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.
460 * Minimum bitrate of the stream, in bits per second.
461 * Zero if unknown or unspecified.
465 * Average bitrate of the stream, in bits per second.
466 * Zero if unknown or unspecified.
471 * The size of the buffer to which the ratecontrol is applied, in bits.
472 * Zero if unknown or unspecified.
477 * The delay between the time the packet this structure is associated with
478 * is received and the time when it should be decoded, in periods of a 27MHz
481 * UINT64_MAX when unknown or unspecified.
487 * This structure supplies correlation between a packet timestamp and a wall clock
488 * production time. The definition follows the Producer Reference Time ('prft')
489 * as defined in ISO/IEC 14496-12
491 typedef struct AVProducerReferenceTime {
493 * A UTC timestamp, in microseconds, since Unix epoch (e.g, av_gettime()).
497 } AVProducerReferenceTime;
500 * The decoder will keep a reference to the frame and may reuse it later.
502 #define AV_GET_BUFFER_FLAG_REF (1 << 0)
505 * The encoder will keep a reference to the packet and may reuse it later.
507 #define AV_GET_ENCODE_BUFFER_FLAG_REF (1 << 0)
509 struct AVCodecInternal;
512 * main external API structure.
513 * New fields can be added to the end with minor version bumps.
514 * Removal, reordering and changes to existing fields require a major
516 * You can use AVOptions (av_opt* / av_set/get*()) to access these fields from user
518 * The name string for AVOptions options matches the associated command line
519 * parameter name and can be found in libavcodec/options_table.h
520 * The AVOption/command line parameter names differ in some cases from the C
521 * structure field names for historic reasons or brevity.
522 * sizeof(AVCodecContext) must not be used outside libav*.
524 typedef struct AVCodecContext {
526 * information on struct for av_log
527 * - set by avcodec_alloc_context3
529 const AVClass *av_class;
530 int log_level_offset;
532 enum AVMediaType codec_type; /* see AVMEDIA_TYPE_xxx */
533 const struct AVCodec *codec;
534 enum AVCodecID codec_id; /* see AV_CODEC_ID_xxx */
537 * fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
538 * This is used to work around some encoder bugs.
539 * A demuxer should set this to what is stored in the field used to identify the codec.
540 * If there are multiple such fields in a container then the demuxer should choose the one
541 * which maximizes the information about the used codec.
542 * If the codec tag field in a container is larger than 32 bits then the demuxer should
543 * remap the longer ID to 32 bits with a table or other structure. Alternatively a new
544 * extra_codec_tag + size could be added but for this a clear advantage must be demonstrated
546 * - encoding: Set by user, if not then the default based on codec_id will be used.
547 * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
549 unsigned int codec_tag;
554 * Private context used for internal data.
556 * Unlike priv_data, this is not codec-specific. It is used in general
557 * libavcodec functions.
559 struct AVCodecInternal *internal;
562 * Private data of the user, can be used to carry app specific stuff.
563 * - encoding: Set by user.
564 * - decoding: Set by user.
569 * the average bitrate
570 * - encoding: Set by user; unused for constant quantizer encoding.
571 * - decoding: Set by user, may be overwritten by libavcodec
572 * if this info is available in the stream
577 * number of bits the bitstream is allowed to diverge from the reference.
578 * the reference can be CBR (for CBR pass1) or VBR (for pass2)
579 * - encoding: Set by user; unused for constant quantizer encoding.
582 int bit_rate_tolerance;
585 * Global quality for codecs which cannot change it per frame.
586 * This should be proportional to MPEG-1/2/4 qscale.
587 * - encoding: Set by user.
593 * - encoding: Set by user.
596 int compression_level;
597 #define FF_COMPRESSION_DEFAULT -1
601 * - encoding: Set by user.
602 * - decoding: Set by user.
608 * - encoding: Set by user.
609 * - decoding: Set by user.
614 * some codecs need / can use extradata like Huffman tables.
615 * MJPEG: Huffman tables
616 * rv10: additional flags
617 * MPEG-4: global headers (they can be in the bitstream or here)
618 * The allocated memory should be AV_INPUT_BUFFER_PADDING_SIZE bytes larger
619 * than extradata_size to avoid problems if it is read with the bitstream reader.
620 * The bytewise contents of extradata must not depend on the architecture or CPU endianness.
621 * Must be allocated with the av_malloc() family of functions.
622 * - encoding: Set/allocated/freed by libavcodec.
623 * - decoding: Set/allocated/freed by user.
629 * This is the fundamental unit of time (in seconds) in terms
630 * of which frame timestamps are represented. For fixed-fps content,
631 * timebase should be 1/framerate and timestamp increments should be
633 * This often, but not always is the inverse of the frame rate or field rate
634 * for video. 1/time_base is not the average frame rate if the frame rate is not
637 * Like containers, elementary streams also can store timestamps, 1/time_base
638 * is the unit in which these timestamps are specified.
639 * As example of such codec time base see ISO/IEC 14496-2:2001(E)
640 * vop_time_increment_resolution and fixed_vop_rate
641 * (fixed_vop_rate == 0 implies that it is different from the framerate)
643 * - encoding: MUST be set by user.
644 * - decoding: the use of this field for decoding is deprecated.
645 * Use framerate instead.
647 AVRational time_base;
650 * For some codecs, the time base is closer to the field rate than the frame rate.
651 * Most notably, H.264 and MPEG-2 specify time_base as half of frame duration
652 * if no telecine is used ...
654 * Set to time_base ticks per frame. Default 1, e.g., H.264/MPEG-2 set it to 2.
661 * Encoding: Number of frames delay there will be from the encoder input to
662 * the decoder output. (we assume the decoder matches the spec)
663 * Decoding: Number of frames delay in addition to what a standard decoder
664 * as specified in the spec would produce.
667 * Number of frames the decoded output will be delayed relative to the
671 * For encoding, this field is unused (see initial_padding).
673 * For decoding, this is the number of samples the decoder needs to
674 * output before the decoder's output is valid. When seeking, you should
675 * start decoding this many samples prior to your desired seek point.
677 * - encoding: Set by libavcodec.
678 * - decoding: Set by libavcodec.
685 * picture width / height.
687 * @note Those fields may not match the values of the last
688 * AVFrame output by avcodec_decode_video2 due frame
691 * - encoding: MUST be set by user.
692 * - decoding: May be set by the user before opening the decoder if known e.g.
693 * from the container. Some decoders will require the dimensions
694 * to be set by the caller. During decoding, the decoder may
695 * overwrite those values as required while parsing the data.
700 * Bitstream width / height, may be different from width/height e.g. when
701 * the decoded frame is cropped before being output or lowres is enabled.
703 * @note Those field may not match the value of the last
704 * AVFrame output by avcodec_receive_frame() due frame
708 * - decoding: May be set by the user before opening the decoder if known
709 * e.g. from the container. During decoding, the decoder may
710 * overwrite those values as required while parsing the data.
712 int coded_width, coded_height;
715 * the number of pictures in a group of pictures, or 0 for intra_only
716 * - encoding: Set by user.
722 * Pixel format, see AV_PIX_FMT_xxx.
723 * May be set by the demuxer if known from headers.
724 * May be overridden by the decoder if it knows better.
726 * @note This field may not match the value of the last
727 * AVFrame output by avcodec_receive_frame() due frame
730 * - encoding: Set by user.
731 * - decoding: Set by user if known, overridden by libavcodec while
734 enum AVPixelFormat pix_fmt;
737 * If non NULL, 'draw_horiz_band' is called by the libavcodec
738 * decoder to draw a horizontal band. It improves cache usage. Not
739 * all codecs can do that. You must check the codec capabilities
741 * When multithreading is used, it may be called from multiple threads
742 * at the same time; threads might draw different parts of the same AVFrame,
743 * or multiple AVFrames, and there is no guarantee that slices will be drawn
745 * The function is also used by hardware acceleration APIs.
746 * It is called at least once during frame decoding to pass
747 * the data needed for hardware render.
748 * In that mode instead of pixel data, AVFrame points to
749 * a structure specific to the acceleration API. The application
750 * reads the structure and can change some fields to indicate progress
753 * - decoding: Set by user.
754 * @param height the height of the slice
755 * @param y the y position of the slice
756 * @param type 1->top field, 2->bottom field, 3->frame
757 * @param offset offset into the AVFrame.data from which the slice should be read
759 void (*draw_horiz_band)(struct AVCodecContext *s,
760 const AVFrame *src, int offset[AV_NUM_DATA_POINTERS],
761 int y, int type, int height);
764 * callback to negotiate the pixelFormat
765 * @param fmt is the list of formats which are supported by the codec,
766 * it is terminated by -1 as 0 is a valid format, the formats are ordered by quality.
767 * The first is always the native one.
768 * @note The callback may be called again immediately if initialization for
769 * the selected (hardware-accelerated) pixel format failed.
770 * @warning Behavior is undefined if the callback returns a value not
771 * in the fmt list of formats.
772 * @return the chosen format
774 * - decoding: Set by user, if not set the native format will be chosen.
776 enum AVPixelFormat (*get_format)(struct AVCodecContext *s, const enum AVPixelFormat * fmt);
779 * maximum number of B-frames between non-B-frames
780 * Note: The output will be delayed by max_b_frames+1 relative to the input.
781 * - encoding: Set by user.
787 * qscale factor between IP and B-frames
788 * If > 0 then the last P-frame quantizer will be used (q= lastp_q*factor+offset).
789 * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
790 * - encoding: Set by user.
793 float b_quant_factor;
796 * qscale offset between IP and B-frames
797 * - encoding: Set by user.
800 float b_quant_offset;
803 * Size of the frame reordering buffer in the decoder.
804 * For MPEG-2 it is 1 IPB or 0 low delay IP.
805 * - encoding: Set by libavcodec.
806 * - decoding: Set by libavcodec.
811 * qscale factor between P- and I-frames
812 * If > 0 then the last P-frame quantizer will be used (q = lastp_q * factor + offset).
813 * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
814 * - encoding: Set by user.
817 float i_quant_factor;
820 * qscale offset between P and I-frames
821 * - encoding: Set by user.
824 float i_quant_offset;
827 * luminance masking (0-> disabled)
828 * - encoding: Set by user.
834 * temporary complexity masking (0-> disabled)
835 * - encoding: Set by user.
838 float temporal_cplx_masking;
841 * spatial complexity masking (0-> disabled)
842 * - encoding: Set by user.
845 float spatial_cplx_masking;
848 * p block masking (0-> disabled)
849 * - encoding: Set by user.
855 * darkness masking (0-> disabled)
856 * - encoding: Set by user.
863 * - encoding: Set by libavcodec.
864 * - decoding: Set by user (or 0).
869 * slice offsets in the frame in bytes
870 * - encoding: Set/allocated by libavcodec.
871 * - decoding: Set/allocated by user (or NULL).
876 * sample aspect ratio (0 if unknown)
877 * That is the width of a pixel divided by the height of the pixel.
878 * Numerator and denominator must be relatively prime and smaller than 256 for some video standards.
879 * - encoding: Set by user.
880 * - decoding: Set by libavcodec.
882 AVRational sample_aspect_ratio;
885 * motion estimation comparison function
886 * - encoding: Set by user.
891 * subpixel motion estimation comparison function
892 * - encoding: Set by user.
897 * macroblock comparison function (not supported yet)
898 * - encoding: Set by user.
903 * interlaced DCT comparison function
904 * - encoding: Set by user.
910 #define FF_CMP_SATD 2
912 #define FF_CMP_PSNR 4
915 #define FF_CMP_ZERO 7
916 #define FF_CMP_VSAD 8
917 #define FF_CMP_VSSE 9
918 #define FF_CMP_NSSE 10
919 #define FF_CMP_W53 11
920 #define FF_CMP_W97 12
921 #define FF_CMP_DCTMAX 13
922 #define FF_CMP_DCT264 14
923 #define FF_CMP_MEDIAN_SAD 15
924 #define FF_CMP_CHROMA 256
927 * ME diamond size & shape
928 * - encoding: Set by user.
934 * amount of previous MV predictors (2a+1 x 2a+1 square)
935 * - encoding: Set by user.
938 int last_predictor_count;
941 * motion estimation prepass comparison function
942 * - encoding: Set by user.
948 * ME prepass diamond size & shape
949 * - encoding: Set by user.
956 * - encoding: Set by user.
959 int me_subpel_quality;
962 * maximum motion estimation search range in subpel units
963 * If 0 then no limit.
965 * - encoding: Set by user.
973 * - decoding: Set by user.
976 #define SLICE_FLAG_CODED_ORDER 0x0001 ///< draw_horiz_band() is called in coded order instead of display
977 #define SLICE_FLAG_ALLOW_FIELD 0x0002 ///< allow draw_horiz_band() with field slices (MPEG-2 field pics)
978 #define SLICE_FLAG_ALLOW_PLANE 0x0004 ///< allow draw_horiz_band() with 1 component at a time (SVQ1)
981 * macroblock decision mode
982 * - encoding: Set by user.
