avutil/mem: add av_memdup()

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavutil/mem.c

@@ -229,6 +229,17 @@ char *av_strdup(const char *s)
     return ptr;
 }
 
+void *av_memdup(const void *p, size_t size)
+{
+    void *ptr = NULL;
+    if (p) {
+        ptr = av_malloc(size);
+        if (ptr)
+            memcpy(ptr, p, size);
+    }
+    return ptr;
+}
+
 void av_dynarray_add(void *tab_ptr, int *nb_ptr, void *elem)
 {
     /* see similar ffmpeg.c:grow_array() */

libavutil/mem.h

@@ -179,6 +179,14 @@ av_alloc_size(1, 2) static inline void *av_mallocz_array(size_t nmemb, size_t si
  */
 char *av_strdup(const char *s) av_malloc_attrib;
 
+/**
+ * Duplicate the buffer p.
+ * @param p buffer to be duplicated
+ * @return Pointer to a newly allocated buffer containing a
+ * copy of p or NULL if the buffer cannot be allocated.
+ */
+void *av_memdup(const void *p, size_t size);
+
 /**
  * Free a memory block which has been allocated with av_malloc(z)() or
  * av_realloc() and set the pointer pointing to it to NULL.