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 AVPacket 37 * 38 * Types and functions for working with AVPacket. 39 * @{ 40 */ 41 enum 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_CHANNEL_COUNT) 63 * s32le channel_count 64 * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT) 65 * u64le channel_layout 66 * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE) 67 * s32le sample_rate 68 * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS) 69 * s32le width 70 * s32le height 71 * @endcode 72 */ 73 AV_PKT_DATA_PARAM_CHANGE, 74 75 /** 76 * An AV_PKT_DATA_H263_MB_INFO side data packet contains a number of 77 * structures with info about macroblocks relevant to splitting the 78 * packet into smaller packets on macroblock edges (e.g. as for RFC 2190). 79 * That is, it does not necessarily contain info about all macroblocks, 80 * as long as the distance between macroblocks in the info is smaller 81 * than the target payload size. 82 * Each MB info structure is 12 bytes, and is laid out as follows: 83 * @code 84 * u32le bit offset from the start of the packet 85 * u8 current quantizer at the start of the macroblock 86 * u8 GOB number 87 * u16le macroblock address within the GOB 88 * u8 horizontal MV predictor 89 * u8 vertical MV predictor 90 * u8 horizontal MV predictor for block number 3 91 * u8 vertical MV predictor for block number 3 92 * @endcode 93 */ 94 AV_PKT_DATA_H263_MB_INFO, 95 96 /** 97 * This side data should be associated with an audio stream and contains 98 * ReplayGain information in form of the AVReplayGain struct. 99 */ 100 AV_PKT_DATA_REPLAYGAIN, 101 102 /** 103 * This side data contains a 3x3 transformation matrix describing an affine 104 * transformation that needs to be applied to the decoded video frames for 105 * correct presentation. 106 * 107 * See libavutil/display.h for a detailed description of the data. 108 */ 109 AV_PKT_DATA_DISPLAYMATRIX, 110 111 /** 112 * This side data should be associated with a video stream and contains 113 * Stereoscopic 3D information in form of the AVStereo3D struct. 114 */ 115 AV_PKT_DATA_STEREO3D, 116 117 /** 118 * This side data should be associated with an audio stream and corresponds 119 * to enum AVAudioServiceType. 120 */ 121 AV_PKT_DATA_AUDIO_SERVICE_TYPE, 122 123 /** 124 * This side data contains quality related information from the encoder. 125 * @code 126 * u32le quality factor of the compressed frame. Allowed range is between 1 (good) and FF_LAMBDA_MAX (bad). 127 * u8 picture type 128 * u8 error count 129 * u16 reserved 130 * u64le[error count] sum of squared differences between encoder in and output 131 * @endcode 132 */ 133 AV_PKT_DATA_QUALITY_STATS, 134 135 /** 136 * This side data contains an integer value representing the stream index 137 * of a "fallback" track. A fallback track indicates an alternate 138 * track to use when the current track can not be decoded for some reason. 139 * e.g. no decoder available for codec. 140 */ 141 AV_PKT_DATA_FALLBACK_TRACK, 142 143 /** 144 * This side data corresponds to the AVCPBProperties struct. 145 */ 146 AV_PKT_DATA_CPB_PROPERTIES, 147 148 /** 149 * Recommmends skipping the specified number of samples 150 * @code 151 * u32le number of samples to skip from start of this packet 152 * u32le number of samples to skip from end of this packet 153 * u8 reason for start skip 154 * u8 reason for end skip (0=padding silence, 1=convergence) 155 * @endcode 156 */ 157 AV_PKT_DATA_SKIP_SAMPLES, 158 159 /** 160 * An AV_PKT_DATA_JP_DUALMONO side data packet indicates that 161 * the packet may contain "dual mono" audio specific to Japanese DTV 162 * and if it is true, recommends only the selected channel to be used. 163 * @code 164 * u8 selected channels (0=mail/left, 1=sub/right, 2=both) 165 * @endcode 166 */ 167 AV_PKT_DATA_JP_DUALMONO, 