<div dir="ltr"> gst_element_link(src,parse); gst_element_link(dec,sink);<div> </div><div>Try to replace by :</div><div> gst_element_link_many(src, parse, dec, NULL);</div> <div> </div><div>The callback pad_added is never called because this element isn't linked to the parser.</div> <div> </div><div>Also, use the environment variable GST_DEBUG to get more debug informations. <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/manual/html/section-checklist-debug.html">http://gstreamer.freedesktop.org/data/doc/gstreamer/head/manual/html/section-checklist-debug.html</a></div> <div> </div><div>Another good way to debug, is to generate dot file of the pipeline. See : <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstInfo.html#GST-DEBUG-BIN-TO-DOT-FILE:CAPS">http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstInfo.html#GST-DEBUG-BIN-TO-DOT-FILE:CAPS</a></div> </div><div class="gmail_extra"> <div class="gmail_quote">On Wed, Feb 5, 2014 at 12:46 PM, aft <<a href="mailto:aftnix@gmail.com" target="_blank">aftnix@gmail.com</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> Hi, I'm trying to implement the following pipeline in 'C': arif@dev:~/GS_samples/cmd_GS$gst-launch-0.10 filesrc location="../sample_media/M1F1-Alaw-AFsp.wav" ! wavparse ! alawdec ! autoaudiosink Here is the implementation which i have written #include <gst/gst.h> void on_pad_added(GstElement *src_element, GstPad *src_pad, gpointer data); static gboolean bus_cb(GstBus *bus, GstMessage *message, gpointer data); static GMainLoop *loop; int main(int argc, char **argv) { GstElement *pipeline; GstElement *src; GstElement *dec; GstElement *parse; GstElement *sink; GstBus *bus; gst_init(&argc, &argv); loop = g_main_loop_new (NULL, FALSE); pipeline = gst_pipeline_new("wav_player"); src = gst_element_factory_make("filesrc","src"); sink = gst_element_factory_make("autoaudiosink","sink"); parse = gst_element_factory_make("wavparse","parse"); dec = gst_element_factory_make("alawdec", "dec"); gst_bin_add_many (GST_BIN(pipeline), src,parse,dec,sink, NULL); g_object_set( G_OBJECT (src) , "location",argv[1], NULL); gst_element_link(src,parse); gst_element_link(dec,sink); g_signal_connect (dec, "pad-added", G_CALLBACK (on_pad_added), dec); bus = gst_pipeline_get_bus(GST_PIPELINE(pipeline)); gst_bus_add_watch (bus, bus_cb, NULL); gst_object_unref(bus); gst_element_set_state(pipeline, GST_STATE_PLAYING); g_main_loop_run(loop); return 0; } void on_pad_added (GstElement *src_element, GstPad *src_pad, gpointer data) { g_print ("linking dynamic pad ...\n"); GstElement *sink_element = (GstElement *) data; GstPad *sink_pad = gst_element_get_static_pad(sink_element, "sink"); gst_pad_link (src_pad, sink_pad); gst_object_unref(sink_pad); } static gboolean bus_cb(GstBus *bus, GstMessage *message, gpointer data) { g_print ("Got %s message\n", GST_MESSAGE_TYPE_NAME (message)); switch (GST_MESSAGE_TYPE (message)) { case GST_MESSAGE_ERROR: { GError *err; gchar *debug; gst_message_parse_error (message, &err, &debug); g_print ("Error: %s\n", err->message); g_error_free (err); g_free (debug); g_main_loop_quit (loop); break; } case GST_MESSAGE_EOS: /* end-of-stream */ g_main_loop_quit (loop); break; default: /* unhandled message */ break; } /* we want to be notified again the next time there is a message * on the bus, so returning TRUE (FALSE means we want to stop watching * for messages on the bus and our callback should not be called again) */ return TRUE; } But this does not work : arif@dev:~/GS_samples/cmd_GS$./a.out ../sample_media/M1F1-Alaw-AFsp.wav Got state-changed message Got state-changed message Got stream-status message Got tag message Got error message Error: Internal data flow error. -- -Cheers -Arif _______________________________________________ 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> </div>