157 AV_CODEC_ID_QPEG,
158 AV_CODEC_ID_PNG,
159 AV_CODEC_ID_PPM,
160 AV_CODEC_ID_PBM,
161 AV_CODEC_ID_PGM,
162 AV_CODEC_ID_PGMYUV,
163 AV_CODEC_ID_PAM,
164 AV_CODEC_ID_FFVHUFF,
165 AV_CODEC_ID_RV30,
166 AV_CODEC_ID_RV40,
167 AV_CODEC_ID_VC1,
168 AV_CODEC_ID_WMV3,
169 AV_CODEC_ID_LOCO,
170 AV_CODEC_ID_WNV1,
171 AV_CODEC_ID_AASC,
172 AV_CODEC_ID_INDEO2,
173 AV_CODEC_ID_FRAPS,
174 AV_CODEC_ID_TRUEMOTION2,
175 AV_CODEC_ID_BMP,
176 AV_CODEC_ID_CSCD,
177 AV_CODEC_ID_MMVIDEO,
178 AV_CODEC_ID_ZMBV,
179 AV_CODEC_ID_AVS,
180 AV_CODEC_ID_SMACKVIDEO,
181 AV_CODEC_ID_NUV,
182 AV_CODEC_ID_KMVC,
183 AV_CODEC_ID_FLASHSV,
184 AV_CODEC_ID_CAVS,
185 AV_CODEC_ID_JPEG2000,
186 AV_CODEC_ID_VMNC,
187 AV_CODEC_ID_VP5,
188 AV_CODEC_ID_VP6,
189 AV_CODEC_ID_VP6F,
190 AV_CODEC_ID_TARGA,
191 AV_CODEC_ID_DSICINVIDEO,
192 AV_CODEC_ID_TIERTEXSEQVIDEO,
193 AV_CODEC_ID_TIFF,
194 AV_CODEC_ID_GIF,
195 AV_CODEC_ID_DXA,
196 AV_CODEC_ID_DNXHD,
197 AV_CODEC_ID_THP,
198 AV_CODEC_ID_SGI,
199 AV_CODEC_ID_C93,
200 AV_CODEC_ID_BETHSOFTVID,
201 AV_CODEC_ID_PTX,
202 AV_CODEC_ID_TXD,
203 AV_CODEC_ID_VP6A,
204 AV_CODEC_ID_AMV,
205 AV_CODEC_ID_VB,
206 AV_CODEC_ID_PCX,
207 AV_CODEC_ID_SUNRAST,
208 AV_CODEC_ID_INDEO4,
209 AV_CODEC_ID_INDEO5,
210 AV_CODEC_ID_MIMIC,
211 AV_CODEC_ID_RL2,
212 AV_CODEC_ID_ESCAPE124,
213 AV_CODEC_ID_DIRAC,
214 AV_CODEC_ID_BFI,
215 AV_CODEC_ID_CMV,
216 AV_CODEC_ID_MOTIONPIXELS,
217 AV_CODEC_ID_TGV,
218 AV_CODEC_ID_TGQ,
219 AV_CODEC_ID_TQI,
220 AV_CODEC_ID_AURA,
221 AV_CODEC_ID_AURA2,
222 AV_CODEC_ID_V210X,
223 AV_CODEC_ID_TMV,
224 AV_CODEC_ID_V210,
225 AV_CODEC_ID_DPX,
226 AV_CODEC_ID_MAD,
227 AV_CODEC_ID_FRWU,
228 AV_CODEC_ID_FLASHSV2,
229 AV_CODEC_ID_CDGRAPHICS,
230 AV_CODEC_ID_R210,
231 AV_CODEC_ID_ANM,
232 AV_CODEC_ID_BINKVIDEO,
233 AV_CODEC_ID_IFF_ILBM,
234 AV_CODEC_ID_IFF_BYTERUN1,
235 AV_CODEC_ID_KGV1,
236 AV_CODEC_ID_YOP,
237 AV_CODEC_ID_VP8,
238 AV_CODEC_ID_PICTOR,
239 AV_CODEC_ID_ANSI,
240 AV_CODEC_ID_A64_MULTI,
241 AV_CODEC_ID_A64_MULTI5,
242 AV_CODEC_ID_R10K,
243 AV_CODEC_ID_MXPEG,
244 AV_CODEC_ID_LAGARITH,
245 AV_CODEC_ID_PRORES,
246 AV_CODEC_ID_JV,
247 AV_CODEC_ID_DFA,
248 AV_CODEC_ID_WMV3IMAGE,
249 AV_CODEC_ID_VC1IMAGE,
250 AV_CODEC_ID_UTVIDEO,
251 AV_CODEC_ID_BMV_VIDEO,
252 AV_CODEC_ID_VBLE,
253 AV_CODEC_ID_DXTORY,
254 AV_CODEC_ID_V410,
255 AV_CODEC_ID_XWD,
256 AV_CODEC_ID_CDXL,
257 AV_CODEC_ID_XBM,
258 AV_CODEC_ID_ZEROCODEC,
259 AV_CODEC_ID_MSS1,
260 AV_CODEC_ID_MSA1,
261 AV_CODEC_ID_TSCC2,
262 AV_CODEC_ID_MTS2,
263 AV_CODEC_ID_CLLC,
264
265 /* various PCM "codecs" */
266 AV_CODEC_ID_FIRST_AUDIO = 0x10000, ///< A dummy id pointing at the start of audio codecs
267 AV_CODEC_ID_PCM_S16LE = 0x10000,
268 AV_CODEC_ID_PCM_S16BE,
269 AV_CODEC_ID_PCM_U16LE,
270 AV_CODEC_ID_PCM_U16BE,
271 AV_CODEC_ID_PCM_S8,
272 AV_CODEC_ID_PCM_U8,
273 AV_CODEC_ID_PCM_MULAW,
274 AV_CODEC_ID_PCM_ALAW,
275 AV_CODEC_ID_PCM_S32LE,
276 AV_CODEC_ID_PCM_S32BE,
277 AV_CODEC_ID_PCM_U32LE,
278 AV_CODEC_ID_PCM_U32BE,
279 AV_CODEC_ID_PCM_S24LE,
280 AV_CODEC_ID_PCM_S24BE,
281 AV_CODEC_ID_PCM_U24LE,
282 AV_CODEC_ID_PCM_U24BE,
283 AV_CODEC_ID_PCM_S24DAUD,
284 AV_CODEC_ID_PCM_ZORK,
285 AV_CODEC_ID_PCM_S16LE_PLANAR,
286 AV_CODEC_ID_PCM_DVD,
287 AV_CODEC_ID_PCM_F32BE,
288 AV_CODEC_ID_PCM_F32LE,
289 AV_CODEC_ID_PCM_F64BE,
290 AV_CODEC_ID_PCM_F64LE,
291 AV_CODEC_ID_PCM_BLURAY,
292 AV_CODEC_ID_PCM_LXF,
293 AV_CODEC_ID_S302M,
294 AV_CODEC_ID_PCM_S8_PLANAR,
295
296 /* various ADPCM codecs */
297 AV_CODEC_ID_ADPCM_IMA_QT = 0x11000,
298 AV_CODEC_ID_ADPCM_IMA_WAV,
299 AV_CODEC_ID_ADPCM_IMA_DK3,
300 AV_CODEC_ID_ADPCM_IMA_DK4,
301 AV_CODEC_ID_ADPCM_IMA_WS,
302 AV_CODEC_ID_ADPCM_IMA_SMJPEG,
303 AV_CODEC_ID_ADPCM_MS,
304 AV_CODEC_ID_ADPCM_4XM,
305 AV_CODEC_ID_ADPCM_XA,
306 AV_CODEC_ID_ADPCM_ADX,
307 AV_CODEC_ID_ADPCM_EA,
308 AV_CODEC_ID_ADPCM_G726,
309 AV_CODEC_ID_ADPCM_CT,
310 AV_CODEC_ID_ADPCM_SWF,
311 AV_CODEC_ID_ADPCM_YAMAHA,
312 AV_CODEC_ID_ADPCM_SBPRO_4,
313 AV_CODEC_ID_ADPCM_SBPRO_3,
314 AV_CODEC_ID_ADPCM_SBPRO_2,
315 AV_CODEC_ID_ADPCM_THP,
316 AV_CODEC_ID_ADPCM_IMA_AMV,
317 AV_CODEC_ID_ADPCM_EA_R1,
318 AV_CODEC_ID_ADPCM_EA_R3,
319 AV_CODEC_ID_ADPCM_EA_R2,
320 AV_CODEC_ID_ADPCM_IMA_EA_SEAD,
321 AV_CODEC_ID_ADPCM_IMA_EA_EACS,
322 AV_CODEC_ID_ADPCM_EA_XAS,
323 AV_CODEC_ID_ADPCM_EA_MAXIS_XA,
324 AV_CODEC_ID_ADPCM_IMA_ISS,
325 AV_CODEC_ID_ADPCM_G722,
326 AV_CODEC_ID_ADPCM_IMA_APC,
327
328 /* AMR */
329 AV_CODEC_ID_AMR_NB = 0x12000,
330 AV_CODEC_ID_AMR_WB,
331
332 /* RealAudio codecs*/
333 AV_CODEC_ID_RA_144 = 0x13000,
334 AV_CODEC_ID_RA_288,
335
336 /* various DPCM codecs */
337 AV_CODEC_ID_ROQ_DPCM = 0x14000,
338 AV_CODEC_ID_INTERPLAY_DPCM,
339 AV_CODEC_ID_XAN_DPCM,
340 AV_CODEC_ID_SOL_DPCM,
341
342 /* audio codecs */
343 AV_CODEC_ID_MP2 = 0x15000,
344 AV_CODEC_ID_MP3, ///< preferred ID for decoding MPEG audio layer 1, 2 or 3
345 AV_CODEC_ID_AAC,
346 AV_CODEC_ID_AC3,
347 AV_CODEC_ID_DTS,
348 AV_CODEC_ID_VORBIS,
349 AV_CODEC_ID_DVAUDIO,
350 AV_CODEC_ID_WMAV1,
351 AV_CODEC_ID_WMAV2,
352 AV_CODEC_ID_MACE3,
353 AV_CODEC_ID_MACE6,
354 AV_CODEC_ID_VMDAUDIO,
355 AV_CODEC_ID_FLAC,
356 AV_CODEC_ID_MP3ADU,
357 AV_CODEC_ID_MP3ON4,
358 AV_CODEC_ID_SHORTEN,
359 AV_CODEC_ID_ALAC,
360 AV_CODEC_ID_WESTWOOD_SND1,
361 AV_CODEC_ID_GSM, ///< as in Berlin toast format
362 AV_CODEC_ID_QDM2,
363 AV_CODEC_ID_COOK,
364 AV_CODEC_ID_TRUESPEECH,
365 AV_CODEC_ID_TTA,
366 AV_CODEC_ID_SMACKAUDIO,
367 AV_CODEC_ID_QCELP,
368 AV_CODEC_ID_WAVPACK,
369 AV_CODEC_ID_DSICINAUDIO,
370 AV_CODEC_ID_IMC,
371 AV_CODEC_ID_MUSEPACK7,
372 AV_CODEC_ID_MLP,
373 AV_CODEC_ID_GSM_MS, /* as found in WAV */
374 AV_CODEC_ID_ATRAC3,
375 AV_CODEC_ID_VOXWARE,
376 AV_CODEC_ID_APE,
377 AV_CODEC_ID_NELLYMOSER,
378 AV_CODEC_ID_MUSEPACK8,
379 AV_CODEC_ID_SPEEX,
380 AV_CODEC_ID_WMAVOICE,
381 AV_CODEC_ID_WMAPRO,
382 AV_CODEC_ID_WMALOSSLESS,
383 AV_CODEC_ID_ATRAC3P,
384 AV_CODEC_ID_EAC3,
385 AV_CODEC_ID_SIPR,
386 AV_CODEC_ID_MP1,
387 AV_CODEC_ID_TWINVQ,
388 AV_CODEC_ID_TRUEHD,
389 AV_CODEC_ID_MP4ALS,
390 AV_CODEC_ID_ATRAC1,
391 AV_CODEC_ID_BINKAUDIO_RDFT,
392 AV_CODEC_ID_BINKAUDIO_DCT,
393 AV_CODEC_ID_AAC_LATM,
394 AV_CODEC_ID_QDMC,
395 AV_CODEC_ID_CELT,
396 AV_CODEC_ID_G723_1,
397 AV_CODEC_ID_G729,
398 AV_CODEC_ID_8SVX_EXP,
399 AV_CODEC_ID_8SVX_FIB,
400 AV_CODEC_ID_BMV_AUDIO,
401 AV_CODEC_ID_RALF,
402 AV_CODEC_ID_IAC,
403 AV_CODEC_ID_ILBC,
404
405 /* subtitle codecs */
406 AV_CODEC_ID_FIRST_SUBTITLE = 0x17000, ///< A dummy ID pointing at the start of subtitle codecs.
407 AV_CODEC_ID_DVD_SUBTITLE = 0x17000,
408 AV_CODEC_ID_DVB_SUBTITLE,
409 AV_CODEC_ID_TEXT, ///< raw UTF-8 text
410 AV_CODEC_ID_XSUB,
411 AV_CODEC_ID_SSA,
412 AV_CODEC_ID_MOV_TEXT,
413 AV_CODEC_ID_HDMV_PGS_SUBTITLE,
414 AV_CODEC_ID_DVB_TELETEXT,
415 AV_CODEC_ID_SRT,
416
417 /* other specific kind of codecs (generally used for attachments) */
418 AV_CODEC_ID_FIRST_UNKNOWN = 0x18000, ///< A dummy ID pointing at the start of various fake codecs.
419 AV_CODEC_ID_TTF = 0x18000,
420
421 AV_CODEC_ID_PROBE = 0x19000, ///< codec_id is not known (like AV_CODEC_ID_NONE) but lavf should attempt to identify it
422
423 AV_CODEC_ID_MPEG2TS = 0x20000, /**< _FAKE_ codec to indicate a raw MPEG-2 TS
424 * stream (only used by libavformat) */
425 AV_CODEC_ID_MPEG4SYSTEMS = 0x20001, /**< _FAKE_ codec to indicate a MPEG-4 Systems
426 * stream (only used by libavformat) */
427 AV_CODEC_ID_FFMETADATA = 0x21000, ///< Dummy codec for streams containing only metadata information.
428
429 #if FF_API_CODEC_ID
430 #include "old_codec_ids.h"
431 #endif
432 };
433
434 #if FF_API_CODEC_ID
435 #define CodecID AVCodecID
436 #endif
437
438 #if FF_API_OLD_DECODE_AUDIO
439 /* in bytes */
440 #define AVCODEC_MAX_AUDIO_FRAME_SIZE 192000 // 1 second of 48khz 32bit audio
441 #endif
442
443 /**
444 * @ingroup lavc_decoding
445 * Required number of additionally allocated bytes at the end of the input bitstream for decoding.
446 * This is mainly needed because some optimized bitstream readers read
447 * 32 or 64 bit at once and could read over the end.<br>
448 * Note: If the first 23 bits of the additional bytes are not 0, then damaged
449 * MPEG bitstreams could cause overread and segfault.
450 */
451 #define FF_INPUT_BUFFER_PADDING_SIZE 8
452
453 /**
454 * @ingroup lavc_encoding
455 * minimum encoding buffer size
456 * Used to avoid some checks during header writing.
457 */
458 #define FF_MIN_BUFFER_SIZE 16384
459
460
461 /**
462 * @ingroup lavc_encoding
463 * motion estimation type.
