Tiny SV2P model.

def next_frame_sv2p_tiny():
  """Tiny SV2P model."""
  hparams = next_frame_sv2p_atari_softmax()
  hparams.batch_size = 2
  hparams.tiny_mode = True
  hparams.num_masks = 1
  hparams.video_modality_loss_cutoff = 0.4
  hparams.video_num_input_frames = 4
  hparams.video_num_target_frames = 4
  return hparams