gstreamer/gst/stereo/gststereo.c
2017-05-18 10:53:48 +01:00

214 lines
5.8 KiB
C

/* GStreamer
* Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
*
* 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.
*/
/* This effect is borrowed from xmms-0.6.1, though I mangled it so badly in
* the process of copying it over that the xmms people probably won't want
* any credit for it ;-)
*/
/**
* SECTION:element-stereo
* @title: stereo
*
* Create a wide stereo effect.
*
* ## Example pipelines
* |[
* gst-launch-1.0 -v filesrc location=sine.ogg ! oggdemux ! vorbisdec ! audioconvert ! stereo ! audioconvert ! audioresample ! alsasink
* ]| Play an Ogg/Vorbis file.
*
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "gststereo.h"
#include <gst/gst.h>
#include <gst/base/gstbasetransform.h>
#include <gst/audio/audio.h>
#include <gst/audio/gstaudiofilter.h>
#define ALLOWED_CAPS \
"audio/x-raw," \
" format = "GST_AUDIO_NE (S16) "," \
" rate = (int) [ 1, MAX ]," \
" channels = (int) 2"
/* Stereo signals and args */
enum
{
/* FILL ME */
LAST_SIGNAL
};
enum
{
PROP_0,
PROP_ACTIVE,
PROP_STEREO
};
static void gst_stereo_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec);
static void gst_stereo_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec);
static GstFlowReturn gst_stereo_transform_ip (GstBaseTransform * base,
GstBuffer * outbuf);
G_DEFINE_TYPE (GstStereo, gst_stereo, GST_TYPE_AUDIO_FILTER);
static void
gst_stereo_class_init (GstStereoClass * klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
GstBaseTransformClass *trans_class = GST_BASE_TRANSFORM_CLASS (klass);
GstAudioFilterClass *audiofilter_class = GST_AUDIO_FILTER_CLASS (klass);
GstCaps *caps;
gst_element_class_set_static_metadata (element_class, "Stereo effect",
"Filter/Effect/Audio",
"Muck with the stereo signal to enhance its 'stereo-ness'",
"Erik Walthinsen <omega@cse.ogi.edu>");
caps = gst_caps_from_string (ALLOWED_CAPS);
gst_audio_filter_class_add_pad_templates (audiofilter_class, caps);
gst_caps_unref (caps);
gobject_class->set_property = gst_stereo_set_property;
gobject_class->get_property = gst_stereo_get_property;
g_object_class_install_property (gobject_class, PROP_ACTIVE,
g_param_spec_boolean ("active", "active", "active",
TRUE,
G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class, PROP_STEREO,
g_param_spec_float ("stereo", "stereo", "stereo",
0.0, 1.0, 0.1f,
G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE | G_PARAM_STATIC_STRINGS));
trans_class->transform_ip = GST_DEBUG_FUNCPTR (gst_stereo_transform_ip);
}
static void
gst_stereo_init (GstStereo * stereo)
{
stereo->active = TRUE;
stereo->stereo = 0.1f;
}
static GstFlowReturn
gst_stereo_transform_ip (GstBaseTransform * base, GstBuffer * outbuf)
{
GstStereo *stereo = GST_STEREO (base);
gint samples;
gint i;
gdouble avg, ldiff, rdiff, tmp;
gdouble mul = stereo->stereo;
gint16 *data;
GstMapInfo info;
if (!gst_buffer_map (outbuf, &info, GST_MAP_READWRITE))
return GST_FLOW_ERROR;
data = (gint16 *) info.data;
samples = info.size / 2;
if (GST_CLOCK_TIME_IS_VALID (GST_BUFFER_TIMESTAMP (outbuf)))
gst_object_sync_values (GST_OBJECT (stereo), GST_BUFFER_TIMESTAMP (outbuf));
if (stereo->active) {
for (i = 0; i < samples / 2; i += 2) {
avg = (data[i] + data[i + 1]) / 2;
ldiff = data[i] - avg;
rdiff = data[i + 1] - avg;
tmp = avg + ldiff * mul;
if (tmp < -32768)
tmp = -32768;
if (tmp > 32767)
tmp = 32767;
data[i] = tmp;
tmp = avg + rdiff * mul;
if (tmp < -32768)
tmp = -32768;
if (tmp > 32767)
tmp = 32767;
data[i + 1] = tmp;
}
}
gst_buffer_unmap (outbuf, &info);
return GST_FLOW_OK;
}
static void
gst_stereo_set_property (GObject * object, guint prop_id, const GValue * value,
GParamSpec * pspec)
{
GstStereo *stereo = GST_STEREO (object);
switch (prop_id) {
case PROP_ACTIVE:
stereo->active = g_value_get_boolean (value);
break;
case PROP_STEREO:
stereo->stereo = g_value_get_float (value) * 10.0;
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_stereo_get_property (GObject * object, guint prop_id, GValue * value,
GParamSpec * pspec)
{
GstStereo *stereo = GST_STEREO (object);
switch (prop_id) {
case PROP_ACTIVE:
g_value_set_boolean (value, stereo->active);
break;
case PROP_STEREO:
g_value_set_float (value, stereo->stereo / 10.0);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static gboolean
plugin_init (GstPlugin * plugin)
{
return gst_element_register (plugin, "stereo", GST_RANK_NONE,
GST_TYPE_STEREO);
}
GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
GST_VERSION_MINOR,
stereo,
"Muck with the stereo signal, enhance its 'stereo-ness'",
plugin_init, VERSION, GST_LICENSE, GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN)