def merge(inputs, targets):
      """Split inputs and targets into lists."""
      inputs = tf.unstack(inputs, axis=1)
      targets = tf.unstack(targets, axis=1)
      assert len(inputs) == hparams.video_num_input_frames
      assert len(targets) == hparams.video_num_target_frames
      return inputs + targets
Split inputs and targets into lists.
tensor2tensor/models/video/base.py