youtube_dl/swfinterp.py

   1 from __future__ import unicode_literals
   2
   3 import collections
   4 import io
   5 import zlib
   6
   7 from .compat import compat_str
   8 from .utils import (
   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, static_properties=None):
  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         self.static_properties = static_properties if static_properties else {}
  73
  74         self.variables = _ScopeDict(self)
  75         self.constants = {}
  76
  77     def make_object(self):
  78         return _AVMClass_Object(self)
  79
  80     def __repr__(self):
  81         return '_AVMClass(%s)' % (self.name)
  82
  83     def register_methods(self, methods):
  84         self.method_names.update(methods.items())
  85         self.method_idxs.update(dict(
  86             (idx, name)
  87             for name, idx in methods.items()))
  88
  89
  90 class _Multiname(object):
  91     def __init__(self, kind):
  92         self.kind = kind
  93
  94     def __repr__(self):
  95         return '[MULTINAME kind: 0x%x]' % self.kind
  96
  97
  98 def _read_int(reader):
  99     res = 0
 100     shift = 0
 101     for _ in range(5):
 102         buf = reader.read(1)
 103         assert len(buf) == 1
 104         b = struct_unpack('<B', buf)[0]
 105         res = res | ((b & 0x7f) << shift)
 106         if b & 0x80 == 0:
 107             break
 108         shift += 7
 109     return res
 110
 111
 112 def _u30(reader):
 113     res = _read_int(reader)
 114     assert res & 0xf0000000 == 0
 115     return res
 116 _u32 = _read_int
 117
 118
 119 def _s32(reader):
 120     v = _read_int(reader)
 121     if v & 0x80000000 != 0:
 122         v = - ((v ^ 0xffffffff) + 1)
 123     return v
 124
 125
 126 def _s24(reader):
 127     bs = reader.read(3)
 128     assert len(bs) == 3
 129     last_byte = b'\xff' if (ord(bs[2:3]) >= 0x80) else b'\x00'
 130     return struct_unpack('<i', bs + last_byte)[0]
 131
 132
 133 def _read_string(reader):
 134     slen = _u30(reader)
 135     resb = reader.read(slen)
 136     assert len(resb) == slen
 137     return resb.decode('utf-8')
 138
 139
 140 def _read_bytes(count, reader):
 141     assert count >= 0
 142     resb = reader.read(count)
 143     assert len(resb) == count
 144     return resb
 145
 146
 147 def _read_byte(reader):
 148     resb = _read_bytes(1, reader=reader)
 149     res = struct_unpack('<B', resb)[0]
 150     return res
 151
 152
 153 StringClass = _AVMClass('(no name idx)', 'String')
 154 ByteArrayClass = _AVMClass('(no name idx)', 'ByteArray')
 155 TimerClass = _AVMClass('(no name idx)', 'Timer')
 156 TimerEventClass = _AVMClass('(no name idx)', 'TimerEvent', {'TIMER': 'timer'})
 157 _builtin_classes = {
 158     StringClass.name: StringClass,
 159     ByteArrayClass.name: ByteArrayClass,
 160     TimerClass.name: TimerClass,
 161     TimerEventClass.name: TimerEventClass,
 162 }
 163
 164
 165 class _Undefined(object):
 166     def __bool__(self):
 167         return False
 168     __nonzero__ = __bool__
 169
 170     def __hash__(self):
 171         return 0
 172
 173     def __str__(self):
 174         return 'undefined'
 175     __repr__ = __str__
 176
 177 undefined = _Undefined()
 178
 179
 180 class SWFInterpreter(object):
 181     def __init__(self, file_contents):
 182         self._patched_functions = {
 183             (TimerClass, 'addEventListener'): lambda params: undefined,
 184         }
 185         code_tag = next(tag
 186                         for tag_code, tag in _extract_tags(file_contents)
 187                         if tag_code == 82)
 188         p = code_tag.index(b'\0', 4) + 1
 189         code_reader = io.BytesIO(code_tag[p:])
 190
 191         # Parse ABC (AVM2 ByteCode)
 192
 193         # Define a couple convenience methods
 194         u30 = lambda *args: _u30(*args, reader=code_reader)
 195         s32 = lambda *args: _s32(*args, reader=code_reader)
 196         u32 = lambda *args: _u32(*args, reader=code_reader)
 197         read_bytes = lambda *args: _read_bytes(*args, reader=code_reader)
 198         read_byte = lambda *args: _read_byte(*args, reader=code_reader)
 199
 200         # minor_version + major_version
 201         read_bytes(2 + 2)
 202
 203         # Constant pool
 204         int_count = u30()
 205         self.constant_ints = [0]
 206         for _c in range(1, int_count):
 207             self.constant_ints.append(s32())
 208         self.constant_uints = [0]
 209         uint_count = u30()
 210         for _c in range(1, uint_count):
 211             self.constant_uints.append(u32())
 212         double_count = u30()
 213         read_bytes(max(0, (double_count - 1)) * 8)
 214         string_count = u30()
 215         self.constant_strings = ['']
