aboutsummaryrefslogtreecommitdiffstats
path: root/meta-ivi-common/recipes-multimedia/pulseaudio/pulseaudio-9.0/0002-volume-ramp-additions-to-the-low-level-infra.patch
blob: 9cee6f5de4e71adaa99aeb54814c9d71bca149cc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
From 7757059ffc6e63ea20ba9013682d72d619e7aefc Mon Sep 17 00:00:00 2001
From: Sangchul Lee <sangchul1011@gmail.com>
Date: Sat, 27 Aug 2016 21:33:16 +0900
Subject: [PATCH 2/6] volume ramp: additions to the low level infra

The original patch is
 - https://review.tizen.org/git/?p=platform/upstream/pulseaudio.git;a=commit;h=df1c4275ed79e0b708c75b92f9d247e0492bc1f0
 - by Jaska Uimonen <jaska.uimonen <at> helsinki.fi>

Signed-off-by: Sangchul Lee <sc11.lee@samsung.com>
---
 src/map-file        |   4 +
 src/pulse/def.h     |  13 ++-
 src/pulse/volume.c  |  74 ++++++++++++-
 src/pulse/volume.h  |  33 ++++++
 src/pulsecore/mix.c | 310 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/pulsecore/mix.h |  27 +++++
 6 files changed, 459 insertions(+), 2 deletions(-)

diff --git a/src/map-file b/src/map-file
index 93a62b8..ef9b57d 100644
--- a/src/map-file
+++ b/src/map-file
@@ -138,6 +138,10 @@ pa_cvolume_max_mask;
 pa_cvolume_merge;
 pa_cvolume_min;
 pa_cvolume_min_mask;
+pa_cvolume_ramp_equal;
+pa_cvolume_ramp_init;
+pa_cvolume_ramp_set;
+pa_cvolume_ramp_channel_ramp_set;
 pa_cvolume_remap;
 pa_cvolume_scale;
 pa_cvolume_scale_mask;
diff --git a/src/pulse/def.h b/src/pulse/def.h
index 680bdc9..bc3cedd 100644
--- a/src/pulse/def.h
+++ b/src/pulse/def.h
@@ -347,11 +347,15 @@ typedef enum pa_stream_flags {
      * consider absolute when the sink is in flat volume mode,
      * relative otherwise. \since 0.9.20 */
 
-    PA_STREAM_PASSTHROUGH = 0x80000U
+    PA_STREAM_PASSTHROUGH = 0x80000U,
     /**< Used to tag content that will be rendered by passthrough sinks.
      * The data will be left as is and not reformatted, resampled.
      * \since 1.0 */
 
+    PA_STREAM_START_RAMP_MUTED = 0x100000U
+    /**< Used to tag content that the stream will be started ramp volume
+     * muted so that you can nicely fade it in */
+
 } pa_stream_flags_t;
 
 /** \cond fulldocs */
@@ -380,6 +384,7 @@ typedef enum pa_stream_flags {
 #define PA_STREAM_FAIL_ON_SUSPEND PA_STREAM_FAIL_ON_SUSPEND
 #define PA_STREAM_RELATIVE_VOLUME PA_STREAM_RELATIVE_VOLUME
 #define PA_STREAM_PASSTHROUGH PA_STREAM_PASSTHROUGH
+#define PA_STREAM_START_RAMP_MUTED PA_STREAM_START_RAMP_MUTED
 
 /** \endcond */
 
@@ -1047,6 +1052,12 @@ typedef enum pa_port_available {
 /** \endcond */
 #endif
 
+/** \cond fulldocs */
+#define PA_VOLUMER_RAMP_TYPE_LINEAR PA_VOLUMER_RAMP_TYPE_LINEAR
+#define PA_VOLUMER_RAMP_TYPE_LOGARITHMIC PA_VOLUMER_RAMP_TYPE_LOGARITHMIC
+#define PA_VOLUMER_RAMP_TYPE_CUBIC PA_VOLUMER_RAMP_TYPE_CUBIC
+/** \endcond */
+
 PA_C_DECL_END
 
