[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 )