Downsampling for saving CPU

[Iainmf]

Actually, now that I think about it, it might be possible depending on the layout of your compressor. You could do calculate gain reduction every 'x' samples, as long as you are calculating before the envelope follower and your envelope follower is running at the sample rate. The envelope follower will smooth out the steps. Although the attack and release times will have to be long enough to smooth the steps.

[Iainmf]

Here is a band-limited hard limiter with the gain reduction calculated every 16 samples.