 #endif
diff --git a/src/pulse/volume.c b/src/pulse/volume.c
index 1667b94..85072c1 100644
--- a/src/pulse/volume.c
+++ b/src/pulse/volume.c
@@ -445,7 +445,10 @@ int pa_cvolume_channels_equal_to(const pa_cvolume *a, pa_volume_t v) {
     unsigned c;
     pa_assert(a);
 
-    pa_return_val_if_fail(pa_cvolume_valid(a), 0);
+    if (pa_cvolume_valid(a) == 0)
+        abort();
+
+    /* pa_return_val_if_fail(pa_cvolume_valid(a), 0); */
     pa_return_val_if_fail(PA_VOLUME_IS_VALID(v), 0);
 
     for (c = 0; c < a->channels; c++)
@@ -977,3 +980,72 @@ pa_cvolume* pa_cvolume_dec(pa_cvolume *v, pa_volume_t dec) {
 
     return pa_cvolume_scale(v, m);
 }
+
+int pa_cvolume_ramp_equal(const pa_cvolume_ramp *a, const pa_cvolume_ramp *b) {
+    int i;
+    pa_assert(a);
+    pa_assert(b);
+
+    if (PA_UNLIKELY(a == b))
+        return 1;
+
+    if (a->channels != b->channels)
+        return 0;
+
+    for (i = 0; i < a->channels; i++) {
+        if (a->ramps[i].type != b->ramps[i].type ||
+            a->ramps[i].length != b->ramps[i].length ||
+            a->ramps[i].target != b->ramps[i].target)
+            return 0;
+    }
+
+    return 1;
+}
+
+pa_cvolume_ramp* pa_cvolume_ramp_init(pa_cvolume_ramp *ramp) {
+    unsigned c;
+
+    pa_assert(ramp);
+
+    ramp->channels = 0;
+
+    for (c = 0; c < PA_CHANNELS_MAX; c++) {
+        ramp->ramps[c].type = PA_VOLUME_RAMP_TYPE_LINEAR;
+        ramp->ramps[c].length = 0;
+        ramp->ramps[c].target = PA_VOLUME_INVALID;
+    }
+
+    return ramp;
+}
+
+pa_cvolume_ramp* pa_cvolume_ramp_set(pa_cvolume_ramp *ramp, unsigned channels, pa_volume_ramp_type_t type, long time, pa_volume_t vol) {
+    int i;
+
+    pa_assert(ramp);
+    pa_assert(channels > 0);
+    pa_assert(time >= 0);
+    pa_assert(channels <= PA_CHANNELS_MAX);
+
+    ramp->channels = (uint8_t) channels;
+
+    for (i = 0; i < ramp->channels; i++) {
+        ramp->ramps[i].type = type;
+        ramp->ramps[i].length = time;
+        ramp->ramps[i].target = PA_CLAMP_VOLUME(vol);
+    }
+
+    return ramp;
+}
+
+pa_cvolume_ramp* pa_cvolume_ramp_channel_ramp_set(pa_cvolume_ramp *ramp, unsigned channel, pa_volume_ramp_type_t type, long time, pa_volume_t vol) {
+
+    pa_assert(ramp);
+    pa_assert(channel <= ramp->channels);
+    pa_assert(time >= 0);
+
+    ramp->ramps[channel].type = type;
+    ramp->ramps[channel].length = time;
+    ramp->ramps[channel].target = PA_CLAMP_VOLUME(vol);
+
+    return ramp;
+}
diff --git a/src/pulse/volume.h b/src/pulse/volume.h
index 8cf4fa4..2ae3451 100644
--- a/src/pulse/volume.h
+++ b/src/pulse/volume.h
@@ -431,6 +431,39 @@ pa_cvolume* pa_cvolume_inc(pa_cvolume *v, pa_volume_t inc);
  * the channels are kept. \since 0.9.16 */
 pa_cvolume* pa_cvolume_dec(pa_cvolume *v, pa_volume_t dec);
 