464 */
465 enum Motion_Est_ID {
466 ME_ZERO = 1, ///< no search, that is use 0,0 vector whenever one is needed
467 ME_FULL,
468 ME_LOG,
469 ME_PHODS,
470 ME_EPZS, ///< enhanced predictive zonal search
471 ME_X1, ///< reserved for experiments
472 ME_HEX, ///< hexagon based search
473 ME_UMH, ///< uneven multi-hexagon search
474 ME_ITER, ///< iterative search
475 ME_TESA, ///< transformed exhaustive search algorithm
476 };
477
478 /**
479 * @ingroup lavc_decoding
480 */
481 enum AVDiscard{
482 /* We leave some space between them for extensions (drop some
483 * keyframes for intra-only or drop just some bidir frames). */
484 AVDISCARD_NONE =-16, ///< discard nothing
485 AVDISCARD_DEFAULT = 0, ///< discard useless packets like 0 size packets in avi
486 AVDISCARD_NONREF = 8, ///< discard all non reference
487 AVDISCARD_BIDIR = 16, ///< discard all bidirectional frames
488 AVDISCARD_NONKEY = 32, ///< discard all frames except keyframes
489 AVDISCARD_ALL = 48, ///< discard all
490 };
491
492 enum AVColorPrimaries{
493 AVCOL_PRI_BT709 = 1, ///< also ITU-R BT1361 / IEC 61966-2-4 / SMPTE RP177 Annex B
494 AVCOL_PRI_UNSPECIFIED = 2,
495 AVCOL_PRI_BT470M = 4,
496 AVCOL_PRI_BT470BG = 5, ///< also ITU-R BT601-6 625 / ITU-R BT1358 625 / ITU-R BT1700 625 PAL & SECAM
497 AVCOL_PRI_SMPTE170M = 6, ///< also ITU-R BT601-6 525 / ITU-R BT1358 525 / ITU-R BT1700 NTSC
498 AVCOL_PRI_SMPTE240M = 7, ///< functionally identical to above
499 AVCOL_PRI_FILM = 8,
500 AVCOL_PRI_NB , ///< Not part of ABI
501 };
502
503 enum AVColorTransferCharacteristic{
504 AVCOL_TRC_BT709 = 1, ///< also ITU-R BT1361
505 AVCOL_TRC_UNSPECIFIED = 2,
506 AVCOL_TRC_GAMMA22 = 4, ///< also ITU-R BT470M / ITU-R BT1700 625 PAL & SECAM
507 AVCOL_TRC_GAMMA28 = 5, ///< also ITU-R BT470BG
508 AVCOL_TRC_SMPTE240M = 7,
509 AVCOL_TRC_NB , ///< Not part of ABI
510 };
511
512 enum AVColorSpace{
513 AVCOL_SPC_RGB = 0,
514 AVCOL_SPC_BT709 = 1, ///< also ITU-R BT1361 / IEC 61966-2-4 xvYCC709 / SMPTE RP177 Annex B
515 AVCOL_SPC_UNSPECIFIED = 2,
516 AVCOL_SPC_FCC = 4,
517 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
518 AVCOL_SPC_SMPTE170M = 6, ///< also ITU-R BT601-6 525 / ITU-R BT1358 525 / ITU-R BT1700 NTSC / functionally identical to above
519 AVCOL_SPC_SMPTE240M = 7,
520 AVCOL_SPC_YCOCG = 8, ///< Used by Dirac / VC-2 and H.264 FRext, see ITU-T SG16
521 AVCOL_SPC_NB , ///< Not part of ABI
522 };
523
524 enum AVColorRange{
525 AVCOL_RANGE_UNSPECIFIED = 0,
526 AVCOL_RANGE_MPEG = 1, ///< the normal 219*2^(n-8) "MPEG" YUV ranges
527 AVCOL_RANGE_JPEG = 2, ///< the normal 2^n-1 "JPEG" YUV ranges
528 AVCOL_RANGE_NB , ///< Not part of ABI
529 };
530
531 /**
532 * X X 3 4 X X are luma samples,
533 * 1 2 1-6 are possible chroma positions
534 * X X 5 6 X 0 is undefined/unknown position
535 */
536 enum AVChromaLocation{
537 AVCHROMA_LOC_UNSPECIFIED = 0,
538 AVCHROMA_LOC_LEFT = 1, ///< mpeg2/4, h264 default
539 AVCHROMA_LOC_CENTER = 2, ///< mpeg1, jpeg, h263
540 AVCHROMA_LOC_TOPLEFT = 3, ///< DV
541 AVCHROMA_LOC_TOP = 4,
542 AVCHROMA_LOC_BOTTOMLEFT = 5,
543 AVCHROMA_LOC_BOTTOM = 6,
544 AVCHROMA_LOC_NB , ///< Not part of ABI
545 };
546
547 enum AVAudioServiceType {
548 AV_AUDIO_SERVICE_TYPE_MAIN = 0,
549 AV_AUDIO_SERVICE_TYPE_EFFECTS = 1,
550 AV_AUDIO_SERVICE_TYPE_VISUALLY_IMPAIRED = 2,
551 AV_AUDIO_SERVICE_TYPE_HEARING_IMPAIRED = 3,
552 AV_AUDIO_SERVICE_TYPE_DIALOGUE = 4,
553 AV_AUDIO_SERVICE_TYPE_COMMENTARY = 5,
554 AV_AUDIO_SERVICE_TYPE_EMERGENCY = 6,
555 AV_AUDIO_SERVICE_TYPE_VOICE_OVER = 7,
556 AV_AUDIO_SERVICE_TYPE_KARAOKE = 8,
557 AV_AUDIO_SERVICE_TYPE_NB , ///< Not part of ABI
558 };
559
560 /**
561 * @ingroup lavc_encoding
562 */
563 typedef struct RcOverride{
564 int start_frame;
565 int end_frame;
566 int qscale; // If this is 0 then quality_factor will be used instead.
567 float quality_factor;
568 } RcOverride;
569
570 #define FF_MAX_B_FRAMES 16
571
572 /* encoding support
573 These flags can be passed in AVCodecContext.flags before initialization.
574 Note: Not everything is supported yet.
575 */
576
577 #define CODEC_FLAG_QSCALE 0x0002 ///< Use fixed qscale.
578 #define CODEC_FLAG_4MV 0x0004 ///< 4 MV per MB allowed / advanced prediction for H.263.
579 #define CODEC_FLAG_QPEL 0x0010 ///< Use qpel MC.
580 #define CODEC_FLAG_GMC 0x0020 ///< Use GMC.
581 #define CODEC_FLAG_MV0 0x0040 ///< Always try a MB with MV=<0,0>.
582 /**
583 * The parent program guarantees that the input for B-frames containing
584 * streams is not written to for at least s->max_b_frames+1 frames, if
585 * this is not set the input will be copied.
586 */
587 #define CODEC_FLAG_INPUT_PRESERVED 0x0100
588 #define CODEC_FLAG_PASS1 0x0200 ///< Use internal 2pass ratecontrol in first pass mode.
589 #define CODEC_FLAG_PASS2 0x0400 ///< Use internal 2pass ratecontrol in second pass mode.
590 #define CODEC_FLAG_GRAY 0x2000 ///< Only decode/encode grayscale.
591 #define CODEC_FLAG_EMU_EDGE 0x4000 ///< Don't draw edges.
592 #define CODEC_FLAG_PSNR 0x8000 ///< error[?] variables will be set during encoding.
593 #define CODEC_FLAG_TRUNCATED 0x00010000 /** Input bitstream might be truncated at a random
594 location instead of only at frame boundaries. */
595 #define CODEC_FLAG_NORMALIZE_AQP 0x00020000 ///< Normalize adaptive quantization.
596 #define CODEC_FLAG_INTERLACED_DCT 0x00040000 ///< Use interlaced DCT.
597 #define CODEC_FLAG_LOW_DELAY 0x00080000 ///< Force low delay.
598 #define CODEC_FLAG_GLOBAL_HEADER 0x00400000 ///< Place global headers in extradata instead of every keyframe.
599 #define CODEC_FLAG_BITEXACT 0x00800000 ///< Use only bitexact stuff (except (I)DCT).
600 /* Fx : Flag for h263+ extra options */
601 #define CODEC_FLAG_AC_PRED 0x01000000 ///< H.263 advanced intra coding / MPEG-4 AC prediction
602 #define CODEC_FLAG_LOOP_FILTER 0x00000800 ///< loop filter
603 #define CODEC_FLAG_INTERLACED_ME 0x20000000 ///< interlaced motion estimation
604 #define CODEC_FLAG_CLOSED_GOP 0x80000000
605 #define CODEC_FLAG2_FAST 0x00000001 ///< Allow non spec compliant speedup tricks.
606 #define CODEC_FLAG2_NO_OUTPUT 0x00000004 ///< Skip bitstream encoding.
607 #define CODEC_FLAG2_LOCAL_HEADER 0x00000008 ///< Place global headers at every keyframe instead of in extradata.
608 #if FF_API_MPV_GLOBAL_OPTS
609 #define CODEC_FLAG_CBP_RD 0x04000000 ///< Use rate distortion optimization for cbp.
610 #define CODEC_FLAG_QP_RD 0x08000000 ///< Use rate distortion optimization for qp selectioon.
611 #define CODEC_FLAG2_STRICT_GOP 0x00000002 ///< Strictly enforce GOP size.
612 #define CODEC_FLAG2_SKIP_RD 0x00004000 ///< RD optimal MB level residual skipping
613 #endif
614 #define CODEC_FLAG2_CHUNKS 0x00008000 ///< Input bitstream might be truncated at a packet boundaries instead of only at frame boundaries.
615
616 /* Unsupported options :
617 * Syntax Arithmetic coding (SAC)
618 * Reference Picture Selection
619 * Independent Segment Decoding */
620 /* /Fx */
621 /* codec capabilities */
622
623 #define CODEC_CAP_DRAW_HORIZ_BAND 0x0001 ///< Decoder can use draw_horiz_band callback.
624 /**
625 * Codec uses get_buffer() for allocating buffers and supports custom allocators.
626 * If not set, it might not use get_buffer() at all or use operations that
627 * assume the buffer was allocated by avcodec_default_get_buffer.
628 */
629 #define CODEC_CAP_DR1 0x0002
630 #define CODEC_CAP_TRUNCATED 0x0008
631 /* Codec can export data for HW decoding (XvMC). */
632 #define CODEC_CAP_HWACCEL 0x0010
633 /**
634 * Encoder or decoder requires flushing with NULL input at the end in order to
635 * give the complete and correct output.
636 *
637 * NOTE: If this flag is not set, the codec is guaranteed to never be fed with
638 * with NULL data. The user can still send NULL data to the public encode
639 * or decode function, but libavcodec will not pass it along to the codec
640 * unless this flag is set.
641 *
642 * Decoders:
643 * The decoder has a non-zero delay and needs to be fed with avpkt->data=NULL,
644 * avpkt->size=0 at the end to get the delayed data until the decoder no longer
645 * returns frames.
646 *
647 * Encoders:
648 * The encoder needs to be fed with NULL data at the end of encoding until the
649 * encoder no longer returns data.
650 *
651 * NOTE: For encoders implementing the AVCodec.encode2() function, setting this
652 * flag also means that the encoder must set the pts and duration for
653 * each output packet. If this flag is not set, the pts and duration will
654 * be determined by libavcodec from the input frame.
655 */
656 #define CODEC_CAP_DELAY 0x0020
657 /**
658 * Codec can be fed a final frame with a smaller size.
659 * This can be used to prevent truncation of the last audio samples.
660 */
661 #define CODEC_CAP_SMALL_LAST_FRAME 0x0040
662 /**
663 * Codec can export data for HW decoding (VDPAU).
664 */
665 #define CODEC_CAP_HWACCEL_VDPAU 0x0080
666 /**
667 * Codec can output multiple frames per AVPacket
668 * Normally demuxers return one frame at a time, demuxers which do not do
669 * are connected to a parser to split what they return into proper frames.
670 * This flag is reserved to the very rare category of codecs which have a
671 * bitstream that cannot be split into frames without timeconsuming
672 * operations like full decoding. Demuxers carring such bitstreams thus
673 * may return multiple frames in a packet. This has many disadvantages like
674 * prohibiting stream copy in many cases thus it should only be considered
675 * as a last resort.
676 */
677 #define CODEC_CAP_SUBFRAMES 0x0100
678 /**
679 * Codec is experimental and is thus avoided in favor of non experimental
680 * encoders
681 */
682 #define CODEC_CAP_EXPERIMENTAL 0x0200
683 /**
684 * Codec should fill in channel configuration and samplerate instead of container
685 */
686 #define CODEC_CAP_CHANNEL_CONF 0x0400
687 /**
688 * Codec is able to deal with negative linesizes
689 */
690 #define CODEC_CAP_NEG_LINESIZES 0x0800
691 /**
692 * Codec supports frame-level multithreading.
693 */
694 #define CODEC_CAP_FRAME_THREADS 0x1000
695 /**
696 * Codec supports slice-based (or partition-based) multithreading.
697 */
698 #define CODEC_CAP_SLICE_THREADS 0x2000
699 /**
700 * Codec supports changed parameters at any point.
701 */
702 #define CODEC_CAP_PARAM_CHANGE 0x4000
703 /**
704 * Codec supports avctx->thread_count == 0 (auto).
705 */
706 #define CODEC_CAP_AUTO_THREADS 0x8000
707 /**
708 * Audio encoder supports receiving a different number of samples in each call.
709 */
710 #define CODEC_CAP_VARIABLE_FRAME_SIZE 0x10000
711
712 //The following defines may change, don't expect compatibility if you use them.
713 #define MB_TYPE_INTRA4x4 0x0001
714 #define MB_TYPE_INTRA16x16 0x0002 //FIXME H.264-specific
715 #define MB_TYPE_INTRA_PCM 0x0004 //FIXME H.264-specific
716 #define MB_TYPE_16x16 0x0008
717 #define MB_TYPE_16x8 0x0010
718 #define MB_TYPE_8x16 0x0020
719 #define MB_TYPE_8x8 0x0040
720 #define MB_TYPE_INTERLACED 0x0080
721 #define MB_TYPE_DIRECT2 0x0100 //FIXME
722 #define MB_TYPE_ACPRED 0x0200
723 #define MB_TYPE_GMC 0x0400
724 #define MB_TYPE_SKIP 0x0800
725 #define MB_TYPE_P0L0 0x1000
726 #define MB_TYPE_P1L0 0x2000
727 #define MB_TYPE_P0L1 0x4000
728 #define MB_TYPE_P1L1 0x8000
729 #define MB_TYPE_L0 (MB_TYPE_P0L0 | MB_TYPE_P1L0)
730 #define MB_TYPE_L1 (MB_TYPE_P0L1 | MB_TYPE_P1L1)
731 #define MB_TYPE_L0L1 (MB_TYPE_L0 | MB_TYPE_L1)
732 #define MB_TYPE_QUANT 0x00010000
733 #define MB_TYPE_CBP 0x00020000
734 //Note bits 24-31 are reserved for codec specific use (h264 ref0, mpeg1 0mv, ...)
735
736 /**
737 * Pan Scan area.
738 * This specifies the area which should be displayed.
739 * Note there may be multiple such areas for one frame.
740 */
741 typedef struct AVPanScan{
742 /**
743 * id
744 * - encoding: Set by user.
745 * - decoding: Set by libavcodec.
746 */
747 int id;
748
749 /**
750 * width and height in 1/16 pel
751 * - encoding: Set by user.
752 * - decoding: Set by libavcodec.
753 */
754 int width;
755 int height;
756
757 /**
758 * position of the top left corner in 1/16 pel for up to 3 fields/frames
759 * - encoding: Set by user.
760 * - decoding: Set by libavcodec.
761 */
762 int16_t position[3][2];
763 }AVPanScan;
764
765 #define FF_QSCALE_TYPE_MPEG1 0
766 #define FF_QSCALE_TYPE_MPEG2 1
767 #define FF_QSCALE_TYPE_H264 2
768 #define FF_QSCALE_TYPE_VP56 3
769
770 #define FF_BUFFER_TYPE_INTERNAL 1
771 #define FF_BUFFER_TYPE_USER 2 ///< direct rendering buffers (image is (de)allocated by user)
772 #define FF_BUFFER_TYPE_SHARED 4 ///< Buffer from somewhere else; don't deallocate image (data/base), all other tables are not shared.
773 #define FF_BUFFER_TYPE_COPY 8 ///< Just a (modified) copy of some other buffer, don't deallocate anything.
774
775 #define FF_BUFFER_HINTS_VALID 0x01 // Buffer hints value is meaningful (if 0 ignore).
776 #define FF_BUFFER_HINTS_READABLE 0x02 // Codec will read from buffer.
777 #define FF_BUFFER_HINTS_PRESERVE 0x04 // User must not alter buffer content.
778 #define FF_BUFFER_HINTS_REUSABLE 0x08 // Codec will reuse the buffer (update).
779
780 /**
781 * @defgroup lavc_packet AVPacket
782 *
783 * Types and functions for working with AVPacket.
784 * @{
785 */
786 enum AVPacketSideDataType {
787 AV_PKT_DATA_PALETTE,
788 AV_PKT_DATA_NEW_EXTRADATA,
789
790 /**
791 * An AV_PKT_DATA_PARAM_CHANGE side data packet is laid out as follows:
792 * @code
793 * u32le param_flags
794 * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT)
795 * s32le channel_count
796 * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT)
797 * u64le channel_layout
798 * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE)
799 * s32le sample_rate
800 * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS)
801 * s32le width
802 * s32le height
803 * @endcode
804 */
805 AV_PKT_DATA_PARAM_CHANGE,
806
807 /**
808 * An AV_PKT_DATA_H263_MB_INFO side data packet contains a number of
809 * structures with info about macroblocks relevant to splitting the
810 * packet into smaller packets on macroblock edges (e.g. as for RFC 2190).
811 * That is, it does not necessarily contain info about all macroblocks,
812 * as long as the distance between macroblocks in the info is smaller
813 * than the target payload size.
814 * Each MB info structure is 12 bytes, and is laid out as follows:
815 * @code
816 * u32le bit offset from the start of the packet
817 * u8 current quantizer at the start of the macroblock
818 * u8 GOB number
819 * u16le macroblock address within the GOB
820 * u8 horizontal MV predictor
821 * u8 vertical MV predictor
822 * u8 horizontal MV predictor for block number 3
823 * u8 vertical MV predictor for block number 3
824 * @endcode
825 */
826 AV_PKT_DATA_H263_MB_INFO,
827 };
828
829 typedef struct AVPacket {
830 /**
831 * Presentation timestamp in AVStream->time_base units; the time at which
832 * the decompressed packet will be presented to the user.
833 * Can be AV_NOPTS_VALUE if it is not stored in the file.
834 * pts MUST be larger or equal to dts as presentation cannot happen before
835 * decompression, unless one wants to view hex dumps. Some formats misuse
836 * the terms dts and pts/cts to mean something different. Such timestamps
837 * must be converted to true pts/dts before they are stored in AVPacket.
838 */
839 int64_t pts;
840 /**
841 * Decompression timestamp in AVStream->time_base units; the time at which
842 * the packet is decompressed.
843 * Can be AV_NOPTS_VALUE if it is not stored in the file.
844 */
845 int64_t dts;
846 uint8_t *data;
847 int size;
848 int stream_index;
849 /**
850 * A combination of AV_PKT_FLAG values
851 */
852 int flags;
853 /**
854 * Additional packet data that can be provided by the container.
855 * Packet can contain several types of side information.
856 */
857 struct {
858 uint8_t *data;
859 int size;
860 enum AVPacketSideDataType type;
861 } *side_data;
862 int side_data_elems;
863
864 /**
865 * Duration of this packet in AVStream->time_base units, 0 if unknown.
