ext/theora/: Mark discontinuities of > 3/4 of a frame, reinit encoder.

Original commit message from CVS:
* ext/theora/gsttheoraenc.h:
* ext/theora/theoraenc.c: (gst_theora_enc_init),
(theora_enc_reset), (theora_enc_clear), (theora_enc_sink_setcaps),
(theora_buffer_from_packet), (theora_enc_is_discontinuous),
(theora_enc_chain), (theora_enc_change_state):
Mark discontinuities of > 3/4 of a frame, reinit encoder.

* tests/check/pipelines/theoraenc.c: (check_buffer_granulepos),
(GST_START_TEST), (theoraenc_suite):
Enable discontinuity test, fix it.

ChangeLog

@@ -1,3 +1,16 @@
+2006-11-22  Michael Smith  <msmith@fluendo.com>
+
+	* ext/theora/gsttheoraenc.h:
+	* ext/theora/theoraenc.c: (gst_theora_enc_init),
+	(theora_enc_reset), (theora_enc_clear), (theora_enc_sink_setcaps),
+	(theora_buffer_from_packet), (theora_enc_is_discontinuous),
+	(theora_enc_chain), (theora_enc_change_state):
+	  Mark discontinuities of > 3/4 of a frame, reinit encoder.
+
+	* tests/check/pipelines/theoraenc.c: (check_buffer_granulepos),
+	(GST_START_TEST), (theoraenc_suite):
+	  Enable discontinuity test, fix it.
+
 2006-11-21  Tim-Philipp Müller  <tim at centricular dot net>
 
 	* ext/pango/gsttextoverlay.c: (gst_text_overlay_init),

ext/theora/gsttheoraenc.h

@@ -93,6 +93,9 @@ struct _GstTheoraEnc
   gint fps_n, fps_d;
   GstClockTime next_ts;
 
+  GstClockTime expected_ts;
+  gboolean next_discont;
+
   guint packetno;
   guint64 bytes_out;
   guint64 granulepos_offset;

ext/theora/theoraenc.c

@@ -292,6 +292,7 @@ gst_theora_enc_init (GstTheoraEnc * enc, GstTheoraEncClass * g_class)
   GST_DEBUG_OBJECT (enc,
       "keyframe_frequency_force is %d, granule shift is %d",
       enc->info.keyframe_frequency_force, enc->granule_shift);
+  enc->expected_ts = GST_CLOCK_TIME_NONE;
 }
 
 static void
@@ -307,6 +308,26 @@ theora_enc_finalize (GObject * object)
   G_OBJECT_CLASS (parent_class)->finalize (object);
 }
 
+static void
+theora_enc_reset (GstTheoraEnc * enc)
+{
+  theora_clear (&enc->state);
+  theora_encode_init (&enc->state, &enc->info);
+}
+
+static void
+theora_enc_clear (GstTheoraEnc * enc)
+{
+  enc->packetno = 0;
+  enc->bytes_out = 0;
+  enc->granulepos_offset = 0;
+  enc->timestamp_offset = 0;
+
+  enc->next_ts = GST_CLOCK_TIME_NONE;
+  enc->next_discont = FALSE;
+  enc->expected_ts = GST_CLOCK_TIME_NONE;
+}
+
 static gboolean
 theora_enc_sink_setcaps (GstPad * pad, GstCaps * caps)
 {
@@ -374,7 +395,7 @@ theora_enc_sink_setcaps (GstPad * pad, GstCaps * caps)
       "keyframe_frequency_force is %d, granule shift is %d",
       enc->info.keyframe_frequency_force, enc->granule_shift);
 
-  theora_encode_init (&enc->state, &enc->info);
+  theora_enc_reset (enc);
 
   gst_object_unref (enc);
 
@@ -418,6 +439,11 @@ theora_buffer_from_packet (GstTheoraEnc * enc, ogg_packet * packet,
   GST_BUFFER_TIMESTAMP (buf) = timestamp + enc->timestamp_offset;
   GST_BUFFER_DURATION (buf) = duration;
 
+  if (enc->next_discont) {
+    GST_BUFFER_FLAG_SET (buf, GST_BUFFER_FLAG_DISCONT);
+    enc->next_discont = FALSE;
+  }
+
   /* the second most significant bit of the first data byte is cleared
    * for keyframes */
   if ((packet->packet[0] & 0x40) == 0) {
@@ -543,6 +569,34 @@ theora_enc_sink_event (GstPad * pad, GstEvent * event)
   return res;
 }
 
+static gboolean
+theora_enc_is_discontinuous (GstTheoraEnc * enc, GstBuffer * buffer)
+{
+  GstClockTime ts = GST_BUFFER_TIMESTAMP (buffer);
+  GstClockTimeDiff max_diff;
+
+  /* Allow 3/4 a frame off */
+  max_diff = (enc->info.fps_denominator * GST_SECOND * 3) /
+      (enc->info.fps_numerator * 4);
+
+  if (ts != GST_CLOCK_TIME_NONE && enc->expected_ts != GST_CLOCK_TIME_NONE) {
+    if ((GstClockTimeDiff) (ts - enc->expected_ts) > max_diff) {
+      GST_DEBUG_OBJECT (enc, "Incoming TS %" GST_TIME_FORMAT
+          " exceeds expected value %" GST_TIME_FORMAT
+          " by too much, marking discontinuity",
+          GST_TIME_ARGS (ts), GST_TIME_ARGS (enc->expected_ts));
+      return TRUE;
+    }
+  }
+
+  if (GST_CLOCK_TIME_IS_VALID (GST_BUFFER_DURATION (buffer)))
+    enc->expected_ts = ts + GST_BUFFER_DURATION (buffer);
+  else
+    enc->expected_ts = GST_CLOCK_TIME_NONE;
+
+  return FALSE;
+}
+
 static GstFlowReturn
 theora_enc_chain (GstPad * pad, GstBuffer * buffer)
 {
@@ -784,6 +838,16 @@ theora_enc_chain (GstPad * pad, GstBuffer * buffer)
       buffer = newbuf;
     }
 
