FFmpeg  n5.1.2
avcodec.h
Go to the documentation of this file.
1 /*
2  * copyright (c) 2001 Fabrice Bellard
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #ifndef AVCODEC_AVCODEC_H
22 #define AVCODEC_AVCODEC_H
23 
24 /**
25  * @file
26  * @ingroup libavc
27  * Libavcodec external API header
28  */
29 
30 #include "libavutil/samplefmt.h"
31 #include "libavutil/attributes.h"
32 #include "libavutil/avutil.h"
33 #include "libavutil/buffer.h"
34 #include "libavutil/dict.h"
35 #include "libavutil/frame.h"
36 #include "libavutil/log.h"
37 #include "libavutil/pixfmt.h"
38 #include "libavutil/rational.h"
39 
40 #include "codec.h"
41 #include "codec_desc.h"
42 #include "codec_par.h"
43 #include "codec_id.h"
44 #include "defs.h"
45 #include "packet.h"
46 #include "version_major.h"
47 #ifndef HAVE_AV_CONFIG_H
48 /* When included as part of the ffmpeg build, only include the major version
49  * to avoid unnecessary rebuilds. When included externally, keep including
50  * the full version information. */
51 #include "version.h"
52 #endif
53 
54 /**
55  * @defgroup libavc libavcodec
56  * Encoding/Decoding Library
57  *
58  * @{
59  *
60  * @defgroup lavc_decoding Decoding
61  * @{
62  * @}
63  *
64  * @defgroup lavc_encoding Encoding
65  * @{
66  * @}
67  *
68  * @defgroup lavc_codec Codecs
69  * @{
70  * @defgroup lavc_codec_native Native Codecs
71  * @{
72  * @}
73  * @defgroup lavc_codec_wrappers External library wrappers
74  * @{
75  * @}
76  * @defgroup lavc_codec_hwaccel Hardware Accelerators bridge
77  * @{
78  * @}
79  * @}
80  * @defgroup lavc_internal Internal
81  * @{
82  * @}
83  * @}
84  */
85 
86 /**
87  * @ingroup libavc
88  * @defgroup lavc_encdec send/receive encoding and decoding API overview
89  * @{
90  *
91  * The avcodec_send_packet()/avcodec_receive_frame()/avcodec_send_frame()/
92  * avcodec_receive_packet() functions provide an encode/decode API, which
93  * decouples input and output.
94  *
95  * The API is very similar for encoding/decoding and audio/video, and works as
96  * follows:
97  * - Set up and open the AVCodecContext as usual.
98  * - Send valid input:
99  * - For decoding, call avcodec_send_packet() to give the decoder raw
100  * compressed data in an AVPacket.
101  * - For encoding, call avcodec_send_frame() to give the encoder an AVFrame
102  * containing uncompressed audio or video.
103  *
104  * In both cases, it is recommended that AVPackets and AVFrames are
105  * refcounted, or libavcodec might have to copy the input data. (libavformat
106  * always returns refcounted AVPackets, and av_frame_get_buffer() allocates
107  * refcounted AVFrames.)
108  * - Receive output in a loop. Periodically call one of the avcodec_receive_*()
109  * functions and process their output:
110  * - For decoding, call avcodec_receive_frame(). On success, it will return
111  * an AVFrame containing uncompressed audio or video data.
112  * - For encoding, call avcodec_receive_packet(). On success, it will return
113  * an AVPacket with a compressed frame.
114  *
115  * Repeat this call until it returns AVERROR(EAGAIN) or an error. The
116  * AVERROR(EAGAIN) return value means that new input data is required to
117  * return new output. In this case, continue with sending input. For each
118  * input frame/packet, the codec will typically return 1 output frame/packet,
119  * but it can also be 0 or more than 1.
120  *
121  * At the beginning of decoding or encoding, the codec might accept multiple
122  * input frames/packets without returning a frame, until its internal buffers
123  * are filled. This situation is handled transparently if you follow the steps
124  * outlined above.
125  *
126  * In theory, sending input can result in EAGAIN - this should happen only if
127  * not all output was received. You can use this to structure alternative decode
128  * or encode loops other than the one suggested above. For example, you could
129  * try sending new input on each iteration, and try to receive output if that
130  * returns EAGAIN.
131  *
132  * End of stream situations. These require "flushing" (aka draining) the codec,
133  * as the codec might buffer multiple frames or packets internally for
134  * performance or out of necessity (consider B-frames).
135  * This is handled as follows:
136  * - Instead of valid input, send NULL to the avcodec_send_packet() (decoding)
137  * or avcodec_send_frame() (encoding) functions. This will enter draining
138  * mode.
139  * - Call avcodec_receive_frame() (decoding) or avcodec_receive_packet()
140  * (encoding) in a loop until AVERROR_EOF is returned. The functions will
141  * not return AVERROR(EAGAIN), unless you forgot to enter draining mode.
142  * - Before decoding can be resumed again, the codec has to be reset with
143  * avcodec_flush_buffers().
144  *
145  * Using the API as outlined above is highly recommended. But it is also
146  * possible to call functions outside of this rigid schema. For example, you can
147  * call avcodec_send_packet() repeatedly without calling
148  * avcodec_receive_frame(). In this case, avcodec_send_packet() will succeed
149  * until the codec's internal buffer has been filled up (which is typically of
150  * size 1 per output frame, after initial input), and then reject input with
151  * AVERROR(EAGAIN). Once it starts rejecting input, you have no choice but to
152  * read at least some output.
153  *
154  * Not all codecs will follow a rigid and predictable dataflow; the only
155  * guarantee is that an AVERROR(EAGAIN) return value on a send/receive call on
156  * one end implies that a receive/send call on the other end will succeed, or
157  * at least will not fail with AVERROR(EAGAIN). In general, no codec will
158  * permit unlimited buffering of input or output.
159  *
160  * A codec is not allowed to return AVERROR(EAGAIN) for both sending and receiving. This
161  * would be an invalid state, which could put the codec user into an endless
162  * loop. The API has no concept of time either: it cannot happen that trying to
163  * do avcodec_send_packet() results in AVERROR(EAGAIN), but a repeated call 1 second
164  * later accepts the packet (with no other receive/flush API calls involved).
165  * The API is a strict state machine, and the passage of time is not supposed
166  * to influence it. Some timing-dependent behavior might still be deemed
167  * acceptable in certain cases. But it must never result in both send/receive
168  * returning EAGAIN at the same time at any point. It must also absolutely be
169  * avoided that the current state is "unstable" and can "flip-flop" between
170  * the send/receive APIs allowing progress. For example, it's not allowed that
171  * the codec randomly decides that it actually wants to consume a packet now
172  * instead of returning a frame, after it just returned AVERROR(EAGAIN) on an
173  * avcodec_send_packet() call.
174  * @}
175  */
176 
177 /**
178  * @defgroup lavc_core Core functions/structures.
179  * @ingroup libavc
180  *
181  * Basic definitions, functions for querying libavcodec capabilities,
182  * allocating core structures, etc.
183  * @{
184  */
185 
186 /**
187  * @ingroup lavc_encoding
188  * minimum encoding buffer size
189  * Used to avoid some checks during header writing.
190  */
191 #define AV_INPUT_BUFFER_MIN_SIZE 16384
192 
193 /**
194  * @ingroup lavc_encoding
195  */
196 typedef struct RcOverride{
199  int qscale; // If this is 0 then quality_factor will be used instead.
201 } RcOverride;
202 
203 /* encoding support
204  These flags can be passed in AVCodecContext.flags before initialization.
205  Note: Not everything is supported yet.
206 */
207 
208 /**
209  * Allow decoders to produce frames with data planes that are not aligned
210  * to CPU requirements (e.g. due to cropping).
211  */
212 #define AV_CODEC_FLAG_UNALIGNED (1 << 0)
213 /**
214  * Use fixed qscale.
215  */
216 #define AV_CODEC_FLAG_QSCALE (1 << 1)
217 /**
218  * 4 MV per MB allowed / advanced prediction for H.263.
219  */
220 #define AV_CODEC_FLAG_4MV (1 << 2)
221 /**
222  * Output even those frames that might be corrupted.
223  */
224 #define AV_CODEC_FLAG_OUTPUT_CORRUPT (1 << 3)
225 /**
226  * Use qpel MC.
227  */
228 #define AV_CODEC_FLAG_QPEL (1 << 4)
229 /**
230  * Don't output frames whose parameters differ from first
231  * decoded frame in stream.
232  */
233 #define AV_CODEC_FLAG_DROPCHANGED (1 << 5)
234 /**
235  * Use internal 2pass ratecontrol in first pass mode.
236  */
237 #define AV_CODEC_FLAG_PASS1 (1 << 9)
238 /**
239  * Use internal 2pass ratecontrol in second pass mode.
240  */
241 #define AV_CODEC_FLAG_PASS2 (1 << 10)
242 /**
243  * loop filter.
244  */
245 #define AV_CODEC_FLAG_LOOP_FILTER (1 << 11)
246 /**
247  * Only decode/encode grayscale.
248  */
249 #define AV_CODEC_FLAG_GRAY (1 << 13)
250 /**
251  * error[?] variables will be set during encoding.
252  */
253 #define AV_CODEC_FLAG_PSNR (1 << 15)
254 #if FF_API_FLAG_TRUNCATED
255 /**
256  * Input bitstream might be truncated at a random location
257  * instead of only at frame boundaries.
258  *
259  * @deprecated use codec parsers for packetizing input
260  */
261 #define AV_CODEC_FLAG_TRUNCATED (1 << 16)
262 #endif
263 /**
264  * Use interlaced DCT.
265  */
266 #define AV_CODEC_FLAG_INTERLACED_DCT (1 << 18)
267 /**
268  * Force low delay.
269  */
270 #define AV_CODEC_FLAG_LOW_DELAY (1 << 19)
271 /**
272  * Place global headers in extradata instead of every keyframe.
273  */
274 #define AV_CODEC_FLAG_GLOBAL_HEADER (1 << 22)
275 /**
276  * Use only bitexact stuff (except (I)DCT).
277  */
278 #define AV_CODEC_FLAG_BITEXACT (1 << 23)
279 /* Fx : Flag for H.263+ extra options */
280 /**
281  * H.263 advanced intra coding / MPEG-4 AC prediction
282  */
283 #define AV_CODEC_FLAG_AC_PRED (1 << 24)
284 /**
285  * interlaced motion estimation
286  */
287 #define AV_CODEC_FLAG_INTERLACED_ME (1 << 29)
288 #define AV_CODEC_FLAG_CLOSED_GOP (1U << 31)
289 
290 /**
291  * Allow non spec compliant speedup tricks.
292  */
293 #define AV_CODEC_FLAG2_FAST (1 << 0)
294 /**
295  * Skip bitstream encoding.
296  */
297 #define AV_CODEC_FLAG2_NO_OUTPUT (1 << 2)
298 /**
299  * Place global headers at every keyframe instead of in extradata.
300  */
301 #define AV_CODEC_FLAG2_LOCAL_HEADER (1 << 3)
302 
303 /**
304  * timecode is in drop frame format. DEPRECATED!!!!
305  */
306 #define AV_CODEC_FLAG2_DROP_FRAME_TIMECODE (1 << 13)
307 
308 /**
309  * Input bitstream might be truncated at a packet boundaries
310  * instead of only at frame boundaries.
311  */
312 #define AV_CODEC_FLAG2_CHUNKS (1 << 15)
313 /**
314  * Discard cropping information from SPS.
315  */
316 #define AV_CODEC_FLAG2_IGNORE_CROP (1 << 16)
317 
318 /**
319  * Show all frames before the first keyframe
320  */
321 #define AV_CODEC_FLAG2_SHOW_ALL (1 << 22)
322 /**
323  * Export motion vectors through frame side data
324  */
325 #define AV_CODEC_FLAG2_EXPORT_MVS (1 << 28)
326 /**
327  * Do not skip samples and export skip information as frame side data
328  */
329 #define AV_CODEC_FLAG2_SKIP_MANUAL (1 << 29)
330 /**
331  * Do not reset ASS ReadOrder field on flush (subtitles decoding)
332  */
333 #define AV_CODEC_FLAG2_RO_FLUSH_NOOP (1 << 30)
334 
335 /* Unsupported options :
336  * Syntax Arithmetic coding (SAC)
337  * Reference Picture Selection
338  * Independent Segment Decoding */
339 /* /Fx */
340 /* codec capabilities */
341 
342 /* Exported side data.
343  These flags can be passed in AVCodecContext.export_side_data before initialization.
344 */
345 /**
346  * Export motion vectors through frame side data
347  */
348 #define AV_CODEC_EXPORT_DATA_MVS (1 << 0)
349 /**
350  * Export encoder Producer Reference Time through packet side data
351  */
352 #define AV_CODEC_EXPORT_DATA_PRFT (1 << 1)
353 /**
354  * Decoding only.
355  * Export the AVVideoEncParams structure through frame side data.
356  */
357 #define AV_CODEC_EXPORT_DATA_VIDEO_ENC_PARAMS (1 << 2)
358 /**
359  * Decoding only.
360  * Do not apply film grain, export it instead.
361  */
362 #define AV_CODEC_EXPORT_DATA_FILM_GRAIN (1 << 3)
363 
364 /**
365  * The decoder will keep a reference to the frame and may reuse it later.
366  */
367 #define AV_GET_BUFFER_FLAG_REF (1 << 0)
368 
369 /**
370  * The encoder will keep a reference to the packet and may reuse it later.
371  */
372 #define AV_GET_ENCODE_BUFFER_FLAG_REF (1 << 0)
373 
374 struct AVCodecInternal;
375 
376 /**
377  * main external API structure.
378  * New fields can be added to the end with minor version bumps.
379  * Removal, reordering and changes to existing fields require a major
380  * version bump.
381  * You can use AVOptions (av_opt* / av_set/get*()) to access these fields from user
382  * applications.
383  * The name string for AVOptions options matches the associated command line
384  * parameter name and can be found in libavcodec/options_table.h
385  * The AVOption/command line parameter names differ in some cases from the C
386  * structure field names for historic reasons or brevity.
387  * sizeof(AVCodecContext) must not be used outside libav*.
388  */
389 typedef struct AVCodecContext {
390  /**
391  * information on struct for av_log
392  * - set by avcodec_alloc_context3
393  */
396 
397  enum AVMediaType codec_type; /* see AVMEDIA_TYPE_xxx */
398  const struct AVCodec *codec;
399  enum AVCodecID codec_id; /* see AV_CODEC_ID_xxx */
400 
401  /**
402  * fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
403  * This is used to work around some encoder bugs.
404  * A demuxer should set this to what is stored in the field used to identify the codec.
405  * If there are multiple such fields in a container then the demuxer should choose the one
406  * which maximizes the information about the used codec.
407  * If the codec tag field in a container is larger than 32 bits then the demuxer should
408  * remap the longer ID to 32 bits with a table or other structure. Alternatively a new
409  * extra_codec_tag + size could be added but for this a clear advantage must be demonstrated
410  * first.
411  * - encoding: Set by user, if not then the default based on codec_id will be used.
412  * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
413  */
414  unsigned int codec_tag;
415 
416  void *priv_data;
417 
418  /**
419  * Private context used for internal data.
420  *
421  * Unlike priv_data, this is not codec-specific. It is used in general
422  * libavcodec functions.
423  */
424  struct AVCodecInternal *internal;
425 
426  /**
427  * Private data of the user, can be used to carry app specific stuff.
428  * - encoding: Set by user.
429  * - decoding: Set by user.
430  */
431  void *opaque;
432 
433  /**
434  * the average bitrate
435  * - encoding: Set by user; unused for constant quantizer encoding.
436  * - decoding: Set by user, may be overwritten by libavcodec
437  * if this info is available in the stream
438  */
439  int64_t bit_rate;
440 
441  /**
442  * number of bits the bitstream is allowed to diverge from the reference.
443  * the reference can be CBR (for CBR pass1) or VBR (for pass2)
444  * - encoding: Set by user; unused for constant quantizer encoding.
445  * - decoding: unused
446  */
448 
449  /**
450  * Global quality for codecs which cannot change it per frame.
451  * This should be proportional to MPEG-1/2/4 qscale.
452  * - encoding: Set by user.
453  * - decoding: unused
454  */
456 
457  /**
458  * - encoding: Set by user.
459  * - decoding: unused
460  */
462 #define FF_COMPRESSION_DEFAULT -1
463 
464  /**
465  * AV_CODEC_FLAG_*.
466  * - encoding: Set by user.
467  * - decoding: Set by user.
468  */
469  int flags;
470 
471  /**
472  * AV_CODEC_FLAG2_*
473  * - encoding: Set by user.
474  * - decoding: Set by user.
475  */
476  int flags2;
477 
478  /**
479  * some codecs need / can use extradata like Huffman tables.
480  * MJPEG: Huffman tables
481  * rv10: additional flags
482  * MPEG-4: global headers (they can be in the bitstream or here)
483  * The allocated memory should be AV_INPUT_BUFFER_PADDING_SIZE bytes larger
484  * than extradata_size to avoid problems if it is read with the bitstream reader.
485  * The bytewise contents of extradata must not depend on the architecture or CPU endianness.
486  * Must be allocated with the av_malloc() family of functions.
487  * - encoding: Set/allocated/freed by libavcodec.
488  * - decoding: Set/allocated/freed by user.
489  */
490  uint8_t *extradata;
492 
493  /**
494  * This is the fundamental unit of time (in seconds) in terms
495  * of which frame timestamps are represented. For fixed-fps content,
496  * timebase should be 1/framerate and timestamp increments should be
497  * identically 1.
498  * This often, but not always is the inverse of the frame rate or field rate
499  * for video. 1/time_base is not the average frame rate if the frame rate is not
500  * constant.
501  *
502  * Like containers, elementary streams also can store timestamps, 1/time_base
503  * is the unit in which these timestamps are specified.
504  * As example of such codec time base see ISO/IEC 14496-2:2001(E)
505  * vop_time_increment_resolution and fixed_vop_rate
506  * (fixed_vop_rate == 0 implies that it is different from the framerate)
507  *
508  * - encoding: MUST be set by user.
