[FFmpeg-devel] [PATCH 1/2] avcodec/nvenc: Include NVENC SDK header

[Andreas Cadhalpun]

On 10.12.2015 19:48, Matt Oliver wrote:
> On 11 December 2015 at 04:23, Andreas Cadhalpun <
> andreas.cadhalpun at googlemail.com> wrote:
> 
>> On 10.12.2015 17:42, Matt Oliver wrote:
>>> Im not sure that Debian not including libcuda is a valid argument for it
>>> not being a system library as thats just one OS.
>>
>> The GPL defines a system library only in the context of a specific
>> operating system. So what is a system library differs from one OS to
>> another.
>> Therefore one can't just claim something is a system library and thus it's
>> fine to use it, unless specifying the specific OS one talks about.
>>
> 
> So does that mean that the discussion is not so much about whether it is a
> system lib or not but on what OSs it can be considered a system lib?

Yes, that's the relevant topic.

>> So I dont believe that just because
>>> some systems dont have it doesnt stop it from being a system library.
>>
>> You're treating being a system library as something OS-agnostic, which
>> it isn't. A library can be a system library on Windows, but not on Android.
>>
>> Whether or not it's a system library on Windows doesn't matter for any
>> other OS.
>>
> 
> OK so by that logic does that mean we can say that it IS a system lib on
> Windows and is therefore GPL compliant?

If it is a system library on Windows (which I don't know), it is
GPL-compatible to distribute a FFmpeg binary for Windows with nvenc enabled.

> So then the issue becomes what OSs can we say it is a system lib on.
> If the option is disabled by default on
> these other OSs then would you agree that ffmpeg is remaining GPL compliant
> and its upto the OS distributors who enable the nvenc option when packaging
> ffmpeg to be doing so as they also have the appropriate nvenc system libs.

Yes, the FFmpeg project doesn't distribute binaries itself, only sources,
which is GPL compliant.
Thus nvenc is only a potential problem for distributors of compiled ffmpeg
binaries.

Best regards,
Andreas