code: def _test_ffmpeg_io_tensor_mkv(video_path):
      """test_ffmpeg_io_tensor_mkv"""
      mkv_path = os.path.join(
          os.path.dirname(os.path.abspath(__file__)),
          "test_video",
          "test5.mkv",
      )
      mkv = tfio.IOTensor.from_ffmpeg(mkv_path)
      assert mkv("a:0").shape.as_list() == [None, 2]
      assert mkv("a:0").dtype == tf.float32
      assert mkv("a:0").rate == 48000
      assert mkv("s:0").shape.as_list() == [None]
      assert mkv("s:0").dtype == tf.string
      assert mkv("s:0")[0] == ["...the colossus of Rhodes!\r\n"]
      assert mkv("s:0")[1] == ["No!\r\n"]
      assert mkv("s:0")[2] == [
          "The colossus of Rhodes\\Nand it is here just for you Proog.\r\n"
      ]
      assert mkv("s:0")[3] == ["It is there...\r\n"]
      assert mkv("s:0")[4] == ["I'm telling you,\\NEmo...\r\n"]
  
      video = tfio.IOTensor.from_ffmpeg(video_path)
      assert video("v:0").shape.as_list() == [None, 320, 560, 3]
      assert video("v:0").dtype == tf.uint8
      assert len(video("v:0")) == 166
      assert video("v:0").to_tensor().shape == [166, 320, 560, 3]
  
file_path: io/tests/test_ffmpeg.py
imports: import os
  import sys
  import pytest
  import numpy
  import tensorflow
  import tensorflow_io
label_desc: Use image node_id 4 for calling a global function with example usage: _test_ffmpeg_io_tensor_mkv(video_path) without return types