<div dir="ltr">Hi, gstreamer-devel:     Oh, I think you can use a buffer/data probe to achieve this. Modify the buffer, add a rectangle on every frame. Or, modify the xvimagesink.  :) Eric Zhang <div class="gmail_quote"> 2008/8/26 Bruno <<a href="mailto:botte.pub@gmail.com">botte.pub@gmail.com</a>> <blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> Yep that is what I was doing before. Do you think I can draw rectangles over the cam image when using xvimagesink ? <div>2008/8/26, Eric Zhang <<a href="mailto:nicolas.m.zhang@gmail.com" target="_blank">nicolas.m.zhang@gmail.com</a>>:<div> <div></div><div class="Wj3C7c"><div> <blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> Hi, gstreamer-devel:     If you only want to `ximagesink' or `xvimagesink' draws images in your GtkDrawingArea, there is a very simple way to achieve this:     Just connect the `expose-event' signal of GtkDrawingArea and pass the window ID to the sink element: // Drawing on our drawing area g_signal_connect(G_OBJECT(area), "expose-event", G_CALLBACK(expose_cb), NULL); /* Callback to be called when the drawing area is exposed */ static gboolean expose_cb(GtkWidget * widget, GdkEventExpose * event, gpointer data) {     // `play-videosink' is your video sink element     gst_x_overlay_set_xwindow_id(GST_X_OVERLAY(play->videosink),                          GDK_WINDOW_XWINDOW(widget->window));     return FALSE; }     That's it. If you want to draw the image yourself while not using `xvimagesink' or `ximagesink', then I think this is a Gtk+ problem, not a gstreamer issue. Eric Zhang Bruno wrote: > Hello all, > > I still have some questions about gstreamer. > > Actually I'd like to change the way my program work, in order to > display a frame from the camera only once the image processing has > been done, and with a rectangle over the face of the person. > > So I changed my pipeline (removed the screen_sink element), and I'd > like to send a buffer from my image processing function to the gtk > drawing area where the camera image was displayed before. I tried to > do it with gtk drawing area (and with gtk image too with no sucess), > but I can't find the way to change the image contained in the drawing > area. > > Here is my code : > > > > ///// IMAGE PROCESSING CALLBACK > > /* Callback to be called when data goes through the pad */ > static gboolean process_frame(GstElement *video_sink, >         GstBuffer *buffer, GstPad *pad, AppData *appdata) > { >         int x, y; >         // getting the pointer to camera buffer >         unsigned char *data_photo = (unsigned char *) > GST_BUFFER_DATA(buffer); > > > // REMOVED PART WHERE THE COORDINATES OF THE POSITION OF THE FACE IS > CALCULATED // > > > // THIS PART IS WHAT I TRIED, BUT I HAVE A SEGMENTATION FAULT WHEN > CREATING PIXBUF // >         GdkPixbuf *newscreen; >         //newscreen = gdk_pixbuf_new_from_data(data_photo, >                     //GDK_COLORSPACE_RGB, /* RGB-colorspace */ >                     //FALSE, /* No alpha-channel */ >                     //8, /* Bits per RGB-component */ >                     //IMAGE_WIDTH, IMAGE_HEIGHT, /* Dimensions */ >                     //3*IMAGE_WIDTH, /* Number of bytes between lines > (ie stride) */ >                     //NULL, NULL); /* Callbacks */ > > > gdk_draw_pixmap(GDK_DRAWABLE(appdata->screen), > appdata->screen->style->black_gc, GDK_DRAWABLE(newscreen), 0, 0, 0, 0, > -1, -1); > >         return TRUE; > } > > > > > > /////// PIPELINE > > > /* Initialize the the Gstreamer pipeline. Below is a diagram >  * of the pipeline that will be created: >  * >  * |Camera|  |CSP   |  |Screen|  |Screen|   |Image     | >  * |src   |->|Filter|->|queue |->|sink  |-> |processing|->  Display >  */ > static gboolean initialize_pipeline(AppData *appdata, >         int *argc, char ***argv) > { >     GstElement *pipeline, *camera_src, *screen_sink; >     GstElement *screen_queue; >     GstElement *csp_filter; >     GstCaps *caps; >     GstBus *bus; >     GstPad *sinkpad; > >     /* Initialize Gstreamer */ >     gst_init(argc, argv); > >     /* Create pipeline and attach a callback to it's >      * message bus */ >     pipeline = gst_pipeline_new("test-camera"); > >     bus = gst_pipeline_get_bus(GST_PIPELINE(pipeline)); >     