2 * copyright (c) 2001 Fabrice Bellard
4 * This file is part of FFmpeg.
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 #ifndef AVCODEC_AVCODEC_H
22 #define AVCODEC_AVCODEC_H
27 * Libavcodec external API header
31 #include "libavutil/samplefmt.h"
32 #include "libavutil/attributes.h"
33 #include "libavutil/avutil.h"
34 #include "libavutil/buffer.h"
35 #include "libavutil/cpu.h"
36 #include "libavutil/channel_layout.h"
37 #include "libavutil/dict.h"
38 #include "libavutil/frame.h"
39 #include "libavutil/hwcontext.h"
40 #include "libavutil/log.h"
41 #include "libavutil/pixfmt.h"
42 #include "libavutil/rational.h"
46 #include "codec_desc.h"
47 #include "codec_par.h"
53 * @defgroup libavc libavcodec
54 * Encoding/Decoding Library
58 * @defgroup lavc_decoding Decoding
62 * @defgroup lavc_encoding Encoding
66 * @defgroup lavc_codec Codecs
68 * @defgroup lavc_codec_native Native Codecs
71 * @defgroup lavc_codec_wrappers External library wrappers
74 * @defgroup lavc_codec_hwaccel Hardware Accelerators bridge
78 * @defgroup lavc_internal Internal
86 * @defgroup lavc_encdec send/receive encoding and decoding API overview
89 * The avcodec_send_packet()/avcodec_receive_frame()/avcodec_send_frame()/
90 * avcodec_receive_packet() functions provide an encode/decode API, which
91 * decouples input and output.
93 * The API is very similar for encoding/decoding and audio/video, and works as
95 * - Set up and open the AVCodecContext as usual.
97 * - For decoding, call avcodec_send_packet() to give the decoder raw
98 * compressed data in an AVPacket.
99 * - For encoding, call avcodec_send_frame() to give the encoder an AVFrame
100 * containing uncompressed audio or video.
102 * In both cases, it is recommended that AVPackets and AVFrames are
103 * refcounted, or libavcodec might have to copy the input data. (libavformat
104 * always returns refcounted AVPackets, and av_frame_get_buffer() allocates
105 * refcounted AVFrames.)
106 * - Receive output in a loop. Periodically call one of the avcodec_receive_*()
107 * functions and process their output:
108 * - For decoding, call avcodec_receive_frame(). On success, it will return
109 * an AVFrame containing uncompressed audio or video data.
110 * - For encoding, call avcodec_receive_packet(). On success, it will return
111 * an AVPacket with a compressed frame.
113 * Repeat this call until it returns AVERROR(EAGAIN) or an error. The
114 * AVERROR(EAGAIN) return value means that new input data is required to
115 * return new output. In this case, continue with sending input. For each
116 * input frame/packet, the codec will typically return 1 output frame/packet,
117 * but it can also be 0 or more than 1.
119 * At the beginning of decoding or encoding, the codec might accept multiple
120 * input frames/packets without returning a frame, until its internal buffers
121 * are filled. This situation is handled transparently if you follow the steps
124 * In theory, sending input can result in EAGAIN - this should happen only if
125 * not all output was received. You can use this to structure alternative decode
126 * or encode loops other than the one suggested above. For example, you could
127 * try sending new input on each iteration, and try to receive output if that
130 * End of stream situations. These require "flushing" (aka draining) the codec,
131 * as the codec might buffer multiple frames or packets internally for
132 * performance or out of necessity (consider B-frames).
133 * This is handled as follows:
134 * - Instead of valid input, send NULL to the avcodec_send_packet() (decoding)
135 * or avcodec_send_frame() (encoding) functions. This will enter draining
137 * - Call avcodec_receive_frame() (decoding) or avcodec_receive_packet()
138 * (encoding) in a loop until AVERROR_EOF is returned. The functions will
139 * not return AVERROR(EAGAIN), unless you forgot to enter draining mode.
140 * - Before decoding can be resumed again, the codec has to be reset with
141 * avcodec_flush_buffers().
143 * Using the API as outlined above is highly recommended. But it is also
144 * possible to call functions outside of this rigid schema. For example, you can
145 * call avcodec_send_packet() repeatedly without calling
146 * avcodec_receive_frame(). In this case, avcodec_send_packet() will succeed
147 * until the codec's internal buffer has been filled up (which is typically of
148 * size 1 per output frame, after initial input), and then reject input with
149 * AVERROR(EAGAIN). Once it starts rejecting input, you have no choice but to
150 * read at least some output.
152 * Not all codecs will follow a rigid and predictable dataflow; the only
153 * guarantee is that an AVERROR(EAGAIN) return value on a send/receive call on
154 * one end implies that a receive/send call on the other end will succeed, or
155 * at least will not fail with AVERROR(EAGAIN). In general, no codec will
156 * permit unlimited buffering of input or output.
158 * This API replaces the following legacy functions:
159 * - avcodec_decode_video2() and avcodec_decode_audio4():
160 * Use avcodec_send_packet() to feed input to the decoder, then use
161 * avcodec_receive_frame() to receive decoded frames after each packet.
162 * Unlike with the old video decoding API, multiple frames might result from
163 * a packet. For audio, splitting the input packet into frames by partially
164 * decoding packets becomes transparent to the API user. You never need to
165 * feed an AVPacket to the API twice (unless it is rejected with AVERROR(EAGAIN) - then
166 * no data was read from the packet).
167 * Additionally, sending a flush/draining packet is required only once.
168 * - avcodec_encode_video2()/avcodec_encode_audio2():
169 * Use avcodec_send_frame() to feed input to the encoder, then use
170 * avcodec_receive_packet() to receive encoded packets.
171 * Providing user-allocated buffers for avcodec_receive_packet() is not
173 * - The new API does not handle subtitles yet.
175 * Mixing new and old function calls on the same AVCodecContext is not allowed,
176 * and will result in undefined behavior.
178 * Some codecs might require using the new API; using the old API will return
179 * an error when calling it. All codecs support the new API.
181 * A codec is not allowed to return AVERROR(EAGAIN) for both sending and receiving. This
182 * would be an invalid state, which could put the codec user into an endless
183 * loop. The API has no concept of time either: it cannot happen that trying to
184 * do avcodec_send_packet() results in AVERROR(EAGAIN), but a repeated call 1 second
185 * later accepts the packet (with no other receive/flush API calls involved).
186 * The API is a strict state machine, and the passage of time is not supposed
187 * to influence it. Some timing-dependent behavior might still be deemed
188 * acceptable in certain cases. But it must never result in both send/receive
189 * returning EAGAIN at the same time at any point. It must also absolutely be
190 * avoided that the current state is "unstable" and can "flip-flop" between
191 * the send/receive APIs allowing progress. For example, it's not allowed that
192 * the codec randomly decides that it actually wants to consume a packet now
193 * instead of returning a frame, after it just returned AVERROR(EAGAIN) on an
194 * avcodec_send_packet() call.
199 * @defgroup lavc_core Core functions/structures.
202 * Basic definitions, functions for querying libavcodec capabilities,
203 * allocating core structures, etc.
208 * @ingroup lavc_decoding
209 * Required number of additionally allocated bytes at the end of the input bitstream for decoding.
210 * This is mainly needed because some optimized bitstream readers read
211 * 32 or 64 bit at once and could read over the end.<br>
212 * Note: If the first 23 bits of the additional bytes are not 0, then damaged
213 * MPEG bitstreams could cause overread and segfault.
215 #define AV_INPUT_BUFFER_PADDING_SIZE 64
218 * @ingroup lavc_encoding
219 * minimum encoding buffer size
220 * Used to avoid some checks during header writing.
222 #define AV_INPUT_BUFFER_MIN_SIZE 16384
225 * @ingroup lavc_decoding
228 /* We leave some space between them for extensions (drop some
229 * keyframes for intra-only or drop just some bidir frames). */
230 AVDISCARD_NONE =-16, ///< discard nothing
231 AVDISCARD_DEFAULT = 0, ///< discard useless packets like 0 size packets in avi
232 AVDISCARD_NONREF = 8, ///< discard all non reference
233 AVDISCARD_BIDIR = 16, ///< discard all bidirectional frames
234 AVDISCARD_NONINTRA= 24, ///< discard all non intra frames
235 AVDISCARD_NONKEY = 32, ///< discard all frames except keyframes
236 AVDISCARD_ALL = 48, ///< discard all
239 enum AVAudioServiceType {
240 AV_AUDIO_SERVICE_TYPE_MAIN = 0,
241 AV_AUDIO_SERVICE_TYPE_EFFECTS = 1,
242 AV_AUDIO_SERVICE_TYPE_VISUALLY_IMPAIRED = 2,
243 AV_AUDIO_SERVICE_TYPE_HEARING_IMPAIRED = 3,
244 AV_AUDIO_SERVICE_TYPE_DIALOGUE = 4,
245 AV_AUDIO_SERVICE_TYPE_COMMENTARY = 5,
246 AV_AUDIO_SERVICE_TYPE_EMERGENCY = 6,
247 AV_AUDIO_SERVICE_TYPE_VOICE_OVER = 7,
248 AV_AUDIO_SERVICE_TYPE_KARAOKE = 8,
249 AV_AUDIO_SERVICE_TYPE_NB , ///< Not part of ABI
253 * @ingroup lavc_encoding
255 typedef struct RcOverride{
258 int qscale; // If this is 0 then quality_factor will be used instead.
259 float quality_factor;
263 These flags can be passed in AVCodecContext.flags before initialization.
264 Note: Not everything is supported yet.
268 * Allow decoders to produce frames with data planes that are not aligned
269 * to CPU requirements (e.g. due to cropping).
271 #define AV_CODEC_FLAG_UNALIGNED (1 << 0)
275 #define AV_CODEC_FLAG_QSCALE (1 << 1)
277 * 4 MV per MB allowed / advanced prediction for H.263.
279 #define AV_CODEC_FLAG_4MV (1 << 2)
281 * Output even those frames that might be corrupted.
283 #define AV_CODEC_FLAG_OUTPUT_CORRUPT (1 << 3)
287 #define AV_CODEC_FLAG_QPEL (1 << 4)
289 * Don't output frames whose parameters differ from first
290 * decoded frame in stream.
292 #define AV_CODEC_FLAG_DROPCHANGED (1 << 5)
294 * Use internal 2pass ratecontrol in first pass mode.
296 #define AV_CODEC_FLAG_PASS1 (1 << 9)
298 * Use internal 2pass ratecontrol in second pass mode.
300 #define AV_CODEC_FLAG_PASS2 (1 << 10)
304 #define AV_CODEC_FLAG_LOOP_FILTER (1 << 11)
306 * Only decode/encode grayscale.
308 #define AV_CODEC_FLAG_GRAY (1 << 13)
310 * error[?] variables will be set during encoding.
312 #define AV_CODEC_FLAG_PSNR (1 << 15)
314 * Input bitstream might be truncated at a random location
315 * instead of only at frame boundaries.
317 #define AV_CODEC_FLAG_TRUNCATED (1 << 16)
319 * Use interlaced DCT.
321 #define AV_CODEC_FLAG_INTERLACED_DCT (1 << 18)
325 #define AV_CODEC_FLAG_LOW_DELAY (1 << 19)
327 * Place global headers in extradata instead of every keyframe.
329 #define AV_CODEC_FLAG_GLOBAL_HEADER (1 << 22)
331 * Use only bitexact stuff (except (I)DCT).
333 #define AV_CODEC_FLAG_BITEXACT (1 << 23)
334 /* Fx : Flag for H.263+ extra options */
336 * H.263 advanced intra coding / MPEG-4 AC prediction
338 #define AV_CODEC_FLAG_AC_PRED (1 << 24)
340 * interlaced motion estimation
342 #define AV_CODEC_FLAG_INTERLACED_ME (1 << 29)
343 #define AV_CODEC_FLAG_CLOSED_GOP (1U << 31)
346 * Allow non spec compliant speedup tricks.
348 #define AV_CODEC_FLAG2_FAST (1 << 0)
350 * Skip bitstream encoding.
352 #define AV_CODEC_FLAG2_NO_OUTPUT (1 << 2)
354 * Place global headers at every keyframe instead of in extradata.
356 #define AV_CODEC_FLAG2_LOCAL_HEADER (1 << 3)
359 * timecode is in drop frame format. DEPRECATED!!!!
361 #define AV_CODEC_FLAG2_DROP_FRAME_TIMECODE (1 << 13)
364 * Input bitstream might be truncated at a packet boundaries
365 * instead of only at frame boundaries.
367 #define AV_CODEC_FLAG2_CHUNKS (1 << 15)
369 * Discard cropping information from SPS.
371 #define AV_CODEC_FLAG2_IGNORE_CROP (1 << 16)
374 * Show all frames before the first keyframe
376 #define AV_CODEC_FLAG2_SHOW_ALL (1 << 22)
378 * Export motion vectors through frame side data
380 #define AV_CODEC_FLAG2_EXPORT_MVS (1 << 28)
382 * Do not skip samples and export skip information as frame side data
384 #define AV_CODEC_FLAG2_SKIP_MANUAL (1 << 29)
386 * Do not reset ASS ReadOrder field on flush (subtitles decoding)
388 #define AV_CODEC_FLAG2_RO_FLUSH_NOOP (1 << 30)
390 /* Unsupported options :
391 * Syntax Arithmetic coding (SAC)
392 * Reference Picture Selection
393 * Independent Segment Decoding */
395 /* codec capabilities */
397 /* Exported side data.
398 These flags can be passed in AVCodecContext.export_side_data before initialization.
401 * Export motion vectors through frame side data
403 #define AV_CODEC_EXPORT_DATA_MVS (1 << 0)
405 * Export encoder Producer Reference Time through packet side data
407 #define AV_CODEC_EXPORT_DATA_PRFT (1 << 1)
410 * Export the AVVideoEncParams structure through frame side data.
412 #define AV_CODEC_EXPORT_DATA_VIDEO_ENC_PARAMS (1 << 2)
415 * Do not apply film grain, export it instead.
417 #define AV_CODEC_EXPORT_DATA_FILM_GRAIN (1 << 3)
421 * This specifies the area which should be displayed.
422 * Note there may be multiple such areas for one frame.
424 typedef struct AVPanScan {
427 * - encoding: Set by user.
428 * - decoding: Set by libavcodec.
433 * width and height in 1/16 pel
434 * - encoding: Set by user.
435 * - decoding: Set by libavcodec.
441 * position of the top left corner in 1/16 pel for up to 3 fields/frames
442 * - encoding: Set by user.
443 * - decoding: Set by libavcodec.
445 int16_t position[3][2];
449 * This structure describes the bitrate properties of an encoded bitstream. It
450 * roughly corresponds to a subset the VBV parameters for MPEG-2 or HRD
451 * parameters for H.264/HEVC.
453 typedef struct AVCPBProperties {
455 * Maximum bitrate of the stream, in bits per second.
456 * Zero if unknown or unspecified.
458 #if FF_API_UNSANITIZED_BITRATES
464 * Minimum bitrate of the stream, in bits per second.
