[FFmpeg-devel] mac, ios clock_gettime patch

[Wang Bin]

>
> So how is it possible that clock_gettime() must not be defined to allow
> starting the executable, but this object has to be?


Because I build ffmpeg with cc and linker flag "-mmacosx-version-min=10.7"
to support lower os versions. If no such flag, the target os is the sdk
version you use, e.g. 10.x. Then the symbol is not compiled as a weak
symbol and it must be resolved at runtime.
You can see all weak symbols using `nm -mg libavcodec.dylib |grep -E
"undefined.*weak"`