Audacity

Interested in helping to compare various pitch and tempo
changing algorithms?  I've compared a three free ones
here, and I'd like some feedback:

   http://spaghetticode.org/pitchtempotest/

All three implementations are open-source (GPL or Wide-Open
License) so in theory we could integrate any of them into
Audacity.  I want to know which one people think sounds best.

Please let me know if you are aware of any other free
pitch/tempo shifters.  Also, if you happen to own any
non-free pitch/tempo shifters and want to add to the
experiment, it might be nice to see how these three
compare to shareware/commercial solutions.

- Dominic

[Audacity-devel] Re: [Audacity-users] Pitch and tempo shifters From: Mat Schaffer <schapht@dr...> - 2002-11-30 07:07 I'd say WSOLA wins for me. pitchscalehq seemed to change the tone of the input wave in all cases. But it almost had a good showing on the rock-tempo.wav, were it not for metal tank style reverb. I remeber that SonicFoundry's stuff usually does a pretty good job of this (SoundForge and Acid in particular). Don't know what kind of compression they use. I'll see if I can track down some samples of what these tests would yield from these programs. -Mat On Sat, 2002-11-30 at 01:01, Dominic Mazzoni wrote: > Interested in helping to compare various pitch and tempo > changing algorithms? I've compared a three free ones > here, and I'd like some feedback: > > http://spaghetticode.org/pitchtempotest/ > > All three implementations are open-source (GPL or Wide-Open > License) so in theory we could integrate any of them into > Audacity. I want to know which one people think sounds best. > > Please let me know if you are aware of any other free > pitch/tempo shifters. Also, if you happen to own any > non-free pitch/tempo shifters and want to add to the > experiment, it might be nice to see how these three > compare to shareware/commercial solutions. > > - Dominic > > > > ------------------------------------------------------- > This SF.net email is sponsored by: Get the new Palm Tungsten T > handheld. Power & Color in a compact size! > http://ads.sourceforge.net/cgi-bin/redirect.pl?palm0002en > _______________________________________________ > Audacity-users mailing list > Audacity-users@... > https://lists.sourceforge.net/lists/listinfo/audacity-users

Re: [Audacity-devel] Re: [Audacity-users] Pitch and tempo shifters From: Steve Jolly <steve@jo...> - 2002-11-30 08:37 And I seem to remember that recent versions of Cakewalk do a pretty good job too... I'll try and run those samples through it next time I've got my laptop in the vicinity of a fast internet connection :-) Steve Mat Schaffer wrote: > I'd say WSOLA wins for me. pitchscalehq seemed to change the tone of > the input wave in all cases. But it almost had a good showing on the > rock-tempo.wav, were it not for metal tank style reverb. > I remeber that SonicFoundry's stuff usually does a pretty good job of > this (SoundForge and Acid in particular). Don't know what kind of > compression they use. I'll see if I can track down some samples of what > these tests would yield from these programs. > -Mat > > On Sat, 2002-11-30 at 01:01, Dominic Mazzoni wrote: > >>Interested in helping to compare various pitch and tempo >>changing algorithms? I've compared a three free ones >>here, and I'd like some feedback: >> >> http://spaghetticode.org/pitchtempotest/ >> >>All three implementations are open-source (GPL or Wide-Open >>License) so in theory we could integrate any of them into >>Audacity. I want to know which one people think sounds best. >> >>Please let me know if you are aware of any other free >>pitch/tempo shifters. Also, if you happen to own any >>non-free pitch/tempo shifters and want to add to the >>experiment, it might be nice to see how these three >>compare to shareware/commercial solutions. >> >>- Dominic >> >> >> >>------------------------------------------------------- >>This SF.net email is sponsored by: Get the new Palm Tungsten T >>handheld. Power & Color in a compact size! >>http://ads.sourceforge.net/cgi-bin/redirect.pl?palm0002en >>_______________________________________________ >>Audacity-users mailing list >>Audacity-users@... >>https://lists.sourceforge.net/lists/listinfo/audacity-users > > > > > > ------------------------------------------------------- > This SF.net email is sponsored by: Get the new Palm Tungsten T > handheld. Power & Color in a compact size! > http://ads.sourceforge.net/cgi-bin/redirect.pl?palm0002en > _______________________________________________ > Audacity-devel mailing list > Audacity-devel@... > https://lists.sourceforge.net/lists/listinfo/audacity-devel

Re: [Audacity-devel] Pitch and tempo shifters From: Steve Harris <S.Harris@ec...> - 2002-11-30 12:55 On Fri, Nov 29, 2002 at 10:01:13 -0800, Dominic Mazzoni wrote: > Interested in helping to compare various pitch and tempo > changing algorithms? I've compared a three free ones > here, and I'd like some feedback: > > http://spaghetticode.org/pitchtempotest/ Just a quick note, PVOC implementations (like pitchscalehq) can be daramatically improved in sound quality (time smear - the anoying metalic sound) by increasing the window overlap. Unfortunatly this makes the cpu cost go up, so it isn't really practical for realtime, but (IIRC) its the method of choice for very high quality. I think WSOLA is a better performance/quality trandeoff though. It would pay you to also include some of the simple AM type pitch shifters, they are very simple and are better under some circumstances. - Steve

