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_PACKET_H
22 #define AVCODEC_PACKET_H
27 #include "libavutil/attributes.h"
28 #include "libavutil/buffer.h"
29 #include "libavutil/dict.h"
30 #include "libavutil/rational.h"
32 #include "libavcodec/version.h"
35 * @defgroup lavc_packet AVPacket
37 * Types and functions for working with AVPacket.
40 enum AVPacketSideDataType {
42 * An AV_PKT_DATA_PALETTE side data packet contains exactly AVPALETTE_SIZE
43 * bytes worth of palette. This side data signals that a new palette is
49 * The AV_PKT_DATA_NEW_EXTRADATA is used to notify the codec or the format
50 * that the extradata buffer was changed and the receiving side should
51 * act upon it appropriately. The new extradata is embedded in the side
52 * data buffer and should be immediately used for processing the current
55 AV_PKT_DATA_NEW_EXTRADATA,
58 * An AV_PKT_DATA_PARAM_CHANGE side data packet is laid out as follows:
61 * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT)
63 * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT)
64 * u64le channel_layout
65 * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE)
67 * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS)
72 AV_PKT_DATA_PARAM_CHANGE,
75 * An AV_PKT_DATA_H263_MB_INFO side data packet contains a number of
76 * structures with info about macroblocks relevant to splitting the
77 * packet into smaller packets on macroblock edges (e.g. as for RFC 2190).
78 * That is, it does not necessarily contain info about all macroblocks,
79 * as long as the distance between macroblocks in the info is smaller
80 * than the target payload size.
81 * Each MB info structure is 12 bytes, and is laid out as follows:
83 * u32le bit offset from the start of the packet
84 * u8 current quantizer at the start of the macroblock
86 * u16le macroblock address within the GOB
87 * u8 horizontal MV predictor
88 * u8 vertical MV predictor
89 * u8 horizontal MV predictor for block number 3
90 * u8 vertical MV predictor for block number 3
93 AV_PKT_DATA_H263_MB_INFO,
96 * This side data should be associated with an audio stream and contains
97 * ReplayGain information in form of the AVReplayGain struct.
99 AV_PKT_DATA_REPLAYGAIN,
102 * This side data contains a 3x3 transformation matrix describing an affine
103 * transformation that needs to be applied to the decoded video frames for
104 * correct presentation.
106 * See libavutil/display.h for a detailed description of the data.
108 AV_PKT_DATA_DISPLAYMATRIX,
111 * This side data should be associated with a video stream and contains
112 * Stereoscopic 3D information in form of the AVStereo3D struct.
114 AV_PKT_DATA_STEREO3D,
117 * This side data should be associated with an audio stream and corresponds
118 * to enum AVAudioServiceType.
120 AV_PKT_DATA_AUDIO_SERVICE_TYPE,
123 * This side data contains quality related information from the encoder.
125 * u32le quality factor of the compressed frame. Allowed range is between 1 (good) and FF_LAMBDA_MAX (bad).
129 * u64le[error count] sum of squared differences between encoder in and output
132 AV_PKT_DATA_QUALITY_STATS,
135 * This side data contains an integer value representing the stream index
136 * of a "fallback" track. A fallback track indicates an alternate
137 * track to use when the current track can not be decoded for some reason.
138 * e.g. no decoder available for codec.
140 AV_PKT_DATA_FALLBACK_TRACK,
143 * This side data corresponds to the AVCPBProperties struct.
145 AV_PKT_DATA_CPB_PROPERTIES,
148 * Recommmends skipping the specified number of samples
150 * u32le number of samples to skip from start of this packet
151 * u32le number of samples to skip from end of this packet
152 * u8 reason for start skip
153 * u8 reason for end skip (0=padding silence, 1=convergence)
156 AV_PKT_DATA_SKIP_SAMPLES,
159 * An AV_PKT_DATA_JP_DUALMONO side data packet indicates that
160 * the packet may contain "dual mono" audio specific to Japanese DTV
161 * and if it is true, recommends only the selected channel to be used.
