Vegas in RGB and vuy

CowDoc wrote on 6/20/2006, 12:05 AM

I recently had some home movies converted to Quicktime .mov files using a wetgate Rank system. They used a 4:2:2, 8 bit BlackMagic 2vuy codec. I would like to archive the individual movies. So, I need to split the 1.5 hour compilation back into short clips. Mechanically, this is an easy task. However there is a hidden dilema.

Vegas operates in RGB color space. The movie is in vuy color space. Using a vectorscope, I verified that just splitting the movie and resaving the shorter clip resulted in a color shift. The problem is the vuy to RGB to vuy conversion. RGB has a smaller color space than vuy. Here's a link that explains the problem.

http://developer.apple.com/quicktime/icefloe/dispatch027.html

I read that Vegas only operates in RGB when you add effects. If you just split and save a video, it should stay in vuy space. However, that doesn't appear to be the case. Would someone please recommend a way to trim the movie into short clips without color loss?

Once I begin editing, naturally I will be stuck with RGB limitations. However I would prefer to archive the backups before any loss.

I checked VirtualDub, but it also operates in RGB. I am currently looking at AviSynth as it claims to operate in vuy. Unfortunately, it's not user friendly. I'm still hoping for a Vegas solution.

Thanks,
Barry

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CowDoc wrote on 6/21/2006, 4:40 PM

I've already posted on the Apple Quicktime forum. I'll also check out the BMD forum. Thanks for the suggestions. As you said, I'm not going to lose any sleep over it, but it seems plain wrong that you have to lose information (useful of not) when working with digital files.

Barry

CowDoc wrote on 6/22/2006, 12:03 AM

For everyone's information ( since this was such a hot topic.... not), yes if you split a Quicktime .mov (2vuy) file using Quicktime Pro, the split is lossless and there is no color shift. I verified this by using the vectorscope, waveform, RGB and histogram tools from Vegas, looking at color bar videos, before and after splitting. They were identical.

So it can be done and quite easily. However, beware splitting vuy color space files with any program other than Quicktime Pro (or possible Final Cut). There will be a color shift with virtually any other program.

Thanks for all the suggestions everyone. I'm now a happy camper.

Barry