io_scene_fbx/fbx2json.py

   1 #!/usr/bin/env python3
   2 # SPDX-FileCopyrightText: 2006-2012 assimp team
   3 # SPDX-FileCopyrightText: 2013 Blender Foundation
   4 #
   5 # SPDX-License-Identifier: GPL-2.0-or-later
   6
   7 """
   8 Usage
   9 =====
  10
  11    fbx2json [FILES]...
  12
  13 This script will write a JSON file for each FBX argument given.
  14
  15
  16 Output
  17 ======
  18
  19 The JSON data is formatted into a list of nested lists of 4 items:
  20
  21    ``[id, [data, ...], "data_types", [subtree, ...]]``
  22
  23 Where each list may be empty, and the items in
  24 the subtree are formatted the same way.
  25
  26 data_types is a string, aligned with data that spesifies a type
  27 for each property.
  28
  29 The types are as follows:
  30
  31 * 'Z': - INT8
  32 * 'Y': - INT16
  33 * 'C': - BOOL
  34 * 'I': - INT32
  35 * 'F': - FLOAT32
  36 * 'D': - FLOAT64
  37 * 'L': - INT64
  38 * 'R': - BYTES
  39 * 'S': - STRING
  40 * 'f': - FLOAT32_ARRAY
  41 * 'i': - INT32_ARRAY
  42 * 'd': - FLOAT64_ARRAY
  43 * 'l': - INT64_ARRAY
  44 * 'b': - BOOL ARRAY
  45 * 'c': - BYTE ARRAY
  46
  47 Note that key:value pairs aren't used since the id's are not
  48 ensured to be unique.
  49 """
  50
  51
  52 # ----------------------------------------------------------------------------
  53 # FBX Binary Parser
  54
  55 from struct import unpack
  56 import array
  57 import zlib
  58
  59 # at the end of each nested block, there is a NUL record to indicate
  60 # that the sub-scope exists (i.e. to distinguish between P: and P : {})
  61 _BLOCK_SENTINEL_LENGTH = ...
  62 _BLOCK_SENTINEL_DATA = ...
  63 read_fbx_elem_uint = ...
  64 _IS_BIG_ENDIAN = (__import__("sys").byteorder != 'little')
  65 _HEAD_MAGIC = b'Kaydara FBX Binary\x20\x20\x00\x1a\x00'
  66 from collections import namedtuple
  67 FBXElem = namedtuple("FBXElem", ("id", "props", "props_type", "elems"))
  68 del namedtuple
  69
  70
  71 def read_uint(read):
  72     return unpack(b'<I', read(4))[0]
  73
  74
  75 def read_uint64(read):
  76     return unpack(b'<Q', read(8))[0]
  77
  78
  79 def read_ubyte(read):
  80     return unpack(b'B', read(1))[0]
  81
  82
  83 def read_string_ubyte(read):
  84     size = read_ubyte(read)
  85     data = read(size)
  86     return data
  87
  88
  89 def unpack_array(read, array_type, array_stride, array_byteswap):
  90     length = read_uint(read)
  91     encoding = read_uint(read)
  92     comp_len = read_uint(read)
  93
  94     data = read(comp_len)
  95
  96     if encoding == 0:
  97         pass
  98     elif encoding == 1:
  99         data = zlib.decompress(data)
 100
 101     assert(length * array_stride == len(data))
 102
 103     data_array = array.array(array_type, data)
 104     if array_byteswap and _IS_BIG_ENDIAN:
 105         data_array.byteswap()
 106     return data_array
 107
 108
 109 read_data_dict = {
 110     b'Z'[0]: lambda read: unpack(b'<b', read(1))[0],  # 8 bit int
 111     b'Y'[0]: lambda read: unpack(b'<h', read(2))[0],  # 16 bit int
 112     b'C'[0]: lambda read: unpack(b'?', read(1))[0],   # 1 bit bool (yes/no)
 113     b'I'[0]: lambda read: unpack(b'<i', read(4))[0],  # 32 bit int
 114     b'F'[0]: lambda read: unpack(b'<f', read(4))[0],  # 32 bit float
 115     b'D'[0]: lambda read: unpack(b'<d', read(8))[0],  # 64 bit float
 116     b'L'[0]: lambda read: unpack(b'<q', read(8))[0],  # 64 bit int
 117     b'R'[0]: lambda read: read(read_uint(read)),      # binary data
 118     b'S'[0]: lambda read: read(read_uint(read)),      # string data
 119     b'f'[0]: lambda read: unpack_array(read, 'f', 4, False),  # array (float)
 120     b'i'[0]: lambda read: unpack_array(read, 'i', 4, True),   # array (int)
 121     b'd'[0]: lambda read: unpack_array(read, 'd', 8, False),  # array (double)
 122     b'l'[0]: lambda read: unpack_array(read, 'q', 8, True),   # array (long)
 123     b'b'[0]: lambda read: unpack_array(read, 'b', 1, False),  # array (bool)
 124     b'c'[0]: lambda read: unpack_array(read, 'B', 1, False),  # array (ubyte)
 125     }
 126
 127
 128 # FBX 7500 (aka FBX2016) introduces incompatible changes at binary level:
 129 #   * The NULL block marking end of nested stuff switches from 13 bytes long to 25 bytes long.
