_ Git - youtube-dl/blob - youtube_dl/swfinterp.py

   1 from __future__ import unicode_literals
   2
   3 import collections
   4 import io
   5 import zlib
   6
   7 from .utils import (
   8     compat_str,
   9     ExtractorError,
  10     struct_unpack,
  11 )
  12
  13
  14 def _extract_tags(file_contents):
  15     if file_contents[1:3] != b'WS':
  16         raise ExtractorError(
  17             'Not an SWF file; header is %r' % file_contents[:3])
  18     if file_contents[:1] == b'C':
  19         content = zlib.decompress(file_contents[8:])
  20     else:
  21         raise NotImplementedError(
  22             'Unsupported compression format %r' %
  23             file_contents[:1])
  24
  25     # Determine number of bits in framesize rectangle
  26     framesize_nbits = struct_unpack('!B', content[:1])[0] >> 3
  27     framesize_len = (5 + 4 * framesize_nbits + 7) // 8
  28
  29     pos = framesize_len + 2 + 2
  30     while pos < len(content):
  31         header16 = struct_unpack('<H', content[pos:pos + 2])[0]
  32         pos += 2
  33         tag_code = header16 >> 6
  34         tag_len = header16 & 0x3f
  35         if tag_len == 0x3f:
  36             tag_len = struct_unpack('<I', content[pos:pos + 4])[0]
  37             pos += 4
  38         assert pos + tag_len <= len(content), \
  39             ('Tag %d ends at %d+%d - that\'s longer than the file (%d)'
  40                 % (tag_code, pos, tag_len, len(content)))
  41         yield (tag_code, content[pos:pos + tag_len])
  42         pos += tag_len
  43
  44
  45 class _AVMClass_Object(object):
  46     def __init__(self, avm_class):
  47         self.avm_class = avm_class
  48
  49     def __repr__(self):
  50         return '%s#%x' % (self.avm_class.name, id(self))
  51
  52
  53 class _ScopeDict(dict):
  54     def __init__(self, avm_class):
  55         super(_ScopeDict, self).__init__()
  56         self.avm_class = avm_class
  57
  58     def __repr__(self):
  59         return '%s__Scope(%s)' % (
  60             self.avm_class.name,
  61             super(_ScopeDict, self).__repr__())
  62
  63
  64 class _AVMClass(object):
  65     def __init__(self, name_idx, name):
  66         self.name_idx = name_idx
  67         self.name = name
  68         self.method_names = {}
  69         self.method_idxs = {}
  70         self.methods = {}
  71         self.method_pyfunctions = {}
  72
  73         self.variables = _ScopeDict(self)
  74
  75     def make_object(self):
  76         return _AVMClass_Object(self)
  77
  78     def __repr__(self):
  79         return '_AVMClass(%s)' % (self.name)
  80
  81     def register_methods(self, methods):
  82         self.method_names.update(methods.items())
  83         self.method_idxs.update(dict(
  84             (idx, name)
  85             for name, idx in methods.items()))
  86
  87
  88 class _Multiname(object):
  89     def __init__(self, kind):
  90         self.kind = kind
  91
  92     def __repr__(self):
  93         return '[MULTINAME kind: 0x%x]' % self.kind
  94
  95
  96 def _read_int(reader):
  97     res = 0
  98     shift = 0
  99     for _ in range(5):
 100         buf = reader.read(1)
 101         assert len(buf) == 1
 102         b = struct_unpack('<B', buf)[0]
 103         res = res | ((b & 0x7f) << shift)
 104         if b & 0x80 == 0:
 105             break
 106         shift += 7
 107     return res
 108
 109
 110 def _u30(reader):
 111     res = _read_int(reader)
 112     assert res & 0xf0000000 == 0
 113     return res
 114 _u32 = _read_int
 115
 116
 117 def _s32(reader):
 118     v = _read_int(reader)
 119     if v & 0x80000000 != 0:
 120         v = - ((v ^ 0xffffffff) + 1)
 121     return v
 122
 123
 124 def _s24(reader):
