[mythtv-users] firewire to change channel but use coax to record

Shawn Flynn sflynn1 at rogers.com
Mon Jun 9 22:39:14 UTC 2008

> From: mythtv-users-bounces at mythtv.org
[mailto:mythtv-users-bounces at mythtv.org] On Behalf Of Scott Bickford
> Sent: June 9, 2008 1:35 PM
> To: Discussion about mythtv
> Subject: [mythtv-users] firewire to change channel but use coax to record
> I am still having problems recording from firewire (SA4250 STB) from 
> time to time, but for whatever reason channel change works ok 
> (without a script).  So, instead of  getting an  IR blaster, I 
> thought I saw a thread about using firewire to change channel on STB 
> and use a tuner (connected to STB via coax) (in my case a PVR-350) to 
> record.  Obviously, because I am writing, I thought I had seen it 
> under input groups and/or mythtv documentation, but just cannot find 
> it.  How do I set this up?
I do exactly the same thing with my configuration... SA4250HDC that will not
work reliaby to capture via firewire (damn you Rogers Cable), but has
flawless firewire channel changes. I have it connected to the svideo input
of a pvr150 and use the sa4250ch_guid firewire channel changer from the
ubuntu forums ( http://ph.ubuntuforums.com/showthread.php?t=756508 ). I've
been running it for 3+ months this way and haven't missed a recording yet.
As soon as I see mythtv support for the HD-PVR, I'll switch this connection
over to one of those and be even happier.

I'm not in front of my backend atm, so the following is from memory. It
should at least get you in the right general section for making it work. If
you need clarification let me know and I'll do a step-by-step tonight when I
can sit in front of my backend machine. 

Just go into the 'input connections' section of mythtv-setup for your pvr350
card and point the appropriate input to your digital cable video source. You
mentioned using coax input (I assume you mean the f-connector RF tuner
input), but I highly recommend using svideo if you can. Within that setup is
a location for specifying a channel change script if needed. Place the
/full/path/to/sa4250ch in that field, then continue through to the end of
mythtv-setup as normal. You should now be able to select digital cable
channels on that input of the pvr350 and the external changer script will
tune the SA4250 to the correct channel. 

One other hint I found was to go in to the setup menu for the SA4250 and
change the 'power on' option to power up the box whenever a number key is
pressed. If for any reason your SA4250 gets powered off (like when a
firmware update is pushed from your cable provider in the middle of the
night) it will power itself back on during the channel change for the next
recording. No more recording 2 hours of black screen instead of that "can't
miss" movie you just missed.
Shawn Flynn

More information about the mythtv-users mailing list