+/** Volume ramp type
+*/
+typedef enum pa_volume_ramp_type {
+    PA_VOLUME_RAMP_TYPE_LINEAR = 0,        /**< linear */
+    PA_VOLUME_RAMP_TYPE_LOGARITHMIC = 1,   /**< logarithmic */
+    PA_VOLUME_RAMP_TYPE_CUBIC = 2,
+} pa_volume_ramp_type_t;
+
+/** A structure encapsulating a volume ramp */
+typedef struct pa_volume_ramp_t {
+    pa_volume_ramp_type_t type;
+    long length;
+    pa_volume_t target;
+} pa_volume_ramp_t;
+
+/** A structure encapsulating a multichannel volume ramp */
+typedef struct pa_cvolume_ramp {
+    uint8_t channels;
+    pa_volume_ramp_t ramps[PA_CHANNELS_MAX];
+} pa_cvolume_ramp;
+
+/** Return non-zero when *a == *b */
+int pa_cvolume_ramp_equal(const pa_cvolume_ramp *a, const pa_cvolume_ramp *b);
+
+/** Init volume ramp struct */
+pa_cvolume_ramp* pa_cvolume_ramp_init(pa_cvolume_ramp *ramp);
+
+/** Set first n channels of ramp struct to certain value */
+pa_cvolume_ramp* pa_cvolume_ramp_set(pa_cvolume_ramp *ramp, unsigned channel, pa_volume_ramp_type_t type, long time, pa_volume_t vol);
+
+/** Set individual channel in the channel struct */
+pa_cvolume_ramp* pa_cvolume_ramp_channel_ramp_set(pa_cvolume_ramp *ramp, unsigned channel, pa_volume_ramp_type_t type, long time, pa_volume_t vol);
+
 PA_C_DECL_END
 
 #endif
diff --git a/src/pulsecore/mix.c b/src/pulsecore/mix.c
index 59622d7..1e4cc1e 100644
--- a/src/pulsecore/mix.c
+++ b/src/pulsecore/mix.c
@@ -724,3 +724,313 @@ void pa_volume_memchunk(
 