986 #define FF_MB_DECISION_SIMPLE 0 ///< uses mb_cmp
987 #define FF_MB_DECISION_BITS 1 ///< chooses the one which needs the fewest bits
988 #define FF_MB_DECISION_RD 2 ///< rate distortion
991 * custom intra quantization matrix
992 * Must be allocated with the av_malloc() family of functions, and will be freed in
993 * avcodec_free_context().
994 * - encoding: Set/allocated by user, freed by libavcodec. Can be NULL.
995 * - decoding: Set/allocated/freed by libavcodec.
997 uint16_t *intra_matrix;
1000 * custom inter quantization matrix
1001 * Must be allocated with the av_malloc() family of functions, and will be freed in
1002 * avcodec_free_context().
1003 * - encoding: Set/allocated by user, freed by libavcodec. Can be NULL.
1004 * - decoding: Set/allocated/freed by libavcodec.
1006 uint16_t *inter_matrix;
1009 * precision of the intra DC coefficient - 8
1010 * - encoding: Set by user.
1011 * - decoding: Set by libavcodec
1013 int intra_dc_precision;
1016 * Number of macroblock rows at the top which are skipped.
1017 * - encoding: unused
1018 * - decoding: Set by user.
1023 * Number of macroblock rows at the bottom which are skipped.
1024 * - encoding: unused
1025 * - decoding: Set by user.
1030 * minimum MB Lagrange multiplier
1031 * - encoding: Set by user.
1032 * - decoding: unused
1037 * maximum MB Lagrange multiplier
1038 * - encoding: Set by user.
1039 * - decoding: unused
1044 * - encoding: Set by user.
1045 * - decoding: unused
1051 * - encoding: Set by user.
1052 * - decoding: unused
1057 * number of reference frames
1058 * - encoding: Set by user.
1059 * - decoding: Set by lavc.
1064 * Note: Value depends upon the compare function used for fullpel ME.
1065 * - encoding: Set by user.
1066 * - decoding: unused
1071 * Chromaticity coordinates of the source primaries.
1072 * - encoding: Set by user
1073 * - decoding: Set by libavcodec
1075 enum AVColorPrimaries color_primaries;
1078 * Color Transfer Characteristic.
1079 * - encoding: Set by user
1080 * - decoding: Set by libavcodec
1082 enum AVColorTransferCharacteristic color_trc;
1085 * YUV colorspace type.
1086 * - encoding: Set by user
1087 * - decoding: Set by libavcodec
1089 enum AVColorSpace colorspace;
1092 * MPEG vs JPEG YUV range.
1093 * - encoding: Set by user
1094 * - decoding: Set by libavcodec
1096 enum AVColorRange color_range;
1099 * This defines the location of chroma samples.
1100 * - encoding: Set by user
1101 * - decoding: Set by libavcodec
1103 enum AVChromaLocation chroma_sample_location;
1107 * Indicates number of picture subdivisions. Used for parallelized
1109 * - encoding: Set by user
1110 * - decoding: unused
1115 * - encoding: set by libavcodec
1116 * - decoding: Set by user.
1118 enum AVFieldOrder field_order;
1121 int sample_rate; ///< samples per second
1122 int channels; ///< number of audio channels
1125 * audio sample format
1126 * - encoding: Set by user.
1127 * - decoding: Set by libavcodec.
1129 enum AVSampleFormat sample_fmt; ///< sample format
1131 /* The following data should not be initialized. */
1133 * Number of samples per channel in an audio frame.
1135 * - encoding: set by libavcodec in avcodec_open2(). Each submitted frame
1136 * except the last must contain exactly frame_size samples per channel.
1137 * May be 0 when the codec has AV_CODEC_CAP_VARIABLE_FRAME_SIZE set, then the
1138 * frame size is not restricted.
1139 * - decoding: may be set by some decoders to indicate constant frame size
1144 * Frame counter, set by libavcodec.
1146 * - decoding: total number of frames returned from the decoder so far.
1147 * - encoding: total number of frames passed to the encoder so far.
1149 * @note the counter is not incremented if encoding/decoding resulted in
1155 * number of bytes per packet if constant and known or 0
1156 * Used by some WAV based audio codecs.
1161 * Audio cutoff bandwidth (0 means "automatic")
1162 * - encoding: Set by user.
1163 * - decoding: unused
1168 * Audio channel layout.
1169 * - encoding: set by user.
1170 * - decoding: set by user, may be overwritten by libavcodec.
1172 uint64_t channel_layout;
1175 * Request decoder to use this channel layout if it can (0 for default)
1176 * - encoding: unused
1177 * - decoding: Set by user.
1179 uint64_t request_channel_layout;
1182 * Type of service that the audio stream conveys.
1183 * - encoding: Set by user.
1184 * - decoding: Set by libavcodec.
1186 enum AVAudioServiceType audio_service_type;
1189 * desired sample format
1190 * - encoding: Not used.
1191 * - decoding: Set by user.
1192 * Decoder will decode to this format if it can.
1194 enum AVSampleFormat request_sample_fmt;
1197 * This callback is called at the beginning of each frame to get data
1198 * buffer(s) for it. There may be one contiguous buffer for all the data or
1199 * there may be a buffer per each data plane or anything in between. What
1200 * this means is, you may set however many entries in buf[] you feel necessary.
1201 * Each buffer must be reference-counted using the AVBuffer API (see description
1204 * The following fields will be set in the frame before this callback is
1207 * - width, height (video only)
1208 * - sample_rate, channel_layout, nb_samples (audio only)
1209 * Their values may differ from the corresponding values in
1210 * AVCodecContext. This callback must use the frame values, not the codec
1211 * context values, to calculate the required buffer size.
1213 * This callback must fill the following fields in the frame:
1217 * * if the data is planar audio with more than 8 channels, then this
1218 * callback must allocate and fill extended_data to contain all pointers
1219 * to all data planes. data[] must hold as many pointers as it can.
1220 * extended_data must be allocated with av_malloc() and will be freed in
1222 * * otherwise extended_data must point to data
1223 * - buf[] must contain one or more pointers to AVBufferRef structures. Each of
1224 * the frame's data and extended_data pointers must be contained in these. That
1225 * is, one AVBufferRef for each allocated chunk of memory, not necessarily one
1226 * AVBufferRef per data[] entry. See: av_buffer_create(), av_buffer_alloc(),
1227 * and av_buffer_ref().
1228 * - extended_buf and nb_extended_buf must be allocated with av_malloc() by
1229 * this callback and filled with the extra buffers if there are more
1230 * buffers than buf[] can hold. extended_buf will be freed in
1233 * If AV_CODEC_CAP_DR1 is not set then get_buffer2() must call
1234 * avcodec_default_get_buffer2() instead of providing buffers allocated by
1237 * Each data plane must be aligned to the maximum required by the target
1240 * @see avcodec_default_get_buffer2()
1244 * If AV_GET_BUFFER_FLAG_REF is set in flags then the frame may be reused
1245 * (read and/or written to if it is writable) later by libavcodec.
1247 * avcodec_align_dimensions2() should be used to find the required width and
1248 * height, as they normally need to be rounded up to the next multiple of 16.
1250 * Some decoders do not support linesizes changing between frames.
1252 * If frame multithreading is used, this callback may be called from a
1253 * different thread, but not from more than one at once. Does not need to be
1256 * @see avcodec_align_dimensions2()
1260 * Decoders request a buffer of a particular size by setting
1261 * AVFrame.nb_samples prior to calling get_buffer2(). The decoder may,
1262 * however, utilize only part of the buffer by setting AVFrame.nb_samples
1263 * to a smaller value in the output frame.
1265 * As a convenience, av_samples_get_buffer_size() and
1266 * av_samples_fill_arrays() in libavutil may be used by custom get_buffer2()
1267 * functions to find the required data size and to fill data pointers and
1268 * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
1269 * since all planes must be the same size.
1271 * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
1273 * - encoding: unused
1274 * - decoding: Set by libavcodec, user can override.
1276 int (*get_buffer2)(struct AVCodecContext *s, AVFrame *frame, int flags);
1278 #if FF_API_OLD_ENCDEC
1280 * If non-zero, the decoded audio and video frames returned from
1281 * avcodec_decode_video2() and avcodec_decode_audio4() are reference-counted
1282 * and are valid indefinitely. The caller must free them with
1283 * av_frame_unref() when they are not needed anymore.
1284 * Otherwise, the decoded frames must not be freed by the caller and are
1285 * only valid until the next decode call.
1287 * This is always automatically enabled if avcodec_receive_frame() is used.
1289 * - encoding: unused
1290 * - decoding: set by the caller before avcodec_open2().
1292 attribute_deprecated
1293 int refcounted_frames;
1296 /* - encoding parameters */
1297 float qcompress; ///< amount of qscale change between easy & hard scenes (0.0-1.0)
1298 float qblur; ///< amount of qscale smoothing over time (0.0-1.0)
1302 * - encoding: Set by user.
1303 * - decoding: unused
1309 * - encoding: Set by user.
1310 * - decoding: unused
1315 * maximum quantizer difference between frames
1316 * - encoding: Set by user.
1317 * - decoding: unused
1322 * decoder bitstream buffer size
1323 * - encoding: Set by user.
1324 * - decoding: unused
1329 * ratecontrol override, see RcOverride
1330 * - encoding: Allocated/set/freed by user.
1331 * - decoding: unused
1333 int rc_override_count;
1334 RcOverride *rc_override;
1338 * - encoding: Set by user.
1339 * - decoding: Set by user, may be overwritten by libavcodec.
1341 int64_t rc_max_rate;
1345 * - encoding: Set by user.
1346 * - decoding: unused
1348 int64_t rc_min_rate;
1351 * Ratecontrol attempt to use, at maximum, <value> of what can be used without an underflow.
1352 * - encoding: Set by user.
1353 * - decoding: unused.
1355 float rc_max_available_vbv_use;
1358 * Ratecontrol attempt to use, at least, <value> times the amount needed to prevent a vbv overflow.
1359 * - encoding: Set by user.
1360 * - decoding: unused.
1362 float rc_min_vbv_overflow_use;
1365 * Number of bits which should be loaded into the rc buffer before decoding starts.
1366 * - encoding: Set by user.
1367 * - decoding: unused
1369 int rc_initial_buffer_occupancy;
1372 * trellis RD quantization
1373 * - encoding: Set by user.
1374 * - decoding: unused
1379 * pass1 encoding statistics output buffer
1380 * - encoding: Set by libavcodec.
1381 * - decoding: unused
1386 * pass2 encoding statistics input buffer
1387 * Concatenated stuff from stats_out of pass1 should be placed here.
1388 * - encoding: Allocated/set/freed by user.
1389 * - decoding: unused
1394 * Work around bugs in encoders which sometimes cannot be detected automatically.
1395 * - encoding: Set by user
1396 * - decoding: Set by user
1398 int workaround_bugs;
1399 #define FF_BUG_AUTODETECT 1 ///< autodetection
1400 #define FF_BUG_XVID_ILACE 4
1401 #define FF_BUG_UMP4 8
1402 #define FF_BUG_NO_PADDING 16
1403 #define FF_BUG_AMV 32
1404 #define FF_BUG_QPEL_CHROMA 64
1405 #define FF_BUG_STD_QPEL 128
1406 #define FF_BUG_QPEL_CHROMA2 256
1407 #define FF_BUG_DIRECT_BLOCKSIZE 512
1408 #define FF_BUG_EDGE 1024
1409 #define FF_BUG_HPEL_CHROMA 2048
1410 #define FF_BUG_DC_CLIP 4096
1411 #define FF_BUG_MS 8192 ///< Work around various bugs in Microsoft's broken decoders.
1412 #define FF_BUG_TRUNCATED 16384
1413 #define FF_BUG_IEDGE 32768
1416 * strictly follow the standard (MPEG-4, ...).
1417 * - encoding: Set by user.
1418 * - decoding: Set by user.
1419 * Setting this to STRICT or higher means the encoder and decoder will
1420 * generally do stupid things, whereas setting it to unofficial or lower
1421 * will mean the encoder might produce output that is not supported by all
1422 * spec-compliant decoders. Decoders don't differentiate between normal,
1423 * unofficial and experimental (that is, they always try to decode things
1424 * when they can) unless they are explicitly asked to behave stupidly
1425 * (=strictly conform to the specs)
1427 int strict_std_compliance;
1428 #define FF_COMPLIANCE_VERY_STRICT 2 ///< Strictly conform to an older more strict version of the spec or reference software.
1429 #define FF_COMPLIANCE_STRICT 1 ///< Strictly conform to all the things in the spec no matter what consequences.
1430 #define FF_COMPLIANCE_NORMAL 0
1431 #define FF_COMPLIANCE_UNOFFICIAL -1 ///< Allow unofficial extensions
1432 #define FF_COMPLIANCE_EXPERIMENTAL -2 ///< Allow nonstandardized experimental things.
1435 * error concealment flags
1436 * - encoding: unused
1437 * - decoding: Set by user.
1439 int error_concealment;
1440 #define FF_EC_GUESS_MVS 1
1441 #define FF_EC_DEBLOCK 2
1442 #define FF_EC_FAVOR_INTER 256
1446 * - encoding: Set by user.
1447 * - decoding: Set by user.