465 * Zero if unknown or unspecified.
467 #if FF_API_UNSANITIZED_BITRATES
473 * Average bitrate of the stream, in bits per second.
474 * Zero if unknown or unspecified.
476 #if FF_API_UNSANITIZED_BITRATES
483 * The size of the buffer to which the ratecontrol is applied, in bits.
484 * Zero if unknown or unspecified.
489 * The delay between the time the packet this structure is associated with
490 * is received and the time when it should be decoded, in periods of a 27MHz
493 * UINT64_MAX when unknown or unspecified.
499 * This structure supplies correlation between a packet timestamp and a wall clock
500 * production time. The definition follows the Producer Reference Time ('prft')
501 * as defined in ISO/IEC 14496-12
503 typedef struct AVProducerReferenceTime {
505 * A UTC timestamp, in microseconds, since Unix epoch (e.g, av_gettime()).
509 } AVProducerReferenceTime;
512 * The decoder will keep a reference to the frame and may reuse it later.
514 #define AV_GET_BUFFER_FLAG_REF (1 << 0)
517 * The encoder will keep a reference to the packet and may reuse it later.
519 #define AV_GET_ENCODE_BUFFER_FLAG_REF (1 << 0)
521 struct AVCodecInternal;
524 * main external API structure.
525 * New fields can be added to the end with minor version bumps.
526 * Removal, reordering and changes to existing fields require a major
528 * You can use AVOptions (av_opt* / av_set/get*()) to access these fields from user
530 * The name string for AVOptions options matches the associated command line
531 * parameter name and can be found in libavcodec/options_table.h
532 * The AVOption/command line parameter names differ in some cases from the C
533 * structure field names for historic reasons or brevity.
534 * sizeof(AVCodecContext) must not be used outside libav*.
536 typedef struct AVCodecContext {
538 * information on struct for av_log
539 * - set by avcodec_alloc_context3
541 const AVClass *av_class;
542 int log_level_offset;
544 enum AVMediaType codec_type; /* see AVMEDIA_TYPE_xxx */
545 const struct AVCodec *codec;
546 enum AVCodecID codec_id; /* see AV_CODEC_ID_xxx */
549 * fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
550 * This is used to work around some encoder bugs.
551 * A demuxer should set this to what is stored in the field used to identify the codec.
552 * If there are multiple such fields in a container then the demuxer should choose the one
553 * which maximizes the information about the used codec.
554 * If the codec tag field in a container is larger than 32 bits then the demuxer should
555 * remap the longer ID to 32 bits with a table or other structure. Alternatively a new
556 * extra_codec_tag + size could be added but for this a clear advantage must be demonstrated
558 * - encoding: Set by user, if not then the default based on codec_id will be used.
559 * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
561 unsigned int codec_tag;
566 * Private context used for internal data.
568 * Unlike priv_data, this is not codec-specific. It is used in general
569 * libavcodec functions.
571 struct AVCodecInternal *internal;
574 * Private data of the user, can be used to carry app specific stuff.
575 * - encoding: Set by user.
576 * - decoding: Set by user.
581 * the average bitrate
582 * - encoding: Set by user; unused for constant quantizer encoding.
583 * - decoding: Set by user, may be overwritten by libavcodec
584 * if this info is available in the stream
589 * number of bits the bitstream is allowed to diverge from the reference.
590 * the reference can be CBR (for CBR pass1) or VBR (for pass2)
591 * - encoding: Set by user; unused for constant quantizer encoding.
594 int bit_rate_tolerance;
597 * Global quality for codecs which cannot change it per frame.
598 * This should be proportional to MPEG-1/2/4 qscale.
599 * - encoding: Set by user.
605 * - encoding: Set by user.
608 int compression_level;
609 #define FF_COMPRESSION_DEFAULT -1
613 * - encoding: Set by user.
614 * - decoding: Set by user.
620 * - encoding: Set by user.
621 * - decoding: Set by user.
626 * some codecs need / can use extradata like Huffman tables.
627 * MJPEG: Huffman tables
628 * rv10: additional flags
629 * MPEG-4: global headers (they can be in the bitstream or here)
630 * The allocated memory should be AV_INPUT_BUFFER_PADDING_SIZE bytes larger
631 * than extradata_size to avoid problems if it is read with the bitstream reader.
632 * The bytewise contents of extradata must not depend on the architecture or CPU endianness.
633 * Must be allocated with the av_malloc() family of functions.
634 * - encoding: Set/allocated/freed by libavcodec.
635 * - decoding: Set/allocated/freed by user.
641 * This is the fundamental unit of time (in seconds) in terms
642 * of which frame timestamps are represented. For fixed-fps content,
643 * timebase should be 1/framerate and timestamp increments should be
645 * This often, but not always is the inverse of the frame rate or field rate
646 * for video. 1/time_base is not the average frame rate if the frame rate is not
649 * Like containers, elementary streams also can store timestamps, 1/time_base
650 * is the unit in which these timestamps are specified.
651 * As example of such codec time base see ISO/IEC 14496-2:2001(E)
652 * vop_time_increment_resolution and fixed_vop_rate
653 * (fixed_vop_rate == 0 implies that it is different from the framerate)
655 * - encoding: MUST be set by user.
656 * - decoding: the use of this field for decoding is deprecated.
657 * Use framerate instead.
659 AVRational time_base;
662 * For some codecs, the time base is closer to the field rate than the frame rate.
663 * Most notably, H.264 and MPEG-2 specify time_base as half of frame duration
664 * if no telecine is used ...
666 * Set to time_base ticks per frame. Default 1, e.g., H.264/MPEG-2 set it to 2.
673 * Encoding: Number of frames delay there will be from the encoder input to
674 * the decoder output. (we assume the decoder matches the spec)
675 * Decoding: Number of frames delay in addition to what a standard decoder
676 * as specified in the spec would produce.
679 * Number of frames the decoded output will be delayed relative to the
683 * For encoding, this field is unused (see initial_padding).
685 * For decoding, this is the number of samples the decoder needs to
686 * output before the decoder's output is valid. When seeking, you should
687 * start decoding this many samples prior to your desired seek point.
689 * - encoding: Set by libavcodec.
690 * - decoding: Set by libavcodec.
697 * picture width / height.
699 * @note Those fields may not match the values of the last
700 * AVFrame output by avcodec_decode_video2 due frame
703 * - encoding: MUST be set by user.
704 * - decoding: May be set by the user before opening the decoder if known e.g.
705 * from the container. Some decoders will require the dimensions
706 * to be set by the caller. During decoding, the decoder may
707 * overwrite those values as required while parsing the data.
712 * Bitstream width / height, may be different from width/height e.g. when
713 * the decoded frame is cropped before being output or lowres is enabled.
715 * @note Those field may not match the value of the last
716 * AVFrame output by avcodec_receive_frame() due frame
720 * - decoding: May be set by the user before opening the decoder if known
721 * e.g. from the container. During decoding, the decoder may
722 * overwrite those values as required while parsing the data.
724 int coded_width, coded_height;
727 * the number of pictures in a group of pictures, or 0 for intra_only
728 * - encoding: Set by user.
734 * Pixel format, see AV_PIX_FMT_xxx.
735 * May be set by the demuxer if known from headers.
736 * May be overridden by the decoder if it knows better.
738 * @note This field may not match the value of the last
739 * AVFrame output by avcodec_receive_frame() due frame
742 * - encoding: Set by user.
743 * - decoding: Set by user if known, overridden by libavcodec while
746 enum AVPixelFormat pix_fmt;
749 * If non NULL, 'draw_horiz_band' is called by the libavcodec
750 * decoder to draw a horizontal band. It improves cache usage. Not
751 * all codecs can do that. You must check the codec capabilities
753 * When multithreading is used, it may be called from multiple threads
754 * at the same time; threads might draw different parts of the same AVFrame,
755 * or multiple AVFrames, and there is no guarantee that slices will be drawn
757 * The function is also used by hardware acceleration APIs.
758 * It is called at least once during frame decoding to pass
759 * the data needed for hardware render.
760 * In that mode instead of pixel data, AVFrame points to
761 * a structure specific to the acceleration API. The application
762 * reads the structure and can change some fields to indicate progress
765 * - decoding: Set by user.
766 * @param height the height of the slice
767 * @param y the y position of the slice
768 * @param type 1->top field, 2->bottom field, 3->frame
769 * @param offset offset into the AVFrame.data from which the slice should be read
771 void (*draw_horiz_band)(struct AVCodecContext *s,
772 const AVFrame *src, int offset[AV_NUM_DATA_POINTERS],
773 int y, int type, int height);
776 * callback to negotiate the pixelFormat
777 * @param fmt is the list of formats which are supported by the codec,
778 * it is terminated by -1 as 0 is a valid format, the formats are ordered by quality.
779 * The first is always the native one.
780 * @note The callback may be called again immediately if initialization for
781 * the selected (hardware-accelerated) pixel format failed.
782 * @warning Behavior is undefined if the callback returns a value not
783 * in the fmt list of formats.
784 * @return the chosen format
786 * - decoding: Set by user, if not set the native format will be chosen.
788 enum AVPixelFormat (*get_format)(struct AVCodecContext *s, const enum AVPixelFormat * fmt);
791 * maximum number of B-frames between non-B-frames
792 * Note: The output will be delayed by max_b_frames+1 relative to the input.
793 * - encoding: Set by user.
799 * qscale factor between IP and B-frames
800 * If > 0 then the last P-frame quantizer will be used (q= lastp_q*factor+offset).
801 * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
802 * - encoding: Set by user.
805 float b_quant_factor;
808 * qscale offset between IP and B-frames
809 * - encoding: Set by user.
812 float b_quant_offset;
815 * Size of the frame reordering buffer in the decoder.
816 * For MPEG-2 it is 1 IPB or 0 low delay IP.
817 * - encoding: Set by libavcodec.
818 * - decoding: Set by libavcodec.
823 * qscale factor between P- and I-frames
824 * If > 0 then the last P-frame quantizer will be used (q = lastp_q * factor + offset).
825 * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
826 * - encoding: Set by user.
829 float i_quant_factor;
832 * qscale offset between P and I-frames
833 * - encoding: Set by user.
836 float i_quant_offset;
839 * luminance masking (0-> disabled)
840 * - encoding: Set by user.
846 * temporary complexity masking (0-> disabled)
847 * - encoding: Set by user.
850 float temporal_cplx_masking;
853 * spatial complexity masking (0-> disabled)
854 * - encoding: Set by user.
857 float spatial_cplx_masking;
860 * p block masking (0-> disabled)
861 * - encoding: Set by user.
867 * darkness masking (0-> disabled)
868 * - encoding: Set by user.
875 * - encoding: Set by libavcodec.
876 * - decoding: Set by user (or 0).
881 * slice offsets in the frame in bytes
882 * - encoding: Set/allocated by libavcodec.
883 * - decoding: Set/allocated by user (or NULL).
888 * sample aspect ratio (0 if unknown)
889 * That is the width of a pixel divided by the height of the pixel.
890 * Numerator and denominator must be relatively prime and smaller than 256 for some video standards.
891 * - encoding: Set by user.
892 * - decoding: Set by libavcodec.
894 AVRational sample_aspect_ratio;
897 * motion estimation comparison function
898 * - encoding: Set by user.
903 * subpixel motion estimation comparison function
904 * - encoding: Set by user.
909 * macroblock comparison function (not supported yet)
910 * - encoding: Set by user.
915 * interlaced DCT comparison function
916 * - encoding: Set by user.
922 #define FF_CMP_SATD 2
924 #define FF_CMP_PSNR 4
927 #define FF_CMP_ZERO 7
928 #define FF_CMP_VSAD 8
929 #define FF_CMP_VSSE 9
930 #define FF_CMP_NSSE 10
931 #define FF_CMP_W53 11
932 #define FF_CMP_W97 12
933 #define FF_CMP_DCTMAX 13
934 #define FF_CMP_DCT264 14
935 #define FF_CMP_MEDIAN_SAD 15
936 #define FF_CMP_CHROMA 256
939 * ME diamond size & shape
940 * - encoding: Set by user.
946 * amount of previous MV predictors (2a+1 x 2a+1 square)
947 * - encoding: Set by user.
950 int last_predictor_count;
953 * motion estimation prepass comparison function
954 * - encoding: Set by user.
960 * ME prepass diamond size & shape
961 * - encoding: Set by user.
968 * - encoding: Set by user.
971 int me_subpel_quality;
974 * maximum motion estimation search range in subpel units
975 * If 0 then no limit.
977 * - encoding: Set by user.
985 * - decoding: Set by user.
988 #define SLICE_FLAG_CODED_ORDER 0x0001 ///< draw_horiz_band() is called in coded order instead of display
989 #define SLICE_FLAG_ALLOW_FIELD 0x0002 ///< allow draw_horiz_band() with field slices (MPEG-2 field pics)
990 #define SLICE_FLAG_ALLOW_PLANE 0x0004 ///< allow draw_horiz_band() with 1 component at a time (SVQ1)
993 * macroblock decision mode
994 * - encoding: Set by user.
998 #define FF_MB_DECISION_SIMPLE 0 ///< uses mb_cmp
999 #define FF_MB_DECISION_BITS 1 ///< chooses the one which needs the fewest bits
1000 #define FF_MB_DECISION_RD 2 ///< rate distortion
1003 * custom intra quantization matrix
1004 * Must be allocated with the av_malloc() family of functions, and will be freed in
1005 * avcodec_free_context().
1006 * - encoding: Set/allocated by user, freed by libavcodec. Can be NULL.
1007 * - decoding: Set/allocated/freed by libavcodec.
1009 uint16_t *intra_matrix;
1012 * custom inter quantization matrix
1013 * Must be allocated with the av_malloc() family of functions, and will be freed in
1014 * avcodec_free_context().
1015 * - encoding: Set/allocated by user, freed by libavcodec. Can be NULL.
1016 * - decoding: Set/allocated/freed by libavcodec.
1018 uint16_t *inter_matrix;
1021 * precision of the intra DC coefficient - 8
1022 * - encoding: Set by user.
1023 * - decoding: Set by libavcodec
1025 int intra_dc_precision;
1028 * Number of macroblock rows at the top which are skipped.
1029 * - encoding: unused
1030 * - decoding: Set by user.
1035 * Number of macroblock rows at the bottom which are skipped.
1036 * - encoding: unused
1037 * - decoding: Set by user.
1042 * minimum MB Lagrange multiplier
1043 * - encoding: Set by user.
1044 * - decoding: unused
1049 * maximum MB Lagrange multiplier
1050 * - encoding: Set by user.
1051 * - decoding: unused
1056 * - encoding: Set by user.
1057 * - decoding: unused
1063 * - encoding: Set by user.
1064 * - decoding: unused
1069 * number of reference frames
1070 * - encoding: Set by user.
1071 * - decoding: Set by lavc.
1076 * Note: Value depends upon the compare function used for fullpel ME.
1077 * - encoding: Set by user.
1078 * - decoding: unused
1083 * Chromaticity coordinates of the source primaries.
