[GStreamer] improved duration query support in the HTTP source element

https://bugs.webkit.org/show_bug.cgi?id=159204

Reviewed by Carlos Garcia Campos.

When we have the Content-Length value it is possible to infer the TIME
duration in most cases by performing a convert query in the downstream
elements. This is especially useful when the duration query wasn't
managed by the sinks and thus reached the source element.

* platform/graphics/gstreamer/WebKitWebSourceGStreamer.cpp:
(webKitWebSrcQueryWithParent):

Canonical link: https://commits.webkit.org/177303@main
git-svn-id: https://svn.webkit.org/repository/webkit/trunk@202556 268f45cc-cd09-0410-ab3c-d52691b4dbfc

Source/WebCore/ChangeLog

@@ -1,3 +1,18 @@
+2016-06-28  Philippe Normand  <pnormand@igalia.com>
+
+        [GStreamer] improved duration query support in the HTTP source element
+        https://bugs.webkit.org/show_bug.cgi?id=159204
+
+        Reviewed by Carlos Garcia Campos.
+
+        When we have the Content-Length value it is possible to infer the TIME
+        duration in most cases by performing a convert query in the downstream
+        elements. This is especially useful when the duration query wasn't
+        managed by the sinks and thus reached the source element.
+
+        * platform/graphics/gstreamer/WebKitWebSourceGStreamer.cpp:
+        (webKitWebSrcQueryWithParent):
+
 2016-06-28  Youenn Fablet  <youenn@apple.com>
 
         Binding generator should generate accessors for constructors safely accessed from JS builtin

Source/WebCore/platform/graphics/gstreamer/WebKitWebSourceGStreamer.cpp

@@ -675,6 +675,13 @@ static gboolean webKitWebSrcQueryWithParent(GstPad* pad, GstObject* parent, GstQ
         if (format == GST_FORMAT_BYTES && src->priv->size > 0) {
             gst_query_set_duration(query, format, src->priv->size);
             result = TRUE;
+        } else if (format == GST_FORMAT_TIME) {
+            gint64 duration = -1;
+            GRefPtr<GstPad> target = adoptGRef(gst_ghost_pad_get_target(GST_GHOST_PAD_CAST(pad)));
+            GRefPtr<GstPad> peer = adoptGRef(gst_pad_get_peer(target.get()));
+            result = gst_pad_query_convert(peer.get(), GST_FORMAT_BYTES, src->priv->size, format, &duration);
+            if (result)
+                gst_query_set_duration(query, format, duration);
         }
         break;
     }