3 * Copyright (C) 2007 Sebastian Dröge <slomo@circular-chaos.org>
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-audiodynamic
24 * This element can act as a compressor or expander. A compressor changes the
25 * amplitude of all samples above a specific threshold with a specific ratio,
26 * a expander does the same for all samples below a specific threshold. If
27 * soft-knee mode is selected the ratio is applied smoothly.
30 * <title>Example launch line</title>
32 * gst-launch audiotestsrc wave=saw ! audiodynamic characteristics=soft-knee mode=compressor threshold=0.5 rate=0.5 ! alsasink
33 * gst-launch filesrc location="melo1.ogg" ! oggdemux ! vorbisdec ! audioconvert ! audiodynamic characteristics=hard-knee mode=expander threshold=0.2 rate=4.0 ! alsasink
34 * gst-launch audiotestsrc wave=saw ! audioconvert ! audiodynamic ! audioconvert ! alsasink
39 /* TODO: Implement attack and release parameters */
46 #include <gst/base/gstbasetransform.h>
47 #include <gst/audio/audio.h>
48 #include <gst/audio/gstaudiofilter.h>
50 #include "audiodynamic.h"
52 #define GST_CAT_DEFAULT gst_audio_dynamic_debug
53 GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT);
55 /* Filter signals and args */
71 #define ALLOWED_CAPS \
73 " format=(string) {"GST_AUDIO_NE(S16)","GST_AUDIO_NE(F32)"}," \
74 " rate=(int)[1,MAX]," \
75 " channels=(int)[1,MAX]," \
76 " layout=(string) {interleaved, non-interleaved}"
78 G_DEFINE_TYPE (GstAudioDynamic, gst_audio_dynamic, GST_TYPE_AUDIO_FILTER);
80 static void gst_audio_dynamic_set_property (GObject * object, guint prop_id,
81 const GValue * value, GParamSpec * pspec);
82 static void gst_audio_dynamic_get_property (GObject * object, guint prop_id,
83 GValue * value, GParamSpec * pspec);
85 static gboolean gst_audio_dynamic_setup (GstAudioFilter * filter,
86 const GstAudioInfo * info);
87 static GstFlowReturn gst_audio_dynamic_transform_ip (GstBaseTransform * base,
91 gst_audio_dynamic_transform_hard_knee_compressor_int (GstAudioDynamic * filter,
92 gint16 * data, guint num_samples);
94 gst_audio_dynamic_transform_hard_knee_compressor_float (GstAudioDynamic *
95 filter, gfloat * data, guint num_samples);
97 gst_audio_dynamic_transform_soft_knee_compressor_int (GstAudioDynamic * filter,
98 gint16 * data, guint num_samples);
100 gst_audio_dynamic_transform_soft_knee_compressor_float (GstAudioDynamic *
101 filter, gfloat * data, guint num_samples);
102 static void gst_audio_dynamic_transform_hard_knee_expander_int (GstAudioDynamic
103 * filter, gint16 * data, guint num_samples);
105 gst_audio_dynamic_transform_hard_knee_expander_float (GstAudioDynamic * filter,
106 gfloat * data, guint num_samples);
107 static void gst_audio_dynamic_transform_soft_knee_expander_int (GstAudioDynamic
108 * filter, gint16 * data, guint num_samples);
110 gst_audio_dynamic_transform_soft_knee_expander_float (GstAudioDynamic * filter,
111 gfloat * data, guint num_samples);
113 static GstAudioDynamicProcessFunc process_functions[] = {
114 (GstAudioDynamicProcessFunc)
115 gst_audio_dynamic_transform_hard_knee_compressor_int,
116 (GstAudioDynamicProcessFunc)
117 gst_audio_dynamic_transform_hard_knee_compressor_float,
118 (GstAudioDynamicProcessFunc)
