dvbsuboverlay: properly force end-of-display-set

... which is upon receiving new data with different PTS spec-wise,
or optionally upon each packet of subtitle data if desired by property.

Fixes https://bugzilla.gnome.org/show_bug.cgi?id=669310

3 files changed, 52 insertions, 4 deletions

diff --git a/gst/dvbsuboverlay/dvb-sub.c b/gst/dvbsuboverlay/dvb-sub.c
index 097268bee..403dcb3ae 100644
--- a/gst/dvbsuboverlay/dvb-sub.c
+++ b/gst/dvbsuboverlay/dvb-sub.c
@@ -1185,7 +1185,7 @@ _dvb_sub_parse_display_definition_segment (DvbSub * dvb_sub, guint8 * buf,
 
 static gint
 _dvb_sub_parse_end_of_display_set (DvbSub * dvb_sub, guint16 page_id,
-    guint8 * buf, gint buf_size, guint64 pts)
+    guint64 pts)
 {
   DVBSubRegionDisplay *display;
   DVBSubtitles *sub;
@@ -1193,7 +1193,7 @@ _dvb_sub_parse_end_of_display_set (DvbSub * dvb_sub, guint16 page_id,
   guint32 *clut_table;
   int i;
 
-  GST_DEBUG ("DISPLAY SET END: page_id = %u, length = %d", page_id, buf_size);
+  GST_DEBUG ("DISPLAY SET END: page_id = %u, length = %d", page_id);
 
   sub = g_slice_new0 (DVBSubtitles);
 
@@ -1384,7 +1384,13 @@ dvb_sub_feed_with_pts (DvbSub * dvb_sub, guint64 pts, guint8 * data, gint len)
 
   GST_DEBUG ("pts=%" G_GUINT64_FORMAT " and length %d", pts, len);
 
-  g_return_val_if_fail (data != NULL, -1);
+  g_return_val_if_fail (data != NULL || len == 0, -1);
+
+  if (G_UNLIKELY (data == NULL)) {
+    GST_DEBUG ("no data; forcing end-of-display-set");
+    _dvb_sub_parse_end_of_display_set (dvb_sub, 0, pts);
+    return 0;
+  }
 
   if (len <= 3) {               /* len(0x20 0x00 end_of_PES_data_field_marker) */
     GST_WARNING ("Data length too short");
@@ -1451,7 +1457,7 @@ dvb_sub_feed_with_pts (DvbSub * dvb_sub, guint64 pts, guint8 * data, gint len)
         break;
       case DVB_SUB_SEGMENT_END_OF_DISPLAY_SET:
         GST_DEBUG ("End of display set at buffer pos %u", pos);
-        _dvb_sub_parse_end_of_display_set (dvb_sub, page_id, data + pos, segment_len, pts);     /* FIXME: Not sure about args */
+        _dvb_sub_parse_end_of_display_set (dvb_sub, page_id, pts);      /* FIXME: Not sure about args */
         break;
       default:
         GST_FIXME ("Unhandled segment type 0x%x", segment_type);
diff --git a/gst/dvbsuboverlay/gstdvbsuboverlay.c b/gst/dvbsuboverlay/gstdvbsuboverlay.c
index 5cd7a7fb8..80f0ea25a 100644
--- a/gst/dvbsuboverlay/gstdvbsuboverlay.c
+++ b/gst/dvbsuboverlay/gstdvbsuboverlay.c
@@ -57,10 +57,12 @@ enum
   PROP_0,
   PROP_ENABLE,
   PROP_MAX_PAGE_TIMEOUT,
+  PROP_FORCE_END
 };
 
 #define DEFAULT_ENABLE (TRUE)
 #define DEFAULT_MAX_PAGE_TIMEOUT (0)
+#define DEFAULT_FORCE_END (FALSE)
 
 static GstStaticPadTemplate src_factory = GST_STATIC_PAD_TEMPLATE ("src",
     GST_PAD_SRC,
@@ -153,6 +155,11 @@ gst_dvbsub_overlay_class_init (GstDVBSubOverlayClass * klass)
           0, G_MAXINT, DEFAULT_MAX_PAGE_TIMEOUT,
           G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
 
+  g_object_class_install_property (gobject_class, PROP_FORCE_END,
+      g_param_spec_boolean ("force-end", "Force End",
+          "Assume PES-aligned subtitles and force end-of-display",
+          DEFAULT_FORCE_END, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+
   gstelement_class->change_state =
       GST_DEBUG_FUNCPTR (gst_dvbsub_overlay_change_state);
 }
@@ -181,6 +188,9 @@ gst_dvbsub_overlay_flush_subtitles (GstDVBSubOverlay * render)
     dvb_sub_set_callbacks (render->dvb_sub, &dvbsub_callbacks, render);
   }
 
