Re: [Matroska-general] Re: help on libmpdemux usage (Modifié par Jérôme Cornet)

Steve Lhomme steve.lhomme at
Sat Jan 17 11:24:26 CET 2004

ChristianHJW wrote:

> D Richard Felker III wrote:
>> Not at all. Someone is perfectly free to make a plugin for a
>> proprietary system out of GPL code for their own private use, but the
>> GPL does not give them permission to distribute this derived work
>> since it is linked (even dynamically) to proprietary code.
>> Rich
> Hmmm, interesting discussion. I have to think through this a second 
> time, but it seems Richard has just been proving to me that a GPL 
> license is basically incompatible with *M$ DirectShow* also, and thus we 
> presently dont allow anybody else to make and release a DirectShow 
> parser filter for our stuff, as long as we have this license type for 
> our main lib. Have to check if QPL would maybe allow, but i dont think 
> it will be less restrictive in this respect.

Don't worry, you're not the first person to ask about this. And if there 
was a definitive answer noone would need to question it again. But 
actually there is *no* answer to this... My opinion is that a DSF is 
just a standalone piece of code, that could be used by a DirectShow 
clone that could be GPLed. So it's not hard linked in any kind to 
anything proprietary. Sowe don't mind about it.

> Of course, this is currently no issue as we, the license holders, are 
> distributing our own DShow parser/muxer filters, but to stress the same 
> example as discussed here, if anybody wanted to make a Quicktime plugin 
> using libmatroska/libebml, he'd violate the GPL doing so :O !! And 
> jcsston is just working on a Helix/RealNetworks muxer for matroska, and 
> using libmatroska for that ! As Helix itself is not GPL, but using a 
> different license style to the best of my knowledge, you basically cant 
> use any GPL plugins with it without violating GPL itself ?

The license for Helix is compatible with the GPL. It's stated on Real's 
site. Of course Quicktime may be another problem...

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