AVS › AVS Forum › HDTV › HDTV Programming › Comcast HD Quality Reduction: Details, Screenshots
New Posts  All Forums:Forum Nav:

Comcast HD Quality Reduction: Details, Screenshots - Page 8  

post #211 of 2079
3/24/08 at 11:38am
Thread Starter 
Quote:
Originally Posted by demarco5 View Post

where is the video post?

The videos are above the screenshots in the first post to this thread.

I will post more as time permits.

AVS Top Picks

post #212 of 2079
3/24/08 at 12:20pm
BFDTV,

Just wanted to say nice job on starting this thread. I feel like I noticed a drop in HD quality when we received a bunch of new HD channels in the Blacksburg area in December. I know that this area used to be serviced by Adelphia, which you noted in your first post as possibly being the exception to this problem. I am away from home right now but am interested in checking it out when I get back. Is there an easy and simple way to check to see how my channels are grouped, or do I need specialized equipment? I have a Sci Atl STB and a Samsung 1080p HDTV.
post #213 of 2079
3/24/08 at 12:32pm
Quote:
Originally Posted by Wizio View Post

Thanks bfdtv for keeping up with the latest on the Comcast HD compression. I guess they didn't expect anyone to notice the quality difference or just really don't care what people think. Over the weekend, I watched several NCAA basketball games on CBS in HD with Comcast. I noticed artifacts and even blurring at times. I think I'll go with the QAM signal this weekend and should hopefully get a much better picture. I pay Comcast $196 a month for their triple play services and this includes the movie channels...guess I can't blame anyone but myself for feeling ripped off. For now, the only way to go for television is Comcast or the dish but AT&T may be in here and up the stakes soon. Until then, I only see it degrading further in the future if Comcast has a monopoly in some markets.

Let's not get carried away, if you've got PQ issues with your CBS station it's most likely a multicasting situation. It's possible that Comcast is further compressing your local signals, but I really doubt it.

The subject of this thread is the national HD channels that Comcast provides. Your local stations are handled in a different manner.
post #214 of 2079
3/24/08 at 12:56pm
wait so comcast is only messin up the national channels not the locals like NBC CBS ABC?

b/c those locals look like they got worse for me? your telling me they didnt?
post #215 of 2079
3/24/08 at 1:07pm
Quote:
Originally Posted by demarco5 View Post

wait so comcast is only messin up the national channels not the locals like NBC CBS ABC?

b/c those locals look like they got worse for me? your telling me they didnt?

I have no way of knowing for sure what Comcast is doing with your local channels. Your local channels are most likely received via an antenna farm or a fiber connection with the local stations and then fed to the local headends.

The channels being discussed in this thread are national HD channels that have been sent through the CMC in Colorado via satellite, your local channels are not handled in the same way.

So, bottom line, if you're having issues with your local stations then it's a local issue and is not related to bfdtv's findings/subject of this thread.

If you do a scan and discover that Comcast is putting, say, your local ABC, NBC and CBS all in one 256QAM slot - 3-HD per slot - then I would contact the respective stations and see if it being done with their consent. I really doubt that is happening though.
post #216 of 2079
3/24/08 at 1:17pm
Thanks for the help i just bought a 120hz 1080p samsung, blurays look great but comcast looks horrible, the locals arent too bad but everything else is grainy.....

i went from a 32inch 1080i olevia to this, and it seems like the olevia looks better (for cable feeds like NCAA hoops), what sense does that make?!?

CBS march madness basketball doesnt look that good on the samsung.....any input?
post #217 of 2079
3/24/08 at 1:26pm
Quote:
Originally Posted by demarco5 View Post

Thanks for the help i just bought a 120hz 1080p samsung, blurays look great but comcast looks horrible, the locals arent too bad but everything else is grainy.....

i went from a 32inch 1080i olevia to this, and it seems like the olevia looks better (for cable feeds like NCAA hoops), what sense does that make?!?

CBS march madness basketball doesnt look that good on the samsung.....any input?

I would check in your local Comcast thread and/or the Samsung thread for your model and see if others are seeing the same things you are. You might find that your local CBS multicasts and that may be causing the PQ to be affected on the HD channel. The folks in your local thread will also probably know if Comcast is doing any 3-1 channel packing with the locals.

