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• Compile FFmpeg Zeranoe Build with Visual Studio 2013

  29 août 2017, par mFeinstein

  I downloaded the most recent Zeranoe dev build here, included the header files to my code, placed extern "C" around the includes, since this is a C++ project and FFmpeg is a C library, and added the libs to Visual Studio as well, and I get this linker error :

  1>Camera.obj : error LNK2019 : unresolved external symbol _av_free referenced in function __catch$ ?NewFrameReceived@Camera@MicroDFV_Camera@@AAEXKKKGPAE@Z$0
  1>Camera.obj : error LNK2019 : unresolved external symbol _av_freep referenced in function __catch$ ?NewFrameReceived@Camera@MicroDFV_Camera@@AAEXKKKGPAE@Z$0
  1>Camera.obj : error LNK2019 : unresolved external symbol _av_frame_alloc referenced in function __catch$ ?NewFrameReceived@Camera@MicroDFV_Camera@@AAEXKKKGPAE@Z$0
  1>Camera.obj : error LNK2019 : unresolved external symbol _av_frame_free referenced in function __catch$ ?NewFrameReceived@Camera@MicroDFV_Camera@@AAEXKKKGPAE@Z$0
  1>Camera.obj : error LNK2019 : unresolved external symbol _avcodec_register_all referenced in function __catch$ ??0Camera@MicroDFV_Camera@@QAE@V ?$basic_string@DU ?$char_traits@D@std@@V ?$allocator@D@2@@std@@0PAX@Z$0
  1>Camera.obj : error LNK2019 : unresolved external symbol _avcodec_alloc_context3 referenced in function __catch$ ?NewFrameReceived@Camera@MicroDFV_Camera@@AAEXKKKGPAE@Z$0
  1>Camera.obj : error LNK2019 : unresolved external symbol _avcodec_open2 referenced in function __catch$ ?NewFrameReceived@Camera@MicroDFV_Camera@@AAEXKKKGPAE@Z$0
  1>Camera.obj : error LNK2019 : unresolved external symbol _avcodec_close referenced in function __catch$ ?NewFrameReceived@Camera@MicroDFV_Camera@@AAEXKKKGPAE@Z$0
  1>Camera.obj : error LNK2019 : unresolved external symbol _av_init_packet referenced in function __catch$ ?NewFrameReceived@Camera@MicroDFV_Camera@@AAEXKKKGPAE@Z$0
  1>Camera.obj : error LNK2019 : unresolved external symbol _av_packet_unref referenced in function __catch$ ?NewFrameReceived@Camera@MicroDFV_Camera@@AAEXKKKGPAE@Z$0
  1>Camera.obj : error LNK2019 : unresolved external symbol _avcodec_find_encoder referenced in function __catch$ ?NewFrameReceived@Camera@MicroDFV_Camera@@AAEXKKKGPAE@Z$0
  1>Camera.obj : error LNK2019 : unresolved external symbol _avcodec_encode_video2 referenced in function __catch$ ?NewFrameReceived@Camera@MicroDFV_Camera@@AAEXKKKGPAE@Z$0
  1>Camera.obj : error LNK2019 : unresolved external symbol _av_opt_set referenced in function __catch$ ?NewFrameReceived@Camera@MicroDFV_Camera@@AAEXKKKGPAE@Z$0
  1>Camera.obj : error LNK2019 : unresolved external symbol _av_image_alloc referenced in function __catch$ ?NewFrameReceived@Camera@MicroDFV_Camera@@AAEXKKKGPAE@Z$0
  1>M :\Desktop\OpenCVTest\Debug\OpenCVTest.exe : fatal error LNK1120 : 14 unresolved externals

  Searching here and on Google I found many recommendations, such as to add #pragma comment(lib,...), and that the libs are static, so their order is important, and none of this helps.

  So I scratched my head even more and realized that the Zeranoe build is made with MinGW-w64, so probably it won’t link with Visual Studio. I inspected the lib using dumpbin and the symbols on the libs don’t have the underscore, so I am pretty sure it won’t work.

  The other Zeranoe builds for Windows don’t have libs, they are just plain .exe or exe + .dll.

  Will I have to make my own VS2013 build of FFmpeg to link it, or is there some alternative way ?

• Running an .exe on cmd line from a visual studio c++ project

  28 novembre 2017, par Pop24

  BACKGROUND

  I have a visual studio c++ project "VideoAnalyser" which analyses a video for specific features based predominantly on OPENCV.

  I now want to run this project against a large directory of video files. The issue I have is that they must first be converted to .avi file format in order to utilise the OPENCV functions within my project. I can do this with FFMPEG. It is a large directory and i do not want to create duplicates of every video file with the format changed. Rather, I’d take the video file, convert it, then run the "Video Analyser" against it destroy the reformatted file and then move onto the next video file and repeat. I can run FFMPEG independantly on the command line with no issues, however I’m unsure how to integrate this into my "Video Analyser" project which leads to...

  MY QUESTION

  How do I get my "VideoAnalyser" c++ project to run the FFMPEG exectuable through the cmd line ?

• ffmpeg shared libraries setup on visual studio 2013

  19 décembre 2017, par Hyun Jung

  Setting up ffmpeg shared libraries that are downloaded from ffmpeg zenaroe (https://ffmpeg.zeranoe.com/builds/) for windows_64bit. The IDE is VS2013.

  I downloaded dev and shared build for windows 64bit.

  And followed steps like bellow but when building, linker error happens. The object file is created so compiling seems done. But there seems to be a problem finding referenced functions at the linking stage.

  1. Create win32 project and main.cpp
  2. Copy ffmpeg_dev’s include and lib folders to solution directory.
  3. Open project properties and add the include dir and the lib dir.
  4. Add lib names to linker input.

  5. Build

     main.cpp

     extern "C"{
     
     #include 
     
     }
     
     int main(void){
     
     
     
         av_register_all();
     
     
     
         return 0;
     
     }

  The linker error is :

  LNK2019 unresloved external symbol _av_register_all referenced in function _main.