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>

Go to the source code of this file.

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
static void	frac_init (FFFrac *f, int64_t val, int64_t num, int64_t den)
	f = val + (num / den) + 0.5. More...
static void	frac_add (FFFrac *f, int64_t incr)
	Fractional addition to f: f = f + (incr / f->den). More...
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. More...
int	avformat_alloc_output_context2 (AVFormatContext **avctx, AVOutputFormat *oformat, const char *format, const char *filename)
	Allocate an AVFormatContext for an output format. More...
static int	validate_codec_tag (AVFormatContext *s, AVStream *st)
static int	init_muxer (AVFormatContext *s, AVDictionary **options)
static int	init_pts (AVFormatContext *s)
static int	write_header_internal (AVFormatContext *s)
int	avformat_write_header (AVFormatContext *s, AVDictionary **options)
	Allocate the stream private data and write the stream header to an output media file. More...
static int	write_packet (AVFormatContext *s, AVPacket *pkt)
	Make timestamps non negative, move side data from payload to internal struct, call muxer, and restore sidedata. More...
static int	check_packet (AVFormatContext *s, AVPacket *pkt)
static int	prepare_input_packet (AVFormatContext *s, AVPacket *pkt)
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...
static int	interleave_compare_dts (AVFormatContext *s, AVPacket *next, AVPacket *pkt)
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...
const AVPacket *	ff_interleaved_peek (AVFormatContext *s, int stream, int64_t *ts_offset)
	Find the next packet in the interleaving queue for the given stream. More...
static int	interleave_packet (AVFormatContext *s, AVPacket *out, AVPacket *in, int flush)
	Interleave an AVPacket correctly so it can be muxed. 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...
static int	av_write_uncoded_frame_internal (AVFormatContext *s, int stream_index, AVFrame *frame, int interleaved)
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

Definition in file mux.c.

Macro Definition Documentation

#define AV_PKT_FLAG_UNCODED_FRAME   0x2000

Definition at line 528 of file mux.c.

Referenced by av_write_uncoded_frame_internal(), ff_interleave_add_packet(), and write_packet().

#define UNCODED_FRAME_PACKET_SIZE   (INT_MIN / 3 * 2 + (int)sizeof(AVFrame))

Definition at line 534 of file mux.c.

Referenced by av_write_uncoded_frame_internal(), ff_interleave_add_packet(), and write_packet().

#define CHUNK_START   0x1000

Definition at line 861 of file mux.c.

Referenced by ff_interleave_add_packet().

Function Documentation

static void frac_init ( FFFrac *  f, int64_t  val, int64_t  num, int64_t  den  )

static

f = val + (num / den) + 0.5.

'num' is normalized so that it is such as 0 <= num < den.

Parameters

f	fractional number
val	integer value
num	must be >= 0
den	must be >= 1

Definition at line 64 of file mux.c.

Referenced by init_pts().

static void frac_add ( FFFrac *  f, int64_t  incr  )

static

Fractional addition to f: f = f + (incr / f->den).

Parameters

f	fractional number
incr	increment, can be positive or negative

Definition at line 82 of file mux.c.

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.

Definition at line 102 of file mux.c.

Referenced by nut_write_header().

enum AVChromaLocation ff_choose_chroma_location	(	AVFormatContext *	s,
		AVStream *	st
	)

Chooses a timebase for muxing the specified stream.

Definition at line 118 of file mux.c.

Referenced by mxf_write_header().

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

Definition at line 148 of file mux.c.

Referenced by avdevice_list_output_sinks(), chunk_mux_init(), hls_mux_init(), main(), open_output_file(), open_slave(), segment_mux_init(), and write_packet().

static int validate_codec_tag ( AVFormatContext *  s, AVStream *  st  )

static

Check that tag + id is in the table If neither is in the table -> OK If tag is in the table with another id -> FAIL If id is in the table with another tag -> FAIL unless strict < normal

Definition at line 201 of file mux.c.

Referenced by init_muxer().

static int init_muxer ( AVFormatContext *  s, AVDictionary **  options  )

static

Definition at line 235 of file mux.c.

Referenced by avformat_write_header().

static int init_pts ( AVFormatContext *  s )

static

Definition at line 439 of file mux.c.

Referenced by avformat_write_header().

static int write_header_internal ( AVFormatContext *  s )

static

Definition at line 476 of file mux.c.

Referenced by av_write_frame(), av_write_trailer(), avformat_write_header(), and write_packet().

static int write_packet ( AVFormatContext *  s, AVPacket *  pkt  )

static

Make timestamps non negative, move side data from payload to internal struct, call muxer, and restore sidedata.

FIXME: this function should NEVER get undefined pts/dts beside when the AVFMT_NOTIMESTAMPS is set. Those additional safety checks should be dropped once the correct checks are set in the callers.

Definition at line 657 of file mux.c.

Referenced by av_interleaved_write_frame(), av_write_frame(), and av_write_trailer().

static int check_packet ( AVFormatContext *  s, AVPacket *  pkt  )

static

Definition at line 749 of file mux.c.

Referenced by prepare_input_packet().

static int prepare_input_packet ( AVFormatContext *  s, AVPacket *  pkt  )

static

Definition at line 768 of file mux.c.

Referenced by av_interleaved_write_frame(), and av_write_frame().

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

Definition at line 863 of file mux.c.

Referenced by ff_audio_rechunk_interleave(), and ff_interleave_packet_per_dts().

static int interleave_compare_dts ( AVFormatContext *  s, AVPacket *  next, AVPacket *  pkt  )

static

Definition at line 941 of file mux.c.

Referenced by 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

Definition at line 964 of file mux.c.

Referenced by gxf_interleave_packet(), and interleave_packet().

const AVPacket* ff_interleaved_peek	(	AVFormatContext *	s,
		int	stream,
		int64_t *	ts_offset
	)

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

The packet is not removed from the interleaving queue, but only a pointer to it is returned.

Parameters

ts_offset

the ts difference between packet in the que and the muxer.

Returns

a pointer to the next packet, or NULL if no packet is queued for this stream.

Definition at line 1044 of file mux.c.

Referenced by mov_flush_fragment().

static int interleave_packet ( AVFormatContext *  s, AVPacket *  out, AVPacket *  in, int  flush  )

static

Interleave an AVPacket correctly so it can be muxed.

Parameters

out	the interleaved packet will be output here
in	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

Definition at line 1072 of file mux.c.

Referenced by av_interleaved_write_frame(), and av_write_trailer().

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

Definition at line 1251 of file mux.c.

Referenced by dash_write_packet(), ff_mov_add_hinted_packet(), hds_write_packet(), hls_write_packet(), ism_write_packet(), rtsp_write_packet(), sap_write_packet(), and seg_write_packet().

static int av_write_uncoded_frame_internal ( AVFormatContext *  s, int  stream_index, AVFrame *  frame, int  interleaved  )

static

Definition at line 1280 of file mux.c.

Referenced by av_interleaved_write_uncoded_frame(), and av_write_uncoded_frame().