pcapparse: optionally output relative timestamps, possibly shifted by offset

That is, output timestamps can then either be the absolute capture time,
or the relative capture time (w.r.t. to first output buffer), or the relative
capture time incremented by some offset.

2 files changed, 26 insertions, 0 deletions

diff --git a/gst/pcapparse/gstpcapparse.c b/gst/pcapparse/gstpcapparse.c
index c559a5855..69c22f6ae 100644
--- a/gst/pcapparse/gstpcapparse.c
+++ b/gst/pcapparse/gstpcapparse.c
@@ -64,6 +64,7 @@ enum
   PROP_SRC_PORT,
   PROP_DST_PORT,
   PROP_CAPS,
+  PROP_OFFSET,
   PROP_LAST
 };
 
@@ -143,6 +144,11 @@ gst_pcap_parse_class_init (GstPcapParseClass * klass)
           "The caps of the source pad", GST_TYPE_CAPS,
           G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
 
+  g_object_class_install_property (gobject_class, PROP_OFFSET,
+      g_param_spec_int64 ("offset", "Offset",
+          "Relative timestamp offset (ns) to apply (-1 = use absolute packet time)",
+          -1, G_MAXINT64, -1, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+
   GST_DEBUG_CATEGORY_INIT (gst_pcap_parse_debug, "pcapparse", 0, "pcap parser");
 }
 
@@ -165,6 +171,7 @@ gst_pcap_parse_init (GstPcapParse * self, GstPcapParseClass * gclass)
   self->dst_ip = -1;
   self->src_port = -1;
   self->dst_port = -1;
+  self->offset = -1;
 
   self->adapter = gst_adapter_new ();
 
@@ -234,6 +241,10 @@ gst_pcap_parse_get_property (GObject * object, guint prop_id,
       gst_value_set_caps (value, self->caps);
       break;
 
+    case PROP_OFFSET:
+      g_value_set_int64 (value, self->offset);
+      break;
+
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
@@ -283,6 +294,11 @@ gst_pcap_parse_set_property (GObject * object, guint prop_id,
       gst_pad_set_caps (self->src_pad, new_caps);
       break;
     }
+
+    case PROP_OFFSET:
+      self->offset = g_value_get_int64 (value);
+      break;
+
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
@@ -297,6 +313,7 @@ gst_pcap_parse_reset (GstPcapParse * self)
   self->cur_packet_size = -1;
   self->buffer_offset = 0;
   self->cur_ts = GST_CLOCK_TIME_NONE;
+  self->base_ts = GST_CLOCK_TIME_NONE;
   self->newsegment_sent = FALSE;
 
   gst_adapter_clear (self->adapter);
@@ -461,6 +478,13 @@ gst_pcap_parse_chain (GstPad * pad, GstBuffer * buffer)
 
             if (ret == GST_FLOW_OK) {
 
+              if (GST_CLOCK_TIME_IS_VALID (self->cur_ts)) {
+                if (!GST_CLOCK_TIME_IS_VALID (self->base_ts))
+                  self->base_ts = self->cur_ts;
+                if (self->offset >= 0)
+                  self->cur_ts -= self->base_ts + self->offset;
+              }
+
               memcpy (GST_BUFFER_DATA (out_buf), payload_data, payload_size);
               GST_BUFFER_TIMESTAMP (out_buf) = self->cur_ts;
 
diff --git a/gst/pcapparse/gstpcapparse.h b/gst/pcapparse/gstpcapparse.h
index 35742394e..49e432c77 100644
--- a/gst/pcapparse/gstpcapparse.h
+++ b/gst/pcapparse/gstpcapparse.h
@@ -71,6 +71,7 @@ struct _GstPcapParse
   gint32 src_port;
   gint32 dst_port;
   GstCaps *caps;
+  gint64 offset;
 
   /* state */
   GstAdapter * adapter;
@@ -78,6 +79,7 @@ struct _GstPcapParse
   gboolean swap_endian;
   gint64 cur_packet_size;
   GstClockTime cur_ts;
+  GstClockTime base_ts;
   GstPcapParseLinktype linktype;
 
   gboolean newsegment_sent;