 216         for _c in range(1, string_count):
 217             s = _read_string(code_reader)
 218             self.constant_strings.append(s)
 219         namespace_count = u30()
 220         for _c in range(1, namespace_count):
 221             read_bytes(1)  # kind
 222             u30()  # name
 223         ns_set_count = u30()
 224         for _c in range(1, ns_set_count):
 225             count = u30()
 226             for _c2 in range(count):
 227                 u30()
 228         multiname_count = u30()
 229         MULTINAME_SIZES = {
 230             0x07: 2,  # QName
 231             0x0d: 2,  # QNameA
 232             0x0f: 1,  # RTQName
 233             0x10: 1,  # RTQNameA
 234             0x11: 0,  # RTQNameL
 235             0x12: 0,  # RTQNameLA
 236             0x09: 2,  # Multiname
 237             0x0e: 2,  # MultinameA
 238             0x1b: 1,  # MultinameL
 239             0x1c: 1,  # MultinameLA
 240         }
 241         self.multinames = ['']
 242         for _c in range(1, multiname_count):
 243             kind = u30()
 244             assert kind in MULTINAME_SIZES, 'Invalid multiname kind %r' % kind
 245             if kind == 0x07:
 246                 u30()  # namespace_idx
 247                 name_idx = u30()
 248                 self.multinames.append(self.constant_strings[name_idx])
 249             elif kind == 0x09:
 250                 name_idx = u30()
 251                 u30()
 252                 self.multinames.append(self.constant_strings[name_idx])
 253             else:
 254                 self.multinames.append(_Multiname(kind))
 255                 for _c2 in range(MULTINAME_SIZES[kind]):
 256                     u30()
 257
 258         # Methods
 259         method_count = u30()
 260         MethodInfo = collections.namedtuple(
 261             'MethodInfo',
 262             ['NEED_ARGUMENTS', 'NEED_REST'])
 263         method_infos = []
 264         for method_id in range(method_count):
 265             param_count = u30()
 266             u30()  # return type
 267             for _ in range(param_count):
 268                 u30()  # param type
 269             u30()  # name index (always 0 for youtube)
 270             flags = read_byte()
 271             if flags & 0x08 != 0:
 272                 # Options present
 273                 option_count = u30()
 274                 for c in range(option_count):
 275                     u30()  # val
 276                     read_bytes(1)  # kind
 277             if flags & 0x80 != 0:
 278                 # Param names present
 279                 for _ in range(param_count):
 280                     u30()  # param name
 281             mi = MethodInfo(flags & 0x01 != 0, flags & 0x04 != 0)
 282             method_infos.append(mi)
 283
 284         # Metadata
 285         metadata_count = u30()
 286         for _c in range(metadata_count):
 287             u30()  # name
 288             item_count = u30()
 289             for _c2 in range(item_count):
 290                 u30()  # key
 291                 u30()  # value
 292
 293         def parse_traits_info():
 294             trait_name_idx = u30()
 295             kind_full = read_byte()
 296             kind = kind_full & 0x0f
 297             attrs = kind_full >> 4
 298             methods = {}
 299             constants = None
 300             if kind == 0x00:  # Slot
 301                 u30()  # Slot id
 302                 u30()  # type_name_idx
 303                 vindex = u30()
 304                 if vindex != 0:
 305                     read_byte()  # vkind
 306             elif kind == 0x06:  # Const
 307                 u30()  # Slot id
 308                 u30()  # type_name_idx
 309                 vindex = u30()
 310                 vkind = 'any'
 311                 if vindex != 0:
 312                     vkind = read_byte()
 313                 if vkind == 0x03:  # Constant_Int
 314                     value = self.constant_ints[vindex]
 315                 elif vkind == 0x04:  # Constant_UInt
 316                     value = self.constant_uints[vindex]
 317                 else:
 318                     return {}, None  # Ignore silently for now
 319                 constants = {self.multinames[trait_name_idx]: value}
 320             elif kind in (0x01, 0x02, 0x03):  # Method / Getter / Setter
 321                 u30()  # disp_id
 322                 method_idx = u30()
 323                 methods[self.multinames[trait_name_idx]] = method_idx
 324             elif kind == 0x04:  # Class
 325                 u30()  # slot_id
 326                 u30()  # classi
 327             elif kind == 0x05:  # Function
 328                 u30()  # slot_id
 329                 function_idx = u30()
