baseparse: Restructure event handling

Make the event handling more like what videodecoder does,
to ensure that all events are passed to child classes before being
placed on the pending queue or pushed onward.

diff --git a/libs/gst/base/gstbaseparse.c b/libs/gst/base/gstbaseparse.c
index 926a0d5..fe021df 100644 (file)
--- a/libs/gst/base/gstbaseparse.c
+++ b/libs/gst/base/gstbaseparse.c
@@ -427,10 +427,10 @@ static void gst_base_parse_loop (GstPad * pad);
 static GstFlowReturn gst_base_parse_parse_frame (GstBaseParse * parse,
     GstBaseParseFrame * frame);
 
-static gboolean gst_base_parse_sink_eventfunc (GstBaseParse * parse,
+static gboolean gst_base_parse_sink_default (GstBaseParse * parse,
     GstEvent * event);
 
-static gboolean gst_base_parse_src_eventfunc (GstBaseParse * parse,
+static gboolean gst_base_parse_src_default (GstBaseParse * parse,
     GstEvent * event);
 
 static void gst_base_parse_drain (GstBaseParse * parse);
@@ -535,8 +535,8 @@ gst_base_parse_class_init (GstBaseParseClass * klass)
 #endif
 
   /* Default handlers */
-  klass->sink_event = gst_base_parse_sink_eventfunc;
-  klass->src_event = gst_base_parse_src_eventfunc;
+  klass->sink_event = gst_base_parse_sink_default;
+  klass->src_event = gst_base_parse_src_default;
   klass->convert = gst_base_parse_convert_default;
 
   GST_DEBUG_CATEGORY_INIT (gst_base_parse_debug, "baseparse", 0,
@@ -866,53 +866,17 @@ gst_base_parse_convert (GstBaseParse * parse,
 static gboolean
 gst_base_parse_sink_event (GstPad * pad, GstObject * parent, GstEvent * event)
 {
-  GstBaseParse *parse;
-  GstBaseParseClass *bclass;
+  GstBaseParse *parse = GST_BASE_PARSE (parent);
+  GstBaseParseClass *bclass = GST_BASE_PARSE_GET_CLASS (parse);
   gboolean ret;
 
-  parse = GST_BASE_PARSE (parent);
-  bclass = GST_BASE_PARSE_GET_CLASS (parse);
-
-  GST_DEBUG_OBJECT (parse, "handling event %d, %s", GST_EVENT_TYPE (event),
-      GST_EVENT_TYPE_NAME (event));
-
-  /* Cache all serialized events except EOS, SEGMENT and FLUSH_STOP if we have a
-   * pending segment */
-  if (parse->priv->pending_segment && GST_EVENT_IS_SERIALIZED (event)
-      && GST_EVENT_TYPE (event) != GST_EVENT_EOS
-      && GST_EVENT_TYPE (event) != GST_EVENT_SEGMENT
-      && GST_EVENT_TYPE (event) != GST_EVENT_FLUSH_START
-      && GST_EVENT_TYPE (event) != GST_EVENT_FLUSH_STOP
-      && GST_EVENT_TYPE (event) != GST_EVENT_CAPS) {
-
-    if (GST_EVENT_TYPE (event) == GST_EVENT_TAG)
-      /* See if any bitrate tags were posted */
-      gst_base_parse_handle_tag (parse, event);
-
-    parse->priv->pending_events =
-        g_list_prepend (parse->priv->pending_events, event);
-    ret = TRUE;
-  } else {
-    if (GST_EVENT_TYPE (event) == GST_EVENT_EOS &&
-        parse->priv->framecount < MIN_FRAMES_TO_POST_BITRATE)
-      /* We've not posted bitrate tags yet - do so now */
-      gst_base_parse_post_bitrates (parse, TRUE, TRUE, TRUE);
-
-    if (bclass->sink_event)
-      ret = bclass->sink_event (parse, event);
-    else {
-      gst_event_unref (event);
-      ret = FALSE;
-    }
-  }
-
-  GST_DEBUG_OBJECT (parse, "event handled");
+  ret = bclass->sink_event (parse, event);
 
   return ret;
 }
 
 
-/* gst_base_parse_sink_eventfunc:
+/* gst_base_parse_sink_default:
  * @parse: #GstBaseParse.
  * @event: #GstEvent to be handled.
  *
@@ -924,17 +888,19 @@ gst_base_parse_sink_event (GstPad * pad, GstObject * parent, GstEvent * event)
  * Returns: %TRUE if the event was handled and not need forwarding.
  */
 static gboolean
-gst_base_parse_sink_eventfunc (GstBaseParse * parse, GstEvent * event)
+gst_base_parse_sink_default (GstBaseParse * parse, GstEvent * event)
 {
-  gboolean ret;
+  GstBaseParseClass *klass = GST_BASE_PARSE_GET_CLASS (parse);
+  gboolean ret = FALSE;
+  gboolean forward_immediate = FALSE;
+
+  GST_DEBUG_OBJECT (parse, "handling event %d, %s", GST_EVENT_TYPE (event),
+      GST_EVENT_TYPE_NAME (event));
 
   switch (GST_EVENT_TYPE (event)) {
     case GST_EVENT_CAPS:
     {
       GstCaps *caps;
-      GstBaseParseClass *klass;
-
-      klass = GST_BASE_PARSE_GET_CLASS (parse);
 
       gst_event_parse_caps (event, &caps);
       GST_DEBUG_OBJECT (parse, "caps: %" GST_PTR_FORMAT, caps);
@@ -946,6 +912,7 @@ gst_base_parse_sink_eventfunc (GstBaseParse * parse, GstEvent * event)
 
