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Add a simple example application for the spectrum element, include it in the docs, and fix some documentation ambigui...

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Original commit message from CVS:
* docs/plugins/Makefile.am:
* gst/spectrum/gstspectrum.c:
* tests/examples/spectrum/.cvsignore:
* tests/examples/spectrum/Makefile.am:
* tests/examples/spectrum/spectrum-example.c:
Add a simple example application for the spectrum element, include it
in the docs, and fix some documentation ambiguities.
Fixes: #348085
This commit is contained in:
Jan Schmidt 2008-02-09 01:45:32 +00:00
parent 6afa17d8f0
commit 1ba01acdc0
6 changed files with 157 additions and 10 deletions
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13
ChangeLog
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@ -1,3 +1,16 @@
2008-02-09 Jan Schmidt <jan.schmidt@sun.com>
* docs/plugins/Makefile.am:
* gst/spectrum/gstspectrum.c:
* tests/examples/spectrum/.cvsignore:
* tests/examples/spectrum/Makefile.am:
* tests/examples/spectrum/spectrum-example.c:
Add a simple example application for the spectrum element, include it
in the docs, and fix some documentation ambiguities.
Fixes: #348085
2008-02-08 Jan Schmidt <jan.schmidt@sun.com>
* gst/equalizer/Makefile.am:

3
docs/plugins/Makefile.am
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@ -154,7 +154,8 @@ EXTRA_HFILES = \
# example code that needs to be converted to xml and placed in xml/
EXAMPLE_CFILES = \
$(top_srcdir)/tests/examples/level/level-example.c
$(top_srcdir)/tests/examples/level/level-example.c \
$(top_srcdir)/tests/examples/spectrum/spectrum-example.c
# Images to copy into HTML directory.
HTML_IMAGES =

22
gst/spectrum/gstspectrum.c
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@ -25,19 +25,19 @@
* <refsect2>
* <para>
* The Spectrum element analyzes the frequency spectrum of an audio signal.
* If #GstSpectrum:message property is #TRUE it sends analysis results as
* application message named
* If the #GstSpectrum:message property is #TRUE, it sends analysis results as
* application messages named
* <classname>&quot;spectrum&quot;</classname> after each interval of time given
* by the #GstSpectrum:interval property.
* </para>
* <para>
* The message's structure contains three fields:
* The message's structure contains some combination of these fields:
* <itemizedlist>
* <listitem>
* <para>
* #GstClockTime
* <classname>&quot;endtime&quot;</classname>:
* the end time of the buffer that triggered the message
* the end time of the buffer that triggered the message. Always present.
* </para>
* </listitem>
* <listitem>
@ -45,24 +45,30 @@
* #GstValueList of #gfloat
* <classname>&quot;magnitude&quot;</classname>:
* the level for each frequency band in dB. All values below the value of the
* #GstSpectrum:threshold property will be set to the threshold.
* #GstSpectrum:threshold property will be set to the threshold. Only present
* if the message-magnitude property is true.
* </para>
* </listitem>
* <listitem>
* <para>
* #GstValueList of #gfloat
* <classname>&quot;phase&quot;</classname>:
* the phase for each frequency band. The value is between -pi and pi.
* The phase for each frequency band. The value is between -pi and pi. Only
* present if the message-phase property is true.
* </para>
* </listitem>
* </itemizedlist>
* </para>
* <para>
* This element cannot be used with the gst-launch command in a sensible way.
* The included demo shows how to use it in an application.
* This sample code demonstrates how to use it in an application.
* </para>
* <title>Example application</title>
* <para>
* <include xmlns="http://www.w3.org/2003/XInclude" href="element-spectrum-example.xml" />
* </para>
* <para>
* Last reviewed on 2008-02-07 (0.10.6)
* Last reviewed on 2008-02-09 (0.10.6)
* </para>
* </refsect2>
*/

1
tests/examples/spectrum/.gitignore vendored
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@ -1,2 +1,3 @@
demo-audiotest
demo-osssrc
spectrum-example

