AVPlayer fast forward/backward 用平移手势跳过

Question

在过去的两天里，我一直在为一个烦人的故障而烦恼，希望有人能给出一些启示。

基本设置： 我有一个带有播放器的 AVPlayerLayer，视图中有一个平移手势识别器，我希望用户能够来回滑动手指，视频会相应地寻找。

要点： 我希望如果用户抬起手指并再次放置，在屏幕上的任何位置快进或快退以在 [=37= 恢复]完全与它停止的同一帧并从那里继续前进。

我看到了这两个问题： Pan Gesture with AVPlayer 和 Pan to seek AVPlayer

我在这里尝试了 Apple 的建议：https://developer.apple.com/library/content/qa/qa1820/_index.html 同样，但问题是每当我开始一个新的平移手势时，播放器都会跳几帧然后继续。

我最新的方法是在搜索完成块完成后设置当前时间，然后尝试将新的搜索时间附加到该时间。

这是我的设置：

self.item = [AVPlayerItem playerItemWithURL:resource];
self.player = [AVPlayer playerWithPlayerItem:self.item];
self.playerLayer = [AVPlayerLayer playerLayerWithPlayer:self.player];

[self.view.layer addSublayer:self.playerLayer];
self.playerLayer.frame = self.view.bounds;

UIPanGestureRecognizer *recognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(swipe:)];

[self.view addGestureRecognizer:recognizer];

我的手势识别器处理：

- (void)swipe:(UIPanGestureRecognizer *)paramRecognizer
{
    switch(paramRecognizer.state) {
      //  case UIGestureRecognizerStateBegan:
        case UIGestureRecognizerStateChanged:
        {
            [self.player pause];
            
            CGPoint translation = [paramRecognizer translationInView:self.view];
            
            float horizontalTranslation = translation.x;
            
            float durationInSeconds = CMTimeGetSeconds(self.player.currentItem.asset.duration);
            
            //I'd like to be able to swipe across the whole view.
            float translationLimit = self.view.bounds.size.width;
            float minTranslation = 0;
            float maxTranslation = translationLimit;
            
            if (horizontalTranslation > maxTranslation) {
                horizontalTranslation = maxTranslation;
            }
            
            if (horizontalTranslation < minTranslation) {
                horizontalTranslation = minTranslation;
            }
            
        float timeToSeekTo = [self normalize:horizontalTranslation
                                 andMinDelta:minTranslation
                                 andMaxDelta:maxTranslation
                              andMinDuration:0
                              andMaxDuration:durationInSeconds];
            
            if(CMTIME_IS_VALID(self.currentTime)){
                float seconds = self.currentTime.value/self.currentTime.timescale;
        
                [self.player seekToTime:CMTimeMakeWithSeconds(seconds+timeToSeekTo, self.player.currentTime.timescale)
                        toleranceBefore:kCMTimeZero
                         toleranceAfter:kCMTimeZero completionHandler:^(BOOL finished)
                 {
                     if(finished)
                    self.currentTime = self.player.currentItem.currentTime;
                }];
            }
            else
            {
                [self.player seekToTime:CMTimeMakeWithSeconds(timeToSeekTo,
                                                              self.player.currentTime.timescale) toleranceBefore:kCMTimeZero
                         toleranceAfter:kCMTimeZero completionHandler:^(BOOL finished) {
                             if(finished)
                    self.currentTime = self.player.currentItem.currentTime;
                }];
            }
            
        }
            break;
    }
}

归一化方法是这样的：

- (float)normalize:(float)delta
       andMinDelta:(float)minDelta
       andMaxDelta:(float)maxDelta
    andMinDuration:(float)minDuration
    andMaxDuration:(float)maxDuration
{
  float result = ((delta - minDelta) * (maxDuration - minDuration) / (maxDelta - minDelta) + minDuration);
  return result;
}

任何帮助将不胜感激！

Answer 1

在 UIGestureRecognizerStateBegan 上从 AVPlayer 保存 CMTime 然后做你的增量变化平移，然后在 UIGestureRecognizerStateEnded 上找回原来保存的时间？

请注意，为了更流畅，请不要暂停视频，将速率设置为 0。

AVPlayer fast forward/backward 用平移手势跳过

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avplayerlayer