# The power of digital subchannels



## PF9 (Jul 10, 2009)

Digital subchannels can be used to show any type of programming. Either a simulcast of a sister station, a network which is otherwise unavailable in the area, weather info, the sky is the limit!

Some stations have a general entertainment independent subchannel, having a program lineup similar to the old days.

Think about it. 25 years ago, there were only 3 commercial networks, and many independent stations. Now there are 6 commercial networks, and fewer independents.

I would like to see more stations launch a subchannel with a general entertainment lineup akin to the 1980s, especially in markets where there are currently no such stations.


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## Steve Mehs (Mar 21, 2002)

I'd love to see all subchannels disappear yesterday. They should be outlawed. No reason to sacrifice the quality of popular content for niche content no one cares about. HD should be broadcast at 19Mbps, period. Pretty sad that I can get better picture quality on some of my local channels on cable then I could over the air, since Time Warner is receiving them first a direct fiber feed BEFORE they're compressed the hell out of thanks to the notion more is better.

Anyone who is a fan of quality should be against subchannels. CBS has it right on. They do not allow their owned and operated stations to broadcast digital subchannels.


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## CCarncross (Jul 19, 2005)

Absolutely no sub-channels. There is only so much bandwidth for channel, and it gets divided up when you start adding sub-channels, PBS looks like crap because of it..


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## LarryFlowers (Sep 22, 2006)

No Subchannels... not ever... If a stations claims to be broadcasting HD and they have subchannels it should be false advertising.


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## PF9 (Jul 10, 2009)

LarryFlowers said:


> No Subchannels... not ever... If a stations claims to be broadcasting HD and they have subchannels it should be false advertising.


Without subchannels, certain markets would otherwise not have access to certain networks (there are only two stations in the BG KY market for example, and they carry CBS, the CW and FOX on their subchannels, depending on the station).

Now, let's wait for more subchannel supporters to post, before more naysayers do (the discussion should be fair and balanced).


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## Jim5506 (Jun 7, 2004)

One sub channel can be tolerated, especially of the main channel is 720p.

We have a channel the is broadcasting 2 720p (CW and MYTV) and one 480p (Telmundo) signal on one frequency.

Surprisingly the HD picture is not that bad.


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## Steve Mehs (Mar 21, 2002)

The CW broadcasts at 1080i not 720p, not sure what your local affiliate is doing there.. If you had two 720p and one 480p, that means your two 'high def' stations are broadcasting at a bitrate of ~7.8Mbps, that's about 2 1/2 times less than they should be at, that's pathetic. The compression artifacts should be as plain as day especially when comparing it to a station that gets all or just about all 19Mbps. My Network TV doesn't have much HD content to begin with so maybe it's not noticeable as much. Try putting NBC and CBS on the same frequency, especially and try watching football or NCAA basketball on CBS or the NHL on NBC and see how good it looks.


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## Tower Guy (Jul 27, 2005)

PF9 said:


> Now, let's wait for more subchannel supporters to post, before more naysayers do (the discussion should be fair and balanced).


The devil is in the details.

A proper statistically multiplexed subchannel has very little effect on the level of artifacts in the main channel. I've seen a low priority subchannel drop to 800 kb/s when the main channel needed more bandwidth. The addition of buffers to spread the extra data out in time reduces that paltry rate that even further. Yet, the complexity and expense of such a setup suggests that they are in use by too few broadcasters.

A curmudgeon could even argue that a broadcaster who limits his OTA HD signal to 15 mb/s would look better on cable because the grooming equipment that cable uses tends to degrade the 15 mb/s signal less than it does to a full 19.39 mb/s HD signal.


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