The Magic 8 Ball speaks out on FOX HDTV - More Bits Are HERE! - Page 5  

My experiences with the HD Tandbergs were at higher bit rates, ~55Mb/s, so I can't speak speak of personal experience at ATSC rates. Don't know about WB, but I guess one could find out. AFIAK theCW will be on the same transponder UPN is now.

OK, I thought that they were going to have a constant 4-HD and 4-SD per transponder. Dynamically allocation SD and HD streams is no big deal.

If, for primetime programming, the need is only for 3-HD and 4-SD, why not set up the two transponders on G4R (is that the primary, or is G3 the primary?) such that one transponder has 2-HD and 2-SD and the other transponder with 1-HD and 2-SD? What is gained by having each transponder set up for 3-HD and 4-SD and duplicate the programming on both transponders? That sounds like a total waste of satellite time/expense. Plus, is the East/Central really different?

I'm trying to understand their feed logic during primetime.

I don't follow football, but do understand the need.

Didn't know they stopped making them. Memory lapse on the receiver count :) Yes, I know that the receiver has NTSC video output. But, you will only get video/audio output if the signal it is receiving is DVB-S MPEG-2 (nnn x 480), not DVB-S ATSC or DVB-S HD. The receiver will not decode ATSC streams and neither will it decode HD streams. It'll receive all the QPSK/8PSK DVB-S you throw at it, but will only provide composite output for one kind of stream. Everythig else has to be handled externally via the SDI or ASI outputs.

Neat, Linux. I'm even more impressed with the unit. If the ASI input only comes from a single IRD, and not via a switched ASI selector, what good are the backup receivers? If the HD IRD fails, it would mean that a station engineer would have to pull the cable from one IRD and plug it into the backup. Depending on the station, there may not be an engineer there during primetime and the board operator, in most cases, isn't allowed to touch the hardware. Fox builds in all this great remote selectivity and one can't quickly change to a backup.

What a surprise there :D How do you feel about that?

I'll see if I can find out.

For HD you are probably correct. That is my current theory. But for SD, it seems they are clearing out a VCN for The CW. The problem with the current location is that it is only good for prime time. They will have the afternoon feed to do now and when it occurs, CBS is using the VCT/VCN that UPN has been using. If they continue the separate east/central and mountain feeds, they'll need two VCNs.

Another person reminded me of this, so we'll see what happens.

FOX only needs two transponders per bird during football season. Not every area in the Central and Moutain time zones observes daylight savings time so it takes a third feed. That was the major problem ABC had when it went HD with GMA. Central and Moutain couldn't take the HD feed live until ABC made some changes.

The HD streams are ATSC compatable. The SD streams are not.

Correct, but when more HD viewers are watching, it would not surprise me if FOX provides a second splicer for the B receiver for redundancy.

In a nutshell, not much of a difference.

The images are here: http://vidiot.com/Fox-060721.zip [9 Mb]

The average bitrate for the 24 episode was 10.20 Mbps. Within the range that it was before the transponder change, maybe 1 Mbps higher. To be fair, this needs to be done over several shows. The best comparison would be to use the same episode of Prison Break that I used before.

While it would be nice to see the average bitrate around 12 Mbps, leaving 5 Mbps for the SD stream that so many stations want, :mad: it isn't always the bitrate that can provide the best picture quality. As mentioned previously, the WB encoder doesn't suffer from the macroblocking that Fox has and the bitrate they are using is just as low.

The thing the viewer sees is the macroblocking suring fades and scene change locations. What is strange is that it doesn't occur at every cut. I haven't looked for a pattern as to when it does occur. I wasn't watching to see what the IPB sequence was at the scene change locations.

The images that I link to above still have the same problem as before. Absolutely nothing has changed in reagrds to the encoding problem.

I ran the TP file through mpeg2repair (I recorded the complete mux, SD stream and all). Even though I can't see what the differences are in the report, the program sees each and every net to local and local to net transition and reports on it. It is probably because the audio changes from DD5.1 to DD2.0 and vice-versa. For some reason, mpeg2repair, reports the audio to be DD5.1 in all cases, while VideoReDo does not.

In any event, there is my report.

OK, this makes sense. My comments were based on a report e-mailed to me from another person that ran one of the muxes through TSReader and said that all streams reported as being ATSC, HD and SD. This was quite a while ago.

I made a comment that it didn't make sense to ATSC the SD as it would mean everyone would need an external box to convert to baseband video/audio for analog station transmission. This even included the Canadian stations that are fed the new episodes in advance (otherwise known as the clean feed :) )

Nice to know that the SD portion is still just DVB-S MPEG-2 (whatever the standard is).

As a side note I'd love to be able to receive the network HD sat feed. Why? Two reasons: 1) no local station bugs - I HATE bugs and all its ilk; 2) no local station screwups [the local affiliate really screwed up the last Tru Calling that was aired]. There obviously isn't an advantage quality wise, just the two reasons that I mentioned. But it ain't gonna happen in my lifetime. :)

What surprises me is that they are still sending syndicate programming in analog mode. Pretty much every station these days has a 4:2:2 QPSK DVB-S receiver. Instead of dropping to analog, dropping to QPSK would provide higher quality and at least 2-3 streams in which to send material.