 125     bs = reader.read(3)
 126     assert len(bs) == 3
 127     last_byte = b'\xff' if (ord(bs[2:3]) >= 0x80) else b'\x00'
 128     return struct_unpack('<i', bs + last_byte)[0]
 129
 130
 131 def _read_string(reader):
 132     slen = _u30(reader)
 133     resb = reader.read(slen)
 134     assert len(resb) == slen
 135     return resb.decode('utf-8')
 136
 137
 138 def _read_bytes(count, reader):
 139     assert count >= 0
 140     resb = reader.read(count)
 141     assert len(resb) == count
 142     return resb
 143
 144
 145 def _read_byte(reader):
 146     resb = _read_bytes(1, reader=reader)
 147     res = struct_unpack('<B', resb)[0]
 148     return res
 149
 150
 151 StringClass = _AVMClass('(no name idx)', 'String')
 152 ByteArrayClass = _AVMClass('(no name idx)', 'ByteArray')
 153 _builtin_classes = {
 154     StringClass.name: StringClass,
 155     ByteArrayClass.name: ByteArrayClass,
 156 }
 157
 158
 159 class _Undefined(object):
 160     def __boolean__(self):
 161         return False
 162
 163     def __hash__(self):
 164         return 0
 165
 166 undefined = _Undefined()
 167
 168
 169 class SWFInterpreter(object):
 170     def __init__(self, file_contents):
 171         self._patched_functions = {}
 172         code_tag = next(tag
 173                         for tag_code, tag in _extract_tags(file_contents)
 174                         if tag_code == 82)
 175         p = code_tag.index(b'\0', 4) + 1
 176         code_reader = io.BytesIO(code_tag[p:])
 177
 178         # Parse ABC (AVM2 ByteCode)
 179
 180         # Define a couple convenience methods
 181         u30 = lambda *args: _u30(*args, reader=code_reader)
 182         s32 = lambda *args: _s32(*args, reader=code_reader)
 183         u32 = lambda *args: _u32(*args, reader=code_reader)
 184         read_bytes = lambda *args: _read_bytes(*args, reader=code_reader)
 185         read_byte = lambda *args: _read_byte(*args, reader=code_reader)
 186
 187         # minor_version + major_version
 188         read_bytes(2 + 2)
 189
 190         # Constant pool
 191         int_count = u30()
 192         for _c in range(1, int_count):
 193             s32()
 194         uint_count = u30()
 195         for _c in range(1, uint_count):
 196             u32()
 197         double_count = u30()
 198         read_bytes(max(0, (double_count - 1)) * 8)
 199         string_count = u30()
 200         self.constant_strings = ['']
 201         for _c in range(1, string_count):
 202             s = _read_string(code_reader)
 203             self.constant_strings.append(s)
 204         namespace_count = u30()
 205         for _c in range(1, namespace_count):
 206             read_bytes(1)  # kind
 207             u30()  # name
 208         ns_set_count = u30()
 209         for _c in range(1, ns_set_count):
 210             count = u30()
 211             for _c2 in range(count):
 212                 u30()
 213         multiname_count = u30()
 214         MULTINAME_SIZES = {
 215             0x07: 2,  # QName
 216             0x0d: 2,  # QNameA
 217             0x0f: 1,  # RTQName
 218             0x10: 1,  # RTQNameA
 219             0x11: 0,  # RTQNameL
 220             0x12: 0,  # RTQNameLA
 221             0x09: 2,  # Multiname
 222             0x0e: 2,  # MultinameA
 223             0x1b: 1,  # MultinameL
 224             0x1c: 1,  # MultinameLA
 225         }
 226         self.multinames = ['']
 227         for _c in range(1, multiname_count):
 228             kind = u30()
 229             assert kind in MULTINAME_SIZES, 'Invalid multiname kind %r' % kind
 230             if kind == 0x07:
 231                 u30()  # namespace_idx
 232                 name_idx = u30()
 233                 self.multinames.append(self.constant_strings[name_idx])
