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HDTV must not be degraded: CRTC

19K views 75 replies 29 participants last post by  studlygoorite 
#1 · (Edited)
This thread is to discuss the current and growing practise by most TV broadcast distributors (cablevision, satellite, telco, etc) to re-compress HDTV channels to use less bandwidth.

In many cases this additional compression results in degradation of the image by causing soft edges (mosquito noise), macroblocking and adding other errors and artifacts.

This additional compression is in violation of CRTC directives that state:
program signals should be of the same quality and in the same format as those received by the BDU, without any degradation.
In fact, not only HD but also SD digital TV stations are covered. For reference I will post the relevant sections of the CRTC notices.

Do you want the distributors (Shaw, Rogers, etc) left to decide how much compression is too much? Or do you want your HDTV channels in the original quality that the broadcaster intended and provided?

You can submit a complaint to the CRTC stating that you object to the image degradation caused by additional compression the distributors are applying to the HD and SD digital TV signals you receive from them, in violation of CRTC notices 2006-74 and 2003-61.
 
#60 · (Edited)
Satellite help please

Thanks 57 and smallmj.

One thing that I've been trying to figure out since I got Shaw's letter is (paragraph 4) the effect of Shaw Broadcasting Services / StarChoice. If, as Shaw claims, all of their cable systems are now using the satellite service as their source, then that may be the original source of overcompression on Shaw Cable.

According to Shaw Broadcasting's channel charts, the HD signals are carried on Anik F2 in groups of 3 HD per transponder, for example:
Code:
[B]VCT  	DBS  	CATV  			Trans- 	Modulation 	Symbol
ID 	VCN 	VCN 	Program 	ponder 	FEC 		Rate[/B]
517 	276 	900 	Nat Geo HD 	F2 T2 	8PSK--2/3 	20.5
517 	277 	901 	Showcase HD 	F2 T2 	8PSK--2/3 	20.5
517 	279 	903 	Discovery HD 	F2 T2 	8PSK--2/3 	20.5
I'm not a satellite guy, but from some research I've done it looks to me like a transponder using this modulation/FEC/symbol rate has a bandwidth of about 38 Mbps (making it roughly equivalent to a 6 MHz QAM 256). If that's correct, then the signals are indeed compressed down to 3 HD per ~QAM on the satellite.

So the complaint may have to encompass the satellite feeds, which complicates things because Shaw could try to claim that Shaw Broadcasting is doing the extra compression, not Shaw Cable. (6 of one, half a dozen of the other... but it is a technicality they could try to exploit)

Is the Anik F2 satellite signal the same HD signal that StarChoice subscribers receive directly? StarChoice is a BDU and should be covered by the CRTC directive the same as Shaw Cable. In that case, StarChoice should not be adding extra compression, and then Shaw Cable would have no excuse either.

Help? Can anyone confirm/clarify?
 
#61 ·
I believe that satellite transponders only have about 30 Mbps. BEV now does "rate shaping" of the 3 channels on many of their channels. A select few channels seem to get more bandwidth. They also change almost all of the channels to 720P (the ones that aren't already). See the BEV compression thread. I don't believe that *C does rate shaping and they change everything to 1080i, so they may have 15 Mbps at 2 channels per.
 
#63 ·
Starchoice has three channels per transponders, however they provided approximately 37.6 Mbps per transponder. This is because Starchoice uses 8PSK modulation for their HD transponders. The capture that I've taken from my Shaw DCT via firewire definetly shows that the files have a significant amount of variation in the bitrate(ranging from 7-15 megabits), so I can't believe that *C doesn't perform statisical muxing. Still since *C DSR don't have firewire ports it's difficult to prove.
 
#64 ·
I think that's right, StarChoice's HD transponders are 8PSK according to their charts and by my calculations that's ~38 Mbps.

StarChoice may be using stat muxing to fit those 3 HD per transponder, but that still requires shaving the bitrates (adding extra compression).

It's starting to look like Rogers is one of the few BDUs that can still deliver a full quality HD signal to the home!
 
#66 ·
Thanks for the reminder of Kaphyr's excellent site for Videotron information. He lists every QAM and the signals (and bitrates) carried.

Thanks to his hard work, I can see that Videotron does indeed only put 2 HD signals per 38 Mbps QAM.

(I only wish I were fluent in French and didn't have to rely on Google's page translation.)
 
#67 ·
This has been gnawing at me for years, having a 174" screen doesn't help, thanks for all this information. I have Shaw Direct and have terrible picture quality, I have had Bell Satellite and Direct TV. Direct TV is by far the best picture and I was wondering if anyone knew, now that this is 7 years past the start of this thread, who has the best picture quality. I have been waiting for Bell Fibe for a couple years now and it's still not available in my area. My area is Stoney Creek Ontario and Bell Satellite, Shaw Satellite and Cogeco are the only games in town with Bell Fibe, hopefully just around the corner.
 
#68 ·
I forgot to mention that 90% of the hockey games I watch, mostly HNIC, only have stereo sound when 5.1 is being sent. I have had talks with the people responsible for the productions and they could not tell me what the problem was, I am now thinking that Shaw Direct's Compression is responsible for the loss of the surrounds in the audio stream, would anyone agree?
 
#69 ·
Yet another fine example of a CRTC directive that was ignored by most broadcasters and BDUs and almost never enforced. The only time I've ever seen anything done was when a consumer campaign was launched against improper simsubbing of degraded Global TV signals on Bell TV. (Bell started simsubbing before Global even had an OTA transmitter and the audio on Global's signal was defective.)

Shaw Direct has a very long record for messing with HD signals and degrading sound quality. CBS from Seattle is an example of a station that was always in DD2.0 on SD (when I had it) but often broadcasts in DD5.1. SD does not typically overcompress their HD signals but often has other technical issues that affect signal quality. I've yet to see any BDU HD signal that matches the original OTA signal in quality.
 
#70 ·
When I was speaking with the Executive Producer For Remote Broadcasts for HNIC I mentioned, and had proof, that Bell Satellite, Cogeco Cable and my Shaw Direct were all suffering from the same problem. Is it possible all three are squeezing the full 5.1 audio out of their signal? I gave up blaming CBC as I noticed that TSN and Sportsnet Broadcasts also had the same issues.
 
#73 ·
- watching the same on Apple TV is way better.
I've noticed that Netflix is using DD+ on some shows which is capable of much better sound than DD5.1. Apple TV may be doing something similar. Superior picture and audio quality is yet another thing that's going to put the nail in the coffin of incumbent BDUs. If they can't deliver real HD video and audio quality, despite CRTC rulings that they must, it's time for some competition that will. It's too bad that VOD is killing off Blu-ray. A lot of people don't realize what they are missing with the lousy HD quality that BDUs deliver, myself included.
 
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