163 * u8 selected channels (0=mail/left, 1=sub/right, 2=both)
166 AV_PKT_DATA_JP_DUALMONO,
169 * A list of zero terminated key/value strings. There is no end marker for
170 * the list, so it is required to rely on the side data size to stop.
172 AV_PKT_DATA_STRINGS_METADATA,
175 * Subtitle event position
183 AV_PKT_DATA_SUBTITLE_POSITION,
186 * Data found in BlockAdditional element of matroska container. There is
187 * no end marker for the data, so it is required to rely on the side data
188 * size to recognize the end. 8 byte id (as found in BlockAddId) followed
191 AV_PKT_DATA_MATROSKA_BLOCKADDITIONAL,
194 * The optional first identifier line of a WebVTT cue.
196 AV_PKT_DATA_WEBVTT_IDENTIFIER,
199 * The optional settings (rendering instructions) that immediately
200 * follow the timestamp specifier of a WebVTT cue.
202 AV_PKT_DATA_WEBVTT_SETTINGS,
205 * A list of zero terminated key/value strings. There is no end marker for
206 * the list, so it is required to rely on the side data size to stop. This
207 * side data includes updated metadata which appeared in the stream.
209 AV_PKT_DATA_METADATA_UPDATE,
212 * MPEGTS stream ID as uint8_t, this is required to pass the stream ID
213 * information from the demuxer to the corresponding muxer.
215 AV_PKT_DATA_MPEGTS_STREAM_ID,
218 * Mastering display metadata (based on SMPTE-2086:2014). This metadata
219 * should be associated with a video stream and contains data in the form
220 * of the AVMasteringDisplayMetadata struct.
222 AV_PKT_DATA_MASTERING_DISPLAY_METADATA,
225 * This side data should be associated with a video stream and corresponds
226 * to the AVSphericalMapping structure.
228 AV_PKT_DATA_SPHERICAL,
231 * Content light level (based on CTA-861.3). This metadata should be
232 * associated with a video stream and contains data in the form of the
233 * AVContentLightMetadata struct.
235 AV_PKT_DATA_CONTENT_LIGHT_LEVEL,
238 * ATSC A53 Part 4 Closed Captions. This metadata should be associated with
239 * a video stream. A53 CC bitstream is stored as uint8_t in AVPacketSideData.data.
240 * The number of bytes of CC data is AVPacketSideData.size.
245 * This side data is encryption initialization data.
246 * The format is not part of ABI, use av_encryption_init_info_* methods to
249 AV_PKT_DATA_ENCRYPTION_INIT_INFO,
252 * This side data contains encryption info for how to decrypt the packet.
253 * The format is not part of ABI, use av_encryption_info_* methods to access.
255 AV_PKT_DATA_ENCRYPTION_INFO,
258 * Active Format Description data consisting of a single byte as specified
259 * in ETSI TS 101 154 using AVActiveFormatDescription enum.
264 * Producer Reference Time data corresponding to the AVProducerReferenceTime struct,
265 * usually exported by some encoders (on demand through the prft flag set in the
266 * AVCodecContext export_side_data field).
271 * ICC profile data consisting of an opaque octet buffer following the
272 * format described by ISO 15076-1.
274 AV_PKT_DATA_ICC_PROFILE,
279 * dolby-vision-bitstreams-within-the-iso-base-media-file-format-v2.1.2, section 2.2
280 * dolby-vision-bitstreams-in-mpeg-2-transport-stream-multiplex-v1.2, section 3.3
281 * Tags are stored in struct AVDOVIDecoderConfigurationRecord.
283 AV_PKT_DATA_DOVI_CONF,
286 * The number of side data types.
287 * This is not part of the public API/ABI in the sense that it may
288 * change when new side data types are added.
289 * This must stay the last enum value.