 330                 methods[function_idx] = self.multinames[trait_name_idx]
 331             else:
 332                 raise ExtractorError('Unsupported trait kind %d' % kind)
 333
 334             if attrs & 0x4 != 0:  # Metadata present
 335                 metadata_count = u30()
 336                 for _c3 in range(metadata_count):
 337                     u30()  # metadata index
 338
 339             return methods, constants
 340
 341         # Classes
 342         class_count = u30()
 343         classes = []
 344         for class_id in range(class_count):
 345             name_idx = u30()
 346
 347             cname = self.multinames[name_idx]
 348             avm_class = _AVMClass(name_idx, cname)
 349             classes.append(avm_class)
 350
 351             u30()  # super_name idx
 352             flags = read_byte()
 353             if flags & 0x08 != 0:  # Protected namespace is present
 354                 u30()  # protected_ns_idx
 355             intrf_count = u30()
 356             for _c2 in range(intrf_count):
 357                 u30()
 358             u30()  # iinit
 359             trait_count = u30()
 360             for _c2 in range(trait_count):
 361                 trait_methods, trait_constants = parse_traits_info()
 362                 avm_class.register_methods(trait_methods)
 363                 if trait_constants:
 364                     avm_class.constants.update(trait_constants)
 365
 366         assert len(classes) == class_count
 367         self._classes_by_name = dict((c.name, c) for c in classes)
 368
 369         for avm_class in classes:
 370             avm_class.cinit_idx = u30()
 371             trait_count = u30()
 372             for _c2 in range(trait_count):
 373                 trait_methods, trait_constants = parse_traits_info()
 374                 avm_class.register_methods(trait_methods)
 375                 if trait_constants:
 376                     avm_class.constants.update(trait_constants)
 377
 378         # Scripts
 379         script_count = u30()
 380         for _c in range(script_count):
 381             u30()  # init
 382             trait_count = u30()
 383             for _c2 in range(trait_count):
 384                 parse_traits_info()
 385
 386         # Method bodies
 387         method_body_count = u30()
 388         Method = collections.namedtuple('Method', ['code', 'local_count'])
 389         self._all_methods = []
 390         for _c in range(method_body_count):
 391             method_idx = u30()
 392             u30()  # max_stack
 393             local_count = u30()
 394             u30()  # init_scope_depth
 395             u30()  # max_scope_depth
 396             code_length = u30()
 397             code = read_bytes(code_length)
 398             m = Method(code, local_count)
 399             self._all_methods.append(m)
 400             for avm_class in classes:
 401                 if method_idx in avm_class.method_idxs:
 402                     avm_class.methods[avm_class.method_idxs[method_idx]] = m
 403             exception_count = u30()
 404             for _c2 in range(exception_count):
 405                 u30()  # from
 406                 u30()  # to
 407                 u30()  # target
 408                 u30()  # exc_type
 409                 u30()  # var_name
 410             trait_count = u30()
 411             for _c2 in range(trait_count):
 412                 parse_traits_info()
 413
 414         assert p + code_reader.tell() == len(code_tag)
 415
 416     def patch_function(self, avm_class, func_name, f):
 417         self._patched_functions[(avm_class, func_name)] = f
 418
 419     def extract_class(self, class_name, call_cinit=True):
 420         try:
 421             res = self._classes_by_name[class_name]
 422         except KeyError:
 423             raise ExtractorError('Class %r not found' % class_name)
 424
 425         if call_cinit and hasattr(res, 'cinit_idx'):
 426             res.register_methods({'$cinit': res.cinit_idx})
 427             res.methods['$cinit'] = self._all_methods[res.cinit_idx]
 428             cinit = self.extract_function(res, '$cinit')
 429             cinit([])
 430
 431         return res
 432
 433     def extract_function(self, avm_class, func_name):
 434         p = self._patched_functions.get((avm_class, func_name))
 435         if p:
 436             return p
 437         if func_name in avm_class.method_pyfunctions:
 438             return avm_class.method_pyfunctions[func_name]
 439         if func_name in self._classes_by_name:
 440             return self._classes_by_name[func_name].make_object()
 441         if func_name not in avm_class.methods:
 442             raise ExtractorError('Cannot find function %s.%s' % (
 443                 avm_class.name, func_name))
