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/channel_layout.h"
35#include "libavutil/dict.h"
36#include "libavutil/frame.h"
37#include "libavutil/log.h"
38#include "libavutil/pixfmt.h"
39#include "libavutil/rational.h"
40
41#include "codec.h"
42#include "codec_id.h"
43#include "defs.h"
44#include "packet.h"
45#include "version_major.h"
46#ifndef HAVE_AV_CONFIG_H
47/* When included as part of the ffmpeg build, only include the major version
48 * to avoid unnecessary rebuilds. When included externally, keep including
49 * the full version information. */
50#include "version.h"
51
52#include "codec_desc.h"
53#include "codec_par.h"
54#endif
55
56struct AVCodecParameters;
57
58/**
59 * @defgroup libavc libavcodec
60 * Encoding/Decoding Library
61 *
62 * @{
63 *
64 * @defgroup lavc_decoding Decoding
65 * @{
66 * @}
67 *
68 * @defgroup lavc_encoding Encoding
69 * @{
70 * @}
71 *
72 * @defgroup lavc_codec Codecs
73 * @{
74 * @defgroup lavc_codec_native Native Codecs
75 * @{
76 * @}
77 * @defgroup lavc_codec_wrappers External library wrappers
78 * @{
79 * @}
80 * @defgroup lavc_codec_hwaccel Hardware Accelerators bridge
81 * @{
82 * @}
83 * @}
84 * @defgroup lavc_internal Internal
85 * @{
86 * @}
87 * @}
88 */
89
90/**
91 * @ingroup libavc
92 * @defgroup lavc_encdec send/receive encoding and decoding API overview
93 * @{
94 *
95 * The avcodec_send_packet()/avcodec_receive_frame()/avcodec_send_frame()/
96 * avcodec_receive_packet() functions provide an encode/decode API, which
97 * decouples input and output.
98 *
99 * The API is very similar for encoding/decoding and audio/video, and works as
100 * follows:
101 * - Set up and open the AVCodecContext as usual.
102 * - Send valid input:
103 * - For decoding, call avcodec_send_packet() to give the decoder raw
104 * compressed data in an AVPacket.
105 * - For encoding, call avcodec_send_frame() to give the encoder an AVFrame
106 * containing uncompressed audio or video.
107 *
108 * In both cases, it is recommended that AVPackets and AVFrames are
109 * refcounted, or libavcodec might have to copy the input data. (libavformat
110 * always returns refcounted AVPackets, and av_frame_get_buffer() allocates
111 * refcounted AVFrames.)
112 * - Receive output in a loop. Periodically call one of the avcodec_receive_*()
113 * functions and process their output:
114 * - For decoding, call avcodec_receive_frame(). On success, it will return
115 * an AVFrame containing uncompressed audio or video data.
116 * - For encoding, call avcodec_receive_packet(). On success, it will return
117 * an AVPacket with a compressed frame.
118 *
119 * Repeat this call until it returns AVERROR(EAGAIN) or an error. The
120 * AVERROR(EAGAIN) return value means that new input data is required to
121 * return new output. In this case, continue with sending input. For each
122 * input frame/packet, the codec will typically return 1 output frame/packet,
123 * but it can also be 0 or more than 1.
124 *
125 * At the beginning of decoding or encoding, the codec might accept multiple
126 * input frames/packets without returning a frame, until its internal buffers
127 * are filled. This situation is handled transparently if you follow the steps
128 * outlined above.
129 *
130 * In theory, sending input can result in EAGAIN - this should happen only if
131 * not all output was received. You can use this to structure alternative decode
132 * or encode loops other than the one suggested above. For example, you could
133 * try sending new input on each iteration, and try to receive output if that
134 * returns EAGAIN.
135 *
136 * End of stream situations. These require "flushing" (aka draining) the codec,
137 * as the codec might buffer multiple frames or packets internally for
138 * performance or out of necessity (consider B-frames).
139 * This is handled as follows:
140 * - Instead of valid input, send NULL to the avcodec_send_packet() (decoding)
141 * or avcodec_send_frame() (encoding) functions. This will enter draining
142 * mode.
143 * - Call avcodec_receive_frame() (decoding) or avcodec_receive_packet()
144 * (encoding) in a loop until AVERROR_EOF is returned. The functions will
145 * not return AVERROR(EAGAIN), unless you forgot to enter draining mode.
146 * - Before decoding can be resumed again, the codec has to be reset with
147 * avcodec_flush_buffers().
148 *
149 * Using the API as outlined above is highly recommended. But it is also
150 * possible to call functions outside of this rigid schema. For example, you can
151 * call avcodec_send_packet() repeatedly without calling
152 * avcodec_receive_frame(). In this case, avcodec_send_packet() will succeed
153 * until the codec's internal buffer has been filled up (which is typically of
154 * size 1 per output frame, after initial input), and then reject input with
155 * AVERROR(EAGAIN). Once it starts rejecting input, you have no choice but to
156 * read at least some output.
157 *
158 * Not all codecs will follow a rigid and predictable dataflow; the only
159 * guarantee is that an AVERROR(EAGAIN) return value on a send/receive call on
160 * one end implies that a receive/send call on the other end will succeed, or
161 * at least will not fail with AVERROR(EAGAIN). In general, no codec will
162 * permit unlimited buffering of input or output.
163 *
164 * A codec is not allowed to return AVERROR(EAGAIN) for both sending and receiving. This
165 * would be an invalid state, which could put the codec user into an endless
166 * loop. The API has no concept of time either: it cannot happen that trying to
167 * do avcodec_send_packet() results in AVERROR(EAGAIN), but a repeated call 1 second
168 * later accepts the packet (with no other receive/flush API calls involved).
169 * The API is a strict state machine, and the passage of time is not supposed
170 * to influence it. Some timing-dependent behavior might still be deemed
171 * acceptable in certain cases. But it must never result in both send/receive
172 * returning EAGAIN at the same time at any point. It must also absolutely be
173 * avoided that the current state is "unstable" and can "flip-flop" between
174 * the send/receive APIs allowing progress. For example, it's not allowed that
175 * the codec randomly decides that it actually wants to consume a packet now
176 * instead of returning a frame, after it just returned AVERROR(EAGAIN) on an
177 * avcodec_send_packet() call.
178 * @}
179 */
180
181/**
182 * @defgroup lavc_core Core functions/structures.
183 * @ingroup libavc
184 *
185 * Basic definitions, functions for querying libavcodec capabilities,
186 * allocating core structures, etc.
187 * @{
188 */
189
190/**
191 * @ingroup lavc_encoding
192 */
193typedef struct RcOverride{
194 int start_frame;
195 int end_frame;
196 int qscale; // If this is 0 then quality_factor will be used instead.
197 float quality_factor;
198} RcOverride;
199
200/* encoding support
201 These flags can be passed in AVCodecContext.flags before initialization.
202 Note: Not everything is supported yet.
203*/
204
205/**
206 * Allow decoders to produce frames with data planes that are not aligned
207 * to CPU requirements (e.g. due to cropping).
208 */
209#define AV_CODEC_FLAG_UNALIGNED (1 << 0)
210/**
211 * Use fixed qscale.
212 */
213#define AV_CODEC_FLAG_QSCALE (1 << 1)
214/**
215 * 4 MV per MB allowed / advanced prediction for H.263.
216 */
217#define AV_CODEC_FLAG_4MV (1 << 2)
218/**
219 * Output even those frames that might be corrupted.
220 */
221#define AV_CODEC_FLAG_OUTPUT_CORRUPT (1 << 3)
222/**
223 * Use qpel MC.
224 */
225#define AV_CODEC_FLAG_QPEL (1 << 4)
226/**
227 * Request the encoder to output reconstructed frames, i.e.\ frames that would
228 * be produced by decoding the encoded bitstream. These frames may be retrieved
229 * by calling avcodec_receive_frame() immediately after a successful call to
230 * avcodec_receive_packet().
231 *
232 * Should only be used with encoders flagged with the
233 * @ref AV_CODEC_CAP_ENCODER_RECON_FRAME capability.
234 *
235 * @note
236 * Each reconstructed frame returned by the encoder corresponds to the last
237 * encoded packet, i.e. the frames are returned in coded order rather than
238 * presentation order.
239 *
240 * @note
241 * Frame parameters (like pixel format or dimensions) do not have to match the
242 * AVCodecContext values. Make sure to use the values from the returned frame.
243 */
244#define AV_CODEC_FLAG_RECON_FRAME (1 << 6)
245/**
246 * @par decoding
247 * Request the decoder to propagate each packet's AVPacket.opaque and
248 * AVPacket.opaque_ref to its corresponding output AVFrame.
249 *
250 * @par encoding:
251 * Request the encoder to propagate each frame's AVFrame.opaque and
252 * AVFrame.opaque_ref values to its corresponding output AVPacket.
253 *
254 * @par
255 * May only be set on encoders that have the
256 * @ref AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE capability flag.
257 *
258 * @note
259 * While in typical cases one input frame produces exactly one output packet
260 * (perhaps after a delay), in general the mapping of frames to packets is
261 * M-to-N, so
262 * - Any number of input frames may be associated with any given output packet.
263 * This includes zero - e.g. some encoders may output packets that carry only
264 * metadata about the whole stream.
265 * - A given input frame may be associated with any number of output packets.
266 * Again this includes zero - e.g. some encoders may drop frames under certain
267 * conditions.
268 * .
269 * This implies that when using this flag, the caller must NOT assume that
270 * - a given input frame's opaques will necessarily appear on some output packet;
271 * - every output packet will have some non-NULL opaque value.
272 * .
273 * When an output packet contains multiple frames, the opaque values will be
274 * taken from the first of those.
275 *
276 * @note
277 * The converse holds for decoders, with frames and packets switched.
278 */
279#define AV_CODEC_FLAG_COPY_OPAQUE (1 << 7)
280/**
281 * Signal to the encoder that the values of AVFrame.duration are valid and
282 * should be used (typically for transferring them to output packets).
283 *
284 * If this flag is not set, frame durations are ignored.
285 */
286#define AV_CODEC_FLAG_FRAME_DURATION (1 << 8)
287/**
288 * Use internal 2pass ratecontrol in first pass mode.
289 */
290#define AV_CODEC_FLAG_PASS1 (1 << 9)
291/**
292 * Use internal 2pass ratecontrol in second pass mode.
293 */
294#define AV_CODEC_FLAG_PASS2 (1 << 10)
295/**
296 * loop filter.
297 */
298#define AV_CODEC_FLAG_LOOP_FILTER (1 << 11)
299/**
300 * Only decode/encode grayscale.
301 */
302#define AV_CODEC_FLAG_GRAY (1 << 13)
303/**
304 * error[?] variables will be set during encoding.
305 */
306#define AV_CODEC_FLAG_PSNR (1 << 15)
307/**
308 * Use interlaced DCT.
309 */
310#define AV_CODEC_FLAG_INTERLACED_DCT (1 << 18)
311/**
312 * Force low delay.
313 */
314#define AV_CODEC_FLAG_LOW_DELAY (1 << 19)
315/**
316 * Place global headers in extradata instead of every keyframe.
317 */
318#define AV_CODEC_FLAG_GLOBAL_HEADER (1 << 22)
319/**
320 * Use only bitexact stuff (except (I)DCT).
321 */
322#define AV_CODEC_FLAG_BITEXACT (1 << 23)
323/* Fx : Flag for H.263+ extra options */
324/**
325 * H.263 advanced intra coding / MPEG-4 AC prediction
326 */
327#define AV_CODEC_FLAG_AC_PRED (1 << 24)
328/**
329 * interlaced motion estimation
330 */
331#define AV_CODEC_FLAG_INTERLACED_ME (1 << 29)
332#define AV_CODEC_FLAG_CLOSED_GOP (1U << 31)
333
334/**
335 * Allow non spec compliant speedup tricks.
336 */
337#define AV_CODEC_FLAG2_FAST (1 << 0)
338/**
339 * Skip bitstream encoding.
340 */
341#define AV_CODEC_FLAG2_NO_OUTPUT (1 << 2)
342/**
343 * Place global headers at every keyframe instead of in extradata.
344 */
345#define AV_CODEC_FLAG2_LOCAL_HEADER (1 << 3)
346
347/**
348 * Input bitstream might be truncated at a packet boundaries
349 * instead of only at frame boundaries.
350 */
351#define AV_CODEC_FLAG2_CHUNKS (1 << 15)
352/**
353 * Discard cropping information from SPS.
354 */
355#define AV_CODEC_FLAG2_IGNORE_CROP (1 << 16)
356
357/**
358 * Show all frames before the first keyframe
359 */
360#define AV_CODEC_FLAG2_SHOW_ALL (1 << 22)
361/**
362 * Export motion vectors through frame side data
363 */
364#define AV_CODEC_FLAG2_EXPORT_MVS (1 << 28)
365/**
366 * Do not skip samples and export skip information as frame side data
367 */
368#define AV_CODEC_FLAG2_SKIP_MANUAL (1 << 29)
369/**
370 * Do not reset ASS ReadOrder field on flush (subtitles decoding)
371 */
372#define AV_CODEC_FLAG2_RO_FLUSH_NOOP (1 << 30)
373/**
374 * Generate/parse ICC profiles on encode/decode, as appropriate for the type of
375 * file. No effect on codecs which cannot contain embedded ICC profiles, or
376 * when compiled without support for lcms2.
377 */
378#define AV_CODEC_FLAG2_ICC_PROFILES (1U << 31)
379
380/* Exported side data.
381 These flags can be passed in AVCodecContext.export_side_data before initialization.
382*/
383/**
384 * Export motion vectors through frame side data
385 */
386#define AV_CODEC_EXPORT_DATA_MVS (1 << 0)
387/**
388 * Export encoder Producer Reference Time through packet side data
389 */
390#define AV_CODEC_EXPORT_DATA_PRFT (1 << 1)
391/**
392 * Decoding only.
393 * Export the AVVideoEncParams structure through frame side data.
394 */
395#define AV_CODEC_EXPORT_DATA_VIDEO_ENC_PARAMS (1 << 2)
396/**
397 * Decoding only.
398 * Do not apply film grain, export it instead.