1450 #define FF_DEBUG_PICT_INFO 1
1451 #define FF_DEBUG_RC 2
1452 #define FF_DEBUG_BITSTREAM 4
1453 #define FF_DEBUG_MB_TYPE 8
1454 #define FF_DEBUG_QP 16
1455 #define FF_DEBUG_DCT_COEFF 0x00000040
1456 #define FF_DEBUG_SKIP 0x00000080
1457 #define FF_DEBUG_STARTCODE 0x00000100
1458 #define FF_DEBUG_ER 0x00000400
1459 #define FF_DEBUG_MMCO 0x00000800
1460 #define FF_DEBUG_BUGS 0x00001000
1461 #define FF_DEBUG_BUFFERS 0x00008000
1462 #define FF_DEBUG_THREADS 0x00010000
1463 #define FF_DEBUG_GREEN_MD 0x00800000
1464 #define FF_DEBUG_NOMC 0x01000000
1467 * Error recognition; may misdetect some more or less valid parts as errors.
1468 * - encoding: Set by user.
1469 * - decoding: Set by user.
1471 int err_recognition;
1474 * Verify checksums embedded in the bitstream (could be of either encoded or
1475 * decoded data, depending on the codec) and print an error message on mismatch.
1476 * If AV_EF_EXPLODE is also set, a mismatching checksum will result in the
1477 * decoder returning an error.
1479 #define AV_EF_CRCCHECK (1<<0)
1480 #define AV_EF_BITSTREAM (1<<1) ///< detect bitstream specification deviations
1481 #define AV_EF_BUFFER (1<<2) ///< detect improper bitstream length
1482 #define AV_EF_EXPLODE (1<<3) ///< abort decoding on minor error detection
1484 #define AV_EF_IGNORE_ERR (1<<15) ///< ignore errors and continue
1485 #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
1486 #define AV_EF_COMPLIANT (1<<17) ///< consider all spec non compliances as errors
1487 #define AV_EF_AGGRESSIVE (1<<18) ///< consider things that a sane encoder should not do as an error
1491 * opaque 64-bit number (generally a PTS) that will be reordered and
1492 * output in AVFrame.reordered_opaque
1493 * - encoding: Set by libavcodec to the reordered_opaque of the input
1494 * frame corresponding to the last returned packet. Only
1495 * supported by encoders with the
1496 * AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE capability.
1497 * - decoding: Set by user.
1499 int64_t reordered_opaque;
1502 * Hardware accelerator in use
1503 * - encoding: unused.
1504 * - decoding: Set by libavcodec
1506 const struct AVHWAccel *hwaccel;
1509 * Hardware accelerator context.
1510 * For some hardware accelerators, a global context needs to be
1511 * provided by the user. In that case, this holds display-dependent
1512 * data FFmpeg cannot instantiate itself. Please refer to the
1513 * FFmpeg HW accelerator documentation to know how to fill this.
1514 * - encoding: unused
1515 * - decoding: Set by user
1517 void *hwaccel_context;
1521 * - encoding: Set by libavcodec if flags & AV_CODEC_FLAG_PSNR.
1522 * - decoding: unused
1524 uint64_t error[AV_NUM_DATA_POINTERS];
1527 * DCT algorithm, see FF_DCT_* below
1528 * - encoding: Set by user.
1529 * - decoding: unused
1532 #define FF_DCT_AUTO 0
1533 #define FF_DCT_FASTINT 1
1534 #define FF_DCT_INT 2
1535 #define FF_DCT_MMX 3
1536 #define FF_DCT_ALTIVEC 5
1537 #define FF_DCT_FAAN 6
1540 * IDCT algorithm, see FF_IDCT_* below.
1541 * - encoding: Set by user.
1542 * - decoding: Set by user.
1545 #define FF_IDCT_AUTO 0
1546 #define FF_IDCT_INT 1
1547 #define FF_IDCT_SIMPLE 2
1548 #define FF_IDCT_SIMPLEMMX 3
1549 #define FF_IDCT_ARM 7
1550 #define FF_IDCT_ALTIVEC 8
1551 #define FF_IDCT_SIMPLEARM 10
1552 #define FF_IDCT_XVID 14
1553 #define FF_IDCT_SIMPLEARMV5TE 16
1554 #define FF_IDCT_SIMPLEARMV6 17
1555 #define FF_IDCT_FAAN 20
1556 #define FF_IDCT_SIMPLENEON 22
1557 #define FF_IDCT_NONE 24 /* Used by XvMC to extract IDCT coefficients with FF_IDCT_PERM_NONE */
1558 #define FF_IDCT_SIMPLEAUTO 128
1561 * bits per sample/pixel from the demuxer (needed for huffyuv).
1562 * - encoding: Set by libavcodec.
1563 * - decoding: Set by user.
1565 int bits_per_coded_sample;
1568 * Bits per sample/pixel of internal libavcodec pixel/sample format.
1569 * - encoding: set by user.
1570 * - decoding: set by libavcodec.
1572 int bits_per_raw_sample;
1575 * low resolution decoding, 1-> 1/2 size, 2->1/4 size
1576 * - encoding: unused
1577 * - decoding: Set by user.
1581 #if FF_API_CODED_FRAME
1583 * the picture in the bitstream
1584 * - encoding: Set by libavcodec.
1585 * - decoding: unused
1587 * @deprecated use the quality factor packet side data instead
1589 attribute_deprecated AVFrame *coded_frame;
1594 * is used to decide how many independent tasks should be passed to execute()
1595 * - encoding: Set by user.
1596 * - decoding: Set by user.
1601 * Which multithreading methods to use.
1602 * Use of FF_THREAD_FRAME will increase decoding delay by one frame per thread,
1603 * so clients which cannot provide future frames should not use it.
1605 * - encoding: Set by user, otherwise the default is used.
1606 * - decoding: Set by user, otherwise the default is used.
1609 #define FF_THREAD_FRAME 1 ///< Decode more than one frame at once
1610 #define FF_THREAD_SLICE 2 ///< Decode more than one part of a single frame at once
1613 * Which multithreading methods are in use by the codec.
1614 * - encoding: Set by libavcodec.
1615 * - decoding: Set by libavcodec.
1617 int active_thread_type;
1619 #if FF_API_THREAD_SAFE_CALLBACKS
1621 * Set by the client if its custom get_buffer() callback can be called
1622 * synchronously from another thread, which allows faster multithreaded decoding.
1623 * draw_horiz_band() will be called from other threads regardless of this setting.
1624 * Ignored if the default get_buffer() is used.
1625 * - encoding: Set by user.
1626 * - decoding: Set by user.
1628 * @deprecated the custom get_buffer2() callback should always be
1629 * thread-safe. Thread-unsafe get_buffer2() implementations will be
1630 * invalid starting with LIBAVCODEC_VERSION_MAJOR=60; in other words,
1631 * libavcodec will behave as if this field was always set to 1.
1632 * Callers that want to be forward compatible with future libavcodec
1633 * versions should wrap access to this field in
1634 * #if LIBAVCODEC_VERSION_MAJOR < 60
1636 attribute_deprecated
1637 int thread_safe_callbacks;
1641 * The codec may call this to execute several independent things.
1642 * It will return only after finishing all tasks.
1643 * The user may replace this with some multithreaded implementation,
1644 * the default implementation will execute the parts serially.
1645 * @param count the number of things to execute
1646 * - encoding: Set by libavcodec, user can override.
1647 * - decoding: Set by libavcodec, user can override.
1649 int (*execute)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size);
1652 * The codec may call this to execute several independent things.
1653 * It will return only after finishing all tasks.
1654 * The user may replace this with some multithreaded implementation,
1655 * the default implementation will execute the parts serially.
1656 * Also see avcodec_thread_init and e.g. the --enable-pthread configure option.
1657 * @param c context passed also to func
1658 * @param count the number of things to execute
1659 * @param arg2 argument passed unchanged to func
1660 * @param ret return values of executed functions, must have space for "count" values. May be NULL.
1661 * @param func function that will be called count times, with jobnr from 0 to count-1.
1662 * threadnr will be in the range 0 to c->thread_count-1 < MAX_THREADS and so that no
1663 * two instances of func executing at the same time will have the same threadnr.
1664 * @return always 0 currently, but code should handle a future improvement where when any call to func
1665 * returns < 0 no further calls to func may be done and < 0 is returned.
1666 * - encoding: Set by libavcodec, user can override.
1667 * - decoding: Set by libavcodec, user can override.
1669 int (*execute2)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count);
1672 * noise vs. sse weight for the nsse comparison function
1673 * - encoding: Set by user.
1674 * - decoding: unused
1680 * - encoding: Set by user.
1681 * - decoding: Set by libavcodec.
1684 #define FF_PROFILE_UNKNOWN -99
1685 #define FF_PROFILE_RESERVED -100
1687 #define FF_PROFILE_AAC_MAIN 0
1688 #define FF_PROFILE_AAC_LOW 1
1689 #define FF_PROFILE_AAC_SSR 2
1690 #define FF_PROFILE_AAC_LTP 3
1691 #define FF_PROFILE_AAC_HE 4
1692 #define FF_PROFILE_AAC_HE_V2 28
1693 #define FF_PROFILE_AAC_LD 22
1694 #define FF_PROFILE_AAC_ELD 38
1695 #define FF_PROFILE_MPEG2_AAC_LOW 128
1696 #define FF_PROFILE_MPEG2_AAC_HE 131
1698 #define FF_PROFILE_DNXHD 0
1699 #define FF_PROFILE_DNXHR_LB 1
1700 #define FF_PROFILE_DNXHR_SQ 2
1701 #define FF_PROFILE_DNXHR_HQ 3
1702 #define FF_PROFILE_DNXHR_HQX 4
1703 #define FF_PROFILE_DNXHR_444 5
1705 #define FF_PROFILE_DTS 20
1706 #define FF_PROFILE_DTS_ES 30
1707 #define FF_PROFILE_DTS_96_24 40
1708 #define FF_PROFILE_DTS_HD_HRA 50
1709 #define FF_PROFILE_DTS_HD_MA 60
1710 #define FF_PROFILE_DTS_EXPRESS 70
1712 #define FF_PROFILE_MPEG2_422 0
1713 #define FF_PROFILE_MPEG2_HIGH 1
1714 #define FF_PROFILE_MPEG2_SS 2
1715 #define FF_PROFILE_MPEG2_SNR_SCALABLE 3
1716 #define FF_PROFILE_MPEG2_MAIN 4
1717 #define FF_PROFILE_MPEG2_SIMPLE 5
1719 #define FF_PROFILE_H264_CONSTRAINED (1<<9) // 8+1; constraint_set1_flag
1720 #define FF_PROFILE_H264_INTRA (1<<11) // 8+3; constraint_set3_flag
1722 #define FF_PROFILE_H264_BASELINE 66
1723 #define FF_PROFILE_H264_CONSTRAINED_BASELINE (66|FF_PROFILE_H264_CONSTRAINED)
1724 #define FF_PROFILE_H264_MAIN 77
1725 #define FF_PROFILE_H264_EXTENDED 88
1726 #define FF_PROFILE_H264_HIGH 100
1727 #define FF_PROFILE_H264_HIGH_10 110
1728 #define FF_PROFILE_H264_HIGH_10_INTRA (110|FF_PROFILE_H264_INTRA)
1729 #define FF_PROFILE_H264_MULTIVIEW_HIGH 118
1730 #define FF_PROFILE_H264_HIGH_422 122
1731 #define FF_PROFILE_H264_HIGH_422_INTRA (122|FF_PROFILE_H264_INTRA)
1732 #define FF_PROFILE_H264_STEREO_HIGH 128
1733 #define FF_PROFILE_H264_HIGH_444 144
1734 #define FF_PROFILE_H264_HIGH_444_PREDICTIVE 244
1735 #define FF_PROFILE_H264_HIGH_444_INTRA (244|FF_PROFILE_H264_INTRA)
1736 #define FF_PROFILE_H264_CAVLC_444 44
1738 #define FF_PROFILE_VC1_SIMPLE 0
1739 #define FF_PROFILE_VC1_MAIN 1
1740 #define FF_PROFILE_VC1_COMPLEX 2
1741 #define FF_PROFILE_VC1_ADVANCED 3
1743 #define FF_PROFILE_MPEG4_SIMPLE 0
1744 #define FF_PROFILE_MPEG4_SIMPLE_SCALABLE 1
1745 #define FF_PROFILE_MPEG4_CORE 2
1746 #define FF_PROFILE_MPEG4_MAIN 3
1747 #define FF_PROFILE_MPEG4_N_BIT 4
1748 #define FF_PROFILE_MPEG4_SCALABLE_TEXTURE 5
1749 #define FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION 6
1750 #define FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE 7
1751 #define FF_PROFILE_MPEG4_HYBRID 8
1752 #define FF_PROFILE_MPEG4_ADVANCED_REAL_TIME 9
1753 #define FF_PROFILE_MPEG4_CORE_SCALABLE 10
1754 #define FF_PROFILE_MPEG4_ADVANCED_CODING 11
1755 #define FF_PROFILE_MPEG4_ADVANCED_CORE 12
1756 #define FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE 13
1757 #define FF_PROFILE_MPEG4_SIMPLE_STUDIO 14
1758 #define FF_PROFILE_MPEG4_ADVANCED_SIMPLE 15
1760 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_0 1
1761 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_1 2
1762 #define FF_PROFILE_JPEG2000_CSTREAM_NO_RESTRICTION 32768
1763 #define FF_PROFILE_JPEG2000_DCINEMA_2K 3
1764 #define FF_PROFILE_JPEG2000_DCINEMA_4K 4
1766 #define FF_PROFILE_VP9_0 0
1767 #define FF_PROFILE_VP9_1 1
1768 #define FF_PROFILE_VP9_2 2
1769 #define FF_PROFILE_VP9_3 3
1771 #define FF_PROFILE_HEVC_MAIN 1
1772 #define FF_PROFILE_HEVC_MAIN_10 2
1773 #define FF_PROFILE_HEVC_MAIN_STILL_PICTURE 3
1774 #define FF_PROFILE_HEVC_REXT 4
1776 #define FF_PROFILE_VVC_MAIN_10 1
1777 #define FF_PROFILE_VVC_MAIN_10_444 33
1779 #define FF_PROFILE_AV1_MAIN 0
1780 #define FF_PROFILE_AV1_HIGH 1
1781 #define FF_PROFILE_AV1_PROFESSIONAL 2
1783 #define FF_PROFILE_MJPEG_HUFFMAN_BASELINE_DCT 0xc0
1784 #define FF_PROFILE_MJPEG_HUFFMAN_EXTENDED_SEQUENTIAL_DCT 0xc1
1785 #define FF_PROFILE_MJPEG_HUFFMAN_PROGRESSIVE_DCT 0xc2
1786 #define FF_PROFILE_MJPEG_HUFFMAN_LOSSLESS 0xc3
1787 #define FF_PROFILE_MJPEG_JPEG_LS 0xf7
1789 #define FF_PROFILE_SBC_MSBC 1
1791 #define FF_PROFILE_PRORES_PROXY 0
1792 #define FF_PROFILE_PRORES_LT 1
1793 #define FF_PROFILE_PRORES_STANDARD 2
1794 #define FF_PROFILE_PRORES_HQ 3
1795 #define FF_PROFILE_PRORES_4444 4
1796 #define FF_PROFILE_PRORES_XQ 5
1798 #define FF_PROFILE_ARIB_PROFILE_A 0
1799 #define FF_PROFILE_ARIB_PROFILE_C 1
1801 #define FF_PROFILE_KLVA_SYNC 0
1802 #define FF_PROFILE_KLVA_ASYNC 1
1806 * - encoding: Set by user.
