mediactrl.cpp

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}

//---------------------------------------------------------------------------
// wxGStreamerMediaBackend::OnVideoCapsReady
//
// Called by gstreamer when the video caps for the media is ready
//---------------------------------------------------------------------------
void wxGStreamerMediaBackend::OnVideoCapsReady(GstPad* pad, GParamSpec* pspec, gpointer data)
{
    wxGStreamerMediaBackend::TransCapsToVideoSize((wxGStreamerMediaBackend*) data, pad);    
}

//---------------------------------------------------------------------------
// wxGStreamerMediaBackend::DoLoad
//
// 1) Stops/Cleanups the previous instance if there is any
// 2) Creates the gstreamer playbin
// 3) If there is no playbin bail out
// 4) Set up the error and end-of-stream callbacks for our player
// 5) Make our video sink and make sure it supports the x overlay interface
// 6) Make sure the passed URI is valid and tell playbin to load it
// 7) Use the xoverlay extension to tell gstreamer to play in our window
// 8) Get the video size - pause required to set the stream in action
//---------------------------------------------------------------------------
bool wxGStreamerMediaBackend::DoLoad(const wxString& locstring)
{
    //1
    Cleanup();
    
    //2
    m_player    = gst_element_factory_make ("playbin", "play");

    //3
    if (!m_player)
        return false;
        
    //4
    g_signal_connect (m_player, "eos", G_CALLBACK (OnFinish), this);
    g_signal_connect (m_player, "error", G_CALLBACK (OnError), this);

    //5
    GstElement* overlay = NULL;
    GstElement* videosink;
    GstElement* audiosink = NULL; //NULL usually autodetects on gstreamer

#if defined(__WXGTK__) && wxUSE_DYNLIB_CLASS

    //use gnome-specific gstreamer extensions
    //if synthisis (?) file not found, it 
    //spits out a warning and uses ximagesink
    wxDynamicLibrary gstgconf;
    if(gstgconf.Load(gstgconf.CanonicalizeName(wxT("gstgconf-0.8"))))
    {
        typedef GstElement* (*LPgst_gconf_get_default_video_sink) (void);
        typedef GstElement* (*LPgst_gconf_get_default_audio_sink) (void);
        LPgst_gconf_get_default_video_sink pGst_gconf_get_default_video_sink = 
        (LPgst_gconf_get_default_video_sink)
            gstgconf.GetSymbol(wxT("gst_gconf_get_default_video_sink"));
        LPgst_gconf_get_default_audio_sink pGst_gconf_get_default_audio_sink = 
        (LPgst_gconf_get_default_audio_sink)
            gstgconf.GetSymbol(wxT("gst_gconf_get_default_audio_sink"));

        if (pGst_gconf_get_default_video_sink)        
        {
            videosink = (*pGst_gconf_get_default_video_sink) ();
            wxASSERT( GST_IS_BIN(videosink) );
            overlay = gst_bin_get_by_interface (GST_BIN (videosink),
                                            GST_TYPE_X_OVERLAY);
        }
        if (pGst_gconf_get_default_audio_sink)        
        {
            audiosink = (*pGst_gconf_get_default_audio_sink) ();
        }
        
        gstgconf.Detach();
    }
        
        if ( ! GST_IS_X_OVERLAY(overlay) )
        {
#endif
            wxLogDebug(wxT("Could not load Gnome preferences, reverting to xvimagesink for video for gstreamer"));
            videosink = gst_element_factory_make ("xvimagesink", "videosink");
            if ( !GST_IS_OBJECT(videosink) )
                videosink = gst_element_factory_make ("ximagesink", "videosink");
            
            overlay = videosink;
        
            wxASSERT( GST_IS_X_OVERLAY(overlay) );
            if ( ! GST_IS_X_OVERLAY(overlay) )
                return false;
#if defined(__WXGTK__) && wxUSE_DYNLIB_CLASS
        }
#endif

    g_object_set (G_OBJECT (m_player),
                    "video-sink", videosink,
                    "audio-sink", audiosink,
                    NULL);    

    //6
    wxASSERT(gst_uri_protocol_is_valid("file"));
    wxASSERT(gst_uri_is_valid(locstring.mb_str()));

    g_object_set (G_OBJECT (m_player), "uri", (const char*)locstring.mb_str(), NULL);
        
