1 files changed, 161 insertions, 0 deletions
diff --git a/polyp/volume.c b/polyp/volume.c
new file mode 100644
index 00000000..bb9d30db
--- /dev/null
+++ b/polyp/volume.c
@@ -0,0 +1,161 @@
+/* $Id$ */
+
+/***
+  This file is part of polypaudio.
+ 
+  polypaudio is free software; you can redistribute it and/or modify
+  it under the terms of the GNU Lesser General Public License as published
+  by the Free Software Foundation; either version 2 of the License,
+  or (at your option) any later version.
+ 
+  polypaudio is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  General Public License for more details.
+ 
+  You should have received a copy of the GNU Lesser General Public License
+  along with polypaudio; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+  USA.
+***/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <assert.h>
+
+#include "volume.h"
+
+int pa_cvolume_equal(const struct pa_cvolume *a, const struct pa_cvolume *b) {
+    int i;
+    assert(a);
+    assert(b);
+
+    if (a->channels != b->channels)
+        return 0;
+    
+    for (i = 0; i < a->channels; i++)
+        if (a->values[i] != b->values[i])
+            return 0;
+
+    return 1;
+}
+
+void pa_cvolume_set(struct pa_cvolume *a, pa_volume_t v) {
+    int i;
+    assert(a);
+
+    a->channels = PA_CHANNELS_MAX;
+
+    for (i = 0; i < a->channels; i++)
+        a->values[i] = v;
+}
+
+void pa_cvolume_reset(struct pa_cvolume *a) {
+    assert(a);
+    pa_cvolume_set(a, PA_VOLUME_NORM);
+}
+
+void pa_cvolume_mute(struct pa_cvolume *a) {
+    assert(a);
+    pa_cvolume_set(a, PA_VOLUME_MUTED);
+}
+
+pa_volume_t pa_cvolume_avg(const struct pa_cvolume *a) {
+    uint64_t sum = 0;
+    int i;
+    assert(a);
+
+    for (i = 0; i < a->channels; i++)
+        sum += a->values[i];
+
+    sum /= a->channels;
+
+    return (pa_volume_t) sum;
+}
+
+pa_volume_t pa_sw_volume_multiply(pa_volume_t a, pa_volume_t b) {
+    uint64_t p = a;
+    p *= b;
+    p /= PA_VOLUME_NORM;
+
+    return pa_sw_volume_from_linear(pa_sw_volume_to_linear(a)* pa_sw_volume_to_linear(b));
+}
+
+#define USER_DECIBEL_RANGE 30
+
+pa_volume_t pa_sw_volume_from_dB(double dB) {
+    if (dB <= -USER_DECIBEL_RANGE)
+        return PA_VOLUME_MUTED;
+
+    return (pa_volume_t) ((dB/USER_DECIBEL_RANGE+1)*PA_VOLUME_NORM);
+}
+
+double pa_sw_volume_to_dB(pa_volume_t v) {
+    if (v == PA_VOLUME_MUTED)
+        return PA_DECIBEL_MININFTY;
+
+    return ((double) v/PA_VOLUME_NORM-1)*USER_DECIBEL_RANGE;
+}
+
+pa_volume_t pa_sw_volume_from_linear(double v) {
+
+    if (v <= 0)
+        return PA_VOLUME_MUTED;
+
+    if (v == 1)
+        return PA_VOLUME_NORM;
+
+    return pa_sw_volume_from_dB(20*log10(v));
+}
+
+double pa_sw_volume_to_linear(pa_volume_t v) {
+
+    if (v == PA_VOLUME_MUTED)
+        return 0;
+
+    return pow(10, pa_sw_volume_to_dB(v)/20);
+    
+}
+
+char *pa_cvolume_snprintf(char *s, size_t l, const struct pa_cvolume *c, unsigned channels) {
+    unsigned c;
+    int first = 1;
+    
+    assert(s);
+    assert(l > 0);
+    assert(c);
+
+    if (channels > PA_CHANNELS_MAX || channels <= 0)
+        channels = PA_CHANNELS_MAX;
+
+    *s = 0;
+
+    for (c = 0; c < channels && l > 1; c++) {
+        l -= snprintf(s, l, "%s%u: %3u%%",
+                      first ? "" : " ",
+                      c,
+                      (c->channels[c]*100)/PA_VOLUME_NORM);
+
+        s = strchr(s, 0);
+    }
+
+    return s;
+}
+
+
+/** Return non-zero if the volume of all channels is equal to the specified value */
+int pa_cvolume_channels_equal_to(const struct pa_cvolume *a, uint8_t channels, pa_volume_t v) {
+    unsigned c;
+    assert(a);
+
+    if (channels > PA_CHANNELS_MAX)
+        channels = PA_CHANNELS_MAX;
+
+    for (c = 0; c < channels; c++)
+        if (a->map[c] != v)
+            return 0;
+
+    return 1;
+}