未解决的外部因素试图使用ffmpeg。

I'm trying to use some functions from ffmpeg and am running into resilient linker errors. Here's what I did:

我正在尝试使用ffmpeg中的一些函数，并遇到了弹性链接器错误。这是我所做的:

• Downloaded the latest 32-bit "Dev" build from http://ffmpeg.zeranoe.com/builds/ (i.e. ffmpeg-20130418-git-ee94362-win32-dev)
• 从http://ffmpeg.zeranoe.com/builds/(即ffmpeg-20130418-git-ee94362-win32-dev)下载最新的32位“Dev”。
• Created a "General - empty" C++ project in Visual Studio 2012 Premium
• 在Visual Studio 2012 Premium中创建了一个“通用-空”c++项目
• Added the [ffmpeg]/lib folder to Linker -> Input -> "Additional Library Directories"
• 将[ffmpeg]/lib文件夹添加到Linker ->输入->“附加库目录”
• Added "swscale.lib;avutil.lib;avformat.lib;avdevice.lib;avcodec.lib;" to Linker -> Input -> "Additional Dependencies"
• 添加“swscale.lib;avutil.lib;avformat.lib;avdevice.lib;avcodec.lib;”到链接器->输入->“附加依赖项”
• Added the following under C++ -> General -> Additional Include Directories:
  • [ffmpeg]/include
  • ffmpeg /包括
  • [ffmpeg]/include/libswscale
  • ffmpeg / include / libswscale
  • [ffmpeg]/include/libavformat
  • ffmpeg / include / libavformat
• 在c++ ->通用->附加目录下增加以下内容:[ffmpeg]/ Include [ffmpeg]/ Include /libswscale [ffmpeg]/ Include /libavformat

This is my main.cpp:

这是我main.cpp:

#include "avformat.h"

int main()
{
    av_register_all();
} 

This fails with:

这个操作失败:

error LNK2019: unresolved external symbol "void __cdecl av_register_all(void)" (?av_register_all@@YAXXZ) referenced in function _main

错误LNK2019:未解决的外部符号“void __cdecl av_register_all(void)”(av_register_all@yaxxz)在函数_main中引用。

How can I fix this error?

我如何修正这个错误?

1 个解决方案

#1

As you're using C++, you need to surround your ffmpeg #include statements with extern "C" like this :

当您使用c++时，您需要将ffmpeg #include语句括起来，使用如下形式的extern "C"语句:

extern "C"
{
    #include "avformat.h"
}