Add video recording wrapper

webrtc/tools/run_video_analysis.py

Index: webrtc/tools/run_video_analysis.py
diff --git a/webrtc/tools/run_video_analysis.py b/webrtc/tools/run_video_analysis.py
new file mode 100755
index 0000000000000000000000000000000000000000..a1376b896ffc69718d80d1bdeac58ea57da6d1d1
--- /dev/null
+++ b/webrtc/tools/run_video_analysis.py
@@ -0,0 +1,464 @@
+#!/usr/bin/env python
+# Copyright (c) 2017 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 subprocess
+import sys
+import time
+import glob
+import re
+
+# Used to time-stamp output files and directories
+CURRENT_TIME = time.strftime("%d_%m_%Y-%H:%M:%S")
+
+def _parseArgs():

[kjellander_webrtc, 2017/02/22 12:30:51]

Chromium has two exceptions from the standard google python style guide:
* Indentation: use 2, not 4, spaces
* Naming: Functions and Method names use CapWords() style, not
lower_with_under()
The only exception to this rule is the main() function -- we do not use Main()

http://dev.chromium.org/chromium-os/python-style-guidelines

Please update all functions in this script to align with that.

[janssonWebRTC, 2017/03/07 14:23:45]

In my opinion the linter should catch these things, enforcing style manually
must be a lot of work......Can we update the linter, if so where?

Changed it all according to the style.

[kjellander_webrtc, 2017/03/08 07:31:21]

You're right, I filed https://bugs.chromium.org/p/webrtc/issues/detail?id=7303
and I think it can be improved. Thanks for raising this concern.

+  """Registers the command-line options."""
+  usage = 'usage: %prog [options]'
+  parser = optparse.OptionParser(usage=usage)
+
+  parser.add_option('--frame_width', type='string', default='1280',
+                    help='Width of the recording. Default: %default')
+  parser.add_option('--frame_height', type='string', default='720',
+                    help='Height of the recording. Default: %default')
+  parser.add_option('--framerate', type='string', default='60',
+                    help='Recording framerate. Default: %default')
+  parser.add_option('--ref_duration', type='string', default='20',
+                    help='Reference recording duration. Default: %default')
+  parser.add_option('--test_duration', type='string', default='10',
+                    help='Test recording duration. Default: %default')
+  parser.add_option('--ref_video_device', type='string', default='/dev/video0',
+                    help='Reference recording device. Default: %default')
+  parser.add_option('--test_video_device', type='string', default='/dev/video1',
+                    help='Test recording device. Default: %default')
+  parser.add_option('--app_name', type='string',
+                    help='Name of the app under test.')
+  parser.add_option('--recording_api', type='string', default='Video4Linux2',
+                    help='Recording API to use. Default: %default')
+  parser.add_option('--pixel_format', type='string', default='yuv420p',
+                    help='Recording pixel format Default: %default')
+  parser.add_option('--ref_ffmpeg', type='string',

[kjellander_webrtc, 2017/02/22 12:30:50]

When do you need two different ffmpeg binaries? This runs on one machine.

[janssonWebRTC, 2017/03/07 14:23:45]

Initially I could not run the same executable at the same time but that works
now, not sure why that was.

Removed the 2nd ffmpeg.

[kjellander_webrtc, 2017/03/08 07:31:20]

Acknowledged.

