Question

In my app I have 52 mp3 and when I load my view controller I alloc all 52 mp3 in this way:

NSString *pathFrase1 = [NSString stringWithFormat:@"%@/%@",[[NSBundle mainBundle] resourcePath],[NSString stringWithFormat:@"a%d_1a.mp3",set]];
NSURL *filePath1 = [NSURL fileURLWithPath:pathFrase1 isDirectory:NO];
f1 = [[AVAudioPlayer alloc] initWithContentsOfURL:filePath1 error:nil];
[f1 prepareToPlay];

but it’s very slow when I open viewcontroller, then is there a way to alloc mp3 when I use it? and release its AVAudioPlayer??

Answer 1

Sure, but there will be a delay as the AVAudioPlayer is allocated and prepared for playing. Can you predict what will play and when? If so, maybe you can load a couple of seconds before you need a particular mp3 to play.

An alternative, which may not work depending on your timing requirements, is the following:

- (void)prepareAudioPlayer {
    static int index = -1;
    index = index + 1;
    if (index < [[self FileNames] count]) {
        NSError *err = nil;
        NSString *audioFilePath = @""; // Figure out how to get each file name here
        NSURL *audioFileURL = [NSURL fileURLWithPath:audioFilePath];
        AVAudioPlayer *player = [[AVAudioPlayer alloc] initWithContentsOfURL:audioFileURL error:&err];
        if (err) {
            NSLog(@"Audio Player Error: %@", [err description]);
        }
        [player prepareToPlay];
        // Add this player to the "AudioPlayers" array
        [[self AudioPlayers] addObject:player];
        // Recurse until all players are loaded
        [self prepareAudioPlayer];
    }
}

This solution requires properties of FileNames and AudioPlayers.

Once this is set up, you could do something like the following (probably in viewDidLoad):

// Make the file name array 
[self setFileNames:[NSMutableArray array]];
// Initiate the audio player loading
[self performSelectorInBackground:@selector(prepareAudioPlayer) withObject:nil];

Later, when you need to play a particular file, you can find the index of the file name in the FileNames array and the call play on the AVAudioPlayer for that index in the AudioPlayers array.

This seems like maybe not the best way to do things, but it might work if you require it this way.