1/*
2 * AVPacket public API
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21#ifndef AVCODEC_PACKET_H
22#define AVCODEC_PACKET_H
23
24#include <stddef.h>
25#include <stdint.h>
26
27#include "libavutil/attributes.h"
28#include "libavutil/buffer.h"
29#include "libavutil/dict.h"
30#include "libavutil/rational.h"
31#include "libavutil/version.h"
32
33#include "libavcodec/version_major.h"
34
35/**
36 * @defgroup lavc_packet_side_data AVPacketSideData
37 *
38 * Types and functions for working with AVPacketSideData.
39 * @{
40 */
41enum AVPacketSideDataType {
42 /**
43 * An AV_PKT_DATA_PALETTE side data packet contains exactly AVPALETTE_SIZE
44 * bytes worth of palette. This side data signals that a new palette is
45 * present.
46 */
47 AV_PKT_DATA_PALETTE,
48
49 /**
50 * The AV_PKT_DATA_NEW_EXTRADATA is used to notify the codec or the format
51 * that the extradata buffer was changed and the receiving side should
52 * act upon it appropriately. The new extradata is embedded in the side
53 * data buffer and should be immediately used for processing the current
54 * frame or packet.
55 */
56 AV_PKT_DATA_NEW_EXTRADATA,
57
58 /**
59 * An AV_PKT_DATA_PARAM_CHANGE side data packet is laid out as follows:
60 * @code
61 * u32le param_flags
62 * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE)
63 * s32le sample_rate
64 * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS)
65 * s32le width
66 * s32le height
67 * @endcode
68 */
69 AV_PKT_DATA_PARAM_CHANGE,
70
71 /**
72 * An AV_PKT_DATA_H263_MB_INFO side data packet contains a number of
73 * structures with info about macroblocks relevant to splitting the
74 * packet into smaller packets on macroblock edges (e.g. as for RFC 2190).
75 * That is, it does not necessarily contain info about all macroblocks,
76 * as long as the distance between macroblocks in the info is smaller
77 * than the target payload size.
78 * Each MB info structure is 12 bytes, and is laid out as follows:
79 * @code
80 * u32le bit offset from the start of the packet
81 * u8 current quantizer at the start of the macroblock
82 * u8 GOB number
83 * u16le macroblock address within the GOB
84 * u8 horizontal MV predictor
85 * u8 vertical MV predictor
86 * u8 horizontal MV predictor for block number 3
87 * u8 vertical MV predictor for block number 3
88 * @endcode
89 */
90 AV_PKT_DATA_H263_MB_INFO,
91
92 /**
93 * This side data should be associated with an audio stream and contains
94 * ReplayGain information in form of the AVReplayGain struct.
95 */
96 AV_PKT_DATA_REPLAYGAIN,
97
98 /**
99 * This side data contains a 3x3 transformation matrix describing an affine
100 * transformation that needs to be applied to the decoded video frames for
101 * correct presentation.
102 *
103 * See libavutil/display.h for a detailed description of the data.
104 */
105 AV_PKT_DATA_DISPLAYMATRIX,
106
107 /**
108 * This side data should be associated with a video stream and contains
109 * Stereoscopic 3D information in form of the AVStereo3D struct.
110 */
111 AV_PKT_DATA_STEREO3D,
112
113 /**
114 * This side data should be associated with an audio stream and corresponds
115 * to enum AVAudioServiceType.
116 */
117 AV_PKT_DATA_AUDIO_SERVICE_TYPE,
118
119 /**
120 * This side data contains quality related information from the encoder.
121 * @code
122 * u32le quality factor of the compressed frame. Allowed range is between 1 (good) and FF_LAMBDA_MAX (bad).
123 * u8 picture type
124 * u8 error count
125 * u16 reserved
126 * u64le[error count] sum of squared differences between encoder in and output
127 * @endcode
128 */
129 AV_PKT_DATA_QUALITY_STATS,
130
131 /**
132 * This side data contains an integer value representing the stream index
133 * of a "fallback" track. A fallback track indicates an alternate
134 * track to use when the current track can not be decoded for some reason.
135 * e.g. no decoder available for codec.
