Comcast has begun compressing HDTV shows in order to deliver more HD channels to you while using the same amount of bandwidth. They didn't use to do this before, but now, when compared to Verizon FiOS, the channels are grainy and blocky and full of artifacts—a result of shoving three channels into a space where only two previously occupied. A guy at AVSForum measured how the new bitrate stacks up against Verizon.
DVice has a side-by-side of the FiOS vs. Comcast comparison as well, and things look pretty damn ugly.
The forum poster says that the compression isn't too horrible with still images, but gets really bad when stuff moves around.
The greatest differences are seen with movement. With slow movement on Comcast, the first thing you notice is added noise and a softer image, as fine detail is filtered from the picture signal. The greater the rate of movement, the more detail you lose and the more noise you see. With intense movement, you see more blocking and skipped frames. In VideoRedo, I noticed that a number of frames in the FiOS signal simply did not exist in the Comcast signal during motion intensive scenes. This may be responsible for the stutter and excessive motion blur seen with some video sequences on Comcast.To Comcast's credit, I saw little to no difference on movie channels such as HBO, Cinemax, and Starz. I did see some blurring and reduced detail during fast movement on Starz, but the recordings from Cinemax and HBO were virtually identical, even on action movies such as 300 and Gladiator. When there was blocking on the Comcast feed of Cinemax, that blocking was also on the FiOS feed.













Comments
Hurray for FiOS being available in my area within the next month!
I will gladly take fewer high quality channels over more crappy looking channels.
I was watching HD on DirecTV this weekend for the first time. I was pretty disappointed with the quality in action scenes and in other fast moving objects. I have cable and have been quite satisfied (Insight). It's not flawless, but is light years ahead of those Comcast samples.
One more reason not to like Comcast...
That chart is Awesome!!!!!!!!!!!!
@James: I live in an Insight area that was just migrated to Comcast. April 30th is when Comcast fully takes over.
I have used Comcast for the last few years in the Washington, DC area, and recently switched to FIOS. Not only did FIOS deliver better SD and HD images, but there was a significant difference in the overall quality of the service. With Comcast, the images tend to stutter approximately once per minute, and the sound will frequently cut out for as long at ten seconds.
I'm very happy with my choice to change providers, despite the fact that Verizon provides zero customer support on weekends or non-work hours.
I've noticed this for a while. Maybe they've started by doing it in our area (North Bay Area).
One more reason for me to switch to FIOS as soon as I can get it.
It really is disappointing to buy an HDTV only to have the incoming signal look like crap.
All the more reason for Verizon to HURRY UP AND PUT FIOS IN MY NEIGHBORHOOD.
I am trying to give you lots of money, guys, what's the problem?!
No surprise. Pretty soon we arent even gonna know what a true high def video, or even audio, signal looks/sounds like. Its kind of like the frog in hot water theory.
It all started with audio. MP3 completely murders an audio stream and we accept it. MPEG video does the same exact thing. And again, its accepted. Compressed High Def looks great on still or slow moving images, but let a fast moving scene such as explosions or waves pop up. It looks like the TV is barfing.
I realize that compression is necessary to facilitate the 46,315 channels we crave, but come on. There HAS to be a happy medium.
I did not expect that such a move would be allowable. The original resistance from cable providers vs the FCC's decree to go HDTV was regarding the bandwidth. They could fit something like eight standard def channels in the bandwidth used for a single HDTV broadcast. The FCC - for once - put their figurative foot down and made it mandatory.
I suppose that in light of the slack given to dish-based cable providers, this might be overlooked for a few years. That is, unless enough Comcast users complain about the poor picture quality and threaten to defect. Money talks, after all.
COMCAST - Nobody will ever nnotice.
kp
Food Network HD?
