AVPlayer got the metadata but not playing

问题:

I'm trying to do a very simple application, the purpose is listening an audio stream (AAC 64 kbps). To do so I'm using AVPlayer from the Apple AVFoundation has follow :

ViewController.m

#import "ViewController.h"
@interface ViewController ()
@end

@implementation ViewController
@synthesize playerItem, player;

- (void)viewDidLoad
{
    [super viewDidLoad];
}

- (void) viewWillAppear:(BOOL)animated{
    [super viewWillAppear:animated];
    playerItem = [AVPlayerItem playerItemWithURL:[NSURL URLWithString:@"http://stream.myjungly.fr/MYJUNGLY2"]];
    [playerItem addObserver:self forKeyPath:@"timedMetadata" options:NSKeyValueObservingOptionNew context:nil];

    player = [AVPlayer playerWithPlayerItem:playerItem];
    [player play];

    NSLog(@"player item error : %@", playerItem.error.description);
    NSLog(@"player error : %@", player.error.description);
}

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

    if ([keyPath isEqualToString:@"timedMetadata"])
    {
        AVPlayerItem* _playerItem = object;
        for (AVMetadataItem* metadata in _playerItem.timedMetadata)
        {
            NSLog(@"\nkey: %@\nkeySpace: %@\ncommonKey: %@\nvalue: %@", [metadata.key description], metadata.keySpace, metadata.commonKey, metadata.stringValue);
        }
    }
}

@end

My object player and playerItem are strong properties :

ViewController.h

@interface ViewController : UIViewController

@property (nonatomic, strong) AVPlayerItem* playerItem;
@property (nonatomic, strong) AVPlayer* player;

@end

The Key Value Observer is working great, here is my log :

2013-05-14 11:18:03.725 MusicAvPlayer[6494:907] player item error : (null)
2013-05-14 11:18:03.728 MusicAvPlayer[6494:907] player error : (null)
2013-05-14 11:18:08.140 MusicAvPlayer[6494:907] 
key: title
keySpace: comn
commonKey: title
value: Alabama Shakes - Be Mine

But the audio is not played, I've go no sound ! Any idea why ?

EDIT: I already look at this questions :

No sound coming from AVPlayer

AVAudioPlayer, No Sound

AVAudioPlayer not playing any sound

That's why I'm using a strong property, so I guess my problem is not ARC related

回答1:

I found problem : the iphone was in silent mode ... so no sound can go out on the speaker, the the sound was played when I was using the head phone.

But I've got a new question now : how can you play sound on the speaker when the phone is in silent mode ? (like the official Music application)

EDIT : ... and the answer is there : Play sound on iPhone even in silent mode

回答2:

// Init PlayerItem
playerItem = [AVPlayerItem playerItemWithURL:[NSURL URLWithString:@"http://stream.myjungly.fr/MYJUNGLY2"]];

// Init Player Obj
player = [AVPlayer playerWithPlayerItem:playerItem];
// Add objserver on Player
[player addObserver:self forKeyPath:@"status" options:0 context:nil];

Add Observer Method your Class

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object
                        change:(NSDictionary *)change context:(void *)context {
    if (object == player && [keyPath isEqualToString:@"status"]) {
        if (player.status == AVPlayerStatusReadyToPlay) {
            // Start playing...
            [player play];
        } else if (player.status == AVPlayerStatusFailed) {
            // something went wrong. player.error should contain some information
        }
    }
    if ([keyPath isEqualToString:@"timedMetadata"])
    {
        AVPlayerItem* _playerItem = object;
        for (AVMetadataItem* metadata in _playerItem.timedMetadata)
        {
            NSLog(@"\nkey: %@\nkeySpace: %@\ncommonKey: %@\nvalue: %@", [metadata.key description], metadata.keySpace, metadata.commonKey, metadata.stringValue);
        }
    }

}