matroskamux: reduce newsegment event spam and set discont flag where needed

Only send newsegment events with new positions downstream when actually
needed, instead of sending multiple newsegment events with new seek
positions in a row. Also set the discont flag on buffers after a
discontinuity.

gst/matroska/ebml-write.c

@@ -41,7 +41,6 @@ GST_BOILERPLATE_FULL (GstEbmlWrite, gst_ebml_write, GstObject, GST_TYPE_OBJECT,
 
 static void gst_ebml_write_finalize (GObject * object);
 
-
 static void
 gst_ebml_write_base_init (gpointer g_class)
 {
@@ -60,6 +59,7 @@ gst_ebml_write_init (GstEbmlWrite * ebml, GstEbmlWriteClass * klass)
 {
   ebml->srcpad = NULL;
   ebml->pos = 0;
+  ebml->last_pos = G_MAXUINT64; /* force newsegment event */
 
   ebml->cache = NULL;
   ebml->streamheader = NULL;
@@ -89,6 +89,7 @@ gst_ebml_write_finalize (GObject * object)
     gst_caps_unref (ebml->caps);
     ebml->caps = NULL;
   }
+
   GST_CALL_PARENT (G_OBJECT_CLASS, finalize, (object));
 }
 
@@ -126,6 +127,7 @@ void
 gst_ebml_write_reset (GstEbmlWrite * ebml)
 {
   ebml->pos = 0;
+  ebml->last_pos = G_MAXUINT64; /* force newsegment event */
 
   if (ebml->cache) {
     gst_byte_writer_free (ebml->cache);
@@ -133,7 +135,6 @@ gst_ebml_write_reset (GstEbmlWrite * ebml)
   }
   ebml->last_write_result = GST_FLOW_OK;
   ebml->timestamp = GST_CLOCK_TIME_NONE;
-  ebml->need_newsegment = TRUE;
 }
 
 
@@ -204,6 +205,22 @@ gst_ebml_write_set_cache (GstEbmlWrite * ebml, guint size)
   ebml->cache_pos = ebml->pos;
 }
 
+static gboolean
+gst_ebml_writer_send_new_segment_event (GstEbmlWrite * ebml, guint64 new_pos)
+{
+  gboolean res;
+
+  GST_INFO ("seeking to %" G_GUINT64_FORMAT, new_pos);
+
+  res = gst_pad_push_event (ebml->srcpad,
+      gst_event_new_new_segment (FALSE, 1.0, GST_FORMAT_BYTES, new_pos, -1, 0));
+
+  if (!res)
+    GST_WARNING ("seek to %" G_GUINT64_FORMAT "failed", new_pos);
+
+  return res;
+}
+
 /**
  * gst_ebml_write_flush_cache:
  * @ebml: a #GstEbmlWrite.
@@ -225,11 +242,9 @@ gst_ebml_write_flush_cache (GstEbmlWrite * ebml, gboolean is_keyframe)
   GST_BUFFER_OFFSET (buffer) = ebml->pos - GST_BUFFER_SIZE (buffer);
   GST_BUFFER_OFFSET_END (buffer) = ebml->pos;
   if (ebml->last_write_result == GST_FLOW_OK) {
-    if (ebml->need_newsegment) {
+    if (GST_BUFFER_OFFSET (buffer) != ebml->last_pos) {
-      GstEvent *ev;
+      gst_ebml_writer_send_new_segment_event (ebml, GST_BUFFER_OFFSET (buffer));
-      ev = gst_event_new_new_segment (FALSE, 1.0, GST_FORMAT_BYTES, 0, -1, 0);
+      GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_DISCONT);
-      if (gst_pad_push_event (ebml->srcpad, ev))
-        ebml->need_newsegment = FALSE;
     }
     if (ebml->writing_streamheader) {
       GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_IN_CAPS);
@@ -237,6 +252,7 @@ gst_ebml_write_flush_cache (GstEbmlWrite * ebml, gboolean is_keyframe)
     if (!is_keyframe) {
       GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_DELTA_UNIT);
     }
+    ebml->last_pos = ebml->pos;
     ebml->last_write_result = gst_pad_push (ebml->srcpad, buffer);
   } else {
     gst_buffer_unref (buffer);
@@ -394,13 +410,6 @@ gst_ebml_write_element_push (GstEbmlWrite * ebml, GstBuffer * buf)
   }
 
