/// <summary>
/// Records an MP4 video to a StorageFile and adds rotation metadata to it
/// </summary>
/// <returns></returns>
private async Task StartRecordingAsync()
{
try
{
// Create storage file for the capture
var videoFile = await _captureFolder.CreateFileAsync("SimpleVideo.mp4", CreationCollisionOption.GenerateUniqueName);
var encodingProfile = MediaEncodingProfile.CreateMp4(VideoEncodingQuality.Auto);
// Calculate rotation angle, taking mirroring into account if necessary
var rotationAngle = CameraRotationHelper.ConvertSimpleOrientationToClockwiseDegrees(_rotationHelper.GetCameraCaptureOrientation());
encodingProfile.Video.Properties.Add(RotationKey, PropertyValue.CreateInt32(rotationAngle));
Debug.WriteLine("Starting recording to " + videoFile.Path);
await _mediaCapture.StartRecordToStorageFileAsync(encodingProfile, videoFile);
_isRecording = true;
Debug.WriteLine("Started recording!");
}
catch (Exception ex)
{
// File I/O errors are reported as exceptions
Debug.WriteLine("Exception when starting video recording: " + ex.ToString());
}
}
/// <summary>
/// Uses the current device orientation in space and page orientation on the screen to calculate the rotation
/// transformation to apply to the controls
/// </summary>
private void UpdateButtonOrientation()
{
// Rotate the buttons in the UI to match the rotation of the device
var angle = CameraRotationHelper.ConvertSimpleOrientationToClockwiseDegrees(_rotationHelper.GetUIOrientation());
var transform = new RotateTransform {
Angle = angle
};
// The RenderTransform is safe to use (i.e. it won't cause layout issues) in this case, because these buttons have a 1:1 aspect ratio
PhotoButton.RenderTransform = transform;
VideoButton.RenderTransform = transform;
}
/// <summary>
/// Gets the current orientation of the UI in relation to the device (when AutoRotationPreferences cannot be honored) and applies a corrective rotation to the preview
/// </summary>
private async Task SetPreviewRotationAsync()
{
// Only need to update the orientation if the camera is mounted on the device
if (_externalCamera)
{
return;
}
// Add rotation metadata to the preview stream to make sure the aspect ratio / dimensions match when rendering and getting preview frames
var rotation = _rotationHelper.GetCameraPreviewOrientation();
var props = _mediaCapture.VideoDeviceController.GetMediaStreamProperties(MediaStreamType.VideoPreview);
props.Properties.Add(RotationKey, CameraRotationHelper.ConvertSimpleOrientationToClockwiseDegrees(rotation));
await _mediaCapture.SetEncodingPropertiesAsync(MediaStreamType.VideoPreview, props, null);
}