For a column on HDTV in Sunday's (3-18) Register, the WTNH general manager has this to say about HDTV and cable:
WTNH and MYTV9 broadcast in 720p (P is for progressive line scan)
In short, progressive scanning particularly stands out in Live sports (NASCAR, Golf Football) – capturing the essence of movement
Cable does pass through one line for the most part. However, broadcast stations do have ability to muli-cast. They can pass through their HD channel and offer other services such as weather channels, news or Hispanic programming. This process is titled “Retransmission” and is negotiated through cable and/or satellite providers. You may recall Congress formed this act back in 1992…
Specific to us (WTNH/MYTV9) we have digital agreements in place with Cox cable and Comcast in our market. They both represent about 71% of the entire cable market. Our company Lin; remains in negotiations with MetroCast, Cablevision and Charter that represent the remaining cable households. I anticipate that a retrans deal will come to fruition sooner than later.
Specific to Cox and my remarks on multi casting, we will be launching a separate channel titled News Express. It will be a 24/7 channel programmed with key elements of local news, weather, traffic and live cams from around the state. Cox will carry this on their digital tier. More to come as we are two weeks out from launch.
Hope that address’s your questions. Here are a few industry links that may assist you specific to HD.