Recherche avancée

Sur d’autres sites (2523)

• Can't link FFmpeg in Visual Studio 2013

  22 février 2016, par Sir DrinksCoffeeALot

  I’m struggling with this for past 3-4 days with barely any progress. I’ve downloaded "dev" and "shared" archives and extracted them. "Dev" archive has .lib and .h files and "Shared" has .dll files needed for running app. These are the steps that i’ve done linking-wise :

  Project -> Properties -> Configuration Properties -> VC++ Directories -> Include Directories -> ...\ dev\ include

  Project -> Properties -> Configuration Properties -> VC++ Directories -> Library Directories -> ...\ dev\ lib

  Project -> Properties -> Configuration Properties -> C/C++ -> General -> Additional Include Directories -> ...\ dev\ include

  Project -> Properties -> Configuration Properties -> Linker -> General -> Additional Library Directories -> ...\ dev\ lib

  Project -> Properties -> Configuration Properties -> Linker -> Input -> Additional Dependencies -> avcodec.lib ... swscale.lib

  And when i try to build it i get following error :

  Error 1 error LNK2019: unresolved external symbol _avcodec_register_all referenced in function _main...

  I have no idea why,somehow .lib are not getting linked or something or i’ve done something wrong. It’s getting really frustrating and ffmpeg is crucial in project that i’m working on, basicly i can’t do anything without it. So please if someone could point me in right direction i would aprreciate it very much.

  This is the example that im trying to build.

  #include 
  
  extern "C"
  
  {
  
  
  
  #include "libavcodec\avcodec.h"
  
  }
  
  
  
  
  
  #pragma comment(lib, "avcodec.lib")
  
  
  
  int main()
  
  {
  
      printf("Trying avcodec_register_all... ");
  
      avcodec_register_all();
  
      printf("Done.\n");
  
      return 0;
  
  }

  Thank you in advance.

• 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 ?

• 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.