+
+
+def parse_dfxp_time_expr(time_expr):
+ if not time_expr:
+ return
+
+ mobj = re.match(r'^(?P<time_offset>\d+(?:\.\d+)?)s?$', time_expr)
+ if mobj:
+ return float(mobj.group('time_offset'))
+
+ mobj = re.match(r'^(\d+):(\d\d):(\d\d(?:(?:\.|:)\d+)?)$', time_expr)
+ if mobj:
+ return 3600 * int(mobj.group(1)) + 60 * int(mobj.group(2)) + float(mobj.group(3).replace(':', '.'))
+
+
+def srt_subtitles_timecode(seconds):
+ return '%02d:%02d:%02d,%03d' % (seconds / 3600, (seconds % 3600) / 60, seconds % 60, (seconds % 1) * 1000)
+
+
+def dfxp2srt(dfxp_data):
+ _x = functools.partial(xpath_with_ns, ns_map={
+ 'ttml': 'http://www.w3.org/ns/ttml',
+ 'ttaf1': 'http://www.w3.org/2006/10/ttaf1',
+ 'ttaf1_0604': 'http://www.w3.org/2006/04/ttaf1',
+ })
+
+ class TTMLPElementParser(object):
+ out = ''
+
+ def start(self, tag, attrib):
+ if tag in (_x('ttml:br'), _x('ttaf1:br'), 'br'):
+ self.out += '\n'
+
+ def end(self, tag):
+ pass
+
+ def data(self, data):
+ self.out += data
+
+ def close(self):
+ return self.out.strip()
+
+ def parse_node(node):
+ target = TTMLPElementParser()
+ parser = xml.etree.ElementTree.XMLParser(target=target)
+ parser.feed(xml.etree.ElementTree.tostring(node))
+ return parser.close()
+
+ dfxp = compat_etree_fromstring(dfxp_data.encode('utf-8'))
+ out = []
+ paras = dfxp.findall(_x('.//ttml:p')) or dfxp.findall(_x('.//ttaf1:p')) or dfxp.findall(_x('.//ttaf1_0604:p')) or dfxp.findall('.//p')
+
+ if not paras:
+ raise ValueError('Invalid dfxp/TTML subtitle')
+
+ for para, index in zip(paras, itertools.count(1)):
+ begin_time = parse_dfxp_time_expr(para.attrib.get('begin'))
+ end_time = parse_dfxp_time_expr(para.attrib.get('end'))
+ dur = parse_dfxp_time_expr(para.attrib.get('dur'))
+ if begin_time is None:
+ continue
+ if not end_time:
+ if not dur:
+ continue
+ end_time = begin_time + dur
+ out.append('%d\n%s --> %s\n%s\n\n' % (
+ index,
+ srt_subtitles_timecode(begin_time),
+ srt_subtitles_timecode(end_time),
+ parse_node(para)))
+
+ return ''.join(out)
+
+
+def cli_option(params, command_option, param):
+ param = params.get(param)
+ if param:
+ param = compat_str(param)
+ return [command_option, param] if param is not None else []
+
+
+def cli_bool_option(params, command_option, param, true_value='true', false_value='false', separator=None):
+ param = params.get(param)
+ assert isinstance(param, bool)
+ if separator:
+ return [command_option + separator + (true_value if param else false_value)]