509  * - decoding: the use of this field for decoding is deprecated.
510  * Use framerate instead.
511  */
513 
514  /**
515  * For some codecs, the time base is closer to the field rate than the frame rate.
516  * Most notably, H.264 and MPEG-2 specify time_base as half of frame duration
517  * if no telecine is used ...
518  *
519  * Set to time_base ticks per frame. Default 1, e.g., H.264/MPEG-2 set it to 2.
520  */
522 
523  /**
524  * Codec delay.
525  *
526  * Encoding: Number of frames delay there will be from the encoder input to
527  * the decoder output. (we assume the decoder matches the spec)
528  * Decoding: Number of frames delay in addition to what a standard decoder
529  * as specified in the spec would produce.
530  *
531  * Video:
532  * Number of frames the decoded output will be delayed relative to the
533  * encoded input.
534  *
535  * Audio:
536  * For encoding, this field is unused (see initial_padding).
537  *
538  * For decoding, this is the number of samples the decoder needs to
539  * output before the decoder's output is valid. When seeking, you should
540  * start decoding this many samples prior to your desired seek point.
541  *
542  * - encoding: Set by libavcodec.
543  * - decoding: Set by libavcodec.
544  */
545  int delay;
546 
547 
548  /* video only */
549  /**
550  * picture width / height.
551  *
552  * @note Those fields may not match the values of the last
553  * AVFrame output by avcodec_receive_frame() due frame
554  * reordering.
555  *
556  * - encoding: MUST be set by user.
557  * - decoding: May be set by the user before opening the decoder if known e.g.
558  * from the container. Some decoders will require the dimensions
559  * to be set by the caller. During decoding, the decoder may
560  * overwrite those values as required while parsing the data.
561  */
562  int width, height;
563 
564  /**
565  * Bitstream width / height, may be different from width/height e.g. when
566  * the decoded frame is cropped before being output or lowres is enabled.
567  *
568  * @note Those field may not match the value of the last
569  * AVFrame output by avcodec_receive_frame() due frame
570  * reordering.
571  *
572  * - encoding: unused
573  * - decoding: May be set by the user before opening the decoder if known
574  * e.g. from the container. During decoding, the decoder may
575  * overwrite those values as required while parsing the data.
576  */
578 
579  /**
580  * the number of pictures in a group of pictures, or 0 for intra_only
581  * - encoding: Set by user.
582  * - decoding: unused
583  */
584  int gop_size;
585 
586  /**
587  * Pixel format, see AV_PIX_FMT_xxx.
588  * May be set by the demuxer if known from headers.
589  * May be overridden by the decoder if it knows better.
590  *
591  * @note This field may not match the value of the last
592  * AVFrame output by avcodec_receive_frame() due frame
593  * reordering.
594  *
595  * - encoding: Set by user.
596  * - decoding: Set by user if known, overridden by libavcodec while
597  * parsing the data.
598  */
599  enum AVPixelFormat pix_fmt;
600 
601  /**
602  * If non NULL, 'draw_horiz_band' is called by the libavcodec
603  * decoder to draw a horizontal band. It improves cache usage. Not
604  * all codecs can do that. You must check the codec capabilities
605  * beforehand.
606  * When multithreading is used, it may be called from multiple threads
607  * at the same time; threads might draw different parts of the same AVFrame,
608  * or multiple AVFrames, and there is no guarantee that slices will be drawn
609  * in order.
610  * The function is also used by hardware acceleration APIs.
611  * It is called at least once during frame decoding to pass
612  * the data needed for hardware render.
613  * In that mode instead of pixel data, AVFrame points to
614  * a structure specific to the acceleration API. The application
615  * reads the structure and can change some fields to indicate progress
616  * or mark state.
617  * - encoding: unused
618  * - decoding: Set by user.
619  * @param height the height of the slice
620  * @param y the y position of the slice
621  * @param type 1->top field, 2->bottom field, 3->frame
622  * @param offset offset into the AVFrame.data from which the slice should be read
623  */
624  void (*draw_horiz_band)(struct AVCodecContext *s,
625  const AVFrame *src, int offset[AV_NUM_DATA_POINTERS],
626  int y, int type, int height);
627 
628  /**
629  * Callback to negotiate the pixel format. Decoding only, may be set by the
630  * caller before avcodec_open2().
631  *
632  * Called by some decoders to select the pixel format that will be used for
633  * the output frames. This is mainly used to set up hardware acceleration,
634  * then the provided format list contains the corresponding hwaccel pixel
635  * formats alongside the "software" one. The software pixel format may also
636  * be retrieved from \ref sw_pix_fmt.
637  *
638  * This callback will be called when the coded frame properties (such as
639  * resolution, pixel format, etc.) change and more than one output format is
640  * supported for those new properties. If a hardware pixel format is chosen
641  * and initialization for it fails, the callback may be called again
642  * immediately.
643  *
644  * This callback may be called from different threads if the decoder is
645  * multi-threaded, but not from more than one thread simultaneously.
646  *
647  * @param fmt list of formats which may be used in the current
648  * configuration, terminated by AV_PIX_FMT_NONE.
649  * @warning Behavior is undefined if the callback returns a value other
650  * than one of the formats in fmt or AV_PIX_FMT_NONE.
651  * @return the chosen format or AV_PIX_FMT_NONE
652  */
653  enum AVPixelFormat (*get_format)(struct AVCodecContext *s, const enum AVPixelFormat * fmt);
654 
655  /**
656  * maximum number of B-frames between non-B-frames
657  * Note: The output will be delayed by max_b_frames+1 relative to the input.
658  * - encoding: Set by user.
659  * - decoding: unused
660  */
662 
663  /**
664  * qscale factor between IP and B-frames
665  * If > 0 then the last P-frame quantizer will be used (q= lastp_q*factor+offset).
666  * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
667  * - encoding: Set by user.
668  * - decoding: unused
669  */
671 
672  /**
673  * qscale offset between IP and B-frames
674  * - encoding: Set by user.
675  * - decoding: unused
676  */
678 
679  /**
680  * Size of the frame reordering buffer in the decoder.
681  * For MPEG-2 it is 1 IPB or 0 low delay IP.
682  * - encoding: Set by libavcodec.
683  * - decoding: Set by libavcodec.
684  */
686 
687  /**
688  * qscale factor between P- and I-frames
689  * If > 0 then the last P-frame quantizer will be used (q = lastp_q * factor + offset).
690  * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
691  * - encoding: Set by user.
692  * - decoding: unused
693  */
695 
696  /**
697  * qscale offset between P and I-frames
698  * - encoding: Set by user.
699  * - decoding: unused
700  */
702 
703  /**
704  * luminance masking (0-> disabled)
705  * - encoding: Set by user.
706  * - decoding: unused
707  */
709 
710  /**
711  * temporary complexity masking (0-> disabled)
712  * - encoding: Set by user.
713  * - decoding: unused
714  */
716 
717  /**
718  * spatial complexity masking (0-> disabled)
719  * - encoding: Set by user.
720  * - decoding: unused
721  */
723 
724  /**
725  * p block masking (0-> disabled)
726  * - encoding: Set by user.
727  * - decoding: unused
728  */
729  float p_masking;
730 
731  /**
732  * darkness masking (0-> disabled)
733  * - encoding: Set by user.
734  * - decoding: unused
735  */
737 
738  /**
739  * slice count
740  * - encoding: Set by libavcodec.
741  * - decoding: Set by user (or 0).
742  */
744 
745  /**
746  * slice offsets in the frame in bytes
747  * - encoding: Set/allocated by libavcodec.
748  * - decoding: Set/allocated by user (or NULL).
749  */
751 
752  /**
753  * sample aspect ratio (0 if unknown)
754  * That is the width of a pixel divided by the height of the pixel.
755  * Numerator and denominator must be relatively prime and smaller than 256 for some video standards.
756  * - encoding: Set by user.
757  * - decoding: Set by libavcodec.
758  */
760 
761  /**
762  * motion estimation comparison function
763  * - encoding: Set by user.
764  * - decoding: unused
765  */
766  int me_cmp;
767  /**
768  * subpixel motion estimation comparison function
769  * - encoding: Set by user.
770  * - decoding: unused
771  */
773  /**
774  * macroblock comparison function (not supported yet)
775  * - encoding: Set by user.
776  * - decoding: unused
777  */
778  int mb_cmp;
779  /**
780  * interlaced DCT comparison function
781  * - encoding: Set by user.
782  * - decoding: unused
783  */
785 #define FF_CMP_SAD 0
786 #define FF_CMP_SSE 1
787 #define FF_CMP_SATD 2
788 #define FF_CMP_DCT 3
789 #define FF_CMP_PSNR 4
790 #define FF_CMP_BIT 5
791 #define FF_CMP_RD 6
792 #define FF_CMP_ZERO 7
793 #define FF_CMP_VSAD 8
794 #define FF_CMP_VSSE 9
795 #define FF_CMP_NSSE 10
796 #define FF_CMP_W53 11
797 #define FF_CMP_W97 12
798 #define FF_CMP_DCTMAX 13
799 #define FF_CMP_DCT264 14
800 #define FF_CMP_MEDIAN_SAD 15
801 #define FF_CMP_CHROMA 256
802 
803  /**
804  * ME diamond size & shape
805  * - encoding: Set by user.
806  * - decoding: unused
807  */
808  int dia_size;
809 
810  /**
811  * amount of previous MV predictors (2a+1 x 2a+1 square)
812  * - encoding: Set by user.
813  * - decoding: unused
814  */
816 
817  /**
818  * motion estimation prepass comparison function
819  * - encoding: Set by user.
820  * - decoding: unused
821  */
823 
824  /**
825  * ME prepass diamond size & shape
826  * - encoding: Set by user.
827  * - decoding: unused
828  */
830 
831  /**
832  * subpel ME quality
833  * - encoding: Set by user.
834  * - decoding: unused
835  */
837 
838  /**
839  * maximum motion estimation search range in subpel units
840  * If 0 then no limit.
841  *
842  * - encoding: Set by user.
843  * - decoding: unused
844  */
845  int me_range;
846 
847  /**
848  * slice flags
849  * - encoding: unused
850  * - decoding: Set by user.
851  */
853 #define SLICE_FLAG_CODED_ORDER 0x0001 ///< draw_horiz_band() is called in coded order instead of display
854 #define SLICE_FLAG_ALLOW_FIELD 0x0002 ///< allow draw_horiz_band() with field slices (MPEG-2 field pics)
855 #define SLICE_FLAG_ALLOW_PLANE 0x0004 ///< allow draw_horiz_band() with 1 component at a time (SVQ1)
856 
857  /**
858  * macroblock decision mode
859  * - encoding: Set by user.
860  * - decoding: unused
861  */
863 #define FF_MB_DECISION_SIMPLE 0 ///< uses mb_cmp
864 #define FF_MB_DECISION_BITS 1 ///< chooses the one which needs the fewest bits
865 #define FF_MB_DECISION_RD 2 ///< rate distortion
866 
867  /**
868  * custom intra quantization matrix
869  * Must be allocated with the av_malloc() family of functions, and will be freed in
870  * avcodec_free_context().
871  * - encoding: Set/allocated by user, freed by libavcodec. Can be NULL.
872  * - decoding: Set/allocated/freed by libavcodec.
873  */
874  uint16_t *intra_matrix;
875 
876  /**
877  * custom inter quantization matrix
878  * Must be allocated with the av_malloc() family of functions, and will be freed in
879  * avcodec_free_context().
880  * - encoding: Set/allocated by user, freed by libavcodec. Can be NULL.
881  * - decoding: Set/allocated/freed by libavcodec.
882  */
883  uint16_t *inter_matrix;
884 
885  /**
886  * precision of the intra DC coefficient - 8
887  * - encoding: Set by user.
888  * - decoding: Set by libavcodec
889  */
891 
892  /**
893  * Number of macroblock rows at the top which are skipped.
894  * - encoding: unused
895  * - decoding: Set by user.
896  */
897  int skip_top;
898 
899  /**
900  * Number of macroblock rows at the bottom which are skipped.
901  * - encoding: unused
902  * - decoding: Set by user.
903  */
905 
906  /**
907  * minimum MB Lagrange multiplier
908  * - encoding: Set by user.
909  * - decoding: unused
910  */
911  int mb_lmin;
912 
913  /**
914  * maximum MB Lagrange multiplier
915  * - encoding: Set by user.
916  * - decoding: unused
917  */
918  int mb_lmax;
919 
920  /**
921  * - encoding: Set by user.
922  * - decoding: unused
923  */
925 
926  /**
927  * minimum GOP size
928  * - encoding: Set by user.
929  * - decoding: unused
930  */
932 
933  /**
934  * number of reference frames
935  * - encoding: Set by user.
936  * - decoding: Set by lavc.
937  */
938  int refs;
939 
940  /**
941  * Note: Value depends upon the compare function used for fullpel ME.
942  * - encoding: Set by user.
943  * - decoding: unused
944  */
946 
947  /**
948  * Chromaticity coordinates of the source primaries.
949  * - encoding: Set by user
950  * - decoding: Set by libavcodec
951  */
953 
954  /**
955  * Color Transfer Characteristic.
956  * - encoding: Set by user
957  * - decoding: Set by libavcodec
958  */
960 
961  /**
962  * YUV colorspace type.
963  * - encoding: Set by user
964  * - decoding: Set by libavcodec
965  */
967 
968  /**
969  * MPEG vs JPEG YUV range.
970  * - encoding: Set by user
971  * - decoding: Set by libavcodec
972  */
974 
975  /**
976  * This defines the location of chroma samples.
977  * - encoding: Set by user
978  * - decoding: Set by libavcodec
979  */
981 
982  /**
983  * Number of slices.
984  * Indicates number of picture subdivisions. Used for parallelized
985  * decoding.
986  * - encoding: Set by user
987  * - decoding: unused
988  */
989  int slices;
990 
991  /** Field order
992  * - encoding: set by libavcodec
993  * - decoding: Set by user.
994  */
996 
997  /* audio only */
998  int sample_rate; ///< samples per second
999 
1000 #if FF_API_OLD_CHANNEL_LAYOUT
1001  /**
1002  * number of audio channels
1003  * @deprecated use ch_layout.nb_channels
1004  */
1007 #endif
1008 
1009  /**
1010  * audio sample format
1011  * - encoding: Set by user.
1012  * - decoding: Set by libavcodec.
1013  */
1014  enum AVSampleFormat sample_fmt; ///< sample format
1015 
1016  /* The following data should not be initialized. */
1017  /**
1018  * Number of samples per channel in an audio frame.
1019  *
1020  * - encoding: set by libavcodec in avcodec_open2(). Each submitted frame
1021  * except the last must contain exactly frame_size samples per channel.
1022  * May be 0 when the codec has AV_CODEC_CAP_VARIABLE_FRAME_SIZE set, then the
1023  * frame size is not restricted.
1024  * - decoding: may be set by some decoders to indicate constant frame size
1025  */
1027 
1028  /**
1029  * Frame counter, set by libavcodec.
1030  *
1031  * - decoding: total number of frames returned from the decoder so far.
1032  * - encoding: total number of frames passed to the encoder so far.
1033  *
1034  * @note the counter is not incremented if encoding/decoding resulted in
1035  * an error.
1036  */
1038 
1039  /**
1040  * number of bytes per packet if constant and known or 0
1041  * Used by some WAV based audio codecs.
1042  */
1044 
1045  /**
1046  * Audio cutoff bandwidth (0 means "automatic")
1047  * - encoding: Set by user.
1048  * - decoding: unused
1049  */
1050  int cutoff;
1051 
1052 #if FF_API_OLD_CHANNEL_LAYOUT
1053  /**
1054  * Audio channel layout.
1055  * - encoding: set by user.
1056  * - decoding: set by user, may be overwritten by libavcodec.
1057  * @deprecated use ch_layout
1058  */
1060  uint64_t channel_layout;
1061 
1062  /**
1063  * Request decoder to use this channel layout if it can (0 for default)
1064  * - encoding: unused
1065  * - decoding: Set by user.
1066  * @deprecated use "downmix" codec private option
1067  */
1070 #endif
1071 
1072  /**
1073  * Type of service that the audio stream conveys.
1074  * - encoding: Set by user.
1075  * - decoding: Set by libavcodec.
1076  */
1078 
1079  /**
1080  * desired sample format
1081  * - encoding: Not used.
1082  * - decoding: Set by user.
1083  * Decoder will decode to this format if it can.
1084  */
1086 
1087  /**
1088  * This callback is called at the beginning of each frame to get data
1089  * buffer(s) for it. There may be one contiguous buffer for all the data or
1090  * there may be a buffer per each data plane or anything in between. What
1091  * this means is, you may set however many entries in buf[] you feel necessary.
1092  * Each buffer must be reference-counted using the AVBuffer API (see description
1093  * of buf[] below).
1094  *
1095  * The following fields will be set in the frame before this callback is
1096  * called:
1097  * - format
1098  * - width, height (video only)
1099  * - sample_rate, channel_layout, nb_samples (audio only)
1100  * Their values may differ from the corresponding values in
1101  * AVCodecContext. This callback must use the frame values, not the codec
1102  * context values, to calculate the required buffer size.
1103  *
1104  * This callback must fill the following fields in the frame:
1105  * - data[]
1106  * - linesize[]
1107  * - extended_data:
1108  * * if the data is planar audio with more than 8 channels, then this
1109  * callback must allocate and fill extended_data to contain all pointers
1110  * to all data planes. data[] must hold as many pointers as it can.
1111  * extended_data must be allocated with av_malloc() and will be freed in
1112  * av_frame_unref().
1113  * * otherwise extended_data must point to data
1114  * - buf[] must contain one or more pointers to AVBufferRef structures. Each of
1115  * the frame's data and extended_data pointers must be contained in these. That
1116  * is, one AVBufferRef for each allocated chunk of memory, not necessarily one
1117  * AVBufferRef per data[] entry. See: av_buffer_create(), av_buffer_alloc(),
1118  * and av_buffer_ref().
1119  * - extended_buf and nb_extended_buf must be allocated with av_malloc() by
1120  * this callback and filled with the extra buffers if there are more
1121  * buffers than buf[] can hold. extended_buf will be freed in
1122  * av_frame_unref().
