How to use JpegBitmapDecoder in Systems.Windows.Forms.UserControl

Question

Is there a way that I can use the BitmapFrame returned from JpegBitmapDecoder in the UserControl.OnPaint() method? I was told that the performance of JPEG decoding from Systems.Windows.Media.Imaging is much better than the one in GDI+ used by Systems.Windows.Forms library. However, my application is written with Systems.Windows.Forms library already and I don't want to change everything. All I need is a faster way to decompress the JPEG frame and draw it in OnPaint() method.

Answer 1

I figured out the answer myself. Here are the sample code:

JpegBitmapDecoder decoder = new JpegBitmapDecoder(pixelStream, BitmapCreateOptions.None, BitmapCacheOption.None);
BitmapFrame frame = decoder.Frames[0];
frame.CopyPixels(pixelBuffer, stride, 0);

pixelBuffer is a preallocated byte array. And then I can use it to construct a Bitmap use in OnPaint().

Answer 2

If your answer is sufficient will you please accept it so the question will get closed?

In any case I was curious if you were then using a Graphics.DrawImage() to paint your Bitmap? I was recently working with Graphics.DrawImage() and found it to be pretty slow. Wondering if your pre-decoding actually sped up the process.