1084 * - encoding: Set by user
1085 * - decoding: Set by libavcodec
1087 enum AVColorPrimaries color_primaries;
1090 * Color Transfer Characteristic.
1091 * - encoding: Set by user
1092 * - decoding: Set by libavcodec
1094 enum AVColorTransferCharacteristic color_trc;
1097 * YUV colorspace type.
1098 * - encoding: Set by user
1099 * - decoding: Set by libavcodec
1101 enum AVColorSpace colorspace;
1104 * MPEG vs JPEG YUV range.
1105 * - encoding: Set by user
1106 * - decoding: Set by libavcodec
1108 enum AVColorRange color_range;
1111 * This defines the location of chroma samples.
1112 * - encoding: Set by user
1113 * - decoding: Set by libavcodec
1115 enum AVChromaLocation chroma_sample_location;
1119 * Indicates number of picture subdivisions. Used for parallelized
1121 * - encoding: Set by user
1122 * - decoding: unused
1127 * - encoding: set by libavcodec
1128 * - decoding: Set by user.
1130 enum AVFieldOrder field_order;
1133 int sample_rate; ///< samples per second
1134 int channels; ///< number of audio channels
1137 * audio sample format
1138 * - encoding: Set by user.
1139 * - decoding: Set by libavcodec.
1141 enum AVSampleFormat sample_fmt; ///< sample format
1143 /* The following data should not be initialized. */
1145 * Number of samples per channel in an audio frame.
1147 * - encoding: set by libavcodec in avcodec_open2(). Each submitted frame
1148 * except the last must contain exactly frame_size samples per channel.
1149 * May be 0 when the codec has AV_CODEC_CAP_VARIABLE_FRAME_SIZE set, then the
1150 * frame size is not restricted.
1151 * - decoding: may be set by some decoders to indicate constant frame size
1156 * Frame counter, set by libavcodec.
1158 * - decoding: total number of frames returned from the decoder so far.
1159 * - encoding: total number of frames passed to the encoder so far.
1161 * @note the counter is not incremented if encoding/decoding resulted in
1167 * number of bytes per packet if constant and known or 0
1168 * Used by some WAV based audio codecs.
1173 * Audio cutoff bandwidth (0 means "automatic")
1174 * - encoding: Set by user.
1175 * - decoding: unused
1180 * Audio channel layout.
1181 * - encoding: set by user.
1182 * - decoding: set by user, may be overwritten by libavcodec.
1184 uint64_t channel_layout;
1187 * Request decoder to use this channel layout if it can (0 for default)
1188 * - encoding: unused
1189 * - decoding: Set by user.
1191 uint64_t request_channel_layout;
1194 * Type of service that the audio stream conveys.
1195 * - encoding: Set by user.
1196 * - decoding: Set by libavcodec.
1198 enum AVAudioServiceType audio_service_type;
1201 * desired sample format
1202 * - encoding: Not used.
1203 * - decoding: Set by user.
1204 * Decoder will decode to this format if it can.
1206 enum AVSampleFormat request_sample_fmt;
1209 * This callback is called at the beginning of each frame to get data
1210 * buffer(s) for it. There may be one contiguous buffer for all the data or
1211 * there may be a buffer per each data plane or anything in between. What
1212 * this means is, you may set however many entries in buf[] you feel necessary.
1213 * Each buffer must be reference-counted using the AVBuffer API (see description
1216 * The following fields will be set in the frame before this callback is
1219 * - width, height (video only)
1220 * - sample_rate, channel_layout, nb_samples (audio only)
1221 * Their values may differ from the corresponding values in
1222 * AVCodecContext. This callback must use the frame values, not the codec
1223 * context values, to calculate the required buffer size.
1225 * This callback must fill the following fields in the frame:
1229 * * if the data is planar audio with more than 8 channels, then this
1230 * callback must allocate and fill extended_data to contain all pointers
1231 * to all data planes. data[] must hold as many pointers as it can.
1232 * extended_data must be allocated with av_malloc() and will be freed in
1234 * * otherwise extended_data must point to data
1235 * - buf[] must contain one or more pointers to AVBufferRef structures. Each of
1236 * the frame's data and extended_data pointers must be contained in these. That
1237 * is, one AVBufferRef for each allocated chunk of memory, not necessarily one
1238 * AVBufferRef per data[] entry. See: av_buffer_create(), av_buffer_alloc(),
1239 * and av_buffer_ref().
1240 * - extended_buf and nb_extended_buf must be allocated with av_malloc() by
1241 * this callback and filled with the extra buffers if there are more
1242 * buffers than buf[] can hold. extended_buf will be freed in
1245 * If AV_CODEC_CAP_DR1 is not set then get_buffer2() must call
1246 * avcodec_default_get_buffer2() instead of providing buffers allocated by
1249 * Each data plane must be aligned to the maximum required by the target
1252 * @see avcodec_default_get_buffer2()
1256 * If AV_GET_BUFFER_FLAG_REF is set in flags then the frame may be reused
1257 * (read and/or written to if it is writable) later by libavcodec.
1259 * avcodec_align_dimensions2() should be used to find the required width and
1260 * height, as they normally need to be rounded up to the next multiple of 16.
1262 * Some decoders do not support linesizes changing between frames.
1264 * If frame multithreading is used, this callback may be called from a
1265 * different thread, but not from more than one at once. Does not need to be
1268 * @see avcodec_align_dimensions2()
1272 * Decoders request a buffer of a particular size by setting
1273 * AVFrame.nb_samples prior to calling get_buffer2(). The decoder may,
1274 * however, utilize only part of the buffer by setting AVFrame.nb_samples
1275 * to a smaller value in the output frame.
1277 * As a convenience, av_samples_get_buffer_size() and
1278 * av_samples_fill_arrays() in libavutil may be used by custom get_buffer2()
1279 * functions to find the required data size and to fill data pointers and
1280 * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
1281 * since all planes must be the same size.
1283 * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
1285 * - encoding: unused
1286 * - decoding: Set by libavcodec, user can override.
1288 int (*get_buffer2)(struct AVCodecContext *s, AVFrame *frame, int flags);
1290 #if FF_API_OLD_ENCDEC
1292 * If non-zero, the decoded audio and video frames returned from
1293 * avcodec_decode_video2() and avcodec_decode_audio4() are reference-counted
1294 * and are valid indefinitely. The caller must free them with
1295 * av_frame_unref() when they are not needed anymore.
1296 * Otherwise, the decoded frames must not be freed by the caller and are
1297 * only valid until the next decode call.
1299 * This is always automatically enabled if avcodec_receive_frame() is used.
1301 * - encoding: unused
1302 * - decoding: set by the caller before avcodec_open2().
1304 attribute_deprecated
1305 int refcounted_frames;
1308 /* - encoding parameters */
1309 float qcompress; ///< amount of qscale change between easy & hard scenes (0.0-1.0)
1310 float qblur; ///< amount of qscale smoothing over time (0.0-1.0)
1314 * - encoding: Set by user.
1315 * - decoding: unused
1321 * - encoding: Set by user.
1322 * - decoding: unused
1327 * maximum quantizer difference between frames
1328 * - encoding: Set by user.
1329 * - decoding: unused
1334 * decoder bitstream buffer size
1335 * - encoding: Set by user.
1336 * - decoding: unused
1341 * ratecontrol override, see RcOverride
1342 * - encoding: Allocated/set/freed by user.
1343 * - decoding: unused
1345 int rc_override_count;
1346 RcOverride *rc_override;
1350 * - encoding: Set by user.
1351 * - decoding: Set by user, may be overwritten by libavcodec.
1353 int64_t rc_max_rate;
1357 * - encoding: Set by user.
1358 * - decoding: unused
1360 int64_t rc_min_rate;
1363 * Ratecontrol attempt to use, at maximum, <value> of what can be used without an underflow.
1364 * - encoding: Set by user.
1365 * - decoding: unused.
1367 float rc_max_available_vbv_use;
1370 * Ratecontrol attempt to use, at least, <value> times the amount needed to prevent a vbv overflow.
1371 * - encoding: Set by user.
1372 * - decoding: unused.
1374 float rc_min_vbv_overflow_use;
1377 * Number of bits which should be loaded into the rc buffer before decoding starts.
1378 * - encoding: Set by user.
1379 * - decoding: unused
1381 int rc_initial_buffer_occupancy;
1384 * trellis RD quantization
1385 * - encoding: Set by user.
1386 * - decoding: unused
1391 * pass1 encoding statistics output buffer
1392 * - encoding: Set by libavcodec.
1393 * - decoding: unused
1398 * pass2 encoding statistics input buffer
1399 * Concatenated stuff from stats_out of pass1 should be placed here.
1400 * - encoding: Allocated/set/freed by user.
1401 * - decoding: unused
1406 * Work around bugs in encoders which sometimes cannot be detected automatically.
1407 * - encoding: Set by user
1408 * - decoding: Set by user
1410 int workaround_bugs;
1411 #define FF_BUG_AUTODETECT 1 ///< autodetection
1412 #define FF_BUG_XVID_ILACE 4
1413 #define FF_BUG_UMP4 8
1414 #define FF_BUG_NO_PADDING 16
1415 #define FF_BUG_AMV 32
1416 #define FF_BUG_QPEL_CHROMA 64
1417 #define FF_BUG_STD_QPEL 128
1418 #define FF_BUG_QPEL_CHROMA2 256
1419 #define FF_BUG_DIRECT_BLOCKSIZE 512
1420 #define FF_BUG_EDGE 1024
1421 #define FF_BUG_HPEL_CHROMA 2048
1422 #define FF_BUG_DC_CLIP 4096
1423 #define FF_BUG_MS 8192 ///< Work around various bugs in Microsoft's broken decoders.
1424 #define FF_BUG_TRUNCATED 16384
1425 #define FF_BUG_IEDGE 32768
1428 * strictly follow the standard (MPEG-4, ...).
1429 * - encoding: Set by user.
1430 * - decoding: Set by user.
1431 * Setting this to STRICT or higher means the encoder and decoder will
1432 * generally do stupid things, whereas setting it to unofficial or lower
1433 * will mean the encoder might produce output that is not supported by all
1434 * spec-compliant decoders. Decoders don't differentiate between normal,
1435 * unofficial and experimental (that is, they always try to decode things
1436 * when they can) unless they are explicitly asked to behave stupidly
1437 * (=strictly conform to the specs)
1439 int strict_std_compliance;
1440 #define FF_COMPLIANCE_VERY_STRICT 2 ///< Strictly conform to an older more strict version of the spec or reference software.
1441 #define FF_COMPLIANCE_STRICT 1 ///< Strictly conform to all the things in the spec no matter what consequences.
1442 #define FF_COMPLIANCE_NORMAL 0
1443 #define FF_COMPLIANCE_UNOFFICIAL -1 ///< Allow unofficial extensions
1444 #define FF_COMPLIANCE_EXPERIMENTAL -2 ///< Allow nonstandardized experimental things.
1447 * error concealment flags
1448 * - encoding: unused
1449 * - decoding: Set by user.
1451 int error_concealment;
1452 #define FF_EC_GUESS_MVS 1
1453 #define FF_EC_DEBLOCK 2
1454 #define FF_EC_FAVOR_INTER 256
1458 * - encoding: Set by user.
1459 * - decoding: Set by user.
1462 #define FF_DEBUG_PICT_INFO 1
1463 #define FF_DEBUG_RC 2
1464 #define FF_DEBUG_BITSTREAM 4
1465 #define FF_DEBUG_MB_TYPE 8
1466 #define FF_DEBUG_QP 16
1467 #define FF_DEBUG_DCT_COEFF 0x00000040
1468 #define FF_DEBUG_SKIP 0x00000080
1469 #define FF_DEBUG_STARTCODE 0x00000100
1470 #define FF_DEBUG_ER 0x00000400
1471 #define FF_DEBUG_MMCO 0x00000800
1472 #define FF_DEBUG_BUGS 0x00001000
1473 #define FF_DEBUG_BUFFERS 0x00008000
1474 #define FF_DEBUG_THREADS 0x00010000
1475 #define FF_DEBUG_GREEN_MD 0x00800000
1476 #define FF_DEBUG_NOMC 0x01000000
1479 * Error recognition; may misdetect some more or less valid parts as errors.
1480 * - encoding: Set by user.
1481 * - decoding: Set by user.
1483 int err_recognition;
1486 * Verify checksums embedded in the bitstream (could be of either encoded or
1487 * decoded data, depending on the codec) and print an error message on mismatch.
1488 * If AV_EF_EXPLODE is also set, a mismatching checksum will result in the
1489 * decoder returning an error.
1491 #define AV_EF_CRCCHECK (1<<0)
1492 #define AV_EF_BITSTREAM (1<<1) ///< detect bitstream specification deviations
1493 #define AV_EF_BUFFER (1<<2) ///< detect improper bitstream length
1494 #define AV_EF_EXPLODE (1<<3) ///< abort decoding on minor error detection
1496 #define AV_EF_IGNORE_ERR (1<<15) ///< ignore errors and continue
1497 #define AV_EF_CAREFUL (1<<16) ///< consider things that violate the spec, are fast to calculate and have not been seen in the wild as errors
1498 #define AV_EF_COMPLIANT (1<<17) ///< consider all spec non compliances as errors
1499 #define AV_EF_AGGRESSIVE (1<<18) ///< consider things that a sane encoder should not do as an error
1503 * opaque 64-bit number (generally a PTS) that will be reordered and
1504 * output in AVFrame.reordered_opaque
1505 * - encoding: Set by libavcodec to the reordered_opaque of the input
1506 * frame corresponding to the last returned packet. Only
1507 * supported by encoders with the
1508 * AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE capability.
1509 * - decoding: Set by user.
1511 int64_t reordered_opaque;
1514 * Hardware accelerator in use
1515 * - encoding: unused.
1516 * - decoding: Set by libavcodec
1518 const struct AVHWAccel *hwaccel;
1521 * Hardware accelerator context.
1522 * For some hardware accelerators, a global context needs to be
1523 * provided by the user. In that case, this holds display-dependent
1524 * data FFmpeg cannot instantiate itself. Please refer to the
1525 * FFmpeg HW accelerator documentation to know how to fill this.
1526 * - encoding: unused
1527 * - decoding: Set by user
1529 void *hwaccel_context;
1533 * - encoding: Set by libavcodec if flags & AV_CODEC_FLAG_PSNR.
1534 * - decoding: unused
1536 uint64_t error[AV_NUM_DATA_POINTERS];
1539 * DCT algorithm, see FF_DCT_* below
1540 * - encoding: Set by user.
1541 * - decoding: unused
1544 #define FF_DCT_AUTO 0
1545 #define FF_DCT_FASTINT 1
1546 #define FF_DCT_INT 2
1547 #define FF_DCT_MMX 3
1548 #define FF_DCT_ALTIVEC 5
1549 #define FF_DCT_FAAN 6
1552 * IDCT algorithm, see FF_IDCT_* below.
1553 * - encoding: Set by user.
1554 * - decoding: Set by user.