1123  *
1124  * If AV_CODEC_CAP_DR1 is not set then get_buffer2() must call
1125  * avcodec_default_get_buffer2() instead of providing buffers allocated by
1126  * some other means.
1127  *
1128  * Each data plane must be aligned to the maximum required by the target
1129  * CPU.
1130  *
1131  * @see avcodec_default_get_buffer2()
1132  *
1133  * Video:
1134  *
1135  * If AV_GET_BUFFER_FLAG_REF is set in flags then the frame may be reused
1136  * (read and/or written to if it is writable) later by libavcodec.
1137  *
1138  * avcodec_align_dimensions2() should be used to find the required width and
1139  * height, as they normally need to be rounded up to the next multiple of 16.
1140  *
1141  * Some decoders do not support linesizes changing between frames.
1142  *
1143  * If frame multithreading is used, this callback may be called from a
1144  * different thread, but not from more than one at once. Does not need to be
1145  * reentrant.
1146  *
1147  * @see avcodec_align_dimensions2()
1148  *
1149  * Audio:
1150  *
1151  * Decoders request a buffer of a particular size by setting
1152  * AVFrame.nb_samples prior to calling get_buffer2(). The decoder may,
1153  * however, utilize only part of the buffer by setting AVFrame.nb_samples
1154  * to a smaller value in the output frame.
1155  *
1156  * As a convenience, av_samples_get_buffer_size() and
1157  * av_samples_fill_arrays() in libavutil may be used by custom get_buffer2()
1158  * functions to find the required data size and to fill data pointers and
1159  * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
1160  * since all planes must be the same size.
1161  *
1162  * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
1163  *
1164  * - encoding: unused
1165  * - decoding: Set by libavcodec, user can override.
1166  */
1167  int (*get_buffer2)(struct AVCodecContext *s, AVFrame *frame, int flags);
1168 
1169  /* - encoding parameters */
1170  float qcompress; ///< amount of qscale change between easy & hard scenes (0.0-1.0)
1171  float qblur; ///< amount of qscale smoothing over time (0.0-1.0)
1172 
1173  /**
1174  * minimum quantizer
1175  * - encoding: Set by user.
1176  * - decoding: unused
1177  */
1178  int qmin;
1179 
1180  /**
1181  * maximum quantizer
1182  * - encoding: Set by user.
1183  * - decoding: unused
1184  */
1185  int qmax;
1186 
1187  /**
1188  * maximum quantizer difference between frames
1189  * - encoding: Set by user.
1190  * - decoding: unused
1191  */
1193 
1194  /**
1195  * decoder bitstream buffer size
1196  * - encoding: Set by user.
1197  * - decoding: unused
1198  */
1200 
1201  /**
1202  * ratecontrol override, see RcOverride
1203  * - encoding: Allocated/set/freed by user.
1204  * - decoding: unused
1205  */
1208 
1209  /**
1210  * maximum bitrate
1211  * - encoding: Set by user.
1212  * - decoding: Set by user, may be overwritten by libavcodec.
1213  */
1214  int64_t rc_max_rate;
1215 
1216  /**
1217  * minimum bitrate
1218  * - encoding: Set by user.
1219  * - decoding: unused
1220  */
1221  int64_t rc_min_rate;
1222 
1223  /**
1224  * Ratecontrol attempt to use, at maximum, <value> of what can be used without an underflow.
1225  * - encoding: Set by user.
1226  * - decoding: unused.
1227  */
1229 
1230  /**
1231  * Ratecontrol attempt to use, at least, <value> times the amount needed to prevent a vbv overflow.
1232  * - encoding: Set by user.
1233  * - decoding: unused.
1234  */
1236 
1237  /**
1238  * Number of bits which should be loaded into the rc buffer before decoding starts.
1239  * - encoding: Set by user.
1240  * - decoding: unused
1241  */
1243 
1244  /**
1245  * trellis RD quantization
1246  * - encoding: Set by user.
1247  * - decoding: unused
1248  */
1249  int trellis;
1250 
1251  /**
1252  * pass1 encoding statistics output buffer
1253  * - encoding: Set by libavcodec.
1254  * - decoding: unused
1255  */
1256  char *stats_out;
1257 
1258  /**
1259  * pass2 encoding statistics input buffer
1260  * Concatenated stuff from stats_out of pass1 should be placed here.
1261  * - encoding: Allocated/set/freed by user.
1262  * - decoding: unused
1263  */
1264  char *stats_in;
1265 
1266  /**
1267  * Work around bugs in encoders which sometimes cannot be detected automatically.
1268  * - encoding: Set by user
1269  * - decoding: Set by user
1270  */
1272 #define FF_BUG_AUTODETECT 1 ///< autodetection
1273 #define FF_BUG_XVID_ILACE 4
1274 #define FF_BUG_UMP4 8
1275 #define FF_BUG_NO_PADDING 16
1276 #define FF_BUG_AMV 32
1277 #define FF_BUG_QPEL_CHROMA 64
1278 #define FF_BUG_STD_QPEL 128
1279 #define FF_BUG_QPEL_CHROMA2 256
1280 #define FF_BUG_DIRECT_BLOCKSIZE 512
1281 #define FF_BUG_EDGE 1024
1282 #define FF_BUG_HPEL_CHROMA 2048
1283 #define FF_BUG_DC_CLIP 4096
1284 #define FF_BUG_MS 8192 ///< Work around various bugs in Microsoft's broken decoders.
1285 #define FF_BUG_TRUNCATED 16384
1286 #define FF_BUG_IEDGE 32768
1287 
1288  /**
1289  * strictly follow the standard (MPEG-4, ...).
1290  * - encoding: Set by user.
1291  * - decoding: Set by user.
1292  * Setting this to STRICT or higher means the encoder and decoder will
1293  * generally do stupid things, whereas setting it to unofficial or lower
1294  * will mean the encoder might produce output that is not supported by all
1295  * spec-compliant decoders. Decoders don't differentiate between normal,
1296  * unofficial and experimental (that is, they always try to decode things
1297  * when they can) unless they are explicitly asked to behave stupidly
1298  * (=strictly conform to the specs)
1299  */
1301 #define FF_COMPLIANCE_VERY_STRICT 2 ///< Strictly conform to an older more strict version of the spec or reference software.
1302 #define FF_COMPLIANCE_STRICT 1 ///< Strictly conform to all the things in the spec no matter what consequences.
1303 #define FF_COMPLIANCE_NORMAL 0
1304 #define FF_COMPLIANCE_UNOFFICIAL -1 ///< Allow unofficial extensions
1305 #define FF_COMPLIANCE_EXPERIMENTAL -2 ///< Allow nonstandardized experimental things.
1306 
1307  /**
1308  * error concealment flags
1309  * - encoding: unused
1310  * - decoding: Set by user.
1311  */
1313 #define FF_EC_GUESS_MVS 1
1314 #define FF_EC_DEBLOCK 2
1315 #define FF_EC_FAVOR_INTER 256
1316 
1317  /**
1318  * debug
1319  * - encoding: Set by user.
1320  * - decoding: Set by user.
1321  */
1322  int debug;
1323 #define FF_DEBUG_PICT_INFO 1
1324 #define FF_DEBUG_RC 2
1325 #define FF_DEBUG_BITSTREAM 4
1326 #define FF_DEBUG_MB_TYPE 8
1327 #define FF_DEBUG_QP 16
1328 #define FF_DEBUG_DCT_COEFF 0x00000040
1329 #define FF_DEBUG_SKIP 0x00000080
1330 #define FF_DEBUG_STARTCODE 0x00000100
1331 #define FF_DEBUG_ER 0x00000400
1332 #define FF_DEBUG_MMCO 0x00000800
1333 #define FF_DEBUG_BUGS 0x00001000
1334 #define FF_DEBUG_BUFFERS 0x00008000
1335 #define FF_DEBUG_THREADS 0x00010000
1336 #define FF_DEBUG_GREEN_MD 0x00800000
1337 #define FF_DEBUG_NOMC 0x01000000
1338 
1339  /**
1340  * Error recognition; may misdetect some more or less valid parts as errors.
1341  * - encoding: Set by user.
1342  * - decoding: Set by user.
1343  */
1345 
1346 /**
1347  * Verify checksums embedded in the bitstream (could be of either encoded or
1348  * decoded data, depending on the codec) and print an error message on mismatch.
1349  * If AV_EF_EXPLODE is also set, a mismatching checksum will result in the
1350  * decoder returning an error.
1351  */
1352 #define AV_EF_CRCCHECK (1<<0)
1353 #define AV_EF_BITSTREAM (1<<1) ///< detect bitstream specification deviations
1354 #define AV_EF_BUFFER (1<<2) ///< detect improper bitstream length
1355 #define AV_EF_EXPLODE (1<<3) ///< abort decoding on minor error detection
1356 
1357 #define AV_EF_IGNORE_ERR (1<<15) ///< ignore errors and continue
1358 #define AV_EF_CAREFUL (1<<16) ///< consider things that violate the spec, are fast to calculate and have not been seen in the wild as errors
1359 #define AV_EF_COMPLIANT (1<<17) ///< consider all spec non compliances as errors
1360 #define AV_EF_AGGRESSIVE (1<<18) ///< consider things that a sane encoder should not do as an error
1361 
1362 
1363  /**
1364  * opaque 64-bit number (generally a PTS) that will be reordered and
1365  * output in AVFrame.reordered_opaque
1366  * - encoding: Set by libavcodec to the reordered_opaque of the input
1367  * frame corresponding to the last returned packet. Only
1368  * supported by encoders with the
1369  * AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE capability.
1370  * - decoding: Set by user.
1371  */
1373 
1374  /**
1375  * Hardware accelerator in use
1376  * - encoding: unused.
1377  * - decoding: Set by libavcodec
1378  */
1379  const struct AVHWAccel *hwaccel;
1380 
1381  /**
1382  * Hardware accelerator context.
1383  * For some hardware accelerators, a global context needs to be
1384  * provided by the user. In that case, this holds display-dependent
1385  * data FFmpeg cannot instantiate itself. Please refer to the
1386  * FFmpeg HW accelerator documentation to know how to fill this.
1387  * - encoding: unused
1388  * - decoding: Set by user
1389  */
1391 
1392  /**
1393  * error
1394  * - encoding: Set by libavcodec if flags & AV_CODEC_FLAG_PSNR.
1395  * - decoding: unused
1396  */
1398 
1399  /**
1400  * DCT algorithm, see FF_DCT_* below
1401  * - encoding: Set by user.
1402  * - decoding: unused
1403  */
1405 #define FF_DCT_AUTO 0
1406 #define FF_DCT_FASTINT 1
1407 #define FF_DCT_INT 2
1408 #define FF_DCT_MMX 3
1409 #define FF_DCT_ALTIVEC 5
1410 #define FF_DCT_FAAN 6
1411 
1412  /**
1413  * IDCT algorithm, see FF_IDCT_* below.
1414  * - encoding: Set by user.
1415  * - decoding: Set by user.
1416  */
1418 #define FF_IDCT_AUTO 0
1419 #define FF_IDCT_INT 1
1420 #define FF_IDCT_SIMPLE 2
1421 #define FF_IDCT_SIMPLEMMX 3
1422 #define FF_IDCT_ARM 7
1423 #define FF_IDCT_ALTIVEC 8
1424 #define FF_IDCT_SIMPLEARM 10
1425 #define FF_IDCT_XVID 14
1426 #define FF_IDCT_SIMPLEARMV5TE 16
1427 #define FF_IDCT_SIMPLEARMV6 17
1428 #define FF_IDCT_FAAN 20
1429 #define FF_IDCT_SIMPLENEON 22
1430 #if FF_API_IDCT_NONE
1431 // formerly used by xvmc
1432 #define FF_IDCT_NONE 24
1433 #endif
1434 #define FF_IDCT_SIMPLEAUTO 128
1435 
1436  /**
1437  * bits per sample/pixel from the demuxer (needed for huffyuv).
1438  * - encoding: Set by libavcodec.
1439  * - decoding: Set by user.
1440  */
1442 
1443  /**
1444  * Bits per sample/pixel of internal libavcodec pixel/sample format.
1445  * - encoding: set by user.
1446  * - decoding: set by libavcodec.
1447  */
1449 
1450  /**
1451  * low resolution decoding, 1-> 1/2 size, 2->1/4 size
1452  * - encoding: unused
1453  * - decoding: Set by user.
1454  */
1455  int lowres;
1456 
1457  /**
1458  * thread count
1459  * is used to decide how many independent tasks should be passed to execute()
1460  * - encoding: Set by user.
1461  * - decoding: Set by user.
1462  */
1464 
1465  /**
1466  * Which multithreading methods to use.
1467  * Use of FF_THREAD_FRAME will increase decoding delay by one frame per thread,
1468  * so clients which cannot provide future frames should not use it.
1469  *
1470  * - encoding: Set by user, otherwise the default is used.
1471  * - decoding: Set by user, otherwise the default is used.
1472  */
1474 #define FF_THREAD_FRAME 1 ///< Decode more than one frame at once
1475 #define FF_THREAD_SLICE 2 ///< Decode more than one part of a single frame at once
1476 
1477  /**
1478  * Which multithreading methods are in use by the codec.
1479  * - encoding: Set by libavcodec.
1480  * - decoding: Set by libavcodec.
1481  */
1483 
1484 #if FF_API_THREAD_SAFE_CALLBACKS
1485  /**
1486  * Set by the client if its custom get_buffer() callback can be called
1487  * synchronously from another thread, which allows faster multithreaded decoding.
1488  * draw_horiz_band() will be called from other threads regardless of this setting.
1489  * Ignored if the default get_buffer() is used.
1490  * - encoding: Set by user.
1491  * - decoding: Set by user.
1492  *
1493  * @deprecated the custom get_buffer2() callback should always be
1494  * thread-safe. Thread-unsafe get_buffer2() implementations will be
1495  * invalid starting with LIBAVCODEC_VERSION_MAJOR=60; in other words,
1496  * libavcodec will behave as if this field was always set to 1.
1497  * Callers that want to be forward compatible with future libavcodec
1498  * versions should wrap access to this field in
1499  * #if LIBAVCODEC_VERSION_MAJOR < 60
1500  */
1503 #endif
1504 
1505  /**
1506  * The codec may call this to execute several independent things.
1507  * It will return only after finishing all tasks.
1508  * The user may replace this with some multithreaded implementation,
1509  * the default implementation will execute the parts serially.
1510  * @param count the number of things to execute
1511  * - encoding: Set by libavcodec, user can override.
1512  * - decoding: Set by libavcodec, user can override.
1513  */
1514  int (*execute)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size);
1515 
1516  /**
1517  * The codec may call this to execute several independent things.
1518  * It will return only after finishing all tasks.
1519  * The user may replace this with some multithreaded implementation,
1520  * the default implementation will execute the parts serially.
1521  * @param c context passed also to func
1522  * @param count the number of things to execute
1523  * @param arg2 argument passed unchanged to func
1524  * @param ret return values of executed functions, must have space for "count" values. May be NULL.
1525  * @param func function that will be called count times, with jobnr from 0 to count-1.
1526  * threadnr will be in the range 0 to c->thread_count-1 < MAX_THREADS and so that no
1527  * two instances of func executing at the same time will have the same threadnr.
1528  * @return always 0 currently, but code should handle a future improvement where when any call to func
1529  * returns < 0 no further calls to func may be done and < 0 is returned.
1530  * - encoding: Set by libavcodec, user can override.
1531  * - decoding: Set by libavcodec, user can override.
1532  */
1533  int (*execute2)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count);
1534 
1535  /**
1536  * noise vs. sse weight for the nsse comparison function
1537  * - encoding: Set by user.
1538  * - decoding: unused
1539  */
1541 
1542  /**
1543  * profile
1544  * - encoding: Set by user.
1545  * - decoding: Set by libavcodec.