+    if (theora_enc_is_discontinuous (enc, buffer)) {
+      theora_enc_reset (enc);
+      enc->granulepos_offset =
+          gst_util_uint64_scale (GST_BUFFER_TIMESTAMP (buffer), enc->fps_n,
+          GST_SECOND * enc->fps_d);
+      enc->timestamp_offset = GST_BUFFER_TIMESTAMP (buffer);
+      enc->next_ts = 0;
+      enc->next_discont = TRUE;
+    }
+
     res = theora_encode_YUVin (&enc->state, &yuv);
 
     ret = GST_FLOW_OK;
@@ -863,6 +927,8 @@ theora_enc_change_state (GstElement * element, GstStateChange transition)
       theora_clear (&enc->state);
       theora_comment_clear (&enc->comment);
       theora_info_clear (&enc->info);
+
+      theora_enc_clear (enc);
       break;
     case GST_STATE_CHANGE_READY_TO_NULL:
       break;

tests/check/pipelines/theoraenc.c

@@ -62,6 +62,7 @@ static void
 check_buffer_granulepos (GstBuffer * buffer, gint64 granulepos)
 {
   GstClockTime clocktime;
+  int framecount;
 
   fail_unless (GST_BUFFER_OFFSET_END (buffer) == granulepos,
       "expected granulepos %" G_GUINT64_FORMAT
@@ -70,8 +71,10 @@ check_buffer_granulepos (GstBuffer * buffer, gint64 granulepos)
 
   /* contrary to what we record as TIMESTAMP, we can use OFFSET to check
    * the granulepos correctly here */
-  clocktime = gst_util_uint64_scale (GST_BUFFER_OFFSET_END (buffer), GST_SECOND,
+  framecount = GST_BUFFER_OFFSET_END (buffer);
-      FRAMERATE);
+  framecount = granulepos >> GRANULEPOS_SHIFT;
+  framecount += granulepos & ((1 << GRANULEPOS_SHIFT) - 1);
+  clocktime = gst_util_uint64_scale (framecount, GST_SECOND, FRAMERATE);
 
   fail_unless (clocktime == GST_BUFFER_OFFSET (buffer),
       "expected OFFSET set to clocktime %" GST_TIME_FORMAT
@@ -287,7 +290,6 @@ GST_START_TEST (test_continuity)
 
 GST_END_TEST;
 
-#if 0
 static gboolean
 drop_second_data_buffer (GstPad * droppad, GstBuffer * buffer, gpointer unused)
 {
@@ -301,7 +303,6 @@ GST_START_TEST (test_discontinuity)
   gchar *pipe_str;
   GstBuffer *buffer;
   GError *error = NULL;
-  GstClockTime timestamp;
   guint drop_id;
 
   pipe_str = g_strdup_printf ("videotestsrc"
@@ -336,7 +337,8 @@ GST_START_TEST (test_discontinuity)
     gst_object_unref (sink);
   }
 
-  drop_id = gst_pad_add_buffer_probe (droppad, drop_second_data_buffer, NULL);
+  drop_id = gst_pad_add_buffer_probe (droppad,
+      G_CALLBACK (drop_second_data_buffer), NULL);
   gst_buffer_straw_start_pipeline (bin, pad);
 
   /* header packets should have timestamp == NONE, granulepos 0 */
@@ -374,7 +376,9 @@ GST_START_TEST (test_discontinuity)
     /* check discontinuity with the next buffer */
     buffer = gst_buffer_straw_get_buffer (bin, pad);
     check_buffer_duration (buffer, GST_SECOND / 10);
-    check_buffer_granulepos (buffer, 2);
+    /* After a discont, we'll always get a keyframe, so this one should be 
+     * 2<<GRANULEPOS_SHIFT */
+    check_buffer_granulepos (buffer, 2 << GRANULEPOS_SHIFT);
     check_buffer_is_header (buffer, FALSE);
     fail_unless (GST_BUFFER_IS_DISCONT (buffer),
         "expected discontinuous buffer yo");
@@ -390,7 +394,6 @@ GST_START_TEST (test_discontinuity)
 }
 
 GST_END_TEST;
-#endif /* 0 */
 
 #endif /* #ifndef GST_DISABLE_PARSE */
 
@@ -405,9 +408,7 @@ theoraenc_suite (void)
 #ifndef GST_DISABLE_PARSE
   tcase_add_test (tc_chain, test_granulepos_offset);
   tcase_add_test (tc_chain, test_continuity);
-#if 0
   tcase_add_test (tc_chain, test_discontinuity);
-#endif /* 0 */
 #endif
 
   return s;