     pa_memblock_release(c->memblock);
 }
+
+static void calc_linear_integer_volume_no_mapping(int32_t linear[], float volume[], unsigned nchannels) {
+    unsigned channel, padding;
+
+    pa_assert(linear);
+    pa_assert(volume);
+
+    for (channel = 0; channel < nchannels; channel++)
+        linear[channel] = (int32_t) lrint(volume[channel] * 0x10000U);
+
+    for (padding = 0; padding < VOLUME_PADDING; padding++, channel++)
+        linear[channel] = linear[padding];
+}
+
+static void calc_linear_float_volume_no_mapping(float linear[], float volume[], unsigned nchannels) {
+    unsigned channel, padding;
+
+    pa_assert(linear);
+    pa_assert(volume);
+
+    for (channel = 0; channel < nchannels; channel++)
+        linear[channel] = volume[channel];
+
+    for (padding = 0; padding < VOLUME_PADDING; padding++, channel++)
+        linear[channel] = linear[padding];
+}
+
+typedef void (*pa_calc_volume_no_mapping_func_t) (void *volumes, float *volume, int channels);
+
+static const pa_calc_volume_no_mapping_func_t calc_volume_table_no_mapping[] = {
+  [PA_SAMPLE_U8]        = (pa_calc_volume_no_mapping_func_t) calc_linear_integer_volume_no_mapping,
+  [PA_SAMPLE_ALAW]      = (pa_calc_volume_no_mapping_func_t) calc_linear_integer_volume_no_mapping,
+  [PA_SAMPLE_ULAW]      = (pa_calc_volume_no_mapping_func_t) calc_linear_integer_volume_no_mapping,
+  [PA_SAMPLE_S16LE]     = (pa_calc_volume_no_mapping_func_t) calc_linear_integer_volume_no_mapping,
+  [PA_SAMPLE_S16BE]     = (pa_calc_volume_no_mapping_func_t) calc_linear_integer_volume_no_mapping,
+  [PA_SAMPLE_FLOAT32LE] = (pa_calc_volume_no_mapping_func_t) calc_linear_float_volume_no_mapping,
+  [PA_SAMPLE_FLOAT32BE] = (pa_calc_volume_no_mapping_func_t) calc_linear_float_volume_no_mapping,
+  [PA_SAMPLE_S32LE]     = (pa_calc_volume_no_mapping_func_t) calc_linear_integer_volume_no_mapping,
+  [PA_SAMPLE_S32BE]     = (pa_calc_volume_no_mapping_func_t) calc_linear_integer_volume_no_mapping,
+  [PA_SAMPLE_S24LE]     = (pa_calc_volume_no_mapping_func_t) calc_linear_integer_volume_no_mapping,
+  [PA_SAMPLE_S24BE]     = (pa_calc_volume_no_mapping_func_t) calc_linear_integer_volume_no_mapping,
+  [PA_SAMPLE_S24_32LE]  = (pa_calc_volume_no_mapping_func_t) calc_linear_integer_volume_no_mapping,
+  [PA_SAMPLE_S24_32BE]  = (pa_calc_volume_no_mapping_func_t) calc_linear_integer_volume_no_mapping
+};
+
+static const unsigned format_sample_size_table[] = {
+  [PA_SAMPLE_U8]        = 1,
+  [PA_SAMPLE_ALAW]      = 1,
+  [PA_SAMPLE_ULAW]      = 1,
+  [PA_SAMPLE_S16LE]     = 2,
+  [PA_SAMPLE_S16BE]     = 2,
+  [PA_SAMPLE_FLOAT32LE] = 4,
+  [PA_SAMPLE_FLOAT32BE] = 4,
+  [PA_SAMPLE_S32LE]     = 4,
+  [PA_SAMPLE_S32BE]     = 4,
+  [PA_SAMPLE_S24LE]     = 3,
+  [PA_SAMPLE_S24BE]     = 3,
+  [PA_SAMPLE_S24_32LE]  = 4,
+  [PA_SAMPLE_S24_32BE]  = 4
+};
+
+static float calc_volume_ramp_linear(pa_volume_ramp_int_t *ramp) {
+    pa_assert(ramp);
+    pa_assert(ramp->length > 0);
+
+    /* basic linear interpolation */
+    return ramp->start + (ramp->length - ramp->left) * (ramp->end - ramp->start) / (float) ramp->length;
+}
+
+static float calc_volume_ramp_logarithmic(pa_volume_ramp_int_t *ramp) {
+    float x_val, s, e;
+    long temp;
+
+    pa_assert(ramp);
+    pa_assert(ramp->length > 0);
+
+    if (ramp->end > ramp->start) {
+        temp = ramp->left;
+        s = ramp->end;
+        e = ramp->start;
+    } else {
+        temp = ramp->length - ramp->left;
+        s = ramp->start;
+        e = ramp->end;
+    }
+
+    x_val = temp == 0 ? 0.0 : powf(temp, 10);
+
+    /* base 10 logarithmic interpolation */
+    return s + x_val * (e - s) / powf(ramp->length, 10);
+}
+
+static float calc_volume_ramp_cubic(pa_volume_ramp_int_t *ramp) {
+    float x_val, s, e;
+    long temp;
+
+    pa_assert(ramp);
+    pa_assert(ramp->length > 0);
+
+    if (ramp->end > ramp->start) {
+        temp = ramp->left;
+        s = ramp->end;
+        e = ramp->start;
+    } else {
+        temp = ramp->length - ramp->left;
+        s = ramp->start;
+        e = ramp->end;
+    }
+
+    x_val = temp == 0 ? 0.0 : cbrtf(temp);
+
+    /* cubic interpolation */
+    return s + x_val * (e - s) / cbrtf(ramp->length);
+}
+
+typedef float (*pa_calc_volume_ramp_func_t) (pa_volume_ramp_int_t *);
+
+static const pa_calc_volume_ramp_func_t calc_volume_ramp_table[] = {
+    [PA_VOLUME_RAMP_TYPE_LINEAR] = (pa_calc_volume_ramp_func_t) calc_volume_ramp_linear,
+    [PA_VOLUME_RAMP_TYPE_LOGARITHMIC] = (pa_calc_volume_ramp_func_t) calc_volume_ramp_logarithmic,
+    [PA_VOLUME_RAMP_TYPE_CUBIC] = (pa_calc_volume_ramp_func_t) calc_volume_ramp_cubic
+};
+
+static void calc_volume_ramps(pa_cvolume_ramp_int *ram, float *vol)
+{
+    int i;
+
+    for (i = 0; i < ram->channels; i++) {
+        if (ram->ramps[i].left <= 0) {
+            if (ram->ramps[i].target == PA_VOLUME_NORM) {
+                vol[i] = 1.0;
+            }
+        } else {
+            vol[i] = ram->ramps[i].curr = calc_volume_ramp_table[ram->ramps[i].type] (&ram->ramps[i]);
+            ram->ramps[i].left--;
+        }
+    }
+}
+
+void pa_volume_ramp_memchunk(
+        pa_memchunk *c,
+        const pa_sample_spec *spec,
+        pa_cvolume_ramp_int *ramp) {
+
+    void *ptr;
+    volume_val linear[PA_CHANNELS_MAX + VOLUME_PADDING];
