Spot, Just curious about HDlink and Vegas conversion.

epirb wrote on 2/6/2005, 9:43 AM
Just wondering what the difference is/would be between having HD link do the on the fly conversion to the intermeadiary avi.or having Vegas render the M2t file from the timeline. I already know that the time factor is night and day, but is there a diff in quality or the color space issue discussed in the other post.
Think 2 ways;
Rendering M2t file on timeline to new track, with project properties set to the HDV 1080 60i and render set the same.

Or lets say you want to do the downconversion to DV widescreen in Vegas.
Any advantage to rendering the M2t file from the T/L to dv widescreen directly instead of the inter. Avi?
then editing with the dv file?

reason I 'm asking I haven't finished building my new PC yet and the old one has a tendency to drop frames/ pixelate the inter. avi on the fly. but just capturing the M2t file then converting in HD link after works fine.
Besides for stuff I plan on just outputing to dv for right now, the M2t files take up much less space then the inter., and I dont mind the wait of Vegas rendering the M2t.

Comments

Spot|DSE wrote on 2/6/2005, 10:03 AM
Always let Cineform do the conversion. I do the conversion on the fly, but keep the M2T file.
The reason you want Cineform to do the conversion is that they've developed a proprietary mapping for the ITU 601 vs ITU 709 change.
Now, if you want to downconvert, I've not tested the DV vs M2T, because in that case, you're going to a colorspace that is supposed to end up as ITU709. Mark may have done this already, I'll play with it. You can always import and render color bars, measure them against the M2T file.
But realize you're shifting color if you let Vegas render the M2T to the avi for you.
Hulk wrote on 2/6/2005, 11:07 AM
I agree 100%. Let Cineform do the conversion and save the mt2 files for archiving purposes. With the veg project file and the mt2 files you can alway bring the project back for future tweaking.

I can discern no difference in final output between mt2 and CFHD when using them in the timeline. And the CFHD gets the 709 color conversion right without any additional filtering so just by having to apply a color filter you're not going to be able to do any smartrendering of the timeline. So if you're going to be rerendering either way you might as well get speed and colorspace conversion benefits of the CFHD.

As far as downconverting I'm not sure about the best workflow. Spot is correct in saying that some testing is in order. Them me think about that one...

- Mark
Hulk wrote on 2/6/2005, 11:51 AM
Okay, more info.

709 (HDV) and 601 (DV) colorspace is not an issue when working in the RGB domain (Vegas).

The only thing you need to worry about when mixing DV and Sony encoded CFHD events in the timeline is the dynamic range cgRBG/vgRGB issue.

Be sure to use the colorblend preset on the VASST site for this dynamic range issue. In the case of mixing DV and CFHD events, the color blend preset should only be applied to the CFHD events (or tracks) that contain only CFHD events, NOT to the preview window.
epirb wrote on 2/6/2005, 1:24 PM
Thanks, but what I noticed I imported the mt2 file on the t/l added time code burn. Placed the CFHD avi on a track above the same lined them up.
It seemed to me that the m2t file's colors were less saturated, both on my computer monitor of the preview window and then output to a std ntsc monitor composite out. but I do agree, its nice to save the m2t files archive those for later use then use hd link to CFHD them when needed.
Hulk wrote on 2/6/2005, 6:40 PM
Did you apply the mt2 color blend preset from the VASST site to the mt2 files? Vegas 5 is currently reading the ITU709 colorspace of mt2 files as 601. The colorblend preset fixes that.

Yes, mt2 looks less saturated than CFHD without correction.

- Mark