[mythtv-users] determining power state of firewire cable box
Preston Crow
pc-mythtv08a at crowcastle.net
Sat Jun 13 20:59:10 UTC 2009
On Tue, 2008-12-30 at 12:16 -0800, Sam Logen wrote:
> I've got a motorola DCH-3200 attached to my mythtv setup via a
> firewire cable.
I know that this is an old thread, but I just got the same box, and was
dealing with some of the same problems.
> The way I've set up my boot process, it primes the firewire port
> before mythtv starts up.
I haven't figured out exactly how best to do that. I wish that Myth
would do that automatically as part of the firewire tuning process.
> I've downloaded and compiled the latest "6200ch" from svn. I noticed
> that this script has the capacity to toggle the power state of the
> cable box. So I modified its source to include my box's vendorid,
> then compiled it. Toggling the power of the cable box with "-w"
> works, but all it does is toggle.
Yup. But then I realized that the current trunk version of Myth handles
tuning of firewire without using an external tuner. In fact, I couldn't
get it working with 6200ch, but letting Myth change the channels works.
It will even turn on the box if it's off.
> Is there a simple way to query the power state of the cable box via
> the firewire connection, so that if it returns a value meaning the box
> is off, it can power it on with the 6200ch "-w" switch?
Yes, there is. I took the code from Myth's firewire tuning code, and
added it to 6200ch, creating a '-q' option to query the power state.
That made it easy to create a channel change script that powers the box
on if needed (which I needed to record with the PVR-250 on 5C-encrypted
channels).
I can post my changes if anyone wants them. I'm looking for the best
way to get them incorporated into the subversion code base.
On a related note, I have some follow-up questions:
Is there any command to query the currently tuned channel?
When watching shows over firewire, I get a bit of a stutter. I think
this is coming from the cable box (skipping back produces the same
stutter, and there are no digital artifacts). Has anyone else seen
this?
With the DCH-3200, I'm only able to get it to work in broadcast mode at
100Mbps. Does that really matter? Has anyone had success with other
modes? What is the advantage of point-to-point mode?
More information about the mythtv-users
mailing list