Skip to Content.
Sympa Menu

cc-metadata - Embedded CC License Info in Different File Types

cc-metadata AT lists.ibiblio.org

Subject: discussion of the Creative Commons Metadata work

List archive

Chronological Thread  
  • From: admin AT delegatetechnologies.com
  • To: cc-metadata AT lists.ibiblio.org
  • Subject: Embedded CC License Info in Different File Types
  • Date: Fri, 16 Apr 2004 00:20:59 -0700 (PDT)

Hello All,

I’ve been out of the CC Development loop for about 3 months now taking
care of some other things, but I’ve tried to keep up with some of the
discussions that have been going on in this list. During my time away,
I’ve had the opportunity to think about some of the concepts that the
Creative Commons is trying to accomplish through a few of their
“Technology Challenges” and would like to open a discussion about the
approach towards integrating CC Licensing into as many different file
types as possible.

So here it is:

When looking at integrating CC License info into a number of different
file types, the current “suggested” approach is to find a place within
each file format’s specification to put the CC info. (i.e. in mp3’s it is
suggested to use the “TCOP” frame in the ID3 specification for storing a
url to a license page, Ogg files should have the license put in the
“comments” field, etc. All of which are places that are “native” to the
format.) I have a number of questions that come from this:

1) What are the pros and cons of fitting CC License information into
existing file formats by finding an open field in the specification to put
it (i.e. the “TCOP” frame), versus a “header” or “footer” scheme created
by the CC community that is devised to store license information that is
common across all file types? (i.e. add extra header or footer bytes to
the beginning or end of a file that contain the information)

2) Would there be any problems that could arise by adding extra data
to the beginning or ending of a file that is not part of a predefined
specification for that file format? (i.e. would it cause an MP3 player or
a picture editing application to crash because it doesn’t know how to
handle the extra data?) (NOTE: I’ve built a prototype application that
allows me to take a file of any type, and add a copyright header to the
file. I’ve only tested a few common file types such as MP3, PDF and JPG,
but so far I have not seen any side effects from doing this method. The
mp3 players, PDF readers and JPG editors seem to open up the modified
files without any problems and seem to ignore the added bytes that contain
the copyright info….but that is not to say there aren’t any side effects.)
I would be interested in hearing someone else’s opinion on the side
effects or any other questions I’ve missed on this.

Here are some thoughts on it:

If I could be sure that adding extra header or footer data to a file would
not break anything, my vote would be for a common scheme across all file
types. This would save a lot of headaches for implementing read/write
libraries for every type of file that we wanted to put CC license info in.
We would have one library that allowed us to add header information to
any file type that comes in. Here might be a suggested byte scheme:

TAG $xx xx xx “CCL” 3 bytes
Size $xx xx xx xx 4 bytes
Content $xx xx xx xx … n bytes

A 3 byte long field that says “CCL” for “Creative Commons License, next is
a size field that is 4 bytes long that tells how long the content field is
going to be, then the n byte content field that holds the copyright
information.

Any thoughts??

Highest Regards,

Steve Griffin
steve AT delegatetechnologies.com
http://www.delegatetechnologies.com






Archive powered by MHonArc 2.6.24.

Top of Page