+ return [command_option, true_value if param else false_value]
+
+
+def cli_valueless_option(params, command_option, param, expected_value=True):
+ param = params.get(param)
+ return [command_option] if param == expected_value else []
+
+
+def cli_configuration_args(params, param, default=[]):
+ ex_args = params.get(param)
+ if ex_args is None:
+ return default
+ assert isinstance(ex_args, list)
+ return ex_args
+
+
+class ISO639Utils(object):
+ # See http://www.loc.gov/standards/iso639-2/ISO-639-2_utf-8.txt
+ _lang_map = {
+ 'aa': 'aar',
+ 'ab': 'abk',
+ 'ae': 'ave',
+ 'af': 'afr',
+ 'ak': 'aka',
+ 'am': 'amh',
+ 'an': 'arg',
+ 'ar': 'ara',
+ 'as': 'asm',
+ 'av': 'ava',
+ 'ay': 'aym',
+ 'az': 'aze',
+ 'ba': 'bak',
+ 'be': 'bel',
+ 'bg': 'bul',
+ 'bh': 'bih',
+ 'bi': 'bis',
+ 'bm': 'bam',
+ 'bn': 'ben',
+ 'bo': 'bod',
+ 'br': 'bre',
+ 'bs': 'bos',
+ 'ca': 'cat',
+ 'ce': 'che',
+ 'ch': 'cha',
+ 'co': 'cos',
+ 'cr': 'cre',
+ 'cs': 'ces',
+ 'cu': 'chu',
+ 'cv': 'chv',
+ 'cy': 'cym',
+ 'da': 'dan',
+ 'de': 'deu',
+ 'dv': 'div',
+ 'dz': 'dzo',
+ 'ee': 'ewe',
+ 'el': 'ell',
+ 'en': 'eng',
+ 'eo': 'epo',
+ 'es': 'spa',
+ 'et': 'est',
+ 'eu': 'eus',
+ 'fa': 'fas',
+ 'ff': 'ful',
+ 'fi': 'fin',
+ 'fj': 'fij',
+ 'fo': 'fao',
+ 'fr': 'fra',
+ 'fy': 'fry',
+ 'ga': 'gle',
+ 'gd': 'gla',
+ 'gl': 'glg',
+ 'gn': 'grn',
+ 'gu': 'guj',
+ 'gv': 'glv',
+ 'ha': 'hau',
+ 'he': 'heb',
+ 'hi': 'hin',
+ 'ho': 'hmo',
+ 'hr': 'hrv',
+ 'ht': 'hat',
+ 'hu': 'hun',
+ 'hy': 'hye',
+ 'hz': 'her',
+ 'ia': 'ina',
+ 'id': 'ind',
+ 'ie': 'ile',
+ 'ig': 'ibo',
+ 'ii': 'iii',
+ 'ik': 'ipk',
+ 'io': 'ido',
+ 'is': 'isl',
+ 'it': 'ita',
+ 'iu': 'iku',
+ 'ja': 'jpn',
+ 'jv': 'jav',
+ 'ka': 'kat',
+ 'kg': 'kon',
+ 'ki': 'kik',
+ 'kj': 'kua',
+ 'kk': 'kaz',
+ 'kl': 'kal',
+ 'km': 'khm',
+ 'kn': 'kan',
+ 'ko': 'kor',
+ 'kr': 'kau',
+ 'ks': 'kas',
+ 'ku': 'kur',
+ 'kv': 'kom',
+ 'kw': 'cor',
+ 'ky': 'kir',
+ 'la': 'lat',
+ 'lb': 'ltz',
+ 'lg': 'lug',
+ 'li': 'lim',
+ 'ln': 'lin',
+ 'lo': 'lao',
+ 'lt': 'lit',
+ 'lu': 'lub',
+ 'lv': 'lav',
+ 'mg': 'mlg',
+ 'mh': 'mah',
+ 'mi': 'mri',
+ 'mk': 'mkd',
+ 'ml': 'mal',
+ 'mn': 'mon',
+ 'mr': 'mar',
+ 'ms': 'msa',
+ 'mt': 'mlt',
+ 'my': 'mya',
+ 'na': 'nau',
+ 'nb': 'nob',
+ 'nd': 'nde',
+ 'ne': 'nep',
+ 'ng': 'ndo',
+ 'nl': 'nld',
+ 'nn': 'nno',
+ 'no': 'nor',
+ 'nr': 'nbl',
+ 'nv': 'nav',
+ 'ny': 'nya',
+ 'oc': 'oci',
+ 'oj': 'oji',
+ 'om': 'orm',
