DF vs NDF

rmack350 wrote on 4/23/2008, 10:28 AM
This is a bit of a vent but also highlights a shortcoming of Vegas.

We shoot a regular hardware teardown session avery month or two. Been doing it for many years and all the editing has been done in M100 and then Premiere. Everything has been shot in DV and ingested from a deck via SDI.

I also use the footage for stills on the web, and I find Vegas to be much easier to work with, provided I reingest all the footage locally over 1394 from my DSR11 deck.

When we shoot, we log all the shots as we go. It makes life much easier later on and Media100 and PPro can import the text file and do a batch capture based on it.

Vegas can also use the log and do a batch capture, using the media logger tool in Veggie Toolkit.

Here's the problem and the gripe. Many DVCam cameras can be set to Drop Frame or Non Drop Frame. Our shooter (also the paycheck signer) has always set the camera (a DSR500) to NDF and the loged timecodes are based on NDF timecode.

So here's the problem. Vegas and Vidcap always assume that the timecode coming in on a DV stream is Drop Frame. It's actually the spec for consumer DV. Now, consumer DV camcorders always start the timecode at 00:00:00;00, but we can and do set the hour numbers on our tapes, so tape 4 starts at 04:00:00;00. Standard practice in the biz.

So, I've got timecode numbers in a log that are based on NDF timecode display, I import them into Vegas (with the ruler set to DF, don't get excited, it's worse if the ruler is set to NDF), then recapture all the offline media and Vidcap captures at the exact timecodes I have in the log, but of course by hour 4 these are pretty far off because Vidcap assumes these are DF times.

If I import the log with the ruler set to NDF, and then recapture offline clips, Vidcap actually adjusts all the timecodes to be farther off, Presumably because it thinks that the numbers must have been DF to begin with.

End result is that as far as I can see there's no way within Vegas to actually get the correct capture, short of converting all the NDF timecodes to DF in the log before I import it.

My needs in this particular process are an afterthought. The main production wants NDF timecode and it works for them, so I can't make them change it. Vegas doesn't have a means of fixing it because they've never accounted for DV footage having NDF timecode (And I think on the tape it's just a frame count, except that we actually do get to start the tapes at the timecode of our choosing). It's not that I really need a frame accurate capture, but by hour 4 I'm far enough out that I can't always find the frames I expect in the clips.

Bah! Kind of wish SCS would think a bit farther ahead with this stuff. Vidcap is anemic. In the mean time, I wish I could find something that could take a log file and convert all the time codes from NDF to DF. So far, all I can find is calculators that would let me manually change one field at a time. Too slow.

I suppose I could try to capture using PPro, but Vegas can't read the timecode when Premier captures the clips. Bah Again!

Rob

Comments

riredale wrote on 4/23/2008, 12:50 PM
Why not just set the camera to DF? NDF exists in a limbo in the sense that it reads like a time, but it's not a time--it's a frame count with weird divisors.

I think there is at least one calculator out there that can take in DF or NDF time and output frame count. From that point on one could work strictly in frame numbers, yes?
johnmeyer wrote on 4/23/2008, 1:01 PM
Building on the idea in the previous post, you can take any set of frame numbers and paste them into the Edit details window in Vegas. If you temporarily set the ruler to frame numbers, you will get markers at the correct locations. You can then use scripts to either cut at these points, or create subclips with the markers embedded, or pretty much anything else. Also, if this doesn't work exactly as you want, you can certainly create a spreadsheet that will make the DF to NDF (or vice versa) conversion and then use the result.

rmack350 wrote on 4/23/2008, 2:26 PM
Ah, but you miss the point. I cannot tell the other person what to do, and a calculator still makes you enter everything into the log file one by one. In the time it would take me to do that i'd have three people tell me to stop screwing around with Vegas and just use the house edit system. So it's a non starter.

Rob
rmack350 wrote on 4/23/2008, 2:32 PM
The conversion would be better but I don't know how to do that in Excel. I'd be more than happy to learn though.

I had thought about capturing whole tapes and trying to import the log data to make regions, but that's not quite as clean as you make it sound. I'd have to get the clips to line up with their timecode locations on the timeline first. And I'm not sure that this gets me a recapturable list...Maybe it would after jumping though a few hoops.

Ideally I need for Vidcap to be able to recapture the clips when I need them again in a year or two.

Rob Mack
rmack350 wrote on 4/23/2008, 3:35 PM
John,

I think in the end I may have gotten caught up in some red herrings. Someone else had trouble with their timecodes going into PPro, and I was seeing footage that didn't match the description in the log, but I just rechecked the very last few clips on tape 4 and they seem right "as-is" so I hope I was just snapping at soap bubbles.

Regardless of whether my problem was real or not, your idea worked more simply that you might have thought.

A text log is a prety simple thing and if you copy the text and paste it into edit details while the timeline ruler is in one mode, change the ruler setting, and then copy everything back out of edit details, you've got a conversion of the timecode. The trick is to figure out what's the right direction to convert, but it seems to do the trick. I just pasted the numbers back into a spreadsheet alongside the reel numbers and it looks doable.

In the end, I don't think I needed to do this after all (my head is still spinning though), but it's a good trick.

Rob
johnmeyer wrote on 4/23/2008, 6:56 PM
In the end, I don't think I needed to do this after all (my head is still spinning though), but it's a good trick.

Glad it provided a way to get the job done. The Edit details view is one of the most amazingly powerful, yet underused features in Vegas. I have some nifty little external utilities that can race through a DV file and find all timecode discontinuities which it puts into a text file. I copy/paste these into Vegas and immediately have scene detection, even if I captured everything into one file.

I have another little utility I wrote that finds all frames less than a certain luma value, and it puts out the frame number. I import that and immediately have markers wherever the video has been faded to black (useful for detecting commercials in video captured off the air).

I have another one that can find dropped frames, and yet another that does optical scene detection. I can go on, but you get the idea. It provides a great way to interface with other programs, just like you're doing.

rmack350 wrote on 4/23/2008, 9:00 PM
I agree. Edit details is very powerful. It's the fastest way to get rid of all your markers, for instance. Also the fastest way to find single frame events. Etc, Etc.

Rob Mack