+                    help='Path to the ffmpeg executable for the reference \
+                    device.')
+  parser.add_option('--test_ffmpeg', type='string',
+                    help='Path to the ffmpeg executable for the test device.')
+  parser.add_option('--video_container', type='string', default='yuv',
+                    help='Video container for the recordings. \
+                    Default: %default')
+  parser.add_option('--compare_videos_script', type='string',
+                    default='compare_videos.py',
+                    help='Path to script used to compare and generate metrics. \
+                    Default: %default')
+  parser.add_option('--frame_analyzer', type='string',
+                    default='../../out/Default/frame_analyzer',
+                    help='Path to the frame analyzer executable. \
+                    Default: %default')
+  parser.add_option('--zxing_path', type='string',
+                    help='Path to the zebra xing barcode analyzer.')
+  parser.add_option('--ref_crop_width', type='string', default='950',
+                    help='Cropping width. \
+                    Default: %default')
+  parser.add_option('--ref_crop_height', type='string', default='420',
+                    help='Cropping height. \
+                    Default: %default')
+  parser.add_option('--ref_crop_x_axis_start', type='string', default='130',
+                    help='y coordinate where cropping starts from. \
+                    Default: %default')
+  parser.add_option('--ref_crop_y_axis_start', type='string', default='56',
+                    help='x coordinate where cropping starts from. \
+                    Default: %default')
+  parser.add_option('--test_crop_width', type='string', default='950',
+                    help='Cropping width. \
+                    Default: %default')
+  parser.add_option('--test_crop_height', type='string', default='420',
+                    help='Cropping height. \
+                    Default: %default')
+  parser.add_option('--test_crop_x_axis_start', type='string', default='130',
+                    help='y coordinate where cropping starts from. \
+                    Default: %default')
+  parser.add_option('--test_crop_y_axis_start', type='string', default='56',
+                    help='x coordinate where cropping starts from. \
+                    Default: %default')
+  parser.add_option('--ref_rec_dir', type='string', default='ref',
+                    help='Path to where reference recordings will be created. \
+                    Ideally keep the ref and test directories on separate \
+                    drives. Default: %default')
+  parser.add_option('--test_rec_dir', type='string', default='test',
+                    help='Path to where test recordings will be created. \
+                    Ideally keep the ref and test directories on separate \
+                    drives. Default: %default')
+
+  options, _ = parser.parse_args()
+
+  if not options.app_name:
+    parser.error('You must provide an application name!')
+
+  if not options.ref_ffmpeg:
+    parser.error('You most provide location for the reference device ffmpeg \
+        executable.')
+  if not os.path.exists(options.ref_ffmpeg):

[kjellander_webrtc, 2017/02/22 12:30:50]

I usually use os.path.isfile instead, since if you would have a directory named
this, the check would not trigger.
Same below.

[janssonWebRTC, 2017/03/07 14:23:45]

Done.

+    parser.error('Cannot find the reference device ffmpeg executable.')
+
+  if not options.test_ffmpeg:
+    parser.error('You most provide location for the test device ffmpeg  \

[kjellander_webrtc, 2017/02/22 12:30:50]

Skip the \, it's not needed if you end the string with ' on this line (and begin
with ' on the next)
The style guide forbids \

[janssonWebRTC, 2017/03/07 14:23:45]

Done.

+        executable.')
+  if not os.path.exists(options.test_ffmpeg):
+    parser.error('Cannot find the test device ffmpeg executable.')
+
+  # compare_videos.py dependencies.
+  if not os.path.exists(options.compare_videos_script):
+    parser.warning('Cannot find compare_videos.py script, no metrics will be \
+        generated!')

[kjellander_webrtc, 2017/02/22 12:30:51]

align indent with the above (
https://google.github.io/styleguide/pyguide.html?showone=Line_length#Line_length

[janssonWebRTC, 2017/03/07 14:23:45]

Done.

+  if not os.path.exists(options.frame_analyzer):
+    parser.warning('Cannot find frame_analyzer, no metrics will be generated!')
+  if not os.path.exists(options.frame_analyzer):

[kjellander_webrtc, 2017/02/22 12:30:50]

options.zxing_path

[janssonWebRTC, 2017/03/07 14:23:45]

Done.

+    parser.warning('Cannot find Zebra Xing, no metrics will be generated!')
+
+  return options
+
+
+def create_recording_dirs(options):
+  """Creates root directories for reference and test recordings and

[kjellander_webrtc, 2017/02/22 12:30:49]

Make the summary line fit on a single line

Quoting https://www.python.org/dev/peps/pep-0257/#multi-line-docstrings:
"Multi-line docstrings consist of a summary line just like a one-line docstring,
followed by a blank line, followed by a more elaborate description"

[janssonWebRTC, 2017/03/07 14:23:45]

Done.

+  sub-directories using <options.app_name + '_' + CURRENT_TIME>.
+
+  Args:
+    options(object): Contains all the provided command line options.
+  Return:
+    record_paths(dict): key: value pair with reference and test file
+    absolute paths.

[kjellander_webrtc, 2017/02/22 12:30:50]

+4 spaces indent before "absolute" here.

[janssonWebRTC, 2017/03/07 14:23:45]

Done.

+  """
+  # Create root directories for the video recordings.
+  if not os.path.exists(options.ref_rec_dir):

[kjellander_webrtc, 2017/02/22 12:30:50]

Use os.path.isdir

[janssonWebRTC, 2017/03/07 14:23:44]

Done.