119 gst_audio_dynamic_transform_soft_knee_compressor_int,
120 (GstAudioDynamicProcessFunc)
121 gst_audio_dynamic_transform_soft_knee_compressor_float,
122 (GstAudioDynamicProcessFunc)
123 gst_audio_dynamic_transform_hard_knee_expander_int,
124 (GstAudioDynamicProcessFunc)
125 gst_audio_dynamic_transform_hard_knee_expander_float,
126 (GstAudioDynamicProcessFunc)
127 gst_audio_dynamic_transform_soft_knee_expander_int,
128 (GstAudioDynamicProcessFunc)
129 gst_audio_dynamic_transform_soft_knee_expander_float
134 CHARACTERISTICS_HARD_KNEE = 0,
135 CHARACTERISTICS_SOFT_KNEE
138 #define GST_TYPE_AUDIO_DYNAMIC_CHARACTERISTICS (gst_audio_dynamic_characteristics_get_type ())
140 gst_audio_dynamic_characteristics_get_type (void)
142 static GType gtype = 0;
145 static const GEnumValue values[] = {
146 {CHARACTERISTICS_HARD_KNEE, "Hard Knee (default)",
148 {CHARACTERISTICS_SOFT_KNEE, "Soft Knee (smooth)",
153 gtype = g_enum_register_static ("GstAudioDynamicCharacteristics", values);
164 #define GST_TYPE_AUDIO_DYNAMIC_MODE (gst_audio_dynamic_mode_get_type ())
166 gst_audio_dynamic_mode_get_type (void)
168 static GType gtype = 0;
171 static const GEnumValue values[] = {
172 {MODE_COMPRESSOR, "Compressor (default)",
174 {MODE_EXPANDER, "Expander", "expander"},
178 gtype = g_enum_register_static ("GstAudioDynamicMode", values);
184 gst_audio_dynamic_set_process_function (GstAudioDynamic * filter)
188 if (GST_AUDIO_FILTER_FORMAT (filter) == GST_AUDIO_FORMAT_UNKNOWN)
191 func_index = (filter->mode == MODE_COMPRESSOR) ? 0 : 4;
192 func_index += (filter->characteristics == CHARACTERISTICS_HARD_KNEE) ? 0 : 2;
194 (GST_AUDIO_FILTER_FORMAT (filter) == GST_AUDIO_FORMAT_F32) ? 1 : 0;
196 if (func_index >= 0 && func_index < 8) {
197 filter->process = process_functions[func_index];
204 /* GObject vmethod implementations */
207 gst_audio_dynamic_class_init (GstAudioDynamicClass * klass)
209 GObjectClass *gobject_class;
210 GstElementClass *gstelement_class;
213 GST_DEBUG_CATEGORY_INIT (gst_audio_dynamic_debug, "audiodynamic", 0,
214 "audiodynamic element");
216 gobject_class = (GObjectClass *) klass;
217 gstelement_class = (GstElementClass *) klass;
219 gobject_class->set_property = gst_audio_dynamic_set_property;
220 gobject_class->get_property = gst_audio_dynamic_get_property;
222 g_object_class_install_property (gobject_class, PROP_CHARACTERISTICS,
223 g_param_spec_enum ("characteristics", "Characteristics",
224 "Selects whether the ratio should be applied smooth (soft-knee) "
225 "or hard (hard-knee).",
226 GST_TYPE_AUDIO_DYNAMIC_CHARACTERISTICS, CHARACTERISTICS_HARD_KNEE,
227 G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
229 g_object_class_install_property (gobject_class, PROP_MODE,
230 g_param_spec_enum ("mode", "Mode",
231 "Selects whether the filter should work on loud samples (compressor) or"
232 "quiet samples (expander).",
233 GST_TYPE_AUDIO_DYNAMIC_MODE, MODE_COMPRESSOR,
234 G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
236 g_object_class_install_property (gobject_class, PROP_THRESHOLD,
237 g_param_spec_float ("threshold", "Threshold",
238 "Threshold until the filter is activated", 0.0, 1.0,
240 G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE | G_PARAM_STATIC_STRINGS));
