OpenGL sync to vblank and interlaced fields

[Moe1]

Originally Posted by darklegion

He's using a VGA > Scart adapter, which doesn't involve the video-out portion of the card.

That's right. We are not using the video part but only the RGB (like a common VGA monitor but with specific resolution).

About our problem, I did try differents settings with no solution.
Apparently, with Mythtv, some channels are fine (no interlace ghosts), but others are not.
They looks like the two half frame were inverted. I mean that when there is a movement on the movie, a part of the movement is on the first half frame and the second part of the movement on the second half. If those two half frame are inverted, the movement appears t be going forward and backward very fast, which does the ghost effect.

I can't explain if it is coming from the DVB-T MPEG2 stream which is encoded that way, or because of the Xorg driver which doesn't handle correctly the 2 half frames (taking them from 2 different buffers ?).