Today I used my three OSMO Action 4's on a multicam shoot with timecode.  The OSMO Action 4 separates clips into what appears to be 2 minute segments with my settings.  Unfortunately subsequent files do not always end and begin on the next timecode frame.  When added to a timeline with timecode there are gaps in the footage because the two files either (1) have the wrong timecode, or (2) the sequencing has dropped a frame.

For example, here are two files that the OSMO Action 4 produced as I continuously shot, along with their beginning and ending timecode values:

DJI_20230926130416_0011_D_A00_005.MP4. 13:12:07.11  13:14:07.09
DJI_20230926130416_0011_D_A00_006.MP4. 13:14:07.11 13:16:07.08 --- Where's frame 10?  
DJI_20230926130416_0011_D_A00_007.MP4. 13:16:07.09 13:18:07.05

...this is just one example, there are many examples of this in my over 160 separate files across multiple cameras!  I included an attachment with the metadata for all of the files so you can detect all of the gaps like the one called out above.

DJI, this is a serious bug!  I ended up having to close the gaps by hand and I still don't know if I'm missing frames of video from my shoot!

[Edit: The attached metadata has three cameras A00, B00, and C00 in it, all are OSMO Action 4's.  The gaps will appear on the A00 and B00 cameras.  Those two cameras ran continuoulsy in 4K/24fps/RS/DLOG-M/20m loop mode.  They were jam sync'd with my RODE Wireless PRO receiver with batteries in them and then plugged into USB power as well so that the battery and camera would function continuously.  The start/stop of the recordings was performed with the DJI GPS Remote.]

Hi, just wanted to know what firmware are you on?

Firmware Version: 01.02.06.10 which is the latest at this point per the mimo app.

DJI Please confirm that you’ve seen this bug report.

For those watching this thread.  I've been informed that the engineers are looking into it....

Dear Ron,

Thanks for contacting DJI Technical Support.

We are deeply sorry for the bad experience, in order to better assist you, we are now further discussing your problem with our advanced engineers, and we will reply to you as soon as possible.

Rest assured that we do understand your feelings and should you have any further questions or suggestions. Please feel free to let us know, and we will try our best to help you based on your feedback.

Thanks for your cooperation and understanding.

Best Regards,
Shelley
DJI Technical Support
Online Service: Click Here (Mon-Sun 00:00-24:00)
Website: https://www.dji.com/support

A quick update for those following this bug....DJI continues to ask for additional information regarding this issue which simply tells me it hasn't hit the engineering team yet.

I've been going back and forth with DJI on this....so to simplify things I produced this video showing how easy it is to reproduce this issue.  I record how to easily reproduce the issue and describe it in detail soup to nuts.

Here’s another update for those following the thread.  TLDR: DJI acknowledges it is a bug but states its challenging to fix.  

I’m still trying to convince them as the typical engineering response is initially it can’t be fixed but engineers are typically smart and can think through how to fix it.  It can even be fixed after the file is written to storage if necessary so there’s no real hardware limitation.  The “split logic” response simply means that the logic for file creation and looping are logically separated and the two would need to know about one another to correctly fix this issue.  Adding a “dependency” in generic file creation logic is typically bucked by software engineers but there are ways to loosely couple the logic.  The 25/50 fps suggestion is also not really valid, especially here in the USA and shouldn’t matter either.  I’ve asked for it to be escalated.

Tina.wang （DJI Support）
2023/10/18 GMT+8 15:08

Hello, Ron,

We received feedback from the engineer:

This problem is caused by hardware limitations and split logic factors that make it impossible to achieve 100% continuation of the timecode. It is recommended that the recording specification be recorded using 25FPS or 50FPS frame rate, or record using a timecode-enabled mode other than loop recording。

We hope this will be of help.

Best Regards
Tina

HI, ronj

We are looking into this issue.
What you report seems to be more likely happen in loop recording.

Current suggestion is to use normal video recording with timecode.

DJI-ytao Posted at 10-18 01:01
HI, ronj

We are looking into this issue.

I'm really glad you're looking into it.  Unfortunately, I need to use loop recording mode *and*  timecode.  Why?  Looping mode with timecode is very beneficial, in fact it’s arguably the best use case for timecode.  The use case is that I don't know when or if the action I'm capturing is going to be used or not until after it has taken place.  I'm kayak fishing and I want to only keep the footage where I'm catching fish.  That is the perfect scenario for looping.  

But since looping overwrites the oldest files I don’t know where my externally captured audio will line up with that file, thus timecode is needed to perform the alignment in post production.

I'm confident you'll find a way to fix it.

ronj Posted at 10-18 04:39
I'm really glad you're looking into it.  Unfortunately, I need to use loop recording mode *and*  timecode.  Why?  Looping mode with timecode is very beneficial, in fact it’s arguably the best use case for timecode.  The use case is that I don't know when or if the action I'm capturing is going to be used or not until after it has taken place.  I'm kayak fishing and I want to only keep the footage where I'm catching fish.  That is the perfect scenario for looping.  

But since looping overwrites the oldest files I don’t know where my externally captured audio will line up with that file, thus timecode is needed to perform the alignment in post production.

Thank for sharing the user case.

I am not sure whether 60 secs pre-rec could help with fishing.

DJI-ytao Posted at 10-18 07:03
Thank for sharing the user case.

I am not sure whether 60 secs pre-rec could help with fishing.

Nope, but a 10 minute pre-record would work.

Ok everyone, the final answer is that DJI acknowledges the bug but cannot fix it.  Looks like we'll have to manually fix these 1 frame gaps during post processing which just means that the amount of time spent in post processing goes up.

Here's the final response from the back and forth with the engineering team...

Hello, Ron,

We have received a reply from the engineer regarding your feedback:

Due to some problems involving precision errors such as the Non-integer frame rate configuration of the sensor and the coupling clock configuration limit, it is hard to ensure that a sensor is in an extremely accurate frame rate output state, and there are also some problems of minimal errors at the current file segmentation time, because the timecode is extremely sensitive to minimal error accuracy, it cannot be completely solved at present right now.

We really appreciate your valuable time and we would be most grateful to receive your continuous valuable feedback about the timecode!  DJI is continuously seeking customer feedback to drive improvements to our products and customer experiences.

Thank you for choosing DJI and have a nice day
Tina

Another report came in that this is entirely related to loop mode.  In continuous shooting mode when the camera segments the recordings, timecode works properly across those segments.  When looping the segments exhibit the buggy behavior.

I'm extremely disappointed, I exchanged my Osmo Action 1 cameras for the new Osmo Action 4 thinking about using timecode to synchronize my videos, but when I put the videos in the timeline they don't match. If you synchronize a section manually and drag all the other videos together, they will misalign along the timeline. Before starting recording, I synchronize the time code of the two cameras in DJI MIMO

DJI, this is the original poster.  This is a very serious bug that I urge you to reconsider fixing.  It takes me over an hour to "manually fix" the issues caused by this bug every single video I create.  I notice this posting is no longer searchable but it needs to be so that others are able to find it.