libavcodec/audioconvert.c File Reference

audio conversion More...

#include "libavutil/avstring.h"
#include "libavutil/libm.h"
#include "avcodec.h"
#include "audioconvert.h"

Go to the source code of this file.

Data Structures

struct SampleFmtInfo

struct AVAudioConvert

Defines

#define CONV(ofmt, otype, ifmt, expr)

Functions

const char * avcodec_get_sample_fmt_name (int sample_fmt)

enum SampleFormat avcodec_get_sample_fmt (const char *name)

void avcodec_sample_fmt_string (char *buf, int buf_size, int sample_fmt)

Generate string corresponding to the sample format with number sample_fmt, or a header if sample_fmt is negative.

static const char * get_channel_name (int channel_id)

int64_t avcodec_guess_channel_layout (int nb_channels, enum CodecID codec_id, const char *fmt_name)

Guess the channel layout.

void avcodec_get_channel_layout_string (char *buf, int buf_size, int nb_channels, int64_t channel_layout)

Return description of channel layout.

int avcodec_channel_layout_num_channels (int64_t channel_layout)

AVAudioConvert * av_audio_convert_alloc (enum SampleFormat out_fmt, int out_channels, enum SampleFormat in_fmt, int in_channels, const float *matrix, int flags)

Create an audio sample format converter context.

void av_audio_convert_free (AVAudioConvert *ctx)

Free audio sample format converter context.

int av_audio_convert (AVAudioConvert *ctx, void *const out[6], const int out_stride[6], const void *const in[6], const int in_stride[6], int len)

Convert between audio sample formats.

Variables

static const SampleFmtInfo sample_fmt_info [SAMPLE_FMT_NB]

this table gives more information about formats

static const char *const channel_names []

struct {

   const char *   name

   int   nb_channels

   int64_t   layout

} channel_layout_map []

Detailed Description

audio conversion

Author:: Michael Niedermayer <michaelni@gmx.at>

Definition in file audioconvert.c.

Define Documentation

#define CONV	(	ofmt,
		otype,
		ifmt,
		expr	)

Value:

if(ctx->fmt_pair == ofmt + SAMPLE_FMT_NB*ifmt){\
    do{\
        *(otype*)po = expr; pi += is; po += os;\
    }while(po < end);\
}

Referenced by av_audio_convert().

Function Documentation

int av_audio_convert	(	AVAudioConvert *	ctx,
		void *const	out[6],
		const int	out_stride[6],
		const void *const	in[6],
		const int	in_stride[6],
		int	len
	)

Convert between audio sample formats.

Parameters:

`[in]`	out	array of output buffers for each channel. set to NULL to ignore processing of the given channel.
`[in]`	out_stride	distance between consecutive output samples (measured in bytes)
`[in]`	in	array of input buffers for each channel
`[in]`	in_stride	distance between consecutive input samples (measured in bytes)
	len	length of audio frame size (measured in samples)

Definition at line 188 of file audioconvert.c.

Referenced by audio_decode_frame(), audio_resample(), and do_audio_out().

AVAudioConvert* av_audio_convert_alloc	(	enum SampleFormat	out_fmt,
		int	out_channels,
		enum SampleFormat	in_fmt,
		int	in_channels,
		const float *	matrix,
		int	flags
	)

Create an audio sample format converter context.

Parameters:

	out_fmt	Output sample format
	out_channels	Number of output channels
	in_fmt	Input sample format
	in_channels	Number of input channels
`[in]`	matrix	Channel mixing matrix (of dimension in_channel*out_channels). Set to NULL to ignore.
	flags	See FF_MM_xx

Returns:: NULL on error

Definition at line 167 of file audioconvert.c.

Referenced by audio_decode_frame(), av_audio_resample_init(), and do_audio_out().

void av_audio_convert_free ( AVAudioConvert * ctx )

Free audio sample format converter context.

Definition at line 183 of file audioconvert.c.

Referenced by audio_decode_frame(), audio_resample_close(), av_audio_resample_init(), do_audio_out(), and stream_component_close().

int avcodec_channel_layout_num_channels ( int64_t channel_layout )

Returns:: the number of channels in the channel layout.

Definition at line 153 of file audioconvert.c.

Referenced by new_audio_stream(), and set_channel_info().

void avcodec_get_channel_layout_string	(	char *	buf,
		int	buf_size,
		int	nb_channels,
		int64_t	channel_layout
	)

Return description of channel layout.

Definition at line 124 of file audioconvert.c.

Referenced by avcodec_string().

enum SampleFormat avcodec_get_sample_fmt ( const char * name )

Returns:: SAMPLE_FMT_NONE on error

Definition at line 54 of file audioconvert.c.

Referenced by opt_audio_sample_fmt().

const char* avcodec_get_sample_fmt_name ( int sample_fmt )

Returns:: NULL on error

Definition at line 47 of file audioconvert.c.