 444         m = avm_class.methods[func_name]
 445
 446         def resfunc(args):
 447             # Helper functions
 448             coder = io.BytesIO(m.code)
 449             s24 = lambda: _s24(coder)
 450             u30 = lambda: _u30(coder)
 451
 452             registers = [avm_class.variables] + list(args) + [None] * m.local_count
 453             stack = []
 454             scopes = collections.deque([
 455                 self._classes_by_name, avm_class.constants, avm_class.variables])
 456             while True:
 457                 opcode = _read_byte(coder)
 458                 if opcode == 9:  # label
 459                     pass  # Spec says: "Do nothing."
 460                 elif opcode == 16:  # jump
 461                     offset = s24()
 462                     coder.seek(coder.tell() + offset)
 463                 elif opcode == 17:  # iftrue
 464                     offset = s24()
 465                     value = stack.pop()
 466                     if value:
 467                         coder.seek(coder.tell() + offset)
 468                 elif opcode == 18:  # iffalse
 469                     offset = s24()
 470                     value = stack.pop()
 471                     if not value:
 472                         coder.seek(coder.tell() + offset)
 473                 elif opcode == 19:  # ifeq
 474                     offset = s24()
 475                     value2 = stack.pop()
 476                     value1 = stack.pop()
 477                     if value2 == value1:
 478                         coder.seek(coder.tell() + offset)
 479                 elif opcode == 20:  # ifne
 480                     offset = s24()
 481                     value2 = stack.pop()
 482                     value1 = stack.pop()
 483                     if value2 != value1:
 484                         coder.seek(coder.tell() + offset)
 485                 elif opcode == 21:  # iflt
 486                     offset = s24()
 487                     value2 = stack.pop()
 488                     value1 = stack.pop()
 489                     if value1 < value2:
 490                         coder.seek(coder.tell() + offset)
 491                 elif opcode == 32:  # pushnull
 492                     stack.append(None)
 493                 elif opcode == 33:  # pushundefined
 494                     stack.append(undefined)
 495                 elif opcode == 36:  # pushbyte
 496                     v = _read_byte(coder)
 497                     stack.append(v)
 498                 elif opcode == 37:  # pushshort
 499                     v = u30()
 500                     stack.append(v)
 501                 elif opcode == 38:  # pushtrue
 502                     stack.append(True)
 503                 elif opcode == 39:  # pushfalse
 504                     stack.append(False)
 505                 elif opcode == 40:  # pushnan
 506                     stack.append(float('NaN'))
 507                 elif opcode == 42:  # dup
 508                     value = stack[-1]
 509                     stack.append(value)
 510                 elif opcode == 44:  # pushstring
 511                     idx = u30()
 512                     stack.append(self.constant_strings[idx])
 513                 elif opcode == 48:  # pushscope
 514                     new_scope = stack.pop()
 515                     scopes.append(new_scope)
 516                 elif opcode == 66:  # construct
 517                     arg_count = u30()
 518                     args = list(reversed(
 519                         [stack.pop() for _ in range(arg_count)]))
 520                     obj = stack.pop()
 521                     res = obj.avm_class.make_object()
 522                     stack.append(res)
 523                 elif opcode == 70:  # callproperty
 524                     index = u30()
 525                     mname = self.multinames[index]
 526                     arg_count = u30()
 527                     args = list(reversed(
 528                         [stack.pop() for _ in range(arg_count)]))
 529                     obj = stack.pop()
 530
 531                     if obj == StringClass:
 532                         if mname == 'String':
 533                             assert len(args) == 1
 534                             assert isinstance(args[0], (
 535                                 int, compat_str, _Undefined))
 536                             if args[0] == undefined:
 537                                 res = 'undefined'
 538                             else:
 539                                 res = compat_str(args[0])
 540                             stack.append(res)
 541                             continue
 542                         else:
 543                             raise NotImplementedError(
