OTA TV Stations Streaming?

[fybush]

The full OTA ATSC bitstream is 19.39 mbps.

Do you know what DISH or DirecTV uses as their HD bitstream size?

I'm not sure there's a direct comparison that would be of any real use. The 19.39 mbps for the ATSC bitstream fills the 6 MHz bandwidth of a North American TV channel. Dish and Direct allocate their bandwidth differently - I think they're using transponders that are either 24 or 36 MHz wide. But they're also packing many, many more services into each of those transponders.

The more relevant statistic, probably, is how big a datastream each program service gets. If you're watching a typical terrestrial OTA ATSC station that's running one HD service and one low-bitrate SD service (say, a weather channel), that HD service is getting 12-16 mbps of data allocated to it...which is generally a FAR bigger pipe than satellite or QAM cable will provide. Even allowing for improved compression algorithms on satellite or cable, the odd are you're still going to end up getting a better picture OTA than on any other service.

But it's important to note that a lot of factors can skew that equation. F'rinstance...the PBS outlet here in town crams one HD and two SD subchannels down its OTA pipe, plus a bunch of audio and data services. Some of those SD services end up getting very data-crunched on the OTA signal, with lots of pixillation and motion blurring. But we (yeah, I work there, part-time) also have a really, really fat fiber pipe to the cable company, so the cable headend gets much better versions of those SD channels, though they get somewhat crunched down again on the way out to the end user. If we ever had a FiOS-like fiber-to-the-home video service here, we could probably provide even better pictures that way.

 

[landtuna]

Scott,

I spent the better part of the afternoon reading up on this subject and understand better the different factors involved. There are quite a few articles out there dealing with the sat HD services and at least one lawsuit targeting DirecTV for uber-compression (something in the neighborhood of 8-9 Mb which is about half the OTA width).

Thanks much for the explanation.

 

[JeeperOne]

I was looking at this from a technical perspective rather than a marketing or political view.

With all the issues revolving around OTA DTV reception now would it be technically possible to do a full stream?

The full OTA ATSC bitstream is 19.39 mbps. There aren't many ISPs that can support that kind of bandwidth to the home, and the cost to serve all that bandwidth would be prohibitive to the streaming provider.

Of course, you don't need to stream the entire 19.39 mbps at once, in most cases. If you're willing to tolerate more latency for error correction, there are compression algorithms that can produce a decently plausible HD picture using far less bandwidth. (This is possible in part because streaming is bi-directional, so if a packet is lost, it can be resent; you don't have that option on one-way OTA broadcasting.)

Even so, you're still eating up a LOT of bandwidth...way less efficient than OTA broadcast to reach a mass audience.

Not only that, but Internet streaming doesn't require 19 Mbps. to get a clear picture. One good look at such places as LiveStream or UStream is proof of that (In fact, Gannett has all of its stations on the former service).

I see TV stations doing in the next year or so what radio stations have done since about 2003 or so by putting on more self-produced programming, high school sports (There's no reason why they can't do so now) & airing Internet ads & PSAs. In addition, they could also stream their cam network, live radar, news channel (I'm honestly surprised KMGH 7 doesn't stream its NewsChannel 247 channel on Comcast Channel 247, which just simply loops their latest newscast or ABC News Now, which as an ABC affiliate, you would think they would have access to).

Just my opinion & $.02 worth.....

Cheers

 

[Tim L]

It's a good quality picture but it is very small. Way too small to read any text and almost too small to identify the faces of the actors.

Windows Media Player has a Fullscreen option at the bottom right of the player..

 

[landtuna]

It's a good quality picture but it is very small. Way too small to read any text and almost too small to identify the faces of the actors.

Windows Media Player has a Fullscreen option at the bottom right of the player..

On my system the stream comes up as an active server page and is displayed using Firefox. There is no full screen option nor did I see any way to bring the stream in using Media Player (or any other video program).