Did anyone read the article in yesterday's USA Today (14Aug08) about subchannels? It was pretty much one-sided and seemed like it was written with information coming from the sub-channel programmers (like ThisTV, .2 Network, etc.)

They mentioned only the positives about multicasting and how it's going to revolutionize OTA viewing habits and such. Not one mention about any downsides to multicasting, such as bit starving the main channel and the possibility of channels not putting out an HD feed at all.

There was one blurb in the second to last paragraph about new compression techniques.

Stations could have room for several additional channels and services as engineers find new ways to compress digital bits.

I don't think they'd be able to further compress MPEG-2 much more, right? And going to MPEG-4/h264 would require all new tuners for viewers, and I don't think the government wants to do another coupon program ... right?

Anyways, here's a scan of the article. It's from the 14Aug08 USAToday Life section. EDIT - I couldn't upload the PDF since it's bigger than 500kb.

Here's the web link. LINK (http://www.usatoday.com/money/media/2008-08-13-digital-tv-extra-local-channels_N.htm)

I don't think they'd be able to further compress MPEG-2 much more, right? And going to MPEG-4/h264 would require all new tuners for viewers, and I don't think the government wants to do another coupon program ... right?


I'm in no way advocating multicasting in the US model - however SD and HD MPEG2 encoding has advanced significantly over the years, so if a station has older, less efficient MPEG2 encoding hardware (and if network distribution is also using older, less efficient encoders as well) then replacing them with newer encoders can either improve picture quality, or allow picture quality at the previous level, but at a lower data rate.

I'm not for a moment saying that the gains are enough to allow clean multicasting of HD and SD within the 19.2Mbs payload of a single ATSC 6MHz 8VSB channel, but MPEG2 encoding has improved significantly since the late 80s when it was introduced in HD in the US (and in SD in the UK).

It would be interesting to know the age and quality of the encoders in use in the US for the various networks (both for the network distribution and final encoding chains)

MPEG2 encoders have improved dramatically since digital transmissions began in November 1998. I remember an early football game when the ball was kicked throught the air the encoders lost the football and it was not visable until it was caught. And that was with the full 19.3 MBPS.

Rick R

You still can't see the football on our NBC affiliate (http://www.ky3.com/). :(

OK, so maybe MPEG-2 encoders have gotten better, but even watching the Olympics on my NBC station (Channel 10 in Philly), when the action heats up, the screen goes to all hell. Channel 10 has a weather sub-channel on it.

Imagine if they started putting up an SD movie channel plus the weather station along with the HD channel. It would look even crappier than it does now.

In Philly, only Fox and CBS don't have subchannels. I'm just fearing the day when all of the stations have subchannels and the HD channel is down to 10 Mbps. At that point, I might as well go back to an SDTV (well not really).

ft

I'm just fearing the day when all of the stations have subchannels and the HD channel is down to 10 Mbps.

That day is already here ... my local CBS/CW affiliate is cramming "HD" feeds for both CBS and CW plus a radar sweep on to one transmitter. It looks simply "maaahhvalous" darling. :rolleyes:

Oh yeah ... they are cross converting both network feeds to 720p first.

OK, so maybe MPEG-2 encoders have gotten better, but even watching the Olympics on my NBC station (Channel 10 in Philly), when the action heats up, the screen goes to all hell. Channel 10 has a weather sub-channel on it.


I guess the question is how old/good are the MPEG2 encoders used by your local station for the HD and SD feeds (if the subchannel is compressed efficiently it will take less data from the main channel etc.)

Also - how old/good are the NBC network encoders used for network distribution to your local station.

And again - I'm not trying to justify subchannels - just put some context around MPEG2 encoder efficiency. There have certainly been major improvements since the late 90s era.


Imagine if they started putting up an SD movie channel plus the weather station along with the HD channel. It would look even crappier than it does now.

In Philly, only Fox and CBS don't have subchannels. I'm just fearing the day when all of the stations have subchannels and the HD channel is down to 10 Mbps. At that point, I might as well go back to an SDTV (well not really).

ft
Fox leave space for local additiona of a single sub-channel in their splicer distribution - so even if your local station isn't using the space for a sub-channel - the main feed isn't improved in quality by the lack of a channel as the sub-channel space is still not used by the main channel and is instead replaced by null packets.

(Fox distribute their network feed pre-encoded for broadcast, with local stations just on-passing (to allow bug addition) via their splicer)

Fox leave space for local additiona of a single sub-channel in their splicer distribution - so even if your local station isn't using the space for a sub-channel - the main feed isn't improved in quality by the lack of a channel as the sub-channel space is still not used by the main channel and is instead replaced by null packets.

(Fox distribute their network feed pre-encoded for broadcast, with local stations just on-passing (to allow bug addition) via their splicer)O my dont give anyone else this hair brained idea. It leaves absolutely no hope for any great PQ for the NFL on FOX. At lkeast if it isnt predownrezzed
and bitstarved to 16 mbps there is at least hope that your local affiliate for CBS or etc isnt downrezzing and you will get a great HD picture.