1807 * - decoding: Set by libavcodec.
1810 #define FF_LEVEL_UNKNOWN -99
1813 * Skip loop filtering for selected frames.
1814 * - encoding: unused
1815 * - decoding: Set by user.
1817 enum AVDiscard skip_loop_filter;
1820 * Skip IDCT/dequantization for selected frames.
1821 * - encoding: unused
1822 * - decoding: Set by user.
1824 enum AVDiscard skip_idct;
1827 * Skip decoding for selected frames.
1828 * - encoding: unused
1829 * - decoding: Set by user.
1831 enum AVDiscard skip_frame;
1834 * Header containing style information for text subtitles.
1835 * For SUBTITLE_ASS subtitle type, it should contain the whole ASS
1836 * [Script Info] and [V4+ Styles] section, plus the [Events] line and
1837 * the Format line following. It shouldn't include any Dialogue line.
1838 * - encoding: Set/allocated/freed by user (before avcodec_open2())
1839 * - decoding: Set/allocated/freed by libavcodec (by avcodec_open2())
1841 uint8_t *subtitle_header;
1842 int subtitle_header_size;
1845 * Audio only. The number of "priming" samples (padding) inserted by the
1846 * encoder at the beginning of the audio. I.e. this number of leading
1847 * decoded samples must be discarded by the caller to get the original audio
1848 * without leading padding.
1850 * - decoding: unused
1851 * - encoding: Set by libavcodec. The timestamps on the output packets are
1852 * adjusted by the encoder so that they always refer to the
1853 * first sample of the data actually contained in the packet,
1854 * including any added padding. E.g. if the timebase is
1855 * 1/samplerate and the timestamp of the first input sample is
1856 * 0, the timestamp of the first output packet will be
1859 int initial_padding;
1862 * - decoding: For codecs that store a framerate value in the compressed
1863 * bitstream, the decoder may export it here. { 0, 1} when
1865 * - encoding: May be used to signal the framerate of CFR content to an
1868 AVRational framerate;
1871 * Nominal unaccelerated pixel format, see AV_PIX_FMT_xxx.
1872 * - encoding: unused.
1873 * - decoding: Set by libavcodec before calling get_format()
1875 enum AVPixelFormat sw_pix_fmt;
1878 * Timebase in which pkt_dts/pts and AVPacket.dts/pts are.
1879 * - encoding unused.
1880 * - decoding set by user.
1882 AVRational pkt_timebase;
1886 * - encoding: unused.
1887 * - decoding: set by libavcodec.
1889 const AVCodecDescriptor *codec_descriptor;
1892 * Current statistics for PTS correction.
1893 * - decoding: maintained and used by libavcodec, not intended to be used by user apps
1894 * - encoding: unused
1896 int64_t pts_correction_num_faulty_pts; /// Number of incorrect PTS values so far
1897 int64_t pts_correction_num_faulty_dts; /// Number of incorrect DTS values so far
1898 int64_t pts_correction_last_pts; /// PTS of the last frame
1899 int64_t pts_correction_last_dts; /// DTS of the last frame
1902 * Character encoding of the input subtitles file.
1903 * - decoding: set by user
1904 * - encoding: unused
1909 * Subtitles character encoding mode. Formats or codecs might be adjusting
1910 * this setting (if they are doing the conversion themselves for instance).
1911 * - decoding: set by libavcodec
1912 * - encoding: unused
1914 int sub_charenc_mode;
1915 #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)
1916 #define FF_SUB_CHARENC_MODE_AUTOMATIC 0 ///< libavcodec will select the mode itself
1917 #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
1918 #define FF_SUB_CHARENC_MODE_IGNORE 2 ///< neither convert the subtitles, nor check them for valid UTF-8
1921 * Skip processing alpha if supported by codec.
1922 * Note that if the format uses pre-multiplied alpha (common with VP6,
1923 * and recommended due to better video quality/compression)
1924 * the image will look as if alpha-blended onto a black background.
1925 * However for formats that do not use pre-multiplied alpha
1926 * there might be serious artefacts (though e.g. libswscale currently
1927 * assumes pre-multiplied alpha anyway).
1929 * - decoding: set by user
1930 * - encoding: unused
1935 * Number of samples to skip after a discontinuity
1936 * - decoding: unused
1937 * - encoding: set by libavcodec
1943 * @deprecated unused
1945 attribute_deprecated
1947 #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 //visualize forward predicted MVs of P frames
1948 #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 //visualize forward predicted MVs of B frames
1949 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
1953 * custom intra quantization matrix
1954 * - encoding: Set by user, can be NULL.
1955 * - decoding: unused.
1957 uint16_t *chroma_intra_matrix;
1960 * dump format separator.
1961 * can be ", " or "\n " or anything else
1962 * - encoding: Set by user.
1963 * - decoding: Set by user.
1965 uint8_t *dump_separator;
1968 * ',' separated list of allowed decoders.
1969 * If NULL then all are allowed
1970 * - encoding: unused
1971 * - decoding: set by user
1973 char *codec_whitelist;
1976 * Properties of the stream that gets decoded
1977 * - encoding: unused
1978 * - decoding: set by libavcodec
1980 unsigned properties;
1981 #define FF_CODEC_PROPERTY_LOSSLESS 0x00000001
1982 #define FF_CODEC_PROPERTY_CLOSED_CAPTIONS 0x00000002
1985 * Additional data associated with the entire coded stream.
1987 * - decoding: unused
1988 * - encoding: may be set by libavcodec after avcodec_open2().
1990 AVPacketSideData *coded_side_data;
1991 int nb_coded_side_data;
1994 * A reference to the AVHWFramesContext describing the input (for encoding)
1995 * or output (decoding) frames. The reference is set by the caller and
1996 * afterwards owned (and freed) by libavcodec - it should never be read by
1997 * the caller after being set.
1999 * - decoding: This field should be set by the caller from the get_format()
2000 * callback. The previous reference (if any) will always be
2001 * unreffed by libavcodec before the get_format() call.
2003 * If the default get_buffer2() is used with a hwaccel pixel
2004 * format, then this AVHWFramesContext will be used for
2005 * allocating the frame buffers.
2007 * - encoding: For hardware encoders configured to use a hwaccel pixel
2008 * format, this field should be set by the caller to a reference
2009 * to the AVHWFramesContext describing input frames.
2010 * AVHWFramesContext.format must be equal to
2011 * AVCodecContext.pix_fmt.
2013 * This field should be set before avcodec_open2() is called.
2015 AVBufferRef *hw_frames_ctx;
2018 * Control the form of AVSubtitle.rects[N]->ass
2019 * - decoding: set by user
2020 * - encoding: unused
2022 int sub_text_format;
2023 #define FF_SUB_TEXT_FMT_ASS 0
2026 * Audio only. The amount of padding (in samples) appended by the encoder to
2027 * the end of the audio. I.e. this number of decoded samples must be
2028 * discarded by the caller from the end of the stream to get the original
2029 * audio without any trailing padding.
2031 * - decoding: unused
2032 * - encoding: unused
2034 int trailing_padding;
2037 * The number of pixels per image to maximally accept.
2039 * - decoding: set by user
2040 * - encoding: set by user
2045 * A reference to the AVHWDeviceContext describing the device which will
2046 * be used by a hardware encoder/decoder. The reference is set by the
2047 * caller and afterwards owned (and freed) by libavcodec.
2049 * This should be used if either the codec device does not require
2050 * hardware frames or any that are used are to be allocated internally by
2051 * libavcodec. If the user wishes to supply any of the frames used as
2052 * encoder input or decoder output then hw_frames_ctx should be used
2053 * instead. When hw_frames_ctx is set in get_format() for a decoder, this
2054 * field will be ignored while decoding the associated stream segment, but
2055 * may again be used on a following one after another get_format() call.
2057 * For both encoders and decoders this field should be set before
2058 * avcodec_open2() is called and must not be written to thereafter.
2060 * Note that some decoders may require this field to be set initially in
2061 * order to support hw_frames_ctx at all - in that case, all frames
2062 * contexts used must be created on the same device.
2064 AVBufferRef *hw_device_ctx;
2067 * Bit set of AV_HWACCEL_FLAG_* flags, which affect hardware accelerated
2068 * decoding (if active).
2069 * - encoding: unused
2070 * - decoding: Set by user (either before avcodec_open2(), or in the
2071 * AVCodecContext.get_format callback)
2076 * Video decoding only. Certain video codecs support cropping, meaning that
2077 * only a sub-rectangle of the decoded frame is intended for display. This
2078 * option controls how cropping is handled by libavcodec.
2080 * When set to 1 (the default), libavcodec will apply cropping internally.
2081 * I.e. it will modify the output frame width/height fields and offset the
2082 * data pointers (only by as much as possible while preserving alignment, or
2083 * by the full amount if the AV_CODEC_FLAG_UNALIGNED flag is set) so that
2084 * the frames output by the decoder refer only to the cropped area. The
2085 * crop_* fields of the output frames will be zero.
2087 * When set to 0, the width/height fields of the output frames will be set
2088 * to the coded dimensions and the crop_* fields will describe the cropping
2089 * rectangle. Applying the cropping is left to the caller.
2091 * @warning When hardware acceleration with opaque output frames is used,
2092 * libavcodec is unable to apply cropping from the top/left border.
2094 * @note when this option is set to zero, the width/height fields of the
2095 * AVCodecContext and output AVFrames have different meanings. The codec
2096 * context fields store display dimensions (with the coded dimensions in
2097 * coded_width/height), while the frame fields store the coded dimensions
2098 * (with the display dimensions being determined by the crop_* fields).
2103 * Video decoding only. Sets the number of extra hardware frames which
2104 * the decoder will allocate for use by the caller. This must be set
2105 * before avcodec_open2() is called.
2107 * Some hardware decoders require all frames that they will use for
2108 * output to be defined in advance before decoding starts. For such
2109 * decoders, the hardware frame pool must therefore be of a fixed size.
2110 * The extra frames set here are on top of any number that the decoder
2111 * needs internally in order to operate normally (for example, frames
2112 * used as reference pictures).
2114 int extra_hw_frames;
2117 * The percentage of damaged samples to discard a frame.
2119 * - decoding: set by user
2120 * - encoding: unused
2122 int discard_damaged_percentage;
2125 * The number of samples per frame to maximally accept.
2127 * - decoding: set by user
2128 * - encoding: set by user
2130 int64_t max_samples;
2133 * Bit set of AV_CODEC_EXPORT_DATA_* flags, which affects the kind of
2134 * metadata exported in frame, packet, or coded stream side data by
2135 * decoders and encoders.