 544                                 'Function String.%s is not yet implemented'
 545                                 % mname)
 546                     elif isinstance(obj, _AVMClass_Object):
 547                         func = self.extract_function(obj.avm_class, mname)
 548                         res = func(args)
 549                         stack.append(res)
 550                         continue
 551                     elif isinstance(obj, _AVMClass):
 552                         func = self.extract_function(obj, mname)
 553                         res = func(args)
 554                         stack.append(res)
 555                         continue
 556                     elif isinstance(obj, _ScopeDict):
 557                         if mname in obj.avm_class.method_names:
 558                             func = self.extract_function(obj.avm_class, mname)
 559                             res = func(args)
 560                         else:
 561                             res = obj[mname]
 562                         stack.append(res)
 563                         continue
 564                     elif isinstance(obj, compat_str):
 565                         if mname == 'split':
 566                             assert len(args) == 1
 567                             assert isinstance(args[0], compat_str)
 568                             if args[0] == '':
 569                                 res = list(obj)
 570                             else:
 571                                 res = obj.split(args[0])
 572                             stack.append(res)
 573                             continue
 574                         elif mname == 'charCodeAt':
 575                             assert len(args) <= 1
 576                             idx = 0 if len(args) == 0 else args[0]
 577                             assert isinstance(idx, int)
 578                             res = ord(obj[idx])
 579                             stack.append(res)
 580                             continue
 581                     elif isinstance(obj, list):
 582                         if mname == 'slice':
 583                             assert len(args) == 1
 584                             assert isinstance(args[0], int)
 585                             res = obj[args[0]:]
 586                             stack.append(res)
 587                             continue
 588                         elif mname == 'join':
 589                             assert len(args) == 1
 590                             assert isinstance(args[0], compat_str)
 591                             res = args[0].join(obj)
 592                             stack.append(res)
 593                             continue
 594                     raise NotImplementedError(
 595                         'Unsupported property %r on %r'
 596                         % (mname, obj))
 597                 elif opcode == 71:  # returnvoid
 598                     res = undefined
 599                     return res
 600                 elif opcode == 72:  # returnvalue
 601                     res = stack.pop()
 602                     return res
 603                 elif opcode == 73:  # constructsuper
 604                     # Not yet implemented, just hope it works without it
 605                     arg_count = u30()
 606                     args = list(reversed(
 607                         [stack.pop() for _ in range(arg_count)]))
 608                     obj = stack.pop()
 609                 elif opcode == 74:  # constructproperty
 610                     index = u30()
 611                     arg_count = u30()
 612                     args = list(reversed(
 613                         [stack.pop() for _ in range(arg_count)]))
 614                     obj = stack.pop()
 615
 616                     mname = self.multinames[index]
 617                     assert isinstance(obj, _AVMClass)
 618
 619                     # We do not actually call the constructor for now;
 620                     # we just pretend it does nothing
 621                     stack.append(obj.make_object())
 622                 elif opcode == 79:  # callpropvoid
 623                     index = u30()
 624                     mname = self.multinames[index]
 625                     arg_count = u30()
 626                     args = list(reversed(
 627                         [stack.pop() for _ in range(arg_count)]))
 628                     obj = stack.pop()
 629                     if isinstance(obj, _AVMClass_Object):
 630                         func = self.extract_function(obj.avm_class, mname)
 631                         res = func(args)
 632                         assert res is undefined
 633                         continue