242 g_object_class_install_property (gobject_class, PROP_RATIO,
243 g_param_spec_float ("ratio", "Ratio",
244 "Ratio that should be applied", 0.0, G_MAXFLOAT,
246 G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE | G_PARAM_STATIC_STRINGS));
248 gst_element_class_set_details_simple (gstelement_class,
249 "Dynamic range controller", "Filter/Effect/Audio",
250 "Compressor and Expander", "Sebastian Dröge <slomo@circular-chaos.org>");
252 caps = gst_caps_from_string (ALLOWED_CAPS);
253 gst_audio_filter_class_add_pad_templates (GST_AUDIO_FILTER_CLASS (klass),
255 gst_caps_unref (caps);
257 GST_AUDIO_FILTER_CLASS (klass)->setup =
258 GST_DEBUG_FUNCPTR (gst_audio_dynamic_setup);
259 GST_BASE_TRANSFORM_CLASS (klass)->transform_ip =
260 GST_DEBUG_FUNCPTR (gst_audio_dynamic_transform_ip);
264 gst_audio_dynamic_init (GstAudioDynamic * filter)
267 filter->threshold = 0.0;
268 filter->characteristics = CHARACTERISTICS_HARD_KNEE;
269 filter->mode = MODE_COMPRESSOR;
270 gst_base_transform_set_in_place (GST_BASE_TRANSFORM (filter), TRUE);
271 gst_base_transform_set_gap_aware (GST_BASE_TRANSFORM (filter), TRUE);
275 gst_audio_dynamic_set_property (GObject * object, guint prop_id,
276 const GValue * value, GParamSpec * pspec)
278 GstAudioDynamic *filter = GST_AUDIO_DYNAMIC (object);
281 case PROP_CHARACTERISTICS:
282 filter->characteristics = g_value_get_enum (value);
283 gst_audio_dynamic_set_process_function (filter);
286 filter->mode = g_value_get_enum (value);
287 gst_audio_dynamic_set_process_function (filter);
290 filter->threshold = g_value_get_float (value);
293 filter->ratio = g_value_get_float (value);
296 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
302 gst_audio_dynamic_get_property (GObject * object, guint prop_id,
303 GValue * value, GParamSpec * pspec)
305 GstAudioDynamic *filter = GST_AUDIO_DYNAMIC (object);
308 case PROP_CHARACTERISTICS:
309 g_value_set_enum (value, filter->characteristics);
312 g_value_set_enum (value, filter->mode);
315 g_value_set_float (value, filter->threshold);
318 g_value_set_float (value, filter->ratio);
321 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
326 /* GstAudioFilter vmethod implementations */
329 gst_audio_dynamic_setup (GstAudioFilter * base, const GstAudioInfo * info)
331 GstAudioDynamic *filter = GST_AUDIO_DYNAMIC (base);
334 ret = gst_audio_dynamic_set_process_function (filter);
340 gst_audio_dynamic_transform_hard_knee_compressor_int (GstAudioDynamic * filter,
341 gint16 * data, guint num_samples)
344 glong thr_p = filter->threshold * G_MAXINT16;
345 glong thr_n = filter->threshold * G_MININT16;
347 /* Nothing to do for us if ratio is 1.0 or if the threshold
349 if (filter->threshold == 1.0 || filter->ratio == 1.0)
352 for (; num_samples; num_samples--) {
356 val = thr_p + (val - thr_p) * filter->ratio;
357 } else if (val < thr_n) {
358 val = thr_n + (val - thr_n) * filter->ratio;
360 *data++ = (gint16) CLAMP (val, G_MININT16, G_MAXINT16);
365 gst_audio_dynamic_transform_hard_knee_compressor_float (GstAudioDynamic *
366 filter, gfloat * data, guint num_samples)
368 gdouble val, threshold = filter->threshold;
370 /* Nothing to do for us if ratio == 1.0.