866 * Equals next_pts - this_pts in presentation order.
867 */
868 int duration;
869 void (*destruct)(struct AVPacket *);
870 void *priv;
871 int64_t pos; ///< byte position in stream, -1 if unknown
872
873 /**
874 * Time difference in AVStream->time_base units from the pts of this
875 * packet to the point at which the output from the decoder has converged
876 * independent from the availability of previous frames. That is, the
877 * frames are virtually identical no matter if decoding started from
878 * the very first frame or from this keyframe.
879 * Is AV_NOPTS_VALUE if unknown.
880 * This field is not the display duration of the current packet.
881 * This field has no meaning if the packet does not have AV_PKT_FLAG_KEY
882 * set.
883 *
884 * The purpose of this field is to allow seeking in streams that have no
885 * keyframes in the conventional sense. It corresponds to the
886 * recovery point SEI in H.264 and match_time_delta in NUT. It is also
887 * essential for some types of subtitle streams to ensure that all
888 * subtitles are correctly displayed after seeking.
889 */
890 int64_t convergence_duration;
891 } AVPacket;
892 #define AV_PKT_FLAG_KEY 0x0001 ///< The packet contains a keyframe
893 #define AV_PKT_FLAG_CORRUPT 0x0002 ///< The packet content is corrupted
894
895 enum AVSideDataParamChangeFlags {
896 AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT = 0x0001,
897 AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT = 0x0002,
898 AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE = 0x0004,
899 AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS = 0x0008,
900 };
901 /**
902 * @}
903 */
904
905 /**
906 * Audio Video Frame.
907 * New fields can be added to the end of AVFRAME with minor version
908 * bumps. Removal, reordering and changes to existing fields require
909 * a major version bump.
910 * sizeof(AVFrame) must not be used outside libav*.
911 */
912 typedef struct AVFrame {
913 #define AV_NUM_DATA_POINTERS 8
914 /**
915 * pointer to the picture/channel planes.
916 * This might be different from the first allocated byte
917 * - encoding: Set by user
918 * - decoding: set by AVCodecContext.get_buffer()
919 */
920 uint8_t *data[AV_NUM_DATA_POINTERS];
921
922 /**
923 * Size, in bytes, of the data for each picture/channel plane.
924 *
925 * For audio, only linesize[0] may be set. For planar audio, each channel
926 * plane must be the same size.
927 *
928 * - encoding: Set by user
929 * - decoding: set by AVCodecContext.get_buffer()
930 */
931 int linesize[AV_NUM_DATA_POINTERS];
932
933 /**
934 * pointers to the data planes/channels.
935 *
936 * For video, this should simply point to data[].
937 *
938 * For planar audio, each channel has a separate data pointer, and
939 * linesize[0] contains the size of each channel buffer.
940 * For packed audio, there is just one data pointer, and linesize[0]
941 * contains the total size of the buffer for all channels.
942 *
943 * Note: Both data and extended_data will always be set by get_buffer(),
944 * but for planar audio with more channels that can fit in data,
945 * extended_data must be used by the decoder in order to access all
946 * channels.
947 *
948 * encoding: unused
949 * decoding: set by AVCodecContext.get_buffer()
950 */
951 uint8_t **extended_data;
952
953 /**
954 * width and height of the video frame
955 * - encoding: unused
956 * - decoding: Read by user.
957 */
958 int width, height;
959
960 /**
961 * number of audio samples (per channel) described by this frame
962 * - encoding: Set by user
963 * - decoding: Set by libavcodec
964 */
965 int nb_samples;
966
967 /**
968 * format of the frame, -1 if unknown or unset
969 * Values correspond to enum PixelFormat for video frames,
970 * enum AVSampleFormat for audio)
971 * - encoding: unused
972 * - decoding: Read by user.
973 */
974 int format;
975
976 /**
977 * 1 -> keyframe, 0-> not
978 * - encoding: Set by libavcodec.
979 * - decoding: Set by libavcodec.
980 */
981 int key_frame;
982
983 /**
984 * Picture type of the frame, see ?_TYPE below.
985 * - encoding: Set by libavcodec. for coded_picture (and set by user for input).
986 * - decoding: Set by libavcodec.
987 */
988 enum AVPictureType pict_type;
989
990 /**
991 * pointer to the first allocated byte of the picture. Can be used in get_buffer/release_buffer.
992 * This isn't used by libavcodec unless the default get/release_buffer() is used.
993 * - encoding:
994 * - decoding:
995 */
996 uint8_t *base[AV_NUM_DATA_POINTERS];
997
998 /**
999 * sample aspect ratio for the video frame, 0/1 if unknown/unspecified
1000 * - encoding: unused
1001 * - decoding: Read by user.
1002 */
1003 AVRational sample_aspect_ratio;
1004
1005 /**
1006 * presentation timestamp in time_base units (time when frame should be shown to user)
1007 * If AV_NOPTS_VALUE then frame_rate = 1/time_base will be assumed.
1008 * - encoding: MUST be set by user.
1009 * - decoding: Set by libavcodec.
1010 */
1011 int64_t pts;
1012
1013 /**
1014 * reordered pts from the last AVPacket that has been input into the decoder
1015 * - encoding: unused
1016 * - decoding: Read by user.
1017 */
1018 int64_t pkt_pts;
1019
1020 /**
1021 * dts from the last AVPacket that has been input into the decoder
1022 * - encoding: unused
1023 * - decoding: Read by user.
1024 */
1025 int64_t pkt_dts;
1026
1027 /**
1028 * picture number in bitstream order
1029 * - encoding: set by
1030 * - decoding: Set by libavcodec.
1031 */
1032 int coded_picture_number;
1033 /**
1034 * picture number in display order
1035 * - encoding: set by
1036 * - decoding: Set by libavcodec.
1037 */
1038 int display_picture_number;
1039
1040 /**
1041 * quality (between 1 (good) and FF_LAMBDA_MAX (bad))
1042 * - encoding: Set by libavcodec. for coded_picture (and set by user for input).
1043 * - decoding: Set by libavcodec.
1044 */
1045 int quality;
1046
1047 /**
1048 * is this picture used as reference
1049 * The values for this are the same as the MpegEncContext.picture_structure
1050 * variable, that is 1->top field, 2->bottom field, 3->frame/both fields.
1051 * Set to 4 for delayed, non-reference frames.
1052 * - encoding: unused
1053 * - decoding: Set by libavcodec. (before get_buffer() call)).
1054 */
1055 int reference;
1056
1057 /**
1058 * QP table
1059 * - encoding: unused
1060 * - decoding: Set by libavcodec.
1061 */
1062 int8_t *qscale_table;
1063 /**
1064 * QP store stride
1065 * - encoding: unused
1066 * - decoding: Set by libavcodec.
1067 */
1068 int qstride;
1069
1070 /**
1071 *
1072 */
1073 int qscale_type;
1074
1075 /**
1076 * mbskip_table[mb]>=1 if MB didn't change
1077 * stride= mb_width = (width+15)>>4
1078 * - encoding: unused
1079 * - decoding: Set by libavcodec.
1080 */
1081 uint8_t *mbskip_table;
1082
1083 /**
1084 * motion vector table
1085 * @code
1086 * example:
1087 * int mv_sample_log2= 4 - motion_subsample_log2;
1088 * int mb_width= (width+15)>>4;
1089 * int mv_stride= (mb_width << mv_sample_log2) + 1;
1090 * motion_val[direction][x + y*mv_stride][0->mv_x, 1->mv_y];
1091 * @endcode
1092 * - encoding: Set by user.
1093 * - decoding: Set by libavcodec.
1094 */
1095 int16_t (*motion_val[2])[2];
1096
1097 /**
1098 * macroblock type table
1099 * mb_type_base + mb_width + 2
1100 * - encoding: Set by user.
1101 * - decoding: Set by libavcodec.
1102 */
1103 uint32_t *mb_type;
1104
1105 /**
1106 * DCT coefficients
1107 * - encoding: unused
1108 * - decoding: Set by libavcodec.
1109 */
1110 short *dct_coeff;
1111
1112 /**
1113 * motion reference frame index
1114 * the order in which these are stored can depend on the codec.
1115 * - encoding: Set by user.
1116 * - decoding: Set by libavcodec.
1117 */
1118 int8_t *ref_index[2];
1119
1120 /**
1121 * for some private data of the user
1122 * - encoding: unused
1123 * - decoding: Set by user.
1124 */
1125 void *opaque;
1126
1127 /**
1128 * error
1129 * - encoding: Set by libavcodec. if flags&CODEC_FLAG_PSNR.
1130 * - decoding: unused
1131 */
1132 uint64_t error[AV_NUM_DATA_POINTERS];
1133
1134 /**
1135 * type of the buffer (to keep track of who has to deallocate data[*])
1136 * - encoding: Set by the one who allocates it.
1137 * - decoding: Set by the one who allocates it.
1138 * Note: User allocated (direct rendering) & internal buffers cannot coexist currently.
1139 */
1140 int type;
1141
1142 /**
1143 * When decoding, this signals how much the picture must be delayed.
1144 * extra_delay = repeat_pict / (2*fps)
1145 * - encoding: unused
1146 * - decoding: Set by libavcodec.
1147 */
1148 int repeat_pict;
1149
1150 /**
1151 * The content of the picture is interlaced.
1152 * - encoding: Set by user.
1153 * - decoding: Set by libavcodec. (default 0)
1154 */
1155 int interlaced_frame;
1156
1157 /**
1158 * If the content is interlaced, is top field displayed first.
1159 * - encoding: Set by user.
1160 * - decoding: Set by libavcodec.
1161 */
1162 int top_field_first;
1163
1164 /**
1165 * Tell user application that palette has changed from previous frame.
1166 * - encoding: ??? (no palette-enabled encoder yet)
1167 * - decoding: Set by libavcodec. (default 0).
1168 */
1169 int palette_has_changed;
1170
1171 /**
1172 * codec suggestion on buffer type if != 0
1173 * - encoding: unused
1174 * - decoding: Set by libavcodec. (before get_buffer() call)).
1175 */
1176 int buffer_hints;
1177
1178 /**
1179 * Pan scan.
1180 * - encoding: Set by user.
1181 * - decoding: Set by libavcodec.
1182 */
1183 AVPanScan *pan_scan;
1184
1185 /**
1186 * reordered opaque 64bit (generally an integer or a double precision float
1187 * PTS but can be anything).
1188 * The user sets AVCodecContext.reordered_opaque to represent the input at
1189 * that time,
1190 * the decoder reorders values as needed and sets AVFrame.reordered_opaque
1191 * to exactly one of the values provided by the user through AVCodecContext.reordered_opaque
1192 * @deprecated in favor of pkt_pts
1193 * - encoding: unused
1194 * - decoding: Read by user.
1195 */
1196 int64_t reordered_opaque;
1197
1198 /**
1199 * hardware accelerator private data (Libav-allocated)
1200 * - encoding: unused
1201 * - decoding: Set by libavcodec
1202 */
1203 void *hwaccel_picture_private;
1204
1205 /**
1206 * the AVCodecContext which ff_thread_get_buffer() was last called on
1207 * - encoding: Set by libavcodec.
1208 * - decoding: Set by libavcodec.
1209 */
1210 struct AVCodecContext *owner;
1211
1212 /**
1213 * used by multithreading to store frame-specific info
1214 * - encoding: Set by libavcodec.
1215 * - decoding: Set by libavcodec.
1216 */
1217 void *thread_opaque;
1218
1219 /**
1220 * log2 of the size of the block which a single vector in motion_val represents:
1221 * (4->16x16, 3->8x8, 2-> 4x4, 1-> 2x2)
1222 * - encoding: unused
1223 * - decoding: Set by libavcodec.
1224 */
1225 uint8_t motion_subsample_log2;
1226
1227 /**
1228 * Sample rate of the audio data.
1229 *
1230 * - encoding: unused
1231 * - decoding: set by get_buffer()
1232 */
1233 int sample_rate;
1234
1235 /**
1236 * Channel layout of the audio data.
1237 *
1238 * - encoding: unused
1239 * - decoding: set by get_buffer()
1240 */
1241 uint64_t channel_layout;
1242 } AVFrame;
1243
1244 struct AVCodecInternal;
1245
1246 enum AVFieldOrder {
1247 AV_FIELD_UNKNOWN,
1248 AV_FIELD_PROGRESSIVE,
1249 AV_FIELD_TT, //< Top coded_first, top displayed first
1250 AV_FIELD_BB, //< Bottom coded first, bottom displayed first
1251 AV_FIELD_TB, //< Top coded first, bottom displayed first
1252 AV_FIELD_BT, //< Bottom coded first, top displayed first
1253 };
1254
1255 /**
1256 * main external API structure.
1257 * New fields can be added to the end with minor version bumps.
1258 * Removal, reordering and changes to existing fields require a major
1259 * version bump.
1260 * sizeof(AVCodecContext) must not be used outside libav*.
1261 */
1262 typedef struct AVCodecContext {
1263 /**
1264 * information on struct for av_log
1265 * - set by avcodec_alloc_context3
1266 */
1267 const AVClass *av_class;
1268 int log_level_offset;
1269
1270 enum AVMediaType codec_type; /* see AVMEDIA_TYPE_xxx */
1271 struct AVCodec *codec;
1272 char codec_name[32];
1273 enum AVCodecID codec_id; /* see AV_CODEC_ID_xxx */
1274
1275 /**
1276 * fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
1277 * This is used to work around some encoder bugs.
1278 * A demuxer should set this to what is stored in the field used to identify the codec.
1279 * If there are multiple such fields in a container then the demuxer should choose the one
1280 * which maximizes the information about the used codec.
1281 * If the codec tag field in a container is larger than 32 bits then the demuxer should
1282 * remap the longer ID to 32 bits with a table or other structure. Alternatively a new
1283 * extra_codec_tag + size could be added but for this a clear advantage must be demonstrated
1284 * first.
1285 * - encoding: Set by user, if not then the default based on codec_id will be used.
1286 * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
1287 */
1288 unsigned int codec_tag;
1289
1290 /**
1291 * fourcc from the AVI stream header (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
1292 * This is used to work around some encoder bugs.
1293 * - encoding: unused
1294 * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
1295 */
1296 unsigned int stream_codec_tag;
1297
1298 #if FF_API_SUB_ID
1299 /**
1300 * @deprecated this field is unused
1301 */
1302 attribute_deprecated int sub_id;
1303 #endif
1304
1305 void *priv_data;
1306
1307 /**
1308 * Private context used for internal data.
1309 *
1310 * Unlike priv_data, this is not codec-specific. It is used in general
1311 * libavcodec functions.
1312 */
1313 struct AVCodecInternal *internal;
1314
1315 /**
1316 * Private data of the user, can be used to carry app specific stuff.
1317 * - encoding: Set by user.
1318 * - decoding: Set by user.
1319 */
1320 void *opaque;
1321
1322 /**
1323 * the average bitrate
1324 * - encoding: Set by user; unused for constant quantizer encoding.
1325 * - decoding: Set by libavcodec. 0 or some bitrate if this info is available in the stream.
1326 */
1327 int bit_rate;
1328
1329 /**
1330 * number of bits the bitstream is allowed to diverge from the reference.
1331 * the reference can be CBR (for CBR pass1) or VBR (for pass2)
1332 * - encoding: Set by user; unused for constant quantizer encoding.
1333 * - decoding: unused
1334 */
1335 int bit_rate_tolerance;
1336
1337 /**
1338 * Global quality for codecs which cannot change it per frame.
1339 * This should be proportional to MPEG-1/2/4 qscale.
1340 * - encoding: Set by user.
1341 * - decoding: unused
1342 */
1343 int global_quality;
1344
1345 /**
1346 * - encoding: Set by user.
1347 * - decoding: unused
1348 */
1349 int compression_level;
1350 #define FF_COMPRESSION_DEFAULT -1
1351
1352 /**
1353 * CODEC_FLAG_*.
1354 * - encoding: Set by user.
1355 * - decoding: Set by user.
1356 */
1357 int flags;
1358
1359 /**
1360 * CODEC_FLAG2_*
1361 * - encoding: Set by user.
1362 * - decoding: Set by user.
1363 */
1364 int flags2;
1365
1366 /**
1367 * some codecs need / can use extradata like Huffman tables.
1368 * mjpeg: Huffman tables
1369 * rv10: additional flags
1370 * mpeg4: global headers (they can be in the bitstream or here)
1371 * The allocated memory should be FF_INPUT_BUFFER_PADDING_SIZE bytes larger
1372 * than extradata_size to avoid prolems if it is read with the bitstream reader.
1373 * The bytewise contents of extradata must not depend on the architecture or CPU endianness.
1374 * - encoding: Set/allocated/freed by libavcodec.
1375 * - decoding: Set/allocated/freed by user.
1376 */
1377 uint8_t *extradata;
1378 int extradata_size;
1379
1380 /**
1381 * This is the fundamental unit of time (in seconds) in terms
1382 * of which frame timestamps are represented. For fixed-fps content,
1383 * timebase should be 1/framerate and timestamp increments should be
1384 * identically 1.
1385 * - encoding: MUST be set by user.
1386 * - decoding: Set by libavcodec.
1387 */
1388 AVRational time_base;
1389
1390 /**
1391 * For some codecs, the time base is closer to the field rate than the frame rate.
1392 * Most notably, H.264 and MPEG-2 specify time_base as half of frame duration
1393 * if no telecine is used ...
1394 *
1395 * Set to time_base ticks per frame. Default 1, e.g., H.264/MPEG-2 set it to 2.
1396 */
1397 int ticks_per_frame;
1398
1399 /**
1400 * Encoder delay.