 634                     if isinstance(obj, _ScopeDict):
 635                         assert mname in obj.avm_class.method_names
 636                         func = self.extract_function(obj.avm_class, mname)
 637                         res = func(args)
 638                         assert res is undefined
 639                         continue
 640                     if mname == 'reverse':
 641                         assert isinstance(obj, list)
 642                         obj.reverse()
 643                     else:
 644                         raise NotImplementedError(
 645                             'Unsupported (void) property %r on %r'
 646                             % (mname, obj))
 647                 elif opcode == 86:  # newarray
 648                     arg_count = u30()
 649                     arr = []
 650                     for i in range(arg_count):
 651                         arr.append(stack.pop())
 652                     arr = arr[::-1]
 653                     stack.append(arr)
 654                 elif opcode == 93:  # findpropstrict
 655                     index = u30()
 656                     mname = self.multinames[index]
 657                     for s in reversed(scopes):
 658                         if mname in s:
 659                             res = s
 660                             break
 661                     else:
 662                         res = scopes[0]
 663                     if mname not in res and mname in _builtin_classes:
 664                         stack.append(_builtin_classes[mname])
 665                     else:
 666                         stack.append(res[mname])
 667                 elif opcode == 94:  # findproperty
 668                     index = u30()
 669                     mname = self.multinames[index]
 670                     for s in reversed(scopes):
 671                         if mname in s:
 672                             res = s
 673                             break
 674                     else:
 675                         res = avm_class.variables
 676                     stack.append(res)
 677                 elif opcode == 96:  # getlex
 678                     index = u30()
 679                     mname = self.multinames[index]
 680                     for s in reversed(scopes):
 681                         if mname in s:
 682                             scope = s
 683                             break
 684                     else:
 685                         scope = avm_class.variables
 686
 687                     if mname in scope:
 688                         res = scope[mname]
 689                     elif mname in _builtin_classes:
 690                         res = _builtin_classes[mname]
 691                     else:
 692                         # Assume uninitialized
 693                         # TODO warn here
 694                         res = undefined
 695                     stack.append(res)
 696                 elif opcode == 97:  # setproperty
 697                     index = u30()
 698                     value = stack.pop()
 699                     idx = self.multinames[index]
 700                     if isinstance(idx, _Multiname):
 701                         idx = stack.pop()
 702                     obj = stack.pop()
 703                     obj[idx] = value
 704                 elif opcode == 98:  # getlocal
 705                     index = u30()
 706                     stack.append(registers[index])
 707                 elif opcode == 99:  # setlocal
 708                     index = u30()
 709                     value = stack.pop()
 710                     registers[index] = value
 711                 elif opcode == 102:  # getproperty
 712                     index = u30()
 713                     pname = self.multinames[index]
 714                     if pname == 'length':
 715                         obj = stack.pop()
 716                         assert isinstance(obj, (compat_str, list))
 717                         stack.append(len(obj))
 718                     elif isinstance(pname, compat_str):  # Member access
 719                         obj = stack.pop()
 720                         if isinstance(obj, _AVMClass):
 721                             res = obj.static_properties[pname]
 722                             stack.append(res)
 723                             continue
 724
 725                         assert isinstance(obj, (dict, _ScopeDict)),\
 726                             'Accessing member %r on %r' % (pname, obj)
 727                         res = obj.get(pname, undefined)
 728                         stack.append(res)
 729                     else:  # Assume attribute access
 730                         idx = stack.pop()
 731                         assert isinstance(idx, int)