Sounds good in theory, but in this particular case, it wouldn't make a whit of difference. Why? Because their SOURCE material is exceedingly poor. Has been for as long as I can remember (going back at least 15+ years). Not sure what is going on there, but it all looks like 5+ generations of Betacam SP through composite in/out. One trip through analog C-Band isn't hurting it. Ever seen a syndicated episode of The Simpsons? Lordy -- that's unwatchable.

FOX just recently began full time encryption. They had been doing part time for a while now.

Haven't looked in years. Last I remember is watching the clean feeds to Canada, and that was many years ago. :)

Ya, I knew that they've been playing with it, based on what I've been reading on the engineering web site. So, I knew it was going to happen. That said, the reasons why I prefer the net feed still stands.

One can always dream :D

One can always dream that the two factions in the hi-def DVD war will see the light and make a single hi-def DVD standard so we don't have another Beta/VHS type war. Then we can get TV programs released on hi-def DVD and not have the Fox encoder problem and extremely bit-limited ATSC DTV standard.

Ya, I know, if the show doesn't make it to air first, it'll never make it to DVD :)

Same here! Those looked nice though -- it's the domestic syndication stuff that looks really bad. What's incredible is that it was bad in 1990, and it's STILL bad. :confused:

Warner Bros. is using Tandberg at the GDMX facility as well. There is a world of difference in the encoding quality that I see from Fox and from what I see from The WB.

Something I noticed when reviewing Fox after the bitrate changes, whcih I didn't notice before is that image material from the next frame is appearing in the current frame. It isn't new. I went back and checked.

The best way to see it is during their closing credits. Use VRD and step through the frames. find a point where the text changes. Now back up a frame and you'll see pieces of the high contrast text appearing in the frame before the text actually shows up.

I then went back and tooked at actual program material, and sure enough, it is there as well.

I don't know what settings they are using. or what they are feeding it, but it is pure crap. And you can tell Fox engineering I said so, not that they'd probably give-a-damn. If little ole The WB/Warner Bros. can get it right, Fox definately should.

I think Fox's aggressive muxing is partly to blame. It's oriented more towards efficiency than PQ. Their system will probably be locked into MPEG 2 HD long after mezzanine approaches have migrated to better codecs. Dropping the SD feeds, or changing them to a newer codec will help.

I think you hit the nail on the head. Just goes to show Fox's continued disregard toward their viewers. First they go anamorphic widescreen, saying that is good enough. Finally they were shamed into going real HD (being shamed into real HD obviously wasn't the sole reason). Secondly they kill programs without giving them a real chance, making viewers wonder if they should even bother with Fox programs, since the odds are they'll get pulled anyway. Lastly, when they do go real HD, they use a transmission method that compromises PQ, because they are trying to stuff 20 pounds of manure down a 10 pound pipe.

I will give Fox high marks for the ATSC/splicer distribution method, as it provides the cleanest transition to/from net that I've seen anywhere.

But, because each transponder has to support a max of 4-HD and 4-SD streams, PQ is suffering. That said. during weekday primetime, they should be able to reduce the mux configuration to 2-HD and 2-SD per transponder and still provide the coverage they need on the primary bird. At 73+ Mbps on each transponder, they should be able to pump out HD at the max average and fix the encoder so that the macroblocking doesn't occur. As I said, if Warner Bros. can set their encoder right, so can Fox.

Unfortunately Fox is stuck with MPEG-2 for the life of DTV, since that is the codec that is locked into the standard. So the HD feed is stuck there, because the ATSC is generated in LA. As for the SD, sure, they could go to MPEG-4, but then they'd either have to replace the Wegner 5000 receivers or provide an external box to decode the MPEG-4 stream. Not worth the expense, since SD is being turned off in a few years. That fits in with your last suggestion, i.e., drop SD. Once the analog is turned off, all the stations will need is the HD feed, so the SDs can go away. That will give bits back to HD. Will it help? No idea.

The point is, Fox engineering can do something about it now. But, as viewers we need to scream louder about the poor PQ they are sending out.

I'd love to know if our local thread Fox affiliate engineers have had any discussions with network engineering about the PQ and what the net's response has been.

I'd be happy to eat crow if Fox is going to have the PQ fix by the time the new season starts in a month.

I don't want to be too positive about this, hopefully NFL Football might end up looking a little bit better. I think preseason starts around Aug 6 or so.

Not too far away...

Maybe. Maybe not. Don't sell the farm on that one just yet.

I could see SD changing, but isn't the HD splicer concept based on ATSC streams? Has AVC or VC1 been converted to MPEG 2 without going through a complete re-encode? At some point the SD will be a moot point because it will be dropped. Using downconverters and AFD will become more practical.