168 169 /** 170 * A list of zero terminated key/value strings. There is no end marker for 171 * the list, so it is required to rely on the side data size to stop. 172 */ 173 AV_PKT_DATA_STRINGS_METADATA, 174 175 /** 176 * Subtitle event position 177 * @code 178 * u32le x1 179 * u32le y1 180 * u32le x2 181 * u32le y2 182 * @endcode 183 */ 184 AV_PKT_DATA_SUBTITLE_POSITION, 185 186 /** 187 * Data found in BlockAdditional element of matroska container. There is 188 * no end marker for the data, so it is required to rely on the side data 189 * size to recognize the end. 8 byte id (as found in BlockAddId) followed 190 * by data. 191 */ 192 AV_PKT_DATA_MATROSKA_BLOCKADDITIONAL, 193 194 /** 195 * The optional first identifier line of a WebVTT cue. 196 */ 197 AV_PKT_DATA_WEBVTT_IDENTIFIER, 198 199 /** 200 * The optional settings (rendering instructions) that immediately 201 * follow the timestamp specifier of a WebVTT cue. 202 */ 203 AV_PKT_DATA_WEBVTT_SETTINGS, 204 205 /** 206 * A list of zero terminated key/value strings. There is no end marker for 207 * the list, so it is required to rely on the side data size to stop. This 208 * side data includes updated metadata which appeared in the stream. 209 */ 210 AV_PKT_DATA_METADATA_UPDATE, 211 212 /** 213 * MPEGTS stream ID as uint8_t, this is required to pass the stream ID 214 * information from the demuxer to the corresponding muxer. 215 */ 216 AV_PKT_DATA_MPEGTS_STREAM_ID, 217 218 /** 219 * Mastering display metadata (based on SMPTE-2086:2014). This metadata 220 * should be associated with a video stream and contains data in the form 221 * of the AVMasteringDisplayMetadata struct. 222 */ 223 AV_PKT_DATA_MASTERING_DISPLAY_METADATA, 224 225 /** 226 * This side data should be associated with a video stream and corresponds 227 * to the AVSphericalMapping structure. 228 */ 229 AV_PKT_DATA_SPHERICAL, 230 231 /** 232 * Content light level (based on CTA-861.3). This metadata should be 233 * associated with a video stream and contains data in the form of the 234 * AVContentLightMetadata struct. 235 */ 236 AV_PKT_DATA_CONTENT_LIGHT_LEVEL, 237 238 /** 239 * ATSC A53 Part 4 Closed Captions. This metadata should be associated with 240 * a video stream. A53 CC bitstream is stored as uint8_t in AVPacketSideData.data. 241 * The number of bytes of CC data is AVPacketSideData.size. 242 */ 243 AV_PKT_DATA_A53_CC, 244 245 /** 246 * This side data is encryption initialization data. 247 * The format is not part of ABI, use av_encryption_init_info_* methods to 248 * access. 249 */ 250 AV_PKT_DATA_ENCRYPTION_INIT_INFO, 251 252 /** 253 * This side data contains encryption info for how to decrypt the packet. 254 * The format is not part of ABI, use av_encryption_info_* methods to access. 255 */ 256 AV_PKT_DATA_ENCRYPTION_INFO, 257 258 /** 259 * Active Format Description data consisting of a single byte as specified 260 * in ETSI TS 101 154 using AVActiveFormatDescription enum. 261 */ 262 AV_PKT_DATA_AFD, 263 264 /** 265 * Producer Reference Time data corresponding to the AVProducerReferenceTime struct, 266 * usually exported by some encoders (on demand through the prft flag set in the 267 * AVCodecContext export_side_data field). 268 */ 269 AV_PKT_DATA_PRFT, 270 271 /** 272 * ICC profile data consisting of an opaque octet buffer following the 273 * format described by ISO 15076-1. 274 */ 275 AV_PKT_DATA_ICC_PROFILE, 276 277 /** 278 * DOVI configuration 279 * ref: 280 * dolby-vision-bitstreams-within-the-iso-base-media-file-format-v2.1.2, section 2.2 281 * dolby-vision-bitstreams-in-mpeg-2-transport-stream-multiplex-v1.2, section 3.3 282 * Tags are stored in struct AVDOVIDecoderConfigurationRecord. 