Convert 64bit fixed point to 32bit fixed point

Question

If for example two numbers are multiplicated, one is in 8.24 format and second is in 2.30 format, product of those two is number with format 10.54, how to go back to 32bit fixed point format?

Answer 1

The same way rounding always works. Remove the trailing 32 digits. Either by actual rounding, or simple truncation. In any way you should arrive at a 10.22 number.