Check for you area in the below list,

http://www.avsforum.com/avs-vb/showthread.php?t=453241
post #218 of 2079
3/24/08 at 1:40pm
Quote:
Originally Posted by xela19115 View Post

One other thing that can be done is to bring this to the attention of content providers like GE which owns NBC, USA, Sci-Fi, Universal and other channels, as well as Scripps Media (TLC, Food, etc.) and others that Comcast is degrading quality of their programming and thus reducing the incentive to watch their content and that will directly affect the advertising revenue these companies will be getting. Since dollar talks louder than anything else it may induce these content providers to have a word with Comcast and ask them "politely" to cease and desist that type "bandwidth management" on video from these companies.

I was thinking along those lines the other day when one of the "stretch" channels was showing an infomercial for a weight loss company and the "afters" looked like porkers. I wanted to contact the company and let them know but got off onto other things.
post #219 of 2079
3/24/08 at 1:43pm
thanks, i have direct TV also just for the nfl ticket, im gonna try bringing my set downstairs today and plug it in to see if theres a difference
post #220 of 2079
3/24/08 at 2:36pm
Quote:
Originally Posted by maxman View Post

I was thinking along those lines the other day when one of the "stretch" channels was showing an infomercial for a weight loss company and the "afters" looked like porkers. I wanted to contact the company and let them know but got off onto other things.

An e-mail petition with reference to this thread and links to posts on other websites to content providers as well as some more mainstream, "non-geek" websites like USA Today or CNN.com usually helps. Also sending an e-mail to respected A/V publications to give Comcast a good thrashing in their respective publications usually helps.

Comcast may think that their customer base are idiots who wouldn't know better but as this forum seems to show some people here know probably more than some of their engineers. And I firmly believe that until any business is faced with a massive financial loss due to the customer attrition or people canceling their service(s) they do not modify their practices and continue to provide sub-par services/goods all while charging the maximum possible rate. Dollar talks... Vote with your wallet!
post #221 of 2079
3/24/08 at 3:33pm
One of the best examples of how bad this new compression is, can be seen during WWE RAW on USA HD mondays or ECW on SciFi HD tuesdays. Check it out to see how horrible it is. With all the pyro and flash bulbs going off, it's really unwatchable. The WWE Smackdown on local HD looks great though. I've sent e-mails to Comcast with no response. Today I e-mailed SciFi, USA Network, and WWE to let them know how poorly their programming is being delivered.
post #222 of 2079
3/24/08 at 6:08pm
I recorded some content off Universal HD using QAM tuner and below are 2 samples of that. I run them through TSReader lite. These are unprocessed TP files that were dumped from QAM tuner to hard drive.

As you can see the bitrates for 1920x1080i content are in 7 Mbps neighborhood.
post #223 of 2079
3/24/08 at 6:30pm
It appears that Comcast has made the decision to go with more HD channels to compete with FiOS and Satellite. Hopefully when they reclaim the additional bandwidth by eliminating analog channels they will reconsider their decision to scale back the HD quality. The most important thing it to make sure Comcast is aware of your displeasure in their degradating the HD picture quality!

The main reason I purchased a large screen HD television was to get great HD quality! I for one would for now rather have less HD channels and better HD picture quality. If you feel the same way please write Comcast and let them know how you feel! As much as I dislike Verizon I may have no choice but to switch when it is available if Comcast does not improve the HD quality. One thing Comcast may be forgetting it is the HD nuts like us that purchase the most expensive programming packages and we demand rhe best picture quality.
post #224 of 2079
3/24/08 at 6:34pm
when faces are up close on the screen they look perfect but when they are not zoomed in on, the faces look fuzzy...llike its hard to explain its like it doesnt have any edges just a million blocks making up the face.....

can anyone help with this?
post #225 of 2079
3/24/08 at 6:52pm
Quote:
Originally Posted by PaulGo View Post

It appears that Comcast has made the decision to go with more HD channels to compete with FiOS and Satellite. Hopefully when they reclaim the additional bandwidth by eliminating analog channels they will reconsider their decision to scale back the HD quality. The most important thing it to make sure Comcast is aware of your displeasure in their degradating the HD picture quality!

The main reason I purchased a large screen HD television was to get great HD quality! I for one would for now rather have less HD channels and better HD picture quality. If you feel the same way please write Comcast and let them know how you feel! As much as I dislike Verizon I may have no choice but to switch when it is available if Comcast does not improve the HD quality. One thing Comcast may be forgetting it is the HD nuts like us that purchase the most expensive programming packages and we demand rhe best picture quality.

Paul I'd hate to predict but I believe that even when Comcast reclaims the analog bandwidth the customers will get just more of the same 3:1 compressed HD if Comcast will see that they can get away with it. Also Comcast's SD national video feeds are compressed 16:1 which degrades SD video as well. Their transrating gear basically has very sophisticated hardware and software algorithms to determine what bits can be dropped on a floor before the video totally craps out. If the video is somewhat viewable then it's acceptable to Comcast.

