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AllStar
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Discussion Starter · #1 ·
Hey there,

I sent the following email to D* the other day...

Hello,

I recently bought a 65" DLP television and I have my HR10 and HR20 receivers hooked up using the HDMI ports. There is a night and day difference between the quality of my local HD channels over the antenna as opposed to the satellite. There is noticeable pixelation and motion blur with the HR20. I know you have a fixed number of satellites with a fixed amount of bandwidth so I know you have to compress the video signal, but I feel that you are compressing it too much. I spent a lot of money
on a high end television and I would like to watch high definition programming in HD...not an overly compressed scaled down version.

Thanks
The next day I received an email saying I should reset my receiver or try unplugging it. Are the tech support people this oblivious? I called up D* and told the guy exactly what the issue was and he still said it was the receiver. I have a service call set up this Saturday for them to come out.

I don't know how much D* pays a technician to come out, but I bet if more and more people would start complaining and D* had to keep sending out techs they may get the message.

:mad: :mad: :mad:
 

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Godfather
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Oliwa said:
Hey there,

I sent the following email to D* the other day...

The next day I received an email saying I should reset my receiver or try unplugging it. Are the tech support people this oblivious? I called up D* and told the guy exactly what the issue was and he still said it was the receiver. I have a service call set up this Saturday for them to come out.

I don't know how much D* pays a technician to come out, but I bet if more and more people would start complaining and D* had to keep sending out techs they may get the message.

:mad: :mad: :mad:
These guys haven't so much as a single freakin' clue. The real issue though is subscriber apathy. So few people know what an HD signal should look like that D* and every other distributor of HD literally gets away with providing shoddy product. The broadcasters doing multicasting are equally guilty. Only when there becomes a groundswell of subscriber complaints and those complaints grab the attention of the news media will anything be done, if even then.

Like you, I too have a brand new 65" DLP HDTV and OTA HD signals are simply stunning. The material coming from D* on HDNet and DiscoveryHD are also quite good. Even ESPN-HD is watchable.

What IS NOT watchable is this macroblocking-laden crap coming from D*'s new MPEG4-compressed HD locals. Those signals, one and all, are a disgrace and not at all what I bought an HD TV for.

Fortunately I live only 14 miles from the "antenna farm" where 90% of all Houston's TV transmitters are located. Therefore I can get **ALL** of my HD locals from OTA.
 

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Godfather
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Oliwa said:
Hey there,

I sent the following email to D* the other day...

The next day I received an email saying I should reset my receiver or try unplugging it. Are the tech support people this oblivious? I called up D* and told the guy exactly what the issue was and he still said it was the receiver. I have a service call set up this Saturday for them to come out.

I don't know how much D* pays a technician to come out, but I bet if more and more people would start complaining and D* had to keep sending out techs they may get the message.

:mad: :mad: :mad:
I have the same problem with local hd channels in the chicagoland area. Abc hd is always pixilated,sometimes CBS and NBC hd can also have same problem. I never have any problem with non local hd channels. D* needs to address this problem ASAP,but they won't. I'm fortunate I live only 20 mile do west of the city and will be having an OTA antenna installed after Christmas. There are alot of people complaining about local hd channels.Buy the way my signal strength on 103 sat are all 95 or greater,thats where I get local hd channels.
 

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I recently went into the local TV store to see a 1080 line set. When I looked closely at satellite HD on a 1080 line monitor, I noticed the macroblocks spanned over several lines and columns of pixels. This tends to dilute the picture definition.

The sales person said this was caused by the store's video distribution system and that it wouldn't be a problem at home. Maybe Oliwa is expecting too much and is being to critical.


--- CHAS
 

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AllStar
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Cap'n Preshoot;748897 said:
What IS NOT watchable is this macroblocking-laden crap coming from D*'s new MPEG4-compressed HD locals. Those signals, one and all, are a disgrace and not at all what I bought an HD TV for.

Fortunately I live only 14 miles from the "antenna farm" where 90% of all Houston's TV transmitters are located. Therefore I can get **ALL** of my HD locals from OTA.
I live in Houston as well and as you know, NBC has always been pretty awful OTA in standard broadcast. I just recently purchased a Samsung HL-S6187W DLP unit and would like to try out this OTA HD reception you say that's stunning. Given my past experience with OTA signals from NBC prior to going HD was awful, would their HD signal be any better? What kind of atenna do you suggest I get to get OTA HD signals from the locals with good reception?

Please don't tell me that I'll have to deck my roof with a similar set of those antennas you have displaying in your avatar.:eek2:
 

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Godfather
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You have many issues going on....

Over compression...

Bit rates extremely low (10-14Mbps) or roughly 50-70% of my cable companies sampling bit rate.