I have comcast...and my picture does not look like that. I think that this is very misleading. Who knows where these screen shots came from. My regular tv without HD doesnt even look like that. I wouldnt be suprised if these shots were actually posted by Verizon FIOS
I wonder what kind of deal HBO and Skinemax have worked out to prevent this. I don't doubt they saw this one coming. HBO, the greatest thing on television.
Whether you agree with more government interference or not, it does seem as though a company should not be able to call highly compressed HD video as high definition. When you compare over the air HD & Blu-ray level quality to what these compressed examples are like, there really is no comparison. Heck, I would rather watch a DVD of a movie than the 'HD download' version of it that the various folks put out, because in my experience the quality is much better.
That said, I do think this stuff is so confusing to the average person that there is not much that can be done. We will have everything labeled as 'HD', and people will not know whether it is 'good HD', 'bad HD' or 'ugly HD' until they use it.
Am I missing something?
Isn't the idea of HD be better image quality? If I get a picture worst than regular TV signal via analogue TV, what is the point? It's far cheaper, SURE you don' have the 300 channels, however do you really need all of these?
The only advantage I see, id that your channels are in wide screen for your wide screen TV, so you don't see people fatter, and squished vertically than what they really are.
CRT's for the WIN!
Man, we have FIOS, but not the TV service due to super lame city franchise BS.
I have Comcast and can say those bitrates are spot-on as far as the CC portion of the chart goes.
That's Comcastic!
(sorry could not resist)
I've done everyting I could do to avoid Comcast for the past several years (only one landlord would not allow me to install Sat.) originally for the Comcastic customer service. It's nice to see that their service delivery is now on par w/ their customer service.
can anyone explain why Comcast is more than happy to deliver a box, but when I cancel service, I have to drive to the worst part of town to return the box? Even though they have trucks going past my block every day?
How can we be certain the lower bits-per-second is coming from using more aggressive compression on the stream, or is it from downrezzing 1920x1080 to 1440x1080 ("HD Lite")? This is what I would like to know. DishNetwork and DirectTV do a little of both: take 1920 down to 1440 (or 1280)... and use more aggressive (read: more blocky with action) compression.
Cable has been lower image quality than OTA for quite some time. I remember watching shows and seeing very noticeable MPEG artifacts over analog SD cable.
The transition to HD has only made the low quality product that they offer even worse. I can't believe how much people pay for such crap quality.
The reason to get cable is the quantity not the quality of content.
Three words: Class action suit!
If the company advertises High Definition (despite tiny print disclaimers), and fails to deliver High Definition, one sues for breach of contract and false advertising.
So which service has the best HD quality???
Also, where does Time Warner Cable fit into this equation for us Los Angeles and Southern California people?
Time Warner bought out Comcast, FYI so we are actually ex-Comcast here
Fuck. That's all I can say.
Perhaps this explains all the signal problems I keep having too.
This whole story is an April Fools Joke! Comcast wouldn't do that to people. My service is great.
***DUSTYBUTT NEATLY FOLDS CHECK FROM
COMCAST AND TUCKS IT INTO HIS POCKET***
Gotta Love Comcast's 8bit HDTV broadcasting.
I don't see any real reason to pay for HD if they're going to compress it that badly. OTA's the only way to get HD...
Even viewing on a 720p set you can see vast differences in the quality between "HD" stations at Comcast's current rates of compression. Some 1080i broadcasts look amazing, others already suffer from compression artifacts.
It's good to finally see some discussion on bitrates. There should be certainly some baseline bitrate standard for a cable company to be allowed to call a broadcast "HD". I'll certainly be calling Comcast to complain.
And its only going to get worse as they try to shove all those channels through. Thank you OTA!
I'm curious too as to where TWC fits on this spectrum. I have to assume, given that they broadcast a roughly equivalent amount of analog channels that they are facing the same problems, and may have implemented the same solution. Since I just signed up for Fios Data at my new apartment I'd like to see if there's a New York comparison out there for TWC vs. Fios.