    //7    
#ifdef __WXGTK__
    if(!GTK_WIDGET_REALIZED(m_ctrl->m_wxwindow))
    {
        //Not realized yet - set to connect at realization time
        gtk_signal_connect( GTK_OBJECT(m_ctrl->m_wxwindow), 
                            "realize",
                            GTK_SIGNAL_FUNC(wxGStreamerMediaBackend::OnGTKRealize),
                            (gpointer) this );
    }        
    else
    {
        wxYield(); //see realize callback...
        GdkWindow *window = GTK_PIZZA(m_ctrl->m_wxwindow)->bin_window;
        wxASSERT(window);
#endif

 
    gst_x_overlay_set_xwindow_id( GST_X_OVERLAY(overlay),
#ifdef __WXGTK__
                        GDK_WINDOW_XWINDOW( window )
#else
                        ctrl->GetHandle()
#endif
                                  );

#ifdef __WXGTK__                                  
    } //end else block
#endif 
    
    //8
	int nResult = gst_element_set_state (m_player, GST_STATE_PAUSED);
	if(nResult != GST_STATE_SUCCESS)
	{
	    wxLogDebug(wxT("Could not set initial state to paused!"));
	    return false;
	}

    const GList *list = NULL;
    g_object_get (G_OBJECT (m_player), "stream-info", &list, NULL);

    bool bVideoFound = false;

    for ( ; list != NULL; list = list->next)
    {
        GObject *info = (GObject *) list->data;
        gint type;
        GParamSpec *pspec;
        GEnumValue *val;
        GstPad *pad = NULL;

        g_object_get (info, "type", &type, NULL);
        pspec = g_object_class_find_property (
                        G_OBJECT_GET_CLASS (info), "type");
        val = g_enum_get_value (G_PARAM_SPEC_ENUM (pspec)->enum_class, type);

        if (strstr (val->value_name, "VIDEO"))
        {
            //Newer gstreamer 0.8+ is SUPPOSED to have "object"...
            //but a lot of old plugins still use "pad" :)
            pspec = g_object_class_find_property (
                        G_OBJECT_GET_CLASS (info), "object");
                        
            if (!pspec)
                g_object_get (info, "pad", &pad, NULL);
            else
                g_object_get (info, "object", &pad, NULL);
            
            pad = (GstPad *) GST_PAD_REALIZE (pad);
            wxASSERT(pad);

            if(!wxGStreamerMediaBackend::TransCapsToVideoSize(this, pad));
            {
                //wait for those caps to get ready
                g_signal_connect(
                pad, 
                "notify::caps", 
                G_CALLBACK(wxGStreamerMediaBackend::OnVideoCapsReady),
                this);
            }

            bVideoFound = true;
            break;
        }//end if video
        else
        {
            m_videoSize = wxSize(0,0);
            PostRecalcSize();
        }
    }//end searching through info list    

    if(!bVideoFound)
    {
        wxLogDebug(wxT("No video found for gstreamer stream"));
    }
    m_nPausedPos = 0;

    //send loaded event
    wxMediaEvent theEvent(wxEVT_MEDIA_LOADED,
                            m_ctrl->GetId());
    m_ctrl->AddPendingEvent(theEvent);
    
    return true;
}

//---------------------------------------------------------------------------
// wxGStreamerMediaBackend::Play
//
// Sets the stream to a playing state
//---------------------------------------------------------------------------
bool wxGStreamerMediaBackend::Play()
{
    if (gst_element_set_state (m_player, GST_STATE_PLAYING)
            != GST_STATE_SUCCESS)
        return false;
    return true;
}

//---------------------------------------------------------------------------
// wxGStreamerMediaBackend::Pause
//
// Marks where we paused and pauses the stream
//---------------------------------------------------------------------------
bool wxGStreamerMediaBackend::Pause()
{
    m_nPausedPos = GetPosition();
    if (gst_element_set_state (m_player, GST_STATE_PAUSED)
            != GST_STATE_SUCCESS)
        return false;
    return true;
}

//---------------------------------------------------------------------------
// wxGStreamerMediaBackend::Stop
//
// Pauses the stream and sets the position to 0
//---------------------------------------------------------------------------
bool wxGStreamerMediaBackend::Stop()
{
    if (gst_element_set_state (m_player,
                    GST_STATE_PAUSED)    != GST_STATE_SUCCESS)
        return false;
    return wxGStreamerMediaBackend::SetPosition(0);
}

//---------------------------------------------------------------------------
// wxGStreamerMediaBackend::GetState
//
// Gets the state of the stream
//---------------------------------------------------------------------------
wxMediaState wxGStreamerMediaBackend::GetState()
{
    switch(GST_STATE(m_player))
    {
        case GST_STATE_PLAYING:
            return wxMEDIASTATE_PLAYING;
        case GST_STATE_PAUSED:
            if (m_nPausedPos == 0)
                return wxMEDIASTATE_STOPPED;
            else
                return wxMEDIASTATE_PAUSED;
        default://case GST_STATE_READY:
            return wxMEDIASTATE_STOPPED;
    }
}