 234             elif kind == 0x09:
 235                 name_idx = u30()
 236                 u30()
 237                 self.multinames.append(self.constant_strings[name_idx])
 238             else:
 239                 self.multinames.append(_Multiname(kind))
 240                 for _c2 in range(MULTINAME_SIZES[kind]):
 241                     u30()
 242
 243         # Methods
 244         method_count = u30()
 245         MethodInfo = collections.namedtuple(
 246             'MethodInfo',
 247             ['NEED_ARGUMENTS', 'NEED_REST'])
 248         method_infos = []
 249         for method_id in range(method_count):
 250             param_count = u30()
 251             u30()  # return type
 252             for _ in range(param_count):
 253                 u30()  # param type
 254             u30()  # name index (always 0 for youtube)
 255             flags = read_byte()
 256             if flags & 0x08 != 0:
 257                 # Options present
 258                 option_count = u30()
 259                 for c in range(option_count):
 260                     u30()  # val
 261                     read_bytes(1)  # kind
 262             if flags & 0x80 != 0:
 263                 # Param names present
 264                 for _ in range(param_count):
 265                     u30()  # param name
 266             mi = MethodInfo(flags & 0x01 != 0, flags & 0x04 != 0)
 267             method_infos.append(mi)
 268
 269         # Metadata
 270         metadata_count = u30()
 271         for _c in range(metadata_count):
 272             u30()  # name
 273             item_count = u30()
 274             for _c2 in range(item_count):
 275                 u30()  # key
 276                 u30()  # value
 277
 278         def parse_traits_info():
 279             trait_name_idx = u30()
 280             kind_full = read_byte()
 281             kind = kind_full & 0x0f
 282             attrs = kind_full >> 4
 283             methods = {}
 284             if kind in [0x00, 0x06]:  # Slot or Const
 285                 u30()  # Slot id
 286                 u30()  # type_name_idx
 287                 vindex = u30()
 288                 if vindex != 0:
 289                     read_byte()  # vkind
 290             elif kind in [0x01, 0x02, 0x03]:  # Method / Getter / Setter
 291                 u30()  # disp_id
 292                 method_idx = u30()
 293                 methods[self.multinames[trait_name_idx]] = method_idx
 294             elif kind == 0x04:  # Class
 295                 u30()  # slot_id
 296                 u30()  # classi
 297             elif kind == 0x05:  # Function
 298                 u30()  # slot_id
 299                 function_idx = u30()
 300                 methods[function_idx] = self.multinames[trait_name_idx]
 301             else:
 302                 raise ExtractorError('Unsupported trait kind %d' % kind)
 303
 304             if attrs & 0x4 != 0:  # Metadata present
 305                 metadata_count = u30()
 306                 for _c3 in range(metadata_count):
 307                     u30()  # metadata index
 308
 309             return methods
 310
 311         # Classes
 312         class_count = u30()
 313         classes = []
 314         for class_id in range(class_count):
 315             name_idx = u30()
 316
 317             cname = self.multinames[name_idx]
 318             avm_class = _AVMClass(name_idx, cname)
 319             classes.append(avm_class)
 320
 321             u30()  # super_name idx
 322             flags = read_byte()
 323             if flags & 0x08 != 0:  # Protected namespace is present
 324                 u30()  # protected_ns_idx
 325             intrf_count = u30()
 326             for _c2 in range(intrf_count):