+    os.makedirs(options.ref_rec_dir)
+  if not os.path.exists(options.test_rec_dir):
+    os.makedirs(options.test_rec_dir)
+  # Create and time-stamp directories for all the output files.

[kjellander_webrtc, 2017/02/22 12:30:50]

+1 blank line before comment

[janssonWebRTC, 2017/03/07 14:23:44]

Done.

+  ref_rec_dir = os.path.join(options.ref_rec_dir, options.app_name + '_' + \
+      CURRENT_TIME)
+  test_rec_dir = os.path.join(options.test_rec_dir, options.app_name + '_' + \
+      CURRENT_TIME)
+
+  os.makedirs(ref_rec_dir)
+  os.makedirs(test_rec_dir)
+
+  record_paths = {
+    'ref_rec_location' : os.path.abspath(ref_rec_dir),
+    'test_rec_location' : os.path.abspath(test_rec_dir)
+  }
+
+  return record_paths
+
+
+def restart_magewell_devices(options):
+  """Tries to find the provided options.ref_video_device and

[kjellander_webrtc, 2017/02/22 12:30:50]

Same comment here about the docstring summary line.

[janssonWebRTC, 2017/03/07 14:23:45]

Done.

+  options.test_video_device devices which use video4linux and then do a soft
+  reset by using USB unbind and bind. This is due to Magewell capture devices
+  have proven to be unstable after the first recording attempt.
+
+  Args:
+    options(object): Contains all the provided command line options.
+  """
+  # Get the dev/videoN device name from the command line arguments.
+  ref_magewell = options.ref_video_device.split('/')[2]
+  test_magewell = options.test_video_device.split('/')[2]
+
+  # Find the device location including USB and USB Bus ID's.
+  ref_magewell_device = \
+      glob.glob('/sys/bus/usb/devices/usb*/**/**/video4linux/' + ref_magewell)
+  test_magewell_device = \
+      glob.glob('/sys/bus/usb/devices/usb*/**/**/video4linux/' + test_magewell)
+
+  magewell_usb_ports = []
+  # Figure out the USB bus and port ID for each device.
+  ref_magewell_path = str(ref_magewell_device).split('/')
+  for directory in ref_magewell_path:
+    # Find the folder with pattern "N-N", e.g. "4-3" or \
+    # "[USB bus ID]-[USB port]"
+    if re.match(r'^\d-\d$', directory):
+      magewell_usb_ports.append(directory)
+
+  test_magewell_path = str(test_magewell_device).split('/')
+  for directory in test_magewell_path:
+    # Find the folder with pattern "N-N", e.g. "4-3" or \
+    # "[USB bus ID]-[USB port]"
+    if re.match(r'^\d-\d$', directory):
+      magewell_usb_ports.append(directory)
+
+  print '\nResetting USB ports where magewell devices are connected...'
+  # Use the USB bus and port ID (e.g. 4-3) to unbind and bind the USB devices
+  # (i.e. soft eject and insert).
+  try:
+    for usb_port in magewell_usb_ports:
+      echo_cmd = ['echo', usb_port]
+      unbind_cmd = ['sudo', 'tee', '/sys/bus/usb/drivers/usb/unbind']
+      bind_cmd = ['sudo', 'tee', '/sys/bus/usb/drivers/usb/bind']

[kjellander_webrtc, 2017/02/22 12:30:50]

Will the script ask for sudo password in a clear way if it's needed here? I'm
afraid it might get stuck etc.

[janssonWebRTC, 2017/03/07 14:23:45]

Yes it will but for me it's quite clear that it asks for it.

[kjellander_webrtc, 2017/03/08 07:31:20]

Acknowledged.

+
+      # TODO(jansson) Figure out a way to call on echo once for bind & unbind
+      # if possible.
+      echo_unbind = subprocess.Popen(echo_cmd, stdout=subprocess.PIPE)
+      unbind = subprocess.Popen(unbind_cmd, stdin=echo_unbind.stdout)
+      echo_unbind.stdout.close()
+      unbind.communicate()
+      unbind.wait()
+
+      echo_bind = subprocess.Popen(echo_cmd, stdout=subprocess.PIPE)
+      bind = subprocess.Popen(bind_cmd, stdin=echo_bind.stdout)
+      echo_bind.stdout.close()
+      bind.communicate()
+      bind.wait()
+  except OSError as e:
+    print 'Error while resetting magewell devices: ' + e
+    raise
+
+  print 'Reset done!\n'
+
+
+def start_recording(options, record_paths):
+  """Starts recording from the two specified video devices with
+
+  Args:
+    options(object): Contains all the provided command line options.
+    record_paths(dict): key: value pair with reference and test file
+    absolute paths.
+  """
+  ref_file_name = options.app_name + '_' + CURRENT_TIME + '_ref.' + \