+  render->last_text_pts = GST_CLOCK_TIME_NONE;
+  render->pending_sub = FALSE;
+
   g_mutex_unlock (render->dvbsub_mutex);
 }
 
@@ -234,6 +244,7 @@ gst_dvbsub_overlay_init (GstDVBSubOverlay * render,
 
   render->enable = DEFAULT_ENABLE;
   render->max_page_timeout = DEFAULT_MAX_PAGE_TIMEOUT;
+  render->force_end = DEFAULT_FORCE_END;
 
   render->dvbsub_mutex = g_mutex_new ();
   gst_dvbsub_overlay_flush_subtitles (render);
@@ -281,6 +292,9 @@ gst_dvbsub_overlay_set_property (GObject * object, guint prop_id,
     case PROP_MAX_PAGE_TIMEOUT:
       g_atomic_int_set (&overlay->max_page_timeout, g_value_get_int (value));
       break;
+    case PROP_FORCE_END:
+      g_atomic_int_set (&overlay->force_end, g_value_get_boolean (value));
+      break;
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
@@ -300,6 +314,9 @@ gst_dvbsub_overlay_get_property (GObject * object, guint prop_id,
     case PROP_MAX_PAGE_TIMEOUT:
       g_value_set_int (value, g_atomic_int_get (&overlay->max_page_timeout));
       break;
+    case PROP_FORCE_END:
+      g_value_set_boolean (value, g_atomic_int_get (&overlay->force_end));
+      break;
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
@@ -717,8 +734,15 @@ gst_dvbsub_overlay_process_text (GstDVBSubOverlay * overlay, GstBuffer * buffer,
   GST_DEBUG_OBJECT (overlay, "Feeding %u bytes to libdvbsub", size);
   g_mutex_lock (overlay->dvbsub_mutex);
   dvb_sub_feed_with_pts (overlay->dvb_sub, pts, data, size);
+  overlay->pending_sub = TRUE;
   g_mutex_unlock (overlay->dvbsub_mutex);
   gst_buffer_unref (buffer);
+
+  if (overlay->pending_sub && overlay->force_end) {
+    GST_DEBUG_OBJECT (overlay, "forcing subtitle end");
+    dvb_sub_feed_with_pts (overlay->dvb_sub, overlay->last_text_pts, NULL, 0);
+    g_assert (overlay->pending_sub == FALSE);
+  }
 }
 
 static void
@@ -738,6 +762,7 @@ new_dvb_subtitles_cb (DvbSub * dvb_sub, DVBSubtitles * subs, gpointer user_data)
       GST_TIME_ARGS (subs->pts));
 
   g_queue_push_tail (overlay->pending_subtitles, subs);
+  overlay->pending_sub = FALSE;
 }
 
 static GstFlowReturn
@@ -785,6 +810,17 @@ gst_dvbsub_overlay_chain_text (GstPad * pad, GstBuffer * buffer)
     return GST_FLOW_OK;
   }
 
+  /* spec states multiple PES packets may have same PTS,
+   * and same PTS packets make up a display set */
+  if (overlay->pending_sub &&
+      overlay->last_text_pts != GST_BUFFER_TIMESTAMP (buffer)) {
+    GST_DEBUG_OBJECT (overlay, "finishing previous subtitle");
+    dvb_sub_feed_with_pts (overlay->dvb_sub, overlay->last_text_pts, NULL, 0);
+    overlay->pending_sub = FALSE;
+  }
+
+  overlay->last_text_pts = GST_BUFFER_TIMESTAMP (buffer);
+
   /* As the passed start and stop is equal, we shouldn't need to care about out of segment at all,
    * the subtitle data for the PTS is completely out of interest to us. A given display set must
    * carry the same PTS value. */
diff --git a/gst/dvbsuboverlay/gstdvbsuboverlay.h b/gst/dvbsuboverlay/gstdvbsuboverlay.h
index 012c728eb..2e30b4e3a 100644
--- a/gst/dvbsuboverlay/gstdvbsuboverlay.h
+++ b/gst/dvbsuboverlay/gstdvbsuboverlay.h
@@ -45,6 +45,7 @@ struct _GstDVBSubOverlay
   /* properties */
   gboolean enable;
   gint max_page_timeout;
+  gboolean force_end;
 
   /* <private> */
   GstSegment video_segment;
@@ -61,6 +62,11 @@ struct _GstDVBSubOverlay
 
   GMutex *dvbsub_mutex; /* protects the queue and the DvbSub instance */
   DvbSub *dvb_sub;
+
+  /* subtitle data submitted to dvb_sub but no sub received yet */
+  gboolean pending_sub;
+  /* last text pts */
+  GstClockTime last_text_pts;
 };
 
 struct _GstDVBSubOverlayClass