 327                 u30()
 328             u30()  # iinit
 329             trait_count = u30()
 330             for _c2 in range(trait_count):
 331                 trait_methods = parse_traits_info()
 332                 avm_class.register_methods(trait_methods)
 333
 334         assert len(classes) == class_count
 335         self._classes_by_name = dict((c.name, c) for c in classes)
 336
 337         for avm_class in classes:
 338             u30()  # cinit
 339             trait_count = u30()
 340             for _c2 in range(trait_count):
 341                 trait_methods = parse_traits_info()
 342                 avm_class.register_methods(trait_methods)
 343
 344         # Scripts
 345         script_count = u30()
 346         for _c in range(script_count):
 347             u30()  # init
 348             trait_count = u30()
 349             for _c2 in range(trait_count):
 350                 parse_traits_info()
 351
 352         # Method bodies
 353         method_body_count = u30()
 354         Method = collections.namedtuple('Method', ['code', 'local_count'])
 355         for _c in range(method_body_count):
 356             method_idx = u30()
 357             u30()  # max_stack
 358             local_count = u30()
 359             u30()  # init_scope_depth
 360             u30()  # max_scope_depth
 361             code_length = u30()
 362             code = read_bytes(code_length)
 363             for avm_class in classes:
 364                 if method_idx in avm_class.method_idxs:
 365                     m = Method(code, local_count)
 366                     avm_class.methods[avm_class.method_idxs[method_idx]] = m
 367             exception_count = u30()
 368             for _c2 in range(exception_count):
 369                 u30()  # from
 370                 u30()  # to
 371                 u30()  # target
 372                 u30()  # exc_type
 373                 u30()  # var_name
 374             trait_count = u30()
 375             for _c2 in range(trait_count):
 376                 parse_traits_info()
 377
 378         assert p + code_reader.tell() == len(code_tag)
 379
 380     def patch_function(self, avm_class, func_name, f):
 381         self._patched_functions[(avm_class, func_name)] = f
 382
 383     def extract_class(self, class_name):
 384         try:
 385             return self._classes_by_name[class_name]
 386         except KeyError:
 387             raise ExtractorError('Class %r not found' % class_name)
 388
 389     def extract_function(self, avm_class, func_name):
 390         p = self._patched_functions.get((avm_class, func_name))
 391         if p:
 392             return p
 393         if func_name in avm_class.method_pyfunctions:
 394             return avm_class.method_pyfunctions[func_name]
 395         if func_name in self._classes_by_name:
 396             return self._classes_by_name[func_name].make_object()
 397         if func_name not in avm_class.methods:
 398             raise ExtractorError('Cannot find function %s.%s' % (
 399                 avm_class.name, func_name))
 400         m = avm_class.methods[func_name]
 401
 402         def resfunc(args):
 403             # Helper functions
 404             coder = io.BytesIO(m.code)
 405             s24 = lambda: _s24(coder)
 406             u30 = lambda: _u30(coder)
 407
 408             registers = [avm_class.variables] + list(args) + [None] * m.local_count
 409             stack = []
 410             scopes = collections.deque([
 411                 self._classes_by_name, avm_class.variables])
 412             while True:
 413                 opcode = _read_byte(coder)
 414                 if opcode == 9:  # label
 415                     pass  # Spec says: "Do nothing."
