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,
185 const GstAudioInfo * info)
189 if (GST_AUDIO_INFO_FORMAT (info) == GST_AUDIO_FORMAT_UNKNOWN)
192 func_index = (filter->mode == MODE_COMPRESSOR) ? 0 : 4;
193 func_index += (filter->characteristics == CHARACTERISTICS_HARD_KNEE) ? 0 : 2;
194 func_index += (GST_AUDIO_INFO_FORMAT (info) == 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,
284 GST_AUDIO_FILTER_INFO (filter));
287 filter->mode = g_value_get_enum (value);
288 gst_audio_dynamic_set_process_function (filter,
289 GST_AUDIO_FILTER_INFO (filter));
292 filter->threshold = g_value_get_float (value);
295 filter->ratio = g_value_get_float (value);
298 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
304 gst_audio_dynamic_get_property (GObject * object, guint prop_id,
305 GValue * value, GParamSpec * pspec)
307 GstAudioDynamic *filter = GST_AUDIO_DYNAMIC (object);
310 case PROP_CHARACTERISTICS:
311 g_value_set_enum (value, filter->characteristics);
314 g_value_set_enum (value, filter->mode);
317 g_value_set_float (value, filter->threshold);
320 g_value_set_float (value, filter->ratio);
323 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
328 /* GstAudioFilter vmethod implementations */
331 gst_audio_dynamic_setup (GstAudioFilter * base, const GstAudioInfo * info)
333 GstAudioDynamic *filter = GST_AUDIO_DYNAMIC (base);
336 ret = gst_audio_dynamic_set_process_function (filter, info);
342 gst_audio_dynamic_transform_hard_knee_compressor_int (GstAudioDynamic * filter,
343 gint16 * data, guint num_samples)
346 glong thr_p = filter->threshold * G_MAXINT16;
347 glong thr_n = filter->threshold * G_MININT16;
349 /* Nothing to do for us if ratio is 1.0 or if the threshold
351 if (filter->threshold == 1.0 || filter->ratio == 1.0)
354 for (; num_samples; num_samples--) {
358 val = thr_p + (val - thr_p) * filter->ratio;
359 } else if (val < thr_n) {
360 val = thr_n + (val - thr_n) * filter->ratio;
362 *data++ = (gint16) CLAMP (val, G_MININT16, G_MAXINT16);
367 gst_audio_dynamic_transform_hard_knee_compressor_float (GstAudioDynamic *
368 filter, gfloat * data, guint num_samples)
370 gdouble val, threshold = filter->threshold;
372 /* Nothing to do for us if ratio == 1.0.
373 * As float values can be above 1.0 we have to do something
374 * if threshold is greater than 1.0. */
375 if (filter->ratio == 1.0)
378 for (; num_samples; num_samples--) {
381 if (val > threshold) {
382 val = threshold + (val - threshold) * filter->ratio;
383 } else if (val < -threshold) {
384 val = -threshold + (val + threshold) * filter->ratio;
386 *data++ = (gfloat) val;
391 gst_audio_dynamic_transform_soft_knee_compressor_int (GstAudioDynamic * filter,
392 gint16 * data, guint num_samples)
395 glong thr_p = filter->threshold * G_MAXINT16;
396 glong thr_n = filter->threshold * G_MININT16;
397 gdouble a_p, b_p, c_p;
398 gdouble a_n, b_n, c_n;
400 /* Nothing to do for us if ratio is 1.0 or if the threshold
402 if (filter->threshold == 1.0 || filter->ratio == 1.0)
405 /* We build a 2nd degree polynomial here for
406 * values greater than threshold or small than
408 * f(t) = t, f'(t) = 1, f'(m) = r
410 * a = (1-r)/(2*(t-m))
411 * b = (r*t - m)/(t-m)
412 * c = t * (1 - b - a*t)
413 * f(x) = ax^2 + bx + c
416 /* shouldn't happen because this would only be the case
417 * for threshold == 1.0 which we catch above */
418 g_assert (thr_p - G_MAXINT16 != 0);
419 g_assert (thr_n - G_MININT != 0);
421 a_p = (1 - filter->ratio) / (2 * (thr_p - G_MAXINT16));
422 b_p = (filter->ratio * thr_p - G_MAXINT16) / (thr_p - G_MAXINT16);
423 c_p = thr_p * (1 - b_p - a_p * thr_p);
424 a_n = (1 - filter->ratio) / (2 * (thr_n - G_MININT16));
425 b_n = (filter->ratio * thr_n - G_MININT16) / (thr_n - G_MININT16);
426 c_n = thr_n * (1 - b_n - a_n * thr_n);
428 for (; num_samples; num_samples--) {
432 val = a_p * val * val + b_p * val + c_p;
433 } else if (val < thr_n) {
434 val = a_n * val * val + b_n * val + c_n;
436 *data++ = (gint16) CLAMP (val, G_MININT16, G_MAXINT16);
441 gst_audio_dynamic_transform_soft_knee_compressor_float (GstAudioDynamic *
442 filter, gfloat * data, guint num_samples)
445 gdouble threshold = filter->threshold;
446 gdouble a_p, b_p, c_p;
447 gdouble a_n, b_n, c_n;
449 /* Nothing to do for us if ratio == 1.0.