290 * If its value becomes huge, some code using it
291 * needs to be updated as it assumes it to be smaller than other limits.
296 #define AV_PKT_DATA_QUALITY_FACTOR AV_PKT_DATA_QUALITY_STATS //DEPRECATED
298 typedef struct AVPacketSideData {
301 enum AVPacketSideDataType type;
305 * This structure stores compressed data. It is typically exported by demuxers
306 * and then passed as input to decoders, or received as output from encoders and
307 * then passed to muxers.
309 * For video, it should typically contain one compressed frame. For audio it may
310 * contain several compressed frames. Encoders are allowed to output empty
311 * packets, with no compressed data, containing only side data
312 * (e.g. to update some stream parameters at the end of encoding).
314 * AVPacket is one of the few structs in FFmpeg, whose size is a part of public
315 * ABI. Thus it may be allocated on stack and no new fields can be added to it
316 * without libavcodec and libavformat major bump.
318 * The semantics of data ownership depends on the buf field.
319 * If it is set, the packet data is dynamically allocated and is
320 * valid indefinitely until a call to av_packet_unref() reduces the
321 * reference count to 0.
323 * If the buf field is not set av_packet_ref() would make a copy instead
324 * of increasing the reference count.
326 * The side data is always allocated with av_malloc(), copied by
327 * av_packet_ref() and freed by av_packet_unref().
330 * @see av_packet_unref
332 typedef struct AVPacket {
334 * A reference to the reference-counted buffer where the packet data is
336 * May be NULL, then the packet data is not reference-counted.
340 * Presentation timestamp in AVStream->time_base units; the time at which
341 * the decompressed packet will be presented to the user.
342 * Can be AV_NOPTS_VALUE if it is not stored in the file.
343 * pts MUST be larger or equal to dts as presentation cannot happen before
344 * decompression, unless one wants to view hex dumps. Some formats misuse
345 * the terms dts and pts/cts to mean something different. Such timestamps
346 * must be converted to true pts/dts before they are stored in AVPacket.
350 * Decompression timestamp in AVStream->time_base units; the time at which
351 * the packet is decompressed.
352 * Can be AV_NOPTS_VALUE if it is not stored in the file.
359 * A combination of AV_PKT_FLAG values
363 * Additional packet data that can be provided by the container.
364 * Packet can contain several types of side information.
366 AVPacketSideData *side_data;
370 * Duration of this packet in AVStream->time_base units, 0 if unknown.
371 * Equals next_pts - this_pts in presentation order.
375 int64_t pos; ///< byte position in stream, -1 if unknown
377 #if FF_API_CONVERGENCE_DURATION
379 * @deprecated Same as the duration field, but as int64_t. This was required
380 * for Matroska subtitles, whose duration values could overflow when the
381 * duration field was still an int.
384 int64_t convergence_duration;
388 #define AV_PKT_FLAG_KEY 0x0001 ///< The packet contains a keyframe
389 #define AV_PKT_FLAG_CORRUPT 0x0002 ///< The packet content is corrupted
391 * Flag is used to discard packets which are required to maintain valid
392 * decoder state but are not required for output and should be dropped
395 #define AV_PKT_FLAG_DISCARD 0x0004
397 * The packet comes from a trusted source.
399 * Otherwise-unsafe constructs such as arbitrary pointers to data
400 * outside the packet may be followed.
402 #define AV_PKT_FLAG_TRUSTED 0x0008
404 * Flag is used to indicate packets that contain frames that can
405 * be discarded by the decoder. I.e. Non-reference frames.
407 #define AV_PKT_FLAG_DISPOSABLE 0x0010
409 enum AVSideDataParamChangeFlags {
410 AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT = 0x0001,
411 AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT = 0x0002,
412 AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE = 0x0004,
413 AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS = 0x0008,
417 * Allocate an AVPacket and set its fields to default values. The resulting
418 * struct must be freed using av_packet_free().
