HDTV Question, CGI, Pixellation

I have an almost new Toshiba Regzla LCD TV, 37". It’s been great for sports, movies and such.

I always understood that sometimes very fast action sequences tend to blur and pixellate during those types of sequences, which is almost always in movies.

Recently, I rented off PPV “Speedracer” in HD, I have Comcast, never had an issue with HD movies before, really.

“Speedracer” was almost unbearable to watch. Massive pixellation during every racing sequence, a lot of seemingly slow response time by the set to “catch up” with the action on the screen.

What gives? Was it just that that particular movie title had so much over the top fast action sequences that this kind of viewing experience is to be expected? Was it the massive amount of CGI causing this (or making the issue worse)?

Is there any way to mitigate this effect by altering settings on the TV itself?

I was really disappointed in the way that looked. My son didn’t seem to mind, but I was hoping to recreate the theater experience we had when we saw it there and it was abysmal by comparison.

This sounds like there’s a signal quality problem. There is some error correction in the encoding of the digital signal to account for transmission noise and losses, but when your signal is bad and you lose too much of the data, the result you get is “macro-blocking”, which looks pixelly (but the blocks are a little bigger than pixels) and pauses that might lead to a laggy picture that isn’t synchronized with the audio. On a high def, high action movie, there will probably be more data traveling over the wires (high action means less compressible), so if your signal is borderline, the problems might only pop up when watching this type of movie.

No way. The actual stuff in the video stream is just pixels, whether it was generated by CGI or by pointing a camera at something. Being CGI or not may effect how well a particular video stream will compress, but the type of action probably has a bigger impact.

Call the cable company and let them know. Make sure you mention that it only happens with high def, high action content. They should send someone out to check your signal levels and whatnot, and hopefully whoever comes out will try playing the same video as a test.

I’m not sure that this is the same phenomenon that the OP describes. Perhaps s/he can clarify whether the “Massive pixellation during every racing sequence” descrbed is the large 1"x1" squares that indicate a signal issue or whether it is smaller looking pixels that might be due to overambitious compression schemes.

So, OP, could you describe what you’re seeing with a little more detail?

Sounds like too little bandwidth. Fast-changing scenes require a lot of bandwidth to render accurately (the majority of the pixels change on every frame). If your video provider are a bunch of cheapskates, they won’t allocate enough bandwidth to do this accurately, and the video will look good on static scenes, and crummy on moving ones. I’ve seen this a lot on DirectTV football games.

Speed Racer in HD, with its super-saturated colors and wild action, is probably a data-compression nightmare. The simple story is that the more simultaneous colors and detail in the scene required, and the more variance from one frame of the movie to the next, the harder it is to satisfactorily compress the signal. I can’t imagine a better test of Comcast’s capacity to deliver a good HD product.

That said, they should be delivering a good product, call them and ride them hard until they can support (it they are even able to with bandwidth limitations).

I’m with Gargoyle… call up Compcast and raise a stink.

It’s not your television. Many cable providers compress the hell out of their signals.

Massive pixellation refers to quantity, not size…it isn’t those big black squares I’m seeing, it’s more of a blurred quality to fast action scenes.

I read Gargoyle’s post and it makes sense. I have watched other action movies in HD with very little of this effect before (except maybe in large explosions), but Speedracer’s color saturation and fast frame action probably is what’s taxing the signal’s compression or lack thereof.

I will put a call into Comcast, and if I get through (can be a BIG if) to someone perhaps I can resolve this issue. My DVR doesn’t seem to work anymore so I need to exchange the box anyway.

Could it be the HD box’s ability to translate the signal (ie, do I have a bad box?) or is it just the straight signal?