In my mind the biggest problem right now is that vast majority of the public that bought or is buying HD sets has absolutely no idea what a real, high quality HD video suppose to look like. A few people who prefer to spend their time on sites like this and invested money in a really good gear do but these people are a minority that Comcast ignores. But as other mediums for HD video delivery like Blu-Ray players or online services like iTunes or Voodoo become more prevalent people will vote with their feet and wallets. I for one will be very shortly switching to FIOS. I heard that they don't mess with video the "Comcastic" way.
post #226 of 2079
3/24/08 at 7:24pm
Quote:
Originally Posted by xela19115 View Post

Paul I'd hate to predict but I believe that even when Comcast reclaims the analog bandwidth the customers will get just more of the same 3:1 compressed HD if Comcast will see that they can get away with it. Also Comcast's SD national video feeds are compressed 16:1 which degrades SD video as well. Their transrating gear basically has very sophisticated hardware and software algorithms to determine what bits can be dropped on a floor before the video totally craps out. If the video is somewhat viewable then it's acceptable to Comcast.

In my mind the biggest problem right now is that vast majority of the public that bought or is buying HD sets has absolutely no idea what a real, high quality HD video suppose to look like. A few people who prefer to spend their time on sites like this and invested money in a really good gear do but these people are a minority that Comcast ignores. But as other mediums for HD video delivery like Blu-Ray players or online services like iTunes or Voodoo become more prevalent people will vote with their feet and wallets. I for one will be very shortly switching to FIOS. I heard that they don't mess with video the "Comcastic" way.

And that's why we need to let Comcast know how displeased we are with the video quality! I understand that Comcast still has very high bit rate on their HD VOD service. It would be interesting if someone who has the equipment to measure this could confirm this. Another solution as to how Comcast could regain HD picture quality is if they go to Mpeg-4 as the satellite services are doing, but that would require a large investment in new hardware. Also the Spectrum overlay technology could be yet another solution for gaining additional bandwidth.

http://www.avsforum.com/avs-vb/showt...9#post10338739
post #227 of 2079
3/24/08 at 7:37pm
Quote:
Originally Posted by PaulGo View Post

And that's why we need to let Comcast know how displeased we are with the video quality! I understand that Comcast still has very high bit rate on their HD VOD service. It would be interesting if someone who has the equipment to measure this could confirm this. Another solution as to how Comcast could regain HD picture quality is if they go to Mpeg-4 as the satellite services are doing, but that would require a large investment in new hardware. Also the Spectrum overlay technology could be yet another solution for gaining additional bandwidth.

http://www.avsforum.com/avs-vb/showt...9#post10338739

The VOD service is done on a local (node basis) and is similar to SDV. That allows the bitrate to be higher than signals from central head end QAMs.

RE: the other solutions - they all take TIME to implement. Comcrap has sat on their asses for so long (total lack of forward thinking) and have allowed the competition (satellite) to establish a more HD scenario. Cramming multiple HD channels per QAM is their only viable QUICK solution.

But, IF THEY GET AWAY WITH IT, they will never have the incentive to do it right.
post #228 of 2079
3/24/08 at 7:39pm
Quote:
Originally Posted by PaulGo View Post

...I for one would for now rather have less HD channels and better HD picture quality...

Less? How could we have any less? I already HAVE less!!!
post #229 of 2079
3/24/08 at 7:54pm
Thread Starter 
Quote:
Originally Posted by demarco5 View Post

when faces are up close on the screen they look perfect but when they are not zoomed in on, the faces look fuzzy...llike its hard to explain its like it doesnt have any edges just a million blocks making up the face.....

That's the result of overcompression.

The more detail in the picture, the more bits are necessary to represent that detail. Cable providers can apply a filter to remove some of that detail -- softening the image -- to reduce the bits required. If enough bits still aren't available after that filtering, you get blocks.
post #230 of 2079
3/24/08 at 8:00pm
makes sense to me but......my 32 inch olevia downstairs, hooked up to the same comcast HD has way better faces more crisp faces....and that tv was 3times less price then this one.....thats whats getting me mad!
post #231 of 2079
3/24/08 at 8:55pm
Thread Starter 
Quote:
Originally Posted by briansemerick View Post

MHD 17.73 Mbps 13.21 Mbps -34.2%

i'm surprised at that - i think it looks and sounds awesome. i wonder what it'd look like in 17.73 Mbps....