6
tests/examples/spectrum/Makefile.am
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@ -1,5 +1,5 @@
if HAVE_GTK
noinst_PROGRAMS = demo-osssrc demo-audiotest
noinst_PROGRAMS = demo-osssrc demo-audiotest spectrum-example
endif
demo_osssrc_SOURCES = demo-osssrc.c
@ -10,3 +10,7 @@ demo_audiotest_SOURCES = demo-audiotest.c
demo_audiotest_CFLAGS = $(GST_BASE_CFLAGS) $(GST_CFLAGS) $(GTK_CFLAGS)
demo_audiotest_LDFLAGS = $(GST_BASE_LIBS) $(GST_LIBS) $(GTK_LIBS)
spectrum_example_SOURCES = spectrum-example.c
spectrum_example_CFLAGS = $(GST_BASE_CFLAGS) $(GST_CFLAGS) $(GTK_CFLAGS)
spectrum_example_LDFLAGS = $(GST_BASE_LIBS) $(GST_LIBS) $(GTK_LIBS)

122
tests/examples/spectrum/spectrum-example.c Normal file
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@ -0,0 +1,122 @@
/* GStreamer
* Copyright (C) 2006 Stefan Kost <ensonic@users.sf.net>
* Copyright (C) 2008 Jan Schmidt <jan.schmidt@sun.com>
*
* 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.
*/
#include <string.h>
#include <gst/gst.h>
static guint spect_bands = 20;
#define AUDIOFREQ 32000
/* receive spectral data from element message */
gboolean
message_handler (GstBus * bus, GstMessage * message, gpointer data)
{
if (message->type == GST_MESSAGE_ELEMENT) {
const GstStructure *s = gst_message_get_structure (message);
const gchar *name = gst_structure_get_name (s);
GstClockTime endtime;
if (strcmp (name, "spectrum") == 0) {
const GValue *magnitudes;
const GValue *phases;
const GValue *mag, *phase;
gdouble freq;
guint i;
if (!gst_structure_get_clock_time (s, "endtime", &endtime))
endtime = GST_CLOCK_TIME_NONE;
g_print ("New spectrum message, endtime %" GST_TIME_FORMAT "\n",
GST_TIME_ARGS (endtime));
magnitudes = gst_structure_get_value (s, "magnitude");
phases = gst_structure_get_value (s, "phase");
for (i = 0; i < spect_bands; ++i) {
freq = (gdouble) ((AUDIOFREQ / 2) * i + AUDIOFREQ / 4) / spect_bands;
mag = gst_value_list_get_value (magnitudes, i);
phase = gst_value_list_get_value (phases, i);
if (mag != NULL && phase != NULL) {
g_print ("band %d (freq %g): magnitude %f dB phase %f\n", i, freq,
g_value_get_float (mag), g_value_get_float (phase));
}
}
g_print ("\n");
}
}
return TRUE;
}
int
main (int argc, char *argv[])
{
GstElement *bin;
GstElement *src, *audioconvert, *spectrum, *sink;
GstBus *bus;
GstCaps *caps;
GMainLoop *loop;
gst_init (&argc, &argv);
bin = gst_pipeline_new ("bin");
src = gst_element_factory_make ("audiotestsrc", "src");
g_object_set (G_OBJECT (src), "wave", 0, "freq", 6000.0, NULL);
audioconvert = gst_element_factory_make ("audioconvert", NULL);
g_assert (audioconvert);
spectrum = gst_element_factory_make ("spectrum", "spectrum");
g_object_set (G_OBJECT (spectrum), "bands", spect_bands, "threshold", -80,
"message", TRUE, "message-phase", TRUE, NULL);
sink = gst_element_factory_make ("fakesink", "sink");
g_object_set (G_OBJECT (sink), "sync", TRUE, NULL);
gst_bin_add_many (GST_BIN (bin), src, audioconvert, spectrum, sink, NULL);
caps = gst_caps_new_simple ("audio/x-raw-int",
"rate", G_TYPE_INT, AUDIOFREQ, NULL);
if (!gst_element_link (src, audioconvert) ||
!gst_element_link_filtered (audioconvert, spectrum, caps) ||
!gst_element_link (spectrum, sink)) {
fprintf (stderr, "can't link elements\n");
exit (1);
}
gst_caps_unref (caps);
bus = gst_element_get_bus (bin);
gst_bus_add_watch (bus, message_handler, NULL);
gst_object_unref (bus);
gst_element_set_state (bin, GST_STATE_PLAYING);
/* we need to run a GLib main loop to get the messages */
loop = g_main_loop_new (NULL, FALSE);
g_main_loop_run (loop);
gst_element_set_state (bin, GST_STATE_NULL);
gst_object_unref (bin);
return 0;
}