Color Settings in Mainconcept for HDV to DVD

TCProdStudio wrote on 8/12/2010, 12:46 AM
Hello,
I'd like to perform a Rec.709 to Rec.601 color space conversion when rendering an HDV timeline to MPEG2 with the built-in Mainconcept encoder (DVD Architect PAL video stream template): what settings should be used in the Advanced Video tab for the following parameters:
Color primaries, Transfer, Matrix coefficients and Sampling format? I think the template defaults would not perform the conversion.
This conversion is required in order to get accurate colors on DVD from an HDV source, and it is provided by some standalone encoders as a filter that can be applied to the source.

Comments

TCProdStudio wrote on 8/12/2010, 5:49 AM
Thanks for pointing me to these detailed info.
My point is actually simpler: my small tests showed the following:
HDV source (m2t) -> edit in VMS9 -> render as MPEG2 (DVD-A template) with no access to custom settings ==> colors on the DVD are inaccurate (more red), both an a 32" CRT and a 50" Plasma.
HDV source (m2t) -> edit in VMS9 -> resize through Avisynth -> encode to MPEG2 with Procoder with a 709->601 colorspace conversion filter ==> colors correspond to the source.
Base for the comparison is the original footage on the camera which is connected over IEEE1394 to the CRT TV (via a DVD recorder) and directly over HDMI to the Plasma.

So now that I have the possibility to tweak the Mainconcept settings within VMS10, I was wondering if this conversion could be made there, without leaving Vegas.
I assume the "Advanced video" settings refer to the rendering target, question is whether the source is (implicitly) interpreted correctly by the plugin.

What I could do is take my one minute test HDV timeline and try rendering with the different options for Transfer and Matrix coefficients...
GlennChan wrote on 8/14/2010, 10:43 AM
This may be a situation where you are trying to make two wrongs equal a right?

Vegas will go from Rec. 709 Y'CbCr --> RGB (either computer RGB or studio RGB) --> Rec. 601 Y'CbCr. The simple answer is... this is correct (as long as the output codec is expecting and receiving the right kind of RGB levels... either computer or studio). You will not have the problem with a mix-up of the different luma co-efficients between 709 and 601.

You don't need to do anything special other than making sure that your levels are correct (a manual process; see the levels article linked to in this thread).

If you want too much detail, see http://www.glennchan.info/articles/technical/hd-versus-sd-color-space/hd-versus-sd-color-space.htm

2- If you are seeing a difference in colors, then maybe some of your equipment is not converting HD->SD correctly, or...
Vegas' preview can sometimes be wrong because of the levels issues. You need to manually deal with that.
musicvid10 wrote on 8/14/2010, 11:16 AM
Thank you Glenn!
Your clear explanation is very much appreciated.

TCProdStudio wrote on 8/19/2010, 2:34 AM
Thank you. I understand that Vegas is supposed to correctly do the color space conversion 709->601 for me, I don't need to amend Mainconcept's settings.
However, I do get a reddish color shift on the MPEG2 output that I don't have when rendering the same timeline with an external encoder in which a color space converion filter is applied.
I don't do any CC at all. The equipment I use is obviously the same for both methods, and the colors I observe on the source HDV footage (on both CRT and Plasma) seem very natural.

Could it help if I applied a CC filter "Computer RGB to Studio RGB" to the HDV source before rendering to MPEG-2 ?