371 * As float values can be above 1.0 we have to do something
372 * if threshold is greater than 1.0. */
373 if (filter->ratio == 1.0)
376 for (; num_samples; num_samples--) {
379 if (val > threshold) {
380 val = threshold + (val - threshold) * filter->ratio;
381 } else if (val < -threshold) {
382 val = -threshold + (val + threshold) * filter->ratio;
384 *data++ = (gfloat) val;
389 gst_audio_dynamic_transform_soft_knee_compressor_int (GstAudioDynamic * filter,
390 gint16 * data, guint num_samples)
393 glong thr_p = filter->threshold * G_MAXINT16;
394 glong thr_n = filter->threshold * G_MININT16;
395 gdouble a_p, b_p, c_p;
396 gdouble a_n, b_n, c_n;
398 /* Nothing to do for us if ratio is 1.0 or if the threshold
400 if (filter->threshold == 1.0 || filter->ratio == 1.0)
403 /* We build a 2nd degree polynomial here for
404 * values greater than threshold or small than
406 * f(t) = t, f'(t) = 1, f'(m) = r
408 * a = (1-r)/(2*(t-m))
409 * b = (r*t - m)/(t-m)
410 * c = t * (1 - b - a*t)
411 * f(x) = ax^2 + bx + c
414 /* shouldn't happen because this would only be the case
415 * for threshold == 1.0 which we catch above */
416 g_assert (thr_p - G_MAXINT16 != 0);
417 g_assert (thr_n - G_MININT != 0);
419 a_p = (1 - filter->ratio) / (2 * (thr_p - G_MAXINT16));
420 b_p = (filter->ratio * thr_p - G_MAXINT16) / (thr_p - G_MAXINT16);
421 c_p = thr_p * (1 - b_p - a_p * thr_p);
422 a_n = (1 - filter->ratio) / (2 * (thr_n - G_MININT16));
423 b_n = (filter->ratio * thr_n - G_MININT16) / (thr_n - G_MININT16);
424 c_n = thr_n * (1 - b_n - a_n * thr_n);
426 for (; num_samples; num_samples--) {
430 val = a_p * val * val + b_p * val + c_p;
431 } else if (val < thr_n) {
432 val = a_n * val * val + b_n * val + c_n;
434 *data++ = (gint16) CLAMP (val, G_MININT16, G_MAXINT16);
439 gst_audio_dynamic_transform_soft_knee_compressor_float (GstAudioDynamic *
440 filter, gfloat * data, guint num_samples)
443 gdouble threshold = filter->threshold;
444 gdouble a_p, b_p, c_p;
445 gdouble a_n, b_n, c_n;
447 /* Nothing to do for us if ratio == 1.0.
448 * As float values can be above 1.0 we have to do something
449 * if threshold is greater than 1.0. */
450 if (filter->ratio == 1.0)
453 /* We build a 2nd degree polynomial here for
454 * values greater than threshold or small than
456 * f(t) = t, f'(t) = 1, f'(m) = r
458 * a = (1-r)/(2*(t-m))
459 * b = (r*t - m)/(t-m)
460 * c = t * (1 - b - a*t)
461 * f(x) = ax^2 + bx + c
464 /* FIXME: If treshold is the same as the maximum
465 * we need to raise it a bit to prevent
466 * division by zero. */
467 if (threshold == 1.0)
468 threshold = 1.0 + 0.00001;
470 a_p = (1.0 - filter->ratio) / (2.0 * (threshold - 1.0));
471 b_p = (filter->ratio * threshold - 1.0) / (threshold - 1.0);
472 c_p = threshold * (1.0 - b_p - a_p * threshold);
473 a_n = (1.0 - filter->ratio) / (2.0 * (-threshold + 1.0));
474 b_n = (-filter->ratio * threshold + 1.0) / (-threshold + 1.0);
475 c_n = -threshold * (1.0 - b_n + a_n * threshold);
477 for (; num_samples; num_samples--) {