If I remember the comment correctly (I am too lazy to scroll up and look, sorry) was that FOX was stuck with MPEG2 with the splicer. The only LEGAL requirement that the FCC imposes on MPEG2 is at least ONE stream will be MPEG2 at 480i. And every station who has a splicer has a MPEG2 encoder for non network programming that not only will do 1080i, 720p, but will do 480p as well. There is no reason to think that with the proliferation of MPEG4 that in the future we will not see MPEG4 HD OTA distribution. Now what you can technically do and what you can realistically do ARE horses of a different color. But, IMHO, to say that FOX is STUCK with ATSC MPEG2 would NOT be a bet I would be willing to take. Having seen what those guys at the FOX Labs have done in the past, I have to put my faith in them.

Remember, ATSC (8VSB) is a transprot protocol for OTA broadcasts. It doesn't care what the payload is, MPEG2, MPEG4, AES/EBU, etc as long as it doesn't exceed the bandwidth limitations of ATSC.

It is an interesting time we are moving into.

But the end-user tuner does doesn't it? To go MPEG4 you'd have to replace every ATSC tuner in the market and I can't see that happening for a long, long time. Just look at the pain and suffering we've gone through just to get where we are today. :p

Exactly. What broadcaster is going to change to a codec that most receivers don't have? If there is a point where manufacturers include AVC and/or VC1, then that may happen. We can all hope for an improved OTA codec but, as keenan said, it's not going to happen any time soon.

What would be interesting if there was a mezzanine codec that was compatible with MPEG 2 or converted while still in the compressed domain. Something along the lines of what SBR does for audio. OK Fox Labs, get to work :D

Like I said, it can technically be done, but is it realistic. Right now it isn't, but in the future, it may very well be. Just because it can't be done today doesn't mean it can't ever be done.

You quoted correctly. Your second statement is also very true, I think. I'd have to dig through all of the ATSC documents, but doesn't the standard limit the MPEG to MPEG-2?

All of the ATSC DTV receivers that I have (2 STB and 1 PCI) are MPEG-2 only. All of them would be worthless for decoding MPEG-4. That includes all of the STBs and displays with built in ATSC DTV tuners. The MPEG-4 stream would not be viewable.

The PCI card that I have would not be completely worthless, as the transport stream can be recorded and different software can be used to extract the MPEG-4.

You certainly couldn't send to the homes a MPEG-4 only HD stream. IMHO, to have both a MPEG-2 and MPEG-4 of the same HD program would bit starve the MPEG-2 stream, pissing off the viewers.

My bet is on there not being any MPEG-4 streams in ATSC HDTV streams. Not in my lifetime.

MPEG 4 will be used OTA when it becomes obsolete.

ROTFL :D

There is no "technical" reason why you can't send MPEG4 OTA and there is nothing to say that OTA receivers couldn't have MPEG4 included in them. The FCC says that at least ONE stream will be MPEG2 at 480i. Beyond that, it is up to the stations. You can send WMA or Real Player, etc if you want. Receivers for these other formats are always an issue. USDTV was preparing to launch MPEG4 with is OTA service before they filed for bankrupcy and MPEG4 encoders are now becoming readily available.

OK, sort of got me there. I meant OTA broadcasters. Changing the Fox splicer HD distribution codec would mean every Fox station would be changing to that format unless the splicer had a converter to go from a mezzanine codec to MPEG 2. Sat and cable companies can use whatever codec they wish because they can supply the decoder. I can't see TV stations giving away STBs, and then getting viewers to use it.

Perhaps if future sets included MPEG 4 decoders to be compatible with cable reception, then OTA could move to a better codec. But even if that started now a switch would be many years out. It would be nice if future sets and STBs had the ability to be upgraded to future codecs the same way new players can be downloaded for playout on a computer. The problem is that codecs increasingly need more processing power and thus require a hardware upgrade.

MPEG 4 is an improved DCT based compressor. It seems newer codecs are wavelet based. I think we have a ways to go in improving bitrate efficiency for MPEG4 and future codecs.

As a Charter subscriber, all I can say is as far as I'm concerned there is no such thing as FOX HDTV. I wish baseball would move its contract to a real HD network, like ESPN.

And guess what they have to do... yep, you guessed it, replace all of the existing MPGE-2 HD receivers and DVRs with units that can receiver/decode/play/view MPEG-4.

I'm guessing that some owners of DVRs will get screwed and will be forced to spend more money before they can record the MPEG-4 HD programming. If it were me, I'd sue (class action). Since I don't have a pizza-pan system, it doesn't affect me.

But, OTA DTV reception does affect me. I very seriously doubt that the broadcast industry would be willing to replace, for free, all of the STBs and TV sets that have ATSC tuners. Nor should I be expected to fork over more money to receive added MPEG-4 capability, even if the MPEG-2 is left there.

It is bad enough that we forked over tons of money to go MPEG-2. To ask for more money before DTV is even the only way to get OTA, is just asking too much.

Actually not. As you and I have said in our postings, to do so with OTA would require a hardware changeout and that is exactly what they are doing with the pizza-pan customers. Having that happening with the OTA viewer base is like waiting for Hell to freeze over. Not gonna happen.