MPMoviePlayerController在后台播放airPlay，双击主页按钮时崩溃

Question

当我进入主屏幕并且app在后台时，MPMoviePlayerController成功播放了airPlay。 但是，当我双击主页按钮时，应用程序崩溃了。 这发生在iOS 5上，但不是4.3。

为了排除其他代码，我创建了一个新的空项目，只在按下按钮时执行下面的代码。

moviePlayerController = [[MPMoviePlayerController alloc] initWithContentURL:[NSURL URLWithString:@"http://devimages.apple.com/iphone/samples/bipbop/gear1/prog_index.m3u8"]];

NSError *setCategoryError = nil; 
[[AVAudioSession sharedInstance] setCategory: AVAudioSessionCategoryPlayback error: &setCategoryError]; 

[[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(moviePlaybackComplete:)
                                             name:MPMoviePlayerPlaybackDidFinishNotification
                                           object:moviePlayerController];

[moviePlayerController setMovieSourceType:MPMovieSourceTypeStreaming];
[self addObservers];
[self.delegate addSubview:moviePlayerController.view];
if([moviePlayerController respondsToSelector:@selector(setAllowsAirPlay:)])
{
    [moviePlayerController setAllowsAirPlay:YES];
}

moviePlayerController.fullscreen = YES;

moviePlayerController.scalingMode = MPMovieScalingModeAspectFit;
[moviePlayerController prepareToPlay];
[moviePlayerController play];

在控制台中，我在崩溃时得到以下输出：

Jan 27 12:08:01 unknown mediaserverd[295] <Error>: <<<< FIGSERVER >>>> FigPlayerRemoteServer_KillAndForceCrashReport: RPCTimeout message received to terminate [295] with reason 'fig rpc timeout -- FigSharedRemote_VolumeCategoryForAudioCategory'
Jan 27 12:08:01 unknown ReportCrash[308] <Notice>: MS:Notice: Installing: (null) [ReportCrash] (675.00)
Jan 27 12:08:01 unknown ReportCrash[308] <Error>: Saved crashreport to /Library/Logs/CrashReporter/mediaserverd-2012-01-27-120801.plist using uid: 0 gid: 0, synthetic_euid: 0 egid: 0
Jan 27 12:08:01 unknown mediaserverd[295] <Error>: <<<< FIGSERVER >>>> FigPlayerRemoteServer_KillAndForceCrashReport: RPCTimeout message received; stackshot generated
Jan 27 12:08:01 unknown mediaserverd[295] <Error>: <<<< FIGSERVER >>>> FigPlayerRemoteServer_KillAndForceCrashReport: TERMINATING our process [295]
Jan 27 12:08:02 unknown com.apple.launchd[1] <Notice>: (com.apple.mediaserverd) Exited: Killed: 9
Jan 27 12:08:02 unknown mediaserverd[310] <Notice>: MS:Notice: Installing: com.apple.mediaserverd [mediaserverd] (675.00)
Jan 27 12:08:02 unknown kernel[0] <Debug>: Sandbox: ignoring builtin profile for platform app: /usr/sbin/mediaserverd
Jan 27 12:08:02 unknown kernel[0] <Debug>: Sandbox: ignoring builtin profile for platform app: /usr/sbin/mediaserverd
Jan 27 12:08:03 unknown mediaserverd[310] <Error>: 12:08:03.383370 com.apple.AVConference: /SourceCache/GameKitServices/GameKitServices-344.3/AVConference.subproj/Sources/AVConferenceServer.m:1862: AVConferenceServerStart aborting - device doesn't support conferencing

并在crashreport中：

Exception Type:  EXC_CRASH (SIGABRT)
Exception Codes: 0x00000000, 0x00000000
Crashed Thread:  0

Last Exception Backtrace:
0   CoreFoundation                  0x33bab8bf 0x33af2000 + 759999
1   libobjc.A.dylib                 0x31bcd1e5 0x31bc4000 + 37349
2   AVFoundation                    0x374f6cb5 -[AVPlayerItem _attachToPlayer:forImmediateEnqueueing:shouldAppendItem:] + 341
3   AVFoundation                    0x374e71f7 -[AVPlayer _insertPlaybackItemOfItem:inPlayerQueueAfterPlaybackItemOfItem:] + 43
4   AVFoundation                    0x374eebf3 __-[AVPlayer _attachItem:andPerformOperation:withObject:]_block_invoke_2 + 1099
5   libdispatch.dylib               0x3641cd55 0x3641c000 + 3413
6   libdispatch.dylib               0x36427e8d 0x3641c000 + 48781
7   CoreFoundation                  0x33b7e2dd 0x33af2000 + 574173
8   CoreFoundation                  0x33b014dd 0x33af2000 + 62685
9   CoreFoundation                  0x33b013a5 0x33af2000 + 62373
10  GraphicsServices                0x31f56fcd 0x31f53000 + 16333
11  UIKit                           0x36d57743 0x36d26000 + 202563
12  AirplayTest                     0x00002e45 main (main.m:16)
13  AirplayTest                     0x00002dd4 start + 40

有什么线索可能是错的？

Answer 1

这似乎是iOS 5.0版中的一个错误。 随着iOS 5.1的发布，似乎已经修复。

感谢@Cyril对此进行确认。

Answer 2

您是否尝试过为iOS 5设置电影播放器​​控制器的useApplicationAudioSession属性为NO（即模拟iOS 3.1默认行为）？ iOS 5中的音频会话处理似乎存在一些错误，当您在应用程序之间切换，处理中断等时，可能导致音频服务器死机。

如果这样修复它，请向Apple提交错误报告，因为它更像是一个黑客攻击而不是修复！