Mac下编译ffmpeg出现“ERROR: x265 not found using pkg-config”

x265已经编译成功，但是ffmpeg/configure出现错误

　　ERROR: x265 not found using pkg-config

看了一下config.log，出了一坨“Undefined symbols for architecture x86_64” 的错误

Undefined symbols for architecture x86_64:
  "vtable for __cxxabiv1::__class_type_info", referenced from:
      ...
  "vtable for __cxxabiv1::__si_class_type_info", referenced from:
      ...
  "vtable for __cxxabiv1::__vmi_class_type_info", referenced from:
　　　 ...
  ...
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
ERROR: x265 not found using pkg-config

google 了半天，有些帖子说在x265.pc的“Libs.private:”里添加“-lstdc++”能解决。

- Libs.private: -lto_library -lc++ -ldl
+ Libs.private: -lto_library -lc++ -lstdc++ -ldl

试了一下，确实可以。

原来是苹果对应GNU的libstdc++搞了个自己的libc++，导致Mac下GCC链接出了问题。自动化编译时在脚本里添加一行

export LDFLAGS="${LDFLAGS} -lstdc++"

就好。MAC和linux下都能顺利编过。因为Linux上本来就是使用的libstdc++。