[FFmpeg-trac] #8836(avformat:new): Request: allow custom AviSynth DLL path

[FFmpeg]

#8836: Request: allow custom AviSynth DLL path
----------------------------------+---------------------------------------
             Reporter:  stax76    |                     Type:  enhancement
               Status:  new       |                 Priority:  normal
            Component:  avformat  |                  Version:  unspecified
             Keywords:            |               Blocked By:
             Blocking:            |  Reproduced by developer:  0
Analyzed by developer:  0         |
----------------------------------+---------------------------------------
 I would like to suggest adding support to define the AviSynth DLL location
 via command line.

 If this is too much work then support via environment variable would be
 sufficient.

 Or better support for both env var and CLI were CLI has higher priority.

 Why is it important?

 In staxrip we want to support installed avisynth and also portable
 avisynth. We want to have the possibility to use portable mode even when
 avisynth is installed. This is currently not possible because avisynth is
 installed in system32. Only a soft link workaround is possible but this
 requires admin rights or developer mode and that is very unfortunate for a
 portable app.

 Currently, staxrip uses about ten avisynth reader tools and ffmpeg is the
 only one that blocks default DLL loading by the OS, this is extremely
 unfortunate because portable mode will not work even when avisynth is not
 installed.

 Sample code found in the frameserver.dll of staxrip:

 {{{
 WCHAR* dllPath = _wgetenv(L"AviSynthDLL");
 HMODULE dll;

 if (FileExists(dllPath))
     dll = LoadLibrary(dllPath);
 else
     dll = LoadLibrary(L"AviSynth.dll");
 }}}

--
Ticket URL: <https://trac.ffmpeg.org/ticket/8836>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker