tweak_options.py - webm/vpx_codec_comparison - Git at Google

 #!/usr/bin/python
 #
 # Copyright 2013 Google Inc.
 # All Rights Reserved.
 #
 # Tweak options.
 #
 # Command line:
 #    tweak-options.py [--options] <bitrate> <video>
 #
 # Algorithm:
 # - Find runs with good performance for this bitrate and video
 # - Create configs that are like this, but novel.
 #
 __author__ = "hta@google.com (Harald Alvestrand)"

 import glob
 import md5
 import os
 import random
 import re
 import stat
 import sys

 from optparse import OptionParser

 class Option(object):
   def __init__(self, name, values):
     self.name = name
     self.values = values

   def PickAnother(self, not_this):
     index = random.randint(0, len(self.values)-1)
     if self.values[index] == not_this:
       return self.values[(index + 1) % len(self.values)]
     return self.values[index]

   def OptionString(self, value):
     return '--' + self.name + '=' + value

   def ChangedOption(self, matchval):
     print "ChangedOption called on ", matchval.group(1)
     result = self.OptionString(self.PickAnother(matchval.group(1)))
     print "Returning", result
     return result

   def PatchConfig(self, config):
     """ Modify a configuration by changing the value of this parameter."""
     newconfig = re.sub('--' + self.name + '=' + '(\S+)',  self.ChangedOption,
                        config)
     assert(config != newconfig)
     return newconfig

 class ChoiceOption(Option):
   def __init__(self, flags):
      self.values = flags

   def PatchConfig(self, config):
     """ Modify a configuration by replacing the instance of this option."""
     current_flag = ''
     for flag in self.values:
       if config.find(' --' + flag + ' ') >= 0:
         current_flag = flag
         break
     if current_flag == '':
       raise Exception('No choice option alternative given')
     next_flag = self.PickAnother(current_flag)
     print "Changing from", current_flag, "to", next_flag
     newconfig = re.sub('--' + current_flag + ' ',
                        '--' + next_flag + ' ', config)
     assert(config != newconfig)
     return newconfig

 options = [
   Option('overshoot-pct', ['0', '15', '30', '45']),
   Option('undershoot-pct', ['0', '25', '50', '75', '100']),
   # CQ mode is not considered for end-usage at the moment.
   Option('end-usage', ['cbr', 'vbr']),
   # End-usage cq doesn't really make sense unless we also set q to something
   # between min and max. This is being checked.
   # Option('end-usage', ['cbr', 'vbr', 'cq']),
   Option('end-usage', ['cbr', 'vbr']),
   Option('cpu-used', ['-16', '0', '16']),
   Option('min-q', ['0', '2', '4', '8', '16', '24']),
   Option('max-q', ['32', '56', '63']),
   Option('buf-sz', ['200', '500', '1000', '2000', '4000', '8000', '16000']),
   Option('buf-initial-sz', ['200', '400', '800', '1000', '2000', '4000', '8000', '16000']),
   Option('max-intra-rate', ['100', '200', '400', '600', '800', '1200']),
   Option('resize-allowed', ['0', '1']),
   Option('lag-in-frames', ['0', '1', '2', '4', '8']),
   ChoiceOption(['good', 'best', 'rt']),
 ]

 class Config(object):

   def __init__(self, dirname, results=''):
     self.dirname = dirname
     self.results = results
     # These 2 values are read when needed.
     self.config = ''
     self.measurer = ''

   def EncoderFileName(self):
     return self.dirname + '/encoder'

   def MeasurerFileName(self):
     return self.dirname + '/measurer'

   def Score(self):
     """Computes the "quality" of the encoding.

     This function should be changed to fit the purpose of the experiment;
     this version works well for finding the best PSNR encoding below
     some bandwidth bound.
     """
     if self.results == '':
       return 0.0
     m = re.match(r'target_rate=(\d+)\nencoded_rate=(\d+)\npsnr=([\d\.]+)',
                  self.results)
     if m:
       target_rate = int(m.group(1))
       encoded_rate = int(m.group(2))
       psnr=float(m.group(3))
       score = psnr
       # Penalize by 0.1 dB per 1 kbits/sec overshoot.
       # TODO(hta): Consider whether this should be adjusted based on old runs.
       if target_rate < encoded_rate:
         score = score - (encoded_rate - target_rate) * 0.1
       return score

