在 UICollectionView 上使用 AVPlayer 和 AVPlayerLayer 显示多个视频

Question

我正在使用 AVPlayer 和 AVPlayerLayer classes 在具有水平滚动的 UICollectionView 单元格上全屏显示 "n" 个视频的应用程序。我在 UIScrollView 上启用了分页设置。因为我只需要玩当前位置的玩家，否则 "Previous & next" 单元格玩家应该处于 "pause" 状态。

我正在获取 url 格式的视频。所以最初我需要下载，然后它就会开始播放。所以每个人都不需要从 URL 下载视频。所以我决定将下载的视频缓存在本地。所以我下载并将其存储在本地文件中。然后我从本地加载视频如果它存在于本地文件中。

问题：

(一)。 "Play & pause" 在其相关索引上无法正常工作。最初播放索引为“0”。当我滚动到下一个索引时，当前索引播放器应该正在播放，下一个索引播放器应该处于 "Pause" 状态。未正确同步。

(b)。我可以看到上一个播放器的视频剪辑，直到下一个播放器开始播放。

(c)。所有查看的音频同时在后台播放以及在释放播放器时播放。（我的意思是，我可以在关闭某些视图或视图控制器后听到声音）

(d) 需要维护内存泄漏问题。

下面是我试过的源码方式，

- (void)setVideoLoading:(NSString *)videoUrl{

    NSString *urlString = videoUrl;

    SHAREDATA.videoUrl = [NSURL URLWithString:urlString];

    AVURLAsset *asset = [AVURLAsset URLAssetWithURL:SHAREDATA.videoUrl options:nil];

    NSArray *requestedKeys = @[@"playable"];

    //Tells the asset to load the values of any of the specified keys that are not already loaded.
    [asset loadValuesAsynchronouslyForKeys:requestedKeys completionHandler:^{

        dispatch_async(dispatch_get_main_queue(), ^{

            AVPlayerItem *item = [AVPlayerItem playerItemWithAsset: asset];

            if (self.avPlayer)
            {
                /* Remove existing player item key value observers and notifications. */

                [self.avPlayer removeObserver:self forKeyPath:@"status" context:nil];

                [[NSNotificationCenter defaultCenter] removeObserver:self
                                                                name:AVPlayerItemDidPlayToEndTimeNotification
                                                              object:self.avPlayer.currentItem];
            }

            self.avPlayer = [AVPlayer playerWithPlayerItem:item];

            self.avPlayerLayer = [AVPlayerLayer playerLayerWithPlayer:self.avPlayer];

            if (_typeOfContentMode == UIViewContentModeScaleAspectFit) {

                self.avPlayerLayer.videoGravity = AVLayerVideoGravityResizeAspect;
            }
            else if (_typeOfContentMode == UIViewContentModeScaleAspectFill)
            {
                self.avPlayerLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;
            }


            self.avPlayerLayer.frame = CGRectMake(0, 0, _videoBackgroundView.frame.size.width, _videoBackgroundView.frame.size.height);

            [_videoBackgroundView.layer addSublayer:self.avPlayerLayer];

            self.avPlayer.actionAtItemEnd = AVPlayerActionAtItemEndNone;

            self.avPlayer.muted = NO;

            [self.avPlayer addObserver:self
                                forKeyPath:@"status"
                                   options:NSKeyValueObservingOptionInitial | NSKeyValueObservingOptionNew
                                   context:nil];
        });
    }];

下面是KVO方法

- (void)observeValueForKeyPath:(NSString *)keyPath
                      ofObject:(id)object
                        change:(NSDictionary *)change
                       context:(void *)context {

    if (object == self.avPlayer && [keyPath isEqualToString:@"status"]) {

        if (self.avPlayer.status == AVPlayerStatusReadyToPlay) {

            [_videoProgressView setProgress:0 animated:NO];

            [self setVideoPlayEnabled];

            [self setAutoUpdateTimer];

            [[NSNotificationCenter defaultCenter] removeObserver:self name:AVPlayerItemDidPlayToEndTimeNotification object:[self.avPlayer currentItem]];

            [[NSNotificationCenter defaultCenter] addObserver:self
                                                     selector:@selector(playerItemDidReachEnd:)
                                                         name:AVPlayerItemDidPlayToEndTimeNotification
                                                       object:[self.avPlayer currentItem]];
        }
        else if (self.avPlayer.status == AVPlayerStatusFailed ||
                 self.avPlayer.status == AVPlayerStatusUnknown) {

            [SVProgressHUD dismiss];

            if (self.avPlayer.rate>0 && !self.avPlayer.error)
            {
                [self.avPlayer setRate:0.0];

