[mythtv-users] Assorted Questions about improving MythTV experience

[Ray Olszewski]

See below.

At 11:36 AM 6/21/2003 -0400, Robert Schultz wrote:
>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?

Not *quite* "all the CPU they need", but you can certainly give them 
priority over gcc. The Unix/Linux "nice" and "renice" commands are what you 
want to investigate.


>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?

NTP (Network Time Protocol) hs the standard Internet service for 
synchronizing a computer's clock with official time for your time zone (not 
your ZIP code). "ntpdate" is one client-level Linux app that does this; I 
think ntpd is the name of the daemon process that acts as both client and 
server.

This is, alas, a bit short of setting "a date/time that's most accurate for 
TV watching in my area" ... mainly because what you describe is not well 
defined. My experience is that the various stations are not themselves 
consistent about when they see the hour and half-hour changing, leaving it 
looking like there are teensy, 1- or 2-minute time zones separating 
stations. So "accuracy" for recording purposes depends on which stations 
you record from.

What is needed is an ability in Myth to have a "start early" offset of the 
same form as the "record past the end" offset that it already has. This 
capability would solve several problems, including this "mini-tome-zome" 
one and the need to allow for latency when changing channels on an external 
device like a satellite or digital-cable selector. But I am not a Myth 
developer, and the developers seem not to agree that this feature is 
needed, so I expect it will not appear any time soon.

I don't use a PVR 250, so I''m skipping the next few questions.
[...]
>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).

I've had trouble with this too. I tried adding the "xset" command to 
/home/mythtv/.xsession, but with mixed success. I too would be curious 
about how others have gotten this to work reliably.