Re: [Audacity-devel] Pitch and tempo shifters From: Anthony Airon Oetzmann <Anthony.Oetzmann@ep...> - 2002-11-30 23:52 On Sat, 30 Nov 2002 12:54:05 +0000, Steve Harris wrote: >On Fri, Nov 29, 2002 at 10:01:13 -0800, Dominic Mazzoni wrote: >> Interested in helping to compare various pitch and tempo >> changing algorithms? I've compared a three free ones >> here, and I'd like some feedback: >> >> http://spaghetticode.org/pitchtempotest/ > >Just a quick note, PVOC implementations (like pitchscalehq) can be >daramatically improved in sound quality (time smear - the anoying metalic >sound) by increasing the window overlap. Unfortunatly this makes the cpu >cost go up, so it isn't really practical for realtime, but (IIRC) its the >method of choice for very high quality. > >I think WSOLA is a better performance/quality trandeoff though. It would >pay you to also include some of the simple AM type pitch shifters, they >are very simple and are better under some circumstances. Most tools come with a choice of algorythems anyway. VocAlign has five and Soundforge 19. Some fit better for speech, some don't. I have yet to download that gigantic pack. Is it Flac'ed ? Time to call a DSL buddy. Hmm. Tony

Re: [Audacity-devel] Pitch and tempo shifters From: Dominic Mazzoni <dominic@mi...> - 2002-12-01 02:33 Steve Harris wrote: > On Fri, Nov 29, 2002 at 10:01:13 -0800, Dominic Mazzoni wrote: >>Interested in helping to compare various pitch and tempo >>changing algorithms? I've compared a three free ones >>here, and I'd like some feedback: >> >> http://spaghetticode.org/pitchtempotest/ > > Just a quick note, PVOC implementations (like pitchscalehq) can be > daramatically improved in sound quality (time smear - the anoying metalic > sound) by increasing the window overlap. Unfortunatly this makes the cpu > cost go up, so it isn't really practical for realtime, but (IIRC) its the > method of choice for very high quality. I tried 16 and 32 for the overlap, and it still sounded tinny. The samples on the web page used 16. Do you think it would sound better if I upped it to 128? (It would take quite a while to process!) > I think WSOLA is a better performance/quality trandeoff though. It would > pay you to also include some of the simple AM type pitch shifters, they > are very simple and are better under some circumstances. AM = amplitude modulation? What do you mean by that? Any example source code? - Dominic

Re: [Audacity-devel] Pitch and tempo shifters From: Steve Harris <S.Harris@ec...> - 2002-12-01 10:59 On Sat, Nov 30, 2002 at 06:39:40 -0800, Dominic Mazzoni wrote: > Steve Harris wrote: > >On Fri, Nov 29, 2002 at 10:01:13 -0800, Dominic Mazzoni wrote: > >>Interested in helping to compare various pitch and tempo > >>changing algorithms? I've compared a three free ones > >>here, and I'd like some feedback: > >> > >> http://spaghetticode.org/pitchtempotest/ > > > >Just a quick note, PVOC implementations (like pitchscalehq) can be > >daramatically improved in sound quality (time smear - the anoying metalic > >sound) by increasing the window overlap. Unfortunatly this makes the cpu > >cost go up, so it isn't really practical for realtime, but (IIRC) its the > >method of choice for very high quality. > > I tried 16 and 32 for the overlap, and it still sounded tinny. The > samples on the web page used 16. Do you think it would sound better if > I upped it to 128? (It would take quite a while to process!) Well the ideal is onw window for each input sample, ie overlap=window size! Now you see you see why I said it was not practical for realtime ;) > >I think WSOLA is a better performance/quality trandeoff though. It would > >pay you to also include some of the simple AM type pitch shifters, they > >are very simple and are better under some circumstances. > > AM = amplitude modulation? What do you mean by that? Any example > source code? Amplitude modulation, yes. You have two buffers filled from the input signal, but out of phase with each other. Then you read from them at the right rate to get the output pitch, and crossfade between them such that as the read pointer crosses the write pointer the amplitude is 0.0 and when it is 180deg from the write pointer its 1.0. [I think thats right anyway, its based on my understnading of how tape based pitch shifters worked] I think its best to crossfade with a sin function. There are variations, but I dont know what they are. Its not a very high quality shift (it doesn't take care of formants or anything, and it drops/repeats bits of the input) but it is valid as an effect, and works well for certain unvoiced sounds. I've been meaning to do a plugin that implements this for ages, but never got round to it. If I have time I'l take a stab at it later today. - Steve

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