O my dont give anyone else this hair brained idea. It leaves absolutely no hope for any great PQ for the NFL on FOX. At lkeast if it isnt predownrezzed
and bitstarved to 16 mbps there is at least hope that your local affiliate for CBS or etc isnt downrezzing and you will get a great HD picture.

Yep - though on the upside (always try to be half-full not half-empty!) it means that Fox network encoders are encoding everyones picture, so only local content is dependent on the quality of your local station's encoder (unless that is part of the hardware installation at Fox stations with the splicer) It also means that Fox can improve picture quality by replacing just a couple of encoders rather than the encoders at every station. (And also removes concatenation issues for the network distribution - and saves distribution costs as well...)

"Oh who needs HD anyway? Give me more Weather channels, shopping channels, reality programming, alternate language programs, re-runs of re-runs of old network and syndicated shows on wannabe networks,.

More subchannels means more choices and more opportunities to see commercials and more revenue for local stations and....."

<alarm rings and Local Station Owner wakes up with a brilliant idea.....>

Yes, the encoders are improving and compression technologies are advancing - but the question is whether or not the proliferation of subchannels will outpace that advancement. The problem is the fact that mediocre PQ has been deemed acceptable by broadcasters up until now. Technological advancements have nothing to do with changing that philosophy, only in increasing the number of channels that can be carried.

That day is already here ... my local CBS/CW affiliate is cramming "HD" feeds for both CBS and CW plus a radar sweep on to one transmitter. It looks simply "maaahhvalous" darling. :rolleyes:

Oh yeah ... they are cross converting both network feeds to 720p first.

On the flipside if you're into saving transport streams from your favorite shows, you can fit two episodes on a single layer DVD+R disc instead of just one (like everyone else). Half the media at a fraction of the quality! lol

... why can't these leechers use PAX TV's, or a local religious channels spare bandwidth??

The goofy thing about my market is none of the 3 720p station (my50, FOX, ABC) have any subchannels and all but 1 of the 1080i channels do have them, and obviously can't handle the hit in bandwidth.

Didn't read the article, but this damn subchannel crap precludes me from recording any HD programming. Granted, I have an HD divver that came out before multicasting but nevertheless I should be able to record the channel I want without subchannel interference. SD recordings go through the whole program but get only 15 minutes out of usually 1 hr HD programs.

To paraphrase Mr. Mackie, "Subchannels are bad mmmkay?"

Yes, the encoders are improving and compression technologies are advancing - but the question is whether or not the proliferation of subchannels will outpace that advancement. The problem is the fact that mediocre PQ has been deemed acceptable by broadcasters up until now. Technological advancements have nothing to do with changing that philosophy, only in increasing the number of channels that can be carried.And with that, nothing more needs to be said about the subject.

If it were up to me, I just would've closed the thread on that note. :cool:

Considering Gannett owns USA Today and Gannett is big into subchannels - in fact taking more bandwidth than the average subchannels - well, you do the math.

I'm betting in 10 years all the subchannels will be exclusively infomercials and shopping networks.

O my dont give anyone else this hair brained idea. It leaves absolutely no hope for any great PQ for the NFL on FOX. At lkeast if it isnt predownrezzed
and bitstarved to 16 mbps there is at least hope that your local affiliate for CBS or etc isnt downrezzing and you will get a great HD picture.

Where I live, FOX has no subchannels. NBC has 3 subchannels. Football looks much better on NBC than FOX. Fox is 720p and NBC is 1080i. Why would FOX look worse since it has the full bandwith available? Someone mentioned that FOX broadcasts some baseball games as upconverted 480 to 720. Is that what is happening with football games?

Our local in Memphis recently purchased a new encoder last year. I can't remember but I think it was a Tanberg. I was told by the engineer that in test they said it could handle 1080i perfectly fine with no issues at 15 mbps total, video, audiio, epg, etc. He admitted that the tests that were run by Tanberg were called into question as he has not seen the good PQ that they expected.

Yet they still multicast and screw up the picture.

Where I live, FOX has no subchannels. NBC has 3 subchannels.I thought you were in the Chicago area, Doogie, since you've participated in our local OTA thread (?). NBC only has one weather subchannel here.

Where I live, FOX has no subchannels. NBC has 3 subchannels. Football looks much better on NBC than FOX. Fox is 720p and NBC is 1080i. Why would FOX look worse since it has the full bandwith available? Someone mentioned that FOX broadcasts some baseball games as upconverted 480 to 720. Is that what is happening with football games?

Ah - but don't forget that the Fox NETWORK encode the signal your station broadcasts - not your local station. (This is the splicer tech that Fox use instead of the local station encoders that NBC, CBS and ABC use) Fox encode their encoded feed (that stations just pass on) to allow local stations to add a sub-channel if they want to - i.e. they cap the bitrate. Thus even if your local Fox station doesn't have a sub-channel it won't use the full 19.2Mbs ATSC payload - it will just fill the space left by Fox for subchannel(s) with null packets.

