Calibrating Color before Capture

[signal]

I've used a few tools for DV that have "scopes" for doing calibration with colorbars and other test patterns (DVRack and Matrox RTX in Premiere PRO).

It has come in handy when using an analog to DV converter (such as a Canopus ADVC110) in that I can play color bars on different LD players or VCRs and get the color tweaked to "standard" settings before doing the capture.

With Analog Capture Cards, do you folks normally just eyeball color settings or are there other tools to help make sure things are calibrated ahead of time (short of a real vector scope and color processing hardware)?

[signal]

I tried trial versions of Vegas and Ulead and although they claim they have vectorscopes, it's either only with DV or on the Timeline and not during a capture or preview of capture.

DVRack (now being assimilated by the Adobe Borg) would be perfect except only works with DV.

[Mug Funky]

you could give ffdshow's avisynth support a shot - set ffdshow to be your directshow DV codec, then in ffdshow config put "histogram()" in the avisynth section and enable avisynth processing.

this will give you the choice of a colour histogram (like what photoshop, gimp, etc give with their level adjustment), a waveform monitor (per-line luma and chroma intensities - quite useful), or a vectorscope (to check white balance - keep the bigger blotches in the centre to white balance. also if you have colourbars you can use the scope to line the colours up nicely).

you can even stack them next to each other, though if it changes the frame size your capture program or ffdshow will probably crap themselves.

[edit]

btw, this will work for any type of uncompressed/compressed video that ffdshow can process - which is most of them :)

[signal]

Hmm.. maybe I'm missing something..

I'm not working with an AVI but want to tie in what the capture card is getting directly to the vectorscope plugin.

Sounds like the description above would be for something that's already been captured?

There was a product called VScope (not to be confused with the plugin) that might explain things better:

http://www.digilava.com/vscope.htm

Problem is it isn't downloadable anymore and folks there aren't answering their email. I know it's old (circa 1999) and only works with VFW so as far as compatibility and accuracy goes I'd need to try it.

[FlimsyFeet]

I wonder, could you turn on RGB filtering for capturing with VirtualDub and use Trevlac's colortools plugin during preview?

[signal]

Ah!! There ya go. That does work!
Thanks FlimsyFeet!

With this BT8x8 based card and BTWDM drivers:

1. Use Preview mode (not much choice around that)
2. Must have acceleration mode on (using both fields)
3. Make sure RGB Filtering is selected
4. Add Trevlac's colortools filter
5. Configure the filter (don't use passthru)

Now you have the realtime graphs you can use to check your inputs.

How accurate the results are remain to be seen.
Will be doing some tests this week.