399 */
400#define AV_CODEC_EXPORT_DATA_FILM_GRAIN (1 << 3)
401
402/**
403 * Decoding only.
404 * Do not apply picture enhancement layers, export them instead.
405 */
406#define AV_CODEC_EXPORT_DATA_ENHANCEMENTS (1 << 4)
407
408/**
409 * The decoder will keep a reference to the frame and may reuse it later.
410 */
411#define AV_GET_BUFFER_FLAG_REF (1 << 0)
412
413/**
414 * The encoder will keep a reference to the packet and may reuse it later.
415 */
416#define AV_GET_ENCODE_BUFFER_FLAG_REF (1 << 0)
417
418/**
419 * The decoder will bypass frame threading and return the next frame as soon as
420 * possible. Note that this may deliver frames earlier than the advertised
421 * `AVCodecContext.delay`. No effect when frame threading is disabled, or on
422 * encoding.
423 */
424#define AV_CODEC_RECEIVE_FRAME_FLAG_SYNCHRONOUS (1 << 0)
425
426/**
427 * main external API structure.
428 * New fields can be added to the end with minor version bumps.
429 * Removal, reordering and changes to existing fields require a major
430 * version bump.
431 * You can use AVOptions (av_opt* / av_set/get*()) to access these fields from user
432 * applications.
433 * The name string for AVOptions options matches the associated command line
434 * parameter name and can be found in libavcodec/options_table.h
435 * The AVOption/command line parameter names differ in some cases from the C
436 * structure field names for historic reasons or brevity.
437 * sizeof(AVCodecContext) must not be used outside libav*.
438 */
439typedef struct AVCodecContext {
440 /**
441 * information on struct for av_log
442 * - set by avcodec_alloc_context3
443 */
444 const AVClass *av_class;
445 int log_level_offset;
446
447 enum AVMediaType codec_type; /* see AVMEDIA_TYPE_xxx */
448 const struct AVCodec *codec;
449 enum AVCodecID codec_id; /* see AV_CODEC_ID_xxx */
450
451 /**
452 * fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
453 * This is used to work around some encoder bugs.
454 * A demuxer should set this to what is stored in the field used to identify the codec.
455 * If there are multiple such fields in a container then the demuxer should choose the one
456 * which maximizes the information about the used codec.
457 * If the codec tag field in a container is larger than 32 bits then the demuxer should
458 * remap the longer ID to 32 bits with a table or other structure. Alternatively a new
459 * extra_codec_tag + size could be added but for this a clear advantage must be demonstrated
460 * first.
461 * - encoding: Set by user, if not then the default based on codec_id will be used.
462 * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
463 */
464 unsigned int codec_tag;
465
466 void *priv_data;
467
468 /**
469 * Private context used for internal data.
470 *
471 * Unlike priv_data, this is not codec-specific. It is used in general
472 * libavcodec functions.
473 */
474 struct AVCodecInternal *internal;
475
476 /**
477 * Private data of the user, can be used to carry app specific stuff.
478 * - encoding: Set by user.
479 * - decoding: Set by user.
480 */
481 void *opaque;
482
483 /**
484 * the average bitrate
485 * - encoding: Set by user; unused for constant quantizer encoding.
486 * - decoding: Set by user, may be overwritten by libavcodec
487 * if this info is available in the stream
488 */
489 int64_t bit_rate;
490
491 /**
492 * AV_CODEC_FLAG_*.
493 * - encoding: Set by user.
494 * - decoding: Set by user.
495 */
496 int flags;
497
498 /**
499 * AV_CODEC_FLAG2_*
500 * - encoding: Set by user.
501 * - decoding: Set by user.
502 */
503 int flags2;
504
505 /**
506 * Out-of-band global headers that may be used by some codecs.
507 *
508 * - decoding: Should be set by the caller when available (typically from a
509 * demuxer) before opening the decoder; some decoders require this to be
510 * set and will fail to initialize otherwise.
511 *
512 * The array must be allocated with the av_malloc() family of functions;
513 * allocated size must be at least AV_INPUT_BUFFER_PADDING_SIZE bytes
514 * larger than extradata_size.
515 *
516 * - encoding: May be set by the encoder in avcodec_open2() (possibly
517 * depending on whether the AV_CODEC_FLAG_GLOBAL_HEADER flag is set).
518 *
519 * After being set, the array is owned by the codec and freed in
520 * avcodec_free_context().
521 */
522 uint8_t *extradata;
523 int extradata_size;
524
525 /**
526 * This is the fundamental unit of time (in seconds) in terms
527 * of which frame timestamps are represented. For fixed-fps content,
528 * timebase should be 1/framerate and timestamp increments should be
529 * identically 1.
530 * This often, but not always is the inverse of the frame rate or field rate
531 * for video. 1/time_base is not the average frame rate if the frame rate is not
532 * constant.
533 *
534 * Like containers, elementary streams also can store timestamps, 1/time_base
535 * is the unit in which these timestamps are specified.
536 * As example of such codec time base see ISO/IEC 14496-2:2001(E)
537 * vop_time_increment_resolution and fixed_vop_rate
538 * (fixed_vop_rate == 0 implies that it is different from the framerate)
539 *
540 * - encoding: MUST be set by user.
541 * - decoding: unused.
542 */
543 AVRational time_base;
544
545 /**
546 * Timebase in which pkt_dts/pts and AVPacket.dts/pts are expressed.
547 * - encoding: unused.
548 * - decoding: set by user.
549 */
550 AVRational pkt_timebase;
551
552 /**
553 * - decoding: For codecs that store a framerate value in the compressed
554 * bitstream, the decoder may export it here. { 0, 1} when
555 * unknown.
556 * - encoding: May be used to signal the framerate of CFR content to an
557 * encoder.
558 */
559 AVRational framerate;
560
561 /**
562 * Codec delay.
563 *
564 * Encoding: Number of frames delay there will be from the encoder input to
565 * the decoder output. (we assume the decoder matches the spec)
566 * Decoding: Number of frames delay in addition to what a standard decoder
567 * as specified in the spec would produce.
568 *
569 * Video:
570 * Number of frames the decoded output will be delayed relative to the
571 * encoded input.
572 *
573 * Audio:
574 * For encoding, this field is unused (see initial_padding).
575 *
576 * For decoding, this is the number of samples the decoder needs to
577 * output before the decoder's output is valid. When seeking, you should
578 * start decoding this many samples prior to your desired seek point.
579 *
580 * - encoding: Set by libavcodec.
581 * - decoding: Set by libavcodec.
582 */
583 int delay;
584
585
586 /* video only */
587 /**
588 * picture width / height.
589 *
590 * @note Those fields may not match the values of the last
591 * AVFrame output by avcodec_receive_frame() due frame
592 * reordering.
593 *
594 * - encoding: MUST be set by user.
595 * - decoding: May be set by the user before opening the decoder if known e.g.
596 * from the container. Some decoders will require the dimensions
597 * to be set by the caller. During decoding, the decoder may
598 * overwrite those values as required while parsing the data.
599 */
600 int width, height;
601
602 /**
603 * Bitstream width / height, may be different from width/height e.g. when
604 * the decoded frame is cropped before being output or lowres is enabled.
605 *
606 * @note Those field may not match the value of the last
607 * AVFrame output by avcodec_receive_frame() due frame
608 * reordering.
609 *
610 * - encoding: unused
611 * - decoding: May be set by the user before opening the decoder if known
612 * e.g. from the container. During decoding, the decoder may
613 * overwrite those values as required while parsing the data.
614 */
615 int coded_width, coded_height;
616
617 /**
618 * sample aspect ratio (0 if unknown)
619 * That is the width of a pixel divided by the height of the pixel.
620 * Numerator and denominator must be relatively prime and smaller than 256 for some video standards.
621 * - encoding: Set by user.
622 * - decoding: Set by libavcodec.
623 */
624 AVRational sample_aspect_ratio;
625
626 /**
627 * Pixel format, see AV_PIX_FMT_xxx.
628 * May be set by the demuxer if known from headers.
629 * May be overridden by the decoder if it knows better.
630 *
631 * @note This field may not match the value of the last
632 * AVFrame output by avcodec_receive_frame() due frame
633 * reordering.
634 *
635 * - encoding: Set by user.
636 * - decoding: Set by user if known, overridden by libavcodec while
637 * parsing the data.
638 */
639 enum AVPixelFormat pix_fmt;
640
641 /**
642 * Nominal unaccelerated pixel format, see AV_PIX_FMT_xxx.
643 * - encoding: unused.
644 * - decoding: Set by libavcodec before calling get_format()
645 */
646 enum AVPixelFormat sw_pix_fmt;
647
648 /**
649 * Chromaticity coordinates of the source primaries.
650 * - encoding: Set by user
651 * - decoding: Set by libavcodec
652 */
653 enum AVColorPrimaries color_primaries;
654
655 /**
656 * Color Transfer Characteristic.
657 * - encoding: Set by user
658 * - decoding: Set by libavcodec
659 */
660 enum AVColorTransferCharacteristic color_trc;
661
662 /**
663 * YUV colorspace type.
664 * - encoding: Set by user
665 * - decoding: Set by libavcodec
666 */
667 enum AVColorSpace colorspace;
668
669 /**
670 * MPEG vs JPEG YUV range.
671 * - encoding: Set by user to override the default output color range value,
672 * If not specified, libavcodec sets the color range depending on the
673 * output format.
674 * - decoding: Set by libavcodec, can be set by the user to propagate the
675 * color range to components reading from the decoder context.
676 */
677 enum AVColorRange color_range;
678
679 /**
680 * This defines the location of chroma samples.
681 * - encoding: Set by user
682 * - decoding: Set by libavcodec
683 */
684 enum AVChromaLocation chroma_sample_location;
685
686 /** Field order
687 * - encoding: set by libavcodec
688 * - decoding: Set by user.
689 */
690 enum AVFieldOrder field_order;
691
692 /**
693 * number of reference frames
694 * - encoding: Set by user.
695 * - decoding: Set by lavc.
696 */
697 int refs;
698
699 /**
700 * Size of the frame reordering buffer in the decoder.
701 * For MPEG-2 it is 1 IPB or 0 low delay IP.
702 * - encoding: Set by libavcodec.
703 * - decoding: Set by libavcodec.
704 */
705 int has_b_frames;
706
707 /**
708 * slice flags
709 * - encoding: unused
710 * - decoding: Set by user.
711 */
712 int slice_flags;
713#define SLICE_FLAG_CODED_ORDER 0x0001 ///< draw_horiz_band() is called in coded order instead of display
714#define SLICE_FLAG_ALLOW_FIELD 0x0002 ///< allow draw_horiz_band() with field slices (MPEG-2 field pics)
715#define SLICE_FLAG_ALLOW_PLANE 0x0004 ///< allow draw_horiz_band() with 1 component at a time (SVQ1)
716
717 /**
718 * If non NULL, 'draw_horiz_band' is called by the libavcodec
719 * decoder to draw a horizontal band. It improves cache usage. Not
720 * all codecs can do that. You must check the codec capabilities
721 * beforehand.
722 * When multithreading is used, it may be called from multiple threads
723 * at the same time; threads might draw different parts of the same AVFrame,
724 * or multiple AVFrames, and there is no guarantee that slices will be drawn
725 * in order.
726 * The function is also used by hardware acceleration APIs.
727 * It is called at least once during frame decoding to pass
728 * the data needed for hardware render.
729 * In that mode instead of pixel data, AVFrame points to
730 * a structure specific to the acceleration API. The application
731 * reads the structure and can change some fields to indicate progress
732 * or mark state.
733 * - encoding: unused
734 * - decoding: Set by user.
735 * @param height the height of the slice
736 * @param y the y position of the slice
737 * @param type 1->top field, 2->bottom field, 3->frame
738 * @param offset offset into the AVFrame.data from which the slice should be read
739 */
740 void (*draw_horiz_band)(struct AVCodecContext *s,
741 const AVFrame *src, int offset[AV_NUM_DATA_POINTERS],
742 int y, int type, int height);
743
744 /**
745 * Callback to negotiate the pixel format. Decoding only, may be set by the
746 * caller before avcodec_open2().
747 *
748 * Called by some decoders to select the pixel format that will be used for
749 * the output frames. This is mainly used to set up hardware acceleration,
750 * then the provided format list contains the corresponding hwaccel pixel
751 * formats alongside the "software" one. The software pixel format may also
752 * be retrieved from \ref sw_pix_fmt.
753 *
754 * This callback will be called when the coded frame properties (such as
755 * resolution, pixel format, etc.) change and more than one output format is
756 * supported for those new properties. If a hardware pixel format is chosen
757 * and initialization for it fails, the callback may be called again
758 * immediately.
759 *
760 * This callback may be called from different threads if the decoder is
761 * multi-threaded, but not from more than one thread simultaneously.
762 *
763 * @param fmt list of formats which may be used in the current
764 * configuration, terminated by AV_PIX_FMT_NONE.
765 * @warning Behavior is undefined if the callback returns a value other
766 * than one of the formats in fmt or AV_PIX_FMT_NONE.
767 * @return the chosen format or AV_PIX_FMT_NONE
768 */
769 enum AVPixelFormat (*get_format)(struct AVCodecContext *s, const enum AVPixelFormat * fmt);
770
771 /**
772 * maximum number of B-frames between non-B-frames
773 * Note: The output will be delayed by max_b_frames+1 relative to the input.
774 * - encoding: Set by user.
775 * - decoding: unused
776 */
777 int max_b_frames;
778
779 /**
780 * qscale factor between IP and B-frames
781 * If > 0 then the last P-frame quantizer will be used (q= lastp_q*factor+offset).
782 * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
783 * - encoding: Set by user.
784 * - decoding: unused
785 */
786 float b_quant_factor;
787
788 /**
789 * qscale offset between IP and B-frames
790 * - encoding: Set by user.
791 * - decoding: unused
792 */
793 float b_quant_offset;
794
795 /**
796 * qscale factor between P- and I-frames
797 * If > 0 then the last P-frame quantizer will be used (q = lastp_q * factor + offset).
798 * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
799 * - encoding: Set by user.
