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A comparison of Discovery HD between FiOS and cable with a 35.8% average bitrate reduction.  (Source: AVSForums user "bfdtv")
Canadian cable company compresses curious channel choices

HDTV enthusiasts in Canada having a chuckle at the expense of Comcast customers earlier this week are scheduled to receive similar treatment shortly. Beginning April 9th, Rogers Cable, one of the major cable companies serving the province of Ontario, is scheduled to begin compressing over a dozen high-definition channels.

Digital Home Canada
, a major site for Canadian consumer electronics, reported having been passed a technical brief from Rogers Network Engineering and Operations stating the impending compression and a listing of affected channels, shown below:
  • HD PBS Buffalo
  • HD WGN
  • HD The Score
  • HD Showcase
  • HD National Geographic
  • HD Mpix
  • HD Discovery
  • HD MORE
  • HD TMN
  • HD NBC Seattle
  • HD SUN
  • HD RAP
  • HDA&E
  • HDCNN
  • HDNET
The selection of channels is similar in scope to those being compressed by Comcast -- so-called "premium stations" that most subscribers typically purchase as part of a bundle above and beyond the basic digital and HD channels. A sample of the compression artifacts seen on the Comcast feed of Discovery HD, compared to the same channel on Verizon's FiOS fiber-optic network can be seen to the right -- providing an estimation of what Canadians are in for.

Major American networks such as ABC and FOX, and Canadian networks CBC, CTV, Global, and sports network TSN were omitted from the list. While the American networks -- and The Sports Network -- may have been given a pass due to the large number of viewers, the immunity granted to the CBC may have roots within the regulations of the Canadian Radio-television and Telecommunications Commission (CRTC.)

In the CRTC Broadcasting Public Notice dated June 12, 2002, paragraph 61 states that:
Accordingly, as a matter of policy, the Commission considers that a DTV signal distributed by a BDU [broadcasting distribution undertaking] to its subscribers should be of the same quality and in the same format as that received by the BDU, without any degradation.
However, no specific wording to this effect could be found within current CRTC regulations to this effect. With other major cable companies likely to follow suit, and opinions regarding the quality of Bell ExpressVu satellite service being less than stellar among the DigitalHome.ca enthusiasts, the only remaining option for Canadian HDTV owners to obtain a crystal-clear signal may be to dust off the old antenna and fly it proudly on their roof.


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Confusingly stated
By Flunk on 4/3/2008 9:06:07 PM , Rating: 5
This post is confusing and it infers things that are not true.

All digital TV boardcasts are compressed. Rogers will be increasing the compression on selected HD channels, not just beginning to compress them now.

The reason for the lower quality of Bell ExpressVu's image is that they already compress the video more than Rogers does at the moment. Satellite systems are very bandwidth constrained in comparison to terrestrial cable networks and must use more compression and/or a very large number of satellites to compete.

As a side note, who thinks that they are slowly makeing themselves irrelevant by reducing the quality of their content internet-based alternatives just keeps increaseing.




RE: Confusingly stated
By KristopherKubicki (blog) on 4/3/2008 9:21:26 PM , Rating: 2
Totally with you on that. Such a huge selling point of Comcast over DirecTV in my area is that DirecTV HD looks horrrrrible next to Comcast HD.


RE: Confusingly stated
By wordsworm on 4/3/2008 10:19:03 PM , Rating: 2
Don't cable companies get their broadcasts from satellite?


RE: Confusingly stated
By Flunk on 4/3/2008 11:39:00 PM , Rating: 2
For the most case yes, but the satellites that send the feeds to cable companies broadcast less compressed signals, they can do this because they don't have to carry 200 channels like the satellites that broadcast to consumers.

It is not a failure in the technology but a constraint of available bandwidth. They have to juggle individual stream quality vs number of streams carried.


RE: Confusingly stated
By Oregonian2 on 4/4/2008 12:45:53 AM , Rating: 3
It's also worthy to note that DirecTV is switching from MPEG2 to MPEG4 for HD (the new satellite that was put up a few weeks ago is supposed to be part of it) and quality is supposed to be improved with the switch.


RE: Confusingly stated
By Alexstarfire on 4/4/2008 5:10:38 AM , Rating: 3
I should hope so, MPEG2 is horrible.


RE: Confusingly stated
By SunAngel on 4/4/2008 9:08:10 AM , Rating: 3
... but your still ripping your dvds to your pc to watch, right?


RE: Confusingly stated
By Alexstarfire on 4/4/2008 8:03:03 PM , Rating: 1
Yea, but I don't convert them to anything. I just take the whole ISO. I'm not saying they can't have good quality, but the quality to compression ratio is horrible. 2x the bitrate and it still doesn't look as good as my DivX files.


RE: Confusingly stated
By mindless1 on 4/5/2008 6:43:48 AM , Rating: 3
It's a little crazy how quickly you've gotten spoiled. In the grand scheme of things people managed to watch and enjoy TV fine for several decades of less than MPEG2 quality.

