Generation loss rendering to DV codec from Vegas? at DVinfo.net

Yang Wen · December 1st, 2009, 03:25 PM

I have an already rendered DV AVI file that's 2+ hours long. I need to change a couple of scenes in this 2 hour clip. I was wondering if I can swap out the scenes on the finished AVI file and re-render it to another AVI with minimum generation loss? Would Vegas be intelligent enough to not re-render parts of the AVI that has not been modified?

I've seen the message "No re-compression required" once in a while when the original clip had no effects applied to it.. I'm hoping this can confirm my theory.

Mike Kujbida · December 1st, 2009, 04:12 PM

You are correct in your thinking.
The only time Vegas needs to recompress (re-render) a clip is when it has been changed in some way, shape or form.
If nothing was done to it, then it's untouched.
A number of years ago, one Vegas user did a test that went to 100 generations.
The 100th generation was virtually identical to the original clip so we know the encoder in Vegas is one of, if not the best, DV encoder there is.

Craig Parkes · December 1st, 2009, 06:27 PM

Mike - it's not the quality of the encoder, it's just that it's not re-encoding to DV codec when it doesn't have to. Most NLE's will do the exact same thing.

Yang Wen · December 1st, 2009, 09:40 PM

Cool thanks guys!

John Cline · December 2nd, 2009, 05:08 PM

If nothing has changed, then it just copies the data from one file to the other. This is a completely lossless procedure, only the portions of the program that have been modified from the original will actually be encoded. For those portions which do get reencoded, extensive testing has proven that the Sony DV codec is the best DV codec there is and the loss is extremely minimal.

December 1st, 2009, 03:25 PM	#1
Yang Wen Major Player Join Date: May 2003 Location: Chicago, IL Posts: 991	Generation loss rendering to DV codec from Vegas? I have an already rendered DV AVI file that's 2+ hours long. I need to change a couple of scenes in this 2 hour clip. I was wondering if I can swap out the scenes on the finished AVI file and re-render it to another AVI with minimum generation loss? Would Vegas be intelligent enough to not re-render parts of the AVI that has not been modified? I've seen the message "No re-compression required" once in a while when the original clip had no effects applied to it.. I'm hoping this can confirm my theory.

December 1st, 2009, 06:27 PM	#3
Craig Parkes Major Player Join Date: Dec 2006 Location: Auckland, New Zealand Posts: 444	Mike - it's not the quality of the encoder, it's just that it's not re-encoding to DV codec when it doesn't have to. Most NLE's will do the exact same thing. __________________ www.afterglow.co.nz

December 1st, 2009, 04:12 PM	#2
Mike Kujbida Inner Circle Join Date: May 2005 Location: Windsor, ON Canada Posts: 2,770	You are correct in your thinking. The only time Vegas needs to recompress (re-render) a clip is when it has been changed in some way, shape or form. If nothing was done to it, then it's untouched. A number of years ago, one Vegas user did a test that went to 100 generations. The 100th generation was virtually identical to the original clip so we know the encoder in Vegas is one of, if not the best, DV encoder there is.

December 1st, 2009, 09:40 PM	#4
Yang Wen Major Player Join Date: May 2003 Location: Chicago, IL Posts: 991	Cool thanks guys!

December 2nd, 2009, 05:08 PM	#5
John Cline Major Player Join Date: Oct 2002 Location: Albuquerque, New Mexico USA Posts: 333	If nothing has changed, then it just copies the data from one file to the other. This is a completely lossless procedure, only the portions of the program that have been modified from the original will actually be encoded. For those portions which do get reencoded, extensive testing has proven that the Sony DV codec is the best DV codec there is and the loss is extremely minimal.