That combined with 1920x1080i down rezzed to 1280x1081i, 1/3 of your pixels thrown away...

Combine the thrown away pixels and the fact it is interlaced, and your roughly only scanning 60% as much data per frame (1280x1080 / 2) vs (1280x720 and 1920x1080/2)...

Better known as HD Lite.

Hopefully the new sats and bandwidth will not JUST allow more channels, but also fix all of the above problems.

Look at it this way.....

In terms of pixels per scan frame (approximations):
1080p - 2 Million
1080i - Just over 1 Million
720p - Just under 1 million
D* 1080i Lite - Under 700K
480P - Little over 300K

So D* HD is really just the midway point between DVD quality SD, and current HD, and only 1/3 of future 1080p..

Unfortunately, I hear rumors that my cable company might have to start compressing HD also someday soon... :( It's all about bandwidth. D* is launching sats and can fix the BW problem, unless they continue with the quantity over quality plan they have been on for the last decade and simply try to get likt 100 markets to have overcompressed HD locals.
 

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AllStar
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ClubSteeler, how do you come up with all those figures?

Bit rates extremely low (10-14Mbps) or roughly 50-70% of my cable companies sampling bit rate.

That combined with 1920x1080i down rezzed to 1280x1081i, 1/3 of your pixels thrown away...

Combine the thrown away pixels and the fact it is interlaced, and your roughly only scanning 60% as much data per frame (1280x1080 / 2) vs (1280x720 and 1920x1080/2)...
 

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Godfather
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Da Rafsta said:
ClubSteeler, how do you come up with all those figures?
Orignal Quote:
Bit rates extremely low (10-14Mbps) or roughly 50-70% of my cable companies sampling bit rate.Sorry man, I lost the web page, but someone out there actually used some equipment to test and measure this stuff. There were actually some D* and E* HD channels that sampled at 9Mbps or less, when 10Mbps is the high end for Mpeg2 DVD. Drastic undersampling. Most HD channels were around 12Mbps, some up to 14Mbps. Ideally, you'd like to be over 18Mbps, I believe with a maximum of something like 19.4Mbps (for MPEG2 that is).

Hey I found it:
http://www.widemovies.com/dfwbitrate.html

Now the green channels will not have THAT much more macroblocking and the like, but the others will. red channels are just unacceptable. Actually this looks a bit better than last time I checked it.

That combined with 1920x1080i down rezzed to 1280x1080i, 1/3 of your pixels thrown away...Notice how The new commercial with Jessica Simpson no longer says "FULL 1080i"? They cut that out. Now she just says, "in 1080i, don't totally know what that is, buh I wunnit." It is a known fact that they dropped down to 1280x1080i, and are in fact being sued for it in court.

Combine the thrown away pixels and the fact it is interlaced, and your roughly only scanning 60% as much data per frame (1280x1080 / 2) vs (1280x720 and 1920x1080/2)...The above numbers are just multiplying horizontal x vertical and if interl;aced, dividing by 2.

Just remember, on a standard def DVD, during a fast action scene, they pump up the bitrate to 10Mbps to avoid macroblocking and bit starving. Can you image what 12 or 13Mbps will look like on a HD broadcast where up to 5 times the amount of data has to be transferred? I mean, any fast motion and forget about it, your screen is going to look like it's 16x12 with big square pixels.

And those channels that are BLACK!!! Well their simply taking a SD channel and trying to force HD bitstream down it's throat!!! Doesn't work too well...

The following channels are examples of 1920x1080i channels received by D* at 19.2Mbps, and down they down rezzed them and undersampled them, as an example:

Keep in mind, these signals in pure form would be 1920x1080i at 19.2Mbps.
TNT-HD: 1280x1080i, 13.7 Mbps
CBS HD: 1280x1080i, 13.6 Mbps
Universal HD: 1280x1080i, 13.1 Mbps
HDNet: 1280x1080i, 12.9 Mbps
Discovery HD Theater: 1280x1080i, 12.2 Mbps
HBO HD: 1280x1080i, 9.5Mbps
Shotime HD: 1280x1080i, 8.0 Mbps
HDNet Movies: 1280x1080i, 7.4 Mbps

The above paragraph is copied from:
http://www.hdtvarcade.com/hdtvforum/lofiversion/index.php?t5144.html
 

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If you search 8VSB you can find a technical discussion by David Sparano that explains how DTV is transmitted:


'The MPEG-II encoder takes baseband digital video and performs bit rate compression using the techniques of discrete cosine transform, run length coding, and bi-directional motion prediction - all of which are beyond the scope of this article. The MPEG-II encoder then multiplexes this compressed video information together with pre-coded Dolby AC-3 audio and any ancillary data that will be transmitted. The result is a stream of highly compressed MPEG-II data packets with a data frequency of only 19.39 Mbit/Sec. This is by no means a trivial task since the high resolution digital video (or multiple standard resolution video) input to the MPEG-II encoder could easily have a data rate of 1 Gbit/sec or more. This 19.39 Mbit/sec data stream is known as the DTV Transport Layer. It is output from the MPEG-II encoder and input to the 8-VSB exciter in serial form, according to the SMPTE-310 interface standard. '

It gets very compex from here and concentrates on OTA broadcasting. But the key point seems to be, the bit stream of the 19.39 Mbit/Sec DTV Transport Layer is what must be recovered at the receiver to reproduce the raw DTV information.

