timecodestamper: Clean up old LTC timecodes on LTC discontinuity

We might have some old timecodes that are in the future now and have to
drop those to make sure that our queue is correctly ordered and we don't
have multiple timecodes for the same running time.

diff --git a/gst/timecode/gsttimecodestamper.c b/gst/timecode/gsttimecodestamper.c
index f122e29..900c23f 100644 (file)
--- a/gst/timecode/gsttimecodestamper.c
+++ b/gst/timecode/gsttimecodestamper.c
@@ -1659,8 +1659,8 @@ gst_timecodestamper_ltcpad_chain (GstPad * pad,
 
   if (!timecodestamper->stream_align) {
     timecodestamper->stream_align =
-        gst_audio_stream_align_new (timecodestamper->ainfo.rate, GST_SECOND,
-        40 * GST_MSECOND);
+        gst_audio_stream_align_new (timecodestamper->ainfo.rate,
+        500 * GST_MSECOND, 20 * GST_MSECOND);
   }
 
   discont =
@@ -1669,8 +1669,11 @@ gst_timecodestamper_ltcpad_chain (GstPad * pad,
       &timestamp, &duration, NULL);
 
   if (discont) {
-    if (timecodestamper->ltc_dec)
+    if (timecodestamper->ltc_dec) {
+      GST_WARNING_OBJECT (timecodestamper, "Got discont at %" GST_TIME_FORMAT,
+          GST_TIME_ARGS (timestamp));
       ltc_decoder_queue_flush (timecodestamper->ltc_dec);
+    }
     timecodestamper->ltc_total = 0;
   }
 
@@ -1750,8 +1753,26 @@ gst_timecodestamper_ltcpad_chain (GstPad * pad,
           0, 0, timecodestamper->ltc_daily_jam, 0,
           stc.hours, stc.mins, stc.secs, stc.frame, 0);
 
-      g_queue_push_tail (&timecodestamper->ltc_current_tcs,
-          g_steal_pointer (&ltc_tc));
+      /* If we have a discontinuity it might happen that we're getting
+       * timecodes that are in the past relative to timecodes we already have
+       * in our queue. We have to get rid of all the timecodes that are in the
+       * future now. */
+      if (discont) {
+        TimestampedTimecode *tmp;
+
+        while ((tmp = g_queue_peek_tail (&timecodestamper->ltc_current_tcs)) &&
+            tmp->running_time >= ltc_running_time) {
+          gst_video_time_code_clear (&tmp->timecode);
+          g_free (tmp);
+          g_queue_pop_tail (&timecodestamper->ltc_current_tcs);
+        }
+
+        g_queue_push_tail (&timecodestamper->ltc_current_tcs,
+            g_steal_pointer (&ltc_tc));
+      } else {
+        g_queue_push_tail (&timecodestamper->ltc_current_tcs,
+            g_steal_pointer (&ltc_tc));
+      }
     }
   }