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/* GStreamer
* Copyright (C) 2013 David Schleef <ds@schleef.org>
*
* 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 Street, Suite 500,
* Boston, MA 02110-1335, USA.
*/
/**
* SECTION:element-gstaudiochannelmix
*
* The audiochannelmix element mixes channels in stereo audio based on
* properties set on the element. The primary purpose is reconstruct
* equal left/right channels on an input stream that has audio in only
* one channel.
*
* <refsect2>
* <title>Example launch line</title>
* |[
* gst-launch-1.0 -v audiotestsrc ! audiochannelmix ! autoaudiosink
* ]|
* </refsect2>
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <gst/gst.h>
#include <gst/audio/gstaudiofilter.h>
#include "gstaudiochannelmix.h"
#include <math.h>
GST_DEBUG_CATEGORY_STATIC (gst_audio_channel_mix_debug_category);
#define GST_CAT_DEFAULT gst_audio_channel_mix_debug_category
/* prototypes */
static void gst_audio_channel_mix_set_property (GObject * object,
guint property_id, const GValue * value, GParamSpec * pspec);
static void gst_audio_channel_mix_get_property (GObject * object,
guint property_id, GValue * value, GParamSpec * pspec);
static gboolean gst_audio_channel_mix_setup (GstAudioFilter * filter,
const GstAudioInfo * info);
static GstFlowReturn gst_audio_channel_mix_transform_ip (GstBaseTransform *
trans, GstBuffer * buf);
enum
{
PROP_0,
PROP_LEFT_TO_LEFT,
PROP_LEFT_TO_RIGHT,
PROP_RIGHT_TO_LEFT,
PROP_RIGHT_TO_RIGHT
};
/* pad templates */
static GstStaticPadTemplate gst_audio_channel_mix_src_template =
GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("audio/x-raw,format=S16LE,rate=[1,max],"
"channels=2,layout=interleaved")
);
static GstStaticPadTemplate gst_audio_channel_mix_sink_template =
GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("audio/x-raw,format=S16LE,rate=[1,max],"
"channels=2,layout=interleaved")
);
/* class initialization */
G_DEFINE_TYPE_WITH_CODE (GstAudioChannelMix, gst_audio_channel_mix,
GST_TYPE_AUDIO_FILTER,
GST_DEBUG_CATEGORY_INIT (gst_audio_channel_mix_debug_category,
"audiochannelmix", 0, "debug category for audiochannelmix element"));
static void
gst_audio_channel_mix_class_init (GstAudioChannelMixClass * klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
GstBaseTransformClass *base_transform_class =
GST_BASE_TRANSFORM_CLASS (klass);
GstAudioFilterClass *audio_filter_class = GST_AUDIO_FILTER_CLASS (klass);
/* Setting up pads and setting metadata should be moved to
base_class_init if you intend to subclass this class. */
gst_element_class_add_static_pad_template (GST_ELEMENT_CLASS (klass),
&gst_audio_channel_mix_src_template);
gst_element_class_add_static_pad_template (GST_ELEMENT_CLASS (klass),
&gst_audio_channel_mix_sink_template);
gst_element_class_set_static_metadata (GST_ELEMENT_CLASS (klass),
"Simple stereo audio mixer", "Audio/Mixer", "Mixes left/right channels "
"of stereo audio", "David Schleef <ds@schleef.org>");
gobject_class->set_property = gst_audio_channel_mix_set_property;
gobject_class->get_property = gst_audio_channel_mix_get_property;
audio_filter_class->setup = GST_DEBUG_FUNCPTR (gst_audio_channel_mix_setup);
base_transform_class->transform_ip =
GST_DEBUG_FUNCPTR (gst_audio_channel_mix_transform_ip);
g_object_class_install_property (gobject_class, PROP_LEFT_TO_LEFT,
g_param_spec_double ("left-to-left", "Left to Left",
"Left channel to left channel gain",
-G_MAXDOUBLE, G_MAXDOUBLE, 1.0,