2137 * - decoding: set by user
2138 * - encoding: set by user
2140 int export_side_data;
2143 * This callback is called at the beginning of each packet to get a data
2146 * The following field will be set in the packet before this callback is
2149 * This callback must use the above value to calculate the required buffer size,
2150 * which must padded by at least AV_INPUT_BUFFER_PADDING_SIZE bytes.
2152 * This callback must fill the following fields in the packet:
2153 * - data: alignment requirements for AVPacket apply, if any. Some architectures and
2154 * encoders may benefit from having aligned data.
2155 * - buf: must contain a pointer to an AVBufferRef structure. The packet's
2156 * data pointer must be contained in it. See: av_buffer_create(), av_buffer_alloc(),
2157 * and av_buffer_ref().
2159 * If AV_CODEC_CAP_DR1 is not set then get_encode_buffer() must call
2160 * avcodec_default_get_encode_buffer() instead of providing a buffer allocated by
2163 * The flags field may contain a combination of AV_GET_ENCODE_BUFFER_FLAG_ flags.
2164 * They may be used for example to hint what use the buffer may get after being
2166 * Implementations of this callback may ignore flags they don't understand.
2167 * If AV_GET_ENCODE_BUFFER_FLAG_REF is set in flags then the packet may be reused
2168 * (read and/or written to if it is writable) later by libavcodec.
2170 * This callback must be thread-safe, as when frame threading is used, it may
2171 * be called from multiple threads simultaneously.
2173 * @see avcodec_default_get_encode_buffer()
2175 * - encoding: Set by libavcodec, user can override.
2176 * - decoding: unused
2178 int (*get_encode_buffer)(struct AVCodecContext *s, AVPacket *pkt, int flags);
2183 struct MpegEncContext;
2186 * @defgroup lavc_hwaccel AVHWAccel
2188 * @note Nothing in this structure should be accessed by the user. At some
2189 * point in future it will not be externally visible at all.
2193 typedef struct AVHWAccel {
2195 * Name of the hardware accelerated codec.
2196 * The name is globally unique among encoders and among decoders (but an
2197 * encoder and a decoder can share the same name).
2202 * Type of codec implemented by the hardware accelerator.
2204 * See AVMEDIA_TYPE_xxx
2206 enum AVMediaType type;
2209 * Codec implemented by the hardware accelerator.
2211 * See AV_CODEC_ID_xxx
2216 * Supported pixel format.
2218 * Only hardware accelerated formats are supported here.
2220 enum AVPixelFormat pix_fmt;
2223 * Hardware accelerated codec capabilities.
2224 * see AV_HWACCEL_CODEC_CAP_*
2228 /*****************************************************************
2229 * No fields below this line are part of the public API. They
2230 * may not be used outside of libavcodec and can be changed and
2232 * New public fields should be added right above.
2233 *****************************************************************
2237 * Allocate a custom buffer
2239 int (*alloc_frame)(AVCodecContext *avctx, AVFrame *frame);
2242 * Called at the beginning of each frame or field picture.
2244 * Meaningful frame information (codec specific) is guaranteed to
2245 * be parsed at this point. This function is mandatory.
2247 * Note that buf can be NULL along with buf_size set to 0.
2248 * Otherwise, this means the whole frame is available at this point.
2250 * @param avctx the codec context
2251 * @param buf the frame data buffer base
2252 * @param buf_size the size of the frame in bytes
2253 * @return zero if successful, a negative value otherwise
2255 int (*start_frame)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
2258 * Callback for parameter data (SPS/PPS/VPS etc).
2260 * Useful for hardware decoders which keep persistent state about the
2261 * video parameters, and need to receive any changes to update that state.
2263 * @param avctx the codec context
2264 * @param type the nal unit type
2265 * @param buf the nal unit data buffer
2266 * @param buf_size the size of the nal unit in bytes
2267 * @return zero if successful, a negative value otherwise
2269 int (*decode_params)(AVCodecContext *avctx, int type, const uint8_t *buf, uint32_t buf_size);
2272 * Callback for each slice.
2274 * Meaningful slice information (codec specific) is guaranteed to
2275 * be parsed at this point. This function is mandatory.
2276 * The only exception is XvMC, that works on MB level.
2278 * @param avctx the codec context
2279 * @param buf the slice data buffer base
2280 * @param buf_size the size of the slice in bytes
2281 * @return zero if successful, a negative value otherwise
2283 int (*decode_slice)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
2286 * Called at the end of each frame or field picture.
2288 * The whole picture is parsed at this point and can now be sent
2289 * to the hardware accelerator. This function is mandatory.
2291 * @param avctx the codec context
2292 * @return zero if successful, a negative value otherwise
2294 int (*end_frame)(AVCodecContext *avctx);
2297 * Size of per-frame hardware accelerator private data.
2299 * Private data is allocated with av_mallocz() before
2300 * AVCodecContext.get_buffer() and deallocated after
2301 * AVCodecContext.release_buffer().
2303 int frame_priv_data_size;
2306 * Called for every Macroblock in a slice.
2308 * XvMC uses it to replace the ff_mpv_reconstruct_mb().
2309 * Instead of decoding to raw picture, MB parameters are
2310 * stored in an array provided by the video driver.
2312 * @param s the mpeg context
2314 void (*decode_mb)(struct MpegEncContext *s);
2317 * Initialize the hwaccel private data.
2319 * This will be called from ff_get_format(), after hwaccel and
2320 * hwaccel_context are set and the hwaccel private data in AVCodecInternal
2323 int (*init)(AVCodecContext *avctx);
2326 * Uninitialize the hwaccel private data.
2328 * This will be called from get_format() or avcodec_close(), after hwaccel
2329 * and hwaccel_context are already uninitialized.
2331 int (*uninit)(AVCodecContext *avctx);
2334 * Size of the private data to allocate in
2335 * AVCodecInternal.hwaccel_priv_data.
2340 * Internal hwaccel capabilities.
2345 * Fill the given hw_frames context with current codec parameters. Called
2346 * from get_format. Refer to avcodec_get_hw_frames_parameters() for
2349 * This CAN be called before AVHWAccel.init is called, and you must assume
2350 * that avctx->hwaccel_priv_data is invalid.
2352 int (*frame_params)(AVCodecContext *avctx, AVBufferRef *hw_frames_ctx);
2356 * HWAccel is experimental and is thus avoided in favor of non experimental
2359 #define AV_HWACCEL_CODEC_CAP_EXPERIMENTAL 0x0200
2362 * Hardware acceleration should be used for decoding even if the codec level
2363 * used is unknown or higher than the maximum supported level reported by the
2366 * It's generally a good idea to pass this flag unless you have a specific
2367 * reason not to, as hardware tends to under-report supported levels.
2369 #define AV_HWACCEL_FLAG_IGNORE_LEVEL (1 << 0)
2372 * Hardware acceleration can output YUV pixel formats with a different chroma
2373 * sampling than 4:2:0 and/or other than 8 bits per component.
2375 #define AV_HWACCEL_FLAG_ALLOW_HIGH_DEPTH (1 << 1)
2378 * Hardware acceleration should still be attempted for decoding when the
2379 * codec profile does not match the reported capabilities of the hardware.
2381 * For example, this can be used to try to decode baseline profile H.264
2382 * streams in hardware - it will often succeed, because many streams marked
2383 * as baseline profile actually conform to constrained baseline profile.
2385 * @warning If the stream is actually not supported then the behaviour is
2386 * undefined, and may include returning entirely incorrect output
2387 * while indicating success.
2389 #define AV_HWACCEL_FLAG_ALLOW_PROFILE_MISMATCH (1 << 2)
2395 enum AVSubtitleType {
2398 SUBTITLE_BITMAP, ///< A bitmap, pict will be set
2401 * Plain text, the text field must be set by the decoder and is
2402 * authoritative. ass and pict fields may contain approximations.
2407 * Formatted text, the ass field must be set by the decoder and is
2408 * authoritative. pict and text fields may contain approximations.
2413 #define AV_SUBTITLE_FLAG_FORCED 0x00000001
2415 typedef struct AVSubtitleRect {
2416 int x; ///< top left corner of pict, undefined when pict is not set
2417 int y; ///< top left corner of pict, undefined when pict is not set
2418 int w; ///< width of pict, undefined when pict is not set
2419 int h; ///< height of pict, undefined when pict is not set
2420 int nb_colors; ///< number of colors in pict, undefined when pict is not set
2423 * data+linesize for the bitmap of this subtitle.
2424 * Can be set for text/ass as well once they are rendered.
2429 enum AVSubtitleType type;
2431 char *text; ///< 0 terminated plain UTF-8 text
2434 * 0 terminated ASS/SSA compatible event line.
2435 * The presentation of this is unaffected by the other values in this
2443 typedef struct AVSubtitle {
2444 uint16_t format; /* 0 = graphics */
2445 uint32_t start_display_time; /* relative to packet pts, in ms */
2446 uint32_t end_display_time; /* relative to packet pts, in ms */
2448 AVSubtitleRect **rects;
2449 int64_t pts; ///< Same as packet pts, in AV_TIME_BASE
2453 * Return the LIBAVCODEC_VERSION_INT constant.
2455 unsigned avcodec_version(void);
2458 * Return the libavcodec build-time configuration.
2460 const char *avcodec_configuration(void);
2463 * Return the libavcodec license.
2465 const char *avcodec_license(void);
2468 * Allocate an AVCodecContext and set its fields to default values. The
2469 * resulting struct should be freed with avcodec_free_context().
2471 * @param codec if non-NULL, allocate private data and initialize defaults
2472 * for the given codec. It is illegal to then call avcodec_open2()
2473 * with a different codec.
2474 * If NULL, then the codec-specific defaults won't be initialized,
2475 * which may result in suboptimal default settings (this is
2476 * important mainly for encoders, e.g. libx264).
2478 * @return An AVCodecContext filled with default values or NULL on failure.
2480 AVCodecContext *avcodec_alloc_context3(const AVCodec *codec);
2483 * Free the codec context and everything associated with it and write NULL to
2484 * the provided pointer.
2486 void avcodec_free_context(AVCodecContext **avctx);
2489 * Get the AVClass for AVCodecContext. It can be used in combination with
2490 * AV_OPT_SEARCH_FAKE_OBJ for examining options.
2492 * @see av_opt_find().
2494 const AVClass *avcodec_get_class(void);
2496 #if FF_API_GET_FRAME_CLASS
2498 * @deprecated This function should not be used.
2500 attribute_deprecated
2501 const AVClass *avcodec_get_frame_class(void);
2505 * Get the AVClass for AVSubtitleRect. It can be used in combination with
2506 * AV_OPT_SEARCH_FAKE_OBJ for examining options.
2508 * @see av_opt_find().
2510 const AVClass *avcodec_get_subtitle_rect_class(void);
2513 * Fill the parameters struct based on the values from the supplied codec
2514 * context. Any allocated fields in par are freed and replaced with duplicates
2515 * of the corresponding fields in codec.
2517 * @return >= 0 on success, a negative AVERROR code on failure
2519 int avcodec_parameters_from_context(AVCodecParameters *par,
2520 const AVCodecContext *codec);
2523 * Fill the codec context based on the values from the supplied codec
2524 * parameters. Any allocated fields in codec that have a corresponding field in
2525 * par are freed and replaced with duplicates of the corresponding field in par.
2526 * Fields in codec that do not have a counterpart in par are not touched.
2528 * @return >= 0 on success, a negative AVERROR code on failure.
2530 int avcodec_parameters_to_context(AVCodecContext *codec,
2531 const AVCodecParameters *par);
2534 * Initialize the AVCodecContext to use the given AVCodec. Prior to using this
2535 * function the context has to be allocated with avcodec_alloc_context3().
2537 * The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(),
2538 * avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for
2539 * retrieving a codec.
2541 * @warning This function is not thread safe!
2543 * @note Always call this function before using decoding routines (such as
2544 * @ref avcodec_receive_frame()).
2547 * av_dict_set(&opts, "b", "2.5M", 0);
2548 * codec = avcodec_find_decoder(AV_CODEC_ID_H264);
2552 * context = avcodec_alloc_context3(codec);
2554 * if (avcodec_open2(context, codec, opts) < 0)
2558 * @param avctx The context to initialize.
2559 * @param codec The codec to open this context for. If a non-NULL codec has been
2560 * previously passed to avcodec_alloc_context3() or
2561 * for this context, then this parameter MUST be either NULL or
2562 * equal to the previously passed codec.
2563 * @param options A dictionary filled with AVCodecContext and codec-private options.
2564 * On return this object will be filled with options that were not found.
2566 * @return zero on success, a negative value on error
2567 * @see avcodec_alloc_context3(), avcodec_find_decoder(), avcodec_find_encoder(),
2568 * av_dict_set(), av_opt_find().
2570 int avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options);
2573 * Close a given AVCodecContext and free all the data associated with it
2574 * (but not the AVCodecContext itself).
2576 * Calling this function on an AVCodecContext that hasn't been opened will free
2577 * the codec-specific data allocated in avcodec_alloc_context3() with a non-NULL
2578 * codec. Subsequent calls will do nothing.
