Info on how to reproduce it with very little effort: 

Convert some movie into m2v and force intra dc precision to 11:
ffmpeg -i somemovie -sameq -dc 11 out_11.m2v

on unit simply play it using vaapi:
mplayer -vo vaapi -va vaapi out_11.m2v 

The DC-levels on the I-frames are completely off. Using -dc 10 on the ffmpeg 
line will produce a movie that is perfectly playable.

I assume the problem lies either in the va-backend (driver), in the micro code 
of the chip (driver binary blob) or in the chip itself (HW problem). Can you 
confirm?

Also I haven't read the MPEG2 spec closely enough to confirm that a intra dc 
precision value of 3 (i.e. 11 bits) are ok when using main profile...

Kind regards, Andreas Larsson

> Another problem I've stumbled upon is that when using intra_dc_precision = 3 
> (i.e. 11-bit DC-predictors) the chip doesn't decode the stream properly. The 
> DC levels are completely off both in luma and in chroma. Decoding the same 
> stream using VLC or software mplayer etc displays it correctly.
> 
> VA: v0.31.1 VAProfileMPEG2Main + VAEntrypointVLD
> CPU : Intel ATOM Z510
> GFX: Intel US15W
> OS: Linux Fedora 14
> X.Org: X.Org X Server 1.9.4
> GFX-driver: Intel(R) Embedded Media and Graphics Driver version 1.14.2443
> 
> Switching to intra_dc_precision = 2 (i.e. 10-bit DC predictors) decodes 
> correctly though. Do you have any erratas on this or any helpful insights?
> 
> Kind regards, Andreas Larsson

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