weird video screenshot problem

[Tiemo Hollmann TB]

Hello,

I am experiencing a very weird problem, taking a screenshot from a video on
Windows. Perhaps anybody has an idea where to look for?

 

I have two programs, where I am playing the same mp4 videos. The user can
make screenshots from the paused video and store them as JPGs/PNGs. If the
user has the windows display settings text size at 100%, everything works
fine in both programs. When setting the windows display text size to 125% or
above, the quality of the screenshot in one of the both programs gets almost
unusable. The image is corrupted by many bad pixels (red, black and lost
pixels). The other program still shows a fine screenshot.

 

My first idea was, that there must be a difference in the build of the
standalones, so I tested the two stacks in the same LC 9.0.2 (and down to LC
8) IDE with the same result. I compared the two stacks and didn't found a
relevant difference in displaying the video and taking the screenshot. Both
codes are almost the same here. The relevant code looks like:

set the alwaysBuffer of player "VideoPlayer" to false

start player "VideoPlayer"

stop player "VideoPlayer"

export snapshot from rect (globalLoc(topLeft of player "VideoPlayer") ,
globalLoc(bottomRight of player "VideoPlayer")) to gScreenshot as PNG

put gScreenshot into img "ScreenshotImg"

 

Here you can download an example of the two screenshots in a pdf:
http://www.kestner.de/material/screenshot-test.pdf

 

Has anybody ever seen such a phenomenon? Any idea what could cause this
issue in combination with the text size of > 100%? And for what difference I
could look for in my two programs what could cause this issue in one of
them?

 

Thanks for any ideas

Tiemo