ISTR that Fox were still using some 480i SD 16:9 gear for some coverage as well. (Fox Widescreen vs Fox HD?)

Yes, the encoders are improving and compression technologies are advancing - but the question is whether or not the proliferation of subchannels will outpace that advancement. The problem is the fact that mediocre PQ has been deemed acceptable by broadcasters up until now. Technological advancements have nothing to do with changing that philosophy, only in increasing the number of channels that can be carried.

In the analog TV days there was only one channel so it made sense to make it as good as it could be. There was no financial incentive other than whatever better equipment cost to do otherwise. With DTV there is a financial incentive to add more channels if a station can find something to put on one that generates more revenue than it costs. The equipment cost to add a subchannel is low. It is the programming that costs money. The people that run TV stations in almost all cases are former sales people not engineers. At this point, as far as I know, the satellite companies are not carrying anybodies subchannels and some cable companies do not carry them either. This is all subject to negotiation between the stations and the multichannel providers. If multichannel provider carriage increases the incentive to add subchannels will also increase.

Unfortunately the people that decide what is good enough HD picture quality are not engineers and have a financial incentive to reduce HD quality if they see profit in subchannels. There is not much we engineers can do about it. The picture quality here for the Olympics on NBC is terrible whenever there is rapid motion. I wish people would complain to the station about it but I suspect that not many do.

I thought you were in the Chicago area, Doogie, since you've participated in our local OTA thread (?). NBC only has one weather subchannel here.

Actually NBC has 2 subchannels. The NBC-HD channel and the weather channel. I was thinking ABC which has 3 subchannels.

People will want more channels and viewing choices. Broadcasting companies will compete for those viewers.

AVS members need to remember that most people don't own 60" Plasmas or 52" LCD's. Many people own 37" LCD's and DVD quality will look great to them. Channels will be able to jam more subchannels and it won't look horrible on a 32" or 37" HDTV. On a 50" or 60" it might not look good, but what is the % of people who have a large flat panel HDTV?

As long as picture quality is no less than DVD, 99% of the people will be very happy.

I own a bigger plasma and want to upgrade from 50" to 60", but I'm not going to be greedy and demand the broadcasting companies serve my picture quality needs by screwing over 90% of the people with smaller televisions who would benefit from more programming choices. There is Blu-Ray for people who demand 1080p. OTA will never be 1080p so the videophiles will never be 100% satisfied. They'll watch television on a 100" projector screen and find flaws.

WCIU is such a success they added MeTV and now Me-Too and a fourth ethnic channel. I think they are setting the gold standard. If you don't like the King of Queens on WCIU, then maybe you'll like Star Trek on MeTV, and if you don't like that there is Maverick on Me-Too. It's much better than only having one choice on that channel! Channel 26 is offering 4 different viewing choices.

I'd like to see FOX add FX, I'd like to see ABC add ABC Family. How many people watch the weather channel on ABC or NBC? Wouldn't it be better if they added a real channel with entertainment?

KVPT PBS Fresno (rebroadcast on a digital translator station in Bakersfield) has a simulcast of their analog channel on 18-1 and the national PBS HD Channel on 18-2. The HD quality was great despite the one SD channel. Then they added V-ME on 18-1. The HD quality noticeably dropped, even on Bright House cable, which retransmits the OTA broadcast.

Aren't most station using the encoders they started out with?

Actually NBC has 2 subchannels. The NBC-HD channel and the weather channel. I was thinking ABC which has 3 subchannels.I don't consider the main channels subs, that's why I said NBC has one.

I'm not going to be greedy and demand the broadcasting companies serve my picture quality needs by screwing over 90% of the people with smaller televisions who would benefit from more programming choices. There is Blu-Ray for people who demand 1080p. OTA will never be 1080p so the videophiles will never be 100% satisfied. They'll watch television on a 100" projector screen and find flaws.

WCIU is such a success they added MeTV and now Me-Too and a fourth ethnic channel. I think they are setting the gold standard. If you don't like the King of Queens on WCIU, then maybe you'll like Star Trek on MeTV, and if you don't like that there is Maverick on Me-Too. It's much better than only having one choice on that channel! Channel 26 is offering 4 different viewing choices.

I'd like to see FOX add FX, I'd like to see ABC add ABC Family. How many people watch the weather channel on ABC or NBC? Wouldn't it be better if they added a real channel with entertainment?

I will. It's a crime that broadcast stations would degrade their main HD feed for subchannels. Take off the blinders!! They don't care about giving viewers "options", it's about advertising and money. We have a local CBS subchannel in Cleveland that shows 24/7 weather, except part of the time they show commercials. The only subchannel that has been "good" relatively speaking is NBC Weather Plus, since they show weather info all the time(unlike the Weather Channel or the local CBS copy-cat). Unfortunately both NBC and CBS HD suffer from these channels. So far Cleveland Market has been lucky as CW, ABC, MNTV and FOX are subchannel free. And you can guarantee that they will hear from me if garbage like that Mee TV is added or channels of old movies or shopping get added to the major networks. We have an PAX affiliate, a Univision affiliate and an independent station that show paid programming all day. None of these have subchannels. Yet they would be perfect candidates(as all are 480i).

