[mythtv-users] multiple tuner question

[Bruce Markey]

Tom Trelvik wrote:
> Bruce Markey wrote:
> 
>> As for splitting to a digital cable box, analog channels will
>> be degraded through the box as it is just passing the analog
>> signal along. For digital channels, there are TCP/IP packets
>> going over the cable so as long as there aren't data errors,
>> a weak signal will look indentical to a strong signal. However,
>> if there is intermittent data loss there would be blocks of
>> garbage on the screen.
> 
> 
>     Digital cable runs over TCP/IP?! 

Uh-huh, that's what makes it digital =). It is essentially
a cable modem (or is a cable modem essentially a digital
cable device?). When the tech came to set up my first cable
box, he hit some magic double bucky that brought up the
network info page with the MAC address, netmask, default
route, etc. I assume that the IP is from DHCP. I also assume
that these addresses are a private internet (lowercase "i").


> Is there a standard for it 

there must be

> (whatever protocol they're using over TCP/IP) that most/all digital 
> cable providers follow?  Is it an open standard that mere mortals can 
> lay eyes on (ala an RFC)?

Well, the first page of a google search for digital cable
protocol has this:

   http://www.scte.org/documents/pdf/SCTE402001DVS313.pdf

I've never really looked into it because I've assumed that if
it was easy to grab the MPEG streams everyone would already
do it. I'm sure if you google you'll find something about why
this can't be done easily.

--  bjm