iPhone: Streaming music while application is in background - iphone

Question

I have an app that streams music using AudioStreamer class by Matt Gallagher. This works fine as a background process except I want to be able to skip to the next song once the stream is finished. Unfortunately this part doesn't work.
Initially I had a timer that was monitoring the stream but realized that when the app backgrounds this timer no longer runs. So I tried adding a delegate callback in the packet read function:
void ASReadStreamCallBack(CFReadStreamRef aStream, CFStreamEventType eventType, void* inClientInfo)
{
AudioStreamer* streamer = (AudioStreamer *)inClientInfo;
double percent = [streamer progress]/[streamer duration];
if(percent>=0.98 || (percent>=0.95 && [streamer isIdle])){
if([streamer.delegate respondsToSelector:#selector(didFinishPlayingStream:)] ){
[streamer.delegate didFinishPlayingStream:streamer];
streamer.delegate = nil;
}
}
[streamer handleReadFromStream:aStream eventType:eventType];
}
This works fine when the app is in the foreground but no longer works when the app is backgrounding. The delegate method basically sends a request to get the stream URL for the next song, then once it has it creates a new AudioStreamer class

Answer 1

While the app is in background you can implemente the delegate to handle the different remote control states.
- (void)remoteControlReceivedWithEvent:(UIEvent *)receivedEvent {
switch (receivedEvent.subtype) {
case UIEventSubtypeRemoteControlTogglePlayPause:
if (player.isPlaying) {
[player pause];
} else {
[player start];
}
break;
case UIEventSubtypeRemoteControlPreviousTrack:
break;
case UIEventSubtypeRemoteControlNextTrack:
[self skipSong:nil];
break;
default:
break;
} }
Something like this works for me.

Answer 2

I've uploaded my AudioPlayer/streamer class inspired in part by Matt Gallagher's AudioStreamer to
https://code.google.com/p/audjustable.
One of the cooler features is its support for gapless playback. This means the AudioQueue is never closed between gaps; keeping iOS from suspending your app.
You can implement AudioPlayerDelegate:didFinishBufferingSourceWithQueueItemId and AudioPlayerDelegate:didFinishPlayingQueueItemId to queue up the next track by calling AudioPlayer:queueDataSource.
Let me know if you need help using it.