1401 *
1402 * Video:
1403 * Number of frames the decoded output will be delayed relative to the
1404 * encoded input.
1405 *
1406 * Audio:
1407 * Number of "priming" samples added to the beginning of the stream
1408 * during encoding. The decoded output will be delayed by this many
1409 * samples relative to the input to the encoder. Note that this field is
1410 * purely informational and does not directly affect the pts output by
1411 * the encoder, which should always be based on the actual presentation
1412 * time, including any delay.
1413 *
1414 * - encoding: Set by libavcodec.
1415 * - decoding: unused
1416 */
1417 int delay;
1418
1419
1420 /* video only */
1421 /**
1422 * picture width / height.
1423 * - encoding: MUST be set by user.
1424 * - decoding: Set by libavcodec.
1425 * Note: For compatibility it is possible to set this instead of
1426 * coded_width/height before decoding.
1427 */
1428 int width, height;
1429
1430 /**
1431 * Bitstream width / height, may be different from width/height.
1432 * - encoding: unused
1433 * - decoding: Set by user before init if known. Codec should override / dynamically change if needed.
1434 */
1435 int coded_width, coded_height;
1436
1437 #define FF_ASPECT_EXTENDED 15
1438
1439 /**
1440 * the number of pictures in a group of pictures, or 0 for intra_only
1441 * - encoding: Set by user.
1442 * - decoding: unused
1443 */
1444 int gop_size;
1445
1446 /**
1447 * Pixel format, see PIX_FMT_xxx.
1448 * May be set by the demuxer if known from headers.
1449 * May be overriden by the decoder if it knows better.
1450 * - encoding: Set by user.
1451 * - decoding: Set by user if known, overridden by libavcodec if known
1452 */
1453 enum PixelFormat pix_fmt;
1454
1455 /**
1456 * Motion estimation algorithm used for video coding.
1457 * 1 (zero), 2 (full), 3 (log), 4 (phods), 5 (epzs), 6 (x1), 7 (hex),
1458 * 8 (umh), 9 (iter), 10 (tesa) [7, 8, 10 are x264 specific, 9 is snow specific]
1459 * - encoding: MUST be set by user.
1460 * - decoding: unused
1461 */
1462 int me_method;
1463
1464 /**
1465 * If non NULL, 'draw_horiz_band' is called by the libavcodec
1466 * decoder to draw a horizontal band. It improves cache usage. Not
1467 * all codecs can do that. You must check the codec capabilities
1468 * beforehand.
1469 * When multithreading is used, it may be called from multiple threads
1470 * at the same time; threads might draw different parts of the same AVFrame,
1471 * or multiple AVFrames, and there is no guarantee that slices will be drawn
1472 * in order.
1473 * The function is also used by hardware acceleration APIs.
1474 * It is called at least once during frame decoding to pass
1475 * the data needed for hardware render.
1476 * In that mode instead of pixel data, AVFrame points to
1477 * a structure specific to the acceleration API. The application
1478 * reads the structure and can change some fields to indicate progress
1479 * or mark state.
1480 * - encoding: unused
1481 * - decoding: Set by user.
1482 * @param height the height of the slice
1483 * @param y the y position of the slice
1484 * @param type 1->top field, 2->bottom field, 3->frame
1485 * @param offset offset into the AVFrame.data from which the slice should be read
1486 */
1487 void (*draw_horiz_band)(struct AVCodecContext *s,
1488 const AVFrame *src, int offset[AV_NUM_DATA_POINTERS],
1489 int y, int type, int height);
1490
1491 /**
1492 * callback to negotiate the pixelFormat
1493 * @param fmt is the list of formats which are supported by the codec,
1494 * it is terminated by -1 as 0 is a valid format, the formats are ordered by quality.
1495 * The first is always the native one.
1496 * @return the chosen format
1497 * - encoding: unused
1498 * - decoding: Set by user, if not set the native format will be chosen.
1499 */
1500 enum PixelFormat (*get_format)(struct AVCodecContext *s, const enum PixelFormat * fmt);
1501
1502 /**
1503 * maximum number of B-frames between non-B-frames
1504 * Note: The output will be delayed by max_b_frames+1 relative to the input.
1505 * - encoding: Set by user.
1506 * - decoding: unused
1507 */
1508 int max_b_frames;
1509
1510 /**
1511 * qscale factor between IP and B-frames
1512 * If > 0 then the last P-frame quantizer will be used (q= lastp_q*factor+offset).
1513 * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1514 * - encoding: Set by user.
1515 * - decoding: unused
1516 */
1517 float b_quant_factor;
1518
1519 /** obsolete FIXME remove */
1520 int rc_strategy;
1521 #define FF_RC_STRATEGY_XVID 1
1522
1523 int b_frame_strategy;
1524
1525 #if FF_API_MPV_GLOBAL_OPTS
1526 /**
1527 * luma single coefficient elimination threshold
1528 * - encoding: Set by user.
1529 * - decoding: unused
1530 */
1531 attribute_deprecated int luma_elim_threshold;
1532
1533 /**
1534 * chroma single coeff elimination threshold
1535 * - encoding: Set by user.
1536 * - decoding: unused
1537 */
1538 attribute_deprecated int chroma_elim_threshold;
1539 #endif
1540
1541 /**
1542 * qscale offset between IP and B-frames
1543 * - encoding: Set by user.
1544 * - decoding: unused
1545 */
1546 float b_quant_offset;
1547
1548 /**
1549 * Size of the frame reordering buffer in the decoder.
1550 * For MPEG-2 it is 1 IPB or 0 low delay IP.
1551 * - encoding: Set by libavcodec.
1552 * - decoding: Set by libavcodec.
1553 */
1554 int has_b_frames;
1555
1556 /**
1557 * 0-> h263 quant 1-> mpeg quant
1558 * - encoding: Set by user.
1559 * - decoding: unused
1560 */
1561 int mpeg_quant;
1562
1563 /**
1564 * qscale factor between P and I-frames
1565 * If > 0 then the last p frame quantizer will be used (q= lastp_q*factor+offset).
1566 * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1567 * - encoding: Set by user.
1568 * - decoding: unused
1569 */
1570 float i_quant_factor;
1571
1572 /**
1573 * qscale offset between P and I-frames
1574 * - encoding: Set by user.
1575 * - decoding: unused
1576 */
1577 float i_quant_offset;
1578
1579 /**
1580 * luminance masking (0-> disabled)
1581 * - encoding: Set by user.
1582 * - decoding: unused
1583 */
1584 float lumi_masking;
1585
1586 /**
1587 * temporary complexity masking (0-> disabled)
1588 * - encoding: Set by user.
1589 * - decoding: unused
1590 */
1591 float temporal_cplx_masking;
1592
1593 /**
1594 * spatial complexity masking (0-> disabled)
1595 * - encoding: Set by user.
1596 * - decoding: unused
1597 */
1598 float spatial_cplx_masking;
1599
1600 /**
1601 * p block masking (0-> disabled)
1602 * - encoding: Set by user.
1603 * - decoding: unused
1604 */
1605 float p_masking;
1606
1607 /**
1608 * darkness masking (0-> disabled)
1609 * - encoding: Set by user.
1610 * - decoding: unused
1611 */
1612 float dark_masking;
1613
1614 /**
1615 * slice count
1616 * - encoding: Set by libavcodec.
1617 * - decoding: Set by user (or 0).
1618 */
1619 int slice_count;
1620 /**
1621 * prediction method (needed for huffyuv)
1622 * - encoding: Set by user.
1623 * - decoding: unused
1624 */
1625 int prediction_method;
1626 #define FF_PRED_LEFT 0
1627 #define FF_PRED_PLANE 1
1628 #define FF_PRED_MEDIAN 2
1629
1630 /**
1631 * slice offsets in the frame in bytes
1632 * - encoding: Set/allocated by libavcodec.
1633 * - decoding: Set/allocated by user (or NULL).
1634 */
1635 int *slice_offset;
1636
1637 /**
1638 * sample aspect ratio (0 if unknown)
1639 * That is the width of a pixel divided by the height of the pixel.
1640 * Numerator and denominator must be relatively prime and smaller than 256 for some video standards.
1641 * - encoding: Set by user.
1642 * - decoding: Set by libavcodec.
1643 */
1644 AVRational sample_aspect_ratio;
1645
1646 /**
1647 * motion estimation comparison function
1648 * - encoding: Set by user.
1649 * - decoding: unused
1650 */
1651 int me_cmp;
1652 /**
1653 * subpixel motion estimation comparison function
1654 * - encoding: Set by user.
1655 * - decoding: unused
1656 */
1657 int me_sub_cmp;
1658 /**
1659 * macroblock comparison function (not supported yet)
1660 * - encoding: Set by user.
1661 * - decoding: unused
1662 */
1663 int mb_cmp;
1664 /**
1665 * interlaced DCT comparison function
1666 * - encoding: Set by user.
1667 * - decoding: unused
1668 */
1669 int ildct_cmp;
1670 #define FF_CMP_SAD 0
1671 #define FF_CMP_SSE 1
1672 #define FF_CMP_SATD 2
1673 #define FF_CMP_DCT 3
1674 #define FF_CMP_PSNR 4
1675 #define FF_CMP_BIT 5
1676 #define FF_CMP_RD 6
1677 #define FF_CMP_ZERO 7
1678 #define FF_CMP_VSAD 8
1679 #define FF_CMP_VSSE 9
1680 #define FF_CMP_NSSE 10
1681 #define FF_CMP_W53 11
1682 #define FF_CMP_W97 12
1683 #define FF_CMP_DCTMAX 13
1684 #define FF_CMP_DCT264 14
1685 #define FF_CMP_CHROMA 256
1686
1687 /**
1688 * ME diamond size & shape
1689 * - encoding: Set by user.
1690 * - decoding: unused
1691 */
1692 int dia_size;
1693
1694 /**
1695 * amount of previous MV predictors (2a+1 x 2a+1 square)
1696 * - encoding: Set by user.
1697 * - decoding: unused
1698 */
1699 int last_predictor_count;
1700
1701 /**
1702 * prepass for motion estimation
1703 * - encoding: Set by user.
1704 * - decoding: unused
1705 */
1706 int pre_me;
1707
1708 /**
1709 * motion estimation prepass comparison function
1710 * - encoding: Set by user.
1711 * - decoding: unused
1712 */
1713 int me_pre_cmp;
1714
1715 /**
1716 * ME prepass diamond size & shape
1717 * - encoding: Set by user.
1718 * - decoding: unused
1719 */
1720 int pre_dia_size;
1721
1722 /**
1723 * subpel ME quality
1724 * - encoding: Set by user.
1725 * - decoding: unused
1726 */
1727 int me_subpel_quality;
1728
1729 /**
1730 * DTG active format information (additional aspect ratio
1731 * information only used in DVB MPEG-2 transport streams)
1732 * 0 if not set.
1733 *
1734 * - encoding: unused
1735 * - decoding: Set by decoder.
1736 */
1737 int dtg_active_format;
1738 #define FF_DTG_AFD_SAME 8
1739 #define FF_DTG_AFD_4_3 9
1740 #define FF_DTG_AFD_16_9 10
1741 #define FF_DTG_AFD_14_9 11
1742 #define FF_DTG_AFD_4_3_SP_14_9 13
1743 #define FF_DTG_AFD_16_9_SP_14_9 14
1744 #define FF_DTG_AFD_SP_4_3 15
1745
1746 /**
1747 * maximum motion estimation search range in subpel units
1748 * If 0 then no limit.
1749 *
1750 * - encoding: Set by user.
1751 * - decoding: unused
1752 */
1753 int me_range;
1754
1755 /**
1756 * intra quantizer bias
1757 * - encoding: Set by user.
1758 * - decoding: unused
1759 */
1760 int intra_quant_bias;
1761 #define FF_DEFAULT_QUANT_BIAS 999999
1762
1763 /**
1764 * inter quantizer bias
1765 * - encoding: Set by user.
1766 * - decoding: unused
1767 */
1768 int inter_quant_bias;
1769
1770 #if FF_API_COLOR_TABLE_ID
1771 /**
1772 * color table ID
1773 * - encoding: unused
1774 * - decoding: Which clrtable should be used for 8bit RGB images.
1775 * Tables have to be stored somewhere. FIXME
1776 */
1777 attribute_deprecated int color_table_id;
1778 #endif
1779
1780 /**
1781 * slice flags
1782 * - encoding: unused
1783 * - decoding: Set by user.
1784 */
1785 int slice_flags;
1786 #define SLICE_FLAG_CODED_ORDER 0x0001 ///< draw_horiz_band() is called in coded order instead of display
1787 #define SLICE_FLAG_ALLOW_FIELD 0x0002 ///< allow draw_horiz_band() with field slices (MPEG2 field pics)
1788 #define SLICE_FLAG_ALLOW_PLANE 0x0004 ///< allow draw_horiz_band() with 1 component at a time (SVQ1)
1789
1790 /**
1791 * XVideo Motion Acceleration
1792 * - encoding: forbidden
1793 * - decoding: set by decoder
1794 */
1795 int xvmc_acceleration;
1796
1797 /**
1798 * macroblock decision mode
1799 * - encoding: Set by user.
1800 * - decoding: unused
1801 */
1802 int mb_decision;
1803 #define FF_MB_DECISION_SIMPLE 0 ///< uses mb_cmp
1804 #define FF_MB_DECISION_BITS 1 ///< chooses the one which needs the fewest bits
1805 #define FF_MB_DECISION_RD 2 ///< rate distortion
1806
1807 /**
1808 * custom intra quantization matrix
1809 * - encoding: Set by user, can be NULL.
1810 * - decoding: Set by libavcodec.
1811 */
1812 uint16_t *intra_matrix;
1813
1814 /**
1815 * custom inter quantization matrix
1816 * - encoding: Set by user, can be NULL.
1817 * - decoding: Set by libavcodec.
1818 */
1819 uint16_t *inter_matrix;
1820
1821 /**
1822 * scene change detection threshold
1823 * 0 is default, larger means fewer detected scene changes.
1824 * - encoding: Set by user.
1825 * - decoding: unused
1826 */
1827 int scenechange_threshold;
1828
1829 /**
1830 * noise reduction strength
1831 * - encoding: Set by user.
1832 * - decoding: unused
1833 */
1834 int noise_reduction;
1835
1836 #if FF_API_INTER_THRESHOLD
1837 /**
1838 * @deprecated this field is unused
1839 */
1840 attribute_deprecated int inter_threshold;
1841 #endif
1842
1843 #if FF_API_MPV_GLOBAL_OPTS
1844 /**
1845 * @deprecated use mpegvideo private options instead
1846 */
1847 attribute_deprecated int quantizer_noise_shaping;
1848 #endif
1849
1850 /**
1851 * Motion estimation threshold below which no motion estimation is
1852 * performed, but instead the user specified motion vectors are used.
1853 *
1854 * - encoding: Set by user.
1855 * - decoding: unused
1856 */
1857 int me_threshold;
1858
1859 /**
1860 * Macroblock threshold below which the user specified macroblock types will be used.
1861 * - encoding: Set by user.
1862 * - decoding: unused
1863 */
1864 int mb_threshold;
1865
1866 /**
1867 * precision of the intra DC coefficient - 8
1868 * - encoding: Set by user.
1869 * - decoding: unused
1870 */
1871 int intra_dc_precision;
1872
1873 /**
1874 * Number of macroblock rows at the top which are skipped.
1875 * - encoding: unused
1876 * - decoding: Set by user.
1877 */
1878 int skip_top;
1879
1880 /**
1881 * Number of macroblock rows at the bottom which are skipped.
1882 * - encoding: unused
1883 * - decoding: Set by user.
1884 */
1885 int skip_bottom;
1886
1887 /**
1888 * Border processing masking, raises the quantizer for mbs on the borders
1889 * of the picture.
1890 * - encoding: Set by user.
1891 * - decoding: unused
1892 */
1893 float border_masking;
1894
1895 /**
1896 * minimum MB lagrange multipler
1897 * - encoding: Set by user.
1898 * - decoding: unused
1899 */
1900 int mb_lmin;
1901
1902 /**
1903 * maximum MB lagrange multipler
1904 * - encoding: Set by user.
1905 * - decoding: unused
1906 */
1907 int mb_lmax;
1908
1909 /**
1910 *
1911 * - encoding: Set by user.
1912 * - decoding: unused
1913 */
1914 int me_penalty_compensation;
1915
1916 /**
1917 *
1918 * - encoding: Set by user.
1919 * - decoding: unused
1920 */
1921 int bidir_refine;
1922
1923 /**
1924 *
1925 * - encoding: Set by user.
1926 * - decoding: unused
1927 */
1928 int brd_scale;
1929
1930 /**
1931 * minimum GOP size
1932 * - encoding: Set by user.
1933 * - decoding: unused
1934 */
1935 int keyint_min;
1936
1937 /**
1938 * number of reference frames
1939 * - encoding: Set by user.
1940 * - decoding: Set by lavc.
1941 */
1942 int refs;
1943
1944 /**
1945 * chroma qp offset from luma
1946 * - encoding: Set by user.
1947 * - decoding: unused
1948 */
1949 int chromaoffset;
1950
1951 /**
1952 * Multiplied by qscale for each frame and added to scene_change_score.
1953 * - encoding: Set by user.
1954 * - decoding: unused
1955 */
1956 int scenechange_factor;
1957
1958 /**
1959 *
1960 * Note: Value depends upon the compare function used for fullpel ME.
1961 * - encoding: Set by user.
1962 * - decoding: unused
1963 */
1964 int mv0_threshold;
1965
1966 /**
1967 * Adjust sensitivity of b_frame_strategy 1.
1968 * - encoding: Set by user.