800 * - decoding: unused
801 */
802 float i_quant_factor;
803
804 /**
805 * qscale offset between P and I-frames
806 * - encoding: Set by user.
807 * - decoding: unused
808 */
809 float i_quant_offset;
810
811 /**
812 * luminance masking (0-> disabled)
813 * - encoding: Set by user.
814 * - decoding: unused
815 */
816 float lumi_masking;
817
818 /**
819 * temporary complexity masking (0-> disabled)
820 * - encoding: Set by user.
821 * - decoding: unused
822 */
823 float temporal_cplx_masking;
824
825 /**
826 * spatial complexity masking (0-> disabled)
827 * - encoding: Set by user.
828 * - decoding: unused
829 */
830 float spatial_cplx_masking;
831
832 /**
833 * p block masking (0-> disabled)
834 * - encoding: Set by user.
835 * - decoding: unused
836 */
837 float p_masking;
838
839 /**
840 * darkness masking (0-> disabled)
841 * - encoding: Set by user.
842 * - decoding: unused
843 */
844 float dark_masking;
845
846 /**
847 * noise vs. sse weight for the nsse comparison function
848 * - encoding: Set by user.
849 * - decoding: unused
850 */
851 int nsse_weight;
852
853 /**
854 * motion estimation comparison function
855 * - encoding: Set by user.
856 * - decoding: unused
857 */
858 int me_cmp;
859 /**
860 * subpixel motion estimation comparison function
861 * - encoding: Set by user.
862 * - decoding: unused
863 */
864 int me_sub_cmp;
865 /**
866 * macroblock comparison function (not supported yet)
867 * - encoding: Set by user.
868 * - decoding: unused
869 */
870 int mb_cmp;
871 /**
872 * interlaced DCT comparison function
873 * - encoding: Set by user.
874 * - decoding: unused
875 */
876 int ildct_cmp;
877#define FF_CMP_SAD 0
878#define FF_CMP_SSE 1
879#define FF_CMP_SATD 2
880#define FF_CMP_DCT 3
881#define FF_CMP_PSNR 4
882#define FF_CMP_BIT 5
883#define FF_CMP_RD 6
884#define FF_CMP_ZERO 7
885#define FF_CMP_VSAD 8
886#define FF_CMP_VSSE 9
887#define FF_CMP_NSSE 10
888#define FF_CMP_W53 11
889#define FF_CMP_W97 12
890#define FF_CMP_DCTMAX 13
891#define FF_CMP_DCT264 14
892#define FF_CMP_MEDIAN_SAD 15
893#define FF_CMP_CHROMA 256
894
895 /**
896 * ME diamond size & shape
897 * - encoding: Set by user.
898 * - decoding: unused
899 */
900 int dia_size;
901
902 /**
903 * amount of previous MV predictors (2a+1 x 2a+1 square)
904 * - encoding: Set by user.
905 * - decoding: unused
906 */
907 int last_predictor_count;
908
909 /**
910 * motion estimation prepass comparison function
911 * - encoding: Set by user.
912 * - decoding: unused
913 */
914 int me_pre_cmp;
915
916 /**
917 * ME prepass diamond size & shape
918 * - encoding: Set by user.
919 * - decoding: unused
920 */
921 int pre_dia_size;
922
923 /**
924 * subpel ME quality
925 * - encoding: Set by user.
926 * - decoding: unused
927 */
928 int me_subpel_quality;
929
930 /**
931 * maximum motion estimation search range in subpel units
932 * If 0 then no limit.
933 *
934 * - encoding: Set by user.
935 * - decoding: unused
936 */
937 int me_range;
938
939 /**
940 * macroblock decision mode
941 * - encoding: Set by user.
942 * - decoding: unused
943 */
944 int mb_decision;
945#define FF_MB_DECISION_SIMPLE 0 ///< uses mb_cmp
946#define FF_MB_DECISION_BITS 1 ///< chooses the one which needs the fewest bits
947#define FF_MB_DECISION_RD 2 ///< rate distortion
948
949 /**
950 * custom intra quantization matrix
951 * Must be allocated with the av_malloc() family of functions, and will be freed in
952 * avcodec_free_context().
953 * - encoding: Set/allocated by user, freed by libavcodec. Can be NULL.
954 * - decoding: Set/allocated/freed by libavcodec.
955 */
956 uint16_t *intra_matrix;
957
958 /**
959 * custom inter quantization matrix
960 * Must be allocated with the av_malloc() family of functions, and will be freed in
961 * avcodec_free_context().
962 * - encoding: Set/allocated by user, freed by libavcodec. Can be NULL.
963 * - decoding: Set/allocated/freed by libavcodec.
964 */
965 uint16_t *inter_matrix;
966
967 /**
968 * custom intra quantization matrix
969 * - encoding: Set by user, can be NULL.
970 * - decoding: unused.
971 */
972 uint16_t *chroma_intra_matrix;
973
974#if FF_API_INTRA_DC_PRECISION
975 /**
976 * precision of the intra DC coefficient - 8
977 * - encoding: Set by user.
978 * - decoding: Set by libavcodec
979 * @deprecated Use the MPEG-2 encoder's private option "intra_dc_precision" instead.
980 */
981 attribute_deprecated
982 int intra_dc_precision;
983#endif
984
985 /**
986 * minimum MB Lagrange multiplier
987 * - encoding: Set by user.
988 * - decoding: unused
989 */
990 int mb_lmin;
991
992 /**
993 * maximum MB Lagrange multiplier
994 * - encoding: Set by user.
995 * - decoding: unused
996 */
997 int mb_lmax;
998
999 /**
1000 * - encoding: Set by user.
1001 * - decoding: unused
1002 */
1003 int bidir_refine;
1004
1005 /**
1006 * minimum GOP size
1007 * - encoding: Set by user.
1008 * - decoding: unused
1009 */
1010 int keyint_min;
1011
1012 /**
1013 * the number of pictures in a group of pictures, or 0 for intra_only
1014 * - encoding: Set by user.
1015 * - decoding: unused
1016 */
1017 int gop_size;
1018
1019 /**
1020 * Note: Value depends upon the compare function used for fullpel ME.
1021 * - encoding: Set by user.
1022 * - decoding: unused
1023 */
1024 int mv0_threshold;
1025
1026 /**
1027 * Number of slices.
1028 * Indicates number of picture subdivisions. Used for parallelized
1029 * decoding.
1030 * - encoding: Set by user
1031 * - decoding: unused
1032 */
1033 int slices;
1034
1035 /* audio only */
1036 int sample_rate; ///< samples per second
1037
1038 /**
1039 * audio sample format
1040 * - encoding: Set by user.
1041 * - decoding: Set by libavcodec.
1042 */
1043 enum AVSampleFormat sample_fmt; ///< sample format
1044
1045 /**
1046 * Audio channel layout.
1047 * - encoding: must be set by the caller, to one of AVCodec.ch_layouts.
1048 * - decoding: may be set by the caller if known e.g. from the container.
1049 * The decoder can then override during decoding as needed.
1050 */
1051 AVChannelLayout ch_layout;
1052
1053 /* The following data should not be initialized. */
1054 /**
1055 * Number of samples per channel in an audio frame.
1056 *
1057 * - encoding: set by libavcodec in avcodec_open2(). Each submitted frame
1058 * except the last must contain exactly frame_size samples per channel.
1059 * May be 0 when the codec has AV_CODEC_CAP_VARIABLE_FRAME_SIZE set, then the
1060 * frame size is not restricted.
1061 * - decoding: may be set by some decoders to indicate constant frame size
1062 */
1063 int frame_size;
1064
1065 /**
1066 * number of bytes per packet if constant and known or 0
1067 * Used by some WAV based audio codecs.
1068 */
1069 int block_align;
1070
1071 /**
1072 * Audio cutoff bandwidth (0 means "automatic")
1073 * - encoding: Set by user.
1074 * - decoding: unused
1075 */
1076 int cutoff;
1077
1078 /**
1079 * Type of service that the audio stream conveys.
1080 * - encoding: Set by user.
1081 * - decoding: Set by libavcodec.
1082 */
1083 enum AVAudioServiceType audio_service_type;
1084
1085 /**
1086 * desired sample format
1087 * - encoding: Not used.
1088 * - decoding: Set by user.
1089 * Decoder will decode to this format if it can.
1090 */
1091 enum AVSampleFormat request_sample_fmt;
1092
1093 /**
1094 * Audio only. The number of "priming" samples (padding) inserted by the
1095 * encoder at the beginning of the audio. I.e. this number of leading
1096 * decoded samples must be discarded by the caller to get the original audio
1097 * without leading padding.
1098 *
1099 * - decoding: unused
1100 * - encoding: Set by libavcodec. The timestamps on the output packets are
1101 * adjusted by the encoder so that they always refer to the
1102 * first sample of the data actually contained in the packet,
1103 * including any added padding. E.g. if the timebase is
1104 * 1/samplerate and the timestamp of the first input sample is
1105 * 0, the timestamp of the first output packet will be
1106 * -initial_padding.
1107 */
1108 int initial_padding;
1109
1110 /**
1111 * Audio only. The amount of padding (in samples) appended by the encoder to
1112 * the end of the audio. I.e. this number of decoded samples must be
1113 * discarded by the caller from the end of the stream to get the original
1114 * audio without any trailing padding.
1115 *
1116 * - decoding: unused
1117 * - encoding: unused
1118 */
1119 int trailing_padding;
1120
1121 /**
1122 * Number of samples to skip after a discontinuity
1123 * - decoding: unused
1124 * - encoding: set by libavcodec
1125 */
1126 int seek_preroll;
1127
1128 /**
1129 * This callback is called at the beginning of each frame to get data
1130 * buffer(s) for it. There may be one contiguous buffer for all the data or
1131 * there may be a buffer per each data plane or anything in between. What
1132 * this means is, you may set however many entries in buf[] you feel necessary.
1133 * Each buffer must be reference-counted using the AVBuffer API (see description
1134 * of buf[] below).
1135 *
1136 * The following fields will be set in the frame before this callback is
1137 * called:
1138 * - format
1139 * - width, height (video only)
1140 * - sample_rate, channel_layout, nb_samples (audio only)
1141 * Their values may differ from the corresponding values in
1142 * AVCodecContext. This callback must use the frame values, not the codec
1143 * context values, to calculate the required buffer size.
1144 *
1145 * This callback must fill the following fields in the frame:
1146 * - data[]
1147 * - linesize[]
1148 * - extended_data:
1149 * * if the data is planar audio with more than 8 channels, then this
1150 * callback must allocate and fill extended_data to contain all pointers
1151 * to all data planes. data[] must hold as many pointers as it can.
1152 * extended_data must be allocated with av_malloc() and will be freed in
1153 * av_frame_unref().
1154 * * otherwise extended_data must point to data
1155 * - buf[] must contain one or more pointers to AVBufferRef structures. Each of
1156 * the frame's data and extended_data pointers must be contained in these. That
1157 * is, one AVBufferRef for each allocated chunk of memory, not necessarily one
1158 * AVBufferRef per data[] entry. See: av_buffer_create(), av_buffer_alloc(),
1159 * and av_buffer_ref().
1160 * - extended_buf and nb_extended_buf must be allocated with av_malloc() by
1161 * this callback and filled with the extra buffers if there are more
1162 * buffers than buf[] can hold. extended_buf will be freed in
1163 * av_frame_unref().
1164 * Decoders will generally initialize the whole buffer before it is output
1165 * but it can in rare error conditions happen that uninitialized data is passed
1166 * through. \important The buffers returned by get_buffer* should thus not contain sensitive
1167 * data.
1168 *
1169 * If AV_CODEC_CAP_DR1 is not set then get_buffer2() must call
1170 * avcodec_default_get_buffer2() instead of providing buffers allocated by
1171 * some other means.
1172 *
1173 * Each data plane must be aligned to the maximum required by the target
1174 * CPU.
1175 *
1176 * @see avcodec_default_get_buffer2()
1177 *
1178 * Video:
1179 *
1180 * If AV_GET_BUFFER_FLAG_REF is set in flags then the frame may be reused
1181 * (read and/or written to if it is writable) later by libavcodec.
1182 *
1183 * avcodec_align_dimensions2() should be used to find the required width and
1184 * height, as they normally need to be rounded up to the next multiple of 16.
1185 *
1186 * Some decoders do not support linesizes changing between frames.
1187 *
1188 * If frame multithreading is used, this callback may be called from a
1189 * different thread, but not from more than one at once. Does not need to be
1190 * reentrant.
1191 *
1192 * @see avcodec_align_dimensions2()
1193 *
1194 * Audio:
1195 *
1196 * Decoders request a buffer of a particular size by setting
1197 * AVFrame.nb_samples prior to calling get_buffer2(). The decoder may,
1198 * however, utilize only part of the buffer by setting AVFrame.nb_samples
1199 * to a smaller value in the output frame.
1200 *
1201 * As a convenience, av_samples_get_buffer_size() and
1202 * av_samples_fill_arrays() in libavutil may be used by custom get_buffer2()
1203 * functions to find the required data size and to fill data pointers and
1204 * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
1205 * since all planes must be the same size.
1206 *
1207 * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
1208 *
1209 * - encoding: unused
1210 * - decoding: Set by libavcodec, user can override.
1211 */
1212 int (*get_buffer2)(struct AVCodecContext *s, AVFrame *frame, int flags);
1213
1214 /* - encoding parameters */
1215 /**
1216 * number of bits the bitstream is allowed to diverge from the reference.
1217 * the reference can be CBR (for CBR pass1) or VBR (for pass2)
1218 * - encoding: Set by user; unused for constant quantizer encoding.
1219 * - decoding: unused
1220 */
1221 int bit_rate_tolerance;
1222
1223 /**
1224 * Global quality for codecs which cannot change it per frame.
1225 * This should be proportional to MPEG-1/2/4 qscale.
1226 * - encoding: Set by user.
1227 * - decoding: unused
1228 */
1229 int global_quality;
1230
1231 /**
1232 * - encoding: Set by user.
1233 * - decoding: unused
1234 */
1235 int compression_level;
1236#define FF_COMPRESSION_DEFAULT -1
1237
1238 float qcompress; ///< amount of qscale change between easy & hard scenes (0.0-1.0)
1239 float qblur; ///< amount of qscale smoothing over time (0.0-1.0)
1240
1241 /**
1242 * minimum quantizer
1243 * - encoding: Set by user.