+ 'or': 'ori',
+ 'os': 'oss',
+ 'pa': 'pan',
+ 'pi': 'pli',
+ 'pl': 'pol',
+ 'ps': 'pus',
+ 'pt': 'por',
+ 'qu': 'que',
+ 'rm': 'roh',
+ 'rn': 'run',
+ 'ro': 'ron',
+ 'ru': 'rus',
+ 'rw': 'kin',
+ 'sa': 'san',
+ 'sc': 'srd',
+ 'sd': 'snd',
+ 'se': 'sme',
+ 'sg': 'sag',
+ 'si': 'sin',
+ 'sk': 'slk',
+ 'sl': 'slv',
+ 'sm': 'smo',
+ 'sn': 'sna',
+ 'so': 'som',
+ 'sq': 'sqi',
+ 'sr': 'srp',
+ 'ss': 'ssw',
+ 'st': 'sot',
+ 'su': 'sun',
+ 'sv': 'swe',
+ 'sw': 'swa',
+ 'ta': 'tam',
+ 'te': 'tel',
+ 'tg': 'tgk',
+ 'th': 'tha',
+ 'ti': 'tir',
+ 'tk': 'tuk',
+ 'tl': 'tgl',
+ 'tn': 'tsn',
+ 'to': 'ton',
+ 'tr': 'tur',
+ 'ts': 'tso',
+ 'tt': 'tat',
+ 'tw': 'twi',
+ 'ty': 'tah',
+ 'ug': 'uig',
+ 'uk': 'ukr',
+ 'ur': 'urd',
+ 'uz': 'uzb',
+ 've': 'ven',
+ 'vi': 'vie',
+ 'vo': 'vol',
+ 'wa': 'wln',
+ 'wo': 'wol',
+ 'xh': 'xho',
+ 'yi': 'yid',
+ 'yo': 'yor',
+ 'za': 'zha',
+ 'zh': 'zho',
+ 'zu': 'zul',
+ }
+
+ @classmethod
+ def short2long(cls, code):
+ """Convert language code from ISO 639-1 to ISO 639-2/T"""
+ return cls._lang_map.get(code[:2])
+
+ @classmethod
+ def long2short(cls, code):
+ """Convert language code from ISO 639-2/T to ISO 639-1"""
+ for short_name, long_name in cls._lang_map.items():
+ if long_name == code:
+ return short_name
+
+
+class ISO3166Utils(object):
+ # From http://data.okfn.org/data/core/country-list
+ _country_map = {
+ 'AF': 'Afghanistan',
+ 'AX': 'Åland Islands',
+ 'AL': 'Albania',
+ 'DZ': 'Algeria',
+ 'AS': 'American Samoa',
+ 'AD': 'Andorra',
+ 'AO': 'Angola',
+ 'AI': 'Anguilla',
+ 'AQ': 'Antarctica',
+ 'AG': 'Antigua and Barbuda',
+ 'AR': 'Argentina',
+ 'AM': 'Armenia',
+ 'AW': 'Aruba',
+ 'AU': 'Australia',
+ 'AT': 'Austria',
+ 'AZ': 'Azerbaijan',
+ 'BS': 'Bahamas',
+ 'BH': 'Bahrain',
+ 'BD': 'Bangladesh',
+ 'BB': 'Barbados',
+ 'BY': 'Belarus',
+ 'BE': 'Belgium',
+ 'BZ': 'Belize',
+ 'BJ': 'Benin',
+ 'BM': 'Bermuda',
+ 'BT': 'Bhutan',
+ 'BO': 'Bolivia, Plurinational State of',
+ 'BQ': 'Bonaire, Sint Eustatius and Saba',
+ 'BA': 'Bosnia and Herzegovina',
+ 'BW': 'Botswana',
+ 'BV': 'Bouvet Island',
+ 'BR': 'Brazil',
+ 'IO': 'British Indian Ocean Territory',
+ 'BN': 'Brunei Darussalam',
+ 'BG': 'Bulgaria',
+ 'BF': 'Burkina Faso',
+ 'BI': 'Burundi',
+ 'KH': 'Cambodia',
+ 'CM': 'Cameroon',
+ 'CA': 'Canada',
+ 'CV': 'Cape Verde',
+ 'KY': 'Cayman Islands',
+ 'CF': 'Central African Republic',
+ 'TD': 'Chad',
+ 'CL': 'Chile',
+ 'CN': 'China',
+ 'CX': 'Christmas Island',
