[mythtv-users] Problems with mythtv and Radeon HD video cards

Jesse Burt genecide at comcast.net
Sat May 3 14:24:19 UTC 2008

Jay Summet wrote:
>> I am trying to get mythtv working in combination with an ATI Radeon HD 
>> video card, without much luck. The card is an Asus Radeon PRO 
>> 2600/HTDI/256M, and I'm using the open-source radeonhd driver. 
> I'm afraid this may not be a lot of help:  Without hardware acceleration
> you will need a beast of a machine to play HD content at good resolutions.
> I build a MythTV box using an ATI card and could never get XVMC working
> with it (My 3.2Mhz CPU  was near 90-100% utilization all the time when
> playing MPEG2 (HD) streams on a 1024x768 resolution display, and the
> video would stutter any time any other process on the BE/FE did some work.)
> Yes, I'd prefer to use all open source drivers myself, but without
> hardware video/mpeg2 acceleration, mythtv at HD just doesn't work.
> Jay

I would check processor usage while this happens using top/htop, etc. 
You can also attach an excerpt of your backend/frontend log so we can 
see what is going on.
I don't use the RadeonHD driver myself, but can you check if you have Xv 
support (not sure if this has been implemented in RadeonHD or if so, for 
all chips)? You could also see if your chip is supported by the Radeon 
driver; if it is perhaps you'd have better luck with it.

Not to sound argumentative- just informational, but it isn't necessary 
to have hardware acceleration (XvMC) to playback HD smoothly, as many on 
the list have found. Not all, but many have found it to be troublesome 
too. I don't use XvMC on my nVidia 5500 BE/FE combo and 1080i (on a 
1680x1050x32 display) plays back with about 80% usage on a 1st gen 
Athlon64 3400+ (2.4GHz). The most I use is Xv, which, I suppose you 
could call a form of hardware acceleration, though afaik all it does is 
have the GPU scale the video. This doesn't mean, however, that bad 
drivers won't affect the playback even if you aren't using GPU 
assistance. For example, my Turion64 2.2GHz laptop with a red-headed 
stepchild XPress 200M has with past drivers (open and proprietary) 
played back 1080i using just Xv just fine as well. The current drivers 
though...gack, and XvMC isn't even available with an ATI-based card.

Jesse Burt

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