AVAsset定向/旋转问题

Question

尝试使用雷大教程修复定向问题。

左-视频应该怎么看(肖像)，右不想要的旋转结果

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代码使用

   func setUpVideoNew()
    {

        let originalVideoTrack = asset.tracksWithMediaType(AVMediaTypeVideo)[0]
        let composition = AVMutableComposition()
        let videoTrack = composition.addMutableTrackWithMediaType(AVMediaTypeVideo, preferredTrackID: 1)
        let timeRange = originalVideoTrack.timeRange
        do {
            try videoTrack.insertTimeRange(timeRange, ofTrack: originalVideoTrack, atTime: kCMTimeZero)
        } catch {

        }
        let mainInstruction = AVMutableVideoCompositionInstruction()
        mainInstruction.timeRange = timeRange

        let firstlayerInstruction = AVMutableVideoCompositionLayerInstruction(assetTrack: videoTrack)
        let firstAssetTrack = originalVideoTrack


        //MARK - Fix Rotation
        var firstAssetOrientation_ = UIImageOrientation.Up

        var isFirstAssetPortrait_ = false

        var firstTransform = videoTrack.preferredTransform;
        if firstTransform.a == 0 && firstTransform.b == 1.0 && firstTransform.c == -1.0 && firstTransform.d == 0 {
            firstAssetOrientation_ = UIImageOrientation.Right;
            isFirstAssetPortrait_ = true;
        }
        if (firstTransform.a == 0 && firstTransform.b == -1.0 && firstTransform.c == 1.0 && firstTransform.d == 0) {
            firstAssetOrientation_ =  UIImageOrientation.Left;
            isFirstAssetPortrait_ = true;
        }
        if (firstTransform.a == 1.0 && firstTransform.b == 0 && firstTransform.c == 0 && firstTransform.d == 1.0) {
            firstAssetOrientation_ =  UIImageOrientation.Up;
        }
        if (firstTransform.a == -1.0 && firstTransform.b == 0 && firstTransform.c == 0 && firstTransform.d == -1.0) {
            firstAssetOrientation_ = UIImageOrientation.Down;
        }

        firstlayerInstruction.setTransform(asset.preferredTransform, atTime: kCMTimeZero)
        mainInstruction.layerInstructions = [firstlayerInstruction]


        let videoComposition = AVMutableVideoComposition()
        videoComposition.frameDuration = CMTimeMake(1, 30)
        videoComposition.instructions = [mainInstruction]

        var naturalSizeFirst = CGSize()

        if(isFirstAssetPortrait_){
            naturalSizeFirst = CGSizeMake(videoTrack.naturalSize.height, videoTrack.naturalSize.width);
        } else {
            naturalSizeFirst = videoTrack.naturalSize;
        }
        videoComposition.renderSize = naturalSizeFirst
        let playerItem = AVPlayerItem(asset: composition)
        playerItem.videoComposition = videoComposition
        player = AVPlayer(playerItem: playerItem)
        let playerLayer = AVPlayerLayer(player: player)
        print(videoPreview.frame)
        print(videoPreview.bounds)
        playerLayer.frame = self.videoPreview.bounds

        player.play()
        self.videoPreview.layer.addSublayer(playerLayer)



    }

有什么建议吗？

Answer 1

当状态栏改变方向时，您应该注册通知，如下所示：

    NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("statusBarOrientationChange:"), name: UIApplicationDidChangeStatusBarOrientationNotification, object: nil)

在此之后，用于编辑AVLayer维度的开关语句将如下所示

    switch (UIApplication.sharedApplication().statusBarOrientation){
        case .Unknown :
        case .PortraitUpsideDown :
        case .Portrait
        case .LandscapeLeft :
        case .LandscapeRight :
    }

当您到达正确的方向时，您将需要应用如下所示的CGAffineTransform：

asset.transform = CGAffineTransformMake(M_PI * (180) / 180.0)

希望这能帮上忙！

Answer 2

如果问题是在整个app中旋转中的iPhone，请确保应用程序在Info.plist文件中具有正确的支持接口方向。弹出到Info.plist中，检查下面两个数组(支持的接口方向和支持的接口方向(iPad) )。确保他们都增加了所有四个方向。如果没有，鼠标移动到支持的界面方向，按下箭头，然后按下显示在“支持的界面方向”上的+符号，然后添加任何缺失的方向。对“支持的接口方向(iPad)”数组也做同样的操作。

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如果这不起作用，--这可能是视频的一个问题。在这里查看问题并接受答案：如何解决iOS中的视频定位问题。这里有一个很好的方法可以将目标-c转换为https://objectivec2swift.com/#/converter/code。

如果您的应用程序不旋转，并且希望视频只旋转：：

将此放在您的视图中，您希望锁定在纵向模式中：

override func supportedInterfaceOrientations() -> UIInterfaceOrientationMask {
 return UIInterfaceOrientationMask.Portrait
}

然后，在您的视频视图中：

override func supportedInterfaceOrientations() -> UIInterfaceOrientationMask {
 return UIInterfaceOrientationMask.All
}

为了更好地衡量，您可能也希望这两个视图都是这样的：

override func shouldAutorotate() -> Bool {
 return true
}

资料来源：如何快速锁定主视图的纵向定位.