AVFoundation exporting orientation wrong

Question

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

Answer 1

here is the document for the orientation at Apple:

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

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!

Answer 2

Maybe U should check the videoTrack's preferredTransform so to give it a exact renderSize and transform:

CGAffineTransform transform = assetVideoTrack.preferredTransform;
CGFloat rotation = [self rotationWithTransform:transform]; 
//if been rotated
        if (rotation != 0)
        {
            //if rotation is 360°
            if (fabs((rotation - M_PI * 2)) >= valueOfError) {

                CGFloat m = rotation / M_PI;
                CGAffineTransform t1;
                //rotation is 90° or 270°
                if (fabs(m - 1/2.0) < valueOfError || fabs(m - 3/2.0) < valueOfError) {
                    self.mutableVideoComposition.renderSize = CGSizeMake(assetVideoTrack.naturalSize.height,assetVideoTrack.naturalSize.width);
                    t1 = CGAffineTransformMakeTranslation(assetVideoTrack.naturalSize.height, 0);
                }
                //rotation is 180°
                if (fabs(m - 1.0) < valueOfError) {
                    t1 = CGAffineTransformMakeTranslation(assetVideoTrack.naturalSize.width, assetVideoTrack.naturalSize.height);
                }
                CGAffineTransform t2 = CGAffineTransformRotate(t1,rotation);
                //                CGAffineTransform transform = makeTransform(1.0, 1.0, 90, videoTrack.naturalSize.height, 0);
                [passThroughLayer setTransform:t2 atTime:kCMTimeZero];
            }
        }

//convert transform to radian
- (CGFloat)rotationWithTransform:(CGAffineTransform)t
{
    return atan2f(t.b, t.a);
}