1244 * - decoding: unused
1245 */
1246 int qmin;
1247
1248 /**
1249 * maximum quantizer
1250 * - encoding: Set by user.
1251 * - decoding: unused
1252 */
1253 int qmax;
1254
1255 /**
1256 * maximum quantizer difference between frames
1257 * - encoding: Set by user.
1258 * - decoding: unused
1259 */
1260 int max_qdiff;
1261
1262 /**
1263 * decoder bitstream buffer size
1264 * - encoding: Set by user.
1265 * - decoding: May be set by libavcodec.
1266 */
1267 int rc_buffer_size;
1268
1269 /**
1270 * ratecontrol override, see RcOverride
1271 * - encoding: Allocated/set/freed by user.
1272 * - decoding: unused
1273 */
1274 int rc_override_count;
1275 RcOverride *rc_override;
1276
1277 /**
1278 * maximum bitrate
1279 * - encoding: Set by user.
1280 * - decoding: Set by user, may be overwritten by libavcodec.
1281 */
1282 int64_t rc_max_rate;
1283
1284 /**
1285 * minimum bitrate
1286 * - encoding: Set by user.
1287 * - decoding: unused
1288 */
1289 int64_t rc_min_rate;
1290
1291 /**
1292 * Ratecontrol attempt to use, at maximum, <value> of what can be used without an underflow.
1293 * - encoding: Set by user.
1294 * - decoding: unused.
1295 */
1296 float rc_max_available_vbv_use;
1297
1298 /**
1299 * Ratecontrol attempt to use, at least, <value> times the amount needed to prevent a vbv overflow.
1300 * - encoding: Set by user.
1301 * - decoding: unused.
1302 */
1303 float rc_min_vbv_overflow_use;
1304
1305 /**
1306 * Number of bits which should be loaded into the rc buffer before decoding starts.
1307 * - encoding: Set by user.
1308 * - decoding: unused
1309 */
1310 int rc_initial_buffer_occupancy;
1311
1312 /**
1313 * trellis RD quantization
1314 * - encoding: Set by user.
1315 * - decoding: unused
1316 */
1317 int trellis;
1318
1319 /**
1320 * pass1 encoding statistics output buffer
1321 * - encoding: Set by libavcodec.
1322 * - decoding: unused
1323 */
1324 char *stats_out;
1325
1326 /**
1327 * pass2 encoding statistics input buffer
1328 * Concatenated stuff from stats_out of pass1 should be placed here.
1329 * - encoding: Allocated/set/freed by user.
1330 * - decoding: unused
1331 */
1332 char *stats_in;
1333
1334 /**
1335 * Work around bugs in encoders which sometimes cannot be detected automatically.
1336 * - encoding: Set by user
1337 * - decoding: Set by user
1338 */
1339 int workaround_bugs;
1340#define FF_BUG_AUTODETECT 1 ///< autodetection
1341#define FF_BUG_XVID_ILACE 4
1342#define FF_BUG_UMP4 8
1343#define FF_BUG_NO_PADDING 16
1344#define FF_BUG_AMV 32
1345#define FF_BUG_QPEL_CHROMA 64
1346#define FF_BUG_STD_QPEL 128
1347#define FF_BUG_QPEL_CHROMA2 256
1348#define FF_BUG_DIRECT_BLOCKSIZE 512
1349#define FF_BUG_EDGE 1024
1350#define FF_BUG_HPEL_CHROMA 2048
1351#define FF_BUG_DC_CLIP 4096
1352#define FF_BUG_MS 8192 ///< Work around various bugs in Microsoft's broken decoders.
1353#define FF_BUG_TRUNCATED 16384
1354#define FF_BUG_IEDGE 32768
1355
1356 /**
1357 * strictly follow the standard (MPEG-4, ...).
1358 * - encoding: Set by user.
1359 * - decoding: Set by user.
1360 * Setting this to STRICT or higher means the encoder and decoder will
1361 * generally do stupid things, whereas setting it to unofficial or lower
1362 * will mean the encoder might produce output that is not supported by all
1363 * spec-compliant decoders. Decoders don't differentiate between normal,
1364 * unofficial and experimental (that is, they always try to decode things
1365 * when they can) unless they are explicitly asked to behave stupidly
1366 * (=strictly conform to the specs)
1367 * This may only be set to one of the FF_COMPLIANCE_* values in defs.h.
1368 */
1369 int strict_std_compliance;
1370
1371 /**
1372 * error concealment flags
1373 * - encoding: unused
1374 * - decoding: Set by user.
1375 */
1376 int error_concealment;
1377#define FF_EC_GUESS_MVS 1
1378#define FF_EC_DEBLOCK 2
1379#define FF_EC_FAVOR_INTER 256
1380
1381 /**
1382 * debug
1383 * - encoding: Set by user.
1384 * - decoding: Set by user.
1385 */
1386 int debug;
1387#define FF_DEBUG_PICT_INFO 1
1388#define FF_DEBUG_RC 2
1389#define FF_DEBUG_BITSTREAM 4
1390#define FF_DEBUG_MB_TYPE 8
1391#define FF_DEBUG_QP 16
1392#define FF_DEBUG_DCT_COEFF 0x00000040
1393#define FF_DEBUG_SKIP 0x00000080
1394#define FF_DEBUG_STARTCODE 0x00000100
1395#define FF_DEBUG_ER 0x00000400
1396#define FF_DEBUG_MMCO 0x00000800
1397#define FF_DEBUG_BUGS 0x00001000
1398#define FF_DEBUG_BUFFERS 0x00008000
1399#define FF_DEBUG_THREADS 0x00010000
1400#define FF_DEBUG_GREEN_MD 0x00800000
1401#define FF_DEBUG_NOMC 0x01000000
1402
1403 /**
1404 * Error recognition; may misdetect some more or less valid parts as errors.
1405 * This is a bitfield of the AV_EF_* values defined in defs.h.
1406 *
1407 * - encoding: Set by user.
1408 * - decoding: Set by user.
1409 */
1410 int err_recognition;
1411
1412 /**
1413 * Hardware accelerator in use
1414 * - encoding: unused.
1415 * - decoding: Set by libavcodec
1416 */
1417 const struct AVHWAccel *hwaccel;
1418
1419 /**
1420 * Legacy hardware accelerator context.
1421 *
1422 * For some hardware acceleration methods, the caller may use this field to
1423 * signal hwaccel-specific data to the codec. The struct pointed to by this
1424 * pointer is hwaccel-dependent and defined in the respective header. Please
1425 * refer to the FFmpeg HW accelerator documentation to know how to fill
1426 * this.
1427 *
1428 * In most cases this field is optional - the necessary information may also
1429 * be provided to libavcodec through @ref hw_frames_ctx or @ref
1430 * hw_device_ctx (see avcodec_get_hw_config()). However, in some cases it
1431 * may be the only method of signalling some (optional) information.
1432 *
1433 * The struct and its contents are owned by the caller.
1434 *
1435 * - encoding: May be set by the caller before avcodec_open2(). Must remain
1436 * valid until avcodec_free_context().
1437 * - decoding: May be set by the caller in the get_format() callback.
1438 * Must remain valid until the next get_format() call,
1439 * or avcodec_free_context() (whichever comes first).
1440 */
1441 void *hwaccel_context;
1442
1443 /**
1444 * A reference to the AVHWFramesContext describing the input (for encoding)
1445 * or output (decoding) frames. The reference is set by the caller and
1446 * afterwards owned (and freed) by libavcodec - it should never be read by
1447 * the caller after being set.
1448 *
1449 * - decoding: This field should be set by the caller from the get_format()
1450 * callback. The previous reference (if any) will always be
1451 * unreffed by libavcodec before the get_format() call.
1452 *
1453 * If the default get_buffer2() is used with a hwaccel pixel
1454 * format, then this AVHWFramesContext will be used for
1455 * allocating the frame buffers.
1456 *
1457 * - encoding: For hardware encoders configured to use a hwaccel pixel
1458 * format, this field should be set by the caller to a reference
1459 * to the AVHWFramesContext describing input frames.
1460 * AVHWFramesContext.format must be equal to
1461 * AVCodecContext.pix_fmt.
1462 *
1463 * This field should be set before avcodec_open2() is called.
1464 */
1465 AVBufferRef *hw_frames_ctx;
1466
1467 /**
1468 * A reference to the AVHWDeviceContext describing the device which will
1469 * be used by a hardware encoder/decoder. The reference is set by the
1470 * caller and afterwards owned (and freed) by libavcodec.
1471 *
1472 * This should be used if either the codec device does not require
1473 * hardware frames or any that are used are to be allocated internally by
1474 * libavcodec. If the user wishes to supply any of the frames used as
1475 * encoder input or decoder output then hw_frames_ctx should be used
1476 * instead. When hw_frames_ctx is set in get_format() for a decoder, this
1477 * field will be ignored while decoding the associated stream segment, but
1478 * may again be used on a following one after another get_format() call.
1479 *
1480 * For both encoders and decoders this field should be set before
1481 * avcodec_open2() is called and must not be written to thereafter.
1482 *
1483 * Note that some decoders may require this field to be set initially in
1484 * order to support hw_frames_ctx at all - in that case, all frames
1485 * contexts used must be created on the same device.
1486 */
1487 AVBufferRef *hw_device_ctx;
1488
1489 /**
1490 * Bit set of AV_HWACCEL_FLAG_* flags, which affect hardware accelerated
1491 * decoding (if active).
1492 * - encoding: unused
1493 * - decoding: Set by user (either before avcodec_open2(), or in the
1494 * AVCodecContext.get_format callback)
1495 */
1496 int hwaccel_flags;
1497
1498 /**
1499 * Video decoding only. Sets the number of extra hardware frames which
1500 * the decoder will allocate for use by the caller. This must be set
1501 * before avcodec_open2() is called.
1502 *
1503 * Some hardware decoders require all frames that they will use for
1504 * output to be defined in advance before decoding starts. For such
1505 * decoders, the hardware frame pool must therefore be of a fixed size.
1506 * The extra frames set here are on top of any number that the decoder
1507 * needs internally in order to operate normally (for example, frames
1508 * used as reference pictures).
1509 */
1510 int extra_hw_frames;
1511
1512 /**
1513 * error
1514 * - encoding: Set by libavcodec if flags & AV_CODEC_FLAG_PSNR.
1515 * - decoding: unused
1516 */
1517 uint64_t error[AV_NUM_DATA_POINTERS];
1518
1519 /**
1520 * DCT algorithm, see FF_DCT_* below
1521 * - encoding: Set by user.
1522 * - decoding: unused
1523 */
1524 int dct_algo;
1525#define FF_DCT_AUTO 0
1526#define FF_DCT_FASTINT 1
1527#define FF_DCT_INT 2
1528#define FF_DCT_MMX 3
1529#define FF_DCT_ALTIVEC 5
1530#define FF_DCT_FAAN 6
1531#define FF_DCT_NEON 7
1532
1533 /**
1534 * IDCT algorithm, see FF_IDCT_* below.
1535 * - encoding: Set by user.
1536 * - decoding: Set by user.
1537 */
1538 int idct_algo;
1539#define FF_IDCT_AUTO 0
1540#define FF_IDCT_INT 1
1541#define FF_IDCT_SIMPLE 2
1542#define FF_IDCT_SIMPLEMMX 3
1543#define FF_IDCT_ARM 7
1544#define FF_IDCT_ALTIVEC 8
1545#define FF_IDCT_SIMPLEARM 10
1546#define FF_IDCT_XVID 14
1547#define FF_IDCT_SIMPLEARMV5TE 16
1548#define FF_IDCT_SIMPLEARMV6 17
1549#define FF_IDCT_FAAN 20
1550#define FF_IDCT_SIMPLENEON 22
1551#define FF_IDCT_SIMPLEAUTO 128
1552
1553 /**
1554 * bits per sample/pixel from the demuxer (needed for huffyuv).
1555 * - encoding: Set by libavcodec.
1556 * - decoding: Set by user.
1557 */
1558 int bits_per_coded_sample;
1559
1560 /**
1561 * Bits per sample/pixel of internal libavcodec pixel/sample format.
1562 * - encoding: set by user.
1563 * - decoding: set by libavcodec.
1564 */
1565 int bits_per_raw_sample;
1566
1567 /**
1568 * thread count
1569 * is used to decide how many independent tasks should be passed to execute()
1570 * - encoding: Set by user.
1571 * - decoding: Set by user.
1572 */
1573 int thread_count;
1574
1575 /**
1576 * Which multithreading methods to use.
1577 * Use of FF_THREAD_FRAME will increase decoding delay by one frame per thread,
1578 * so clients which cannot provide future frames should not use it.
1579 *
1580 * - encoding: Set by user, otherwise the default is used.
1581 * - decoding: Set by user, otherwise the default is used.
1582 */
1583 int thread_type;
1584#define FF_THREAD_FRAME 1 ///< Decode more than one frame at once
1585#define FF_THREAD_SLICE 2 ///< Decode more than one part of a single frame at once
1586
1587 /**
1588 * Which multithreading methods are in use by the codec.
1589 * - encoding: Set by libavcodec.
1590 * - decoding: Set by libavcodec.
1591 */
1592 int active_thread_type;
1593
1594 /**
1595 * The codec may call this to execute several independent things.
1596 * It will return only after finishing all tasks.
1597 * The user may replace this with some multithreaded implementation,
1598 * the default implementation will execute the parts serially.
1599 * @param count the number of things to execute
1600 * - encoding: Set by libavcodec, user can override.
1601 * - decoding: Set by libavcodec, user can override.
1602 */
1603 int (*execute)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size);
1604
1605 /**
1606 * The codec may call this to execute several independent things.
1607 * It will return only after finishing all tasks.
1608 * The user may replace this with some multithreaded implementation,
1609 * the default implementation will execute the parts serially.
1610 * @param c context passed also to func
1611 * @param count the number of things to execute
1612 * @param arg2 argument passed unchanged to func
1613 * @param ret return values of executed functions, must have space for "count" values. May be NULL.