@TVGenius: It must be nice to live in an area where you can get a decent signal. There are areas of the country where, due to geographical features, OTA is not viable. If I could get OTA, I would. For now if I want to get HD broadcasts, I must pay a cable provider.
Seriously, tho'.
I moved to Northern VA from Baltimore last November and had to wait 3 months to re-subscribe to Comcast because they only offered deals to new customers. After a 90 day break in service you qualify as a new customer.
The first two things I noticed when I turned on my TV was that:
a) The Scientific Atlanta HD box is PURE GARBAGE
and
b) Tons of artifacts during fast screen motion, especially on water surface shots in HD.
I actually blamed it on my TV... Now I know... Those Schiesty bastards!
The sand in the KY is that I have NO CHOICE if I want to have any variety. The place where I live is on the NOVA historic register so I can't have a dish, and FIOS isn't in the area yet.
F*** CONCAST!
Unfortunately for me, I live in a city where Comcast broadcast sports reign supreme (Philadelphia). Supposedly, Comcast and Verizon had signed a deal that FiOS would receive all of Comcast's sports channels if they didn't bring FiOS into the city itself. Therefore, no FiOS for me. :(
Wow, that's pretty terrible.
I have Cox HD here in Arizona, and must say the HD channels are pretty glorious. w00t.
This explains a lot. AT&T is offering Comcast cable in my neighborhood and it was going to be cheaper than the Time Warner that I already had with more HD channels. But then I heard from some people that already had it and said the picture quality was terrible so I'm glad I didn't switch.
@SchruteBuck: "Food Network HD?"
Iron chef Masaharu Morimoto here.
That's why they're canceling "Emeril Live." Apparently, the FCC deemed any images of Emeril Lagasse broadcast in HD as obscene and indecent. And frankly, who can argue with that? Now if only there was some kind of noise gate we could apply to Rachael Ray's voice... One more 'EVOO' and I'm gonna use my sushi knife on my wrist.
@frigg: yes, but doesn't Giada De Laurentiis make up for everything?
If I am paying extra for the HD channels from Comcast I had better be getting the Full 1080p from the service, else I will be one of the complaints to the FCC.
Isn't there some standards group that decides who can use the HDTV branding and who cannot?? Bozos who try to push substandard service levels and still claim it to be something like HDTV when it is obviously not should not be allowed to use the brand HDTV.
Maybe the government arm that regulates cable companies needs to step in here, and pronto!
@shrike3815: Umm, 1080p isn't in the HDTV spec. It's 1080i or 720p, and it depends on the channel, not the provider.
However, even if it was 1080p, Comcast could (and would) still compress it into pixelated garbage - it would just be a lot of pixels of garbage.
Degrade peer 2 peer access. Degraded HDTV quality. Still raising prices. Comca$t is bulletproof.
@MisterSleep: Have you ever seen her beak in HD? I'm with frigg.
Standard definition channels coming from Comcast and into my HDTV look like absolute garbage -- I've seen streaming WWW videos that come in clearer. HBO looks okay in high def and so do the national networks. But it's pretty sad that as an HD subscriber I get far better results by plugging in my antenna for watching LOST. As a side note it's almost worth it just to have MHD and Sci Fi HD. But it's still pretty annoying. Who do we write to about this?
Wow... I JUST got off the phone with Comcast, after signing up for a package deal ($60 for cable and internet) but also adding HD for $7 more and $20 installation. Then I go here and read this. Awesome . . .
As far as I understand it, and I very well may not, "HD" defines the resolution of the picture, not the bitrate at which that picture is brought to your TV. The issue is that Comcast is restricting the bitrate so much that they must compress the 720 or 1080 lines of resolution to the point where it just looks crappy.
So, technically, they are sending you an HD picture. If the FCC were to do anything it would be to define a minimum allowable bitrate (for a given compression standard) for HDTV transmissions.
I haven't seen any problems with my Comcast HD box yet. Nothing on the massively blocky side like that comparison shot yet.