 416                 elif opcode == 16:  # jump
 417                     offset = s24()
 418                     coder.seek(coder.tell() + offset)
 419                 elif opcode == 17:  # iftrue
 420                     offset = s24()
 421                     value = stack.pop()
 422                     if value:
 423                         coder.seek(coder.tell() + offset)
 424                 elif opcode == 18:  # iffalse
 425                     offset = s24()
 426                     value = stack.pop()
 427                     if not value:
 428                         coder.seek(coder.tell() + offset)
 429                 elif opcode == 19:  # ifeq
 430                     offset = s24()
 431                     value2 = stack.pop()
 432                     value1 = stack.pop()
 433                     if value2 == value1:
 434                         coder.seek(coder.tell() + offset)
 435                 elif opcode == 20:  # ifne
 436                     offset = s24()
 437                     value2 = stack.pop()
 438                     value1 = stack.pop()
 439                     if value2 != value1:
 440                         coder.seek(coder.tell() + offset)
 441                 elif opcode == 21:  # iflt
 442                     offset = s24()
 443                     value2 = stack.pop()
 444                     value1 = stack.pop()
 445                     if value1 < value2:
 446                         coder.seek(coder.tell() + offset)
 447                 elif opcode == 32:  # pushnull
 448                     stack.append(None)
 449                 elif opcode == 33:  # pushundefined
 450                     stack.append(undefined)
 451                 elif opcode == 36:  # pushbyte
 452                     v = _read_byte(coder)
 453                     stack.append(v)
 454                 elif opcode == 38:  # pushtrue
 455                     stack.append(True)
 456                 elif opcode == 39:  # pushfalse
 457                     stack.append(False)
 458                 elif opcode == 40:  # pushnan
 459                     stack.append(float('NaN'))
 460                 elif opcode == 42:  # dup
 461                     value = stack[-1]
 462                     stack.append(value)
 463                 elif opcode == 44:  # pushstring
 464                     idx = u30()
 465                     stack.append(self.constant_strings[idx])
 466                 elif opcode == 48:  # pushscope
 467                     new_scope = stack.pop()
 468                     scopes.append(new_scope)
 469                 elif opcode == 66:  # construct
 470                     arg_count = u30()
 471                     args = list(reversed(
 472                         [stack.pop() for _ in range(arg_count)]))
 473                     obj = stack.pop()
 474                     res = obj.avm_class.make_object()
 475                     stack.append(res)
 476                 elif opcode == 70:  # callproperty
 477                     index = u30()
 478                     mname = self.multinames[index]
 479                     arg_count = u30()
 480                     args = list(reversed(
 481                         [stack.pop() for _ in range(arg_count)]))
 482                     obj = stack.pop()
 483
 484                     if obj == StringClass:
 485                         if mname == 'String':
 486                             assert len(args) == 1
 487                             assert isinstance(args[0], (
 488                                 int, compat_str, _Undefined))
 489                             if args[0] == undefined:
 490                                 res = 'undefined'
 491                             else:
 492                                 res = compat_str(args[0])
 493                             stack.append(res)
 494                             continue
 495                         else:
 496                             raise NotImplementedError(
 497                                 'Function String.%s is not yet implemented'
 498                                 % mname)
 499                     elif isinstance(obj, _AVMClass_Object):
 500                         func = self.extract_function(obj.avm_class, mname)
 501                         res = func(args)
 502                         stack.append(res)
 503                         continue
 504                     elif isinstance(obj, _AVMClass):
 505                         func = self.extract_function(obj, mname)
 506                         res = func(args)
 507                         stack.append(res)
 508                         continue
 509                     elif isinstance(obj, _ScopeDict):
 510                         if mname in obj.avm_class.method_names:
 511                             func = self.extract_function(obj.avm_class, mname)
 512                             res = func(args)
 513                         else:
 514                             res = obj[mname]
 515                         stack.append(res)
 516                         continue
 517                     elif isinstance(obj, compat_str):
 518                         if mname == 'split':
 519                             assert len(args) == 1
 520                             assert isinstance(args[0], compat_str)
 521                             if args[0] == '':
 522                                 res = list(obj)
 523                             else:
 524                                 res = obj.split(args[0])
 525                             stack.append(res)
 526                             continue