   if (ebml->last_write_result == GST_FLOW_OK) {
-    if (ebml->need_newsegment) {
-      GstEvent *ev;
-
-      ev = gst_event_new_new_segment (FALSE, 1.0, GST_FORMAT_BYTES, 0, -1, 0);
-      if (gst_pad_push_event (ebml->srcpad, ev))
-        ebml->need_newsegment = FALSE;
-    }
     buf = gst_buffer_make_metadata_writable (buf);
     gst_buffer_set_caps (buf, ebml->caps);
     GST_BUFFER_OFFSET (buf) = ebml->pos - GST_BUFFER_SIZE (buf);
@@ -409,6 +418,12 @@ gst_ebml_write_element_push (GstEbmlWrite * ebml, GstBuffer * buf)
       GST_BUFFER_FLAG_SET (buf, GST_BUFFER_FLAG_IN_CAPS);
     }
     GST_BUFFER_FLAG_SET (buf, GST_BUFFER_FLAG_DELTA_UNIT);
+
+    if (GST_BUFFER_OFFSET (buf) != ebml->last_pos) {
+      gst_ebml_writer_send_new_segment_event (ebml, GST_BUFFER_OFFSET (buf));
+      GST_BUFFER_FLAG_SET (buf, GST_BUFFER_FLAG_DISCONT);
+    }
+    ebml->last_pos = ebml->pos;
     ebml->last_write_result = gst_pad_push (ebml->srcpad, buf);
   } else {
     gst_buffer_unref (buf);
@@ -426,8 +441,6 @@ gst_ebml_write_element_push (GstEbmlWrite * ebml, GstBuffer * buf)
 void
 gst_ebml_write_seek (GstEbmlWrite * ebml, guint64 pos)
 {
-  GstEvent *event;
-
   if (ebml->writing_streamheader) {
     GST_DEBUG ("wanting to seek to pos %" G_GUINT64_FORMAT, pos);
     if (pos >= ebml->streamheader_pos &&
@@ -447,6 +460,7 @@ gst_ebml_write_seek (GstEbmlWrite * ebml, guint64 pos)
     /* within bounds? */
     if (pos >= ebml->cache_pos &&
         pos <= ebml->cache_pos + ebml->cache->parent.size) {
+      GST_DEBUG ("seeking in cache to %" G_GUINT64_FORMAT, pos);
       ebml->pos = pos;
       gst_byte_writer_set_pos (ebml->cache, ebml->pos - ebml->cache_pos);
       return;
@@ -456,13 +470,7 @@ gst_ebml_write_seek (GstEbmlWrite * ebml, guint64 pos)
     }
   }
 
-  event = gst_event_new_new_segment (FALSE, 1.0, GST_FORMAT_BYTES, pos, -1, 0);
+  GST_INFO ("scheduling seek to %" G_GUINT64_FORMAT, pos);
-  if (gst_pad_push_event (ebml->srcpad, event)) {
-    GST_DEBUG ("Seek'd to offset %" G_GUINT64_FORMAT " from %" G_GUINT64_FORMAT,
-        pos, ebml->pos);
-  } else {
-    GST_WARNING ("Seek to offset %" G_GUINT64_FORMAT " failed", pos);
-  }
   ebml->pos = pos;
 }
 

gst/matroska/ebml-write.h

@@ -47,6 +47,7 @@ typedef struct _GstEbmlWrite {
 
   GstPad *srcpad;
   guint64 pos;
+  guint64 last_pos;
   GstClockTime timestamp;
 
   GstByteWriter *cache;
@@ -54,8 +55,6 @@ typedef struct _GstEbmlWrite {
 
   GstFlowReturn last_write_result;
 
-  gboolean need_newsegment;
-
   gboolean writing_streamheader;
   GstByteWriter *streamheader;
   guint64 streamheader_pos;