1557 #define FF_IDCT_AUTO 0
1558 #define FF_IDCT_INT 1
1559 #define FF_IDCT_SIMPLE 2
1560 #define FF_IDCT_SIMPLEMMX 3
1561 #define FF_IDCT_ARM 7
1562 #define FF_IDCT_ALTIVEC 8
1563 #define FF_IDCT_SIMPLEARM 10
1564 #define FF_IDCT_XVID 14
1565 #define FF_IDCT_SIMPLEARMV5TE 16
1566 #define FF_IDCT_SIMPLEARMV6 17
1567 #define FF_IDCT_FAAN 20
1568 #define FF_IDCT_SIMPLENEON 22
1569 #define FF_IDCT_NONE 24 /* Used by XvMC to extract IDCT coefficients with FF_IDCT_PERM_NONE */
1570 #define FF_IDCT_SIMPLEAUTO 128
1573 * bits per sample/pixel from the demuxer (needed for huffyuv).
1574 * - encoding: Set by libavcodec.
1575 * - decoding: Set by user.
1577 int bits_per_coded_sample;
1580 * Bits per sample/pixel of internal libavcodec pixel/sample format.
1581 * - encoding: set by user.
1582 * - decoding: set by libavcodec.
1584 int bits_per_raw_sample;
1587 * low resolution decoding, 1-> 1/2 size, 2->1/4 size
1588 * - encoding: unused
1589 * - decoding: Set by user.
1593 #if FF_API_CODED_FRAME
1595 * the picture in the bitstream
1596 * - encoding: Set by libavcodec.
1597 * - decoding: unused
1599 * @deprecated use the quality factor packet side data instead
1601 attribute_deprecated AVFrame *coded_frame;
1606 * is used to decide how many independent tasks should be passed to execute()
1607 * - encoding: Set by user.
1608 * - decoding: Set by user.
1613 * Which multithreading methods to use.
1614 * Use of FF_THREAD_FRAME will increase decoding delay by one frame per thread,
1615 * so clients which cannot provide future frames should not use it.
1617 * - encoding: Set by user, otherwise the default is used.
1618 * - decoding: Set by user, otherwise the default is used.
1621 #define FF_THREAD_FRAME 1 ///< Decode more than one frame at once
1622 #define FF_THREAD_SLICE 2 ///< Decode more than one part of a single frame at once
1625 * Which multithreading methods are in use by the codec.
1626 * - encoding: Set by libavcodec.
1627 * - decoding: Set by libavcodec.
1629 int active_thread_type;
1631 #if FF_API_THREAD_SAFE_CALLBACKS
1633 * Set by the client if its custom get_buffer() callback can be called
1634 * synchronously from another thread, which allows faster multithreaded decoding.
1635 * draw_horiz_band() will be called from other threads regardless of this setting.
1636 * Ignored if the default get_buffer() is used.
1637 * - encoding: Set by user.
1638 * - decoding: Set by user.
1640 * @deprecated the custom get_buffer2() callback should always be
1641 * thread-safe. Thread-unsafe get_buffer2() implementations will be
1642 * invalid starting with LIBAVCODEC_VERSION_MAJOR=60; in other words,
1643 * libavcodec will behave as if this field was always set to 1.
1644 * Callers that want to be forward compatible with future libavcodec
1645 * versions should wrap access to this field in
1646 * #if LIBAVCODEC_VERSION_MAJOR < 60
1648 attribute_deprecated
1649 int thread_safe_callbacks;
1653 * The codec may call this to execute several independent things.
1654 * It will return only after finishing all tasks.
1655 * The user may replace this with some multithreaded implementation,
1656 * the default implementation will execute the parts serially.
1657 * @param count the number of things to execute
1658 * - encoding: Set by libavcodec, user can override.
1659 * - decoding: Set by libavcodec, user can override.
1661 int (*execute)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size);
1664 * The codec may call this to execute several independent things.
1665 * It will return only after finishing all tasks.
1666 * The user may replace this with some multithreaded implementation,
1667 * the default implementation will execute the parts serially.
1668 * Also see avcodec_thread_init and e.g. the --enable-pthread configure option.
1669 * @param c context passed also to func
1670 * @param count the number of things to execute
1671 * @param arg2 argument passed unchanged to func
1672 * @param ret return values of executed functions, must have space for "count" values. May be NULL.
1673 * @param func function that will be called count times, with jobnr from 0 to count-1.
1674 * threadnr will be in the range 0 to c->thread_count-1 < MAX_THREADS and so that no
1675 * two instances of func executing at the same time will have the same threadnr.
1676 * @return always 0 currently, but code should handle a future improvement where when any call to func
1677 * returns < 0 no further calls to func may be done and < 0 is returned.
1678 * - encoding: Set by libavcodec, user can override.
1679 * - decoding: Set by libavcodec, user can override.
1681 int (*execute2)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count);
1684 * noise vs. sse weight for the nsse comparison function
1685 * - encoding: Set by user.
1686 * - decoding: unused
1692 * - encoding: Set by user.
1693 * - decoding: Set by libavcodec.
1696 #define FF_PROFILE_UNKNOWN -99
1697 #define FF_PROFILE_RESERVED -100
1699 #define FF_PROFILE_AAC_MAIN 0
1700 #define FF_PROFILE_AAC_LOW 1
1701 #define FF_PROFILE_AAC_SSR 2
1702 #define FF_PROFILE_AAC_LTP 3
1703 #define FF_PROFILE_AAC_HE 4
1704 #define FF_PROFILE_AAC_HE_V2 28
1705 #define FF_PROFILE_AAC_LD 22
1706 #define FF_PROFILE_AAC_ELD 38
1707 #define FF_PROFILE_MPEG2_AAC_LOW 128
1708 #define FF_PROFILE_MPEG2_AAC_HE 131
1710 #define FF_PROFILE_DNXHD 0
1711 #define FF_PROFILE_DNXHR_LB 1
1712 #define FF_PROFILE_DNXHR_SQ 2
1713 #define FF_PROFILE_DNXHR_HQ 3
1714 #define FF_PROFILE_DNXHR_HQX 4
1715 #define FF_PROFILE_DNXHR_444 5
1717 #define FF_PROFILE_DTS 20
1718 #define FF_PROFILE_DTS_ES 30
1719 #define FF_PROFILE_DTS_96_24 40
1720 #define FF_PROFILE_DTS_HD_HRA 50
1721 #define FF_PROFILE_DTS_HD_MA 60
1722 #define FF_PROFILE_DTS_EXPRESS 70
1724 #define FF_PROFILE_MPEG2_422 0
1725 #define FF_PROFILE_MPEG2_HIGH 1
1726 #define FF_PROFILE_MPEG2_SS 2
1727 #define FF_PROFILE_MPEG2_SNR_SCALABLE 3
1728 #define FF_PROFILE_MPEG2_MAIN 4
1729 #define FF_PROFILE_MPEG2_SIMPLE 5
1731 #define FF_PROFILE_H264_CONSTRAINED (1<<9) // 8+1; constraint_set1_flag
1732 #define FF_PROFILE_H264_INTRA (1<<11) // 8+3; constraint_set3_flag
1734 #define FF_PROFILE_H264_BASELINE 66
1735 #define FF_PROFILE_H264_CONSTRAINED_BASELINE (66|FF_PROFILE_H264_CONSTRAINED)
1736 #define FF_PROFILE_H264_MAIN 77
1737 #define FF_PROFILE_H264_EXTENDED 88
1738 #define FF_PROFILE_H264_HIGH 100
1739 #define FF_PROFILE_H264_HIGH_10 110
1740 #define FF_PROFILE_H264_HIGH_10_INTRA (110|FF_PROFILE_H264_INTRA)
1741 #define FF_PROFILE_H264_MULTIVIEW_HIGH 118
1742 #define FF_PROFILE_H264_HIGH_422 122
1743 #define FF_PROFILE_H264_HIGH_422_INTRA (122|FF_PROFILE_H264_INTRA)
1744 #define FF_PROFILE_H264_STEREO_HIGH 128
1745 #define FF_PROFILE_H264_HIGH_444 144
1746 #define FF_PROFILE_H264_HIGH_444_PREDICTIVE 244
1747 #define FF_PROFILE_H264_HIGH_444_INTRA (244|FF_PROFILE_H264_INTRA)
1748 #define FF_PROFILE_H264_CAVLC_444 44
1750 #define FF_PROFILE_VC1_SIMPLE 0
1751 #define FF_PROFILE_VC1_MAIN 1
1752 #define FF_PROFILE_VC1_COMPLEX 2
1753 #define FF_PROFILE_VC1_ADVANCED 3
1755 #define FF_PROFILE_MPEG4_SIMPLE 0
1756 #define FF_PROFILE_MPEG4_SIMPLE_SCALABLE 1
1757 #define FF_PROFILE_MPEG4_CORE 2
1758 #define FF_PROFILE_MPEG4_MAIN 3
1759 #define FF_PROFILE_MPEG4_N_BIT 4
1760 #define FF_PROFILE_MPEG4_SCALABLE_TEXTURE 5
1761 #define FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION 6
1762 #define FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE 7
1763 #define FF_PROFILE_MPEG4_HYBRID 8
1764 #define FF_PROFILE_MPEG4_ADVANCED_REAL_TIME 9
1765 #define FF_PROFILE_MPEG4_CORE_SCALABLE 10
1766 #define FF_PROFILE_MPEG4_ADVANCED_CODING 11
1767 #define FF_PROFILE_MPEG4_ADVANCED_CORE 12
1768 #define FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE 13
1769 #define FF_PROFILE_MPEG4_SIMPLE_STUDIO 14
1770 #define FF_PROFILE_MPEG4_ADVANCED_SIMPLE 15
1772 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_0 1
1773 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_1 2
1774 #define FF_PROFILE_JPEG2000_CSTREAM_NO_RESTRICTION 32768
1775 #define FF_PROFILE_JPEG2000_DCINEMA_2K 3
1776 #define FF_PROFILE_JPEG2000_DCINEMA_4K 4
1778 #define FF_PROFILE_VP9_0 0
1779 #define FF_PROFILE_VP9_1 1
1780 #define FF_PROFILE_VP9_2 2
1781 #define FF_PROFILE_VP9_3 3
1783 #define FF_PROFILE_HEVC_MAIN 1
1784 #define FF_PROFILE_HEVC_MAIN_10 2
1785 #define FF_PROFILE_HEVC_MAIN_STILL_PICTURE 3
1786 #define FF_PROFILE_HEVC_REXT 4
1788 #define FF_PROFILE_VVC_MAIN_10 1
1789 #define FF_PROFILE_VVC_MAIN_10_444 33
1791 #define FF_PROFILE_AV1_MAIN 0
1792 #define FF_PROFILE_AV1_HIGH 1
1793 #define FF_PROFILE_AV1_PROFESSIONAL 2
1795 #define FF_PROFILE_MJPEG_HUFFMAN_BASELINE_DCT 0xc0
1796 #define FF_PROFILE_MJPEG_HUFFMAN_EXTENDED_SEQUENTIAL_DCT 0xc1
1797 #define FF_PROFILE_MJPEG_HUFFMAN_PROGRESSIVE_DCT 0xc2
1798 #define FF_PROFILE_MJPEG_HUFFMAN_LOSSLESS 0xc3
1799 #define FF_PROFILE_MJPEG_JPEG_LS 0xf7
1801 #define FF_PROFILE_SBC_MSBC 1
1803 #define FF_PROFILE_PRORES_PROXY 0
1804 #define FF_PROFILE_PRORES_LT 1
1805 #define FF_PROFILE_PRORES_STANDARD 2
1806 #define FF_PROFILE_PRORES_HQ 3
1807 #define FF_PROFILE_PRORES_4444 4
1808 #define FF_PROFILE_PRORES_XQ 5
1810 #define FF_PROFILE_ARIB_PROFILE_A 0
1811 #define FF_PROFILE_ARIB_PROFILE_C 1
1813 #define FF_PROFILE_KLVA_SYNC 0
1814 #define FF_PROFILE_KLVA_ASYNC 1
1818 * - encoding: Set by user.
1819 * - decoding: Set by libavcodec.
1822 #define FF_LEVEL_UNKNOWN -99
1825 * Skip loop filtering for selected frames.
1826 * - encoding: unused
1827 * - decoding: Set by user.
1829 enum AVDiscard skip_loop_filter;
1832 * Skip IDCT/dequantization for selected frames.
1833 * - encoding: unused
1834 * - decoding: Set by user.
1836 enum AVDiscard skip_idct;
1839 * Skip decoding for selected frames.
1840 * - encoding: unused
1841 * - decoding: Set by user.
1843 enum AVDiscard skip_frame;
1846 * Header containing style information for text subtitles.
1847 * For SUBTITLE_ASS subtitle type, it should contain the whole ASS
1848 * [Script Info] and [V4+ Styles] section, plus the [Events] line and
1849 * the Format line following. It shouldn't include any Dialogue line.
1850 * - encoding: Set/allocated/freed by user (before avcodec_open2())
1851 * - decoding: Set/allocated/freed by libavcodec (by avcodec_open2())
1853 uint8_t *subtitle_header;
1854 int subtitle_header_size;
1857 * Audio only. The number of "priming" samples (padding) inserted by the
1858 * encoder at the beginning of the audio. I.e. this number of leading
1859 * decoded samples must be discarded by the caller to get the original audio
1860 * without leading padding.
1862 * - decoding: unused
1863 * - encoding: Set by libavcodec. The timestamps on the output packets are
1864 * adjusted by the encoder so that they always refer to the
1865 * first sample of the data actually contained in the packet,
1866 * including any added padding. E.g. if the timebase is
1867 * 1/samplerate and the timestamp of the first input sample is
1868 * 0, the timestamp of the first output packet will be
1871 int initial_padding;
1874 * - decoding: For codecs that store a framerate value in the compressed
1875 * bitstream, the decoder may export it here. { 0, 1} when
1877 * - encoding: May be used to signal the framerate of CFR content to an
1880 AVRational framerate;
1883 * Nominal unaccelerated pixel format, see AV_PIX_FMT_xxx.
1884 * - encoding: unused.
1885 * - decoding: Set by libavcodec before calling get_format()
1887 enum AVPixelFormat sw_pix_fmt;
1890 * Timebase in which pkt_dts/pts and AVPacket.dts/pts are.
1891 * - encoding unused.
1892 * - decoding set by user.
1894 AVRational pkt_timebase;
1898 * - encoding: unused.
1899 * - decoding: set by libavcodec.
1901 const AVCodecDescriptor *codec_descriptor;
1904 * Current statistics for PTS correction.
1905 * - decoding: maintained and used by libavcodec, not intended to be used by user apps
1906 * - encoding: unused
1908 int64_t pts_correction_num_faulty_pts; /// Number of incorrect PTS values so far
1909 int64_t pts_correction_num_faulty_dts; /// Number of incorrect DTS values so far
1910 int64_t pts_correction_last_pts; /// PTS of the last frame
1911 int64_t pts_correction_last_dts; /// DTS of the last frame
1914 * Character encoding of the input subtitles file.