gst_bus_add_watch(bus, (GstBusFunc)bus_callback, appdata); >     gst_object_unref(GST_OBJECT(bus)); > >     /* Save pipeline to the AppData structure */ >     appdata->pipeline = pipeline; > >     /* Create elements */ >     /* Camera video stream comes from a Video4Linux driver */ >     camera_src = gst_element_factory_make(VIDEO_SRC, "camera_src"); >     /* Colorspace filter is needed to make sure that sinks understands >      * the stream coming from the camera */ >     csp_filter = gst_element_factory_make("ffmpegcolorspace", > "csp_filter"); >     /* Queue creates new thread for the stream */ >     screen_queue = gst_element_factory_make("queue", "screen_queue"); >     /* Sink that shows the image on screen. Xephyr doesn't support XVideo >      * extension, so it needs to use ximagesink, but the device uses >      * xvimagesink */ >     //screen_sink = gst_element_factory_make(VIDEO_SINK, "screen_sink"); > >     sinkpad = gst_element_get_static_pad(screen_queue,"sink"); >     gst_pad_add_buffer_probe(sinkpad,G_CALLBACK(process_frame), appdata); > > >     /* Check that elements are correctly initialized */ >     if(!(pipeline && camera_src /*&& screen_sink*/ && csp_filter && > screen_queue)) >     { >         g_critical("Couldn't create pipeline elements"); >         return FALSE; >     } > > >     /* Add elements to the pipeline. This has to be done prior to >      * linking them */ >     gst_bin_add_many(GST_BIN(pipeline), camera_src, csp_filter, >             screen_queue, /*screen_sink,*/ NULL); > >     /* Specify what kind of video is wanted from the camera */ >     caps = gst_caps_new_simple("video/x-raw-rgb", >             "width", G_TYPE_INT, IMAGE_WIDTH, >             "height", G_TYPE_INT, IMAGE_HEIGHT, >             "framerate", GST_TYPE_FRACTION, FRAMERATE, 1, >             NULL); > > >     /* Link the camera source and colorspace filter using capabilities >      * specified */ >     if(!gst_element_link_filtered(camera_src, csp_filter, caps)) >     { >         return FALSE; >     } >     gst_caps_unref(caps); > >     /* Connect Colorspace Filter -> Screen Queue -> Screen Sink >      * This finalizes the initialization of the screen-part of the > pipeline */ >     if(!gst_element_link_many(csp_filter, screen_queue, /*screen_sink, > */NULL)) >     { >         return FALSE; >     } > >     gst_element_set_state(pipeline, GST_STATE_PAUSED); > >     return TRUE; > } > > > > > > > > /////// MAIN FUNCTION > > > int main(int argc, char **argv) > { > // variables for face detection >     // main structure for vjdetect > >     pdata = (mainstruct*) calloc(1, sizeof(mainstruct)); >     // Allocate memory for array of face detections returned by > facedetector (VjDetect). >     pdata->pFaceDetections = (FLY_Rect > *)calloc(MAX_NUMBER_OF_FACE_DETECTIONS, sizeof(FLY_Rect)); >     init(pdata); > >     AppData appdata; >     appdata.expression = 0; >     GtkWidget *hbox, *vbox_button, *vbox, *button1, *button2; > > >     /* Initialize and create the GUI */ > >     example_gui_initialize( >         &appdata.program, &appdata.window, >         &argc, &argv, "Expression Detector"); > >     vbox = gtk_vbox_new(FALSE, 0); >     hbox = gtk_hbox_new(FALSE, 0); >     vbox_button = gtk_vbox_new(FALSE, 0); > >     gtk_box_pack_start(GTK_BOX(hbox), vbox, FALSE, FALSE, 0); >     gtk_box_pack_start(GTK_BOX(hbox), vbox_button, FALSE, FALSE, 0); > >     appdata.screen = gtk_drawing_area_new(); >     gtk_widget_set_size_request(appdata.screen, 500, 380); >     gtk_box_pack_start(GTK_BOX(vbox), appdata.screen, FALSE, FALSE, 0); > >     button1 = gtk_toggle_button_new_with_label("Run/Stop"); >     gtk_widget_set_size_request(button1, 170, 75); >     gtk_box_pack_start(GTK_BOX(vbox_button), button1, FALSE, FALSE, 0); > >     button2 = gtk_toggle_button_new_with_label("Expressions ON/OFF"); >     gtk_widget_set_size_request(button2, 170, 75); >     gtk_box_pack_start(GTK_BOX(vbox_button), button2, FALSE, FALSE, 0); > > >     appdata.anger = gtk_image_new_from_file("./smileys/anger.jpg"); >     gtk_widget_set_size_request(appdata.anger, 160, 180); >     appdata.disgust = gtk_image_new_from_file("./smileys/disgust.jpg"); >     gtk_widget_set_size_request(appdata.disgust, 160, 180); >     appdata.fear = gtk_image_new_from_file("./smileys/fear.jpg"); >     