 732                         obj = stack.pop()
 733                         assert isinstance(obj, list)
 734                         stack.append(obj[idx])
 735                 elif opcode == 104:  # initproperty
 736                     index = u30()
 737                     value = stack.pop()
 738                     idx = self.multinames[index]
 739                     if isinstance(idx, _Multiname):
 740                         idx = stack.pop()
 741                     obj = stack.pop()
 742                     obj[idx] = value
 743                 elif opcode == 115:  # convert_
 744                     value = stack.pop()
 745                     intvalue = int(value)
 746                     stack.append(intvalue)
 747                 elif opcode == 128:  # coerce
 748                     u30()
 749                 elif opcode == 130:  # coerce_a
 750                     value = stack.pop()
 751                     # um, yes, it's any value
 752                     stack.append(value)
 753                 elif opcode == 133:  # coerce_s
 754                     assert isinstance(stack[-1], (type(None), compat_str))
 755                 elif opcode == 147:  # decrement
 756                     value = stack.pop()
 757                     assert isinstance(value, int)
 758                     stack.append(value - 1)
 759                 elif opcode == 149:  # typeof
 760                     value = stack.pop()
 761                     return {
 762                         _Undefined: 'undefined',
 763                         compat_str: 'String',
 764                         int: 'Number',
 765                         float: 'Number',
 766                     }[type(value)]
 767                 elif opcode == 160:  # add
 768                     value2 = stack.pop()
 769                     value1 = stack.pop()
 770                     res = value1 + value2
 771                     stack.append(res)
 772                 elif opcode == 161:  # subtract
 773                     value2 = stack.pop()
 774                     value1 = stack.pop()
 775                     res = value1 - value2
 776                     stack.append(res)
 777                 elif opcode == 162:  # multiply
 778                     value2 = stack.pop()
 779                     value1 = stack.pop()
 780                     res = value1 * value2
 781                     stack.append(res)
 782                 elif opcode == 164:  # modulo
 783                     value2 = stack.pop()
 784                     value1 = stack.pop()
 785                     res = value1 % value2
 786                     stack.append(res)
 787                 elif opcode == 168:  # bitand
 788                     value2 = stack.pop()
 789                     value1 = stack.pop()
 790                     assert isinstance(value1, int)
 791                     assert isinstance(value2, int)
 792                     res = value1 & value2
 793                     stack.append(res)
 794                 elif opcode == 171:  # equals
 795                     value2 = stack.pop()
 796                     value1 = stack.pop()
 797                     result = value1 == value2
 798                     stack.append(result)
 799                 elif opcode == 175:  # greaterequals
 800                     value2 = stack.pop()
 801                     value1 = stack.pop()
 802                     result = value1 >= value2
 803                     stack.append(result)
 804                 elif opcode == 192:  # increment_i
 805                     value = stack.pop()
 806                     assert isinstance(value, int)
 807                     stack.append(value + 1)
 808                 elif opcode == 208:  # getlocal_0
 809                     stack.append(registers[0])
 810                 elif opcode == 209:  # getlocal_1
 811                     stack.append(registers[1])
 812                 elif opcode == 210:  # getlocal_2
 813                     stack.append(registers[2])
 814                 elif opcode == 211:  # getlocal_3
 815                     stack.append(registers[3])
 816                 elif opcode == 212:  # setlocal_0
 817                     registers[0] = stack.pop()
 818                 elif opcode == 213:  # setlocal_1
 819                     registers[1] = stack.pop()
 820                 elif opcode == 214:  # setlocal_2
 821                     registers[2] = stack.pop()
 822                 elif opcode == 215:  # setlocal_3
 823                     registers[3] = stack.pop()
 824                 else:
 825                     raise NotImplementedError(
 826                         'Unsupported opcode %d' % opcode)
 827
 828         avm_class.method_pyfunctions[func_name] = resfunc
 829         return resfunc