old_contents: import os
  import subprocess
  
  import av
  import av.datasets
  
  
  # We want an H.264 stream in the Annex B byte-stream format.
  # We haven't exposed bitstream filters yet, so we're gonna use the `ffmpeg` CLI.
  h264_path = 'night-sky.h264'
  if not os.path.exists(h264_path):
      subprocess.check_call(['ffmpeg',
          '-i', av.datasets.curated('pexels/time-lapse-video-of-night-sky-857195.mp4'),
          '-vcodec', 'copy', 
          '-an', 
          '-bsf:v', 'h264_mp4toannexb',
          h264_path,
      ])
  
  
  fh = open(h264_path, 'rb')
  
  codec = av.CodecContext.create('h264', 'r')
  
  while True:
  
      chunk = fh.read(1 << 16)
  
      packets = codec.parse(chunk)
      print("Parsed {} packets from {} bytes:".format(len(packets), len(chunk)))
  
      for packet in packets:
  
          print('   ', packet)
  
          frames = codec.decode(packet)
          for frame in frames:
              print('       ', frame)
  
      # We wait until the end to bail so that the last empty `buf` flushes
      # the parser.
      if not chunk:
          break
  
new_contents: import os
  import subprocess
  
  import av
  import av.datasets
  
  
  # We want an H.264 stream in the Annex B byte-stream format.
  # We haven't exposed bitstream filters yet, so we're gonna use the `ffmpeg` CLI.
  h264_path = 'night-sky.h264'
  if not os.path.exists(h264_path):
      subprocess.check_call([
          'ffmpeg',
          '-i', av.datasets.curated('pexels/time-lapse-video-of-night-sky-857195.mp4'),
          '-vcodec', 'copy',
          '-an',
          '-bsf:v', 'h264_mp4toannexb',
          h264_path,
      ])
  
  
  fh = open(h264_path, 'rb')
  
  codec = av.CodecContext.create('h264', 'r')
  
  while True:
  
      chunk = fh.read(1 << 16)
  
      packets = codec.parse(chunk)
      print("Parsed {} packets from {} bytes:".format(len(packets), len(chunk)))
  
      for packet in packets:
  
          print('   ', packet)
  
          frames = codec.decode(packet)
          for frame in frames:
              print('       ', frame)
  
      # We wait until the end to bail so that the last empty `buf` flushes
      # the parser.
      if not chunk:
          break
  
subject: Fix styling for flake8.