GST_PARAM_CONTROLLABLE | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class, PROP_LEFT_TO_RIGHT,
g_param_spec_double ("left-to-right", "Left to Right",
"Left channel to right channel gain",
-G_MAXDOUBLE, G_MAXDOUBLE, 0.0,
GST_PARAM_CONTROLLABLE | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class, PROP_RIGHT_TO_LEFT,
g_param_spec_double ("right-to-left", "Right to Left",
"Right channel to left channel gain",
-G_MAXDOUBLE, G_MAXDOUBLE, 0.0,
GST_PARAM_CONTROLLABLE | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class, PROP_RIGHT_TO_RIGHT,
g_param_spec_double ("right-to-right", "Right to Right",
"Right channel to right channel gain",
-G_MAXDOUBLE, G_MAXDOUBLE, 1.0,
GST_PARAM_CONTROLLABLE | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
}
static void
gst_audio_channel_mix_init (GstAudioChannelMix * audiochannelmix)
{
audiochannelmix->left_to_left = 1.0;
audiochannelmix->left_to_right = 0.0;
audiochannelmix->right_to_left = 0.0;
audiochannelmix->right_to_right = 1.0;
}
void
gst_audio_channel_mix_set_property (GObject * object, guint property_id,
const GValue * value, GParamSpec * pspec)
{
GstAudioChannelMix *audiochannelmix = GST_AUDIO_CHANNEL_MIX (object);
GST_DEBUG_OBJECT (audiochannelmix, "set_property");
switch (property_id) {
case PROP_LEFT_TO_LEFT:
audiochannelmix->left_to_left = g_value_get_double (value);
break;
case PROP_LEFT_TO_RIGHT:
audiochannelmix->left_to_right = g_value_get_double (value);
break;
case PROP_RIGHT_TO_LEFT:
audiochannelmix->right_to_left = g_value_get_double (value);
break;
case PROP_RIGHT_TO_RIGHT:
audiochannelmix->right_to_right = g_value_get_double (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
break;
}
}
void
gst_audio_channel_mix_get_property (GObject * object, guint property_id,
GValue * value, GParamSpec * pspec)
{
GstAudioChannelMix *audiochannelmix = GST_AUDIO_CHANNEL_MIX (object);
GST_DEBUG_OBJECT (audiochannelmix, "get_property");
switch (property_id) {
case PROP_LEFT_TO_LEFT:
g_value_set_double (value, audiochannelmix->left_to_left);
break;
case PROP_LEFT_TO_RIGHT:
g_value_set_double (value, audiochannelmix->left_to_right);
break;
case PROP_RIGHT_TO_LEFT:
g_value_set_double (value, audiochannelmix->right_to_left);
break;
case PROP_RIGHT_TO_RIGHT:
g_value_set_double (value, audiochannelmix->right_to_right);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
break;
}
}
static gboolean
gst_audio_channel_mix_setup (GstAudioFilter * filter, const GstAudioInfo * info)
{
#ifndef GST_DISABLE_GST_DEBUG
GstAudioChannelMix *audiochannelmix = GST_AUDIO_CHANNEL_MIX (filter);
GST_DEBUG_OBJECT (audiochannelmix, "setup");
#endif
return TRUE;
}
static GstFlowReturn
gst_audio_channel_mix_transform_ip (GstBaseTransform * trans, GstBuffer * buf)
{
GstAudioChannelMix *audiochannelmix = GST_AUDIO_CHANNEL_MIX (trans);
int n;
GstMapInfo map;
int i;
double ll = audiochannelmix->left_to_left;
double lr = audiochannelmix->left_to_right;
double rl = audiochannelmix->right_to_left;
double rr = audiochannelmix->right_to_right;
int l, r;
gint16 *data;
GST_DEBUG_OBJECT (audiochannelmix, "transform_ip");
gst_buffer_map (buf, &map, GST_MAP_WRITE | GST_MAP_READ);
n = gst_buffer_get_size (buf) >> 2;
data = (gint16 *) map.data;
for (i = 0; i < n; i++) {
l = data[2 * i + 0];
r = data[2 * i + 1];
data[2 * i + 0] = CLAMP (rint (ll * l + rl * r), -32768, 32767);
data[2 * i + 1] = CLAMP (rint (lr * l + rr * r), -32768, 32767);
}
gst_buffer_unmap (buf, &map);
return GST_FLOW_OK;
}
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