[mythtv-users] VDPAU on older pre-G98 8400 GS

Greg Oliver oliver.greg at gmail.com
Tue Jan 5 05:08:51 UTC 2010


On Mon, Jan 4, 2010 at 10:56 PM, Frank Merrill <fmerrill1 at gmail.com> wrote:
> On Mon, Jan 4, 2010 at 11:17 PM, Eric Sharkey <eric at lisaneric.org> wrote:
>> On Mon, Jan 4, 2010 at 11:09 PM, Frank Merrill <fmerrill1 at gmail.com> wrote:
>>> I think the real answer in the end is to just upgrade the card to
>>> something more suitable to doing VDPAU at that resolution,
>>
>> That seems sort of silly.  The card runs acceptably when VDPAU is not
>> being used.  I mostly only turned it on to see what all the fuss was
>> about.  I was surprised that performance went from pretty good to
>> abysmal on such a simple test.  I assumed that I must have done
>> something wrong, which is why I was wondering if anyone on this list
>> had direct personal experience with such a card.
>>
>>
>
> Well, it's not really silly.  One of the primary purposes of VDPAU is
> to move the decoding and deinterlacing from the CPU to the GPU.
> If the GPU isn't as good as the CPU at doing that, then performance
> would go down.
> In your case by not using VDPAU, the card is just an output of the
> stream, and may be fine for what you need.
> I'll make an assumption here that your CPU has enough power to play
> back the content without any issue.
> This isn't an issue with VDPAU, it's an issue with your card not being
> able to utilize that functionality well enough to make it worthwhile
> to use.
>
> If I turn off VDPAU my processor doe the work with an average
> utilization of 40-50%.  With VDPAU, that drops to 4-5%.
> I can then do other things with the CPU at the same time, like
> transcoding or comflagging without getting any pauses during playback.
> In many peoples case, using the CPU is fine, as long as it serves your purposes.

I have a very slow Acwer Revo 1600..  Without the vdpau, I cannot even
play HD..  With it, my CPU runs at 13-14%..  Cheapest HD frontend
($140) I have ever seen :)


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