Koolu as MythTV frontend suggestions

[Ted Roche]

Ben Scott wrote:

>   As I recall, the opinion of some MythTV experts was that the Koolu
> was somewhat underpowered to be doing real-time decoding of compressed
> video. 

I'm certainly not going to get HDTV or 7.1 sound out of the Koolu, but 
that's okay. I'm watching "Crossing Jordan" on it right now, though at 
the wrong resolution. No audio artifacts, and the video is acceptable, 
maybe a little fuzzy, with an occasional glitch. I'll bet I can tune X 
further.

top is showing mythfrontend.re at ~95% CPU pretty consistently. M shows 
160m VIRT, 70m RES and 33m SHR - that's virtual, resident and shared, 
yes? (Yes, I can 'man top' as well as anyone... reading now)

  The Koolu is optimized for lower power, not performance.
> While I'm sure, with sufficient hacking, it could be made to work, the
> extent of that hacking may be well beyond the point of diminishing
> returns.  (Think "rewrite MythTV, X, and the kernel".)
> 
>   No harm in trying, of course.  I just wanted to warn you up front.  :)

Yeah, understood. It's a hobby, not something I need to get done for 
work. If it doesn't work out, I'll bet I can find another purpose for 
the Koolu.  But initial tests look promising.

I do need to delve into the joy that is xorg.conf, though. Initial tests 
  with the configuration I had for the monitor on its previous machines 
failed with "no suitable configurations found," so I'll need to work out 
how to set up a working set of modelines for the Koolu... did this a few 
years ago for another machine, and need to dig up the notes again...

>   If literally *all* you're doing is running a MythTV front end, it
> should be possible to do just that: Run mythfrontend as the only X
> client, eliminating even the window manager.  As a first guess, try
> replacing $HOME/.Xclients with the following:
> 
> 	#! /bin/bash
> 	/usr/bin/mythfrontend
> 
>   I'd suggest creating a separate user account just for the purposes
> of running the MythTV front end, and doing that for the above.  That
> way, you can keep another user account around for trouble-shooting,
> etc.  (Running a lightweight desktop like Xfce, of course.  ;-)  )

That sounds like a good long-term plan. In the entertainment center, the 
Koolu will mostly be a dedicated device. If we're only watching TV for a 
couple of hours in evenings, it probably makes more sense to leave it 
off the rest of the time and let it be a single-function dedicated 
machine. OTOH, it could provide some backend services (DNS, NTP, DHCP) 
on it's off-hours, maybe even an inhouse LAMP server. Need to balance 
the utility with the complexity and cost...

>> I'm also planning on reviewing the xorg.conf and see if there are
>> things there worth tweaking.
> 
>   Worth trying.  I have an amd(4) man page on my FC6 box (xorg 7.1).
> It doesn't look overly promising, but maybe the newer releases are
> better, or the man page is incomplete.  Also see if that chip/driver
> supports DRI and if your kernel modules for that are loaded.

Notes from http://www.math.ucla.edu/~jimc/koolu/details.shtml seem to 
indicate DRI is not available, but have some other valuable clues.

>   Can't hurt, but if the network was the problem you'd likely see it
> for all your MythTV front ends (and I take it you don't).

Yeah, I didn't volunteer that. There are days when playback is poor, 
with no other obvious differences, I suspect a gremlin running around 
the network wires, just generally poor throughput.

Thanks for the pointers, this is another item on the round tuit list.