Comcast Compresses HD - No One Shocked

[nosferatu]

i have a Basic comcast service and let me tell you .... with a tv that is 8 years old watching CSI is like watching tv back in 1990 when i was a kid ,when there was more snowflakes rather than picture on the screen. next few months im getting samsung 550 46' and updating to FIOS. The only reason im with comcast is that for 62$ i get 25 channels and Cable internet

 

[aarond]

I have time warner basic cable only because i had no choice. it was broadband for $49.99 or broadband and basic cable for $44.99, go figure?
when the guy came to hook up I was watching ABC/HD ota and he asks so you already have cable? I ask him since when does time warner have any channel close to this quality. he started telling me about the hd package. i had him go get an hd box from the truck and hooked it up we toggled between my free hd and the pay hd. i think that even he was surprised at how much better the free hd was. he put the hd box back in the truck. i would like to have Discovery hd but i'm not paying 20 extra bucks for one semi hd channel.

 

[marvelman74]

I work for comcast (a recent Insight acquisition) in central Illinois. and dont like them any more than the next guy. Some people really hate us. It is quite frustrating going into someones house for a service call and get to hear 10 minutes of ranting before they let me fix their problem. But on to the compression issue. I know for a fact that in our system 2 to 1 compression is the most we do. Many people have asked about it but we dont do more than 2 to 1. We run a 875mhz system and there is only so much bandwidth. There are 75 analog channel, to many digitals to count and then the broadband frequencies. If we did no compression then channels would have to be taken out for them to be added.
One possible reason for poor HD reception in some homes is that HD is sent over cable at a really high frequency. If your getting audio drop outs and pixelation then it can be result of weak signal on the high end. Low signal hitting your house from the plant, too many splits, old splitters that dont pass up to 1 gig, long lengths of cables and such will greatly effect your HD pics.

I dont want to start any arguments on here but that is what is going on in the system I work in. Other Comcast systems may not be so Comcastic.

And only if the broadcasters could figure out their end so I dont get cutouts in American Idol........

 

[MUDSHARK]

My friend swore up and down there was no PQ difference between Comcast HD and Direct TV HD, he goes and buys a 58" Panny, orders Comcast HD, compares my PQ (Direct TV HD) to his.......................he's getting rid of Comcast. He's not a techie or an A/V'er, just an attorney.........yet he could see the difference.

 

[TBG]

Some real compression numbers...

This may come as a surprise to some, but fitting 3 HD signals in 1 channel in cable provides about the same bit rate as what typical broadcasters provide.

First, understand that we're not talking about "3 to 1" compression. An uncompressed HD signal is 1.5 Gb/s, so any consumer HD MPEG-2 source, typically 10-20 Mb/s (and this includes digital cable, broadcast, satellite, Blu-Ray) will be more like 100:1 compression.

Your local TV station can fit 19.2 Mb/s in their 6 MHz channel. Most carry sub channels with weather, news, local programming, etc., and what's left for the HD signal is usually closer to 12-15 Mb/s.

Assuming your cable company is using 256-QAM modulation, they can fit 40 Mb/s in that same 6 MHz channel. So, even with 3 HD services in one RF channel, it's around 13.3 Mb/s, so it's about the same bit rate as the HD channel from your local OTA station.

 

[audioman00]

Hey CLINT!! reguarding comcast compression

Good job standing up for signal integrity. Your a stand up guy man!