Extend video render size and add background ios swift

🎤 General Discussion Swift
3

Hi I’m actually having a very similar issue to the one above, I’m using one of ray wanderlichs’s old tutorial on how to merge two videos using avfoundation and when ever i do that the output video is never centered, the scale aspect ratio of the video is fine its just the video isnt centered on the screen like its supposed to, any help please ?
here is my layer instruction code:

static func orientationFromTransform(_ transform: CGAffineTransform) → (orientation: UIImage.Orientation, isPortrait: Bool) {
var assetOrientation = UIImage.Orientation.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)
}

static func videoCompositionInstruction(_ track: AVCompositionTrack, asset: AVAsset) -> AVMutableVideoCompositionLayerInstruction {
    let instruction = AVMutableVideoCompositionLayerInstruction(assetTrack: track)
    let assetTrack = asset.tracks(withMediaType: AVMediaType.video)[0]
    
    let transform = assetTrack.preferredTransform
    let assetInfo = orientationFromTransform(transform)
    
    var scaleToFitRatio = UIScreen.main.bounds.width / assetTrack.naturalSize.width
    if assetInfo.isPortrait {
        scaleToFitRatio = UIScreen.main.bounds.width / assetTrack.naturalSize.height
        let scaleFactor = CGAffineTransform(scaleX: scaleToFitRatio, y: scaleToFitRatio)
        instruction.setTransform(assetTrack.preferredTransform.concatenating(scaleFactor), at: CMTime.zero)
    } else {
        let scaleFactor = CGAffineTransform(scaleX: scaleToFitRatio, y: scaleToFitRatio)
        var concat = assetTrack.preferredTransform.concatenating(scaleFactor)
            .concatenating(CGAffineTransform(translationX: 0, y: UIScreen.main.bounds.width / 2))
        if assetInfo.orientation == .down {
            let fixUpsideDown = CGAffineTransform(rotationAngle: CGFloat(Double.pi))
            let windowBounds = UIScreen.main.bounds
            let yFix = assetTrack.naturalSize.height + windowBounds.height
            let centerFix = CGAffineTransform(translationX: assetTrack.naturalSize.width, y: yFix)
            concat = fixUpsideDown.concatenating(centerFix).concatenating(scaleFactor)
        }
        instruction.setTransform(concat, at: CMTime.zero)
    }
    
    return instruction
}