Playing audio file at different pitches. Phonon? Qt Multimedia?

[jvalverde]

No replies? Is that weird my question? Or doesn't it have any interest?
Juan

[SixDegrees]

Your question isn't clear. If you want to raise or lower pitch and are content to let the playback time drift, simply change the sampling rate. If you want to keep the playback time constant while changing pitch, that's a much harder trick to pull off and requires Fourier transforms or similar techniques.

Since you seem to have encountered this elsewhere, use that library. Qt is just C++, and can link with and use any existing C/C++ software toolkits.

[jvalverde]

Hi
Thank yo so much for your reply.
I would say that if I'm looking for an specific effect on Phonon or a way to change pitch in Qt Multimadia, it is clear that the old trick of changing the sample rate is not valid for me in this particular project, althought I could have said so in my first post specifically, so the question is more clear. So yes, maybe the question is not totally clear.
I didn't say that I have found any library or whatever elsewhere (quote: "Since you seem to have encountered this elsewhere, use that library"), I don't know where you find that info. In any case, I thank you again ofr your reply, and now it seems clera to me that there's no direct way to do what I need with either Phonon or Qt Multimedia. I'll have to look for this somewhere else.

Juan

[Tirkedi]

In gstreamer-backend on linux you got the speed effect "pitch" ;-)