partial void ChooseVideoTapped(UIBarButtonItem sender)
{
var videoPicker = new UIImagePickerController {
ModalPresentationStyle = UIModalPresentationStyle.CurrentContext,
SourceType = UIImagePickerControllerSourceType.SavedPhotosAlbum,
MediaTypes = new string[] { UTType.Movie }
};
videoPicker.FinishedPickingMedia += (object s, UIImagePickerMediaPickedEventArgs e) => {
displayLink.Paused = true;
playButton.Title = "Play";
popover.Dismiss(true);
outputFrames.Clear();
presentationTimes.Clear();
lastCallbackTime = 0.0;
var asset = AVAsset.FromUrl(e.MediaUrl);
if (assetReader != null && assetReader.Status == AVAssetReaderStatus.Reading)
{
bufferSemaphore.Release();
assetReader.CancelReading();
}
backgroundQueue.DispatchAsync(() => ReadSampleBuffers(asset));
};
videoPicker.Canceled += (object s, EventArgs e) => DismissViewController(true, null);
if (UIDevice.CurrentDevice.UserInterfaceIdiom == UIUserInterfaceIdiom.Pad)
{
popover = new UIPopoverController(videoPicker);
popover.PresentFromBarButtonItem(sender, UIPopoverArrowDirection.Down, true);
}
}
private void StartReadingAndWriting()
{
// Instruct the asset reader and asset writer to get ready to do work
if (!_assetReader.StartReading())
{
throw new NSErrorException(_assetReader.Error);
}
if (!_assetWriter.StartWriting())
{
throw new NSErrorException(_assetWriter.Error);
}
// Start a sample-writing session
_assetWriter.StartSessionAtSourceTime(_timeRange.Start);
// Only set audio handler(obj-c delegate) for audio-only assets, else let the video channel drive progress
AVReaderWriter audioHandler = _videoSampleBufferChannel == null ? this : null;
var audioTask = StartReadingAsync(_audioSampleBufferChannel, audioHandler);
var videoTask = StartReadingAsync(_videoSampleBufferChannel, this);
// Set up a callback for when the sample writing is finished
Task.WhenAll(audioTask, videoTask).ContinueWith(_ => {
if (_cancellationTokenSrc.Token.IsCancellationRequested)
{
_assetReader.CancelReading();
_assetWriter.CancelWriting();
throw new OperationCanceledException();
}
if (_assetReader.Status != AVAssetReaderStatus.Failed)
{
_assetWriter.FinishWriting(() => {
bool success = _assetWriter.Status == AVAssetWriterStatus.Completed;
ReadingAndWritingDidFinish(success, _assetWriter.Error);
});
}
}, _cancellationTokenSrc.Token);
}
void StartReadingAndWriting(CMTimeRange timeRange)
{
// Instruct the asset reader and asset writer to get ready to do work
if (!assetReader.StartReading())
{
throw new NSErrorException(assetReader.Error);
}
if (!assetWriter.StartWriting())
{
throw new NSErrorException(assetWriter.Error);
}
// Start a sample-writing session
assetWriter.StartSessionAtSourceTime(timeRange.Start);
Task audioTask = Start(audioSampleBufferChannel);
Task videoTask = Start(videoSampleBufferChannel);
// Set up a callback for when the sample writing is finished
Task.WhenAll(audioTask, videoTask).ContinueWith(_ => {
if (cancellationTokenSrc.Token.IsCancellationRequested)
{
assetReader.CancelReading();
assetWriter.CancelWriting();
throw new OperationCanceledException();
}
if (assetReader.Status != AVAssetReaderStatus.Failed)
{
assetWriter.FinishWriting(() => {
bool success = assetWriter.Status == AVAssetWriterStatus.Completed;
ReadingAndWritingDidFinish(success, assetWriter.Error);
});
}
}, cancellationTokenSrc.Token);
}