450 * As float values can be above 1.0 we have to do something
451 * if threshold is greater than 1.0. */
452 if (filter->ratio == 1.0)
455 /* We build a 2nd degree polynomial here for
456 * values greater than threshold or small than
458 * f(t) = t, f'(t) = 1, f'(m) = r
460 * a = (1-r)/(2*(t-m))
461 * b = (r*t - m)/(t-m)
462 * c = t * (1 - b - a*t)
463 * f(x) = ax^2 + bx + c
466 /* FIXME: If treshold is the same as the maximum
467 * we need to raise it a bit to prevent
468 * division by zero. */
469 if (threshold == 1.0)
470 threshold = 1.0 + 0.00001;
472 a_p = (1.0 - filter->ratio) / (2.0 * (threshold - 1.0));
473 b_p = (filter->ratio * threshold - 1.0) / (threshold - 1.0);
474 c_p = threshold * (1.0 - b_p - a_p * threshold);
475 a_n = (1.0 - filter->ratio) / (2.0 * (-threshold + 1.0));
476 b_n = (-filter->ratio * threshold + 1.0) / (-threshold + 1.0);
477 c_n = -threshold * (1.0 - b_n + a_n * threshold);
479 for (; num_samples; num_samples--) {
483 val = 1.0 + (val - 1.0) * filter->ratio;
484 } else if (val > threshold) {
485 val = a_p * val * val + b_p * val + c_p;
486 } else if (val < -1.0) {
487 val = -1.0 + (val + 1.0) * filter->ratio;
488 } else if (val < -threshold) {
489 val = a_n * val * val + b_n * val + c_n;
491 *data++ = (gfloat) val;
496 gst_audio_dynamic_transform_hard_knee_expander_int (GstAudioDynamic * filter,
497 gint16 * data, guint num_samples)
500 glong thr_p = filter->threshold * G_MAXINT16;
501 glong thr_n = filter->threshold * G_MININT16;
502 gdouble zero_p, zero_n;
504 /* Nothing to do for us here if threshold equals 0.0
505 * or ratio equals 1.0 */
506 if (filter->threshold == 0.0 || filter->ratio == 1.0)
509 /* zero crossing of our function */
510 if (filter->ratio != 0.0) {
511 zero_p = thr_p - thr_p / filter->ratio;
512 zero_n = thr_n - thr_n / filter->ratio;
514 zero_p = zero_n = 0.0;
522 for (; num_samples; num_samples--) {
525 if (val < thr_p && val > zero_p) {
526 val = filter->ratio * val + thr_p * (1 - filter->ratio);
527 } else if ((val <= zero_p && val > 0) || (val >= zero_n && val < 0)) {
529 } else if (val > thr_n && val < zero_n) {
530 val = filter->ratio * val + thr_n * (1 - filter->ratio);
532 *data++ = (gint16) CLAMP (val, G_MININT16, G_MAXINT16);
537 gst_audio_dynamic_transform_hard_knee_expander_float (GstAudioDynamic * filter,
538 gfloat * data, guint num_samples)
540 gdouble val, threshold = filter->threshold, zero;
542 /* Nothing to do for us here if threshold equals 0.0
543 * or ratio equals 1.0 */
544 if (filter->threshold == 0.0 || filter->ratio == 1.0)
547 /* zero crossing of our function */
548 if (filter->ratio != 0.0)
549 zero = threshold - threshold / filter->ratio;
556 for (; num_samples; num_samples--) {
559 if (val < threshold && val > zero) {
560 val = filter->ratio * val + threshold * (1.0 - filter->ratio);
561 } else if ((val <= zero && val > 0.0) || (val >= -zero && val < 0.0)) {
563 } else if (val > -threshold && val < -zero) {
564 val = filter->ratio * val - threshold * (1.0 - filter->ratio);
566 *data++ = (gfloat) val;
571 gst_audio_dynamic_transform_soft_knee_expander_int (GstAudioDynamic * filter,
572 gint16 * data, guint num_samples)
575 glong thr_p = filter->threshold * G_MAXINT16;
576 glong thr_n = filter->threshold * G_MININT16;
577 gdouble zero_p, zero_n;
578 gdouble a_p, b_p, c_p;
579 gdouble a_n, b_n, c_n;
582 /* Nothing to do for us here if threshold equals 0.0
583 * or ratio equals 1.0 */
584 if (filter->threshold == 0.0 || filter->ratio == 1.0)