+    float vol[PA_CHANNELS_MAX + VOLUME_PADDING];
+    pa_do_volume_func_t do_volume;
+    long length_in_frames;
+    int i;
+
+    pa_assert(c);
+    pa_assert(spec);
+    pa_assert(pa_frame_aligned(c->length, spec));
+    pa_assert(ramp);
+
+    length_in_frames = c->length / format_sample_size_table[spec->format] / spec->channels;
+
+    if (pa_memblock_is_silence(c->memblock)) {
+        for (i = 0; i < ramp->channels; i++) {
+            if (ramp->ramps[i].length > 0)
+                ramp->ramps[i].length -= length_in_frames;
+        }
+        return;
+    }
+
+    if (spec->format < 0 || spec->format >= PA_SAMPLE_MAX) {
+      pa_log_warn("Unable to change volume of format");
+      return;
+    }
+
+    do_volume = pa_get_volume_func(spec->format);
+    pa_assert(do_volume);
+
+    ptr = (uint8_t*) pa_memblock_acquire(c->memblock) + c->index;
+
+    for (i = 0; i < length_in_frames; i++) {
+        calc_volume_ramps(ramp, vol);
+        calc_volume_table_no_mapping[spec->format] ((void *)linear, vol, spec->channels);
+
+        /* we only process one frame per iteration */
+        do_volume (ptr, (void *)linear, spec->channels, format_sample_size_table[spec->format] * spec->channels);
+
+        /* pa_log_debug("1: %d  2: %d", linear[0], linear[1]); */
+
+        ptr = (uint8_t*)ptr + format_sample_size_table[spec->format] * spec->channels;
+    }
+
+    pa_memblock_release(c->memblock);
+}
+
+pa_cvolume_ramp_int* pa_cvolume_ramp_convert(const pa_cvolume_ramp *src, pa_cvolume_ramp_int *dst, int sample_rate) {
+
+    int i, j, channels, remaining_channels;
+    float temp;
+
+    if (dst->channels < src->channels) {
+        channels = dst->channels;
+        remaining_channels = 0;
+    }
+    else {
+        channels = src->channels;
+        remaining_channels = dst->channels;
+    }
+
+    for (i = 0; i < channels; i++) {
+        dst->ramps[i].type = src->ramps[i].type;
+        /* ms to samples */
+        dst->ramps[i].length = src->ramps[i].length * sample_rate / 1000;
+        dst->ramps[i].left = dst->ramps[i].length;
+        dst->ramps[i].start = dst->ramps[i].end;
+        dst->ramps[i].target = src->ramps[i].target;
+        /* scale to pulse internal mapping so that when ramp is over there's no glitch in volume */
+        temp = src->ramps[i].target / (float)0x10000U;
+        dst->ramps[i].end = temp * temp * temp;
+    }
+
+    j = i;
+
+    for (i--; j < remaining_channels; j++) {
+        dst->ramps[j].type = dst->ramps[i].type;
+        dst->ramps[j].length = dst->ramps[i].length;
+        dst->ramps[j].left = dst->ramps[i].left;
+        dst->ramps[j].start = dst->ramps[i].start;
+        dst->ramps[j].target = dst->ramps[i].target;
+        dst->ramps[j].end = dst->ramps[i].end;
+    }
+
+    return dst;
+}
+
+bool pa_cvolume_ramp_active(pa_cvolume_ramp_int *ramp) {
+    int i;
+
+    for (i = 0; i < ramp->channels; i++) {
+        if (ramp->ramps[i].left > 0)
+            return true;
+    }
+
+    return false;
+}
+
+bool pa_cvolume_ramp_target_active(pa_cvolume_ramp_int *ramp) {
+    int i;
+
+    for (i = 0; i < ramp->channels; i++) {
+        if (ramp->ramps[i].target != PA_VOLUME_NORM)
+            return true;
+    }
+
+    return false;
+}
+
+pa_cvolume * pa_cvolume_ramp_get_targets(pa_cvolume_ramp_int *ramp, pa_cvolume *volume) {
+    int i = 0;
+
+    volume->channels = ramp->channels;
+
+    for (i = 0; i < ramp->channels; i++)
+        volume->values[i] = ramp->ramps[i].target;
+
+    return volume;
+}
+
+pa_cvolume_ramp_int* pa_cvolume_ramp_start_from(pa_cvolume_ramp_int *src, pa_cvolume_ramp_int *dst) {
+    int i;
+
+    for (i = 0; i < src->channels; i++) {
+        /* if new vols are invalid, copy old ramp i.e. no effect */
+        if (dst->ramps[i].target == PA_VOLUME_INVALID)
+            dst->ramps[i] = src->ramps[i];
+        /* if there's some old ramp still left */
+        else if (src->ramps[i].left > 0)
+            dst->ramps[i].start = src->ramps[i].curr;
+    }
+
+    return dst;
+}
+
+pa_cvolume_ramp_int* pa_cvolume_ramp_int_init(pa_cvolume_ramp_int *src, pa_volume_t vol, int channels) {
+    int i;
+    float temp;
+
+    src->channels = channels;
+
+    for (i = 0; i < channels; i++) {
+        src->ramps[i].type = PA_VOLUME_RAMP_TYPE_LINEAR;
+        src->ramps[i].length = 0;
+        src->ramps[i].left = 0;
+        if (vol == PA_VOLUME_NORM) {
+            src->ramps[i].start = 1.0;
+            src->ramps[i].end = 1.0;
+            src->ramps[i].curr = 1.0;
+        }
+        else if (vol == PA_VOLUME_MUTED) {
+            src->ramps[i].start = 0.0;
+            src->ramps[i].end = 0.0;
+            src->ramps[i].curr = 0.0;
+        }
+        else {
+            temp = vol / (float)0x10000U;
+            src->ramps[i].start = temp * temp * temp;
+            src->ramps[i].end = src->ramps[i].start;
+            src->ramps[i].curr = src->ramps[i].start;
+        }
+        src->ramps[i].target = vol;
+    }
+
+    return src;
+}
diff --git a/src/pulsecore/mix.h b/src/pulsecore/mix.h
index 8102bcd..0f86b6f 100644
--- a/src/pulsecore/mix.h
+++ b/src/pulsecore/mix.h
@@ -59,4 +59,31 @@ void pa_volume_memchunk(
     const pa_sample_spec *spec,
     const pa_cvolume *volume);
 
