rtpdtmfsrc: Put the inter digit interval at the end, not at the start

The reason is to let rtpdtmfmux drop buffers during the inter digit interval,
this way, there will be more silence around the DTMF tones so IVFs will have
a better chance recognizing them.

diff --git a/gst/dtmf/gstrtpdtmfsrc.c b/gst/dtmf/gstrtpdtmfsrc.c
index 8d37f31..19acc6c 100644 (file)
--- a/gst/dtmf/gstrtpdtmfsrc.c
+++ b/gst/dtmf/gstrtpdtmfsrc.c
@@ -514,8 +514,7 @@ gst_rtp_dtmf_prepare_timestamps (GstRTPDTMFSrc * dtmfsrc)
     if (clock == NULL)
       return FALSE;
 
-    dtmfsrc->timestamp = gst_clock_get_time (clock)
-        + (MIN_INTER_DIGIT_INTERVAL * GST_MSECOND)
+    dtmfsrc->start_timestamp = gst_clock_get_time (clock)
         - gst_element_get_base_time (GST_ELEMENT (dtmfsrc));
     dtmfsrc->start_timestamp = dtmfsrc->timestamp;
     gst_object_unref (clock);
@@ -591,7 +590,6 @@ gst_rtp_dtmf_prepare_buffer_data (GstRTPDTMFSrc * dtmfsrc, GstBuffer * buf)
     GST_BUFFER_DURATION (buf) = dtmfsrc->ptime * GST_MSECOND;
   GST_BUFFER_TIMESTAMP (buf) = dtmfsrc->timestamp;
 
-  dtmfsrc->timestamp += GST_BUFFER_DURATION (buf);
 
   payload = (GstRTPDTMFPayload *) gst_rtp_buffer_get_payload (buf);
 
@@ -606,6 +604,18 @@ gst_rtp_dtmf_prepare_buffer_data (GstRTPDTMFSrc * dtmfsrc, GstBuffer * buf)
   if (dtmfsrc->redundancy_count == 0)
     dtmfsrc->payload->duration += dtmfsrc->ptime * dtmfsrc->clock_rate / 1000;
 
+  if (dtmfsrc->redundancy_count == 0 && dtmfsrc->last_packet) {
+    GstClockTime inter_digit_interval = MIN_INTER_DIGIT_INTERVAL;
+
+    if (inter_digit_interval % dtmfsrc->ptime != 0)
+      inter_digit_interval += dtmfsrc->ptime -
+          (MIN_INTER_DIGIT_INTERVAL % dtmfsrc->ptime);
+
+    GST_BUFFER_DURATION (buf) += inter_digit_interval * GST_MSECOND;
+  }
+
+  if (GST_CLOCK_TIME_IS_VALID (dtmfsrc->timestamp))
+    dtmfsrc->timestamp += GST_BUFFER_DURATION (buf);
 }
 
 static GstBuffer *