gtk_widget_set_size_request(appdata.fear, 160, 180); >     appdata.happy = gtk_image_new_from_file("./smileys/happy.jpg"); >     gtk_widget_set_size_request(appdata.happy, 160, 180); >     appdata.neutral = gtk_image_new_from_file("./smileys/neutral.jpg"); >     gtk_widget_set_size_request(appdata.neutral, 160, 180); >     appdata.sad = gtk_image_new_from_file("./smileys/sad.jpg"); >     gtk_widget_set_size_request(appdata.sad, 160, 180); >     appdata.surprise = gtk_image_new_from_file("./smileys/surprise.jpg"); >     gtk_widget_set_size_request(appdata.surprise, 160, 180); >     appdata.unknown = gtk_image_new_from_file("./smileys/unknown.jpg"); >     gtk_widget_set_size_request(appdata.unknown, 160, 180); > >     appdata.smiley = gtk_image_new_from_file("./smileys/unknown.jpg"); >     gtk_widget_set_size_request(appdata.smiley, 160, 180); >     gtk_box_pack_start(GTK_BOX(vbox_button), appdata.smiley, FALSE, > FALSE, 0); > >     g_signal_connect(G_OBJECT(button1), "clicked", >              G_CALLBACK(button1_pressed), &appdata); > >     g_signal_connect(G_OBJECT(button2), "clicked", >              G_CALLBACK(button2_pressed), &appdata); > > >     gtk_container_add(GTK_CONTAINER(appdata.window), hbox); > >     /* Initialize the GTK pipeline */ >     if(!initialize_pipeline(&appdata, &argc, &argv)) >     { >         hildon_banner_show_information( >                 GTK_WIDGET(appdata.window), >                 "gtk-dialog-error", >                 "Failed to initialize pipeline"); >     } > > > >     g_signal_connect(G_OBJECT(appdata.window), "destroy", >             G_CALLBACK(destroy_pipeline), &appdata); > > >     /* Begin the main application */ >     example_gui_run(appdata.program, appdata.window); > >     /* Free the gstreamer resources. Elements added >      * to the pipeline will be freed automatically */ > >     return 0; > } > > > What I'd like to do is to modify the data_photo buffer to draw a > rectangle in it (in the process_frame function), and draw the content > in the appdata.screen GtkWidget. (by the way screen is declared as a > GtkWidget * in the appdata structure). > > Thanks in advance for your help ! > Bruno > > ------------------------------------------------------------------------ > > ------------------------------------------------------------------------- > This SF.Net email is sponsored by the Moblin Your Move Developer's challenge > Build the coolest Linux based applications with Moblin SDK & win great prizes > Grand prize is a trip for two to an Open Source event anywhere in the world > <a href="http://moblin-contest.org/redirect.php?banner_id=100&url=/" target="_blank">http://moblin-contest.org/redirect.php?banner_id=100&url=/</a> > ------------------------------------------------------------------------ > > _______________________________________________ > gstreamer-devel mailing list > <a href="mailto:gstreamer-devel@lists.sourceforge.net" target="_blank">gstreamer-devel@lists.sourceforge.net</a> > <a href="https://lists.sourceforge.net/lists/listinfo/gstreamer-devel" target="_blank">https://lists.sourceforge.net/lists/listinfo/gstreamer-devel</a> > ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world <a href="http://moblin-contest.org/redirect.php?banner_id=100&url=/" target="_blank">http://moblin-contest.org/redirect.php?banner_id=100&url=/</a> _______________________________________________ gstreamer-devel mailing list <a href="mailto:gstreamer-devel@lists.sourceforge.net" target="_blank">gstreamer-devel@lists.sourceforge.net</a> <a href="https://lists.sourceforge.net/lists/listinfo/gstreamer-devel" target="_blank">https://lists.sourceforge.net/lists/listinfo/gstreamer-devel</a> </blockquote></div></div></div></div> ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world <a href="http://moblin-contest.org/redirect.php?banner_id=100&url=/" target="_blank">http://moblin-contest.org/redirect.php?banner_id=100&url=/</a> _______________________________________________ gstreamer-devel mailing list <a href="mailto:gstreamer-devel@lists.sourceforge.net">gstreamer-devel@lists.sourceforge.net</a> <a href="https://lists.sourceforge.net/lists/listinfo/gstreamer-devel" target="_blank">https://lists.sourceforge.net/lists/listinfo/gstreamer-devel</a> </blockquote></div> </div>