Uses for 10-2 - 10-5

[sfrazier9999]

Is WBNS going to broadcast anything on anything besides 10-1? If so, when?

[Thombil]

I hope not!:D

[sfrazier9999]

Why not?

[vasqued2]

Because it would degrade the quality of 10-1.

[Thombil]

I'm sure that if they did multicast on the sub channels it would be something I would not care to watch and it would degrade the quality of the 10-1 programing. WBNS locally and CBS nationally seem to understand the importance of quality video when it comes to HDTV.

It is the station I watch more than others.

[nicjimbass]

How much degradation happens with multiple sub channels? I watch 4.1 and 6.1 regulalrly, as well as 34.1 and 20.1 occaisionaly, and to me, there's not a drop in quality compared to 10.1.... am I just not seeing it?

[Robbiee19]

How much degradation happens with multiple sub channels? I watch 4.1 and 6.1 regulalrly, as well as 34.1 and 20.1 occaisionaly, and to me, there's not a drop in quality compared to 10.1.... am I just not seeing it?I guess some people do, but I agree with you I don't see any degradation between 4.1, 6.1 and 10.1 at all. Picture quality is equal on all of the channels.

[Thombil]

Did you ever watch the NCAA tournament when WBNS was multicasting 4 games at one time? It was not watchable.

[Robbiee19]

Did you ever watch the NCAA tournament when WBNS was multicasting 4 games at one time? It was not watchable.Yes I did. The sub were ok not great but they were watchable for me. The 1 HD was very good.

[TvPat]

Here are the bitrates of the local stations in megabits per second (Mbps), according to http://www.rabbitears.info

4.1 - 16.7 Mbps
4.2 - 1.6 Mbps
6.1 - 13.5 Mbps
6.2 - 3.5 Mbps
10.1 - 18.2 Mbps
28.1 - 16.4 Mbps
34.1 - 13.25 Mbps
34.2 - 1.1 Mbps
34.3 - 2.65 Mbps
51.1 - 9 Mbps
53.1 - 16.9 Mbps

The maximum bandwidth if an ATSC broadcast channel is 19.38 Mbps. Uncompressed ATSC video at 1080i is 1485 Mbps, so all of the stations are compressing the video at least 80 times uncompressed. I seriously doubt if you could see a difference between 16.7 and 18.2 Mbps unless you have the eye of a surgeon sitting a foot away from the TV.

CBS distributes its HD feed at 45 Mbps. Affiliates then re-compress it. In WBNS's case, it is 18.2 Mbps. They actually have 1.1 Mbps available without affecting thier current HD picture. That would not be sufficient to show a basketball game, but you wouldn't have to change the main feed much to add a 3 Mbps feed.

WBNS's main motivation for no multicast is economic, not picture quality. Tom Griesdorn of WBNS was quoted in the Dispatch a few weeks ago saying this on the subject of multicasting:

"I don't see anything sustaining itself," he said. "It's all based upon, 'How attractive is the offering?' Are viewers willing to invest time in watching retro TV or movie TV, especially given the 400-plus channel offerings of cable and satellite now?"

Frank Wilson even stated in this forum that their number one reason for not doing the NCAA multicast was the reduced "return on investment" of only doing one game.

CBS definitely looks visually better than than the other networks, but it is as much due to their distribution system as it is their affiliates' bit rate. Below is a quote from http://forums.highdefdigest.com/hdtv-programming-info/68632-question-about-hdtv-bitrate.html discussing network bitrates for sporting events.


(1) FOX takes its 1.0Gbps (uncompressed) 720p truck feed, compresses it down to 73Mbps or less for their operations center, and then uplinks it to satellite at 14.6Mbps for distribution to local affiliates.

FOX affiliates pass this feed through without any extra processing or compression using specialized equipment provided by FOX.

(2) CBS takes a 1.5Gbps (uncompressed) 1080i truck feed, compresses it down to 45Mbps for their operations center, and then uplinks it to satellite at 45Mbps for distribution to affiliates.

CBS affiliates process and re-compress this 45Mbps feed to 19.4Mbps or less. Some CBS affiliates have newer/better encoders than others.

(3) ABC takes a 1Gbps (uncompressed) 720p feed at the truck, compresses it down to 45Mbps for their operations center, and then uplinks it to satellite at 40Mbps for distribution to affiliates.

ABC affiliates process and re-compress this 40Mbps feed to 19.4Mbps or less. Some ABC affiliates have newer/better encoders than others.

(4) NBC takes a 1.5Gbps (uncompressed) 1080i feed at the truck, compresses it down to ~38Mbps for their operations center, which then recompresses and uplinks it to satellite at 24Mbps for distribution to affiliates.

[willcail]

How hard is to muticast ONN? Since the Dispatch Group owns the cable network. Wouldn't cost them that much to have a 24 hour news channel that airs ONN CBS news programs. If they can afford to have another free magazine then they can afford to muticast. Plus it will have must carry status on all three cable systems.

WSYX DT. can broadcast MYTV in HD if they want to. Until or if they ever moved from VHF 13 to UHF 48.

