Digital TV changeover

Twelve channels now, bitches.

Bucket said:

Twelve channels now, bitches.

Great! Just make sure you let us know when you go beyond 30 (that's how many I get to see in the hillbilly region of Greece I'm living in ;-)

That'll be never, unless I move to a hillside and get a roof antenna. Or the TV stations decide to address the digital reception problem. *snort*

I really don't watch much TV, though.

I guess the real limit is the transmission itself. If it can only display X number of frames/second, then it's limited, unless it can find an initial frame and go from there, negating any past and future prediction frames. It'll look all weird, being only part of the image will move for about 1/3 to 3 seconds (depending on compression rate).
The reason I think it's possible, is that as I said, I noticed TV's are getting fast at ploping channels onto the screen. Old DTV-100 took about 5 to 7 seconds, and my bedroom one can do it in under 2.


My living room TV says it gets 47 channels, most are multicast (counting each sub-channel as one), so not as impressive. It counted analog 4 and 5 from Boston, as they are looping DTV conversion guides. (Makes grand total of 49 channels.)

Georgef551 said:

I guess the real limit is the transmission itself. If it can only display X number of frames/second, then it's limited, unless it can find an initial frame and go from there, negating any past and future prediction frames.

Pretty much so. You can even witness that phenomenon with youtube videos and saved video files in any major MPEG/MPEG2 format: only a handful of frames are "main" or I-frames that can be displayed directly like a JPG photo, and the others are dependent upon it (or even upon future ones, in advanced formats like MPEG4). This affects which frames you can seek directly to (if at all), and how much you must buffer before displaying anything.

Since even old DVRs and DTVs must still be able to process stuff real-time, the difference is more likely due to different amount of buffering and/or a lower "display" threshold (e.g. start displaying only with the buffer 100% or 80% full). In any case, "fixing" this would negate the mechanism that makes digital video possible. Analog TVs and videocassettes can get away with it because they are using the equivalent of uncompressed data all the way (the closest there is to that in digital systems is Motion JPEG, which however gives enormous file sizes and lesser quality compared to codecs such as MPEG4, and is mostly used in cheapo digicams).

I thought analog broadcasts were supposed to be gone now - there's still (at least) four stations broadcasting analog here in New Mexico. In fact, only two of the major networks have even switched to digital here (NBC and CBS). A look at AntennaWeb shows most of the digital channels for New Mexico are really from towns on the border inside Texas, Colorado, or Arizona.

I think the change initially affects national networks at first, regional ones may elect not to change for a little while longer (or at all, if they are some small-town stations). Anyway, had DTV not been pimped so much (practically government and telco-mandated just to sell more licenses), it would be something akin to digital radio, for which nobody gives a fuck. It's plausible there might be relatively long coexistence period, especially if local interests dictate so.

Low powered stations (like college campuses, and similar markets) are not affected by the DTV switch. In those cases, those stations can continue on with analog broadcasting (as going digital would really shrink the fringe area signifigantly).

Maes, one thing I gdo notice about the lower MPEG stations, they do take longer to pop up. I can only imagine how many hours a Comcast HD channel takes to show. :)