1546  */
1547  int profile;
1548 #define FF_PROFILE_UNKNOWN -99
1549 #define FF_PROFILE_RESERVED -100
1550 
1551 #define FF_PROFILE_AAC_MAIN 0
1552 #define FF_PROFILE_AAC_LOW 1
1553 #define FF_PROFILE_AAC_SSR 2
1554 #define FF_PROFILE_AAC_LTP 3
1555 #define FF_PROFILE_AAC_HE 4
1556 #define FF_PROFILE_AAC_HE_V2 28
1557 #define FF_PROFILE_AAC_LD 22
1558 #define FF_PROFILE_AAC_ELD 38
1559 #define FF_PROFILE_MPEG2_AAC_LOW 128
1560 #define FF_PROFILE_MPEG2_AAC_HE 131
1561 
1562 #define FF_PROFILE_DNXHD 0
1563 #define FF_PROFILE_DNXHR_LB 1
1564 #define FF_PROFILE_DNXHR_SQ 2
1565 #define FF_PROFILE_DNXHR_HQ 3
1566 #define FF_PROFILE_DNXHR_HQX 4
1567 #define FF_PROFILE_DNXHR_444 5
1568 
1569 #define FF_PROFILE_DTS 20
1570 #define FF_PROFILE_DTS_ES 30
1571 #define FF_PROFILE_DTS_96_24 40
1572 #define FF_PROFILE_DTS_HD_HRA 50
1573 #define FF_PROFILE_DTS_HD_MA 60
1574 #define FF_PROFILE_DTS_EXPRESS 70
1575 
1576 #define FF_PROFILE_MPEG2_422 0
1577 #define FF_PROFILE_MPEG2_HIGH 1
1578 #define FF_PROFILE_MPEG2_SS 2
1579 #define FF_PROFILE_MPEG2_SNR_SCALABLE 3
1580 #define FF_PROFILE_MPEG2_MAIN 4
1581 #define FF_PROFILE_MPEG2_SIMPLE 5
1582 
1583 #define FF_PROFILE_H264_CONSTRAINED (1<<9) // 8+1; constraint_set1_flag
1584 #define FF_PROFILE_H264_INTRA (1<<11) // 8+3; constraint_set3_flag
1585 
1586 #define FF_PROFILE_H264_BASELINE 66
1587 #define FF_PROFILE_H264_CONSTRAINED_BASELINE (66|FF_PROFILE_H264_CONSTRAINED)
1588 #define FF_PROFILE_H264_MAIN 77
1589 #define FF_PROFILE_H264_EXTENDED 88
1590 #define FF_PROFILE_H264_HIGH 100
1591 #define FF_PROFILE_H264_HIGH_10 110
1592 #define FF_PROFILE_H264_HIGH_10_INTRA (110|FF_PROFILE_H264_INTRA)
1593 #define FF_PROFILE_H264_MULTIVIEW_HIGH 118
1594 #define FF_PROFILE_H264_HIGH_422 122
1595 #define FF_PROFILE_H264_HIGH_422_INTRA (122|FF_PROFILE_H264_INTRA)
1596 #define FF_PROFILE_H264_STEREO_HIGH 128
1597 #define FF_PROFILE_H264_HIGH_444 144
1598 #define FF_PROFILE_H264_HIGH_444_PREDICTIVE 244
1599 #define FF_PROFILE_H264_HIGH_444_INTRA (244|FF_PROFILE_H264_INTRA)
1600 #define FF_PROFILE_H264_CAVLC_444 44
1601 
1602 #define FF_PROFILE_VC1_SIMPLE 0
1603 #define FF_PROFILE_VC1_MAIN 1
1604 #define FF_PROFILE_VC1_COMPLEX 2
1605 #define FF_PROFILE_VC1_ADVANCED 3
1606 
1607 #define FF_PROFILE_MPEG4_SIMPLE 0
1608 #define FF_PROFILE_MPEG4_SIMPLE_SCALABLE 1
1609 #define FF_PROFILE_MPEG4_CORE 2
1610 #define FF_PROFILE_MPEG4_MAIN 3
1611 #define FF_PROFILE_MPEG4_N_BIT 4
1612 #define FF_PROFILE_MPEG4_SCALABLE_TEXTURE 5
1613 #define FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION 6
1614 #define FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE 7
1615 #define FF_PROFILE_MPEG4_HYBRID 8
1616 #define FF_PROFILE_MPEG4_ADVANCED_REAL_TIME 9
1617 #define FF_PROFILE_MPEG4_CORE_SCALABLE 10
1618 #define FF_PROFILE_MPEG4_ADVANCED_CODING 11
1619 #define FF_PROFILE_MPEG4_ADVANCED_CORE 12
1620 #define FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE 13
1621 #define FF_PROFILE_MPEG4_SIMPLE_STUDIO 14
1622 #define FF_PROFILE_MPEG4_ADVANCED_SIMPLE 15
1623 
1624 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_0 1
1625 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_1 2
1626 #define FF_PROFILE_JPEG2000_CSTREAM_NO_RESTRICTION 32768
1627 #define FF_PROFILE_JPEG2000_DCINEMA_2K 3
1628 #define FF_PROFILE_JPEG2000_DCINEMA_4K 4
1629 
1630 #define FF_PROFILE_VP9_0 0
1631 #define FF_PROFILE_VP9_1 1
1632 #define FF_PROFILE_VP9_2 2
1633 #define FF_PROFILE_VP9_3 3
1634 
1635 #define FF_PROFILE_HEVC_MAIN 1
1636 #define FF_PROFILE_HEVC_MAIN_10 2
1637 #define FF_PROFILE_HEVC_MAIN_STILL_PICTURE 3
1638 #define FF_PROFILE_HEVC_REXT 4
1639 
1640 #define FF_PROFILE_VVC_MAIN_10 1
1641 #define FF_PROFILE_VVC_MAIN_10_444 33
1642 
1643 #define FF_PROFILE_AV1_MAIN 0
1644 #define FF_PROFILE_AV1_HIGH 1
1645 #define FF_PROFILE_AV1_PROFESSIONAL 2
1646 
1647 #define FF_PROFILE_MJPEG_HUFFMAN_BASELINE_DCT 0xc0
1648 #define FF_PROFILE_MJPEG_HUFFMAN_EXTENDED_SEQUENTIAL_DCT 0xc1
1649 #define FF_PROFILE_MJPEG_HUFFMAN_PROGRESSIVE_DCT 0xc2
1650 #define FF_PROFILE_MJPEG_HUFFMAN_LOSSLESS 0xc3
1651 #define FF_PROFILE_MJPEG_JPEG_LS 0xf7
1652 
1653 #define FF_PROFILE_SBC_MSBC 1
1654 
1655 #define FF_PROFILE_PRORES_PROXY 0
1656 #define FF_PROFILE_PRORES_LT 1
1657 #define FF_PROFILE_PRORES_STANDARD 2
1658 #define FF_PROFILE_PRORES_HQ 3
1659 #define FF_PROFILE_PRORES_4444 4
1660 #define FF_PROFILE_PRORES_XQ 5
1661 
1662 #define FF_PROFILE_ARIB_PROFILE_A 0
1663 #define FF_PROFILE_ARIB_PROFILE_C 1
1664 
1665 #define FF_PROFILE_KLVA_SYNC 0
1666 #define FF_PROFILE_KLVA_ASYNC 1
1667 
1668  /**
1669  * level
1670  * - encoding: Set by user.
1671  * - decoding: Set by libavcodec.
1672  */
1673  int level;
1674 #define FF_LEVEL_UNKNOWN -99
1675 
1676  /**
1677  * Skip loop filtering for selected frames.
1678  * - encoding: unused
1679  * - decoding: Set by user.
1680  */
1682 
1683  /**
1684  * Skip IDCT/dequantization for selected frames.
1685  * - encoding: unused
1686  * - decoding: Set by user.
1687  */
1688  enum AVDiscard skip_idct;
1689 
1690  /**
1691  * Skip decoding for selected frames.
1692  * - encoding: unused
1693  * - decoding: Set by user.
1694  */
1695  enum AVDiscard skip_frame;
1696 
1697  /**
1698  * Header containing style information for text subtitles.
1699  * For SUBTITLE_ASS subtitle type, it should contain the whole ASS
1700  * [Script Info] and [V4+ Styles] section, plus the [Events] line and
1701  * the Format line following. It shouldn't include any Dialogue line.
1702  * - encoding: Set/allocated/freed by user (before avcodec_open2())
1703  * - decoding: Set/allocated/freed by libavcodec (by avcodec_open2())
1704  */
1707 
1708  /**
1709  * Audio only. The number of "priming" samples (padding) inserted by the
1710  * encoder at the beginning of the audio. I.e. this number of leading
1711  * decoded samples must be discarded by the caller to get the original audio
1712  * without leading padding.
1713  *
1714  * - decoding: unused
1715  * - encoding: Set by libavcodec. The timestamps on the output packets are
1716  * adjusted by the encoder so that they always refer to the
1717  * first sample of the data actually contained in the packet,
1718  * including any added padding. E.g. if the timebase is
1719  * 1/samplerate and the timestamp of the first input sample is
1720  * 0, the timestamp of the first output packet will be
1721  * -initial_padding.
1722  */
1724 
1725  /**
1726  * - decoding: For codecs that store a framerate value in the compressed
1727  * bitstream, the decoder may export it here. { 0, 1} when
1728  * unknown.
1729  * - encoding: May be used to signal the framerate of CFR content to an
1730  * encoder.
1731  */
1733 
1734  /**
1735  * Nominal unaccelerated pixel format, see AV_PIX_FMT_xxx.
1736  * - encoding: unused.
1737  * - decoding: Set by libavcodec before calling get_format()
1738  */
1740 
1741  /**
1742  * Timebase in which pkt_dts/pts and AVPacket.dts/pts are.
1743  * - encoding unused.
1744  * - decoding set by user.
1745  */
1747 
1748  /**
1749  * AVCodecDescriptor
1750  * - encoding: unused.
1751  * - decoding: set by libavcodec.
1752  */
1754 
1755  /**
1756  * Current statistics for PTS correction.
1757  * - decoding: maintained and used by libavcodec, not intended to be used by user apps
1758  * - encoding: unused
1759  */
1760  int64_t pts_correction_num_faulty_pts; /// Number of incorrect PTS values so far
1761  int64_t pts_correction_num_faulty_dts; /// Number of incorrect DTS values so far
1762  int64_t pts_correction_last_pts; /// PTS of the last frame
1763  int64_t pts_correction_last_dts; /// DTS of the last frame
1764 
1765  /**
1766  * Character encoding of the input subtitles file.
1767  * - decoding: set by user
1768  * - encoding: unused
1769  */
1771 
1772  /**
1773  * Subtitles character encoding mode. Formats or codecs might be adjusting
1774  * this setting (if they are doing the conversion themselves for instance).
1775  * - decoding: set by libavcodec
1776  * - encoding: unused
1777  */
1779 #define FF_SUB_CHARENC_MODE_DO_NOTHING -1 ///< do nothing (demuxer outputs a stream supposed to be already in UTF-8, or the codec is bitmap for instance)
1780 #define FF_SUB_CHARENC_MODE_AUTOMATIC 0 ///< libavcodec will select the mode itself
1781 #define FF_SUB_CHARENC_MODE_PRE_DECODER 1 ///< the AVPacket data needs to be recoded to UTF-8 before being fed to the decoder, requires iconv
1782 #define FF_SUB_CHARENC_MODE_IGNORE 2 ///< neither convert the subtitles, nor check them for valid UTF-8
1783 
1784  /**
1785  * Skip processing alpha if supported by codec.
1786  * Note that if the format uses pre-multiplied alpha (common with VP6,
1787  * and recommended due to better video quality/compression)
1788  * the image will look as if alpha-blended onto a black background.
1789  * However for formats that do not use pre-multiplied alpha
1790  * there might be serious artefacts (though e.g. libswscale currently
1791  * assumes pre-multiplied alpha anyway).
1792  *
1793  * - decoding: set by user
1794  * - encoding: unused
1795  */
1797 
1798  /**
1799  * Number of samples to skip after a discontinuity
1800  * - decoding: unused
1801  * - encoding: set by libavcodec
1802  */
1804 
1805 #if FF_API_DEBUG_MV
1806  /**
1807  * @deprecated unused
1808  */
1811 #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 //visualize forward predicted MVs of P frames
1812 #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 //visualize forward predicted MVs of B frames
1813 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
1814 #endif
1815 
1816  /**
1817  * custom intra quantization matrix
1818  * - encoding: Set by user, can be NULL.
1819  * - decoding: unused.
1820  */
1822 
1823  /**
1824  * dump format separator.
1825  * can be ", " or "\n " or anything else
1826  * - encoding: Set by user.
1827  * - decoding: Set by user.
1828  */
1829  uint8_t *dump_separator;
1830 
1831  /**
1832  * ',' separated list of allowed decoders.
1833  * If NULL then all are allowed
1834  * - encoding: unused
1835  * - decoding: set by user
1836  */
1838 
1839  /**
1840  * Properties of the stream that gets decoded
1841  * - encoding: unused
1842  * - decoding: set by libavcodec
1843  */
1844  unsigned properties;
1845 #define FF_CODEC_PROPERTY_LOSSLESS 0x00000001
1846 #define FF_CODEC_PROPERTY_CLOSED_CAPTIONS 0x00000002
1847 #define FF_CODEC_PROPERTY_FILM_GRAIN 0x00000004
1848 
1849  /**
1850  * Additional data associated with the entire coded stream.
1851  *
1852  * - decoding: unused
1853  * - encoding: may be set by libavcodec after avcodec_open2().
1854  */
1857 
1858  /**
1859  * A reference to the AVHWFramesContext describing the input (for encoding)
1860  * or output (decoding) frames. The reference is set by the caller and
1861  * afterwards owned (and freed) by libavcodec - it should never be read by
1862  * the caller after being set.
1863  *
1864  * - decoding: This field should be set by the caller from the get_format()
1865  * callback. The previous reference (if any) will always be
1866  * unreffed by libavcodec before the get_format() call.
1867  *
1868  * If the default get_buffer2() is used with a hwaccel pixel
1869  * format, then this AVHWFramesContext will be used for
1870  * allocating the frame buffers.
1871  *
1872  * - encoding: For hardware encoders configured to use a hwaccel pixel
1873  * format, this field should be set by the caller to a reference
1874  * to the AVHWFramesContext describing input frames.
1875  * AVHWFramesContext.format must be equal to
1876  * AVCodecContext.pix_fmt.
1877  *
1878  * This field should be set before avcodec_open2() is called.
1879  */
1881 
1882 #if FF_API_SUB_TEXT_FORMAT
1883  /**
1884  * @deprecated unused
1885  */
1888 #define FF_SUB_TEXT_FMT_ASS 0
1889 #endif
1890 
1891  /**
1892  * Audio only. The amount of padding (in samples) appended by the encoder to
1893  * the end of the audio. I.e. this number of decoded samples must be
1894  * discarded by the caller from the end of the stream to get the original
1895  * audio without any trailing padding.
1896  *
1897  * - decoding: unused
1898  * - encoding: unused
1899  */
1901 
1902  /**
1903  * The number of pixels per image to maximally accept.
1904  *
1905  * - decoding: set by user
1906  * - encoding: set by user
1907  */
1908  int64_t max_pixels;
1909 
1910  /**
1911  * A reference to the AVHWDeviceContext describing the device which will
1912  * be used by a hardware encoder/decoder. The reference is set by the
1913  * caller and afterwards owned (and freed) by libavcodec.
1914  *
1915  * This should be used if either the codec device does not require
1916  * hardware frames or any that are used are to be allocated internally by
1917  * libavcodec. If the user wishes to supply any of the frames used as
1918  * encoder input or decoder output then hw_frames_ctx should be used
1919  * instead. When hw_frames_ctx is set in get_format() for a decoder, this
1920  * field will be ignored while decoding the associated stream segment, but
1921  * may again be used on a following one after another get_format() call.
1922  *
1923  * For both encoders and decoders this field should be set before
1924  * avcodec_open2() is called and must not be written to thereafter.
1925  *
1926  * Note that some decoders may require this field to be set initially in
1927  * order to support hw_frames_ctx at all - in that case, all frames
1928  * contexts used must be created on the same device.
1929  */
1931 
1932  /**
1933  * Bit set of AV_HWACCEL_FLAG_* flags, which affect hardware accelerated
1934  * decoding (if active).
1935  * - encoding: unused
1936  * - decoding: Set by user (either before avcodec_open2(), or in the
1937  * AVCodecContext.get_format callback)
1938  */
1940 
1941  /**
1942  * Video decoding only. Certain video codecs support cropping, meaning that
1943  * only a sub-rectangle of the decoded frame is intended for display. This
1944  * option controls how cropping is handled by libavcodec.
1945  *
1946  * When set to 1 (the default), libavcodec will apply cropping internally.
1947  * I.e. it will modify the output frame width/height fields and offset the
1948  * data pointers (only by as much as possible while preserving alignment, or
1949  * by the full amount if the AV_CODEC_FLAG_UNALIGNED flag is set) so that
1950  * the frames output by the decoder refer only to the cropped area. The
1951  * crop_* fields of the output frames will be zero.
1952  *
1953  * When set to 0, the width/height fields of the output frames will be set
1954  * to the coded dimensions and the crop_* fields will describe the cropping
1955  * rectangle. Applying the cropping is left to the caller.
1956  *
1957  * @warning When hardware acceleration with opaque output frames is used,
1958  * libavcodec is unable to apply cropping from the top/left border.
1959  *
1960  * @note when this option is set to zero, the width/height fields of the
1961  * AVCodecContext and output AVFrames have different meanings. The codec
1962  * context fields store display dimensions (with the coded dimensions in
1963  * coded_width/height), while the frame fields store the coded dimensions
1964  * (with the display dimensions being determined by the crop_* fields).
1965  */
1967 
1968  /*
1969  * Video decoding only. Sets the number of extra hardware frames which
1970  * the decoder will allocate for use by the caller. This must be set
1971  * before avcodec_open2() is called.
1972  *
1973  * Some hardware decoders require all frames that they will use for
1974  * output to be defined in advance before decoding starts. For such
1975  * decoders, the hardware frame pool must therefore be of a fixed size.
1976  * The extra frames set here are on top of any number that the decoder
1977  * needs internally in order to operate normally (for example, frames
1978  * used as reference pictures).
1979  */
1981 
1982  /**
1983  * The percentage of damaged samples to discard a frame.
1984  *
1985  * - decoding: set by user
1986  * - encoding: unused
1987  */
1989 
1990  /**
1991  * The number of samples per frame to maximally accept.
1992  *
1993  * - decoding: set by user
1994  * - encoding: set by user
1995  */
1996  int64_t max_samples;
1997 
1998  /**
1999  * Bit set of AV_CODEC_EXPORT_DATA_* flags, which affects the kind of
2000  * metadata exported in frame, packet, or coded stream side data by
2001  * decoders and encoders.
2002  *
2003  * - decoding: set by user
2004  * - encoding: set by user
2005  */
2007 
2008  /**
2009  * This callback is called at the beginning of each packet to get a data
2010  * buffer for it.
2011  *
2012  * The following field will be set in the packet before this callback is
2013  * called:
2014  * - size
2015  * This callback must use the above value to calculate the required buffer size,
2016  * which must padded by at least AV_INPUT_BUFFER_PADDING_SIZE bytes.
2017  *
2018  * In some specific cases, the encoder may not use the entire buffer allocated by this
2019  * callback. This will be reflected in the size value in the packet once returned by
2020  * avcodec_receive_packet().
2021  *
2022  * This callback must fill the following fields in the packet:
2023  * - data: alignment requirements for AVPacket apply, if any. Some architectures and
2024  * encoders may benefit from having aligned data.
2025  * - buf: must contain a pointer to an AVBufferRef structure. The packet's
2026  * data pointer must be contained in it. See: av_buffer_create(), av_buffer_alloc(),
2027  * and av_buffer_ref().
2028  *
2029  * If AV_CODEC_CAP_DR1 is not set then get_encode_buffer() must call
2030  * avcodec_default_get_encode_buffer() instead of providing a buffer allocated by
2031  * some other means.
2032  *
2033  * The flags field may contain a combination of AV_GET_ENCODE_BUFFER_FLAG_ flags.
2034  * They may be used for example to hint what use the buffer may get after being
2035  * created.
