Comments

farss wrote on 11/25/2005, 1:33 PM
Simple,
buy a better TV!
Make yourself a test DVD. Just a black frame with a thin vertical line. Then add a larger white block on one side of the line but not touching it, have the block blink on and off every couple of seconds. Play this back through the TV. Notice how the line distorts when the big white block appears. This is due to poor power supply regulation, would have added maybe $1 to the cost of the TV to avoid it.
One way you can make this less obvious is to have less contrast in the video or less overal difference in brightness down the frame but really why change your work just because of a poor TV!
One other thing that you should check is that your levels, particularly the highlights are not out of spec, there's a good tutorial in two parts on this on the VASST site by Glen, even though this will not have a major impact on the problem sure worth a read anyway for other reasons.
Bob.
johnmeyer wrote on 11/25/2005, 1:44 PM
Rendered mpeg2 video that I made into a DVD looks fine on the PC.

HOW did you render it?? Did you render in Vegas? In an external MPEG-2 encoder? In DVDA?

The problem is a classic motion estimation artifact. If you use the "default" template in Vegas, for instance, this uses a terrible setting for "Video Quality" (15 instead of the maximum 31). Always use one of the DVD Architect templates for rendering from Vegas.

You might also get artifacts if you render at too low an average bitrate, although I would not expect to see the kind of artifacts you describe. However, if you are rendering at less than 4,000,000 bps, you might try a short clip of the same video rendered at 7,000,000 bps and see if it looks better.

Finally, if you are using an external MPEG-2 encoder (TMPGEnc, for example) all bets are off. Many of these are extremely good (TMPGEnc included), but they often have many, many settings that, if inadvertently nudged, can produce some pretty nasty results.
TheHappyFriar wrote on 11/25/2005, 1:56 PM
is it in motion only? If it is, the fields could be backwards. backwards is subjective though. :D
PeterWright wrote on 11/25/2005, 3:44 PM
I often get this with HDV material, but it's related to preview quality setting.

When I render I always use Best quality and the wavy lines disappear.
gzabetas wrote on 11/29/2005, 1:58 PM
Thank you very much to all for their replies. Sorry it took me a while to get back but I was fighting a cold.
I will attempt all solutions recommended here and get back here.

In regards to the bad TV, I even had it happen on my newer Magvanox, which makes me gear towards possible illegas levels (Had some Magic Bullet effects on it) ot the settings on the output.

Oh, and it was rendered in Vegas as a DVD NTSC template.
Again, it always looks good on the PC screen.

thanks all.
johnmeyer wrote on 11/29/2005, 3:05 PM
Illegal levels could definitely cause the TV monitor to curve the lines, especially if the contrast (which affects the whites) was set too high to begin with.
craftech wrote on 11/29/2005, 4:17 PM
Common problem with Sony cameras if that is what you have. Especially noticeable near end of zoom range and with wide angle lenses.

John
gzabetas wrote on 12/1/2005, 11:59 AM
Unfortunately, this is still a problem.
I re-rendered the project with the highlights in legal values (added the Vegas broadcast filter that brought the highlights under IRE 100), and I also changed the quality from 15->31 Best.
Still shows every vertical wall edge as an S-SHAPED curve.
I would say its both TVs but this never happens on any of thousand of DVDs I have watched.
The only thing I have not tried yet is to use the DVDArchitect template. That's my last attempt, then I am out of ideas. Thanks all.
farss wrote on 12/1/2005, 12:08 PM
Are you really certain it's never happened on any of the 1000s of DVDs you've watched on those TVs?
We're always watching something we've made, looking for errors, if it's a Hollywood DVD we watch the movie, not look for technical problems.
But why keep redoing the project, that's the quickest way to loose heart in this game. Use Vegas's media generators to create some test DVDs, this only takes a few minutes to do and you can control what's happening.
I'd still bet it's the TV, bear in mind most stuff shot on film has lower overall contrast as they're well lit, that has a big impact on how badly you see this problem on the TV.
If you play the DVD on a computer and it looks fine, then there's only two possibilities, interlace problems or the TVs themselves. This doesn't sound like an interlacing problem.
Bob.
PeterWright wrote on 12/1/2005, 3:50 PM
When I mentioned Best rendering quality, I was referring to the setting in File > Properties > Video > Full Resolution rendering quality. Have you tried that?
gzabetas wrote on 12/1/2005, 7:43 PM
Well, I tried the vertical bars and the half black half white media generated files and they worked fine.
Included my footage (this time I set the File->Properties-> Render quality to Best) and I still have the vertical shape giving me a SWIRL type effect on the edge of this wall.
Almost like a magnetic field is sucking the wall towards the right.
Would have to be something with my footage. Just to add that the footage is from an Elura2 progressive mode with 16:9 aspect. I have rendered numerous projects with these modes with no problems. For some reason I am wondering if the MAGIC BULLET deformed the footage somehow making it illegal. This was my first time rendering a Bullet affected file.
farss wrote on 12/2/2005, 1:11 AM
Is this a static shot or are you panning or anything like that?
If MB had deformed the wall then you'd see it when you played it back on a PC.
Can you perhaps email me a frame of the shot?
Bob.
gzabetas wrote on 12/2/2005, 7:46 AM
Thanks Bob,
I am at work now, but will email you a snapshot later. Keep in mind that it will look OK on the computer. You may have to render it for a TV.
Actually, I have a field monitor stashed away that I will hunt down and try the video on it. I think it will show the same effect.
gzabetas wrote on 12/2/2005, 5:57 PM
Got your email Bob.
Thanks for the explanation. For the record here it was related to a high contrast situation with blown highlights next to a column.
johnmeyer wrote on 12/2/2005, 7:06 PM
For the record here it was related to a high contrast situation with blown highlights next to a column.

Hey, isn't that what I said (almost exactly) four days ago? I guess Bob's accent makes it clearer. I've got to work on that ...
gzabetas wrote on 12/2/2005, 10:05 PM
thanks as well John.
Didn't mean to imply otherwise. Only added that Bob gave me a detailed look on where in my frame I was getting the problem.
So based on both your inputs I had concurrence which actually gave more weight to the solution.
There was not a single post here that I did not weigh and appreciate.
Thanks to all.
farss wrote on 12/2/2005, 10:53 PM
John,
not to labour a point but the issue isn't that the levels are illegal, the levels can be well within legal and you'll still strike this problem. Well it isn't really OUR problem at all, it's just the poor design of the average CRT based TV.
Where it gets really nasty is with 4:3 on cheapo 16:9 sets, like the one I have, you can see the edge of the frame being bent and it doesn't take much to make it happen, I'd say 30% of the off air stuff ends up bent to varying degrees.
Bob.
johnmeyer wrote on 12/3/2005, 12:02 AM
Sometimes you can "fix" the problem just by turning down the contrast. In fact, calibration procedures for cheap monitors tell you to turn up the contrast until you get bent lines, and then back off a little.