/// <summary>
/// Use this function to declare a new stream description
/// </summary>
/// <param name="streamDescription"></param>
public void AddStream(StreamDescription streamDescription)
{
if (!StreamDescriptions.Contains(streamDescription))
{
StreamDescriptions.Add(streamDescription);
}
}
/// <summary>
/// Start the video stream. This just prepares the stream for capture, and doesn't start collecting frames
/// </summary>
/// <param name="streamDesc">The description of the stream to start.</param>
public async void Start(StreamDescription streamDesc)
{
#if CAN_USE_UWP_TYPES
lock (stateLock)
{
if (State != CameraState.Initialized)
{
throw new InvalidOperationException("Start cannot be called until the camera is in the Initialized state");
}
State = CameraState.Starting;
}
Resolution = streamDesc.Resolution;
CameraType = streamDesc.CameraType;
StreamDescriptionInternal desc = streamDesc as StreamDescriptionInternal;
MediaCaptureInitializationSettings initSettings = new MediaCaptureInitializationSettings()
{
SourceGroup = desc.FrameSourceGroup,
SharingMode = MediaCaptureSharingMode.ExclusiveControl,
MemoryPreference = MediaCaptureMemoryPreference.Cpu,
StreamingCaptureMode = StreamingCaptureMode.Video
};
// initialize the media device
mediaCapture = new MediaCapture();
try
{
await mediaCapture.InitializeAsync(initSettings);
}
catch (Exception ex)
{
System.Diagnostics.Debug.WriteLine($"MediaCapture initialization failed: {ex.Message}");
mediaCapture.Dispose();
mediaCapture = null;
}
if (mediaCapture != null)
{
// get access to the video device controller for property settings
videoDeviceController = mediaCapture.VideoDeviceController;
// choose media source
MediaFrameSource frameSource = mediaCapture.FrameSources[desc.FrameSourceInfo.Id];
MediaFrameFormat preferredFormat = null;
foreach (MediaFrameFormat format in frameSource.SupportedFormats)
{
if (format.VideoFormat.Width == desc.Resolution.Width && format.VideoFormat.Height == desc.Resolution.Height && Math.Abs((double)format.FrameRate.Numerator / (double)format.FrameRate.Denominator - desc.Resolution.Framerate) < epsilon)
{
preferredFormat = format;
break;
}
}
if (preferredFormat != null && preferredFormat != frameSource.CurrentFormat)
{
await frameSource.SetFormatAsync(preferredFormat);
}
else
{
System.Diagnostics.Debug.WriteLine($"failed to set desired frame format");
}
// set up frame readercapture frame data
frameReader = await mediaCapture.CreateFrameReaderAsync(frameSource);
frameReader.FrameArrived += OnMediaFrameArrived;
await frameReader.StartAsync();
lock (stateLock)
{
State = CameraState.Ready;
OnCameraStarted?.Invoke(this, true);
}
}
else
{
lock (stateLock)
{
// drop back to initialized when the camera doesn't initialize
State = CameraState.Initialized;
OnCameraStarted?.Invoke(this, false);
}
}
#else
await Task.CompletedTask;
#endif
}
