Originally Posted by tylerSC
While channel surfing I noticed the SEC basketball telecast with Auburn v. Miss St appeared much sharper on 9.5 than 62.1. Much better pic quality on WSOC rather than WYCW. And I don't know if it's a factor, but WSOC broadcasts in 720p as does the ESPN produced SEC, and WYCW is 1080i. But both channels are one HD channel and one SD subchannel, so all things should be about equal in that regard. Just an observation. And come tomorrow, I will check out the NBC Superbowl broadcast on both WCNC-36 and WYFF-4. It would be nice if WCNC would drop the Live Well channel for a few hours to increase the pic quality on the HD telecast. Same for This on channel 4. But we'll see tomorrow.
There are a number of factors that determine picture quality and certainly bandwidth is the most important but not the only one. It would be interesting to know if the basketball game was actually produced and transmitted to stations in 720p or 1080i. One station had to cross convert to their transmit format. Most cross conversions don't significantly impact video quality but it's possible.
Every station has an MPEG2 encoder to compress the video for transmission. As you can imagine, current encoders do a much better job of encoding than early models. Depending on the age of encoders, two stations can devote the same bandwidth to their HD video but not have identical picture quality. One very important factor is how the encoder deals with fast motion which requires more bandwidth to prevent pixelization. Those that use statmuxing (VBR) will generally do better than those using CBR. The majority of stations use statmuxing for that reason.
As for dropping sub-channels, reconfiguring an encoding system is not a trivial task and not recommended on Super Bowl Sunday. A small configuration error in encoding can cause problems with receivers and the last thing you want is receivers unable to decode your bit-stream. Many DTV receivers don't handle major encoding changes well, especially when a whole program stream is eliminated.
I will be interested to know how you think WYFF and WCNC compare for Super Bowl video quality.