I'm using AVAudioPlayer from iOS SDK for playing short sounds on each click in tableView rows.
I have manually made @selector
on button in each row that fires up method playSound:(id)receiver {}
. From receiver I get sound url so I can play it up.
This method looks like that:
- (void)playSound:(id)sender {
[audioPlayer prepareToPlay];
UIButton *audioButton = (UIButton *)sender;
[audioButton setImage:[UIImage imageNamed:@"sound_preview.png"] forState:UIControlStateNormal];
NSString *soundUrl = [[listOfItems objectForKey:[NSString stringWithFormat:@"%i",currentPlayingIndex]] objectForKey:@"sound_url"];
//here I get mp3 file from http url via NSRequest in NSData
NSData *soundData = [sharedAppSettingsController getSoundUrl:defaultDictionaryID uri:soundUrl];
NSError *error;
audioPlayer = [[AVAudioPlayer alloc] initWithData:soundData error:&error];
audioPlayer.numberOfLoops = 0;
if (error) {
NSLog(@"Error: %@",[error description]);
}
else {
audioPlayer.delegate = self;
[audioPlayer play];
}
}
Everything works fine except for the first play of some sound. The application freezes for about 2 seconds and than sound is played. Second and every other sound play works just right after click on sound button.
I wonder why there is that about 2 seconds freeze on first play when application starts?
Best Answer
From your code snippet,
audioPlayer
must be an ivar, right?At the top of the method, you invoke
-prepareToPlay
on the existingaudioPlayer
instance (which could be nil, at least on the first pass).Later in the method, you replace this existing audio player with a brand new AVAudioPlayer instance. The previous
-prepareToPlay
is wasted. And you're leaking memory with each new AVAudioPlayer.Instead of caching sound data or URLs, I would try creating a cache of AVAudioPlayer objects, one for each sound. In your
-playSound:
method, get a reference to the appropriate audio player for the table row, and-play
.You can use
-tableView:cellForRowAtIndexPath:
as the appropriate point to get the AVAudioPlayer instance for that row, maybe lazily creating the instance and caching it there as well.You can try
-tableView:willDisplayCell:forRowAtIndexPath:
as the point where you would invoke-prepareToPlay
on the row's AVAudioPlayer instance.Or you could just do the prepare in
-tableView:cellForRowAtIndexPath:
. Experiment and see which works best.