public static async Task <ContinuousAutoFocus> StartAsync(FocusControl control)
{
var autoFocus = new ContinuousAutoFocus(control);
AutoFocusRange range;
if (control.SupportedFocusRanges.Contains(AutoFocusRange.FullRange))
{
range = AutoFocusRange.FullRange;
}
else if (control.SupportedFocusRanges.Contains(AutoFocusRange.Normal))
{
range = AutoFocusRange.Normal;
}
else
{
// Auto-focus disabled
return(autoFocus);
}
FocusMode mode;
if (control.SupportedFocusModes.Contains(FocusMode.Continuous))
{
mode = FocusMode.Continuous;
}
else if (control.SupportedFocusModes.Contains(FocusMode.Single))
{
mode = FocusMode.Single;
}
else
{
// Auto-focus disabled
return(autoFocus);
}
if (mode == FocusMode.Continuous)
{
// True continuous auto-focus
var settings = new FocusSettings()
{
AutoFocusRange = range,
Mode = mode,
WaitForFocus = false,
DisableDriverFallback = false
};
control.Configure(settings);
await control.FocusAsync();
}
else
{
// Simulated continuous auto-focus
var settings = new FocusSettings()
{
AutoFocusRange = range,
Mode = mode,
WaitForFocus = true,
DisableDriverFallback = false
};
control.Configure(settings);
var ignore = Task.Run(async() => { await autoFocus.DriveAutoFocusAsync(); });
}
return(autoFocus);
}
// Must be called on the UI thread
private async Task DisposeCaptureAsync()
{
Preview.Source = null;
if (autoFocus != null)
{
autoFocus.Dispose();
autoFocus = null;
}
MediaCapture mediaCapture;
lock (this)
{
mediaCapture = this.mediaCapture;
this.mediaCapture = null;
}
if (mediaCapture != null)
{
mediaCapture.Failed -= OnMediaCaptureFailed;
await mediaCapture.StopPreviewAsync();
mediaCapture.Dispose();
}
}
public static async Task<ContinuousAutoFocus> StartAsync(FocusControl control)
{
var autoFocus = new ContinuousAutoFocus(control);
AutoFocusRange range;
if (control.SupportedFocusRanges.Contains(AutoFocusRange.FullRange))
{
range = AutoFocusRange.FullRange;
}
else if (control.SupportedFocusRanges.Contains(AutoFocusRange.Normal))
{
range = AutoFocusRange.Normal;
}
else
{
// Auto-focus disabled
return autoFocus;
}
FocusMode mode;
if (control.SupportedFocusModes.Contains(FocusMode.Continuous))
{
mode = FocusMode.Continuous;
}
else if (control.SupportedFocusModes.Contains(FocusMode.Single))
{
mode = FocusMode.Single;
}
else
{
// Auto-focus disabled
return autoFocus;
}
if (mode == FocusMode.Continuous)
{
// True continuous auto-focus
var settings = new FocusSettings()
{
AutoFocusRange = range,
Mode = mode,
WaitForFocus = false,
DisableDriverFallback = false
};
control.Configure(settings);
await control.FocusAsync();
}
else
{
// Simulated continuous auto-focus
var settings = new FocusSettings()
{
AutoFocusRange = range,
Mode = mode,
WaitForFocus = true,
DisableDriverFallback = false
};
control.Configure(settings);
var ignore = Task.Run(async () => { await autoFocus.DriveAutoFocusAsync(); });
}
return autoFocus;
}
private async Task InitializeCaptureAsync()
{
if (isMediaCaptureInitializing || (mediaCapture != null))
return;
isMediaCaptureInitializing = true;
try
{
var settings = new MediaCaptureInitializationSettings
{
VideoDeviceId = await GetBackOrDefaulCameraIdAsync(),
StreamingCaptureMode = StreamingCaptureMode.Video
};
var newMediaCapture = new MediaCapture();
await newMediaCapture.InitializeAsync(settings);
// Select the capture resolution closest to screen resolution
var formats = newMediaCapture.VideoDeviceController.GetAvailableMediaStreamProperties(MediaStreamType.VideoPreview);
var format = (VideoEncodingProperties)formats.OrderBy((item) =>
{
var props = (VideoEncodingProperties)item;
return Math.Abs(props.Width - this.ActualHeight) + Math.Abs(props.Height - this.ActualWidth);
}).First();
Debug.WriteLine("{0} x {1}", format.Width, format.Height);
await newMediaCapture.VideoDeviceController.SetMediaStreamPropertiesAsync(MediaStreamType.VideoPreview, format);
// Disable flash control if supported
if (newMediaCapture.VideoDeviceController.FlashControl.Supported)
newMediaCapture.VideoDeviceController.FlashControl.Enabled = false;
// Prepare bitmap for reports
bitmapWithBarcode = new WriteableBitmap((int)format.Width, (int)format.Height);
// Make the preview full screen
Preview.Width = this.ActualHeight;
Preview.Height = this.ActualWidth;
// Enable QR code detection
var definition = new LumiaAnalyzerDefinition(ColorMode.Yuv420Sp, Math.Min(format.Width, 800), AnalyzeBitmap);
await newMediaCapture.AddEffectAsync(MediaStreamType.VideoPreview, definition.ActivatableClassId, definition.Properties);
// Start preview
Preview.Source = newMediaCapture;
await newMediaCapture.StartPreviewAsync();
newMediaCapture.Failed += OnMediaCaptureFailed;
autoFocus = await ContinuousAutoFocus.StartAsync(newMediaCapture.VideoDeviceController.FocusControl);
mediaCapture = newMediaCapture;
}
catch (Exception e)
{
Debug.WriteLine("Failed to start the camera: {0}", e.Message);
}
isMediaCaptureInitializing = false;
}