1915 * - decoding: set by user
1916 * - encoding: unused
1921 * Subtitles character encoding mode. Formats or codecs might be adjusting
1922 * this setting (if they are doing the conversion themselves for instance).
1923 * - decoding: set by libavcodec
1924 * - encoding: unused
1926 int sub_charenc_mode;
1927 #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)
1928 #define FF_SUB_CHARENC_MODE_AUTOMATIC 0 ///< libavcodec will select the mode itself
1929 #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
1930 #define FF_SUB_CHARENC_MODE_IGNORE 2 ///< neither convert the subtitles, nor check them for valid UTF-8
1933 * Skip processing alpha if supported by codec.
1934 * Note that if the format uses pre-multiplied alpha (common with VP6,
1935 * and recommended due to better video quality/compression)
1936 * the image will look as if alpha-blended onto a black background.
1937 * However for formats that do not use pre-multiplied alpha
1938 * there might be serious artefacts (though e.g. libswscale currently
1939 * assumes pre-multiplied alpha anyway).
1941 * - decoding: set by user
1942 * - encoding: unused
1947 * Number of samples to skip after a discontinuity
1948 * - decoding: unused
1949 * - encoding: set by libavcodec
1955 * @deprecated unused
1957 attribute_deprecated
1959 #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 //visualize forward predicted MVs of P frames
1960 #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 //visualize forward predicted MVs of B frames
1961 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
1965 * custom intra quantization matrix
1966 * - encoding: Set by user, can be NULL.
1967 * - decoding: unused.
1969 uint16_t *chroma_intra_matrix;
1972 * dump format separator.
1973 * can be ", " or "\n " or anything else
1974 * - encoding: Set by user.
1975 * - decoding: Set by user.
1977 uint8_t *dump_separator;
1980 * ',' separated list of allowed decoders.
1981 * If NULL then all are allowed
1982 * - encoding: unused
1983 * - decoding: set by user
1985 char *codec_whitelist;
1988 * Properties of the stream that gets decoded
1989 * - encoding: unused
1990 * - decoding: set by libavcodec
1992 unsigned properties;
1993 #define FF_CODEC_PROPERTY_LOSSLESS 0x00000001
1994 #define FF_CODEC_PROPERTY_CLOSED_CAPTIONS 0x00000002
1997 * Additional data associated with the entire coded stream.
1999 * - decoding: unused
2000 * - encoding: may be set by libavcodec after avcodec_open2().
2002 AVPacketSideData *coded_side_data;
2003 int nb_coded_side_data;
2006 * A reference to the AVHWFramesContext describing the input (for encoding)
2007 * or output (decoding) frames. The reference is set by the caller and
2008 * afterwards owned (and freed) by libavcodec - it should never be read by
2009 * the caller after being set.
2011 * - decoding: This field should be set by the caller from the get_format()
2012 * callback. The previous reference (if any) will always be
2013 * unreffed by libavcodec before the get_format() call.
2015 * If the default get_buffer2() is used with a hwaccel pixel
2016 * format, then this AVHWFramesContext will be used for
2017 * allocating the frame buffers.
2019 * - encoding: For hardware encoders configured to use a hwaccel pixel
2020 * format, this field should be set by the caller to a reference
2021 * to the AVHWFramesContext describing input frames.
2022 * AVHWFramesContext.format must be equal to
2023 * AVCodecContext.pix_fmt.
2025 * This field should be set before avcodec_open2() is called.
2027 AVBufferRef *hw_frames_ctx;
2030 * Control the form of AVSubtitle.rects[N]->ass
2031 * - decoding: set by user
2032 * - encoding: unused
2034 int sub_text_format;
2035 #define FF_SUB_TEXT_FMT_ASS 0
2038 * Audio only. The amount of padding (in samples) appended by the encoder to
2039 * the end of the audio. I.e. this number of decoded samples must be
2040 * discarded by the caller from the end of the stream to get the original
2041 * audio without any trailing padding.
2043 * - decoding: unused
2044 * - encoding: unused
2046 int trailing_padding;
2049 * The number of pixels per image to maximally accept.
2051 * - decoding: set by user
2052 * - encoding: set by user
2057 * A reference to the AVHWDeviceContext describing the device which will
2058 * be used by a hardware encoder/decoder. The reference is set by the
2059 * caller and afterwards owned (and freed) by libavcodec.
2061 * This should be used if either the codec device does not require
2062 * hardware frames or any that are used are to be allocated internally by
2063 * libavcodec. If the user wishes to supply any of the frames used as
2064 * encoder input or decoder output then hw_frames_ctx should be used
2065 * instead. When hw_frames_ctx is set in get_format() for a decoder, this
2066 * field will be ignored while decoding the associated stream segment, but
2067 * may again be used on a following one after another get_format() call.
2069 * For both encoders and decoders this field should be set before
2070 * avcodec_open2() is called and must not be written to thereafter.
2072 * Note that some decoders may require this field to be set initially in
2073 * order to support hw_frames_ctx at all - in that case, all frames
2074 * contexts used must be created on the same device.
2076 AVBufferRef *hw_device_ctx;
2079 * Bit set of AV_HWACCEL_FLAG_* flags, which affect hardware accelerated
2080 * decoding (if active).
2081 * - encoding: unused
2082 * - decoding: Set by user (either before avcodec_open2(), or in the
2083 * AVCodecContext.get_format callback)
2088 * Video decoding only. Certain video codecs support cropping, meaning that
2089 * only a sub-rectangle of the decoded frame is intended for display. This
2090 * option controls how cropping is handled by libavcodec.
2092 * When set to 1 (the default), libavcodec will apply cropping internally.
2093 * I.e. it will modify the output frame width/height fields and offset the
2094 * data pointers (only by as much as possible while preserving alignment, or
2095 * by the full amount if the AV_CODEC_FLAG_UNALIGNED flag is set) so that
2096 * the frames output by the decoder refer only to the cropped area. The
2097 * crop_* fields of the output frames will be zero.
2099 * When set to 0, the width/height fields of the output frames will be set
2100 * to the coded dimensions and the crop_* fields will describe the cropping
2101 * rectangle. Applying the cropping is left to the caller.
2103 * @warning When hardware acceleration with opaque output frames is used,
2104 * libavcodec is unable to apply cropping from the top/left border.
2106 * @note when this option is set to zero, the width/height fields of the
2107 * AVCodecContext and output AVFrames have different meanings. The codec
2108 * context fields store display dimensions (with the coded dimensions in
2109 * coded_width/height), while the frame fields store the coded dimensions
2110 * (with the display dimensions being determined by the crop_* fields).
2115 * Video decoding only. Sets the number of extra hardware frames which
2116 * the decoder will allocate for use by the caller. This must be set
2117 * before avcodec_open2() is called.
2119 * Some hardware decoders require all frames that they will use for
2120 * output to be defined in advance before decoding starts. For such
2121 * decoders, the hardware frame pool must therefore be of a fixed size.
2122 * The extra frames set here are on top of any number that the decoder
2123 * needs internally in order to operate normally (for example, frames
2124 * used as reference pictures).
2126 int extra_hw_frames;
2129 * The percentage of damaged samples to discard a frame.
2131 * - decoding: set by user
2132 * - encoding: unused
2134 int discard_damaged_percentage;
2137 * The number of samples per frame to maximally accept.
2139 * - decoding: set by user
2140 * - encoding: set by user
2142 int64_t max_samples;
2145 * Bit set of AV_CODEC_EXPORT_DATA_* flags, which affects the kind of
2146 * metadata exported in frame, packet, or coded stream side data by
2147 * decoders and encoders.
2149 * - decoding: set by user
2150 * - encoding: set by user
2152 int export_side_data;
2155 * This callback is called at the beginning of each packet to get a data
2158 * The following field will be set in the packet before this callback is
2161 * This callback must use the above value to calculate the required buffer size,
2162 * which must padded by at least AV_INPUT_BUFFER_PADDING_SIZE bytes.
2164 * This callback must fill the following fields in the packet:
2165 * - data: alignment requirements for AVPacket apply, if any. Some architectures and
2166 * encoders may benefit from having aligned data.
2167 * - buf: must contain a pointer to an AVBufferRef structure. The packet's
2168 * data pointer must be contained in it. See: av_buffer_create(), av_buffer_alloc(),
2169 * and av_buffer_ref().
2171 * If AV_CODEC_CAP_DR1 is not set then get_encode_buffer() must call
2172 * avcodec_default_get_encode_buffer() instead of providing a buffer allocated by
2175 * The flags field may contain a combination of AV_GET_ENCODE_BUFFER_FLAG_ flags.
2176 * They may be used for example to hint what use the buffer may get after being
2178 * Implementations of this callback may ignore flags they don't understand.
2179 * If AV_GET_ENCODE_BUFFER_FLAG_REF is set in flags then the packet may be reused
2180 * (read and/or written to if it is writable) later by libavcodec.
2182 * This callback must be thread-safe, as when frame threading is used, it may
2183 * be called from multiple threads simultaneously.
2185 * @see avcodec_default_get_encode_buffer()
2187 * - encoding: Set by libavcodec, user can override.
2188 * - decoding: unused
2190 int (*get_encode_buffer)(struct AVCodecContext *s, AVPacket *pkt, int flags);
2195 struct MpegEncContext;
2198 * @defgroup lavc_hwaccel AVHWAccel
2200 * @note Nothing in this structure should be accessed by the user. At some
2201 * point in future it will not be externally visible at all.
2205 typedef struct AVHWAccel {
2207 * Name of the hardware accelerated codec.
2208 * The name is globally unique among encoders and among decoders (but an
2209 * encoder and a decoder can share the same name).
2214 * Type of codec implemented by the hardware accelerator.
2216 * See AVMEDIA_TYPE_xxx
2218 enum AVMediaType type;
2221 * Codec implemented by the hardware accelerator.
2223 * See AV_CODEC_ID_xxx
2228 * Supported pixel format.
2230 * Only hardware accelerated formats are supported here.
2232 enum AVPixelFormat pix_fmt;
2235 * Hardware accelerated codec capabilities.
2236 * see AV_HWACCEL_CODEC_CAP_*
2240 /*****************************************************************
2241 * No fields below this line are part of the public API. They
2242 * may not be used outside of libavcodec and can be changed and
2244 * New public fields should be added right above.
2245 *****************************************************************
2249 * Allocate a custom buffer
2251 int (*alloc_frame)(AVCodecContext *avctx, AVFrame *frame);
2254 * Called at the beginning of each frame or field picture.
2256 * Meaningful frame information (codec specific) is guaranteed to
2257 * be parsed at this point. This function is mandatory.
2259 * Note that buf can be NULL along with buf_size set to 0.
2260 * Otherwise, this means the whole frame is available at this point.
2262 * @param avctx the codec context
2263 * @param buf the frame data buffer base
2264 * @param buf_size the size of the frame in bytes
2265 * @return zero if successful, a negative value otherwise
2267 int (*start_frame)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
2270 * Callback for parameter data (SPS/PPS/VPS etc).
2272 * Useful for hardware decoders which keep persistent state about the
2273 * video parameters, and need to receive any changes to update that state.
2275 * @param avctx the codec context
2276 * @param type the nal unit type
2277 * @param buf the nal unit data buffer
2278 * @param buf_size the size of the nal unit in bytes
2279 * @return zero if successful, a negative value otherwise
2281 int (*decode_params)(AVCodecContext *avctx, int type, const uint8_t *buf, uint32_t buf_size);
2284 * Callback for each slice.
2286 * Meaningful slice information (codec specific) is guaranteed to
2287 * be parsed at this point. This function is mandatory.
2288 * The only exception is XvMC, that works on MB level.
2290 * @param avctx the codec context
2291 * @param buf the slice data buffer base
2292 * @param buf_size the size of the slice in bytes
2293 * @return zero if successful, a negative value otherwise
2295 int (*decode_slice)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
2298 * Called at the end of each frame or field picture.
2300 * The whole picture is parsed at this point and can now be sent
2301 * to the hardware accelerator. This function is mandatory.
2303 * @param avctx the codec context
2304 * @return zero if successful, a negative value otherwise
2306 int (*end_frame)(AVCodecContext *avctx);
2309 * Size of per-frame hardware accelerator private data.
2311 * Private data is allocated with av_mallocz() before
2312 * AVCodecContext.get_buffer() and deallocated after
2313 * AVCodecContext.release_buffer().
2315 int frame_priv_data_size;
2318 * Called for every Macroblock in a slice.
2320 * XvMC uses it to replace the ff_mpv_reconstruct_mb().
2321 * Instead of decoding to raw picture, MB parameters are
2322 * stored in an array provided by the video driver.
2324 * @param s the mpeg context
2326 void (*decode_mb)(struct MpegEncContext *s);
2329 * Initialize the hwaccel private data.
2331 * This will be called from ff_get_format(), after hwaccel and
2332 * hwaccel_context are set and the hwaccel private data in AVCodecInternal
2335 int (*init)(AVCodecContext *avctx);
2338 * Uninitialize the hwaccel private data.
2340 * This will be called from get_format() or avcodec_close(), after hwaccel
2341 * and hwaccel_context are already uninitialized.
2343 int (*uninit)(AVCodecContext *avctx);
2346 * Size of the private data to allocate in
2347 * AVCodecInternal.hwaccel_priv_data.
2352 * Internal hwaccel capabilities.
2357 * Fill the given hw_frames context with current codec parameters. Called
2358 * from get_format. Refer to avcodec_get_hw_frames_parameters() for
2361 * This CAN be called before AVHWAccel.init is called, and you must assume
2362 * that avctx->hwaccel_priv_data is invalid.
2364 int (*frame_params)(AVCodecContext *avctx, AVBufferRef *hw_frames_ctx);
2368 * HWAccel is experimental and is thus avoided in favor of non experimental
2371 #define AV_HWACCEL_CODEC_CAP_EXPERIMENTAL 0x0200
2374 * Hardware acceleration should be used for decoding even if the codec level
2375 * used is unknown or higher than the maximum supported level reported by the
2378 * It's generally a good idea to pass this flag unless you have a specific
2379 * reason not to, as hardware tends to under-report supported levels.
2381 #define AV_HWACCEL_FLAG_IGNORE_LEVEL (1 << 0)
2384 * Hardware acceleration can output YUV pixel formats with a different chroma
2385 * sampling than 4:2:0 and/or other than 8 bits per component.
2387 #define AV_HWACCEL_FLAG_ALLOW_HIGH_DEPTH (1 << 1)
2390 * Hardware acceleration should still be attempted for decoding when the
2391 * codec profile does not match the reported capabilities of the hardware.
2393 * For example, this can be used to try to decode baseline profile H.264
2394 * streams in hardware - it will often succeed, because many streams marked
2395 * as baseline profile actually conform to constrained baseline profile.
2397 * @warning If the stream is actually not supported then the behaviour is
2398 * undefined, and may include returning entirely incorrect output
2399 * while indicating success.
2401 #define AV_HWACCEL_FLAG_ALLOW_PROFILE_MISMATCH (1 << 2)
2407 enum AVSubtitleType {
2410 SUBTITLE_BITMAP, ///< A bitmap, pict will be set
2413 * Plain text, the text field must be set by the decoder and is
2414 * authoritative. ass and pict fields may contain approximations.
