API: gst_base_src_query_latency(). Added method so that subclasses can easily get the latency values of the base sour...

Original commit message from CVS:
* docs/libs/gstreamer-libs-sections.txt:
* libs/gst/base/gstbasesrc.c: (gst_base_src_query_latency),
(gst_base_src_default_query), (gst_base_src_get_range):
* libs/gst/base/gstbasesrc.h:
API: gst_base_src_query_latency(). Added method so that subclasses can
easily get the latency values of the base source class.

ChangeLog

@@ -1,3 +1,12 @@
+2007-05-03  Wim Taymans  <wim@fluendo.com>
+
+	* docs/libs/gstreamer-libs-sections.txt:
+	* libs/gst/base/gstbasesrc.c: (gst_base_src_query_latency),
+	(gst_base_src_default_query), (gst_base_src_get_range):
+	* libs/gst/base/gstbasesrc.h:
+	API: gst_base_src_query_latency(). Added method so that subclasses can
+	easily get the latency values of the base source class.
+
 2007-05-02  Zaheer Abbas Merali  <<zaheerabbas at merali dot org>>
 
 	* tools/gst-inspect.c (print_implementation_info):

docs/libs/gstreamer-libs-sections.txt

@@ -154,6 +154,7 @@ gst_base_src_wait_playing
 gst_base_src_is_live
 gst_base_src_set_live
 gst_base_src_set_format
+gst_base_src_query_latency
 
 GST_BASE_SRC_PAD
 <SUBSECTION Standard>

libs/gst/base/gstbasesrc.c

@@ -546,6 +546,40 @@ gst_base_src_set_format (GstBaseSrc * src, GstFormat format)
   gst_segment_init (&src->segment, format);
 }
 
+/**
+ * gst_base_src_query_latency:
+ * @src: the source
+ * @live: if the source is live
+ * @min_latency: the min latency of the source
+ * @max_latency: the max latency of the source
+ *
+ * Query the source for the latency parameters. @live will be TRUE when @src is
+ * configured as a live source. @min_latency will be set as the latency between
+ * calling the create function and the timestamp on the resulting buffer.
+ * @max_latency is always the undefined value of -1.
+ *
+ * This function is mostly used by subclasses. 
+ *
+ * Returns: TRUE if the query succeeded.
+ *
+ * Since: 0.10.13
+ */
+gboolean
+gst_base_src_query_latency (GstBaseSrc * src, gboolean * live,
+    GstClockTime * min_latency, GstClockTime * max_latency)
+{
+  GST_LIVE_LOCK (src);
+  if (live)
+    *live = src->is_live;
+  if (min_latency)
+    *min_latency = 0;
+  if (max_latency)
+    *max_latency = -1;
+  GST_LIVE_UNLOCK (src);
+
+  return TRUE;
+}
+
 static gboolean
 gst_base_src_setcaps (GstPad * pad, GstCaps * caps)
 {
@@ -740,14 +774,16 @@ gst_base_src_default_query (GstBaseSrc * src, GstQuery * query)
       break;
     }
     case GST_QUERY_LATENCY:
-      /* we can only report the fact that we are live or not, we know nothing
+    {
-       * about latency. Subclasses should override and implement something
+      GstClockTime min, max;
-       * usefull */
+      gboolean live;
-      GST_LIVE_LOCK (src);
+
-      gst_query_set_latency (query, src->is_live, 0, -1);
+      /* Subclasses should override and implement something usefull */
-      GST_LIVE_UNLOCK (src);
+      res = gst_base_src_query_latency (src, &live, &min, &max);
-      res = TRUE;
+
+      gst_query_set_latency (query, live, min, max);
       break;
+    }
     case GST_QUERY_JITTER:
     case GST_QUERY_RATE:
     default:

libs/gst/base/gstbasesrc.h

@@ -237,6 +237,10 @@ gboolean	gst_base_src_is_live	   (GstBaseSrc *src);
 
 void		gst_base_src_set_format	   (GstBaseSrc *src, GstFormat format);
 
+gboolean        gst_base_src_query_latency (GstBaseSrc *src, gboolean * live,
+                                            GstClockTime * min_latency, 
+					    GstClockTime * max_latency);
+
 G_END_DECLS
 
 #endif /* __GST_BASE_SRC_H__ */