Designed to survive: Open and Embedded annotation

Why should your annotations be stored in an embedded and open way?

Digital memories are precious and should not be lost. The same can be said of annotations. They are necessary to improve searching and browsing of your multimedia documents. It takes time and patience to annotate (assign date/keywords and location information) so your annotations should be safe at all time. The annotations should able to travel with the files even when they are burned, copied or published on the Internet for example. There are software which stores your annotation in a proprietary format databases. This is dangerous because if you decide to change for another software, every annotations you have written will be lost.
Nobody wants to invest its time on writing annotations without being confident that they will be stored in a way which is also readable by other softwares.

That´s why open standards are important to give you the choice of which software will manage your data and not lock you in. It is also important that your annotations are embedded inside the file for safety. The annotations will always be preserved as long as the file is preserved.

Which open standards for multimedia files ?

For digital photography, IPTC and XMP are the two main open standards.
IPTC can be saved in: JPG, TIFF, PNG, MIFF, PS, PDF, PSD and DNG.
XMP can be saved in: JPG, JP2, TIFF, PNG, MIFF, PS, PDF, PSD and DNG.

For digital music, ID3 is the major standard for audio formats such as MP3, MPEG, AIFF, OGG, FLAC, APE and RealAudio files.

For digital video, AVI can save RIFF info tags and MOV has Quicktime info tags.

For all file formats which do not offer open embedded metadata facilities, the solution is to store the annotation in an external file using an open format such as XMP. In that way, we lose the safety provided by embedding, but we preserve the openness of the annotations.

How does Contenta store metadata ?

Contenta stores metadata in a portable way for the files which can handle it. Every annotation you edit is also stored in a database for performance purpose. The metadata stored inside the files and in the database are always in synch.

If a file format does not support embedded metadata and is annotated, Contenta will save the annotation in a sidecar file. You lose the benefit of embedded annotation, but not the benefit of openness.


The edition of annotations is done in batch. You make your selection of documents and drag´n drop them into a list. Four different editors are then available for the edition of general (rating, time, keywords), photo (location, subject, …), music (genre, artist, album, .. ) and video (title, casts, plot summary, …) annotations. The edit box features auto-complete to facilitate editing.




All annotations present in the collection are used to provide structure to the browsing system. The annotations improve the browsing, which in turn also helps to find documents which lack proper metadata to let you improves the annotation. With Contenta, annotation creates a virtuous circle to let you improve the organization of your collection in an iterative manner.