[mythtv-users] cable box woes

[David Watkins]

On 05/10/05, Steve <stgarf at gmail.com> wrote:
> I have a Scientific Atlanta Cable box that outputs cable via S-Video into my
> PVR-500. I'm not sure exactly where I plug it into my PVR-500 and I'm also
> not sure what settings need to be modified in mythtv-setup. (video0/s-video1
> or 2, video1/s-video1 or2). I've tried both S-Video slots on my PVR-500 with
> various settings in mythtv-setup to no avail. They way it's supposed to work
> (AFAIK) is that lirc sends a change channel command to my cable box, the
> cable box switches to the specified channel, outputs via the s-video cable
> into my PVR-500 and myth records via the S-Video port on the 500.

That's pretty much correct.  The steps are:

1) You tell the mythtv frontend that you want to change channel.
2) The frontend tells the backend, which calls a channel change
script, which you have provided.
3)  The channel change script either uses lirc to drive an ir-blaster
which mimics your remote control to change channel on the cable box or
sends a code via a serial interface to the cable box (if your box has
a serial input that is).
4)  Assuming the channel change script completes successfully then
mythtv will register the change and select guide information to match
the new channel accordingly.