--- CHAS
 

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Godfather
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HIPAR said:
If you search 8VSB you can find a technical discussion by David Sparano that explains how DTV is transmitted:

'The MPEG-II encoder takes baseband digital video and performs bit rate compression using the techniques of discrete cosine transform, run length coding, and bi-directional motion prediction - all of which are beyond the scope of this article. The MPEG-II encoder then multiplexes this compressed video information together with pre-coded Dolby AC-3 audio and any ancillary data that will be transmitted. The result is a stream of highly compressed MPEG-II data packets with a data frequency of only 19.39 Mbit/Sec. This is by no means a trivial task since the high resolution digital video (or multiple standard resolution video) input to the MPEG-II encoder could easily have a data rate of 1 Gbit/sec or more. This 19.39 Mbit/sec data stream is known as the DTV Transport Layer. It is output from the MPEG-II encoder and input to the 8-VSB exciter in serial form, according to the SMPTE-310 interface standard. '

It gets very compex from here and concentrates on OTA broadcasting. But the key point seems to be, the bit stream of the 19.39 Mbit/Sec DTV Transport Layer is what must be recovered at the receiver to reproduce the raw DTV information.

--- CHAS
19.39 is the thoeretical maximum... The actuals (plus I heard there is another layer of compression by teh sats themselves, but have idea if this is true) as measured at the stb outputs are shown in my link.

Much like a DVD recorder... I can record at 1 hr, 2 hr, 3hr, 4hr, and 6 hr, some even offer 8 to 10 hr recording modes. All these all go on the same 4.7 GB disc, but I can adjust sample rate to get more or less to fit on that disc. Of course the 1hr mode looks worlds better than the 8hr.....
Compression at its simplest......

This explains why some channels (HD or SD) look better than others.

In fact, DirecTV tries to dynamically allocate bandwidth to make more room for the broadcasts that need it most.

Now that sounds really complicated to me, and I'm sure it is. But it just goes to show you that no 2 channels are created equally. They might not only be different, but can change on the fly.
 

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AllStar
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ClubSteeler said:
That combined with 1920x1080i down rezzed to 1280x1080i, 1/3 of your pixels thrown away...Notice how The new commercial with Jessica Simpson no longer says "FULL 1080i"? They cut that out. Now she just says, "in 1080i, don't totally know what that is, buh I wunnit." It is a known fact that they dropped down to 1280x1080i, and are in fact being sued for it in court.
Man...thanks for all the info. Hmmm...I'd say HDNet Movies, HDNet, Discovery HD, TNT HD all look fantastic, had no idea they weren't even broadcasting it in it's full res. Crazy how these cats get away with that. I know technically they're still well within the HD requirements....but down rezzing? What do they get out of it? Oh well...won't complain as those channels don't look anywhere near as bad as NFL HD broadcast games do.

In regards to what I quoted you on, with D* being taken to court about it.....IYO, there's no chance anything worthwile will come out of it really, correct?
 

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I can't even begin to guess how DirecTV receives all of it's video feeds. But I would suspect that if the feeds don't arrive in the specified 19.39 Mbit/sec DTV Transport format, they are 'watered down' on arrival.

So then they take all of the feeds and send them to the MPEG4 compressor. My understanding of MPEG compression is that it is not a lossless process. That means you cannot recover the input data with bit by bit identity to the input. Compressing an already compressed stream will only make matters worse. But I remember reading somewhere, that MPEG4 mitigates this problem by allocating bits between channels within a transponder. Channels without motion give up their bits to channels with more motion.

I'm amazed it all works as well as it does.

--- CHAS
 

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ClubSteeler said:
In fact, DirecTV tries to dynamically allocate bandwidth to make more room for the broadcasts that need it most.

Now that sounds really complicated to me, and I'm sure it is.
That is exactly what they do. They constantly sample all of the video/audio feeds that are multiplexed on a given transponder, and dynamically allocate bandwidth as needed. So if one channel has high activity video, such as sports, and another channel has a talking head reporting something, the talking head is going to get a lot less bandwidth than the sports - for that instant. The next instant it may all change.