And I do not think broadcasters should screw "over 90% of the people with smaller televisions who would benefit from more programming choices"(sic). I think the broadcasters should NOT screw over the MAJORITY of their viewers who receive the channel through a cable TV or satellite system. Why should cable/satellite viewers suffer through crappy local broadcast just to give those who won't get cable more channels?

Why should cable/satellite viewers suffer through crappy local broadcast just to give those who won't get cable more channels?

OTA is broadcast over public airways. OTA is not a feed for cable/satellite. OTA is to serve the public needs, and most people don't need a 1080 feed.

Why should people have to pay for cable to get more viewing choices? Most people would be happy to get more programming for free OTA.

If you have 1 channel dedicate 100% of bandwith for 1080i, you would have a few videophiles happy.

If you have 1 channel add 4 subchannels, the majority will be happy with more viewing choices.

I'll give you an example. WCIU broadcasts some baseball games in HD. The baseball games don't look any worse than FOX baseball in HD. The same channel also has 3 more subchannels that broadcast drama, comedies, westerns, science fiction, and lots of good entertainment. Should WCIU eliminate the 3 subchannels so the baseball game gets more bandwith? How would that be fair to the viewers who preffer Star Trek, King of Queens, Gunsmoke, Bonanza, or All in the Family? If WCIU went from 4 viewing choices to only 1, then most of those shows would get elminated. How does that make life better for the majority of people?

Why should people have to pay for cable to get more viewing choices? Most people would be happy to get more programming for free OTA.You are participating in the wrong forum. You want www.quantity over quality.com.

OTA is broadcast over public airways. OTA is not a feed for cable/satellite. OTA is to serve the public needs, and most people don't need a 1080 feed.

Not everyone gets TV through OTA anymore. A large enough portion of the population has cable/satellite. Whether it's OTA or cable, we all watch the same affiliates in a given market. EVERY broadcast TV station has been serving public needs with a SINGLE 480i feed for the last almost 60 years. They can just aw well serve the public with a SINGLE 720p or 1080i feed. I'd think that most people would define "serving the public needs" as providing local news and weather information as well as a decent amount of entertainment and educational programming, which OTA stations have been doing since before DTV. I get the feeling from your earlier statements about FOX providing FX OTA or ABC giving ESPN OTA your definition of "serving the public needs" is giving people who pay nothing for TV cable channels. Which won't happen for many reasons including carriage issues and the fact that these channels make money from cable/satellite presence.

Why should people have to pay for cable to get more viewing choices? Most people would be happy to get more programming for free OTA.

If you have 1 channel dedicate 100% of bandwith for 1080i, you would have a few videophiles happy.

If you have 1 channel add 4 subchannels, the majority will be happy with more viewing choices.

Tell that to the over 50% of people who subscribe to cable/satellite. It's not about making a few videophiles happy. It's about truth in advertising and providing a quality product. HDTV is supposed to be the "very best". Yet if you have a 1080i feed shared with one or two subchannels, that 1080i feed looks like crap. Starting 2/17/09, that HDTV feed won't just be for those with HDTVs. Everyone will be tapping into that feed through a converter box or digital cable/satellite. How much lower should the standards be? Should that feed only have to be good enough so SDTV viewers have a decent picture? Should affiliates be allowed to degrade and bandwidth starve HD channels just to make money? Let's say DT-2 and DT-3 are going to show paid programming all day. Or one is going to be the fourth weather subchannel in one market. Is that OK? It's "more choices", but it's crap. An HDTV feed should not be ruined for crap.

I'll give you an example. WCIU broadcasts some baseball games in HD. The baseball games don't look any worse than FOX baseball in HD. The same channel also has 3 more subchannels that broadcast drama, comedies, westerns, science fiction, and lots of good entertainment. Should WCIU eliminate the 3 subchannels so the baseball game gets more bandwith? How would that be fair to the viewers who preffer Star Trek, King of Queens, Gunsmoke, Bonanza, or All in the Family? If WCIU went from 4 viewing choices to only 1, then most of those shows would get elminated. How does that make life better for the majority of people?

In this case you're lucky it's a 720p channel. If it were a 1080i channel with all those subs, the main feed would probably be horrendous. But I have to ask why THREE channels are necessary for this? Why not one that shows a full lineup of shows? Why would anyone need three versions of TV Land, especially OTA? Does anyone really need that many choices?

Back to the 1080i issue. The Cleveland CBS affiliate WOIO (1080i) has one subchannel that shows 24 hour news/weather info. This results in a degraded picture on HD CBS programming. When you mix a poor quality HD channel with an even poorer quality analog upconvert, the result is a nightmare. Which we saw last season when many CBS NFL games were not HD, so the station was forced to upconvert from the analog feed. Let's just say the SD digital channel on cable looked better. I digress...

You are participating in the wrong forum. You want www.quantity over quality.com.

Who defines quality Ken?

Is picture quality determined by someone looking at OTA on a 100 inch projector screen?

Is picture quality determined by someone looking at a 26" LCD at home?

Most people own smaller HDTV's, 32" and 37". Will people with small HDTV's see any difference between a 720 or 1080 broadcast?

Ken, you're on the wrong side of the issue. Most people will benefit from more programming choice and the decrease in picture quality will be minimal for them. I've gotten used to watching upconverted 480 to 720 and it's not bad. I don't need 1080 to be happy on a 50" plasma.

OK, so maybe MPEG-2 encoders have gotten better, but even watching the Olympics on my NBC station (Channel 10 in Philly), when the action heats up, the screen goes to all hell. Channel 10 has a weather sub-channel on it.

Imagine if they started putting up an SD movie channel plus the weather station along with the HD channel. It would look even crappier than it does now.

In Philly, only Fox and CBS don't have subchannels. I'm just fearing the day when all of the stations have subchannels and the HD channel is down to 10 Mbps. At that point, I might as well go back to an SDTV (well not really).

ft


+1, same here just north with same sources.

Ken, you're on the wrong side of the issue. Most people will benefit from more programming choice and the decrease in picture quality will be minimal for them. I've gotten used to watching upconverted 480 to 720 and it's not bad. I don't need 1080 to be happy on a 50" plasma.

Sorry ... when folks start realizing that their 50" plasma looks worse with HD than their old 27" analog set looked with SD, there could be a lot of po'd folks ... then again the world is full of sheep too. :)

The point that Ken was making is that this is the "HDTV Forum" not the "I want more channels at any cost forum." Therefore, you shouldn't expect much sympathy for your position here.

Who defines quality Ken?

Ken, you're on the wrong side of the issue. Most people will benefit from more programming choice and the decrease in picture quality will be minimal for them. I've gotten used to watching upconverted 480 to 720 and it's not bad. I don't need 1080 to be happy on a 50" plasma.

I'll take quality over choices anyday. Anyone who cares about PQ wil las well.
No will joesixpack, don't know...but I'd consider my brother one and he cares now that he is getting educated on the matter.
For those buying 32" and smaller LCD, no they don't care nor will likely be able to tell a difference.
While properly upscaled lower esolutions can look good, they can't 'touch' HD if you have a good HD display and properly calibrated.

Ken, you're on the wrong side of the issue.You don't really get the point, do you? Like I said, you're in the wrong forum.

http://smileys.on-my-web.com/repository/Laughing/drunk-irish-048.gif
You still can't see the football on our NBC affiliate (http://www.ky3.com/). :(

As mentioned earlier some affiliates of 1080i networks (particularly PBS) are cross-converting to 720p in order to lower the bitrate of the HD program and add more subchannels. I've speculated for some time now whether OTA 1080i will fade away. Another format which doesn't seem to be in use yet (at least I haven't come across it) is SD 16:9 on OTA. Just wait until some station GMs decide that they can use that instead of HD and add even more subchannels.

Providers could take advantage of the decline of OTA quality and take a fiber feed using their own encoder rather than just using the same one used for OTA. They could truly claim a superior product compared to OTA.

Cable/sat providers rarely seem concerned with providing quality. Between cable killing the quality of analog channels with excessive amplification and filtering and killing HD with 3:1 channel mappings and HDlite on satellite, I doubt we'll see something like that. The only player who might even be interested is Verizon, but at $50k for an encoder times 7 or 8 HD stations in a market, that's a pretty big outlay for relatively little benefit.

OTA is broadcast over public airways. OTA is not a feed for cable/satellite. OTA is to serve the public needs, and most people don't need a 1080 feed.
Then why even send HD?

fyi...we will not get ESPN OTA.

Cable/sat providers rarely seem concerned with providing quality. Between cable killing the quality of analog channels with excessive amplification and filtering and killing HD with 3:1 channel mappings and HDlite on satellite, I doubt we'll see something like that. The only player who might even be interested is Verizon, but at $50k for an encoder times 7 or 8 HD stations in a market, that's a pretty big outlay for relatively little benefit.The encoder prices are falling. Ten years ago HD encoders were in the hundreds of thousand dollars. I think good encoders will be under 10k. I saw a realtime soft encoder demonstrated and that could lower prices further. With nearly every channel going HD at some point cable providers may have to bite the MPEG4 bullet as the sat providers have done and locating the encoder at the station could significantly improve PQ. It would also add a selling point for the providers service. I know that quantity sells over quality but in this case it could be a real justification for those who are presently satisfied with OTA. E* ads already compare their 1080p service with BluRay quality so it appears that PQ is already a selling point. At least that's a step up from it's 1080i - I don't know what it is but I want it.

I have no idea if this would happen but it does show that broadcast stations can move past OTA PQ limitations. Eventually I think stations or even networks may move to internet distribution. The entire concept of network, station, and providers could well be challenged by the increasing capacity of optical and wireless services.

