new filter: Vectorscope/Waveformmonitor

[hanfrunz]

Hello everyone,

here is just a little preview of my next filter:

vectorscope (http://www.geocities.com/hanfrunz/vectorscope_0.1.zip)

The whole package including sources will follow the next days.

hanfrunz

[sh0dan]

I cannot download, even if I copy+paste the URL. :(

[hanfrunz]

mmh i tried, and it works... (if i copy and paste!)
maybe i should look for a new webspace...

hanfrunz

[sh0dan]

Got it (geocities is sometimes a bit vodooish).

Anyway - what am I watching. At first looks is seems like Histogram(mode="classic"), but horizontally - is that completely wrong?

[trevlac]

@hanfrunz

Interesting .....

You decided to mimic the trace. Do you think that is better than only showing the digital points? I did a test with 75% color bars and they hit all of the targets. Good job.

The vector size would be nicer if it was more like a zoom to the center. A full 1024x1024 is a bit hard to work with.

I have a number of technical questions, just to see how you did certain things. Will you provide source when you are closer?

..........

I made a vectorscope/wfm for vdub. I posted an avisynth usage thread a few weeks back. Really helped me learn about color.

http://forum.doom9.org/showthread.php?s=&threadid=72634&highlight=vectorscope

Here (http://trevlac.us/colorCorrection/clrtools.ace) is the source.

[hanfrunz]

Hi trevlac,

i wanted to simulate a real vectorscope, maybe i will add an option to turn the line-drawing of (costs a lot of cpu time...) I'm just thinking of coding a gui-based scope, which pops up if you play a video (if it's in the filterchain) I am just experimenting with OpenGL to draw the lines, but it is too slow...

If have cleaned up the code i will upload it. What questions do you have?

hanfrunz

[trevlac]

Hi,

A gui based one sounds good. Real usefulness is all about how you can view and tweak. I never tried to do the line drawing, because I was afraid it would be too slow.

Some questions ... you don't really have to answer. I just wanted to compare notes. I can do that with the source.

- Calc you used to scale Cb and Cr. In their digital form, they never hit the targets. I had to scale to 'analog' YUV values. Made sense after I did it (seeing that an analog scope uses a YUV signal), but I was doing a bit of guessing.

- Do you change the intensity if you draw in the same spot often

- Did you find a reference on the vector target placement?

- Have you thought about some more wfm options like a full composite signal?



I think this stuff is great. I'm not sure why more people don't talk about using scopes to analyze the signal. I'm a bit of a novice, but I've found it very helpful to see what a certain tweak does to a chart (vs by eye).

[hanfrunz]

i wanted to emulate a tektronix wfm601, this a digital scope. So there is no scaling at all. I just take the pure YUY2-data and then draw the lines. The line-drawing function, works like that: calculate next point to draw, check the brightness, add 2 (i think i used 2...), paint. So i a line is drawn often it gets brighter and brighter...
The markers: i don't know if the size is in any spec. i just made it looking good to me. The values of an EBU colorbar are defined in Rec.601 for example. (use google). Hopefully a lot of WFM functions will follow. I started a Diamond Display, but there is a tektronix-copyright, so i stopped developing this...

hanfrunz

[rfmmars]

I have tried many times to download but link is dead to file.

richard

[trevlac]

@Richard

I had to cut the link, past it into a new browser window, and try a few times to get it to work.

@hanfrunz

I looked at the vectorscope a little closer. I don't think you have the targets in the 'standard' spots. Red should be at the top. Here is a link about scopes. It shows some 'specs' about the scale on a scope.

http://www.rcc.ryerson.ca/rta/tvtech/the_book/chapter07/main.html


@sh0dan

If I may for hanfrunz, the WFM is basically the same as histogram clasic (which is not actually a histogram afaik ). Quite useful in adjusting levels.

The vectorscope, on the other hand, is an invaluable tool for adjusting UV.

Forgive me if this is basic stuff for you. I'm just learning the topic and like to talk about it. :D

[stickboy]

LoadPlugin fails when I try to load the DLL. Are there any dependencies?

(No, I don't think my problem is related to the avisynth.cpp changes I suggested (http://forum.doom9.org/showthread.php?s=&threadid=73520); I can't get it to load with the 2004-03-18 avisynth.dll build either.)

[timecop]

you need msvcr70.dll
(or he needs to recompile the plugin linking crt in statically)