1614 * @param func function that will be called count times, with jobnr from 0 to count-1.
1615 * threadnr will be in the range 0 to c->thread_count-1 < MAX_THREADS and so that no
1616 * two instances of func executing at the same time will have the same threadnr.
1617 * @return always 0 currently, but code should handle a future improvement where when any call to func
1618 * returns < 0 no further calls to func may be done and < 0 is returned.
1619 * - encoding: Set by libavcodec, user can override.
1620 * - decoding: Set by libavcodec, user can override.
1621 */
1622 int (*execute2)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count);
1623
1624 /**
1625 * profile
1626 * - encoding: Set by user.
1627 * - decoding: Set by libavcodec.
1628 * See the AV_PROFILE_* defines in defs.h.
1629 */
1630 int profile;
1631
1632 /**
1633 * Encoding level descriptor.
1634 * - encoding: Set by user, corresponds to a specific level defined by the
1635 * codec, usually corresponding to the profile level, if not specified it
1636 * is set to AV_LEVEL_UNKNOWN.
1637 * - decoding: Set by libavcodec.
1638 * See AV_LEVEL_* in defs.h.
1639 */
1640 int level;
1641
1642#if FF_API_CODEC_PROPS
1643 /**
1644 * Properties of the stream that gets decoded
1645 * - encoding: unused
1646 * - decoding: set by libavcodec
1647 */
1648 attribute_deprecated
1649 unsigned properties;
1650#define FF_CODEC_PROPERTY_LOSSLESS 0x00000001
1651#define FF_CODEC_PROPERTY_CLOSED_CAPTIONS 0x00000002
1652#define FF_CODEC_PROPERTY_FILM_GRAIN 0x00000004
1653#endif
1654
1655 /**
1656 * Skip loop filtering for selected frames.
1657 * - encoding: unused
1658 * - decoding: Set by user.
1659 */
1660 enum AVDiscard skip_loop_filter;
1661
1662 /**
1663 * Skip IDCT/dequantization for selected frames.
1664 * - encoding: unused
1665 * - decoding: Set by user.
1666 */
1667 enum AVDiscard skip_idct;
1668
1669 /**
1670 * Skip decoding for selected frames.
1671 * - encoding: unused
1672 * - decoding: Set by user.
1673 */
1674 enum AVDiscard skip_frame;
1675
1676 /**
1677 * Skip processing alpha if supported by codec.
1678 * Note that if the format uses pre-multiplied alpha (common with VP6,
1679 * and recommended due to better video quality/compression)
1680 * the image will look as if alpha-blended onto a black background.
1681 * However for formats that do not use pre-multiplied alpha
1682 * there might be serious artefacts (though e.g. libswscale currently
1683 * assumes pre-multiplied alpha anyway).
1684 *
1685 * - decoding: set by user
1686 * - encoding: unused
1687 */
1688 int skip_alpha;
1689
1690 /**
1691 * Number of macroblock rows at the top which are skipped.
1692 * - encoding: unused
1693 * - decoding: Set by user.
1694 */
1695 int skip_top;
1696
1697 /**
1698 * Number of macroblock rows at the bottom which are skipped.
1699 * - encoding: unused
1700 * - decoding: Set by user.
1701 */
1702 int skip_bottom;
1703
1704 /**
1705 * low resolution decoding, 1-> 1/2 size, 2->1/4 size
1706 * - encoding: unused
1707 * - decoding: Set by user.
1708 */
1709 int lowres;
1710
1711 /**
1712 * AVCodecDescriptor
1713 * - encoding: unused.
1714 * - decoding: set by libavcodec.
1715 */
1716 const struct AVCodecDescriptor *codec_descriptor;
1717
1718 /**
1719 * Character encoding of the input subtitles file.
1720 * - decoding: set by user
1721 * - encoding: unused
1722 */
1723 char *sub_charenc;
1724
1725 /**
1726 * Subtitles character encoding mode. Formats or codecs might be adjusting
1727 * this setting (if they are doing the conversion themselves for instance).
1728 * - decoding: set by libavcodec
1729 * - encoding: unused
1730 */
1731 int sub_charenc_mode;
1732#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)
1733#define FF_SUB_CHARENC_MODE_AUTOMATIC 0 ///< libavcodec will select the mode itself
1734#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
1735#define FF_SUB_CHARENC_MODE_IGNORE 2 ///< neither convert the subtitles, nor check them for valid UTF-8
1736
1737 /**
1738 * Header containing style information for text subtitles.
1739 * For SUBTITLE_ASS subtitle type, it should contain the whole ASS
1740 * [Script Info] and [V4+ Styles] section, plus the [Events] line and
1741 * the Format line following. It shouldn't include any Dialogue line.
1742 *
1743 * - encoding: May be set by the caller before avcodec_open2() to an array
1744 * allocated with the av_malloc() family of functions.
1745 * - decoding: May be set by libavcodec in avcodec_open2().
1746 *
1747 * After being set, the array is owned by the codec and freed in
1748 * avcodec_free_context().
1749 */
1750 int subtitle_header_size;
1751 uint8_t *subtitle_header;
1752
1753 /**
1754 * dump format separator.
1755 * can be ", " or "\n " or anything else
1756 * - encoding: Set by user.
1757 * - decoding: Set by user.
1758 */
1759 uint8_t *dump_separator;
1760
1761 /**
1762 * ',' separated list of allowed decoders.
1763 * If NULL then all are allowed
1764 * - encoding: unused
1765 * - decoding: set by user
1766 */
1767 char *codec_whitelist;
1768
1769 /**
1770 * Additional data associated with the entire coded stream.
1771 *
1772 * - decoding: may be set by user before calling avcodec_open2().
1773 * - encoding: may be set by libavcodec after avcodec_open2().
1774 */
1775 AVPacketSideData *coded_side_data;
1776 int nb_coded_side_data;
1777
1778 /**
1779 * Bit set of AV_CODEC_EXPORT_DATA_* flags, which affects the kind of
1780 * metadata exported in frame, packet, or coded stream side data by
1781 * decoders and encoders.
1782 *
1783 * - decoding: set by user
1784 * - encoding: set by user
1785 */
1786 int export_side_data;
1787
1788 /**
1789 * The number of pixels per image to maximally accept.
1790 *
1791 * - decoding: set by user
1792 * - encoding: set by user
1793 */
1794 int64_t max_pixels;
1795
1796 /**
1797 * Video decoding only. Certain video codecs support cropping, meaning that
1798 * only a sub-rectangle of the decoded frame is intended for display. This
1799 * option controls how cropping is handled by libavcodec.
1800 *
1801 * When set to 1 (the default), libavcodec will apply cropping internally.
1802 * I.e. it will modify the output frame width/height fields and offset the
1803 * data pointers (only by as much as possible while preserving alignment, or
1804 * by the full amount if the AV_CODEC_FLAG_UNALIGNED flag is set) so that
1805 * the frames output by the decoder refer only to the cropped area. The
1806 * crop_* fields of the output frames will be zero.
1807 *
1808 * When set to 0, the width/height fields of the output frames will be set
1809 * to the coded dimensions and the crop_* fields will describe the cropping
1810 * rectangle. Applying the cropping is left to the caller.
1811 *
1812 * @warning When hardware acceleration with opaque output frames is used,
1813 * libavcodec is unable to apply cropping from the top/left border.
1814 *
1815 * @note when this option is set to zero, the width/height fields of the
1816 * AVCodecContext and output AVFrames have different meanings. The codec
1817 * context fields store display dimensions (with the coded dimensions in
1818 * coded_width/height), while the frame fields store the coded dimensions
1819 * (with the display dimensions being determined by the crop_* fields).
1820 */
1821 int apply_cropping;
1822
1823 /**
1824 * The percentage of damaged samples to discard a frame.
1825 *
1826 * - decoding: set by user
1827 * - encoding: unused
1828 */
1829 int discard_damaged_percentage;
1830
1831 /**
1832 * The number of samples per frame to maximally accept.
1833 *
1834 * - decoding: set by user
1835 * - encoding: set by user
1836 */
1837 int64_t max_samples;
1838
1839 /**
1840 * This callback is called at the beginning of each packet to get a data
1841 * buffer for it.
1842 *
1843 * The following field will be set in the packet before this callback is
1844 * called:
1845 * - size
1846 * This callback must use the above value to calculate the required buffer size,
1847 * which must padded by at least AV_INPUT_BUFFER_PADDING_SIZE bytes.
1848 *
1849 * In some specific cases, the encoder may not use the entire buffer allocated by this
1850 * callback. This will be reflected in the size value in the packet once returned by
1851 * avcodec_receive_packet().
1852 *
1853 * This callback must fill the following fields in the packet:
1854 * - data: alignment requirements for AVPacket apply, if any. Some architectures and
1855 * encoders may benefit from having aligned data.
1856 * - buf: must contain a pointer to an AVBufferRef structure. The packet's
1857 * data pointer must be contained in it. See: av_buffer_create(), av_buffer_alloc(),
1858 * and av_buffer_ref().
1859 *
1860 * If AV_CODEC_CAP_DR1 is not set then get_encode_buffer() must call
1861 * avcodec_default_get_encode_buffer() instead of providing a buffer allocated by
1862 * some other means.
1863 *
1864 * The flags field may contain a combination of AV_GET_ENCODE_BUFFER_FLAG_ flags.
1865 * They may be used for example to hint what use the buffer may get after being
1866 * created.
1867 * Implementations of this callback may ignore flags they don't understand.
1868 * If AV_GET_ENCODE_BUFFER_FLAG_REF is set in flags then the packet may be reused
1869 * (read and/or written to if it is writable) later by libavcodec.
1870 *
1871 * This callback must be thread-safe, as when frame threading is used, it may
1872 * be called from multiple threads simultaneously.
1873 *
1874 * @see avcodec_default_get_encode_buffer()
1875 *
1876 * - encoding: Set by libavcodec, user can override.
1877 * - decoding: unused
1878 */
1879 int (*get_encode_buffer)(struct AVCodecContext *s, AVPacket *pkt, int flags);
1880
1881 /**
1882 * Frame counter, set by libavcodec.
1883 *
1884 * - decoding: total number of frames returned from the decoder so far.
1885 * - encoding: total number of frames passed to the encoder so far.
1886 *
1887 * @note the counter is not incremented if encoding/decoding resulted in
1888 * an error.
1889 */
1890 int64_t frame_num;
1891
1892 /**
1893 * Decoding only. May be set by the caller before avcodec_open2() to an
1894 * av_malloc()'ed array (or via AVOptions). Owned and freed by the decoder
1895 * afterwards.
1896 *
1897 * Side data attached to decoded frames may come from several sources:
1898 * 1. coded_side_data, which the decoder will for certain types translate
1899 * from packet-type to frame-type and attach to frames;
1900 * 2. side data attached to an AVPacket sent for decoding (same
1901 * considerations as above);
1902 * 3. extracted from the coded bytestream.
1903 * The first two cases are supplied by the caller and typically come from a
1904 * container.
1905 *
1906 * This array configures decoder behaviour in cases when side data of the
1907 * same type is present both in the coded bytestream and in the
1908 * user-supplied side data (items 1. and 2. above). In all cases, at most
1909 * one instance of each side data type will be attached to output frames. By
1910 * default it will be the bytestream side data. Adding an
1911 * AVPacketSideDataType value to this array will flip the preference for
1912 * this type, thus making the decoder prefer user-supplied side data over
1913 * bytestream. In case side data of the same type is present both in
1914 * coded_data and attacked to a packet, the packet instance always has
1915 * priority.
1916 *
1917 * The array may also contain a single -1, in which case the preference is
1918 * switched for all side data types.
1919 */
1920 int *side_data_prefer_packet;
1921 /**
1922 * Number of entries in side_data_prefer_packet.
1923 */
1924 unsigned nb_side_data_prefer_packet;
1925
1926 /**
1927 * Array containing static side data, such as HDR10 CLL / MDCV structures.
1928 * Side data entries should be allocated by usage of helpers defined in
1929 * libavutil/frame.h.
1930 *
1931 * - encoding: may be set by user before calling avcodec_open2() for
1932 * encoder configuration. Afterwards owned and freed by the
1933 * encoder.
1934 * - decoding: may be set by libavcodec in avcodec_open2().
1935 */
1936 AVFrameSideData **decoded_side_data;
1937 int nb_decoded_side_data;
1938
1939 /**
1940 * Indicates how the alpha channel of the video is represented.
1941 * - encoding: Set by user
1942 * - decoding: Set by libavcodec
1943 */
1944 enum AVAlphaMode alpha_mode;
1945} AVCodecContext;
1946
1947/**
1948 * @defgroup lavc_hwaccel AVHWAccel
1949 *
1950 * @note Nothing in this structure should be accessed by the user. At some
1951 * point in future it will not be externally visible at all.
1952 *
1953 * @{
1954 */
1955typedef struct AVHWAccel {
1956 /**
1957 * Name of the hardware accelerated codec.
1958 * The name is globally unique among encoders and among decoders (but an
1959 * encoder and a decoder can share the same name).
1960 */
1961 const char *name;
1962
1963 /**
1964 * Type of codec implemented by the hardware accelerator.
1965 *
1966 * See AVMEDIA_TYPE_xxx
1967 */
1968 enum AVMediaType type;
1969
1970 /**
1971 * Codec implemented by the hardware accelerator.
1972 *
1973 * See AV_CODEC_ID_xxx
1974 */
1975 enum AVCodecID id;
1976
1977 /**
1978 * Supported pixel format.
1979 *
1980 * Only hardware accelerated formats are supported here.
1981 */
1982 enum AVPixelFormat pix_fmt;
1983
1984 /**
1985 * Hardware accelerated codec capabilities.
1986 * see AV_HWACCEL_CODEC_CAP_*
1987 */
1988 int capabilities;
1989} AVHWAccel;
1990
1991/**
1992 * HWAccel is experimental and is thus avoided in favor of non experimental
1993 * codecs
1994 */
1995#define AV_HWACCEL_CODEC_CAP_EXPERIMENTAL 0x0200
1996
1997/**
1998 * Hardware acceleration should be used for decoding even if the codec level
1999 * used is unknown or higher than the maximum supported level reported by the
2000 * hardware driver.
