Scale video view based on the aspect ratio

Question

I want to scale a video stream on devices with different screen sizes. The sender's video size can be different also.

The code what I have till now:

public func videoView(_ videoView: RTCEAGLVideoView, didChangeVideoSize size: CGSize) {
        // scale by height
        let w = renderer.bounds.height * size.width / size.height
        let h = renderer.bounds.height
        let x = (w - renderer.bounds.width) / 2
        renderer.frame = CGRect(x: -x, y: 0, width: w, height: h)
    }

The renderer is a view where the video is rendered in. This scales, but not in the right way. Some part of the video is lost, the height is fine. But the width is cropped what I understand.

Is it possible to achieve a solution that displays the video full screen (on the receiver side) without losing its aspect ratio?

Answer 1

Try using AVMakeRect(aspectRatio:insideRect). This method finds the minimum rect that preserves the aspectRatio inside the specified rect.

You can read more about it here

In general you will specify your UIScreen bounds as an insideRect: parameter and the size of your media in aspectRatio. There might be a case where the rect would be slightly smaller than your UIScreen size. In that case i suggest using technique called letter boxing