[gsb]

How hard is to muticast ONN?
Somebody asked about that a while back, and the answer was that retransmission agreements with cable companies prohibit putting ONN over the air (see this message (http://www.hdcolumbus.net/vb-hdtv/showthread.php?p=11063)).


WSYX DT. can broadcast MYTV in HD if they want to.
There's not enough bandwidth to broadcast two HD signals (i.e., 6.1 and 6.2 can't both be HD).

[nicjimbass]

Did you ever watch the NCAA tournament when WBNS was multicasting 4 games at one time? It was not watchable.

I remember watching last year, although not closely. I know the substations were bad enough for me not to worry about them, but I didn't notice anything wrong with the main HD channel. Also, WOUB used to have 3 substations (but have since moved to 2) and even then, the HD channel was fine. It just seems like maybe I'm missing something as alot of people seem bothered by the idea of substations. I love the idea of more channels (since I can't afford cable TV but love variety), but, again, I haven't seen much of a difference in quality between stations that hve them, and those that do not.

[hdtvnewbie]

http://ohiomedia.blogspot.com/search?q=720p

From Ohio Media Watch:

OMW readers in the Youngstown/Warren area tell us that New Vision has been experimenting further in the past few days, offering up both CBS and Fox programming in HD format via WKBN-DT 27.1 and 27.2.

How are they doing it?

As near as we can tell, the station is testing new, more advanced encoding equipment, and is apparently cross-converting the CBS HD feed from 1080i resolution to 720p. Fox is already at 720p, and 720p - so we're told - takes less bandwidth on a digital channel than 1080i does.

We have no idea if this experiment will continue...or if the station believes that the two-HD feed picture quality is good enough...

[gsb]

Does the DTV standard provide for 480i anamorphic? It wouldn't be HD, of course, but I would think you could get DVD-like quality for 16:9 programs on subchannels.

Now, e.g., 34.3 is practically worthless. The (originally) HD programming on 34.3 is letterboxed (16:9 on 4:3, i.e., letterboxed and pillarboxed) so that it's shrunken to a small fraction of the screen, basically unwatchable, plus the resolution for HD shows is thus worse than SD programming.

[TvPat]

KXII in Sherman, TX broadcasts three channels over its digital signal. Two are HD.
12.1 CBS HD 1080i
12.2 MyTv 480i
12.3 Fox 720p

Here's an article discussing it.
http://broadcastengineering.com/hdtv/kxii-hd-sd-channel/

In the satelliteguys.us forum, they discuss the picture quality. The reviews are actually pretty good. I'dd like to see it for myself.
http://www.satelliteguys.us/hd-over-air-ota/83269-kxii-delivers-2-hd-1-sd-channel-same-time.html

I would get used to multicasting. As soon as stations find a way to make money on it, whether it's entertainment programming or home shopping, they will all do it.

[vman41]

Does the DTV standard provide for 480i anamorphic? It wouldn't be HD, of course, but I would think you could get DVD-like quality for 16:9 programs on subchannels.

The ATSC standard does provide for a variety widescreen 480 line formats, both interlaced and progressive. For some reason, stations have found in infeasible to switch resolutions to match the source material aspect ratio and instead use letterboxing and cropping fit it into the format they've chosen for that sub-channel.

[TvPat]

ABC has announced that they are adding a new multicast channel to their owned and operated stations. It is a full 720p channel, not a low bit rate weather channel. It looks like it's a network with all talk shows, which takes very little bandwidth.
http://livewellhd.com/story?id=6777600

Users in this forum don't seem to be too happy about the picture quality of WABC in New York and WLS in Chicago.
http://www.dslreports.com/forum/r22197804-Re-Live-Well-HD-replacing-WABC-

According to a post in this forum
http://www.dslreports.com/forum/r22193307-WABC-closing-up-shop-Live-Well-HD-ABC-station-added
the bit rates for WABC in New York are now:
7-1 - 10.4 mbps
7-2 - 5.1 mbps
7-3 - 2 mbps
10.4 mbps is not very much for ABC. Sports like college football and NBA will look terrible.

The HD multicast thing seems to be a growing trend. WKBN in Youngstown broadcasts CBS HD on 27.1 and Fox HD on 27.2, both in 720p. The CBS is downconverted from the CBS native 1080i. I would be curious to see what that looks like. (My guess is not good.)

[Scott]

This is not good news.

[Thombil]

Desperate times call for desperate measures I guess.:confused:

[willcail]

If you haven't heard that WBNS DT is going to muticast after all. 10.2 will be an Accuweather affiliate/local weather info coming around June 12th.

Plus the Dispatch Group other TV station WTHR muticast the following:

13.1 NBC HD
13.2 SkyTrak WX Network
13.3 Universal Sports

[Timcredible]

jeez, this stinks. for those that don't use ota to get these stations, it won't matter, but to those of us using ota for these channels, it's easy to notice the drop in quality of the hd channel when the subchannel nonsense is added. i'm sure that as long as stations get advertising dollars, they'll do whatever makes them the most money, but it sure does defeat the purpose of hdtv to the ota crowd - we might as well have stayed with sdtv. for reference, the ota quality of the cbs march madness of years gone by was unwatchable, and the current pbs station is horrible with their 4 subchannels. i sure don't see any reason to be wasting money buying a 120hz or led hdtv in the future since there will be ever more subchannels.

