Extracting from AVI

Per1 wrote on 6/18/2007, 10:44 PM

Hi,

What is the best method to extract pieces of an AVI file, without any loss of quality?

I thought of:

1. Importing into Vegas
2. Render as AVI ("Best" quality)

Will this work or will the rendered AVI-file have lower quality/resolution than the original?

Is there other (smarter/better) ways in Vegas to extract parts (as individual files) in Vegas?

The "problems" is that I have a 3-camera clip (3 files), each with 3 footage sections in each, that I have to a) sync (easy) in Vegas, b) and then cut up to pieces to get 9 individual files, where groups of 3 are perfectly in sync.

Like

AVI-file A: clip 1 | clip 2 | clip 3
AVI-file B: clip 1 | clip 2 | clip 3
AVI-file C: clip 1 | clip 2 | clip 3

"|" = marker in time line

to get files A1, A2, A3, B1, ..., C3.

Comments

Spot|DSE wrote on 6/18/2007, 11:13 PM

If the avi is a DV codec AVI, then rendering is lossless if it's cuts-only

rmack350 wrote on 6/18/2007, 11:18 PM

You realize that there are all sorts of AVI files using any one of a large number of codecs?

So, if you are using DV avi files and you then cut and render the portions as a DV avi file (same codec) Vegas will just copy the data to the new file. No loss at all. This may not be the case with every single variation of AVI file, though.

Taking a avi file and adding other audio to it? Hmm. I don't really know if mixing in external audio would affect the video stream. I'd like to think it wouldn't.

Usually you can get a good sense of whether Vegas is doing straight copies of footage by how fast it happens. There's no rendering involved and the preview screen is black during the copy process.

Rob Mack

Per1 wrote on 6/19/2007, 2:16 PM

The AVI is a result from a Capture in Vegas of a DV tape.
Codec - don't know much about this stuff.
Can one assume that DV-tape read with Vegas have the proper Codec?

I imported one of the AVI-files generated by Vegas Capture and took a selection and rendered as AVI. I didn't touch any of the settings in the Render As dialog except specifying Best as option. The preview is all black all the time and it goes fast.

Would one assume that this is loss-less?

If one uses Vegas to read the DV-tapes will the "codec" always be the same or is there any other "link" in the "chain" that decides which codec it will be?

Regards

John_Cline wrote on 6/19/2007, 2:37 PM

Unless you tell Vegas otherwise, it will always use its own DV codec to read and write DV .AVI files. This is the preferred method as the DV codec in Vegas is the best quality DV codec available.

And, yes, if the preview window remains black, then the "render" is absolutely lossless.

John

bStro wrote on 6/19/2007, 6:44 PM

2. Render as AVI ("Best" quality)

Generally speaking, there's no need to use "Best" quality. It's helpful, especially with still images, if you do a lot of zooming within your project (using Pan & Crop or track motion), but otherwise it's not really an improvement over Good.

Rob

Chienworks wrote on 6/19/2007, 9:00 PM

Also, if Vegas is performing a smart render, none of the settings such as "best" are used at all. If they were, Vegas would be re-rendering instead of smart rendering.