Lossless format for saving project renders

irascian · #1 (**permalink**) 10-11-2008, 09:03 AM

Here's a dumb question, but one I've really been struggling with.

I bring my video in from a PMW-EX1, exported from clip browser as .mxf files, presumably the hightest quality I can get from the camera. But I want to render out that video with overlays etc without losing any quality (ie lossless compression). I will do final lossy compression when I bring multiple renders together (eg I often want to edit a title sequence in a separate project from the main file).

But THERE IS NO "RENDER AS .MXF" in Sony Vegas Pro 8.0c. So what format should I be using to ensure I don't lose quality?

No matter what format I try I seem to lose quality every time I render - presumably because compression is being applied every time I render something out. What format in Sony Vegas Pro 7.0 should I select to ensure I keep the same original .mxf quality across the interim renders I make to add green screen/titles/animations etc?

Mark W · #2 (**permalink**) 10-11-2008, 12:07 PM

Hmm, an intersesting question.

First let me take on step back and look at codec loss from my own experiments / expiriences.

When I started editing DV I thought it was obvious that repeated trips through the dv codec would ruin video - but it does not. I just repeated something i tried years ago. Below are 2 screen grabs, the first is after only one render, the next is the same clip reimported and re rendered ten times, ten trips through the codec, ten recompressions - and it is exactly the same - no loss!

Next pics are vastly cropped to show how tiny the loss is, you really need to flick between them in the editor to see a very slight blurring of detail - consequently I dont worry and just use dv for re imports. Codec used is the panasomic DV codec, I prefer this to the mainconcept dv codec - mainconcept gives soft results to my eye and it is very slow to render.

Now to your files. Slightly more complicated. Your camera produces data that is less compressed than HDV so I can understand your wish not to degrade the video untill the final render.

My understanding is that the sony yuv codec is designed for just your situation. It renders to very large files but is claimed to be 'lossless'. I havent tested this but given the tiny losses shown in the pics I suspect that yuv will perform similarly or better.

The ' huff ' codec also claims to be lossless but on my system it is clunky to edit on and I cant see it's benefit.