+ 'CC': 'Cocos (Keeling) Islands',
+ 'CO': 'Colombia',
+ 'KM': 'Comoros',
+ 'CG': 'Congo',
+ 'CD': 'Congo, the Democratic Republic of the',
+ 'CK': 'Cook Islands',
+ 'CR': 'Costa Rica',
+ 'CI': 'Côte d\'Ivoire',
+ 'HR': 'Croatia',
+ 'CU': 'Cuba',
+ 'CW': 'Curaçao',
+ 'CY': 'Cyprus',
+ 'CZ': 'Czech Republic',
+ 'DK': 'Denmark',
+ 'DJ': 'Djibouti',
+ 'DM': 'Dominica',
+ 'DO': 'Dominican Republic',
+ 'EC': 'Ecuador',
+ 'EG': 'Egypt',
+ 'SV': 'El Salvador',
+ 'GQ': 'Equatorial Guinea',
+ 'ER': 'Eritrea',
+ 'EE': 'Estonia',
+ 'ET': 'Ethiopia',
+ 'FK': 'Falkland Islands (Malvinas)',
+ 'FO': 'Faroe Islands',
+ 'FJ': 'Fiji',
+ 'FI': 'Finland',
+ 'FR': 'France',
+ 'GF': 'French Guiana',
+ 'PF': 'French Polynesia',
+ 'TF': 'French Southern Territories',
+ 'GA': 'Gabon',
+ 'GM': 'Gambia',
+ 'GE': 'Georgia',
+ 'DE': 'Germany',
+ 'GH': 'Ghana',
+ 'GI': 'Gibraltar',
+ 'GR': 'Greece',
+ 'GL': 'Greenland',
+ 'GD': 'Grenada',
+ 'GP': 'Guadeloupe',
+ 'GU': 'Guam',
+ 'GT': 'Guatemala',
+ 'GG': 'Guernsey',
+ 'GN': 'Guinea',
+ 'GW': 'Guinea-Bissau',
+ 'GY': 'Guyana',
+ 'HT': 'Haiti',
+ 'HM': 'Heard Island and McDonald Islands',
+ 'VA': 'Holy See (Vatican City State)',
+ 'HN': 'Honduras',
+ 'HK': 'Hong Kong',
+ 'HU': 'Hungary',
+ 'IS': 'Iceland',
+ 'IN': 'India',
+ 'ID': 'Indonesia',
+ 'IR': 'Iran, Islamic Republic of',
+ 'IQ': 'Iraq',
+ 'IE': 'Ireland',
+ 'IM': 'Isle of Man',
+ 'IL': 'Israel',
+ 'IT': 'Italy',
+ 'JM': 'Jamaica',
+ 'JP': 'Japan',
+ 'JE': 'Jersey',
+ 'JO': 'Jordan',
+ 'KZ': 'Kazakhstan',
+ 'KE': 'Kenya',
+ 'KI': 'Kiribati',
+ 'KP': 'Korea, Democratic People\'s Republic of',
+ 'KR': 'Korea, Republic of',
+ 'KW': 'Kuwait',
+ 'KG': 'Kyrgyzstan',
+ 'LA': 'Lao People\'s Democratic Republic',
+ 'LV': 'Latvia',
+ 'LB': 'Lebanon',
+ 'LS': 'Lesotho',
+ 'LR': 'Liberia',
+ 'LY': 'Libya',
+ 'LI': 'Liechtenstein',
+ 'LT': 'Lithuania',
+ 'LU': 'Luxembourg',
+ 'MO': 'Macao',
+ 'MK': 'Macedonia, the Former Yugoslav Republic of',
+ 'MG': 'Madagascar',
+ 'MW': 'Malawi',
+ 'MY': 'Malaysia',
+ 'MV': 'Maldives',
+ 'ML': 'Mali',
+ 'MT': 'Malta',
+ 'MH': 'Marshall Islands',
+ 'MQ': 'Martinique',
+ 'MR': 'Mauritania',
+ 'MU': 'Mauritius',
+ 'YT': 'Mayotte',
+ 'MX': 'Mexico',
+ 'FM': 'Micronesia, Federated States of',
+ 'MD': 'Moldova, Republic of',
+ 'MC': 'Monaco',
+ 'MN': 'Mongolia',
+ 'ME': 'Montenegro',
+ 'MS': 'Montserrat',
+ 'MA': 'Morocco',
+ 'MZ': 'Mozambique',
+ 'MM': 'Myanmar',
