Color space problem with Vegas Video 5.0d and Connect HD

mdopp wrote on 1/7/2005, 7:44 AM

I have tested the new HDV-templates of Vegas Video 5.0d and the new option to play back video to the Sony HDR-FX1 camcorder via Connect HD.
I am pretty sure there is an error in Connect HD that messes up the color space when writing back to the camera !

When transferring the m2t file from the camera to an avi Connect HD will ensure the proper colorspace transformation from ITU 709 to ITU 601.

When rendering this AVI from the Vegas timeline (in ITU 601 colorspace) to HD-mpg (for example using the HD1080-60i template) the colorspace should remain in 601. That's what Connect HD does.

However when rendering the Vegas timeline to HDV-m2t (for example using the new HDV1080-60i template) the colorspace should be 709 since that is what the camera expects. But Connect HD still converts the colorspace to 601!
If you now transfer this file back to the camera and reload it via Connect HD the 709 to 601 conversion is applied a second time resulting in totally wrong colors.

Anybody else found this ?
Martin

Comments

SonyDennis wrote on 1/7/2005, 8:07 AM

Martin:

We're aware of this issue, and we're working on a knowledgebase article about it.

Basically, there are two issues, and both can be fixed with existing filters, and will be addressed fully in a future version of Vegas. Issue one is that HDV uses Rec. 709 color space, but our MPEG-2 plug-in is fixed at Rec. 601. The second issue is that the Connect HD CFHD codec stretches the YUV from the MPEG into "computer RGB" (0-255) instead of leaving it at "video RGB" (16-235) like Vegas prefers. Our recommendation in the knowledgebase article will most likely be to edit in the computer RGB space, and apply a filter on your final render output that adjusts the levels in such a way that it fixes both issues. Likewise, if you wish to use captured .m2t files on the timeline, we can profile a filter that adjusts them as if they were decoded using Rec. 709 and optionally shifts the levels too. While we don't want to treat any colorspace issues as "minor" we thought it was important get the rendering ability in the hands of folks with cameras.

///d@

Wolfgang S. wrote on 1/9/2005, 2:27 AM

Is it correct that the 709 color space is applied for NTSC only in hDV, while for PAL you have to stick to the 601 color space?

mdopp wrote on 1/10/2005, 1:08 PM

The 709 color space is also used for 1080/50i HDV and in the HDR-FX1E camera. I don't believe there is such a thing as "PAL HD" since PAL always refers to Standard Definition (720x576).
Martin

mjroddy wrote on 1/10/2005, 3:02 PM

Where can I read abou this "601 vs. 709 colour space?" I'm trying to understand HDV and these terms are new to me.

Coursedesign wrote on 1/10/2005, 8:41 PM

This isn't bad:

http://www.videotek.com/app58.htm