Screen size may have an impact on seeing resolution differences, but most of the PQ problems with OTA broadcasters are related to insufficient bandwidth, not downrezzing. You'll still see motion artifacts on smaller screens.

Who defines quality Ken?

Is picture quality determined by someone looking at OTA on a 100 inch projector screen?

Is picture quality determined by someone looking at a 26" LCD at home?

Most people own smaller HDTV's, 32" and 37". Will people with small HDTV's see any difference between a 720 or 1080 broadcast?

Ken, you're on the wrong side of the issue. Most people will benefit from more programming choice and the decrease in picture quality will be minimal for them. I've gotten used to watching upconverted 480 to 720 and it's not bad. I don't need 1080 to be happy on a 50" plasma.


Two points doogie. Are you really being given a choice? It three or 4 weather radar maps a choice. Is poor quality low bite rate SD content really a choice. Just what compelling programming will they be running on these subchannels? None that is what. Any such programming will be on the main channel. As for PQ, if you can'e see the effects of subchannels on a 26" screen, you need to have your eyes checked. Also, the poor color reproduction and murkiness of the standard subchannel fare is clearly visible on a screen of any size. It is dreadful and something the broadcasters should be ashamed of offering. In the past, they sure would have.

1 subchannel doesn't seem to affect the HD channel noticeably. 2 or more does.

1 subchannel doesn't seem to affect the HD channel noticeably. 2 or more does.

What a Ridiculous statement.

Perhaps 1 Subchannel at 1.5Mbps might now affect the HD Channels Noticeably, but try 1 Subschannel @ 5Mbps and see how you feel about it.

2 Subchannels at 1.5Mbps each for a total 3 Mbps would affect the HD less than 1 of 5 Mbps.

So your premise is just wrong.

For those that think multicasting doesn't effect HD PQ, move down to Memphis. Our CBS, NBC, CW, and PBS (side converting to 720) all do, and their PQ is terrible.

Two points doogie. Are you really being given a choice? It three or 4 weather radar maps a choice. Is poor quality low bite rate SD content really a choice. Just what compelling programming will they be running on these subchannels?This is another of doogie's long running misconceptions. He thinks subchannels will carry ESPN, CNN, etc. It's been explained to him a number of times why this will not happen, IIRC he was also told about USDTV. Unfortunately, he thinks he knows better.

You can thank the FCC for only mandating digital and not HD for the picture quality issues. If they had mandated that all digital signals had to be HD, you'd probably see a difference.

FYI, it seems that WNYW-DT and WWOR-DT are the only Fox/MNTV O&Os that have sub-channels and all they show is each others programming. What a waste.

You can thank the FCC for only mandating digital and not HD for the picture quality issues. If they had mandated that all digital signals had to be HD, you'd probably see a difference.

Exactly. And that's been one of my fears. Since HD is in no way required, I'm waiting for the first station to have the huevos to downrez HD to 16:9 480i or even 4:3 480i just to add more subchannels. To completely eliminate their HDTV feed. SInce some HDTV stations are already running THREE subchannels and a crappy HD feed, they could realistically dump HD for four SD feeds or even more. I'm sure then doogie houser would be happy but the rest of us on the HDTV forum would be pissed.

FYI, it seems that WNYW-DT and WWOR-DT are the only Fox/MNTV O&Os that have sub-channels and all they show is each others programming. What a waste.

That is a waste. This is one of the reasons why I actually like 4:3 safe graphics/bugs on HDTV channels. Another fear I had was the networks were going to use a DT-2(or even 3 in some cases) subchannel to carry what used to be the "analog" feed. I'll take cropping the sides off HDTV any day over another bandwidth wasting subchannel. I can live with the CBS eye towards the center of the screen. I cannot live with more macroblocking and an awful HDTV picture.

It was pointed out that subchannels on Fox affiliates do not affect HD network PQ. That assumes the subchannel is added with Fox's splicer.

It was pointed out that subchannels on Fox affiliates do not affect HD network PQ. That assumes the subchannel is added with Fox's splicer.

Understood. I'm just curious as to why none of the other Fox's O&Os besides NYC have them.

On the other hand, AFAIK all of CBS' O&Os (including their CW O&Os and the few independents that they also own) are sub-channel free, and you rarely hear complaints about PQ from those that live in those markets.

Understood. I'm just curious as to why none of the other Fox's O&Os besides NYC have them.

Because FOX has yet to complete work on the news channel poised for subchannel use. Mu guess is that is will be something like Headline News.....

Screen size may have an impact on seeing resolution differences, but most of the PQ problems with OTA broadcasters are related to insufficient bandwidth, not downrezzing. You'll still see motion artifacts on smaller screens.

You hit the nail on the head. I sit about 10 feet from my 30" set in my bedroom. I can tell bad HD way easier on that set than I can my 1080p 60" set from 10 feet. Why? Because on my 30" set it has to figure out how do cram 1080 lines down to aprox the 800 it actualy sends out. When you give it blocky HD on top of it, well look out buddy. It's horrendous.

