+
+
+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
Rapsys Git / youtubedl / blobdiff