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• How to use ffmpeg commands assuming having prebuilt .so files in android

  23 mars 2018, par Hossein Yazdanfar

  I found some github projects that pushed ffmpeg latest version .so files.

  unfortunately many projects are so old...

  I read a lot but i got errors to reach my goal.

  I want to use those .so file in android project(android studio,and with java) and doing thing by passing commands.

  any one can tell me procedure or code ?

  the sample project that having .so file :
  ffmpeg 4 android

• Revision fec6886f2c : Remove labels from quantize Use break instead of goto for early exit. Unbreaks

  19 juin 2014, par Johann

  Changed Paths :
   Modify /vp8/encoder/x86/quantize_sse2.c

  
   Modify /vp8/encoder/x86/quantize_sse4.c

  
  
  Remove labels from quantize

  Use break instead of goto for early exit. Unbreaks Visual Studio
  builds.

  Change-Id : I96dee43a3c82145d4abe0d6a99af6e6e1a3991b5

• Emscripten : Linking library to project

  13 avril 2021, par locust

  I'm trying to build a small project that uses ffmpeg library to WebAssembly, with use of Emscripten. Before that, I tried it out by transpiling some simple program from C into Wasm and it worked fine, but that time I was not using any additional libraries.

  


  For C++ I'm working with Visual Studio and FFmpeg I linked in project's "Properties" as follows :

  


  


  1. all .h header files I placed in "include" catalog and I added it as "Additional Include Directories" in "C/C++" section

     


  


  2. all .lib and .dll.a (for example avcodec.lib or libavcodec.dll.a) files I placed in "lib" and added as "Additional Library Directories" in "Linker" section

     


  


  


  All includes and the program itself works fine, so now I was trying to prepare a Wasm module with Emscripten with the same same command that I used earlier, but already knowing that is not going to work :

  


  em++ cut_video.cpp -Os -g1 -L lib -I include -s WASM=1 -s FORCE_FILESYSTEM=1 -s ALLOW_MEMORY_GROWTH=1 -s EXPORT_ES6=1 -s MODULARIZE=1 -s "EXPORT_NAME='Editor'" -s "ENVIRONMENT='web'" -s EXPORTED_FUNCTIONS="['_doubler', '_cut_video', '_cut_video1']" -s ERROR_ON_UNDEFINED_SYMBOLS=0  -s ASSERTIONS=1 --bind -o cutter.js


  


  I added the "-I include" parameter which is suppose to be pointing to the same header files, that I mentioned above, and it seems to be fine for Emscripten, because the initial error was solved by it.
Emscripten already found out the problem with functions from ffmpeg library, so I added "ERROR_ON_UNDEFINED_SYMBOLS=0" just to see what will happen when I will add this module to front-end app. Obviously it end up with error "missing function : av_register_all", which is first ffmpeg function within my code.

  


  All explanations that can be helpful I found really unclear for me, because generally I'm not working with C++ or Linux environment, so I'm not fimilliar with Makefile or so.

  


  Is there a way, basing on what I described and how my project was prepared with Visual Studio, to tell the Emscripten to use those pre-build .dll.a or .lib files of FFmpeg for my app ? Or how should I modify my project to make it acceptable for Emscripten ?

  


  Edit : Since cut_video.cpp file is quite big, maybe it's a better idea to just paste here a link to this file on github instead of the big block of code.