[mythtv-users] Two tuners showed up

Simon Hobson linux at thehobsons.co.uk
Sat Aug 6 17:13:06 UTC 2011

Jay Ashworth wrote:

>You're confusing "OTA multicast" with "Cable multicast", I think, Stephen.
>While multirec probably *would* handle OTA multicast, where a station sends
>some auxiliary programs multiplexed into its signal, what Multirec is really
>aimed at is CATV multicast, where the cable company multiplexes several
>*primary channels* into one RF carrier, such that you might have the SDTV
>signals for *all of your local network affiliates* on one carrier, and could
>thus record programs from all of them with only one tuner.

What you describe is exactly what is standard for terrestrial 
broadcast (DVB-T, aka Freeview in the UK) once you've gone digital. 
Rather than redesignating the spectrum as lots of narrow channels, 
they've kept the same (8MHz wide ?) channels but stuck a digital 
multiplex on them. Far more flexible as the broadcaster can then 
apply various tradeoffs - higher compression (hence lower quality) to 
fit more programs in, or have less programs at a better quality.

In a lot of ways, CATV is the same as broadcast, but the signal is 
constrained down a thin tube instead of splattered over hundreds (or 
thousands) of square miles.

Simon Hobson

Visit http://www.magpiesnestpublishing.co.uk/ for books by acclaimed
author Gladys Hobson. Novels - poetry - short stories - ideal as
Christmas stocking fillers. Some available as e-books.

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