[mythtv-users] Minor MythTV firewire channel-changing issue

Marc Barrett mnealbarrett at cox.net
Sat Feb 21 19:22:11 UTC 2009

I have a MythTV 0.21 setup involving a firewire connection
to a Motorola DCH-3200 STB.  Let's say I am watching a 
certain channel, say channel 303.  I used the MythTV 
program guide to change to that channel, and not the STB
itself, so MythTV "knows" that it is on that channel, and I 
am watching live TV on the channel.  I go ahead and 
schedule a recording for the same channel, or a recording
is already scheduled for that channel.  I have noticed that
when the recording is scheduled to start, it first asks if I 
want to continue to watch it while it records (no problems
here).  Then, MythTV tries to change the channel to the 
channel that it is already on.

This is the problem.  First, whenever you do a channel-change
with a firewire setup, there is always a chance that something
will crash or hang or the connection won't be negotiated right
or whatever.  Second, even if everything works right, the 
channel-change over firewire (even to a channel that it is already
on)  takes a good 7 or 8 seconds, and that much of the program 
that is being recorded ends up being missed (not recorded).

I know MythTV likes to change the channel at the beginning
of a scheduled recording so that, just in case the STB isn't on
the right channel, then the program will be recorded properly.
I was just wondering if it would be much of a big deal to add
a little something to MythTV so that if live TV is being watched
through MythTV, the currently-being-watched channel is the 
same as the one scheduled to be recorded, and a firewire 
connection is involved, then to not bother trying to change the
channel at the beginning of the recording.

More information about the mythtv-users mailing list