matroskademux: Improve detection of being stuck at the same offset

Only error out if we read from the same position again and got the
same length. Just the same position is not necessarily enough.

diff --git a/gst/matroska/matroska-demux.c b/gst/matroska/matroska-demux.c
index 9b2bb0a..3356879 100644 (file)
--- a/gst/matroska/matroska-demux.c
+++ b/gst/matroska/matroska-demux.c
@@ -1541,6 +1541,7 @@ gst_matroska_demux_search_cluster (GstMatroskaDemux * demux, gint64 * pos)
   guint64 length;
   guint32 id;
   guint needed;
+  gint64 oldpos, oldlength;
 
   orig_offset = demux->common.offset;
 
@@ -1569,6 +1570,7 @@ gst_matroska_demux_search_cluster (GstMatroskaDemux * demux, gint64 * pos)
   }
 
   /* read in at newpos and scan for ebml cluster id */
+  oldpos = oldlength = -1;
   while (1) {
     GstByteReader reader;
     gint cluster_pos;
@@ -1587,6 +1589,15 @@ gst_matroska_demux_search_cluster (GstMatroskaDemux * demux, gint64 * pos)
     gst_buffer_map (buf, &map, GST_MAP_READ);
     data = map.data;
     size = map.size;
+    if (oldpos == newpos && oldlength == map.size) {
+      GST_ERROR_OBJECT (demux, "Stuck at same position");
+      ret = GST_FLOW_ERROR;
+      goto exit;
+    } else {
+      oldpos = newpos;
+      oldlength = map.size;
+    }
+
     gst_byte_reader_init (&reader, data, size);
   resume:
     cluster_pos = gst_byte_reader_masked_scan_uint32 (&reader, 0xffffffff,
@@ -1610,11 +1621,6 @@ gst_matroska_demux_search_cluster (GstMatroskaDemux * demux, gint64 * pos)
         GST_DEBUG_OBJECT (demux, "cluster is first cluster -> OK");
         break;
       }
-      if (newpos == demux->common.offset) {
-        GST_ERROR_OBJECT (demux, "Stuck at the same offset");
-        ret = GST_FLOW_ERROR;
-        goto exit;
-      }
       demux->common.offset = newpos;
       ret = gst_matroska_read_common_peek_id_length_pull (&demux->common,
           GST_ELEMENT_CAST (demux), &id, &length, &needed);