2001 *
2002 * It's generally a good idea to pass this flag unless you have a specific
2003 * reason not to, as hardware tends to under-report supported levels.
2004 */
2005#define AV_HWACCEL_FLAG_IGNORE_LEVEL (1 << 0)
2006
2007/**
2008 * Hardware acceleration can output YUV pixel formats with a different chroma
2009 * sampling than 4:2:0 and/or other than 8 bits per component.
2010 */
2011#define AV_HWACCEL_FLAG_ALLOW_HIGH_DEPTH (1 << 1)
2012
2013/**
2014 * Hardware acceleration should still be attempted for decoding when the
2015 * codec profile does not match the reported capabilities of the hardware.
2016 *
2017 * For example, this can be used to try to decode baseline profile H.264
2018 * streams in hardware - it will often succeed, because many streams marked
2019 * as baseline profile actually conform to constrained baseline profile.
2020 *
2021 * @warning If the stream is actually not supported then the behaviour is
2022 * undefined, and may include returning entirely incorrect output
2023 * while indicating success.
2024 */
2025#define AV_HWACCEL_FLAG_ALLOW_PROFILE_MISMATCH (1 << 2)
2026
2027/**
2028 * Some hardware decoders (namely nvdec) can either output direct decoder
2029 * surfaces, or make an on-device copy and return said copy.
2030 * There is a hard limit on how many decoder surfaces there can be, and it
2031 * cannot be accurately guessed ahead of time.
2032 * For some processing chains, this can be okay, but others will run into the
2033 * limit and in turn produce very confusing errors that require fine tuning of
2034 * more or less obscure options by the user, or in extreme cases cannot be
2035 * resolved at all without inserting an avfilter that forces a copy.
2036 *
2037 * Thus, the hwaccel will by default make a copy for safety and resilience.
2038 * If a users really wants to minimize the amount of copies, they can set this
2039 * flag and ensure their processing chain does not exhaust the surface pool.
2040 */
2041#define AV_HWACCEL_FLAG_UNSAFE_OUTPUT (1 << 3)
2042
2043/**
2044 * @}
2045 */
2046
2047enum AVSubtitleType {
2048 SUBTITLE_NONE,
2049
2050 SUBTITLE_BITMAP, ///< A bitmap, pict will be set
2051
2052 /**
2053 * Plain text, the text field must be set by the decoder and is
2054 * authoritative. ass and pict fields may contain approximations.
2055 */
2056 SUBTITLE_TEXT,
2057
2058 /**
2059 * Formatted text, the ass field must be set by the decoder and is
2060 * authoritative. pict and text fields may contain approximations.
2061 */
2062 SUBTITLE_ASS,
2063};
2064
2065#define AV_SUBTITLE_FLAG_FORCED 0x00000001
2066
2067typedef struct AVSubtitleRect {
2068 int x; ///< top left corner of pict, undefined when pict is not set
2069 int y; ///< top left corner of pict, undefined when pict is not set
2070 int w; ///< width of pict, undefined when pict is not set
2071 int h; ///< height of pict, undefined when pict is not set
2072 int nb_colors; ///< number of colors in pict, undefined when pict is not set
2073
2074 /**
2075 * data+linesize for the bitmap of this subtitle.
2076 * Can be set for text/ass as well once they are rendered.
2077 */
2078 uint8_t *data[4];
2079 int linesize[4];
2080
2081 int flags;
2082 enum AVSubtitleType type;
2083
2084 char *text; ///< 0 terminated plain UTF-8 text
2085
2086 /**
2087 * 0 terminated ASS/SSA compatible event line.
2088 * The presentation of this is unaffected by the other values in this
2089 * struct.
2090 */
2091 char *ass;
2092} AVSubtitleRect;
2093
2094typedef struct AVSubtitle {
2095 uint16_t format; /* 0 = graphics */
2096 uint32_t start_display_time; /* relative to packet pts, in ms */
2097 uint32_t end_display_time; /* relative to packet pts, in ms */
2098 unsigned num_rects;
2099 AVSubtitleRect **rects;
2100 int64_t pts; ///< Same as packet pts, in AV_TIME_BASE
2101} AVSubtitle;
2102
2103/**
2104 * Return the LIBAVCODEC_VERSION_INT constant.
2105 */
2106unsigned avcodec_version(void);
2107
2108/**
2109 * Return the libavcodec build-time configuration.
2110 */
2111const char *avcodec_configuration(void);
2112
2113/**
2114 * Return the libavcodec license.
2115 */
2116const char *avcodec_license(void);
2117
2118/**
2119 * Allocate an AVCodecContext and set its fields to default values. The
2120 * resulting struct should be freed with avcodec_free_context().
2121 *
2122 * @param codec if non-NULL, allocate private data and initialize defaults
2123 * for the given codec. It is illegal to then call avcodec_open2()
2124 * with a different codec.
2125 * If NULL, then the codec-specific defaults won't be initialized,
2126 * which may result in suboptimal default settings (this is
2127 * important mainly for encoders, e.g. libx264).
2128 *
2129 * @return An AVCodecContext filled with default values or NULL on failure.
2130 */
2131AVCodecContext *avcodec_alloc_context3(const AVCodec *codec);
2132
2133/**
2134 * Free the codec context and everything associated with it and write NULL to
2135 * the provided pointer.
2136 */
2137void avcodec_free_context(AVCodecContext **avctx);
2138
2139/**
2140 * Get the AVClass for AVCodecContext. It can be used in combination with
2141 * AV_OPT_SEARCH_FAKE_OBJ for examining options.
2142 *
2143 * @see av_opt_find().
2144 */
2145const AVClass *avcodec_get_class(void);
2146
2147/**
2148 * Get the AVClass for AVSubtitleRect. It can be used in combination with
2149 * AV_OPT_SEARCH_FAKE_OBJ for examining options.
2150 *
2151 * @see av_opt_find().
2152 */
2153const AVClass *avcodec_get_subtitle_rect_class(void);
2154
2155/**
2156 * Fill the parameters struct based on the values from the supplied codec
2157 * context. Any allocated fields in par are freed and replaced with duplicates
2158 * of the corresponding fields in codec.
2159 *
2160 * @return >= 0 on success, a negative AVERROR code on failure
2161 */
2162int avcodec_parameters_from_context(struct AVCodecParameters *par,
2163 const AVCodecContext *codec);
2164
2165/**
2166 * Fill the codec context based on the values from the supplied codec
2167 * parameters. Any allocated fields in codec that have a corresponding field in
2168 * par are freed and replaced with duplicates of the corresponding field in par.
2169 * Fields in codec that do not have a counterpart in par are not touched.
2170 *
2171 * @return >= 0 on success, a negative AVERROR code on failure.
2172 */
2173int avcodec_parameters_to_context(AVCodecContext *codec,
2174 const struct AVCodecParameters *par);
2175
2176/**
2177 * Initialize the AVCodecContext to use the given AVCodec. Prior to using this
2178 * function the context has to be allocated with avcodec_alloc_context3().
2179 *
2180 * The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(),
2181 * avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for
2182 * retrieving a codec.
2183 *
2184 * Depending on the codec, you might need to set options in the codec context
2185 * also for decoding (e.g. width, height, or the pixel or audio sample format in
2186 * the case the information is not available in the bitstream, as when decoding
2187 * raw audio or video).
2188 *
2189 * Options in the codec context can be set either by setting them in the options
2190 * AVDictionary, or by setting the values in the context itself, directly or by
2191 * using the av_opt_set() API before calling this function.
2192 *
2193 * Example:
2194 * @code
2195 * av_dict_set(&opts, "b", "2.5M", 0);
2196 * codec = avcodec_find_decoder(AV_CODEC_ID_H264);
2197 * if (!codec)
2198 * exit(1);
2199 *
2200 * context = avcodec_alloc_context3(codec);
2201 *
2202 * if (avcodec_open2(context, codec, opts) < 0)
2203 * exit(1);
2204 * @endcode
2205 *
2206 * In the case AVCodecParameters are available (e.g. when demuxing a stream
2207 * using libavformat, and accessing the AVStream contained in the demuxer), the
2208 * codec parameters can be copied to the codec context using
2209 * avcodec_parameters_to_context(), as in the following example:
2210 *
2211 * @code
2212 * AVStream *stream = ...;
2213 * context = avcodec_alloc_context3(codec);
2214 * if (avcodec_parameters_to_context(context, stream->codecpar) < 0)
2215 * exit(1);
2216 * if (avcodec_open2(context, codec, NULL) < 0)
2217 * exit(1);
2218 * @endcode
2219 *
2220 * @note Always call this function before using decoding routines (such as
2221 * @ref avcodec_receive_frame()).
2222 *
2223 * @param avctx The context to initialize.
2224 * @param codec The codec to open this context for. If a non-NULL codec has been
2225 * previously passed to avcodec_alloc_context3() or
2226 * for this context, then this parameter MUST be either NULL or
2227 * equal to the previously passed codec.
2228 * @param options A dictionary filled with AVCodecContext and codec-private
2229 * options, which are set on top of the options already set in
2230 * avctx, can be NULL. On return this object will be filled with
2231 * options that were not found in the avctx codec context.
2232 *
2233 * @return zero on success, a negative value on error
2234 * @see avcodec_alloc_context3(), avcodec_find_decoder(), avcodec_find_encoder(),
2235 * av_dict_set(), av_opt_set(), av_opt_find(), avcodec_parameters_to_context()
2236 */
2237int avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options);
2238
2239/**
2240 * Free all allocated data in the given subtitle struct.
2241 *
2242 * @param sub AVSubtitle to free.
2243 */
2244void avsubtitle_free(AVSubtitle *sub);
2245
2246/**
2247 * @}
2248 */
2249
2250/**
2251 * @addtogroup lavc_decoding
2252 * @{
2253 */
2254
2255/**
2256 * The default callback for AVCodecContext.get_buffer2(). It is made public so
2257 * it can be called by custom get_buffer2() implementations for decoders without
2258 * AV_CODEC_CAP_DR1 set.
2259 */
2260int avcodec_default_get_buffer2(AVCodecContext *s, AVFrame *frame, int flags);
2261
2262/**
2263 * The default callback for AVCodecContext.get_encode_buffer(). It is made public so
2264 * it can be called by custom get_encode_buffer() implementations for encoders without
2265 * AV_CODEC_CAP_DR1 set.
2266 */
2267int avcodec_default_get_encode_buffer(AVCodecContext *s, AVPacket *pkt, int flags);
2268
2269/**
2270 * Modify width and height values so that they will result in a memory
2271 * buffer that is acceptable for the codec if you do not use any horizontal
2272 * padding.
2273 *
2274 * May only be used if a codec with AV_CODEC_CAP_DR1 has been opened.
2275 */
2276void avcodec_align_dimensions(AVCodecContext *s, int *width, int *height);
2277
2278/**
2279 * Modify width and height values so that they will result in a memory
2280 * buffer that is acceptable for the codec if you also ensure that all
2281 * line sizes are a multiple of the respective linesize_align[i].
2282 *
2283 * May only be used if a codec with AV_CODEC_CAP_DR1 has been opened.
2284 */
2285void avcodec_align_dimensions2(AVCodecContext *s, int *width, int *height,
2286 int linesize_align[AV_NUM_DATA_POINTERS]);
2287
2288/**
2289 * Decode a subtitle message.
2290 * Return a negative value on error, otherwise return the number of bytes used.
2291 * If no subtitle could be decompressed, got_sub_ptr is zero.
2292 * Otherwise, the subtitle is stored in *sub.
2293 * Note that AV_CODEC_CAP_DR1 is not available for subtitle codecs. This is for
2294 * simplicity, because the performance difference is expected to be negligible
2295 * and reusing a get_buffer written for video codecs would probably perform badly
2296 * due to a potentially very different allocation pattern.
2297 *
2298 * Some decoders (those marked with AV_CODEC_CAP_DELAY) have a delay between input
2299 * and output. This means that for some packets they will not immediately
2300 * produce decoded output and need to be flushed at the end of decoding to get
2301 * all the decoded data. Flushing is done by calling this function with packets
2302 * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
2303 * returning subtitles. It is safe to flush even those decoders that are not
2304 * marked with AV_CODEC_CAP_DELAY, then no subtitles will be returned.
2305 *
2306 * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
2307 * before packets may be fed to the decoder.
2308 *
2309 * @param avctx the codec context
2310 * @param[out] sub The preallocated AVSubtitle in which the decoded subtitle will be stored,
2311 * must be freed with avsubtitle_free if *got_sub_ptr is set.
2312 * @param[in,out] got_sub_ptr Zero if no subtitle could be decompressed, otherwise, it is nonzero.
2313 * @param[in] avpkt The input AVPacket containing the input buffer.
2314 */
2315int avcodec_decode_subtitle2(AVCodecContext *avctx, AVSubtitle *sub,
2316 int *got_sub_ptr, const AVPacket *avpkt);
2317
2318/**
2319 * Supply raw packet data as input to a decoder.
2320 *
2321 * Internally, this call will copy relevant AVCodecContext fields, which can
2322 * influence decoding per-packet, and apply them when the packet is actually
2323 * decoded. (For example AVCodecContext.skip_frame, which might direct the
2324 * decoder to drop the frame contained by the packet sent with this function.)
2325 *
2326 * @warning The input buffer, avpkt->data must be AV_INPUT_BUFFER_PADDING_SIZE
2327 * larger than the actual read bytes because some optimized bitstream
2328 * readers read 32 or 64 bits at once and could read over the end.
2329 *
2330 * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
2331 * before packets may be fed to the decoder.
2332 *
2333 * @param avctx codec context
2334 * @param[in] avpkt The input AVPacket. Usually, this will be a single video
2335 * frame, or several complete audio frames.
2336 * Ownership of the packet remains with the caller, and the
2337 * decoder will not write to the packet. The decoder may create
2338 * a reference to the packet data (or copy it if the packet is
2339 * not reference-counted).
2340 * Unlike with older APIs, the packet is always fully consumed,
2341 * and if it contains multiple frames (e.g. some audio codecs),
2342 * will require you to call avcodec_receive_frame() multiple
2343 * times afterwards before you can send a new packet.