481 val = 1.0 + (val - 1.0) * filter->ratio;
482 } else if (val > threshold) {
483 val = a_p * val * val + b_p * val + c_p;
484 } else if (val < -1.0) {
485 val = -1.0 + (val + 1.0) * filter->ratio;
486 } else if (val < -threshold) {
487 val = a_n * val * val + b_n * val + c_n;
489 *data++ = (gfloat) val;
494 gst_audio_dynamic_transform_hard_knee_expander_int (GstAudioDynamic * filter,
495 gint16 * data, guint num_samples)
498 glong thr_p = filter->threshold * G_MAXINT16;
499 glong thr_n = filter->threshold * G_MININT16;
500 gdouble zero_p, zero_n;
502 /* Nothing to do for us here if threshold equals 0.0
503 * or ratio equals 1.0 */
504 if (filter->threshold == 0.0 || filter->ratio == 1.0)
507 /* zero crossing of our function */
508 if (filter->ratio != 0.0) {
509 zero_p = thr_p - thr_p / filter->ratio;
510 zero_n = thr_n - thr_n / filter->ratio;
512 zero_p = zero_n = 0.0;
520 for (; num_samples; num_samples--) {
523 if (val < thr_p && val > zero_p) {
524 val = filter->ratio * val + thr_p * (1 - filter->ratio);
525 } else if ((val <= zero_p && val > 0) || (val >= zero_n && val < 0)) {
527 } else if (val > thr_n && val < zero_n) {
528 val = filter->ratio * val + thr_n * (1 - filter->ratio);
530 *data++ = (gint16) CLAMP (val, G_MININT16, G_MAXINT16);
535 gst_audio_dynamic_transform_hard_knee_expander_float (GstAudioDynamic * filter,
536 gfloat * data, guint num_samples)
538 gdouble val, threshold = filter->threshold, zero;
540 /* Nothing to do for us here if threshold equals 0.0
541 * or ratio equals 1.0 */
542 if (filter->threshold == 0.0 || filter->ratio == 1.0)
545 /* zero crossing of our function */
546 if (filter->ratio != 0.0)
547 zero = threshold - threshold / filter->ratio;
554 for (; num_samples; num_samples--) {
557 if (val < threshold && val > zero) {
558 val = filter->ratio * val + threshold * (1.0 - filter->ratio);
559 } else if ((val <= zero && val > 0.0) || (val >= -zero && val < 0.0)) {
561 } else if (val > -threshold && val < -zero) {
562 val = filter->ratio * val - threshold * (1.0 - filter->ratio);
564 *data++ = (gfloat) val;
569 gst_audio_dynamic_transform_soft_knee_expander_int (GstAudioDynamic * filter,
570 gint16 * data, guint num_samples)
573 glong thr_p = filter->threshold * G_MAXINT16;
574 glong thr_n = filter->threshold * G_MININT16;
575 gdouble zero_p, zero_n;
576 gdouble a_p, b_p, c_p;
577 gdouble a_n, b_n, c_n;
580 /* Nothing to do for us here if threshold equals 0.0
581 * or ratio equals 1.0 */
582 if (filter->threshold == 0.0 || filter->ratio == 1.0)
585 /* zero crossing of our function */
586 zero_p = (thr_p * (filter->ratio - 1.0)) / (1.0 + filter->ratio);
587 zero_n = (thr_n * (filter->ratio - 1.0)) / (1.0 + filter->ratio);
594 /* shouldn't happen as this would only happen
595 * with threshold == 0.0 */
596 g_assert (thr_p != 0);
597 g_assert (thr_n != 0);
599 /* We build a 2n degree polynomial here for values between
600 * 0 and threshold or 0 and -threshold with:
601 * f(t) = t, f'(t) = 1, f(z) = 0, f'(z) = r