[Timcredible]

I guess some people do, but I agree with you I don't see any degradation between 4.1, 6.1 and 10.1 at all. Picture quality is equal on all of the channels.

do you get the local channels via directv? if so, you won't be subject to the loss of signal quality that those of using ota signals are.

[willcail]

The main DTV channels don't broadcast in HD all the time. WSYX and WTTE broadcast in 720p. Plus the digital muticasting uses hardly any bandwith any ways. The up coming Accuweather subchannel only takes up to 1.6 to 2.0 MBPS anyways. Cable companies compress the HD feed anyways.
There is nothing worng in multicasting, gives a person more choices.

The 120 hz HDTV's are a joke, the human eye can only sees 30 fps, and the same goes with Monster cables.

[Thombil]

When it all starts to look like WOSU and it's 4 feeds, HDTV will be a memory of the good old days.

[willcail]

When did WOSU DT start broadcasting three digital subchannels?

34.1 WOSU HD
34.2 The Ohio Channel
34.3 WOSU plus Create

Unless you are picking up that other PBS station that broadcast on PSIP 42.

[DublinDoodah]

The 120 hz HDTV's are a joke, the human eye can only sees 30 fps, and the same goes with Monster cables.Non sequitur.

[Timcredible]

The main DTV channels don't broadcast in HD all the time. WSYX and WTTE broadcast in 720p.
from everything i've read, 720p and 1080i take about the same bandwidth
Plus the digital muticasting uses hardly any bandwith any ways. The up coming Accuweather subchannel only takes up to 1.6 to 2.0 MBPS anyways.
so, they each take about 10% away from the overall bandwidth. when you do 3 of them like wosu, it's very noticeable

There is nothing worng in multicasting, gives a person more choices.unless you want the choice of a good ota hd picture. some people prefer more channels of lesser quality, and some people prefer less channels with higher quality. over the years, this forum has always been split on this subject, doubt that will ever change.

The 120 hz HDTV's are a joke, the human eye can only sees 30 fps, and the same goes with Monster cables.
if we can only see 30fps, why is 720p video 60fps?

[zelig2]

The 120 hz HDTV's are a joke, the human eye can only sees 30 fps, and the same goes with Monster cables.

120Hz LCDs have nothing to do with visual frame rates. It's all for increased motion resolution.

[rossl]

Cable companies compress the HD feed anyways.


Cable companies don't compress the feeds.

Everything you said in your post is wrong.

Got any more excuses?

:doh:

[TvPat]

Here comes another station multicasting two HD feeds.

WLIO, NBC channel 35 in Lima, recently bought the 3 low power analog stations in Lima that were carrying ABC, CBS, and Fox. They are moving channel 35 to channel 8, their digital channel. When analog 35 goes off the air they are starting a new low power digital channel there. Each channel is going to carry 2 HD feeds.

Here are the future channels. (8 is full power, 35 will be low power.)
8.1 NBC HD
8.2 Fox HD
35.1 CBS HD
35.2 ABC HD

Now word on how the stations will share the bandwidth, but I would imagine since WLIO is a primary NBC affiliate they will get the largest chunk.

Here is the engineers blog from that station that talks about it.
http://www.wlio.net/index.php?entry=entry090420-200230

[hdtvnewbie]

from everything i've read, 720p and 1080i take about the same bandwidth

From what I've read, 720p takes far less bandwith and is supposedly choppier with action programs. However, I don't notice much of a difference with basketball on ABC. I think it looks pretty good to me.

[bspvette86]

Cable companies don't compress the feeds.

Everything you said in your post is wrong.

Got any more excuses?

:doh:

All OTA HD content uses Mpeg2 compression which is a lossy compression. What determines whether there is significant quality degredation is the bit rate that is used. Some cable companies do recompress the transport stream to a lower bit rate. If you have a PC tuner card that can capture OTA and QAM, you can easily check the bit rates of both.

[gsb]

From what I've read, 720p takes far less bandwith [than 1080i]
According to A/54A, Recommended Practice: Guide to the Use of the ATSC Digital Television Standard, they're actually about the same bandwidth: bit rates of 1.106 Gbps for 720p and 1.244 Gbps for 1080i, prior to compression.

The reason is that 720p is 720×1280 pixels at 60 frames per second, while 1080i is 1080×1920 pixels at 30 frames per second (interlaced so you can think of it as 60 half-frames per second).

Quoting their calculations:

"720 × 1280 × 60 × 2 × 10 = 1.105920 Gbps (the 2 represents the factor needed for 4:2:2 color subsampling, and the 10 is for 10-bit systems)

"1080 × 1920 × 30 × 2 × 10 = 1.244160 Gbps (the 2 represents the factor needed for 4:2:2 color subsampling, and the 10 is for 10-bit systems) "