AVFoundation 导出方向错误

我正在尝试将图像和视频结合起来。我将它们组合并导出，但它是横向旋转的。

抱歉批量粘贴代码。我已经看到了有关应用转换的答案compositionVideoTrack.preferredTransform但这没有任何作用。添加到AVMutableVideoCompositionInstruction也什么都不做。

我觉得这个领域是事情开始出错的地方。这儿这儿：

// I feel like this loading here is the problem
        let videoTrack = videoAsset.tracksWithMediaType(AVMediaTypeVideo)[0]

        // because it makes our parentLayer and videoLayer sizes wrong
        let videoSize       = videoTrack.naturalSize

        // this is returning 1920x1080, so it is rotating the video
        print("\(videoSize.width) , \(videoSize.height)")

所以到这里我们的帧大小对于方法的其余部分来说是错误的。现在，当我们尝试创建覆盖图像层时，框架不正确：

    let aLayer = CALayer()
    aLayer.contents = UIImage(named: "OverlayTestImageOverlay")?.CGImage
    aLayer.frame = CGRectMake(0, 0, videoSize.width, videoSize.height)
    aLayer.opacity = 1

这是我的完整方法。

  func combineImageVid() {

        let path = NSBundle.mainBundle().pathForResource("SampleMovie", ofType:"MOV")
        let fileURL = NSURL(fileURLWithPath: path!)

        let videoAsset = AVURLAsset(URL: fileURL)
        let mixComposition = AVMutableComposition()

        let compositionVideoTrack = mixComposition.addMutableTrackWithMediaType(AVMediaTypeVideo, preferredTrackID: kCMPersistentTrackID_Invalid)

        var clipVideoTrack = videoAsset.tracksWithMediaType(AVMediaTypeVideo)

        do {
            try compositionVideoTrack.insertTimeRange(CMTimeRangeMake(kCMTimeZero, videoAsset.duration), ofTrack: clipVideoTrack[0], atTime: kCMTimeZero)
        }
        catch _ {
            print("failed to insertTimeRange")
        }


        compositionVideoTrack.preferredTransform = videoAsset.preferredTransform

        // I feel like this loading here is the problem
        let videoTrack = videoAsset.tracksWithMediaType(AVMediaTypeVideo)[0]

        // because it makes our parentLayer and videoLayer sizes wrong
        let videoSize       = videoTrack.naturalSize

        // this is returning 1920x1080, so it is rotating the video
        print("\(videoSize.width) , \(videoSize.height)")

        let aLayer = CALayer()
        aLayer.contents = UIImage(named: "OverlayTestImageOverlay")?.CGImage
        aLayer.frame = CGRectMake(0, 0, videoSize.width, videoSize.height)
        aLayer.opacity = 1


        let parentLayer     = CALayer()
        let videoLayer      = CALayer()

        parentLayer.frame   = CGRectMake(0, 0, videoSize.width, videoSize.height)
        videoLayer.frame    = CGRectMake(0, 0, videoSize.width, videoSize.height)

        parentLayer.addSublayer(videoLayer)
        parentLayer.addSublayer(aLayer)


        let videoComp = AVMutableVideoComposition()
        videoComp.renderSize = videoSize
        videoComp.frameDuration = CMTimeMake(1, 30)
        videoComp.animationTool = AVVideoCompositionCoreAnimationTool(postProcessingAsVideoLayer: videoLayer, inLayer: parentLayer)

        let instruction = AVMutableVideoCompositionInstruction()

        instruction.timeRange = CMTimeRangeMake(kCMTimeZero, mixComposition.duration)

        let mixVideoTrack = mixComposition.tracksWithMediaType(AVMediaTypeVideo)[0]
        mixVideoTrack.preferredTransform = CGAffineTransformMakeRotation(CGFloat(M_PI * 90.0 / 180))

        let layerInstruction = AVMutableVideoCompositionLayerInstruction(assetTrack: mixVideoTrack)
        instruction.layerInstructions = [layerInstruction]
        videoComp.instructions = [instruction]


        //  create new file to receive data
        let dirPaths = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)
        let docsDir: AnyObject = dirPaths[0]
        let movieFilePath = docsDir.stringByAppendingPathComponent("result.mov")
        let movieDestinationUrl = NSURL(fileURLWithPath: movieFilePath)

        do {
            try NSFileManager.defaultManager().removeItemAtPath(movieFilePath)
        }
        catch _ {}


        // use AVAssetExportSession to export video
        let assetExport = AVAssetExportSession(asset: mixComposition, presetName:AVAssetExportPresetHighestQuality)
        assetExport?.videoComposition = videoComp
        assetExport!.outputFileType = AVFileTypeQuickTimeMovie
        assetExport!.outputURL = movieDestinationUrl
        assetExport!.exportAsynchronouslyWithCompletionHandler({
            switch assetExport!.status{
            case  AVAssetExportSessionStatus.Failed:
                print("failed \(assetExport!.error)")
            case AVAssetExportSessionStatus.Cancelled:
                print("cancelled \(assetExport!.error)")
            default:
                print("Movie complete")


                // play video
                NSOperationQueue.mainQueue().addOperationWithBlock({ () -> Void in
                    print(movieDestinationUrl)
                })
            }
        })
    }

This is what I'm getting exported:

