3 * Copyright (C) 2008 Wim Taymans <wim.taymans@gmail.com>
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Library General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Library General Public License for more details.
15 * You should have received a copy of the GNU Library General Public
16 * License along with this library; if not, write to the
17 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 * Boston, MA 02111-1307, USA.
22 * SECTION:element-audiokaraoke
24 * Remove the voice from audio by filtering the center channel.
25 * This plugin is useful for karaoke applications.
28 * <title>Example launch line</title>
30 * gst-launch filesrc location=song.ogg ! oggdemux ! vorbisdec ! audiokaraoke ! audioconvert ! alsasink
42 #include <gst/base/gstbasetransform.h>
43 #include <gst/audio/audio.h>
44 #include <gst/audio/gstaudiofilter.h>
46 #include "audiokaraoke.h"
48 #define GST_CAT_DEFAULT gst_audio_karaoke_debug
49 GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT);
51 /* Filter signals and args */
58 #define DEFAULT_LEVEL 1.0
59 #define DEFAULT_MONO_LEVEL 1.0
60 #define DEFAULT_FILTER_BAND 220.0
61 #define DEFAULT_FILTER_WIDTH 100.0
73 #define ALLOWED_CAPS \
75 " format=(string){"GST_AUDIO_NE(S16)","GST_AUDIO_NE(F32)"}," \
76 " rate=(int)[1,MAX]," \
78 " channel-mask=(bitmask)0x3," \
79 " layout=(string) interleaved"
81 G_DEFINE_TYPE (GstAudioKaraoke, gst_audio_karaoke, GST_TYPE_AUDIO_FILTER);
83 static void gst_audio_karaoke_set_property (GObject * object, guint prop_id,
84 const GValue * value, GParamSpec * pspec);
85 static void gst_audio_karaoke_get_property (GObject * object, guint prop_id,
86 GValue * value, GParamSpec * pspec);
88 static gboolean gst_audio_karaoke_setup (GstAudioFilter * filter,
89 const GstAudioInfo * info);
90 static GstFlowReturn gst_audio_karaoke_transform_ip (GstBaseTransform * base,
93 static void gst_audio_karaoke_transform_int (GstAudioKaraoke * filter,
94 gint16 * data, guint num_samples);
95 static void gst_audio_karaoke_transform_float (GstAudioKaraoke * filter,
96 gfloat * data, guint num_samples);
98 /* GObject vmethod implementations */
101 gst_audio_karaoke_class_init (GstAudioKaraokeClass * klass)
103 GObjectClass *gobject_class;
104 GstElementClass *gstelement_class;
107 GST_DEBUG_CATEGORY_INIT (gst_audio_karaoke_debug, "audiokaraoke", 0,
108 "audiokaraoke element");
110 gobject_class = (GObjectClass *) klass;
111 gstelement_class = (GstElementClass *) klass;
113 gobject_class->set_property = gst_audio_karaoke_set_property;
114 gobject_class->get_property = gst_audio_karaoke_get_property;
116 g_object_class_install_property (gobject_class, PROP_LEVEL,
117 g_param_spec_float ("level", "Level",
118 "Level of the effect (1.0 = full)", 0.0, 1.0, DEFAULT_LEVEL,
119 G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE | G_PARAM_STATIC_STRINGS));
121 g_object_class_install_property (gobject_class, PROP_MONO_LEVEL,
122 g_param_spec_float ("mono-level", "Mono Level",
123 "Level of the mono channel (1.0 = full)", 0.0, 1.0, DEFAULT_LEVEL,
124 G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE | G_PARAM_STATIC_STRINGS));
126 g_object_class_install_property (gobject_class, PROP_FILTER_BAND,
127 g_param_spec_float ("filter-band", "Filter Band",
128 "The Frequency band of the filter", 0.0, 441.0, DEFAULT_FILTER_BAND,
129 G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE | G_PARAM_STATIC_STRINGS));
131 g_object_class_install_property (gobject_class, PROP_FILTER_WIDTH,
132 g_param_spec_float ("filter-width", "Filter Width",
133 "The Frequency width of the filter", 0.0, 100.0, DEFAULT_FILTER_WIDTH,
134 G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE | G_PARAM_STATIC_STRINGS));
136 gst_element_class_set_details_simple (gstelement_class, "AudioKaraoke",
137 "Filter/Effect/Audio",
138 "Removes voice from sound", "Wim Taymans <wim.taymans@gmail.com>");
140 caps = gst_caps_from_string (ALLOWED_CAPS);
141 gst_audio_filter_class_add_pad_templates (GST_AUDIO_FILTER_CLASS (klass),
143 gst_caps_unref (caps);
145 GST_AUDIO_FILTER_CLASS (klass)->setup =
146 GST_DEBUG_FUNCPTR (gst_audio_karaoke_setup);
147 GST_BASE_TRANSFORM_CLASS (klass)->transform_ip =
148 GST_DEBUG_FUNCPTR (gst_audio_karaoke_transform_ip);
152 gst_audio_karaoke_init (GstAudioKaraoke * filter)