604 * a = (1 - r^2) / (4 * t)
606 * c = t * (1.0 - b - a*t)
607 * f(x) = ax^2 + bx + c */
608 r2 = filter->ratio * filter->ratio;
609 a_p = (1.0 - r2) / (4.0 * thr_p);
610 b_p = (1.0 + r2) / 2.0;
611 c_p = thr_p * (1.0 - b_p - a_p * thr_p);
612 a_n = (1.0 - r2) / (4.0 * thr_n);
613 b_n = (1.0 + r2) / 2.0;
614 c_n = thr_n * (1.0 - b_n - a_n * thr_n);
616 for (; num_samples; num_samples--) {
619 if (val < thr_p && val > zero_p) {
620 val = a_p * val * val + b_p * val + c_p;
621 } else if ((val <= zero_p && val > 0) || (val >= zero_n && val < 0)) {
623 } else if (val > thr_n && val < zero_n) {
624 val = a_n * val * val + b_n * val + c_n;
626 *data++ = (gint16) CLAMP (val, G_MININT16, G_MAXINT16);
631 gst_audio_dynamic_transform_soft_knee_expander_float (GstAudioDynamic * filter,
632 gfloat * data, guint num_samples)
635 gdouble threshold = filter->threshold;
637 gdouble a_p, b_p, c_p;
638 gdouble a_n, b_n, c_n;
641 /* Nothing to do for us here if threshold equals 0.0
642 * or ratio equals 1.0 */
643 if (filter->threshold == 0.0 || filter->ratio == 1.0)
646 /* zero crossing of our function */
647 zero = (threshold * (filter->ratio - 1.0)) / (1.0 + filter->ratio);
652 /* shouldn't happen as this only happens with
653 * threshold == 0.0 */
654 g_assert (threshold != 0.0);
656 /* We build a 2n degree polynomial here for values between
657 * 0 and threshold or 0 and -threshold with:
658 * f(t) = t, f'(t) = 1, f(z) = 0, f'(z) = r
661 * a = (1 - r^2) / (4 * t)
663 * c = t * (1.0 - b - a*t)
664 * f(x) = ax^2 + bx + c */
665 r2 = filter->ratio * filter->ratio;
666 a_p = (1.0 - r2) / (4.0 * threshold);
667 b_p = (1.0 + r2) / 2.0;
668 c_p = threshold * (1.0 - b_p - a_p * threshold);
669 a_n = (1.0 - r2) / (-4.0 * threshold);
670 b_n = (1.0 + r2) / 2.0;
671 c_n = -threshold * (1.0 - b_n + a_n * threshold);
673 for (; num_samples; num_samples--) {
676 if (val < threshold && val > zero) {
677 val = a_p * val * val + b_p * val + c_p;
678 } else if ((val <= zero && val > 0.0) || (val >= -zero && val < 0.0)) {
680 } else if (val > -threshold && val < -zero) {
681 val = a_n * val * val + b_n * val + c_n;
683 *data++ = (gfloat) val;
687 /* GstBaseTransform vmethod implementations */
689 gst_audio_dynamic_transform_ip (GstBaseTransform * base, GstBuffer * buf)
691 GstAudioDynamic *filter = GST_AUDIO_DYNAMIC (base);
693 GstClockTime timestamp, stream_time;
696 timestamp = GST_BUFFER_TIMESTAMP (buf);
698 gst_segment_to_stream_time (&base->segment, GST_FORMAT_TIME, timestamp);
700 GST_DEBUG_OBJECT (filter, "sync to %" GST_TIME_FORMAT,
701 GST_TIME_ARGS (timestamp));
703 if (GST_CLOCK_TIME_IS_VALID (stream_time))
704 gst_object_sync_values (GST_OBJECT (filter), stream_time);
706 if (gst_base_transform_is_passthrough (base) ||
707 G_UNLIKELY (GST_BUFFER_FLAG_IS_SET (buf, GST_BUFFER_FLAG_GAP)))
710 gst_buffer_map (buf, &map, GST_MAP_READWRITE);
711 num_samples = map.size / GST_AUDIO_FILTER_BPS (filter);
713 filter->process (filter, map.data, num_samples);
715 gst_buffer_unmap (buf, &map);