From 927aac74ab5fa1326faa33c41b967e550088d5d5 Mon Sep 17 00:00:00 2001
From: Campbell Barton <ideasman42@gmail.com>
Date: Tue, 15 Jun 2010 12:06:30 +0000
Subject: [PATCH] - module for reading blend start/end frames and scene name
 (useful for finding the total frame count without loading a blend file) -
 added render api as unstable to the docs.

---
 release/scripts/modules/blend_render_info.py | 99 ++++++++++++++++++++
 source/blender/python/doc/sphinx_doc_gen.py  |  1 +
 2 files changed, 100 insertions(+)
 create mode 100755 release/scripts/modules/blend_render_info.py

diff --git a/release/scripts/modules/blend_render_info.py b/release/scripts/modules/blend_render_info.py
new file mode 100755
index 00000000000..b7018ad6b64
--- /dev/null
+++ b/release/scripts/modules/blend_render_info.py
@@ -0,0 +1,99 @@
+#!/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 #####
+
+# <pep8 compliant>
+
+# This module can get render info without running from inside blender.
+#
+# This struct wont change according to Ton.
+# Note that the size differs on 32/64bit
+#
+# typedef struct BHead {
+#     int code, len;
+#     void *old;
+#     int SDNAnr, nr;
+# } BHead;
+
+def read_blend_rend_chunk(path):
+
+    import struct
+
+    file = open(path, 'rb')
+    
+    head = file.read(7)
+
+    if head[0:2] == b'\x1f\x8b': # gzip magic
+        import gzip
+        file.close()
+        file = gzip.open(path, 'rb')
+        head = file.read(7)
+
+    if head != b'BLENDER':
+        print("not a blend file:", path)
+        file.close()
+        return []
+
+    is_64_bit = (file.read(1) == b'-')
+
+    # true for PPC, false for X86
+    is_big_endian = (file.read(1) == b'V')
+
+    # Now read the bhead chunk!!!
+    file.read(3) # skip the version
+
+    scenes = []
+    
+    sizeof_bhead = 24 if is_64_bit else 20
+
+    while file.read(4) == b'REND':
+        sizeof_bhead_left = sizeof_bhead - 4
+        
+        rend_length = struct.unpack('>i' if is_big_endian else '<i', file.read(4))[0]
+        sizeof_bhead_left -= 4
+
+        # We dont care about the rest of the bhead struct
+        file.read(sizeof_bhead_left)
+        
+        # Now we want the scene name, start and end frame. this is 32bites long
+        start_frame, end_frame = struct.unpack('>2i' if is_big_endian else '<2i', file.read(8))
+
+        scene_name = file.read(24)
+
+        scene_name = scene_name[:scene_name.index(b'\0')]
+
+        try:
+            scene_name = str(scene_name, 'utf8')
+        except TypeError:
+            pass
+
+        scenes.append((start_frame, end_frame, scene_name))
+
+    return scenes
+
+
+def main():
+    import sys
+    for arg in sys.argv[1:]:
+        if arg.lower().endswith('.blend'):
+            for value in read_blend_rend_chunk(arg):
+                print("%d %d %s" % value)
+
+if __name__ == '__main__':
+    main()
diff --git a/source/blender/python/doc/sphinx_doc_gen.py b/source/blender/python/doc/sphinx_doc_gen.py
index 4640ba4c1ef..3b0b9f60795 100644
--- a/source/blender/python/doc/sphinx_doc_gen.py
+++ b/source/blender/python/doc/sphinx_doc_gen.py
@@ -331,6 +331,7 @@ def rna2sphinx(BASEPATH):
     fw("   \n")
     fw("   The following areas are subject to change.\n")
     fw("      * operator names and arguments\n")
+    fw("      * render api\n")
     fw("      * function calls with the data api (any function calls with values accessed from bpy.data), including functions for importing and exporting meshes\n")
     fw("      * class registration (Operator, Panels, Menus, Headers)\n")
     fw("      * modules: bpy.props, blf)\n")