136 */
137 AV_PKT_DATA_FALLBACK_TRACK,
138
139 /**
140 * This side data corresponds to the AVCPBProperties struct.
141 */
142 AV_PKT_DATA_CPB_PROPERTIES,
143
144 /**
145 * Recommends skipping the specified number of samples
146 * @code
147 * u32le number of samples to skip from start of this packet
148 * u32le number of samples to skip from end of this packet
149 * u8 reason for start skip
150 * u8 reason for end skip (0=padding silence, 1=convergence)
151 * @endcode
152 */
153 AV_PKT_DATA_SKIP_SAMPLES,
154
155 /**
156 * An AV_PKT_DATA_JP_DUALMONO side data packet indicates that
157 * the packet may contain "dual mono" audio specific to Japanese DTV
158 * and if it is true, recommends only the selected channel to be used.
159 * @code
160 * u8 selected channels (0=main/left, 1=sub/right, 2=both)
161 * @endcode
162 */
163 AV_PKT_DATA_JP_DUALMONO,
164
165 /**
166 * A list of zero terminated key/value strings. There is no end marker for
167 * the list, so it is required to rely on the side data size to stop.
168 */
169 AV_PKT_DATA_STRINGS_METADATA,
170
171 /**
172 * Subtitle event position
173 * @code
174 * u32le x1
175 * u32le y1
176 * u32le x2
177 * u32le y2
178 * @endcode
179 */
180 AV_PKT_DATA_SUBTITLE_POSITION,
181
182 /**
183 * Data found in BlockAdditional element of matroska container. There is
184 * no end marker for the data, so it is required to rely on the side data
185 * size to recognize the end. 8 byte id (as found in BlockAddId) followed
186 * by data.
187 */
188 AV_PKT_DATA_MATROSKA_BLOCKADDITIONAL,
189
190 /**
191 * The optional first identifier line of a WebVTT cue.
192 */
193 AV_PKT_DATA_WEBVTT_IDENTIFIER,
194
195 /**
196 * The optional settings (rendering instructions) that immediately
197 * follow the timestamp specifier of a WebVTT cue.
198 */
199 AV_PKT_DATA_WEBVTT_SETTINGS,
200
201 /**
202 * A list of zero terminated key/value strings. There is no end marker for
203 * the list, so it is required to rely on the side data size to stop. This
204 * side data includes updated metadata which appeared in the stream.
205 */
206 AV_PKT_DATA_METADATA_UPDATE,
207
208 /**
209 * MPEGTS stream ID as uint8_t, this is required to pass the stream ID
210 * information from the demuxer to the corresponding muxer.
211 */
212 AV_PKT_DATA_MPEGTS_STREAM_ID,
213
214 /**
215 * Mastering display metadata (based on SMPTE-2086:2014). This metadata
216 * should be associated with a video stream and contains data in the form
217 * of the AVMasteringDisplayMetadata struct.
218 */
219 AV_PKT_DATA_MASTERING_DISPLAY_METADATA,
220
221 /**
222 * This side data should be associated with a video stream and corresponds
223 * to the AVSphericalMapping structure.
224 */
225 AV_PKT_DATA_SPHERICAL,
226
227 /**
228 * Content light level (based on CTA-861.3). This metadata should be
229 * associated with a video stream and contains data in the form of the
230 * AVContentLightMetadata struct.
231 */
232 AV_PKT_DATA_CONTENT_LIGHT_LEVEL,
233
234 /**
235 * ATSC A53 Part 4 Closed Captions. This metadata should be associated with
236 * a video stream. A53 CC bitstream is stored as uint8_t in AVPacketSideData.data.
237 * The number of bytes of CC data is AVPacketSideData.size.
238 */
239 AV_PKT_DATA_A53_CC,
240
241 /**
242 * This side data is encryption initialization data.
243 * The format is not part of ABI, use av_encryption_init_info_* methods to
244 * access.
245 */
246 AV_PKT_DATA_ENCRYPTION_INIT_INFO,
247
248 /**
249 * This side data contains encryption info for how to decrypt the packet.
250 * The format is not part of ABI, use av_encryption_info_* methods to access.
