TBandlimitedInterpolator Class

Summary

Changes sampling frequency by a rational factor.

Hierarchy
TAnalysis <--TSignal <--TBandlimitedInterpolator

Subclasses
None

Description

The sampling frequency of the Input is changed by a rational factor by using bandlimited interpolation. An example is resampling of an audio signal with 48kHz to 44kHz. The interpolation quality can achieve SNR (signal to noise ratio) of up to 180dB in double precision. This component does not feature antialising filters. More about backgrounds of bandlimited interpolation can be found in [1].

Note: Data.Length may vary from iteration to iteration. If the input has integer number of samples and the rate is changed by a rational factor the output will have a rational number of samples (in general). For some pairs of input buffer length and resampling factors (least common nominator) the output will also have fixed length. If the frequency is changed from 8000Hz to 11025Hz, the input buffer must have a length which is a multiple of 320 and the output will be a multiple of 441. (8000/25 = 320, 11025/25 = 441)

See Also
[1] Bandlimited interpolation
TSignalRateConverter
TSignalInterpolator
TSignalDecimator

Properties

Name	Summary
AutoFilterLength
FilterLength
FilterStart
FilterStop
ImpulseFactor
ResampleFactor
Ripple
ScaleFactor

Methods

Name	Summary
PrepareFilter
Reset
SetFilterLength