DPX header reading

[NMAAHC]

We use Pomfort DPXHeaderEditor to add metadata to our DPX files.

The Pomfort editor has a field called DPX Reel Name, which we like to add metadata to. I'm attaching a .png of the Pomfort application window so you can see what I'm talking about - 1199WP_00086400_Pomfort.png

Unfortunately, this field is not being read by exiftool. I can see the metadata we added when I open the .dpx file in Hex Fiend or any other hex reader. It sits starting at offset 1972, which in the SMPTE spec for DPX (SMPTE 268M) is defined as:

Field: 72 ; Offset: 1972 ; Length: 76 ; Type: TBD ; Content: Reserved for future use

Is it possible to have exiftool read this data from offset 1972? It would be amazingly helpful to us.

If it would help to have a .dpx example with our metadata embedded I can provide that, but it is 24MB so it can't be uploaded to the forum.

Thank you.

[Phil Harvey]

The DPX sample would be very useful.  My email is philharvey66 at gmail.com

- Phil

[Phil Harvey]

I got your sample, thanks.  I can add this feature easily.  How do you want the data decoded?  As an ASCII string?

How is this?:

76 bytes at offset 1972.  ASCII string.  Tag name: "Reserved".  Marked as "Unknown" so it will only be extracted with the -u option.

- Phil

[NMAAHC]

I got your sample, thanks.  I can add this feature easily.  How do you want the data decoded?  As an ASCII string?

ASCII string would be perfect.

How is this?:

76 bytes at offset 1972.  ASCII string.  Tag name: "Reserved".  Marked as "Unknown" so it will only be extracted with the -u option.

That looks great. Would it be possible to have it work without the -u flag? Most of the metadata extraction will be performed on the backend by microservice scripts and I don't know if adding in the -u flag will require tweaking several other scripts. If not, no big deal.

Thank you very much, Phil

-Bleakley

- Phil

[Phil Harvey]

I don't want to add this without -u if it isn't part of the official specification, or widely used otherwise.

- Phil

[NMAAHC]

Ok.

We are working with FADGI (Federal Agencies Digitization Guidelines Initiative) to develop a tool and standards for metadata embedding in DPX file, so I do see this field being used consistently in the future. But, I doubt SMPTE will ever rewrite the spec to specify anything other than Reserved For Future Use. Whatever you feel is best.

One other thing - in the SMPTE spec Reserved For Future Use is listed as the content description for fields 16, 29, 42.3, 57, and 74. (Their respective offsets are: 664, 1356, 1644, 1864, 1972) So, perhaps to avoid potential confusion in the future, the Tag Name in exiftool should read "Reserved 5" or something?

-Bleakley

[Phil Harvey]

Reserved5 sounds good for an Unknown-type tag.  Do you have a suggested name if you want it to show up as a normal tag (without -u)?

- Phil

[NMAAHC]

Great!

Suggest name would be DPX Reel Name, but I could see that FADGI standards recommending Reel Name be field 16 (offset 664) instead. This is our workaround for the time being since editing into offset 1972 is easier in our current workflow.

So I can let our IT team know, when would this feature be available and it will require just a quick update of exiftool on our end, yes?

Many thanks,
Bleakley

[Phil Harvey]

Hi Bleakley,

You can use the attached config file to extract this tag right now (with the name "DPXReelName").  You may want to use this config file even after I update ExifTool because I think I want to call this tag "Reserved5" and mark it as Unknown.  This config file will override the new "Reserved5" definition if you update ExifTool in the future.

See the sample config file for instructions on how to activate a config file.

- Phil

[NMAAHC]

Thanks! We will try it right now.

Bleakley