[kjellander_webrtc, 2017/02/22 12:30:50]

Use Python string formatters instead, i.e. 
ref_file_name = '%s_%s_ref.%s' % (options.app_name, CURRENT_TIME,
options.video_container)

Then you can linebreak easier (before %, or inside the parentheses).

Same applies below.

[janssonWebRTC, 2017/03/07 14:23:44]

Done.

+      options.video_container
+  ref_file_location = os.path.join(record_paths['ref_rec_location'],
+      ref_file_name)
+
+  test_file_name = options.app_name + '_' + CURRENT_TIME + '_test.' + \
+      options.video_container
+  test_file_location = os.path.join(record_paths['test_rec_location'],
+      test_file_name)
+
+  # Reference video recorder command line.
+  ref_cmd = [
+    options.ref_ffmpeg,
+    '-v', 'error',
+    '-s', options.frame_width + 'x' + options.frame_height,
+    '-framerate', options.framerate,
+    '-f', options.recording_api,
+    '-i', options.ref_video_device,
+    '-pix_fmt', options.pixel_format,
+    '-s', options.frame_width + 'x' + options.frame_height,
+    '-t', options.ref_duration,
+    '-framerate', options.framerate,
+    ref_file_location
+  ]
+
+  # Test video recorder command line.
+  test_cmd = [
+    options.test_ffmpeg,
+    '-v', 'error',
+    '-s', options.frame_width + 'x' + options.frame_height,
+    '-framerate', options.framerate,
+    '-f', options.recording_api,
+    '-i', options.test_video_device,
+    '-pix_fmt', options.pixel_format,
+    '-s', options.frame_width + 'x' + options.frame_height,
+    '-t', options.test_duration,
+    '-framerate', options.framerate,
+    test_file_location
+  ]
+  try:
+    print 'Trying to record from reference recorder...'
+    ref_recorder = subprocess.Popen(ref_cmd, stderr=None)
+    # Start the 2nd recording a little later to ensure the 1st one has started.
+    # TODO(jansson) Check that the ref_recorder output file exists rather than
+    # using sleep.
+    time.sleep(5)

[kjellander_webrtc, 2017/02/22 12:30:51]

Maybe this should be a flag as well? Constants like this hidden deep in the
script is undesired.
At least refactor it into a constant in the top of the file, like
DELAY_BEFORE_RECORDING_SECONDS = 5 if you don't think a flag is needed.

[janssonWebRTC, 2017/03/07 14:23:45]

Made it a flag.

[kjellander_webrtc, 2017/03/08 07:31:20]

Acknowledged.

+    print 'Trying to record from test recorder...'
+    test_recorder = subprocess.Popen(test_cmd, stderr=None)

[kjellander_webrtc, 2017/02/22 12:30:50]

Why stderr=None ? Don't you risk to ignore errors then?

[janssonWebRTC, 2017/03/07 14:23:45]

This was just a default setting. Will fix.

[kjellander_webrtc, 2017/03/08 07:31:20]

Acknowledged.

+    test_recorder.wait()
+    ref_recorder.wait()
+
+    print 'Ref file recorded to: ' + os.path.abspath(ref_file_location)
+    print 'Test file recorded to: ' + os.path.abspath(test_file_location)
+    print 'Recording done!\n'
+    return flip_and_crop_recordings(options, test_file_name,
+        record_paths['test_rec_location'], ref_file_name,
+        record_paths['ref_rec_location'])
+  except subprocess.CalledProcessError as e:
+    print 'Something went wrong when trying to record: ' + e
+    raise
+
+
+def flip_and_crop_recordings(options, test_file_name, test_file_location,
+    ref_file_name, ref_file_location):

[kjellander_webrtc, 2017/02/22 12:30:50]

indent aligning with ( above

[janssonWebRTC, 2017/03/07 14:23:45]

Done.

