How to fix” /usr/include/string.h:369:26: error: ambiguates old declaration ‘const char* strcasestr(const char*, const char*)’” Faacffmpeg Posted on December 10, 2014 | by admin Fix for error when compiling faac for ffmpeg. /usr/include/string.h:369:26: error: ambiguates old declaration ‘const char* strcasestr(const char*, const char*)’ Remove line 126 containing strcasestr from mpeg4ip.h found in the common/mp4v2 folder