[linux-audio-user] extreme time stretching

Erik de Castro Lopo erikd-lad at mega-nerd.com
Tue Mar 16 01:25:30 EST 2004


On Mon, 15 Mar 2004 23:09:22 -0500
Eric Dantan Rzewnicki <eric at zhevny.com> wrote:

<snip>

> If you compile 
> ecasound with SRC support the shift is limited to 12x in either 
> direction.

That was true for SRC up to and including 0.0.15. For version 0.1.0
released a couple of days ago, that has changed to +/- 256.

Also, be aware that this is not a pitch shift effect, because the
durartion is not constant. The effect is more accurately described
as a vari-speed effect.

> But, as Steve pointed out to me on #lad last week(?) you can 
> do multiple iterations to get greater shifts/stretches. Using SRC the 
> resulting sound is somehow smoother sounding than with the internal 
> ecasound version.

If the internal ecasound on is linear or polynomial interpolation,
then that would make a lot of sense.

Erik
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  Erik de Castro Lopo  nospam at mega-nerd.com (Yes it's valid)
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