[gstreamermm] typefind example: Output more information.

[Murray Cumming <murrayc src gnome org>]

commit 68ba99acc7c9e6b875e2bfc3972739010042df30
Author: Murray Cumming <murrayc murrayc com>
Date:   Mon Aug 3 17:43:25 2009 +0200

    typefind example: Output more information.
    
    * examples/typefind/main.cc: on_typefind_have_type(): Output more than
    just the mime type (name). Added commented-out id3demux element which
    should result in such extra information when using an mp3 file, but
    it fails to link.

 ChangeLog                 |    9 +++++++++
 examples/typefind/main.cc |   27 ++++++++++++++++++++++++++-
 2 files changed, 35 insertions(+), 1 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index 497cfd6..386ae5f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,14 @@
 2009-08-03  Murray Cumming  <murrayc murrayc com>
 
+	typefind example: Output more information.
+
+	* examples/typefind/main.cc: on_typefind_have_type(): Output more than 
+	just the mime type (name). Added commented-out id3demux element which 
+	should result in such extra information when using an mp3 file, but 
+	it fails to link.
+
+2009-08-03  Murray Cumming  <murrayc murrayc com>
+
 	generate_plugin_gmmproc_file: Minor improvements.
 	
 	* tools/extra_defs_gen/generate_plugin_gmmproc_file.cc: 
diff --git a/examples/typefind/main.cc b/examples/typefind/main.cc
index ffa2804..dc10c80 100644
--- a/examples/typefind/main.cc
+++ b/examples/typefind/main.cc
@@ -22,6 +22,16 @@
 Glib::RefPtr<Glib::MainLoop> mainloop;
 bool have_type = false;
 
+static bool on_structure_foreach(const Glib::QueryQuark& id, const Glib::ValueBase& value)
+{
+  const Glib::ustring str_id = id;
+  gchar* str_value = g_strdup_value_contents(value.gobj());
+  std::cout << "Structure field: id=" << str_id << ", value=" << str_value << std::endl;
+  g_free(str_value);
+
+  return true;
+}
+
 static void on_typefind_have_type(guint probability, const Glib::RefPtr<Gst::Caps>& caps)
 {
   have_type = true;
@@ -34,10 +44,18 @@ static void on_typefind_have_type(guint probability, const Glib::RefPtr<Gst::Cap
     return;
   }
 
-  const Gst::Structure structure = caps->get_structure(0);
+  if(!caps->size())
+  {
+    std::cerr << "on_typefind_have_type(): caps is empty" << std::endl;
+    return;
+  }
+
+  Gst::Structure structure = caps->get_structure(0);
   const Glib::ustring mime_type = structure.get_name();
   std::cout << "have-type: mime_type=" << mime_type << std::endl;
 
+  structure.foreach( sigc::ptr_fun(&on_structure_foreach) );
+
   if(mainloop)
     mainloop->quit();
   else
@@ -65,6 +83,10 @@ int main(int argc, char** argv)
   Glib::RefPtr<Gst::FileSrc> element_source = Gst::FileSrc::create();
   element_source->property_location() = filename;
 
+  //If using an MP3 file, this should provide more Caps information from typefind.
+  //Glib::RefPtr<Gst::Element> element_id3demux = Gst::ElementFactory::create_element("id3demux");
+  //g_assert(element_id3demux);
+
   Glib::RefPtr<Gst::TypeFindElement> element_typefind = Gst::TypeFindElement::create();
   element_typefind->signal_have_type().connect(
     sigc::ptr_fun(&on_typefind_have_type) );
@@ -76,6 +98,7 @@ int main(int argc, char** argv)
   {
 #endif
     pipeline->add(element_source)->add(element_typefind)->add(element_sink);
+    //pipeline->add(element_source)->add(element_id3demux)->add(element_typefind)->add(element_sink);
 #ifdef GLIBMM_EXCEPTIONS_ENABLED
   }
   catch (std::runtime_error& ex)
@@ -90,12 +113,14 @@ int main(int argc, char** argv)
   try
   {
 #endif
+    //element_source->link(element_id3demux)->link(element_typefind)->link(element_sink);
     element_source->link(element_typefind)->link(element_sink);
 #ifdef GLIBMM_EXCEPTIONS_ENABLED
   }
   catch(const std::runtime_error& error)
   {
     std::cerr << "Exception while linking: " << error.what() << std::endl;
+    return 1;
   }
 #endif