autoaudiosrc: use audiotestsrc as fallback element instead of fakesrc

fakesrc doesn't announce audio caps, so most audio pipelines will
just error out with not-negotiated if a fallback element is created.

gst/autodetect/gstautoaudiosrc.c

@@ -49,9 +49,30 @@ static GstStaticPadTemplate src_template = GST_STATIC_PAD_TEMPLATE ("src",
     GST_PAD_ALWAYS,
     GST_STATIC_CAPS_ANY);
 
+static GstElement *
+gst_auto_audio_src_create_fake_element (GstAutoDetect * autodetect)
+{
+  GstElement *fake;
+
+  fake = gst_element_factory_make ("audiotestsrc", "fake-auto-audio-src");
+  if (fake != NULL) {
+    g_object_set (fake, "is-live", TRUE, NULL);
+    gst_util_set_object_arg (G_OBJECT (fake), "wave", "silence");
+  } else {
+    GST_ELEMENT_ERROR (autodetect, RESOURCE, NOT_FOUND,
+        ("Failed to find usable audio source element."),
+        ("Failed to find a usable audio source and couldn't create an audio"
+            "testsrc as fallback either, check your GStreamer installation."));
+    /* This will error out with not-negotiated.. */
+    fake = gst_element_factory_make ("fakesrc", "fake-auto-audio-src");
+  }
+  return fake;
+}
+
 static void
 gst_auto_audio_src_class_init (GstAutoAudioSrcClass * klass)
 {
+  GstAutoDetectClass *autoclass = GST_AUTO_DETECT_CLASS (klass);
   GstElementClass *eklass = GST_ELEMENT_CLASS (klass);
 
   gst_element_class_add_pad_template (eklass,
@@ -61,6 +82,8 @@ gst_auto_audio_src_class_init (GstAutoAudioSrcClass * klass)
       "Wrapper audio source for automatically detected audio source",
       "Jan Schmidt <thaytan@noraisin.net>, "
       "Stefan Kost <ensonic@users.sf.net>");
+
+  autoclass->create_fake_element = gst_auto_audio_src_create_fake_element;
 }
 
 static void

gst/autodetect/gstautodetect.c

@@ -119,7 +119,7 @@ gst_auto_detect_clear_kid (GstAutoDetect * self)
 }
 
 static GstElement *
-gst_auto_detect_create_fake_element (GstAutoDetect * self)
+gst_auto_detect_create_fake_element_default (GstAutoDetect * self)
 {
   GstElement *fake;
   gchar dummy_factory[10], dummy_name[20];
@@ -132,6 +132,20 @@ gst_auto_detect_create_fake_element (GstAutoDetect * self)
   return fake;
 }
 
+static GstElement *
+gst_auto_detect_create_fake_element (GstAutoDetect * self)
+{
+  GstAutoDetectClass *klass = GST_AUTO_DETECT_GET_CLASS (self);
+  GstElement *fake;
+
+  if (klass->create_fake_element)
+    fake = klass->create_fake_element (self);
+  else
+    fake = gst_auto_detect_create_fake_element_default (self);
+
+  return fake;
+}
+
 static gboolean
 gst_auto_detect_attach_ghost_pad (GstAutoDetect * self)
 {

gst/autodetect/gstautodetect.h

@@ -60,9 +60,10 @@ typedef struct _GstAutoDetect {
 typedef struct _GstAutoDetectClass {
   GstBinClass parent_class;
   
-  /*< public >*/
+  /*< private >*/
   /* virtual methods for subclasses */
   void (*configure)(GstAutoDetect *self, GstElement *kid);
+  GstElement * (*create_fake_element) (GstAutoDetect * autodetect);
 } GstAutoDetectClass;
 
 GType   gst_auto_detect_get_type    (void);