[LinuxDVD] CSS license Colin Davis cdavis@thepentagon.com Mon, 05 Jul 1999 14:46:42 -0400 From what I have been able to find, it would seem that Matsushita licenses the CSS encryption technology froo of charge. I believe this is the only remaining barrier for DVD playback under linux. (We have MPEG-2 and AC-3, so we should be able to watch and listen to unencrypted DVDs, yes?) If Mr. Volcko's idea of creating a general CSS library for linux could be accomplished, Would the situation then be resolved? Has anyone contacted Matsushita about a license? Did they have any comments on the issue? Thanks -- Colin 'almost there' Davis
[LinuxDVD] CSS license Paul Volcko pvolcko@concentric.net Mon, 5 Jul 1999 14:46:05 -0400 > From what I have been able to find, it would seem that Matsushita > licenses the CSS encryption technology froo of charge. I believe this is > the only remaining barrier for DVD playback under linux. (We have MPEG-2 > and AC-3, so we should be able to watch and listen to unencrypted DVDs, > yes?) CSS is fre of charge. As Andres notes, though, there is a lot of stuff you have to sign off on and the likelyhood of them licensing to individuals or a non-company affiliated group is very small I think. I'm not sure on that though. As for MPEG-2 and AC-3. It remains to be seen if the publicly available AC-3 decoder is in fact legal. It may infringe on software patents held by Dolby. I believe that Arron Holtzman is looking into this with Dolby now. MPEG-2's patents are handled by MPEGLA (www.mpegla.com). I've recently recieved all the licensing information from them. They claim that their MPEG-2 patent portfolio is required for any implementation of an MPEG-2 encoder or decoder. This seems to follow since I have not seen a freely available MPEG-2 decoder (in software) put out there yet. If anyone has legal background and would like to look into this stuff it would be very helpful. We need to establish that the AC-3 decoder that Arron Holtzman made is not infringing on any dolby patents (patent US5632005 seems to be the Dolby AC-3 related patent). We also need to establish that the mpegla portfolio is not essential to creating a software mpeg-2 decoder. Keep in mind. It is possible to make an MPEG-2 software decoder and freely distribute the module for decoding. That has no royalties or fees associated with it, but once that decoder is used in a system it becomes subject to the mpegla licensing of $4.00 per copy of software distributed. So, it is not clear that CSS is the only hurdle in place right now. It is probably the only technical hurdle, not the only legal one though. > If Mr. Volcko's idea of creating a general CSS library for linux could > be accomplished, Would the situation then be resolved? It would not be simply a CSS library. It would incorporate use of hardware and software decoders (through either direct driver interfacing or interface modules to make them compliant with the DVD API interface on the decoder end). It would also handle all DVD spec related stuff, including parsing of IFO files, and breaking the VOB files into Video, Audio, and SubPic streams (and navigation info) as needed by the decoders being used. CSS negotiation between DVD drive and hardware decoders would probably be possible, using Andrew Veliaths work as a starting point), but a full CSS decryptor in software and in the API may not be possible under the licensing and NDAs for gaining that information from Matsushita. This remains to be seen though. > Has anyone contacted Matsushita about a license? Did they have any > comments on the issue? The group I'm involved with, LSDVD Project, will be shortly. We are currently concentrating on getting something actually coded up right now with the DVD spec information we have. We are also working with Convergence and hopefully Sigma Designs. I've been looking into the decoder licensing thus far and haven't contacted Matsushita (very long distance phone call :) yet. Paul Volcko LSDVD Project
[LinuxDVD] CSS license Andreas Bogk andreas@andreas.org 05 Jul 1999 20:22:15 -0400 Colin Davis <cdavis@thepentagon.com> writes: > From what I have been able to find, it would seem that Matsushita > licenses the CSS encryption technology froo of charge. I believe this is Yes, it's free of charge. Still you're required to agree to a lot of legalese. We're trying to acquire a CSS license, but Matsushita is a little unresponsive. It can't hurt if different parties try this as well. Andreas -- "We show that all proposed quantum bit commitment schemes are insecure because the sender, Alice, can almost always cheat successfully by using an Einstein-Podolsky-Rosen type of attack and delaying her measurement until she opens her commitment." ( http://xxx.lanl.gov/abs/quant-ph/9603004 )