 527                         elif mname == 'charCodeAt':
 528                             assert len(args) <= 1
 529                             idx = 0 if len(args) == 0 else args[0]
 530                             assert isinstance(idx, int)
 531                             res = ord(obj[idx])
 532                             stack.append(res)
 533                             continue
 534                     elif isinstance(obj, list):
 535                         if mname == 'slice':
 536                             assert len(args) == 1
 537                             assert isinstance(args[0], int)
 538                             res = obj[args[0]:]
 539                             stack.append(res)
 540                             continue
 541                         elif mname == 'join':
 542                             assert len(args) == 1
 543                             assert isinstance(args[0], compat_str)
 544                             res = args[0].join(obj)
 545                             stack.append(res)
 546                             continue
 547                     raise NotImplementedError(
 548                         'Unsupported property %r on %r'
 549                         % (mname, obj))
 550                 elif opcode == 71:  # returnvoid
 551                     res = undefined
 552                     return res
 553                 elif opcode == 72:  # returnvalue
 554                     res = stack.pop()
 555                     return res
 556                 elif opcode == 74:  # constructproperty
 557                     index = u30()
 558                     arg_count = u30()
 559                     args = list(reversed(
 560                         [stack.pop() for _ in range(arg_count)]))
 561                     obj = stack.pop()
 562
 563                     mname = self.multinames[index]
 564                     assert isinstance(obj, _AVMClass)
 565
 566                     # We do not actually call the constructor for now;
 567                     # we just pretend it does nothing
 568                     stack.append(obj.make_object())
 569                 elif opcode == 79:  # callpropvoid
 570                     index = u30()
 571                     mname = self.multinames[index]
 572                     arg_count = u30()
 573                     args = list(reversed(
 574                         [stack.pop() for _ in range(arg_count)]))
 575                     obj = stack.pop()
 576                     if isinstance(obj, _AVMClass_Object):
 577                         func = self.extract_function(obj.avm_class, mname)
 578                         res = func(args)
 579                         assert res is undefined
 580                         continue
 581                     if isinstance(obj, _ScopeDict):
 582                         assert mname in obj.avm_class.method_names
 583                         func = self.extract_function(obj.avm_class, mname)
 584                         res = func(args)
 585                         assert res is undefined
 586                         continue
 587                     if mname == 'reverse':
 588                         assert isinstance(obj, list)
 589                         obj.reverse()
 590                     else:
 591                         raise NotImplementedError(
 592                             'Unsupported (void) property %r on %r'
 593                             % (mname, obj))
 594                 elif opcode == 86:  # newarray
 595                     arg_count = u30()
 596                     arr = []
 597                     for i in range(arg_count):
 598                         arr.append(stack.pop())
 599                     arr = arr[::-1]
 600                     stack.append(arr)
 601                 elif opcode == 93:  # findpropstrict
 602                     index = u30()
 603                     mname = self.multinames[index]
 604                     for s in reversed(scopes):
 605                         if mname in s:
 606                             res = s
 607                             break
 608                     else:
 609                         res = scopes[0]
 610                     if mname not in res and mname in _builtin_classes:
 611                         stack.append(_builtin_classes[mname])
 612                     else:
 613                         stack.append(res[mname])
 614                 elif opcode == 94:  # findproperty
 615                     index = u30()
 616                     mname = self.multinames[index]
 617                     for s in reversed(scopes):
 618                         if mname in s:
 619                             res = s
 620                             break
 621                     else:
 622                         res = avm_class.variables
 623                     stack.append(res)
 624                 elif opcode == 96:  # getlex
 625                     index = u30()
 626                     mname = self.multinames[index]
 627                     for s in reversed(scopes):
 628                         if mname in s:
 629                             scope = s
 630                             break
 631                     else:
 632                         scope = avm_class.variables
 633                     # I cannot find where static variables are initialized
 634                     # so let's just return None
 635                     res = scope.get(mname)
 636                     stack.append(res)
 637                 elif opcode == 97:  # setproperty
 638                     index = u30()
