public async Task <ICameraPreview> OpenWithPreviewAsync(Xamarin.Forms.Size previewRequestSize)
{
await OpenAsync(true);
var stateCallback = new StateCallback();
stateCallback.Configured += SessionConfigured;
stateCallback.ConfigureFailed += SessionConfigureFailed;
var previewSurface = _cameraPreview.CreateSurface(previewRequestSize);
_previewRequestBuilder.AddTarget(previewSurface);
_previewRequestBuilder.Set(CaptureRequest.ControlAfMode, (int)ControlAFMode.ContinuousPicture);
var characteristics = _manager.GetCameraCharacteristics(_cameraDevice.Id);
var map = (StreamConfigurationMap)characteristics.Get(CameraCharacteristics.ScalerStreamConfigurationMap);
// ReSharper disable once CoVariantArrayConversion
_imageSize = (Size)Collections.Max(
Arrays.AsList(map.GetOutputSizes((int)ImageFormatType.Jpeg)),
new CompareSizesByArea());
_imageReader = ImageReader.NewInstance(_imageSize.Width, _imageSize.Height,
ImageFormatType.Jpeg, /* maxImages */ 2);
_imageAvailableListener = new ImageAvailableListener();
_imageAvailableListener.ImageAvailable += CaptureAvailable;
_imageReader.SetOnImageAvailableListener(_imageAvailableListener, _backgroundThread.Handler);
var surfaces = new List <Surface> {
previewSurface, _imageReader.Surface
};
_cameraDevice.CreateCaptureSession(surfaces, stateCallback, null);
return(_cameraPreview);
}
public Surface CreateSurface(Size requestSize)
{
var requestPixelSize = ToPixels(requestSize);
var bufferSize = GetBufferSize(requestPixelSize);
Size = DimensionUtils.ToXamarinFormsSize(bufferSize);
var pixelSize = new System.Drawing.Size {
Width = bufferSize.Width, Height = bufferSize.Height
};
PixelSize = pixelSize;
ConfigureTransform(requestPixelSize.Width, requestPixelSize.Height);
_imageReader = ImageReader.NewInstance(bufferSize.Width, bufferSize.Height, ImageFormatType.Yuv420888, 4);
_imageAvailableListener = new ImageAvailableListener();
_imageAvailableListener.ImageAvailable += PreviewImageAvailable;
_imageReader.SetOnImageAvailableListener(_imageAvailableListener, _backgroundHandler);
return(_imageReader.Surface);
}