I'm trying to use the currentPlaybackRate property on MPMusicPlayerController to adjust the tempo of a music track as it plays. The property works as expected when the rate is less than 0.90 or greater than 1.13, but for the range just above and below 1, there seems to be no change in tempo. Here's what I'm trying:
UIAppDelegate.musicPlayer = [MPMusicPlayerController iPodMusicPlayer];
... load music player with track from library
[UIAppDelegate.musicPlayer play];
- (void)speedUp{
UIAppDelegate.musicPlayer.currentPlaybackRate = UIAppDelegate.musicPlayer.currentPlaybackRate + 0.03125;
}
- (void)speedDown
{
UIAppDelegate.musicPlayer.currentPlaybackRate = UIAppDelegate.musicPlayer.currentPlaybackRate - 0.03125;
}
I can monitor the value currentPlaybackRate and see that it's being correctly set, but there seems to be no different in playback tempo until the 0.9 or 1.13 threshold has been reached. Does anyone have any guidance or experience on the matter?