我正在尝试在UWP应用程序中获取RTSP视频的快照。要复制我使用VLC.MediaElement库的视频(欢迎使用更好的库的任何建议(。目前,我正在使用此方法获得视频快照:
private async void PhotoButton_Click(object sender, RoutedEventArgs e)
{
Media.Pause();
RenderTargetBitmap renderTargetBitmap = new RenderTargetBitmap();
await renderTargetBitmap.RenderAsync(Media, ((int)Media.Width / 2), ((int)Media.Height / 2));
ImgPreview.Source = renderTargetBitmap;
Media.Play();
}
IMGPREVIEW元素中的结果不错,但是当我将其保存到具有此函数的文件中时:
private async void SaveButton_Click(object sender, RoutedEventArgs e)
{
try
{
StorageLibrary lib = await StorageLibrary.GetLibraryAsync(KnownLibraryId.Pictures);
StorageFolder folder = lib.SaveFolder;
StorageFile file = await folder.CreateFileAsync("TestPhoto_" + DateTime.Now.Ticks + ".jpg", CreationCollisionOption.GenerateUniqueName);
DisplayInformation display = DisplayInformation.GetForCurrentView();
RenderTargetBitmap rtb = new RenderTargetBitmap();
await rtb.RenderAsync(ImgPreview);
IBuffer pixels = await rtb.GetPixelsAsync();
DataReader data = DataReader.FromBuffer(pixels);
byte[] bytes = new byte[pixels.Length];
data.ReadBytes(bytes);
using (IRandomAccessStream stream = await file.OpenAsync(FileAccessMode.ReadWrite))
{
BitmapEncoder encoder = await BitmapEncoder.CreateAsync(BitmapEncoder.JpegEncoderId, stream);
encoder.SetPixelData(
BitmapPixelFormat.Bgra8,
BitmapAlphaMode.Ignore,
(uint)rtb.PixelWidth,
(uint)rtb.PixelHeight,
display.RawDpiX,
display.RawDpiY,
bytes);
await encoder.FlushAsync();
storage.doPut(file.Path, file.Name);
}
}
catch (Exception ex)
{
}
}
结果是超级模糊,对于我的应用,我需要更高质量的图像。我试图玩DPI,但唯一的结果是带有Wierd对角线带的完全位移的像素地图。
有没有办法解决这个问题?感谢您的任何帮助。
结果是超级模糊,对于我的应用,我需要更高质量的图像。
我检查了您的代码,我发现您获得> imgpreview 的RenderTargetBitmap
,这是无需的,您可以直接使用Medialement的RenderTargetBitMap,以避免图像质量损失。
您将获得一半尺寸的RenderTargetBitmap
,以下将导致较低的图像质量。
await renderTargetBitmap.RenderAsync(Media, ((int)Media.Width / 2), ((int)Media.Height / 2));
请使用全尺寸。
await renderTargetBitmap.RenderAsync(Media, ((int)Media.Width), ((int)Media.Height));
......
private RenderTargetBitmap renderTargetBitmap;
private async void SaveButton_Click(object sender, RoutedEventArgs e)
{
try
{
StorageLibrary lib = await StorageLibrary.GetLibraryAsync(KnownLibraryId.Pictures);
StorageFolder folder = lib.SaveFolder;
StorageFile file = await folder.CreateFileAsync("TestPhoto_" + DateTime.Now.Ticks + ".jpg", CreationCollisionOption.GenerateUniqueName);
DisplayInformation display = DisplayInformation.GetForCurrentView();
IBuffer pixels = await renderTargetBitmap.GetPixelsAsync();
DataReader data = DataReader.FromBuffer(pixels);
byte[] bytes = new byte[pixels.Length];
data.ReadBytes(bytes);
using (IRandomAccessStream stream = await file.OpenAsync(FileAccessMode.ReadWrite))
{
BitmapEncoder encoder = await BitmapEncoder.CreateAsync(BitmapEncoder.JpegEncoderId, stream);
encoder.SetPixelData(
BitmapPixelFormat.Bgra8,
BitmapAlphaMode.Ignore,
(uint)renderTargetBitmap.PixelWidth,
(uint)renderTargetBitmap.PixelHeight,
display.RawDpiX,
display.RawDpiY,
bytes);
await encoder.FlushAsync();
//storage.doPut(file.Path, file.Name);
}
}
catch (Exception ex)
{
}
}