154 gst_base_transform_set_in_place (GST_BASE_TRANSFORM (filter), TRUE);
155 gst_base_transform_set_gap_aware (GST_BASE_TRANSFORM (filter), TRUE);
157 filter->level = DEFAULT_LEVEL;
158 filter->mono_level = DEFAULT_MONO_LEVEL;
159 filter->filter_band = DEFAULT_FILTER_BAND;
160 filter->filter_width = DEFAULT_FILTER_WIDTH;
164 update_filter (GstAudioKaraoke * filter)
169 rate = GST_AUDIO_FILTER_RATE (filter);
173 C = exp (-2 * G_PI * filter->filter_width / rate);
174 B = -4 * C / (1 + C) * cos (2 * G_PI * filter->filter_band / rate);
175 A = sqrt (1 - B * B / (4 * C)) * (1 - C);
185 gst_audio_karaoke_set_property (GObject * object, guint prop_id,
186 const GValue * value, GParamSpec * pspec)
188 GstAudioKaraoke *filter;
190 filter = GST_AUDIO_KARAOKE (object);
194 filter->level = g_value_get_float (value);
196 case PROP_MONO_LEVEL:
197 filter->mono_level = g_value_get_float (value);
199 case PROP_FILTER_BAND:
200 filter->filter_band = g_value_get_float (value);
201 update_filter (filter);
203 case PROP_FILTER_WIDTH:
204 filter->filter_width = g_value_get_float (value);
205 update_filter (filter);
208 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
214 gst_audio_karaoke_get_property (GObject * object, guint prop_id,
215 GValue * value, GParamSpec * pspec)
217 GstAudioKaraoke *filter;
219 filter = GST_AUDIO_KARAOKE (object);
223 g_value_set_float (value, filter->level);
225 case PROP_MONO_LEVEL:
226 g_value_set_float (value, filter->mono_level);
228 case PROP_FILTER_BAND:
229 g_value_set_float (value, filter->filter_band);
231 case PROP_FILTER_WIDTH:
232 g_value_set_float (value, filter->filter_width);
235 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
240 /* GstAudioFilter vmethod implementations */
243 gst_audio_karaoke_setup (GstAudioFilter * base, const GstAudioInfo * info)
245 GstAudioKaraoke *filter = GST_AUDIO_KARAOKE (base);
248 switch (GST_AUDIO_INFO_FORMAT (info)) {
249 case GST_AUDIO_FORMAT_S16:
250 filter->process = (GstAudioKaraokeProcessFunc)
251 gst_audio_karaoke_transform_int;
253 case GST_AUDIO_FORMAT_F32:
254 filter->process = (GstAudioKaraokeProcessFunc)
255 gst_audio_karaoke_transform_float;
261 update_filter (filter);
267 gst_audio_karaoke_transform_int (GstAudioKaraoke * filter,
268 gint16 * data, guint num_samples)
275 channels = GST_AUDIO_FILTER_CHANNELS (filter);
276 level = filter->level * 256;
278 for (i = 0; i < num_samples; i += channels) {
279 /* get left and right inputs */
284 y = (filter->A * x - filter->B * filter->y1) - filter->C * filter->y2;
285 filter->y2 = filter->y1;
287 /* filter mono signal */
288 o = (int) (y * filter->mono_level);
289 o = CLAMP (o, G_MININT16, G_MAXINT16);
290 o = (o * level) >> 8;
291 /* now cut the center */
292 x = l - ((r * level) >> 8) + o;
293 r = r - ((l * level) >> 8) + o;
294 data[i] = CLAMP (x, G_MININT16, G_MAXINT16);
295 data[i + 1] = CLAMP (r, G_MININT16, G_MAXINT16);
300 gst_audio_karaoke_transform_float (GstAudioKaraoke * filter,
301 gfloat * data, guint num_samples)
308 channels = GST_AUDIO_FILTER_CHANNELS (filter);
310 for (i = 0; i < num_samples; i += channels) {
311 /* get left and right inputs */
315 y = (filter->A * ((l + r) / 2.0) - filter->B * filter->y1) -
316 filter->C * filter->y2;
317 filter->y2 = filter->y1;
319 /* filter mono signal */
320 o = y * filter->mono_level * filter->level;
321 /* now cut the center */
322 data[i] = l - (r * filter->level) + o;
323 data[i + 1] = r - (l * filter->level) + o;
327 /* GstBaseTransform vmethod implementations */
329 gst_audio_karaoke_transform_ip (GstBaseTransform * base, GstBuffer * buf)
331 GstAudioKaraoke *filter = GST_AUDIO_KARAOKE (base);
333 GstClockTime timestamp, stream_time;
336 timestamp = GST_BUFFER_TIMESTAMP (buf);
338 gst_segment_to_stream_time (&base->segment, GST_FORMAT_TIME, timestamp);
340 GST_DEBUG_OBJECT (filter, "sync to %" GST_TIME_FORMAT,
341 GST_TIME_ARGS (timestamp));
343 if (GST_CLOCK_TIME_IS_VALID (stream_time))
344 gst_object_sync_values (GST_OBJECT (filter), stream_time);
346 if (gst_base_transform_is_passthrough (base) ||
347 G_UNLIKELY (GST_BUFFER_FLAG_IS_SET (buf, GST_BUFFER_FLAG_GAP)))
350 gst_buffer_map (buf, &map, GST_MAP_READWRITE);
351 num_samples = map.size / GST_AUDIO_FILTER_BPS (filter);
353 filter->process (filter, map.data, num_samples);
355 gst_buffer_unmap (buf, &map);