Crossfading-transition between more than 2 videos.
Angel Martin
amartin at vicomtech.org
Mon Sep 26 05:10:30 PDT 2011
Hello,
I suggest you to remove variable start and duration attributes and put fixed
values instead in order to have a clear schedule of the different elements
involved.
Moreover, the priority of the operation should be always minor that the
videos involved, I suggest you to put a 0 always in the transition operation
priority.
Best Regards,
Angel
2011/9/25 Rossana Guerra <guerra.rossana at gmail.com>
> Hello everyone, I am trying to do crossfade between 3 videos. It works fine
> when I do the same with 2, but when I put the 3rd something happens and the
> player displays only the first.
> Actually I use 2 videos, and I did a playlist such video1 -> video2 ->
> video2, where the 3rd time, I set the new starting time of the video2
> object.
>
> video1 starts at 0, and its durations is dur1
> I use an operator to handle the alpha channel, it starts at dur1 -
> dur_crossfade
> video2, starts at dur1 - dur_crossfade
> And the starting time of video 2 the third time is dur1 + dur2 -
> dur_crossfade.
>
> Maybe it's something wrong with the priority or start properties values, I
> am very new with GStreamer, I could make several mistakes.
>
> Thanks and regards,
>
> Rossana
>
>
> Here's the code:
>
>
> const gint dur_crossfade = 500;
>
> // Error handler
> static gboolean bus_call (GstBus *bus, GstMessage *msg, gpointer data)
> {
>
> :::::::::::::::::::::::::::::::::
> return TRUE;
> }
>
> static void on_pad_added (GstElement *element, GstPad *pad, gpointer data)
> {
> GstPad *sinkpad = NULL;
> GstElement * queue = (GstElement *) data;
>
> /* Ahora linkeo el pad de comp con sink pad */
> g_print ("Dynamic pad created, linking queue\n");
> sinkpad = gst_element_get_static_pad (queue, "sink");
>
> gst_pad_link (pad, sinkpad);
>
> gst_object_unref (sinkpad);
>
> }
>
> GstElement * getBin(const gchar * nomBin, GstElement * &alfa1, GstElement
> *&smpte, GstElement * &color, gint transicion = 1)
> {
>
> GstElement * bin = gst_bin_new(nomBin);
>
> if (!bin)
> {
> g_printerr ("No se pudo crear el bin. Saliendo\n");
> return NULL;
> }
>
> alfa1 = gst_element_factory_make ("alpha","alfa1");
> smpte = gst_element_factory_make ("smptealpha","smpte");
> color = gst_element_factory_make ("ffmpegcolorspace", "color");
> GstElement * mixer = gst_element_factory_make("videomixer", "mixer");
>
>
> if ((!alfa1) || (!smpte) || (!color) || (!mixer))
> {
> g_printerr ("Alguno de los elementos del Bin no pudo ser creado.
> Saliendo\n");
> return NULL;
> }
>
> // Anexamos al bin
> gst_bin_add_many(GST_BIN (bin),alfa1,smpte,mixer,color,NULL);
>
> // Enlazamos elementos
> gst_element_link (alfa1, mixer);
> gst_element_link (smpte, mixer);
> gst_element_link (mixer,color);
>
> g_object_set(smpte,"type", transicion, NULL);
>
> return bin;
> }
>
> void getAndSetController(GstElement * smpte, gdouble duracion)
> {
> GstController * ctrl = NULL;
> if (!(ctrl = gst_controller_new (G_OBJECT (smpte), "alpha",NULL))) {
> GST_WARNING ("No puede controlar el elemento fuente\n");
> return;
> }
>
> // Todo valor GValue debe inicializarse en 0
> GValue val_double = { 0, };
> g_value_init (&val_double, G_TYPE_DOUBLE);
>
>
> // Create de controller, source and set the interpolation mode
>
> GstInterpolationControlSource * csource =
> gst_interpolation_control_source_new();