420 * @return An AVPacket filled with default values or NULL on failure.
422 * @note this only allocates the AVPacket itself, not the data buffers. Those
423 * must be allocated through other means such as av_new_packet.
427 AVPacket *av_packet_alloc(void);
430 * Create a new packet that references the same data as src.
432 * This is a shortcut for av_packet_alloc()+av_packet_ref().
434 * @return newly created AVPacket on success, NULL on error.
436 * @see av_packet_alloc
439 AVPacket *av_packet_clone(const AVPacket *src);
442 * Free the packet, if the packet is reference counted, it will be
443 * unreferenced first.
445 * @param pkt packet to be freed. The pointer will be set to NULL.
446 * @note passing NULL is a no-op.
448 void av_packet_free(AVPacket **pkt);
451 * Initialize optional fields of a packet with default values.
453 * Note, this does not touch the data and size members, which have to be
454 * initialized separately.
458 void av_init_packet(AVPacket *pkt);
461 * Allocate the payload of a packet and initialize its fields with
465 * @param size wanted payload size
466 * @return 0 if OK, AVERROR_xxx otherwise
468 int av_new_packet(AVPacket *pkt, int size);
471 * Reduce packet size, correctly zeroing padding
474 * @param size new size
476 void av_shrink_packet(AVPacket *pkt, int size);
479 * Increase packet size, correctly zeroing padding
482 * @param grow_by number of bytes by which to increase the size of the packet
484 int av_grow_packet(AVPacket *pkt, int grow_by);
487 * Initialize a reference-counted packet from av_malloc()ed data.
489 * @param pkt packet to be initialized. This function will set the data, size,
490 * and buf fields, all others are left untouched.
491 * @param data Data allocated by av_malloc() to be used as packet data. If this
492 * function returns successfully, the data is owned by the underlying AVBuffer.
493 * The caller may not access the data through other means.
494 * @param size size of data in bytes, without the padding. I.e. the full buffer
495 * size is assumed to be size + AV_INPUT_BUFFER_PADDING_SIZE.
497 * @return 0 on success, a negative AVERROR on error
499 int av_packet_from_data(AVPacket *pkt, uint8_t *data, int size);
501 #if FF_API_AVPACKET_OLD_API
503 * @warning This is a hack - the packet memory allocation stuff is broken. The
504 * packet is allocated if it was not really allocated.
506 * @deprecated Use av_packet_ref or av_packet_make_refcounted
509 int av_dup_packet(AVPacket *pkt);
511 * Copy packet, including contents
513 * @return 0 on success, negative AVERROR on fail
515 * @deprecated Use av_packet_ref
518 int av_copy_packet(AVPacket *dst, const AVPacket *src);
521 * Copy packet side data
523 * @return 0 on success, negative AVERROR on fail
525 * @deprecated Use av_packet_copy_props
528 int av_copy_packet_side_data(AVPacket *dst, const AVPacket *src);
533 * @deprecated Use av_packet_unref
535 * @param pkt packet to free
538 void av_free_packet(AVPacket *pkt);
541 * Allocate new information of a packet.
544 * @param type side information type
545 * @param size side information size
546 * @return pointer to fresh allocated data or NULL otherwise
548 uint8_t* av_packet_new_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
552 * Wrap an existing array as a packet side data.
555 * @param type side information type
556 * @param data the side data array. It must be allocated with the av_malloc()
557 * family of functions. The ownership of the data is transferred to
559 * @param size side information size
560 * @return a non-negative number on success, a negative AVERROR code on
561 * failure. On failure, the packet is unchanged and the data remains
562 * owned by the caller.
564 int av_packet_add_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
565 uint8_t *data, size_t size);
568 * Shrink the already allocated side data buffer
571 * @param type side information type
572 * @param size new side information size
573 * @return 0 on success, < 0 on failure
575 int av_packet_shrink_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
579 * Get side information from packet.
