[mythtv-users] Assorted Questions about improving MythTV experience

[Robert Schultz]

I have some assorted questions about how to improve my MythTV experience.
My system is a Athlon XP1800+ system with 512MB of RAM.
It's got two WinTV PVR 250 tuner cards using the latest CVS dumps of 
both IVTV and MythTV as of June 17th.
I'm using RedHat 9.0, with a NVIDIA GeForce 4 MX card with TV-Out (using 
NVIDIA drivers). I output to a monitor with XFree+Fluxbox at 1152x768 
using the VGA hookup. I'm using the Yellow composite hookup to output to 
my 27" Sharp TV at 640x480.
I capture TV at 720x480


First, is there a way I can set 'process priority'?
This is kind of a general linux question I suppose but I need to know 
how it fits in within the MythTV environment.

Basically if I'm watching TV and I go and compile something on the box, 
gcc will take up almost the entire CPU and my TV watching will become 
jittery, jumpy and usntable.
I figure there has got to be a way to say 'mythfrontend' and 
'mythbackend' should use all the CPU they need. They get priority. gcc 
can only use what's left.
How can this be done, and do I need to do it to both front and back end 
processes?


Secondly, the date and time for my machine.
Initially when I first started mythtv, and recoreded a show, it must 
have been many minutes off. Because the recording stopped many minutes 
before the show ended.
I found a website online showing what the 'official US Eastern time' 
should be and set it to it.
It's a lot better now, most recordings start within 1 minute of the air 
showing, but some start a few seconds after the show has started.
I'd like to see if I can 'synchronize my clock' with a date/time that's 
most accurate for TV watching in my area (Zip code 16743)
Any ideas?


Thirdly, the 'General Playback' settings.
I'm watching the recordings and Live TV using yellow composite out to my 
Sharp 27" televsion.
If I turn of 'Deinterlace Playback' (since the TV is interlaced) will 
there be any side effects?
Does this option affect recording or just playback?
What about 'Fixed aspect ratio'? Is it wise to turn on, or leave off 
when I'm using 640x480 (already 4:3) on my TV out?
Does anyone have any experience with using 'Jitter Reduction'? Is it 
helpful or hurtful?
And the 'Experimental A/V Sync'. I've only once so far had to exit Live 
TV and go back in due to sound and video not matching (which I thought 
was near impossible with the Pvr250 cards, but I guess not). Just how 
'experimental' and dangerous is this option?


Fourthly, I noticed one of my recordings, half way thru (happened to be 
the show Lucky on FX) started to 'ghost' or 'echo' or 'trail' in the video.
It's not MythTV's output of it, since if I copy the .nuv file to my 
Win32 box, rename to .mpg and play with Media Player, it occurs at the 
same place there too.
I read the past reports and saw the most people don't see it as often if 
they increase to 720x480. But since my capture resolution is already 
that, that isn't an option.
I found on the IVTV lists a handy option:
test_ioctl -c dnr_mode=0,dnr_temporal=0

Many people there have said that fixed the problem for them.
I went ahead and set it on my cards, and put it in my rc.local so it 
gets set every time on boot up.
I hope this fixes it.


Lastly, my system keeps enacting some sort of 'screen saver' when in 
Console AND X after about 5 minutes the screen goes black.
I have had many great inputs about what to do to fix this.
I find if I do all three of these things, it works:
xset off
xset -dpms
setterm -blank 0

But currently I need to do this everytime I open up X.
I'd love for it to happen automatically.
I put setterm -blank 0 in my rc.local file
But where can I put the xset commands?

I tried putting them in the '/etc/X11/xdm/Xsetup_0' file, but it doesn't 
seem to do any good. I still need to open up ETerm and type them in 
manually in order for it to stop the screen blanking after about 5 minutes.
Is there a better place to put these X commands?
I need to make sure it takes affect for both my displays (my Monitor and 
my TV).


And I guess that's it :)
Thanks :)