+  """Performs a horizontal flip of the reference video to match the test video
+  orientation and then crops the ref and test videos using
+  options.ref_crop_height, options.ref_crop_width, options.test_crop_height and
+  options.test_crop_width. Crop starting position is taken from
+  options.ref_crop_x_axis_start, options.ref_crop_y_axis_start,
+  options.test_crop_x_axis_start and options.test_crop_x_axis_start.
+
+  Args:
+    options(object): Contains all the provided command line options.
+    test_file_name(string): Name of the test video file recording.
+    test_file_location(string): Path to the test video file recording.
+    ref_file_name(string): Name of the reference video file recording.
+    ref_file_location(string): Path to the reference video file recording.
+  Return:
+    recording_files_and_time(dict): key: value pair with the path to cropped
+    test and reference video files.

[kjellander_webrtc, 2017/02/22 12:30:50]

+4 indent

[janssonWebRTC, 2017/03/07 14:23:45]

Done.

+  """
+  print 'Trying to crop videos...'
+  # Ref file cropping.

[kjellander_webrtc, 2017/02/22 12:30:50]

+blank line

[janssonWebRTC, 2017/03/07 14:23:44]

Done.

+  cropped_ref_file_name = 'cropped_' + ref_file_name
+  cropped_ref_file = os.path.abspath(\

[kjellander_webrtc, 2017/02/22 12:30:50]

remove \

[janssonWebRTC, 2017/03/07 14:23:44]

Done.

+      os.path.join(ref_file_location, cropped_ref_file_name))
+  ref_crop_parameters = options.ref_crop_width + ':' + \

[kjellander_webrtc, 2017/02/22 12:30:51]

use string formatter

[janssonWebRTC, 2017/03/07 14:23:45]

Done.

+      options.ref_crop_height + ':' + options.ref_crop_x_axis_start + ':' + \
+      options.ref_crop_y_axis_start
+
+  ref_video_crop_cmd = [
+    options.ref_ffmpeg,
+    '-v', 'error',
+    '-s', options.frame_width + 'x' + options.frame_height,
+    '-i', os.path.join(ref_file_location, ref_file_name),
+    # Flip the ref video horizontally before cropping so that we can use the
+    # same coordinates on both ref and test recordings.
+    # Also keep in mind that the X:Y starting positions are critical for the
+    # zxing library, if the barcode is moved within the recording, these
+    # probably need to be changed otherwise barcode decoding will fail.
+    # TODO(jansson) make the entire crop parameter section a command line
+    # argument.
+    '-vf', 'hflip, crop=' + ref_crop_parameters,
+    '-c:a', 'copy',
+    cropped_ref_file
+  ]
+  # Test file cropping.
+  cropped_test_file_name = 'cropped_' + test_file_name
+  cropped_test_file = os.path.abspath(\
+      os.path.join(test_file_location, cropped_test_file_name))
+  test_crop_parameters = options.test_crop_width + ':' + \
+      options.test_crop_height + ':' + options.test_crop_x_axis_start + ':' + \
+      options.test_crop_y_axis_start
+
+  test_video_crop_cmd = [
+    options.test_ffmpeg,
+    '-v', 'error',
+    '-s', options.frame_width + 'x' + options.frame_height,
+    '-i', os.path.join(test_file_location, test_file_name),
+    # TODO(jansson) make the entire crop parameter section a command line
+    # argument.
+    '-vf', 'crop=' + test_crop_parameters,
+    '-c:a', 'copy',
+    cropped_test_file
+  ]
+
+  ref_crop = subprocess.Popen(ref_video_crop_cmd)
+  ref_crop.wait()
+  print 'Ref file cropped to: ' + cropped_ref_file
+
+  try:
+    test_crop = subprocess.Popen(test_video_crop_cmd)
+    test_crop.wait()
+    print 'Test file cropped to: ' + cropped_test_file
+    print 'Cropping done!\n'
+      # Need to return these so they can be used by other parts.
+    cropped_recordings = {
+      'cropped_test_file' : cropped_test_file,
+      'cropped_ref_file' : cropped_ref_file
+    }
+
+    return cropped_recordings
+  except subprocess.CalledProcessError as e:
+    print 'Something went wrong during cropping: ' + e
+    raise
+
+
+def compare_videos(options, recording_result):
+  """Runs the compare_video.py script from src/webrtc/tools using the file paths
+  from recording_result and writes the output to a file named
+  <options.app_name + '_' + CURRENT_TIME + '_result.txt> in the reference video
+  recording folder taken from recording_result.
+
+  Args:
+    options(object): Contains all the provided command line options.
+    recording_files_and_time(dict): key: value pair with the path to cropped
+    test and reference video files
+  """
+  print 'Starting comparison...'
+  print 'Grab a coffee, this might take a few minutes...'
+  cropped_ref_file = recording_result['cropped_ref_file']
+  cropped_test_file = recording_result['cropped_test_file']
+  compare_videos_script = os.path.abspath(options.compare_videos_script)
+  result_file_name = \

[kjellander_webrtc, 2017/02/22 12:30:50]

remove \ and use string formatter instead.

