[FFmpeg-devel] Legal Advice Was: [POLL][RFC] Merge vs Cherry pick for integration of changes

[Baptiste Coudurier]

> On Aug 24, 2025, at 4:11 AM, Kieran Kunhya via ffmpeg-devel <ffmpeg-devel at ffmpeg.org> wrote:
> 
> On Sun, 24 Aug 2025, 11:56 Michael Niedermayer via ffmpeg-devel, <
> ffmpeg-devel at ffmpeg.org> wrote:
> 
>> Hi Kieran
>> 
>> On Sun, Aug 24, 2025 at 07:53:45AM +0100, Kieran Kunhya via ffmpeg-devel
>> wrote:
>>> On Sat, 23 Aug 2025, 21:33 Michael Niedermayer via ffmpeg-devel, <
>>> ffmpeg-devel at ffmpeg.org> wrote:
>>> 
>>>> Hi
>>>> 
>>>> Here is the legal advice that i was given.
>>>> The GA has the full text and that is much more detailed.
>>>> Iam posting the relevant parts so the whole community can see it.
>>>> 
>>>> "a claim that there is GPLv2 code in a file of
>>>> FFmpeg origin that has the LGPLv2.1 license would be a breach of the
>>>> FFmpeg's
>>>> LGPLv2.1 license. While section 3 of the LGPLv2.1 would have allowed
>> him
>>>> to
>>>> take the original FFmpeg files and change the license for them to
>> GPLv2,
>>>> he
>>>> didn't follow the necessary steps to effectively change the license.
>> So
>>>> the
>>>> original code he is building from is still under LGPLv2.1. Since code
>>>> contributions to a copyleft work have to be under the /same /license
>> as
>>>> the
>>>> code you are contributing to (Section 2(c), "You must cause the whole
>> of
>>>> the
>>>> work to be licensed at no charge to all third parties under the terms
>> of
>>>> this
>>>> License"), Paul's contributions to LGPLv2.1 files are under the
>> LGPLv2.1
>>>> license because he didn't exercise the option to change them to GPLv2
>>>> first. A
>>>> claim otherwise would be admitting he is in breach of the FFmpeg
>> license."
>>>> 
>>>> "You can safely assume that any new file he created with a license
>>>> identifier in the file of LGPLv.2.1 is under the LGPLv2.1 license."
>>>> 
>>>> "Paul's response to your use of his code may be to relicense his code
>> under
>>>> the AGPL,* but he cannot change the license retroactively - you would
>>>> have to
>>>> accommodate the AGPL license for any later changes you adopt, but not
>> for
>>>> any
>>>> code you are using from before a license change."
>>>> 
>>>> thx
>>>> 
>>>> [...]
>>>> 
>>> 
>>> Can you confirm the FFlabs lawyer said something different?
>> 
>> I cannot confirm this. I dont remember ever seeing the reply or the
>> question.
>> 
>> My communication with the FFlabs lawyer was through a intermediary
>> developer,
>> who was very busy and the mails where also terse
>> 
>> IIRC i also had to ask multiple times to get any awnser
>> 
> 
> Translation: The FFlabs lawyer didn't agree with my agenda and so I went
> and found one that did.

In all serious matters, that’s called due diligence.

— 
Baptiste