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>
48 #include "audioinvert.h"
50 #define GST_CAT_DEFAULT gst_audio_invert_debug
51 GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT);
53 /* Filter signals and args */
66 #define ALLOWED_CAPS \
68 " format=(string) {"GST_AUDIO_NE(S16)","GST_AUDIO_NE(F32)"}," \
69 " rate=(int)[1,MAX]," \
70 " channels=(int)[1,MAX] "
72 G_DEFINE_TYPE (GstAudioInvert, gst_audio_invert, GST_TYPE_AUDIO_FILTER);
74 static void gst_audio_invert_set_property (GObject * object, guint prop_id,
75 const GValue * value, GParamSpec * pspec);
76 static void gst_audio_invert_get_property (GObject * object, guint prop_id,
77 GValue * value, GParamSpec * pspec);
79 static gboolean gst_audio_invert_setup (GstAudioFilter * filter,
80 const GstAudioInfo * info);
81 static GstFlowReturn gst_audio_invert_transform_ip (GstBaseTransform * base,
84 static void gst_audio_invert_transform_int (GstAudioInvert * filter,
85 gint16 * data, guint num_samples);
86 static void gst_audio_invert_transform_float (GstAudioInvert * filter,
87 gfloat * data, guint num_samples);
89 /* GObject vmethod implementations */
92 gst_audio_invert_class_init (GstAudioInvertClass * klass)
94 GObjectClass *gobject_class;
95 GstElementClass *gstelement_class;
98 GST_DEBUG_CATEGORY_INIT (gst_audio_invert_debug, "audioinvert", 0,
99 "audioinvert element");
101 gobject_class = (GObjectClass *) klass;
102 gstelement_class = (GstElementClass *) klass;
104 gobject_class->set_property = gst_audio_invert_set_property;
105 gobject_class->get_property = gst_audio_invert_get_property;
107 g_object_class_install_property (gobject_class, PROP_DEGREE,
108 g_param_spec_float ("degree", "Degree",
109 "Degree of inversion", 0.0, 1.0,
111 G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE | G_PARAM_STATIC_STRINGS));
113 gst_element_class_set_details_simple (gstelement_class, "Audio inversion",
114 "Filter/Effect/Audio",
115 "Swaps upper and lower half of audio samples",
116 "Sebastian Dröge <slomo@circular-chaos.org>");
118 caps = gst_caps_from_string (ALLOWED_CAPS);
119 gst_audio_filter_class_add_pad_templates (GST_AUDIO_FILTER_CLASS (klass),
121 gst_caps_unref (caps);
123 GST_AUDIO_FILTER_CLASS (klass)->setup =
124 GST_DEBUG_FUNCPTR (gst_audio_invert_setup);
125 GST_BASE_TRANSFORM_CLASS (klass)->transform_ip =
126 GST_DEBUG_FUNCPTR (gst_audio_invert_transform_ip);
130 gst_audio_invert_init (GstAudioInvert * filter)
132 filter->degree = 0.0;
133 gst_base_transform_set_in_place (GST_BASE_TRANSFORM (filter), TRUE);
134 gst_base_transform_set_gap_aware (GST_BASE_TRANSFORM (filter), TRUE);
138 gst_audio_invert_set_property (GObject * object, guint prop_id,
139 const GValue * value, GParamSpec * pspec)
141 GstAudioInvert *filter = GST_AUDIO_INVERT (object);
145 filter->degree = g_value_get_float (value);
146 gst_base_transform_set_passthrough (GST_BASE_TRANSFORM (filter),
147 filter->degree == 0.0);
150 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
156 gst_audio_invert_get_property (GObject * object, guint prop_id,
157 GValue * value, GParamSpec * pspec)
159 GstAudioInvert *filter = GST_AUDIO_INVERT (object);
163 g_value_set_float (value, filter->degree);
166 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
171 /* GstAudioFilter vmethod implementations */
174 gst_audio_invert_setup (GstAudioFilter * base, const GstAudioInfo * info)
176 GstAudioInvert *filter = GST_AUDIO_INVERT (base);
179 switch (GST_AUDIO_INFO_FORMAT (info)) {
180 case GST_AUDIO_FORMAT_S16:
181 filter->process = (GstAudioInvertProcessFunc)
182 gst_audio_invert_transform_int;
184 case GST_AUDIO_FORMAT_F32:
185 filter->process = (GstAudioInvertProcessFunc)
186 gst_audio_invert_transform_float;
196 gst_audio_invert_transform_int (GstAudioInvert * filter,
197 gint16 * data, guint num_samples)
200 gfloat dry = 1.0 - filter->degree;
203 for (i = 0; i < num_samples; i++) {
204 val = (*data) * dry + (-1 - (*data)) * filter->degree;
205 *data++ = (gint16) CLAMP (val, G_MININT16, G_MAXINT16);
210 gst_audio_invert_transform_float (GstAudioInvert * filter,
211 gfloat * data, guint num_samples)
214 gfloat dry = 1.0 - filter->degree;
217 for (i = 0; i < num_samples; i++) {
218 val = (*data) * dry - (*data) * filter->degree;
223 /* GstBaseTransform vmethod implementations */
225 gst_audio_invert_transform_ip (GstBaseTransform * base, GstBuffer * buf)
227 GstAudioInvert *filter = GST_AUDIO_INVERT (base);
229 GstClockTime timestamp, stream_time;
233 timestamp = GST_BUFFER_TIMESTAMP (buf);
235 gst_segment_to_stream_time (&base->segment, GST_FORMAT_TIME, timestamp);
237 GST_DEBUG_OBJECT (filter, "sync to %" GST_TIME_FORMAT,
238 GST_TIME_ARGS (timestamp));
240 if (GST_CLOCK_TIME_IS_VALID (stream_time))
241 gst_object_sync_values (GST_OBJECT (filter), stream_time);
243 if (gst_base_transform_is_passthrough (base) ||
244 G_UNLIKELY (GST_BUFFER_FLAG_IS_SET (buf, GST_BUFFER_FLAG_GAP)))
247 data = gst_buffer_map (buf, &size, NULL, GST_MAP_READWRITE);
248 num_samples = size / GST_AUDIO_FILTER_BPS (filter);
250 filter->process (filter, data, num_samples);
252 gst_buffer_unmap (buf, data, size);