New calibration disc - Page 13

OK, I'll consider keeping them if someone can give me a short, simple (As possible) write up on what one would use these for. I'm the one who will get the questions. I don't believe they fit the spirit of the disc. What would be nice is a gamma test pattern, becasue that *is* something you can adjust, but I don't know how to make one. My instruments tell me the gamma when I run a grayscale.

Its not that I don't appreciate having the freq. patterns, I do, but if they don't do something specific, explainable, and useful (without a oscope)... they are on the chopping block...

FYI, Here's the description from the pattern author (drmpeg): They are "frequency burst patterns".

In order of presentation on beta 4.x:
#1
alternating white/black pixels with the first
bar 4 black/ 4 white pixels, second bar 3 black/3 white,
third bar 2 black/ 2 white and the last bar 1 black/ 1 white.
In other words, they are 1.6875 MHz, 2.25 MHz, 3.375
and 6.75 MHz resolution "patches". I believe the 6.75 MHz
"patch" can be used for 1:1 pixel testing, but I'm not 100%
sure.

#2
sine waves of frequency (in this arrangement)
0.5 MHz, 1.0 MHz, 1.5 MHz, 2.0 MHz
2.5 MHz, 2.75 MHz, 3.0 MHz, 3.25 MHz,
3.5 MHZ, 3.75 MHz, 4.0 MHz, 4.2 MHz
4.4 MHz, 5.0 MHz, 5.5 MHz, 6.0 MHz
The higher frequency sine waves have lot's of sampling
phase error, which is unavoidable. On Avia Pro, they
use frequencies they are integer divisors of 13.5 MHz
to avoid the problem. I think they are called "Nyquist"
bursts..."

S

I haven't read it but this thread:

http://www.avsforum.com/avs-vb/showt...&&#post2852401

looks to be along the lines of something to get you going.

When looking for instructions, functionally speaking my disc is closer to DVE that Avia becasue it has "blacker than black" in it's patterns, and thus has similar gray ramps. They are using DVE in that thread and the guy posted screenshots I think FWIW. I know DVE has some instructions of sorts on their website, look under the DVHS tape version section. Their website is more difficult to find stuff on than their DVD , but it's there.

Thanks Ron, that's interesting stuff. I didn't think you'd care one way or the other if the frequencey patterns were on the caldisc. Your use of the patterns sort of reinforces what I was saying though, for a normal calibrator, not looking with scopes and MATLAB, the patterns are just cool to look at, but provide limited information from just viewing.

CHeers, Scott

Since you ask, this is what I meant:
http://www.videoessentials.com/D_Theater_signals.php
also short snippet:
http://www.videoessentials.com/resou...alibration.php

It is a type on teh opening screen. If you go the right zip file, then you are good. My apologies for not paying better attention to those little things, I've concentrated on the patterns without the corresponding main window update for beta 4. Hope to get beta 5 out soon then wrap it up with the real thing ver 1.0.

I am, but I've been out of town since yesterday afternoon, just getting back. I have a few pending, I'll get beta accounts setup for them and get them out first thing tomorrow morning.

All:

Beta 4.3 is avail for download on the site (www.calibrate.tv). The original 4.2 was really meant to test navigation. Now, 4.3 represents wrapping up and finishing polishing all video patterns including those done through the 4.2x versions. All patterns have now been re-encoded with no mpeg filtering, no offset, etc. All color-critical images have been redesigned so color boundaries fall on 8x8 blocks. All of this was to minimize mpeg artifacts. This re-encode should have cleared up any issues with the freq. patterns, maybe Vern and/or Ron can have a look for us if they have time. I've re-encoded as the pattern author (drmpeg) advised. I also flagged then as 4:3 native DVD aspect to ensure no artifacts were introduced from stretching them to 16:9. Some player don't auto-obey the 4:3/16:9 flag, some do. It might not make any difference, I haven't tested it yet.

There is still no sound, do not adjust your set .

Whats left that's planned for 1.0 (non beta):

- add sound track to auto-gray sequence
- add sound track to lip-sync pattern and test. If I have any trouble syncing the audio, I'll remove the pattern, but I'm not expecting that to happen.
- finalize menus, remove or not the freq. patterns.
- add a 30-80, and possibly a 20-80 "rocking" gray window pattern sequence

Finally, add my edits to Claus's very well done "manual" and hopefully persuade Claus to edit it and help make it look as good as before I "worked on it" . A couple iterations between us and that will be done.

Thanks for everyone's support and patience. Sorry it's taking much longer than originally expected.

Let me know if anyone sees any new issues on Beta 4.3.

Best, Scott

The 4.3 upload failed last night, it is there now.

OK, but what can the freq patterns be used for?

Hmmm, I'll try it but I think that might be the last pattern I'd use for that. It being kinda fuzzy by design to begin with.

If we can find one thing that they can be used to adjust, I'll leave them. If we can't find anything, I don't know. The theme of the disc is "only what's needed to calibrate" (without a scope), bare bones simple. If the freq patterns are helpful for sharpeness then that's good for me. I'll try to confirm, but if anyone else can, that would be great. Thanks for pointing out that possibility Chris.