On Mon, 10 Dec 2001, Mojtaba Hosseini wrote: > I had a couple of questions regarding the Xj3D loader. I would like to > see whether it is possible to contribute to its development especially > towards compatibility with MPEG-4. (Perhaps somehow incorporating the > Java3D MPEG-4 BIFS encoder/decoder we have into the loader). However I > have two main questions:
Alan will probably add more here as he's been dealing with some folks that have contributed an MPEG4 system. This is my understanding of the situation (I was involved in doing reviews of the MPEG4 spec for some time). MPEG specs have huige amounts of patents around them. Prior to the 4 spec, there was a system called patent pooling. Basically, to implement the spec and then distribute it, you had to pay a license fee - regardless of whether your implementation was free or not. So, technically you could implement the spec and hand it out for free, but you'd be in a bit of problems if the people came after you for their royalties. From the 4 spec onwards, the status of the patents is still unclear. My understanding is that even today, a couple of years after the MPEG4 v1 spec came out, they don't have any clear idea as to how much of the spec is encumbered with patents. At the bottom end of the MPEG standard is the Quicktime file/stream format. These are available RF. The BIFS encoding may or may not be available RF. This seems to have been a bone of contention between the web3d consortium and the MPEG group and one of the reasons that BIFs has not been used as the binary format for VRML97/X3D. > 1) Where can I find the legal documentation of how Xj3D can be used? Who > can use it? The license is LGPL - http://www.gnu.org/copyleft/lgpl.html (I think that's the URL, but may be wrong). Basically you can take the code, sell it, modify it etc etc, so long as you make your changes and the original code available. Ideally, you would contribute those changes back to us. > 2) Are there people interested in helping out with the integration of a > Java3D MPEG-4 BIFS codec into the Xj3D loader (if the legal limitations > are overcome)? Or am I on my own on this? Well, we're here and on the Web3D source list. Feel free to talk to us, as naturally we'll be looking at the architecture issues. -- Justin Couch http://www.vlc.com.au/~justin/ Freelance Java Consultant http://www.yumetech.com/ Author, Java 3D FAQ Maintainer http://www.j3d.org/ ------------------------------------------------------------------- "Look through the lens, and the light breaks down into many lights. Turn it or move it, and a new set of arrangements appears... is it a single light or many lights, lights that one must know how to distinguish, recognise and appreciate? Is it one light with many frames or one frame for many lights?" -Subcomandante Marcos ------------------------------------------------------------------- =========================================================================== To unsubscribe, send email to [EMAIL PROTECTED] and include in the body of the message "signoff JAVA3D-INTEREST". For general help, send email to [EMAIL PROTECTED] and include in the body of the message "help".
