Thanks for reporting your issue. Please make sure these boxes are checked before submitting your issue - thank you!

- [X] I looked for a similar issue and couldn't find any.
- [X] I tried with the latest version of GPAC. Installers available at https://gpac.io/downloads/gpac-nightly-builds/
- [X] I give enough information for contributors to reproduce my issue (meaningful title, github labels, platform and compiler, command-line ...). I can share files anonymously with this dropbox: https://www.mediafire.com/filedrop/filedrop_hosted.php?drop=eec9e058a9486fe4e99c33021481d9e1826ca9dbc242a6cfaab0fe95da5e5d95

I am trying to test a file that uses `imda`, which needs support for the `imdt` data reference. I see some work to add the `imda` container, but there does not appear to be `imdt` (under `dref`) support.

A couple of samples are attached as zip - the content should be the same in each, but the `_imda.heif` version is reported as invalid in gpac (and it could well be wrong as well).
[rgb_component.zip](https://github.com/gpac/gpac/files/14164077/rgb_component.zip)



Feature request - imdt support
This is a GitHub Issue
repo:gpac
owner:gpac
Title : Feature request - imdt support
Issue date:

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Thanks for reporting your issue. Please make sure these boxes are checked before submitting your issue - thank you!

- [X] I looked for a similar issue and couldn't find any.
- [X] I tried with the latest version of GPAC. Installers available at https://gpac.io/downloads/gpac-nightly-builds/
- [X] I give enough information for contributors to reproduce my issue (meaningful title, github labels, platform and compiler, command-line ...). I can share files anonymously with this dropbox: https://www.mediafire.com/filedrop/filedrop_hosted.php?drop=eec9e058a9486fe4e99c33021481d9e1826ca9dbc242a6cfaab0fe95da5e5d95

I am trying to test a file that uses `imda`, which needs support for the `imdt` data reference. I see some work to add the `imda` container, but there does not appear to be `imdt` (under `dref`) support.

A couple of samples are attached as zip - the content should be the same in each, but the `_imda.heif` version is reported as invalid in gpac (and it could well be wrong as well).
[rgb_component.zip](https://github.com/gpac/gpac/files/14164077/rgb_component.zip)



--- end body ---

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