Originally Posted by markofmayhem
So it is your opinion that the poor quality is solely based on Imagine's ICE Broadcast solution; the actual squeezing of 3 HD feeds into 1 QAM? I concur, I was being optimistic in thinking it could have been the second sat bounce.
Yep. As pointed out, by placing the three HD video streams into a datastream that is ready for QAM modulation, means they just had to place that stream onto a sat transponder. Since QPSK modulation can get you around 45 Mbps total payload, they went with DCII to send the 38.8 Mbps payload.
If, they would have taken the three video streams and combined them with another sat mux containing three more HD streams and ultimately split them up into three QAM channels (2 per), then I definately would have said that the sat transmission method caused the quality decrease. That said, they probably would have gone to something like DVB-S2 (8PSK), giving then something around 67 Mbps to work with. Add to that used MPEG-4. But the MPEG-4 would have to be re-encoded back to MPEG-2, so the MPEG-2->MPEG-4->MPEG-2 multiconversions could induce other aritifacts. They could have stayed at MPEG-2 and provided the highest bitrate available for QAM.
We know they did this cramming so that they could send out more HD channels in the limited cable bandwidth that they have. Who cares of the channels look like crap, they can still claim high HD count.
I'm guessing that this is ultimately going to come back around and bite them in the ass, as more and more subscribers complain about the horrible quality and the national press start reporting on this fubar.
The only HITS modulation I've seen is QPSK. It sounds as if there is plenty of headroom on the QPSK transponder to introduce enough FEC to ensure the sat transmission is not causing interference, so it must be the "package".
If they pushed 32362 for the SR and 7/8 for the FEC, they could get around 52 Mbps for the total QPSK payload. Most use 3/4 or 5/6 and do set a SR to do around 45 Mbps.
Perhaps 2 HD along with 2 SD per QAM would have been a better starting point than 3 HD.
That would still provide about the same low bitrate for HD. Teo HDs and no SDs is still pushing it.
Didn't Cable Labs announce that 15 Mbps was the "safe harbor" for HD content?
I'm sure there are many sports viewers that will argue with that. Of thos OTA ATSC stations that are doing 1080i, 1-HD and 1-SD, the viewers are bitching about the macroblocking during sports programming. The HD is getting about 15 Mbps.
Personally, I believe that a single HD channel using 1080i can have problems, i.e., the 19.2 Mbps total ATSC payload isn't enough.
With QAM payload being 38.8 Mbps, if I have that right, it as about twice that of ATSC, so they should be able to put 2 HD streams into a channel and be equal to, but no better than ATSC.
What really sucks is that digital video is crystal clear and therefore better than analog video. Well, it most certainly can be, until the idiots with suits and ties too tight around their necks, pull these lame-ass games with the bitrate, thereby killing the "crystal clear" video.