1969 * - decoding: unused
1970 */
1971 int b_sensitivity;
1972
1973 /**
1974 * Chromaticity coordinates of the source primaries.
1975 * - encoding: Set by user
1976 * - decoding: Set by libavcodec
1977 */
1978 enum AVColorPrimaries color_primaries;
1979
1980 /**
1981 * Color Transfer Characteristic.
1982 * - encoding: Set by user
1983 * - decoding: Set by libavcodec
1984 */
1985 enum AVColorTransferCharacteristic color_trc;
1986
1987 /**
1988 * YUV colorspace type.
1989 * - encoding: Set by user
1990 * - decoding: Set by libavcodec
1991 */
1992 enum AVColorSpace colorspace;
1993
1994 /**
1995 * MPEG vs JPEG YUV range.
1996 * - encoding: Set by user
1997 * - decoding: Set by libavcodec
1998 */
1999 enum AVColorRange color_range;
2000
2001 /**
2002 * This defines the location of chroma samples.
2003 * - encoding: Set by user
2004 * - decoding: Set by libavcodec
2005 */
2006 enum AVChromaLocation chroma_sample_location;
2007
2008 /**
2009 * Number of slices.
2010 * Indicates number of picture subdivisions. Used for parallelized
2011 * decoding.
2012 * - encoding: Set by user
2013 * - decoding: unused
2014 */
2015 int slices;
2016
2017 /** Field order
2018 * - encoding: set by libavcodec
2019 * - decoding: Set by libavcodec
2020 */
2021 enum AVFieldOrder field_order;
2022
2023 /* audio only */
2024 int sample_rate; ///< samples per second
2025 int channels; ///< number of audio channels
2026
2027 /**
2028 * audio sample format
2029 * - encoding: Set by user.
2030 * - decoding: Set by libavcodec.
2031 */
2032 enum AVSampleFormat sample_fmt; ///< sample format
2033
2034 /* The following data should not be initialized. */
2035 /**
2036 * Samples per packet, initialized when calling 'init'.
2037 */
2038 int frame_size;
2039
2040 /**
2041 * Frame counter, set by libavcodec.
2042 *
2043 * - decoding: total number of frames returned from the decoder so far.
2044 * - encoding: total number of frames passed to the encoder so far.
2045 *
2046 * @note the counter is not incremented if encoding/decoding resulted in
2047 * an error.
2048 */
2049 int frame_number;
2050
2051 /**
2052 * number of bytes per packet if constant and known or 0
2053 * Used by some WAV based audio codecs.
2054 */
2055 int block_align;
2056
2057 /**
2058 * Audio cutoff bandwidth (0 means "automatic")
2059 * - encoding: Set by user.
2060 * - decoding: unused
2061 */
2062 int cutoff;
2063
2064 #if FF_API_REQUEST_CHANNELS
2065 /**
2066 * Decoder should decode to this many channels if it can (0 for default)
2067 * - encoding: unused
2068 * - decoding: Set by user.
2069 * @deprecated Deprecated in favor of request_channel_layout.
2070 */
2071 int request_channels;
2072 #endif
2073
2074 /**
2075 * Audio channel layout.
2076 * - encoding: set by user.
2077 * - decoding: set by libavcodec.
2078 */
2079 uint64_t channel_layout;
2080
2081 /**
2082 * Request decoder to use this channel layout if it can (0 for default)
2083 * - encoding: unused
2084 * - decoding: Set by user.
2085 */
2086 uint64_t request_channel_layout;
2087
2088 /**
2089 * Type of service that the audio stream conveys.
2090 * - encoding: Set by user.
2091 * - decoding: Set by libavcodec.
2092 */
2093 enum AVAudioServiceType audio_service_type;
2094
2095 /**
2096 * Used to request a sample format from the decoder.
2097 * - encoding: unused.
2098 * - decoding: Set by user.
2099 */
2100 enum AVSampleFormat request_sample_fmt;
2101
2102 /**
2103 * Called at the beginning of each frame to get a buffer for it.
2104 *
2105 * The function will set AVFrame.data[], AVFrame.linesize[].
2106 * AVFrame.extended_data[] must also be set, but it should be the same as
2107 * AVFrame.data[] except for planar audio with more channels than can fit
2108 * in AVFrame.data[]. In that case, AVFrame.data[] shall still contain as
2109 * many data pointers as it can hold.
2110 *
2111 * if CODEC_CAP_DR1 is not set then get_buffer() must call
2112 * avcodec_default_get_buffer() instead of providing buffers allocated by
2113 * some other means.
2114 *
2115 * AVFrame.data[] should be 32- or 16-byte-aligned unless the CPU doesn't
2116 * need it. avcodec_default_get_buffer() aligns the output buffer properly,
2117 * but if get_buffer() is overridden then alignment considerations should
2118 * be taken into account.
2119 *
2120 * @see avcodec_default_get_buffer()
2121 *
2122 * Video:
2123 *
2124 * If pic.reference is set then the frame will be read later by libavcodec.
2125 * avcodec_align_dimensions2() should be used to find the required width and
2126 * height, as they normally need to be rounded up to the next multiple of 16.
2127 *
2128 * If frame multithreading is used and thread_safe_callbacks is set,
2129 * it may be called from a different thread, but not from more than one at
2130 * once. Does not need to be reentrant.
2131 *
2132 * @see release_buffer(), reget_buffer()
2133 * @see avcodec_align_dimensions2()
2134 *
2135 * Audio:
2136 *
2137 * Decoders request a buffer of a particular size by setting
2138 * AVFrame.nb_samples prior to calling get_buffer(). The decoder may,
2139 * however, utilize only part of the buffer by setting AVFrame.nb_samples
2140 * to a smaller value in the output frame.
2141 *
2142 * Decoders cannot use the buffer after returning from
2143 * avcodec_decode_audio4(), so they will not call release_buffer(), as it
2144 * is assumed to be released immediately upon return.
2145 *
2146 * As a convenience, av_samples_get_buffer_size() and
2147 * av_samples_fill_arrays() in libavutil may be used by custom get_buffer()
2148 * functions to find the required data size and to fill data pointers and
2149 * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
2150 * since all planes must be the same size.
2151 *
2152 * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
2153 *
2154 * - encoding: unused
2155 * - decoding: Set by libavcodec, user can override.
2156 */
2157 int (*get_buffer)(struct AVCodecContext *c, AVFrame *pic);
2158
2159 /**
2160 * Called to release buffers which were allocated with get_buffer.
2161 * A released buffer can be reused in get_buffer().
2162 * pic.data[*] must be set to NULL.
2163 * May be called from a different thread if frame multithreading is used,
2164 * but not by more than one thread at once, so does not need to be reentrant.
2165 * - encoding: unused
2166 * - decoding: Set by libavcodec, user can override.
2167 */
2168 void (*release_buffer)(struct AVCodecContext *c, AVFrame *pic);
2169
2170 /**
2171 * Called at the beginning of a frame to get cr buffer for it.
2172 * Buffer type (size, hints) must be the same. libavcodec won't check it.
2173 * libavcodec will pass previous buffer in pic, function should return
2174 * same buffer or new buffer with old frame "painted" into it.
2175 * If pic.data[0] == NULL must behave like get_buffer().
2176 * if CODEC_CAP_DR1 is not set then reget_buffer() must call
2177 * avcodec_default_reget_buffer() instead of providing buffers allocated by
2178 * some other means.
2179 * - encoding: unused
2180 * - decoding: Set by libavcodec, user can override.
2181 */
2182 int (*reget_buffer)(struct AVCodecContext *c, AVFrame *pic);
2183
2184
2185 /* - encoding parameters */
2186 float qcompress; ///< amount of qscale change between easy & hard scenes (0.0-1.0)
2187 float qblur; ///< amount of qscale smoothing over time (0.0-1.0)
2188
2189 /**
2190 * minimum quantizer
2191 * - encoding: Set by user.
2192 * - decoding: unused
2193 */
2194 int qmin;
2195
2196 /**
2197 * maximum quantizer
2198 * - encoding: Set by user.
2199 * - decoding: unused
2200 */
2201 int qmax;
2202
2203 /**
2204 * maximum quantizer difference between frames
2205 * - encoding: Set by user.
2206 * - decoding: unused
2207 */
2208 int max_qdiff;
2209
2210 /**
2211 * ratecontrol qmin qmax limiting method
2212 * 0-> clipping, 1-> use a nice continous function to limit qscale wthin qmin/qmax.
2213 * - encoding: Set by user.
2214 * - decoding: unused
2215 */
2216 float rc_qsquish;
2217
2218 float rc_qmod_amp;
2219 int rc_qmod_freq;
2220
2221 /**
2222 * decoder bitstream buffer size
2223 * - encoding: Set by user.
2224 * - decoding: unused
2225 */
2226 int rc_buffer_size;
2227
2228 /**
2229 * ratecontrol override, see RcOverride
2230 * - encoding: Allocated/set/freed by user.
2231 * - decoding: unused
2232 */
2233 int rc_override_count;
2234 RcOverride *rc_override;
2235
2236 /**
2237 * rate control equation
2238 * - encoding: Set by user
2239 * - decoding: unused
2240 */
2241 const char *rc_eq;
2242
2243 /**
2244 * maximum bitrate
2245 * - encoding: Set by user.
2246 * - decoding: unused
2247 */
2248 int rc_max_rate;
2249
2250 /**
2251 * minimum bitrate
2252 * - encoding: Set by user.
2253 * - decoding: unused
2254 */
2255 int rc_min_rate;
2256
2257 float rc_buffer_aggressivity;
2258
2259 /**
2260 * initial complexity for pass1 ratecontrol
2261 * - encoding: Set by user.
2262 * - decoding: unused
2263 */
2264 float rc_initial_cplx;
2265
2266 /**
2267 * Ratecontrol attempt to use, at maximum, <value> of what can be used without an underflow.
2268 * - encoding: Set by user.
2269 * - decoding: unused.
2270 */
2271 float rc_max_available_vbv_use;
2272
2273 /**
2274 * Ratecontrol attempt to use, at least, <value> times the amount needed to prevent a vbv overflow.
2275 * - encoding: Set by user.
2276 * - decoding: unused.
2277 */
2278 float rc_min_vbv_overflow_use;
2279
2280 /**
2281 * Number of bits which should be loaded into the rc buffer before decoding starts.
2282 * - encoding: Set by user.
2283 * - decoding: unused
2284 */
2285 int rc_initial_buffer_occupancy;
2286
2287 #define FF_CODER_TYPE_VLC 0
2288 #define FF_CODER_TYPE_AC 1
2289 #define FF_CODER_TYPE_RAW 2
2290 #define FF_CODER_TYPE_RLE 3
2291 #define FF_CODER_TYPE_DEFLATE 4
2292 /**
2293 * coder type
2294 * - encoding: Set by user.
2295 * - decoding: unused
2296 */
2297 int coder_type;
2298
2299 /**
2300 * context model
2301 * - encoding: Set by user.
2302 * - decoding: unused
2303 */
2304 int context_model;
2305
2306 /**
2307 * minimum Lagrange multipler
2308 * - encoding: Set by user.
2309 * - decoding: unused
2310 */
2311 int lmin;
2312
2313 /**
2314 * maximum Lagrange multipler
2315 * - encoding: Set by user.
2316 * - decoding: unused
2317 */
2318 int lmax;
2319
2320 /**
2321 * frame skip threshold
2322 * - encoding: Set by user.
2323 * - decoding: unused
2324 */
2325 int frame_skip_threshold;
2326
2327 /**
2328 * frame skip factor
2329 * - encoding: Set by user.
2330 * - decoding: unused
2331 */
2332 int frame_skip_factor;
2333
2334 /**
2335 * frame skip exponent
2336 * - encoding: Set by user.
2337 * - decoding: unused
2338 */
2339 int frame_skip_exp;
2340
2341 /**
2342 * frame skip comparison function
2343 * - encoding: Set by user.
2344 * - decoding: unused
2345 */
2346 int frame_skip_cmp;
2347
2348 /**
2349 * trellis RD quantization
2350 * - encoding: Set by user.
2351 * - decoding: unused
2352 */
2353 int trellis;
2354
2355 /**
2356 * - encoding: Set by user.
2357 * - decoding: unused
2358 */
2359 int min_prediction_order;
2360
2361 /**
2362 * - encoding: Set by user.
2363 * - decoding: unused
2364 */
2365 int max_prediction_order;
2366
2367 /**
2368 * GOP timecode frame start number, in non drop frame format
2369 * - encoding: Set by user.
2370 * - decoding: unused
2371 */
2372 int64_t timecode_frame_start;
2373
2374 /* The RTP callback: This function is called */
2375 /* every time the encoder has a packet to send. */
2376 /* It depends on the encoder if the data starts */
2377 /* with a Start Code (it should). H.263 does. */
2378 /* mb_nb contains the number of macroblocks */
2379 /* encoded in the RTP payload. */
2380 void (*rtp_callback)(struct AVCodecContext *avctx, void *data, int size, int mb_nb);
2381
2382 int rtp_payload_size; /* The size of the RTP payload: the coder will */
2383 /* do its best to deliver a chunk with size */
2384 /* below rtp_payload_size, the chunk will start */
2385 /* with a start code on some codecs like H.263. */
2386 /* This doesn't take account of any particular */
2387 /* headers inside the transmitted RTP payload. */
2388
2389 /* statistics, used for 2-pass encoding */
2390 int mv_bits;
2391 int header_bits;
2392 int i_tex_bits;
2393 int p_tex_bits;
2394 int i_count;
2395 int p_count;
2396 int skip_count;
2397 int misc_bits;
2398
2399 /**
2400 * number of bits used for the previously encoded frame
2401 * - encoding: Set by libavcodec.
2402 * - decoding: unused
2403 */
2404 int frame_bits;
2405
2406 /**
2407 * pass1 encoding statistics output buffer
2408 * - encoding: Set by libavcodec.
2409 * - decoding: unused
2410 */
2411 char *stats_out;
2412
2413 /**
2414 * pass2 encoding statistics input buffer
2415 * Concatenated stuff from stats_out of pass1 should be placed here.
2416 * - encoding: Allocated/set/freed by user.
2417 * - decoding: unused
2418 */
2419 char *stats_in;
2420
2421 /**
2422 * Work around bugs in encoders which sometimes cannot be detected automatically.
2423 * - encoding: Set by user
2424 * - decoding: Set by user
2425 */
2426 int workaround_bugs;
2427 #define FF_BUG_AUTODETECT 1 ///< autodetection
2428 #define FF_BUG_OLD_MSMPEG4 2
2429 #define FF_BUG_XVID_ILACE 4
2430 #define FF_BUG_UMP4 8
2431 #define FF_BUG_NO_PADDING 16
2432 #define FF_BUG_AMV 32
2433 #define FF_BUG_AC_VLC 0 ///< Will be removed, libavcodec can now handle these non-compliant files by default.
2434 #define FF_BUG_QPEL_CHROMA 64
2435 #define FF_BUG_STD_QPEL 128
2436 #define FF_BUG_QPEL_CHROMA2 256
2437 #define FF_BUG_DIRECT_BLOCKSIZE 512
2438 #define FF_BUG_EDGE 1024
2439 #define FF_BUG_HPEL_CHROMA 2048
2440 #define FF_BUG_DC_CLIP 4096
2441 #define FF_BUG_MS 8192 ///< Work around various bugs in Microsoft's broken decoders.
2442 #define FF_BUG_TRUNCATED 16384
2443
2444 /**
2445 * strictly follow the standard (MPEG4, ...).
2446 * - encoding: Set by user.
2447 * - decoding: Set by user.
2448 * Setting this to STRICT or higher means the encoder and decoder will
2449 * generally do stupid things, whereas setting it to unofficial or lower
2450 * will mean the encoder might produce output that is not supported by all
2451 * spec-compliant decoders. Decoders don't differentiate between normal,
2452 * unofficial and experimental (that is, they always try to decode things
2453 * when they can) unless they are explicitly asked to behave stupidly
2454 * (=strictly conform to the specs)
2455 */
2456 int strict_std_compliance;
2457 #define FF_COMPLIANCE_VERY_STRICT 2 ///< Strictly conform to an older more strict version of the spec or reference software.
2458 #define FF_COMPLIANCE_STRICT 1 ///< Strictly conform to all the things in the spec no matter what consequences.
2459 #define FF_COMPLIANCE_NORMAL 0
2460 #define FF_COMPLIANCE_UNOFFICIAL -1 ///< Allow unofficial extensions
2461 #define FF_COMPLIANCE_EXPERIMENTAL -2 ///< Allow nonstandardized experimental things.
2462
2463 /**
2464 * error concealment flags
2465 * - encoding: unused
2466 * - decoding: Set by user.
2467 */
2468 int error_concealment;
2469 #define FF_EC_GUESS_MVS 1
2470 #define FF_EC_DEBLOCK 2
2471
2472 /**
2473 * debug
2474 * - encoding: Set by user.
2475 * - decoding: Set by user.
2476 */
2477 int debug;
2478 #define FF_DEBUG_PICT_INFO 1
2479 #define FF_DEBUG_RC 2
2480 #define FF_DEBUG_BITSTREAM 4
2481 #define FF_DEBUG_MB_TYPE 8
2482 #define FF_DEBUG_QP 16
2483 #define FF_DEBUG_MV 32
2484 #define FF_DEBUG_DCT_COEFF 0x00000040
2485 #define FF_DEBUG_SKIP 0x00000080
2486 #define FF_DEBUG_STARTCODE 0x00000100
2487 #define FF_DEBUG_PTS 0x00000200
2488 #define FF_DEBUG_ER 0x00000400
2489 #define FF_DEBUG_MMCO 0x00000800
2490 #define FF_DEBUG_BUGS 0x00001000
2491 #define FF_DEBUG_VIS_QP 0x00002000
2492 #define FF_DEBUG_VIS_MB_TYPE 0x00004000
2493 #define FF_DEBUG_BUFFERS 0x00008000
2494 #define FF_DEBUG_THREADS 0x00010000
2495
2496 /**
2497 * debug
2498 * - encoding: Set by user.
