i dident found any errors when installing mp4box
other wise it usually says install MP4Box failed. or so but it dident it said MP4Box install completed. and continued with rest 
btw heres message i get at end
make[3]: Leaving directory `/usr/src/ffmpegscript/gpac/applications/mp4client'
install -m 755 -s ../../bin/gcc/MP4Client "/usr/local/cpffmpeg//bin"
make[2]: Leaving directory `/usr/src/ffmpegscript/gpac/applications/mp4client'
make[1]: Leaving directory `/usr/src/ffmpegscript/gpac/applications'
install -d "/usr/local/cpffmpeg//lib64/gpac"
install bin/gcc/*.so "/usr/local/cpffmpeg//lib64/gpac"
rm -f /usr/local/cpffmpeg//lib64/gpac/libgpac.so
rm -f /usr/local/cpffmpeg//lib64/gpac/nposmozilla.so
strip bin/gcc/libgpac.so
install -s -m 755 bin/gcc/libgpac.so /usr/local/cpffmpeg//lib64/libgpac-0.4.5.so
ln -sf libgpac-0.4.5.so /usr/local/cpffmpeg//lib64/libgpac.so
ldconfig || true
install -d "/usr/local/cpffmpeg//man"
install -d "/usr/local/cpffmpeg//man/man1"
if [ -d doc ] ; then \
install -m 644 doc/man/mp4box.1 /usr/local/cpffmpeg//man/man1/ ; \
install -m 644 doc/man/mp4client.1 /usr/local/cpffmpeg//man/man1/ ; \
install -m 644 doc/man/gpac.1 /usr/local/cpffmpeg//man/man1/ ; \
install -d "/usr/local/cpffmpeg//share/gpac" ; \
install -m 644 doc/gpac.mp4 /usr/local/cpffmpeg//share/gpac/ ; \
fi
Installation of gpac-full-0.4.5.tar.gz ....... Completed
okay as i checked log again i noticed it creates a shortcut folder linked towards libgpac-0.4.5.so 