Question

I am building a MP3 player for iOS that plays audio files hosted on the web. I want to offer the ability to play the files offline so I have the files downloading using ASIHTTP but I am cannot seem to find info on initiallzing AVPlayer with a mp3 in the app documents directory. Has anyone done this before? Is it even possible?

*I posted an answer below that shows how to use the iOS AvPlayer for both local and http files. Hope this helps!

Answer 1

I decided to answer my own question because I felt like there is very little documentation on how to use the Apple provided AVPlayer for both local and stream (over http) files. To help understand the solution, I put together a sample project on GitHub in Objective-C and Swift The code below is Objective-C but you can download my Swift example to see that. It is very similar!

What I found is that the two ways of setting up the files are almost identical except for how you instantiate your NSURL for the Asset > PlayerItem > AVPlayer chain.

Here is an outline of the core methods

.h file (partial code)

-(IBAction) BtnGoClick:(id)sender;
-(IBAction) BtnGoLocalClick:(id)sender;
-(IBAction) BtnPlay:(id)sender;
-(IBAction) BtnPause:(id)sender;
-(void) setupAVPlayerForURL: (NSURL*) url;

.m file (partial code)

-(IBAction) BtnGoClick:(id)sender {

    NSURL *url = [[NSURL alloc] initWithString:@""];

    [self setupAVPlayerForURL:url];
}

-(IBAction) BtnGoLocalClick:(id)sender {

    // - - - Pull media from documents folder

    //NSString* saveFileName = @"MyAudio.mp3";
    //NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    //NSString *documentsDirectory = [paths objectAtIndex:0];
    //NSString *path = [documentsDirectory stringByAppendingPathComponent:saveFileName];

    // - - -

    // - - - Pull media from resources folder

    NSString *path = [[NSBundle mainBundle] pathForResource:@"MyAudio" ofType:@"mp3"];

    // - - -

    NSURL *url = [[NSURL alloc] initFileURLWithPath: path];

    [self setupAVPlayerForURL:url];
}

-(void) setupAVPlayerForURL: (NSURL*) url {
    AVAsset *asset = [AVURLAsset URLAssetWithURL:url options:nil];
    AVPlayerItem *anItem = [AVPlayerItem playerItemWithAsset:asset];

    player = [AVPlayer playerWithPlayerItem:anItem];
    [player addObserver:self forKeyPath:@"status" options:0 context:nil];
}


- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {

    if (object == player && [keyPath isEqualToString:@"status"]) {
        if (player.status == AVPlayerStatusFailed) {
            NSLog(@"AVPlayer Failed");
        } else if (player.status == AVPlayerStatusReadyToPlay) {
            NSLog(@"AVPlayer Ready to Play");
        } else if (player.status == AVPlayerItemStatusUnknown) {
            NSLog(@"AVPlayer Unknown");
        }
    }
}

-(IBAction) BtnPlay:(id)sender {
    [player play];
}

-(IBAction) BtnPause:(id)sender {
    [player pause];
}

Check out the Objective-C source code for a working example of this.
Hope this helps!

-Update 12/7/2015 I now have a Swift example of the source code you can view here.