Time stretching audio

It may appear that time stretching audio is a matter of selecting a region of the audio tracks, enabling recording for the desired tracks, going to Audio Render Effect, and applying TimeStretch. In actuality there are 3 audio effects for time stretching: Time Stretch, Resample, and Asset info dialog.

Time Stretch applies a fast Fourier transform to try to change the duration without changing the pitch, but this introduces windowing artifacts to the audio. It is only useful for large changes in time because obvious changes in duration make windowing artifacts less obtrusive.

For smaller changes in duration, in the range of 5%, Resample should be used. This changes the pitch of the audio but small enough changes are not noticeable. Resample does not introduce any windowing artifacts, so this is most useful for slight duration changes where the listener is not supposed to know what is going on.

Another way to change duration slightly is to go to the Resources window, highlight the media folder, right click on an audio file, click on Info. Adjust the sample rate in the Info dialog to adjust the duration. This method also requires left clicking on the right boundary of the audio tracks and dragging left or right to correspond to the length changes.

The CINELERRA-GG Community, 2021