                [self.avPlayer pause];
            }
        }
    }
}

- (void)playerItemDidReachEnd:(NSNotification *)notification {

    [SVProgressHUD dismiss];

    AVPlayerItem *p = [notification object];

    [p seekToTime:kCMTimeZero completionHandler:^(BOOL finished)
     {             
         [self.avPlayer play];
     }];
}

我从 "cellForItemAtIndexPath" 传给 url，我在 "didEndDisplayingCell" 暂停当前玩家。

然后在 "scrollViewDidEndDecelerating" 中，我刚刚检查了 customCell class（在全局变量上声明）的其他全局实例，并暂停了该单元当前播放器。

但 scrollViewDidEndDecelerating 的主要目的是获取当前可见单元格。

- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
    if (self.lastPlayingCell) {

        [self.lastPlayingCell.avPlayer pause];
    }

    // Play/Pause Video
    CGRect visibleRect = (CGRect){.origin = self.videoCollectionView.contentOffset, .size = self.videoCollectionView.bounds.size};

    CGPoint visiblePoint = CGPointMake(CGRectGetMidX(visibleRect), CGRectGetMidY(visibleRect));

    _visibleIndexPath = [self.videoCollectionView indexPathForItemAtPoint:visiblePoint];

    DetailsCollectionCell *cell = (DetailsCollectionCell *)[self.videoCollectionView cellForItemAtIndexPath:_visibleIndexPath];

    if (![cell isEqual: self.lastPlayingCell]) {

        [self.avPlayer play];

        self.lastPlayingCell = cell;//assigned to current visible cell to lastplayingcell instance. 
    }
}

我在这里告知的一件事，我只是将 AVPlayer 显示为 UIView class 的子视图。当我点击视频缩略图（UITableView 上已发布的视频信息列表在它的前一个视图上）时，我的意思是 UITable dodselect 函数，我只是显示 UIView 并移动它的 "Y" 位置值（就像一个当前视图控制器）。

所以我可以像 "Facebook messanger app camera access view" 那样移动视图 "Top & down" 方向。

所以当我关闭视图时，我需要释放 AVPlayer，停止所有观看视频的背景音频并删除注册的观察者 classes，如下所示。

- (void)setRemoveRegisteredObserversAndPlayerRelatedElements
{
    [self.avPlayer removeObserver:self forKeyPath:@"status" context:nil];

    [[NSNotificationCenter defaultCenter] removeObserver:self name:AVPlayerItemDidPlayToEndTimeNotification object:[self.avPlayer currentItem]];

    [self.avPlayerLayer.player pause];

    [self.avPlayer pause];

    self.avPlayer = [AVPlayer playerWithURL:[NSURL URLWithString:@""]];

    [self.avPlayerLayer removeFromSuperlayer];

    self.avPlayerLayer.player = nil;

    self.avPlayerLayer = nil;

    self.avPlayer = nil;
}

任何解决这些问题并在当前索引上流畅播放视频、停止音频和处理内存泄漏的想法。

任何人分享或提出一些建议来实现这一目标。

cellForItemAtIndexPath

- (UICollectionViewCell *) collectionView: (UICollectionView *) collectionView cellForItemAtIndexPath: (NSIndexPath *) indexPath
{
    videoDetailsCollectionCell *videoDetailCell = [collectionView dequeueReusableCellWithReuseIdentifier:kVideoDetailsCollectionCell forIndexPath:indexPath];

    NSDictionary *publishedVideoObject = [self.videoDetailArray objectAtIndex:indexPath.row];

    [videoDetailCell loadVideoURL:publishedVideoObject];

    return videoDetailCell;
}

我已经添加了 ZOWVideoPlayer 库文件中的所有 class 个文件。

最新编辑：

#pragma mark - Load video url for their current index cell
- (videoDetailsCollectionCell *)videoCellFor:(UICollectionView *)collectionView withIndex:(NSIndexPath *)indexPath
{
    videoDetailsCollectionCell * videoCell = [collectionView dequeueReusableCellWithReuseIdentifier:kCustomVideoCell forIndexPath:indexPath];

    //[videoCell.videoView.videoPlayer resume];

    return videoCell;
}

**在 CellForItemAtIndexPath 方法中**

 NSDictionary *publicationObject = [videoDetailArray objectAtIndex:indexPath.row];

    videoDetailsCollectionCell * cell = [self videoCellFor:collectionView withIndex:indexPath];

    cell.mediaUrl = [NSString replaceEmptyStringInsteadOfNull:[NSString stringWithFormat:@"%@",publicationObject.video]];

    return cell;

然后在 scrollViewDidScroll 我是 暂停最后播放的视频 正如你之前提到的。

然后在 scrollViewDidEndDecelerating 我按照下面的答案部分进行操作，除了使用 UICollectionView 而不是 IndexedCollectionView class 用于检索页数信息。

最后我停止了所有播放的视频，如下所示，

  - (void)setPauseTheLastViewedPlayerAudio {

        // Pause last played videos
        if (self.lastPlayedVideo) {

            [self.lastPlayedVideo mute];

            [self.lastPlayedVideo stopVideoPlay];
        }

        _videoDetailArray = nil;

        [_videoCollectionView reloadData];
    }

因为我应该使用 UIPanGestureRecognizer.

