Need to improve low pass filters used in upsampling and downsampling

Submitted by admin on Sun, 04/01/2018 - 20:54

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admin: First posted on 2016 03 30

mic, 2016 03 30: When a wave file is downsampled, a low pass filter must be applied to remove frequencies that are above the new Nyquist frequency for the new sampling rate (above half of the new sampling rate). When a wave is upsampled, a low pass filter must similarly be applied to make sure that no new frequencies are introduced above the original Nyquist frequency. Conversion should be rare. In principle, the user should almost never need to upsample or downsample. On case could be if the user is trying to import a wave into the session, but the wave has a different sampling rate than the session.

Either way, in the current version of Orinj, the low pass filters used when changing the sampling rates of waves need some fixes. These are minor and the result should be barely noticeable.

mic, 2016 03 31: This was fixed with Orinj version 2.5.3, which was uploaded on March 31, 2016.

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