   def FetchEncoder(self):
     if self.config == '':
       with open(self.EncoderFileName()) as encoder:
         self.config = encoder.read()

   def Tweak(self):
     """Returns a Config object that's a tweaked version of this object."""
     self.FetchEncoder()
     with open(self.MeasurerFileName()) as measurerfile:
         self.measurer = measurerfile.read()
     newconfig = options[random.randint(0, len(options)-1)].PatchConfig(self.config)
     m = md5.new()
     m.update(newconfig)
     hashname = m.hexdigest()[:12]
     newconf = Config('vp8/' + hashname)
     newconf.config = newconfig
     newconf.measurer = self.measurer
     return newconf

   def Save(self):
     if os.path.isdir(self.dirname):
       print "Config ", self.dirname, " already exists"
       return False
     else:
       print "Emitting new config ", self.dirname
       os.mkdir(self.dirname)
       with open(self.EncoderFileName(), 'w') as encoder:
         encoder.write(self.config)
       os.chmod(self.EncoderFileName(), stat.S_IXUSR | stat.S_IRUSR)
       with open(self.MeasurerFileName(), 'w') as measurerfile:
         measurerfile.write(self.measurer)
       os.chmod(self.MeasurerFileName(), stat.S_IXUSR | stat.S_IRUSR)
       return True

   def Diff(self, otherconfig):
     """ Show config differences. Assumes that words are the same. """
     self.FetchEncoder()
     otherconfig.FetchEncoder()
     words1 = self.config.split()
     words2 = otherconfig.config.split()
     if len(words1) != len(words2):
       return ['Different lengths']
     difflist = []
     for i in xrange(0,len(words1)):
       if words1[i] != words2[i]:
         difflist.append(words1[i] + " -> " + words2[i])
     return difflist

   def AllSingleHopTweaks(self):
     """ Return all configs that differ by a single config change. """
     configs = []
     for option in options:
       for alternative in option.names:
         # do something intelligent
         pass

     return configs

 def findConfigsWithResult(bitrate, videofilename):
   candidates = []
   basename = os.path.splitext(os.path.basename(videofilename))[0]
   files = glob.glob('vp8/*/' + basename + '.results')
   for file in files:
     with open(file, 'r') as result:
       data = result.read()
       if re.search('target_rate=' + bitrate + '\n', data):
         candidates.append(Config(os.path.dirname(file), data))
   return candidates

 def findMatchingConfigs(bitrate):
   candidates = []
   files = glob.glob('vp8/*/' + 'measurer')
   for file in files:
     with open(file, 'r') as result:
       data = result.read()
       if re.search('target_rate=' + bitrate + '\n', data):
         candidates.append(Config(os.path.dirname(file), data))
   return candidates

 def rankCandidateConfigs(candidates):
   print "Ranking candidates"
   candidates.sort(key=lambda foo: foo.Score())
   trail = None
   if len(candidates) > 1:
     trail = candidates[-2]
     candidate = candidates[-1]
     print "Changes from", trail.dirname, "to", candidate.dirname
     print '\n'.join(trail.Diff(candidate))
     print candidate.EncoderFileName(), ': ', candidate.Score()

 def emitNewConfig(candidates):
   """Tweak the last configuration (highest score) and save it."""
   for i in xrange(10):
     # Since the tweaks are random, and may return a previously tried
     # configuration, try a few times.
     for i in xrange(10):
       if candidates[-1].Tweak().Save():
         return True
     # If there are equivalent candidates, try varying another one.
     if (len(candidates) > 1 and
         candidates[-1].Score() == candidates[-2].Score()):
       candidates.pop()
       print "Skipping to configuration", candidates[-1].dirname
     else:
       return False
   return False

 def main():
   parser = OptionParser()
   parser.add_option("--foo", action="store_true", dest="foo")

