WDM video capture driver for Windows ME

NTDEV
1

Hi,
I encountered 2 problems about WDM video capture driver for Windows ME:

I use amcap.exe to test the video…

  1. the testcap video capture sample of DDK is working normally under Windows
    98SE,
    but it works abnormally under Windows ME (VGA is 16bit HiCoor and 24bit
    Truecolor depth).

  2. My video capture driver works normally under Windows 98SE.
    And under Windows ME, its video is normal in VGA 16 bit environment.
    But the video is upside down in VGA 24bit environment, and
    whenever the amcap window is resized, the video is changed to normal,
    or the system is powered suspend-and-resume, the video is normal, too.

Could anybody answer my question?

Dersheng.Lin

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2

>2. My video capture driver works normally under Windows 98SE.

And under Windows ME, its video is normal in VGA 16 bit environment.
But the video is upside down in VGA 24bit environment, and
whenever the amcap window is resized, the video is changed to normal,
or the system is powered suspend-and-resume, the video is normal, too.

What may be happening is the display surface being used to display video
might be shifting under different conditions. For some reason, an overlay
surface is sometimes not used.

I also seem to remember something about the bitmap height being a negative
number to indicate inverted format. There was also some confusion because
YUV bitmaps were always supposed to be in top to bottom format, and you
needed to ignore the negative height. Microsoft had a technical note about
the whole situation a few years ago.

Part of the problem may have been in the inverted height handling in the
video display driver, so your capture driver may not be the problem. Is it
only specific display drivers that have this problem?

  • Jan

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