poor video playback performace with radeon

[Alex Deucher]

On Tue, Aug 9, 2011 at 6:39 AM, Taneli Vähäkangas
<taneli.vahakangas at cs.helsinki.fi> wrote:
>
> Hello. Thanks for your prompt reply.
>
> On Tue, Aug 09, 2011 at 08:35:27AM +0200, Johannes Truschnigg wrote:
>> Given the system specs below, I'm afraid this is nothing out of the
>> ordinary. H.264 in 1080p generally is quite demanding to decode, and
>> your somewhat dated CPU just might not be up to the task.
>
> I'd like to use the GPU, it should be better suited for the task,
> right?
>
>> You should try to get your hands onto a build of mplayer with the
>> multithreading decoding features of ffmpeg enabled. I'm not sure that
>> will yield real-time decoding of your video source, but it should
>> improve performance a bit nonetheless.
>
> I'll take a look.
>
>> I distantly recall ATI/AMD implementing some GPU video decode
>> acceleration API in their proprietary BLOB drivers, but I'm not sure how
>> (or if, with your card) you can use that.
>
> I'll check out -- but I prefer open source.
>
>> The free drivers don't support video decoding with GPU hardware
>> assistance yet.
>
> This, and this:
>
>> have to get a beefier machine if you don't want to wait for shader-based
>> video decoding (or UVD) support in the free drivers.
>
> How much effort is that? How can I help? Where do I start? I'm no
> stranger to driver development (in kernel), but have never worked
> with X.org (or even XFree86) code.

There is initial shader based decoding for gallium drivers in the mesa
git tree.  At the moment it only supports MPEG1/2, but Christian is
looking into support for newer codecs.

Alex