//---------------------------------------------------------------------------
// wxGStreamerMediaBackend::GetPosition
//
// If paused, returns our marked position - otherwise it queries the 
// GStreamer playbin for the position and returns that
//
//TODO:
//TODO: In lue of the last big TODO, when you pause and seek gstreamer
//TODO: doesn't update the position sometimes, so we need to keep track of whether    
//TODO: we have paused or not and keep track of the time after the pause
//TODO: and whenever the user seeks while paused
//TODO:
//---------------------------------------------------------------------------
wxLongLong wxGStreamerMediaBackend::GetPosition()
{
    if(GetState() != wxMEDIASTATE_PLAYING)
        return m_nPausedPos;
    else
    {
        gint64 pos;
        GstFormat fmtTime = GST_FORMAT_TIME;
    
        if (!gst_element_query (m_player, GST_QUERY_POSITION, &fmtTime, &pos))
            return 0;
        return pos / GST_MSECOND ;
    }
}

//---------------------------------------------------------------------------
// wxGStreamerMediaBackend::SetPosition
//
// Sets the position of the stream
// Note that GST_MSECOND is 1000000 (GStreamer uses nanoseconds - so
// there is 1000000 nanoseconds in a millisecond)
//
// If paused marks where we seeked to 
//---------------------------------------------------------------------------
bool wxGStreamerMediaBackend::SetPosition(wxLongLong where)
{
    if( gst_element_seek (m_player, (GstSeekType) (GST_SEEK_METHOD_SET |
            GST_FORMAT_TIME | GST_SEEK_FLAG_FLUSH),
            where.GetValue() * GST_MSECOND ) )
    {
        if (GetState() != wxMEDIASTATE_PLAYING)
            m_nPausedPos = where;
        
        return true;
    }        
            
    return false;
}

//---------------------------------------------------------------------------
// wxGStreamerMediaBackend::GetDuration
//
// Obtains the total time of our stream
//---------------------------------------------------------------------------
wxLongLong wxGStreamerMediaBackend::GetDuration()
{
    gint64 length;
    GstFormat fmtTime = GST_FORMAT_TIME;

    if(!gst_element_query(m_player, GST_QUERY_TOTAL, &fmtTime, &length))
        return 0;
    return length / GST_MSECOND ;
}

//---------------------------------------------------------------------------
// wxGStreamerMediaBackend::Move
//
// Called when the window is moved - GStreamer takes care of this
// for us so nothing is needed
//---------------------------------------------------------------------------
void wxGStreamerMediaBackend::Move(int x, int y, int w, int h)
{
}

//---------------------------------------------------------------------------
// wxGStreamerMediaBackend::GetVideoSize
//
// Returns our cached video size from Load/OnVideoCapsReady
//---------------------------------------------------------------------------
wxSize wxGStreamerMediaBackend::GetVideoSize() const
{    
    return m_videoSize;
}

//---------------------------------------------------------------------------
// wxGStreamerMediaBackend::GetPlaybackRate
// wxGStreamerMediaBackend::SetPlaybackRate
//
// Obtains/Sets the playback rate of the stream
//
//TODO: PlaybackRate not currently supported via playbin directly -
//TODO: Ronald S. Bultje noted on gstreamer-devel:
//TODO:
//TODO: Like "play at twice normal speed"? Or "play at 25 fps and 44,1 kHz"? As
//TODO: for the first, yes, we have elements for that, btu they"re not part of
//TODO: playbin. You can create a bin (with a ghost pad) containing the actual
//TODO: video/audiosink and the speed-changing element for this, and set that
//TODO: element as video-sink or audio-sink property in playbin. The
//TODO: audio-element is called "speed", the video-element is called "videodrop"
//TODO: (although that appears to be deprecated in favour of "videorate", which
//TODO: again cannot do this, so this may not work at all in the end). For
//TODO: forcing frame/samplerates, see audioscale and videorate. Audioscale is
//TODO: part of playbin.
//---------------------------------------------------------------------------
double wxGStreamerMediaBackend::GetPlaybackRate()
{
    //not currently supported via playbin
    return 1.0;
}

bool wxGStreamerMediaBackend::SetPlaybackRate(double dRate)
{
    //not currently supported via playbin
    return false;
}

#endif //wxUSE_GSTREAMER

//in source file that contains stuff you don't directly use
#include <wx/html/forcelnk.h>
FORCE_LINK_ME(basewxmediabackends);

#endif //wxUSE_MEDIACTRL