libavcodec/resample.c File Reference

samplerate conversion for both audio and video More...

#include "avcodec.h"
#include "audioconvert.h"
#include "libavutil/opt.h"
#include "libavutil/samplefmt.h"

Go to the source code of this file.

Data Structures
struct	ReSampleContext
Defines
#define	MAX_CHANNELS   8
Functions
static const char *	context_to_name (void *ptr)
static void	stereo_to_mono (short *output, short *input, int n1)
static void	mono_to_stereo (short *output, short *input, int n1)
static void	deinterleave (short **output, short *input, int channels, int samples)
static void	interleave (short *output, short **input, int channels, int samples)
static void	ac3_5p1_mux (short *output, short *input1, short *input2, int n)
ReSampleContext *	av_audio_resample_init (int output_channels, int input_channels, int output_rate, int input_rate, enum AVSampleFormat sample_fmt_out, enum AVSampleFormat sample_fmt_in, int filter_length, int log2_phase_count, int linear, double cutoff)
	Initialize audio resampling context.
int	audio_resample (ReSampleContext *s, short *output, short *input, int nb_samples)
void	audio_resample_close (ReSampleContext *s)
	Free resample context.
Variables
static const AVOption	options [] = {{NULL}}
static const AVClass	audioresample_context_class

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Detailed Description

samplerate conversion for both audio and video

Definition in file resample.c.

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Define Documentation

#define MAX_CHANNELS   8

Definition at line 32 of file resample.c.

Referenced by av_audio_resample_init().

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Function Documentation

static void ac3_5p1_mux	(	short *	output,
		short *	input1,
		short *	input2,
		int	n
	)			[static]

Definition at line 133 of file resample.c.

Referenced by audio_resample().

int audio_resample	(	ReSampleContext *	s,
		short *	output,
		short *	input,
		int	nb_samples
	)

Definition at line 228 of file resample.c.

Referenced by do_audio_out().

void audio_resample_close

(

ReSampleContext *

s

)

Free resample context.

Parameters:

s

a non-NULL pointer to a resample context previously created with av_audio_resample_init()

Definition at line 359 of file resample.c.

Referenced by do_audio_out(), and transcode().

ReSampleContext* av_audio_resample_init	(	int	output_channels,
		int	input_channels,
		int	output_rate,
		int	input_rate,
		enum AVSampleFormat	sample_fmt_out,
		enum AVSampleFormat	sample_fmt_in,
		int	filter_length,
		int	log2_phase_count,
		int	linear,
		double	cutoff
	)

Initialize audio resampling context.

Parameters:

	output_channels	number of output channels
	input_channels	number of input channels
	output_rate	output sample rate
	input_rate	input sample rate
	sample_fmt_out	requested output sample format
	sample_fmt_in	input sample format
	filter_length	length of each FIR filter in the filterbank relative to the cutoff frequency
	log2_phase_count	log2 of the number of entries in the polyphase filterbank
	linear	if 1 then the used FIR filter will be linearly interpolated between the 2 closest, if 0 the closest will be used
	cutoff	cutoff frequency, 1.0 corresponds to half the output sampling rate

Returns:

allocated ReSampleContext, NULL if error occurred

Definition at line 150 of file resample.c.

Referenced by do_audio_out().

static const char* context_to_name

(

void *

ptr

)

[static]

Definition at line 36 of file resample.c.

static void deinterleave	(	short **	output,
		short *	input,
		int	channels,
		int	samples
	)			[static]

Definition at line 111 of file resample.c.

Referenced by audio_resample().

static void interleave	(	short *	output,
		short **	input,
		int	channels,
		int	samples
	)			[static]

Definition at line 122 of file resample.c.

Referenced by audio_resample(), and ff_rtsp_make_setup_request().

static void mono_to_stereo	(	short *	output,
		short *	input,
		int	n1
	)			[static]

Definition at line 86 of file resample.c.

Referenced by audio_resample().

static void stereo_to_mono	(	short *	output,
		short *	input,
		int	n1
	)			[static]

Definition at line 61 of file resample.c.

Referenced by audio_resample().

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Variable Documentation

const AVClass audioresample_context_class [static]

Initial value:

 {
    "ReSampleContext", context_to_name, options, LIBAVUTIL_VERSION_INT
}

Definition at line 42 of file resample.c.

const AVOption options[] = {{NULL}} [static]

Definition at line 41 of file resample.c.