/* GStreamer * * audiomix.c: sample audio mixing application * * Copyright (C) 2011 Stefan Sauer <ensonic@users.sf.net> * * 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., 51 Franklin St, Fifth Floor, * Boston, MA 02110-1301, USA. */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include <string.h> #include <gst/gst.h> #include <gtk/gtk.h> /* global items for the interaction */ static GtkWidget *scale; static GObject *volumes[2]; static gint num_vol = 0; static void value_changed_callback (GtkWidget * widget, gpointer * user_data) { gdouble value = gtk_range_get_value (GTK_RANGE (widget)); g_object_set (volumes[0], "volume", 1.0 - value, NULL); g_object_set (volumes[1], "volume", value, NULL); } static void setup_gui (GstElement * volume, gchar * file_name1, gchar * file_name2) { GtkWidget *window, *layout, *label; gchar *name, *ext; window = gtk_window_new (GTK_WINDOW_TOPLEVEL); gtk_window_set_title (GTK_WINDOW (window), "audiomix"); g_signal_connect (window, "destroy", gtk_main_quit, NULL); layout = gtk_grid_new (); g_object_set (G_OBJECT (layout), "column-spacing", 6, NULL); gtk_container_add (GTK_CONTAINER (window), layout); /* channel labels */ name = g_path_get_basename (file_name1); if ((ext = strrchr (name, '.'))) *ext = '\0'; label = gtk_label_new (name); g_free (name); gtk_grid_attach (GTK_GRID (layout), label, 0, 0, 1, 1); gtk_grid_attach (GTK_GRID (layout), gtk_label_new ("|"), 1, 0, 1, 1); name = g_path_get_basename (file_name2); if ((ext = strrchr (name, '.'))) *ext = '\0'; label = gtk_label_new (name); g_free (name); gtk_grid_attach (GTK_GRID (layout), label, 2, 0, 1, 1); /* mix slider */ scale = gtk_scale_new_with_range (GTK_ORIENTATION_HORIZONTAL, 0.0, 1.0, 1.0 / 200.0); gtk_range_set_value (GTK_RANGE (scale), 0.0); gtk_widget_set_size_request (scale, 200, -1); gtk_widget_set_hexpand (scale, TRUE); gtk_grid_attach (GTK_GRID (layout), scale, 0, 1, 3, 1); g_signal_connect (scale, "value-changed", G_CALLBACK (value_changed_callback), volume); gtk_widget_show_all (GTK_WIDGET (window)); } 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); gtk_main_quit (); } static void dynamic_link (GstPadTemplate * templ, GstPad * newpad, gpointer user_data) { GstPad *target = GST_PAD (user_data); gst_pad_link (newpad, target); gst_object_unref (target); } static void make_mixer_channel (GstElement * pipeline, GstElement * mix, gchar * file_name) { GstElement *filesrc, *decodebin, *volume, *convert, *format; GstCaps *caps; /* prepare mixer channel */ filesrc = gst_element_factory_make ("filesrc", NULL); decodebin = gst_element_factory_make ("decodebin", NULL); volume = gst_element_factory_make ("volume", NULL); convert = gst_element_factory_make ("audioconvert", NULL); format = gst_element_factory_make ("capsfilter", NULL); gst_bin_add_many (GST_BIN (pipeline), filesrc, decodebin, volume, convert, format, NULL); gst_element_link (filesrc, decodebin); gst_element_link_many (volume, convert, format, mix, NULL); /* configure elements */ g_object_set (filesrc, "location", file_name, NULL); g_object_set (volume, "volume", (num_vol == 0) ? 1.0 : 0.0, NULL); caps = gst_caps_from_string ("audio/x-raw, " "format = (string) S16LE, " "channels = (int) 2"); g_object_set (format, "caps", caps, NULL); gst_caps_unref (caps); /* remember volume element */ volumes[num_vol++] = (GObject *) volume; /* handle dynamic pads */ g_signal_connect (G_OBJECT (decodebin), "pad-added", G_CALLBACK (dynamic_link), gst_element_get_static_pad (volume, "sink")); } int main (int argc, char *argv[]) { GstElement *pipeline = NULL; GstElement *mix, *convert, *sink; GstBus *bus; if (argc < 3) { g_print ("Usage: audiomix <file1> <file2>\n"); return 1; } gst_init (&argc, &argv); gtk_init (&argc, &argv); /* prepare tail of pipeline */ pipeline = gst_pipeline_new ("audiomix"); mix = gst_element_factory_make ("adder", NULL); convert = gst_element_factory_make ("audioconvert", NULL); sink = gst_element_factory_make ("autoaudiosink", NULL); gst_bin_add_many (GST_BIN (pipeline), mix, convert, sink, NULL); gst_element_link_many (mix, convert, sink, NULL); /* prepare mixer channel strips */ make_mixer_channel (pipeline, mix, argv[1]); make_mixer_channel (pipeline, mix, argv[2]); /* 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); /* setup GUI */ setup_gui (pipeline, argv[1], argv[2]); /* go to main loop */ gst_element_set_state (pipeline, GST_STATE_PLAYING); gtk_main (); gst_element_set_state (pipeline, GST_STATE_NULL); gst_object_unref (pipeline); gst_object_unref (bus); return 0; }