2036  * Implementations of this callback may ignore flags they don't understand.
2037  * If AV_GET_ENCODE_BUFFER_FLAG_REF is set in flags then the packet may be reused
2038  * (read and/or written to if it is writable) later by libavcodec.
2039  *
2040  * This callback must be thread-safe, as when frame threading is used, it may
2041  * be called from multiple threads simultaneously.
2042  *
2043  * @see avcodec_default_get_encode_buffer()
2044  *
2045  * - encoding: Set by libavcodec, user can override.
2046  * - decoding: unused
2047  */
2049 
2050  /**
2051  * Audio channel layout.
2052  * - encoding: must be set by the caller, to one of AVCodec.ch_layouts.
2053  * - decoding: may be set by the caller if known e.g. from the container.
2054  * The decoder can then override during decoding as needed.
2055  */
2057 } AVCodecContext;
2058 
2059 /**
2060  * @defgroup lavc_hwaccel AVHWAccel
2061  *
2062  * @note Nothing in this structure should be accessed by the user. At some
2063  * point in future it will not be externally visible at all.
2064  *
2065  * @{
2066  */
2067 typedef struct AVHWAccel {
2068  /**
2069  * Name of the hardware accelerated codec.
2070  * The name is globally unique among encoders and among decoders (but an
2071  * encoder and a decoder can share the same name).
2072  */
2073  const char *name;
2074 
2075  /**
2076  * Type of codec implemented by the hardware accelerator.
2077  *
2078  * See AVMEDIA_TYPE_xxx
2079  */
2080  enum AVMediaType type;
2081 
2082  /**
2083  * Codec implemented by the hardware accelerator.
2084  *
2085  * See AV_CODEC_ID_xxx
2086  */
2087  enum AVCodecID id;
2088 
2089  /**
2090  * Supported pixel format.
2091  *
2092  * Only hardware accelerated formats are supported here.
2093  */
2094  enum AVPixelFormat pix_fmt;
2095 
2096  /**
2097  * Hardware accelerated codec capabilities.
2098  * see AV_HWACCEL_CODEC_CAP_*
2099  */
2101 
2102  /*****************************************************************
2103  * No fields below this line are part of the public API. They
2104  * may not be used outside of libavcodec and can be changed and
2105  * removed at will.
2106  * New public fields should be added right above.
2107  *****************************************************************
2108  */
2109 
2110  /**
2111  * Allocate a custom buffer
2112  */
2114 
2115  /**
2116  * Called at the beginning of each frame or field picture.
2117  *
2118  * Meaningful frame information (codec specific) is guaranteed to
2119  * be parsed at this point. This function is mandatory.
2120  *
2121  * Note that buf can be NULL along with buf_size set to 0.
2122  * Otherwise, this means the whole frame is available at this point.
2123  *
2124  * @param avctx the codec context
2125  * @param buf the frame data buffer base
2126  * @param buf_size the size of the frame in bytes
2127  * @return zero if successful, a negative value otherwise
2128  */
2129  int (*start_frame)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
2130 
2131  /**
2132  * Callback for parameter data (SPS/PPS/VPS etc).
2133  *
2134  * Useful for hardware decoders which keep persistent state about the
2135  * video parameters, and need to receive any changes to update that state.
2136  *
2137  * @param avctx the codec context
2138  * @param type the nal unit type
2139  * @param buf the nal unit data buffer
2140  * @param buf_size the size of the nal unit in bytes
2141  * @return zero if successful, a negative value otherwise
2142  */
2143  int (*decode_params)(AVCodecContext *avctx, int type, const uint8_t *buf, uint32_t buf_size);
2144 
2145  /**
2146  * Callback for each slice.
2147  *
2148  * Meaningful slice information (codec specific) is guaranteed to
2149  * be parsed at this point. This function is mandatory.
2150  *
2151  * @param avctx the codec context
2152  * @param buf the slice data buffer base
2153  * @param buf_size the size of the slice in bytes
2154  * @return zero if successful, a negative value otherwise
2155  */
2156  int (*decode_slice)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
2157 
2158  /**
2159  * Called at the end of each frame or field picture.
2160  *
2161  * The whole picture is parsed at this point and can now be sent
2162  * to the hardware accelerator. This function is mandatory.
2163  *
2164  * @param avctx the codec context
2165  * @return zero if successful, a negative value otherwise
2166  */
2167  int (*end_frame)(AVCodecContext *avctx);
2168 
2169  /**
2170  * Size of per-frame hardware accelerator private data.
2171  *
2172  * Private data is allocated with av_mallocz() before
2173  * AVCodecContext.get_buffer() and deallocated after
2174  * AVCodecContext.release_buffer().
2175  */
2177 
2178  /**
2179  * Initialize the hwaccel private data.
2180  *
2181  * This will be called from ff_get_format(), after hwaccel and
2182  * hwaccel_context are set and the hwaccel private data in AVCodecInternal
2183  * is allocated.
2184  */
2185  int (*init)(AVCodecContext *avctx);
2186 
2187  /**
2188  * Uninitialize the hwaccel private data.
2189  *
2190  * This will be called from get_format() or avcodec_close(), after hwaccel
2191  * and hwaccel_context are already uninitialized.
2192  */
2193  int (*uninit)(AVCodecContext *avctx);
2194 
2195  /**
2196  * Size of the private data to allocate in
2197  * AVCodecInternal.hwaccel_priv_data.
2198  */
2200 
2201  /**
2202  * Internal hwaccel capabilities.
2203  */
2205 
2206  /**
2207  * Fill the given hw_frames context with current codec parameters. Called
2208  * from get_format. Refer to avcodec_get_hw_frames_parameters() for
2209  * details.
2210  *
2211  * This CAN be called before AVHWAccel.init is called, and you must assume
2212  * that avctx->hwaccel_priv_data is invalid.
2213  */
2214  int (*frame_params)(AVCodecContext *avctx, AVBufferRef *hw_frames_ctx);
2215 } AVHWAccel;
2216 
2217 /**
2218  * HWAccel is experimental and is thus avoided in favor of non experimental
2219  * codecs
2220  */
2221 #define AV_HWACCEL_CODEC_CAP_EXPERIMENTAL 0x0200
2222 
2223 /**
2224  * Hardware acceleration should be used for decoding even if the codec level
2225  * used is unknown or higher than the maximum supported level reported by the
2226  * hardware driver.
2227  *
2228  * It's generally a good idea to pass this flag unless you have a specific
2229  * reason not to, as hardware tends to under-report supported levels.
2230  */
2231 #define AV_HWACCEL_FLAG_IGNORE_LEVEL (1 << 0)
2232 
2233 /**
2234  * Hardware acceleration can output YUV pixel formats with a different chroma
2235  * sampling than 4:2:0 and/or other than 8 bits per component.
2236  */
2237 #define AV_HWACCEL_FLAG_ALLOW_HIGH_DEPTH (1 << 1)
2238 
2239 /**
2240  * Hardware acceleration should still be attempted for decoding when the
2241  * codec profile does not match the reported capabilities of the hardware.
2242  *
2243  * For example, this can be used to try to decode baseline profile H.264
2244  * streams in hardware - it will often succeed, because many streams marked
2245  * as baseline profile actually conform to constrained baseline profile.
2246  *
2247  * @warning If the stream is actually not supported then the behaviour is
2248  * undefined, and may include returning entirely incorrect output
2249  * while indicating success.
2250  */
2251 #define AV_HWACCEL_FLAG_ALLOW_PROFILE_MISMATCH (1 << 2)
2252 
2253 /**
2254  * @}
2255  */
2256 
2259 
2260  SUBTITLE_BITMAP, ///< A bitmap, pict will be set
2261 
2262  /**
2263  * Plain text, the text field must be set by the decoder and is
2264  * authoritative. ass and pict fields may contain approximations.
2265  */
2267 
2268  /**
2269  * Formatted text, the ass field must be set by the decoder and is
2270  * authoritative. pict and text fields may contain approximations.
2271  */
2273 };
2274 
2275 #define AV_SUBTITLE_FLAG_FORCED 0x00000001
2276 
2277 typedef struct AVSubtitleRect {
2278  int x; ///< top left corner of pict, undefined when pict is not set
2279  int y; ///< top left corner of pict, undefined when pict is not set
2280  int w; ///< width of pict, undefined when pict is not set
2281  int h; ///< height of pict, undefined when pict is not set
2282  int nb_colors; ///< number of colors in pict, undefined when pict is not set
2283 
2284  /**
2285  * data+linesize for the bitmap of this subtitle.
2286  * Can be set for text/ass as well once they are rendered.
2287  */
2288  uint8_t *data[4];
2289  int linesize[4];
2290 
2291  enum AVSubtitleType type;
2292 
2293  char *text; ///< 0 terminated plain UTF-8 text
2294 
2295  /**
2296  * 0 terminated ASS/SSA compatible event line.
2297  * The presentation of this is unaffected by the other values in this
2298  * struct.
2299  */
2300  char *ass;
2301 
2302  int flags;
2303 } AVSubtitleRect;
2304 
2305 typedef struct AVSubtitle {
2306  uint16_t format; /* 0 = graphics */
2307  uint32_t start_display_time; /* relative to packet pts, in ms */
2308  uint32_t end_display_time; /* relative to packet pts, in ms */
2309  unsigned num_rects;
2311  int64_t pts; ///< Same as packet pts, in AV_TIME_BASE
2312 } AVSubtitle;
2313 
2314 /**
2315  * Return the LIBAVCODEC_VERSION_INT constant.
2316  */
2317 unsigned avcodec_version(void);
2318 
2319 /**
2320  * Return the libavcodec build-time configuration.
2321  */
2322 const char *avcodec_configuration(void);
2323 
2324 /**
2325  * Return the libavcodec license.
2326  */
2327 const char *avcodec_license(void);
2328 
2329 /**
2330  * Allocate an AVCodecContext and set its fields to default values. The
2331  * resulting struct should be freed with avcodec_free_context().
2332  *
2333  * @param codec if non-NULL, allocate private data and initialize defaults
2334  * for the given codec. It is illegal to then call avcodec_open2()
2335  * with a different codec.
2336  * If NULL, then the codec-specific defaults won't be initialized,
2337  * which may result in suboptimal default settings (this is
2338  * important mainly for encoders, e.g. libx264).
2339  *
2340  * @return An AVCodecContext filled with default values or NULL on failure.
2341  */
2343 
2344 /**
2345  * Free the codec context and everything associated with it and write NULL to
2346  * the provided pointer.
2347  */
2349 
2350 /**
2351  * Get the AVClass for AVCodecContext. It can be used in combination with
2352  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
2353  *
2354  * @see av_opt_find().
2355  */
2357 
2358 #if FF_API_GET_FRAME_CLASS
2359 /**
2360  * @deprecated This function should not be used.
2361  */
2364 #endif
2365 
2366 /**
2367  * Get the AVClass for AVSubtitleRect. It can be used in combination with
2368  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
2369  *
2370  * @see av_opt_find().
2371  */
2373 
2374 /**
2375  * Fill the parameters struct based on the values from the supplied codec
2376  * context. Any allocated fields in par are freed and replaced with duplicates
2377  * of the corresponding fields in codec.
2378  *
2379  * @return >= 0 on success, a negative AVERROR code on failure
2380  */
2382  const AVCodecContext *codec);
2383 
2384 /**
2385  * Fill the codec context based on the values from the supplied codec
2386  * parameters. Any allocated fields in codec that have a corresponding field in
2387  * par are freed and replaced with duplicates of the corresponding field in par.
2388  * Fields in codec that do not have a counterpart in par are not touched.
2389  *
2390  * @return >= 0 on success, a negative AVERROR code on failure.
2391  */
2393  const AVCodecParameters *par);
2394 
2395 /**
2396  * Initialize the AVCodecContext to use the given AVCodec. Prior to using this
2397  * function the context has to be allocated with avcodec_alloc_context3().
2398  *
2399  * The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(),
2400  * avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for
2401  * retrieving a codec.
2402  *
2403  * @note Always call this function before using decoding routines (such as
2404  * @ref avcodec_receive_frame()).
2405  *
2406  * @code
2407  * av_dict_set(&opts, "b", "2.5M", 0);
2408  * codec = avcodec_find_decoder(AV_CODEC_ID_H264);
2409  * if (!codec)
2410  * exit(1);
2411  *
2412  * context = avcodec_alloc_context3(codec);
2413  *
2414  * if (avcodec_open2(context, codec, opts) < 0)
2415  * exit(1);
2416  * @endcode
2417  *
2418  * @param avctx The context to initialize.
2419  * @param codec The codec to open this context for. If a non-NULL codec has been
2420  * previously passed to avcodec_alloc_context3() or
2421  * for this context, then this parameter MUST be either NULL or
2422  * equal to the previously passed codec.
2423  * @param options A dictionary filled with AVCodecContext and codec-private options.
2424  * On return this object will be filled with options that were not found.
2425  *
2426  * @return zero on success, a negative value on error
2427  * @see avcodec_alloc_context3(), avcodec_find_decoder(), avcodec_find_encoder(),
2428  * av_dict_set(), av_opt_find().
2429  */
2430 int avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options);
2431 
2432 /**
2433  * Close a given AVCodecContext and free all the data associated with it
2434  * (but not the AVCodecContext itself).
2435  *
2436  * Calling this function on an AVCodecContext that hasn't been opened will free
2437  * the codec-specific data allocated in avcodec_alloc_context3() with a non-NULL
2438  * codec. Subsequent calls will do nothing.
2439  *
2440  * @note Do not use this function. Use avcodec_free_context() to destroy a
2441  * codec context (either open or closed). Opening and closing a codec context
2442  * multiple times is not supported anymore -- use multiple codec contexts
2443  * instead.
2444  */
2446 
2447 /**
2448  * Free all allocated data in the given subtitle struct.
2449  *
2450  * @param sub AVSubtitle to free.
2451  */
2453 
2454 /**
2455  * @}
2456  */
2457 
2458 /**
2459  * @addtogroup lavc_decoding
2460  * @{
2461  */
2462 
2463 /**
2464  * The default callback for AVCodecContext.get_buffer2(). It is made public so
2465  * it can be called by custom get_buffer2() implementations for decoders without
2466  * AV_CODEC_CAP_DR1 set.
2467  */
2469 
2470 /**
2471  * The default callback for AVCodecContext.get_encode_buffer(). It is made public so
2472  * it can be called by custom get_encode_buffer() implementations for encoders without
2473  * AV_CODEC_CAP_DR1 set.
2474  */
2476 
2477 /**
2478  * Modify width and height values so that they will result in a memory
2479  * buffer that is acceptable for the codec if you do not use any horizontal
2480  * padding.
2481  *
2482  * May only be used if a codec with AV_CODEC_CAP_DR1 has been opened.
2483  */
2485 
2486 /**
2487  * Modify width and height values so that they will result in a memory
2488  * buffer that is acceptable for the codec if you also ensure that all
2489  * line sizes are a multiple of the respective linesize_align[i].
2490  *
2491  * May only be used if a codec with AV_CODEC_CAP_DR1 has been opened.
2492  */
2494  int linesize_align[AV_NUM_DATA_POINTERS]);
2495 
2496 /**
2497  * Converts AVChromaLocation to swscale x/y chroma position.
2498  *
2499  * The positions represent the chroma (0,0) position in a coordinates system
2500  * with luma (0,0) representing the origin and luma(1,1) representing 256,256
2501  *
2502  * @param xpos horizontal chroma sample position
2503  * @param ypos vertical chroma sample position
2504  */
2505 int avcodec_enum_to_chroma_pos(int *xpos, int *ypos, enum AVChromaLocation pos);
2506 
2507 /**
2508  * Converts swscale x/y chroma position to AVChromaLocation.
2509  *
2510  * The positions represent the chroma (0,0) position in a coordinates system
2511  * with luma (0,0) representing the origin and luma(1,1) representing 256,256
2512  *
2513  * @param xpos horizontal chroma sample position
2514  * @param ypos vertical chroma sample position
2515  */
2516 enum AVChromaLocation avcodec_chroma_pos_to_enum(int xpos, int ypos);
2517 
2518 /**
2519  * Decode a subtitle message.
2520  * Return a negative value on error, otherwise return the number of bytes used.
2521  * If no subtitle could be decompressed, got_sub_ptr is zero.
2522  * Otherwise, the subtitle is stored in *sub.
2523  * Note that AV_CODEC_CAP_DR1 is not available for subtitle codecs. This is for
2524  * simplicity, because the performance difference is expected to be negligible
2525  * and reusing a get_buffer written for video codecs would probably perform badly
2526  * due to a potentially very different allocation pattern.
2527  *
2528  * Some decoders (those marked with AV_CODEC_CAP_DELAY) have a delay between input
2529  * and output. This means that for some packets they will not immediately
2530  * produce decoded output and need to be flushed at the end of decoding to get
2531  * all the decoded data. Flushing is done by calling this function with packets
2532  * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
2533  * returning subtitles. It is safe to flush even those decoders that are not
2534  * marked with AV_CODEC_CAP_DELAY, then no subtitles will be returned.
2535  *
2536  * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
2537  * before packets may be fed to the decoder.
2538  *
2539  * @param avctx the codec context
2540  * @param[out] sub The preallocated AVSubtitle in which the decoded subtitle will be stored,
2541  * must be freed with avsubtitle_free if *got_sub_ptr is set.
2542  * @param[in,out] got_sub_ptr Zero if no subtitle could be decompressed, otherwise, it is nonzero.
2543  * @param[in] avpkt The input AVPacket containing the input buffer.
2544  */
2546  int *got_sub_ptr,
2547  AVPacket *avpkt);
2548 
2549 /**
2550  * Supply raw packet data as input to a decoder.
2551  *
2552  * Internally, this call will copy relevant AVCodecContext fields, which can
2553  * influence decoding per-packet, and apply them when the packet is actually
2554  * decoded. (For example AVCodecContext.skip_frame, which might direct the
2555  * decoder to drop the frame contained by the packet sent with this function.)
2556  *
2557  * @warning The input buffer, avpkt->data must be AV_INPUT_BUFFER_PADDING_SIZE
2558  * larger than the actual read bytes because some optimized bitstream
2559  * readers read 32 or 64 bits at once and could read over the end.