Because FOX has yet to complete work on the news channel poised for subchannel use. My guess is that is will be something like Headline News.....If it has some good looking on-air staff, then I might soften my opposition to subchannels. They can save bandwidth by deleting the audio stream :D

If it has some good looking on-air staff, then I might soften my opposition to subchannels. They can save bandwidth by deleting the audio stream :D

i.e. Julie Banderas

You hit the nail on the head. I sit about 10 feet from my 30" set in my bedroom. I can tell bad HD way easier on that set than I can my 1080p 60" set from 10 feet. Why? Because on my 30" set it has to figure out how do cram 1080 lines down to aprox the 800 it actualy sends out. When you give it blocky HD on top of it, well look out buddy. It's horrendous.
Sounds like something isn't right with your setup. Artifacting becomes less noticeable as distance increases or screen size decreases simply because the problems become a smaller part of your field of view. Perhaps your 30" set has edge enhancement/sharpness cranked up, which would cause the boundaries between blocks to become more apparent. Most TVs come by default with the sharpness and contrast cranked up, which tends to make the blocks more visible than they would be a properly adjusted set.

You can thank the FCC for only mandating digital and not HD for the picture quality issues. If they had mandated that all digital signals had to be HD, you'd probably see a difference.

That ruling would have gone the other way. The FCC wants more voices and more choices - not less. Be glad they did not rule.

Exactly. And that's been one of my fears. Since HD is in no way required, I'm waiting for the first station to have the huevos to downrez HD to 16:9 480i or even 4:3 480i just to add more subchannels. To completely eliminate their HDTV feed. SInce some HDTV stations are already running THREE subchannels and a crappy HD feed, they could realistically dump HD for four SD feeds or even more. I'm sure then doogie houser would be happy but the rest of us on the HDTV forum would be pissed.

No need to wait. It has just about happened on many PBS stations.

You hit the nail on the head. I sit about 10 feet from my 30" set in my bedroom. I can tell bad HD way easier on that set than I can my 1080p 60" set from 10 feet. Why? Because on my 30" set it has to figure out how do cram 1080 lines down to aprox the 800 it actualy sends out. When you give it blocky HD on top of it, well look out buddy. It's horrendous.


10 feet is also out of the prime recommended distance for the 30" or the 60".

Sounds like something isn't right with your setup. Artifacting becomes less noticeable as distance increases or screen size decreases simply because the problems become a smaller part of your field of view. Perhaps your 30" set has edge enhancement/sharpness cranked up, which would cause the boundaries between blocks to become more apparent. Most TVs come by default with the sharpness and contrast cranked up, which tends to make the blocks more visible than they would be a properly adjusted set.

Don't ruin a good story with logic and facts:rolleyes:

On the other hand, AFAIK all of CBS' O&Os (including their CW O&Os and the few independents that they also own) are sub-channel free, and you rarely hear complaints about PQ from those that live in those markets.

It may also indicate that CBS have a good distribution infrastructure as well as good final bit rates. AIUI they distribute their network feeds to local stations (O&Os and Affiliates) using more robust and higher bit rate circuits than NBC?

Sounds like something isn't right with your setup. Artifacting becomes less noticeable as distance increases or screen size decreases simply because the problems become a smaller part of your field of view. Perhaps your 30" set has edge enhancement/sharpness cranked up, which would cause the boundaries between blocks to become more apparent. Most TVs come by default with the sharpness and contrast cranked up, which tends to make the blocks more visible than they would be a properly adjusted set.

Also worth pointing out that interlaced CRT displays seem to be much more forgiving of MPEG2 artefacts - both mosquito noise and block edges - than LCDs and Plasmas.

I think this is because the macroblock edges and the mosquito noise both have significant high frequency content, which is rolled off by a CRTs relatively smooth HF roll off (so extremely sharp high frequency edges become slightly blurred - and the artefacts are higher energy high frequency content than most picture detail?) Interlacing also helps with this.

However LCD and Plasma are pixel based - and don't have the same roll-off as a CRT - effectively rendering the MPEG encoding artefacts more clearly, and the de-interlacing also seems to deliver them more clearly.

I've noticed that while real world pictures don't always look hugely better on a decent LCD than on a decent CRT, you see coding artefacts MUCH more clearly on an LCD. Think the frequency response of the two technologies is partially to blame.

But also worth pointing out that severe macroblocking - where each block is essentially just a single square of uniform colour/brightness (where effectively only a DC component is being coded for each block - as there is no data left for Horizontal and Vertical frequency DCT components) are very visible on both technologies - but the edges between blocks are rendered more clearly on fixed pixel displays it appears to me?

Gaussian vs boxcar. I guess the delta and striped phosphors on direct view CRTs alters the gaussian spot shape. Maybe the electronic gamma correction in flat panels also affects this?

It was pointed out that subchannels on Fox affiliates do not affect HD network PQ. That assumes the subchannel is added with Fox's splicer.

Sure they do. If not for the existence of subchannels on some of their affliates, they would send out a full bite rate signal. As it is now, they dumb down their signal for everyone.

