[linux-audio-user] Time/pitch shifting software?

[Chris Cannam]

On Monday 18 Dec 2006 18:41, iain duncan wrote:
> Subjective opinions on which linux time/pitch shifting utility is the
> most usable for changing keys and tempo of music ( no voices )?

There are several LADSPA pitch shifters, some of which are of vaguely 
musical quality (the TAP one, Steve Harris's better one, probably Tim 
Goetze's PVOC Transposer although I don't seem to have that here at the 
moment).

I couldn't think of a Linux application for interactive musical pitch 
shifting -- guessing or being told the current key or pitch and 
adjusting to a different key, rather than just twiddling a multiplier 
in a LADSPA window.  Atte's suggestion of Transcribe looks good.

For time stretching and studying a recording, Sonic Visualiser (mine) is 
handy.  The current Subversion trunk, which is fairly stable and will 
turn into a new release soon, has a much better time stretcher than the 
0.9 release (which can only slow things down and only in big steps).  
It's a bit of a pain to build from Subversion, but it does work on 
Windows and OS/X as well.

Rosegarden can also now do drag-to-fit time stretching using the same 
code as SV.  Again the feature's in Subversion only -- release soon.  
Ardour has done the same thing for ages.  I like Rosegarden's time 
stretcher (a phase vocoder with phase locking at transients) better 
than that in Ardour (or Transcribe), but it's much slower.  Time 
stretcher quality is very subjective though and I don't believe any of 
these is really state of the art.

None of the above can guess the tempo and shift it to a different 
specified tempo.  Freecycle might be able to do that, though I don't 
think it's really designed for it.


Chris