Doing this has allowed DirecTV to cram a lot more channels into a given amount of bandwidth than they could do a couple of years ago. When I first subscribed to DirecTV, there were 3, maybe 4 channels on a given transponder. Today there could easily be a dozen.

Carl
 

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If your DirecTV set top decoder didn't output an approved Advanced Television Systems Committee format like 1080i, you couldn't check out Jessica in HD under any circumstances. She looks good in standard definition too!

--- CHAS
 

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Godfather
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Da Rafsta said:
Man...thanks for all the info. Hmmm...I'd say HDNet Movies, HDNet, Discovery HD, TNT HD all look fantastic, had no idea they weren't even broadcasting it in it's full res. Crazy how these cats get away with that. I know technically they're still well within the HD requirements....but down rezzing? What do they get out of it? Oh well...won't complain as those channels don't look anywhere near as bad as NFL HD broadcast games do.

In regards to what I quoted you on, with D* being taken to court about it.....IYO, there's no chance anything worthwile will come out of it really, correct?
What do they get out of it... ??? More channels squeezed onto their main sats.

Honestly though, if you sitting at a safe viewing distance from your TV, you might not even notice the difference between full 1080i and D* 1080i. It's the lower sample rate during fast motion scenes causing bit starving that I believe to be most people's real complaint.
 

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Legend
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ClubSteeler said:
Combine the thrown away pixels and the fact it is interlaced, and your roughly only scanning 60% as much data per frame (1280x1080 / 2) vs (1280x720 and 1920x1080/2)...
One comment from a novice...

1280x720 would not be divided by 2 as it is not interlaced. Thus the 720p designation.
 

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Mentor
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Da Rafsta said:
I live in Houston as well and as you know, NBC has always been pretty awful OTA in standard broadcast. I just recently purchased a Samsung HL-S6187W DLP unit and would like to try out this OTA HD reception you say that's stunning. Given my past experience with OTA signals from NBC prior to going HD was awful, would their HD signal be any better? What kind of atenna do you suggest I get to get OTA HD signals from the locals with good reception?

Please don't tell me that I'll have to deck my roof with a similar set of those antennas you have displaying in your avatar.:eek2:
Greetings fellow Houstonian!

I think all of the relevant HD towers for Houston are in Sugarland.

AntennaWeb.org will help you know which direction to point your antenna and how powerful yours needs to be.

Yes, in the 80's, we all ripped our antennas down and switched to cable, then in the 90's we put up pizza dishes, now in the 00's, it's time to put those old antennas back up because that is the best way to pick up digital locals since cable and sat both recompress and/or compromise the picture.

It will not be a round dish but the old arrow-shaped monstrosities. :) If this is simply unacceptable to you, you can try a Squareshooter which looks like a flattened DBS dish and some people have results with it.

Ignore anything from Terk especially the ridiculous TV-55. Radio Shack makes a bizarre looking antenna which is a flat mesh with bowties on it. It is lovingly referred to as the Objet d'Art and some people get surprisingly good results on it.

Of course the last time I looked into OTA reception was a couple of years ago so things may have changed substantially.
 

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Godfather
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feldon30 said:
Greetings fellow Houstonian!

I think all of the relevant HD towers for Houston are in Sugarland.

AntennaWeb.org will help you know which direction to point your antenna and how powerful yours needs to be.

Yes, in the 80's, we all ripped our antennas down and switched to cable, then in the 90's we put up pizza dishes, now in the 00's, it's time to put those old antennas back up because that is the best way to pick up digital locals since cable and sat both recompress and/or compromise the picture.

It will not be a round dish but the old arrow-shaped monstrosities. :) If this is simply unacceptable to you, you can try a Squareshooter which looks like a flattened DBS dish and some people have results with it.

Ignore anything from Terk especially the ridiculous TV-55. Radio Shack makes a bizarre looking antenna which is a flat mesh with bowties on it. It is lovingly referred to as the Objet d'Art and some people get surprisingly good results on it.

Of course the last time I looked into OTA reception was a couple of years ago so things may have changed substantially.
PS - Radioshack makes one that looks like a Stealth fighter plane. It comes with an in-line amp. I get all orlando HDTV channels at 97% or better strength from my attic and I am 58 miles away from the antenna farm.

They have a good return policy, so you can return it if it doesn't work. If I remember correctly the model number is 1585... It was $50...
 

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Sorry Oliwa that you were bombarded with all of this technical 'mumbo jumbo' but the discussion does touch on some basic technical limitations of satellite television. Unless you have something fundamentally wrong with your equipment, or perhaps dish pointing, I don't believe there's anything a tech can resolve at your home.

I will not comment on DirecTV customer service.

--- CHAS
 
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