2344 * It can be NULL (or an AVPacket with data set to NULL and
2345 * size set to 0); in this case, it is considered a flush
2346 * packet, which signals the end of the stream. Sending the
2347 * first flush packet will return success. Subsequent ones are
2348 * unnecessary and will return AVERROR_EOF. If the decoder
2349 * still has frames buffered, it will return them after sending
2350 * a flush packet.
2351 *
2352 * @retval 0 success
2353 * @retval AVERROR(EAGAIN) input is not accepted in the current state - user
2354 * must read output with avcodec_receive_frame() (once
2355 * all output is read, the packet should be resent,
2356 * and the call will not fail with EAGAIN).
2357 * @retval AVERROR_EOF the decoder has been flushed, and no new packets can be
2358 * sent to it (also returned if more than 1 flush
2359 * packet is sent)
2360 * @retval AVERROR(EINVAL) codec not opened, it is an encoder, or requires flush
2361 * @retval AVERROR(ENOMEM) failed to add packet to internal queue, or similar
2362 * @retval "another negative error code" legitimate decoding errors
2363 */
2364int avcodec_send_packet(AVCodecContext *avctx, const AVPacket *avpkt);
2365
2366/**
2367 * Return decoded output data from a decoder or encoder (when the
2368 * @ref AV_CODEC_FLAG_RECON_FRAME flag is used).
2369 *
2370 * @param avctx codec context
2371 * @param frame This will be set to a reference-counted video or audio
2372 * frame (depending on the decoder type) allocated by the
2373 * codec. Note that the function will always call
2374 * av_frame_unref(frame) before doing anything else.
2375 * @param flags Combination of AV_CODEC_RECEIVE_FRAME_FLAG_* flags.
2376 *
2377 * @retval 0 success, a frame was returned
2378 * @retval AVERROR(EAGAIN) output is not available in this state - user must
2379 * try to send new input
2380 * @retval AVERROR_EOF the codec has been fully flushed, and there will be
2381 * no more output frames
2382 * @retval AVERROR(EINVAL) codec not opened, or it is an encoder without the
2383 * @ref AV_CODEC_FLAG_RECON_FRAME flag enabled
2384 * @retval "other negative error code" legitimate decoding errors
2385 */
2386int avcodec_receive_frame_flags(AVCodecContext *avctx, AVFrame *frame, unsigned flags);
2387
2388/**
2389 * Alias for `avcodec_receive_frame_flags(avctx, frame, 0)`.
2390 */
2391int avcodec_receive_frame(AVCodecContext *avctx, AVFrame *frame);
2392
2393/**
2394 * Supply a raw video or audio frame to the encoder. Use avcodec_receive_packet()
2395 * to retrieve buffered output packets.
2396 *
2397 * @param avctx codec context
2398 * @param[in] frame AVFrame containing the raw audio or video frame to be encoded.
2399 * Ownership of the frame remains with the caller, and the
2400 * encoder will not write to the frame. The encoder may create
2401 * a reference to the frame data (or copy it if the frame is
2402 * not reference-counted).
2403 * It can be NULL, in which case it is considered a flush
2404 * packet. This signals the end of the stream. If the encoder
2405 * still has packets buffered, it will return them after this
2406 * call. Once flushing mode has been entered, additional flush
2407 * packets are ignored, and sending frames will return
2408 * AVERROR_EOF.
2409 *
2410 * For audio:
2411 * If AV_CODEC_CAP_VARIABLE_FRAME_SIZE is set, then each frame
2412 * can have any number of samples.
2413 * If it is not set, frame->nb_samples must be equal to
2414 * avctx->frame_size for all frames except the last.
2415 * The final frame may be smaller than avctx->frame_size.
2416 * @retval 0 success
2417 * @retval AVERROR(EAGAIN) input is not accepted in the current state - user must
2418 * read output with avcodec_receive_packet() (once all
2419 * output is read, the packet should be resent, and the
2420 * call will not fail with EAGAIN).
2421 * @retval AVERROR_EOF the encoder has been flushed, and no new frames can
2422 * be sent to it
2423 * @retval AVERROR(EINVAL) codec not opened, it is a decoder, or requires flush
2424 * @retval AVERROR(ENOMEM) failed to add packet to internal queue, or similar
2425 * @retval "another negative error code" legitimate encoding errors
2426 */
2427int avcodec_send_frame(AVCodecContext *avctx, const AVFrame *frame);
2428
2429/**
2430 * Read encoded data from the encoder.
2431 *
2432 * @param avctx codec context
2433 * @param avpkt This will be set to a reference-counted packet allocated by the
2434 * encoder. Note that the function will always call
2435 * av_packet_unref(avpkt) before doing anything else.
2436 * @retval 0 success
2437 * @retval AVERROR(EAGAIN) output is not available in the current state - user must
2438 * try to send input
2439 * @retval AVERROR_EOF the encoder has been fully flushed, and there will be no
2440 * more output packets
2441 * @retval AVERROR(EINVAL) codec not opened, or it is a decoder
2442 * @retval "another negative error code" legitimate encoding errors
2443 */
2444int avcodec_receive_packet(AVCodecContext *avctx, AVPacket *avpkt);
2445
2446/**
2447 * Create and return a AVHWFramesContext with values adequate for hardware
2448 * decoding. This is meant to get called from the get_format callback, and is
2449 * a helper for preparing a AVHWFramesContext for AVCodecContext.hw_frames_ctx.
2450 * This API is for decoding with certain hardware acceleration modes/APIs only.
2451 *
2452 * The returned AVHWFramesContext is not initialized. The caller must do this
2453 * with av_hwframe_ctx_init().
2454 *
2455 * Calling this function is not a requirement, but makes it simpler to avoid
2456 * codec or hardware API specific details when manually allocating frames.
2457 *
2458 * Alternatively to this, an API user can set AVCodecContext.hw_device_ctx,
2459 * which sets up AVCodecContext.hw_frames_ctx fully automatically, and makes
2460 * it unnecessary to call this function or having to care about
2461 * AVHWFramesContext initialization at all.
2462 *
2463 * There are a number of requirements for calling this function:
2464 *
2465 * - It must be called from get_format with the same avctx parameter that was
2466 * passed to get_format. Calling it outside of get_format is not allowed, and
2467 * can trigger undefined behavior.
2468 * - The function is not always supported (see description of return values).
2469 * Even if this function returns successfully, hwaccel initialization could
2470 * fail later. (The degree to which implementations check whether the stream
2471 * is actually supported varies. Some do this check only after the user's
2472 * get_format callback returns.)
2473 * - The hw_pix_fmt must be one of the choices suggested by get_format. If the
2474 * user decides to use a AVHWFramesContext prepared with this API function,
2475 * the user must return the same hw_pix_fmt from get_format.
2476 * - The device_ref passed to this function must support the given hw_pix_fmt.
2477 * - After calling this API function, it is the user's responsibility to
2478 * initialize the AVHWFramesContext (returned by the out_frames_ref parameter),
2479 * and to set AVCodecContext.hw_frames_ctx to it. If done, this must be done
2480 * before returning from get_format (this is implied by the normal
2481 * AVCodecContext.hw_frames_ctx API rules).
2482 * - The AVHWFramesContext parameters may change every time time get_format is
2483 * called. Also, AVCodecContext.hw_frames_ctx is reset before get_format. So
2484 * you are inherently required to go through this process again on every
2485 * get_format call.
2486 * - It is perfectly possible to call this function without actually using
2487 * the resulting AVHWFramesContext. One use-case might be trying to reuse a
2488 * previously initialized AVHWFramesContext, and calling this API function
2489 * only to test whether the required frame parameters have changed.
2490 * - Fields that use dynamically allocated values of any kind must not be set
2491 * by the user unless setting them is explicitly allowed by the documentation.
2492 * If the user sets AVHWFramesContext.free and AVHWFramesContext.user_opaque,
2493 * the new free callback must call the potentially set previous free callback.
2494 * This API call may set any dynamically allocated fields, including the free
2495 * callback.
2496 *
2497 * The function will set at least the following fields on AVHWFramesContext
2498 * (potentially more, depending on hwaccel API):
2499 *
2500 * - All fields set by av_hwframe_ctx_alloc().
2501 * - Set the format field to hw_pix_fmt.
2502 * - Set the sw_format field to the most suited and most versatile format. (An
2503 * implication is that this will prefer generic formats over opaque formats
2504 * with arbitrary restrictions, if possible.)
2505 * - Set the width/height fields to the coded frame size, rounded up to the
2506 * API-specific minimum alignment.
2507 * - Only _if_ the hwaccel requires a pre-allocated pool: set the initial_pool_size
2508 * field to the number of maximum reference surfaces possible with the codec,
2509 * plus 1 surface for the user to work (meaning the user can safely reference
2510 * at most 1 decoded surface at a time), plus additional buffering introduced
2511 * by frame threading. If the hwaccel does not require pre-allocation, the
2512 * field is left to 0, and the decoder will allocate new surfaces on demand
2513 * during decoding.
2514 * - Possibly AVHWFramesContext.hwctx fields, depending on the underlying
2515 * hardware API.
2516 *
2517 * Essentially, out_frames_ref returns the same as av_hwframe_ctx_alloc(), but
2518 * with basic frame parameters set.
2519 *
2520 * The function is stateless, and does not change the AVCodecContext or the
2521 * device_ref AVHWDeviceContext.
2522 *
2523 * @param avctx The context which is currently calling get_format, and which
2524 * implicitly contains all state needed for filling the returned
2525 * AVHWFramesContext properly.
2526 * @param device_ref A reference to the AVHWDeviceContext describing the device
2527 * which will be used by the hardware decoder.
2528 * @param hw_pix_fmt The hwaccel format you are going to return from get_format.
2529 * @param out_frames_ref On success, set to a reference to an _uninitialized_
2530 * AVHWFramesContext, created from the given device_ref.
2531 * Fields will be set to values required for decoding.
2532 * Not changed if an error is returned.
2533 * @return zero on success, a negative value on error. The following error codes
2534 * have special semantics:
2535 * AVERROR(ENOENT): the decoder does not support this functionality. Setup
2536 * is always manual, or it is a decoder which does not
2537 * support setting AVCodecContext.hw_frames_ctx at all,
2538 * or it is a software format.
2539 * AVERROR(EINVAL): it is known that hardware decoding is not supported for
2540 * this configuration, or the device_ref is not supported
2541 * for the hwaccel referenced by hw_pix_fmt.
2542 */
2543int avcodec_get_hw_frames_parameters(AVCodecContext *avctx,
2544 AVBufferRef *device_ref,
2545 enum AVPixelFormat hw_pix_fmt,
2546 AVBufferRef **out_frames_ref);
2547
2548enum AVCodecConfig {
2549 AV_CODEC_CONFIG_PIX_FORMAT, ///< AVPixelFormat, terminated by AV_PIX_FMT_NONE
2550 AV_CODEC_CONFIG_FRAME_RATE, ///< AVRational, terminated by {0, 0}
2551 AV_CODEC_CONFIG_SAMPLE_RATE, ///< int, terminated by 0
2552 AV_CODEC_CONFIG_SAMPLE_FORMAT, ///< AVSampleFormat, terminated by AV_SAMPLE_FMT_NONE
2553 AV_CODEC_CONFIG_CHANNEL_LAYOUT, ///< AVChannelLayout, terminated by {0}
2554 AV_CODEC_CONFIG_COLOR_RANGE, ///< AVColorRange, terminated by AVCOL_RANGE_UNSPECIFIED
2555 AV_CODEC_CONFIG_COLOR_SPACE, ///< AVColorSpace, terminated by AVCOL_SPC_UNSPECIFIED
2556 AV_CODEC_CONFIG_ALPHA_MODE, ///< AVAlphaMode, terminated by AVALPHA_MODE_UNSPECIFIED
2557};
2558
2559/**
2560 * Retrieve a list of all supported values for a given configuration type.
2561 *
2562 * @param avctx An optional context to use. Values such as
2563 * `strict_std_compliance` may affect the result. If NULL,
2564 * default values are used.
2565 * @param codec The codec to query, or NULL to use avctx->codec.
2566 * @param config The configuration to query.
2567 * @param flags Currently unused; should be set to zero.
2568 * @param out_configs On success, set to a list of configurations, terminated
2569 * by a config-specific terminator, or NULL if all
2570 * possible values are supported.
2571 * @param out_num_configs On success, set to the number of elements in
2572 *out_configs, excluding the terminator. Optional.
2573 */
2574int avcodec_get_supported_config(const AVCodecContext *avctx,
2575 const AVCodec *codec, enum AVCodecConfig config,
2576 unsigned flags, const void **out_configs,
2577 int *out_num_configs);
2578
2579
2580
2581/**
2582 * @defgroup lavc_parsing Frame parsing
2583 * @{
2584 */
2585
2586enum AVPictureStructure {
2587 AV_PICTURE_STRUCTURE_UNKNOWN, ///< unknown
2588 AV_PICTURE_STRUCTURE_TOP_FIELD, ///< coded as top field
2589 AV_PICTURE_STRUCTURE_BOTTOM_FIELD, ///< coded as bottom field
2590 AV_PICTURE_STRUCTURE_FRAME, ///< coded as frame
2591};
2592
2593typedef struct AVCodecParserContext {
2594 void *priv_data;
2595 const struct AVCodecParser *parser;
2596 int64_t frame_offset; /* offset of the current frame */
2597 int64_t cur_offset; /* current offset
2598 (incremented by each av_parser_parse()) */
2599 int64_t next_frame_offset; /* offset of the next frame */
2600 /* video info */
2601 int pict_type; /* XXX: Put it back in AVCodecContext. */
2602 /**
2603 * This field is used for proper frame duration computation in lavf.
2604 * It signals, how much longer the frame duration of the current frame
2605 * is compared to normal frame duration.
2606 *
2607 * frame_duration = (1 + repeat_pict) * time_base
2608 *
2609 * It is used by codecs like H.264 to display telecined material.
