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Question

What's the deal with Drop-Frame / Non-Drop-Frame Timecode?

Forum|Forum|13 years ago
December 14, 2012
3 replies
57917 views

I'm having trouble with 30fps Drop-Frame and 30fps Non-Drop-Frame timecode formats! I thought 29.97fps means 30fps Drop-Frame, but now I'm all confused.

I'm working with DSLR footage filmed with a frame rate of 29.97. For example, this one clip is listed as (in Project panel)

Media Start: 11:16:11:23

Media End: 11:22:42:22

Duration: 00:06:31:00

Frame Rate: 29.97fps

If I open this clip directly in Source Monitor, the timecode display (yellow, on lower left corner) says 11:16:11:23 at the beginning and 11:22:42:23 at the end. OK. But if I right-click on the timecode display, the pop-up indicates "Non-Drop-Frame"(!!). If I manually change that to "Drop-Frame", the start and end timecode would become 11:16:52:11 and 11:23:23:23, and the duration display (white, on lower right corner) becomes 6:31:12.

Now I create a new sequence of 1080p30, which has a 29.97fps time base. I right-click the yellow timecode display on the upper left corner of the Timeline, it says "30fps Drop-Frame". I drag the said clip onto the sequence. It occupies a length of 6:31:12. If I double-click the clip to open it in Source Monitor, now the Source Monitor timecode display indicates "Drop-Frame", and the start/end timecodes are 11:16:52:11 and 11:23:23:23. Huh??

Now I apply the "Timecode" effect on the clip. The timecode burn-in says 11:16:51:11 at the first frame and 11:23:23:22 at the last frame. I then go to the Effect Controls tab and look at the Timecode effect. It says

Format: SMPTE

Timecode Source: Media

Time Display: 30 Drop Frame

Just playing around, I switch "Timecode Source" to "Clip" - now the timecode burn-in goes from 00:00:00:00 to 00:06:31:11 - and then I switch it back to "Media". Now the Effect Controls tab says:

Format: SMPTE

Timecode Source: Media

Time Display: 30 Non-Drop Frame

And the timecode burn-in says 11:16:11:23 at the first frame and 11:22:42:22 at the last frame!

HUH??

Just for kickers, I switch "Timecode Source" to "Clip" again... Now "Time Display" stays on "30 Non-Drop Frame", and the timecode burn-in goes from 00:00:00:00 to 00:06:30:29.

What's the REAL length of this clip? Is it drop-frame or non-drop-frame? What are the REAL timecodes for it?

Also in a general sense, since I can change the "Time Display" field in the Timecode effect at any time, and change the Timecode display format of the Timeline at any time... How do I avoid creating mismatching timecodes??

Thanks in advance for any clarification!!

This topic has been closed for replies.

Zooropa75Author

Known Participant

I'm sorry, but my main questions still remain unanswered. I really need to get this resolved before I can move forward with this project, because the time codes will be used to guide our editing. The problem is, which time code??

My original post was long so I'll summarize it in simpler fashion:

I have HD footage from a Panasonic AF100 camera, and it's supposed to be 29.97fps. Which I thought means Drop-Frame Timecode.

When I did "New Sequence from Clip", the sequence that was created uses NON-DROP-FRAME Timecode. In this case, the clip's duration and time codes are consistent with how they were listed in Project Panel.

However, when I create a new sequence using one of the templates (such as 1080p30), the sequence uses DROP-FRAME Timecode. If I drag and drop the clip into this sequence, the clip's duration and start/end time codes CHANGE TO SOMETHING DIFFERENT.

Do you see how that's a problem?? If I had a clock in the picture, I would be able to verify which way is "correct". But there isn't.

I'm so frustrated with this that I may have to switch back to FCP for this project, which I don't really want to do!

E

excited_Genie16B8

Legend

Frame rate and timecode are independent. Meaning you can have DF or NDF at any frame rate. DF is the norm. Use that in the camera.

For this project, it seems you've recorded the clips using NDF. No worries. Either use that for your sequence, or change it to DF. Won't make any difference to the final export.

Dragonspear

Participating Frequently

I've got an easy answer for you^^ But first, let me quickly tell you not to implicitly trust manufacturers listed frame rates. Many manufacturers will say things like "60p" or "24p" but in fact mean 59.94 and/or 23.38. Many times when you dig down into your camera manuel, you'll find the "actual" frame rates etc. Don't confuse whole numbers and their decimal counterparts with drop-frame and non-drop frame.

All you need to know is this:

Import your footage into Premiere.
Drag it onto the "Create New Sequence" button to ensure you create a sequence with the same settings as your footage.
Drag the "Timecode" effect onto your video clip.
Select "Media" from the source selection in the timecode effect.
TADA! Your timecode effect will match the timecode of your timeline.

IMPORTANT! For some reason I've noticed that even though the TC effect usually defaults to "Media" for the source, it will NOT show the proper TC until you manually select "MEDIA" from the selection. ...this is the case even when it already starts with it selected. ...weird I know, but that's how it is when I tried it. You have to click on the menu in the effect and then select Media even if it shows "media" when you first apply the effect. ><

PS. From what I can tell, you can trust your source window timecode setting. (right-click the yellow tc numbers you mentioned to see if it's drop/non-drop)

Hope that helps! ^_^

Zooropa75Author

Known Participant

Thank you, Dragonspear. That helps, although I still have some major questions.

Where is the "create new sequence" button? I only know to right-click and choose "New Sequence From Clip". Anyway, I did that with the clip in question, and the sequence created displays 30fps Non-Drop-Frame timecode. Which seems to imply that the clip carries 30fps NDF timecode. But the clip is supposed to be 29.97fps, which I thought means Drop-Frame. Indeed, if I create a new sequence with a "1080p30" template, either under AVCHD or HDV, I get a sequence with 29.97fps time base and DF timecode.

Here is my big question: When I view the clip with NDF timecode setting, or put it in a sequence with NDF timecode, its length is 6:31:00. When I view it with DF timecode setting, or put it in a sequence with DF timecode, its length is 6:31:12. How do I know which one is correct?? Meaning, what's the duration of the event that was recorded in this clip?

I also misspoke when I said this is DSLR footage. It's actually from a Panasonic AF100.

E

excited_Genie16B8

Legend

I only know to right-click and choose "New Sequence From Clip".

That's just as workable.

seems to imply that the clip carries 30fps NDF timecode. But the clip is supposed to be 29.97fps, which I thought means Drop-Frame.

Read post 1 again.

E

excited_Genie16B8

Legend

Simply put, DF and NDF are methods of handling timecode, and do not affect the frame rate of the media itself.

DF is the more accurate with regards to real time, and thus is much more widely used.

J

Jim Curtis

Inspiring

Jim Simon wrote:
Simply put, DF and NDF are methods of handling timecode, and do not affect the frame rate of the media itself.
NDF is the more accurate with regards to real time, and thus is much more widely used.

Jim, DF is more accurate with real time, because of the fractional nature of 29.97. The reason frame numbers are dropped is to keep the running total consistent with real time, and this is why broadcasters generally use DF code.

http://en.wikipedia.org/wiki/SMPTE_timecode#Drop_frame_timecode