M3 DNG files can't be imported into Darktable 3.8.0 - error in Metadata

[JooB]

Hi, if you try to import Mavic 3 DNGs into Darktable for postproduction you get an error message (camera not supported) and just see a skull instead of your image. M2Z and Mini 2 DNGs work without problems like before.

I checked this with the Darktable team and it seems DJI writes an incorrect tag value into the metadata of the pictures.
The tag StripByteCounts has an incorrect value, it should be calculated like this: ImageWidth*ImageHeight*2, but isn't.

Darktable uses RawSpeed to import Raw files and RawSpeed finds this inconsistency, so any other software using RawSpeed will have the same problem. Software using other libraries to import have no problems, like Luminance.

I already opened a ticket at DJI and hope they will fix it very fast.

You can't correct this tag by a batch job using exiv2 etc. because it is write protected.
The only way I found to fix it is manually for each picture. Use a metadata editor like exiv2 to get the wrong value of this tag (always seems to be 41775360) and use a hex editor to search for this value in each DNG and change it to the correct value 5376*3956*2=42534912.

Save and you can import the file into Darktable without problems.

 

[brett8883]

Hi, if you try to import Mavic 3 DNGs into Darktable for postproduction you get an error message (camera not supported) and just see a skull instead of your image. M2Z and Mini 2 DNGs work without problems like before.

I checked this with the Darktable team and it seems DJI writes an incorrect tag value into the metadata of the pictures.
The tag StripByteCounts has an incorrect value, it should be calculated like this: ImageWidth*ImageHeight*2, but isn't.

Darktable uses RawSpeed to import Raw files and RawSpeed finds this inconsistency, so any other software using RawSpeed will have the same problem. Software using other libraries to import have no problems, like Luminance.

I already opened a ticket at DJI and hope they will fix it very fast.

You can't correct this tag by a batch job using exiv2 etc. because it is write protected.
The only way I found to fix it is manually for each picture. Use a metadata editor like exiv2 to get the wrong value of this tag (always seems to be 41775360) and use a hex editor to search for this value in each DNG and change it to the correct value 5376*3956*2=42534912.

Save and you can import the file into Darktable without problems.

Very interesting

 

[SkywalkerFeng]

Hi, if you try to import Mavic 3 DNGs into Darktable for postproduction you get an error message (camera not supported) and just see a skull instead of your image. M2Z and Mini 2 DNGs work without problems like before.

I checked this with the Darktable team and it seems DJI writes an incorrect tag value into the metadata of the pictures.
The tag StripByteCounts has an incorrect value, it should be calculated like this: ImageWidth*ImageHeight*2, but isn't.

Darktable uses RawSpeed to import Raw files and RawSpeed finds this inconsistency, so any other software using RawSpeed will have the same problem. Software using other libraries to import have no problems, like Luminance.

I already opened a ticket at DJI and hope they will fix it very fast.

You can't correct this tag by a batch job using exiv2 etc. because it is write protected.
The only way I found to fix it is manually for each picture. Use a metadata editor like exiv2 to get the wrong value of this tag (always seems to be 41775360) and use a hex editor to search for this value in each DNG and change it to the correct value 5376*3956*2=42534912.

Save and you can import the file into Darktable without problems.

You are lucky to get an error message at all.

I tried to open Mavic 3 DNG files in ACDSee Photo Studio 8 for Mac, and it just greeted me with a black screen. M2P DNG files work without any problem.

IMO, you should prepare for the worst case scenario - it may take a long time for DJI to fix, if they ever decide to fix it at all. For the moment, they are focusing on adding so many other higher priority feature additions.

 

[adcimagery]

That's the quirks of raw file formats. By their nature, they aren't standardized across manufacturers. Hopefully someone can put in a PR for whatever processing library Darktable is using to create an exception for this file. Sounds like it's not a big change as you've already identified the fix.

I'm still waiting for Adobe to update ACR for full compatibility, and that's paid software...

 

[JooB]

Just to add a detail: My Mavic 3 is running the latest firmware 01.00.0400. But earlier versions seem to have the same problem.

 

[Kilrah]

I already opened a ticket at DJI and hope they will fix it very fast.

I wouldn't expect much. Usually it's "if it works in Photoshop/Lightroom it's OK".

 

[calmar81]

I use DxO PureRAW quite regularly in my workflow and they plan adding Mavic 3 compatibility for Q1 2022 (DxO Supported Cameras & Lenses)

I must admit I don't know the software you're referring to, but maybe it's the same with Darktable and they keep adding new camera bodies / lenses?

 

[JooB]

DJI support just informed me that the problem was pushed to the responsible team. They hope a fix will be included in the next firmware update. Wait and see...

@calmar81: Well, even if the error message is about camera support, the real problem is DJI breaks the rule how this tag has to be filled. Camera support in software often is about lens correction etc. and won't fix this problem. Only chance would be building in an exceptional handling of Mavic 3 DNGs in the RawSpeed library used by Darktable, but I have no hope anyone will do this magic trick... but thanks for the tip with PureRaw.

 

[8BitPoro]

I use DxO PureRAW quite regularly in my workflow and they plan adding Mavic 3 compatibility for Q1 2022 (DxO Supported Cameras & Lenses)

I must admit I don't know the software you're referring to, but maybe it's the same with Darktable and they keep adding new camera bodies / lenses?

Just got a trial for DxO PureRaw to try it... M3 still not working with it and DNG's can't be imported into it.

 

[calmar81]

Just got a trial for DxO PureRaw to try it... M3 still not working with it and DNG's can't be imported into it.

Yeah, installed the 1.5 update (I think) the day before yesterday and there were other drones, camera bodies and lenses added but unfortunately not the Mavic 3 … but Q1/2022 is not over yet

 

[JooB]

I'm quite happy that the problem is solved now in the .0700 firmware that was released today. Also the new tele DNG pictures got the correct value set.
I had to open a second ticket after it wasn't fixed in two firmware versions including the 0600 ...