全网首发：编译ffmpeg：error: implicit declaration of function ‘wcsdup‘； did you mean ‘wcscmp‘?

• 具体错误

libavdevice/dshow_pin.c:135:11: error: implicit declaration of function 'wcsdup'; did you mean 'wcscmp'? [-Werror=implicit-function-declaration]
     *id = wcsdup(L"libAV Pin");
           ^~~~~~
           wcscmp

• 解决办法

打开/usr/include/wchar.h，搜索wcscpy，可以发现wcsdup在另外一个#if中定义。将其复制过来即可。大体变成：

wchar_t	*wcscpy (wchar_t *__restrict, const wchar_t *__restrict);

//新加的
wchar_t *wcsdup (const wchar_t *);