--- mem_align.c	2002/06/12 20:38:41	1.6
+++ mem_align.c	2002/12/15 01:12:01	1.13
@@ -1,7 +1,81 @@
+/*****************************************************************************
+ *
+ *  XVID MPEG-4 VIDEO CODEC
+ *  - Aligned memory allocator -
+ *
+ *  Copyright(C) 2002 Michael Militzer <isibaar@xvid.org>
+ *               2002 Edouard Gomez
+ *
+ *  This file is part of XviD, a free MPEG-4 video encoder/decoder
+ *
+ *  XviD 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ *  Under section 8 of the GNU General Public License, the copyright
+ *  holders of XVID explicitly forbid distribution in the following
+ *  countries:
+ *
+ *    - Japan
+ *    - United States of America
+ *
+ *  Linking XviD statically or dynamically with other modules is making a
+ *  combined work based on XviD.  Thus, the terms and conditions of the
+ *  GNU General Public License cover the whole combination.
+ *
+ *  As a special exception, the copyright holders of XviD give you
+ *  permission to link XviD with independent modules that communicate with
+ *  XviD solely through the VFW1.1 and DShow interfaces, regardless of the
+ *  license terms of these independent modules, and to copy and distribute
+ *  the resulting combined work under terms of your choice, provided that
+ *  every copy of the combined work is accompanied by a complete copy of
+ *  the source code of XviD (the version of XviD used to produce the
+ *  combined work), being distributed under the terms of the GNU General
+ *  Public License plus this exception.  An independent module is a module
+ *  which is not derived from or based on XviD.
+ *
+ *  Note that people who make modified versions of XviD are not obligated
+ *  to grant this special exception for their modified versions; it is
+ *  their choice whether to do so.  The GNU General Public License gives
+ *  permission to release a modified version without this exception; this
+ *  exception also makes it possible to release a modified version which
+ *  carries forward this exception.
+ *
+ * $Id: mem_align.c,v 1.13 2002/12/15 01:12:01 edgomez Exp $
+ *
+ ****************************************************************************/
+
 #include <stdlib.h>
 #include <stdio.h>
 #include "mem_align.h"
 
+/*****************************************************************************
+ * xvid_malloc
+ *
+ * This function allocates 'size' bytes (usable by the user) on the heap and
+ * takes care of the requested 'alignment'.
+ * In order to align the allocated memory block, the xvid_malloc allocates
+ * 'size' bytes + 'alignment' bytes. So try to keep alignment very small
+ * when allocating small pieces of memory.
+ *
+ * NB : a block allocated by xvid_malloc _must_ be freed with xvid_free
+ *      (the libc free will return an error)
+ *
+ * Returned value : - NULL on error
+ *                  - Pointer to the allocated aligned block
+ *
+ ****************************************************************************/
+
 void *
 xvid_malloc(size_t size,
 			uint8_t alignment)
@@ -14,10 +88,10 @@
 		if ((mem_ptr = (uint8_t *) malloc(size + 1)) != NULL) {
 
 			/* Store (mem_ptr - "real allocated memory") in *(mem_ptr-1) */
-			*mem_ptr = 0;
+			*mem_ptr = 1;
 
 			/* Return the mem_ptr pointer */
-			return (void *) mem_ptr++;
+			return (void *)(mem_ptr+1);
 
 		}
 
@@ -33,8 +107,8 @@
 
 			/* Align the tmp pointer */
 			mem_ptr =
-				(uint8_t *) ((uint32_t) (tmp + alignment - 1) &
-							 (~(uint32_t) (alignment - 1)));
+				(uint8_t *) ((ptr_t) (tmp + alignment - 1) &
+							 (~(ptr_t) (alignment - 1)));
 
 			/*
 			 * Special case where malloc have already satisfied the alignment
@@ -62,6 +136,16 @@
 
 }
 
+/*****************************************************************************
+ * xvid_free
+ *
+ * Free a previously 'xvid_malloc' allocated block. Does not free NULL
+ * references.
+ *
+ * Returned value : None.
+ *
+ ****************************************************************************/
+
 void
 xvid_free(void *mem_ptr)
 {