CtsVideoCallView.swift

// MARK: - AVCaptureVideoDataOutputSampleBufferDelegate extension {{{
extension CtsVideoCallView: AVCaptureVideoDataOutputSampleBufferDelegate {
  func captureOutput(_ captureOutput: AVCaptureOutput!,
      didOutputSampleBuffer sampleBuffer: CMSampleBuffer!,
      from: AVCaptureConnection!) {
    // get image size for preview and resize preview view accordingly
    let pixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer)
    let attachmentMode = CMAttachmentMode(kCMAttachmentMode_ShouldPropagate)
    let attachments = CMCopyDictionaryOfAttachments(kCFAllocatorDefault, sampleBuffer, attachmentMode)
    let ciImage:CIImage = CIImage(cvPixelBuffer: pixelBuffer!, options: attachments as! [String : Any]?)

    let height = ciImage.extent.height
    let width = ciImage.extent.width

    let videoSizePx = CGSize(width: width, height: height)

    self.localVideoResolution = videoSizePx

    // forward call to rtc video capture
    if let rtcVideoDataOutput = self.rtcVideoDataOutput {
      rtcVideoDataOutput.sampleBufferDelegate.captureOutput?(rtcVideoDataOutput, didOutputSampleBuffer: sampleBuffer, from: from)
    }
  }
}
// }}} AVCaptureVideoDataOutputSampleBufferDelegate extension