[FFmpeg-devel] [PATCH 1/8] compat/cuda: add dynamic loader

[Sven C. Dack]

On 19/10/16 18:56, Andreas Cadhalpun wrote:
> I think you are missing the main problem here: FFmpeg is licensed
> under the LGPL 2.1, which states [1]:
> "  4. You may copy and distribute the Library [...] in object code
> or executable form [...] provided that you accompany it with the
> complete corresponding machine-readable source code"
>
> If during compilation the cuda.h header is used, it is part of the
> complete source code and thus the license requires it to be
> distributed together with the object code. However, you say that
> Nvidia prohibits re-distribution of this header and as a result
> the compiled ffmpeg binaries cannot legally be distributed.
>
> This is why it requires --enable-nonfree.
>
> Best regards,
> Andreas
>
No. This is exactly what I meant with wearing tin foil hats. Just because a 
compiler includes information provided by header files into the compilation 
process does this not imply a transfer of ownership or copyright of this 
information. The header files do not become a part of the source code. You may 
find the ownership and copyright only no longer being easily distinguishable 
once it becomes a binary. The seperation is however still present and there is 
no magical transfer of ownership happening here. Even if there was, who is to 
say ffmpeg isn't becoming part of the header files and thus is now being owned 
by Nvidia?!? For this reason can such an interpretation of the GPL not make good 
sense. It's just absurd.

How is this with compiling under Windows or just using Intel's or Microsoft's 
compiler? Does this make ffmpeg non-free or does ffmpeg there claiming ownership 
over Intel's or Microsoft's header files?

Anyhow, I don't rally want to get too deep into this topic as this is just about 
configure options and I'm already using the --non-free option. I am merely 
curious about this interpretation of the GPL. I find the interpretation to be 
selfish and it's just asking to be challenged.

Sven