2499 * - decoding: Set by user.
2500 */
2501 int debug_mv;
2502 #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 //visualize forward predicted MVs of P frames
2503 #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 //visualize forward predicted MVs of B frames
2504 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
2505
2506 /**
2507 * Error recognition; may misdetect some more or less valid parts as errors.
2508 * - encoding: unused
2509 * - decoding: Set by user.
2510 */
2511 int err_recognition;
2512 #define AV_EF_CRCCHECK (1<<0)
2513 #define AV_EF_BITSTREAM (1<<1)
2514 #define AV_EF_BUFFER (1<<2)
2515 #define AV_EF_EXPLODE (1<<3)
2516
2517 /**
2518 * opaque 64bit number (generally a PTS) that will be reordered and
2519 * output in AVFrame.reordered_opaque
2520 * @deprecated in favor of pkt_pts
2521 * - encoding: unused
2522 * - decoding: Set by user.
2523 */
2524 int64_t reordered_opaque;
2525
2526 /**
2527 * Hardware accelerator in use
2528 * - encoding: unused.
2529 * - decoding: Set by libavcodec
2530 */
2531 struct AVHWAccel *hwaccel;
2532
2533 /**
2534 * Hardware accelerator context.
2535 * For some hardware accelerators, a global context needs to be
2536 * provided by the user. In that case, this holds display-dependent
2537 * data Libav cannot instantiate itself. Please refer to the
2538 * Libav HW accelerator documentation to know how to fill this
2539 * is. e.g. for VA API, this is a struct vaapi_context.
2540 * - encoding: unused
2541 * - decoding: Set by user
2542 */
2543 void *hwaccel_context;
2544
2545 /**
2546 * error
2547 * - encoding: Set by libavcodec if flags&CODEC_FLAG_PSNR.
2548 * - decoding: unused
2549 */
2550 uint64_t error[AV_NUM_DATA_POINTERS];
2551
2552 /**
2553 * DCT algorithm, see FF_DCT_* below
2554 * - encoding: Set by user.
2555 * - decoding: unused
2556 */
2557 int dct_algo;
2558 #define FF_DCT_AUTO 0
2559 #define FF_DCT_FASTINT 1
2560 #define FF_DCT_INT 2
2561 #define FF_DCT_MMX 3
2562 #define FF_DCT_ALTIVEC 5
2563 #define FF_DCT_FAAN 6
2564
2565 /**
2566 * IDCT algorithm, see FF_IDCT_* below.
2567 * - encoding: Set by user.
2568 * - decoding: Set by user.
2569 */
2570 int idct_algo;
2571 #define FF_IDCT_AUTO 0
2572 #define FF_IDCT_INT 1
2573 #define FF_IDCT_SIMPLE 2
2574 #define FF_IDCT_SIMPLEMMX 3
2575 #define FF_IDCT_LIBMPEG2MMX 4
2576 #define FF_IDCT_MMI 5
2577 #define FF_IDCT_ARM 7
2578 #define FF_IDCT_ALTIVEC 8
2579 #define FF_IDCT_SH4 9
2580 #define FF_IDCT_SIMPLEARM 10
2581 #define FF_IDCT_H264 11
2582 #define FF_IDCT_VP3 12
2583 #define FF_IDCT_IPP 13
2584 #define FF_IDCT_XVIDMMX 14
2585 #define FF_IDCT_CAVS 15
2586 #define FF_IDCT_SIMPLEARMV5TE 16
2587 #define FF_IDCT_SIMPLEARMV6 17
2588 #define FF_IDCT_SIMPLEVIS 18
2589 #define FF_IDCT_WMV2 19
2590 #define FF_IDCT_FAAN 20
2591 #define FF_IDCT_EA 21
2592 #define FF_IDCT_SIMPLENEON 22
2593 #define FF_IDCT_SIMPLEALPHA 23
2594 #define FF_IDCT_BINK 24
2595
2596 #if FF_API_DSP_MASK
2597 /**
2598 * Unused.
2599 * @deprecated use av_set_cpu_flags_mask() instead.
2600 */
2601 attribute_deprecated unsigned dsp_mask;
2602 #endif
2603
2604 /**
2605 * bits per sample/pixel from the demuxer (needed for huffyuv).
2606 * - encoding: Set by libavcodec.
2607 * - decoding: Set by user.
2608 */
2609 int bits_per_coded_sample;
2610
2611 /**
2612 * Bits per sample/pixel of internal libavcodec pixel/sample format.
2613 * - encoding: set by user.
2614 * - decoding: set by libavcodec.
2615 */
2616 int bits_per_raw_sample;
2617
2618 /**
2619 * low resolution decoding, 1-> 1/2 size, 2->1/4 size
2620 * - encoding: unused
2621 * - decoding: Set by user.
2622 */
2623 attribute_deprecated int lowres;
2624
2625 /**
2626 * the picture in the bitstream
2627 * - encoding: Set by libavcodec.
2628 * - decoding: Set by libavcodec.
2629 */
2630 AVFrame *coded_frame;
2631
2632 /**
2633 * thread count
2634 * is used to decide how many independent tasks should be passed to execute()
2635 * - encoding: Set by user.
2636 * - decoding: Set by user.
2637 */
2638 int thread_count;
2639
2640 /**
2641 * Which multithreading methods to use.
2642 * Use of FF_THREAD_FRAME will increase decoding delay by one frame per thread,
2643 * so clients which cannot provide future frames should not use it.
2644 *
2645 * - encoding: Set by user, otherwise the default is used.
2646 * - decoding: Set by user, otherwise the default is used.
2647 */
2648 int thread_type;
2649 #define FF_THREAD_FRAME 1 ///< Decode more than one frame at once
2650 #define FF_THREAD_SLICE 2 ///< Decode more than one part of a single frame at once
2651
2652 /**
2653 * Which multithreading methods are in use by the codec.
2654 * - encoding: Set by libavcodec.
2655 * - decoding: Set by libavcodec.
2656 */
2657 int active_thread_type;
2658
2659 /**
2660 * Set by the client if its custom get_buffer() callback can be called
2661 * synchronously from another thread, which allows faster multithreaded decoding.
2662 * draw_horiz_band() will be called from other threads regardless of this setting.
2663 * Ignored if the default get_buffer() is used.
2664 * - encoding: Set by user.
2665 * - decoding: Set by user.
2666 */
2667 int thread_safe_callbacks;
2668
2669 /**
2670 * The codec may call this to execute several independent things.
2671 * It will return only after finishing all tasks.
2672 * The user may replace this with some multithreaded implementation,
2673 * the default implementation will execute the parts serially.
2674 * @param count the number of things to execute
2675 * - encoding: Set by libavcodec, user can override.
2676 * - decoding: Set by libavcodec, user can override.
2677 */
2678 int (*execute)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size);
2679
2680 /**
2681 * The codec may call this to execute several independent things.
2682 * It will return only after finishing all tasks.
2683 * The user may replace this with some multithreaded implementation,
2684 * the default implementation will execute the parts serially.
2685 * Also see avcodec_thread_init and e.g. the --enable-pthread configure option.
2686 * @param c context passed also to func
2687 * @param count the number of things to execute
2688 * @param arg2 argument passed unchanged to func
2689 * @param ret return values of executed functions, must have space for "count" values. May be NULL.
2690 * @param func function that will be called count times, with jobnr from 0 to count-1.
2691 * threadnr will be in the range 0 to c->thread_count-1 < MAX_THREADS and so that no
2692 * two instances of func executing at the same time will have the same threadnr.
2693 * @return always 0 currently, but code should handle a future improvement where when any call to func
2694 * returns < 0 no further calls to func may be done and < 0 is returned.
2695 * - encoding: Set by libavcodec, user can override.
2696 * - decoding: Set by libavcodec, user can override.
2697 */
2698 int (*execute2)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count);
2699
2700 /**
2701 * thread opaque
2702 * Can be used by execute() to store some per AVCodecContext stuff.
2703 * - encoding: set by execute()
2704 * - decoding: set by execute()
2705 */
2706 void *thread_opaque;
2707
2708 /**
2709 * noise vs. sse weight for the nsse comparsion function
2710 * - encoding: Set by user.
2711 * - decoding: unused
2712 */
2713 int nsse_weight;
2714
2715 /**
2716 * profile
2717 * - encoding: Set by user.
2718 * - decoding: Set by libavcodec.
2719 */
2720 int profile;
2721 #define FF_PROFILE_UNKNOWN -99
2722 #define FF_PROFILE_RESERVED -100
2723
2724 #define FF_PROFILE_AAC_MAIN 0
2725 #define FF_PROFILE_AAC_LOW 1
2726 #define FF_PROFILE_AAC_SSR 2
2727 #define FF_PROFILE_AAC_LTP 3
2728 #define FF_PROFILE_AAC_HE 4
2729 #define FF_PROFILE_AAC_HE_V2 28
2730 #define FF_PROFILE_AAC_LD 22
2731 #define FF_PROFILE_AAC_ELD 38
2732
2733 #define FF_PROFILE_DTS 20
2734 #define FF_PROFILE_DTS_ES 30
2735 #define FF_PROFILE_DTS_96_24 40
2736 #define FF_PROFILE_DTS_HD_HRA 50
2737 #define FF_PROFILE_DTS_HD_MA 60
2738
2739 #define FF_PROFILE_MPEG2_422 0
2740 #define FF_PROFILE_MPEG2_HIGH 1
2741 #define FF_PROFILE_MPEG2_SS 2
2742 #define FF_PROFILE_MPEG2_SNR_SCALABLE 3
2743 #define FF_PROFILE_MPEG2_MAIN 4
2744 #define FF_PROFILE_MPEG2_SIMPLE 5
2745
2746 #define FF_PROFILE_H264_CONSTRAINED (1<<9) // 8+1; constraint_set1_flag
2747 #define FF_PROFILE_H264_INTRA (1<<11) // 8+3; constraint_set3_flag
2748
2749 #define FF_PROFILE_H264_BASELINE 66
2750 #define FF_PROFILE_H264_CONSTRAINED_BASELINE (66|FF_PROFILE_H264_CONSTRAINED)
2751 #define FF_PROFILE_H264_MAIN 77
2752 #define FF_PROFILE_H264_EXTENDED 88
2753 #define FF_PROFILE_H264_HIGH 100
2754 #define FF_PROFILE_H264_HIGH_10 110
2755 #define FF_PROFILE_H264_HIGH_10_INTRA (110|FF_PROFILE_H264_INTRA)
2756 #define FF_PROFILE_H264_HIGH_422 122
2757 #define FF_PROFILE_H264_HIGH_422_INTRA (122|FF_PROFILE_H264_INTRA)
2758 #define FF_PROFILE_H264_HIGH_444 144
2759 #define FF_PROFILE_H264_HIGH_444_PREDICTIVE 244
2760 #define FF_PROFILE_H264_HIGH_444_INTRA (244|FF_PROFILE_H264_INTRA)
2761 #define FF_PROFILE_H264_CAVLC_444 44
2762
2763 #define FF_PROFILE_VC1_SIMPLE 0
2764 #define FF_PROFILE_VC1_MAIN 1
2765 #define FF_PROFILE_VC1_COMPLEX 2
2766 #define FF_PROFILE_VC1_ADVANCED 3
2767
2768 #define FF_PROFILE_MPEG4_SIMPLE 0
2769 #define FF_PROFILE_MPEG4_SIMPLE_SCALABLE 1
2770 #define FF_PROFILE_MPEG4_CORE 2
2771 #define FF_PROFILE_MPEG4_MAIN 3
2772 #define FF_PROFILE_MPEG4_N_BIT 4
2773 #define FF_PROFILE_MPEG4_SCALABLE_TEXTURE 5
2774 #define FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION 6
2775 #define FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE 7
2776 #define FF_PROFILE_MPEG4_HYBRID 8
2777 #define FF_PROFILE_MPEG4_ADVANCED_REAL_TIME 9
2778 #define FF_PROFILE_MPEG4_CORE_SCALABLE 10
2779 #define FF_PROFILE_MPEG4_ADVANCED_CODING 11
2780 #define FF_PROFILE_MPEG4_ADVANCED_CORE 12
2781 #define FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE 13
2782 #define FF_PROFILE_MPEG4_SIMPLE_STUDIO 14
2783 #define FF_PROFILE_MPEG4_ADVANCED_SIMPLE 15
2784
2785 /**
2786 * level
2787 * - encoding: Set by user.
2788 * - decoding: Set by libavcodec.
2789 */
2790 int level;
2791 #define FF_LEVEL_UNKNOWN -99
2792
2793 /**
2794 *
2795 * - encoding: unused
2796 * - decoding: Set by user.
2797 */
2798 enum AVDiscard skip_loop_filter;
2799
2800 /**
2801 *
2802 * - encoding: unused
2803 * - decoding: Set by user.
2804 */
2805 enum AVDiscard skip_idct;
2806
2807 /**
2808 *
2809 * - encoding: unused
2810 * - decoding: Set by user.
2811 */
2812 enum AVDiscard skip_frame;
2813
2814 /**
2815 * Header containing style information for text subtitles.
2816 * For SUBTITLE_ASS subtitle type, it should contain the whole ASS
2817 * [Script Info] and [V4+ Styles] section, plus the [Events] line and
2818 * the Format line following. It shouldn't include any Dialogue line.
2819 * - encoding: Set/allocated/freed by user (before avcodec_open2())
2820 * - decoding: Set/allocated/freed by libavcodec (by avcodec_open2())
2821 */
2822 uint8_t *subtitle_header;
2823 int subtitle_header_size;
2824
2825 /**
2826 * Simulates errors in the bitstream to test error concealment.
2827 * - encoding: Set by user.
2828 * - decoding: unused
2829 */
2830 int error_rate;
2831
2832 /**
2833 * Current packet as passed into the decoder, to avoid having
2834 * to pass the packet into every function. Currently only valid
2835 * inside lavc and get/release_buffer callbacks.
2836 * - decoding: set by avcodec_decode_*, read by get_buffer() for setting pkt_pts
2837 * - encoding: unused
2838 */
2839 AVPacket *pkt;
2840
2841 /**
2842 * VBV delay coded in the last frame (in periods of a 27 MHz clock).
2843 * Used for compliant TS muxing.
2844 * - encoding: Set by libavcodec.
2845 * - decoding: unused.
2846 */
2847 uint64_t vbv_delay;
2848 } AVCodecContext;
2849
2850 /**
2851 * AVProfile.
2852 */
2853 typedef struct AVProfile {
2854 int profile;
2855 const char *name; ///< short name for the profile
2856 } AVProfile;
2857
2858 typedef struct AVCodecDefault AVCodecDefault;
2859
2860 /**
2861 * AVCodec.
2862 */
2863 typedef struct AVCodec {
2864 /**
2865 * Name of the codec implementation.
2866 * The name is globally unique among encoders and among decoders (but an
2867 * encoder and a decoder can share the same name).
2868 * This is the primary way to find a codec from the user perspective.
2869 */
2870 const char *name;
2871 /**
2872 * Descriptive name for the codec, meant to be more human readable than name.
2873 * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
2874 */
2875 const char *long_name;
2876 enum AVMediaType type;
2877 enum AVCodecID id;
2878 /**
2879 * Codec capabilities.
2880 * see CODEC_CAP_*
2881 */
2882 int capabilities;
2883 const AVRational *supported_framerates; ///< array of supported framerates, or NULL if any, array is terminated by {0,0}
2884 const enum PixelFormat *pix_fmts; ///< array of supported pixel formats, or NULL if unknown, array is terminated by -1
2885 const int *supported_samplerates; ///< array of supported audio samplerates, or NULL if unknown, array is terminated by 0
2886 const enum AVSampleFormat *sample_fmts; ///< array of supported sample formats, or NULL if unknown, array is terminated by -1
2887 const uint64_t *channel_layouts; ///< array of support channel layouts, or NULL if unknown. array is terminated by 0
2888 attribute_deprecated uint8_t max_lowres; ///< maximum value for lowres supported by the decoder
2889 const AVClass *priv_class; ///< AVClass for the private context
2890 const AVProfile *profiles; ///< array of recognized profiles, or NULL if unknown, array is terminated by {FF_PROFILE_UNKNOWN}
2891
2892 /*****************************************************************
2893 * No fields below this line are part of the public API. They
2894 * may not be used outside of libavcodec and can be changed and
2895 * removed at will.
2896 * New public fields should be added right above.
2897 *****************************************************************
2898 */
2899 int priv_data_size;
2900 struct AVCodec *next;
2901 /**
2902 * @name Frame-level threading support functions
2903 * @{
2904 */
2905 /**
2906 * If defined, called on thread contexts when they are created.
2907 * If the codec allocates writable tables in init(), re-allocate them here.
2908 * priv_data will be set to a copy of the original.
2909 */
2910 int (*init_thread_copy)(AVCodecContext *);
2911 /**
2912 * Copy necessary context variables from a previous thread context to the current one.
2913 * If not defined, the next thread will start automatically; otherwise, the codec
2914 * must call ff_thread_finish_setup().
2915 *
2916 * dst and src will (rarely) point to the same context, in which case memcpy should be skipped.
2917 */
2918 int (*update_thread_context)(AVCodecContext *dst, const AVCodecContext *src);
2919 /** @} */
2920
2921 /**
2922 * Private codec-specific defaults.
