[Intel-gfx] How To Reduce/Eliminate Horizontal Tearing

[Nick Nobody]

On Thu, December 11, 2008 22:00, Zhenyu Wang wrote:
> On 2008.12.11 13:32:35 +0800, Nick Nobody wrote:
>> >>> I'm using Ubuntu 8.10 with a GM945 (at 1920x1080) for my media
>> center
>> >>> PC.
>> >>> The problem I'm running into is a bunch of horizontal tearing on
>> >>> higher
>> >>> resolution videos (720p or greater). From what I can tell it's not a
>> >>> CPU
>> >>> limitation but rather something related to the graphics card...
>> >>>
>> >>> Are there any options that I can enable in my xorg.conf to help
>> >>> reduce/eliminate this tearing? Or is this simply a hardware
>> >>> limitation?
>> >>> Can XvMC somehow help me here?
>> >>
>> >>There aren't any options at this point, but I'm wondering -- is this
>> >>full-screen? If we made full-screen Xv operations block until vblank
>> >>(which would lock up the X server), would that be an acceptable
>> option?
>> >>
>> >>It's actually very easy to do, just stick a 'wait for vblank' command
>> >>into the ring right before the 'copy the new picture' command in the
>> Xv
>> >>extension code. It's just annoying when you're watching a tiny movie
>> and
>> >>your whole session stops responding.
>
> Keith, how about a Xv attribute for this? User can decide if want to turn
> it
> on or off.
>
>>
>> The GM945 only has the overlay adaptor, I initially thought that was the
>> cause too...
>
> No, 945 has texture video support, overlay should do vblank sync for you
> in
> the hw.

Sorry, you're right. I glanced over it when reading through the xvinfo
output.

nick