Subject: Re: [ecasound] making pitch shifter work realtime
From: Kai Vehmanen (k_AT_eca.cx)
Date: Thu Aug 21 2003 - 21:37:56 EEST
On Fri, 15 Aug 2003, janne halttunen wrote:
> been thinking about having a player-system with pitch shifting ability.
> currently it can't be done with ecasound, because the effect cannot
> handle realtime output audiodevices. ofcourse the pitch shifting could
How about using the LADSPA pitchshifters? They are FFT-based and are thus
real-time capable.
> so, the trouble is then to pass this information, if it's readily
> available, from the effect subsystem to the engine. nowdays ecasound
> uses libresample library for the pitch shifter. is there a function for
> querying needed amount of bytes in that? in ecaengine then the buffers
> need be atleast doubled or better quadrupled for insaneous speeds we're
> going to go with pitch shifter. few kilos of extra memory is nothing,
> right?
We'd need to continuously read at a faster/slower rate. The most difficult
problem however is that if multiple chains operate at different speeds,
chain mixing routines just can't handle it.
-- http://www.eca.cx Audio software for Linux!
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