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random February 2016

AVFoundation exporting orientation wrong

I'm attempting to combine an image and a video. I have them combining and exporting however it's rotated side ways.

Sorry for the bulk code paste. I've seen answers about applying a transform to compositionVideoTrack.preferredTransform however that does nothing. Adding to AVMutableVideoCompositionInstruction does nothing also.

I feel like this area is where things start to go wrong. here here:

// 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)")

So by here our frame sizes are wrong for the rest of the method. Now when we try to go and create the overlay image layer the frame is not correct:

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

Here is my complete method.

  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 in        


Allen February 2016

here is the document for the orientation at Apple:


if your original video was taken in portrait mode iOS, it's nature size will still be landscape, but it comes with a metadata of rotate in the mov file. In order to rotate your video, you need to make changes to your 1st piece of code with the following:

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

Yes, you are really close!

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Asked in February 2016
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