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129 lines
4.3 KiB
C
129 lines
4.3 KiB
C
/* GStreamer
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* Copyright (C) 2000,2001,2002,2003,2005
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* Thomas Vander Stichele <thomas at apestaart dot org>
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Library General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Library General Public License for more details.
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*
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* You should have received a copy of the GNU Library General Public
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* License along with this library; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 02111-1307, USA.
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*/
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#include <string.h>
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#include <math.h>
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#include <gst/gst.h>
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static gboolean
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message_handler (GstBus * bus, GstMessage * message, gpointer data)
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{
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if (message->type == GST_MESSAGE_ELEMENT) {
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const GstStructure *s = gst_message_get_structure (message);
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const gchar *name = gst_structure_get_name (s);
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if (strcmp (name, "level") == 0) {
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gint channels;
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GstClockTime endtime;
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gdouble rms_dB, peak_dB, decay_dB;
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gdouble rms;
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const GValue *list;
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const GValue *value;
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gint i;
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if (!gst_structure_get_clock_time (s, "endtime", &endtime))
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g_warning ("Could not parse endtime");
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/* we can get the number of channels as the length of any of the value
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* lists */
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list = gst_structure_get_value (s, "rms");
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channels = gst_value_list_get_size (list);
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g_print ("endtime: %" GST_TIME_FORMAT ", channels: %d\n",
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GST_TIME_ARGS (endtime), channels);
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for (i = 0; i < channels; ++i) {
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g_print ("channel %d\n", i);
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list = gst_structure_get_value (s, "rms");
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value = gst_value_list_get_value (list, i);
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rms_dB = g_value_get_double (value);
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list = gst_structure_get_value (s, "peak");
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value = gst_value_list_get_value (list, i);
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peak_dB = g_value_get_double (value);
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list = gst_structure_get_value (s, "decay");
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value = gst_value_list_get_value (list, i);
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decay_dB = g_value_get_double (value);
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g_print (" RMS: %f dB, peak: %f dB, decay: %f dB\n",
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rms_dB, peak_dB, decay_dB);
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/* converting from dB to normal gives us a value between 0.0 and 1.0 */
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rms = pow (10, rms_dB / 20);
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g_print (" normalized rms value: %f\n", rms);
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}
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}
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}
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/* we handled the message we want, and ignored the ones we didn't want.
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* so the core can unref the message for us */
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return TRUE;
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}
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int
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main (int argc, char *argv[])
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{
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GstElement *audiotestsrc, *audioconvert, *level, *fakesink;
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GstElement *pipeline;
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GstCaps *caps;
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GstBus *bus;
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guint watch_id;
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GMainLoop *loop;
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gst_init (&argc, &argv);
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caps = gst_caps_from_string ("audio/x-raw,channels=2");
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pipeline = gst_pipeline_new (NULL);
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g_assert (pipeline);
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audiotestsrc = gst_element_factory_make ("audiotestsrc", NULL);
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g_assert (audiotestsrc);
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audioconvert = gst_element_factory_make ("audioconvert", NULL);
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g_assert (audioconvert);
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level = gst_element_factory_make ("level", NULL);
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g_assert (level);
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fakesink = gst_element_factory_make ("fakesink", NULL);
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g_assert (fakesink);
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gst_bin_add_many (GST_BIN (pipeline), audiotestsrc, audioconvert, level,
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fakesink, NULL);
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if (!gst_element_link (audiotestsrc, audioconvert))
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g_error ("Failed to link audiotestsrc and audioconvert");
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if (!gst_element_link_filtered (audioconvert, level, caps))
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g_error ("Failed to link audioconvert and level");
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if (!gst_element_link (level, fakesink))
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g_error ("Failed to link level and fakesink");
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/* make sure we'll get messages */
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g_object_set (G_OBJECT (level), "message", TRUE, NULL);
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/* run synced and not as fast as we can */
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g_object_set (G_OBJECT (fakesink), "sync", TRUE, NULL);
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bus = gst_element_get_bus (pipeline);
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watch_id = gst_bus_add_watch (bus, message_handler, NULL);
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gst_element_set_state (pipeline, GST_STATE_PLAYING);
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/* we need to run a GLib main loop to get the messages */
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loop = g_main_loop_new (NULL, FALSE);
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g_main_loop_run (loop);
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g_source_remove (watch_id);
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g_main_loop_unref (loop);
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return 0;
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}
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