A few how to questions on CaptureDevice: Microsoft.Devices

Question

Hi. I'm using CaptureDevice to capture videos (
vcDevice =
CaptureDeviceConfiguration.GetDefaultVideoCaptureDevice();
1. How to I set the recording resolution? (I tried setting the canvas/videobrush resolution but the playback is still normal)
2. How do I get the current size of captured file ex while recording I want to update a textblock and as the video records I want to show how many MB the file is now.
3. does keeping the video preview on uses a lot of battery power?
thanks

Answer 1

this is what I have so far:
// Viewfinder for capturing video.
private VideoBrush videoRecorderBrush;
// Source and device for capturing video.
private CaptureSource _cs;
private AudioVideoCaptureDevice vcDevice;
double w, h;
// File details for storing the recording.
private IsolatedStorageFileStream isoVideoFile;
private FileSink fileSink;
private string isoVideoFileName = "iClips_Video.mp4";
private StorageFile sfVideoFile;
protected async override void OnNavigatedTo(NavigationEventArgs e)
base.OnNavigatedTo(e);
// Initialize the video recorder.
await InitializeVideoRecorder();
//prepare shutter hot keys
CameraButtons.ShutterKeyHalfPressed += OnButtonHalfPress;
CameraButtons.ShutterKeyPressed += OnButtonFullPress;
CameraButtons.ShutterKeyReleased += OnButtonRelease;
// Update the buttons and text on the UI thread based on app state.
private void UpdateUI(ButtonState currentButtonState, string statusMessage)
// Run code on the UI thread.
Dispatcher.BeginInvoke(delegate
switch (currentButtonState)
// When the camera is not supported by the phone.
case ButtonState.CameraNotSupported:
StartRecording.IsEnabled = false;
StopPlaybackRecording.IsEnabled = false;
StartPlayback.IsEnabled = false;
PausePlayback.IsEnabled = false;
break;
// First launch of the application, so no video is available.
case ButtonState.Initialized:
StartRecording.IsEnabled = true;
StopPlaybackRecording.IsEnabled = false;
StartPlayback.IsEnabled = false;
PausePlayback.IsEnabled = false;
break;
// Ready to record, so video is available for viewing.
case ButtonState.Ready:
StartRecording.IsEnabled = true;
StopPlaybackRecording.IsEnabled = false;
StartPlayback.IsEnabled = true;
PausePlayback.IsEnabled = false;
break;
// Video recording is in progress.
case ButtonState.Recording:
StartRecording.IsEnabled = false;
StopPlaybackRecording.IsEnabled = true;
StartPlayback.IsEnabled = false;
PausePlayback.IsEnabled = false;
break;
// Video playback is in progress.
case ButtonState.Playback:
StartRecording.IsEnabled = false;
StopPlaybackRecording.IsEnabled = true;
StartPlayback.IsEnabled = false;
PausePlayback.IsEnabled = true;
break;
// Video playback has been paused.
case ButtonState.Paused:
StartRecording.IsEnabled = false;
StopPlaybackRecording.IsEnabled = true;
StartPlayback.IsEnabled = true;
PausePlayback.IsEnabled = false;
break;
default:
break;
// Display a message.
txtDebug.Text = statusMessage;
// Note the current application state.
currentAppState = currentButtonState;
public async Task InitializeVideoRecorder()
try
if (_cs == null)
CaptureDevice cd= CaptureDeviceConfiguration.GetDefaultVideoCaptureDevice();
_cs = cd as CaptureSource;
CameraSensorLocation location = CameraSensorLocation.Back;
var captureResolutions =
AudioVideoCaptureDevice.GetAvailableCaptureResolutions(location);
vcDevice =
await AudioVideoCaptureDevice.OpenAsync(location,
captureResolutions[0]);
vcDevice.RecordingFailed += OnCaptureFailed;
vcDevice.VideoEncodingFormat = CameraCaptureVideoFormat.H264;
vcDevice.AudioEncodingFormat = CameraCaptureAudioFormat.Aac;
// Initialize the camera if it exists on the phone.
if (vcDevice != null)
//initialize fileSink
InitializeFileSink();
// Create the VideoBrush for the viewfinder.
videoRecorderBrush = new VideoBrush();
videoRecorderBrush.SetSource(CaptureDeviceConfiguration.GetDefaultVideoCaptureDevice());
// Display the viewfinder image on the rectangle.
viewfinderRectangle.Fill = videoRecorderBrush;