       /* will send our own caps downstream */
       gst_event_unref (event);
+      event = NULL;
       break;
     }
     case GST_EVENT_SEGMENT:
@@ -954,13 +921,6 @@ gst_base_parse_sink_eventfunc (GstBaseParse * parse, GstEvent * event)
       GstSegment out_segment;
       gint64 offset = 0, next_pts;
 
-#if 0
-      gdouble rate, applied_rate;
-      GstFormat format;
-      gint64 start, stop, pos, next_ts;
-      gboolean update;
-#endif
-
       gst_event_parse_segment (event, &in_segment);
       gst_segment_init (&out_segment, GST_FORMAT_TIME);
 
@@ -1048,8 +1008,6 @@ gst_base_parse_sink_eventfunc (GstBaseParse * parse, GstEvent * event)
       /* save the segment for later, right before we push a new buffer so that
        * the caps are fixed and the next linked element can receive
        * the segment. */
-      parse->priv->pending_events =
-          g_list_prepend (parse->priv->pending_events, event);
       parse->priv->pending_segment = TRUE;
       ret = TRUE;
 
@@ -1072,15 +1030,11 @@ gst_base_parse_sink_eventfunc (GstBaseParse * parse, GstEvent * event)
     }
 
     case GST_EVENT_FLUSH_START:
+      /* FIXME: locking */
       parse->priv->flushing = TRUE;
-      ret = gst_pad_push_event (parse->srcpad, event);
-      /* Wait for _chain() to exit by taking the srcpad STREAM_LOCK */
-      GST_PAD_STREAM_LOCK (parse->srcpad);
-      GST_PAD_STREAM_UNLOCK (parse->srcpad);
       break;
 
     case GST_EVENT_FLUSH_STOP:
-      ret = gst_pad_push_event (parse->srcpad, event);
       gst_adapter_clear (parse->priv->adapter);
       gst_base_parse_clear_queues (parse);
       parse->priv->flushing = FALSE;
@@ -1088,6 +1042,8 @@ gst_base_parse_sink_eventfunc (GstBaseParse * parse, GstEvent * event)
       parse->priv->last_pts = GST_CLOCK_TIME_NONE;
       parse->priv->last_dts = GST_CLOCK_TIME_NONE;
       parse->priv->new_frame = TRUE;
+
+      forward_immediate = TRUE;
       break;
 
     case GST_EVENT_EOS:
@@ -1112,15 +1068,46 @@ gst_base_parse_sink_eventfunc (GstBaseParse * parse, GstEvent * event)
         parse->priv->pending_events = NULL;
         parse->priv->pending_segment = FALSE;
       }
-      ret = gst_pad_push_event (parse->srcpad, event);
+      forward_immediate = TRUE;
       break;
-
     default:
-      ret =
-          gst_pad_event_default (parse->sinkpad, GST_OBJECT_CAST (parse),
-          event);
       break;
   }
+
+  /* Forward non-serialized events and EOS/FLUSH_STOP immediately.
+   * For EOS this is required because no buffer or serialized event
+   * will come after EOS and nothing could trigger another
+   * _finish_frame() call.   *
+   * If the subclass handles sending of EOS manually it can return
+   * _DROPPED from ::finish() and all other subclasses should have
+   * decoded/flushed all remaining data before this
+   *
+   * For FLUSH_STOP this is required because it is expected
+   * to be forwarded immediately and no buffers are queued anyway.
+   */
+  if (event) {
+    if (!GST_EVENT_IS_SERIALIZED (event) || forward_immediate) {
+      if (GST_EVENT_TYPE (event) == GST_EVENT_EOS &&
+          parse->priv->framecount < MIN_FRAMES_TO_POST_BITRATE) {
+        /* We've not posted bitrate tags yet - do so now */
+        gst_base_parse_post_bitrates (parse, TRUE, TRUE, TRUE);
+      }
+      ret = gst_pad_push_event (parse->srcpad, event);
+    } else {
+      // GST_VIDEO_DECODER_STREAM_LOCK (decoder);
+      if (GST_EVENT_TYPE (event) == GST_EVENT_TAG) {
+        /* See if any bitrate tags were posted */
+        gst_base_parse_handle_tag (parse, event);
+      }
+      parse->priv->pending_events =
+          g_list_prepend (parse->priv->pending_events, event);
+      // GST_VIDEO_DECODER_STREAM_UNLOCK (decoder);
+      ret = TRUE;
+    }
+  }
+
+  GST_DEBUG_OBJECT (parse, "event handled");
+
   return ret;
 }
 
@@ -1216,7 +1203,7 @@ gst_base_parse_is_seekable (GstBaseParse * parse)
   return parse->priv->syncable;
 }
 
-/* gst_base_parse_src_eventfunc:
+/* gst_base_parse_src_default:
  * @parse: #GstBaseParse.
  * @event: #GstEvent that was received.
  *
@@ -1225,7 +1212,7 @@ gst_base_parse_is_seekable (GstBaseParse * parse)
  * Returns: TRUE if the event was handled and can be dropped.
  */
 static gboolean
-gst_base_parse_src_eventfunc (GstBaseParse * parse, GstEvent * event)
+gst_base_parse_src_default (GstBaseParse * parse, GstEvent * event)
 {
   gboolean res = FALSE;