+typedef struct
+{
+ guint count;
+ gboolean live;
+ GstClockTime min, max;
+} LatencyFoldData;
+
+static gboolean
+query_latency_default_fold (const GValue * item, GValue * ret,
+ gpointer user_data)
+{
+ GstPad *pad = g_value_get_object (item), *peer;
+ LatencyFoldData *fold_data = user_data;
+ GstQuery *query;
+ gboolean res = FALSE;
+
+ query = gst_query_new_latency ();
+
+ peer = gst_pad_get_peer (pad);
+ if (peer) {
+ res = gst_pad_peer_query (pad, query);
+ } else {
+ GST_LOG_OBJECT (pad, "No peer pad found, ignoring this pad");
+ }
+
+ if (res) {
+ gboolean live;
+ GstClockTime min, max;
+
+ gst_query_parse_latency (query, &live, &min, &max);
+
+ GST_LOG_OBJECT (pad, "got latency live:%s min:%" G_GINT64_FORMAT
+ " max:%" G_GINT64_FORMAT, live ? "true" : "false", min, max);
+
+ /* FIXME : Why do we only take values into account if it's live ? */
+ if (live || fold_data->count == 0) {
+ if (min > fold_data->min)
+ fold_data->min = min;
+
+ if (fold_data->max == GST_CLOCK_TIME_NONE)
+ fold_data->max = max;
+ else if (max < fold_data->max)
+ fold_data->max = max;
+
+ fold_data->live = live;
+ }
+ fold_data->count += 1;
+ } else if (peer) {
+ GST_DEBUG_OBJECT (pad, "latency query failed");
+ g_value_set_boolean (ret, FALSE);
+ }
+
+ gst_query_unref (query);
+ if (peer)
+ gst_object_unref (peer);
+
+ return TRUE;
+}
+
+static gboolean
+gst_input_selector_query_latency (GstInputSelector * sel, GstPad * pad,
+ GstQuery * query)
+{
+ GstIterator *it;
+ GstIteratorResult res;
+ GValue ret = G_VALUE_INIT;
+ gboolean query_ret;
+ LatencyFoldData fold_data;
+
+ /* This is basically gst_pad_query_latency_default() but with a different
+ * iterator. We query all sinkpads! */
+ it = gst_element_iterate_sink_pads (GST_ELEMENT_CAST (sel));
+ if (!it) {
+ GST_DEBUG_OBJECT (pad, "Can't iterate internal links");
+ return FALSE;
+ }
+
+ g_value_init (&ret, G_TYPE_BOOLEAN);
+
+retry:
+ fold_data.count = 0;
+ fold_data.live = FALSE;
+ fold_data.min = 0;
+ fold_data.max = GST_CLOCK_TIME_NONE;
+
+ g_value_set_boolean (&ret, TRUE);
+ res = gst_iterator_fold (it, query_latency_default_fold, &ret, &fold_data);
+ switch (res) {
+ case GST_ITERATOR_OK:
+ g_assert_not_reached ();
+ break;
+ case GST_ITERATOR_DONE:
+ break;
+ case GST_ITERATOR_ERROR:
+ g_value_set_boolean (&ret, FALSE);
+ break;
+ case GST_ITERATOR_RESYNC:
+ gst_iterator_resync (it);
+ goto retry;
+ default:
+ g_assert_not_reached ();
+ break;
+ }
+ gst_iterator_free (it);
+
+ query_ret = g_value_get_boolean (&ret);
+ if (query_ret) {
+ GST_LOG_OBJECT (pad, "got latency live:%s min:%" G_GINT64_FORMAT
+ " max:%" G_GINT64_FORMAT, fold_data.live ? "true" : "false",
+ fold_data.min, fold_data.max);
+
+ if (fold_data.min > fold_data.max) {
+ GST_ERROR_OBJECT (pad, "minimum latency bigger than maximum latency");
+ }
+
+ gst_query_set_latency (query, fold_data.live, fold_data.min, fold_data.max);
+ } else {
+ GST_LOG_OBJECT (pad, "latency query failed");
+ }
+
+ return query_ret;
+}
+
+static gboolean
+gst_input_selector_query (GstPad * pad, GstObject * parent, GstQuery * query)
+{
+ GstInputSelector *sel = GST_INPUT_SELECTOR (parent);
+
+ switch (GST_QUERY_TYPE (query)) {
+ case GST_QUERY_LATENCY:
+ /* Query all sink pads for the latency, not just the active one */
+ return gst_input_selector_query_latency (sel, pad, query);
+ default:
+ return gst_pad_query_default (pad, parent, query);
+ }
+}
+