Hi!

On Wed, May 02, 2001 at 12:51:31PM +0100, Chris wrote:
> I had a crazy thought today whilst improvising on my trumpet...
> 
> Is it possible to write a noatun plugin that is like a speed control for mp3? 
>  So I'm like imagining a dial like interface or slider that can adjust the 
> speed in realtime.  This would be useful for musicians in some respects.  
> 
> Does anything that can do this already exist?  Is the noatun plugin API 
> capable of handling something like this?

There are usually two ways of adjusting the speed. One is to simply play
the data faster than it was recorded. That costs not much CPU time, but
changes the pitch also. I think it's a thing that you would need to add
as optional interface (besides Arts::PlayObject), and that wouldn't be too
hard to do.

The other is to do real pitch shifting to correct this afterwards (or before)
so that you can only change the speed while keeping the pitch the same. There
is code for pitch shifting as aRts module already. But well, sane pitch
shifting is hard to implement so you'll probably hear artifacts due to the
effect.

But all in all, you should be able to implement both relatively easily, though
you probably won't be able to do it "just" by writing a plugin, it will need
extensions in the playobjects.

   Cu... Stefan
-- 
  -* Stefan Westerfeld, stefan@space.twc.de (PGP!), Hamburg/Germany
     KDE Developer, project infos at http://space.twc.de/~stefan/kde *-         
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