Move ff_dynarray_add to lavu and make it public.

libavutil/mem.c

@@ -171,3 +171,23 @@ char *av_strdup(const char *s)
     return ptr;
 }
 
+/* add one element to a dynamic array */
+void av_dynarray_add(void *tab_ptr, int *nb_ptr, void *elem)
+{
+    /* see similar ffmpeg.c:grow_array() */
+    int nb, nb_alloc;
+    intptr_t *tab;
+
+    nb = *nb_ptr;
+    tab = *(intptr_t**)tab_ptr;
+    if ((nb & (nb - 1)) == 0) {
+        if (nb == 0)
+            nb_alloc = 1;
+        else
+            nb_alloc = nb * 2;
+        tab = av_realloc(tab, nb_alloc * sizeof(intptr_t));
+        *(intptr_t**)tab_ptr = tab;
+    }
+    tab[nb++] = (intptr_t)elem;
+    *nb_ptr = nb;
+}