> gst_controller_set_control_source (ctrl, "alpha", GST_CONTROL_SOURCE
> (csource));
>
>
> gst_interpolation_control_source_set_interpolation_mode(csource,GST_INTERPOLATE_LINEAR);
>
> // Set first value
> g_value_set_double(&val_double, 0.0);
> gst_interpolation_control_source_set(csource,(0 *
> GST_MSECOND),&val_double);
>
> // Ser 2nd value
> g_value_set_double (&val_double, duracion);
> gst_interpolation_control_source_set(csource,(1 *
> GST_MSECOND),&val_double);
>
>
> g_object_unref (csource);
>
> }
>
> void addGhostPadsToBin(GstElement *alfa1, GstElement * smpte, GstElement *
> color, GstElement* bin)
> {
> /* add ghostpad */
> GstPad * pad1 = gst_element_get_static_pad (alfa1, "sink");
> gst_element_add_pad(bin, gst_ghost_pad_new("alfasink1", pad1));
> gst_object_unref (GST_OBJECT (pad1));
>
> GstPad * pad2 = gst_element_get_static_pad (smpte, "sink");
> gst_element_add_pad(bin, gst_ghost_pad_new("alfasink2", pad2));
> gst_object_unref(GST_OBJECT(pad2));
>
> GstPad * pad3 = gst_element_get_static_pad (color, "src");
> gst_element_add_pad(bin, gst_ghost_pad_new("colorsrc", pad3));
> gst_object_unref(GST_OBJECT(pad3));
>
> }
>
> void crossTransicion(gdouble duracion, GstElement * & bin,gint transicion =
> 1)
> {
> // devuelve el bin
> GstElement * alfa1, *smpte, *color;
> alfa1 = 0;
> smpte = 0;
> color = 0;
>
> bin = getBin("bin",alfa1, smpte,color,transicion); // Crea el bin y
> los elementos
>
> getAndSetController(smpte,duracion);
>
> addGhostPadsToBin(alfa1, smpte, color, bin);
>
> }
>
> GstElement * crearVideo(const gchar *nomVideo, GstElement *&comp)
> {
> GstElement* video = NULL;
> if ((video = gst_element_factory_make("gnlfilesource", nomVideo)) ==
> NULL)
> {
> printf ("\n Falló la creacion del gnlfilesource \n");
> return NULL;
> }
>
>
> if (gst_bin_add (GST_BIN (comp), video) == FALSE)
> {
> printf ("\n No pudo agregar video %s a comp \n", nomVideo);
> return NULL;
> }
>
> return video;
> }
>
> void crearCompYoper(GstElement*& compo, GstElement *&op, GstElement*& bin2)
> {
>
> if ((compo = gst_element_factory_make("gnlcomposition",
> "micomposicion")) == NULL)
> {
> printf ("\n Fallo al crear gnlcomposition \n");
> return;
> }
>
> //Aqui se crea el bin
> crossTransicion(dur_crossfade, bin2,1);
>
> op = gst_element_factory_make("gnloperation", "op");
>
> if (gst_bin_add (GST_BIN (op), bin2) == FALSE)
> {
> printf ("\n No pudo agregar el bin a la gnloperacion op \n");
> return;
> }
>
> if (gst_bin_add (GST_BIN (compo), op) == FALSE)
> {
> printf ("\n No pudo agregar la gnloperacion a la gnlcomposition \n");
> return;
> }
>
> }
>
>
> /// Aqui pipeline3
>
> GstElement * getPipeline3(gchar *argv[],GstElement *&video1, gint dur1,
> GstElement *& video2,GstElement *& comp, GstElement *&op)
> {
>
> GstElement *queue, *sink, *pipeline, *bin;
>
> crearCompYoper(comp, op,bin);
>
> video1 = crearVideo("video1",comp);
> video2 = crearVideo("video2",comp);
>
> g_object_set (video1, "location", argv[1], NULL);
> g_object_set(video1, "uri", argv[1],NULL);
> g_object_set (video1, "start", 0 * GST_MSECOND, NULL);
> g_object_set (video1, "duration", dur1 * GST_MSECOND, NULL);
> g_object_set (video1, "media-start", 0* GST_MSECOND, NULL);
> g_object_set (video1, "media-duration", dur1 * GST_MSECOND, NULL);
> g_object_set (video1, "priority", 1,NULL);
>
> // setup the backend viewer
> queue = gst_element_factory_make("queue", "queue");