 639                     value = stack.pop()
 640                     idx = self.multinames[index]
 641                     if isinstance(idx, _Multiname):
 642                         idx = stack.pop()
 643                     obj = stack.pop()
 644                     obj[idx] = value
 645                 elif opcode == 98:  # getlocal
 646                     index = u30()
 647                     stack.append(registers[index])
 648                 elif opcode == 99:  # setlocal
 649                     index = u30()
 650                     value = stack.pop()
 651                     registers[index] = value
 652                 elif opcode == 102:  # getproperty
 653                     index = u30()
 654                     pname = self.multinames[index]
 655                     if pname == 'length':
 656                         obj = stack.pop()
 657                         assert isinstance(obj, (compat_str, list))
 658                         stack.append(len(obj))
 659                     elif isinstance(pname, compat_str):  # Member access
 660                         obj = stack.pop()
 661                         assert isinstance(obj, (dict, _ScopeDict)), \
 662                             'Accessing member %r on %r' % (pname, obj)
 663                         res = obj.get(pname, undefined)
 664                         stack.append(res)
 665                     else:  # Assume attribute access
 666                         idx = stack.pop()
 667                         assert isinstance(idx, int)
 668                         obj = stack.pop()
 669                         assert isinstance(obj, list)
 670                         stack.append(obj[idx])
 671                 elif opcode == 115:  # convert_
 672                     value = stack.pop()
 673                     intvalue = int(value)
 674                     stack.append(intvalue)
 675                 elif opcode == 128:  # coerce
 676                     u30()
 677                 elif opcode == 130:  # coerce_a
 678                     value = stack.pop()
 679                     # um, yes, it's any value
 680                     stack.append(value)
 681                 elif opcode == 133:  # coerce_s
 682                     assert isinstance(stack[-1], (type(None), compat_str))
 683                 elif opcode == 147:  # decrement
 684                     value = stack.pop()
 685                     assert isinstance(value, int)
 686                     stack.append(value - 1)
 687                 elif opcode == 149:  # typeof
 688                     value = stack.pop()
 689                     return {
 690                         _Undefined: 'undefined',
 691                         compat_str: 'String',
 692                         int: 'Number',
 693                         float: 'Number',
 694                     }[type(value)]
 695                 elif opcode == 160:  # add
 696                     value2 = stack.pop()
 697                     value1 = stack.pop()
 698                     res = value1 + value2
 699                     stack.append(res)
 700                 elif opcode == 161:  # subtract
 701                     value2 = stack.pop()
 702                     value1 = stack.pop()
 703                     res = value1 - value2
 704                     stack.append(res)
 705                 elif opcode == 162:  # multiply
 706                     value2 = stack.pop()
 707                     value1 = stack.pop()
 708                     res = value1 * value2
 709                     stack.append(res)
 710                 elif opcode == 164:  # modulo
 711                     value2 = stack.pop()
 712                     value1 = stack.pop()
 713                     res = value1 % value2
 714                     stack.append(res)
 715                 elif opcode == 171:  # equals
 716                     value2 = stack.pop()
 717                     value1 = stack.pop()
 718                     result = value1 == value2
 719                     stack.append(result)
 720                 elif opcode == 175:  # greaterequals
 721                     value2 = stack.pop()
 722                     value1 = stack.pop()
 723                     result = value1 >= value2
 724                     stack.append(result)
 725                 elif opcode == 192:  # increment_i
 726                     value = stack.pop()
 727                     assert isinstance(value, int)
 728                     stack.append(value + 1)
 729                 elif opcode == 208:  # getlocal_0
 730                     stack.append(registers[0])
 731                 elif opcode == 209:  # getlocal_1
 732                     stack.append(registers[1])
 733                 elif opcode == 210:  # getlocal_2
 734                     stack.append(registers[2])
 735                 elif opcode == 211:  # getlocal_3
 736                     stack.append(registers[3])
 737                 elif opcode == 212:  # setlocal_0
 738                     registers[0] = stack.pop()
 739                 elif opcode == 213:  # setlocal_1
 740                     registers[1] = stack.pop()
 741                 elif opcode == 214:  # setlocal_2
 742                     registers[2] = stack.pop()
 743                 elif opcode == 215:  # setlocal_3
 744                     registers[3] = stack.pop()
 745                 else:
 746                     raise NotImplementedError(
 747                         'Unsupported opcode %d' % opcode)
 748
 749         avm_class.method_pyfunctions[func_name] = resfunc
 750         return resfunc
 751