This structure stores compressed data. More...

#include <libavcodec/packet.h>

Data Fields
AVBufferRef *	buf
	A reference to the reference-counted buffer where the packet data is stored. More...

int64_t	pts
	Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will be presented to the user. More...

int64_t	dts
	Decompression timestamp in AVStream->time_base units; the time at which the packet is decompressed. More...

uint8_t *	data

int	size

int	stream_index

int	flags
	A combination of AV_PKT_FLAG values. More...

AVPacketSideData *	side_data
	Additional packet data that can be provided by the container. More...

int	side_data_elems

int64_t	duration
	Duration of this packet in AVStream->time_base units, 0 if unknown. More...

int64_t	pos
	byte position in stream, -1 if unknown More...

void *	opaque
	for some private data of the user More...

AVBufferRef *	opaque_ref
	AVBufferRef for free use by the API user. More...

AVRational	time_base
	Time base of the packet's timestamps. More...

Detailed Description

This structure stores compressed data.

It is typically exported by demuxers and then passed as input to decoders, or received as output from encoders and then passed to muxers.

For video, it should typically contain one compressed frame. For audio it may contain several compressed frames. Encoders are allowed to output empty packets, with no compressed data, containing only side data (e.g. to update some stream parameters at the end of encoding).

The semantics of data ownership depends on the buf field. If it is set, the packet data is dynamically allocated and is valid indefinitely until a call to av_packet_unref() reduces the reference count to 0.

If the buf field is not set av_packet_ref() would make a copy instead of increasing the reference count.

The side data is always allocated with av_malloc(), copied by av_packet_ref() and freed by av_packet_unref().

sizeof(AVPacket) being a part of the public ABI is deprecated. once av_init_packet() is removed, new packets will only be able to be allocated with av_packet_alloc(), and new fields may be added to the end of the struct with a minor bump.

See also: av_packet_alloc; av_packet_ref; av_packet_unref

Examples: decode_audio.c, decode_video.c, demuxing_decoding.c, encode_audio.c, encode_video.c, filtering_audio.c, filtering_video.c, hw_decode.c, muxing.c, qsvdec.c, remuxing.c, transcode_aac.c, transcoding.c, vaapi_encode.c, and vaapi_transcode.c.

Definition at line 351 of file packet.h.

Field Documentation

◆ buf

AVBufferRef* AVPacket::buf

A reference to the reference-counted buffer where the packet data is stored.

May be NULL, then the packet data is not reference-counted.

Definition at line 357 of file packet.h.

◆ pts

int64_t AVPacket::pts

Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will be presented to the user.

Can be AV_NOPTS_VALUE if it is not stored in the file. pts MUST be larger or equal to dts as presentation cannot happen before decompression, unless one wants to view hex dumps. Some formats misuse the terms dts and pts/cts to mean something different. Such timestamps must be converted to true pts/dts before they are stored in AVPacket.

Examples: encode_video.c, muxing.c, and remuxing.c.

Definition at line 367 of file packet.h.

Referenced by encode(), and log_packet().

◆ dts

int64_t AVPacket::dts

Decompression timestamp in AVStream->time_base units; the time at which the packet is decompressed.

Can be AV_NOPTS_VALUE if it is not stored in the file.

Examples: muxing.c, and remuxing.c.

Definition at line 373 of file packet.h.

Referenced by log_packet().

◆ data

uint8_t* AVPacket::data

Examples: decode_audio.c, decode_video.c, encode_audio.c, encode_video.c, and vaapi_encode.c.

Definition at line 374 of file packet.h.

Referenced by encode(), encode_write(), and main().

◆ size

int AVPacket::size

Examples: decode_audio.c, decode_video.c, encode_audio.c, encode_video.c, and vaapi_encode.c.

Definition at line 375 of file packet.h.

Referenced by encode(), encode_write(), and main().

◆ stream_index

int AVPacket::stream_index

Examples: demuxing_decoding.c, filtering_audio.c, filtering_video.c, hw_decode.c, muxing.c, qsvdec.c, remuxing.c, transcoding.c, vaapi_encode.c, and vaapi_transcode.c.

Definition at line 376 of file packet.h.

Referenced by encode_write(), encode_write_frame(), log_packet(), main(), and write_frame().

◆ flags

int AVPacket::flags

A combination of AV_PKT_FLAG values.

Definition at line 380 of file packet.h.

◆ side_data

AVPacketSideData* AVPacket::side_data

Additional packet data that can be provided by the container.

Packet can contain several types of side information.

Definition at line 385 of file packet.h.

◆ side_data_elems

int AVPacket::side_data_elems

Definition at line 386 of file packet.h.

◆ duration

int64_t AVPacket::duration

Duration of this packet in AVStream->time_base units, 0 if unknown.

Equals next_pts - this_pts in presentation order.

Examples: muxing.c, and remuxing.c.

Definition at line 392 of file packet.h.

Referenced by log_packet().

◆ pos

int64_t AVPacket::pos

byte position in stream, -1 if unknown

Examples: remuxing.c.

Definition at line 394 of file packet.h.

Referenced by main().

◆ opaque

void* AVPacket::opaque

for some private data of the user

Definition at line 399 of file packet.h.

◆ opaque_ref

AVBufferRef* AVPacket::opaque_ref

AVBufferRef for free use by the API user.

FFmpeg will never check the contents of the buffer ref. FFmpeg calls av_buffer_unref() on it when the packet is unreferenced. av_packet_copy_props() calls create a new reference with av_buffer_ref() for the target packet's opaque_ref field.

This is unrelated to the opaque field, although it serves a similar purpose.

Definition at line 410 of file packet.h.

◆ time_base

AVRational AVPacket::time_base

Time base of the packet's timestamps.

In the future, this field may be set on packets output by encoders or demuxers, but its value will be by default ignored on input to decoders or muxers.

Definition at line 418 of file packet.h.

The documentation for this struct was generated from the following file:

libavcodec/packet.h

Data Fields