24fps Time Code Drift in Premiere Pro

[Zach Mull]

I have a couple dozen hours worth of MXFs recorded with a NanoFlash, and I am not able to get accurate time code in Premiere Pro. We recorded in true 24fps using the XDCAM HD codec. We can view accurate time code in the Sony XDCAM Browser, but Premiere Pro offsets the time code by more than a minute at the start of a take, and it jumps an additional 4 frames forward at the start of each spanned clip. Not surprisingly, Media Encoder interprets the time code the same way Premiere does, so transcoding through Media Encoder doesn't help. Does anyone know a way to get Premiere Pro to interpret the source time code correctly?

Additional info: We are recording at true 24fps to match animations generated by CAD software that can only produce video at true 24 or true 30. I am aware that Premiere Pro doesn't have a preset for XDCAM HD at true 24fps, and I am playing back in a custom 1080p24 sequence. The time code is off by the same amount whether I am using a time code generator effect in that sequence or viewing the clip in the Source window.

[Jack Zhang]

NDF NTSC MXFs (for all of NTSC's frame rates) all have a problem in Sony Vegas for me: No audio whatsoever. It may be related in some way.

If it's NTSC, I always record drop frame and adapt any CG at perfect 24 to 23.976. It's much better to adapt only the CG clips you need for drop frame than to shoot for your CG IMHO. YMMV.

If you have access to Final Cut, see if MOV produces a different result at perfect 24 or if it's doing the same. It could be as simple as the checkbox in the nano's timecode setting for drop frame had been checked.

[Zach Mull]

Thanks Jack. I agree with you that adapting the CG would be the best solution, but we haven't found the right workflow for that yet. We have tried adapting the CG to 23.976 in the past and didn't like our results, which is why we tried acquiring at true 24 on the video end for this project. We probably won't be doing true 24 again with the NanoFlash after this experience though.

We tried Vegas and saw exactly the same time code interpretation problem as Premiere Pro. Media Composer wouldn't ingest XDCAM at true 24fps at all. I haven't tried FCP yet because there's only one Mac in the office and no FCP licenses, but I will try at it home at some point.

One of my co-workers did figure out a way to deal with it on Windows 7. Using Calibrated Q software, you can rewrap the MXFs from the NanoFlash into MOV containers and use Calibrated Q's XD Decode to view the MOVs in Premiere Pro. That displayed the correct time code.

I also found that it worked for our purposes to manually enter the start time code at the start of each clip using the Modify context menu in Premiere. Since we could see the correct time code in XDCAM Browser, it wasn't outrageously time consuming to enter the start time code for one afternoon's worth of takes, but I think we will use the Calibrated Q software for the rest of the project.

[Jack Zhang]

Can you test if recording native MOV with the calibrated plugin is able to eliminate the MXF step?

[Steve Kalle]

What camera are you using because I bet it doesnt output 24p so the nano is doing magic to interpret & record a different signal. Also, most cameras output 23.98 in 60i and some can output 23.98p (ie EX1/3).