+ 'NA': 'Namibia',
+ 'NR': 'Nauru',
+ 'NP': 'Nepal',
+ 'NL': 'Netherlands',
+ 'NC': 'New Caledonia',
+ 'NZ': 'New Zealand',
+ 'NI': 'Nicaragua',
+ 'NE': 'Niger',
+ 'NG': 'Nigeria',
+ 'NU': 'Niue',
+ 'NF': 'Norfolk Island',
+ 'MP': 'Northern Mariana Islands',
+ 'NO': 'Norway',
+ 'OM': 'Oman',
+ 'PK': 'Pakistan',
+ 'PW': 'Palau',
+ 'PS': 'Palestine, State of',
+ 'PA': 'Panama',
+ 'PG': 'Papua New Guinea',
+ 'PY': 'Paraguay',
+ 'PE': 'Peru',
+ 'PH': 'Philippines',
+ 'PN': 'Pitcairn',
+ 'PL': 'Poland',
+ 'PT': 'Portugal',
+ 'PR': 'Puerto Rico',
+ 'QA': 'Qatar',
+ 'RE': 'Réunion',
+ 'RO': 'Romania',
+ 'RU': 'Russian Federation',
+ 'RW': 'Rwanda',
+ 'BL': 'Saint Barthélemy',
+ 'SH': 'Saint Helena, Ascension and Tristan da Cunha',
+ 'KN': 'Saint Kitts and Nevis',
+ 'LC': 'Saint Lucia',
+ 'MF': 'Saint Martin (French part)',
+ 'PM': 'Saint Pierre and Miquelon',
+ 'VC': 'Saint Vincent and the Grenadines',
+ 'WS': 'Samoa',
+ 'SM': 'San Marino',
+ 'ST': 'Sao Tome and Principe',
+ 'SA': 'Saudi Arabia',
+ 'SN': 'Senegal',
+ 'RS': 'Serbia',
+ 'SC': 'Seychelles',
+ 'SL': 'Sierra Leone',
+ 'SG': 'Singapore',
+ 'SX': 'Sint Maarten (Dutch part)',
+ 'SK': 'Slovakia',
+ 'SI': 'Slovenia',
+ 'SB': 'Solomon Islands',
+ 'SO': 'Somalia',
+ 'ZA': 'South Africa',
+ 'GS': 'South Georgia and the South Sandwich Islands',
+ 'SS': 'South Sudan',
+ 'ES': 'Spain',
+ 'LK': 'Sri Lanka',
+ 'SD': 'Sudan',
+ 'SR': 'Suriname',
+ 'SJ': 'Svalbard and Jan Mayen',
+ 'SZ': 'Swaziland',
+ 'SE': 'Sweden',
+ 'CH': 'Switzerland',
+ 'SY': 'Syrian Arab Republic',
+ 'TW': 'Taiwan, Province of China',
+ 'TJ': 'Tajikistan',
+ 'TZ': 'Tanzania, United Republic of',
+ 'TH': 'Thailand',
+ 'TL': 'Timor-Leste',
+ 'TG': 'Togo',
+ 'TK': 'Tokelau',
+ 'TO': 'Tonga',
+ 'TT': 'Trinidad and Tobago',
+ 'TN': 'Tunisia',
+ 'TR': 'Turkey',
+ 'TM': 'Turkmenistan',
+ 'TC': 'Turks and Caicos Islands',
+ 'TV': 'Tuvalu',
+ 'UG': 'Uganda',
+ 'UA': 'Ukraine',
+ 'AE': 'United Arab Emirates',
+ 'GB': 'United Kingdom',
+ 'US': 'United States',
+ 'UM': 'United States Minor Outlying Islands',
+ 'UY': 'Uruguay',
+ 'UZ': 'Uzbekistan',
+ 'VU': 'Vanuatu',
+ 'VE': 'Venezuela, Bolivarian Republic of',
+ 'VN': 'Viet Nam',
+ 'VG': 'Virgin Islands, British',
+ 'VI': 'Virgin Islands, U.S.',
+ 'WF': 'Wallis and Futuna',
+ 'EH': 'Western Sahara',
+ 'YE': 'Yemen',
+ 'ZM': 'Zambia',
+ 'ZW': 'Zimbabwe',
+ }
+
+ @classmethod
+ def short2full(cls, code):