283 */ 284 AV_PKT_DATA_DOVI_CONF, 285 286 /** 287 * Timecode which conforms to SMPTE ST 12-1:2014. The data is an array of 4 uint32_t 288 * where the first uint32_t describes how many (1-3) of the other timecodes are used. 289 * The timecode format is described in the documentation of av_timecode_get_smpte_from_framenum() 290 * function in libavutil/timecode.h. 291 */ 292 AV_PKT_DATA_S12M_TIMECODE, 293 294 /** 295 * HDR10+ dynamic metadata associated with a video frame. The metadata is in 296 * the form of the AVDynamicHDRPlus struct and contains 297 * information for color volume transform - application 4 of 298 * SMPTE 2094-40:2016 standard. 299 */ 300 AV_PKT_DATA_DYNAMIC_HDR10_PLUS, 301 302 /** 303 * The number of side data types. 304 * This is not part of the public API/ABI in the sense that it may 305 * change when new side data types are added. 306 * This must stay the last enum value. 307 * If its value becomes huge, some code using it 308 * needs to be updated as it assumes it to be smaller than other limits. 309 */ 310 AV_PKT_DATA_NB 311 }; 312 313 #define AV_PKT_DATA_QUALITY_FACTOR AV_PKT_DATA_QUALITY_STATS //DEPRECATED 314 315 typedef struct AVPacketSideData { 316 uint8_t *data; 317 size_t size; 318 enum AVPacketSideDataType type; 319 } AVPacketSideData; 320 321 /** 322 * This structure stores compressed data. It is typically exported by demuxers 323 * and then passed as input to decoders, or received as output from encoders and 324 * then passed to muxers. 325 * 326 * For video, it should typically contain one compressed frame. For audio it may 327 * contain several compressed frames. Encoders are allowed to output empty 328 * packets, with no compressed data, containing only side data 329 * (e.g. to update some stream parameters at the end of encoding). 330 * 331 * The semantics of data ownership depends on the buf field. 332 * If it is set, the packet data is dynamically allocated and is 333 * valid indefinitely until a call to av_packet_unref() reduces the 334 * reference count to 0. 335 * 336 * If the buf field is not set av_packet_ref() would make a copy instead 337 * of increasing the reference count. 338 * 339 * The side data is always allocated with av_malloc(), copied by 340 * av_packet_ref() and freed by av_packet_unref(). 341 * 342 * sizeof(AVPacket) being a part of the public ABI is deprecated. once 343 * av_init_packet() is removed, new packets will only be able to be allocated 344 * with av_packet_alloc(), and new fields may be added to the end of the struct 345 * with a minor bump. 346 * 347 * @see av_packet_alloc 348 * @see av_packet_ref 349 * @see av_packet_unref 350 */ 351 typedef struct AVPacket { 352 /** 353 * A reference to the reference-counted buffer where the packet data is 354 * stored. 355 * May be NULL, then the packet data is not reference-counted. 356 */ 357 AVBufferRef *buf; 358 /** 359 * Presentation timestamp in AVStream->time_base units; the time at which 360 * the decompressed packet will be presented to the user. 361 * Can be AV_NOPTS_VALUE if it is not stored in the file. 362 * pts MUST be larger or equal to dts as presentation cannot happen before 363 * decompression, unless one wants to view hex dumps. Some formats misuse 364 * the terms dts and pts/cts to mean something different. Such timestamps 365 * must be converted to true pts/dts before they are stored in AVPacket. 366 */ 367 int64_t pts; 368 /** 369 * Decompression timestamp in AVStream->time_base units; the time at which 370 * the packet is decompressed. 371 * Can be AV_NOPTS_VALUE if it is not stored in the file. 372 */ 373 int64_t dts; 374 uint8_t *data; 375 int size; 376 int stream_index; 377 /** 378 * A combination of AV_PKT_FLAG values 379 */ 380 int flags; 381 /** 382 * Additional packet data that can be provided by the container. 383 * Packet can contain several types of side information. 384 */ 385 AVPacketSideData *side_data; 386 int side_data_elems; 387 388 /** 389 * Duration of this packet in AVStream->time_base units, 0 if unknown. 