Editing Video (what format to use)

[Tolwyn]

I understand target format vs. native (uncompressed) format.

If I'm starting with a DV compressed format, should I output to that format before editing (e.g. after de-interlacing)?

I captured some video using an ADVC-100 to Scenalyzer.
Type 2 I guess.

I want to de-interlace this using Virtual Dub; crop it, pad it to 720x480 for DVD.

I need to save the clip for editing a bit later.

I don't want a loss in quality, but uncompressed is too big.

I tried Panasonic DV, but it said the format was wrong.
?

[Tolwyn]

Update to problem.
I had cropped it beyond a legal range for the Panasonic DV codec. So THAT portion is answered, but I still would like advice/opinions on what "format" to work in that isn't huge like uncompressed.

[Gazorgan]

If your ultimate destination is DVD/SVCD/VCD/CVD (basically a TV), then you want the finaly compiled video to be interlaced. This means if you capture interlaced, leave it interlaced. Going Interlaced-DeInterlaced-Interlaced will only cause problems.

[Tolwyn]

Ok.

That aside, then.
Let's say I was just normalizing audio or HSV tweaking.

On clips 1, 2, and 3.

I need to save these clips for editing later.

What is the preferred "compression" to save these as before final (target) compression using MPEG2?

[Richard_G]

Why are you normalising before editing? Why bother normalising something you may well not use?

You seem to be making life much more difficult than you need to. If you are starting with interlaced DV format avi, edit it in that format, normalise any audio levels and then convert the finished project to (interlaced) mpeg.

[Tolwyn]

You guys are totally missing the forest for the trees.

Let's say, for some valid reason, I was working with some clips before FINAL editing and then FINAL output.

What is the recommended compression format to be working in that isn't as huge as uncompressed DV?

[Tolwyn]

Huffy?
DV (Panasonic)?
DIVX?

It's like in graphics, when you work in JPG and resave to JPG, and you keep doing that, things get worse.

I assume DV is compressed, obviously, as uncompresed RGB is HUUUUGE. Is there a minimal loss format good for editing in?

If I *had* to resave a stream and I was working in DV, what's the least of all evils?

[djmattyb]

What you need to do is take all the raw footage you have. Then do non destructive editing to it using a program like Premiere. When you are all finished then output to DVD compliant MPG2. Why would you want to edit and then output that to a lossless file? I could maybe understand if you were cutting commercials out and you need the hard drive space, but you never said anything about that. If you have DV or HUFFY to begin with, keep saving as that to preserve quality until you finish editing, then output to MPG2. Make sense?

[Tolwyn]

Yes!
That was my question. Opening and resaving to DV is non-destructive, then?

That was my question.

[Cornucopia]

Yes!
That was my question. Opening and resaving to DV is non-destructive, then?

That was my question.

Was that your question?

The answer is:
MOST apps when editing in DV will avoid creating a new generation/re-compressing, during those scenes where all you did was cuts. They will, of course, HAVE to re-compress anything that you did FX, composites, wipes, fades, motion control, even color correction.
BTW, please don't use the term non-destructive here, it is usually meant to refer to recording and editing on computer where a new playlist/sequence can be made without recording OVER and/or losing the original footage. 99.9% of non-linear editors, even the cheap ones, are non-destructive. You're just confusing the situation by using the wrong term.
Again, if you stick with a good pro video app--Premiere, Vegas, Ulead Videostudio/MediaStudio, AVID, FCP, even VirtualDub--you will have no re-compression on DV cuts material. So, just save that stuff either right back to an archive DV tape for later usage, or copy the DV.avi file(s) to optical disc (CDROM, DVDROM), or just leave it on the hard drive if you've got enough room.

IIWY, I wouldn't transcode this to any other type of compression. Keep it as a DV type until the final time to convert to MPEG2 for DVD.

Also, you shouldn't need to normalize and crop/pad until the last edit/conversion. When you say crop/pad, I assume you want your footage to be letterboxed? Also, not everything should be "normalized", gain-changed maybe--hopefully with dithering--but normalizing isn't a cure-all. Sometimes it makes things worse, particularly if you do it early in the process and add audio FX/DSP later on.

And I agree with Gazorgan, don't de-interlace unless you know you're only going to be viewing this on PC or some other non-interlaced monitor.
It's an extra step that doesn't always improve things, and could possibly make them worse.


Ahh, I see. You don't have a DV cam, you're using the ADVC-100!
Ok, then open the DV.avi files in VDub, and save them to multiple DV.avi segments with max size just less than the size appropriate for your optical disc burner.

HTH,
Scott

[FOO]

Every time you save a video in anything other than
raw or lossless compression you have lost some quality.
DV codecs are lossy. Do all your editing and immediately encode
without an intermediate file. That's what frameserving is for.

[Cornucopia]

Every time you save a video in anything other than
raw or lossless compression you have lost some quality.
DV codecs are lossy. Do all your editing and immediately encode
without an intermediate file. That's what frameserving is for.

Pardon me if I'm misunderstanding, but it seems that you are misinterpreting what I said.

The smarter editing apps will take your DV timeline (which obviously is already compressed once) and, when you want to save a new edited file, will **COPY** the segments that are unchanged or simple cuts, and render & re-compress the remaining segments. This is the best that you can get with compressed material.
Also, the nature of DV compression is such that the 1st generation goes through the most loss. Successive generations of <<edit: the same type of>> compression don't make nearly as much of an impact on the quality. In a sense, the entropy has been pre-filtered out. This is why you can go to ~7-9 generations with DV without getting serious degradation. There are some real good sites on the web dealing with this topic in particular. One by Adam Wilt is very good, IIRC.

Of course, it's always best to have the least amount of generational loss (whether analog or digital) and to streamline your steps to as minimal as possible to retain the best quality. So I do agree with your last statement. However, some segments might need to be rendered beforehand to even be previewed, depending on the complexity.

Scott