class_docstr: Decode mp4 file to frames.
  Args:
      filepath: the file path of mp4 file
class_docstr_tok: ["Decode","mp4","file","to","frames",".","Args",":","filepath",":","the","file","path","of","mp4","file"]
code: def __init__(
      self,
      backend="cv2",
      mode="train",
      sampling_rate=32,
      num_seg=8,
      num_clips=1,
      target_fps=30,
  ):
      self.backend = backend
      # params below only for TimeSformer
      self.mode = mode
      self.sampling_rate = sampling_rate
      self.num_seg = num_seg
      self.num_clips = num_clips
      self.target_fps = target_fps
  
imports: import cv2
  import numpy
  from PIL import Image
  import paddle
label_desc: Use image node_id 1 to create a new VideoDecoder object from inherited base classes: object with example: obj = VideoDecoder(backend, mode, sampling_rate, num_seg, num_clips, target_fps)