// Set the button state and the message.
UpdateUI(ButtonState.Initialized, "Tap record to start recording...");
else
// Disable buttons when the camera is not supported by the phone.
UpdateUI(ButtonState.CameraNotSupported, "A camera is not supported on this phone.");
catch(Exception ex)
MessageBox.Show("InitializeVideoRecorder Error:\n" + ex.Message);
public async void InitializeFileSink()
StorageFolder isoStore = ApplicationData.Current.LocalFolder;
sfVideoFile = await isoStore.CreateFileAsync(
isoVideoFileName,
CreationCollisionOption.ReplaceExisting);
private void OnCaptureFailed(AudioVideoCaptureDevice sender, CaptureFailedEventArgs args)
MessageBox.Show(args.ToString());
private void OnCaptureSourceFailed(object sender, ExceptionRoutedEventArgs e)
MessageBox.Show(e.ErrorException.Message.ToString());
// Set the recording state: display the video on the viewfinder.
private void StartVideoPreview()
try
// Display the video on the viewfinder.
if (_cs.VideoCaptureDevice != null
&& _cs.State == CaptureState.Stopped)
// Add captureSource to videoBrush.
videoRecorderBrush.SetSource(_cs);
// Add videoBrush to the visual tree.
viewfinderRectangle.Fill = videoRecorderBrush;
_cs.Start();
// Set the button states and the message.
UpdateUI(ButtonState.Ready, "Ready to record.");
//Create optional Resolutions
// If preview fails, display an error.
catch (Exception e)
this.Dispatcher.BeginInvoke(delegate()
txtDebug.Text = "ERROR: " + e.Message.ToString();
// Set recording state: start recording.
private void StartVideoRecording()
try
// Connect fileSink to captureSource.
if (_cs.VideoCaptureDevice != null
&& _cs.State == CaptureState.Started)
_cs.Stop();
// Connect the input and output of fileSink.
fileSink.CaptureSource = _cs;
fileSink.IsolatedStorageFileName = isoVideoFileName;
// Begin recording.
if (_cs.VideoCaptureDevice != null
&& _cs.State == CaptureState.Stopped)
_cs.Start();
// Set the button states and the message.
UpdateUI(ButtonState.Recording, "Recording...");
StartTimer();
// If recording fails, display an error.
catch (Exception e)
this.Dispatcher.BeginInvoke(delegate()
txtDebug.Text = "ERROR: " + e.Message.ToString();
// Set the recording state: stop recording.
private void StopVideoRecording()
try
// Stop recording.
if (_cs.VideoCaptureDevice != null
&& _cs.State == CaptureState.Started)
_cs.Stop();
// Disconnect fileSink.
fileSink.CaptureSource = null;
fileSink.IsolatedStorageFileName = null;
// Set the button states and the message.
UpdateUI(ButtonState.Stopped, "Preparing viewfinder...");
StopTimer();
StartVideoPreview();
// If stop fails, display an error.
catch (Exception e)
this.Dispatcher.BeginInvoke(delegate()
txtDebug.Text = "ERROR: " + e.Message.ToString();
// Start the video recording.
private void StartRecording_Click(object sender, EventArgs e)
// Avoid duplicate taps.
StartRecording.IsEnabled = false;
StartVideoRecording();
private void DisposeVideoRecorder()
if (_cs != null)
// Stop captureSource if it is running.
if (_cs.VideoCaptureDevice != null
&& _cs.State == CaptureState.Started)
_cs.Stop();
// Remove the event handler for captureSource.
_cs.CaptureFailed -= OnCaptureFailed;
// Remove the video recording objects.
_cs = null;
vcDevice = null;
fileSink = null;
videoRecorderBrush = null;
private void OnCaptureFailed(object sender, ExceptionRoutedEventArgs e)
throw new NotImplementedException();
//STOP WATCH
private void StartTimer()
dispatcherTimer = new System.Windows.Threading.DispatcherTimer();
dispatcherTimer.Tick += new EventHandler(dispatcherTimer_Tick);
dispatcherTimer.Interval = new TimeSpan(0, 0, 1);
dispatcherTimer.Start();
startTime = System.DateTime.Now;
private void StopTimer()
dispatcherTimer.Stop();
private void dispatcherTimer_Tick(object sender, EventArgs e)
System.DateTime now = System.DateTime.Now;
txtRecTime.Text = now.Subtract(startTime).ToString();
If it doesn't make sense can we start over then from the start: How to I capture video using AudioVideoCapturedevice API?