Oversample the sample data from a DenseTimeValueModel by an integer factor, on the assumption that the model represents audio. More...

#include <WaveformOversampler.h>

Static Public Member Functions
static floatvec_t	getOversampledData (const DenseTimeValueModel &source, int channel, sv_frame_t sourceStartFrame, sv_frame_t sourceFrameCount, int oversampleBy)
	Return an oversampled version of the audio data from the given source sample range. More...

Static Private Member Functions
static floatvec_t	getFixedRatioData (const DenseTimeValueModel &source, int channel, sv_frame_t sourceStartFrame, sv_frame_t sourceFrameCount)

Static Private Attributes
static int	m_filterRatio = 8

static floatvec_t	m_filter
	Precalculated windowed sinc FIR filter for oversampling ratio of 8. More...

Detailed Description

Oversample the sample data from a DenseTimeValueModel by an integer factor, on the assumption that the model represents audio.

Oversampling is carried out using a windowed sinc filter for a fixed 8x ratio with further linear interpolation to handle other ratios. The aim is not to provide the "best-sounding" interpolation, but to provide accurate and predictable projections of the theoretical waveform shape for display rendering without leaving decisions about interpolation up to a resampler library.

Definition at line 31 of file WaveformOversampler.h.

Member Function Documentation

floatvec_t WaveformOversampler::getOversampledData	(	const DenseTimeValueModel &	source,
		int	channel,
		sv_frame_t	sourceStartFrame,
		sv_frame_t	sourceFrameCount,
		int	oversampleBy
	)

static

Return an oversampled version of the audio data from the given source sample range.

Will query sufficient source audio before and after the requested range (where available) to ensure an accurate-looking result after filtering. The returned vector will have sourceFrameCount * oversampleBy samples, except when truncated because the end of the model was reached.

Definition at line 22 of file WaveformOversampler.cpp.

References getFixedRatioData(), in_range_for(), and m_filterRatio.

floatvec_t WaveformOversampler::getFixedRatioData	(	const DenseTimeValueModel &	source,
		int	channel,
		sv_frame_t	sourceStartFrame,
		sv_frame_t	sourceFrameCount
	)