<div class="gmail_quote">2012/1/6 Dejan Tolj <<a href="mailto:dejan1@gmail.com">dejan1@gmail.com</a>> <blockquote class="gmail_quote" style="margin:0pt 0pt 0pt 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"> I am trying to simulate the following gstreamer pipeline using the C API: gst-launch -e videomixer name=mix ! ffmpegcolorspace ! xvimagesink \ videotestsrc pattern=1 ! video/x-raw-yuv,width=100,height=100 ! videobox border-alpha=0 top=0 left=0 ! mix. \ videotestsrc pattern=0 ! video/x-raw-yuv,width=100,height=100 ! videobox border-alpha=0 top=0 left=-100 ! mix. So far I have: #include <gst/gst.h> #include <glib.h> static gboolean bus_call (GstBus *bus, GstMessage *msg, gpointer data) { GMainLoop *loop = (GMainLoop *) data; switch (GST_MESSAGE_TYPE (msg)) { case GST_MESSAGE_EOS: g_print ("End of stream\n"); g_main_loop_quit (loop); break; case GST_MESSAGE_ERROR: { gchar *debug; GError *error; gst_message_parse_error (msg, &error, &debug); g_free (debug); g_printerr ("Error: %s\n", error->message); g_error_free (error); g_main_loop_quit (loop); break; } default: break; } return TRUE; } int main (int argc, char *argv[]) { GMainLoop *loop; GstElement *pipeline; GstElement *source1,*source2; GstElement *scale,*filter; GstElement *videobox1,*videobox2; //just one. GstElement *mixer,*clrspace,*sink; GstCaps *filtercaps; GstBus *bus; /* Initialisation */ gst_init (&argc, &argv); loop = g_main_loop_new (NULL, FALSE); /* Check input arguments */ /*if (argc != 2) { g_printerr ("Usage: %s <Ogg/Vorbis filename>\n", argv[0]); return -1; }*/ //gst-launch videotestsrc pattern=snow ! ximagesink /* Create gstreamer elements */ pipeline = gst_pipeline_new ("player"); source1 = gst_element_factory_make ("videotestsrc", "source1"); source2 = gst_element_factory_make ("videotestsrc", "source2"); // source2 = gst_element_factory_make ("uridecodebin", "file-source2"); scale = gst_element_factory_make ("videoscale", "scale"); filter = gst_element_factory_make("capsfilter","filter"); videobox1 = gst_element_factory_make ("videobox", "videobox1"); videobox2 = gst_element_factory_make ("videobox", "videobox2"); mixer = gst_element_factory_make ("videomixer", "mixer"); clrspace = gst_element_factory_make ("ffmpegcolorspace", "clrspace"); // demuxer = gst_element_factory_make ("oggdemux", "ogg-demuxer"); // decoder = gst_element_factory_make ("vorbisdec", "vorbis-decoder"); // conv = gst_element_factory_make ("audioconvert", "converter"); sink = gst_element_factory_make ("xvimagesink", "sink"); /*if (!pipeline || !source || !demuxer || !decoder || !conv || !sink) { g_printerr ("One element could not be created. Exiting.\n"); return -1; }*/ if (!pipeline || !source1 || !source2 || !sink) { g_printerr ("One element could not be created. Exiting.\n"); return -1; } filtercaps = gst_caps_new_simple ("video/x-raw-yuv", "width", G_TYPE_INT, 200, "height", G_TYPE_INT, 100, NULL); g_object_set (G_OBJECT (filter), "caps", filtercaps, NULL); //gst_caps_unref (filtercaps); g_object_set(videobox1,"border-alpha",0,"top",0,"left",0,NULL); g_object_set(videobox2,"border-alpha",0,"top",0,"left",-200,NULL); /* Set up the pipeline */ /* we set the input filename to the source element */ g_object_set (G_OBJECT (source1), "pattern", 0, NULL); g_object_set (G_OBJECT (source2), "pattern", 1, NULL); /* we add a message handler */ bus = gst_pipeline_get_bus (GST_PIPELINE (pipeline)); gst_bus_add_watch (bus, bus_call, loop); gst_object_unref (bus); /* we add all elements into the pipeline */ gst_bin_add_many (GST_BIN (pipeline), source1,filter,videobox1,mixer,clrspace, sink, source2,videobox2, NULL); /* we link the elements together */ //gst_element_link_many (source1, scale, filter, videobox1, mixer, clrspace, sink); //gst_element_link_many (source2, scale, filter, videobox2, mixer, clrspace, sink); gst_element_link_many (source1, filter, videobox1, mixer, clrspace, sink); gst_element_link_many (source2, filter, videobox2, mixer, clrspace, sink); /* Set the pipeline to "playing" state*/ gst_element_set_state (pipeline, GST_STATE_PLAYING); /* Iterate */ g_print ("Running...\n"); g_main_loop_run (loop); /* Out of the main loop, clean up nicely */ g_print ("Returned, stopping playback\n"); gst_element_set_state (pipeline, GST_STATE_NULL); g_print ("Deleting pipeline\n"); gst_object_unref (GST_OBJECT (pipeline)); return 0; } I have also set debugging on: export GST_DEBUG=3 When I run my program I get the following error: Running... 0:00:00.178663884 4797 0x8937020 WARN basesrc gstbasesrc.c:2582:gst_base_src_loop:<source2> error: Internal data flow error. 0:00:00.178766444 4797 0x8937020 WARN basesrc gstbasesrc.c:2582:gst_base_src_loop:<source2> error: streaming task paused, reason not-linked (-1) Error: Internal data flow error. Returned, stopping playback 0:00:00.202571746 4797 0x893ae00 WARN basetransform gstbasetransform.c:1627:gst_base_transform_prepare_output_buffer:<clrspace> pad-alloc failed: wrong-state 0:00:00.202645907 4797 0x893ae00 WARN basetransform gstbasetransform.c:2335:gst_base_transform_handle_buffer:<clrspace> could not get buffer from pool: wrong-state Deleting pipeline Why is it complaining about source2 not-linked? _______________________________________________ gstreamer-devel mailing list <a href="mailto:gstreamer-devel@lists.freedesktop.org">gstreamer-devel@lists.freedesktop.org</a> <a href="http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel" target="_blank">http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel</a> </blockquote></div> // linking source2 with filter doesn't work, because filter is already linked with source1 gst_element_link_many (source2, filter, videobox2, mixer, clrspace, sink, NULL);