gluploadelement: try to avoid dropping buffers

Without this, a buffer is dropped if glupload indicates that it is
necessary to reconfigure.
Avoid this by explicitly reconfiguring immediately and uploading the buffer
again.

https://bugzilla.gnome.org/show_bug.cgi?id=783521

diff --git a/ext/gl/gstgluploadelement.c b/ext/gl/gstgluploadelement.c
index 1998c77..eaaeaed 100644 (file)
--- a/ext/gl/gstgluploadelement.c
+++ b/ext/gl/gstgluploadelement.c
@@ -232,9 +232,21 @@ gst_gl_upload_element_prepare_output_buffer (GstBaseTransform * bt,
   if (!upload->upload)
     return GST_FLOW_NOT_NEGOTIATED;
 
+again:
   ret = gst_gl_upload_perform_with_buffer (upload->upload, buffer, outbuf);
   if (ret == GST_GL_UPLOAD_RECONFIGURE) {
-    gst_base_transform_reconfigure_src (bt);
+    GstPad *sinkpad = GST_BASE_TRANSFORM_SINK_PAD (bt);
+    GstCaps *incaps = gst_pad_get_current_caps (sinkpad);
+    GST_DEBUG_OBJECT (bt,
+        "Failed to upload with curren caps -- reconfiguring.");
+    /* Note: gst_base_transform_reconfigure_src() cannot be used here.
+     * Reconfiguring must be synchronous to avoid dropping the current
+     * buffer */
+    gst_pad_send_event (sinkpad, gst_event_new_caps (incaps));
+    if (!gst_pad_needs_reconfigure (GST_BASE_TRANSFORM_SRC_PAD (bt))) {
+      GST_DEBUG_OBJECT (bt, "Retry uploading with new caps");
+      goto again;
+    }
     return GST_FLOW_OK;
   }