How is HD delivered locally?

If we have a local CW affiliate, why do they need an HD encoder at
their facilities to deliver HD programming to the local cable
operator? Can the network not provide HD programming direct to the
cable operator for them?

Maybe the local affiliate has to fill in certain slots (i.e. ads)
locally?

And one other question...
It seems that sometimes a 16:9 HD show reverts to 4:3 for a while and
then back to 16:9 after a commercial has been shown. Does the local
affiliate have to do switching manaully for some reason and they
sometimes forget to flip the switch when the show resumes?

Thanks in advance for some insight about this stuff.

Les

You need an encoder to put your normal SD stuff up on your digital channel
(called up-converting). When your network is offering HD it still has to be
processed by an encoder to fit in your 6 meg channel (compressed).
Commercials and upcoverted SD are usually not widescreen format so they are
4X3. When you are watching an HD show, the picture will go to 4X3 during the
commercials for that reason. The local station doesn't flip any switches
during a network HD commercial break, except if it's a local station break
being inserted.
Norm


"Les Blalock" wrote in message
...

If we have a local CW affiliate, why do they need an HD encoder at
their facilities to deliver HD programming to the local cable
operator? Can the network not provide HD programming direct to the
cable operator for them?

Maybe the local affiliate has to fill in certain slots (i.e. ads)
locally?

And one other question...
It seems that sometimes a 16:9 HD show reverts to 4:3 for a while and
then back to 16:9 after a commercial has been shown. Does the local
affiliate have to do switching manaully for some reason and they
sometimes forget to flip the switch when the show resumes?

Thanks in advance for some insight about this stuff.

Les

On Sat, 28 Oct 2006 17:02:17 GMT, "Norm"
wrote:

You need an encoder to put your normal SD stuff up on your digital channel
(called up-converting). When your network is offering HD it still has to be
processed by an encoder to fit in your 6 meg channel (compressed).
Commercials and upcoverted SD are usually not widescreen format so they are
4X3. When you are watching an HD show, the picture will go to 4X3 during the
commercials for that reason. The local station doesn't flip any switches
during a network HD commercial break, except if it's a local station break
being inserted.
Norm

Thanks for that information. I think I'll take a field trip to one of
the local stations to learn more.

Les