   (cmdline_options, args) = parser.parse_args()

   print "Finding candidates"
   candidates = findConfigsWithResult(args[0], args[1])
   if len(candidates) == 0:
     print >> sys.stderr, "No candidates found"
     return 1
   rankCandidateConfigs(candidates)
   if emitNewConfig(candidates):
     return 0
   print >> sys.stderr, "Unable to change configuration"
   return 1

 if __name__ == '__main__':
   sys.exit(main())
	#!/usr/bin/python
	#
	# Copyright 2013 Google Inc.
	# All Rights Reserved.
	#
	# Tweak options.
	#
	# Command line:
	# tweak-options.py [--options] <bitrate> <video>
	#
	# Algorithm:
	# - Find runs with good performance for this bitrate and video
	# - Create configs that are like this, but novel.
	#
	__author__ = "hta@google.com (Harald Alvestrand)"

	import glob
	import md5
	import os
	import random
	import re
	import stat
	import sys

	from optparse import OptionParser

	class Option(object):
	def __init__(self, name, values):
	self.name = name
	self.values = values

	def PickAnother(self, not_this):
	index = random.randint(0, len(self.values)-1)
	if self.values[index] == not_this:
	return self.values[(index + 1) % len(self.values)]
	return self.values[index]

	def OptionString(self, value):
	return '--' + self.name + '=' + value

	def ChangedOption(self, matchval):
	print "ChangedOption called on ", matchval.group(1)
	result = self.OptionString(self.PickAnother(matchval.group(1)))
	print "Returning", result
	return result

	def PatchConfig(self, config):
	""" Modify a configuration by changing the value of this parameter."""
	newconfig = re.sub('--' + self.name + '=' + '(\S+)', self.ChangedOption,
	config)
	assert(config != newconfig)
	return newconfig

	class ChoiceOption(Option):
	def __init__(self, flags):
	self.values = flags

	def PatchConfig(self, config):
	""" Modify a configuration by replacing the instance of this option."""
	current_flag = ''
	for flag in self.values:
	if config.find(' --' + flag + ' ') >= 0:
	current_flag = flag
	break
	if current_flag == '':
	raise Exception('No choice option alternative given')
	next_flag = self.PickAnother(current_flag)
	print "Changing from", current_flag, "to", next_flag
	newconfig = re.sub('--' + current_flag + ' ',
	'--' + next_flag + ' ', config)
	assert(config != newconfig)
	return newconfig

	options = [
	Option('overshoot-pct', ['0', '15', '30', '45']),
	Option('undershoot-pct', ['0', '25', '50', '75', '100']),
	# CQ mode is not considered for end-usage at the moment.
	Option('end-usage', ['cbr', 'vbr']),
	# End-usage cq doesn't really make sense unless we also set q to something
	# between min and max. This is being checked.
	# Option('end-usage', ['cbr', 'vbr', 'cq']),
	Option('end-usage', ['cbr', 'vbr']),
	Option('cpu-used', ['-16', '0', '16']),
	Option('min-q', ['0', '2', '4', '8', '16', '24']),
	Option('max-q', ['32', '56', '63']),
	Option('buf-sz', ['200', '500', '1000', '2000', '4000', '8000', '16000']),
	Option('buf-initial-sz', ['200', '400', '800', '1000', '2000', '4000', '8000', '16000']),
	Option('max-intra-rate', ['100', '200', '400', '600', '800', '1200']),
	Option('resize-allowed', ['0', '1']),
	Option('lag-in-frames', ['0', '1', '2', '4', '8']),
	ChoiceOption(['good', 'best', 'rt']),
	]

	class Config(object):

	def __init__(self, dirname, results=''):
	self.dirname = dirname
	self.results = results
	# These 2 values are read when needed.
	self.config = ''
	self.measurer = ''

	def EncoderFileName(self):
	return self.dirname + '/encoder'

	def MeasurerFileName(self):
	return self.dirname + '/measurer'

	def Score(self):
	"""Computes the "quality" of the encoding.

	This function should be changed to fit the purpose of the experiment;
	this version works well for finding the best PSNR encoding below
	some bandwidth bound.
	"""
	if self.results == '':
	return 0.0
	m = re.match(r'target_rate=(\d+)\nencoded_rate=(\d+)\npsnr=([\d\.]+)',
	self.results)
	if m:
	target_rate = int(m.group(1))
	encoded_rate = int(m.group(2))
	psnr=float(m.group(3))
	score = psnr
	# Penalize by 0.1 dB per 1 kbits/sec overshoot.
	# TODO(hta): Consider whether this should be adjusted based on old runs.
	if target_rate < encoded_rate:
	score = score - (encoded_rate - target_rate) * 0.1
	return score