2560  *
2561  * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
2562  * before packets may be fed to the decoder.
2563  *
2564  * @param avctx codec context
2565  * @param[in] avpkt The input AVPacket. Usually, this will be a single video
2566  * frame, or several complete audio frames.
2567  * Ownership of the packet remains with the caller, and the
2568  * decoder will not write to the packet. The decoder may create
2569  * a reference to the packet data (or copy it if the packet is
2570  * not reference-counted).
2571  * Unlike with older APIs, the packet is always fully consumed,
2572  * and if it contains multiple frames (e.g. some audio codecs),
2573  * will require you to call avcodec_receive_frame() multiple
2574  * times afterwards before you can send a new packet.
2575  * It can be NULL (or an AVPacket with data set to NULL and
2576  * size set to 0); in this case, it is considered a flush
2577  * packet, which signals the end of the stream. Sending the
2578  * first flush packet will return success. Subsequent ones are
2579  * unnecessary and will return AVERROR_EOF. If the decoder
2580  * still has frames buffered, it will return them after sending
2581  * a flush packet.
2582  *
2583  * @return 0 on success, otherwise negative error code:
2584  * AVERROR(EAGAIN): input is not accepted in the current state - user
2585  * must read output with avcodec_receive_frame() (once
2586  * all output is read, the packet should be resent, and
2587  * the call will not fail with EAGAIN).
2588  * AVERROR_EOF: the decoder has been flushed, and no new packets can
2589  * be sent to it (also returned if more than 1 flush
2590  * packet is sent)
2591  * AVERROR(EINVAL): codec not opened, it is an encoder, or requires flush
2592  * AVERROR(ENOMEM): failed to add packet to internal queue, or similar
2593  * other errors: legitimate decoding errors
2594  */
2595 int avcodec_send_packet(AVCodecContext *avctx, const AVPacket *avpkt);
2596 
2597 /**
2598  * Return decoded output data from a decoder.
2599  *
2600  * @param avctx codec context
2601  * @param frame This will be set to a reference-counted video or audio
2602  * frame (depending on the decoder type) allocated by the
2603  * decoder. Note that the function will always call
2604  * av_frame_unref(frame) before doing anything else.
2605  *
2606  * @return
2607  * 0: success, a frame was returned
2608  * AVERROR(EAGAIN): output is not available in this state - user must try
2609  * to send new input
2610  * AVERROR_EOF: the decoder has been fully flushed, and there will be
2611  * no more output frames
2612  * AVERROR(EINVAL): codec not opened, or it is an encoder
2613  * AVERROR_INPUT_CHANGED: current decoded frame has changed parameters
2614  * with respect to first decoded frame. Applicable
2615  * when flag AV_CODEC_FLAG_DROPCHANGED is set.
2616  * other negative values: legitimate decoding errors
2617  */
2619 
2620 /**
2621  * Supply a raw video or audio frame to the encoder. Use avcodec_receive_packet()
2622  * to retrieve buffered output packets.
2623  *
2624  * @param avctx codec context
2625  * @param[in] frame AVFrame containing the raw audio or video frame to be encoded.
2626  * Ownership of the frame remains with the caller, and the
2627  * encoder will not write to the frame. The encoder may create
2628  * a reference to the frame data (or copy it if the frame is
2629  * not reference-counted).
2630  * It can be NULL, in which case it is considered a flush
2631  * packet. This signals the end of the stream. If the encoder
2632  * still has packets buffered, it will return them after this
2633  * call. Once flushing mode has been entered, additional flush
2634  * packets are ignored, and sending frames will return
2635  * AVERROR_EOF.
2636  *
2637  * For audio:
2638  * If AV_CODEC_CAP_VARIABLE_FRAME_SIZE is set, then each frame
2639  * can have any number of samples.
2640  * If it is not set, frame->nb_samples must be equal to
2641  * avctx->frame_size for all frames except the last.
2642  * The final frame may be smaller than avctx->frame_size.
2643  * @return 0 on success, otherwise negative error code:
2644  * AVERROR(EAGAIN): input is not accepted in the current state - user
2645  * must read output with avcodec_receive_packet() (once
2646  * all output is read, the packet should be resent, and
2647  * the call will not fail with EAGAIN).
2648  * AVERROR_EOF: the encoder has been flushed, and no new frames can
2649  * be sent to it
2650  * AVERROR(EINVAL): codec not opened, it is a decoder, or requires flush
2651  * AVERROR(ENOMEM): failed to add packet to internal queue, or similar
2652  * other errors: legitimate encoding errors
2653  */
2655 
2656 /**
2657  * Read encoded data from the encoder.
2658  *
2659  * @param avctx codec context
2660  * @param avpkt This will be set to a reference-counted packet allocated by the
2661  * encoder. Note that the function will always call
2662  * av_packet_unref(avpkt) before doing anything else.
2663  * @return 0 on success, otherwise negative error code:
2664  * AVERROR(EAGAIN): output is not available in the current state - user
2665  * must try to send input
2666  * AVERROR_EOF: the encoder has been fully flushed, and there will be
2667  * no more output packets
2668  * AVERROR(EINVAL): codec not opened, or it is a decoder
2669  * other errors: legitimate encoding errors
2670  */
2672 
2673 /**
2674  * Create and return a AVHWFramesContext with values adequate for hardware
2675  * decoding. This is meant to get called from the get_format callback, and is
2676  * a helper for preparing a AVHWFramesContext for AVCodecContext.hw_frames_ctx.
2677  * This API is for decoding with certain hardware acceleration modes/APIs only.
2678  *
2679  * The returned AVHWFramesContext is not initialized. The caller must do this
2680  * with av_hwframe_ctx_init().
2681  *
2682  * Calling this function is not a requirement, but makes it simpler to avoid
2683  * codec or hardware API specific details when manually allocating frames.
2684  *
2685  * Alternatively to this, an API user can set AVCodecContext.hw_device_ctx,
2686  * which sets up AVCodecContext.hw_frames_ctx fully automatically, and makes
2687  * it unnecessary to call this function or having to care about
2688  * AVHWFramesContext initialization at all.
2689  *
2690  * There are a number of requirements for calling this function:
2691  *
2692  * - It must be called from get_format with the same avctx parameter that was
2693  * passed to get_format. Calling it outside of get_format is not allowed, and
2694  * can trigger undefined behavior.
2695  * - The function is not always supported (see description of return values).
2696  * Even if this function returns successfully, hwaccel initialization could
2697  * fail later. (The degree to which implementations check whether the stream
2698  * is actually supported varies. Some do this check only after the user's
2699  * get_format callback returns.)
2700  * - The hw_pix_fmt must be one of the choices suggested by get_format. If the
2701  * user decides to use a AVHWFramesContext prepared with this API function,
2702  * the user must return the same hw_pix_fmt from get_format.
2703  * - The device_ref passed to this function must support the given hw_pix_fmt.
2704  * - After calling this API function, it is the user's responsibility to
2705  * initialize the AVHWFramesContext (returned by the out_frames_ref parameter),
2706  * and to set AVCodecContext.hw_frames_ctx to it. If done, this must be done
2707  * before returning from get_format (this is implied by the normal
2708  * AVCodecContext.hw_frames_ctx API rules).
2709  * - The AVHWFramesContext parameters may change every time time get_format is
2710  * called. Also, AVCodecContext.hw_frames_ctx is reset before get_format. So
2711  * you are inherently required to go through this process again on every
2712  * get_format call.
2713  * - It is perfectly possible to call this function without actually using
2714  * the resulting AVHWFramesContext. One use-case might be trying to reuse a
2715  * previously initialized AVHWFramesContext, and calling this API function
2716  * only to test whether the required frame parameters have changed.
2717  * - Fields that use dynamically allocated values of any kind must not be set
2718  * by the user unless setting them is explicitly allowed by the documentation.
2719  * If the user sets AVHWFramesContext.free and AVHWFramesContext.user_opaque,
2720  * the new free callback must call the potentially set previous free callback.
2721  * This API call may set any dynamically allocated fields, including the free
2722  * callback.
2723  *
2724  * The function will set at least the following fields on AVHWFramesContext
2725  * (potentially more, depending on hwaccel API):
2726  *
2727  * - All fields set by av_hwframe_ctx_alloc().
2728  * - Set the format field to hw_pix_fmt.
2729  * - Set the sw_format field to the most suited and most versatile format. (An
2730  * implication is that this will prefer generic formats over opaque formats
2731  * with arbitrary restrictions, if possible.)
2732  * - Set the width/height fields to the coded frame size, rounded up to the
2733  * API-specific minimum alignment.
2734  * - Only _if_ the hwaccel requires a pre-allocated pool: set the initial_pool_size
2735  * field to the number of maximum reference surfaces possible with the codec,
2736  * plus 1 surface for the user to work (meaning the user can safely reference
2737  * at most 1 decoded surface at a time), plus additional buffering introduced
2738  * by frame threading. If the hwaccel does not require pre-allocation, the
2739  * field is left to 0, and the decoder will allocate new surfaces on demand
2740  * during decoding.
2741  * - Possibly AVHWFramesContext.hwctx fields, depending on the underlying
2742  * hardware API.
2743  *
2744  * Essentially, out_frames_ref returns the same as av_hwframe_ctx_alloc(), but
2745  * with basic frame parameters set.
2746  *
2747  * The function is stateless, and does not change the AVCodecContext or the
2748  * device_ref AVHWDeviceContext.
2749  *
2750  * @param avctx The context which is currently calling get_format, and which
2751  * implicitly contains all state needed for filling the returned
2752  * AVHWFramesContext properly.
2753  * @param device_ref A reference to the AVHWDeviceContext describing the device
2754  * which will be used by the hardware decoder.
2755  * @param hw_pix_fmt The hwaccel format you are going to return from get_format.
2756  * @param out_frames_ref On success, set to a reference to an _uninitialized_
2757  * AVHWFramesContext, created from the given device_ref.
2758  * Fields will be set to values required for decoding.
2759  * Not changed if an error is returned.
2760  * @return zero on success, a negative value on error. The following error codes
2761  * have special semantics:
2762  * AVERROR(ENOENT): the decoder does not support this functionality. Setup
2763  * is always manual, or it is a decoder which does not
2764  * support setting AVCodecContext.hw_frames_ctx at all,
2765  * or it is a software format.
2766  * AVERROR(EINVAL): it is known that hardware decoding is not supported for
2767  * this configuration, or the device_ref is not supported
2768  * for the hwaccel referenced by hw_pix_fmt.
2769  */
2771  AVBufferRef *device_ref,
2773  AVBufferRef **out_frames_ref);
2774 
2775 
2776 
2777 /**
2778  * @defgroup lavc_parsing Frame parsing
2779  * @{
2780  */
2781 
2784  AV_PICTURE_STRUCTURE_TOP_FIELD, //< coded as top field
2785  AV_PICTURE_STRUCTURE_BOTTOM_FIELD, //< coded as bottom field
2786  AV_PICTURE_STRUCTURE_FRAME, //< coded as frame
2787 };
2788 
2789 typedef struct AVCodecParserContext {
2790  void *priv_data;
2791  const struct AVCodecParser *parser;
2792  int64_t frame_offset; /* offset of the current frame */
2793  int64_t cur_offset; /* current offset
2794  (incremented by each av_parser_parse()) */
2795  int64_t next_frame_offset; /* offset of the next frame */
2796  /* video info */
2797  int pict_type; /* XXX: Put it back in AVCodecContext. */
2798  /**
2799  * This field is used for proper frame duration computation in lavf.
2800  * It signals, how much longer the frame duration of the current frame
2801  * is compared to normal frame duration.
2802  *
2803  * frame_duration = (1 + repeat_pict) * time_base
2804  *
2805  * It is used by codecs like H.264 to display telecined material.
2806  */
2807  int repeat_pict; /* XXX: Put it back in AVCodecContext. */
2808  int64_t pts; /* pts of the current frame */
2809  int64_t dts; /* dts of the current frame */
2810 
2811  /* private data */
2812  int64_t last_pts;
2813  int64_t last_dts;
2815 
2816 #define AV_PARSER_PTS_NB 4
2821 
2822  int flags;
2823 #define PARSER_FLAG_COMPLETE_FRAMES 0x0001
2824 #define PARSER_FLAG_ONCE 0x0002
2825 /// Set if the parser has a valid file offset
2826 #define PARSER_FLAG_FETCHED_OFFSET 0x0004
2827 #define PARSER_FLAG_USE_CODEC_TS 0x1000
2828 
2829  int64_t offset; ///< byte offset from starting packet start
2831 
2832  /**
2833  * Set by parser to 1 for key frames and 0 for non-key frames.
2834  * It is initialized to -1, so if the parser doesn't set this flag,
2835  * old-style fallback using AV_PICTURE_TYPE_I picture type as key frames
2836  * will be used.
2837  */
2839 
2840  // Timestamp generation support:
2841  /**
2842  * Synchronization point for start of timestamp generation.
2843  *
2844  * Set to >0 for sync point, 0 for no sync point and <0 for undefined
2845  * (default).
2846  *
2847  * For example, this corresponds to presence of H.264 buffering period
2848  * SEI message.
2849  */
2851 
2852  /**
2853  * Offset of the current timestamp against last timestamp sync point in
2854  * units of AVCodecContext.time_base.
2855  *
2856  * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
2857  * contain a valid timestamp offset.
2858  *
2859  * Note that the timestamp of sync point has usually a nonzero
2860  * dts_ref_dts_delta, which refers to the previous sync point. Offset of
2861  * the next frame after timestamp sync point will be usually 1.
2862  *
2863  * For example, this corresponds to H.264 cpb_removal_delay.
2864  */
2866 
2867  /**
2868  * Presentation delay of current frame in units of AVCodecContext.time_base.
2869  *
2870  * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
2871  * contain valid non-negative timestamp delta (presentation time of a frame
2872  * must not lie in the past).
2873  *
2874  * This delay represents the difference between decoding and presentation
2875  * time of the frame.
2876  *
2877  * For example, this corresponds to H.264 dpb_output_delay.
2878  */
2880 
2881  /**
2882  * Position of the packet in file.
2883  *
2884  * Analogous to cur_frame_pts/dts
2885  */
2887 
2888  /**
2889  * Byte position of currently parsed frame in stream.
2890  */
2891  int64_t pos;
2892 
2893  /**
2894  * Previous frame byte position.
2895  */
2896  int64_t last_pos;
2897 
2898  /**
2899  * Duration of the current frame.
2900  * For audio, this is in units of 1 / AVCodecContext.sample_rate.
2901  * For all other types, this is in units of AVCodecContext.time_base.
2902  */
2904 
2906 
2907  /**
2908  * Indicate whether a picture is coded as a frame, top field or bottom field.
2909  *
2910  * For example, H.264 field_pic_flag equal to 0 corresponds to
2911  * AV_PICTURE_STRUCTURE_FRAME. An H.264 picture with field_pic_flag
2912  * equal to 1 and bottom_field_flag equal to 0 corresponds to
2913  * AV_PICTURE_STRUCTURE_TOP_FIELD.
2914  */
2916 
2917  /**
2918  * Picture number incremented in presentation or output order.
2919  * This field may be reinitialized at the first picture of a new sequence.
2920  *
2921  * For example, this corresponds to H.264 PicOrderCnt.
2922  */
2924 
2925  /**
2926  * Dimensions of the decoded video intended for presentation.
2927  */
2928  int width;
2929  int height;
2930 
2931  /**
2932  * Dimensions of the coded video.
2933  */
2936 
2937  /**
2938  * The format of the coded data, corresponds to enum AVPixelFormat for video
2939  * and for enum AVSampleFormat for audio.
2940  *
2941  * Note that a decoder can have considerable freedom in how exactly it
2942  * decodes the data, so the format reported here might be different from the
2943  * one returned by a decoder.
2944  */
2945  int format;
2947 
2948 typedef struct AVCodecParser {
2949  int codec_ids[7]; /* several codec IDs are permitted */
2952  /* This callback never returns an error, a negative value means that
2953  * the frame start was in a previous packet. */
2955  AVCodecContext *avctx,
2956  const uint8_t **poutbuf, int *poutbuf_size,
2957  const uint8_t *buf, int buf_size);
2959  int (*split)(AVCodecContext *avctx, const uint8_t *buf, int buf_size);
2960 } AVCodecParser;
2961 
2962 /**
2963  * Iterate over all registered codec parsers.
2964  *
2965  * @param opaque a pointer where libavcodec will store the iteration state. Must
2966  * point to NULL to start the iteration.
2967  *
2968  * @return the next registered codec parser or NULL when the iteration is
2969  * finished
2970  */
2971 const AVCodecParser *av_parser_iterate(void **opaque);
2972 
2974 
2975 /**
2976  * Parse a packet.
2977  *
2978  * @param s parser context.
2979  * @param avctx codec context.
2980  * @param poutbuf set to pointer to parsed buffer or NULL if not yet finished.
2981  * @param poutbuf_size set to size of parsed buffer or zero if not yet finished.
2982  * @param buf input buffer.
2983  * @param buf_size buffer size in bytes without the padding. I.e. the full buffer
2984  size is assumed to be buf_size + AV_INPUT_BUFFER_PADDING_SIZE.
2985  To signal EOF, this should be 0 (so that the last frame
2986  can be output).
2987  * @param pts input presentation timestamp.
2988  * @param dts input decoding timestamp.
2989  * @param pos input byte position in stream.
2990  * @return the number of bytes of the input bitstream used.
2991  *
2992  * Example:
2993  * @code
2994  * while(in_len){
2995  * len = av_parser_parse2(myparser, AVCodecContext, &data, &size,
2996  * in_data, in_len,
2997  * pts, dts, pos);
2998  * in_data += len;
2999  * in_len -= len;
3000  *
3001  * if(size)
3002  * decode_frame(data, size);
3003  * }
3004  * @endcode
3005  */
3007  AVCodecContext *avctx,
3008  uint8_t **poutbuf, int *poutbuf_size,
3009  const uint8_t *buf, int buf_size,
3010  int64_t pts, int64_t dts,
3011  int64_t pos);
3012 
3014 
3015 /**
3016  * @}
3017  * @}
3018  */
3019 
3020 /**
3021  * @addtogroup lavc_encoding
3022  * @{
3023  */
3024 
3025 int avcodec_encode_subtitle(AVCodecContext *avctx, uint8_t *buf, int buf_size,
3026  const AVSubtitle *sub);
3027 
3028 
3029 /**
3030  * @}
3031  */
3032 
3033 /**
3034  * @defgroup lavc_misc Utility functions
3035  * @ingroup libavc
3036  *
3037  * Miscellaneous utility functions related to both encoding and decoding
3038  * (or neither).
