[FFmpeg-devel] Load FDK AAC at run-time

[Kyle Schwarz]

Hi,

I propose that FFmpeg be changed to allow FDK AAC to be loaded at run-time.

There is a demand for FDK AAC, but FDK AAC cannot be compiled into a 
FFmpeg binary and remain compatible with the GPL. FDK AAC can however be 
redistributed as a binary alongside a FFmpeg copy that is GPL.

Currently FFmpeg on Windows requires the FDK AAC .dll file to be present 
to use FFmpeg at all, instead of only loading the .dll file when the 
encoder is actually used.

The license for FDK AAC can be found here: 
<https://github.com/mstorsjo/fdk-aac/blob/master/NOTICE>

Since the FFmpeg section of code that calls the FDK AAC library is LGPL, 
there should be no issue compiling FFmpeg to support a run-time load.

I can begin working on a patch for configure and libfdk-aacenc.c if this 
type of modification would be accepted by FFmpeg.

The configure script would be changed to error if GPL is enabled, *and* 
FDK AAC is not a shared/dynamic library. But if GPL is enabled and FDK 
AAC is a shared/dynamic library then the configure script would continue.

Best regards,
   Kyle Schwarz