2923 */
2924 const AVCodecDefault *defaults;
2925
2926 /**
2927 * Initialize codec static data, called from avcodec_register().
2928 */
2929 void (*init_static_data)(struct AVCodec *codec);
2930
2931 int (*init)(AVCodecContext *);
2932 int (*encode)(AVCodecContext *, uint8_t *buf, int buf_size, void *data);
2933 /**
2934 * Encode data to an AVPacket.
2935 *
2936 * @param avctx codec context
2937 * @param avpkt output AVPacket (may contain a user-provided buffer)
2938 * @param[in] frame AVFrame containing the raw data to be encoded
2939 * @param[out] got_packet_ptr encoder sets to 0 or 1 to indicate that a
2940 * non-empty packet was returned in avpkt.
2941 * @return 0 on success, negative error code on failure
2942 */
2943 int (*encode2)(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame,
2944 int *got_packet_ptr);
2945 int (*decode)(AVCodecContext *, void *outdata, int *outdata_size, AVPacket *avpkt);
2946 int (*close)(AVCodecContext *);
2947 /**
2948 * Flush buffers.
2949 * Will be called when seeking
2950 */
2951 void (*flush)(AVCodecContext *);
2952 } AVCodec;
2953
2954 /**
2955 * AVHWAccel.
2956 */
2957 typedef struct AVHWAccel {
2958 /**
2959 * Name of the hardware accelerated codec.
2960 * The name is globally unique among encoders and among decoders (but an
2961 * encoder and a decoder can share the same name).
2962 */
2963 const char *name;
2964
2965 /**
2966 * Type of codec implemented by the hardware accelerator.
2967 *
2968 * See AVMEDIA_TYPE_xxx
2969 */
2970 enum AVMediaType type;
2971
2972 /**
2973 * Codec implemented by the hardware accelerator.
2974 *
2975 * See AV_CODEC_ID_xxx
2976 */
2977 enum AVCodecID id;
2978
2979 /**
2980 * Supported pixel format.
2981 *
2982 * Only hardware accelerated formats are supported here.
2983 */
2984 enum PixelFormat pix_fmt;
2985
2986 /**
2987 * Hardware accelerated codec capabilities.
2988 * see FF_HWACCEL_CODEC_CAP_*
2989 */
2990 int capabilities;
2991
2992 struct AVHWAccel *next;
2993
2994 /**
2995 * Called at the beginning of each frame or field picture.
2996 *
2997 * Meaningful frame information (codec specific) is guaranteed to
2998 * be parsed at this point. This function is mandatory.
2999 *
3000 * Note that buf can be NULL along with buf_size set to 0.
3001 * Otherwise, this means the whole frame is available at this point.
3002 *
3003 * @param avctx the codec context
3004 * @param buf the frame data buffer base
3005 * @param buf_size the size of the frame in bytes
3006 * @return zero if successful, a negative value otherwise
3007 */
3008 int (*start_frame)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3009
3010 /**
3011 * Callback for each slice.
3012 *
3013 * Meaningful slice information (codec specific) is guaranteed to
3014 * be parsed at this point. This function is mandatory.
3015 *
3016 * @param avctx the codec context
3017 * @param buf the slice data buffer base
3018 * @param buf_size the size of the slice in bytes
3019 * @return zero if successful, a negative value otherwise
3020 */
3021 int (*decode_slice)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3022
3023 /**
3024 * Called at the end of each frame or field picture.
3025 *
3026 * The whole picture is parsed at this point and can now be sent
3027 * to the hardware accelerator. This function is mandatory.
3028 *
3029 * @param avctx the codec context
3030 * @return zero if successful, a negative value otherwise
3031 */
3032 int (*end_frame)(AVCodecContext *avctx);
3033
3034 /**
3035 * Size of HW accelerator private data.
3036 *
3037 * Private data is allocated with av_mallocz() before
3038 * AVCodecContext.get_buffer() and deallocated after
3039 * AVCodecContext.release_buffer().
3040 */
3041 int priv_data_size;
3042 } AVHWAccel;
3043
3044 /**
3045 * @defgroup lavc_picture AVPicture
3046 *
3047 * Functions for working with AVPicture
3048 * @{
3049 */
3050
3051 /**
3052 * four components are given, that's all.
3053 * the last component is alpha
3054 */
3055 typedef struct AVPicture {
3056 uint8_t *data[AV_NUM_DATA_POINTERS];
3057 int linesize[AV_NUM_DATA_POINTERS]; ///< number of bytes per line
3058 } AVPicture;
3059
3060 /**
3061 * @}
3062 */
3063
3064 #define AVPALETTE_SIZE 1024
3065 #define AVPALETTE_COUNT 256
3066
3067 enum AVSubtitleType {
3068 SUBTITLE_NONE,
3069
3070 SUBTITLE_BITMAP, ///< A bitmap, pict will be set
3071
3072 /**
3073 * Plain text, the text field must be set by the decoder and is
3074 * authoritative. ass and pict fields may contain approximations.
3075 */
3076 SUBTITLE_TEXT,
3077
3078 /**
3079 * Formatted text, the ass field must be set by the decoder and is
3080 * authoritative. pict and text fields may contain approximations.
3081 */
3082 SUBTITLE_ASS,
3083 };
3084
3085 typedef struct AVSubtitleRect {
3086 int x; ///< top left corner of pict, undefined when pict is not set
3087 int y; ///< top left corner of pict, undefined when pict is not set
3088 int w; ///< width of pict, undefined when pict is not set
3089 int h; ///< height of pict, undefined when pict is not set
3090 int nb_colors; ///< number of colors in pict, undefined when pict is not set
3091
3092 /**
3093 * data+linesize for the bitmap of this subtitle.
3094 * can be set for text/ass as well once they where rendered
3095 */
3096 AVPicture pict;
3097 enum AVSubtitleType type;
3098
3099 char *text; ///< 0 terminated plain UTF-8 text
3100
3101 /**
3102 * 0 terminated ASS/SSA compatible event line.
3103 * The pressentation of this is unaffected by the other values in this
3104 * struct.
3105 */
3106 char *ass;
3107 } AVSubtitleRect;
3108
3109 typedef struct AVSubtitle {
3110 uint16_t format; /* 0 = graphics */
3111 uint32_t start_display_time; /* relative to packet pts, in ms */
3112 uint32_t end_display_time; /* relative to packet pts, in ms */
3113 unsigned num_rects;
3114 AVSubtitleRect **rects;
3115 int64_t pts; ///< Same as packet pts, in AV_TIME_BASE
3116 } AVSubtitle;
3117
3118 /**
3119 * If c is NULL, returns the first registered codec,
3120 * if c is non-NULL, returns the next registered codec after c,
3121 * or NULL if c is the last one.
3122 */
3123 AVCodec *av_codec_next(AVCodec *c);
3124
3125 /**
3126 * Return the LIBAVCODEC_VERSION_INT constant.
3127 */
3128 unsigned avcodec_version(void);
3129
3130 /**
3131 * Return the libavcodec build-time configuration.
3132 */
3133 const char *avcodec_configuration(void);
3134
3135 /**
3136 * Return the libavcodec license.
3137 */
3138 const char *avcodec_license(void);
3139
3140 /**
3141 * Register the codec codec and initialize libavcodec.
3142 *
3143 * @warning either this function or avcodec_register_all() must be called
3144 * before any other libavcodec functions.
3145 *
3146 * @see avcodec_register_all()
3147 */
3148 void avcodec_register(AVCodec *codec);
3149
3150 /**
3151 * Register all the codecs, parsers and bitstream filters which were enabled at
3152 * configuration time. If you do not call this function you can select exactly
3153 * which formats you want to support, by using the individual registration
3154 * functions.
3155 *
3156 * @see avcodec_register
3157 * @see av_register_codec_parser
3158 * @see av_register_bitstream_filter
3159 */
3160 void avcodec_register_all(void);
3161
3162 /**
3163 * Allocate an AVCodecContext and set its fields to default values. The
3164 * resulting struct can be deallocated by calling avcodec_close() on it followed
3165 * by av_free().
3166 *
3167 * @param codec if non-NULL, allocate private data and initialize defaults
3168 * for the given codec. It is illegal to then call avcodec_open2()
3169 * with a different codec.
3170 * If NULL, then the codec-specific defaults won't be initialized,
3171 * which may result in suboptimal default settings (this is
3172 * important mainly for encoders, e.g. libx264).
3173 *
3174 * @return An AVCodecContext filled with default values or NULL on failure.
3175 * @see avcodec_get_context_defaults
3176 */
3177 AVCodecContext *avcodec_alloc_context3(AVCodec *codec);
3178
3179 /**
3180 * Set the fields of the given AVCodecContext to default values corresponding
3181 * to the given codec (defaults may be codec-dependent).
3182 *
3183 * Do not call this function if a non-NULL codec has been passed
3184 * to avcodec_alloc_context3() that allocated this AVCodecContext.
3185 * If codec is non-NULL, it is illegal to call avcodec_open2() with a
3186 * different codec on this AVCodecContext.
3187 */
3188 int avcodec_get_context_defaults3(AVCodecContext *s, AVCodec *codec);
3189
3190 /**
3191 * Get the AVClass for AVCodecContext. It can be used in combination with
3192 * AV_OPT_SEARCH_FAKE_OBJ for examining options.
3193 *
3194 * @see av_opt_find().
3195 */
3196 const AVClass *avcodec_get_class(void);
3197
3198 /**
3199 * Copy the settings of the source AVCodecContext into the destination
3200 * AVCodecContext. The resulting destination codec context will be
3201 * unopened, i.e. you are required to call avcodec_open2() before you
3202 * can use this AVCodecContext to decode/encode video/audio data.
3203 *
3204 * @param dest target codec context, should be initialized with
3205 * avcodec_alloc_context3(), but otherwise uninitialized
3206 * @param src source codec context
3207 * @return AVERROR() on error (e.g. memory allocation error), 0 on success
3208 */
3209 int avcodec_copy_context(AVCodecContext *dest, const AVCodecContext *src);
3210
3211 /**
3212 * Allocate an AVFrame and set its fields to default values. The resulting
3213 * struct can be deallocated by simply calling av_free().
3214 *
3215 * @return An AVFrame filled with default values or NULL on failure.
3216 * @see avcodec_get_frame_defaults
3217 */
3218 AVFrame *avcodec_alloc_frame(void);
3219
3220 /**
3221 * Set the fields of the given AVFrame to default values.
3222 *
3223 * @param pic The AVFrame of which the fields should be set to default values.
3224 */
3225 void avcodec_get_frame_defaults(AVFrame *pic);
3226
3227 /**
3228 * Initialize the AVCodecContext to use the given AVCodec. Prior to using this
3229 * function the context has to be allocated with avcodec_alloc_context3().
3230 *
3231 * The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(),
3232 * avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for
3233 * retrieving a codec.
3234 *
3235 * @warning This function is not thread safe!
3236 *
3237 * @code
3238 * avcodec_register_all();
3239 * av_dict_set(&opts, "b", "2.5M", 0);
3240 * codec = avcodec_find_decoder(AV_CODEC_ID_H264);
3241 * if (!codec)
3242 * exit(1);
3243 *
3244 * context = avcodec_alloc_context3(codec);
3245 *
3246 * if (avcodec_open2(context, codec, opts) < 0)
3247 * exit(1);
3248 * @endcode
3249 *
3250 * @param avctx The context to initialize.
3251 * @param codec The codec to open this context for. If a non-NULL codec has been
3252 * previously passed to avcodec_alloc_context3() or
3253 * avcodec_get_context_defaults3() for this context, then this
3254 * parameter MUST be either NULL or equal to the previously passed
3255 * codec.
3256 * @param options A dictionary filled with AVCodecContext and codec-private options.
3257 * On return this object will be filled with options that were not found.
3258 *
3259 * @return zero on success, a negative value on error
3260 * @see avcodec_alloc_context3(), avcodec_find_decoder(), avcodec_find_encoder(),
3261 * av_dict_set(), av_opt_find().
3262 */
3263 int avcodec_open2(AVCodecContext *avctx, AVCodec *codec, AVDictionary **options);
3264
3265 /**
3266 * Close a given AVCodecContext and free all the data associated with it
3267 * (but not the AVCodecContext itself).
3268 *
3269 * Calling this function on an AVCodecContext that hasn't been opened will free
3270 * the codec-specific data allocated in avcodec_alloc_context3() /
3271 * avcodec_get_context_defaults3() with a non-NULL codec. Subsequent calls will
3272 * do nothing.
3273 */
3274 int avcodec_close(AVCodecContext *avctx);
3275
3276 /**
3277 * Free all allocated data in the given subtitle struct.
3278 *
3279 * @param sub AVSubtitle to free.
3280 */
3281 void avsubtitle_free(AVSubtitle *sub);
3282
3283 /**
3284 * @}
3285 */
3286
3287 /**
3288 * @addtogroup lavc_packet
3289 * @{
3290 */
3291
3292 /**
3293 * @deprecated use NULL instead
3294 */
3295 attribute_deprecated void av_destruct_packet_nofree(AVPacket *pkt);
3296
3297 /**
3298 * Default packet destructor.
3299 */
3300 void av_destruct_packet(AVPacket *pkt);
3301
3302 /**
3303 * Initialize optional fields of a packet with default values.
3304 *
3305 * Note, this does not touch the data and size members, which have to be
3306 * initialized separately.
3307 *
3308 * @param pkt packet
3309 */
3310 void av_init_packet(AVPacket *pkt);
3311
3312 /**
3313 * Allocate the payload of a packet and initialize its fields with
3314 * default values.
3315 *
3316 * @param pkt packet
3317 * @param size wanted payload size
3318 * @return 0 if OK, AVERROR_xxx otherwise
3319 */
3320 int av_new_packet(AVPacket *pkt, int size);
3321
3322 /**
3323 * Reduce packet size, correctly zeroing padding
3324 *
3325 * @param pkt packet
3326 * @param size new size
3327 */
3328 void av_shrink_packet(AVPacket *pkt, int size);
3329
3330 /**
3331 * Increase packet size, correctly zeroing padding
3332 *
3333 * @param pkt packet
3334 * @param grow_by number of bytes by which to increase the size of the packet
3335 */
3336 int av_grow_packet(AVPacket *pkt, int grow_by);
3337
3338 /**
3339 * @warning This is a hack - the packet memory allocation stuff is broken. The
3340 * packet is allocated if it was not really allocated.
3341 */
3342 int av_dup_packet(AVPacket *pkt);
3343
3344 /**
3345 * Free a packet.
3346 *
3347 * @param pkt packet to free
3348 */
3349 void av_free_packet(AVPacket *pkt);
3350
3351 /**
3352 * Allocate new information of a packet.
3353 *
3354 * @param pkt packet
3355 * @param type side information type
3356 * @param size side information size
3357 * @return pointer to fresh allocated data or NULL otherwise
3358 */
3359 uint8_t* av_packet_new_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
3360 int size);
3361
3362 /**
3363 * Shrink the already allocated side data buffer
3364 *
3365 * @param pkt packet
3366 * @param type side information type
3367 * @param size new side information size
3368 * @return 0 on success, < 0 on failure
3369 */
3370 int av_packet_shrink_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
3371 int size);
3372
3373 /**
3374 * Get side information from packet.
3375 *
3376 * @param pkt packet
3377 * @param type desired side information type
3378 * @param size pointer for side information size to store (optional)
3379 * @return pointer to data if present or NULL otherwise
3380 */
3381 uint8_t* av_packet_get_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
3382 int *size);
3383
3384 /**
3385 * @}
3386 */
3387
3388 /**
3389 * @addtogroup lavc_decoding
3390 * @{
3391 */
3392
3393 /**
3394 * Find a registered decoder with a matching codec ID.
3395 *
3396 * @param id AVCodecID of the requested decoder
3397 * @return A decoder if one was found, NULL otherwise.
3398 */
3399 AVCodec *avcodec_find_decoder(enum AVCodecID id);
3400
3401 /**
3402 * Find a registered decoder with the specified name.
3403 *
3404 * @param name name of the requested decoder
3405 * @return A decoder if one was found, NULL otherwise.
3406 */
3407 AVCodec *avcodec_find_decoder_by_name(const char *name);
3408
3409 int avcodec_default_get_buffer(AVCodecContext *s, AVFrame *pic);
3410 void avcodec_default_release_buffer(AVCodecContext *s, AVFrame *pic);
3411 int avcodec_default_reget_buffer(AVCodecContext *s, AVFrame *pic);
3412
3413 /**
3414 * Return the amount of padding in pixels which the get_buffer callback must
3415 * provide around the edge of the image for codecs which do not have the
3416 * CODEC_FLAG_EMU_EDGE flag.
3417 *
3418 * @return Required padding in pixels.
3419 */
3420 unsigned avcodec_get_edge_width(void);
3421
3422 /**
3423 * Modify width and height values so that they will result in a memory
3424 * buffer that is acceptable for the codec if you do not use any horizontal
3425 * padding.
3426 *
3427 * May only be used if a codec with CODEC_CAP_DR1 has been opened.
3428 * If CODEC_FLAG_EMU_EDGE is not set, the dimensions must have been increased
3429 * according to avcodec_get_edge_width() before.
3430 */
3431 void avcodec_align_dimensions(AVCodecContext *s, int *width, int *height);
3432
3433 /**
3434 * Modify width and height values so that they will result in a memory
3435 * buffer that is acceptable for the codec if you also ensure that all
3436 * line sizes are a multiple of the respective linesize_align[i].
3437 *
3438 * May only be used if a codec with CODEC_CAP_DR1 has been opened.
3439 * If CODEC_FLAG_EMU_EDGE is not set, the dimensions must have been increased
3440 * according to avcodec_get_edge_width() before.
