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wamkuipers

Registriert seit: 24. Mai 2014
1 Beiträge
 
#24

AW: WebCam mit DirectShow

  Alt 24. Mai 2014, 13:57
Bitte entshudige mich, i rede nicht sehr gut Deutsch.

I have a problem with vsample.pas. Basicly i like the software.

I my application
procedure TVideoImage.WndProc(var Msg: TMessage);

calls in fOnNewFrame(self, fWidth, fHeight, fImagePtr[fImagePtrIndex]);

multiple times in a re-entrant way.

That causes even program crashes.

It is not clear why that happens.
I assume that errors occur not caught by
Application.HandleException(Self); // the wrong Thread?

Actually my callback procedure is called in the VCL (mainform) thread which is ok.

I can get clear how it can occur that my call procedure is called again before is has finished!
A posible reason could be improperly handled errors.
Also the DSPACK have a similar behaviour, but even a lot worse.

My callback procedure use (mainform).update calls, which should be allowed in the VCL thread. (With DSPACK the callback procedure does is NOT called in the VCL thread ...)

Further more the video picture blocks with moving the mainwindow with a leftmouse down.

Any sugestions what could cause my trouble?

Kind regards
William
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