390 * Equals next_pts - this_pts in presentation order. 391 */ 392 int64_t duration; 393 394 int64_t pos; ///< byte position in stream, -1 if unknown 395 396 /** 397 * for some private data of the user 398 */ 399 void *opaque; 400 401 /** 402 * AVBufferRef for free use by the API user. FFmpeg will never check the 403 * contents of the buffer ref. FFmpeg calls av_buffer_unref() on it when 404 * the packet is unreferenced. av_packet_copy_props() calls create a new 405 * reference with av_buffer_ref() for the target packet's opaque_ref field. 406 * 407 * This is unrelated to the opaque field, although it serves a similar 408 * purpose. 409 */ 410 AVBufferRef *opaque_ref; 411 412 /** 413 * Time base of the packet's timestamps. 414 * In the future, this field may be set on packets output by encoders or 415 * demuxers, but its value will be by default ignored on input to decoders 416 * or muxers. 417 */ 418 AVRational time_base; 419 } AVPacket; 420 421 #if FF_API_INIT_PACKET 422 attribute_deprecated 423 typedef struct AVPacketList { 424 AVPacket pkt; 425 struct AVPacketList *next; 426 } AVPacketList; 427 #endif 428 429 #define AV_PKT_FLAG_KEY 0x0001 ///< The packet contains a keyframe 430 #define AV_PKT_FLAG_CORRUPT 0x0002 ///< The packet content is corrupted 431 /** 432 * Flag is used to discard packets which are required to maintain valid 433 * decoder state but are not required for output and should be dropped 434 * after decoding. 435 **/ 436 #define AV_PKT_FLAG_DISCARD 0x0004 437 /** 438 * The packet comes from a trusted source. 439 * 440 * Otherwise-unsafe constructs such as arbitrary pointers to data 441 * outside the packet may be followed. 442 */ 443 #define AV_PKT_FLAG_TRUSTED 0x0008 444 /** 445 * Flag is used to indicate packets that contain frames that can 446 * be discarded by the decoder. I.e. Non-reference frames. 447 */ 448 #define AV_PKT_FLAG_DISPOSABLE 0x0010 449 450 /** 451 * Indicates that the frame is an extended discardable frame. It is not on the main reference path and 452 * is referenced only by discardable frames on the branch reference path are discarded by decoder, the 453 * frame can be further discarded. 454 */ 455 #define AV_PKT_FLAG_DISPOSABLE_EXT 0x0020 456 457 enum AVSideDataParamChangeFlags { 458 #if FF_API_OLD_CHANNEL_LAYOUT 459 /** 460 * @deprecated those are not used by any decoder 461 */ 462 AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT = 0x0001, 463 AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT = 0x0002, 464 #endif 465 AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE = 0x0004, 466 AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS = 0x0008, 467 }; 468 469 /** 470 * Allocate an AVPacket and set its fields to default values. The resulting 471 * struct must be freed using av_packet_free(). 472 * 473 * @return An AVPacket filled with default values or NULL on failure. 474 * 475 * @note this only allocates the AVPacket itself, not the data buffers. Those 476 * must be allocated through other means such as av_new_packet. 477 * 478 * @see av_new_packet 479 */ 480 AVPacket *av_packet_alloc(void); 481 482 /** 483 * Create a new packet that references the same data as src. 484 * 485 * This is a shortcut for av_packet_alloc()+av_packet_ref(). 486 * 487 * @return newly created AVPacket on success, NULL on error. 488 * 489 * @see av_packet_alloc 490 * @see av_packet_ref 491 */ 492 AVPacket *av_packet_clone(const AVPacket *src); 493 494 /** 495 * Free the packet, if the packet is reference counted, it will be 496 * unreferenced first. 497 * 498 * @param pkt packet to be freed. The pointer will be set to NULL. 499 * @note passing NULL is a no-op. 500 */ 501 void av_packet_free(AVPacket **pkt); 502 503 #if FF_API_INIT_PACKET 504 /** 505 * Initialize optional fields of a packet with default values. 