Thread: Video playback tearing
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fanoush is offline fanoush
2006-12-05 , 19:42
Posts: 2,152 | Thanked: 1,490 times | Joined on Jan 2006 @ Czech Republic
#4
Originally Posted by Serge
Does LCD controller constantly refresh image on the screen internally and this tearing effect is caused by screen update request coming in the middle of this internal screen refresh phase?
Yes, exactly. Kernel ioctl sends data to memory buffer inside Epson controller and the same memory is periodically sent to LCD display.
Last time it was discussed it looked like there are some registers which might allow to synchronize this ioctl somehow with the internal refresh but the information is not public so only Nokia guys can do it.

I am not sure about generic info on the net but the Epson chip overview is here http://www.erd.epson.com/index.php?o...d=36&Itemid=40
You can also guess how it works from OMAP LCD controller (which is not used in N770) docs - google for spru675.pdf