class_docstr: Base class for encoder decoder RNNT-based models.
code: def input_types(self) -> Optional[Dict[str, NeuralType]]:
      return {
          "input_signal": NeuralType(
              ("B", "C", "T", "H", "W"), VideoSignal(), optional=True
          ),
          "input_signal_length": NeuralType(
              tuple("B"), LengthsType(), optional=True
          ),
      }
  
imports: import copy
  import json
  import os
  import tempfile
  from math import ceil
  from typing import Dict, List, Optional, Tuple, Union
  import torch
  from omegaconf import DictConfig, OmegaConf, open_dict
  from pytorch_lightning import Trainer
  from tqdm.auto import tqdm
  from nemo.collections.asr.data import audio_to_text_dataset
  from nemo.collections.asr.losses.rnnt import RNNTLoss, resolve_rnnt_default_loss_name
  from nemo.collections.asr.metrics.wer import WER
  from nemo.collections.asr.models.asr_model import ASRModel
  from nemo.collections.asr.modules.rnnt import RNNTDecoderJoint
  from nemo.collections.asr.parts.mixins import ASRModuleMixin
  from nemo.collections.asr.parts.submodules.rnnt_decoding import RNNTDecoding, RNNTDecodingConfig
  from nemo.collections.asr.parts.utils.audio_utils import ChannelSelectorType
  from nemo.collections.multimodal.speech_cv.data import video_to_text_dataset
  from nemo.core.classes import Exportable
  from nemo.core.classes.common import PretrainedModelInfo, typecheck
  from nemo.core.classes.mixins import AccessMixin
  from nemo.core.neural_types import AcousticEncodedRepresentation, LengthsType, NeuralType, VideoSignal
  from nemo.utils import logging
label_desc: Use image node_id 11 for calling the VisualEncDecRNNTModel obj's underlying member method code with example usage: obj.input_types() and returns: dict