add support for dB volumes

git-svn-id: file:///home/lennart/svn/public/pulseaudio/trunk@166 fefdeb5f-60dc-0310-8127-8f9354f1896f

doc/todo

@@ -14,7 +14,6 @@
 - remove all gcc warnings
 - esd compatible startup script or personality
 - limit number of concurrent streams
-- decibel macros
 
 ** later ***
 - xmlrpc/http

polyp/Makefile.am

@@ -19,8 +19,8 @@
 
 AM_CFLAGS=-D_GNU_SOURCE -I$(top_srcdir) $(PTHREAD_CFLAGS)
 #AM_CFLAGS+= -DDLSEARCHDIR=\"$(pkglibdir)\" 
-AM_LDADD=$(PTHREAD_LIBS)
+AM_LDADD=$(PTHREAD_LIBS) -lm
-AM_LIBADD=$(PTHREAD_LIBS)
+AM_LIBADD=$(PTHREAD_LIBS) -lm
 
 polypincludedir=$(includedir)/polyp
 
@@ -276,7 +276,7 @@ module_cli_la_LIBADD = $(AM_LIBADD) libcli.la libiochannel.la
 
 module_sine_la_SOURCES = module-sine.c
 module_sine_la_LDFLAGS = -module -avoid-version
-module_sine_la_LIBADD = $(AM_LIBADD) -lm
+module_sine_la_LIBADD = $(AM_LIBADD)
 
 if !X_DISPLAY_MISSING
 module_x11_bell_la_SOURCES = module-x11-bell.c

polyp/cli-text.c

@@ -93,10 +93,11 @@ char *pa_sink_list_to_string(struct pa_core *c) {
         assert(sink->monitor_source);
         pa_strbuf_printf(
             s,
-            "  %c index: %u\n\tname: <%s>\n\tvolume: <0x%04x>\n\tlatency: <%u usec>\n\tmonitor_source: <%u>\n\tsample_spec: <%s>\n",
+            "  %c index: %u\n\tname: <%s>\n\tvolume: <0x%04x> (%0.2fdB)\n\tlatency: <%u usec>\n\tmonitor_source: <%u>\n\tsample_spec: <%s>\n",
             c->default_sink_name && !strcmp(sink->name, c->default_sink_name) ? '*' : ' ',
             sink->index, sink->name,
             (unsigned) sink->volume,
+            pa_volume_to_dB(sink->volume),
             pa_sink_get_latency(sink),
             sink->monitor_source->index,
             ss);
@@ -188,11 +189,12 @@ char *pa_sink_input_list_to_string(struct pa_core *c) {
         pa_sample_spec_snprint(ss, sizeof(ss), &i->sample_spec);
         assert(i->sink);
         pa_strbuf_printf(
-            s, "    index: %u\n\tname: <%s>\n\tsink: <%u>\n\tvolume: <0x%04x>\n\tlatency: <%u usec>\n\tsample_spec: <%s>\n",
+            s, "    index: %u\n\tname: <%s>\n\tsink: <%u>\n\tvolume: <0x%04x> (%0.2fdB)\n\tlatency: <%u usec>\n\tsample_spec: <%s>\n",
             i->index,
             i->name,
             i->sink->index,
             (unsigned) i->volume,
+            pa_volume_to_dB(i->volume),
             pa_sink_input_get_latency(i),
             ss);
 

polyp/sample.c

@@ -25,6 +25,7 @@
 
 #include <stdio.h>
 #include <assert.h>
+#include <math.h>
 
 #include "sample.h"
 
@@ -104,3 +105,17 @@ pa_volume_t pa_volume_multiply(pa_volume_t a, pa_volume_t b) {
 
     return (pa_volume_t) p;
 }
+
+pa_volume_t pa_volume_from_dB(double f) {
+    if (f <= -200)
+        return PA_VOLUME_MUTED;
+
+    return (pa_volume_t) (pow(10, f/20)*PA_VOLUME_NORM);
+}
+
+double pa_volume_to_dB(pa_volume_t v) {
+    if (v == PA_VOLUME_MUTED)
+        return -200;
+
+    return 20*log10((double) v/PA_VOLUME_NORM);
+}

polyp/sample.h

@@ -102,6 +102,12 @@ typedef uint32_t pa_volume_t;
 /** Multiply two volumes specifications, return the result. This uses PA_VOLUME_NORM as neutral element of multiplication. */
 pa_volume_t pa_volume_multiply(pa_volume_t a, pa_volume_t b);
 
+/** Convert volume from decibel to linear level */
+pa_volume_t pa_volume_from_dB(double f);
+
+/** Convert volume from linear level to decibel */
+double pa_volume_to_dB(pa_volume_t v);
+
 PA_C_DECL_END
 
 #endif