251 */
252 AV_PKT_DATA_ENCRYPTION_INFO,
253
254 /**
255 * Active Format Description data consisting of a single byte as specified
256 * in ETSI TS 101 154 using AVActiveFormatDescription enum.
257 */
258 AV_PKT_DATA_AFD,
259
260 /**
261 * Producer Reference Time data corresponding to the AVProducerReferenceTime struct,
262 * usually exported by some encoders (on demand through the prft flag set in the
263 * AVCodecContext export_side_data field).
264 */
265 AV_PKT_DATA_PRFT,
266
267 /**
268 * ICC profile data consisting of an opaque octet buffer following the
269 * format described by ISO 15076-1.
270 */
271 AV_PKT_DATA_ICC_PROFILE,
272
273 /**
274 * DOVI configuration
275 * ref:
276 * dolby-vision-bitstreams-within-the-iso-base-media-file-format-v2.1.2, section 2.2
277 * dolby-vision-bitstreams-in-mpeg-2-transport-stream-multiplex-v1.2, section 3.3
278 * Tags are stored in struct AVDOVIDecoderConfigurationRecord.
279 */
280 AV_PKT_DATA_DOVI_CONF,
281
282 /**
283 * Timecode which conforms to SMPTE ST 12-1:2014. The data is an array of 4 uint32_t
284 * where the first uint32_t describes how many (1-3) of the other timecodes are used.
285 * The timecode format is described in the documentation of av_timecode_get_smpte_from_framenum()
286 * function in libavutil/timecode.h.
287 */
288 AV_PKT_DATA_S12M_TIMECODE,
289
290 /**
291 * HDR10+ dynamic metadata associated with a video frame. The metadata is in
292 * the form of the AVDynamicHDRPlus struct and contains
293 * information for color volume transform - application 4 of
294 * SMPTE 2094-40:2016 standard.
295 */
296 AV_PKT_DATA_DYNAMIC_HDR10_PLUS,
297
298 /**
299 * IAMF Mix Gain Parameter Data associated with the audio frame. This metadata
300 * is in the form of the AVIAMFParamDefinition struct and contains information
301 * defined in sections 3.6.1 and 3.8.1 of the Immersive Audio Model and
302 * Formats standard.
303 */
304 AV_PKT_DATA_IAMF_MIX_GAIN_PARAM,
305
306 /**
307 * IAMF Demixing Info Parameter Data associated with the audio frame. This
308 * metadata is in the form of the AVIAMFParamDefinition struct and contains
309 * information defined in sections 3.6.1 and 3.8.2 of the Immersive Audio Model
310 * and Formats standard.
311 */
312 AV_PKT_DATA_IAMF_DEMIXING_INFO_PARAM,
313
314 /**
315 * IAMF Recon Gain Info Parameter Data associated with the audio frame. This
316 * metadata is in the form of the AVIAMFParamDefinition struct and contains
317 * information defined in sections 3.6.1 and 3.8.3 of the Immersive Audio Model
318 * and Formats standard.
319 */
320 AV_PKT_DATA_IAMF_RECON_GAIN_INFO_PARAM,
321
322 /**
323 * Ambient viewing environment metadata, as defined by H.274. This metadata
324 * should be associated with a video stream and contains data in the form
325 * of the AVAmbientViewingEnvironment struct.
326 */
327 AV_PKT_DATA_AMBIENT_VIEWING_ENVIRONMENT,
328
329 /**
330 * The number of pixels to discard from the top/bottom/left/right border of the
331 * decoded frame to obtain the sub-rectangle intended for presentation.
332 *
333 * @code
334 * u32le crop_top
335 * u32le crop_bottom
336 * u32le crop_left
337 * u32le crop_right
338 * @endcode
339 */
340 AV_PKT_DATA_FRAME_CROPPING,
341
342 /**
343 * Raw LCEVC payload data, as a uint8_t array, with NAL emulation
344 * bytes intact.
345 */
346 AV_PKT_DATA_LCEVC,
347
348 /**
349 * This side data contains information about the reference display width(s)
350 * and reference viewing distance(s) as well as information about the
351 * corresponding reference stereo pair(s), i.e., the pair(s) of views to be
352 * displayed for the viewer's left and right eyes on the reference display
353 * at the reference viewing distance.