2580 * @note Do not use this function. Use avcodec_free_context() to destroy a
2581 * codec context (either open or closed). Opening and closing a codec context
2582 * multiple times is not supported anymore -- use multiple codec contexts
2585 int avcodec_close(AVCodecContext *avctx);
2588 * Free all allocated data in the given subtitle struct.
2590 * @param sub AVSubtitle to free.
2592 void avsubtitle_free(AVSubtitle *sub);
2599 * @addtogroup lavc_decoding
2604 * The default callback for AVCodecContext.get_buffer2(). It is made public so
2605 * it can be called by custom get_buffer2() implementations for decoders without
2606 * AV_CODEC_CAP_DR1 set.
2608 int avcodec_default_get_buffer2(AVCodecContext *s, AVFrame *frame, int flags);
2611 * The default callback for AVCodecContext.get_encode_buffer(). It is made public so
2612 * it can be called by custom get_encode_buffer() implementations for encoders without
2613 * AV_CODEC_CAP_DR1 set.
2615 int avcodec_default_get_encode_buffer(AVCodecContext *s, AVPacket *pkt, int flags);
2618 * Modify width and height values so that they will result in a memory
2619 * buffer that is acceptable for the codec if you do not use any horizontal
2622 * May only be used if a codec with AV_CODEC_CAP_DR1 has been opened.
2624 void avcodec_align_dimensions(AVCodecContext *s, int *width, int *height);
2627 * Modify width and height values so that they will result in a memory
2628 * buffer that is acceptable for the codec if you also ensure that all
2629 * line sizes are a multiple of the respective linesize_align[i].
2631 * May only be used if a codec with AV_CODEC_CAP_DR1 has been opened.
2633 void avcodec_align_dimensions2(AVCodecContext *s, int *width, int *height,
2634 int linesize_align[AV_NUM_DATA_POINTERS]);
2637 * Converts AVChromaLocation to swscale x/y chroma position.
2639 * The positions represent the chroma (0,0) position in a coordinates system
2640 * with luma (0,0) representing the origin and luma(1,1) representing 256,256
2642 * @param xpos horizontal chroma sample position
2643 * @param ypos vertical chroma sample position
2645 int avcodec_enum_to_chroma_pos(int *xpos, int *ypos, enum AVChromaLocation pos);
2648 * Converts swscale x/y chroma position to AVChromaLocation.
2650 * The positions represent the chroma (0,0) position in a coordinates system
2651 * with luma (0,0) representing the origin and luma(1,1) representing 256,256
2653 * @param xpos horizontal chroma sample position
2654 * @param ypos vertical chroma sample position
2656 enum AVChromaLocation avcodec_chroma_pos_to_enum(int xpos, int ypos);
2658 #if FF_API_OLD_ENCDEC
2660 * Decode the audio frame of size avpkt->size from avpkt->data into frame.
2662 * Some decoders may support multiple frames in a single AVPacket. Such
2663 * decoders would then just decode the first frame and the return value would be
2664 * less than the packet size. In this case, avcodec_decode_audio4 has to be
2665 * called again with an AVPacket containing the remaining data in order to
2666 * decode the second frame, etc... Even if no frames are returned, the packet
2667 * needs to be fed to the decoder with remaining data until it is completely
2668 * consumed or an error occurs.
2670 * Some decoders (those marked with AV_CODEC_CAP_DELAY) have a delay between input
2671 * and output. This means that for some packets they will not immediately
2672 * produce decoded output and need to be flushed at the end of decoding to get
2673 * all the decoded data. Flushing is done by calling this function with packets
2674 * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
2675 * returning samples. It is safe to flush even those decoders that are not
2676 * marked with AV_CODEC_CAP_DELAY, then no samples will be returned.
2678 * @warning The input buffer, avpkt->data must be AV_INPUT_BUFFER_PADDING_SIZE
2679 * larger than the actual read bytes because some optimized bitstream
2680 * readers read 32 or 64 bits at once and could read over the end.
2682 * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
2683 * before packets may be fed to the decoder.
2685 * @param avctx the codec context
2686 * @param[out] frame The AVFrame in which to store decoded audio samples.
2687 * The decoder will allocate a buffer for the decoded frame by
2688 * calling the AVCodecContext.get_buffer2() callback.
2689 * When AVCodecContext.refcounted_frames is set to 1, the frame is
2690 * reference counted and the returned reference belongs to the
2691 * caller. The caller must release the frame using av_frame_unref()
2692 * when the frame is no longer needed. The caller may safely write
2693 * to the frame if av_frame_is_writable() returns 1.
2694 * When AVCodecContext.refcounted_frames is set to 0, the returned
2695 * reference belongs to the decoder and is valid only until the
2696 * next call to this function or until closing or flushing the
2697 * decoder. The caller may not write to it.
2698 * @param[out] got_frame_ptr Zero if no frame could be decoded, otherwise it is
2699 * non-zero. Note that this field being set to zero
2700 * does not mean that an error has occurred. For
2701 * decoders with AV_CODEC_CAP_DELAY set, no given decode
2702 * call is guaranteed to produce a frame.
2703 * @param[in] avpkt The input AVPacket containing the input buffer.
2704 * At least avpkt->data and avpkt->size should be set. Some
2705 * decoders might also require additional fields to be set.
2706 * @return A negative error code is returned if an error occurred during
2707 * decoding, otherwise the number of bytes consumed from the input
2708 * AVPacket is returned.
2710 * @deprecated Use avcodec_send_packet() and avcodec_receive_frame().
2712 attribute_deprecated
2713 int avcodec_decode_audio4(AVCodecContext *avctx, AVFrame *frame,
2714 int *got_frame_ptr, const AVPacket *avpkt);
2717 * Decode the video frame of size avpkt->size from avpkt->data into picture.
2718 * Some decoders may support multiple frames in a single AVPacket, such
2719 * decoders would then just decode the first frame.
2721 * @warning The input buffer must be AV_INPUT_BUFFER_PADDING_SIZE larger than
2722 * the actual read bytes because some optimized bitstream readers read 32 or 64
2723 * bits at once and could read over the end.
2725 * @warning The end of the input buffer buf should be set to 0 to ensure that
2726 * no overreading happens for damaged MPEG streams.
2728 * @note Codecs which have the AV_CODEC_CAP_DELAY capability set have a delay
2729 * between input and output, these need to be fed with avpkt->data=NULL,
2730 * avpkt->size=0 at the end to return the remaining frames.
2732 * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
2733 * before packets may be fed to the decoder.
2735 * @param avctx the codec context
2736 * @param[out] picture The AVFrame in which the decoded video frame will be stored.
2737 * Use av_frame_alloc() to get an AVFrame. The codec will
2738 * allocate memory for the actual bitmap by calling the
2739 * AVCodecContext.get_buffer2() callback.
2740 * When AVCodecContext.refcounted_frames is set to 1, the frame is
2741 * reference counted and the returned reference belongs to the
2742 * caller. The caller must release the frame using av_frame_unref()
2743 * when the frame is no longer needed. The caller may safely write
2744 * to the frame if av_frame_is_writable() returns 1.
2745 * When AVCodecContext.refcounted_frames is set to 0, the returned
2746 * reference belongs to the decoder and is valid only until the
2747 * next call to this function or until closing or flushing the
2748 * decoder. The caller may not write to it.
2750 * @param[in] avpkt The input AVPacket containing the input buffer.
2751 * You can create such packet with av_init_packet() and by then setting
2752 * data and size, some decoders might in addition need other fields like
2753 * flags&AV_PKT_FLAG_KEY. All decoders are designed to use the least
2755 * @param[in,out] got_picture_ptr Zero if no frame could be decompressed, otherwise, it is nonzero.
2756 * @return On error a negative value is returned, otherwise the number of bytes
2757 * used or zero if no frame could be decompressed.
2759 * @deprecated Use avcodec_send_packet() and avcodec_receive_frame().
2761 attribute_deprecated
2762 int avcodec_decode_video2(AVCodecContext *avctx, AVFrame *picture,
2763 int *got_picture_ptr,
2764 const AVPacket *avpkt);
2768 * Decode a subtitle message.
2769 * Return a negative value on error, otherwise return the number of bytes used.
2770 * If no subtitle could be decompressed, got_sub_ptr is zero.
2771 * Otherwise, the subtitle is stored in *sub.
2772 * Note that AV_CODEC_CAP_DR1 is not available for subtitle codecs. This is for
2773 * simplicity, because the performance difference is expected to be negligible
2774 * and reusing a get_buffer written for video codecs would probably perform badly
2775 * due to a potentially very different allocation pattern.
2777 * Some decoders (those marked with AV_CODEC_CAP_DELAY) have a delay between input
2778 * and output. This means that for some packets they will not immediately
2779 * produce decoded output and need to be flushed at the end of decoding to get
2780 * all the decoded data. Flushing is done by calling this function with packets
2781 * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
2782 * returning subtitles. It is safe to flush even those decoders that are not
2783 * marked with AV_CODEC_CAP_DELAY, then no subtitles will be returned.
2785 * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
2786 * before packets may be fed to the decoder.
2788 * @param avctx the codec context
2789 * @param[out] sub The preallocated AVSubtitle in which the decoded subtitle will be stored,
2790 * must be freed with avsubtitle_free if *got_sub_ptr is set.
2791 * @param[in,out] got_sub_ptr Zero if no subtitle could be decompressed, otherwise, it is nonzero.
2792 * @param[in] avpkt The input AVPacket containing the input buffer.
2794 int avcodec_decode_subtitle2(AVCodecContext *avctx, AVSubtitle *sub,
2799 * Supply raw packet data as input to a decoder.
2801 * Internally, this call will copy relevant AVCodecContext fields, which can
2802 * influence decoding per-packet, and apply them when the packet is actually
2803 * decoded. (For example AVCodecContext.skip_frame, which might direct the
2804 * decoder to drop the frame contained by the packet sent with this function.)
2806 * @warning The input buffer, avpkt->data must be AV_INPUT_BUFFER_PADDING_SIZE
2807 * larger than the actual read bytes because some optimized bitstream
2808 * readers read 32 or 64 bits at once and could read over the end.
2810 * @warning Do not mix this API with the legacy API (like avcodec_decode_video2())
2811 * on the same AVCodecContext. It will return unexpected results now
2812 * or in future libavcodec versions.
2814 * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
2815 * before packets may be fed to the decoder.
2817 * @param avctx codec context
2818 * @param[in] avpkt The input AVPacket. Usually, this will be a single video
2819 * frame, or several complete audio frames.
2820 * Ownership of the packet remains with the caller, and the
2821 * decoder will not write to the packet. The decoder may create
2822 * a reference to the packet data (or copy it if the packet is
2823 * not reference-counted).
2824 * Unlike with older APIs, the packet is always fully consumed,
2825 * and if it contains multiple frames (e.g. some audio codecs),
2826 * will require you to call avcodec_receive_frame() multiple
2827 * times afterwards before you can send a new packet.
2828 * It can be NULL (or an AVPacket with data set to NULL and
2829 * size set to 0); in this case, it is considered a flush
2830 * packet, which signals the end of the stream. Sending the
2831 * first flush packet will return success. Subsequent ones are
2832 * unnecessary and will return AVERROR_EOF. If the decoder
2833 * still has frames buffered, it will return them after sending
2836 * @return 0 on success, otherwise negative error code:
2837 * AVERROR(EAGAIN): input is not accepted in the current state - user
2838 * must read output with avcodec_receive_frame() (once
2839 * all output is read, the packet should be resent, and
2840 * the call will not fail with EAGAIN).
2841 * AVERROR_EOF: the decoder has been flushed, and no new packets can
2842 * be sent to it (also returned if more than 1 flush
2844 * AVERROR(EINVAL): codec not opened, it is an encoder, or requires flush
2845 * AVERROR(ENOMEM): failed to add packet to internal queue, or similar
2846 * other errors: legitimate decoding errors
2848 int avcodec_send_packet(AVCodecContext *avctx, const AVPacket *avpkt);
2851 * Return decoded output data from a decoder.
2853 * @param avctx codec context
2854 * @param frame This will be set to a reference-counted video or audio
2855 * frame (depending on the decoder type) allocated by the
2856 * decoder. Note that the function will always call
2857 * av_frame_unref(frame) before doing anything else.
2860 * 0: success, a frame was returned
2861 * AVERROR(EAGAIN): output is not available in this state - user must try
2863 * AVERROR_EOF: the decoder has been fully flushed, and there will be
2864 * no more output frames
2865 * AVERROR(EINVAL): codec not opened, or it is an encoder
2866 * AVERROR_INPUT_CHANGED: current decoded frame has changed parameters
2867 * with respect to first decoded frame. Applicable
2868 * when flag AV_CODEC_FLAG_DROPCHANGED is set.
2869 * other negative values: legitimate decoding errors
2871 int avcodec_receive_frame(AVCodecContext *avctx, AVFrame *frame);
2874 * Supply a raw video or audio frame to the encoder. Use avcodec_receive_packet()
2875 * to retrieve buffered output packets.
2877 * @param avctx codec context
2878 * @param[in] frame AVFrame containing the raw audio or video frame to be encoded.