The major differences are seen in movement. Basically any time the camera moves, the artist moves around, or there are pyrotechnics, the FiOS feed looks much better -- more detailed and less (or no) blocking. When the camera is fixed (doesn't move), the artist doesn't move, and there are no pyrotechnics, the differences are not as significant. That said, the FiOS feed was noticeably better on every frame of this particular program (Red Hot Chili Peppers Live in Milan). This was nothing like my last Discovery Theater recording where the Comcast feed looked just as good 90+% of the time.

FiOS


Comcast


FiOS


Comcast


Fios


Comcast


Fios


Comcast


Click for direct links to the full 1920x1080 PNGs. More in the first post.

With the RHCPLIM broadcast on FiOS, I saw large-scale macroblocking on only a few sequences. With the Comcast feed, they were too numerous to count.
post #232 of 2079
3/25/08 at 6:20am
How about someone write this up really nice in the Controversies section on the Comcast wikipedia page?
http://en.wikipedia.org/wiki/Comcast
post #233 of 2079
3/25/08 at 8:56am
see now pics like those just piss me off. i don't see how they can get away with that. thanks man.
post #234 of 2079
3/25/08 at 9:23am
great thread
good work!
post #235 of 2079
3/25/08 at 9:38am
Quote:
Originally Posted by cypherstream View Post

How about someone write this up really nice in the Controversies section on the Comcast wikipedia page?
http://en.wikipedia.org/wiki/Comcast

yes, this needs to be spread around the net as best we can. wiki, digg, hell someone can make a video and post it on youtube.
post #236 of 2079
3/25/08 at 10:03am
Well if you have a Digg acct, you can digg this story here:
http://digg.com/tech_news/Dear_Comca...ality_in_April
post #237 of 2079
3/25/08 at 10:51am
Like any business Comcast watches the bottom line. I have contacted some high ranking officials within Comcast and they are aware of this AVS thread and state they are working on technology solutions to be competitive.

I feel however, that the more people who are aware of the problem and provide feedback both to Comcast and to other media resources will help Comcast (and othe cable companies) reach the "correct" decision as to what the best solution is to be competitive.

With the advent of high definition media such as Blu-ray you do not need a technical person to see the difference between excellent quality high definition media and what Comcast is currently providing. Just as people are slowly starting to become aware of the difference between the picture quality of DVD versus Blu-ray, people will become aware of the difference between lower quality HD cable and higher quality cable and FiOS. As Comcast did a promotion of its picture quality versus satellite, Verzon could do a comparison of its HD picture quality vs Comcast.

On a side note I wonder if othe cable companies are also lowering of HD picture quality to add more HD channels?
post #238 of 2079
3/25/08 at 11:19am
Comcast is not all its cracked up to be. The other issue is drop outs of the HD video/audio.

What good is a HD program if you see black squares in the image and loss of audio?

It happens frequent enough to become annoyed. And they charge us for this garbage.

If they're going to tinker around with the quality, then stop charging us extra for it. It is still better than the SD channels I have to admit. But that's all I'll admit.
post #239 of 2079
3/25/08 at 11:21am
Quote:
Originally Posted by PaulGo View Post


On a side note I wonder if othe cable companies are also lowering of HD picture quality to add more HD channels?

Yes, Comcast's CMC/HITS Quantum operation delivers/sells these same channel packages(as well as SD channel lineups) to many smaller cable systems all over the country.

TW, Cox, etc. probably have their own delivery systems, but for smaller cable companies this one-stop/minimal dish requirement product from Comcast is probably more efficient infrastructure-wise.
post #240 of 2079
3/25/08 at 11:29am
Quote:
Originally Posted by keenan View Post

Yes, Comcast's CMC/HITS Quantum operation delivers/sells these same channel packages(as well as SD channel lineups) to many smaller cable systems all over the country.

TW, Cox, etc. probably have their own delivery systems, but for smaller cable companies this one-stop/minimal dish requirement product from Comcast is probably more efficient infrastructure-wise.

Actually, they don't. Cox and Charter definitely use HITS, and I am pretty sure TW does as well. VZ doesn't (they deliver terrestrially via fiber, so no downlinks are needed), and neither does DirecTV (as they do their own encoding).

This is definitely affecting more than just comcast markets. Beating up on Cox and others on this issue may get them to force Comcast to stop doing this at HITS, and therefore shift the decision on whether or not to do this to the local regions, where additional pressure can be brought to bear.
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: HDTV Programming
This thread is locked  

AVS Top Picks

AVS › AVS Forum › HDTV › HDTV Programming › Comcast HD Quality Reduction: Details, Screenshots