我尝试添加这两种方法来旋转视频：

class func videoCompositionInstructionForTrack(track: AVCompositionTrack, asset: AVAsset) -> AVMutableVideoCompositionLayerInstruction {

    let instruction = AVMutableVideoCompositionLayerInstruction(assetTrack: track)

    let assetTrack = asset.tracksWithMediaType(AVMediaTypeVideo)[0]

    let transform = assetTrack.preferredTransform
    let assetInfo = orientationFromTransform(transform)
    var scaleToFitRatio = UIScreen.mainScreen().bounds.width / assetTrack.naturalSize.width

    if assetInfo.isPortrait {

        scaleToFitRatio = UIScreen.mainScreen().bounds.width / assetTrack.naturalSize.height
        let scaleFactor = CGAffineTransformMakeScale(scaleToFitRatio, scaleToFitRatio)
        instruction.setTransform(CGAffineTransformConcat(assetTrack.preferredTransform, scaleFactor),
            atTime: kCMTimeZero)
    } else {

        let scaleFactor = CGAffineTransformMakeScale(scaleToFitRatio, scaleToFitRatio)
        var concat = CGAffineTransformConcat(CGAffineTransformConcat(assetTrack.preferredTransform, scaleFactor), CGAffineTransformMakeTranslation(0, UIScreen.mainScreen().bounds.width / 2))
        if assetInfo.orientation == .Down {
            let fixUpsideDown = CGAffineTransformMakeRotation(CGFloat(M_PI))
            let windowBounds = UIScreen.mainScreen().bounds
            let yFix = assetTrack.naturalSize.height + windowBounds.height
            let centerFix = CGAffineTransformMakeTranslation(assetTrack.naturalSize.width, yFix)
            concat = CGAffineTransformConcat(CGAffineTransformConcat(fixUpsideDown, centerFix), scaleFactor)
        }
        instruction.setTransform(concat, atTime: kCMTimeZero)
    }

    return instruction
}

class func orientationFromTransform(transform: CGAffineTransform) -> (orientation: UIImageOrientation, isPortrait: Bool) {
    var assetOrientation = UIImageOrientation.Up
    var isPortrait = false
    if transform.a == 0 && transform.b == 1.0 && transform.c == -1.0 && transform.d == 0 {
        assetOrientation = .Right
        isPortrait = true
    } else if transform.a == 0 && transform.b == -1.0 && transform.c == 1.0 && transform.d == 0 {
        assetOrientation = .Left
        isPortrait = true
    } else if transform.a == 1.0 && transform.b == 0 && transform.c == 0 && transform.d == 1.0 {
        assetOrientation = .Up
    } else if transform.a == -1.0 && transform.b == 0 && transform.c == 0 && transform.d == -1.0 {
        assetOrientation = .Down
    }
    return (assetOrientation, isPortrait)
}

更新了我的combineImageVid()方法将其添加到

let instruction = AVMutableVideoCompositionInstruction()

instruction.timeRange = CMTimeRangeMake(kCMTimeZero, mixComposition.duration)

let mixVideoTrack = mixComposition.tracksWithMediaType(AVMediaTypeVideo)[0]

//let layerInstruction = AVMutableVideoCompositionLayerInstruction(assetTrack: mixVideoTrack)
//layerInstruction.setTransform(videoAsset.preferredTransform, atTime: kCMTimeZero)

let layerInstruction = videoCompositionInstructionForTrack(compositionVideoTrack, asset: videoAsset)

这给了我这个输出：

所以我越来越接近了，但我觉得因为轨道最初加载的方式是错误的，所以我需要解决那里的问题。另外，我不知道为什么现在会有一个巨大的黑匣子。我想这可能是因为我的图像层占据了此处加载的视频资源的边界：

aLayer.frame = CGRectMake(0, 0, videoSize.width, videoSize.height)

然而，将其更改为较小的宽度/高度并没有什么区别。然后我考虑添加一个裁剪记录来消除黑色方块，但这也不起作用:(

遵循 Allens 不使用这两种方法的建议：

class func videoCompositionInstructionForTrack(track: AVCompositionTrack, asset: AVAsset) -> AVMutableVideoCompositionLayerInstruction

class func orientationFromTransform(transform: CGAffineTransform) -> (orientation: UIImageOrientation, isPortrait: Bool) 

但将我原来的方法更新为如下所示：

videoLayer.frame    = CGRectMake(0, 0, videoSize.height, videoSize.width) //notice the switched width and height
...
videoComp.renderSize = CGSizeMake(videoSize.height,videoSize.width) //this make the final video in portrait
...
layerInstruction.setTransform(videoTrack.preferredTransform, atTime: kCMTimeZero) //important piece of information let composition know you want to rotate the original video in output

我们已经非常接近了，但是现在的问题似乎是编辑renderSize。如果我将其更改为横向尺寸以外的任何尺寸，我会得到以下结果：

以下是 Apple 的入职培训文档：

https://developer.apple.com/library/ios/qa/qa1744/_index.html https://developer.apple.com/library/ios/qa/qa1744/_index.html

如果您的原始视频是在 iOS 纵向模式下拍摄的，它的自然尺寸仍然是横向的，但它在 mov 文件中带有旋转元数据。为了旋转视频，您需要对第一段代码进行以下更改：

videoLayer.frame    = CGRectMake(0, 0, videoSize.height, videoSize.width) //notice the switched width and height
...
videoComp.renderSize = CGSizeMake(videoSize.height,videoSize.width) //this make the final video in portrait
...
layerInstruction.setTransform(videoTrack.preferredTransform, atTime: kCMTimeZero) //important piece of information let composition know you want to rotate the original video in output

是的，你们真的很接近！