> sink = gst_element_factory_make("autovideosink", "sink");
>
> pipeline = gst_pipeline_new ("video-player");
>
> /* Agrego elementos al pipeline */
>
> gst_bin_add_many (GST_BIN (pipeline),comp, queue, sink, NULL);
>
> g_signal_connect (comp, "pad-added", G_CALLBACK (on_pad_added),queue);
>
> gst_element_link (queue, sink);
>
> cout << "...PLAY" << endl;
>
> gst_element_set_state (pipeline, GST_STATE_PLAYING);
>
> return pipeline;
> }
>
>
> void playSigVideo(gchar *argv[], GstElement *& video2, gint dur1, gint
> dur2,GstElement *&op, GstElement *pip)
> {
> g_object_set (op,"start", (dur1-dur_crossfade) * GST_MSECOND,NULL);
> g_object_set (op,"duration", dur_crossfade * GST_MSECOND,NULL);
> g_object_set (op,"media-start", 0 * GST_MSECOND,NULL);
> g_object_set(op,"media-duration", dur_crossfade * GST_MSECOND,NULL);
> g_object_set(op,"priority",0,NULL);
>
> gst_element_set_state (pip, GST_STATE_PLAYING);
>
> g_object_set (video2, "location", argv[2], NULL);
> g_object_set (video2,"uri",argv[2],NULL);
> g_object_set (video2, "start", (dur1-dur_crossfade) * GST_MSECOND,
> NULL);
> g_object_set (video2, "duration", dur2 * GST_MSECOND, NULL);
> g_object_set (video2, "media-start", 0 * GST_MSECOND, NULL);
> g_object_set (video2, "media-duration", dur2 * GST_MSECOND, NULL);
> g_object_set (video2, "priority", 2,NULL);
>
> g_object_set (op,"start", ((dur2+dur1)- 2*dur_crossfade) *
> GST_MSECOND,NULL);
> g_object_set (op,"duration", dur_crossfade * GST_MSECOND,NULL);
> g_object_set (op,"media-start", 0 * GST_MSECOND,NULL);
> g_object_set(op,"media-duration", dur_crossfade * GST_MSECOND,NULL);
> g_object_set(op,"priority",3,NULL);
>
> g_object_set (video2, "location", argv[1], NULL);
> g_object_set (video2,"uri",argv[1],NULL);
> g_object_set (video2, "start", ((dur2 + dur1) - 2*dur_crossfade) *
> GST_MSECOND, NULL);
> g_object_set (video2, "duration", dur1 * GST_MSECOND, NULL);
> g_object_set (video2, "media-start", 0 * GST_MSECOND, NULL);
> g_object_set (video2, "media-duration", dur1 * GST_MSECOND, NULL);
> g_object_set (video2, "priority", 4,NULL);
>
> }
>
>
> int main(gint argc, gchar *argv[])
> {
> gint dur1 = 9000; // d uration (in ms) to play of first clip
> gint dur2 = 8000; // duration (in ms) to play of second clip
> //gint dur_crossfade = 500; //number of milliseconds to crossfade for
> GMainLoop *loop = NULL;
>
> /* init GStreamer */
> gst_init (&argc, &argv);
> gst_controller_init (&argc, &argv);
>
> loop = g_main_loop_new (NULL, FALSE);
>
> /* chequeamos sintaxis */
> if (argc != 3)
> {
> g_print ("Uso: %s <URI1> <URI2>\n", argv[0]);
> return -1;
> }
>
> GstElement *comp = NULL;
> GstElement *op = NULL;
> GstElement *video1,*video2;
>
> GstElement *play = getPipeline3(argv,video1, dur1,video2,comp, op);
>
> playSigVideo(argv,video2, dur1, dur2,op,play);
>
> GstBus *bus2 = gst_pipeline_get_bus (GST_PIPELINE (play));
> gst_bus_add_watch (bus2, bus_call, loop);
> gst_object_unref (bus2);
>
> //cout << "...PLAY" << endl;
>
>
> /* now run */
> g_main_loop_run (loop);
>
> /* also clean up */
> gst_element_set_state (play, GST_STATE_NULL);
> gst_object_unref (GST_OBJECT (play));
> return 0;
> }
>
>
>
>
> _______________________________________________
> gstreamer-devel mailing list
> gstreamer-devel at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel
>
>
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