Leaving space for a subchannel was one of the reasons Fox reportedly went with 720p. As Ken H pointed out they made plans for that. The network controls the amount of bandwidth the splicer allocates for the HD and subchannel(s). If a station wants two subchannels they need to fit it in the same extra space. It is conceivable that stations can use their own "splicer" or digital processor to rate shape the Fox network feed or even re-encode baseband from an IRD as at least one station has reported to have done. Obviously this is not supported by FBC and is heavily frowned upon to say the least.

As Fox's network feed is encoded only once and 720p is the format, the 15-16Mbs they give it works pretty well even on sports and usually doesn't suffer from noticeable blocking. However the satellite feed is stat muxed with multiple HD and SD programs and there can be a bottleneck if they all get demanding at the same time. From what I hear Fox is planning to drop the SD feeds so that should leave more bandwidth for the HD.

As Fox's network feed is encoded only once and 720p is the format, the 15-16Mbs they give it works pretty well even on sports and usually doesn't suffer from noticeable blocking.
The problem comes in when they send anywhere from 10 - 12 mbps for other programming. I've never seen a non-sporting event get close to 14 mbps on FOX before.

It was pointed out that subchannels on Fox affiliates do not affect HD network PQ. That assumes the subchannel is added with Fox's splicer.

Slightly ambiguous surely?

Yes - whether a local station adds a subchannel or not - the Fox network feed is reduced to the level it would be if a subchannel were added.

However if no Fox local stations added a subchannel - the network COULD be distributed at a higher quality - as there would be no reason to reduce the bitrate to allow for SOME stations to add a subchannel?

The problem comes in when they send anywhere from 10 - 12 mbps for other programming. I've never seen a non-sporting event get close to 14 mbps on FOX before.

Really? I see them often.

http://img139.imageshack.us/img139/5949/foxsuperbowlbx6.jpg (http://imageshack.us)

Really? I see them often.

http://img139.imageshack.us/img139/5949/foxsuperbowlbx6.jpg (http://imageshack.us)
Read my post again.

Slightly ambiguous surely?

Yes - whether a local station adds a subchannel or not - the Fox network feed is reduced to the level it would be if a subchannel were added.

However if no Fox local stations added a subchannel - the network COULD be distributed at a higher quality - as there would be no reason to reduce the bitrate to allow for SOME stations to add a subchannel?I think the splicer is capable of rate shaping so I suppose it's possible that a full channel bitrate could be sent on the network and reduced at stations adding subchannels. However the network fronthaul may be a bottleneck with the three time zone feeds for HD and SD multiplexed on one transponder.

Read my post again.

Check American Idol. Is that Sports?

I believe Fox normally runs 4+4 during primetime on each of the 73Mbit/s transponders used for the Fox network (primary and backup). Not sure how the other 2 are broken down between MNTV and Fox's other services. This time of year, Fox has at least 5 separate feeds they need to provide (East, Mountain, Arizona, Pacific, and Hawaii), though I seem to remember they run a separate one for Central as well so they can insert promos with the correct local time during primetime, not the "8/7c" style used on the other networks. East and Pacific (and Hawaii and everything else) never overlap thanks to Fox's 2 hour primetime, so they could still air 6 separate feeds each night with only 4 slots.

I think the splicer is capable of rate shaping so I suppose it's possible that a full channel bitrate could be sent on the network and reduced at stations adding subchannels. However the network fronthaul may be a bottleneck with the three time zone feeds for HD and SD multiplexed on one transponder.

If you examine the GOP of the Fox stations, you will see they already do quite a bit already from Variable GOP Lengths to different I,B,P frame as needed to make sure the picture best utilizes the bandwidth.

Exactly. It's stat muxed so I don't think that running the full bandwidth on all four HD services would work. 4x18=72 and that's just the HD video.

As far as I am concerned, the fox HD sports programming pales in comparison to CBS in terms of PQ. Having seen the feeds of live sports out of the cameras vs. what is shown on broadcast, they need more bandwidth than what they are using, even for 720p.

Check American Idol. Is that Sports?
As I said, I've never seen them send a bitrate that high on non-sports programming. So they could send it, but I might not see it. We tivo AI for my wife to watch and I might look up every now and then and take a peek, but I really don't care about it.

However checking shows like Bones, House, Prison Break, 24, and SD Hell's Kitchen, SYTYCD, KN, are in the 9 - 12 mbps range.

Then after those shows are over and it goes to local news or programming the video bitrate alone is up to 18 mpbs.

The few times Fox has hit 15.5Mbit/s average bitrate on sports, it has looked spectacular. The BCS Championship Game and Fiesta Bowl in 2007, and the NFC Championship Game in 2008 are the only times I can remember Fox maxing the bitrate, and the threads for each had numerous posts praising the quality of Fox's broadcast. Unfortunately, they usually give sports a paltry 13Mbit/s, which leads to noticeable (to me anyway) mosquito noise and loss of detail compared to the above-mentioned games or MNF games on ESPN.