class_docstr: Video output implemented by streaming to FFmpeg with .mp4 output.
class_docstr_tok: ["Video","output","implemented","by","streaming","to","FFmpeg","with",".mp4","output","."]
code: def available(cls):
      # Silently check if ffmpeg is available.
      try:
          with open(os.devnull, "wb") as devnull:
              subprocess.check_call(
                  ["ffmpeg", "-version"], stdout=devnull, stderr=devnull
              )
          return True
      except (OSError, subprocess.CalledProcessError):
          return False
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import abc
  import os
  import subprocess
  import time
  import numpy
label_desc: Use image node_id 1 for calling the FFmpegVideoOutput obj's underlying member method code with example usage: obj.available(cls) and returns: True, False