354 * The payload is the AV3DReferenceDisplaysInfo struct defined in
355 * libavutil/tdrdi.h.
356 */
357 AV_PKT_DATA_3D_REFERENCE_DISPLAYS,
358
359 /**
360 * Contains the last received RTCP SR (Sender Report) information
361 * in the form of the AVRTCPSenderReport struct.
362 */
363 AV_PKT_DATA_RTCP_SR,
364
365 /**
366 * Extensible image file format metadata. The payload is a buffer containing
367 * EXIF metadata, starting with either 49 49 2a 00, or 4d 4d 00 2a.
368 */
369 AV_PKT_DATA_EXIF,
370
371 /**
372 * The number of side data types.
373 * This is not part of the public API/ABI in the sense that it may
374 * change when new side data types are added.
375 * This must stay the last enum value.
376 * If its value becomes huge, some code using it
377 * needs to be updated as it assumes it to be smaller than other limits.
378 */
379 AV_PKT_DATA_NB
380};
381
382/**
383 * This structure stores auxiliary information for decoding, presenting, or
384 * otherwise processing the coded stream. It is typically exported by demuxers
385 * and encoders and can be fed to decoders and muxers either in a per packet
386 * basis, or as global side data (applying to the entire coded stream).
387 *
388 * Global side data is handled as follows:
389 * - During demuxing, it may be exported through
390 * @ref AVCodecParameters.coded_side_data "AVStream's codec parameters", which can
391 * then be passed as input to decoders through the
392 * @ref AVCodecContext.coded_side_data "decoder context's side data", for
393 * initialization.
394 * - For muxing, it can be fed through @ref AVCodecParameters.coded_side_data
395 * "AVStream's codec parameters", typically the output of encoders through
396 * the @ref AVCodecContext.coded_side_data "encoder context's side data", for
397 * initialization.
398 *
399 * Packet specific side data is handled as follows:
400 * - During demuxing, it may be exported through @ref AVPacket.side_data
401 * "AVPacket's side data", which can then be passed as input to decoders.
402 * - For muxing, it can be fed through @ref AVPacket.side_data "AVPacket's
403 * side data", typically the output of encoders.
404 *
405 * Different modules may accept or export different types of side data
406 * depending on media type and codec. Refer to @ref AVPacketSideDataType for a
407 * list of defined types and where they may be found or used.
408 */
409typedef struct AVPacketSideData {
410 uint8_t *data;
411 size_t size;
412 enum AVPacketSideDataType type;
413} AVPacketSideData;
414
415/**
416 * Allocate a new packet side data.
417 *
418 * @param sd pointer to an array of side data to which the side data should
419 * be added. *sd may be NULL, in which case the array will be
420 * initialized.
421 * @param nb_sd pointer to an integer containing the number of entries in
422 * the array. The integer value will be increased by 1 on success.
423 * @param type side data type
424 * @param size desired side data size
425 * @param flags currently unused. Must be zero
426 *
427 * @return pointer to freshly allocated side data on success, or NULL otherwise.
428 */
429AVPacketSideData *av_packet_side_data_new(AVPacketSideData **psd, int *pnb_sd,
430 enum AVPacketSideDataType type,
431 size_t size, int flags);
432
433/**
434 * Wrap existing data as packet side data.
435 *
436 * @param sd pointer to an array of side data to which the side data should
437 * be added. *sd may be NULL, in which case the array will be
438 * initialized
439 * @param nb_sd pointer to an integer containing the number of entries in
440 * the array. The integer value will be increased by 1 on success.
441 * @param type side data type
442 * @param data a data array. It must be allocated with the av_malloc() family
443 * of functions. The ownership of the data is transferred to the
444 * side data array on success
445 * @param size size of the data array
446 * @param flags currently unused. Must be zero
447 *
448 * @return pointer to freshly allocated side data on success, or NULL otherwise
449 * On failure, the side data array is unchanged and the data remains
450 * owned by the caller.