2879 * Ownership of the frame remains with the caller, and the
2880 * encoder will not write to the frame. The encoder may create
2881 * a reference to the frame data (or copy it if the frame is
2882 * not reference-counted).
2883 * It can be NULL, in which case it is considered a flush
2884 * packet. This signals the end of the stream. If the encoder
2885 * still has packets buffered, it will return them after this
2886 * call. Once flushing mode has been entered, additional flush
2887 * packets are ignored, and sending frames will return
2891 * If AV_CODEC_CAP_VARIABLE_FRAME_SIZE is set, then each frame
2892 * can have any number of samples.
2893 * If it is not set, frame->nb_samples must be equal to
2894 * avctx->frame_size for all frames except the last.
2895 * The final frame may be smaller than avctx->frame_size.
2896 * @return 0 on success, otherwise negative error code:
2897 * AVERROR(EAGAIN): input is not accepted in the current state - user
2898 * must read output with avcodec_receive_packet() (once
2899 * all output is read, the packet should be resent, and
2900 * the call will not fail with EAGAIN).
2901 * AVERROR_EOF: the encoder has been flushed, and no new frames can
2903 * AVERROR(EINVAL): codec not opened, refcounted_frames not set, it is a
2904 * decoder, or requires flush
2905 * AVERROR(ENOMEM): failed to add packet to internal queue, or similar
2906 * other errors: legitimate encoding errors
2908 int avcodec_send_frame(AVCodecContext *avctx, const AVFrame *frame);
2911 * Read encoded data from the encoder.
2913 * @param avctx codec context
2914 * @param avpkt This will be set to a reference-counted packet allocated by the
2915 * encoder. Note that the function will always call
2916 * av_packet_unref(avpkt) before doing anything else.
2917 * @return 0 on success, otherwise negative error code:
2918 * AVERROR(EAGAIN): output is not available in the current state - user
2919 * must try to send input
2920 * AVERROR_EOF: the encoder has been fully flushed, and there will be
2921 * no more output packets
2922 * AVERROR(EINVAL): codec not opened, or it is a decoder
2923 * other errors: legitimate encoding errors
2925 int avcodec_receive_packet(AVCodecContext *avctx, AVPacket *avpkt);
2928 * Create and return a AVHWFramesContext with values adequate for hardware
2929 * decoding. This is meant to get called from the get_format callback, and is
2930 * a helper for preparing a AVHWFramesContext for AVCodecContext.hw_frames_ctx.
2931 * This API is for decoding with certain hardware acceleration modes/APIs only.
2933 * The returned AVHWFramesContext is not initialized. The caller must do this
2934 * with av_hwframe_ctx_init().
2936 * Calling this function is not a requirement, but makes it simpler to avoid
2937 * codec or hardware API specific details when manually allocating frames.
2939 * Alternatively to this, an API user can set AVCodecContext.hw_device_ctx,
2940 * which sets up AVCodecContext.hw_frames_ctx fully automatically, and makes
2941 * it unnecessary to call this function or having to care about
2942 * AVHWFramesContext initialization at all.
2944 * There are a number of requirements for calling this function:
2946 * - It must be called from get_format with the same avctx parameter that was
2947 * passed to get_format. Calling it outside of get_format is not allowed, and
2948 * can trigger undefined behavior.
2949 * - The function is not always supported (see description of return values).
2950 * Even if this function returns successfully, hwaccel initialization could
2951 * fail later. (The degree to which implementations check whether the stream
2952 * is actually supported varies. Some do this check only after the user's
2953 * get_format callback returns.)
2954 * - The hw_pix_fmt must be one of the choices suggested by get_format. If the
2955 * user decides to use a AVHWFramesContext prepared with this API function,
2956 * the user must return the same hw_pix_fmt from get_format.
2957 * - The device_ref passed to this function must support the given hw_pix_fmt.
2958 * - After calling this API function, it is the user's responsibility to
2959 * initialize the AVHWFramesContext (returned by the out_frames_ref parameter),
2960 * and to set AVCodecContext.hw_frames_ctx to it. If done, this must be done
2961 * before returning from get_format (this is implied by the normal
2962 * AVCodecContext.hw_frames_ctx API rules).
2963 * - The AVHWFramesContext parameters may change every time time get_format is
2964 * called. Also, AVCodecContext.hw_frames_ctx is reset before get_format. So
2965 * you are inherently required to go through this process again on every
2967 * - It is perfectly possible to call this function without actually using
2968 * the resulting AVHWFramesContext. One use-case might be trying to reuse a
2969 * previously initialized AVHWFramesContext, and calling this API function
2970 * only to test whether the required frame parameters have changed.
2971 * - Fields that use dynamically allocated values of any kind must not be set
2972 * by the user unless setting them is explicitly allowed by the documentation.
2973 * If the user sets AVHWFramesContext.free and AVHWFramesContext.user_opaque,
2974 * the new free callback must call the potentially set previous free callback.
2975 * This API call may set any dynamically allocated fields, including the free
2978 * The function will set at least the following fields on AVHWFramesContext
2979 * (potentially more, depending on hwaccel API):
2981 * - All fields set by av_hwframe_ctx_alloc().
2982 * - Set the format field to hw_pix_fmt.
2983 * - Set the sw_format field to the most suited and most versatile format. (An
2984 * implication is that this will prefer generic formats over opaque formats
2985 * with arbitrary restrictions, if possible.)
2986 * - Set the width/height fields to the coded frame size, rounded up to the
2987 * API-specific minimum alignment.
2988 * - Only _if_ the hwaccel requires a pre-allocated pool: set the initial_pool_size
2989 * field to the number of maximum reference surfaces possible with the codec,
2990 * plus 1 surface for the user to work (meaning the user can safely reference
2991 * at most 1 decoded surface at a time), plus additional buffering introduced
2992 * by frame threading. If the hwaccel does not require pre-allocation, the
2993 * field is left to 0, and the decoder will allocate new surfaces on demand
2995 * - Possibly AVHWFramesContext.hwctx fields, depending on the underlying
2998 * Essentially, out_frames_ref returns the same as av_hwframe_ctx_alloc(), but
2999 * with basic frame parameters set.
3001 * The function is stateless, and does not change the AVCodecContext or the
3002 * device_ref AVHWDeviceContext.
3004 * @param avctx The context which is currently calling get_format, and which
3005 * implicitly contains all state needed for filling the returned
3006 * AVHWFramesContext properly.
3007 * @param device_ref A reference to the AVHWDeviceContext describing the device
3008 * which will be used by the hardware decoder.
3009 * @param hw_pix_fmt The hwaccel format you are going to return from get_format.
3010 * @param out_frames_ref On success, set to a reference to an _uninitialized_
3011 * AVHWFramesContext, created from the given device_ref.
3012 * Fields will be set to values required for decoding.
3013 * Not changed if an error is returned.
3014 * @return zero on success, a negative value on error. The following error codes
3015 * have special semantics:
3016 * AVERROR(ENOENT): the decoder does not support this functionality. Setup
3017 * is always manual, or it is a decoder which does not
3018 * support setting AVCodecContext.hw_frames_ctx at all,
3019 * or it is a software format.
3020 * AVERROR(EINVAL): it is known that hardware decoding is not supported for
3021 * this configuration, or the device_ref is not supported
3022 * for the hwaccel referenced by hw_pix_fmt.
3024 int avcodec_get_hw_frames_parameters(AVCodecContext *avctx,
3025 AVBufferRef *device_ref,
3026 enum AVPixelFormat hw_pix_fmt,
3027 AVBufferRef **out_frames_ref);
3032 * @defgroup lavc_parsing Frame parsing
3036 enum AVPictureStructure {
3037 AV_PICTURE_STRUCTURE_UNKNOWN, //< unknown
3038 AV_PICTURE_STRUCTURE_TOP_FIELD, //< coded as top field
3039 AV_PICTURE_STRUCTURE_BOTTOM_FIELD, //< coded as bottom field
3040 AV_PICTURE_STRUCTURE_FRAME, //< coded as frame
3043 typedef struct AVCodecParserContext {
3045 struct AVCodecParser *parser;
3046 int64_t frame_offset; /* offset of the current frame */
3047 int64_t cur_offset; /* current offset
3048 (incremented by each av_parser_parse()) */
3049 int64_t next_frame_offset; /* offset of the next frame */
3051 int pict_type; /* XXX: Put it back in AVCodecContext. */
3053 * This field is used for proper frame duration computation in lavf.
3054 * It signals, how much longer the frame duration of the current frame
3055 * is compared to normal frame duration.
3057 * frame_duration = (1 + repeat_pict) * time_base
3059 * It is used by codecs like H.264 to display telecined material.
3061 int repeat_pict; /* XXX: Put it back in AVCodecContext. */
3062 int64_t pts; /* pts of the current frame */
3063 int64_t dts; /* dts of the current frame */
3068 int fetch_timestamp;
3070 #define AV_PARSER_PTS_NB 4
3071 int cur_frame_start_index;
3072 int64_t cur_frame_offset[AV_PARSER_PTS_NB];
3073 int64_t cur_frame_pts[AV_PARSER_PTS_NB];
3074 int64_t cur_frame_dts[AV_PARSER_PTS_NB];
3077 #define PARSER_FLAG_COMPLETE_FRAMES 0x0001
3078 #define PARSER_FLAG_ONCE 0x0002
3079 /// Set if the parser has a valid file offset
3080 #define PARSER_FLAG_FETCHED_OFFSET 0x0004
3081 #define PARSER_FLAG_USE_CODEC_TS 0x1000
3083 int64_t offset; ///< byte offset from starting packet start
3084 int64_t cur_frame_end[AV_PARSER_PTS_NB];
3087 * Set by parser to 1 for key frames and 0 for non-key frames.
3088 * It is initialized to -1, so if the parser doesn't set this flag,
3089 * old-style fallback using AV_PICTURE_TYPE_I picture type as key frames
3094 // Timestamp generation support:
3096 * Synchronization point for start of timestamp generation.
3098 * Set to >0 for sync point, 0 for no sync point and <0 for undefined
3101 * For example, this corresponds to presence of H.264 buffering period
3107 * Offset of the current timestamp against last timestamp sync point in
3108 * units of AVCodecContext.time_base.
3110 * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
3111 * contain a valid timestamp offset.
3113 * Note that the timestamp of sync point has usually a nonzero
3114 * dts_ref_dts_delta, which refers to the previous sync point. Offset of
3115 * the next frame after timestamp sync point will be usually 1.
3117 * For example, this corresponds to H.264 cpb_removal_delay.
3119 int dts_ref_dts_delta;
3122 * Presentation delay of current frame in units of AVCodecContext.time_base.
3124 * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
3125 * contain valid non-negative timestamp delta (presentation time of a frame
3126 * must not lie in the past).
3128 * This delay represents the difference between decoding and presentation
3129 * time of the frame.
3131 * For example, this corresponds to H.264 dpb_output_delay.
3136 * Position of the packet in file.
3138 * Analogous to cur_frame_pts/dts
3140 int64_t cur_frame_pos[AV_PARSER_PTS_NB];
3143 * Byte position of currently parsed frame in stream.
3148 * Previous frame byte position.
3153 * Duration of the current frame.
3154 * For audio, this is in units of 1 / AVCodecContext.sample_rate.
3155 * For all other types, this is in units of AVCodecContext.time_base.
3159 enum AVFieldOrder field_order;
3162 * Indicate whether a picture is coded as a frame, top field or bottom field.
3164 * For example, H.264 field_pic_flag equal to 0 corresponds to
3165 * AV_PICTURE_STRUCTURE_FRAME. An H.264 picture with field_pic_flag
3166 * equal to 1 and bottom_field_flag equal to 0 corresponds to
3167 * AV_PICTURE_STRUCTURE_TOP_FIELD.
3169 enum AVPictureStructure picture_structure;
3172 * Picture number incremented in presentation or output order.
3173 * This field may be reinitialized at the first picture of a new sequence.
3175 * For example, this corresponds to H.264 PicOrderCnt.
3177 int output_picture_number;
3180 * Dimensions of the decoded video intended for presentation.
3186 * Dimensions of the coded video.
3192 * The format of the coded data, corresponds to enum AVPixelFormat for video
3193 * and for enum AVSampleFormat for audio.
3195 * Note that a decoder can have considerable freedom in how exactly it
3196 * decodes the data, so the format reported here might be different from the
3197 * one returned by a decoder.
3200 } AVCodecParserContext;
3202 typedef struct AVCodecParser {
3203 int codec_ids[5]; /* several codec IDs are permitted */
3205 int (*parser_init)(AVCodecParserContext *s);
3206 /* This callback never returns an error, a negative value means that
3207 * the frame start was in a previous packet. */
3208 int (*parser_parse)(AVCodecParserContext *s,
3209 AVCodecContext *avctx,
3210 const uint8_t **poutbuf, int *poutbuf_size,
3211 const uint8_t *buf, int buf_size);
3212 void (*parser_close)(AVCodecParserContext *s);
3213 int (*split)(AVCodecContext *avctx, const uint8_t *buf, int buf_size);
3217 * Iterate over all registered codec parsers.