+ """Convert an ISO 3166-2 country code to the corresponding full name"""
+ return cls._country_map.get(code.upper())
+
+
+class PerRequestProxyHandler(compat_urllib_request.ProxyHandler):
+ def __init__(self, proxies=None):
+ # Set default handlers
+ for type in ('http', 'https'):
+ setattr(self, '%s_open' % type,
+ lambda r, proxy='__noproxy__', type=type, meth=self.proxy_open:
+ meth(r, proxy, type))
+ return compat_urllib_request.ProxyHandler.__init__(self, proxies)
+
+ def proxy_open(self, req, proxy, type):
+ req_proxy = req.headers.get('Ytdl-request-proxy')
+ if req_proxy is not None:
+ proxy = req_proxy
+ del req.headers['Ytdl-request-proxy']
+
+ if proxy == '__noproxy__':
+ return None # No Proxy
+ if compat_urlparse.urlparse(proxy).scheme.lower() in ('socks', 'socks4', 'socks4a', 'socks5'):
+ req.add_header('Ytdl-socks-proxy', proxy)
+ # youtube-dl's http/https handlers do wrapping the socket with socks
+ return None
+ return compat_urllib_request.ProxyHandler.proxy_open(
+ self, req, proxy, type)
+
+
+def ohdave_rsa_encrypt(data, exponent, modulus):
+ '''
+ Implement OHDave's RSA algorithm. See http://www.ohdave.com/rsa/
+
+ Input:
+ data: data to encrypt, bytes-like object
+ exponent, modulus: parameter e and N of RSA algorithm, both integer
+ Output: hex string of encrypted data
+
+ Limitation: supports one block encryption only
+ '''
+
+ payload = int(binascii.hexlify(data[::-1]), 16)
+ encrypted = pow(payload, exponent, modulus)
+ return '%x' % encrypted
+
+
+def encode_base_n(num, n, table=None):
+ FULL_TABLE = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'
+ if not table:
+ table = FULL_TABLE[:n]
+
+ if n > len(table):
+ raise ValueError('base %d exceeds table length %d' % (n, len(table)))
+
+ if num == 0:
+ return table[0]
+
+ ret = ''
+ while num:
+ ret = table[num % n] + ret
+ num = num // n
+ return ret
+
+
+def decode_packed_codes(code):
+ mobj = re.search(
+ r"}\('(.+)',(\d+),(\d+),'([^']+)'\.split\('\|'\)",
+ code)
+ obfucasted_code, base, count, symbols = mobj.groups()
+ base = int(base)
+ count = int(count)
+ symbols = symbols.split('|')
+ symbol_table = {}
+
+ while count:
+ count -= 1
+ base_n_count = encode_base_n(count, base)
+ symbol_table[base_n_count] = symbols[count] or base_n_count
+
+ return re.sub(
+ r'\b(\w+)\b', lambda mobj: symbol_table[mobj.group(0)],
+ obfucasted_code)
+
+
+def parse_m3u8_attributes(attrib):
+ info = {}