451 */
452AVPacketSideData *av_packet_side_data_add(AVPacketSideData **sd, int *nb_sd,
453 enum AVPacketSideDataType type,
454 void *data, size_t size, int flags);
455
456/**
457 * Get side information from a side data array.
458 *
459 * @param sd the array from which the side data should be fetched
460 * @param nb_sd value containing the number of entries in the array.
461 * @param type desired side information type
462 *
463 * @return pointer to side data if present or NULL otherwise
464 */
465const AVPacketSideData *av_packet_side_data_get(const AVPacketSideData *sd,
466 int nb_sd,
467 enum AVPacketSideDataType type);
468
469/**
470 * Remove side data of the given type from a side data array.
471 *
472 * @param sd the array from which the side data should be removed
473 * @param nb_sd pointer to an integer containing the number of entries in
474 * the array. Will be reduced by the amount of entries removed
475 * upon return
476 * @param type side information type
477 */
478void av_packet_side_data_remove(AVPacketSideData *sd, int *nb_sd,
479 enum AVPacketSideDataType type);
480
481/**
482 * Convenience function to free all the side data stored in an array, and
483 * the array itself.
484 *
485 * @param sd pointer to array of side data to free. Will be set to NULL
486 * upon return.
487 * @param nb_sd pointer to an integer containing the number of entries in
488 * the array. Will be set to 0 upon return.
489 */
490void av_packet_side_data_free(AVPacketSideData **sd, int *nb_sd);
491
492struct AVFrameSideData;
493
494/**
495 * Add a new packet side data entry to an array based on existing frame
496 * side data, if a matching type exists for packet side data.
497 *
498 * @param flags Currently unused. Must be 0.
499 * @retval >= 0 Success
500 * @retval AVERROR(EINVAL) The frame side data type does not have a matching
501 * packet side data type.
502 * @retval AVERROR(ENOMEM) Failed to add a side data entry to the array, or
503 * similar.
504 */
505int av_packet_side_data_from_frame(AVPacketSideData **sd, int *nb_sd,
506 const struct AVFrameSideData *src, unsigned int flags);
507/**
508 * Add a new frame side data entry to an array based on existing packet
509 * side data, if a matching type exists for frame side data.
510 *
511 * @param flags Some combination of AV_FRAME_SIDE_DATA_FLAG_* flags,
512 * or 0.
513 * @retval >= 0 Success
514 * @retval AVERROR(EINVAL) The packet side data type does not have a matching
515 * frame side data type.
516 * @retval AVERROR(ENOMEM) Failed to add a side data entry to the array, or
517 * similar.
518 */
519int av_packet_side_data_to_frame(struct AVFrameSideData ***sd, int *nb_sd,
520 const AVPacketSideData *src, unsigned int flags);
521
522const char *av_packet_side_data_name(enum AVPacketSideDataType type);
523
524/**
525 * @}
526 */
527
528/**
529 * @defgroup lavc_packet AVPacket
530 *
531 * Types and functions for working with AVPacket.
532 * @{
533 */
534
535/**
536 * This structure stores compressed data. It is typically exported by demuxers
537 * and then passed as input to decoders, or received as output from encoders and
538 * then passed to muxers.
539 *
540 * For video, it should typically contain one compressed frame. For audio it may
541 * contain several compressed frames. Encoders are allowed to output empty
542 * packets, with no compressed data, containing only side data
543 * (e.g. to update some stream parameters at the end of encoding).
544 *
545 * The semantics of data ownership depends on the buf field.
546 * If it is set, the packet data is dynamically allocated and is
547 * valid indefinitely until a call to av_packet_unref() reduces the
548 * reference count to 0.
549 *
550 * If the buf field is not set av_packet_ref() would make a copy instead
551 * of increasing the reference count.
552 *
553 * The side data is always allocated with av_malloc(), copied by
554 * av_packet_ref() and freed by av_packet_unref().
555 *
556 * sizeof(AVPacket) being a part of the public ABI is deprecated. once
557 * av_init_packet() is removed, new packets will only be able to be allocated
558 * with av_packet_alloc(), and new fields may be added to the end of the struct
559 * with a minor bump.
