From ecf6ed8fc1de440f1af78779e6338ed69e988b87 Mon Sep 17 00:00:00 2001
From: Wim Taymans <wim.taymans@collabora.co.uk>
Date: Tue, 6 Oct 2009 13:33:15 +0200
Subject: [PATCH] jitterbuffer: keep track of offset

Keep track of an outgoing offset that we add to each outgoing buffer to
compensate for PAUSE when buffering.
Adjust the offset when activating.
---
 gst/rtpmanager/gstrtpjitterbuffer.c | 24 ++++++++++++++++++------
 gst/rtpmanager/gstrtpjitterbuffer.h |  2 +-
 2 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/gst/rtpmanager/gstrtpjitterbuffer.c b/gst/rtpmanager/gstrtpjitterbuffer.c
index 69dbdc8b17..7fb1e73310 100644
--- a/gst/rtpmanager/gstrtpjitterbuffer.c
+++ b/gst/rtpmanager/gstrtpjitterbuffer.c
@@ -136,6 +136,7 @@ struct _GstRtpJitterBufferPrivate
   gboolean waiting;
   gboolean discont;
   gboolean active;
+  guint64 out_offset;
 
   /* properties */
   guint latency_ms;
@@ -648,17 +649,26 @@ gst_rtp_jitter_buffer_clear_pt_map (GstRtpJitterBuffer * jitterbuffer)
 
 static void
 gst_rtp_jitter_buffer_set_active (GstRtpJitterBuffer * jbuf, gboolean active,
-    guint64 base_time)
+    guint64 elapsed)
 {
   GstRtpJitterBufferPrivate *priv;
 
   priv = jbuf->priv;
 
   JBUF_LOCK (priv);
-  GST_DEBUG_OBJECT (jbuf, "setting active %d at time %" GST_TIME_FORMAT, active,
-      GST_TIME_ARGS (base_time));
-  priv->active = active;
-  JBUF_SIGNAL (priv);
+  GST_DEBUG_OBJECT (jbuf, "setting active %d with elapsed %" GST_TIME_FORMAT,
+      active, GST_TIME_ARGS (elapsed));
+
+  if (active != priv->active) {
+    /* add the amount of time spent in paused to the output offset. All
+     * outgoing buffers will have this offset applied to their timestamps in
+     * order to make them arrive in time in the sink. */
+    priv->out_offset += elapsed;
+    GST_DEBUG_OBJECT (jbuf, "out offset %" GST_TIME_FORMAT,
+        GST_TIME_ARGS (priv->out_offset));
+    priv->active = active;
+    JBUF_SIGNAL (priv);
+  }
   JBUF_UNLOCK (priv);
 }
 
@@ -1392,8 +1402,10 @@ apply_offset (GstRtpJitterBuffer * jitterbuffer, GstClockTime timestamp)
   if (timestamp == -1)
     return -1;
 
-  /* apply the timestamp offset */
+  /* apply the timestamp offset, this is used for inter stream sync */
   timestamp += priv->ts_offset;
+  /* add the offset, this is used when buffering */
+  timestamp += priv->out_offset;
 
   return timestamp;
 }
diff --git a/gst/rtpmanager/gstrtpjitterbuffer.h b/gst/rtpmanager/gstrtpjitterbuffer.h
index 68604a2b68..b4f2330bf8 100644
--- a/gst/rtpmanager/gstrtpjitterbuffer.h
+++ b/gst/rtpmanager/gstrtpjitterbuffer.h
@@ -77,7 +77,7 @@ struct _GstRtpJitterBufferClass
   /* actions */
   void     (*clear_pt_map)   (GstRtpJitterBuffer *buffer);
 
-  void     (*set_active)     (GstRtpJitterBuffer *buffer, gboolean active, guint64 base_time);
+  void     (*set_active)     (GstRtpJitterBuffer *buffer, gboolean active, guint64 elapsed);
 
   /*< private > */
   gpointer _gst_reserved[GST_PADDING];