Editing Offline RT Non-drop and Drop frame sources – Will this be a problem?

[Mark Raudonis]

G-Video,

The “drop/non-drop” issue is perhaps the most confusing technical nuance of professional video. Add to that the differing frame rates that come with HD and you have a recipe for total flummoxation (my word). So, don’t worry about not quite understanding this. I’ll try to answer your questions.

First, the SMPTE engineers that created “drop frame” timecode should NEVER have named it “drop FRAME”. They should have called it “drop NUMBER”, ’cause that what it does. Drop frame has EXACTLY the same number of frames as Non-drop… it’s only the counting system that’s different. Go to wikipedia and do a search for “drop frame” timecode and you’ll get a pretty good explanation of the difference.

1. Yes, you can use both “flavors” as source material for your sequence. Once a clip is dropped into the seqence, the timecode is irrelevent. The sequence timecode take priority and that’s what carries forward. Your choice for timecode flavor for your sequence depends on your delivery requirements. Most broadcasters specify “Drop frame” code. I’d suggest using that.

3. Again, your source code doesn’t matter. The sequence will read it no matter what. Where many people get tripped up is when they have to generate an EDL of their sequence for uprezzing. If you’re not careful, an EDL can “miss” the designation for drop or nondrop and that WILL screw you up. However, if you aren’t generating an EDL and you’re only working in a timeline, don’t worry about it.
Good luck.
Mark

[G-video]

Hi Mark,

Thanks for taking the time to help me out. I think I understand the difference between “dropping frames” and “drop frame” timecode, so that’s not where my confusion is. I just wanted to make sure I could use both “non-drop” and “drop” frame timecode together when editing and if I could, would I need to take any special steps to insure against any future issues or problems.

You’ve answered that for me. I can use both “flavors” as source material and edit in a “drop” sequence no problem!

But, you said [Mark Raudonis] “3. Again, your source code doesn’t matter. The sequence will read it no matter what. Where many people get tripped up is when they have to generate an EDL of their sequence for uprezzing. If you’re not careful, an EDL can “miss” the designation for drop or nondrop and that WILL screw you up. However, if you aren’t generating an EDL and you’re only working in a timeline, don’t worry about it.”

Ok, so I am editing offlineRT, so I will need to generate an EDL and uprez. So what should I be careful of when doing this? How can an EDL “miss” the designation for drop or nondrop? How can I prevent this?

Thanks so much for your help!

[Mark Raudonis]

[G-Video] “Ok, so I am editing offlineRT, so I will need to generate an EDL and uprez. So what should I be careful of when doing this? How can an EDL “miss” the designation for drop or nondrop? How can I prevent this?”

Well, exactly how, I couldn’t say ’cause there are many ways, but it does happen. For example, your master tapes were prepared with bars and tone in advance by an ambitious camera assistant using non drop. Unbeknownst to him, the shoot calls for Drop frame code. When digitizing, the tape is designated “dropframe” but the code changes as soon as the bars are done. Sometimes the machine will catch this, sometimes it won’t. Stranger things have happened. The important thing is to be aware of it. Know which reel numbers are Drop and which aren’t. Check the EDL against your reels an make sure that it’s accurate. You know that “drop” is designated within an EDL by the use of a semi-colon (;) and non drop uses a plain old colon(:). If you notice a discrepancy, you know you’ve got a problem.

There are many different types of EDLs that you can generate: CMX, Grass Valley, etc. All these different formats have unique quirks in the way they handle TC changes.

Do you REALLY have to use an EDL as your key to on-line? If you had a way to just upres the sequence, bypassing the EDL step life would be much simpler. Do you know about Automatic Duck and it’s ability to “translate” FC sequences to Avid sequences?

Good Luck.

Mark

[G-video]

Hey Mark,

Thanks for your help and advice. I will keep your suggestions into consideration and be careful when I am digitizing and if I end using an EDL. I’ll also look into Automatic Duck. Thanks again!

Glen