Lagging video from blackmagic unless i disable beam sync
I'm getting a PAL signal via a blackmagic grabber. When i display that image on the projector (60Hz) the video is lagging in an annoying way, is simply not smooth. The framerate of millumin is around 34fps weirdly enough. If i then disable beam sync on the mac (in quartz debug), then the framerate jumps up to 60fps, and the video stops lagging. Its super smooth. But now i get the vertical sync lines in the image of course.
Are there any tricks to get better performance without disabling beam sync?
Comments
"Beam sync" in a settings to enable/disable vertical syncing, so all the display managed by OSX are synchronous. This is very recommanded, as no vertical syncing means "screen tearing" (seeing scanlines). Just as you observed.
I doubt vertical sync could change the way Blackmagic acquires the signal.
Millumin uses Blackmagic own libraries, the same as BlackMagic Media Express software : did you run a test with it ?
Also, did you try to unplug all your displays (except the one for the main screen of course) ?
Lastly, did you contact Bmackmagic support about this issue ? This may not be related to Millumin.
Best. Philippe