Cinema DNG Metadata and exiftool implementation

[greg]

Hello,

I use exiftool to check the tags in cinema DNG files. exiftool is a great tool for this kind of investigations but it seems that exiftool only knows the DNG tags and not the cinema DNG tags.

Cinema DNG is similar to DNG but has some special tags are defined for the use of picture sequence.
It seems that exiftool isn't aware of this tags. I tried to change this cinema DNG tags but had no success.
So the question is: Is there a way to change Tags that exiftool isn't aware of?
I tried it this way:
eg. exiftool -IFD0:0xc789 and -EXIF:0xc789 in all kind of variations. So far I had no success.

Maybe there is a chance to implement cDNG support for exiftool. At the moment, there is a growing number of cameras that use this format to record RAW image sequences (internal or with external recorders). All other tags in cDNG are the same as the DNG tags so exiftool is a great help anyway to play around with the metadata in those files.

You can find the current Cinema DNG specification 1.1 here:
http://download.macromedia.com/pub/labs/cinemadng/cinemadng_p1_spec_091009.pdf

The Tags I´m talking about are:
TagName        Code       HexCode in EXIFTOOL
TimeCodes      51043    Exif_0xc763
FrameRate      51044    Exif_0xc764
TStop              51058    Exif_0xc772
ReelName        51081    Exif_0xc789
CameraLabel    51105    Exif_0xc7a1

You can find some cDNG Files with Timecode, FrameRate, ReelName and CameraLabel tags here:
http://www.marquise-tech.com/resources.html#tabs-2
(click download in the menu)

Hopefully there will be a new cinema DNG version after the NAB or IBC 2013

cheers greg

[Phil Harvey]

Hi Greg,

Thanks for the suggestion.

I have two problems adding these new tags:

1) What is the format for TimeCodes (0xc763)?  Like most other video documentation, they charge $ for the privilege of downloading SMPTE 331M-2004 which is referenced from the cDNG 1.0 spec.

2) Where did you find information about ReelName and CameraLabel (and perhaps others)?  These don't appear in the cDNG 1.0 spec.

- Phil

Edit: Ah, OK.  The cDNG 1.1 specification answers both of my questions (well, sort of.  It doesn't explain how to decode the date from the timecode, but at least it shows how to decode the time part).  ExifTool 9.16 will support reading/writing these CinemaDNG tags.

[greg]

Hi Phil,

thanks for the fast reply and the future support of the missing cDNG tags.
The cDNG files I have seen so fare only include time in the TC tag.
Also I haven't seen any files with more then one TC, as the cDNG spces explains you can use several timecodes.
Ikonoskop also encodes the date in the TC tag. Maybe this files are helpful for you.

http://www.ikonoskop.com/downloads/cinemadng/ (bootom of the page)

I had no success to find some information about the date coding in TC.

best greg

[Phil Harvey]

Hi Greg.

ExifTool 9.16 is now available with the ability to read and write these cDNG tags.

Thanks for all your help.

- Phil