--- a/libs/gst/base/gstbaseparse.c
+++ b/libs/gst/base/gstbaseparse.c
@@ -3021,6 +3021,7 @@
   GstBuffer *tmpbuf = NULL;
   guint fsize = 1;
   gint skip = -1;
+  const guint8 *data;
   guint min_size, av;
   GstClockTime pts, dts;
 
@@ -3227,7 +3228,11 @@
     }
 
     /* always pass all available data */
-    tmpbuf = gst_adapter_get_buffer (parse->priv->adapter, av);
+    data = gst_adapter_map (parse->priv->adapter, av);
+    /* arrange for actual data to be copied if subclass tries to,
+     * since what is passed is tied to the adapter */
+    tmpbuf = gst_buffer_new_wrapped_full (GST_MEMORY_FLAG_READONLY |
+        GST_MEMORY_FLAG_NO_SHARE, (gpointer) data, av, 0, av, NULL, NULL);
 
     /* already inform subclass what timestamps we have planned,
      * at least if provided by time-based upstream */
@@ -3242,6 +3247,9 @@
     ret = gst_base_parse_handle_buffer (parse, tmpbuf, &skip, &flush);
     tmpbuf = NULL;
 
+    /* probably already implicitly unmapped due to adapter operation,
+     * but for good measure ... */
+    gst_adapter_unmap (parse->priv->adapter);
     if (ret != GST_FLOW_OK && ret != GST_FLOW_NOT_LINKED) {
       goto done;
     }