Embedded Metadata

Creative Commons licenses are attached to Web pages. But we also want our licenses to be useful for materials distributed in file formats around the Net. The protocol described here works for MP3 files and via XMP embedding many other formats, including PDF, JPEG and video files.

If you just want to get started, try the ccPublisher app, available for Linux, OS X, and Windows.

If your software does not transparently support embedding CC license metadata (you should only have to select a license), do not attempt to do it yourself (it will be a frustrating experience).

Embedding the metadata

Let's say Anita wants to license her song, "Volcano Love," with a Creative Commons license, and release it as an MP3. Here's what she'd do:

First, Anita would put a "Some Rights Reserved" button on the site where her song could be downloaded — along with a link to a license, some RDF metadata, and an assertion about the copyright status of the work. Nothing new here: this is what Creative Commons licensors do now.

With file embedding, though, this page will now serve the added function of verification. Here's how: Anita would insert the URL to that webpage in the copyright field of the MP3 file, along with a short, plain description of the work's license status. We call this the license verification link because it points back to a page that Anita herself controls.

Next, imagine Anita puts the MP3 on a file-sharing network. A user comes across her MP3 and can follow the verification link to Anita's page. In the future, we hope that file-sharing networks, media players, and other applications will build tools that read the verification link automatically and inform users of the copyright assertions like Anita's.

The advantage of the verification link

Embedding this kind of "verification link" in MP3s, as opposed to merely the license metadata, is a measure of protection for artists against the incorrect or fraudulent labeling and sharing of their work.

Verification Link: Also a Traffic Engine

An added benefit of the verification link is that licensors, or the companies who do their hosting, can use them to draw traffic to their websites.

Example:

Ravi is an amateur photographer. He hosts his photos at SNAP, a website devoted to photography. Each time Ravi uploads his photos to the SNAP website, the SNAP software offers Ravi an opportunity to use Creative Commons licenses, and the tools to embed his webpage on SNAP with the appropriate RDF. Next, SNAP's software automatically inserts the verification link into his photo files' copyright fields.

Ravi circulates the photos among his schoolmates, whose photo-viewing software reads the copyright fields and takes them to the SNAP website, where they can see Ravi's whole catalog of photography and links to other SNAP services.

Technical Explanation

See Nonweb Tagging, and for specific formats, see MP3 and XMP (PDF, JPEG, video).