关闭用手指从上到下移动的播放器视图

Answer 1

前段时间我也在为同样的问题苦苦挣扎。我解决这个问题的方法与你的略有不同。

让我一步步解释

我已经在视图控制器中声明了播放器的全局实例，该实例包含当前视频单元播放器实例。
```
@property (nonatomic, strong) InstagramVideoView *sharedVideoPlayer; // Share video player instance
```

视频播放器对象是为每个单元格创建的，它们还为每个视频播放器保存视频 URL。

- (CommonVideoCollectionViewCell *)videoCellFor:(UICollectionView *)collectionView withIndex:(NSIndexPath *)indexPath {
    CommonVideoCollectionViewCell *videoCell = [collectionView dequeueReusableCellWithReuseIdentifier:VideoCollectionViewCellIdentifier forIndexPath:indexPath];
    return videoCell;
}
-(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
  CommonVideoCollectionViewCell *cell = [self videoCellFor:collectionView withIndex:indexPath];
  cell.mediaUrl = tempMedia.media;
  return cell;
}

每次用户尝试滚动集合单元格时，从视频播放器的全局实例暂停视频。这解决了单元格的闪烁问题。

// Pause last played videos if (self.sharedVideoPlayer) { [self.sharedVideoPlayer pause]; [self.sharedVideoPlayer mute]; }

最后一步是在水平集合视图的中心找到当前视频单元格并播放我们保存在当前视频单元格中的URL视频。

-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView {
  if ([scrollView isKindOfClass:[UITableView class]]) {
    return;
  }

IndexedCollectionView *pageContentCollectionView = (IndexedCollectionView *)scrollView;
CGPoint centerPoint = CGPointMake(pageContentCollectionView.center.x + pageContentCollectionView.contentOffset.x,
                              pageContentCollectionView.center.y + pageContentCollectionView.contentOffset.y);

NSIndexPath *centerCellIndexPath = [pageContentCollectionView indexPathForItemAtPoint:centerPoint];
NSArray *visibleCells = [pageContentCollectionView visibleCells];
// Get cell for index & pause video playback
UICollectionViewCell *cell = [pageContentCollectionView cellForItemAtIndexPath:centerCellIndexPath];

for (UICollectionViewCell *tempCell in visibleCells) {
if ([tempCell isKindOfClass:[CommonVideoCollectionViewCell class]]) {
    CommonVideoCollectionViewCell *videoCell = (CommonVideoCollectionViewCell *)tempCell;
    InstagramVideoView *videoPlayer = [videoCell videoView];
    // Pause & mute all the video player instance
    [videoCell.videoView setHidden:YES];
    [videoCell.placeholderImageView setHidden:NO];
    [videoPlayer pause];
    [videoPlayer mute];
    // Check if the central cell is present
    if (tempCell == cell) {
        self.sharedVideoPlayer = videoPlayer;// Save played video player instance
        [self.sharedVideoPlayer playVideoWithURL:[NSURL URLWithString:[(CommonVideoCollectionViewCell *)tempCell mediaUrl]]];
        [videoCell.videoView setHidden:NO];
        [videoCell.placeholderImageView setHidden:YES];
        [videoPlayer resume]; // resume video playback
        [videoPlayer mute];
    }
  }
 }
}

CommonVideoCollectionViewCell

#import<UIKit/UIKit.h>
#import "InstagramVideoView.h"
@interface CommonVideoCollectionViewCell : UICollectionViewCell
@property (weak, nonatomic) IBOutlet InstagramVideoView *videoView;
@property (weak, nonatomic) IBOutlet UIImageView *placeholderImageView;
// Set media url
@property (strong, nonatomic) NSString *mediaUrl;
@end

最终结果-

注意 - 为了流畅地播放视频，播放器将视频缓存在临时内存中。如果您在以下任何步骤中遇到问题，请告诉我。

在 UICollectionView 上使用 AVPlayer 和 AVPlayerLayer 显示多个视频

Display multiple videos using AVPlayer and AVPlayerLayer on UICollectionView

objective-c

video-streaming

avplayer

avplayerlayer

avplayeritem