tinymodem::SampleRateConverter Class Reference

Converts the sample rate of a signal with a windowed sinc low pass filter (by default the cut off is at 45% of the lower sample rate). More...

#include <DSPUtils.h>

Public Member Functions
void	begin (float in_rate, float out_rate, float cutoff=0.45f)
void	reset ()
void	setRateFactor (double factor)
template<class F>
void	write (float x, F out)
	Adds an input sample and calls out(float) for each output sample.
template<class F>
void	writeComplex (float re, float im, F out)

Protected Member Functions
float	kernel (float u)
	kernel at the distance u (in samples of the lower rate)

Protected Attributes
float	table [TABLE+2]
audio_tools::Vector< float >	history
audio_tools::Vector< float >	history_q
double	ratio = 1
double	base_ratio = 1
float	cutoff = 0.45f
bool	bypass = true
float	half_width = HALF_WIDTH
float	kernel_scale = 1
int64_t	count = 0
double	next = 0

Static Protected Attributes
static constexpr int	HALF_WIDTH = 8
static constexpr int	TABLE = 512

Detailed Description

Converts the sample rate of a signal with a windowed sinc low pass filter (by default the cut off is at 45% of the lower sample rate).

Copyright

GPLv3

Member Function Documentation

begin()

void tinymodem::SampleRateConverter::begin ( float in_rate, float out_rate, float cutoff = 0.45f )

inline

Defines the input and output sample rate and the cut off relative to the lower sample rate

kernel()

float tinymodem::SampleRateConverter::kernel ( float u )

inlineprotected

kernel at the distance u (in samples of the lower rate)

reset()

void tinymodem::SampleRateConverter::reset ( )

inline

setRateFactor()

void tinymodem::SampleRateConverter::setRateFactor ( double factor )

inline

Changes the output rate by the indicated factor (e.g. 1.001), e.g. to follow a different clock of the sender

write()

template<class F>

void tinymodem::SampleRateConverter::write ( float x, F out )

inline

Adds an input sample and calls out(float) for each output sample.

writeComplex()

template<class F>

void tinymodem::SampleRateConverter::writeComplex ( float re, float im, F out )

inline

Adds a complex input sample (both parts use the same timing) and calls out(float re, float im) for each output sample

Member Data Documentation

base_ratio

double tinymodem::SampleRateConverter::base_ratio = 1

protected

bypass

bool tinymodem::SampleRateConverter::bypass = true

protected

count

int64_t tinymodem::SampleRateConverter::count = 0

protected

cutoff

float tinymodem::SampleRateConverter::cutoff = 0.45f

protected

HALF_WIDTH

int tinymodem::SampleRateConverter::HALF_WIDTH = 8

staticconstexprprotected

half_width

float tinymodem::SampleRateConverter::half_width = HALF_WIDTH

protected

history

audio_tools::Vector<float> tinymodem::SampleRateConverter::history

protected

history_q

audio_tools::Vector<float> tinymodem::SampleRateConverter::history_q

protected

kernel_scale

float tinymodem::SampleRateConverter::kernel_scale = 1

protected

next

double tinymodem::SampleRateConverter::next = 0

protected

ratio

double tinymodem::SampleRateConverter::ratio = 1

protected

TABLE

int tinymodem::SampleRateConverter::TABLE = 512

staticconstexprprotected

table

float tinymodem::SampleRateConverter::table[TABLE+2]

protected

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

• src/modem/DSPUtils.h