--- a/src/map-file	2016-04-12 15:03:17.009975690 +0200
+++ b/src/map-file	2016-04-12 15:03:52.389975631 +0200
@@ -136,6 +136,9 @@
 pa_cvolume_merge;
 pa_cvolume_min;
 pa_cvolume_min_mask;
+pa_cvolume_ramp_init;
+pa_cvolume_ramp_set;
+pa_cvolume_ramp_channel_ramp_set;
 pa_cvolume_remap;
 pa_cvolume_scale;
 pa_cvolume_scale_mask;
--- a/src/pulse/def.h	2016-04-12 15:05:58.245975421 +0200
+++ b/src/pulse/def.h	2016-04-12 15:13:19.424974685 +0200
@@ -347,11 +347,15 @@
      * 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 @@
 #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 +1052,13 @@
 /** \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
--- a/src/pulse/volume.c	2016-04-12 15:13:38.598974653 +0200
+++ b/src/pulse/volume.c	2016-04-12 15:27:57.729973219 +0200
@@ -445,7 +445,10 @@
     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++)
@@ -986,3 +989,51 @@
 
     return pa_cvolume_scale(v, m);
 }
+
+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;
+}
--- a/src/pulse/volume.h	2016-04-12 15:40:34.989971955 +0200
+++ b/src/pulse/volume.h	2016-04-12 15:38:50.708972129 +0200
@@ -413,6 +413,36 @@
  * 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 pam_cvolume_ramp {
+    uint8_t channels;
+    pa_volume_ramp_t ramps[PA_CHANNELS_MAX];
+} pa_cvolume_ramp;
+
+/** 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
--- a/src/pulsecore/sample-util.c	2016-04-12 15:41:51.812971827 +0200
+++ b/src/pulsecore/sample-util.c	2016-04-12 16:31:56.795966812 +0200
@@ -41,6 +41,13 @@
 
 #define PA_SILENCE_MAX (PA_PAGE_SIZE*16)
 
+#define VOLUME_PADDING 32
+
+typedef union {
+    float f;
+    uint32_t i;
+} volume_val;
+
 pa_memblock *pa_silence_memblock(pa_memblock* b, const pa_sample_spec *spec) {
     void *data;
 
@@ -403,3 +410,292 @@
     usec = pa_bytes_to_usec_round_up(size, from);
     return pa_usec_to_bytes_round_up(usec, to);
 }
+
+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;
+    float temp;
+
+    for (i = 0; i < dst->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;
+    }
+
+    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;
+}
--- a/src/pulsecore/sample-util.h	2016-04-12 15:53:06.327970701 +0200
+++ b/src/pulsecore/sample-util.h	2016-04-12 16:24:16.356967580 +0200
@@ -45,6 +45,33 @@
 
 pa_memchunk* pa_silence_memchunk_get(pa_silence_cache *cache, pa_mempool *pool, pa_memchunk* ret, const pa_sample_spec *spec, size_t length);
 
+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);
+
 size_t pa_frame_align(size_t l, const pa_sample_spec *ss) PA_GCC_PURE;
 
 bool pa_frame_aligned(size_t l, const pa_sample_spec *ss) PA_GCC_PURE;