webrtc/tools/compare_videos.py

#!/usr/bin/env python
# Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
#
# Use of this source code is governed by a BSD-style license
# that can be found in the LICENSE file in the root of the source
# tree. An additional intellectual property rights grant can be found
# in the file PATENTS.  All contributing project authors may
# be found in the AUTHORS file in the root of the source tree.

import optparse
import os
import shutil
import subprocess
import sys
import tempfile


SCRIPT_DIR = os.path.dirname(os.path.abspath(__file__))

# Chrome browsertests will throw away stderr; avoid that output gets lost.
sys.stderr = sys.stdout


def _ParseArgs():
  """Registers the command-line options."""
  usage = 'usage: %prog [options]'
  parser = optparse.OptionParser(usage=usage)

  parser.add_option('--label', type='string', default='MY_TEST',
                    help=('Label of the test, used to identify different '
                          'tests. Default: %default'))
  parser.add_option('--ref_video', type='string',
                    help='Reference video to compare with (YUV).')
  parser.add_option('--test_video', type='string',
                    help=('Test video to be compared with the reference '
                          'video (YUV).'))
  parser.add_option('--frame_analyzer', type='string',
                    help='Path to the frame analyzer executable.')
  parser.add_option('--barcode_decoder', type='string',
                    help=('Path to the barcode decoder script. By default, we '
                          'will assume we can find it in barcode_tools/'
                          'relative to this directory.'))
  parser.add_option('--ffmpeg_path', type='string',
                    help=('The path to where the ffmpeg executable is located. '
                          'If omitted, it will be assumed to be present in the '
                          'PATH with the name ffmpeg[.exe].'))
  parser.add_option('--zxing_path', type='string',
                    help=('The path to where the zxing executable is located. '
                          'If omitted, it will be assumed to be present in the '
                          'PATH with the name zxing[.exe].'))
  parser.add_option('--stats_file_ref', type='string', default='stats_ref.txt',
                    help=('Path to the temporary stats file to be created and '
                          'used for the reference video file. '
                          'Default: %default'))
  parser.add_option('--stats_file_test', type='string',
                    default='stats_test.txt',
                    help=('Path to the temporary stats file to be created and '
                          'used for the test video file. Default: %default'))
  parser.add_option('--stats_file', type='string',
                    help=('DEPRECATED'))
  parser.add_option('--yuv_frame_width', type='int', default=640,
                    help='Width of the YUV file\'s frames. Default: %default')
  parser.add_option('--yuv_frame_height', type='int', default=480,
                    help='Height of the YUV file\'s frames. Default: %default')
  options, _ = parser.parse_args()

  if options.stats_file:
    options.stats_file_test = options.stats_file
    print ('WARNING: Using deprecated switch --stats_file. '
           'The new flag is --stats_file_test.')

  if not options.ref_video:
    parser.error('You must provide a path to the reference video!')
  if not os.path.exists(options.ref_video):
    parser.error('Cannot find the reference video at %s' % options.ref_video)

  if not options.test_video:
    parser.error('You must provide a path to the test video!')
  if not os.path.exists(options.test_video):
    parser.error('Cannot find the test video at %s' % options.test_video)

  if not options.frame_analyzer:
    parser.error('You must provide the path to the frame analyzer executable!')
  if not os.path.exists(options.frame_analyzer):
    parser.error('Cannot find frame analyzer executable at %s!' %
                 options.frame_analyzer)
  return options

def _DevNull():
  """On Windows, sometimes the inherited stdin handle from the parent process
  fails. Workaround this by passing null to stdin to the subprocesses commands.
  This function can be used to create the null file handler.
  """
  return open(os.devnull, 'r')

def DecodeBarcodesInVideo(options, path_to_decoder, video, stat_file):
  # Run barcode decoder on the test video to identify frame numbers.
  png_working_directory = tempfile.mkdtemp()
  cmd = [
    sys.executable,
    path_to_decoder,
    '--yuv_file=%s' % video,
    '--yuv_frame_width=%d' % options.yuv_frame_width,
    '--yuv_frame_height=%d' % options.yuv_frame_height,
    '--stats_file=%s' % stat_file,
    '--png_working_dir=%s' % png_working_directory,
  ]
  if options.zxing_path:
    cmd.append('--zxing_path=%s' % options.zxing_path)
  if options.ffmpeg_path:
    cmd.append('--ffmpeg_path=%s' % options.ffmpeg_path)


  barcode_decoder = subprocess.Popen(cmd, stdin=_DevNull(),
                                     stdout=sys.stdout, stderr=sys.stderr)
  barcode_decoder.wait()

  shutil.rmtree(png_working_directory)
  if barcode_decoder.returncode != 0:
    print 'Failed to run barcode decoder script.'
    return 1
  return 0

def main():
  """The main function.

  A simple invocation is:
  ./webrtc/tools/barcode_tools/compare_videos.py
  --ref_video=<path_and_name_of_reference_video>
  --test_video=<path_and_name_of_test_video>
  --frame_analyzer=<path_and_name_of_the_frame_analyzer_executable>

  Notice that the prerequisites for barcode_decoder.py also applies to this
  script. The means the following executables have to be available in the PATH:
  * zxing
  * ffmpeg
  """
  options = _ParseArgs()

  if options.barcode_decoder:
    path_to_decoder = options.barcode_decoder
  else:
    path_to_decoder = os.path.join(SCRIPT_DIR, 'barcode_tools',
                                   'barcode_decoder.py')

  if DecodeBarcodesInVideo(options, path_to_decoder,
                           options.ref_video, options.stats_file_ref) != 0:
    return 1
  if DecodeBarcodesInVideo(options, path_to_decoder,
                           options.test_video, options.stats_file_test) != 0:
    return 1

  # Run frame analyzer to compare the videos and print output.
  cmd = [
    options.frame_analyzer,
    '--label=%s' % options.label,
    '--reference_file=%s' % options.ref_video,
    '--test_file=%s' % options.test_video,
    '--stats_file_ref=%s' % options.stats_file_ref,
    '--stats_file_test=%s' % options.stats_file_test,
    '--width=%d' % options.yuv_frame_width,
    '--height=%d' % options.yuv_frame_height,
  ]
  frame_analyzer = subprocess.Popen(cmd, stdin=_DevNull(),
                                    stdout=sys.stdout, stderr=sys.stderr)
  frame_analyzer.wait()
  if frame_analyzer.returncode != 0:
    print 'Failed to run frame analyzer.'
    return 1

  return 0

if __name__ == '__main__':
  sys.exit(main())