--- /dev/null
+/*
+ * default memory allocator for libavcodec
+ * Copyright (c) 2002 Fabrice Bellard.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+/**
+ * @file mem.c
+ * default memory allocator for libavcodec.
+ */
+
+#include "avcodec.h"
+
+/* here we can use OS dependant allocation functions */
+#undef malloc
+#undef free
+#undef realloc
+
+#ifdef HAVE_MALLOC_H
+#include <malloc.h>
+#endif
+
+/* you can redefine av_malloc and av_free in your project to use your
+ memory allocator. You do not need to suppress this file because the
+ linker will do it automatically */
+
+/**
+ * Memory allocation of size byte with alignment suitable for all
+ * memory accesses (including vectors if available on the
+ * CPU). av_malloc(0) must return a non NULL pointer.
+ */
+void *av_malloc(unsigned int size)
+{
+ void *ptr;
+
+#if defined (HAVE_MEMALIGN)
+ ptr = memalign(16,size);
+ /* Why 64?
+ Indeed, we should align it:
+ on 4 for 386
+ on 16 for 486
+ on 32 for 586, PPro - k6-III
+ on 64 for K7 (maybe for P3 too).
+ Because L1 and L2 caches are aligned on those values.
+ But I don't want to code such logic here!
+ */
+ /* Why 16?
+ because some cpus need alignment, for example SSE2 on P4, & most RISC cpus
+ it will just trigger an exception and the unaligned load will be done in the
+ exception handler or it will just segfault (SSE2 on P4)
+ Why not larger? because i didnt see a difference in benchmarks ...
+ */
+ /* benchmarks with p3
+ memalign(64)+1 3071,3051,3032
+ memalign(64)+2 3051,3032,3041
+ memalign(64)+4 2911,2896,2915
+ memalign(64)+8 2545,2554,2550
+ memalign(64)+16 2543,2572,2563
+ memalign(64)+32 2546,2545,2571
+ memalign(64)+64 2570,2533,2558
+
+ btw, malloc seems to do 8 byte alignment by default here
+ */
+#else
+ ptr = malloc(size);
+#endif
+ return ptr;
+}
+
+/**
+ * av_realloc semantics (same as glibc): if ptr is NULL and size > 0,
+ * identical to malloc(size). If size is zero, it is identical to
+ * free(ptr) and NULL is returned.
+ */
+void *av_realloc(void *ptr, unsigned int size)
+{
+ return realloc(ptr, size);
+}
+
+/* NOTE: ptr = NULL is explicetly allowed */
+void av_free(void *ptr)
+{
+ /* XXX: this test should not be needed on most libcs */
+ if (ptr)
+ free(ptr);
+}
+