560 *
561 * @see av_packet_alloc
562 * @see av_packet_ref
563 * @see av_packet_unref
564 */
565typedef struct AVPacket {
566 /**
567 * A reference to the reference-counted buffer where the packet data is
568 * stored.
569 * May be NULL, then the packet data is not reference-counted.
570 */
571 AVBufferRef *buf;
572 /**
573 * Presentation timestamp in AVStream->time_base units; the time at which
574 * the decompressed packet will be presented to the user.
575 * Can be AV_NOPTS_VALUE if it is not stored in the file.
576 * pts MUST be larger or equal to dts as presentation cannot happen before
577 * decompression, unless one wants to view hex dumps. Some formats misuse
578 * the terms dts and pts/cts to mean something different. Such timestamps
579 * must be converted to true pts/dts before they are stored in AVPacket.
580 */
581 int64_t pts;
582 /**
583 * Decompression timestamp in AVStream->time_base units; the time at which
584 * the packet is decompressed.
585 * Can be AV_NOPTS_VALUE if it is not stored in the file.
586 */
587 int64_t dts;
588 uint8_t *data;
589 int size;
590 int stream_index;
591 /**
592 * A combination of AV_PKT_FLAG values
593 */
594 int flags;
595 /**
596 * Additional packet data that can be provided by the container.
597 * Packet can contain several types of side information.
598 */
599 AVPacketSideData *side_data;
600 int side_data_elems;
601
602 /**
603 * Duration of this packet in AVStream->time_base units, 0 if unknown.
604 * Equals next_pts - this_pts in presentation order.
605 */
606 int64_t duration;
607
608 int64_t pos; ///< byte position in stream, -1 if unknown
609
610 /**
611 * for some private data of the user
612 */
613 void *opaque;
614
615 /**
616 * AVBufferRef for free use by the API user. FFmpeg will never check the
617 * contents of the buffer ref. FFmpeg calls av_buffer_unref() on it when
618 * the packet is unreferenced. av_packet_copy_props() calls create a new
619 * reference with av_buffer_ref() for the target packet's opaque_ref field.
620 *
621 * This is unrelated to the opaque field, although it serves a similar
622 * purpose.
623 */
624 AVBufferRef *opaque_ref;
625
626 /**
627 * Time base of the packet's timestamps.
628 * In the future, this field may be set on packets output by encoders or
629 * demuxers, but its value will be by default ignored on input to decoders
630 * or muxers.
631 */
632 AVRational time_base;
633} AVPacket;
634
635#if FF_API_INIT_PACKET
636attribute_deprecated
637typedef struct AVPacketList {
638 AVPacket pkt;
639 struct AVPacketList *next;
640} AVPacketList;
641#endif
642
643#define AV_PKT_FLAG_KEY 0x0001 ///< The packet contains a keyframe
644#define AV_PKT_FLAG_CORRUPT 0x0002 ///< The packet content is corrupted
645/**
646 * Flag is used to discard packets which are required to maintain valid
647 * decoder state but are not required for output and should be dropped
648 * after decoding.
649 **/
650#define AV_PKT_FLAG_DISCARD 0x0004
651/**
652 * The packet comes from a trusted source.
653 *
654 * Otherwise-unsafe constructs such as arbitrary pointers to data
655 * outside the packet may be followed.
656 */
657#define AV_PKT_FLAG_TRUSTED 0x0008
658/**
659 * Flag is used to indicate packets that contain frames that can
660 * be discarded by the decoder. I.e. Non-reference frames.
661 */
662#define AV_PKT_FLAG_DISPOSABLE 0x0010
663
664enum AVSideDataParamChangeFlags {
665 AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE = 0x0004,
666 AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS = 0x0008,
667};
668
669/**
670 * Allocate an AVPacket and set its fields to default values. The resulting
671 * struct must be freed using av_packet_free().
672 *
673 * @return An AVPacket filled with default values or NULL on failure.
674 *
675 * @note this only allocates the AVPacket itself, not the data buffers. Those
676 * must be allocated through other means such as av_new_packet.
677 *
678 * @see av_new_packet
679 */
680AVPacket *av_packet_alloc(void);
681
682/**
683 * Create a new packet that references the same data as src.
