how to chroma correct NTSC DV converted to YUY2?

[FredThompson]

When I use AviSynth 2.5.2 to convert a DV source to YUY2, the chroma is getting more saturated. Blacks get blacker, which is fine, but all the colors seem to be denser.

Is this a colorspace difference and something to be expected? If so, is there a somewhat standard correction which can be applied to get the saturation close to the original?

[Si]

What colourspace is your source being delivered as?

Give us a sample of it (and your script) to play with.

regards
Simon

[Mug Funky]

your decoder is changing the luma range from 16-235 to 0-255, and so the contrast is going up.

try using the sony or panasonic DV codecs, or the pinnacle dv25 codec. (the latter is slow as hell, but the best quality IMHO)

a script would indeed help.

[FredThompson]

There's no reason to see the source script. When I saw the problem, I started commenting out source and was left with only the conversion command.

Could be the codec, maybe. I'm using MainConept's codec. The demo (which a lot of people run hacked then malign) is only 2.0.4 but the proper full version is 2.3.1 or something like that. The current vision has a decoder setting to limit to 16-235.

Given the source is S-VHS from broadcast, it's certainly 16-235.

However, if I open the AVI file with VirtualDub, it yields 16-235.

Opening the AVS with another instance of VirtualDub yields 0-255.

Same codec, same settings.

Yes, I can put together a couple of frames. Can't happen until tonight. Still, if this were a codec issue, why would it behave differently for AviSynth than VirtualDub?

[stickboy]

Originally posted by FredThompson
Still, if this were a codec issue, why would it behave differently for AviSynth than VirtualDub?Isn't this the same problem as the typical luma range problems with MJPEG codecs? (i.e., the decompressor outputs a different luma ranges for RGB32 than for YUY2)

[FredThompson]

Oh, I didn't think of that. Thanks, I'll look into it.

[FredThompson]

You are correct. MainConcept codec 2.3.1 includes decoder options to limit RGB to 16-235 and YUV to ITU601r. The RGB setting was enabled but not the YUV setting. That cleared it up. Thanks.