使用AVQueuePlayer时如何在视频之间添加转换？

Question

我正在制作一个视频应用程序,一个接一个地播放大量视频.视频存储在一个AVPlayerItems 数组中.AVQueuePlayer初始化与那些AVPlayerItems和它自动地从该阵列播放视频.

问题是,当它改变播放下一个视频就被卡住了几分之一秒,或者它从一个到另一个过渡的时间创建了一个混蛋.我想改善与某种动画如淡入这一过渡,而更改视频淡出.

我的代码AVQueuePlayer:

AVQueuePlayer *mediaPlayer = [[AVQueuePlayer alloc] initWithItems:arrPlayerItems];
playerLayer=[AVPlayerLayer playerLayerWithPlayer:mediaPlayer];
playerLayer.frame=self.bounds;
playerLayer.videoGravity = AVLayerVideoGravityResizeAspect;
playerLayer.needsDisplayOnBoundsChange = NO;
[self.layer addSublayer:playerLayer];
self.layer.needsDisplayOnBoundsChange = YES;

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

我试图创建在过渡的时间一个新层,通过降低其不透明度和增加新的图层的不透明度动画旧层(创建淡出效果所需的渐暗),但可根据需要它无法正常工作.

自定义转换的代码:

-(void)TransitionInVideos {
    if (roundf(CMTimeGetSeconds(mediaPlayer.currentTime))==roundf(CMTimeGetSeconds(mediaPlayer.currentItem.duration))) {
        [self.layer addSublayer:playerLayerTmp];

        //Animation for the transition between videos
        [self performSelector:@selector(FadeIn) withObject:nil afterDelay:0.3];
        [self performSelector:@selector(FadeOut) withObject:nil afterDelay:0.3];
    }
}

-(void)FadeIn {
    CABasicAnimation* fadeAnim = [CABasicAnimation animationWithKeyPath:@"opacity"];
    fadeAnim.fromValue = [NSNumber numberWithFloat:1.0];
    fadeAnim.toValue = [NSNumber numberWithFloat:0.0];
    fadeAnim.duration = 2.0;
    [playerLayer addAnimation:fadeAnim forKey:@"opacity"];
    [self performSelector:@selector(HideLayer) withObject:nil afterDelay:2.0];
}

-(void)FadeOut {
    CABasicAnimation* fadeAnim = [CABasicAnimation animationWithKeyPath:@"opacity"];
    fadeAnim.fromValue = [NSNumber numberWithFloat:0.0];
    fadeAnim.toValue = [NSNumber numberWithFloat:1.0];
    fadeAnim.duration = 1.0;
    [playerLayerTmp addAnimation:fadeAnim forKey:@"opacity"];
    [self performSelector:@selector(ShowLayer) withObject:nil afterDelay:1.0];
}

-(void)HideLayer {
    playerLayer.opacity=0.0;
}

-(void)ShowLayer {
    playerLayerTmp.opacity=1.0;
}

如何将过渡应用于视频AVQueuePlayer？

Answer 1

我们可以设置不透明度,AVMutableVideoCompositionLayerInstruction以便在导出时添加到视频或AVPlayer作为VideoComposition属性,这将创建淡入和淡出效果.

 [layerInstruction setOpacityRampFromStartOpacity:1.0 toEndOpacity:0.0 timeRange:CMTimeRangeMake(CMTimeSubtract([mutableComposition duration], CMTimeMake(Transition_Time, 1)), [mutableComposition duration])];

 [layerInstruction setOpacityRampFromStartOpacity:0.0 toEndOpacity:1.0 timeRange:CMTimeRangeMake(kCMTimeZero, CMTimeMake(1, 1))];

这是给出效果的代码.

更完整的例子:

• https://developer.apple.com/library/content/samplecode/avloopplayer/Introduction/Intro.html
• https://www.raywenderlich.com/30200/avfoundation-tutorial-adding-overlays-and-animations-to-videos