SF.net SVN: openvrml:[4150] trunk

[<br...@us...>]

Revision: 4150
          http://openvrml.svn.sourceforge.net/openvrml/?rev=4150&view=rev
Author:   braden
Date:     2010-05-28 15:17:16 +0000 (Fri, 28 May 2010)

Log Message:
-----------
Use jpeg_decompress_struct.out_color_components to determine the scan line buffer size.  This addresses a memory corruption issue when reading grayscale JPEGs.

Modified Paths:
--------------
    trunk/ChangeLog
    trunk/src/node/vrml97/image_stream_listener.cpp

Modified: trunk/ChangeLog
===================================================================
--- trunk/ChangeLog	2010-05-27 16:32:54 UTC (rev 4149)
+++ trunk/ChangeLog	2010-05-28 15:17:16 UTC (rev 4150)
@@ -1,3 +1,17 @@
+2010-05-28 Braden McDaniel  <br...@en...>
+
+	Use jpeg_decompress_struct.out_color_components to determine the
+	scan line buffer size.  This addresses a memory corruption issue
+	when reading grayscale JPEGs.
+
+	* src/node/vrml97/image_stream_listener.cpp
+	(openvrml_node_vrml97::image_stream_listener::jpeg_reader::do_read(const
+	std::vector<unsigned char> &)): Use
+	jpeg_decompress_struct.out_color_components to determine the scan
+	line buffer size.  This member isn't set until after the call to
+	jpeg_start_decompress; so move the buffer allocation to the
+	start_decompress section.
+
 2010-05-27 Braden McDaniel  <br...@en...>
 
 	FcFini cannot be called safely from library code.  Calling it is

Modified: trunk/src/node/vrml97/image_stream_listener.cpp
===================================================================
--- trunk/src/node/vrml97/image_stream_listener.cpp	2010-05-27 16:32:54 UTC (rev 4149)
+++ trunk/src/node/vrml97/image_stream_listener.cpp	2010-05-28 15:17:16 UTC (rev 4150)
@@ -458,16 +458,6 @@
         image.comp(this->cinfo_.num_components);
         image.resize(this->cinfo_.image_width, this->cinfo_.image_height);
 
-        const JDIMENSION samples_per_row =
-            this->cinfo_.output_width * this->cinfo_.num_components;
-        static const JDIMENSION num_rows = 1;
-        this->scanlines =
-            (*this->cinfo_.mem->alloc_sarray)(
-                reinterpret_cast<j_common_ptr>(&this->cinfo_),
-                JPOOL_IMAGE,
-                samples_per_row,
-                num_rows);
-
         this->decoder_state = jpeg_reader::start_decompress;
     }
     case jpeg_reader::start_decompress:
@@ -482,6 +472,16 @@
             return; // Input suspended.
         }
 
+        const JDIMENSION samples_per_row =
+            this->cinfo_.output_width * this->cinfo_.out_color_components;
+        static const JDIMENSION num_rows = 1;
+        this->scanlines =
+            (*this->cinfo_.mem->alloc_sarray)(
+                reinterpret_cast<j_common_ptr>(&this->cinfo_),
+                JPOOL_IMAGE,
+                samples_per_row,
+                num_rows);
+
         this->decoder_state = this->cinfo_.buffered_image
             ? jpeg_reader::decompress_progressive
             : jpeg_reader::decompress_sequential;


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