for alignment, We can use more generic function such as

static void int_to_stream(uint32_t val, uint8_t *dest)
{
        int i;
        for(i=0;i<4;i++) {
                *(dest+i) = (val >> (8*i)) & 0xff;
        }
}

static void int64_to_stream(uint64_t val, uint8_t *dest)
{
        int i;
        for(i=0;i<8;i++) {
                *(dest+i) = (val >> (8*i)) & 0xff;
        }
}

YH