Aaron62

Just kind of thought of this one today, but since broadcasters are kind of limited with OTA bandwidth and providing HD, subchannels, and now mobile DTV, is there any room to improve the method and delivery of broadcast signals to allow for more programming? Is Digital the final frontier with broadcasters?

Tower Guy

OTA is limited to MPEG2 encoding. MPEG2 encoding is fairly mature. However, not all stations have the latest technology.

A state of the art encoder system uses statistical multiplexing and multipass encoding. Both of those are options that the station must pay extra for.

I assume that most LA stations have these features. Smaller TV markets probably don't.

Aaron62

Aren't some stations going to be transitioning to MPEG-4 soon?

Trip

MPEG-4 is in the standard but since no consumer receivers support it, it's not happening any time soon.

- Trip

Piggie

It's easy to look back and say what if...........

But to me, between limited to MEG-2, ATSC and 12 MHz bandwidth (about in that order), OTA is near or at it's limit.

Looking back, if there had been an early switch to MEG-4, when only a handful of consumers had purchased ATSC HD tuner TVs, etc, it could have happened. The transition too a decade or more and in that time compression technology moved on. It pretty much limited them from every going to 1080P which will be the standard if not now but soon as "real HD" in a lot of consumers minds.

Then ATSC is a not overall the best standard, but my knowledge there is limited to just reading revues.

If we had a "true" flash cut, and didn't give up channels, we could have gone to a wider TV RF channel.

All this is a dead horse now. And actually, for just putting up an antenna, I am quit pleased to receive 720p and 1080i, though I don't think there is really room in American channels for 1080i, unless there isn't a sub or the sub is very bandwidth limited. On TV's I have watched (all 720p LCDs) cheating just a little on 1080i ends up pixelating movement on the screen.

It's changing fast as prices drop. Just last year, few people could afford 1080p sets. So most had 720p LCD screens. Since an LCD can't do interlace, any interlaced video sent to the set must be converted to progressive scan to display from what I have read. Hence isn't sending 1080i a waste to a lot of sets? Maybe more over if they insist on adding and adding subs, there just isn't room for 1080i in my opinion.

Tower Guy

Much prime time drama is shot on film. By definition film is progressive. This is because there is no movement between interlaced field 1 and field 2.

Therefore, anything shot on film is displayed as 1080p even when transmitted as 1080i.

Tower Guy

Mobile video will be MPEG4, but it won't be HD. Mobile video is an adaption of the ATSC standard meant for handheld and mobile devices. It is intended to be sent simultaneously as an HD signal and take bandwidth that would otherwise be used for an SD subchannel. Depending on the resolution and frame rate, several mobile video channels can fit next to an HD signal.

FOX TV

While DTV was being developed to use the 8-VSB modulation scheme and MPEG-2, the development of MPEG-4 was well under way. It took longer to develop mpeg-2 using 8-VSB modulation than it did to develop MPEG-4.

Technology marches on, and there will be someone who finds a way to do more with the 6 mHz 19.36 megabyte stream we have now, but the draw back will be the backlash from consumers who are deeply committed to MPEG-2 devices now. Could someone do it and possibly still be able to support existing legacy devices? Most likely, but the big deal now is 3-D TV which could benefit from added bandwidth that is not available now.

In some circles, a lot of people think that OTA broadcasting is in its final frontier right now with all of the threats from those who view the bandwidth as a cash cow for their enterprises such as Microsoft and Google to name a few.

Aaron62

Yeah we've debated about it here in the past too. I certainly hope it isn't true.