我想首先为这篇长得可笑的帖子道歉，但我试图提供尽可能多的代码和数据供您参考。
我正在做一个视频项目，我需要 AVQueuePlayer 的灵活性（最重要的是能够自由缩放和布局视频层，以及创建我的自定义控件）。问题是，我需要能够混合不同类型的视频内容（在这种情况下，渐进式下载 .mp4 和 http 流式传输 .m3u8）。这就是事情变得时髦的地方。
首先一些代码让你去：
- (void)viewDidLoad {
[super viewDidLoad];
NSArray *assetsArray = [NSArray arrayWithObjects:
[AVPlayerItem playerItemWithURL: [NSURL URLWithString: kTestPrerollURL]], // .mp4-file on server
[AVPlayerItem playerItemWithURL: [NSURL URLWithString: kTestVideoURL]], // .m3u8-file on server
[AVPlayerItem playerItemWithURL: [NSURL fileURLWithPath: [[NSBundle mainBundle] pathForResource: @"2" ofType:@"m4v"]]], // local m4v-file
[AVPlayerItem playerItemWithURL: [NSURL fileURLWithPath: [[NSBundle mainBundle] pathForResource: @"3" ofType:@"m4v"]]], // local m4v-file
nil];
// Add KVO observation on each player item to track when they are ready for playback
for(id playerItem in assetsArray) {
[playerItem addObserver: self forKeyPath:@"status" options: 0 context: NULL];
}
[self setPlayer: [AVQueuePlayer queuePlayerWithItems: assetsArray]];
[self setPlayerLayer: [AVPlayerLayer playerLayerWithPlayer: [self player]]];
[[self playerLayer] setFrame: [playerView bounds]];
// Additional layer customization...
[[playerView layer] addSublayer: [self playerLayer]];
[playerView setBackgroundColor: [UIColor clearColor]];
[[NSNotificationCenter defaultCenter] addObserver: self
selector: @selector(playerItemDidReachEnd:)
name: AVPlayerItemDidPlayToEndTimeNotification
object: nil];
}
当 AVPlayerItem 改变状态时，会调用这个方法：
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {
// A bunch of loggers...
if([(AVPlayerItem *)object status] == AVPlayerItemStatusReadyToPlay) {
CGSize movieSize = [[[player currentItem] asset] naturalSize];
CGRect playerRect = [playerView frame];
playerRect.size.height = playerRect.size.width * movieSize.height/movieSize.width + 7.0;
[playerView setFrame: playerRect];
[playerLayer setFrame: [playerView bounds]];
[player play];
}
}
如果用户选择按下“下一步”按钮，播放器将跳至下一个剪辑：
- (IBAction)next:(id)sender {
NSLog(@"------ USER SWITCHED TO NEXT ------");
AVPlayerItem *object = (AVPlayerItem *)[player currentItem];
[object removeObserver:self forKeyPath: @"status"];
[player advanceToNextItem];
}
最后，当 AVPlayerItem 到达末尾时，调用此方法：
- (void)playerItemDidReachEnd:(NSNotification *)notification {
NSLog(@"------ PLAYER ITEM DID REACH END ------");
AVPlayerItem *object = (AVPlayerItem *)[notification object];
[object removeObserver:self forKeyPath: @"status"];
}
好的，所以我的问题是混合不同的格式（在这种情况下是 m3u8 文件）会导致一些时髦的行为。
如果我首先在队列中加载 m3u8 文件，它会正常播放，但如果我 advanceToNextItem 应用程序崩溃。NSZombieEnabled 报告：
*** -[Not A Type retain]: message sent to deallocated instance 0x684dfe0
[Switching to process 67957]
调用堆栈显示了一个超出我界限的版本（MyPlayer 是项目的名称）：
po [NSThread callStackSymbols]
2011-01-05 16:12:57.151 MyPlayer[67957:6303] *** __NSAutoreleaseNoPool(): Object 0x56a0580 of class _NSCallStackArray autoreleased with no pool in place - just leaking
<_NSCallStackArray 0x56a0580>(
0 MyPlayer 0x00002154 start + 0,
1 CoreFoundation 0x00e72f22 _CF_forwarding_prep_0 + 50,
2 CoreFoundation 0x00e140bc CFRetain + 92,
3 CFNetwork 0x014c436e _ZN21XConnectionEventQueueI12XLoaderEvent18XLoaderEventParamsE10pushEventsEP20XConnectionEventInfoIS0_S1_El + 120,
4 CFNetwork 0x014c4252 _ZN19URLConnectionLoader16pushEventsLockedEP20XConnectionEventInfoI12XLoaderEvent18XLoaderEventParamsEl + 120,
5 CFNetwork 0x014c41c7 _ZN19URLConnectionLoader10pushEventsEP20XConnectionEventInfoI12XLoaderEvent18XLoaderEventParamsEl + 57,
6 CFNetwork 0x015976b6 _ZN19URLConnectionClient25getRequestForTransmissionEhP14_CFURLResponsePK13_CFURLRequestPP9__CFError + 942,
7 CFNetwork 0x014c3030 _ZN19URLConnectionClient22_clientWillSendRequestEPK13_CFURLRequestP14_CFURLResponsePNS_26ClientConnectionEventQueueE + 230,
8 CFNetwork 0x01597789 _ZN19URLConnectionClient26ClientConnectionEventQueue33processAllEventsAndConsumePayloadEP20XConnectionEventInfoI12XClientEvent18XClientEventParamsEl + 141,
9 CFNetwork 0x014c2e3c _ZN19URLConnectionClient13processEventsEv + 100,
10 CFNetwork 0x014c2cb7 _ZN17MultiplexerSource7performEv + 251,
11 CoreFoundation 0x00ee301f __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 15,
12 CoreFoundation 0x00e4128b __CFRunLoopDoSources0 + 571,
13 CoreFoundation 0x00e40786 __CFRunLoopRun + 470,
14 CoreFoundation 0x00e40240 CFRunLoopRunSpecific + 208,
15 CoreFoundation 0x00e43504 CFRunLoopRun + 84,
16 CoreMedia 0x00cb39af FigThreadGlobalNetworkBufferingRunloop + 149,
17 CoreMedia 0x00cb624a figThreadMain + 308,
18 libSystem.B.dylib 0x9473885d _pthread_start + 345,
19 libSystem.B.dylib 0x947386e2 thread_start + 34
)
如果 .m3u8 文件放置在队列中第一个位置之后的某个位置，我会得到状态 AVPlayerItemStatusFailed，并且剪辑会跳到队列中的下一个剪辑。
我意识到这可能与一些内存管理有关，但同时我开始怀疑它。然而，很明显我做错了什么，所以每一个解决方案的建议都非常受欢迎。