class_docstr: A `tf.Dataset` of Y'CbCr video frames from '.y4m' files.
  
  This dataset yields tuples of `tf.uint8` tensors, where each tuple represents
  one video frame. It reads all files sequentially, and concatenates all frames
  into one big linear sequence.
  
  The first tensor contains the luma plane (Y') and has shape `(H, W, 1)`, where
  `H` and `W` are the height and width of the frame, respectively. The second
  tensor contains the two chroma planes (CbCr) and has shape `(Hc, Wc, 2)`.
  If the file uses 4:2:0 chroma format with vertically and horizontally
  interstitially sited chroma pixels (a.k.a. JPEG or MPEG1-style chroma
  alignment, marked in the file as `C420jpeg`), then `Hc == H/2` and
  `Wc == W/2`. If the file uses 4:4:4 chroma format (marked in the file as
  `C444`), then `Hc == H` and `Wc == W`.
  
  Other chroma formats (as well as interlaced frame formats) are currently not
  supported. Note that this means that the dataset refuses to read files with
  other 4:2:0 chroma alignments (for example, DV or MPEG-2 styles). Any other
  markers in the file (such as frame rate, pixel aspect ratio etc.) are
  silently ignored.
code: def _inputs(self):
      return []
  
imports: import tensorflow
  from tensorflow_compression.python.ops import gen_ops
label_desc: Use image node_id 2 for calling the Y4MDataset obj's underlying member method code with example usage: obj._inputs() and returns: list