+ for (key, val) in re.findall(r'(?P<key>[A-Z0-9-]+)=(?P<val>"[^"]+"|[^",]+)(?:,|$)', attrib):
+ if val.startswith('"'):
+ val = val[1:-1]
+ info[key] = val
+ return info
+
+
+def urshift(val, n):
+ return val >> n if val >= 0 else (val + 0x100000000) >> n
+
+
+# Based on png2str() written by @gdkchan and improved by @yokrysty
+# Originally posted at https://github.com/rg3/youtube-dl/issues/9706
+def decode_png(png_data):
+ # Reference: https://www.w3.org/TR/PNG/
+ header = png_data[8:]
+
+ if png_data[:8] != b'\x89PNG\x0d\x0a\x1a\x0a' or header[4:8] != b'IHDR':
+ raise IOError('Not a valid PNG file.')
+
+ int_map = {1: '>B', 2: '>H', 4: '>I'}
+ unpack_integer = lambda x: compat_struct_unpack(int_map[len(x)], x)[0]
+
+ chunks = []
+
+ while header:
+ length = unpack_integer(header[:4])
+ header = header[4:]
+
+ chunk_type = header[:4]
+ header = header[4:]
+
+ chunk_data = header[:length]
+ header = header[length:]
+
+ header = header[4:] # Skip CRC
+
+ chunks.append({
+ 'type': chunk_type,
+ 'length': length,
+ 'data': chunk_data
+ })
+
+ ihdr = chunks[0]['data']
+
+ width = unpack_integer(ihdr[:4])
+ height = unpack_integer(ihdr[4:8])
+
+ idat = b''
+
+ for chunk in chunks:
+ if chunk['type'] == b'IDAT':
+ idat += chunk['data']
+
+ if not idat:
+ raise IOError('Unable to read PNG data.')
+
+ decompressed_data = bytearray(zlib.decompress(idat))
+
+ stride = width * 3
+ pixels = []
+
+ def _get_pixel(idx):
+ x = idx % stride
+ y = idx // stride
+ return pixels[y][x]
+
+ for y in range(height):
+ basePos = y * (1 + stride)
+ filter_type = decompressed_data[basePos]
+
+ current_row = []
+
+ pixels.append(current_row)
+
+ for x in range(stride):
+ color = decompressed_data[1 + basePos + x]
+ basex = y * stride + x
+ left = 0
+ up = 0
+
+ if x > 2:
+ left = _get_pixel(basex - 3)
+ if y > 0:
+ up = _get_pixel(basex - stride)
+
+ if filter_type == 1: # Sub
+ color = (color + left) & 0xff
+ elif filter_type == 2: # Up
+ color = (color + up) & 0xff
+ elif filter_type == 3: # Average
+ color = (color + ((left + up) >> 1)) & 0xff
+ elif filter_type == 4: # Paeth
+ a = left
+ b = up
+ c = 0
+
+ if x > 2 and y > 0:
+ c = _get_pixel(basex - stride - 3)
+
+ p = a + b - c
+
+ pa = abs(p - a)
+ pb = abs(p - b)
+ pc = abs(p - c)
+
+ if pa <= pb and pa <= pc:
+ color = (color + a) & 0xff
+ elif pb <= pc:
+ color = (color + b) & 0xff
+ else:
+ color = (color + c) & 0xff
+
+ current_row.append(color)
+
+ return width, height, pixels