Cable movies on demand, how to avoid a "pixellated" showing of the movie?

I’ve noticed a peculiar thing when I watch pay-per-view or free-on-demand movies from my cable provider. Especially with the free ones, I notice that I sometimes have problems getting a good clear presentation on my TV. The program will be jerky and occasionally pixellate into green rectangles of various sizes. It doesn’t do this over the whole screen, but just here and there. Still, it’s basically unwatchable. So when this hpapens, my SOP is to power down the cable box and turn it back on, and try the movie again. This usually fixes the problem, although sometimes it takes two or three tries to get it to work.

If I’m interrupted and have to resume watching the movie later, their system will remember where I was and start the movie at the appropriate point, but sometimes I have to go through the same routine as described above to get a good picture

Is there any procedure that will guarantee a good picture from the outset? And arising from that, how do pay-per-view movies work? How does the software and hardware involved deliver the movie to the person who ordered it, and enable the viewer to pause, rewind, fast forward, and play it?

I only know a little about this area, but my guess is a SW error when decompressing the image. You probably have digital cable and the On Demand movies are being heavily compressed. The compression algorithm does stuff like look for areas that change between frames and only send those. These areas would typically be in “boxes”, hence the pixellation. Over compression can cause all kinds of artifacts, but the fact that it can be fixed by resetting the box makes me suspect it is SW on the recieving end causing problems.

I just got digital cable. The image is nice and noise-free, but the artifacts can be a problem. In Alexander, there are dozens of 20 foot spears being waved around and the compression/decompression just couldn’t keep up.

Someone correct me if I’m wrong, but as far as I know, the current generation of “on-demand” is just a fancy name for streaming video – the same technology that powers online move trailers and Youtube. It’s just much faster since it’s coming directly from your cable provider and not over the Internet.

The hardware and software is a combination of some sort of video encoder/decoder (usually using MPEG video compression) and a playback program. Sometimes there’s a hard drive in there (as in the case of TiVo or some cable company PVRs) so the device can store programs locally and not have to re-stream it every time you rewind or fast forward. It’s not terribly different than using Windows Media Player.

As for what you can do about artifacts – not much, I suspect. Have you tried NOT turning off the cable box, just to see if that actually affects anything? I don’t believe it’s actually your or the box’s fault, but I could be wrong.

It’s probably a connection problem. The wiring to your house is probably less than perfect. Bits are being lost. (And perhaps being re-sent but not fast enough.) Also, since this is a shared connection with your neighbors, the heavier demand they put on the connection, the worse yours becomes. There can also be a bottleneck at the head end if a lot of people are doing on-demand at the same time.

The first can be improved by making sure all your house connections are clean, tight, etc. Outside your house is not something for you to do besides calling and complaining. (If you do complain, refer to pay on-demand. You want them to think that they are losing income.)

The second can be improved by watching/recording during “off hours”.

Note that even without pixelation, the picture quality is probably quite degraded. MPEG encoding tries to correct errors but loses quality when they are too many. Pixelation means that even that it overwhelmed.

Right, it’s streaming video. I would doubt that the cause is bandwidth overload on your local loop. It would produce jerky video, but it shouldn’t create green squares. That sounds more like lost packets/inconsistant connection. I’d guess it’s coming from either poor cabling, poor connections, poor splitters, or EM interference acting on any of those things. The wiring inside your home (or possibly that leading immediately to your house) was obviously designed for analog signals, which could be full of noise and degraded without a drastic failure of service. Was your analog picture without especially noticable flaws in the first place?

You can test this out by connecting your cable box immediately to where your cable enters the house, eliminating some of your cabling. If it works better like that, then you know your problem. Alternately, you might have luck waiting for a newer model of cable box (or contacting your cable provider to see if there’s one already available).

Regarding artifacts during general viewing: A newer cable box might be able to do the smoothing. Many HDTVs will be able to smooth the picture as well, but usually only if you connect them via a digital HDMI link (not the three component cables)! HDMI looks nearly identical to the DVI connector on your video card.

actually, hmm, since normal tv looks fine (which is streaming also), but on-demand does not, then actually it might be bandwidth overload (unless your wires are somehow especially crappy for the frequencies used for on-demand streaming). not much you can probably do here, except not watching during peak hours. complain to your cable company, and maybe they’ll reconsider overloading your loop with too many users.

a new cable box may still be relevant, however, if there’s new frequencies that are to be opened up or other ways of boosting the connection speed, or if more buffering will help.