On 18 Jul 2011, at 1704, Andrew Z wrote:

> Phong Nguyen <[log in to unmask]> wrote:
> Even an old Sempron will probably decode most AVIs (MPEG-4 ASP?) with low CPU load; shuffling things to and from the GPU probably won't buy you much and in this case probably costs you overhead. Compressing to MPEG is also probably being done in software and not on the GPU; I'm not aware if there is any Linux support for GPGPU-accelerated encoding even with VAAPI. 
> 
> On 18 Jul 2011, at 1529, Andrew Z wrote:
> 
> > I spent some silly amount of time trying to get all three to perform together.
> > Finally i guess i succeeded, but the results are nowhere to be excited about.
> > 
> > It takes about 40 minutes to transcode of ~800MB avi to mpeg on my ancient Sempron system with 2GB and GT240(512MB) with GPU enabled and ~30minutes w/o GPU. The CPU load is ~80% (GPU enabled) and ~99% (no GPU involved).
> > 
> > I posted results on vlc forum, wondering, pr
>  etty
> much "why bother with vaapi", but i guess the question won't be answered.
> 
> > 
> > Yet, i'm curios what's your experience and thoughts on the matter? 
> > 
> > Andrew
> 
> 
> So you think that round trip to gpu for decoding is not worth an effort?
> dazes on the results its looks this way. But then why bother with this functionality at all?
> -- 

If you are decoding H.264 content to the screen it might well be worth it, particularly on something like a Sempron and especially if you wish to play high definition content. I don't know if you can decode from the GPU to a non-screen target.