+typedef struct pa_volume_ramp_int_t {
+    pa_volume_ramp_type_t type;
+    long length;
+    long left;
+    float start;
+    float end;
+    float curr;
+    pa_volume_t target;
+} pa_volume_ramp_int_t;
+
+typedef struct pa_cvolume_ramp_int {
+    uint8_t channels;
+    pa_volume_ramp_int_t ramps[PA_CHANNELS_MAX];
+} pa_cvolume_ramp_int;
+
+pa_cvolume_ramp_int* pa_cvolume_ramp_convert(const pa_cvolume_ramp *src, pa_cvolume_ramp_int *dst, int sample_rate);
+bool pa_cvolume_ramp_active(pa_cvolume_ramp_int *ramp);
+bool pa_cvolume_ramp_target_active(pa_cvolume_ramp_int *ramp);
+pa_cvolume_ramp_int* pa_cvolume_ramp_start_from(pa_cvolume_ramp_int *src, pa_cvolume_ramp_int *dst);
+pa_cvolume_ramp_int* pa_cvolume_ramp_int_init(pa_cvolume_ramp_int *src, pa_volume_t vol, int channels);
+pa_cvolume * pa_cvolume_ramp_get_targets(pa_cvolume_ramp_int *ramp, pa_cvolume *volume);
+
+void pa_volume_ramp_memchunk(
+        pa_memchunk *c,
+        const pa_sample_spec *spec,
+        pa_cvolume_ramp_int *ramp);
+
 #endif
-- 
1.9.1