
rkulagow at gmail
Feb 29, 2008, 12:19 PM
Post #11 of 14
(1587 views)
Permalink
|
|
Re: Hauppauge HD PVR (A bit more info for those starved for it)
[In reply to]
|
|
Chris Ribe wrote: > > > > I look forward to the day when more broadcasters actually use higher > > bitrates... Here, only CW and NBC use such a high bitrate. > > > > Mike > > Doesn't CBS broadcast in 1080i too? I thought only Fox and ABC used > 720p? > > > Bitrate, not resolution. For example, here at WCJB-TV in sunny > Gainesville, Florida, we use our 19.2 Mbits to broadcast 2 program > streams. One is ABC, which is broadcast at 720p , and one is the CW, > which is broadcast in a 480i format. > > Before these signals leave the building, they are joined together in a > muxer - a fancy computer that takes one HD-SDI video signal, one SDI > video signal, and puts out a single SMPTE 310 signal, which is a fancy > name for baseband ATSC, I believe. > > Anyhow, the muxer tries to squeeze as much video quality into the 19.2 > Mbits as it can, and it dynamically reapportions bandwidth between the 2 > program streams. When all is said and done, the CW usually ends up with > about 5 Mbits and ABC gets about 12.5 Mbits. I honestly do not know > what happens to the other 1,700,000 bits per second. > > The end result is that the CW looks quite good, an ABC does not. Our > neighbors at WUFT, the University of Florida PBS station, do things a > little differently. They have 3 program streams, one which is usually > 1080i and two standard def. The give their HD channel about 14 Mbit and > squeeze their SD channels into about 2 Mbit apiece. Since you're a TV/IT engineer, and apparently have something to do with ABC, can you please look at the "Funky 720p" thread in -dev? ABC seems to be doing weird things with their ATSC programming, and at first all of the responders to the thread were in Chicago, but we just got a datapoint for someone who's down in Texas, so it may be more prevalent. _______________________________________________ mythtv-users mailing list mythtv-users[at]mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
|