Bug 147494

Summary: [API+] Audio Pitch configuration
Product: [Frameworks and Libraries] Phonon Reporter: Bill Robert <bobbug>
Component: frontendAssignee: Matthias Kretz <kretz>
Status: CONFIRMED ---    
Severity: wishlist CC: jb, jonas.vejlin, znovotny
Priority: NOR    
Version: unspecified   
Target Milestone: ---   
Platform: Compiled Sources   
OS: Linux   
Latest Commit: Version Fixed In:
Sentry Crash Report:

Description Bill Robert 2007-07-03 14:18:38 UTC
Version:            (using KDE Devel)
Installed from:    Compiled sources

Some time ago I have suggested this feature for amarok: https://bugs.kde.org/show_bug.cgi?id=145354 but it was rejected because it should be implemented as effect plugin into phonon. So my wish is to add soundtouch integration into Phonon to allow users time-independent pitch adjustment (and the reverse). For example, it would then be possible to set a specific BPM-amount in Amarok, only songs belonging to an interval near the specified BPM-amount could be chosen and then every song could be stretched/shrinked to get the "correct" BPM.
Comment 1 Matthias Kretz 2007-07-04 13:32:14 UTC
I didn't know about the soundtouch library before, thanks for pointing me to it.

Do you think it's enough to have it as a generic effect (i.e. one only the user can select from a list of effects and then set the parameters) or do you see use cases for the effect to be integrated into the application itself?
Comment 2 Bill Robert 2007-07-04 18:01:34 UTC
In the short run, a generic effect would be enough. But in the long run the soundtouch integration could be used by a lot of applications:

Amarok (& Juk):
- To adjust the bpm to a specified value (personally, e. g. when I want to exercise dancing, I sometimes want to lower the bpm-rate; but it would also be a nice-to-have in the fade: That the new song starts with the old song's bpm (or rather: both end/begin in an average of both song's bpms) and slowly changes to the "real" bpm)
- Some songs are sung in a very fast way. If you want to sing it, it would be nice to lower the tempo too.
- Sometimes one simply feels a song would sound better if played slower or faster

Kaffeine (and any other KDE Media Player):
Nowadays if you lower the speed of a film, the sound just stops. With this effect plugin, the sound could continue in half or double the speed (I know this strongly affects the sound quality - but a bad sound is better than no one)

K3B:
Sometimes - even with truncing the songs - they don't fit onto one CD because it would need 30 secs more space. In this case, K3B could offer to speed up the songs a bit (would not be noticeable) to make them fit onto the CD. However, I think this could achieved even without phonon.

System sounds:
Sometimes there are two system sounds overlapping because they follow so near after each other. With this effect plugin, the sounds could just be played faster (should be configurable though)
Comment 3 Jonas Vejlin 2009-07-02 21:59:24 UTC
Is this still valid wish?
Comment 4 Zbynek Novotny 2013-01-04 09:16:25 UTC
Hi all,

I'm not sure if it's ok to post messages in such an old report but lately I've been thinking about creating some sort of effect plugin for Phonon that would utilize the SoundTouch library (basically an equivalent of the plugin called PaceMaker for Windows media player WinAMP). I've created some simple GUI a I'm about to start binding it to the ST library, but I'm not sure how to go about this since it's my first venture into Phonon/Qt. 

The Qt/Phonon documentation suggest to query the backend for available effects but I guess I'd need to create an entirely new effect and I'm not even sure something like that can be done. Maybe the SoundTouch integration should be done at the Phonon backend level.

If anyone reads this and has a suggestion or two, I'd be very much interested in hearing it.

Cheers, Zbynek