[sdlsound] alt_audio_convert

[Glenn Maynard]

On Wed, Mar 12, 2003 at 01:10:36AM +0100, Max Horn wrote:
> Actually even the rate 2 conversion is pretty bad. One might think that 
> just duplicating every sample is sufficient for a rate conversion from 
> 22khz to 44khz (or vice versa, leaving out every second sample) but 
> that's actually not true - you are introducing undesired new bands into 

I don't think anyone thinks this is really a good way to do it.  :)
It's just the easiest, since you don't need any lookahead.  Even a
simple linear filter (one frame of lookahead) would be a lot better (but
still pretty bad).

> the output data. The "proper" way is to add some filters afterwards.... 
> admittedly it's been far too long since i did anything on this topic so 
> please excuse the sloppy wording, but I hope the idea gets across. 
> There are some great "full" resamplers out there, but I am not sure how 
> etc

I believe the alt-convert stuff does all of this.  It's just not yet
fully functional.

-- 
Glenn Maynard