3219 * @param opaque a pointer where libavcodec will store the iteration state. Must
3220 * point to NULL to start the iteration.
3222 * @return the next registered codec parser or NULL when the iteration is
3225 const AVCodecParser *av_parser_iterate(void **opaque);
3227 AVCodecParserContext *av_parser_init(int codec_id);
3232 * @param s parser context.
3233 * @param avctx codec context.
3234 * @param poutbuf set to pointer to parsed buffer or NULL if not yet finished.
3235 * @param poutbuf_size set to size of parsed buffer or zero if not yet finished.
3236 * @param buf input buffer.
3237 * @param buf_size buffer size in bytes without the padding. I.e. the full buffer
3238 size is assumed to be buf_size + AV_INPUT_BUFFER_PADDING_SIZE.
3239 To signal EOF, this should be 0 (so that the last frame
3241 * @param pts input presentation timestamp.
3242 * @param dts input decoding timestamp.
3243 * @param pos input byte position in stream.
3244 * @return the number of bytes of the input bitstream used.
3249 * len = av_parser_parse2(myparser, AVCodecContext, &data, &size,
3256 * decode_frame(data, size);
3260 int av_parser_parse2(AVCodecParserContext *s,
3261 AVCodecContext *avctx,
3262 uint8_t **poutbuf, int *poutbuf_size,
3263 const uint8_t *buf, int buf_size,
3264 int64_t pts, int64_t dts,
3267 void av_parser_close(AVCodecParserContext *s);
3275 * @addtogroup lavc_encoding
3279 #if FF_API_OLD_ENCDEC
3281 * Encode a frame of audio.
3283 * Takes input samples from frame and writes the next output packet, if
3284 * available, to avpkt. The output packet does not necessarily contain data for
3285 * the most recent frame, as encoders can delay, split, and combine input frames
3286 * internally as needed.
3288 * @param avctx codec context
3289 * @param avpkt output AVPacket.
3290 * The user can supply an output buffer by setting
3291 * avpkt->data and avpkt->size prior to calling the
3292 * function, but if the size of the user-provided data is not
3293 * large enough, encoding will fail. If avpkt->data and
3294 * avpkt->size are set, avpkt->destruct must also be set. All
3295 * other AVPacket fields will be reset by the encoder using
3296 * av_init_packet(). If avpkt->data is NULL, the encoder will
3297 * allocate it. The encoder will set avpkt->size to the size
3298 * of the output packet.
3300 * If this function fails or produces no output, avpkt will be
3301 * freed using av_packet_unref().
3302 * @param[in] frame AVFrame containing the raw audio data to be encoded.
3303 * May be NULL when flushing an encoder that has the
3304 * AV_CODEC_CAP_DELAY capability set.
3305 * If AV_CODEC_CAP_VARIABLE_FRAME_SIZE is set, then each frame
3306 * can have any number of samples.
3307 * If it is not set, frame->nb_samples must be equal to
3308 * avctx->frame_size for all frames except the last.
3309 * The final frame may be smaller than avctx->frame_size.
3310 * @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
3311 * output packet is non-empty, and to 0 if it is
3312 * empty. If the function returns an error, the
3313 * packet can be assumed to be invalid, and the
3314 * value of got_packet_ptr is undefined and should
3316 * @return 0 on success, negative error code on failure
3318 * @deprecated use avcodec_send_frame()/avcodec_receive_packet() instead.
3319 * If allowed and required, set AVCodecContext.get_encode_buffer to
3320 * a custom function to pass user supplied output buffers.
3322 attribute_deprecated
3323 int avcodec_encode_audio2(AVCodecContext *avctx, AVPacket *avpkt,
3324 const AVFrame *frame, int *got_packet_ptr);
3327 * Encode a frame of video.
3329 * Takes input raw video data from frame and writes the next output packet, if
3330 * available, to avpkt. The output packet does not necessarily contain data for
3331 * the most recent frame, as encoders can delay and reorder input frames
3332 * internally as needed.
3334 * @param avctx codec context
3335 * @param avpkt output AVPacket.
3336 * The user can supply an output buffer by setting
3337 * avpkt->data and avpkt->size prior to calling the
3338 * function, but if the size of the user-provided data is not
3339 * large enough, encoding will fail. All other AVPacket fields
3340 * will be reset by the encoder using av_init_packet(). If
3341 * avpkt->data is NULL, the encoder will allocate it.
3342 * The encoder will set avpkt->size to the size of the
3343 * output packet. The returned data (if any) belongs to the
3344 * caller, he is responsible for freeing it.
3346 * If this function fails or produces no output, avpkt will be
3347 * freed using av_packet_unref().
3348 * @param[in] frame AVFrame containing the raw video data to be encoded.
3349 * May be NULL when flushing an encoder that has the
3350 * AV_CODEC_CAP_DELAY capability set.
3351 * @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
3352 * output packet is non-empty, and to 0 if it is
3353 * empty. If the function returns an error, the
3354 * packet can be assumed to be invalid, and the
3355 * value of got_packet_ptr is undefined and should
3357 * @return 0 on success, negative error code on failure
3359 * @deprecated use avcodec_send_frame()/avcodec_receive_packet() instead.
3360 * If allowed and required, set AVCodecContext.get_encode_buffer to
3361 * a custom function to pass user supplied output buffers.
3363 attribute_deprecated
3364 int avcodec_encode_video2(AVCodecContext *avctx, AVPacket *avpkt,
3365 const AVFrame *frame, int *got_packet_ptr);
3368 int avcodec_encode_subtitle(AVCodecContext *avctx, uint8_t *buf, int buf_size,
3369 const AVSubtitle *sub);
3377 * @defgroup lavc_misc Utility functions
3380 * Miscellaneous utility functions related to both encoding and decoding
3386 * @defgroup lavc_misc_pixfmt Pixel formats
3388 * Functions for working with pixel formats.
3393 * Return a value representing the fourCC code associated to the
3394 * pixel format pix_fmt, or 0 if no associated fourCC code can be
3397 unsigned int avcodec_pix_fmt_to_codec_tag(enum AVPixelFormat pix_fmt);
3400 * Find the best pixel format to convert to given a certain source pixel
3401 * format. When converting from one pixel format to another, information loss
3402 * may occur. For example, when converting from RGB24 to GRAY, the color
3403 * information will be lost. Similarly, other losses occur when converting from
3404 * some formats to other formats. avcodec_find_best_pix_fmt_of_2() searches which of
3405 * the given pixel formats should be used to suffer the least amount of loss.
3406 * The pixel formats from which it chooses one, are determined by the
3407 * pix_fmt_list parameter.
3410 * @param[in] pix_fmt_list AV_PIX_FMT_NONE terminated array of pixel formats to choose from
3411 * @param[in] src_pix_fmt source pixel format
3412 * @param[in] has_alpha Whether the source pixel format alpha channel is used.
3413 * @param[out] loss_ptr Combination of flags informing you what kind of losses will occur.
3414 * @return The best pixel format to convert to or -1 if none was found.
3416 enum AVPixelFormat avcodec_find_best_pix_fmt_of_list(const enum AVPixelFormat *pix_fmt_list,
3417 enum AVPixelFormat src_pix_fmt,
3418 int has_alpha, int *loss_ptr);
3420 enum AVPixelFormat avcodec_default_get_format(struct AVCodecContext *s, const enum AVPixelFormat * fmt);
3426 void avcodec_string(char *buf, int buf_size, AVCodecContext *enc, int encode);
3429 * Return a name for the specified profile, if available.
3431 * @param codec the codec that is searched for the given profile
3432 * @param profile the profile value for which a name is requested
3433 * @return A name for the profile if found, NULL otherwise.
3435 const char *av_get_profile_name(const AVCodec *codec, int profile);
3438 * Return a name for the specified profile, if available.
3440 * @param codec_id the ID of the codec to which the requested profile belongs
3441 * @param profile the profile value for which a name is requested
3442 * @return A name for the profile if found, NULL otherwise.
3444 * @note unlike av_get_profile_name(), which searches a list of profiles
3445 * supported by a specific decoder or encoder implementation, this
3446 * function searches the list of profiles from the AVCodecDescriptor
3448 const char *avcodec_profile_name(enum AVCodecID codec_id, int profile);
3450 int avcodec_default_execute(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2),void *arg, int *ret, int count, int size);
3451 int avcodec_default_execute2(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2, int, int),void *arg, int *ret, int count);
3452 //FIXME func typedef
3455 * Fill AVFrame audio data and linesize pointers.
3457 * The buffer buf must be a preallocated buffer with a size big enough
3458 * to contain the specified samples amount. The filled AVFrame data
3459 * pointers will point to this buffer.
3461 * AVFrame extended_data channel pointers are allocated if necessary for
3464 * @param frame the AVFrame
3465 * frame->nb_samples must be set prior to calling the
3466 * function. This function fills in frame->data,
3467 * frame->extended_data, frame->linesize[0].
3468 * @param nb_channels channel count
3469 * @param sample_fmt sample format
3470 * @param buf buffer to use for frame data
3471 * @param buf_size size of buffer
3472 * @param align plane size sample alignment (0 = default)
3473 * @return >=0 on success, negative error code on failure
3474 * @todo return the size in bytes required to store the samples in
3475 * case of success, at the next libavutil bump
3477 int avcodec_fill_audio_frame(AVFrame *frame, int nb_channels,
3478 enum AVSampleFormat sample_fmt, const uint8_t *buf,
3479 int buf_size, int align);
3482 * Reset the internal codec state / flush internal buffers. Should be called
3483 * e.g. when seeking or when switching to a different stream.
3485 * @note for decoders, when refcounted frames are not used
3486 * (i.e. avctx->refcounted_frames is 0), this invalidates the frames previously
3487 * returned from the decoder. When refcounted frames are used, the decoder just
3488 * releases any references it might keep internally, but the caller's reference
3491 * @note for encoders, this function will only do something if the encoder
3492 * declares support for AV_CODEC_CAP_ENCODER_FLUSH. When called, the encoder
3493 * will drain any remaining packets, and can then be re-used for a different
3494 * stream (as opposed to sending a null frame which will leave the encoder
3495 * in a permanent EOF state after draining). This can be desirable if the
3496 * cost of tearing down and replacing the encoder instance is high.
3498 void avcodec_flush_buffers(AVCodecContext *avctx);
3501 * Return codec bits per sample.
3503 * @param[in] codec_id the codec
3504 * @return Number of bits per sample or zero if unknown for the given codec.
3506 int av_get_bits_per_sample(enum AVCodecID codec_id);
3509 * Return the PCM codec associated with a sample format.
3510 * @param be endianness, 0 for little, 1 for big,
3511 * -1 (or anything else) for native
3512 * @return AV_CODEC_ID_PCM_* or AV_CODEC_ID_NONE
3514 enum AVCodecID av_get_pcm_codec(enum AVSampleFormat fmt, int be);
3517 * Return codec bits per sample.
3518 * Only return non-zero if the bits per sample is exactly correct, not an
3521 * @param[in] codec_id the codec
3522 * @return Number of bits per sample or zero if unknown for the given codec.
3524 int av_get_exact_bits_per_sample(enum AVCodecID codec_id);
3527 * Return audio frame duration.
3529 * @param avctx codec context
3530 * @param frame_bytes size of the frame, or 0 if unknown
3531 * @return frame duration, in samples, if known. 0 if not able to
3534 int av_get_audio_frame_duration(AVCodecContext *avctx, int frame_bytes);
3537 * This function is the same as av_get_audio_frame_duration(), except it works
3538 * with AVCodecParameters instead of an AVCodecContext.
3540 int av_get_audio_frame_duration2(AVCodecParameters *par, int frame_bytes);
3545 * Same behaviour av_fast_malloc but the buffer has additional
3546 * AV_INPUT_BUFFER_PADDING_SIZE at the end which will always be 0.
3548 * In addition the whole buffer will initially and after resizes
3549 * be 0-initialized so that no uninitialized data will ever appear.
3551 void av_fast_padded_malloc(void *ptr, unsigned int *size, size_t min_size);
3554 * Same behaviour av_fast_padded_malloc except that buffer will always
3555 * be 0-initialized after call.
3557 void av_fast_padded_mallocz(void *ptr, unsigned int *size, size_t min_size);
3560 * Encode extradata length to a buffer. Used by xiph codecs.
3562 * @param s buffer to write to; must be at least (v/255+1) bytes long
3563 * @param v size of extradata in bytes
3564 * @return number of bytes written to the buffer.
3566 unsigned int av_xiphlacing(unsigned char *s, unsigned int v);
3569 * @return a positive value if s is open (i.e. avcodec_open2() was called on it
3570 * with no corresponding avcodec_close()), 0 otherwise.
3572 int avcodec_is_open(AVCodecContext *s);
3575 * Allocate a CPB properties structure and initialize its fields to default
3578 * @param size if non-NULL, the size of the allocated struct will be written
3579 * here. This is useful for embedding it in side data.
3581 * @return the newly allocated struct or NULL on failure
3583 AVCPBProperties *av_cpb_properties_alloc(size_t *size);
3589 #endif /* AVCODEC_AVCODEC_H */