[mythtv-users] Radeon 8500 hdtv questions...

[Raphael Pooser]

chris at cpr.homelinux.net wrote:
> On Tue, Feb 14, 2006 at 08:35:49AM -0700, James Dastrup wrote:
>   
>> If you want to use ATI, you need at least a 9600 and a P4 2.8 (or AMD
>> equivalent).  You'll find that it works just fine, and you will have
>> less problems than with the nVidia cards because there is less to
>> configure - no opengl, no XvMC, no recompiling Myth every time you
>> change the driver version, etc.
>>     
>
> Well, that's *exactly* what I have in my desktop machine (P4 @ 
> 2.8GHz, 1.5Gb RAM, Radeon 9600SE) and so far it's been a total 
> disaster.  I was able to use MythTV back when XFree86 version 
> 4-point-something was current, but ever since the major distros 
> switched to the Xorg 6.9.0 server I haven't been able to watch 
> anything on that machine.  (My XBox works now, and I'm terrified at 
> the prospect of trying to upgrade it to MythTV 0.19.)  If you have an 
> xorg.conf file and Xorg/MythTV package list for Debian that works for 
> a Radeon 9600SE and Myth 0.18 or 0.19 then I'd certainly like to know 
> about it.
>
>   
Hmm, I'm using a 9600 pro and things are working well.  I'm using xorg 
6.8 right now along with the ATI fglrx proprietary driver.  I'm using 
the version released back in about November 05 for the fglrx.  To watch 
anything using an ATI card without getting pauses due to high cpu usage, 
you're going to need the driver working properly in X so that openGL and 
XV work.  You can see some earlier posts from me on this list that dealt 
with sorting out my own confusion on XV vs XVMC, openGL, and properly 
loading the fglrx driver.  At first myth was working fine for me but 
only to watch 480x480 videos and under, because X would use about 70% 
cpu jsut to display the resolution.  After getting xv working x went 
down to 15% for a 640x480 stream.  The only way to do it right is to 
make sure fglrx is getting loaded properly so that X tells you ok I can 
use openGL acceleration.  Check the gears benchmark and you should be 
getting 1000+ fps and not like hundreds only.  If you're only getting 
100s then gl support isn't there and due to the way the driver works 
neither will XV support be there.  Getting the driver in properly hinges 
on having your kernel source uncompressed in the usr/src/linux 
directory, etc, when you try and run the ATI kernel module installer binary.
As far as I know, using the open source radeon driver doesn't help in 
this regard, I have to use fglrx - if someone can confirm on that.  
Apologies if you've got fglrx working right - but do check glx gears and 
let us know the fps.

About HDTV with radeons, the subject of the thread.  I believe on this 
list HDTV has been discussed a lot and people say that you generally 
need high proc clock to watch HDTV, Nvidia or ATI (although some 
reported using a 1700+ even to watch HD with an Nvidia fx5200 and the 
7676 drivers I think).  With XVMC working properly it should take you 
less clocks to watch HDTV on an Nvidia card than on an ATI card, I 
gather.  But with XV working I don't see how one could not view an HDTV 
stream easily with 2GHz + with an ATI card given that my 1.5GHz proc get 
15% usage to display a 640x480 stream with a 9600 and XV working.  So 
really, if you're having problems with xvmc on an nvidia, you should 
still have no problems if your xv is working - should give you same 
performance of an ATI card I would think.
Raphael