x264编译 log2f 链接错误

http://bbs.chinavideo.org/viewthread.php?tid=9715

log2f这个函数在analysis.c中使用到，这个函数并没有定义，所以需要一个宏定义：
#define log2f(x) (logf(x)*1.4426950408889634f)
把这段代码加入到
osdep.h的
#ifdef _MSC_VER
#define inline __inline
#define strcasecmp stricmp
#define strncasecmp strnicmp
#define snprintf _snprintf
#define fseek _fseeki64
#define ftell _ftelli64
#define isfinite _finite
#define strtok_r strtok_s
#define _CRT_SECURE_NO_DEPRECATE
#define X264_VERSION "" // no configure script for msvc
#define log2f(x) (logf(x)*1.4426950408889634f)
#endif

// /linphone-android/submodules/externals/x264/common/osdep.h

#if !HAVE_LOG2F
#define log2f(x) (logf(x)/0.693147180559945f)
#define log2(x) (log(x)/0.693147180559945)
#endif