[mythtv-users] hdtv from a cable box

Jerry Rubinow jerrymr at gmail.com
Wed Jul 27 22:44:33 EDT 2005

On 27/07/05, tgate <tgate at mypublic.net> wrote:
> Uhhh... why not do firewire?  Just ask them for a cable box with
> firewire, connect to your backend, and you can both capture AND change
> channels over firewire. 
> If I might ask. I've setup mythtv a few times and am always looking for a
> more permanent solution.  Currently, I'm debating getting a direcTv receiver
> from 169time.com that has firewire out or switching over to comcast with a
> pair of motorola 6200 STBs (This has been a struggle because comcast
> continues to deny needing to provide a STB with firewire active).  Any
> information on either of these routes would be well appreciated.  
> But specifically, are you able to archive premium channels such as HBO,
> etc...?  Will it also archive non-HD signals the same way?  Is the signal
> that comes over the firewire a uncompressed stream of some sort or is it in
> the original format from the provider?

I have a 6200 STB from Comcast in the Philly area, and I'm in the
midst of setting up a system using firewire - this is what I've
observed so far.  I don't know about premium channels, but Discovery
HD, InHD, InHD2, ESPN, and CSNPHL all seem to be encrypted or
something - they don't produce a readable stream.  However I have no
problem with the HD feeds of the networks, and all the non-HD channels
come in fine over the firewire as well.  It's all mpeg2 over the
firewire.  I think the HD channels are the original format from the
originator, and the rest is all NTSC-sized mpeg2.

I've run into two significant problems so far.  First, while myth has
no trouble telling the channel to change via firewire, and setting up
recordings on different channels works no problem, myth gets extremely
upset if you try to change channels while watching live tv, to the
point of crashing mythfrontend.  I've seen this reported before, and
I'm surprised no one's been annoyed with it enough to fix it.  As soon
as I have a chance to figure out where in the code this is handled,
I'm going to try to see if I can figure out a fix, since the WAF is 0
without this.  Second, there's one channel that seems to confuse
mythfrontend about half the time when it tries to play it.  Sometimes
it plays back fine, sometimes it locks up or crashes mythfrontend.  I
don't think mplayer has a problem with streams recorded from this
channel (not positive, needs more experimentation).  I've seen
suggestions for using some perl script or mencoder to normalize the
stream as a workaround for this, but haven't tried it yet.

Note that the lack of DiscoveryHD, ESPN-HD, etc, is for the Philly
area.  I've seen reports that in some areas, these come in fine.


More information about the mythtv-users mailing list