[Libav-user] Licensing Issues with Modifying libavformat/libavformat.av

Carl Eugen Hoyos cehoyos at ag.or.at
Fri Jun 17 21:38:30 CEST 2016

 <billcame at ...> writes:

> I am compiling FFmpeg for both Mac and Windows.  For Mac, I can 
> compile the source unmodified as is and use it.  For Windows, I 
> have to modify libavformat/libavformat.av in order to allow 2 
> functions to be exported in avformat.dll.  This is the only 
> modification. The two functions are accessible from the 
> unmodified source code compiled as dylibs.
> Is this considered a configuration option while building?  I am 
> concerned about licensing issues modifying FFmpeg source.  When 
> FFmpeg is configured, it is compiled without "--enable-gpl" and 
> without "--enable-nonfree" but with "--enable-shared".

(You are not showing us the complete configure line, so my answer 
is only guessing, please show the complete configure line if you 
need a definite answer.)

I am not sure I understand your question:
The GPL and the LGPL do not just allow you to modify the source 
code, it actually is a fundamental right you have.
Your question sounds to me as if you think it makes a difference 
if you change the source code or not - in fact, it makes no 
difference, you have to fulfill the requirements of the (L)GPL 
not matter if you changed the source code or not.

In any case, your change is clearly not a configuration change 
but a change of the source code (which you are definitely allowed 
to change).

Carl Eugen

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