videorate: Only "close" the segment if it is discontinous

Otherwise, it will drop valid buffers on a simple segment update

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-base/-/merge_requests/767>

gst/videorate/gstvideorate.c

@@ -794,48 +794,14 @@ gst_video_rate_sink_event (GstBaseTransform * trans, GstEvent * event)
     {
       GstSegment segment;
       gint seqnum;
+      GstClockTime base_ts, next_ts;
+      gboolean reset_base_ts = FALSE;
 
       gst_event_copy_segment (event, &segment);
       if (segment.format != GST_FORMAT_TIME)
         goto format_error;
 
-      GST_DEBUG_OBJECT (videorate, "handle NEWSEGMENT");
+      GST_DEBUG_OBJECT (videorate, "handle SEGMENT event");
-
-      /* close up the previous segment, if appropriate */
-      if (videorate->prevbuf) {
-        gint count = 0;
-        GstFlowReturn res;
-
-        res = GST_FLOW_OK;
-        /* fill up to the end of current segment,
-         * or only send out the stored buffer if there is no specific stop.
-         * regardless, prevent going loopy in strange cases */
-        while (res == GST_FLOW_OK && count <= MAGIC_LIMIT
-            && !videorate->drop_only
-            && ((videorate->segment.rate > 0.0
-                    && GST_CLOCK_TIME_IS_VALID (videorate->segment.stop)
-                    && GST_CLOCK_TIME_IS_VALID (videorate->next_ts)
-                    && videorate->next_ts - videorate->segment.base <
-                    videorate->segment.stop) || (videorate->segment.rate < 0.0
-                    && GST_CLOCK_TIME_IS_VALID (videorate->segment.start)
-                    && GST_CLOCK_TIME_IS_VALID (videorate->next_ts)
-                    && videorate->next_ts - videorate->segment.base >=
-                    videorate->segment.start)
-                || count < 1)) {
-          res =
-              gst_video_rate_flush_prev (videorate, count > 0,
-              GST_CLOCK_TIME_NONE);
-          count++;
-        }
-        if (count > 1) {
-          videorate->dup += count - 1;
-          if (!videorate->silent)
-            gst_video_rate_notify_duplicate (videorate);
-        }
-        /* clean up for the new one; _chain will resume from the new start */
-        gst_video_rate_swap_prev (videorate, NULL, 0);
-      }
-
 
       /* We just want to update the accumulated stream_time  */
 
@@ -845,20 +811,68 @@ gst_video_rate_sink_event (GstBaseTransform * trans, GstEvent * event)
         segment.stop = (gint64) (segment.stop / videorate->rate);
       segment.time = (gint64) (segment.time / videorate->rate);
 
-      videorate->base_ts = gst_segment_position_from_running_time (&segment,
+      base_ts = gst_segment_position_from_running_time (&segment,
           GST_FORMAT_TIME,
           gst_segment_to_running_time (&videorate->segment, GST_FORMAT_TIME,
               videorate->base_ts));
-      videorate->next_ts = gst_segment_position_from_running_time (&segment,
+      next_ts = gst_segment_position_from_running_time (&segment,
           GST_FORMAT_TIME,
           gst_segment_to_running_time (&videorate->segment, GST_FORMAT_TIME,
               videorate->next_ts));
 
+      /* Reset if the segment is discontinuous */
+      if (next_ts == GST_CLOCK_TIME_NONE) {
+        reset_base_ts = TRUE;
+
+        /* close up the previous segment, if appropriate */
+        if (videorate->prevbuf) {
+          gint count = 0;
+          GstFlowReturn res;
+
+          res = GST_FLOW_OK;
+          /* fill up to the end of current segment,
+           * or only send out the stored buffer if there is no specific stop.
+           * regardless, prevent going loopy in strange cases */
+          while (res == GST_FLOW_OK && count <= MAGIC_LIMIT
+              && !videorate->drop_only
+              && ((videorate->segment.rate > 0.0
+                      && GST_CLOCK_TIME_IS_VALID (videorate->segment.stop)
+                      && GST_CLOCK_TIME_IS_VALID (videorate->next_ts)
+                      && videorate->next_ts - videorate->segment.base <
+                      videorate->segment.stop) || (videorate->segment.rate < 0.0
+                      && GST_CLOCK_TIME_IS_VALID (videorate->segment.start)
+                      && GST_CLOCK_TIME_IS_VALID (videorate->next_ts)
+                      && videorate->next_ts - videorate->segment.base >=
+                      videorate->segment.start)
+                  || count < 1)) {
+            res =
+                gst_video_rate_flush_prev (videorate, count > 0,
+                GST_CLOCK_TIME_NONE);
+            count++;
+          }
+          if (count > 1) {
+            videorate->dup += count - 1;
+            if (!videorate->silent)
+              gst_video_rate_notify_duplicate (videorate);
+          }
+          /* clean up for the new one; _chain will resume from the new start */
+          gst_video_rate_swap_prev (videorate, NULL, 0);
+        }
+      } else if (base_ts == GST_CLOCK_TIME_NONE) {
+        reset_base_ts = TRUE;
+      }
+
+      if (reset_base_ts) {
+        base_ts = 0;
+        videorate->out_frame_count = 0;
+      }
+      videorate->next_ts = next_ts;
+      videorate->base_ts = base_ts;
+
       gst_segment_copy_into (&segment, &videorate->segment);
       GST_DEBUG_OBJECT (videorate, "updated segment: %" GST_SEGMENT_FORMAT,
           &videorate->segment);
 
-
       seqnum = gst_event_get_seqnum (event);
       gst_event_unref (event);
       event = gst_event_new_segment (&segment);

tests/check/elements/videorate.c

@@ -1645,12 +1645,17 @@ GST_START_TEST (test_segment_update)
     next_ts += GST_SECOND / 25;
   }
   gst_check_drop_buffers ();
+  fail_unless_equals_uint64 (next_ts, 1 * GST_SECOND + (GST_SECOND / 25));
 
   /* Send a pointless segment update, shouldn't change anything */
   gst_segment_init (&segment, GST_FORMAT_TIME);
   segment.position = 5 * GST_SECOND;
   fail_unless (gst_pad_push_event (mysrcpad, gst_event_new_segment (&segment)));
 
+  /* Shouldnt push anything, rest is same as above */
+  fail_unless_equals_int (g_list_length (buffers), 0);
+  assert_videorate_stats (videorate, "second", 2, 26, 0, 25);
+
   /* third buffer */
   third = gst_buffer_new_and_alloc (4);
   GST_BUFFER_TIMESTAMP (third) = 3 * GST_SECOND;
@@ -1671,6 +1676,7 @@ GST_START_TEST (test_segment_update)
 
     next_ts += GST_SECOND / 25;
   }
+  fail_unless_equals_uint64 (next_ts, (25 + 25 + 13) * (GST_SECOND / 25));
 
   /* cleanup */
   gst_buffer_unref (first);