2419 * Formatted text, the ass field must be set by the decoder and is
2420 * authoritative. pict and text fields may contain approximations.
2425 #define AV_SUBTITLE_FLAG_FORCED 0x00000001
2427 typedef struct AVSubtitleRect {
2428 int x; ///< top left corner of pict, undefined when pict is not set
2429 int y; ///< top left corner of pict, undefined when pict is not set
2430 int w; ///< width of pict, undefined when pict is not set
2431 int h; ///< height of pict, undefined when pict is not set
2432 int nb_colors; ///< number of colors in pict, undefined when pict is not set
2435 * data+linesize for the bitmap of this subtitle.
2436 * Can be set for text/ass as well once they are rendered.
2441 enum AVSubtitleType type;
2443 char *text; ///< 0 terminated plain UTF-8 text
2446 * 0 terminated ASS/SSA compatible event line.
2447 * The presentation of this is unaffected by the other values in this
2455 typedef struct AVSubtitle {
2456 uint16_t format; /* 0 = graphics */
2457 uint32_t start_display_time; /* relative to packet pts, in ms */
2458 uint32_t end_display_time; /* relative to packet pts, in ms */
2460 AVSubtitleRect **rects;
2461 int64_t pts; ///< Same as packet pts, in AV_TIME_BASE
2465 * Return the LIBAVCODEC_VERSION_INT constant.
2467 unsigned avcodec_version(void);
2470 * Return the libavcodec build-time configuration.
2472 const char *avcodec_configuration(void);
2475 * Return the libavcodec license.
2477 const char *avcodec_license(void);
2480 * Allocate an AVCodecContext and set its fields to default values. The
2481 * resulting struct should be freed with avcodec_free_context().
2483 * @param codec if non-NULL, allocate private data and initialize defaults
2484 * for the given codec. It is illegal to then call avcodec_open2()
2485 * with a different codec.
2486 * If NULL, then the codec-specific defaults won't be initialized,
2487 * which may result in suboptimal default settings (this is
2488 * important mainly for encoders, e.g. libx264).
2490 * @return An AVCodecContext filled with default values or NULL on failure.
2492 AVCodecContext *avcodec_alloc_context3(const AVCodec *codec);
2495 * Free the codec context and everything associated with it and write NULL to
2496 * the provided pointer.
2498 void avcodec_free_context(AVCodecContext **avctx);
2501 * Get the AVClass for AVCodecContext. It can be used in combination with
2502 * AV_OPT_SEARCH_FAKE_OBJ for examining options.
2504 * @see av_opt_find().
2506 const AVClass *avcodec_get_class(void);
2508 #if FF_API_GET_FRAME_CLASS
2510 * @deprecated This function should not be used.
2512 attribute_deprecated
2513 const AVClass *avcodec_get_frame_class(void);
2517 * Get the AVClass for AVSubtitleRect. It can be used in combination with
2518 * AV_OPT_SEARCH_FAKE_OBJ for examining options.
2520 * @see av_opt_find().
2522 const AVClass *avcodec_get_subtitle_rect_class(void);
2525 * Fill the parameters struct based on the values from the supplied codec
2526 * context. Any allocated fields in par are freed and replaced with duplicates
2527 * of the corresponding fields in codec.
2529 * @return >= 0 on success, a negative AVERROR code on failure
2531 int avcodec_parameters_from_context(AVCodecParameters *par,
2532 const AVCodecContext *codec);
2535 * Fill the codec context based on the values from the supplied codec
2536 * parameters. Any allocated fields in codec that have a corresponding field in
2537 * par are freed and replaced with duplicates of the corresponding field in par.
2538 * Fields in codec that do not have a counterpart in par are not touched.
2540 * @return >= 0 on success, a negative AVERROR code on failure.
2542 int avcodec_parameters_to_context(AVCodecContext *codec,
2543 const AVCodecParameters *par);
2546 * Initialize the AVCodecContext to use the given AVCodec. Prior to using this
2547 * function the context has to be allocated with avcodec_alloc_context3().
2549 * The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(),
2550 * avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for
2551 * retrieving a codec.
2553 * @warning This function is not thread safe!
2555 * @note Always call this function before using decoding routines (such as
2556 * @ref avcodec_receive_frame()).
2559 * av_dict_set(&opts, "b", "2.5M", 0);
2560 * codec = avcodec_find_decoder(AV_CODEC_ID_H264);
2564 * context = avcodec_alloc_context3(codec);
2566 * if (avcodec_open2(context, codec, opts) < 0)
2570 * @param avctx The context to initialize.
2571 * @param codec The codec to open this context for. If a non-NULL codec has been
2572 * previously passed to avcodec_alloc_context3() or
2573 * for this context, then this parameter MUST be either NULL or
2574 * equal to the previously passed codec.
2575 * @param options A dictionary filled with AVCodecContext and codec-private options.
2576 * On return this object will be filled with options that were not found.
2578 * @return zero on success, a negative value on error
2579 * @see avcodec_alloc_context3(), avcodec_find_decoder(), avcodec_find_encoder(),
2580 * av_dict_set(), av_opt_find().
2582 int avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options);
2585 * Close a given AVCodecContext and free all the data associated with it
2586 * (but not the AVCodecContext itself).
2588 * Calling this function on an AVCodecContext that hasn't been opened will free
2589 * the codec-specific data allocated in avcodec_alloc_context3() with a non-NULL
2590 * codec. Subsequent calls will do nothing.
2592 * @note Do not use this function. Use avcodec_free_context() to destroy a
2593 * codec context (either open or closed). Opening and closing a codec context
2594 * multiple times is not supported anymore -- use multiple codec contexts
2597 int avcodec_close(AVCodecContext *avctx);
2600 * Free all allocated data in the given subtitle struct.
2602 * @param sub AVSubtitle to free.
2604 void avsubtitle_free(AVSubtitle *sub);
2611 * @addtogroup lavc_decoding
2616 * The default callback for AVCodecContext.get_buffer2(). It is made public so
2617 * it can be called by custom get_buffer2() implementations for decoders without
2618 * AV_CODEC_CAP_DR1 set.
2620 int avcodec_default_get_buffer2(AVCodecContext *s, AVFrame *frame, int flags);
2623 * The default callback for AVCodecContext.get_encode_buffer(). It is made public so
2624 * it can be called by custom get_encode_buffer() implementations for encoders without
2625 * AV_CODEC_CAP_DR1 set.
2627 int avcodec_default_get_encode_buffer(AVCodecContext *s, AVPacket *pkt, int flags);
2630 * Modify width and height values so that they will result in a memory
2631 * buffer that is acceptable for the codec if you do not use any horizontal
2634 * May only be used if a codec with AV_CODEC_CAP_DR1 has been opened.
2636 void avcodec_align_dimensions(AVCodecContext *s, int *width, int *height);
2639 * Modify width and height values so that they will result in a memory
2640 * buffer that is acceptable for the codec if you also ensure that all
2641 * line sizes are a multiple of the respective linesize_align[i].
2643 * May only be used if a codec with AV_CODEC_CAP_DR1 has been opened.
2645 void avcodec_align_dimensions2(AVCodecContext *s, int *width, int *height,
2646 int linesize_align[AV_NUM_DATA_POINTERS]);
2649 * Converts AVChromaLocation to swscale x/y chroma position.
2651 * The positions represent the chroma (0,0) position in a coordinates system
2652 * with luma (0,0) representing the origin and luma(1,1) representing 256,256
2654 * @param xpos horizontal chroma sample position
2655 * @param ypos vertical chroma sample position
2657 int avcodec_enum_to_chroma_pos(int *xpos, int *ypos, enum AVChromaLocation pos);
2660 * Converts swscale x/y chroma position to AVChromaLocation.
2662 * The positions represent the chroma (0,0) position in a coordinates system
2663 * with luma (0,0) representing the origin and luma(1,1) representing 256,256
2665 * @param xpos horizontal chroma sample position
2666 * @param ypos vertical chroma sample position
2668 enum AVChromaLocation avcodec_chroma_pos_to_enum(int xpos, int ypos);
2670 #if FF_API_OLD_ENCDEC
2672 * Decode the audio frame of size avpkt->size from avpkt->data into frame.
2674 * Some decoders may support multiple frames in a single AVPacket. Such
2675 * decoders would then just decode the first frame and the return value would be
2676 * less than the packet size. In this case, avcodec_decode_audio4 has to be
2677 * called again with an AVPacket containing the remaining data in order to
2678 * decode the second frame, etc... Even if no frames are returned, the packet
2679 * needs to be fed to the decoder with remaining data until it is completely
2680 * consumed or an error occurs.
2682 * Some decoders (those marked with AV_CODEC_CAP_DELAY) have a delay between input
2683 * and output. This means that for some packets they will not immediately
2684 * produce decoded output and need to be flushed at the end of decoding to get
2685 * all the decoded data. Flushing is done by calling this function with packets
2686 * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
2687 * returning samples. It is safe to flush even those decoders that are not
2688 * marked with AV_CODEC_CAP_DELAY, then no samples will be returned.
2690 * @warning The input buffer, avpkt->data must be AV_INPUT_BUFFER_PADDING_SIZE
2691 * larger than the actual read bytes because some optimized bitstream
2692 * readers read 32 or 64 bits at once and could read over the end.
2694 * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
2695 * before packets may be fed to the decoder.
2697 * @param avctx the codec context
2698 * @param[out] frame The AVFrame in which to store decoded audio samples.
2699 * The decoder will allocate a buffer for the decoded frame by
2700 * calling the AVCodecContext.get_buffer2() callback.
2701 * When AVCodecContext.refcounted_frames is set to 1, the frame is
2702 * reference counted and the returned reference belongs to the
2703 * caller. The caller must release the frame using av_frame_unref()
2704 * when the frame is no longer needed. The caller may safely write
2705 * to the frame if av_frame_is_writable() returns 1.
2706 * When AVCodecContext.refcounted_frames is set to 0, the returned
2707 * reference belongs to the decoder and is valid only until the
2708 * next call to this function or until closing or flushing the
2709 * decoder. The caller may not write to it.
2710 * @param[out] got_frame_ptr Zero if no frame could be decoded, otherwise it is
2711 * non-zero. Note that this field being set to zero
2712 * does not mean that an error has occurred. For
2713 * decoders with AV_CODEC_CAP_DELAY set, no given decode
2714 * call is guaranteed to produce a frame.
2715 * @param[in] avpkt The input AVPacket containing the input buffer.
2716 * At least avpkt->data and avpkt->size should be set. Some
2717 * decoders might also require additional fields to be set.
2718 * @return A negative error code is returned if an error occurred during
2719 * decoding, otherwise the number of bytes consumed from the input
2720 * AVPacket is returned.
2722 * @deprecated Use avcodec_send_packet() and avcodec_receive_frame().
2724 attribute_deprecated
2725 int avcodec_decode_audio4(AVCodecContext *avctx, AVFrame *frame,
2726 int *got_frame_ptr, const AVPacket *avpkt);
2729 * Decode the video frame of size avpkt->size from avpkt->data into picture.
2730 * Some decoders may support multiple frames in a single AVPacket, such
2731 * decoders would then just decode the first frame.
2733 * @warning The input buffer must be AV_INPUT_BUFFER_PADDING_SIZE larger than
2734 * the actual read bytes because some optimized bitstream readers read 32 or 64
2735 * bits at once and could read over the end.
2737 * @warning The end of the input buffer buf should be set to 0 to ensure that
2738 * no overreading happens for damaged MPEG streams.
2740 * @note Codecs which have the AV_CODEC_CAP_DELAY capability set have a delay
2741 * between input and output, these need to be fed with avpkt->data=NULL,
2742 * avpkt->size=0 at the end to return the remaining frames.
2744 * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
2745 * before packets may be fed to the decoder.
2747 * @param avctx the codec context
2748 * @param[out] picture The AVFrame in which the decoded video frame will be stored.
2749 * Use av_frame_alloc() to get an AVFrame. The codec will
2750 * allocate memory for the actual bitmap by calling the
2751 * AVCodecContext.get_buffer2() callback.
2752 * When AVCodecContext.refcounted_frames is set to 1, the frame is
2753 * reference counted and the returned reference belongs to the
2754 * caller. The caller must release the frame using av_frame_unref()
2755 * when the frame is no longer needed. The caller may safely write
2756 * to the frame if av_frame_is_writable() returns 1.
2757 * When AVCodecContext.refcounted_frames is set to 0, the returned
2758 * reference belongs to the decoder and is valid only until the
2759 * next call to this function or until closing or flushing the
2760 * decoder. The caller may not write to it.
2762 * @param[in] avpkt The input AVPacket containing the input buffer.
2763 * You can create such packet with av_init_packet() and by then setting
2764 * data and size, some decoders might in addition need other fields like
2765 * flags&AV_PKT_FLAG_KEY. All decoders are designed to use the least
2767 * @param[in,out] got_picture_ptr Zero if no frame could be decompressed, otherwise, it is nonzero.
2768 * @return On error a negative value is returned, otherwise the number of bytes
2769 * used or zero if no frame could be decompressed.
2771 * @deprecated Use avcodec_send_packet() and avcodec_receive_frame().
2773 attribute_deprecated
2774 int avcodec_decode_video2(AVCodecContext *avctx, AVFrame *picture,
2775 int *got_picture_ptr,
2776 const AVPacket *avpkt);
2780 * Decode a subtitle message.
2781 * Return a negative value on error, otherwise return the number of bytes used.
2782 * If no subtitle could be decompressed, got_sub_ptr is zero.
2783 * Otherwise, the subtitle is stored in *sub.
2784 * Note that AV_CODEC_CAP_DR1 is not available for subtitle codecs. This is for
2785 * simplicity, because the performance difference is expected to be negligible
2786 * and reusing a get_buffer written for video codecs would probably perform badly
2787 * due to a potentially very different allocation pattern.
2789 * Some decoders (those marked with AV_CODEC_CAP_DELAY) have a delay between input
2790 * and output. This means that for some packets they will not immediately
2791 * produce decoded output and need to be flushed at the end of decoding to get
2792 * all the decoded data. Flushing is done by calling this function with packets
2793 * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
2794 * returning subtitles. It is safe to flush even those decoders that are not
2795 * marked with AV_CODEC_CAP_DELAY, then no subtitles will be returned.
2797 * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
2798 * before packets may be fed to the decoder.
2800 * @param avctx the codec context
2801 * @param[out] sub The preallocated AVSubtitle in which the decoded subtitle will be stored,
2802 * must be freed with avsubtitle_free if *got_sub_ptr is set.
2803 * @param[in,out] got_sub_ptr Zero if no subtitle could be decompressed, otherwise, it is nonzero.
2804 * @param[in] avpkt The input AVPacket containing the input buffer.
2806 int avcodec_decode_subtitle2(AVCodecContext *avctx, AVSubtitle *sub,
2811 * Supply raw packet data as input to a decoder.