 130 #   * The FBX element metadata (end_offset, prop_count and prop_length) switch from uint32 to uint64.
 131 def init_version(fbx_version):
 132     global _BLOCK_SENTINEL_LENGTH, _BLOCK_SENTINEL_DATA, read_fbx_elem_uint
 133
 134     assert(_BLOCK_SENTINEL_LENGTH == ...)
 135     assert(_BLOCK_SENTINEL_DATA == ...)
 136
 137     if fbx_version < 7500:
 138         _BLOCK_SENTINEL_LENGTH = 13
 139         read_fbx_elem_uint = read_uint
 140     else:
 141         _BLOCK_SENTINEL_LENGTH = 25
 142         read_fbx_elem_uint = read_uint64
 143     _BLOCK_SENTINEL_DATA = (b'\0' * _BLOCK_SENTINEL_LENGTH)
 144
 145
 146 def read_elem(read, tell, use_namedtuple):
 147     # [0] the offset at which this block ends
 148     # [1] the number of properties in the scope
 149     # [2] the length of the property list
 150     end_offset = read_fbx_elem_uint(read)
 151     if end_offset == 0:
 152         return None
 153
 154     prop_count = read_fbx_elem_uint(read)
 155     prop_length = read_fbx_elem_uint(read)
 156
 157     elem_id = read_string_ubyte(read)        # elem name of the scope/key
 158     elem_props_type = bytearray(prop_count)  # elem property types
 159     elem_props_data = [None] * prop_count    # elem properties (if any)
 160     elem_subtree = []                        # elem children (if any)
 161
 162     for i in range(prop_count):
 163         data_type = read(1)[0]
 164         elem_props_data[i] = read_data_dict[data_type](read)
 165         elem_props_type[i] = data_type
 166
 167     if tell() < end_offset:
 168         while tell() < (end_offset - _BLOCK_SENTINEL_LENGTH):
 169             elem_subtree.append(read_elem(read, tell, use_namedtuple))
 170
 171         if read(_BLOCK_SENTINEL_LENGTH) != _BLOCK_SENTINEL_DATA:
 172             raise IOError("failed to read nested block sentinel, "
 173                           "expected all bytes to be 0")
 174
 175     if tell() != end_offset:
 176         raise IOError("scope length not reached, something is wrong")
 177
 178     args = (elem_id, elem_props_data, elem_props_type, elem_subtree)
 179     return FBXElem(*args) if use_namedtuple else args
 180
 181
 182 def parse_version(fn):
 183     """
 184     Return the FBX version,
 185     if the file isn't a binary FBX return zero.
