If I pause it exactly at the time it occurs, it disappears again so I can't Snapshot it using VLC. It lasts only for about a second or two but happens about roughly 30 times, in a one-hour video.
I managed to PrintScreen the line:
[Click to make larger]
But in case it's not too obviously visible, I went over it with a black line:
[Click to make larger]
I tried resetting the preferences, changing the output plugin, the deinterlacing mode, the screen depth, un-installing VLC (and deleting preferences and caches), re-installing different versions, looking through the VLAN forums, asking my friend.
I can't think of anything else to do now.
The best part is, after about 10mins of the video playing, when the diagonal line appears again, the whole video is just stripes running across. Sometimes the stripes are diagonal, following the same gradient of the line that slices through the video, and sometimes they're vertical and horizontal lines. The stripes take after the colour of the video so it's multi-coloured, but it's incomprehensible.
And once you minimize it and maximize it again, the bit that was covered when minimized is either entirely white, entirely black, or the colour of my wallpaper. It's really hard to explain, so if possible, I'll take a screen shot and upload it later ^^.
So if anyone has even the slightest idea what this is and how to fix it, please help!
Thanks. ~