Rogers reportedly implements more compression on HD channels
By Darren Murph 
posted Apr 1st 2009 10:08PM
posted Apr 1st 2009 10:08PM
Sadly, we don't have any reason to believe that this is some nasty April Fool's prank. We heard right around this time last year that Rogers Cable was looking to pull a Shaw and compress its HD signals even further, and now, it seems that said smashing has begun. According to Digital Home, a "majority of all Rogers high definition channels measured are now being compressed." Investigation in the matter has found that around 60 percent of Rogers' HD channels in Toronto were compressed, with HBO, The Movie Network, MPix, Nat Geo, CBS West, ABC West, Fox West, NBC West and PBS suffering the most. We're told that those stations saw typical bitrates of around 10Mbps to 13Mbps, while Rogers SportsNet, CityTV, CBC, CTV, Global and Discovery HD saw streams between 16Mbps and 18Mbps. Any locals care to confirm / deny?
so is the main way cable compaines compress signals is just to significantly lower the bit rate? is it all about the bit rate?
Yes. The lower the bitrate, the more HD channels they can squeeze down the pipe. If you have a 10 Mb pipe and each of your channels take up 1Mb, then you can only have 10 channels. If each channel only takes up .5Mb, then you can have 20. (I made up these numbers, but the concept is established, afaik).
for cable and HD telecasting, what bit rates are considered to be minimum acceptable quality for HD video... i would like some consensus numbers in order to compare how much compressed do cable companies actually do.
Yes, by compressing bit rate they can still offer more channels at HD resolution so the advertising looks better... The lower the bit rate, the lower quality of processing for each pixel on the screen... So you end up with up to 2 million terrible looking dots per frame on the screen but it can still be advertised as "1080P!" This is no different from many streaming HD services available today.
By the way, Bluray offers 40 Mbps bit rate and I think standard definition DVDs are like 12 Mbps...
My bad.. DVDs are only 8 Mbps...
Here is a list of bit rate compression for different formats, streaming services, and broadcasting/cable/satellite services:
http://blogs.zdnet.com/Ou/?p=962&tag=rbxccnbzd1
Another more in depth look at bit rate and compression schemes:http://blogs.zdnet.com/Ou/?p=511
And:
http://blogs.zdnet.com/Ou/?p=959
Take a look..
So comparing cable versus, satellite and FIOS tv for high def channels. is it a huge noticeable difference in the PQ? when it comes to HDTV ive only dealt with Cable (cablevision) and have always been very disappointing in the PQ.