io_scene_fbx/fbx2json.py

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