[janssonWebRTC, 2017/03/07 14:23:45]

Done.

+      os.path.join(os.path.dirname(recording_result['cropped_ref_file']),
+      options.app_name + '_' + CURRENT_TIME + '_result.txt')
+
+  compare_cmd = [
+    sys.executable,
+    compare_videos_script,
+    '--ref_video', cropped_ref_file,
+    '--test_video', cropped_test_file,
+    '--frame_analyzer', os.path.abspath(options.frame_analyzer),
+    '--zxing_path', options.zxing_path,
+    '--ffmpeg_path', options.ref_ffmpeg,
+    '--stats_file_ref', os.path.join(os.path.dirname(cropped_ref_file),
+        cropped_ref_file + '_stats.txt'),
+    '--stats_file_test', os.path.join(os.path.dirname(cropped_test_file),
+        cropped_test_file + '_stats.txt'),
+    '--yuv_frame_height', options.ref_crop_height,
+    '--yuv_frame_width', options.ref_crop_width
+  ]
+
+  try:
+    with open(result_file_name, 'w') as f:
+      compare_video_recordings = subprocess.Popen(compare_cmd, stdout=f)
+      compare_video_recordings.wait()
+      print 'Result recorded to: ' + os.path.abspath(result_file_name)
+      print 'Comparison done!'
+  except subprocess.CalledProcessError as e:
+    print 'Something went wrong when trying to compare videos: ' + e
+    raise
+
+
+def main():
+  """The main function.
+
+  A simple invocation is:
+  ./run_video_analysis.py \
+    --app_name AppRTCMobile \
+    --ref_ffmpeg ./ref_ffmpeg --ref_video_device=/dev/video0 \
+    --test_ffmpeg ./test_ffmpeg --test_video_device=/dev/video1 \
+    --zxing_path ./zxing \
+    --test_crop_width 950 --test_crop_height 420 \
+    --ref_crop_width 950 --ref_crop_height 420 \
+    --test_crop_x_axis_start 130 --test_crop_y_axis_start 56 \
+    --ref_crop_x_axis_start 130 --ref_crop_y_axis_start 56 \
+    --ref_rec_dir /tmp/ref \
+    --test_rec_dir /tmp/test
+
+  This will produce the following files if successful:
+  # Original video recordings.
+  /tmp/ref/AppRTCMobile_<recording date and time>_ref.yuv
+  /tmp/test/AppRTCMobile_<recording date and time>_test.yuv
+
+  # Cropped video recordings according to the crop parameters.
+  /tmp/ref/cropped_AppRTCMobile_<recording date and time>_ref.yuv
+  /tmp/test/cropped_AppRTCMobile_<recording date and time>_ref.yuv
+
+  # Comparison metrics from cropped test and ref videos.
+  /tmp/test/AppRTCMobile_<recording date and time>_result.text
+
+  """
+  options = _parseArgs()
+  restart_magewell_devices(options)
+  record_paths = create_recording_dirs(options)
+  recording_result = start_recording(options, record_paths)
+  # Do not require compare_video.py script to run, no metrics will be generated.
+  if os.path.exists(options.frame_analyzer) or \
+      os.path.exists(options.compare_videos_script) or \
+      os.path.exists(options.zxing_path):
+    compare_videos(options, recording_result)

[kjellander_webrtc, 2017/02/22 12:30:50]

This is a bit unexpected. I suggest you at least add:
else:
  print 'Skipping compare videos step due to frame_analyzer, zxing or
compare_videos flags were not passed.'

[janssonWebRTC, 2017/03/07 14:23:45]

Done.

+

[kjellander_webrtc, 2017/02/22 12:30:50]

+1 blank line for top-level statements.

[janssonWebRTC, 2017/03/07 14:23:45]

Done.

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