iPhone - 播放电影后，播放音频效果不佳

Question

在我的应用程序中，当应用程序启动时，我正在播放介绍视频。稍后在应用程序中，我通过单击按钮播放一些音频文件。但音频播放效果不佳。注意到它的消音和有时低音频等问题。

我发现这个错误是在播放视频时出现的。当我不播放介绍视频时，音频播放得很好。否则就会造成麻烦。

我使用以下代码来设置电影播放器​​：

-(void)setupMovie
{
    NSString* moviePath;
    if ([[UIDevice currentDevice] userInterfaceIdiom] ==  UIUserInterfaceIdiomPad)
    {
        moviePath = [[NSBundle mainBundle] pathForResource:@"ipad" ofType:@"3gp"];
    }
    else 
    {
        moviePath = [[NSBundle mainBundle] pathForResource:@"iphone" ofType:@"3gp"];    

    }

    NSURL* movieURL = [NSURL fileURLWithPath:moviePath];
    playerCtrl =  [[MPMoviePlayerController alloc] initWithContentURL:movieURL];

    if ([[UIDevice currentDevice] userInterfaceIdiom] ==  UIUserInterfaceIdiomPad)
    {
        playerCtrl.view.frame = CGRectMake(0, 0, 1024, 768);
    }
    else 
    {
        playerCtrl.view.frame = CGRectMake(0, 0, 480, 320);     
    }


    playerCtrl.scalingMode = MPMovieScalingModeFill;
    playerCtrl.controlStyle = MPMovieControlStyleNone;
    [playerCtrl prepareToPlay];

    [[NSNotificationCenter defaultCenter] addObserver:self 
                                             selector:@selector(moviePlayerLoadStateChanged:) 
                                                 name:MPMoviePlayerLoadStateDidChangeNotification 
                                               object:nil];

    [[NSNotificationCenter defaultCenter] addObserver:self 
                                             selector:@selector(moviePlayBackDidFinish:) 
                                                 name:MPMoviePlayerPlaybackDidFinishNotification 
                                               object:nil];
}

- (void) moviePlayerLoadStateChanged:(NSNotification*)notification 
{
    if ([playerCtrl loadState] != MPMovieLoadStateUnknown)
    {
        [[NSNotificationCenter  defaultCenter] removeObserver:self 
                                                         name:MPMoviePlayerLoadStateDidChangeNotification 
                                                       object:nil];



        // Play the movie
        [self.view addSubview:playerCtrl.view];
        [playerCtrl play];

        [[NSNotificationCenter defaultCenter] postNotificationName:@"GSPLAYER_STARTED" object:nil];
    }
    else 
    {
        NSLog(@"Player received unknown error");
        [[NSNotificationCenter defaultCenter] postNotificationName:@"GSPLAYER_ERROR" object:nil];
    }
}

当电影结束时，我将加载下一个视图，如下所示：

-(void)playerCompleted
{
    [pv.view removeFromSuperview];
    [pv release];
    pv = nil;
    [self.window addSubview:navigationController.view];
}

以下代码用于播放音频：

-(void)playAudio:(NSString*)filename
{
    self.allowAnimation = NO;
    NSString* bundleName = [[NSBundle mainBundle] pathForResource:[filename lowercaseString] ofType:nil];

    //NSURL* url = [[NSURL alloc] initFileURLWithPath: bundleName];
    NSURL* url = [NSURL fileURLWithPath:bundleName];

    if (appSoundPlayer) {
        [appSoundPlayer release];
    }

    appSoundPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:url error: nil];
    //[appSoundPlayer prepareToPlay];
    [appSoundPlayer setVolume: 1.0];
    [appSoundPlayer setDelegate: self];
    [appSoundPlayer play];  
}

有人之前遇到过此类问题吗？可能存在什么问题以及解决方案是什么？

Answer 1

您是否尝试过设置audioSession属性..只需设置 Audiosesion 在播放音频之前播放..我还没有尝试过这段代码，但我认为这是会话的问题..

appSoundPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:url error: nil];
//[appSoundPlayer prepareToPlay];
[appSoundPlayer setVolume: 1.0];
[appSoundPlayer setDelegate: self];
[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayAndRecord error:nil];
[appSoundPlayer play]

Answer 2

问题出在视频编解码器上。
如果我们使用没有 AAC 格式的 3GP，则 Apple 框架本身存在一些问题。我联系了苹果公司，他们接受了这是一个错误。