2813 * Internally, this call will copy relevant AVCodecContext fields, which can
2814 * influence decoding per-packet, and apply them when the packet is actually
2815 * decoded. (For example AVCodecContext.skip_frame, which might direct the
2816 * decoder to drop the frame contained by the packet sent with this function.)
2818 * @warning The input buffer, avpkt->data must be AV_INPUT_BUFFER_PADDING_SIZE
2819 * larger than the actual read bytes because some optimized bitstream
2820 * readers read 32 or 64 bits at once and could read over the end.
2822 * @warning Do not mix this API with the legacy API (like avcodec_decode_video2())
2823 * on the same AVCodecContext. It will return unexpected results now
2824 * or in future libavcodec versions.
2826 * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
2827 * before packets may be fed to the decoder.
2829 * @param avctx codec context
2830 * @param[in] avpkt The input AVPacket. Usually, this will be a single video
2831 * frame, or several complete audio frames.
2832 * Ownership of the packet remains with the caller, and the
2833 * decoder will not write to the packet. The decoder may create
2834 * a reference to the packet data (or copy it if the packet is
2835 * not reference-counted).
2836 * Unlike with older APIs, the packet is always fully consumed,
2837 * and if it contains multiple frames (e.g. some audio codecs),
2838 * will require you to call avcodec_receive_frame() multiple
2839 * times afterwards before you can send a new packet.
2840 * It can be NULL (or an AVPacket with data set to NULL and
2841 * size set to 0); in this case, it is considered a flush
2842 * packet, which signals the end of the stream. Sending the
2843 * first flush packet will return success. Subsequent ones are
2844 * unnecessary and will return AVERROR_EOF. If the decoder
2845 * still has frames buffered, it will return them after sending
2848 * @return 0 on success, otherwise negative error code:
2849 * AVERROR(EAGAIN): input is not accepted in the current state - user
2850 * must read output with avcodec_receive_frame() (once
2851 * all output is read, the packet should be resent, and
2852 * the call will not fail with EAGAIN).
2853 * AVERROR_EOF: the decoder has been flushed, and no new packets can
2854 * be sent to it (also returned if more than 1 flush
2856 * AVERROR(EINVAL): codec not opened, it is an encoder, or requires flush
2857 * AVERROR(ENOMEM): failed to add packet to internal queue, or similar
2858 * other errors: legitimate decoding errors
2860 int avcodec_send_packet(AVCodecContext *avctx, const AVPacket *avpkt);
2863 * Return decoded output data from a decoder.
2865 * @param avctx codec context
2866 * @param frame This will be set to a reference-counted video or audio
2867 * frame (depending on the decoder type) allocated by the
2868 * decoder. Note that the function will always call
2869 * av_frame_unref(frame) before doing anything else.
2872 * 0: success, a frame was returned
2873 * AVERROR(EAGAIN): output is not available in this state - user must try
2875 * AVERROR_EOF: the decoder has been fully flushed, and there will be
2876 * no more output frames
2877 * AVERROR(EINVAL): codec not opened, or it is an encoder
2878 * AVERROR_INPUT_CHANGED: current decoded frame has changed parameters
2879 * with respect to first decoded frame. Applicable
2880 * when flag AV_CODEC_FLAG_DROPCHANGED is set.
2881 * other negative values: legitimate decoding errors
2883 int avcodec_receive_frame(AVCodecContext *avctx, AVFrame *frame);
2886 * Supply a raw video or audio frame to the encoder. Use avcodec_receive_packet()
2887 * to retrieve buffered output packets.
2889 * @param avctx codec context
2890 * @param[in] frame AVFrame containing the raw audio or video frame to be encoded.
2891 * Ownership of the frame remains with the caller, and the
2892 * encoder will not write to the frame. The encoder may create
2893 * a reference to the frame data (or copy it if the frame is
2894 * not reference-counted).
2895 * It can be NULL, in which case it is considered a flush
2896 * packet. This signals the end of the stream. If the encoder
2897 * still has packets buffered, it will return them after this
2898 * call. Once flushing mode has been entered, additional flush
2899 * packets are ignored, and sending frames will return
2903 * If AV_CODEC_CAP_VARIABLE_FRAME_SIZE is set, then each frame
2904 * can have any number of samples.
2905 * If it is not set, frame->nb_samples must be equal to
2906 * avctx->frame_size for all frames except the last.
2907 * The final frame may be smaller than avctx->frame_size.
2908 * @return 0 on success, otherwise negative error code:
2909 * AVERROR(EAGAIN): input is not accepted in the current state - user
2910 * must read output with avcodec_receive_packet() (once
2911 * all output is read, the packet should be resent, and
2912 * the call will not fail with EAGAIN).
2913 * AVERROR_EOF: the encoder has been flushed, and no new frames can
2915 * AVERROR(EINVAL): codec not opened, refcounted_frames not set, it is a
2916 * decoder, or requires flush
2917 * AVERROR(ENOMEM): failed to add packet to internal queue, or similar
2918 * other errors: legitimate encoding errors
2920 int avcodec_send_frame(AVCodecContext *avctx, const AVFrame *frame);
2923 * Read encoded data from the encoder.
2925 * @param avctx codec context
2926 * @param avpkt This will be set to a reference-counted packet allocated by the
2927 * encoder. Note that the function will always call
2928 * av_packet_unref(avpkt) before doing anything else.
2929 * @return 0 on success, otherwise negative error code:
2930 * AVERROR(EAGAIN): output is not available in the current state - user
2931 * must try to send input
2932 * AVERROR_EOF: the encoder has been fully flushed, and there will be
2933 * no more output packets
2934 * AVERROR(EINVAL): codec not opened, or it is a decoder
2935 * other errors: legitimate encoding errors
2937 int avcodec_receive_packet(AVCodecContext *avctx, AVPacket *avpkt);
2940 * Create and return a AVHWFramesContext with values adequate for hardware
2941 * decoding. This is meant to get called from the get_format callback, and is
2942 * a helper for preparing a AVHWFramesContext for AVCodecContext.hw_frames_ctx.
2943 * This API is for decoding with certain hardware acceleration modes/APIs only.
2945 * The returned AVHWFramesContext is not initialized. The caller must do this
2946 * with av_hwframe_ctx_init().
2948 * Calling this function is not a requirement, but makes it simpler to avoid
2949 * codec or hardware API specific details when manually allocating frames.
2951 * Alternatively to this, an API user can set AVCodecContext.hw_device_ctx,
2952 * which sets up AVCodecContext.hw_frames_ctx fully automatically, and makes
2953 * it unnecessary to call this function or having to care about
2954 * AVHWFramesContext initialization at all.
2956 * There are a number of requirements for calling this function:
2958 * - It must be called from get_format with the same avctx parameter that was
2959 * passed to get_format. Calling it outside of get_format is not allowed, and
2960 * can trigger undefined behavior.
2961 * - The function is not always supported (see description of return values).
2962 * Even if this function returns successfully, hwaccel initialization could
2963 * fail later. (The degree to which implementations check whether the stream
2964 * is actually supported varies. Some do this check only after the user's
2965 * get_format callback returns.)
2966 * - The hw_pix_fmt must be one of the choices suggested by get_format. If the
2967 * user decides to use a AVHWFramesContext prepared with this API function,
2968 * the user must return the same hw_pix_fmt from get_format.
2969 * - The device_ref passed to this function must support the given hw_pix_fmt.
2970 * - After calling this API function, it is the user's responsibility to
2971 * initialize the AVHWFramesContext (returned by the out_frames_ref parameter),
2972 * and to set AVCodecContext.hw_frames_ctx to it. If done, this must be done
2973 * before returning from get_format (this is implied by the normal
2974 * AVCodecContext.hw_frames_ctx API rules).
2975 * - The AVHWFramesContext parameters may change every time time get_format is
2976 * called. Also, AVCodecContext.hw_frames_ctx is reset before get_format. So
2977 * you are inherently required to go through this process again on every
2979 * - It is perfectly possible to call this function without actually using
2980 * the resulting AVHWFramesContext. One use-case might be trying to reuse a
2981 * previously initialized AVHWFramesContext, and calling this API function
2982 * only to test whether the required frame parameters have changed.
2983 * - Fields that use dynamically allocated values of any kind must not be set
2984 * by the user unless setting them is explicitly allowed by the documentation.
2985 * If the user sets AVHWFramesContext.free and AVHWFramesContext.user_opaque,
2986 * the new free callback must call the potentially set previous free callback.
2987 * This API call may set any dynamically allocated fields, including the free
2990 * The function will set at least the following fields on AVHWFramesContext
2991 * (potentially more, depending on hwaccel API):
2993 * - All fields set by av_hwframe_ctx_alloc().
2994 * - Set the format field to hw_pix_fmt.
2995 * - Set the sw_format field to the most suited and most versatile format. (An
2996 * implication is that this will prefer generic formats over opaque formats
2997 * with arbitrary restrictions, if possible.)
2998 * - Set the width/height fields to the coded frame size, rounded up to the
2999 * API-specific minimum alignment.
3000 * - Only _if_ the hwaccel requires a pre-allocated pool: set the initial_pool_size
3001 * field to the number of maximum reference surfaces possible with the codec,
3002 * plus 1 surface for the user to work (meaning the user can safely reference
3003 * at most 1 decoded surface at a time), plus additional buffering introduced
3004 * by frame threading. If the hwaccel does not require pre-allocation, the
3005 * field is left to 0, and the decoder will allocate new surfaces on demand
3007 * - Possibly AVHWFramesContext.hwctx fields, depending on the underlying
3010 * Essentially, out_frames_ref returns the same as av_hwframe_ctx_alloc(), but
3011 * with basic frame parameters set.
3013 * The function is stateless, and does not change the AVCodecContext or the
3014 * device_ref AVHWDeviceContext.
3016 * @param avctx The context which is currently calling get_format, and which
3017 * implicitly contains all state needed for filling the returned
3018 * AVHWFramesContext properly.
3019 * @param device_ref A reference to the AVHWDeviceContext describing the device
3020 * which will be used by the hardware decoder.
3021 * @param hw_pix_fmt The hwaccel format you are going to return from get_format.
3022 * @param out_frames_ref On success, set to a reference to an _uninitialized_
3023 * AVHWFramesContext, created from the given device_ref.
3024 * Fields will be set to values required for decoding.
3025 * Not changed if an error is returned.
3026 * @return zero on success, a negative value on error. The following error codes
3027 * have special semantics:
3028 * AVERROR(ENOENT): the decoder does not support this functionality. Setup
3029 * is always manual, or it is a decoder which does not
3030 * support setting AVCodecContext.hw_frames_ctx at all,
3031 * or it is a software format.
3032 * AVERROR(EINVAL): it is known that hardware decoding is not supported for
3033 * this configuration, or the device_ref is not supported
3034 * for the hwaccel referenced by hw_pix_fmt.
3036 int avcodec_get_hw_frames_parameters(AVCodecContext *avctx,
3037 AVBufferRef *device_ref,
3038 enum AVPixelFormat hw_pix_fmt,
3039 AVBufferRef **out_frames_ref);
3044 * @defgroup lavc_parsing Frame parsing
3048 enum AVPictureStructure {
3049 AV_PICTURE_STRUCTURE_UNKNOWN, //< unknown
3050 AV_PICTURE_STRUCTURE_TOP_FIELD, //< coded as top field
3051 AV_PICTURE_STRUCTURE_BOTTOM_FIELD, //< coded as bottom field
3052 AV_PICTURE_STRUCTURE_FRAME, //< coded as frame
3055 typedef struct AVCodecParserContext {
3057 struct AVCodecParser *parser;
3058 int64_t frame_offset; /* offset of the current frame */
3059 int64_t cur_offset; /* current offset
3060 (incremented by each av_parser_parse()) */
3061 int64_t next_frame_offset; /* offset of the next frame */
3063 int pict_type; /* XXX: Put it back in AVCodecContext. */
3065 * This field is used for proper frame duration computation in lavf.
3066 * It signals, how much longer the frame duration of the current frame
3067 * is compared to normal frame duration.
3069 * frame_duration = (1 + repeat_pict) * time_base
3071 * It is used by codecs like H.264 to display telecined material.
3073 int repeat_pict; /* XXX: Put it back in AVCodecContext. */
3074 int64_t pts; /* pts of the current frame */
3075 int64_t dts; /* dts of the current frame */
3080 int fetch_timestamp;
3082 #define AV_PARSER_PTS_NB 4
3083 int cur_frame_start_index;
3084 int64_t cur_frame_offset[AV_PARSER_PTS_NB];
3085 int64_t cur_frame_pts[AV_PARSER_PTS_NB];
3086 int64_t cur_frame_dts[AV_PARSER_PTS_NB];
3089 #define PARSER_FLAG_COMPLETE_FRAMES 0x0001
3090 #define PARSER_FLAG_ONCE 0x0002
3091 /// Set if the parser has a valid file offset
3092 #define PARSER_FLAG_FETCHED_OFFSET 0x0004
3093 #define PARSER_FLAG_USE_CODEC_TS 0x1000
3095 int64_t offset; ///< byte offset from starting packet start
3096 int64_t cur_frame_end[AV_PARSER_PTS_NB];
3099 * Set by parser to 1 for key frames and 0 for non-key frames.
3100 * It is initialized to -1, so if the parser doesn't set this flag,
3101 * old-style fallback using AV_PICTURE_TYPE_I picture type as key frames
3106 // Timestamp generation support:
3108 * Synchronization point for start of timestamp generation.
3110 * Set to >0 for sync point, 0 for no sync point and <0 for undefined
3113 * For example, this corresponds to presence of H.264 buffering period
3119 * Offset of the current timestamp against last timestamp sync point in
3120 * units of AVCodecContext.time_base.
3122 * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
3123 * contain a valid timestamp offset.
3125 * Note that the timestamp of sync point has usually a nonzero
3126 * dts_ref_dts_delta, which refers to the previous sync point. Offset of
3127 * the next frame after timestamp sync point will be usually 1.
3129 * For example, this corresponds to H.264 cpb_removal_delay.
3131 int dts_ref_dts_delta;
3134 * Presentation delay of current frame in units of AVCodecContext.time_base.
3136 * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
3137 * contain valid non-negative timestamp delta (presentation time of a frame
3138 * must not lie in the past).
3140 * This delay represents the difference between decoding and presentation
3141 * time of the frame.
3143 * For example, this corresponds to H.264 dpb_output_delay.
3148 * Position of the packet in file.
3150 * Analogous to cur_frame_pts/dts
3152 int64_t cur_frame_pos[AV_PARSER_PTS_NB];
3155 * Byte position of currently parsed frame in stream.
3160 * Previous frame byte position.
3165 * Duration of the current frame.
3166 * For audio, this is in units of 1 / AVCodecContext.sample_rate.
3167 * For all other types, this is in units of AVCodecContext.time_base.
3171 enum AVFieldOrder field_order;
3174 * Indicate whether a picture is coded as a frame, top field or bottom field.
3176 * For example, H.264 field_pic_flag equal to 0 corresponds to
3177 * AV_PICTURE_STRUCTURE_FRAME. An H.264 picture with field_pic_flag
3178 * equal to 1 and bottom_field_flag equal to 0 corresponds to
3179 * AV_PICTURE_STRUCTURE_TOP_FIELD.
