Audio::FMultichannelLinearResampler Class Reference

#include <MultichannelLinearResampler.h>

Public Member Functions
SIGNALPROCESSING_API	FMultichannelLinearResampler (int32 InNumChannels)
SIGNALPROCESSING_API void	SetFrameRatio (float InRatio, int32 InNumFramesToInterpolate=0)
SIGNALPROCESSING_API float	MapInputFrameToOutputFrame (float InInputFrameIndex) const
SIGNALPROCESSING_API float	MapOutputFrameToInputFrame (float InOutputFrameIndex) const
SIGNALPROCESSING_API int32	GetNumInputFramesNeededToProduceOutputFrames (int32 InNumOutputFrames) const
SIGNALPROCESSING_API int32	ProcessAndConsumeAudio (FMultichannelCircularBuffer &InAudio, FMultichannelBuffer &OutAudio)
SIGNALPROCESSING_API int32	ProcessAndConsumeAudio (FMultichannelCircularBuffer &InAudio, FMultichannelBufferView &OutAudio)

Static Public Attributes
static SIGNALPROCESSING_API const float	MaxFrameRatio = 100.f
static SIGNALPROCESSING_API const float	MinFrameRatio = 0.001f

Detailed Description

Linear resampler working on multichannel buffers

Constructor & Destructor Documentation

FMultichannelLinearResampler()

Audio::FMultichannelLinearResampler::FMultichannelLinearResampler

(

int32

InNumChannels

)

Construct a linear resampler.

Parameters

InNumChannel

- Number of audio channels in input and output buffers.

Member Function Documentation

GetNumInputFramesNeededToProduceOutputFrames()

int32 Audio::FMultichannelLinearResampler::GetNumInputFramesNeededToProduceOutputFrames

(

int32

InNumOutputFrames

)

const

Returns the minimum number of input frames needed to produce the desired number of output frames given the current state of the resampler.

Parameters

InNumOutputFrames

- The desired number of output frames.

Returns

The minimum number of input frames.

MapInputFrameToOutputFrame()

float Audio::FMultichannelLinearResampler::MapInputFrameToOutputFrame

(

float

InInputFrameIndex

)

const

Translates an input frame index to an output frame index given the state of the resampler.

Note: Indices are relative to the buffers passed to ProcessAudio(...). The resampler does not maintain a sample counter between calls to ProcessAudio(...).

Parameters

InInputFrameIndex

- Index of input frame.

Returns

Index of output frame.

MapOutputFrameToInputFrame()

float Audio::FMultichannelLinearResampler::MapOutputFrameToInputFrame

(

float

InOutputFrameIndex

)

const

Translates an output frame index to an input frame index given the state of the resampler.

Note: Indices are relative to the buffers passed to ProcessAudio(...). The resampler does not maintain a sample counter between calls to ProcessAudio(...).

Parameters

InOutputFrameIndex

- Index of output frame.

Returns

Index of input frame.

ProcessAndConsumeAudio() [1/2]

int32 Audio::FMultichannelLinearResampler::ProcessAndConsumeAudio	(	FMultichannelCircularBuffer &	InAudio,
		FMultichannelBuffer &	OutAudio
	)

Consumes audio from the input buffer and produces audio in the output buffer. The desired number of frames to produce is determined by the output audio buffer size. For the desired number of samples to be produced, the input audio must have the minimum number of frames needed to produce the output frames (see GetNumInputFramesNeededToProduceOutputFrames(...)). Input samples which are no longer needed are removed from the input buffer.

Parameters

InAudio	- Multichannel circular buffer of input audio.
OutAudio	- Multichannel buffer of output audio.

Returns

Actual number of frames produced.

ProcessAndConsumeAudio() [2/2]

int32 Audio::FMultichannelLinearResampler::ProcessAndConsumeAudio	(	FMultichannelCircularBuffer &	InAudio,
		FMultichannelBufferView &	OutAudio
	)

SetFrameRatio()

void Audio::FMultichannelLinearResampler::SetFrameRatio	(	float	InRatio,
		int32	InNumFramesToInterpolate = 0
	)

Sets the number of input frames to read per an output frame. 0.5 is half speed, 1.f is normal speed, 2.0 is double speed.

Parameters

InRatio	- Ratio of input frames consumed per an output frame produced.
InNumFramesToInterpolate	- Number of output frames over which to interpolate the frame ratio.

Member Data Documentation

MaxFrameRatio

const float Audio::FMultichannelLinearResampler::MaxFrameRatio = 100.f

static

MinFrameRatio

const float Audio::FMultichannelLinearResampler::MinFrameRatio = 0.001f

static

---

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

• Engine/Source/Runtime/SignalProcessing/Public/DSP/MultichannelLinearResampler.h
• Engine/Source/Runtime/SignalProcessing/Private/MultichannelLinearResampler.cpp