3 * Copyright (C) 2007 Sebastian Dröge <slomo@circular-chaos.org>
4 * Copyright (C) 2006 Stefan Kost <ensonic@users.sf.net>
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Library General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Library General Public License for more details.
16 * You should have received a copy of the GNU Library General Public
17 * License along with this library; if not, write to the
18 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 * Boston, MA 02111-1307, USA.
23 * SECTION:element-audioinvert
25 * Swaps upper and lower half of audio samples. Mixing an inverted sample on top of
26 * the original with a slight delay can produce effects that sound like resonance.
27 * Creating a stereo sample from a mono source, with one channel inverted produces wide-stereo sounds.
30 * <title>Example launch line</title>
32 * gst-launch audiotestsrc wave=saw ! audioinvert invert=0.4 ! alsasink
33 * gst-launch filesrc location="melo1.ogg" ! oggdemux ! vorbisdec ! audioconvert ! audioinvert invert=0.4 ! alsasink
34 * gst-launch audiotestsrc wave=saw ! audioconvert ! audioinvert invert=0.4 ! audioconvert ! alsasink
44 #include <gst/base/gstbasetransform.h>
45 #include <gst/audio/audio.h>
46 #include <gst/audio/gstaudiofilter.h>
47 #include <gst/controller/gstcontroller.h>
49 #include "audioinvert.h"
51 #define GST_CAT_DEFAULT gst_audio_invert_debug
52 GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT);
54 /* Filter signals and args */
67 #define ALLOWED_CAPS \
69 " format=(string) {"GST_AUDIO_NE(S16)","GST_AUDIO_NE(F32)"}," \
70 " rate=(int)[1,MAX]," \
71 " channels=(int)[1,MAX] "
73 G_DEFINE_TYPE (GstAudioInvert, gst_audio_invert, GST_TYPE_AUDIO_FILTER);
75 static void gst_audio_invert_set_property (GObject * object, guint prop_id,
76 const GValue * value, GParamSpec * pspec);
77 static void gst_audio_invert_get_property (GObject * object, guint prop_id,
78 GValue * value, GParamSpec * pspec);
80 static gboolean gst_audio_invert_setup (GstAudioFilter * filter,
82 static GstFlowReturn gst_audio_invert_transform_ip (GstBaseTransform * base,
85 static void gst_audio_invert_transform_int (GstAudioInvert * filter,
86 gint16 * data, guint num_samples);
87 static void gst_audio_invert_transform_float (GstAudioInvert * filter,
88 gfloat * data, guint num_samples);
90 /* GObject vmethod implementations */
93 gst_audio_invert_class_init (GstAudioInvertClass * klass)
95 GObjectClass *gobject_class;
96 GstElementClass *gstelement_class;
99 GST_DEBUG_CATEGORY_INIT (gst_audio_invert_debug, "audioinvert", 0,
100 "audioinvert element");
102 gobject_class = (GObjectClass *) klass;
103 gstelement_class = (GstElementClass *) klass;
105 gobject_class->set_property = gst_audio_invert_set_property;
106 gobject_class->get_property = gst_audio_invert_get_property;
108 g_object_class_install_property (gobject_class, PROP_DEGREE,
109 g_param_spec_float ("degree", "Degree",
110 "Degree of inversion", 0.0, 1.0,
112 G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE | G_PARAM_STATIC_STRINGS));
114 gst_element_class_set_details_simple (gstelement_class, "Audio inversion",
115 "Filter/Effect/Audio",
116 "Swaps upper and lower half of audio samples",
117 "Sebastian Dröge <slomo@circular-chaos.org>");
119 caps = gst_caps_from_string (ALLOWED_CAPS);
120 gst_audio_filter_class_add_pad_templates (GST_AUDIO_FILTER_CLASS (klass),
122 gst_caps_unref (caps);
124 GST_AUDIO_FILTER_CLASS (klass)->setup =
125 GST_DEBUG_FUNCPTR (gst_audio_invert_setup);
126 GST_BASE_TRANSFORM_CLASS (klass)->transform_ip =
127 GST_DEBUG_FUNCPTR (gst_audio_invert_transform_ip);
131 gst_audio_invert_init (GstAudioInvert * filter)
133 filter->degree = 0.0;
134 gst_base_transform_set_in_place (GST_BASE_TRANSFORM (filter), TRUE);
135 gst_base_transform_set_gap_aware (GST_BASE_TRANSFORM (filter), TRUE);
139 gst_audio_invert_set_property (GObject * object, guint prop_id,
140 const GValue * value, GParamSpec * pspec)
142 GstAudioInvert *filter = GST_AUDIO_INVERT (object);
146 filter->degree = g_value_get_float (value);
147 gst_base_transform_set_passthrough (GST_BASE_TRANSFORM (filter),
148 filter->degree == 0.0);
151 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
157 gst_audio_invert_get_property (GObject * object, guint prop_id,
158 GValue * value, GParamSpec * pspec)
160 GstAudioInvert *filter = GST_AUDIO_INVERT (object);
164 g_value_set_float (value, filter->degree);
167 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
172 /* GstAudioFilter vmethod implementations */
175 gst_audio_invert_setup (GstAudioFilter * base, GstAudioInfo * info)
177 GstAudioInvert *filter = GST_AUDIO_INVERT (base);
180 switch (GST_AUDIO_INFO_FORMAT (info)) {
181 case GST_AUDIO_FORMAT_S16:
182 filter->process = (GstAudioInvertProcessFunc)
183 gst_audio_invert_transform_int;
185 case GST_AUDIO_FORMAT_F32:
186 filter->process = (GstAudioInvertProcessFunc)
187 gst_audio_invert_transform_float;
197 gst_audio_invert_transform_int (GstAudioInvert * filter,
198 gint16 * data, guint num_samples)
201 gfloat dry = 1.0 - filter->degree;
204 for (i = 0; i < num_samples; i++) {
205 val = (*data) * dry + (-1 - (*data)) * filter->degree;
206 *data++ = (gint16) CLAMP (val, G_MININT16, G_MAXINT16);
211 gst_audio_invert_transform_float (GstAudioInvert * filter,
212 gfloat * data, guint num_samples)
215 gfloat dry = 1.0 - filter->degree;
218 for (i = 0; i < num_samples; i++) {
219 val = (*data) * dry - (*data) * filter->degree;
224 /* GstBaseTransform vmethod implementations */
226 gst_audio_invert_transform_ip (GstBaseTransform * base, GstBuffer * buf)
228 GstAudioInvert *filter = GST_AUDIO_INVERT (base);
230 GstClockTime timestamp, stream_time;
234 timestamp = GST_BUFFER_TIMESTAMP (buf);
236 gst_segment_to_stream_time (&base->segment, GST_FORMAT_TIME, timestamp);
238 GST_DEBUG_OBJECT (filter, "sync to %" GST_TIME_FORMAT,
239 GST_TIME_ARGS (timestamp));
241 if (GST_CLOCK_TIME_IS_VALID (stream_time))
242 gst_object_sync_values (G_OBJECT (filter), stream_time);
244 if (gst_base_transform_is_passthrough (base) ||
245 G_UNLIKELY (GST_BUFFER_FLAG_IS_SET (buf, GST_BUFFER_FLAG_GAP)))
248 data = gst_buffer_map (buf, &size, NULL, GST_MAP_READWRITE);
249 num_samples = size / GST_AUDIO_FILTER_BPS (filter);
251 filter->process (filter, data, num_samples);
253 gst_buffer_unmap (buf, data, size);