	def FetchEncoder(self):
	if self.config == '':
	with open(self.EncoderFileName()) as encoder:
	self.config = encoder.read()

	def Tweak(self):
	"""Returns a Config object that's a tweaked version of this object."""
	self.FetchEncoder()
	with open(self.MeasurerFileName()) as measurerfile:
	self.measurer = measurerfile.read()
	newconfig = options[random.randint(0, len(options)-1)].PatchConfig(self.config)
	m = md5.new()
	m.update(newconfig)
	hashname = m.hexdigest()[:12]
	newconf = Config('vp8/' + hashname)
	newconf.config = newconfig
	newconf.measurer = self.measurer
	return newconf

	def Save(self):
	if os.path.isdir(self.dirname):
	print "Config ", self.dirname, " already exists"
	return False
	else:
	print "Emitting new config ", self.dirname
	os.mkdir(self.dirname)
	with open(self.EncoderFileName(), 'w') as encoder:
	encoder.write(self.config)
	os.chmod(self.EncoderFileName(), stat.S_IXUSR \| stat.S_IRUSR)
	with open(self.MeasurerFileName(), 'w') as measurerfile:
	measurerfile.write(self.measurer)
	os.chmod(self.MeasurerFileName(), stat.S_IXUSR \| stat.S_IRUSR)
	return True

	def Diff(self, otherconfig):
	""" Show config differences. Assumes that words are the same. """
	self.FetchEncoder()
	otherconfig.FetchEncoder()
	words1 = self.config.split()
	words2 = otherconfig.config.split()
	if len(words1) != len(words2):
	return ['Different lengths']
	difflist = []
	for i in xrange(0,len(words1)):
	if words1[i] != words2[i]:
	difflist.append(words1[i] + " -> " + words2[i])
	return difflist

	def AllSingleHopTweaks(self):
	""" Return all configs that differ by a single config change. """
	configs = []
	for option in options:
	for alternative in option.names:
	# do something intelligent
	pass

	return configs

	def findConfigsWithResult(bitrate, videofilename):
	candidates = []
	basename = os.path.splitext(os.path.basename(videofilename))[0]
	files = glob.glob('vp8/*/' + basename + '.results')
	for file in files:
	with open(file, 'r') as result:
	data = result.read()
	if re.search('target_rate=' + bitrate + '\n', data):
	candidates.append(Config(os.path.dirname(file), data))
	return candidates

	def findMatchingConfigs(bitrate):
	candidates = []
	files = glob.glob('vp8/*/' + 'measurer')
	for file in files:
	with open(file, 'r') as result:
	data = result.read()
	if re.search('target_rate=' + bitrate + '\n', data):
	candidates.append(Config(os.path.dirname(file), data))
	return candidates

	def rankCandidateConfigs(candidates):
	print "Ranking candidates"
	candidates.sort(key=lambda foo: foo.Score())
	trail = None
	if len(candidates) > 1:
	trail = candidates[-2]
	candidate = candidates[-1]
	print "Changes from", trail.dirname, "to", candidate.dirname
	print '\n'.join(trail.Diff(candidate))
	print candidate.EncoderFileName(), ': ', candidate.Score()

	def emitNewConfig(candidates):
	"""Tweak the last configuration (highest score) and save it."""
	for i in xrange(10):
	# Since the tweaks are random, and may return a previously tried
	# configuration, try a few times.
	for i in xrange(10):
	if candidates[-1].Tweak().Save():
	return True
	# If there are equivalent candidates, try varying another one.
	if (len(candidates) > 1 and
	candidates[-1].Score() == candidates[-2].Score()):
	candidates.pop()
	print "Skipping to configuration", candidates[-1].dirname
	else:
	return False
	return False

	def main():
	parser = OptionParser()
	parser.add_option("--foo", action="store_true", dest="foo")

	(cmdline_options, args) = parser.parse_args()

	print "Finding candidates"
	candidates = findConfigsWithResult(args[0], args[1])
	if len(candidates) == 0:
	print >> sys.stderr, "No candidates found"
	return 1
	rankCandidateConfigs(candidates)
	if emitNewConfig(candidates):
	return 0
	print >> sys.stderr, "Unable to change configuration"
	return 1

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