forked from bartvdbraak/blender
from Shinsuke Irie (irie) with some minor edits. Shinsuke's description from the tracker: --- I have implemented GVFS framework support of blender-thumbnailer.py which allows some file managers like Nautilus and Thunar to show thumbnails in trash or network directories. If Python's gio module is available, the thumbnailer uses it to access to filesystems mounted via GVFS. This change shouldn't affect desktop environments other than GNOME and XFCE. A function gvfs_open() in this patch is defined to solve a stupid incompatibility between Python file object and GIO Seekable object. On Ubuntu 10.10, I confirmed thumbnails can be generated for file://, trash://, sftp://, and smb://.
156 lines
4.3 KiB
Python
Executable File
156 lines
4.3 KiB
Python
Executable File
#!/usr/bin/python
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# ##### BEGIN GPL LICENSE BLOCK #####
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#
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# This program is free software; you can redistribute it and/or
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# modify it under the terms of the GNU General Public License
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# as published by the Free Software Foundation; either version 2
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# of the License, or (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software Foundation,
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# Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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#
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# ##### END GPL LICENSE BLOCK #####
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# <pep8 compliant>
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"""
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Thumbnailer runs with python 2.6 and 3.x.
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To run automatically with nautilus:
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gconftool --type boolean --set /desktop/gnome/thumbnailers/application@x-blender/enable true
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gconftool --type string --set /desktop/gnome/thumbnailers/application@x-blender/command "blender-thumbnailer.py %u %o"
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"""
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import struct
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def open_wrapper_get():
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""" wrap OS spesific read functionality here, fallback to 'open()'
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"""
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def open_gio(path, mode):
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g_file = gio.File(path).read()
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g_file.orig_seek = g_file.seek
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def new_seek(offset, whence=0):
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return g_file.orig_seek(offset, [1, 0, 2][whence])
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g_file.seek = new_seek
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return g_file
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try:
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import gio
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return open_gio
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except ImportError:
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return open
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def blend_extract_thumb(path):
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import os
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open_wrapper = open_wrapper_get()
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# def MAKE_ID(tag): ord(tag[0])<<24 | ord(tag[1])<<16 | ord(tag[2])<<8 | ord(tag[3])
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REND = 1145980242 # MAKE_ID(b'REND')
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TEST = 1414743380 # MAKE_ID(b'TEST')
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blendfile = open_wrapper(path, 'rb')
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head = blendfile.read(12)
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if head[0:2] == b'\x1f\x8b': # gzip magic
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import gzip
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blendfile.close()
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blendfile = gzip.GzipFile('', 'rb', 0, open_wrapper(path, 'rb'))
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head = blendfile.read(12)
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if not head.startswith(b'BLENDER'):
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blendfile.close()
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return None, 0, 0
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is_64_bit = (head[7] == b'-'[0])
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# true for PPC, false for X86
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is_big_endian = (head[8] == b'V'[0])
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# blender pre 2.5 had no thumbs
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if head[9:11] <= b'24':
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return None, 0, 0
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sizeof_bhead = 24 if is_64_bit else 20
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int_endian_pair = '>ii' if is_big_endian else '<ii'
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while True:
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bhead = blendfile.read(sizeof_bhead)
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if len(bhead) < sizeof_bhead:
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return None, 0, 0
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code, length = struct.unpack(int_endian_pair, bhead[0:8]) # 8 == sizeof(int) * 2
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if code == REND:
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blendfile.seek(length, os.SEEK_CUR)
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else:
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break
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if code != TEST:
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return None, 0, 0
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try:
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x, y = struct.unpack(int_endian_pair, blendfile.read(8)) # 8 == sizeof(int) * 2
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except struct.error:
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return None, 0, 0
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length -= 8 # sizeof(int) * 2
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if length != x * y * 4:
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return None, 0, 0
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image_buffer = blendfile.read(length)
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if len(image_buffer) != length:
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return None, 0, 0
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return image_buffer, x, y
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def write_png(buf, width, height):
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import zlib
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# reverse the vertical line order and add null bytes at the start
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width_byte_4 = width * 4
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raw_data = b"".join(b'\x00' + buf[span:span + width_byte_4] for span in range((height - 1) * width * 4, -1, - width_byte_4))
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def png_pack(png_tag, data):
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chunk_head = png_tag + data
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return struct.pack("!I", len(data)) + chunk_head + struct.pack("!I", 0xFFFFFFFF & zlib.crc32(chunk_head))
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return b"".join([
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b'\x89PNG\r\n\x1a\n',
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png_pack(b'IHDR', struct.pack("!2I5B", width, height, 8, 6, 0, 0, 0)),
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png_pack(b'IDAT', zlib.compress(raw_data, 9)),
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png_pack(b'IEND', b'')])
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if __name__ == '__main__':
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import sys
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if len(sys.argv) < 3:
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print("Expected 2 arguments <input.blend> <output.png>")
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else:
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file_in = sys.argv[-2]
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buf, width, height = blend_extract_thumb(file_in)
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if buf:
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file_out = sys.argv[-1]
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f = open(file_out, "wb")
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f.write(write_png(buf, width, height))
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f.close()
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