AVAudioPlayer fade volume out

Question

I have an AVAudioPlayer playing some audio (duh!)

The audio is initiated when the user presses a button. When they release it I want the audio to fade out.

I

Answer 1

In Objective-C try this:

NSURL *trackURL = [[NSURL alloc]initFileURLWithPath:@"path to audio track"];

// fade duration in seconds
NSTimeInterval fadeDuration = 0.3;

// duration of the audio track in seconds
NSTimeInterval audioTrackDuration = 5.0; 

AVAudioPlayer *audioPlayer = [[AVAudioPlayer alloc]  initWithContentsOfURL:trackURL error:nil];
[audioPlayer play];

// first we set the volume to 1 - highest
[audioPlayer setVolume:1.0]; 

// then to 0 - lowest
[musicAudioPlayer setVolume:0 fadeDuration:audioTrackDuration - fadeDuration];