mux.c File Reference

muxing functions for use within libavformat More...

#include "avformat.h"
#include "avio_internal.h"
#include "internal.h"
#include "libavcodec/internal.h"
#include "libavcodec/bytestream.h"
#include "libavutil/opt.h"
#include "libavutil/dict.h"
#include "libavutil/pixdesc.h"
#include "libavutil/timestamp.h"
#include "metadata.h"
#include "id3v2.h"
#include "libavutil/avassert.h"
#include "libavutil/avstring.h"
#include "libavutil/internal.h"
#include "libavutil/mathematics.h"
#include "libavutil/parseutils.h"
#include "libavutil/time.h"
#include "riff.h"
#include "audiointerleave.h"
#include "url.h"
#include <stdarg.h>

Macros
#define	AV_PKT_FLAG_UNCODED_FRAME   0x2000
#define	UNCODED_FRAME_PACKET_SIZE   (INT_MIN / 3 * 2 + (int)sizeof(AVFrame))
#define	CHUNK_START   0x1000

Functions
AVRational	ff_choose_timebase (AVFormatContext *s, AVStream *st, int min_precision)
	Chooses a timebase for muxing the specified stream. More...
enum AVChromaLocation	ff_choose_chroma_location (AVFormatContext *s, AVStream *st)
	Chooses a timebase for muxing the specified stream.
int	avformat_alloc_output_context2 (AVFormatContext **avctx, AVOutputFormat *oformat, const char *format, const char *filename)
	Allocate an AVFormatContext for an output format. More...
int	avformat_init_output (AVFormatContext *s, AVDictionary **options)
	Allocate the stream private data and initialize the codec, but do not write the header. More...
int	avformat_write_header (AVFormatContext *s, AVDictionary **options)
	Allocate the stream private data and write the stream header to an output media file. More...
int	av_write_frame (AVFormatContext *s, AVPacket *pkt)
	Write a packet to an output media file. More...
int	ff_interleave_add_packet (AVFormatContext *s, AVPacket *pkt, int(*compare)(AVFormatContext *, AVPacket *, AVPacket *))
	Add packet to AVFormatContext->packet_buffer list, determining its interleaved position using compare() function argument. More...
int	ff_interleave_packet_per_dts (AVFormatContext *s, AVPacket *out, AVPacket *pkt, int flush)
	Interleave a packet per dts in an output media file. More...
int	ff_interleaved_peek (AVFormatContext *s, int stream, AVPacket *pkt, int add_offset)
	Find the next packet in the interleaving queue for the given stream. More...
int	av_interleaved_write_frame (AVFormatContext *s, AVPacket *pkt)
	Write a packet to an output media file ensuring correct interleaving. More...
int	av_write_trailer (AVFormatContext *s)
	Write the stream trailer to an output media file and free the file private data. More...
int	av_get_output_timestamp (struct AVFormatContext *s, int stream, int64_t *dts, int64_t *wall)
	Get timing information for the data currently output. More...
int	ff_write_chained (AVFormatContext *dst, int dst_stream, AVPacket *pkt, AVFormatContext *src, int interleave)
	Write a packet to another muxer than the one the user originally intended. More...
int	av_write_uncoded_frame (AVFormatContext *s, int stream_index, AVFrame *frame)
	Write an uncoded frame to an output media file. More...
int	av_interleaved_write_uncoded_frame (AVFormatContext *s, int stream_index, AVFrame *frame)
	Write an uncoded frame to an output media file. More...
int	av_write_uncoded_frame_query (AVFormatContext *s, int stream_index)
	Test whether a muxer supports uncoded frame. More...

Detailed Description

muxing functions for use within libavformat

Function Documentation

avformat_alloc_output_context2()

int avformat_alloc_output_context2	(	AVFormatContext **	ctx,
		AVOutputFormat *	oformat,
		const char *	format_name,
		const char *	filename
	)

Allocate an AVFormatContext for an output format.

avformat_free_context() can be used to free the context and everything allocated by the framework within it.

Parameters

*ctx	is set to the created format context, or to NULL in case of failure
oformat	format to use for allocating the context, if NULL format_name and filename are used instead
format_name	the name of output format to use for allocating the context, if NULL filename is used instead
filename	the name of the filename to use for allocating the context, may be NULL

Returns

>= 0 in case of success, a negative AVERROR code in case of failure

ff_choose_timebase()

AVRational ff_choose_timebase	(	AVFormatContext *	s,
		AVStream *	st,
		int	min_precision
	)

Chooses a timebase for muxing the specified stream.

The chosen timebase allows sample accurate timestamps based on the framerate or sample rate for audio streams. It also is at least as precise as 1/min_precision would be.

ff_interleave_add_packet()

int ff_interleave_add_packet	(	AVFormatContext *	s,
		AVPacket *	pkt,
		int(*)(AVFormatContext *, AVPacket *, AVPacket *)	compare
	)

Add packet to AVFormatContext->packet_buffer list, determining its interleaved position using compare() function argument.

Returns

0, or < 0 on error

ff_interleave_packet_per_dts()

int ff_interleave_packet_per_dts	(	AVFormatContext *	s,
		AVPacket *	out,
		AVPacket *	pkt,
		int	flush
	)

Interleave a packet per dts in an output media file.

Packets with pkt->destruct == av_destruct_packet will be freed inside this function, so they cannot be used after it. Note that calling av_packet_unref() on them is still safe.

Parameters

s	media file handle
out	the interleaved packet will be output here
pkt	the input packet
flush	1 if no further packets are available as input and all remaining packets should be output

Returns

1 if a packet was output, 0 if no packet could be output, < 0 if an error occurred

ff_interleaved_peek()

int ff_interleaved_peek	(	AVFormatContext *	s,
		int	stream,
		AVPacket *	pkt,
		int	add_offset
	)

Find the next packet in the interleaving queue for the given stream.

The pkt parameter is filled in with the queued packet, including references to the data (which the caller is not allowed to keep or modify).

Returns

0 if a packet was found, a negative value if no packet was found

ff_write_chained()

int ff_write_chained	(	AVFormatContext *	dst,
		int	dst_stream,
		AVPacket *	pkt,
		AVFormatContext *	src,
		int	interleave
	)

Write a packet to another muxer than the one the user originally intended.

Useful when chaining muxers, where one muxer internally writes a received packet to another muxer.

Parameters

dst	the muxer to write the packet to
dst_stream	the stream index within dst to write the packet to
pkt	the packet to be written
src	the muxer the packet originally was intended for
interleave	0->use av_write_frame, 1->av_interleaved_write_frame

Returns

the value av_write_frame returned