506 * 507 * Note, this does not touch the data and size members, which have to be 508 * initialized separately. 509 * 510 * @param pkt packet 511 * 512 * @see av_packet_alloc 513 * @see av_packet_unref 514 * 515 * @deprecated This function is deprecated. Once it's removed, 516 sizeof(AVPacket) will not be a part of the ABI anymore. 517 */ 518 attribute_deprecated 519 void av_init_packet(AVPacket *pkt); 520 #endif 521 522 /** 523 * Allocate the payload of a packet and initialize its fields with 524 * default values. 525 * 526 * @param pkt packet 527 * @param size wanted payload size 528 * @return 0 if OK, AVERROR_xxx otherwise 529 */ 530 int av_new_packet(AVPacket *pkt, int size); 531 532 /** 533 * Reduce packet size, correctly zeroing padding 534 * 535 * @param pkt packet 536 * @param size new size 537 */ 538 void av_shrink_packet(AVPacket *pkt, int size); 539 540 /** 541 * Increase packet size, correctly zeroing padding 542 * 543 * @param pkt packet 544 * @param grow_by number of bytes by which to increase the size of the packet 545 */ 546 int av_grow_packet(AVPacket *pkt, int grow_by); 547 548 /** 549 * Initialize a reference-counted packet from av_malloc()ed data. 550 * 551 * @param pkt packet to be initialized. This function will set the data, size, 552 * and buf fields, all others are left untouched. 553 * @param data Data allocated by av_malloc() to be used as packet data. If this 554 * function returns successfully, the data is owned by the underlying AVBuffer. 555 * The caller may not access the data through other means. 556 * @param size size of data in bytes, without the padding. I.e. the full buffer 557 * size is assumed to be size + AV_INPUT_BUFFER_PADDING_SIZE. 558 * 559 * @return 0 on success, a negative AVERROR on error 560 */ 561 int av_packet_from_data(AVPacket *pkt, uint8_t *data, int size); 562 563 /** 564 * Allocate new information of a packet. 565 * 566 * @param pkt packet 567 * @param type side information type 568 * @param size side information size 569 * @return pointer to fresh allocated data or NULL otherwise 570 */ 571 uint8_t* av_packet_new_side_data(AVPacket *pkt, enum AVPacketSideDataType type, 572 size_t size); 573 574 /** 575 * Wrap an existing array as a packet side data. 576 * 577 * @param pkt packet 578 * @param type side information type 579 * @param data the side data array. It must be allocated with the av_malloc() 580 * family of functions. The ownership of the data is transferred to 581 * pkt. 582 * @param size side information size 583 * @return a non-negative number on success, a negative AVERROR code on 584 * failure. On failure, the packet is unchanged and the data remains 585 * owned by the caller. 586 */ 587 int av_packet_add_side_data(AVPacket *pkt, enum AVPacketSideDataType type, 588 uint8_t *data, size_t size); 589 590 /** 591 * Shrink the already allocated side data buffer 592 * 593 * @param pkt packet 594 * @param type side information type 595 * @param size new side information size 596 * @return 0 on success, < 0 on failure 597 */ 598 int av_packet_shrink_side_data(AVPacket *pkt, enum AVPacketSideDataType type, 599 size_t size); 600 601 /** 602 * Get side information from packet. 603 * 604 * @param pkt packet 605 * @param type desired side information type 606 * @param size If supplied, *size will be set to the size of the side data 607 * or to zero if the desired side data is not present. 