Provide a header based inline reimplementation of it.
Using av_fopen_utf8 doesn't work outside of the libraries when built with MSVC as shared libraries (in the default configuration, where each DLL gets a separate statically linked CRT).
3fb9244642 fftools: Stop using av_fopen_utf8
fftools/ffmpeg_opt.c | 3 ++-
fftools/fopen_utf8.h | 71 ++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 73 insertions(+), 1 deletion(-)