Intel 945GM and XvMC?

Mon Sep 11 10:00:56 PDT 2006

On Sep 11, 2006, at 1:37 AM, Chad wrote:

> Thank you for all the follow ups.
>
> On 9/11/06, Daniel Stone <daniel at fooishbar.org> wrote:
>> On Sun, Sep 10, 2006 at 11:26:49PM -0700,  
>> galenz at zinkconsulting.com wrote:
>> > I have the 915G / GMA 900 chipset. The XvMC option is a bit  
>> different
>> > than with the older chips, but when XVideo is enabled using the  
>> i810
>> > drivers, review the startup logs for X and you'll see XVideo and
>> > XVideo Motion Compensation load up. As far as I know, the GMA  
>> 950 is
>> > just a faster, better version of the GMA 900.
>>
>> When the XVideo-MotionCompensation extension is loaded, that doesn't
>> mean XvMC is actually in use: it isn't.
>>
>> (Confusing, I know.)
>>
>>
>
> So, is there any way to get it into use?
>
>
>> On Sun, Sep 10, 2006 at 11:26:49PM -0700,  
>> galenz at zinkconsulting.com wrote
>> I have the 915G / GMA 900 chipset. The XvMC option is a bit different
>> than with the older chips, but when XVideo is enabled using the i810
>> drivers, review the startup logs for X and you'll see XVideo and
>> XVideo Motion Compensation load up. As far as I know, the GMA 950 is
>> just a faster, better version of the GMA 900.
>
> This sounds promising, as well as the below information...
>
>> Based on my tests, using VLC and other video players with XVideo
>> output modules, the performance gain is very considerable. Not as
>> amazing as some MPEG-2 acceleration I've seen, but 20% CPU use
>> watching 720p on a Celeron D 3 GHz CPU isn't too shabby. I'm running
>> FC5, VLC 0.85 and everything as x86-64 binaries.
>
> So, with VLC and other players, do you just use the regular xv output,
> or do you use some variation of xvmc output?  If it's just xv, does
> that mean that something like XvMC exists in firmware in the actual
> hardware itself?
>
>> The setting under FC5 had to be changed in order to play HD, you will
>> have to set the CacheLines value - the default is too low, it causes
>> the players to segfault. 1100 works beautifully for 720p playback.
>
> Thank you, I will probably get a board and start testing.
>
>> However, I'm currently struggling to get the 1080i working properly.
>> I have been experimenting with all sorts of things and it still
>> causes all the players to segfault and I'm not sure why. I've been
>> going back and fourth a bunch today in an earlier post regarding this
>> issue - look around the list a bit and you'll see it.
>
> Will do, a quick glance didn't reveal much which is why I posted the
> question.  Of course, the usual problem of not knowing what to search
> for is probably why.
>
> Thanks again!
>
>> Keith wrote:
>> The chip supports it, but the driver code hasn't been written.
>
> So, does that mean someone is going to, or that it doesn't need to be
> done (as Galen noted it 'sorta' seems to work already)?  I'm looking
> at migrating away from via-pro mini-itx boards because it's lacks a
> lot of [working] driver implementation and saw the
> intellinuxgraphics.org project and felt as if it were a great
> alternative for a media platform.  I've found several boards with a
> 945GM chipset on that that have everything I think would be necessary
> in a single-board type solution.  But I also found that with Via.
> Hopefully with Intel seeming/appearing to do things very well from the
> get-go, it won't turn into another Via situation where they promise
> the world from their 'specs' but deliver a little less than par.
>
> In a nutshell I guess:  will the driver code be written?
>
> Thanks again everyone!
>
> -Chad

Chad,

I can tell you that XVideo with my GMA 900 is substantially faster  
than X11 video output. However, as I've said, it's not as good as  
other implementations of MPEG-2 acceleration I've seen.

I have a 3 GHz Celeron in this machine and using x86-64 code, 720p  
plays with about 20% of the CPU - a notable improvement over X11  
video output. That suggests 720p would play on your machine. I  
*still* can't get 1080i working and it's driving me mad. See Andrew  
Barr's post Re: Intel GMA 900 & XVideo Accelleration (i810 drivers).

I guess I have to compile my own build of VLC, just to debug it  
myself... which may or may not yield any useful data... this is what  
I hate about Linux. It can do so much, but it always feels very half- 
baked - like going to the store to get a car, and all you actually  
get is the parts and a lot friendly people who kind of know how to  
help you assemble it, but not many people actually know how to do it  
all. And sometimes, parts are mislabeled or even nonexistent, so you  
have to make your own.... except you're not really a machinist, and  
you might not even have the right tools or know what the part needs  
to be, exactly.

You may want to take a look at this page:
http://mythtv.org/wiki/index.php/XvMC

(Their server appears to be down at the second. In the meantime, try  
Google's cache: http://72.14.203.104/search?q=cache:http://mythtv.org/ 
wiki/index.php/XvMC&hl=en&lr=&oe=US-ASCII&client=safari&rls=en&strip=1 )

It looks like the Unichrome drivers are more complete, supporting  
full XvMC and iDCT. Hello, Intel, let's see those awesome Open Source  
drivers updated to be competitive! Especially with the new X3000  
chipset...

-Galen