3181 enum AVPictureStructure picture_structure;
3184 * Picture number incremented in presentation or output order.
3185 * This field may be reinitialized at the first picture of a new sequence.
3187 * For example, this corresponds to H.264 PicOrderCnt.
3189 int output_picture_number;
3192 * Dimensions of the decoded video intended for presentation.
3198 * Dimensions of the coded video.
3204 * The format of the coded data, corresponds to enum AVPixelFormat for video
3205 * and for enum AVSampleFormat for audio.
3207 * Note that a decoder can have considerable freedom in how exactly it
3208 * decodes the data, so the format reported here might be different from the
3209 * one returned by a decoder.
3212 } AVCodecParserContext;
3214 typedef struct AVCodecParser {
3215 int codec_ids[5]; /* several codec IDs are permitted */
3217 int (*parser_init)(AVCodecParserContext *s);
3218 /* This callback never returns an error, a negative value means that
3219 * the frame start was in a previous packet. */
3220 int (*parser_parse)(AVCodecParserContext *s,
3221 AVCodecContext *avctx,
3222 const uint8_t **poutbuf, int *poutbuf_size,
3223 const uint8_t *buf, int buf_size);
3224 void (*parser_close)(AVCodecParserContext *s);
3225 int (*split)(AVCodecContext *avctx, const uint8_t *buf, int buf_size);
3229 * Iterate over all registered codec parsers.
3231 * @param opaque a pointer where libavcodec will store the iteration state. Must
3232 * point to NULL to start the iteration.
3234 * @return the next registered codec parser or NULL when the iteration is
3237 const AVCodecParser *av_parser_iterate(void **opaque);
3239 AVCodecParserContext *av_parser_init(int codec_id);
3244 * @param s parser context.
3245 * @param avctx codec context.
3246 * @param poutbuf set to pointer to parsed buffer or NULL if not yet finished.
3247 * @param poutbuf_size set to size of parsed buffer or zero if not yet finished.
3248 * @param buf input buffer.
3249 * @param buf_size buffer size in bytes without the padding. I.e. the full buffer
3250 size is assumed to be buf_size + AV_INPUT_BUFFER_PADDING_SIZE.
3251 To signal EOF, this should be 0 (so that the last frame
3253 * @param pts input presentation timestamp.
3254 * @param dts input decoding timestamp.
3255 * @param pos input byte position in stream.
3256 * @return the number of bytes of the input bitstream used.
3261 * len = av_parser_parse2(myparser, AVCodecContext, &data, &size,
3268 * decode_frame(data, size);
3272 int av_parser_parse2(AVCodecParserContext *s,
3273 AVCodecContext *avctx,
3274 uint8_t **poutbuf, int *poutbuf_size,
3275 const uint8_t *buf, int buf_size,
3276 int64_t pts, int64_t dts,
3279 #if FF_API_PARSER_CHANGE
3281 * @return 0 if the output buffer is a subset of the input, 1 if it is allocated and must be freed
3282 * @deprecated Use dump_extradata, remove_extra or extract_extradata
3283 * bitstream filters instead.
3285 attribute_deprecated
3286 int av_parser_change(AVCodecParserContext *s,
3287 AVCodecContext *avctx,
3288 uint8_t **poutbuf, int *poutbuf_size,
3289 const uint8_t *buf, int buf_size, int keyframe);
3291 void av_parser_close(AVCodecParserContext *s);
3299 * @addtogroup lavc_encoding
3303 #if FF_API_OLD_ENCDEC
3305 * Encode a frame of audio.
3307 * Takes input samples from frame and writes the next output packet, if
3308 * available, to avpkt. The output packet does not necessarily contain data for
3309 * the most recent frame, as encoders can delay, split, and combine input frames
3310 * internally as needed.
3312 * @param avctx codec context
3313 * @param avpkt output AVPacket.
3314 * The user can supply an output buffer by setting
3315 * avpkt->data and avpkt->size prior to calling the
3316 * function, but if the size of the user-provided data is not
3317 * large enough, encoding will fail. If avpkt->data and
3318 * avpkt->size are set, avpkt->destruct must also be set. All
3319 * other AVPacket fields will be reset by the encoder using
3320 * av_init_packet(). If avpkt->data is NULL, the encoder will
3321 * allocate it. The encoder will set avpkt->size to the size
3322 * of the output packet.
3324 * If this function fails or produces no output, avpkt will be
3325 * freed using av_packet_unref().
3326 * @param[in] frame AVFrame containing the raw audio data to be encoded.
3327 * May be NULL when flushing an encoder that has the
3328 * AV_CODEC_CAP_DELAY capability set.
3329 * If AV_CODEC_CAP_VARIABLE_FRAME_SIZE is set, then each frame
3330 * can have any number of samples.
3331 * If it is not set, frame->nb_samples must be equal to
3332 * avctx->frame_size for all frames except the last.
3333 * The final frame may be smaller than avctx->frame_size.
3334 * @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
3335 * output packet is non-empty, and to 0 if it is
3336 * empty. If the function returns an error, the
3337 * packet can be assumed to be invalid, and the
3338 * value of got_packet_ptr is undefined and should
3340 * @return 0 on success, negative error code on failure
3342 * @deprecated use avcodec_send_frame()/avcodec_receive_packet() instead.
3343 * If allowed and required, set AVCodecContext.get_encode_buffer to
3344 * a custom function to pass user supplied output buffers.
3346 attribute_deprecated
3347 int avcodec_encode_audio2(AVCodecContext *avctx, AVPacket *avpkt,
3348 const AVFrame *frame, int *got_packet_ptr);
3351 * Encode a frame of video.
3353 * Takes input raw video data from frame and writes the next output packet, if
3354 * available, to avpkt. The output packet does not necessarily contain data for
3355 * the most recent frame, as encoders can delay and reorder input frames
3356 * internally as needed.
3358 * @param avctx codec context
3359 * @param avpkt output AVPacket.
3360 * The user can supply an output buffer by setting
3361 * avpkt->data and avpkt->size prior to calling the
3362 * function, but if the size of the user-provided data is not
3363 * large enough, encoding will fail. All other AVPacket fields
3364 * will be reset by the encoder using av_init_packet(). If
3365 * avpkt->data is NULL, the encoder will allocate it.
3366 * The encoder will set avpkt->size to the size of the
3367 * output packet. The returned data (if any) belongs to the
3368 * caller, he is responsible for freeing it.
3370 * If this function fails or produces no output, avpkt will be
3371 * freed using av_packet_unref().
3372 * @param[in] frame AVFrame containing the raw video data to be encoded.
3373 * May be NULL when flushing an encoder that has the
3374 * AV_CODEC_CAP_DELAY capability set.
3375 * @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
3376 * output packet is non-empty, and to 0 if it is
3377 * empty. If the function returns an error, the
3378 * packet can be assumed to be invalid, and the
3379 * value of got_packet_ptr is undefined and should
3381 * @return 0 on success, negative error code on failure
3383 * @deprecated use avcodec_send_frame()/avcodec_receive_packet() instead.
3384 * If allowed and required, set AVCodecContext.get_encode_buffer to
3385 * a custom function to pass user supplied output buffers.
3387 attribute_deprecated
3388 int avcodec_encode_video2(AVCodecContext *avctx, AVPacket *avpkt,
3389 const AVFrame *frame, int *got_packet_ptr);
3392 int avcodec_encode_subtitle(AVCodecContext *avctx, uint8_t *buf, int buf_size,
3393 const AVSubtitle *sub);
3401 * @defgroup lavc_misc Utility functions
3404 * Miscellaneous utility functions related to both encoding and decoding
3410 * @defgroup lavc_misc_pixfmt Pixel formats
3412 * Functions for working with pixel formats.
3417 * Return a value representing the fourCC code associated to the
3418 * pixel format pix_fmt, or 0 if no associated fourCC code can be
3421 unsigned int avcodec_pix_fmt_to_codec_tag(enum AVPixelFormat pix_fmt);
3424 * Find the best pixel format to convert to given a certain source pixel
3425 * format. When converting from one pixel format to another, information loss
3426 * may occur. For example, when converting from RGB24 to GRAY, the color
3427 * information will be lost. Similarly, other losses occur when converting from
3428 * some formats to other formats. avcodec_find_best_pix_fmt_of_2() searches which of
3429 * the given pixel formats should be used to suffer the least amount of loss.
3430 * The pixel formats from which it chooses one, are determined by the
3431 * pix_fmt_list parameter.
3434 * @param[in] pix_fmt_list AV_PIX_FMT_NONE terminated array of pixel formats to choose from
3435 * @param[in] src_pix_fmt source pixel format
3436 * @param[in] has_alpha Whether the source pixel format alpha channel is used.
3437 * @param[out] loss_ptr Combination of flags informing you what kind of losses will occur.
3438 * @return The best pixel format to convert to or -1 if none was found.
3440 enum AVPixelFormat avcodec_find_best_pix_fmt_of_list(const enum AVPixelFormat *pix_fmt_list,
3441 enum AVPixelFormat src_pix_fmt,
3442 int has_alpha, int *loss_ptr);
3444 enum AVPixelFormat avcodec_default_get_format(struct AVCodecContext *s, const enum AVPixelFormat * fmt);
3450 void avcodec_string(char *buf, int buf_size, AVCodecContext *enc, int encode);
3453 * Return a name for the specified profile, if available.
3455 * @param codec the codec that is searched for the given profile
3456 * @param profile the profile value for which a name is requested
3457 * @return A name for the profile if found, NULL otherwise.
3459 const char *av_get_profile_name(const AVCodec *codec, int profile);
3462 * Return a name for the specified profile, if available.
3464 * @param codec_id the ID of the codec to which the requested profile belongs
3465 * @param profile the profile value for which a name is requested
3466 * @return A name for the profile if found, NULL otherwise.
3468 * @note unlike av_get_profile_name(), which searches a list of profiles
3469 * supported by a specific decoder or encoder implementation, this
3470 * function searches the list of profiles from the AVCodecDescriptor
3472 const char *avcodec_profile_name(enum AVCodecID codec_id, int profile);
3474 int avcodec_default_execute(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2),void *arg, int *ret, int count, int size);
3475 int avcodec_default_execute2(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2, int, int),void *arg, int *ret, int count);
3476 //FIXME func typedef
3479 * Fill AVFrame audio data and linesize pointers.
3481 * The buffer buf must be a preallocated buffer with a size big enough
3482 * to contain the specified samples amount. The filled AVFrame data
3483 * pointers will point to this buffer.
3485 * AVFrame extended_data channel pointers are allocated if necessary for
3488 * @param frame the AVFrame
3489 * frame->nb_samples must be set prior to calling the
3490 * function. This function fills in frame->data,
3491 * frame->extended_data, frame->linesize[0].
3492 * @param nb_channels channel count
3493 * @param sample_fmt sample format
3494 * @param buf buffer to use for frame data
3495 * @param buf_size size of buffer
3496 * @param align plane size sample alignment (0 = default)
3497 * @return >=0 on success, negative error code on failure
3498 * @todo return the size in bytes required to store the samples in
3499 * case of success, at the next libavutil bump
3501 int avcodec_fill_audio_frame(AVFrame *frame, int nb_channels,
3502 enum AVSampleFormat sample_fmt, const uint8_t *buf,
3503 int buf_size, int align);
3506 * Reset the internal codec state / flush internal buffers. Should be called
3507 * e.g. when seeking or when switching to a different stream.
3509 * @note for decoders, when refcounted frames are not used
3510 * (i.e. avctx->refcounted_frames is 0), this invalidates the frames previously
3511 * returned from the decoder. When refcounted frames are used, the decoder just
3512 * releases any references it might keep internally, but the caller's reference
3515 * @note for encoders, this function will only do something if the encoder
3516 * declares support for AV_CODEC_CAP_ENCODER_FLUSH. When called, the encoder
3517 * will drain any remaining packets, and can then be re-used for a different
3518 * stream (as opposed to sending a null frame which will leave the encoder
3519 * in a permanent EOF state after draining). This can be desirable if the
3520 * cost of tearing down and replacing the encoder instance is high.
3522 void avcodec_flush_buffers(AVCodecContext *avctx);
3525 * Return codec bits per sample.
3527 * @param[in] codec_id the codec
3528 * @return Number of bits per sample or zero if unknown for the given codec.
3530 int av_get_bits_per_sample(enum AVCodecID codec_id);
3533 * Return the PCM codec associated with a sample format.
3534 * @param be endianness, 0 for little, 1 for big,
3535 * -1 (or anything else) for native
3536 * @return AV_CODEC_ID_PCM_* or AV_CODEC_ID_NONE
3538 enum AVCodecID av_get_pcm_codec(enum AVSampleFormat fmt, int be);
3541 * Return codec bits per sample.
3542 * Only return non-zero if the bits per sample is exactly correct, not an
3545 * @param[in] codec_id the codec
3546 * @return Number of bits per sample or zero if unknown for the given codec.
3548 int av_get_exact_bits_per_sample(enum AVCodecID codec_id);
3551 * Return audio frame duration.
3553 * @param avctx codec context
3554 * @param frame_bytes size of the frame, or 0 if unknown
3555 * @return frame duration, in samples, if known. 0 if not able to
3558 int av_get_audio_frame_duration(AVCodecContext *avctx, int frame_bytes);
3561 * This function is the same as av_get_audio_frame_duration(), except it works
3562 * with AVCodecParameters instead of an AVCodecContext.
3564 int av_get_audio_frame_duration2(AVCodecParameters *par, int frame_bytes);
3569 * Same behaviour av_fast_malloc but the buffer has additional
3570 * AV_INPUT_BUFFER_PADDING_SIZE at the end which will always be 0.
3572 * In addition the whole buffer will initially and after resizes
3573 * be 0-initialized so that no uninitialized data will ever appear.
3575 void av_fast_padded_malloc(void *ptr, unsigned int *size, size_t min_size);
3578 * Same behaviour av_fast_padded_malloc except that buffer will always
3579 * be 0-initialized after call.
3581 void av_fast_padded_mallocz(void *ptr, unsigned int *size, size_t min_size);
3584 * Encode extradata length to a buffer. Used by xiph codecs.
3586 * @param s buffer to write to; must be at least (v/255+1) bytes long
3587 * @param v size of extradata in bytes
3588 * @return number of bytes written to the buffer.
3590 unsigned int av_xiphlacing(unsigned char *s, unsigned int v);
3593 * @return a positive value if s is open (i.e. avcodec_open2() was called on it
3594 * with no corresponding avcodec_close()), 0 otherwise.
3596 int avcodec_is_open(AVCodecContext *s);
3599 * Allocate a CPB properties structure and initialize its fields to default
3602 * @param size if non-NULL, the size of the allocated struct will be written
3603 * here. This is useful for embedding it in side data.
3605 * @return the newly allocated struct or NULL on failure
3607 AVCPBProperties *av_cpb_properties_alloc(size_t *size);
3613 #endif /* AVCODEC_AVCODEC_H */