Question

我有用于显示AVPlayer播放的PlayerView类。代码来自documentation。

#import <UIKit/UIKit.h>
#import <AVFoundation/AVFoundation.h>

@interface PlayerView : UIView
@property (nonatomic) AVPlayer *player;
@end

@implementation PlayerView
+ (Class)layerClass {
    return [AVPlayerLayer class];
}
- (AVPlayer*)player {
    return [(AVPlayerLayer *)[self layer] player];
}
- (void)setPlayer:(AVPlayer *)player {
    [(AVPlayerLayer *)[self layer] setPlayer:player];
}
@end

我在此PlayerView中设置了我的AVPlayer（包含大小为320x240的视频资产）（frame.size.width = 100，frame.size.height = 100）并调整了我的视频大小。添加PlayerView后如何获得视频大小？

Answer 1

在 iOS 7.0 中添加了新功能：

AVPlayerLayer 拥有 videoRect 属性。

Answer 2

找到解决方案：

添加到PlayerView类：

- (CGRect)videoContentFrame {
    AVPlayerLayer *avLayer = (AVPlayerLayer *)[self layer];
    // AVPlayerLayerContentLayer
    CALayer *layer = (CALayer *)[[avLayer sublayers] objectAtIndex:0];
    CGRect transformedBounds = CGRectApplyAffineTransform(layer.bounds, CATransform3DGetAffineTransform(layer.sublayerTransform));
    return transformedBounds;
}

Answer 3

这是适用于我的解决方案，它考虑了AVPlayer在视图中的位置。我刚刚将它添加到PlayerView自定义类中。我必须解决这个问题，因为看起来videoRect在10.7中没有工作。

- (NSRect) videoRect {
    NSRect theVideoRect = NSMakeRect(0,0,0,0);
    NSRect theLayerRect = self.playerLayer.frame;

    NSSize theNaturalSize = NSSizeFromCGSize([[[self.movie asset] tracksWithMediaType:AVMediaTypeVideo][0] naturalSize]);
    float movieAspectRatio = theNaturalSize.width/theNaturalSize.height;
    float viewAspectRatio = theLayerRect.size.width/theLayerRect.size.height;
    if (viewAspectRatio < movieAspectRatio) {
        theVideoRect.size.width = theLayerRect.size.width;
        theVideoRect.size.height = theLayerRect.size.width/movieAspectRatio;
        theVideoRect.origin.x = 0;
        theVideoRect.origin.y = (theLayerRect.size.height/2) - (theVideoRect.size.height/2);
}
    else if (viewAspectRatio > movieAspectRatio) {

        theVideoRect.size.width = movieAspectRatio * theLayerRect.size.height;
        theVideoRect.size.height = theLayerRect.size.height;
        theVideoRect.origin.x = (theLayerRect.size.width/2) - (theVideoRect.size.width/2);
        theVideoRect.origin.y = 0;
    }
    return theVideoRect;
}

Answer 4

这是移植到iOS的Eric Badros' answer。我还添加了preferredTransform处理。这假定_player是AVPlayer

- (CGRect) videoRect {
    CGRect theVideoRect = CGRectZero;

    // Replace this with whatever frame your AVPlayer is playing inside of:
    CGRect theLayerRect = self.playerLayer.frame;

    AVAssetTrack *track = [_player.currentItem.asset tracksWithMediaType:AVMediaTypeVideo][0];
    CGSize theNaturalSize = [track naturalSize];
    theNaturalSize = CGSizeApplyAffineTransform(theNaturalSize, track.preferredTransform);
    theNaturalSize.width = fabs(theNaturalSize.width);
    theNaturalSize.height = fabs(theNaturalSize.height);

    CGFloat movieAspectRatio = theNaturalSize.width / theNaturalSize.height;
    CGFloat viewAspectRatio = theLayerRect.size.width / theLayerRect.size.height;

    // Note change this *greater than* to a *less than* if your video will play in aspect fit mode (as opposed to aspect fill mode)
    if (viewAspectRatio > movieAspectRatio) {
        theVideoRect.size.width = theLayerRect.size.width;
        theVideoRect.size.height = theLayerRect.size.width / movieAspectRatio;
        theVideoRect.origin.x = 0;
        theVideoRect.origin.y = (theLayerRect.size.height - theVideoRect.size.height) / 2;
    } else if (viewAspectRatio < movieAspectRatio) {
        theVideoRect.size.width = movieAspectRatio * theLayerRect.size.height;
        theVideoRect.size.height = theLayerRect.size.height;
        theVideoRect.origin.x = (theLayerRect.size.width - theVideoRect.size.width) / 2;
        theVideoRect.origin.y = 0;
    }
    return theVideoRect;
}

Answer 5

这对我有用。如果您没有AVPLayerLayer。

- (CGRect)videoRect {
    // @see http://stackoverflow.com/a/6565988/1545158

    AVAssetTrack *track = [[self.player.currentItem.asset tracksWithMediaType:AVMediaTypeVideo] firstObject];
    if (!track) {
        return CGRectZero;
    }

    CGSize trackSize = [track naturalSize];
    CGSize videoViewSize = self.videoView.bounds.size;

    CGFloat trackRatio = trackSize.width / trackSize.height;
    CGFloat videoViewRatio = videoViewSize.width / videoViewSize.height;

    CGSize newSize;

    if (videoViewRatio > trackRatio) {
        newSize = CGSizeMake(trackSize.width * videoViewSize.height / trackSize.height, videoViewSize.height);
    } else {
        newSize = CGSizeMake(videoViewSize.width, trackSize.height * videoViewSize.width / trackSize.width);
    }

    CGFloat newX = (videoViewSize.width - newSize.width) / 2;
    CGFloat newY = (videoViewSize.height - newSize.height) / 2;

    return CGRectMake(newX, newY, newSize.width, newSize.height);

}

Answer 6

这是一个基于 Andrey Banshchikov's answer 的 Swift 解决方案。当您无法访问 AVPLayerLayer 时，他的解决方案特别有用。

func currentVideoFrameSize(playerView: AVPlayerView, player: AVPlayer) -> CGSize {
    // See https://stackoverflow.com/a/40164496/1877617
    let track = player.currentItem?.asset.tracks(withMediaType: .video).first
    if let track = track {
        let trackSize      = track.naturalSize
        let videoViewSize  = playerView.bounds.size
        let trackRatio     = trackSize.width / trackSize.height
        let videoViewRatio = videoViewSize.width / videoViewSize.height
        
        var newSize: CGSize

        if videoViewRatio > trackRatio {
            newSize = CGSize(width: trackSize.width * videoViewSize.height / trackSize.height, height: videoViewSize.height)
        } else {
            newSize = CGSize(width: videoViewSize.width, height: trackSize.height * videoViewSize.width / trackSize.width)
        }
        
        return newSize
    }
    return CGSize.zero
}

如何获取AVPlayer的视频帧？

6 个答案: