/* GStreamer * * sprinkle.c: sample application to dynamically mix tones with adder * * Copyright (C) <2009> Wim Taymans * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. */ /* * Produces a sweeping sprinkle of tones by dynamically adding and removing * elements to adder. * * gcc `pkg-config --cflags --libs gstreamer-0.10` sprinkle3.c -osprinkle3 */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include static GstElement *pipeline, *adder; static GMainLoop *loop; typedef struct { GstElement *bin, *src, *fx; GstPad *src_srcpad; GstPad *fx_sinkpad, *fx_srcpad; GstPad *adder_sinkpad; GstPad *bin_srcpad; gdouble freq; gfloat pos; } SourceInfo; /* dynamically add the source to the pipeline and link it to a new pad on * adder */ static SourceInfo * add_source (gdouble freq, gfloat pos) { SourceInfo *info; info = g_new0 (SourceInfo, 1); info->freq = freq; info->pos = pos; /* make source with unique name */ info->bin = gst_element_factory_make ("bin", NULL); info->src = gst_element_factory_make ("audiotestsrc", NULL); info->fx = gst_element_factory_make ("audiopanorama", NULL); g_object_set (info->src, "freq", freq, "volume", (gdouble) 0.35, NULL); g_object_set (info->fx, "panorama", pos, NULL); /* add to the bin */ gst_bin_add (GST_BIN (info->bin), info->src); gst_bin_add (GST_BIN (info->bin), info->fx); /* get pads from the elements */ info->src_srcpad = gst_element_get_static_pad (info->src, "src"); info->fx_srcpad = gst_element_get_static_pad (info->fx, "src"); info->fx_sinkpad = gst_element_get_static_pad (info->fx, "sink"); /* create and add a pad for the bin */ info->bin_srcpad = gst_ghost_pad_new ("src", info->fx_srcpad); gst_element_add_pad (info->bin, info->bin_srcpad); /* get new pad from adder, adder will now wait for data on this pad */ info->adder_sinkpad = gst_element_get_request_pad (adder, "sink_%u"); /* link inside the bin */ gst_pad_link (info->src_srcpad, info->fx_sinkpad); /* add bin to pipeline */ gst_bin_add (GST_BIN (pipeline), info->bin); /* link bin to adder */ gst_pad_link (info->bin_srcpad, info->adder_sinkpad); /* and play the elements */ gst_element_set_state (info->bin, GST_STATE_PLAYING); g_print ("added freq %5.0f, pos %3.1f\n", info->freq, info->pos); return info; } /* remove the source from the pipeline after removing it from adder */ static void remove_source (SourceInfo * info) { g_print ("remove freq %5.0f, pos %3.1f\n", info->freq, info->pos); /* lock the state so that we can put it to NULL without the parent messing * with our state */ gst_element_set_locked_state (info->bin, TRUE); /* first stop the source. Remember that this might block when in the PAUSED * state. Alternatively one could send EOS to the source, install an event * probe and schedule a state change/unlink/release from the mainthread. */ /* NOTE that the source inside the bin will emit EOS but it will not reach * adder because the element after the source is shut down first. We will send * EOS later */ gst_element_set_state (info->bin, GST_STATE_NULL); /* unlink bin from adder */ gst_pad_unlink (info->bin_srcpad, info->adder_sinkpad); /* release pads */ gst_object_unref (info->src_srcpad); gst_object_unref (info->fx_srcpad); gst_object_unref (info->fx_sinkpad); /* remove from the bin */ gst_bin_remove (GST_BIN (pipeline), info->bin); /* send EOS to the sinkpad to make adder EOS when needed */ gst_pad_send_event (info->adder_sinkpad, gst_event_new_eos ()); /* give back the pad */ gst_element_release_request_pad (adder, info->adder_sinkpad); gst_object_unref (info->adder_sinkpad); g_free (info); } /* we'll keep the state of the sources in this structure. We keep 3 sources * alive */ typedef struct { guint count; SourceInfo *infos[3]; } SprinkleState; static SprinkleState * create_state (void) { SprinkleState *state; state = g_new0 (SprinkleState, 1); return state; } static void free_state (SprinkleState * state) { SourceInfo *info; gint i; for (i = 0; i < 3; i++) { info = state->infos[i]; if (info) remove_source (info); } g_free (state); } static gboolean do_sprinkle (SprinkleState * state) { SourceInfo *info; gint i; /* first remove the oldest info */ info = state->infos[2]; if (info) remove_source (info); /* move sources */ for (i = 2; i > 0; i--) { state->infos[i] = state->infos[i - 1]; } /* add new source, stop adding sources after 10 rounds. */ if (state->count < 20) { state->infos[0] = add_source ( (gdouble) ((state->count * 100) + 200), ((gfloat) (state->count % 5) / 2.0 - 1.0)); state->count++; } else { state->infos[0] = NULL; } GST_DEBUG_BIN_TO_DOT_FILE_WITH_TS (GST_BIN (pipeline), /*GST_DEBUG_GRAPH_SHOW_ALL, */ GST_DEBUG_GRAPH_SHOW_CAPS_DETAILS | GST_DEBUG_GRAPH_SHOW_STATES, "sprinkle3"); return TRUE; } static void message_received (GstBus * bus, GstMessage * message, GstPipeline * pipeline) { const GstStructure *s; s = gst_message_get_structure (message); g_print ("message from \"%s\" (%s): ", GST_STR_NULL (GST_ELEMENT_NAME (GST_MESSAGE_SRC (message))), gst_message_type_get_name (GST_MESSAGE_TYPE (message))); if (s) { gchar *sstr; sstr = gst_structure_to_string (s); g_print ("%s\n", sstr); g_free (sstr); } else { g_print ("no message details\n"); } } static void eos_message_received (GstBus * bus, GstMessage * message, GstPipeline * pipeline) { message_received (bus, message, pipeline); g_main_loop_quit (loop); } int main (int argc, char *argv[]) { GstBus *bus; GstElement *filter, *convert, *sink; GstCaps *caps; gboolean res; SprinkleState *state; gst_init (&argc, &argv); loop = g_main_loop_new (NULL, TRUE); pipeline = gst_pipeline_new ("pipeline"); /* add the fixed part to the pipeline. Remember that we need a capsfilter * after adder so that multiple sources are not racing to negotiate * a format */ adder = gst_element_factory_make ("adder", "adder"); filter = gst_element_factory_make ("capsfilter", "filter"); convert = gst_element_factory_make ("audioconvert", "convert"); sink = gst_element_factory_make ("autoaudiosink", "sink"); caps = gst_caps_new_simple ("audio/x-raw", "format", G_TYPE_STRING, "S16LE", "channels", G_TYPE_INT, 2, "rate", G_TYPE_INT, 44100, NULL); g_object_set (filter, "caps", caps, NULL); gst_caps_unref (caps); gst_bin_add_many (GST_BIN (pipeline), adder, filter, convert, sink, NULL); res = gst_element_link_many (adder, filter, convert, sink, NULL); g_assert (res); /* setup message handling */ bus = gst_pipeline_get_bus (GST_PIPELINE (pipeline)); gst_bus_add_signal_watch_full (bus, G_PRIORITY_HIGH); g_signal_connect (bus, "message::error", (GCallback) message_received, pipeline); g_signal_connect (bus, "message::warning", (GCallback) message_received, pipeline); g_signal_connect (bus, "message::eos", (GCallback) eos_message_received, pipeline); /* we set the pipeline to PLAYING, the pipeline will not yet preroll because * there is no source providing data for it yet */ gst_element_set_state (pipeline, GST_STATE_PLAYING); /* and add the function that modifies the pipeline every 100ms */ state = create_state (); g_timeout_add (100, (GSourceFunc) do_sprinkle, state); /* go to main loop */ g_main_loop_run (loop); gst_element_set_state (pipeline, GST_STATE_NULL); free_state (state); gst_object_unref (bus); gst_object_unref (pipeline); return 0; }