3039  * @{
3040  */
3041 
3042 /**
3043  * @defgroup lavc_misc_pixfmt Pixel formats
3044  *
3045  * Functions for working with pixel formats.
3046  * @{
3047  */
3048 
3049 /**
3050  * Return a value representing the fourCC code associated to the
3051  * pixel format pix_fmt, or 0 if no associated fourCC code can be
3052  * found.
3053  */
3055 
3056 /**
3057  * Find the best pixel format to convert to given a certain source pixel
3058  * format. When converting from one pixel format to another, information loss
3059  * may occur. For example, when converting from RGB24 to GRAY, the color
3060  * information will be lost. Similarly, other losses occur when converting from
3061  * some formats to other formats. avcodec_find_best_pix_fmt_of_2() searches which of
3062  * the given pixel formats should be used to suffer the least amount of loss.
3063  * The pixel formats from which it chooses one, are determined by the
3064  * pix_fmt_list parameter.
3065  *
3066  *
3067  * @param[in] pix_fmt_list AV_PIX_FMT_NONE terminated array of pixel formats to choose from
3068  * @param[in] src_pix_fmt source pixel format
3069  * @param[in] has_alpha Whether the source pixel format alpha channel is used.
3070  * @param[out] loss_ptr Combination of flags informing you what kind of losses will occur.
3071  * @return The best pixel format to convert to or -1 if none was found.
3072  */
3073 enum AVPixelFormat avcodec_find_best_pix_fmt_of_list(const enum AVPixelFormat *pix_fmt_list,
3074  enum AVPixelFormat src_pix_fmt,
3075  int has_alpha, int *loss_ptr);
3076 
3077 enum AVPixelFormat avcodec_default_get_format(struct AVCodecContext *s, const enum AVPixelFormat * fmt);
3078 
3079 /**
3080  * @}
3081  */
3082 
3083 void avcodec_string(char *buf, int buf_size, AVCodecContext *enc, int encode);
3084 
3085 int avcodec_default_execute(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2),void *arg, int *ret, int count, int size);
3086 int avcodec_default_execute2(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2, int, int),void *arg, int *ret, int count);
3087 //FIXME func typedef
3088 
3089 /**
3090  * Fill AVFrame audio data and linesize pointers.
3091  *
3092  * The buffer buf must be a preallocated buffer with a size big enough
3093  * to contain the specified samples amount. The filled AVFrame data
3094  * pointers will point to this buffer.
3095  *
3096  * AVFrame extended_data channel pointers are allocated if necessary for
3097  * planar audio.
3098  *
3099  * @param frame the AVFrame
3100  * frame->nb_samples must be set prior to calling the
3101  * function. This function fills in frame->data,
3102  * frame->extended_data, frame->linesize[0].
3103  * @param nb_channels channel count
3104  * @param sample_fmt sample format
3105  * @param buf buffer to use for frame data
3106  * @param buf_size size of buffer
3107  * @param align plane size sample alignment (0 = default)
3108  * @return >=0 on success, negative error code on failure
3109  * @todo return the size in bytes required to store the samples in
3110  * case of success, at the next libavutil bump
3111  */
3113  enum AVSampleFormat sample_fmt, const uint8_t *buf,
3114  int buf_size, int align);
3115 
3116 /**
3117  * Reset the internal codec state / flush internal buffers. Should be called
3118  * e.g. when seeking or when switching to a different stream.
3119  *
3120  * @note for decoders, this function just releases any references the decoder
3121  * might keep internally, but the caller's references remain valid.
3122  *
3123  * @note for encoders, this function will only do something if the encoder
3124  * declares support for AV_CODEC_CAP_ENCODER_FLUSH. When called, the encoder
3125  * will drain any remaining packets, and can then be re-used for a different
3126  * stream (as opposed to sending a null frame which will leave the encoder
3127  * in a permanent EOF state after draining). This can be desirable if the
3128  * cost of tearing down and replacing the encoder instance is high.
3129  */
3131 
3132 /**
3133  * Return audio frame duration.
3134  *
3135  * @param avctx codec context
3136  * @param frame_bytes size of the frame, or 0 if unknown
3137  * @return frame duration, in samples, if known. 0 if not able to
3138  * determine.
3139  */
3140 int av_get_audio_frame_duration(AVCodecContext *avctx, int frame_bytes);
3141 
3142 /* memory */
3143 
3144 /**
3145  * Same behaviour av_fast_malloc but the buffer has additional
3146  * AV_INPUT_BUFFER_PADDING_SIZE at the end which will always be 0.
3147  *
3148  * In addition the whole buffer will initially and after resizes
3149  * be 0-initialized so that no uninitialized data will ever appear.
3150  */
3151 void av_fast_padded_malloc(void *ptr, unsigned int *size, size_t min_size);
3152 
3153 /**
3154  * Same behaviour av_fast_padded_malloc except that buffer will always
3155  * be 0-initialized after call.
3156  */
3157 void av_fast_padded_mallocz(void *ptr, unsigned int *size, size_t min_size);
3158 
3159 /**
3160  * @return a positive value if s is open (i.e. avcodec_open2() was called on it
3161  * with no corresponding avcodec_close()), 0 otherwise.
3162  */
3164 
3165 /**
3166  * @}
3167  */
3168 
3169 #endif /* AVCODEC_AVCODEC_H */
Macro definitions for various function/variable attributes.
#define attribute_deprecated
Definition: attributes.h:100
#define AV_PARSER_PTS_NB
Definition: avcodec.h:2816
Convenience header that includes libavutil's core.
refcounted data buffer API
AVFieldOrder
Definition: codec_par.h:37
Misc types and constants that do not belong anywhere else.
AVAudioServiceType
Definition: defs.h:57
static int width
static AVPacket * pkt
static enum AVPixelFormat pix_fmt
static int height
static AVFrame * frame
Public dictionary API.
static void encode(AVCodecContext *ctx, AVFrame *frame, AVPacket *pkt, FILE *output)
Definition: encode_audio.c:94
reference-counted frame API
#define AV_NUM_DATA_POINTERS
Definition: frame.h:326
int avcodec_parameters_from_context(AVCodecParameters *par, const AVCodecContext *codec)
Fill the parameters struct based on the values from the supplied codec context.
int avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options)
Initialize the AVCodecContext to use the given AVCodec.
attribute_deprecated const AVClass * avcodec_get_frame_class(void)
const AVClass * avcodec_get_subtitle_rect_class(void)
Get the AVClass for AVSubtitleRect.
AVSubtitleType
Definition: avcodec.h:2257
void avsubtitle_free(AVSubtitle *sub)
Free all allocated data in the given subtitle struct.
AVCodecID
Identify the syntax and semantics of the bitstream.
Definition: codec_id.h:47
const char * avcodec_configuration(void)
Return the libavcodec build-time configuration.
int avcodec_parameters_to_context(AVCodecContext *codec, const AVCodecParameters *par)
Fill the codec context based on the values from the supplied codec parameters.
unsigned avcodec_version(void)
Return the LIBAVCODEC_VERSION_INT constant.
const char * avcodec_license(void)
Return the libavcodec license.
AVCodecContext * avcodec_alloc_context3(const AVCodec *codec)
Allocate an AVCodecContext and set its fields to default values.
const AVClass * avcodec_get_class(void)
Get the AVClass for AVCodecContext.
int avcodec_close(AVCodecContext *avctx)
Close a given AVCodecContext and free all the data associated with it (but not the AVCodecContext its...
void avcodec_free_context(AVCodecContext **avctx)
Free the codec context and everything associated with it and write NULL to the provided pointer.
@ SUBTITLE_BITMAP
A bitmap, pict will be set.
Definition: avcodec.h:2260
@ SUBTITLE_ASS
Formatted text, the ass field must be set by the decoder and is authoritative.
Definition: avcodec.h:2272
@ SUBTITLE_TEXT
Plain text, the text field must be set by the decoder and is authoritative.
Definition: avcodec.h:2266
@ SUBTITLE_NONE
Definition: avcodec.h:2258
int avcodec_default_get_buffer2(AVCodecContext *s, AVFrame *frame, int flags)
The default callback for AVCodecContext.get_buffer2().
int avcodec_receive_frame(AVCodecContext *avctx, AVFrame *frame)
Return decoded output data from a decoder.
int avcodec_enum_to_chroma_pos(int *xpos, int *ypos, enum AVChromaLocation pos)
Converts AVChromaLocation to swscale x/y chroma position.
enum AVChromaLocation avcodec_chroma_pos_to_enum(int xpos, int ypos)
Converts swscale x/y chroma position to AVChromaLocation.
void avcodec_align_dimensions2(AVCodecContext *s, int *width, int *height, int linesize_align[AV_NUM_DATA_POINTERS])
Modify width and height values so that they will result in a memory buffer that is acceptable for the...
AVDiscard
Definition: defs.h:45
int avcodec_decode_subtitle2(AVCodecContext *avctx, AVSubtitle *sub, int *got_sub_ptr, AVPacket *avpkt)
Decode a subtitle message.
void avcodec_align_dimensions(AVCodecContext *s, int *width, int *height)
Modify width and height values so that they will result in a memory buffer that is acceptable for the...
int avcodec_send_packet(AVCodecContext *avctx, const AVPacket *avpkt)
Supply raw packet data as input to a decoder.
int avcodec_receive_packet(AVCodecContext *avctx, AVPacket *avpkt)
Read encoded data from the encoder.
int avcodec_get_hw_frames_parameters(AVCodecContext *avctx, AVBufferRef *device_ref, enum AVPixelFormat hw_pix_fmt, AVBufferRef **out_frames_ref)
Create and return a AVHWFramesContext with values adequate for hardware decoding.
int avcodec_send_frame(AVCodecContext *avctx, const AVFrame *frame)
Supply a raw video or audio frame to the encoder.
int avcodec_default_get_encode_buffer(AVCodecContext *s, AVPacket *pkt, int flags)
The default callback for AVCodecContext.get_encode_buffer().
int avcodec_encode_subtitle(AVCodecContext *avctx, uint8_t *buf, int buf_size, const AVSubtitle *sub)
enum AVPixelFormat avcodec_default_get_format(struct AVCodecContext *s, const enum AVPixelFormat *fmt)
unsigned int avcodec_pix_fmt_to_codec_tag(enum AVPixelFormat pix_fmt)
Return a value representing the fourCC code associated to the pixel format pix_fmt,...
enum AVPixelFormat avcodec_find_best_pix_fmt_of_list(const enum AVPixelFormat *pix_fmt_list, enum AVPixelFormat src_pix_fmt, int has_alpha, int *loss_ptr)
Find the best pixel format to convert to given a certain source pixel format.
void av_fast_padded_malloc(void *ptr, unsigned int *size, size_t min_size)
Same behaviour av_fast_malloc but the buffer has additional AV_INPUT_BUFFER_PADDING_SIZE at the end w...
int av_get_audio_frame_duration(AVCodecContext *avctx, int frame_bytes)
Return audio frame duration.
int avcodec_default_execute2(AVCodecContext *c, int(*func)(AVCodecContext *c2, void *arg2, int, int), void *arg, int *ret, int count)
int avcodec_fill_audio_frame(AVFrame *frame, int nb_channels, enum AVSampleFormat sample_fmt, const uint8_t *buf, int buf_size, int align)
Fill AVFrame audio data and linesize pointers.
void avcodec_string(char *buf, int buf_size, AVCodecContext *enc, int encode)
int avcodec_is_open(AVCodecContext *s)
int avcodec_default_execute(AVCodecContext *c, int(*func)(AVCodecContext *c2, void *arg2), void *arg, int *ret, int count, int size)
void av_fast_padded_mallocz(void *ptr, unsigned int *size, size_t min_size)
Same behaviour av_fast_padded_malloc except that buffer will always be 0-initialized after call.
void avcodec_flush_buffers(AVCodecContext *avctx)
Reset the internal codec state / flush internal buffers.
AVCodecParserContext * av_parser_init(int codec_id)
void av_parser_close(AVCodecParserContext *s)
int av_parser_parse2(AVCodecParserContext *s, AVCodecContext *avctx, uint8_t **poutbuf, int *poutbuf_size, const uint8_t *buf, int buf_size, int64_t pts, int64_t dts, int64_t pos)
Parse a packet.
const AVCodecParser * av_parser_iterate(void **opaque)
Iterate over all registered codec parsers.
AVPictureStructure
Definition: avcodec.h:2782
@ AV_PICTURE_STRUCTURE_FRAME
Definition: avcodec.h:2786
@ AV_PICTURE_STRUCTURE_BOTTOM_FIELD
Definition: avcodec.h:2785
@ AV_PICTURE_STRUCTURE_TOP_FIELD
Definition: avcodec.h:2784
@ AV_PICTURE_STRUCTURE_UNKNOWN
Definition: avcodec.h:2783
struct AVDictionary AVDictionary
Definition: dict.h:84
AVMediaType
Definition: avutil.h:199
AVSampleFormat
Audio sample formats.
Definition: samplefmt.h:55
static enum AVPixelFormat hw_pix_fmt
Definition: hw_decode.c:46
Libavutil version macros.
swscale version macros
pixel format definitions
AVChromaLocation
Location of chroma samples.
Definition: pixfmt.h:618
AVColorRange
Visual content value range.
Definition: pixfmt.h:564
AVPixelFormat
Pixel format.
Definition: pixfmt.h:64
AVColorPrimaries
Chromaticity coordinates of the source primaries.
Definition: pixfmt.h:471
AVColorTransferCharacteristic
Color Transfer Characteristic.
Definition: pixfmt.h:496
AVColorSpace
YUV colorspace type.
Definition: pixfmt.h:525
Utilties for rational number calculation.
A reference to a data buffer.
Definition: buffer.h:82
An AVChannelLayout holds information about the channel layout of audio data.
Describe the class of an AVClass context structure.
Definition: log.h:66
main external API structure.
Definition: avcodec.h:389
int nsse_weight
noise vs.
Definition: avcodec.h:1540
float rc_max_available_vbv_use
Ratecontrol attempt to use, at maximum, of what can be used without an underflow.
Definition: avcodec.h:1228
int skip_top
Number of macroblock rows at the top which are skipped.
Definition: avcodec.h:897
int trellis
trellis RD quantization
Definition: avcodec.h:1249
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:599
int64_t pts_correction_last_dts
PTS of the last frame.
Definition: avcodec.h:1763
int max_qdiff
maximum quantizer difference between frames
Definition: avcodec.h:1192
uint16_t * chroma_intra_matrix
custom intra quantization matrix
Definition: avcodec.h:1821
const AVCodecDescriptor * codec_descriptor
AVCodecDescriptor.
Definition: avcodec.h:1753
int hwaccel_flags
Bit set of AV_HWACCEL_FLAG_* flags, which affect hardware accelerated decoding (if active).
Definition: avcodec.h:1939
int subtitle_header_size
Definition: avcodec.h:1706
int width
picture width / height.
Definition: avcodec.h:562
AVPacketSideData * coded_side_data
Additional data associated with the entire coded stream.
Definition: avcodec.h:1855
int64_t pts_correction_num_faulty_dts
Number of incorrect PTS values so far.
Definition: avcodec.h:1761
char * stats_out
pass1 encoding statistics output buffer
Definition: avcodec.h:1256
int rc_buffer_size
decoder bitstream buffer size
Definition: avcodec.h:1199
AVChannelLayout ch_layout
Audio channel layout.
Definition: avcodec.h:2056
int64_t pts_correction_last_pts
Number of incorrect DTS values so far.
Definition: avcodec.h:1762
int me_cmp
motion estimation comparison function
Definition: avcodec.h:766
int flags2
AV_CODEC_FLAG2_*.
Definition: avcodec.h:476
enum AVSampleFormat sample_fmt
audio sample format
Definition: avcodec.h:1014
int debug
debug
Definition: avcodec.h:1322
enum AVPixelFormat sw_pix_fmt
Nominal unaccelerated pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1739
int global_quality
Global quality for codecs which cannot change it per frame.
Definition: avcodec.h:455
int64_t max_pixels
The number of pixels per image to maximally accept.
Definition: avcodec.h:1908
attribute_deprecated uint64_t request_channel_layout
Request decoder to use this channel layout if it can (0 for default)
Definition: avcodec.h:1069
enum AVColorRange color_range
MPEG vs JPEG YUV range.
Definition: avcodec.h:973
char * sub_charenc
DTS of the last frame.
Definition: avcodec.h:1770
int error_concealment
error concealment flags
Definition: avcodec.h:1312
int dct_algo
DCT algorithm, see FF_DCT_* below.
Definition: avcodec.h:1404
unsigned int codec_tag
fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
Definition: avcodec.h:414
int slice_flags
slice flags
Definition: avcodec.h:852
int strict_std_compliance
strictly follow the standard (MPEG-4, ...).
Definition: avcodec.h:1300
float b_quant_offset
qscale offset between IP and B-frames
Definition: avcodec.h:677
int nb_coded_side_data
Definition: avcodec.h:1856
AVRational pkt_timebase
Timebase in which pkt_dts/pts and AVPacket.dts/pts are.
Definition: avcodec.h:1746
enum AVPixelFormat(* get_format)(struct AVCodecContext *s, const enum AVPixelFormat *fmt)
Callback to negotiate the pixel format.
Definition: avcodec.h:653
enum AVAudioServiceType audio_service_type
Type of service that the audio stream conveys.
Definition: avcodec.h:1077
enum AVColorPrimaries color_primaries
Chromaticity coordinates of the source primaries.
Definition: avcodec.h:952
int me_subpel_quality
subpel ME quality
Definition: avcodec.h:836
AVBufferRef * hw_frames_ctx
A reference to the AVHWFramesContext describing the input (for encoding) or output (decoding) frames.