Referenced by audio_decode_frame(), av_audio_resample_init(), avcodec_string(), and do_audio_out().

int64_t avcodec_guess_channel_layout	(	int	nb_channels,
		enum CodecID	codec_id,
		const char *	fmt_name
	)

Guess the channel layout.

Parameters:

	nb_channels
	codec_id	Codec identifier, or CODEC_ID_NONE if unknown
	fmt_name	Format name, or NULL if unknown

Returns:: Channel layout mask

Definition at line 90 of file audioconvert.c.

Referenced by set_channel_info().

void avcodec_sample_fmt_string	(	char *	buf,
		int	buf_size,
		int	sample_fmt
	)

Generate string corresponding to the sample format with number sample_fmt, or a header if sample_fmt is negative.

Parameters:

`[in]`	buf	the buffer where to write the string
`[in]`	buf_size	the size of buf
`[in]`	sample_fmt	the number of the sample format to print the corresponding info string, or a negative value to print the corresponding header. Meaningful values for obtaining a sample format info vary from 0 to SAMPLE_FMT_NB -1.

Definition at line 64 of file audioconvert.c.

Referenced by opt_audio_sample_fmt().

static const char* get_channel_name ( int channel_id ) [static]

Definition at line 83 of file audioconvert.c.

Referenced by avcodec_get_channel_layout_string().

Variable Documentation

struct { ... } channel_layout_map[] [static]

Referenced by avcodec_get_channel_layout_string().

const char* const channel_names[] [static]

Initial value:

{
    "FL", "FR", "FC", "LFE", "BL",  "BR",  "FLC", "FRC",
    "BC", "SL", "SR", "TC",  "TFL", "TFC", "TFR", "TBL",
    "TBC", "TBR",
    [29] = "DL",
    [30] = "DR",
}

Definition at line 75 of file audioconvert.c.

Referenced by get_channel_name().

int64_t layout

Definition at line 107 of file audioconvert.c.

Referenced by avcodec_get_channel_layout_string().

const char* name

Definition at line 105 of file audioconvert.c.

Referenced by asf_read_header(), av_next_option(), avcodec_get_channel_layout_string(), avcodec_pix_fmt_string(), color_table_compare(), decode_info_header(), dump_format(), ff_metadata_mux_compat(), main(), matroska_convert_tag(), opt_loglevel(), parse_filter(), parse_inputs(), parse_link_name(), parse_outputs(), sdt_cb(), show_formats(), and sws_format_name().

int nb_channels

Definition at line 106 of file audioconvert.c.

const SampleFmtInfo sample_fmt_info[SAMPLE_FMT_NB] [static]

Initial value:

 {
    [SAMPLE_FMT_U8]  = { .name = "u8",  .bits = 8 },
    [SAMPLE_FMT_S16] = { .name = "s16", .bits = 16 },
    [SAMPLE_FMT_S32] = { .name = "s32", .bits = 32 },
    [SAMPLE_FMT_FLT] = { .name = "flt", .bits = 32 },
    [SAMPLE_FMT_DBL] = { .name = "dbl", .bits = 64 },
}

this table gives more information about formats

Definition at line 39 of file audioconvert.c.


Data Structures
struct	SampleFmtInfo
struct	AVAudioConvert
Defines
#define	CONV(ofmt, otype, ifmt, expr)
Functions
const char *	avcodec_get_sample_fmt_name (int sample_fmt)
enum SampleFormat	avcodec_get_sample_fmt (const char *name)
void	avcodec_sample_fmt_string (char *buf, int buf_size, int sample_fmt)
	Generate string corresponding to the sample format with number sample_fmt, or a header if sample_fmt is negative.
static const char *	get_channel_name (int channel_id)
int64_t	avcodec_guess_channel_layout (int nb_channels, enum CodecID codec_id, const char *fmt_name)
	Guess the channel layout.
void	avcodec_get_channel_layout_string (char *buf, int buf_size, int nb_channels, int64_t channel_layout)
	Return description of channel layout.
int	avcodec_channel_layout_num_channels (int64_t channel_layout)
AVAudioConvert *	av_audio_convert_alloc (enum SampleFormat out_fmt, int out_channels, enum SampleFormat in_fmt, int in_channels, const float *matrix, int flags)
	Create an audio sample format converter context.
void	av_audio_convert_free (AVAudioConvert *ctx)
	Free audio sample format converter context.
int	av_audio_convert (AVAudioConvert ctx, void const out[6], const int out_stride[6], const void *const in[6], const int in_stride[6], int len)
	Convert between audio sample formats.
Variables
static const SampleFmtInfo	sample_fmt_info [SAMPLE_FMT_NB]
	this table gives more information about formats
static const char *const	channel_names []
struct {
const char * name
int nb_channels
int64_t layout
}	channel_layout_map []