684 *
685 * This is a shortcut for av_packet_alloc()+av_packet_ref().
686 *
687 * @return newly created AVPacket on success, NULL on error.
688 *
689 * @see av_packet_alloc
690 * @see av_packet_ref
691 */
692AVPacket *av_packet_clone(const AVPacket *src);
693
694/**
695 * Free the packet, if the packet is reference counted, it will be
696 * unreferenced first.
697 *
698 * @param pkt packet to be freed. The pointer will be set to NULL.
699 * @note passing NULL is a no-op.
700 */
701void av_packet_free(AVPacket **pkt);
702
703#if FF_API_INIT_PACKET
704/**
705 * Initialize optional fields of a packet with default values.
706 *
707 * Note, this does not touch the data and size members, which have to be
708 * initialized separately.
709 *
710 * @param pkt packet
711 *
712 * @see av_packet_alloc
713 * @see av_packet_unref
714 *
715 * @deprecated This function is deprecated. Once it's removed,
716 sizeof(AVPacket) will not be a part of the ABI anymore.
717 */
718attribute_deprecated
719void av_init_packet(AVPacket *pkt);
720#endif
721
722/**
723 * Allocate the payload of a packet and initialize its fields with
724 * default values.
725 *
726 * @param pkt packet
727 * @param size wanted payload size
728 * @return 0 if OK, AVERROR_xxx otherwise
729 */
730int av_new_packet(AVPacket *pkt, int size);
731
732/**
733 * Reduce packet size, correctly zeroing padding
734 *
735 * @param pkt packet
736 * @param size new size
737 */
738void av_shrink_packet(AVPacket *pkt, int size);
739
740/**
741 * Increase packet size, correctly zeroing padding
742 *
743 * @param pkt packet
744 * @param grow_by number of bytes by which to increase the size of the packet
745 */
746int av_grow_packet(AVPacket *pkt, int grow_by);
747
748/**
749 * Initialize a reference-counted packet from av_malloc()ed data.
750 *
751 * @param pkt packet to be initialized. This function will set the data, size,
752 * and buf fields, all others are left untouched.
753 * @param data Data allocated by av_malloc() to be used as packet data. If this
754 * function returns successfully, the data is owned by the underlying AVBuffer.
755 * The caller may not access the data through other means.
756 * @param size size of data in bytes, without the padding. I.e. the full buffer
757 * size is assumed to be size + AV_INPUT_BUFFER_PADDING_SIZE.
758 *
759 * @return 0 on success, a negative AVERROR on error
760 */
761int av_packet_from_data(AVPacket *pkt, uint8_t *data, int size);
762
763/**
764 * Allocate new information of a packet.
765 *
766 * @param pkt packet
767 * @param type side information type
768 * @param size side information size
769 * @return pointer to fresh allocated data or NULL otherwise
770 */
771uint8_t* av_packet_new_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
772 size_t size);
773
774/**
775 * Wrap an existing array as a packet side data.
776 *
777 * @param pkt packet
778 * @param type side information type
779 * @param data the side data array. It must be allocated with the av_malloc()
780 * family of functions. The ownership of the data is transferred to
781 * pkt.
782 * @param size side information size
783 * @return a non-negative number on success, a negative AVERROR code on
784 * failure. On failure, the packet is unchanged and the data remains
785 * owned by the caller.
786 */
787int av_packet_add_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
788 uint8_t *data, size_t size);
789
790/**
791 * Shrink the already allocated side data buffer
792 *
793 * @param pkt packet
794 * @param type side information type
795 * @param size new side information size
796 * @return 0 on success, < 0 on failure
797 */
798int av_packet_shrink_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
799 size_t size);
800
801/**
802 * Get side information from packet.
803 *
804 * @param pkt packet
805 * @param type desired side information type
806 * @param size If supplied, *size will be set to the size of the side data
807 * or to zero if the desired side data is not present.
808 * @return pointer to data if present or NULL otherwise
809 */
810uint8_t* av_packet_get_side_data(const AVPacket *pkt, enum AVPacketSideDataType type,
811 size_t *size);
812
813/**
814 * Pack a dictionary for use in side_data.
