Release synfig_0_61_04

[synfig.git] / synfig-core / tags / synfig_0_61_04 / synfig-core / src / modules / mod_libavcodec / libavcodec / mem.c

diff --git a/synfig-core/tags/synfig_0_61_04/synfig-core/src/modules/mod_libavcodec/libavcodec/mem.c b/synfig-core/tags/synfig_0_61_04/synfig-core/src/modules/mod_libavcodec/libavcodec/mem.c
new file mode 100644 (file)
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--- /dev/null
+++ b/synfig-core/tags/synfig_0_61_04/synfig-core/src/modules/mod_libavcodec/libavcodec/mem.c
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+/*
+ * 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);
+}
+