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我在使用ray wenderlich中的視頻合併教程。我總是得到90度旋轉的視頻。當我添加一些不同的咖啡因旋轉代碼時，我的視頻無法看到。你能告訴我，我的代碼包括CGAffineTransformMakeRotation。Swift中的視頻合併方向
我的代碼如下
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)
}
func videoCompositionInstructionForTrack(track: AVCompositionTrack, asset: AVAsset) -> AVMutableVideoCompositionLayerInstruction {
// 1
let instruction = AVMutableVideoCompositionLayerInstruction(assetTrack: track)
// 2
let assetTrack = asset.tracksWithMediaType(AVMediaTypeVideo)[0] as! AVAssetTrack
// 3
var transform = assetTrack.preferredTransform
let assetInfo = orientationFromTransform(transform)
var scaleToFitRatio = UIScreen.mainScreen().bounds.width/assetTrack.naturalSize.width
if assetInfo.isPortrait {
// 4
print("ppppp")
scaleToFitRatio = UIScreen.mainScreen().bounds.width/assetTrack.naturalSize.height
let scaleFactor = CGAffineTransformMakeScale(scaleToFitRatio, scaleToFitRatio)
//instruction.setTransform(t2, atTime: kCMTimeZero)
instruction.setTransform(CGAffineTransformConcat(assetTrack.preferredTransform, scaleFactor),
atTime: kCMTimeZero)
} else {
// 5
let scaleFactor = CGAffineTransformMakeScale(scaleToFitRatio, scaleToFitRatio)
var concat = CGAffineTransformConcat(CGAffineTransformConcat(assetTrack.preferredTransform, scaleFactor), CGAffineTransformMakeTranslation(0, UIScreen.mainScreen().bounds.width/2))
if assetInfo.orientation == .Down {
print("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
}