608 * @return pointer to data if present or NULL otherwise 609 */ 610 uint8_t* av_packet_get_side_data(const AVPacket *pkt, enum AVPacketSideDataType type, 611 size_t *size); 612 613 const char *av_packet_side_data_name(enum AVPacketSideDataType type); 614 615 /** 616 * Pack a dictionary for use in side_data. 617 * 618 * @param dict The dictionary to pack. 619 * @param size pointer to store the size of the returned data 620 * @return pointer to data if successful, NULL otherwise 621 */ 622 uint8_t *av_packet_pack_dictionary(AVDictionary *dict, size_t *size); 623 /** 624 * Unpack a dictionary from side_data. 625 * 626 * @param data data from side_data 627 * @param size size of the data 628 * @param dict the metadata storage dictionary 629 * @return 0 on success, < 0 on failure 630 */ 631 int av_packet_unpack_dictionary(const uint8_t *data, size_t size, 632 AVDictionary **dict); 633 634 /** 635 * Convenience function to free all the side data stored. 636 * All the other fields stay untouched. 637 * 638 * @param pkt packet 639 */ 640 void av_packet_free_side_data(AVPacket *pkt); 641 642 /** 643 * Setup a new reference to the data described by a given packet 644 * 645 * If src is reference-counted, setup dst as a new reference to the 646 * buffer in src. Otherwise allocate a new buffer in dst and copy the 647 * data from src into it. 648 * 649 * All the other fields are copied from src. 650 * 651 * @see av_packet_unref 652 * 653 * @param dst Destination packet. Will be completely overwritten. 654 * @param src Source packet 655 * 656 * @return 0 on success, a negative AVERROR on error. On error, dst 657 * will be blank (as if returned by av_packet_alloc()). 658 */ 659 int av_packet_ref(AVPacket *dst, const AVPacket *src); 660 661 /** 662 * Wipe the packet. 663 * 664 * Unreference the buffer referenced by the packet and reset the 665 * remaining packet fields to their default values. 666 * 667 * @param pkt The packet to be unreferenced. 668 */ 669 void av_packet_unref(AVPacket *pkt); 670 671 /** 672 * Move every field in src to dst and reset src. 673 * 674 * @see av_packet_unref 675 * 676 * @param src Source packet, will be reset 677 * @param dst Destination packet 678 */ 679 void av_packet_move_ref(AVPacket *dst, AVPacket *src); 680 681 /** 682 * Copy only "properties" fields from src to dst. 683 * 684 * Properties for the purpose of this function are all the fields 685 * beside those related to the packet data (buf, data, size) 686 * 687 * @param dst Destination packet 688 * @param src Source packet 689 * 690 * @return 0 on success AVERROR on failure. 691 */ 692 int av_packet_copy_props(AVPacket *dst, const AVPacket *src); 693 694 /** 695 * Ensure the data described by a given packet is reference counted. 696 * 697 * @note This function does not ensure that the reference will be writable. 698 * Use av_packet_make_writable instead for that purpose. 699 * 700 * @see av_packet_ref 701 * @see av_packet_make_writable 702 * 703 * @param pkt packet whose data should be made reference counted. 704 * 705 * @return 0 on success, a negative AVERROR on error. On failure, the 706 * packet is unchanged. 707 */ 708 int av_packet_make_refcounted(AVPacket *pkt); 709 710 /** 711 * Create a writable reference for the data described by a given packet, 712 * avoiding data copy if possible. 713 * 714 * @param pkt Packet whose data should be made writable. 715 * 716 * @return 0 on success, a negative AVERROR on failure. On failure, the 717 * packet is unchanged. 718 */ 719 int av_packet_make_writable(AVPacket *pkt); 720 721 /** 722 * Convert valid timing fields (timestamps / durations) in a packet from one 723 * timebase to another. Timestamps with unknown values (AV_NOPTS_VALUE) will be 724 * ignored. 725 * 726 * @param pkt packet on which the conversion will be performed 727 * @param tb_src source timebase, in which the timing fields in pkt are 728 * expressed 729 * @param tb_dst destination timebase, to which the timing fields will be 730 * converted 731 */ 732 void av_packet_rescale_ts(AVPacket *pkt, AVRational tb_src, AVRational tb_dst); 733 734 /** 735 * @} 736 */ 737 738 #endif // AVCODEC_PACKET_H 739