[Libva] [PATCH] h264: fix 4K decoding (IVB).

[Gwenole Beauchesne]

Hi,

2012/7/2 Oliver Seitz <info at vtnd.de>:
>
>>> I can play a 3840x2160 video by MPlayer-vaapi on my machine.
>
> Is this new on IVB, or should it also work on SNB?

The PRM available at <http://www.intellinuxgraphics.org/> for Ivy
Bridge mentions that the HW decoding engine supports H.264 high
profile up to level 5.1. For Sandy Bridge, the /vaapi.html page on the
same website mentions that it only supports H.264 high profile up to
level 4.1. Based on this data publicly available, you can see that
Sandy Bridge can't support 3840x2160 videos.

However, you pointed an interesting issue whereby our logic to
validate the VA context is suboptimal, if not slightly incorrect. In
particular, SNB could support 3072x672p30 videos as this still lays
into the constraints defined by Table A-1 from the AVC standard.

I propose to make video size validation a function rather than fixed
values. That'd also fix the constraint for IVB whereby only one
dimension could reach 4K (4096 pixels), not both.

Regards,
Gwenole.