def forward(self, input, input2=None):
        '''
        :param input: input feature map
        :return: feature map down-sampled by a factor of 2
        '''
        avg_out = self.avg(input)
        eesp_out = self.eesp(input)
        output = torch.cat([avg_out, eesp_out], 1)
        if input2 is not None:
            #assuming the input is a square image
            w1 = avg_out.size(2)
            while True:
                input2 = F.avg_pool2d(input2, kernel_size=3, padding=1, stride=2)
                w2 = input2.size(2)
                if w2 == w1:
                    break
            output = output + self.inp_reinf(input2)

        return self.act(output) #self.act(output)

        :param input: input feature map
        :return: feature map down-sampled by a factor of 2
        
model/ESPNet_v2/Model.py