ccextractor: Use GstFlowCombiner for aggregated flow returnclosedcaption

Ensures that if ever there's an issue from downstream that needs
to be propagated upstream it is.

Also handle a couple more error cases with GST_FLOW_NOT_NEGOTIATED

2 files changed, 43 insertions, 7 deletions

diff --git a/gst/closedcaption/gstccextractor.c b/gst/closedcaption/gstccextractor.c
index c38754a55..5a83aa2ec 100644
--- a/gst/closedcaption/gstccextractor.c
+++ b/gst/closedcaption/gstccextractor.c
@@ -136,6 +136,15 @@ static void
 gst_cc_extractor_reset (GstCCExtractor * filter)
 {
   filter->caption_type = GST_VIDEO_CAPTION_TYPE_UNKNOWN;
+  gst_flow_combiner_reset (filter->combiner);
+  gst_flow_combiner_add_pad (filter->combiner, filter->srcpad);
+
+  if (filter->captionpad) {
+    gst_flow_combiner_remove_pad (filter->combiner, filter->captionpad);
+    gst_pad_set_active (filter->captionpad, FALSE);
+    gst_element_remove_pad ((GstElement *) filter, filter->captionpad);
+    filter->captionpad = NULL;
+  }
 }
 
 static void
@@ -162,6 +171,8 @@ gst_cc_extractor_init (GstCCExtractor * filter)
   gst_element_add_pad (GST_ELEMENT (filter), filter->sinkpad);
   gst_element_add_pad (GST_ELEMENT (filter), filter->srcpad);
 
+  filter->combiner = gst_flow_combiner_new ();
+
   gst_cc_extractor_reset (filter);
 }
 
@@ -213,13 +224,14 @@ gst_cc_extractor_sink_event (GstPad * pad, GstObject * parent, GstEvent * event)
   return gst_pad_event_default (pad, parent, event);
 }
 
-static void
+static GstFlowReturn
 gst_cc_extractor_handle_meta (GstCCExtractor * filter, GstBuffer * buf,
     GstVideoCaptionMeta * meta)
 {
   GstBuffer *outbuf = NULL;
   GstEvent *event;
   gchar *captionid;
+  GstFlowReturn flow;
 
   GST_DEBUG_OBJECT (filter, "Handling meta");
 
@@ -227,7 +239,8 @@ gst_cc_extractor_handle_meta (GstCCExtractor * filter, GstBuffer * buf,
   if (filter->captionpad != NULL && meta->caption_type != filter->caption_type) {
     GST_ERROR_OBJECT (filter,
         "GstVideoCaptionMeta type changed, Not handled currently");
-    return;
+    flow = GST_FLOW_NOT_NEGOTIATED;
+    goto out;
   }
 
   if (filter->captionpad == NULL) {
@@ -259,7 +272,7 @@ gst_cc_extractor_handle_meta (GstCCExtractor * filter, GstBuffer * buf,
     }
     if (caption_caps == NULL) {
       GST_ERROR_OBJECT (filter, "Unknown/invalid caption type");
-      return;
+      return GST_FLOW_NOT_NEGOTIATED;
     }
 
     /* Create the caption pad and set the caps */
@@ -269,6 +282,7 @@ gst_cc_extractor_handle_meta (GstCCExtractor * filter, GstBuffer * buf,
         GST_DEBUG_FUNCPTR (gst_cc_extractor_iterate_internal_links));
     gst_pad_set_active (filter->captionpad, TRUE);
     gst_element_add_pad (GST_ELEMENT (filter), filter->captionpad);
+    gst_flow_combiner_add_pad (filter->combiner, filter->captionpad);
 
     captionid =
         gst_pad_create_stream_id (filter->captionpad, (GstElement *) filter,
@@ -310,29 +324,43 @@ gst_cc_extractor_handle_meta (GstCCExtractor * filter, GstBuffer * buf,
   GST_BUFFER_DURATION (outbuf) = GST_BUFFER_DURATION (buf);
 
   /* We don't really care about the flow return */
-  gst_pad_push (filter->captionpad, outbuf);
+  flow = gst_pad_push (filter->captionpad, outbuf);
+
+out:
+  /* Set flow return on pad and return combined value */
+  return gst_flow_combiner_update_pad_flow (filter->combiner,
+      filter->captionpad, flow);
 }
 
 static GstFlowReturn
 gst_cc_extractor_chain (GstPad * pad, GstObject * parent, GstBuffer * buf)
 {
   GstCCExtractor *filter = (GstCCExtractor *) parent;
+  GstFlowReturn flow = GST_FLOW_OK;
   GstVideoCaptionMeta *cc_meta;
 
   cc_meta = gst_buffer_get_video_caption_meta (buf);
   if (cc_meta)
-    gst_cc_extractor_handle_meta (filter, buf, cc_meta);
+    flow = gst_cc_extractor_handle_meta (filter, buf, cc_meta);
   else
     GST_DEBUG_OBJECT (filter, "No CC meta on buffer");
 
-  return gst_pad_push (filter->srcpad, buf);
+  /* If there's an issue handling the CC, return immediately */
+  if (flow != GST_FLOW_OK) {
+    gst_buffer_unref (buf);
+    return flow;
+  }
+
+  /* Push the buffer downstream and return the combined flow return */
+  return gst_flow_combiner_update_pad_flow (filter->combiner, filter->srcpad,
+      gst_pad_push (filter->srcpad, buf));
 }
 
 static GstStateChangeReturn
 gst_cc_extractor_change_state (GstElement * element, GstStateChange transition)
 {
   GstStateChangeReturn ret;
-  /* GstCCExtractor *filter = GST_CCEXTRACTOR (element); */
+  GstCCExtractor *filter = GST_CCEXTRACTOR (element);
 
   switch (transition) {
     case GST_STATE_CHANGE_NULL_TO_READY:
@@ -353,6 +381,7 @@ gst_cc_extractor_change_state (GstElement * element, GstStateChange transition)
     case GST_STATE_CHANGE_PLAYING_TO_PAUSED:
       break;
     case GST_STATE_CHANGE_PAUSED_TO_READY:
+      gst_cc_extractor_reset (filter);
       break;
     case GST_STATE_CHANGE_READY_TO_NULL:
     default:
@@ -365,5 +394,9 @@ gst_cc_extractor_change_state (GstElement * element, GstStateChange transition)
 static void
 gst_cc_extractor_finalize (GObject * object)
 {
+  GstCCExtractor *filter = GST_CCEXTRACTOR (object);
+
+  gst_flow_combiner_free (filter->combiner);
+
   G_OBJECT_CLASS (parent_class)->finalize (object);
 }
diff --git a/gst/closedcaption/gstccextractor.h b/gst/closedcaption/gstccextractor.h
index 728072ada..2ad8bd394 100644
--- a/gst/closedcaption/gstccextractor.h
+++ b/gst/closedcaption/gstccextractor.h
@@ -22,6 +22,7 @@
 #define __GST_CCEXTRACTOR_H__
 
 #include <gst/gst.h>
+#include <gst/base/gstflowcombiner.h>
 #include <gst/video/video-anc.h>
 
 G_BEGIN_DECLS
@@ -45,6 +46,8 @@ struct _GstCCExtractor
 
   GstPad *sinkpad, *srcpad, *captionpad;
   GstVideoCaptionType caption_type;
+
+  GstFlowCombiner *combiner;
 };
 
 struct _GstCCExtractorClass