facedetect: Post an useful message

Add a message to be post when faces are found on a frame that
contains all faces on a single message and also has
timestamp/running/segment times for that buffer so it
can be identified.

This message is called 'facedetect' and has a 'faces' list
of structures with all faces.

The old 'face' message is still posted for each face found, but
it is not really useful as it doesn't have any reference to the
buffer that generated it.

diff --git a/ext/opencv/facedetect/gstfacedetect.c b/ext/opencv/facedetect/gstfacedetect.c
index 1ad96df..8c80483 100644 (file)
--- a/ext/opencv/facedetect/gstfacedetect.c
+++ b/ext/opencv/facedetect/gstfacedetect.c
@@ -262,6 +262,28 @@ gst_facedetect_set_caps (GstOpencvVideoFilter * transform, gint in_width,
   return TRUE;
 }
 
+static GstMessage *
+gst_facedetect_message_new (Gstfacedetect * filter, GstBuffer * buf)
+{
+  GstBaseTransform *trans = GST_BASE_TRANSFORM_CAST (filter);
+  GstStructure *s;
+  GstClockTime running_time, stream_time;
+
+  running_time = gst_segment_to_running_time (&trans->segment, GST_FORMAT_TIME,
+      GST_BUFFER_TIMESTAMP (buf));
+  stream_time = gst_segment_to_stream_time (&trans->segment, GST_FORMAT_TIME,
+      GST_BUFFER_TIMESTAMP (buf));
+
+  s = gst_structure_new ("facedetect",
+      "timestamp", G_TYPE_UINT64, GST_BUFFER_TIMESTAMP (buf),
+      "stream-time", G_TYPE_UINT64, stream_time,
+      "running-time", G_TYPE_UINT64, running_time,
+      "duration", G_TYPE_UINT64, GST_BUFFER_DURATION (buf), NULL);
+
+  return gst_message_new_element (GST_OBJECT (filter), s);
+}
+
+
 /* chain function
  * this function does the actual processing
  */
@@ -279,12 +301,21 @@ gst_facedetect_transform_ip (GstOpencvVideoFilter * base, GstBuffer * buf,
   cvClearMemStorage (filter->cvStorage);
 
   if (filter->cvCascade) {
+    GstMessage *msg = NULL;
+    GValue facelist = { 0 };
+
     faces =
         cvHaarDetectObjects (filter->cvGray, filter->cvCascade,
         filter->cvStorage, 1.1, 2, 0, cvSize (30, 30));
 
+    if (faces && faces->total > 0) {
+      msg = gst_facedetect_message_new (filter, buf);
+      g_value_init (&facelist, GST_TYPE_LIST);
+    }
+
     for (i = 0; i < (faces ? faces->total : 0); i++) {
       CvRect *r = (CvRect *) cvGetSeqElem (faces, i);
+      GValue value = { 0 };
 
       GstStructure *s = gst_structure_new ("face",
           "x", G_TYPE_UINT, r->x,
@@ -293,6 +324,12 @@ gst_facedetect_transform_ip (GstOpencvVideoFilter * base, GstBuffer * buf,
           "height", G_TYPE_UINT, r->height, NULL);
 
       GstMessage *m = gst_message_new_element (GST_OBJECT (filter), s);
+
+      g_value_init (&value, GST_TYPE_STRUCTURE);
+      gst_value_set_structure (&value, s);
+      gst_value_list_append_value (&facelist, &value);
+      g_value_unset (&value);
+
       gst_element_post_message (GST_ELEMENT (filter), m);
 
       if (filter->display) {
@@ -311,6 +348,11 @@ gst_facedetect_transform_ip (GstOpencvVideoFilter * base, GstBuffer * buf,
 
     }
 
+    if (msg) {
+      gst_structure_set_value (msg->structure, "faces", &facelist);
+      g_value_unset (&facelist);
+      gst_element_post_message (GST_ELEMENT (filter), msg);
+    }
   }
 
   return GST_FLOW_OK;