juce::LagrangeInterpolator Class Reference

Interpolator for resampling a stream of floats using 4-point lagrange interpolation. More...

#include <juce_LagrangeInterpolator.h>

Collaboration diagram for juce::LagrangeInterpolator:

Public Member Functions
	LagrangeInterpolator () noexcept
	~LagrangeInterpolator () noexcept
int	process (double speedRatio, const float *inputSamples, float *outputSamples, int numOutputSamplesToProduce) noexcept
	Resamples a stream of samples. More...
int	process (double speedRatio, const float *inputSamples, float *outputSamples, int numOutputSamplesToProduce, int available, int wrapAround) noexcept
	Resamples a stream of samples. More...
int	processAdding (double speedRatio, const float *inputSamples, float *outputSamples, int numOutputSamplesToProduce, float gain) noexcept
	Resamples a stream of samples, adding the results to the output data with a gain. More...
int	processAdding (double speedRatio, const float *inputSamples, float *outputSamples, int numOutputSamplesToProduce, int available, int wrapAround, float gain) noexcept
	Resamples a stream of samples, adding the results to the output data with a gain. More...
void	reset () noexcept
	Resets the state of the interpolator. More...

Private Attributes
float	lastInputSamples [5]
double	subSamplePos

Detailed Description

Interpolator for resampling a stream of floats using 4-point lagrange interpolation.

Note that the resampler is stateful, so when there's a break in the continuity of the input stream you're feeding it, you should call reset() before feeding it any new data. And like with any other stateful filter, if you're resampling multiple channels, make sure each one uses its own LagrangeInterpolator object.

See also

CatmullRomInterpolator

{Audio}

Constructor & Destructor Documentation

LagrangeInterpolator()

juce::LagrangeInterpolator::LagrangeInterpolator ( )

noexcept

~LagrangeInterpolator()

juce::LagrangeInterpolator::~LagrangeInterpolator ( )

noexcept

Member Function Documentation

process() [1/2]

int juce::LagrangeInterpolator::process ( double  speedRatio, const float *  inputSamples, float *  outputSamples, int  numOutputSamplesToProduce  )

noexcept

Resamples a stream of samples.

Parameters

speedRatio	the number of input samples to use for each output sample
inputSamples	the source data to read from. This must contain at least (speedRatio * numOutputSamplesToProduce) samples.
outputSamples	the buffer to write the results into
numOutputSamplesToProduce	the number of output samples that should be created

Returns

the actual number of input samples that were used

process() [2/2]

int juce::LagrangeInterpolator::process ( double  speedRatio, const float *  inputSamples, float *  outputSamples, int  numOutputSamplesToProduce, int  available, int  wrapAround  )

noexcept

Resamples a stream of samples.

Parameters

speedRatio	the number of input samples to use for each output sample
inputSamples	the source data to read from. This must contain at least (speedRatio * numOutputSamplesToProduce) samples.
outputSamples	the buffer to write the results into
numOutputSamplesToProduce	the number of output samples that should be created
available	the number of available input samples. If it needs more samples than available, it either wraps back for wrapAround samples, or it feeds zeroes
wrapAround	if the stream exceeds available samples, it wraps back for wrapAround samples. If wrapAround is set to 0, it will feed zeroes.

Returns

the actual number of input samples that were used

processAdding() [1/2]

int juce::LagrangeInterpolator::processAdding ( double  speedRatio, const float *  inputSamples, float *  outputSamples, int  numOutputSamplesToProduce, float  gain  )

noexcept

Resamples a stream of samples, adding the results to the output data with a gain.

Parameters

speedRatio	the number of input samples to use for each output sample
inputSamples	the source data to read from. This must contain at least (speedRatio * numOutputSamplesToProduce) samples.
outputSamples	the buffer to write the results to - the result values will be added to any pre-existing data in this buffer after being multiplied by the gain factor
numOutputSamplesToProduce	the number of output samples that should be created
gain	a gain factor to multiply the resulting samples by before adding them to the destination buffer

Returns

the actual number of input samples that were used

processAdding() [2/2]

int juce::LagrangeInterpolator::processAdding ( double  speedRatio, const float *  inputSamples, float *  outputSamples, int  numOutputSamplesToProduce, int  available, int  wrapAround, float  gain  )

noexcept

Resamples a stream of samples, adding the results to the output data with a gain.

Parameters

speedRatio	the number of input samples to use for each output sample
inputSamples	the source data to read from. This must contain at least (speedRatio * numOutputSamplesToProduce) samples.
outputSamples	the buffer to write the results to - the result values will be added to any pre-existing data in this buffer after being multiplied by the gain factor
numOutputSamplesToProduce	the number of output samples that should be created
available	the number of available input samples. If it needs more samples than available, it either wraps back for wrapAround samples, or it feeds zeroes
wrapAround	if the stream exceeds available samples, it wraps back for wrapAround samples. If wrapAround is set to 0, it will feed zeroes.
gain	a gain factor to multiply the resulting samples by before adding them to the destination buffer

Returns

the actual number of input samples that were used

reset()

void juce::LagrangeInterpolator::reset ( )

noexcept

Resets the state of the interpolator.

Call this when there's a break in the continuity of the input data stream.

Member Data Documentation

lastInputSamples

float juce::LagrangeInterpolator::lastInputSamples[5]

private

subSamplePos

double juce::LagrangeInterpolator::subSamplePos

private

---

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

• juce_LagrangeInterpolator.h