Definition: avcodec.h:1880
int max_b_frames
maximum number of B-frames between non-B-frames Note: The output will be delayed by max_b_frames+1 re...
Definition: avcodec.h:661
int mb_lmax
maximum MB Lagrange multiplier
Definition: avcodec.h:918
int qmin
minimum quantizer
Definition: avcodec.h:1178
int keyint_min
minimum GOP size
Definition: avcodec.h:931
enum AVMediaType codec_type
Definition: avcodec.h:397
float b_quant_factor
qscale factor between IP and B-frames If > 0 then the last P-frame quantizer will be used (q= lastp_q...
Definition: avcodec.h:670
int dia_size
ME diamond size & shape.
Definition: avcodec.h:808
attribute_deprecated int debug_mv
Definition: avcodec.h:1810
int workaround_bugs
Work around bugs in encoders which sometimes cannot be detected automatically.
Definition: avcodec.h:1271
int apply_cropping
Video decoding only.
Definition: avcodec.h:1966
AVRational framerate
Definition: avcodec.h:1732
int bidir_refine
Definition: avcodec.h:924
char * stats_in
pass2 encoding statistics input buffer Concatenated stuff from stats_out of pass1 should be placed he...
Definition: avcodec.h:1264
AVRational sample_aspect_ratio
sample aspect ratio (0 if unknown) That is the width of a pixel divided by the height of the pixel.
Definition: avcodec.h:759
int bits_per_coded_sample
bits per sample/pixel from the demuxer (needed for huffyuv).
Definition: avcodec.h:1441
int rc_override_count
ratecontrol override, see RcOverride
Definition: avcodec.h:1206
uint8_t * dump_separator
dump format separator.
Definition: avcodec.h:1829
attribute_deprecated uint64_t channel_layout
Audio channel layout.
Definition: avcodec.h:1060
int slice_count
slice count
Definition: avcodec.h:743
int ticks_per_frame
For some codecs, the time base is closer to the field rate than the frame rate.
Definition: avcodec.h:521
enum AVFieldOrder field_order
Field order.
Definition: avcodec.h:995
uint16_t * inter_matrix
custom inter quantization matrix Must be allocated with the av_malloc() family of functions,...
Definition: avcodec.h:883
const struct AVHWAccel * hwaccel
Hardware accelerator in use.
Definition: avcodec.h:1379
int active_thread_type
Which multithreading methods are in use by the codec.
Definition: avcodec.h:1482
int(* get_encode_buffer)(struct AVCodecContext *s, AVPacket *pkt, int flags)
This callback is called at the beginning of each packet to get a data buffer for it.
Definition: avcodec.h:2048
int sub_charenc_mode
Subtitles character encoding mode.
Definition: avcodec.h:1778
int64_t reordered_opaque
opaque 64-bit number (generally a PTS) that will be reordered and output in AVFrame....
Definition: avcodec.h:1372
int bit_rate_tolerance
number of bits the bitstream is allowed to diverge from the reference.
Definition: avcodec.h:447
int mb_decision
macroblock decision mode
Definition: avcodec.h:862
int has_b_frames
Size of the frame reordering buffer in the decoder.
Definition: avcodec.h:685
char * codec_whitelist
',' separated list of allowed decoders.
Definition: avcodec.h:1837
int level
level
Definition: avcodec.h:1673
void(* draw_horiz_band)(struct AVCodecContext *s, const AVFrame *src, int offset[AV_NUM_DATA_POINTERS], int y, int type, int height)
If non NULL, 'draw_horiz_band' is called by the libavcodec decoder to draw a horizontal band.
Definition: avcodec.h:624
int64_t bit_rate
the average bitrate
Definition: avcodec.h:439
enum AVDiscard skip_loop_filter
Skip loop filtering for selected frames.
Definition: avcodec.h:1681
int64_t pts_correction_num_faulty_pts
Current statistics for PTS correction.
Definition: avcodec.h:1760
const struct AVCodec * codec
Definition: avcodec.h:398
attribute_deprecated int channels
number of audio channels
Definition: avcodec.h:1006
int rc_initial_buffer_occupancy
Number of bits which should be loaded into the rc buffer before decoding starts.
Definition: avcodec.h:1242
int thread_type
Which multithreading methods to use.
Definition: avcodec.h:1473
int me_sub_cmp
subpixel motion estimation comparison function
Definition: avcodec.h:772
int profile
profile
Definition: avcodec.h:1547
unsigned properties
Properties of the stream that gets decoded.
Definition: avcodec.h:1844
int last_predictor_count
amount of previous MV predictors (2a+1 x 2a+1 square)
Definition: avcodec.h:815
int log_level_offset
Definition: avcodec.h:395
int(* execute)(struct AVCodecContext *c, int(*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size)
The codec may call this to execute several independent things.
Definition: avcodec.h:1514
int bits_per_raw_sample
Bits per sample/pixel of internal libavcodec pixel/sample format.
Definition: avcodec.h:1448
int idct_algo
IDCT algorithm, see FF_IDCT_* below.
Definition: avcodec.h:1417
int export_side_data
Bit set of AV_CODEC_EXPORT_DATA_* flags, which affects the kind of metadata exported in frame,...
Definition: avcodec.h:2006
enum AVColorSpace colorspace
YUV colorspace type.
Definition: avcodec.h:966
enum AVSampleFormat request_sample_fmt
desired sample format
Definition: avcodec.h:1085
int initial_padding
Audio only.
Definition: avcodec.h:1723
float temporal_cplx_masking
temporary complexity masking (0-> disabled)
Definition: avcodec.h:715
int sample_rate
samples per second
Definition: avcodec.h:998
const AVClass * av_class
information on struct for av_log
Definition: avcodec.h:394
float p_masking
p block masking (0-> disabled)
Definition: avcodec.h:729
int delay
Codec delay.
Definition: avcodec.h:545
float dark_masking
darkness masking (0-> disabled)
Definition: avcodec.h:736
int mb_cmp
macroblock comparison function (not supported yet)
Definition: avcodec.h:778
int gop_size
the number of pictures in a group of pictures, or 0 for intra_only
Definition: avcodec.h:584
int frame_number
Frame counter, set by libavcodec.
Definition: avcodec.h:1037
int skip_alpha
Skip processing alpha if supported by codec.
Definition: avcodec.h:1796
int refs
number of reference frames
Definition: avcodec.h:938
int ildct_cmp
interlaced DCT comparison function
Definition: avcodec.h:784
attribute_deprecated int thread_safe_callbacks
Set by the client if its custom get_buffer() callback can be called synchronously from another thread...
Definition: avcodec.h:1502
int mv0_threshold
Note: Value depends upon the compare function used for fullpel ME.
Definition: avcodec.h:945
int mb_lmin
minimum MB Lagrange multiplier
Definition: avcodec.h:911
int64_t rc_max_rate
maximum bitrate
Definition: avcodec.h:1214
int compression_level
Definition: avcodec.h:461
int discard_damaged_percentage
The percentage of damaged samples to discard a frame.
Definition: avcodec.h:1988
int thread_count
thread count is used to decide how many independent tasks should be passed to execute()
Definition: avcodec.h:1463
void * opaque
Private data of the user, can be used to carry app specific stuff.
Definition: avcodec.h:431
int qmax
maximum quantizer
Definition: avcodec.h:1185
void * hwaccel_context
Hardware accelerator context.
Definition: avcodec.h:1390
uint16_t * intra_matrix
custom intra quantization matrix Must be allocated with the av_malloc() family of functions,...
Definition: avcodec.h:874
int coded_height
Definition: avcodec.h:577
enum AVColorTransferCharacteristic color_trc
Color Transfer Characteristic.
Definition: avcodec.h:959
float rc_min_vbv_overflow_use
Ratecontrol attempt to use, at least, times the amount needed to prevent a vbv overflow.
Definition: avcodec.h:1235
uint8_t * subtitle_header
Header containing style information for text subtitles.
Definition: avcodec.h:1705
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented.
Definition: avcodec.h:512
int flags
AV_CODEC_FLAG_*.
Definition: avcodec.h:469
int seek_preroll
Number of samples to skip after a discontinuity.
Definition: avcodec.h:1803
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:490
int me_pre_cmp
motion estimation prepass comparison function
Definition: avcodec.h:822
int64_t rc_min_rate
minimum bitrate
Definition: avcodec.h:1221
int trailing_padding
Audio only.
Definition: avcodec.h:1900
enum AVDiscard skip_idct
Skip IDCT/dequantization for selected frames.
Definition: avcodec.h:1688
int intra_dc_precision
precision of the intra DC coefficient - 8
Definition: avcodec.h:890
enum AVChromaLocation chroma_sample_location
This defines the location of chroma samples.
Definition: avcodec.h:980
int(* execute2)(struct AVCodecContext *c, int(*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count)
The codec may call this to execute several independent things.
Definition: avcodec.h:1533
uint64_t error[AV_NUM_DATA_POINTERS]
error
Definition: avcodec.h:1397
float qcompress
amount of qscale change between easy & hard scenes (0.0-1.0)
Definition: avcodec.h:1170
float qblur
amount of qscale smoothing over time (0.0-1.0)
Definition: avcodec.h:1171
AVBufferRef * hw_device_ctx
A reference to the AVHWDeviceContext describing the device which will be used by a hardware encoder/d...
Definition: avcodec.h:1930
int me_range
maximum motion estimation search range in subpel units If 0 then no limit.
Definition: avcodec.h:845
int extra_hw_frames
Definition: avcodec.h:1980
attribute_deprecated int sub_text_format
Definition: avcodec.h:1887
RcOverride * rc_override
Definition: avcodec.h:1207
int64_t max_samples
The number of samples per frame to maximally accept.
Definition: avcodec.h:1996
enum AVCodecID codec_id
Definition: avcodec.h:399
int pre_dia_size
ME prepass diamond size & shape.
Definition: avcodec.h:829
float lumi_masking
luminance masking (0-> disabled)
Definition: avcodec.h:708
int extradata_size
Definition: avcodec.h:491
int cutoff
Audio cutoff bandwidth (0 means "automatic")
Definition: avcodec.h:1050
int skip_bottom
Number of macroblock rows at the bottom which are skipped.
Definition: avcodec.h:904
int coded_width
Bitstream width / height, may be different from width/height e.g.
Definition: avcodec.h:577
int block_align
number of bytes per packet if constant and known or 0 Used by some WAV based audio codecs.
Definition: avcodec.h:1043
int frame_size
Number of samples per channel in an audio frame.
Definition: avcodec.h:1026
int * slice_offset
slice offsets in the frame in bytes
Definition: avcodec.h:750
float i_quant_factor
qscale factor between P- and I-frames If > 0 then the last P-frame quantizer will be used (q = lastp_...
Definition: avcodec.h:694
int(* get_buffer2)(struct AVCodecContext *s, AVFrame *frame, int flags)
This callback is called at the beginning of each frame to get data buffer(s) for it.
Definition: avcodec.h:1167
int lowres
low resolution decoding, 1-> 1/2 size, 2->1/4 size
Definition: avcodec.h:1455
void * priv_data
Definition: avcodec.h:416
float spatial_cplx_masking
spatial complexity masking (0-> disabled)
Definition: avcodec.h:722
enum AVDiscard skip_frame
Skip decoding for selected frames.
Definition: avcodec.h:1695
int err_recognition
Error recognition; may misdetect some more or less valid parts as errors.
Definition: avcodec.h:1344
float i_quant_offset
qscale offset between P and I-frames
Definition: avcodec.h:701
int slices
Number of slices.
Definition: avcodec.h:989
This struct describes the properties of a single codec described by an AVCodecID.
Definition: codec_desc.h:38
This struct describes the properties of an encoded stream.
Definition: codec_par.h:53
int duration
Duration of the current frame.
Definition: avcodec.h:2903
int dts_ref_dts_delta
Offset of the current timestamp against last timestamp sync point in units of AVCodecContext....
Definition: avcodec.h:2865
int64_t cur_frame_end[AV_PARSER_PTS_NB]
Definition: avcodec.h:2830
int width
Dimensions of the decoded video intended for presentation.
Definition: avcodec.h:2928
enum AVFieldOrder field_order
Definition: avcodec.h:2905
const struct AVCodecParser * parser
Definition: avcodec.h:2791
int64_t pos
Byte position of currently parsed frame in stream.
Definition: avcodec.h:2891
int format
The format of the coded data, corresponds to enum AVPixelFormat for video and for enum AVSampleFormat...
Definition: avcodec.h:2945
int repeat_pict
This field is used for proper frame duration computation in lavf.
Definition: avcodec.h:2807
enum AVPictureStructure picture_structure
Indicate whether a picture is coded as a frame, top field or bottom field.
Definition: avcodec.h:2915
int64_t cur_frame_dts[AV_PARSER_PTS_NB]
Definition: avcodec.h:2820
int64_t cur_frame_pos[AV_PARSER_PTS_NB]
Position of the packet in file.
Definition: avcodec.h:2886
int output_picture_number
Picture number incremented in presentation or output order.
Definition: avcodec.h:2923
int pts_dts_delta
Presentation delay of current frame in units of AVCodecContext.time_base.
Definition: avcodec.h:2879
int64_t next_frame_offset
Definition: avcodec.h:2795
int64_t cur_frame_pts[AV_PARSER_PTS_NB]
Definition: avcodec.h:2819
int64_t cur_frame_offset[AV_PARSER_PTS_NB]
Definition: avcodec.h:2818
int key_frame
Set by parser to 1 for key frames and 0 for non-key frames.
Definition: avcodec.h:2838
int64_t frame_offset
Definition: avcodec.h:2792
int64_t last_pos
Previous frame byte position.
Definition: avcodec.h:2896
int coded_width
Dimensions of the coded video.
Definition: avcodec.h:2934
int64_t offset
byte offset from starting packet start
Definition: avcodec.h:2829
int dts_sync_point
Synchronization point for start of timestamp generation.
Definition: avcodec.h:2850
int priv_data_size
Definition: avcodec.h:2950
int codec_ids[7]
Definition: avcodec.h:2949
int(* split)(AVCodecContext *avctx, const uint8_t *buf, int buf_size)
Definition: avcodec.h:2959
void(* parser_close)(AVCodecParserContext *s)
Definition: avcodec.h:2958
int(* parser_parse)(AVCodecParserContext *s, AVCodecContext *avctx, const uint8_t **poutbuf, int *poutbuf_size, const uint8_t *buf, int buf_size)
Definition: avcodec.h:2954
int(* parser_init)(AVCodecParserContext *s)
Definition: avcodec.h:2951
AVCodec.
Definition: codec.h:196
This structure describes decoded (raw) audio or video data.
Definition: frame.h:325
int priv_data_size
Size of the private data to allocate in AVCodecInternal.hwaccel_priv_data.
Definition: avcodec.h:2199
int(* alloc_frame)(AVCodecContext *avctx, AVFrame *frame)
Allocate a custom buffer.
Definition: avcodec.h:2113
int(* uninit)(AVCodecContext *avctx)
Uninitialize the hwaccel private data.
Definition: avcodec.h:2193
enum AVCodecID id
Codec implemented by the hardware accelerator.
Definition: avcodec.h:2087
int(* start_frame)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size)
Called at the beginning of each frame or field picture.
Definition: avcodec.h:2129
int(* init)(AVCodecContext *avctx)
Initialize the hwaccel private data.
Definition: avcodec.h:2185
const char * name
Name of the hardware accelerated codec.
Definition: avcodec.h:2073
int capabilities
Hardware accelerated codec capabilities.
Definition: avcodec.h:2100
int(* decode_slice)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size)
Callback for each slice.
Definition: avcodec.h:2156
int(* frame_params)(AVCodecContext *avctx, AVBufferRef *hw_frames_ctx)
Fill the given hw_frames context with current codec parameters.
Definition: avcodec.h:2214
int(* decode_params)(AVCodecContext *avctx, int type, const uint8_t *buf, uint32_t buf_size)
Callback for parameter data (SPS/PPS/VPS etc).
Definition: avcodec.h:2143
enum AVPixelFormat pix_fmt
Supported pixel format.
Definition: avcodec.h:2094
int caps_internal
Internal hwaccel capabilities.
Definition: avcodec.h:2204
int(* end_frame)(AVCodecContext *avctx)
Called at the end of each frame or field picture.
Definition: avcodec.h:2167
int frame_priv_data_size
Size of per-frame hardware accelerator private data.
Definition: avcodec.h:2176
enum AVMediaType type
Type of codec implemented by the hardware accelerator.
Definition: avcodec.h:2080
This structure stores compressed data.
Definition: packet.h:351
Rational number (pair of numerator and denominator).
Definition: rational.h:58
int x
top left corner of pict, undefined when pict is not set
Definition: avcodec.h:2278
char * ass
0 terminated ASS/SSA compatible event line.
Definition: avcodec.h:2300
int w
width of pict, undefined when pict is not set
Definition: avcodec.h:2280
int nb_colors
number of colors in pict, undefined when pict is not set
Definition: avcodec.h:2282
char * text
0 terminated plain UTF-8 text
Definition: avcodec.h:2293
uint8_t * data[4]
data+linesize for the bitmap of this subtitle.
Definition: avcodec.h:2288
int y
top left corner of pict, undefined when pict is not set
Definition: avcodec.h:2279
enum AVSubtitleType type
Definition: avcodec.h:2291
int linesize[4]
Definition: avcodec.h:2289
int h
height of pict, undefined when pict is not set
Definition: avcodec.h:2281
uint16_t format
Definition: avcodec.h:2306
uint32_t start_display_time
Definition: avcodec.h:2307
uint32_t end_display_time
Definition: avcodec.h:2308
unsigned num_rects
Definition: avcodec.h:2309
AVSubtitleRect ** rects
Definition: avcodec.h:2310
int64_t pts
Same as packet pts, in AV_TIME_BASE.
Definition: avcodec.h:2311
int qscale
Definition: avcodec.h:199
int start_frame
Definition: avcodec.h:197
int end_frame
Definition: avcodec.h:198
float quality_factor
Definition: avcodec.h:200
static int64_t pts