2610 */
2611 int repeat_pict; /* XXX: Put it back in AVCodecContext. */
2612 int64_t pts; /* pts of the current frame */
2613 int64_t dts; /* dts of the current frame */
2614
2615 /* private data */
2616 int64_t last_pts;
2617 int64_t last_dts;
2618 int fetch_timestamp;
2619
2620#define AV_PARSER_PTS_NB 4
2621 int cur_frame_start_index;
2622 int64_t cur_frame_offset[AV_PARSER_PTS_NB];
2623 int64_t cur_frame_pts[AV_PARSER_PTS_NB];
2624 int64_t cur_frame_dts[AV_PARSER_PTS_NB];
2625
2626 int flags;
2627#define PARSER_FLAG_COMPLETE_FRAMES 0x0001
2628#define PARSER_FLAG_ONCE 0x0002
2629/// Set if the parser has a valid file offset
2630#define PARSER_FLAG_FETCHED_OFFSET 0x0004
2631#define PARSER_FLAG_USE_CODEC_TS 0x1000
2632
2633 int64_t offset; ///< byte offset from starting packet start
2634 int64_t cur_frame_end[AV_PARSER_PTS_NB];
2635
2636 /**
2637 * Set by parser to 1 for key frames and 0 for non-key frames.
2638 * It is initialized to -1, so if the parser doesn't set this flag,
2639 * old-style fallback using AV_PICTURE_TYPE_I picture type as key frames
2640 * will be used.
2641 */
2642 int key_frame;
2643
2644 // Timestamp generation support:
2645 /**
2646 * Synchronization point for start of timestamp generation.
2647 *
2648 * Set to >0 for sync point, 0 for no sync point and <0 for undefined
2649 * (default).
2650 *
2651 * For example, this corresponds to presence of H.264 buffering period
2652 * SEI message.
2653 */
2654 int dts_sync_point;
2655
2656 /**
2657 * Offset of the current timestamp against last timestamp sync point in
2658 * units of AVCodecContext.time_base.
2659 *
2660 * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
2661 * contain a valid timestamp offset.
2662 *
2663 * Note that the timestamp of sync point has usually a nonzero
2664 * dts_ref_dts_delta, which refers to the previous sync point. Offset of
2665 * the next frame after timestamp sync point will be usually 1.
2666 *
2667 * For example, this corresponds to H.264 cpb_removal_delay.
2668 */
2669 int dts_ref_dts_delta;
2670
2671 /**
2672 * Presentation delay of current frame in units of AVCodecContext.time_base.
2673 *
2674 * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
2675 * contain valid non-negative timestamp delta (presentation time of a frame
2676 * must not lie in the past).
2677 *
2678 * This delay represents the difference between decoding and presentation
2679 * time of the frame.
2680 *
2681 * For example, this corresponds to H.264 dpb_output_delay.
2682 */
2683 int pts_dts_delta;
2684
2685 /**
2686 * Position of the packet in file.
2687 *
2688 * Analogous to cur_frame_pts/dts
2689 */
2690 int64_t cur_frame_pos[AV_PARSER_PTS_NB];
2691
2692 /**
2693 * Byte position of currently parsed frame in stream.
2694 */
2695 int64_t pos;
2696
2697 /**
2698 * Previous frame byte position.
2699 */
2700 int64_t last_pos;
2701
2702 /**
2703 * Duration of the current frame.
2704 * For audio, this is in units of 1 / AVCodecContext.sample_rate.
2705 * For all other types, this is in units of AVCodecContext.time_base.
2706 */
2707 int duration;
2708
2709 enum AVFieldOrder field_order;
2710
2711 /**
2712 * Indicate whether a picture is coded as a frame, top field or bottom field.
2713 *
2714 * For example, H.264 field_pic_flag equal to 0 corresponds to
2715 * AV_PICTURE_STRUCTURE_FRAME. An H.264 picture with field_pic_flag
2716 * equal to 1 and bottom_field_flag equal to 0 corresponds to
2717 * AV_PICTURE_STRUCTURE_TOP_FIELD.
2718 */
2719 enum AVPictureStructure picture_structure;
2720
2721 /**
2722 * Picture number incremented in presentation or output order.
2723 * This field may be reinitialized at the first picture of a new sequence.
2724 *
2725 * For example, this corresponds to H.264 PicOrderCnt.
2726 */
2727 int output_picture_number;
2728
2729 /**
2730 * Dimensions of the decoded video intended for presentation.
2731 */
2732 int width;
2733 int height;
2734
2735 /**
2736 * Dimensions of the coded video.
2737 */
2738 int coded_width;
2739 int coded_height;
2740
2741 /**
2742 * The format of the coded data, corresponds to enum AVPixelFormat for video
2743 * and for enum AVSampleFormat for audio.
2744 *
2745 * Note that a decoder can have considerable freedom in how exactly it
2746 * decodes the data, so the format reported here might be different from the
2747 * one returned by a decoder.
2748 */
2749 int format;
2750} AVCodecParserContext;
2751
2752typedef struct AVCodecParser {
2753#if FF_API_PARSER_CODECID
2754 int codec_ids[7]; /* several codec IDs are permitted */
2755#else
2756 enum AVCodecID codec_ids[7]; /* several codec IDs are permitted */
2757#endif
2758#if FF_API_PARSER_PRIVATE
2759 /*****************************************************************
2760 * All fields below this line are not part of the public API. They
2761 * may not be used outside of libavcodec and can be changed and
2762 * removed at will.
2763 * New public fields should be added right above.
2764 *****************************************************************
2765 */
2766 attribute_deprecated
2767 int priv_data_size;
2768 attribute_deprecated
2769 int (*parser_init)(AVCodecParserContext *s);
2770 /* This callback never returns an error, a negative value means that
2771 * the frame start was in a previous packet. */
2772 attribute_deprecated
2773 int (*parser_parse)(AVCodecParserContext *s,
2774 AVCodecContext *avctx,
2775 const uint8_t **poutbuf, int *poutbuf_size,
2776 const uint8_t *buf, int buf_size);
2777 attribute_deprecated
2778 void (*parser_close)(AVCodecParserContext *s);
2779 attribute_deprecated
2780 int (*split)(AVCodecContext *avctx, const uint8_t *buf, int buf_size);
2781#endif
2782} AVCodecParser;
2783
2784/**
2785 * Iterate over all registered codec parsers.
2786 *
2787 * @param opaque a pointer where libavcodec will store the iteration state. Must
2788 * point to NULL to start the iteration.
2789 *
2790 * @return the next registered codec parser or NULL when the iteration is
2791 * finished
2792 */
2793const AVCodecParser *av_parser_iterate(void **opaque);
2794
2795#if FF_API_PARSER_CODECID
2796AVCodecParserContext *av_parser_init(int codec_id);
2797#else
2798AVCodecParserContext *av_parser_init(enum AVCodecID codec_id);
2799#endif
2800
2801/**
2802 * Parse a packet.
2803 *
2804 * @param s parser context.
2805 * @param avctx codec context.
2806 * @param poutbuf set to pointer to parsed buffer or NULL if not yet finished.
2807 * @param poutbuf_size set to size of parsed buffer or zero if not yet finished.
2808 * @param buf input buffer.
2809 * @param buf_size buffer size in bytes without the padding. I.e. the full buffer
2810 size is assumed to be buf_size + AV_INPUT_BUFFER_PADDING_SIZE.
2811 To signal EOF, this should be 0 (so that the last frame
2812 can be output).
2813 * @param pts input presentation timestamp.
2814 * @param dts input decoding timestamp.
2815 * @param pos input byte position in stream.
2816 * @return the number of bytes of the input bitstream used.
2817 *
2818 * Example:
2819 * @code
2820 * while(in_len){
2821 * len = av_parser_parse2(myparser, AVCodecContext, &data, &size,
2822 * in_data, in_len,
2823 * pts, dts, pos);
2824 * in_data += len;
2825 * in_len -= len;
2826 *
2827 * if(size)
2828 * decode_frame(data, size);
2829 * }
2830 * @endcode
2831 */
2832int av_parser_parse2(AVCodecParserContext *s,
2833 AVCodecContext *avctx,
2834 uint8_t **poutbuf, int *poutbuf_size,
2835 const uint8_t *buf, int buf_size,
2836 int64_t pts, int64_t dts,
2837 int64_t pos);
2838
2839void av_parser_close(AVCodecParserContext *s);
2840
2841/**
2842 * @}
2843 * @}
2844 */
2845
2846/**
2847 * @addtogroup lavc_encoding
2848 * @{
2849 */
2850
2851int avcodec_encode_subtitle(AVCodecContext *avctx, uint8_t *buf, int buf_size,
2852 const AVSubtitle *sub);
2853
2854
2855/**
2856 * @}
2857 */
2858
2859/**
2860 * @defgroup lavc_misc Utility functions
2861 * @ingroup libavc
2862 *
2863 * Miscellaneous utility functions related to both encoding and decoding
2864 * (or neither).
2865 * @{
2866 */
2867
2868/**
2869 * @defgroup lavc_misc_pixfmt Pixel formats
2870 *
2871 * Functions for working with pixel formats.
2872 * @{
2873 */
2874
2875/**
2876 * Return a value representing the fourCC code associated to the
2877 * pixel format pix_fmt, or 0 if no associated fourCC code can be
2878 * found.
2879 */
2880unsigned int avcodec_pix_fmt_to_codec_tag(enum AVPixelFormat pix_fmt);
2881
2882/**
2883 * Find the best pixel format to convert to given a certain source pixel
2884 * format. When converting from one pixel format to another, information loss
2885 * may occur. For example, when converting from RGB24 to GRAY, the color
2886 * information will be lost. Similarly, other losses occur when converting from
2887 * some formats to other formats. avcodec_find_best_pix_fmt_of_2() searches which of
2888 * the given pixel formats should be used to suffer the least amount of loss.
2889 * The pixel formats from which it chooses one, are determined by the
2890 * pix_fmt_list parameter.
2891 *
2892 *
2893 * @param[in] pix_fmt_list AV_PIX_FMT_NONE terminated array of pixel formats to choose from
2894 * @param[in] src_pix_fmt source pixel format
2895 * @param[in] has_alpha Whether the source pixel format alpha channel is used.
2896 * @param[out] loss_ptr Combination of flags informing you what kind of losses will occur.
2897 * @return The best pixel format to convert to or -1 if none was found.
2898 */
2899enum AVPixelFormat avcodec_find_best_pix_fmt_of_list(const enum AVPixelFormat *pix_fmt_list,
2900 enum AVPixelFormat src_pix_fmt,
2901 int has_alpha, int *loss_ptr);
2902
2903enum AVPixelFormat avcodec_default_get_format(struct AVCodecContext *s, const enum AVPixelFormat * fmt);
2904
2905/**
2906 * @}
2907 */
2908
2909void avcodec_string(char *buf, int buf_size, AVCodecContext *enc, int encode);
2910
2911int avcodec_default_execute(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2),void *arg, int *ret, int count, int size);
2912int avcodec_default_execute2(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2, int, int),void *arg, int *ret, int count);
2913//FIXME func typedef
2914
2915/**
2916 * Fill AVFrame audio data and linesize pointers.
2917 *
2918 * The buffer buf must be a preallocated buffer with a size big enough
2919 * to contain the specified samples amount. The filled AVFrame data
2920 * pointers will point to this buffer.
2921 *
2922 * AVFrame extended_data channel pointers are allocated if necessary for
2923 * planar audio.
2924 *
2925 * @param frame the AVFrame
2926 * frame->nb_samples must be set prior to calling the
2927 * function. This function fills in frame->data,
2928 * frame->extended_data, frame->linesize[0].
2929 * @param nb_channels channel count
2930 * @param sample_fmt sample format
2931 * @param buf buffer to use for frame data
2932 * @param buf_size size of buffer
2933 * @param align plane size sample alignment (0 = default)
2934 * @return >=0 on success, negative error code on failure
2935 * @todo return the size in bytes required to store the samples in
2936 * case of success, at the next libavutil bump
2937 */
2938int avcodec_fill_audio_frame(AVFrame *frame, int nb_channels,
2939 enum AVSampleFormat sample_fmt, const uint8_t *buf,
2940 int buf_size, int align);
2941
2942/**
2943 * Reset the internal codec state / flush internal buffers. Should be called
2944 * e.g. when seeking or when switching to a different stream.
2945 *
2946 * @note for decoders, this function just releases any references the decoder
2947 * might keep internally, but the caller's references remain valid.
2948 *
2949 * @note for encoders, this function will only do something if the encoder
2950 * declares support for AV_CODEC_CAP_ENCODER_FLUSH. When called, the encoder
2951 * will drain any remaining packets, and can then be reused for a different
2952 * stream (as opposed to sending a null frame which will leave the encoder
2953 * in a permanent EOF state after draining). This can be desirable if the
2954 * cost of tearing down and replacing the encoder instance is high.
2955 */
2956void avcodec_flush_buffers(AVCodecContext *avctx);
2957
2958/**
2959 * Return audio frame duration.
2960 *
2961 * @param avctx codec context
2962 * @param frame_bytes size of the frame, or 0 if unknown
2963 * @return frame duration, in samples, if known. 0 if not able to
2964 * determine.
2965 */
2966int av_get_audio_frame_duration(AVCodecContext *avctx, int frame_bytes);
2967
2968/* memory */
2969
2970/**
2971 * Same behaviour av_fast_malloc but the buffer has additional
2972 * AV_INPUT_BUFFER_PADDING_SIZE at the end which will always be 0.
2973 *
2974 * In addition the whole buffer will initially and after resizes
2975 * be 0-initialized so that no uninitialized data will ever appear.
2976 */
2977void av_fast_padded_malloc(void *ptr, unsigned int *size, size_t min_size);
2978
2979/**
2980 * Same behaviour av_fast_padded_malloc except that buffer will always
2981 * be 0-initialized after call.
2982 */
2983void av_fast_padded_mallocz(void *ptr, unsigned int *size, size_t min_size);
2984
2985/**
2986 * @return a positive value if s is open (i.e. avcodec_open2() was called on it),
2987 * 0 otherwise.
2988 */
2989int avcodec_is_open(AVCodecContext *s);
2990
2991/**
2992 * @}
2993 */
2994
2995#endif /* AVCODEC_AVCODEC_H */
2996