Blocky moving video

raibauer wrote on 12/7/2004, 7:00 AM

Question: I am rendering video to Standard NTSC format using Vegas and then burning to DVD. My PC is not connected to a TV monitor and the preview on my PC screen looks fine. However once I watch the DVD on TV, I notice some funny "blocks" appear in parts of the video where there is fast movement (e.g. a person walking across the screen). It looks almost like a checker-board. I have checked all settings/options to make sure I am using the best available qualioty and the best compression rate on DVD. Still not working. Any idea what this might be? Could it be a problem that is due to poor video capture? Thanks for the help.

Comments

ScottW wrote on 12/7/2004, 7:09 AM

This sounds like a compatability problem with your DVD player. Have you tried other (and more importantly, newer) players?

The reflectivity of a burned disk is different than a commercially stamped disk, some players have issues when the bit rate spikes to handle fast motion - they start seeing a lot of errors in the data stream and you get the blocky effect.

Your best solution will probably be to purchase a newer DVD player. Another thing you can try is to lower your maximum bit rate (assuming you're doing VBR), try CBR or even use a different encoder (TMPGenc and CinemaCraft both produce different output than MainConcept and so they might not spike the bit rate as much for fast motion). I find that having an MPEG analyzer useful for this sort of experimentation - if I can isolate the problem in terms of a particular point in time, then the analyzer can show me what the data rate looks like - if I see spikes in the rate (and lots of little spikes seem to be worse than just one or 2 isolated ones), then I can encode just that section with a different encoder to see if it handles it better, or tweak the bit rate settings with MainConcept to see if I can get something that looks better - a lot of work though when a new DVD player can be purchased for as little as $40.

--Scott

raibauer wrote on 12/7/2004, 7:15 AM

Scott,

Thanks for the reply and suggestion. My DVD player is fairly recent (3 years), but it might be the problem. I'll check by trying on a newer machine. As far as encoders go, can I buy one and use it within the Vegas DVD software?

ScottW wrote on 12/7/2004, 7:22 AM

3 years is ancient. There's a couple of web sites that have reports from different folks on compatability - you might use the name/model of your player and google to see how it stacks up.

As for other encoders, you can frameserve using Satish's stuff to either TMPGenc or CinemaCraft - or you just render out to DV AVI and use the new AVI file as input to the encoders. I'd suggest trying a trial version of the encoder first and also try playing some with the bit rate settings in the MainConcept encoder (for example, 2 pass VBR might help in this situation) before you run out and by another encoder.

A new player is going to be probably the least expensive option, unless you happen to like very expensive players.