If you can't ignore, even forget about whether the quality was the utmost or not, odds are you would've been happier doing something else instead of watching something that captivated you enough that you didn't notice (MPEG2) anymore.


RE: Confusingly stated
By Noya on 4/5/2008 2:54:23 PM , Rating: 2
Yes, and that was on CRT displays that mated perfectly with 480 line signals. The majority of people with HD service have 720/1080p HDTV...and SD looks like crap compared to an HD signal.


RE: Confusingly stated
By Mitch101 on 4/4/2008 9:34:15 AM , Rating: 3
I have one of the MPEG4 units from Direct TV and I feel its on par with OTA reception. I haven't done screen captures to 100% verify but nothing stands out as this doesn't look quite right. My neighbors agree DirectTV's HD looks better than what cable is pushing through. My Local cable company only provides about 13 HD channels and wants $10.00 a month for it. You can get most of them with an antenna.

Our local cable company is back to saying satellite dishes are ugly and lose their signal when it rains. I believe they are too small to be sued for false claims.


RE: Confusingly stated
By Alexstarfire on 4/4/2008 8:06:11 PM , Rating: 2
But it's not false. I will say that if you have a very strong signal that pretty much nothing is going to break it, but I would venture to say that most folks don't have a 90% signal strength or above. We don't lose ours very often even with less than 75% signal strength, but it can happen in some pretty bad weather.


RE: Confusingly stated
By lobadobadingdong on 4/6/2008 12:47:30 PM , Rating: 2
I have 92% signal strength on my dish, and I lose signal occasionally in bad storms (usually no more than 2-3 minutes). When I had cable here I'd lose service for 1/2 a day or more per month, even in good weather. It could just be our crappy cable company, as I didn't have that problem when I had time warner in the last city I lived in.


RE: Confusingly stated
By v1001 on 4/4/2008 2:01:38 AM , Rating: 3
Maybe this was true at one time but I don't think so recently. My HD channels on direcTV look stunning. I mean some times I'm just blown away at how incredible it looks. As good as my HD-DVD's at times. Probably because I just got DirecTV last summer and have all then new dishes and receivers. And mpeg4.

I don't know I was always underwhelmed by my brothers comcast in California and my Moms Comcast in Oregon even before I got HD.


RE: Confusingly stated
By jtemplin on 4/4/2008 12:00:51 AM , Rating: 2
While I won't comment on the article in its entirety, that comparison photo shows an incredible reduction in picture quality. It would have been a bit more scientific to show a before and after shot in addition to the comparison with a hi-quality competitor. That way we have a baseline for comparison.

That said, if worst case scenario is from Fios-->38% compression I woulnd't be a happy customer if thats what my premium package got downgraded to. To address your point: sure all channels may be compressed and it isn't a new "evil" practice, BUT the level of compression is significant. I am a big proponent of the theory of psycho-adaptive compression (or maybe perceptual encoding?). The idea being you compress the signal in just the right way to remove information that you cannot perceive (eg in audio, extra-audible frequencies)from a signal and thus jettison superfluous bits.

In truth, I always prefer the least lossy form of compression, but compromises must inevitably be made because of prohibitive bandwidth requirements. For example, a Full Aperture 4K stream is at least .850-1.2 GB/s (not bits...). Peace


RE: Confusingly stated
By danrien on 4/4/2008 2:41:04 AM , Rating: 3
quote:
I am a big proponent of the theory of psycho-adaptive compression (or maybe perceptual encoding?). The idea being you compress the signal in just the right way to remove information that you cannot perceive (eg in audio, extra-audible frequencies)from a signal and thus jettison superfluous bits.


Generally, that's what compression means in the analog world. While 1:1 compression can be done (i.e., you get out what you put in, such as is the case with audio in FLAC format), in terms of file size (and bandwidth), it is still prohibitive.... a normal person without a golden ear probably couldn't tell you if there was a difference between a well encoded 128kbps MP3 stream and a FLAC or lossless audio stream, but they might tell you that the lossless feels like it's better. However, when you tell that same person that they can fit about 10 times more MP3 files (an exaggeration possibly) than FLAC or WAV files on to that MP3 player, they'll choose the MP3 hands down.

In general, for video the situation is the same, however, the signal is inherently much more complex and the human eye can perceive many more shades of light than the human ear can detect different frequencies of audio, thus the difficulty in making a truly "good" video compression algorithm.

Sorry I've been looking at signals stuff for the past semester and my brain is becoming obsessed with these thoughts, so I felt the need to go on an explanatory rant.


RE: Confusingly stated
By omnicronx on 4/4/2008 8:48:24 AM , Rating: 2
Of course its compressed, its an MPEG2 stream. But even some BD's are encoded in mpeg2 and the quality is quite good as long as the bitrate is high enough, with little to no compression artifacts. Its when the cable companies start to try and fit as many channels in that 6mhz space that problems arise.

And just so everyone knows, rogers has always put extra compression on their HD channels, far more it seems than our American counterparts, just not as much as bell, as the OP has noted..


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