Question

我正在使用AVFoundation为iOS定制视频播放器。我们的想法是能够通过手势切换到不同的视频（点按，滑动等等）。 现在玩家在模拟器上完美运行，但是当我在实际设备上测试时，在3或4次滑动后视图变为空白。我甚至为我的播放器创建了播放控件，当视图变为空白时，这些控件正确加载但什么都不做。有什么想法吗？这是播放器的初始化

            - (id)initWithContentURL:(NSString *)aContentURL delegate:(id)aDelegate {
        self = [super initWithNibName:@"NoCashMoviePlayer" bundle:nil];
        if (self == nil)
            return nil;
        delegate = aDelegate;
        systemPath = [aContentURL retain];
        contentURL = [[NSURL alloc]initFileURLWithPath:systemPath];
        asset = [AVURLAsset URLAssetWithURL:contentURL options:nil];
        playerItem = [AVPlayerItem playerItemWithAsset:asset];
        isPaused = false;
        controlsHidden = false;
        self.player = [[AVPlayer playerWithPlayerItem:playerItem] retain];
         duration = self.player.currentItem.asset.duration;

        return self;
    }

这是播放视频的代码：

    -(void)playMovie{

        UITapGestureRecognizer *tapRecon = [[UITapGestureRecognizer alloc]initWithTarget:self   action:@selector(toggleControls:)];
        [tapRecon setNumberOfTapsRequired:2]; 
        [self.movieContainer addGestureRecognizer:tapRecon];
        [tapRecon release];

        NSLog(@"Playing item: %@",contentURL);
        playerLayer = [AVPlayerLayer playerLayerWithPlayer:player];
        [movieContainer.layer addSublayer:playerLayer];
        playerLayer.frame = movieContainer.layer.bounds;
        playerLayer.videoGravity = AVLayerVideoGravityResizeAspect;
        self.seeker.alpha = 1.0;
        [self.view addSubview:movieContainer];
        [self.movieContainer addSubview:controls];
        [self setSlider];
        [player play];
        player.actionAtItemEnd = AVPlayerActionAtItemEndNone; 

        [[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(playerItemDidReachEnd:)
                                             name:AVPlayerItemDidPlayToEndTimeNotification
                                           object:[player currentItem]];


    }

选择要播放的片段的代码：

    -(void)viewSelect: (double) curTime{ 
        self.myView.backgroundColor = [UIColor blackColor];
        UISwipeGestureRecognizer *swipeRecognizer = [[UISwipeGestureRecognizer alloc]initWithTarget:self action:@selector(handleSwipeFrom:)]; 
        swipeRecognizer.direction = UISwipeGestureRecognizerDirectionRight; 
         [self.myView addGestureRecognizer:swipeRecognizer]; 
        [swipeRecognizer release];

        UISwipeGestureRecognizer *leftRecognizer = [[UISwipeGestureRecognizer alloc]initWithTarget:self action:@selector(handleSwipeFromLeft:)]; 
        swipeRecognizer.direction = UISwipeGestureRecognizerDirectionLeft; 
        [self.myView addGestureRecognizer:leftRecognizer]; 
        [leftRecognizer release];


        if(isMain){
            [UIView animateWithDuration:0.5 delay:0.0 options:UIViewAnimationTransitionFlipFromLeft animations:^{
                self.myView.alpha = 1.0;
                moviePlayer = [[NoCashMoviePlayer alloc]initWithContentURL:[self movieURL:vidIndex] delegate:self];
                self.moviePlayer.view.frame = self.myView.bounds;
                self.moviePlayer.view.autoresizingMask = UIViewAutoresizingFlexibleWidth |UIViewAutoresizingFlexibleHeight;
                 [self.myView addSubview:moviePlayer.view];

            }completion:^(BOOL finished) {
                [self.moviePlayer.player seekToTime:CMTimeMake(curTime, 1)];
                [self.moviePlayer playMovie];
            }];
        }else{

            [UIView animateWithDuration:0.5 delay:0.0 options:UIViewAnimationTransitionFlipFromLeft animations:^{
                self.otherView.alpha = 1.0;
                moviePlayer = [[NoCashMoviePlayer alloc]initWithContentURL:[self movieURL:vidIndex] delegate:self];
                self.moviePlayer.view.frame = self.otherView.bounds;
                self.moviePlayer.view.autoresizingMask = UIViewAutoresizingFlexibleWidth |UIViewAutoresizingFlexibleHeight;
                [self.otherView addSubview:moviePlayer.view];

            }completion:^(BOOL finished) {

               [self.moviePlayer.player seekToTime:CMTimeMake(curTime, 1)];
                [self.moviePlayer playMovie];
            }];
        }
    }

最后一次手势动作：

    - (void)handleSwipeFromLeft:(UISwipeGestureRecognizer *)recognizer { 

        double elapsedTime = 0.0;
        if(vidIndex==0){
            vidIndex = 3;
        }else vidIndex = vidIndex --;
        elapsedTime = [self.moviePlayer currentTimeInSeconds];
        [self.moviePlayer stopMovie];
        isMain = !isMain;
        [self viewSelect: elapsedTime];

    }

编辑：尝试使用不同的AVPlayerLayers为每个视频文件，相同的情况，在模拟器中工作，而不是在iPad上。

编辑2：我运行了仪器来分析核心动画性能，当视频播放时，它显示的帧速率约为30 fps，当播放器空白时，它一直下降到1或2 fps。这可能是可能的，但仍然，如果它有助于提供更多的光......

编辑3：好的，我终于到了某个地方，我知道问题是什么，我有一个核心动画内存泄漏，在模拟器中它“有效”，因为计算机的内存比iPad多很多，但是由于iPad的内存非常有限，因此它可以很快停止工作。如果有人对Core Animation漏洞有任何建议，那将非常受欢迎。

Answer 1

我终于解决了这个问题。我的设计确实很差，它的内存管理非常糟糕等等。我所做的不是发布我能做的一切，包括视图，图层，玩家，资产等，我只是创建了一种方法来更新玩家的资产和物品，回收玩家，视图，图层等。

    [player pause];
    contentURL = [[NSURL alloc] initFileURLWithPath:newPath];
    AVAsset *newAsset = [AVURLAsset URLAssetWithURL:contentURL options:nil];
    AVPlayerItem *newPlayerItem = [AVPlayerItem playerItemWithAsset:newAsset];
    [player replaceCurrentItemWithPlayerItem:newPlayerItem];
    [contentURL release];

现在它正在创造奇迹。谢谢大家的帮助。

Answer 2

代码中有2个位置保留了一个对象，我在您发布的代码中的任何位置都没有看到相应的版本。我首先要确保内存引用计数增量和减量都是适当平衡的。

第一个保留对我来说很可疑。通常，您应首先自动释放您要分配的变量，然后保留，如下所示：

[systemPath autorelease];
systemPath = [aContentURL retain]

在上面的代码中很容易看出保留/释放匹配得以维持，并且远不如其他方案容易出错。请注意，如果systemPath == aContentURL，则不会释放该对象。

使用AVPlayer在iphone上播放许多不同的视频

2 个答案: