[mythtv-users] newbie pcHDTV questions

[Daniel Walton]

For reference for anyone installing this card in the future, here are some notes
I took while using Jarod's guide to setup my hdtv card:

Step 7 - Don't install the ATrpms kernel, the hd drivers won't compile with it.
The only kernel I found that would compile and install the drivers without a
hitch was 2.4.22-1.2174.nptl.  I tried Knoppmyth R4V2 but the box locks up
whenever you try to install the drivers.

Step 10 - "apt-get install mythtv-suite" put all of my myth* executables in
/usr/bin but when I compiled and installed the latest CVS they went into
/usr/local/bin.  I soft linked the /usr/bin ones to clean this up.

Speaking of compiling CVS, I had to download and install lame in order to get
all the needed .h files.  I think I read later that there is a way for me to
apt-get the source code for lame but I'm not positive.

Step 18 - Be sure your kernel supports XFS before you convert your video
partition.  I learned this one the hard way :)

Misc

- You'll want to soft link /dev/dtv to /dev/videoX where X is some # video you
don't already have.  Myth won't let you select /dev/dtv thus this step.

- Be sure to set the default channel type to ATSC and you have to assign the
frequency for each station in mythtvsetup.


> >
> > Any XFree86 config settings that you would recommend that aren't in Jarod's doc?
>
>
> I am using the 540p & 540pw modelines which Doug Larrick came up with.
>
> Search the users forum:
>
> http://www.gossamer-threads.com/archive/MythTV_C2/Users_F11/
>
> for "540pw" and you should be able to find his post.  I would bet that Jarod
> has the same modelines on his HDTV page somewhere:
>
> http://wilsonet.com/mythtv/mythhd.php
>

ack, I think I will give those a try before I go down the windows and powerstrip
path.

>
> > Right now it is taking me about 85% of my cpu on a Athlon 2800 to play a HD
> > stream.
>
>
> Sounds about right.  I use a 2.8 GHz P4.  I can play back 1 HD stream, while
> another is recording.  I can *NOT* have mythcommflag running and playback an HD
> stream at the same time.  I would like to build a second box dedicated to
> being a Myth frontend.  The decoding would happend on the frontend box,
> while commercial flagging occured on the backend.  In theory, I should be
> able to make the frontend box quieter, as well.
>
> Even under ideal conditions, the video playback will studder on occation.
> Based on comments which Daniel Thor Kristjansson has made, I believe that
> this happends when the decoder gets behind a little and skips several frames
> to catch up.  If I understand Daniel's comments, the decoder actually skips
> more frames than is really necessary, which can cause a very noticeable jump
> in the video.
>

yep, I'm seeing this.  The video play fine and then hiccups for a second and
then all is fine again.

> I am currently using a 2.4.25 kernel under Fedora Core.  In general, that
> combination is giving me the best results I have seen.  pdicamillo posted a
> patch in the pchdtv support forums, to allow the HD-2000 drivers to build
> with the 2.4.25 kernel, if you are interested.
>

Thanks, but I think if I recompile one more kernel this week I'll scream :)

Daniel