def read_bits(self, amt, signed=False):
        """
        read bits from the stream.
        """

        if amt == 0:
            #yes, this needs to be an explicit check, because some types ask for a 0 signed bits,
            #and we don't want to do a negative bit shift.
            return 0

        if signed:
            #not sure if this is actually right.
            sign = self.read_bits(1)
            num = self.read_bits(amt-1)
            if sign:
                mask = (1 << (amt-1))-1
                num = (num ^ mask)+1
                num *= -1
            return num

        result = 0
        for _ in range(amt):
            if self.bit_idx == 0:
                self.bit_read_val = self.read(1)[0]
            bit = (self.bit_read_val >> (7-self.bit_idx)) & 1
            result = (result << 1) | bit
            self.bit_idx = (self.bit_idx + 1)%8

        return result