3441 */
3442 void avcodec_align_dimensions2(AVCodecContext *s, int *width, int *height,
3443 int linesize_align[AV_NUM_DATA_POINTERS]);
3444
3445 #if FF_API_OLD_DECODE_AUDIO
3446 /**
3447 * Wrapper function which calls avcodec_decode_audio4.
3448 *
3449 * @deprecated Use avcodec_decode_audio4 instead.
3450 *
3451 * Decode the audio frame of size avpkt->size from avpkt->data into samples.
3452 * Some decoders may support multiple frames in a single AVPacket, such
3453 * decoders would then just decode the first frame. In this case,
3454 * avcodec_decode_audio3 has to be called again with an AVPacket that contains
3455 * the remaining data in order to decode the second frame etc.
3456 * If no frame
3457 * could be outputted, frame_size_ptr is zero. Otherwise, it is the
3458 * decompressed frame size in bytes.
3459 *
3460 * @warning You must set frame_size_ptr to the allocated size of the
3461 * output buffer before calling avcodec_decode_audio3().
3462 *
3463 * @warning The input buffer must be FF_INPUT_BUFFER_PADDING_SIZE larger than
3464 * the actual read bytes because some optimized bitstream readers read 32 or 64
3465 * bits at once and could read over the end.
3466 *
3467 * @warning The end of the input buffer avpkt->data should be set to 0 to ensure that
3468 * no overreading happens for damaged MPEG streams.
3469 *
3470 * @warning You must not provide a custom get_buffer() when using
3471 * avcodec_decode_audio3(). Doing so will override it with
3472 * avcodec_default_get_buffer. Use avcodec_decode_audio4() instead,
3473 * which does allow the application to provide a custom get_buffer().
3474 *
3475 * @note You might have to align the input buffer avpkt->data and output buffer
3476 * samples. The alignment requirements depend on the CPU: On some CPUs it isn't
3477 * necessary at all, on others it won't work at all if not aligned and on others
3478 * it will work but it will have an impact on performance.
3479 *
3480 * In practice, avpkt->data should have 4 byte alignment at minimum and
3481 * samples should be 16 byte aligned unless the CPU doesn't need it
3482 * (AltiVec and SSE do).
3483 *
3484 * @note Codecs which have the CODEC_CAP_DELAY capability set have a delay
3485 * between input and output, these need to be fed with avpkt->data=NULL,
3486 * avpkt->size=0 at the end to return the remaining frames.
3487 *
3488 * @param avctx the codec context
3489 * @param[out] samples the output buffer, sample type in avctx->sample_fmt
3490 * If the sample format is planar, each channel plane will
3491 * be the same size, with no padding between channels.
3492 * @param[in,out] frame_size_ptr the output buffer size in bytes
3493 * @param[in] avpkt The input AVPacket containing the input buffer.
3494 * You can create such packet with av_init_packet() and by then setting
3495 * data and size, some decoders might in addition need other fields.
3496 * All decoders are designed to use the least fields possible though.
3497 * @return On error a negative value is returned, otherwise the number of bytes
3498 * used or zero if no frame data was decompressed (used) from the input AVPacket.
3499 */
3500 attribute_deprecated int avcodec_decode_audio3(AVCodecContext *avctx, int16_t *samples,
3501 int *frame_size_ptr,
3502 AVPacket *avpkt);
3503 #endif
3504
3505 /**
3506 * Decode the audio frame of size avpkt->size from avpkt->data into frame.
3507 *
3508 * Some decoders may support multiple frames in a single AVPacket. Such
3509 * decoders would then just decode the first frame. In this case,
3510 * avcodec_decode_audio4 has to be called again with an AVPacket containing
3511 * the remaining data in order to decode the second frame, etc...
3512 * Even if no frames are returned, the packet needs to be fed to the decoder
3513 * with remaining data until it is completely consumed or an error occurs.
3514 *
3515 * @warning The input buffer, avpkt->data must be FF_INPUT_BUFFER_PADDING_SIZE
3516 * larger than the actual read bytes because some optimized bitstream
3517 * readers read 32 or 64 bits at once and could read over the end.
3518 *
3519 * @note You might have to align the input buffer. The alignment requirements
3520 * depend on the CPU and the decoder.
3521 *
3522 * @param avctx the codec context
3523 * @param[out] frame The AVFrame in which to store decoded audio samples.
3524 * Decoders request a buffer of a particular size by setting
3525 * AVFrame.nb_samples prior to calling get_buffer(). The
3526 * decoder may, however, only utilize part of the buffer by
3527 * setting AVFrame.nb_samples to a smaller value in the
3528 * output frame.
3529 * @param[out] got_frame_ptr Zero if no frame could be decoded, otherwise it is
3530 * non-zero.
3531 * @param[in] avpkt The input AVPacket containing the input buffer.
3532 * At least avpkt->data and avpkt->size should be set. Some
3533 * decoders might also require additional fields to be set.
3534 * @return A negative error code is returned if an error occurred during
3535 * decoding, otherwise the number of bytes consumed from the input
3536 * AVPacket is returned.
3537 */
3538 int avcodec_decode_audio4(AVCodecContext *avctx, AVFrame *frame,
3539 int *got_frame_ptr, AVPacket *avpkt);
3540
3541 /**
3542 * Decode the video frame of size avpkt->size from avpkt->data into picture.
3543 * Some decoders may support multiple frames in a single AVPacket, such
3544 * decoders would then just decode the first frame.
3545 *
3546 * @warning The input buffer must be FF_INPUT_BUFFER_PADDING_SIZE larger than
3547 * the actual read bytes because some optimized bitstream readers read 32 or 64
3548 * bits at once and could read over the end.
3549 *
3550 * @warning The end of the input buffer buf should be set to 0 to ensure that
3551 * no overreading happens for damaged MPEG streams.
3552 *
3553 * @note You might have to align the input buffer avpkt->data.
3554 * The alignment requirements depend on the CPU: on some CPUs it isn't
3555 * necessary at all, on others it won't work at all if not aligned and on others
3556 * it will work but it will have an impact on performance.
3557 *
3558 * In practice, avpkt->data should have 4 byte alignment at minimum.
3559 *
3560 * @note Codecs which have the CODEC_CAP_DELAY capability set have a delay
3561 * between input and output, these need to be fed with avpkt->data=NULL,
3562 * avpkt->size=0 at the end to return the remaining frames.
3563 *
3564 * @param avctx the codec context
3565 * @param[out] picture The AVFrame in which the decoded video frame will be stored.
3566 * Use avcodec_alloc_frame to get an AVFrame, the codec will
3567 * allocate memory for the actual bitmap.
3568 * with default get/release_buffer(), the decoder frees/reuses the bitmap as it sees fit.
3569 * with overridden get/release_buffer() (needs CODEC_CAP_DR1) the user decides into what buffer the decoder
3570 * decodes and the decoder tells the user once it does not need the data anymore,
3571 * the user app can at this point free/reuse/keep the memory as it sees fit.
3572 *
3573 * @param[in] avpkt The input AVpacket containing the input buffer.
3574 * You can create such packet with av_init_packet() and by then setting
3575 * data and size, some decoders might in addition need other fields like
3576 * flags&AV_PKT_FLAG_KEY. All decoders are designed to use the least
3577 * fields possible.
3578 * @param[in,out] got_picture_ptr Zero if no frame could be decompressed, otherwise, it is nonzero.
3579 * @return On error a negative value is returned, otherwise the number of bytes
3580 * used or zero if no frame could be decompressed.
3581 */
3582 int avcodec_decode_video2(AVCodecContext *avctx, AVFrame *picture,
3583 int *got_picture_ptr,
3584 AVPacket *avpkt);
3585
3586 /**
3587 * Decode a subtitle message.
3588 * Return a negative value on error, otherwise return the number of bytes used.
3589 * If no subtitle could be decompressed, got_sub_ptr is zero.
3590 * Otherwise, the subtitle is stored in *sub.
3591 * Note that CODEC_CAP_DR1 is not available for subtitle codecs. This is for
3592 * simplicity, because the performance difference is expect to be negligible
3593 * and reusing a get_buffer written for video codecs would probably perform badly
3594 * due to a potentially very different allocation pattern.
3595 *
3596 * @param avctx the codec context
3597 * @param[out] sub The AVSubtitle in which the decoded subtitle will be stored, must be
3598 freed with avsubtitle_free if *got_sub_ptr is set.
3599 * @param[in,out] got_sub_ptr Zero if no subtitle could be decompressed, otherwise, it is nonzero.
3600 * @param[in] avpkt The input AVPacket containing the input buffer.
3601 */
3602 int avcodec_decode_subtitle2(AVCodecContext *avctx, AVSubtitle *sub,
3603 int *got_sub_ptr,
3604 AVPacket *avpkt);
3605
3606 /**
3607 * @defgroup lavc_parsing Frame parsing
3608 * @{
3609 */
3610
3611 typedef struct AVCodecParserContext {
3612 void *priv_data;
3613 struct AVCodecParser *parser;
3614 int64_t frame_offset; /* offset of the current frame */
3615 int64_t cur_offset; /* current offset
3616 (incremented by each av_parser_parse()) */
3617 int64_t next_frame_offset; /* offset of the next frame */
3618 /* video info */
3619 int pict_type; /* XXX: Put it back in AVCodecContext. */
3620 /**
3621 * This field is used for proper frame duration computation in lavf.
3622 * It signals, how much longer the frame duration of the current frame
3623 * is compared to normal frame duration.
3624 *
3625 * frame_duration = (1 + repeat_pict) * time_base
3626 *
3627 * It is used by codecs like H.264 to display telecined material.
3628 */
3629 int repeat_pict; /* XXX: Put it back in AVCodecContext. */
3630 int64_t pts; /* pts of the current frame */
3631 int64_t dts; /* dts of the current frame */
3632
3633 /* private data */
3634 int64_t last_pts;
3635 int64_t last_dts;
3636 int fetch_timestamp;
3637
3638 #define AV_PARSER_PTS_NB 4
3639 int cur_frame_start_index;
3640 int64_t cur_frame_offset[AV_PARSER_PTS_NB];
3641 int64_t cur_frame_pts[AV_PARSER_PTS_NB];
3642 int64_t cur_frame_dts[AV_PARSER_PTS_NB];
3643
3644 int flags;
3645 #define PARSER_FLAG_COMPLETE_FRAMES 0x0001
3646 #define PARSER_FLAG_ONCE 0x0002
3647 /// Set if the parser has a valid file offset
3648 #define PARSER_FLAG_FETCHED_OFFSET 0x0004
3649
3650 int64_t offset; ///< byte offset from starting packet start
3651 int64_t cur_frame_end[AV_PARSER_PTS_NB];
3652
3653 /**
3654 * Set by parser to 1 for key frames and 0 for non-key frames.
3655 * It is initialized to -1, so if the parser doesn't set this flag,
3656 * old-style fallback using AV_PICTURE_TYPE_I picture type as key frames
3657 * will be used.
3658 */
3659 int key_frame;
3660
3661 /**
3662 * Time difference in stream time base units from the pts of this
3663 * packet to the point at which the output from the decoder has converged
3664 * independent from the availability of previous frames. That is, the
3665 * frames are virtually identical no matter if decoding started from
3666 * the very first frame or from this keyframe.
3667 * Is AV_NOPTS_VALUE if unknown.
3668 * This field is not the display duration of the current frame.
3669 * This field has no meaning if the packet does not have AV_PKT_FLAG_KEY
3670 * set.
3671 *
3672 * The purpose of this field is to allow seeking in streams that have no
3673 * keyframes in the conventional sense. It corresponds to the
3674 * recovery point SEI in H.264 and match_time_delta in NUT. It is also
3675 * essential for some types of subtitle streams to ensure that all
3676 * subtitles are correctly displayed after seeking.
3677 */
3678 int64_t convergence_duration;
3679
3680 // Timestamp generation support:
3681 /**
3682 * Synchronization point for start of timestamp generation.
3683 *
3684 * Set to >0 for sync point, 0 for no sync point and <0 for undefined
3685 * (default).
3686 *
3687 * For example, this corresponds to presence of H.264 buffering period
3688 * SEI message.
3689 */
3690 int dts_sync_point;
3691
3692 /**
3693 * Offset of the current timestamp against last timestamp sync point in
3694 * units of AVCodecContext.time_base.
3695 *
3696 * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
3697 * contain a valid timestamp offset.
3698 *
3699 * Note that the timestamp of sync point has usually a nonzero
3700 * dts_ref_dts_delta, which refers to the previous sync point. Offset of
3701 * the next frame after timestamp sync point will be usually 1.
3702 *
3703 * For example, this corresponds to H.264 cpb_removal_delay.
3704 */
3705 int dts_ref_dts_delta;
3706
3707 /**
3708 * Presentation delay of current frame in units of AVCodecContext.time_base.
3709 *
3710 * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
3711 * contain valid non-negative timestamp delta (presentation time of a frame
3712 * must not lie in the past).
3713 *
3714 * This delay represents the difference between decoding and presentation
3715 * time of the frame.
3716 *
3717 * For example, this corresponds to H.264 dpb_output_delay.
3718 */
3719 int pts_dts_delta;
3720
3721 /**
3722 * Position of the packet in file.
3723 *
3724 * Analogous to cur_frame_pts/dts
3725 */
3726 int64_t cur_frame_pos[AV_PARSER_PTS_NB];
3727
3728 /**
3729 * Byte position of currently parsed frame in stream.
3730 */
3731 int64_t pos;
3732
3733 /**
3734 * Previous frame byte position.
3735 */
3736 int64_t last_pos;
3737
3738 /**
3739 * Duration of the current frame.
3740 * For audio, this is in units of 1 / AVCodecContext.sample_rate.
3741 * For all other types, this is in units of AVCodecContext.time_base.
3742 */
3743 int duration;
3744 } AVCodecParserContext;
3745
3746 typedef struct AVCodecParser {
3747 int codec_ids[5]; /* several codec IDs are permitted */
3748 int priv_data_size;
3749 int (*parser_init)(AVCodecParserContext *s);
3750 int (*parser_parse)(AVCodecParserContext *s,
3751 AVCodecContext *avctx,
3752 const uint8_t **poutbuf, int *poutbuf_size,
3753 const uint8_t *buf, int buf_size);
3754 void (*parser_close)(AVCodecParserContext *s);
3755 int (*split)(AVCodecContext *avctx, const uint8_t *buf, int buf_size);
3756 struct AVCodecParser *next;
3757 } AVCodecParser;
3758
3759 AVCodecParser *av_parser_next(AVCodecParser *c);
3760
3761 void av_register_codec_parser(AVCodecParser *parser);
3762 AVCodecParserContext *av_parser_init(int codec_id);
3763
3764 /**
3765 * Parse a packet.
3766 *
3767 * @param s parser context.
3768 * @param avctx codec context.
3769 * @param poutbuf set to pointer to parsed buffer or NULL if not yet finished.
3770 * @param poutbuf_size set to size of parsed buffer or zero if not yet finished.
3771 * @param buf input buffer.
3772 * @param buf_size input length, to signal EOF, this should be 0 (so that the last frame can be output).
3773 * @param pts input presentation timestamp.
3774 * @param dts input decoding timestamp.
3775 * @param pos input byte position in stream.
3776 * @return the number of bytes of the input bitstream used.
3777 *
3778 * Example:
3779 * @code
3780 * while(in_len){
3781 * len = av_parser_parse2(myparser, AVCodecContext, &data, &size,
3782 * in_data, in_len,
3783 * pts, dts, pos);
3784 * in_data += len;
3785 * in_len -= len;
3786 *
3787 * if(size)
3788 * decode_frame(data, size);
3789 * }
3790 * @endcode
3791 */
3792 int av_parser_parse2(AVCodecParserContext *s,
3793 AVCodecContext *avctx,
3794 uint8_t **poutbuf, int *poutbuf_size,
3795 const uint8_t *buf, int buf_size,
3796 int64_t pts, int64_t dts,
3797 int64_t pos);
3798
3799 int av_parser_change(AVCodecParserContext *s,
3800 AVCodecContext *avctx,
3801 uint8_t **poutbuf, int *poutbuf_size,
3802 const uint8_t *buf, int buf_size, int keyframe);
3803 void av_parser_close(AVCodecParserContext *s);
3804
3805 /**
3806 * @}
3807 * @}
3808 */
3809
3810 /**
3811 * @addtogroup lavc_encoding
3812 * @{
3813 */
3814
3815 /**
3816 * Find a registered encoder with a matching codec ID.
3817 *
3818 * @param id AVCodecID of the requested encoder
3819 * @return An encoder if one was found, NULL otherwise.
3820 */
3821 AVCodec *avcodec_find_encoder(enum AVCodecID id);
3822
3823 /**
3824 * Find a registered encoder with the specified name.
3825 *
3826 * @param name name of the requested encoder
3827 * @return An encoder if one was found, NULL otherwise.
3828 */
3829 AVCodec *avcodec_find_encoder_by_name(const char *name);
3830
3831 #if FF_API_OLD_ENCODE_AUDIO
3832 /**
3833 * Encode an audio frame from samples into buf.
3834 *
3835 * @deprecated Use avcodec_encode_audio2 instead.
3836 *
3837 * @note The output buffer should be at least FF_MIN_BUFFER_SIZE bytes large.
3838 * However, for codecs with avctx->frame_size equal to 0 (e.g. PCM) the user
3839 * will know how much space is needed because it depends on the value passed
3840 * in buf_size as described below. In that case a lower value can be used.
3841 *
3842 * @param avctx the codec context
3843 * @param[out] buf the output buffer
3844 * @param[in] buf_size the output buffer size