Cineform Decoding Colorspace

Streamworks Audio wrote on 3/13/2010, 11:09 PM
Anybody know why the videos I encode in a third party app with my Cineform codec (from Neo Scene - but not encoded in Neo Scene) when opened in Vegas have a Computer color space - i.e Luma levels of 0-255 instead of the 16-235 levels from the original source?

When I encode my source in Virtual Dub with my Black Magic MJPEG codec and open that in Vegas the levels are 16-235 as should be (same as the source) however if I encode the same source in Virtual Dub with my Cine Form codec - when opened in Vegas the levels are 0-255. Not a huge deal but that means I need to correct the levels again before encoded to the final AVC file (as the levels need to be 16-235)

Is virtual dub able to use a codec that is more than 8bits and that the cineform codec is using more than 8bits and thus the diff. in levels in Vegas?

Curious....


Chris

Comments

jabloomf1230 wrote on 3/14/2010, 10:59 AM
See if this thread helps:

http://www.sonycreativesoftware.com/forums/ShowMessage.asp?ForumID=4&MessageID=689155
Streamworks Audio wrote on 3/14/2010, 2:08 PM
Thanks.... smae idea but he seems to be having the reverse problem. My Source is 16-235 and encoding in Virtual Dub - when that avi file is brought into Vegas it decodes it as 0-255.

Weird...

Chris
GlennChan wrote on 3/14/2010, 2:08 PM
Maybe it is because:

Your third party app is decoding the video to computer RGB levels.... 0-255 (RGB).
The Cineform codec is expecting studio RGB levels... 16-235 (RGB). Because you didn't feed it studio RGB levels, it won't decode to studio RGB levels.
Maybe the Blackmagic codec expects computer RGB levels in Virtualdub but will decode to studio RGB in Vegas.

I'm not 100% familiar with your third party application so this may or may not be the case.
Streamworks Audio wrote on 3/14/2010, 2:38 PM
Thanks Glen,

The 3rd party app is Virtual Dub - the source is AVCHD (16-235) which is loaded into a Avisynth script and the decoder being used for that is FFDShow... the script is loaded into Virtual Dub - from there I do two tests... one where I encode a passage using the Cineform codec and another where I encode the same passage with the Black Magic 8bit MJPEG codec. I load both avi files into Vegas and the Cineform one decodes to 0-255 and the MJPEG codec to 16-235.

So maybe you are right - maybe Virtual Dub is sending 0-255 to the encoders... Cinefor decodes in Vegas whatever was encoded... where as the MJPEG codec decodes to 16-235

Can't they (codecs) all just get along? ;-)
David Newman wrote on 3/14/2010, 9:32 PM
The CineForm codec control panel allows you to set whether source RGB is interpreted as studio RGB (16-235) or computer RGB (0 - 255.)
Laurence wrote on 3/15/2010, 2:05 PM
...like Glen said. Yeah it sounds like you've got the Cineform codec control panel set to decode from sRGB to cRGB levels and when it gets cRGB levels in the first place it is doing an extra unneeded compensation.
Streamworks Audio wrote on 3/15/2010, 2:34 PM
I have tried every possible configuration in the Control Panel... same results....
GlennChan wrote on 3/16/2010, 10:15 PM
Maybe you're in the wrong control panel? Or it is not enabled for your version of Cineform. I don't have Cineform on my system ATM so I don't know for sure.

But I remember that one version of Cineform definitely had that setting, and it worked.
Laurence wrote on 3/17/2010, 12:18 AM
You may be playing around with a second generation render that already has the color space encoded wrong into the actual video. That would explain why the control panel doesn't seem to be working.
GlennChan wrote on 3/17/2010, 10:28 PM
The setting affects the decoding. I can't remember if it affects the encoding.
Streamworks Audio wrote on 3/18/2010, 9:36 AM
There is a check box for each Encoding and Decoding for each option in the encoder (I am not at that machine at the moment so I can't remember the exact working for the RGB option... I will get that later). I think I tried both options when encoding... I will play around with it later.

Chris
jabloomf1230 wrote on 3/18/2010, 10:08 AM
Keep in mind that some versions of Cineform come with both a VFW and a DirectShow codec. There are both 32 bit and 64 bit versions of the VFW flavor. Each has it's own property dialog, as I recall.
Streamworks Audio wrote on 3/18/2010, 10:11 AM
Might have something there.... yeah I am encoding with the 32bit codec (in a 32bit app) and using 64bit Vegas (64bit Cineform codec to decode).

Chris
Streamworks Audio wrote on 3/18/2010, 11:52 AM
Tried all possible combonations of the 'Use Video Systems RGB' in both the 32bit and 64bit codec properties windows... still the same.

One more thing I noticed though... if I encode to Uncompressed RGB24 - that file too in Vegas opens with 0-255 colorspace.... while encoding to Uncompressed YUV2 when opened in Vegas opens to 16-235

Even with the colordepth set to YUV2 before encoding from Virtual Dub with Cineform.... still opens in Vegas as 0-255

Weird...