 186     """
 187     with open(fn, 'rb') as f:
 188         read = f.read
 189
 190         if read(len(_HEAD_MAGIC)) != _HEAD_MAGIC:
 191             return 0
 192
 193         return read_uint(read)
 194
 195
 196 def parse(fn, use_namedtuple=True):
 197     root_elems = []
 198
 199     with open(fn, 'rb') as f:
 200         read = f.read
 201         tell = f.tell
 202
 203         if read(len(_HEAD_MAGIC)) != _HEAD_MAGIC:
 204             raise IOError("Invalid header")
 205
 206         fbx_version = read_uint(read)
 207         init_version(fbx_version)
 208
 209         while True:
 210             elem = read_elem(read, tell, use_namedtuple)
 211             if elem is None:
 212                 break
 213             root_elems.append(elem)
 214
 215     args = (b'', [], bytearray(0), root_elems)
 216     return FBXElem(*args) if use_namedtuple else args, fbx_version
 217
 218
 219 # ----------------------------------------------------------------------------
 220 # Inline Modules
 221
 222 # pyfbx.data_types
 223 data_types = type(array)("data_types")
 224 data_types.__dict__.update(
 225 dict(
 226 INT8 = b'Z'[0],
 227 INT16 = b'Y'[0],
 228 BOOL = b'C'[0],
 229 INT32 = b'I'[0],
 230 FLOAT32 = b'F'[0],
 231 FLOAT64 = b'D'[0],
 232 INT64 = b'L'[0],
 233 BYTES = b'R'[0],
 234 STRING = b'S'[0],
 235 FLOAT32_ARRAY = b'f'[0],
 236 INT32_ARRAY = b'i'[0],
 237 FLOAT64_ARRAY = b'd'[0],
 238 INT64_ARRAY = b'l'[0],
 239 BOOL_ARRAY = b'b'[0],
 240 BYTE_ARRAY = b'c'[0],
 241 ))
 242
 243 # pyfbx.parse_bin
 244 parse_bin = type(array)("parse_bin")
 245 parse_bin.__dict__.update(
 246 dict(
 247 parse = parse
 248 ))
 249
 250
 251 # ----------------------------------------------------------------------------
 252 # JSON Converter
 253 # from pyfbx import parse_bin, data_types
 254 import json
 255 import array
 256
 257
 258 def fbx2json_property_as_string(prop, prop_type):
 259     if prop_type == data_types.STRING:
 260         prop_str = prop.decode('utf-8')
 261         prop_str = prop_str.replace('\x00\x01', '::')
 262         return json.dumps(prop_str)
 263     else:
 264         prop_py_type = type(prop)
 265         if prop_py_type == bytes:
 266             return json.dumps(repr(prop)[2:-1])
 267         elif prop_py_type == bool:
 268             return json.dumps(prop)
 269         elif prop_py_type == array.array:
 270             return repr(list(prop))
 271
 272     return repr(prop)
 273
 274
 275 def fbx2json_properties_as_string(fbx_elem):
 276     return ", ".join(fbx2json_property_as_string(*prop_item)
 277                      for prop_item in zip(fbx_elem.props,
 278                                           fbx_elem.props_type))
 279
 280
 281 def fbx2json_recurse(fw, fbx_elem, ident, is_last):
 282     fbx_elem_id = fbx_elem.id.decode('utf-8')
 283     fw('%s["%s", ' % (ident, fbx_elem_id))
 284     fw('[%s], ' % fbx2json_properties_as_string(fbx_elem))
 285     fw('"%s", ' % (fbx_elem.props_type.decode('ascii')))
 286
 287     fw('[')
 288     if fbx_elem.elems:
 289         fw('\n')
 290         ident_sub = ident + "    "
 291         for fbx_elem_sub in fbx_elem.elems:
 292             fbx2json_recurse(fw, fbx_elem_sub, ident_sub,
 293                              fbx_elem_sub is fbx_elem.elems[-1])
 294     fw(']')
 295
 296     fw(']%s' % ('' if is_last else ',\n'))
 297
 298
 299 def fbx2json(fn):
 300     import os
 301
 302     fn_json = "%s.json" % os.path.splitext(fn)[0]
 303     print("Writing: %r " % fn_json, end="")
 304     fbx_root_elem, fbx_version = parse(fn, use_namedtuple=True)
 305     print("(Version %d) ..." % fbx_version)
 306
 307     with open(fn_json, 'w', encoding="ascii", errors='xmlcharrefreplace') as f:
 308         fw = f.write
 309         fw('[\n')
 310         ident_sub = "    "
 311         for fbx_elem_sub in fbx_root_elem.elems:
 312             fbx2json_recurse(f.write, fbx_elem_sub, ident_sub,
 313                              fbx_elem_sub is fbx_root_elem.elems[-1])
 314         fw(']\n')
 315
 316
 317 # ----------------------------------------------------------------------------
 318 # Command Line
 319
 320 def main():
 321     import sys
 322
 323     if "--help" in sys.argv:
 324         print(__doc__)
 325         return
 326
 327     for arg in sys.argv[1:]:
 328         try:
 329             fbx2json(arg)
 330         except:
 331             print("Failed to convert %r, error:" % arg)
 332
 333             import traceback
 334             traceback.print_exc()
 335
 336
 337 if __name__ == "__main__":
 338     main()