David Van Brink wrote:

Are there any known patent issues with using madplayer in a product? I am unclear on if there are algorithms which are generically off-limits, or what. I'm asking on the list since I assume the answer will be of general interest.

My answer is, generally: Certain third parties may claim to have patent rights to some algorithms implemented by MAD. I make no representation that MAD, incorporated into a product or alone, either does or does not infringe upon any alleged patent. If you use MAD, it is your responsibility to obtain whatever patent license(s) are required.

To the best of my knowledge, relevant patent licensing information can be found here:

http://www.mp3licensing.com/

At the time I write this, the following statement could be found on the above site: "No license fee is expected for desktop software mp3 decoders/players that are distributed free-of-charge via the Internet for personal use of end-users." However, a patent license royalty is asked, on the site, for most other kinds of decoders.

Note that somehow a royalty for "Electronic Music Distribution" is also asked, and eventually a royalty for broadcasting/streaming may be included, but I fail to understand the legal assumption for these -- other than patents, I presume. Do your own research and reach your own conclusions.

And, for that matter, are there licensing issues for madplayer itself, were it to be used in a commercial application?

Copyright is an entirely different matter. With few exceptions, I hold the copyright for the code in MAD. I have made the code freely available by licensing it under the GNU GPL, which means (generally speaking) you can do whatever you like with it so long as you give others the same rights I gave you. This applies also to derivative works -- and this I know is sometimes problematic especially in some commercial environments.

If you'd like to use MAD commercially, I encourage you to consider whether the GPL really presents a problem for you. If not, you don't need to do anything special -- the GPL is your license. If, however, you really need different terms, I do entertain requests for alternate licensing, and will negotiate with you for equitable compensation.

Hope this helps.