Gargle Filter Sample
The Gargle Filter is an audio effect transform filter.
The Gargle filter modulates the waveform passing through it by multiplying the waveform by another waveform that is mathematically generated within the filter. The modulating waveform is, by default, a triangular wave. The property sheet also offers the alternative of a square wave. You can set the frequency of the modulating wave through the filter's property sheet. At low modulation frequencies, the effect sounds like a tremolo. At higher modulation frequencies, it sounds like a distortion, adding extra frequencies above and below the original unmodulated sound.
Downloading the Sample
To download the DirectShow SDK samples, install the latest version of the Windows SDK.
This sample is installed under the following path: [SDK Root]\Samples\Multimedia\DirectShow\Filters\Gargle.