asked on

Fastest way to capture screen

I need a fastest way to capture a screen.

The scenario:
- I play an AVI file in screen position 0,0
- within 1 second, I will try to capture as much as possible in that screen position with size = 320x240
- Each captured image will be saved as JPG.

Currently, I am using Bitblt like this :

DC := getDC(GetDesktopWindow);

jpg.CompressionQuality := 60;
done := FALSE;

Timer1.Interval := 1000;
Timer1.Enabled := TRUE;
while not done do
begin
BitBlt(bmp.Canvas.Handle, 0, 0, 320, 240, DC, 0, 0, SRCOPY);
jpg.Assign(bmp);
jpg.SaveToFile('capture'+IntToStr(ctr)+'.jpg');
Inc(ctr);
Application.ProcessMessage;
end;

ReleaseDC(DC, DC);

Using Pentium 4 2.0 GHz, I can capture about 53 files.

But I need to optimize this code. Is it possible?

ASKER CERTIFIED SOLUTION

GloomyFriar

membership

This solution is only available to members.

To access this solution, you must be a member of Experts Exchange.

Start Free Trial

gmayo

Using JPG will slow it down (compression algorithms take time). Using BMP will use up more disk space and may take longer to write to disk. Try a different format (BMP, GIF, etc) and see whether it is any quicker.

Geoff M.

LeVuHoang

does anybody know a sample to copy screen using DirectX by Delphi ???

ZolikaP

try to capture not the hole screen, just the range that is usefull for you...
put all pictures in a stream in your own format, and make pictures after you've finished the capture.

regards,
Zoltan.

SOLUTION