587 /* zero crossing of our function */
588 zero_p = (thr_p * (filter->ratio - 1.0)) / (1.0 + filter->ratio);
589 zero_n = (thr_n * (filter->ratio - 1.0)) / (1.0 + filter->ratio);
596 /* shouldn't happen as this would only happen
597 * with threshold == 0.0 */
598 g_assert (thr_p != 0);
599 g_assert (thr_n != 0);
601 /* We build a 2n degree polynomial here for values between
602 * 0 and threshold or 0 and -threshold with:
603 * f(t) = t, f'(t) = 1, f(z) = 0, f'(z) = r
606 * a = (1 - r^2) / (4 * t)
608 * c = t * (1.0 - b - a*t)
609 * f(x) = ax^2 + bx + c */
610 r2 = filter->ratio * filter->ratio;
611 a_p = (1.0 - r2) / (4.0 * thr_p);
612 b_p = (1.0 + r2) / 2.0;
613 c_p = thr_p * (1.0 - b_p - a_p * thr_p);
614 a_n = (1.0 - r2) / (4.0 * thr_n);
615 b_n = (1.0 + r2) / 2.0;
616 c_n = thr_n * (1.0 - b_n - a_n * thr_n);
618 for (; num_samples; num_samples--) {
621 if (val < thr_p && val > zero_p) {
622 val = a_p * val * val + b_p * val + c_p;
623 } else if ((val <= zero_p && val > 0) || (val >= zero_n && val < 0)) {
625 } else if (val > thr_n && val < zero_n) {
626 val = a_n * val * val + b_n * val + c_n;
628 *data++ = (gint16) CLAMP (val, G_MININT16, G_MAXINT16);
633 gst_audio_dynamic_transform_soft_knee_expander_float (GstAudioDynamic * filter,
634 gfloat * data, guint num_samples)
637 gdouble threshold = filter->threshold;
639 gdouble a_p, b_p, c_p;
640 gdouble a_n, b_n, c_n;
643 /* Nothing to do for us here if threshold equals 0.0
644 * or ratio equals 1.0 */
645 if (filter->threshold == 0.0 || filter->ratio == 1.0)
648 /* zero crossing of our function */
649 zero = (threshold * (filter->ratio - 1.0)) / (1.0 + filter->ratio);
654 /* shouldn't happen as this only happens with
655 * threshold == 0.0 */
656 g_assert (threshold != 0.0);
658 /* We build a 2n degree polynomial here for values between
659 * 0 and threshold or 0 and -threshold with:
660 * f(t) = t, f'(t) = 1, f(z) = 0, f'(z) = r
663 * a = (1 - r^2) / (4 * t)
665 * c = t * (1.0 - b - a*t)
666 * f(x) = ax^2 + bx + c */
667 r2 = filter->ratio * filter->ratio;
668 a_p = (1.0 - r2) / (4.0 * threshold);
669 b_p = (1.0 + r2) / 2.0;
670 c_p = threshold * (1.0 - b_p - a_p * threshold);
671 a_n = (1.0 - r2) / (-4.0 * threshold);
672 b_n = (1.0 + r2) / 2.0;
673 c_n = -threshold * (1.0 - b_n + a_n * threshold);
675 for (; num_samples; num_samples--) {
678 if (val < threshold && val > zero) {
679 val = a_p * val * val + b_p * val + c_p;
680 } else if ((val <= zero && val > 0.0) || (val >= -zero && val < 0.0)) {
682 } else if (val > -threshold && val < -zero) {
683 val = a_n * val * val + b_n * val + c_n;
685 *data++ = (gfloat) val;
689 /* GstBaseTransform vmethod implementations */
691 gst_audio_dynamic_transform_ip (GstBaseTransform * base, GstBuffer * buf)
693 GstAudioDynamic *filter = GST_AUDIO_DYNAMIC (base);
695 GstClockTime timestamp, stream_time;
698 timestamp = GST_BUFFER_TIMESTAMP (buf);
700 gst_segment_to_stream_time (&base->segment, GST_FORMAT_TIME, timestamp);
702 GST_DEBUG_OBJECT (filter, "sync to %" GST_TIME_FORMAT,
703 GST_TIME_ARGS (timestamp));
705 if (GST_CLOCK_TIME_IS_VALID (stream_time))
706 gst_object_sync_values (GST_OBJECT (filter), stream_time);
708 if (gst_base_transform_is_passthrough (base) ||
709 G_UNLIKELY (GST_BUFFER_FLAG_IS_SET (buf, GST_BUFFER_FLAG_GAP)))
712 gst_buffer_map (buf, &map, GST_MAP_READWRITE);
713 num_samples = map.size / GST_AUDIO_FILTER_BPS (filter);
715 filter->process (filter, map.data, num_samples);
717 gst_buffer_unmap (buf, &map);