Wrong AC_CHECK_LIB for the vpx library

[giulianoc]

Hi,
in vireo/vireo/configure.ac we have the following row to check the existence of the vpx library.
AC_CHECK_LIB([vpx], [vpx_free])
I guess this is wrong because in my case did not find the vpx_free function.
In fact AC_CHECK_LB build the program
#ifdef __cplusplus
extern "C"
#endif
char vpx_free ();
int
main ()
{
return vpx_free ();
return 0;
}
and it fails when it is compiled
g++ -o conftest -g -O2 -fvisibility=hidden -fvisibility-inlines-hidden -I/app/2/giuliano/tmp/vireo/vireoBinaries/include -I/app/2/giuliano/tmp/vireo/libwebm -L/app/2/giuliano/tmp/vireo/vireoBinaries/lib -L/app/2/giuliano/tmp/vireo/libwebm a.cpp -lvorbisenc -lvorbis -lpthread -logg -lfdk-aac -llsmash -lvpx
/tmp/ccUMBT2f.o: In function main': /app/2/giuliano/tmp/vireo/vireo/vireo/a.cpp:10: undefined reference to vpx_free()'
collect2: error: ld returned 1 exit status

I suggest to change the check using the following row
AC_CHECK_LIB([vpx], [vpx_codec_dec_init_ver])
This one works fine.
Best regards
giu