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View Full Version : Comcast (and industry as a whole) taking some bad press on its over compression of HD


Hansen
04-21-08, 11:37 AM
Article from MSNBC discussing Comcast's (as well as others) degrading (over compression) of the HD signals. Nothing new, but interesting that the issue is starting to get some mainstream press coverage.

http://www.msnbc.msn.com/id/24238071/

veryoldschool
04-21-08, 12:01 PM
Three HD channels into the space of on analog channel? :confused:
I don't care what encoding they're using, it can't be HD.
With MPEG-2, three [maybe five] SD channels fit into the space of one analog channel.

jpl
04-21-08, 01:09 PM
Three HD channels into the space of on analog channel? :confused:
I don't care what encoding they're using, it can't be HD.
With MPEG-2, three [maybe five] SD channels fit into the space of one analog channel.

No, that's not correct. With standard mpeg-2 you can fit 9 - 10 SD channels in one analog slot, or 2 HD channels. Each slot can handle ~39 Mbps, and with HD stations peaking at around 19 Mbps (based on how they're broadcast), you can fit 2 HD channels comfortably in that slot. Comcast is squeezing 3 channels in to one of those slots, which is the cause of all the contraversy.

Heck, when it comes to digital music, you can easily fit 47 channels (all of Music Choice, e.g.) in one slot.

This is exactly why I scoff when people tell me that traditional cable is tapped out in terms of bandwidth. It's not. With 860MHz cable systems (basically the max that's out there), you can fit 135 such slots. If you go all digital, you can easily fit 150 HD channels, plus 500 - 600 SD channels into that space.

hdtvfan0001
04-21-08, 04:20 PM
In any case - this information addresses the myth that the cable advertising seems to want to mislead the public with these days.

Greg Alsobrook
04-21-08, 04:24 PM
all I know... is that here in Memphis... Comcast looks TERRIBLE in SD and HD...

dtv757
04-21-08, 06:39 PM
here is the thread from AVS forum. FiOS is mindblowing compared to cable!!!
http://www.avsforum.com/avs-vb/showthread.php?t=1008271

Thaedron
04-21-08, 08:10 PM
A friend (who has TWC) sent me the same article earlier today. Maybe someday soon we'll get past the quantity comparisons only and get to comparing quality and quantity.

wilbur_the_goose
04-22-08, 08:00 AM
If you want proof, compare ESPN-HD on D* to a simulcast game not on ESPN. The MPEG-4 blows MPEG-2 away.

Steve Mehs
04-22-08, 03:46 PM
I often feel sorry for Comcast, they are the whipping boy of the MSO industry, the mighty DirecTV or even better Verizon could kill little puppies and the cable hating media bias would still find a way to blame Comcast. But this is one time I feel Comcast is in the wrong. They should have moved to SDV. When showing HD content, all 40 HD channels I get from Time Warner are pristine. Hopefully Comcast can get their act together, and find a solution to this problem that will make consumers happy.

Greg Alsobrook
04-22-08, 06:21 PM
If you want proof, compare ESPN-HD on D* to a simulcast game not on ESPN. The MPEG-4 blows MPEG-2 away.

i thought espn-hd was still mpeg-2??

Michael D'Angelo
04-22-08, 06:22 PM
i thought espn-hd was still mpeg-2??

ESPN HD is still MPEG2.

SDizzle
04-22-08, 06:27 PM
i thought espn-hd was still mpeg-2??

I think he meant an ESPN game that is MPEG2 to say a FOX HD game that is MPEG4? That's what I thought he meant. Cause he says MPEG4 is better than MPEG2.

Greg Alsobrook
04-22-08, 08:37 PM
I think he meant an ESPN game that is MPEG2 to say a FOX HD game that is MPEG4? That's what I thought he meant. Cause he says MPEG4 is better than MPEG2.

ahh... yeah, i can see that after i re-read it...

jpl
04-24-08, 08:06 AM
ahh... yeah, i can see that after i re-read it...

It's still an invalid comparison. ESPN-HD on DirecTV is still probably over-compressed. Where as the local broadcast (in mpeg4) is not. All that comparison tells me is that overcompression is bad. It doesn't tell me that mpeg4 is better than mpeg2. Besides, if the source is mpeg2 (which the local fox broadcast most probably is) and you're converting that to mpeg4 (which is what DirecTV is doing), how is it possible that THAT feed would be superior to an uncompressed mpeg-2 feed? It's not possible. Data loss is data loss - even though mpeg4 is more efficient at compression, and helps minimize the data loss, going from an mpeg2 source to an mpeg4 feed will still involve loss of data.

The story would most definitely be different if the channel sources (ESPN and the local fox affiliate) were both broadcasting in mpeg4.