ctc.py 文件源码

def forward(self, inputs):
        xp = cuda.get_array_module(inputs[0])
        self.input_length = inputs[0]

        # The length of path is (2 * label_length + 1)
        self.path_length = 2 * inputs[1] + 1

        batch_size = len(inputs[2])
        yseq_shape = (len(inputs) - 3,) + inputs[3].shape
        self.yseq = _softmax(xp.vstack(inputs[3::]).reshape(yseq_shape), xp)
        log_yseq = self.log_matrix(self.yseq, xp)
        self.path = _label_to_path(inputs[2], self.blank_symbol, xp)
        self.prob_trans = self.calc_trans(self.path, log_yseq, xp)

        loss = utils.force_array(xp.sum(
            _logsumexp(self.prob_trans[0], xp, axis=1)))
        loss /= -batch_size
        return loss,