reply to MovieLover76
Re: But how lossy?
In so much as it's a 19Mbps stream, yes. However, the broadcaster can do what ever they wish in that space... one high rate HD stream, one lower rate HD and two SD's, etc. FCC rules prohibit cable systems from modifying OTA broadcasts -- they have to broadcast what they're handed. (the broadcaster can hand them a different stream than their transmitter, and that's ok. PBS does that around here.) And ATSC (8VSB) is MPEG-2, and so's the US cable network.
ATSC HDTV is a set standard
There is an entire website dedicated to keeping track of the compression/bit rate being used by DirecTV and it will show you what shows are being shown at what rate.
I dont recall what it is, but I am sure your friend Google can find it for you.
I wasn't talking about DISH and/or Directv -- who use MPEG-4 and various patented variable field compression Magic(tm) to reduce the bit rate even more. Or Uverse who use low bitrates and smoothing (aka "blurring") to reduce their bandwidth. (if all you watch is Uverse, you won't notice it.)
I was talking about ATSC (over-the-air) and CABLE broadcasts -- which are MPEG-2, still.