c++ - Windows 中的 ffmpeg/libav 链接问题

Question

我已经将 ffmpeg 和 libav 从 Linux 交叉编译到 Windows (mingw32)。所以，我已经有了我的 .a 文件并准备好用于在我的 MSVC2010 项目中进行链接。问题是我收到链接错误，我不明白为什么:

1>RTSPCapture.obj : error LNK2019: unresolved external symbol _avformat_free_context referenced in function "public: int __thiscall Imagsa::RTSPCapture::dumpSync(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &,class std::basic_stringstream<char,struct std::char_traits<char>,class std::allocator<char> > &,double *,class std::vector<class Imagsa::MjpegFrame,class std::allocator<class Imagsa::MjpegFrame> > &)" (?dumpSync@RTSPCapture@Imagsa@@QAEHABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@0AAV?$basic_stringstream@DU?$char_traits@D@std@@V?$allocator@D@2@@4@PANAAV?$vector@VMjpegFrame@Imagsa@@V?$allocator@VMjpegFrame@Imagsa@@@std@@@4@@Z)
1>RTSPCapture.obj : error LNK2019: unresolved external symbol _avio_close referenced in function "public: int __thiscall Imagsa::RTSPCapture::dumpSync(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &,class std::basic_stringstream<char,struct std::char_traits<char>,class std::allocator<char> > &,double *,class std::vector<class Imagsa::MjpegFrame,class std::allocator<class Imagsa::MjpegFrame> > &)" (?dumpSync@RTSPCapture@Imagsa@@QAEHABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@0AAV?$basic_stringstream@DU?$char_traits@D@std@@V?$allocator@D@2@@4@PANAAV?$vector@VMjpegFrame@Imagsa@@V?$allocator@VMjpegFrame@Imagsa@@@std@@@4@@Z)
1>RTSPCapture.obj : error LNK2019: unresolved external symbol _avcodec_close referenced in function "public: int __thiscall Imagsa::RTSPCapture::dumpSync(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &,class std::basic_stringstream<char,struct std::char_traits<char>,class std::allocator<char> > &,double *,class std::vector<class Imagsa::MjpegFrame,class std::allocator<class Imagsa::MjpegFrame> > &)" (?dumpSync@RTSPCapture@Imagsa@@QAEHABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@0AAV?$basic_stringstream@DU?$char_traits@D@std@@V?$allocator@D@2@@4@PANAAV?$vector@VMjpegFrame@Imagsa@@V?$allocator@VMjpegFrame@Imagsa@@@std@@@4@@Z)

有人知道会发生什么吗？

Answer 1

在包含 libav* header 时，您必须使用 C 风格的名称修饰。

extern "C"
{
#include <libavcodec/avcodec.h>
#include <libavcodec/avcodec.h>
...
}