815 *
816 * @param dict The dictionary to pack.
817 * @param size pointer to store the size of the returned data
818 * @return pointer to data if successful, NULL otherwise
819 */
820uint8_t *av_packet_pack_dictionary(AVDictionary *dict, size_t *size);
821/**
822 * Unpack a dictionary from side_data.
823 *
824 * @param data data from side_data
825 * @param size size of the data
826 * @param dict the metadata storage dictionary
827 * @return 0 on success, < 0 on failure
828 */
829int av_packet_unpack_dictionary(const uint8_t *data, size_t size,
830 AVDictionary **dict);
831
832/**
833 * Convenience function to free all the side data stored.
834 * All the other fields stay untouched.
835 *
836 * @param pkt packet
837 */
838void av_packet_free_side_data(AVPacket *pkt);
839
840/**
841 * Setup a new reference to the data described by a given packet
842 *
843 * If src is reference-counted, setup dst as a new reference to the
844 * buffer in src. Otherwise allocate a new buffer in dst and copy the
845 * data from src into it.
846 *
847 * All the other fields are copied from src.
848 *
849 * @see av_packet_unref
850 *
851 * @param dst Destination packet. Will be completely overwritten.
852 * @param src Source packet
853 *
854 * @return 0 on success, a negative AVERROR on error. On error, dst
855 * will be blank (as if returned by av_packet_alloc()).
856 */
857int av_packet_ref(AVPacket *dst, const AVPacket *src);
858
859/**
860 * Wipe the packet.
861 *
862 * Unreference the buffer referenced by the packet and reset the
863 * remaining packet fields to their default values.
864 *
865 * @param pkt The packet to be unreferenced.
866 */
867void av_packet_unref(AVPacket *pkt);
868
869/**
870 * Move every field in src to dst and reset src.
871 *
872 * @see av_packet_unref
873 *
874 * @param src Source packet, will be reset
875 * @param dst Destination packet
876 */
877void av_packet_move_ref(AVPacket *dst, AVPacket *src);
878
879/**
880 * Copy only "properties" fields from src to dst.
881 *
882 * Properties for the purpose of this function are all the fields
883 * beside those related to the packet data (buf, data, size)
884 *
885 * @param dst Destination packet
886 * @param src Source packet
887 *
888 * @return 0 on success AVERROR on failure.
889 */
890int av_packet_copy_props(AVPacket *dst, const AVPacket *src);
891
892/**
893 * Ensure the data described by a given packet is reference counted.
894 *
895 * @note This function does not ensure that the reference will be writable.
896 * Use av_packet_make_writable instead for that purpose.
897 *
898 * @see av_packet_ref
899 * @see av_packet_make_writable
900 *
901 * @param pkt packet whose data should be made reference counted.
902 *
903 * @return 0 on success, a negative AVERROR on error. On failure, the
904 * packet is unchanged.
905 */
906int av_packet_make_refcounted(AVPacket *pkt);
907
908/**
909 * Create a writable reference for the data described by a given packet,
910 * avoiding data copy if possible.
911 *
912 * @param pkt Packet whose data should be made writable.
913 *
914 * @return 0 on success, a negative AVERROR on failure. On failure, the
915 * packet is unchanged.
916 */
917int av_packet_make_writable(AVPacket *pkt);
918
919/**
920 * Convert valid timing fields (timestamps / durations) in a packet from one
921 * timebase to another. Timestamps with unknown values (AV_NOPTS_VALUE) will be
922 * ignored.
923 *
924 * @param pkt packet on which the conversion will be performed
925 * @param tb_src source timebase, in which the timing fields in pkt are
926 * expressed
927 * @param tb_dst destination timebase, to which the timing fields will be
928 * converted
929 */
930void av_packet_rescale_ts(AVPacket *pkt, AVRational tb_src, AVRational tb_dst);
931
932/**
933 * Allocate an AVContainerFifo instance for AVPacket.
934 *
935 * @param flags currently unused
936 */
937struct AVContainerFifo *av_container_fifo_alloc_avpacket(unsigned flags);
938
939/**
940 * @}
941 */
942
943#endif // AVCODEC_PACKET_H
944