Re: <gstmm.h> include errors

[José Alburquerque <jaalburquerque cox net>]

José Alburquerque wrote:
> What I'm trying to do is run the debugger across all the code and see 
> where I'm encountering the problem.  I can see the gstreammermm code, 
> but I can't see the glibmm, gstreamer and other library code because my 
> distribution has separated the libraries (like glibmm, gtkmm, gstreamer) 
> from the symbols (by stripping).  They provide debugging packages with 
> the symbols, but I can't figure out how to get gdb to show me the source 
> code using the debugging packages.
>
>   

Okay, by reading the gdb docs, I found out that I needed to have the 
source of the libraries that I want to debug so I installed the source 
of those libraries (glibmm, etc.).  I now can debug fine and here's what 
I found:  Gst::Element::create(), which looks like the following:

namespace Gst
{

Glib::RefPtr<Element>
Element::create(const Glib::ustring& factoryname, const Glib::ustring& name)
{
 GstElement * element = gst_element_factory_make(factoryname.c_str(), 
name.c_str());
 return wrap(element, false);
}

succeeds when calling "gst_element_factory_make()" and element is a 
valid pointer, but fails when returning the value from 
Gst::wrap(GstElement*, bool takecopy) so I changed 
Gst::wrap(GstElement*,bool) from

namespace Gst
{

Glib::RefPtr<Gst::Element> wrap(GstElement* object, bool take_copy)
{
 return Glib::RefPtr<Gst::Element>( dynamic_cast<Gst::Element*> 
(Glib::wrap_auto ((GObject*)(object), take_copy)) );
 //We use dynamic_cast<> in case of multiple inheritance.
}

} /* namespace Gst */

to:

namespace Gst
{

Glib::RefPtr<Gst::Element> wrap(GstElement* object, bool take_copy)
{
 Glib::ObjectBase* objBase =Glib::wrap_auto ((GObject*)(object), 
take_copy);
 Gst::Element* e = dynamic_cast<Gst::Element*>(objBase);
 std::cout << typeid(*e).name() << std::endl;
 Glib::RefPtr<Gst::Element> element = Glib::RefPtr<Gst::Element>( 
dynamic_cast<Gst::Element*>(e) );
 return element;
 //We use dynamic_cast<> in case of multiple inheritance.
}

} /* namespace Gst */

When I ran the code using the second definition of 
Gst::wrap(GstElement*,bool), the program crashes on the 3rd line 
(std::cout << ...) with the following error:

terminate called after throwing an instance of 'std::bad_typeid'
 what():  std::bad_typeid

-Jose