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Diffstat (limited to 'bin/blender-thumbnailer.py')
-rwxr-xr-x | bin/blender-thumbnailer.py | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/bin/blender-thumbnailer.py b/bin/blender-thumbnailer.py new file mode 100755 index 00000000000..27d6259d172 --- /dev/null +++ b/bin/blender-thumbnailer.py @@ -0,0 +1,131 @@ +#!/usr/bin/python + +# ##### BEGIN GPL LICENSE BLOCK ##### +# +# This program is free software; you can redistribute it and/or +# modify it under the terms of the GNU General Public License +# as published by the Free Software Foundation; either version 2 +# of the License, or (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program; if not, write to the Free Software Foundation, +# Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. +# +# ##### END GPL LICENSE BLOCK ##### + +""" +Thumbnailer runs with python 2.6 and 3.x. +To run automatically with nautilus: + gconftool --type boolean --set /desktop/gnome/thumbnailers/application@x-blender/enable true + gconftool --type string --set /desktop/gnome/thumbnailers/application@x-blender/command "blender-thumbnailer.py %i %o" +""" + +import struct + +def blend_extract_thumb(path): + import os + + # def MAKE_ID(tag): ord(tag[0])<<24 | ord(tag[1])<<16 | ord(tag[2])<<8 | ord(tag[3]) + REND = 1145980242 # MAKE_ID(b'REND') + TEST = 1414743380 # MAKE_ID(b'TEST') + + blendfile = open(path, 'rb') + + head = blendfile.read(12) + + if head[0:2] == b'\x1f\x8b': # gzip magic + import gzip + blendfile.close() + blendfile = gzip.open(path, 'rb') + head = blendfile.read(12) + + if not head.startswith(b'BLENDER'): + blendfile.close() + return None, 0, 0 + + is_64_bit = (head[7] == b'-') + + # true for PPC, false for X86 + is_big_endian = (head[8] == b'V') + + # blender pre 2.5 had no thumbs + if head[9:11] <= b'24': + return None, 0, 0 + + sizeof_bhead = 24 if is_64_bit else 20 + int_endian_pair = '>ii' if is_big_endian else '<ii' + + while True: + bhead = blendfile.read(sizeof_bhead) + + if len(bhead) < sizeof_bhead: + return None, 0, 0 + + code, length = struct.unpack(int_endian_pair, bhead[0:8]) # 8 == sizeof(int) * 2 + + if code == REND: + blendfile.seek(length, os.SEEK_CUR) + else: + break + + + if code != TEST: + return None, 0, 0 + + try: + x, y = struct.unpack(int_endian_pair, blendfile.read(8)) # 8 == sizeof(int) * 2 + except struct.error: + return None, 0, 0 + + length -= 8 # sizeof(int) * 2 + + if length != x * y * 4: + return None, 0, 0 + + image_buffer = blendfile.read(length) + + if len(image_buffer) != length: + return None, 0, 0 + + return image_buffer, x, y + + +def write_png(buf, width, height): + import zlib + + # reverse the vertical line order and add null bytes at the start + width_byte_4 = width * 4 + raw_data = b"".join([b'\x00' + buf[span:span + width_byte_4] for span in range((height - 1) * width * 4, -1, - width_byte_4)]) + + def png_pack(png_tag, data): + chunk_head = png_tag + data + return struct.pack("!I", len(data)) + chunk_head + struct.pack("!I", 0xFFFFFFFF & zlib.crc32(chunk_head)) + + return b"".join([ + b'\x89PNG\r\n\x1a\n', + png_pack(b'IHDR', struct.pack("!2I5B", width, height, 8, 6, 0, 0, 0)), + png_pack(b'IDAT', zlib.compress(raw_data, 9)), + png_pack(b'IEND', b'')]) + + +if __name__ == '__main__': + import sys + + if len(sys.argv) < 2: + print("Expected 2 arguments <input.blend> <output.png>") + else: + file_in = sys.argv[-2] + + buf, width, height = blend_extract_thumb(file_in) + + if buf: + file_out = sys.argv[-1] + + f = open(file_out, "wb") + f.write(write_png(buf, width, height)) + f.close() |