basetransform: Reconfigure before propose_allocation

There exist cases where a reconfigure event was propagated from
downstream, but caps didn't change. In this case, we would
reconfigure only when the next buffer arrives. The problem is that
due to the allocation query being cached, the return query parameters
endup outdated.

In this patch we refactor the reconfigurating code into a function, and
along with reconfiguring when a new buffer comes in, we also reconfigure
when a query allocation arrives.

https://bugzilla.gnome.org/show_bug.cgi?id=753850

diff --git a/libs/gst/base/gstbasetransform.c b/libs/gst/base/gstbasetransform.c
index 4565f4f..7ef7bc9 100644 (file)
--- a/libs/gst/base/gstbasetransform.c
+++ b/libs/gst/base/gstbasetransform.c
@@ -1452,6 +1452,37 @@ gst_base_transform_default_propose_allocation (GstBaseTransform * trans,
 }
 
 static gboolean
+gst_base_transform_reconfigure (GstBaseTransform * trans)
+{
+  gboolean reconfigure, ret = TRUE;
+
+  reconfigure = gst_pad_check_reconfigure (trans->srcpad);
+
+  if (G_UNLIKELY (reconfigure)) {
+    GstCaps *incaps;
+
+    GST_DEBUG_OBJECT (trans, "we had a pending reconfigure");
+
+    incaps = gst_pad_get_current_caps (trans->sinkpad);
+    if (incaps == NULL)
+      goto done;
+
+    /* if we need to reconfigure we pretend new caps arrived. This
+     * will reconfigure the transform with the new output format. */
+    if (!gst_base_transform_setcaps (trans, trans->sinkpad, incaps)) {
+      GST_ELEMENT_WARNING (trans, STREAM, FORMAT,
+          ("not negotiated"), ("not negotiated"));
+      ret = FALSE;
+    }
+
+    gst_caps_unref (incaps);
+  }
+
+done:
+  return ret;
+}
+
+static gboolean
 gst_base_transform_default_query (GstBaseTransform * trans,
     GstPadDirection direction, GstQuery * query)
 {
@@ -1479,6 +1510,10 @@ gst_base_transform_default_query (GstBaseTransform * trans,
       if (direction != GST_PAD_SINK)
         goto done;
 
+      ret = gst_base_transform_reconfigure (trans);
+      if (G_UNLIKELY (!ret))
+        goto done;
+
       GST_OBJECT_LOCK (trans);
       if (!priv->negotiated && !priv->passthrough && (klass->set_caps != NULL)) {
         GST_DEBUG_OBJECT (trans,
@@ -1489,7 +1524,6 @@ gst_base_transform_default_query (GstBaseTransform * trans,
 
       decide_query = trans->priv->query;
       trans->priv->query = NULL;
-
       GST_OBJECT_UNLOCK (trans);
 
       GST_DEBUG_OBJECT (trans,
@@ -1986,31 +2020,12 @@ default_submit_input_buffer (GstBaseTransform * trans, gboolean is_discont,
   GstBaseTransformClass *bclass = GST_BASE_TRANSFORM_GET_CLASS (trans);
   GstBaseTransformPrivate *priv = trans->priv;
   GstFlowReturn ret = GST_FLOW_OK;
-  gboolean reconfigure;
   GstClockTime running_time;
   GstClockTime timestamp;
 
-  reconfigure = gst_pad_check_reconfigure (trans->srcpad);
-
-  if (G_UNLIKELY (reconfigure)) {
-    GstCaps *incaps;
-
-    GST_DEBUG_OBJECT (trans, "we had a pending reconfigure");
-
-    incaps = gst_pad_get_current_caps (trans->sinkpad);
-    if (incaps == NULL)
-      goto no_reconfigure;
-
-    /* if we need to reconfigure we pretend new caps arrived. This
-     * will reconfigure the transform with the new output format. */
-    if (!gst_base_transform_setcaps (trans, trans->sinkpad, incaps)) {
-      gst_caps_unref (incaps);
-      goto not_negotiated;
-    }
-    gst_caps_unref (incaps);
-  }
+  if (G_UNLIKELY (!gst_base_transform_reconfigure (trans)))
+    goto not_negotiated;
 
-no_reconfigure:
   if (GST_BUFFER_OFFSET_IS_VALID (inbuf))
     GST_DEBUG_OBJECT (trans,
         "handling buffer %p of size %" G_GSIZE_FORMAT " and offset %"
@@ -2102,8 +2117,6 @@ not_negotiated:
     gst_buffer_unref (inbuf);
     if (GST_PAD_IS_FLUSHING (trans->srcpad))
       return GST_FLOW_FLUSHING;
-    GST_ELEMENT_WARNING (trans, STREAM, FORMAT,
-        ("not negotiated"), ("not negotiated"));
     return GST_FLOW_NOT_NEGOTIATED;
   }
 }