Copy Protection on Digital Cable

[jeff b]

Hi All,
I know that this may be off topic, however there are enough video savvy people here that I thought I might find some info.

I've got two Panasonic TV's running on two separate digital cable boxes (SA Explorer 3200) that were installed with newly available digital cable by the provider in the last six months. In low ambient light conditions, I have flickering on low luma (dark areas). The cause of the problem shows up on a waveform monitor as a single straight line, just above full black, and it makes both TV's flicker in the near black range.

I suspect that it's some cheesy copy protection because a Sima SCC color corrector easily removes it (and the problem). Also, this is only present on the digital tier of the cable system (all channels above 101) where, incidentally, all the pay channels are. The analog tier of the cable system doesn't have this additional component to the video coming out of the box (all channels between 2 and 99).

I've made a complaint to the cable company (Charter), and have had two visits from technicians who have been shown the problem, and who acknowledge it's there, and who have also claimed that they've never seen this problem.

Oddly enough, they never took a look at the output of the box while they were here. They only took readiings on the cable input to the box, the cable input to my house, and readings off the box's menus.

Their conclusion was "no problem found", so now I enter into step three in the cable company's "process" for handling complaints, wherein I'll be sending them an exhaustively long letter. In this letter, I'd like to include if I elicited any responses from people on the net who either know about this, have directed me to other websites describing a copy protection scheme that would "fit the bill", or other Charter customers who have the same problem, no matter what part of the world they may come from.

Any responses that might help me find information pertinent to this situation would be greatly appreciated. Personally, I have no problem with copy protection as long as it's not going to be a problem for the primary thing I'm paying for: real time viewing. However, I do have a problem with not being informed about the fact that copy protection is present in anything I may pay for, whether it's cable service or commerically recorded media.

Jeff B

p.s.- oh yes, and by the way, this component in the video output of the boxes causes VHS recordings to come out degraded, ie- lowered brightness, shifted chroma.

[jeff b]

Just an update, for anyone who might find this of interest...

I've had a total of five visits from service guys on this problem, have talked to the day supervisor once on the phone, and written two letters that I hand delivered. So far, no-one has analyzed the NTSC output on any of the three converter boxes that have been tried at this location. The situation has now been in limbo for a week, with no further communication from the cable company.

Apparently, they don't own a waveform monitor.

Of particular interest to this group, though, would be the fact that the cable converter (Scientific Atlanta Explorer 3200) is designed to pass Macrovision copy protection elements.

The subject was discussed on the phone, however, and I've been told that there is no copy protection added to the Charter system here at this time. Consequently, the nearly solid line of false sync pulses that are unintentionally coming out of converter boxes at this location are a fluke result of the cable box design. On a scope, it looks like a solid line across the video portion of the waveform, just above black. It causes both of my TV's to pulse luma levels up and down about 3 times a second, down near black. Very annoying, to say the least!

All of the technicians that have come to house have seen and acknowledged the problem, however, as it shows up on the TV sets. So hopefully, there will be some kind of resolution to this problem.

Meanwhile, I have to use a proc amp to watch TV... a very expensive solution, considering the price I pay for the cable service.

Jeff B

[Hulk]

Jeff,

Interesting, thanks for the info.

I have stayed away from digital cable after seeing it at my parents house. It seems as though they are so stingy with the bandwidth in order to cram as many channels as possible that is is constant noticable macroblocking.

I'm kind of tired of the whole cable tv monopoly as well.

They advertise all of this high quality service and yada yada. But if you actually take a good look and point out the problems with the image they act like your crazy. At this point I refuse to pay extra money to "upgrade" to digital. In my area you get NO extra channels (okay, maybe like 1 encore channel) and pay and extra $10 a month.

-Mark

[jeff b]

Hi Mark,

Aside from the one problem here, the entire cable service on both the analog and digital tiers is nothing short of FABULOUS. I'm especially amazed at how good the MPEG2 compressed video on the digital tier comes through. It's as good and usually a bit better than commercial DVD quality.

I use my SIMA SCC color corrector to eliminate the one problem I do have, for the time being.

I think that one of the problems that exists regarding compromised and bad cable service (especially digital) is that so many customers simply don't realize there's a problem that they should be complaining about to the cable company. In the case of macroblocking at your parents' house, this is caused by weak signal into the converter if it's chronic. The indices on the converter box menus will indicate this as soon as a technician brings them up, and will elicit a call to check and repair the line.

I've also found that a single "F" connector not being screwed on really tight can seriously degrade both the analog and digital tiers here, as well. It doesn't take hardly any attenuation at all to seriously degrade the huge bandwidth going into the box. It's just not the same as a single composite video signal on an RCA or S-Video connection, or the RF connection on the output of the converter.

Jeff B