Я пытаюсь сохранить SoftwareBitmap в файл.
Но я получаю сообщение об ошибке "Параметр неверен", когда я это делаю: StorageFile.GetFileFromPathAsync ()
ЗДЕСЬ ОШИБКА...….
pathname = "diag ProcessFrame .JPG"
КОД ДЛЯ ОБРАБОТКИ СОБЫТИЙ ДЛЯ WEBCAM USB FRAME ... ……
private void FrameReader_FrameArrived(MediaFrameReader sender, MediaFrameArrivedEventArgs args)
{
// Get frame image from camera:
using (var frame = sender.TryAcquireLatestFrame()) // ==> MediaFrameReference
{
// Got image?
if (frame != null)
{
var renderer = _frameRenderers[frame.SourceKind];
renderer.ProcessFrame(frame);
}
}
}
// Process latest frame received from USB webcam.
public void ProcessFrame( MediaFrameReference frame)
{
// Convert frame to a SoftwareBitmap of a valid format to display in an Image control:
// SoftwareBitmap Class
// https://docs.microsoft.com/en-us/uwp/api/windows.graphics.imaging.softwarebitmap?f1url=https%3A%2F%2Fmsdn.microsoft.com%2Fquery%2Fdev15.query%3FappId%3DDev15IDEF1%26l%3DEN-US%26k%3Dk(Windows.Graphics.Imaging.SoftwareBitmap)%3Bk(TargetFrameworkMoniker-.NETCore%2CVersion%3Dv5.0)%3Bk(DevLang-csharp)%26rd%3Dtrue
var softwareBitmap = FrameRenderer.ConvertToDisplayableImage(frame?.VideoMediaFrame);
if (softwareBitmap != null)
{
// Swap the processed frame to _backBuffer and trigger UI thread to render it
softwareBitmap = Interlocked.Exchange(ref _backBuffer, softwareBitmap); // does bytes = h X w ?
// UI thread always reset _backBuffer before using it. Unused bitmap should be disposed.
softwareBitmap?.Dispose();
//////////////////////// DISPLAY FRAME LOCALLY /////////////////////////
// Changes to xaml ImageElement must happen in UI thread through Dispatcher
var task = _imageElement.Dispatcher.RunAsync(CoreDispatcherPriority.Normal,
async () =>
{
// Keep draining frames from the backbuffer until the backbuffer is empty.
SoftwareBitmap latest_frame_SoftwareBitmap;
while (( latest_frame_SoftwareBitmap = Interlocked.Exchange(ref _backBuffer, null)) != null)
{
// Diag to save frame to a file:
//VideoMediaFrame inputFrame = frame.VideoMediaFrame;
//SoftwareBitmap frame_SoftwareBitmap = inputFrame.SoftwareBitmap;
Common.SaveSoftwareBitmapToFile( latest_frame_SoftwareBitmap, "diag ProcessFrame .JPG");
. . .
}
// Saves encoded (ie. compressed) SoftwareBitmap image pixel data to a specific file pathname.
public static async void SaveSoftwareBitmapToFile(SoftwareBitmap softwareBitmap, String pathname)
{
StorageFile outputFile = await StorageFile.GetFileFromPathAsync( pathname );
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ERROR OCCURS HERE
using (IRandomAccessStream stream = await outputFile.OpenAsync(FileAccessMode.ReadWrite))
{
// Create an encoder with the desired format
BitmapEncoder encoder = await BitmapEncoder.CreateAsync(BitmapEncoder.JpegEncoderId, stream);
// Set the software bitmap
encoder.SetSoftwareBitmap(softwareBitmap);
// Set additional encoding parameters, if needed
//encoder.BitmapTransform.ScaledWidth = 320;
//encoder.BitmapTransform.ScaledHeight = 240;
//encoder.BitmapTransform.Rotation = Windows.Graphics.Imaging.BitmapRotation.Clockwise90Degrees;
//encoder.BitmapTransform.InterpolationMode = BitmapInterpolationMode.Fant;
encoder.IsThumbnailGenerated = true;
try
{
await encoder.FlushAsync();
}
catch (Exception err)
{
const int WINCODEC_ERR_UNSUPPORTEDOPERATION = unchecked((int)0x88982F81);
switch (err.HResult)
{
case WINCODEC_ERR_UNSUPPORTEDOPERATION:
// If the encoder does not support writing a thumbnail, then try again
// but disable thumbnail generation.
encoder.IsThumbnailGenerated = false;
break;
default:
throw;
}
}
if (encoder.IsThumbnailGenerated == false)
{
await encoder.FlushAsync();
}
}
}