582 * @param type desired side information type
583 * @param size If supplied, *size will be set to the size of the side data
584 * or to zero if the desired side data is not present.
585 * @return pointer to data if present or NULL otherwise
587 uint8_t* av_packet_get_side_data(const AVPacket *pkt, enum AVPacketSideDataType type,
590 #if FF_API_MERGE_SD_API
592 int av_packet_merge_side_data(AVPacket *pkt);
595 int av_packet_split_side_data(AVPacket *pkt);
598 const char *av_packet_side_data_name(enum AVPacketSideDataType type);
601 * Pack a dictionary for use in side_data.
603 * @param dict The dictionary to pack.
604 * @param size pointer to store the size of the returned data
605 * @return pointer to data if successful, NULL otherwise
607 uint8_t *av_packet_pack_dictionary(AVDictionary *dict, int *size);
609 * Unpack a dictionary from side_data.
611 * @param data data from side_data
612 * @param size size of the data
613 * @param dict the metadata storage dictionary
614 * @return 0 on success, < 0 on failure
616 int av_packet_unpack_dictionary(const uint8_t *data, int size, AVDictionary **dict);
620 * Convenience function to free all the side data stored.
621 * All the other fields stay untouched.
625 void av_packet_free_side_data(AVPacket *pkt);
628 * Setup a new reference to the data described by a given packet
630 * If src is reference-counted, setup dst as a new reference to the
631 * buffer in src. Otherwise allocate a new buffer in dst and copy the
632 * data from src into it.
634 * All the other fields are copied from src.
636 * @see av_packet_unref
638 * @param dst Destination packet. Will be completely overwritten.
639 * @param src Source packet
641 * @return 0 on success, a negative AVERROR on error. On error, dst
642 * will be blank (as if returned by av_packet_alloc()).
644 int av_packet_ref(AVPacket *dst, const AVPacket *src);
649 * Unreference the buffer referenced by the packet and reset the
650 * remaining packet fields to their default values.
652 * @param pkt The packet to be unreferenced.
654 void av_packet_unref(AVPacket *pkt);
657 * Move every field in src to dst and reset src.
659 * @see av_packet_unref
661 * @param src Source packet, will be reset
662 * @param dst Destination packet
664 void av_packet_move_ref(AVPacket *dst, AVPacket *src);
667 * Copy only "properties" fields from src to dst.
669 * Properties for the purpose of this function are all the fields
670 * beside those related to the packet data (buf, data, size)
672 * @param dst Destination packet
673 * @param src Source packet
675 * @return 0 on success AVERROR on failure.
677 int av_packet_copy_props(AVPacket *dst, const AVPacket *src);
680 * Ensure the data described by a given packet is reference counted.
682 * @note This function does not ensure that the reference will be writable.
683 * Use av_packet_make_writable instead for that purpose.
686 * @see av_packet_make_writable
688 * @param pkt packet whose data should be made reference counted.
690 * @return 0 on success, a negative AVERROR on error. On failure, the
691 * packet is unchanged.
693 int av_packet_make_refcounted(AVPacket *pkt);
696 * Create a writable reference for the data described by a given packet,
697 * avoiding data copy if possible.
699 * @param pkt Packet whose data should be made writable.
701 * @return 0 on success, a negative AVERROR on failure. On failure, the
702 * packet is unchanged.
704 int av_packet_make_writable(AVPacket *pkt);
707 * Convert valid timing fields (timestamps / durations) in a packet from one
708 * timebase to another. Timestamps with unknown values (AV_NOPTS_VALUE) will be
711 * @param pkt packet on which the conversion will be performed
712 * @param tb_src source timebase, in which the timing fields in pkt are
714 * @param tb_dst destination timebase, to which the timing fields will be
717 void av_packet_rescale_ts(AVPacket *pkt, AVRational tb_src, AVRational tb_dst);
723 #endif // AVCODEC_PACKET_H