add user volume API

git-svn-id: file:///home/lennart/svn/public/pulseaudio/trunk@255 fefdeb5f-60dc-0310-8127-8f9354f1896f

doc/todo

@@ -1,6 +1,7 @@
 *** $Id$ ***
 
 *** 0.6 ****
+- latency interpolation
 - per-channel volume
 - unix socket directories include user name
 - add sample directory
@@ -22,7 +23,7 @@
 
 backends for:
 - portaudio  (semi-done)
+- gstreamer (semi-done)
 - alsa-lib
 - sdl
-- gstreamer (semi-done)
 - OSS (esddsp style)

polyp/Makefile.am

@@ -33,7 +33,7 @@ AM_LDADD=$(PTHREAD_LIBS) -lm
 AM_LIBADD=$(PTHREAD_LIBS) -lm
 
 EXTRA_DIST = default.pa.in daemon.conf.in client.conf.in depmod.py esdcompat.sh.in
-bin_PROGRAMS = polypaudio pacat pactl paplay
+bin_PROGRAMS = polypaudio pacat pactl paplay voltest
 bin_SCRIPTS = esdcompat.sh
 noinst_PROGRAMS = \
 		mainloop-test \
@@ -408,6 +408,10 @@ mainloop_test_SOURCES = mainloop-test.c
 mainloop_test_CFLAGS = $(AM_CFLAGS)
 mainloop_test_LDADD = $(AM_LDADD) libpolyp-mainloop-@PA_MAJORMINOR@.la libpolyp-@PA_MAJORMINOR@.la
 
+voltest_SOURCES = voltest.c sample.c
+voltest_CFLAGS = $(AM_CFLAGS)
+voltest_LDADD = $(AM_LDADD)
+
 cpulimit_test_SOURCES = cpulimit-test.c cpulimit.c util.c log.c
 cpulimit_test_CFLAGS = $(AM_CFLAGS)
 cpulimit_test_LDADD = $(AM_LDADD) libpolyp-mainloop-@PA_MAJORMINOR@.la

polyp/polyplib-version.h.in

@@ -27,6 +27,8 @@
 /** \file
  * Define header version */
 
+PA_C_DECL_BEGIN
+
 /** Return the version of the header files. Keep in mind that this is
 a macro and not a function, so it is impossible to get the pointer of
 it. */
@@ -40,4 +42,6 @@ const char* pa_get_library_version(void);
  * PA_API_VERSION undefined.  */
 #define PA_API_VERSION @PA_API_VERSION@
 
+PA_C_DECL_END
+
 #endif

polyp/sample.c

@@ -125,6 +125,22 @@ double pa_volume_to_dB(pa_volume_t v) {
     return 20*log10((double) v/PA_VOLUME_NORM);
 }
 
+#define USER_DECIBEL_RANGE 30
+
+double pa_volume_to_user(pa_volume_t v) {
+    double dB = pa_volume_to_dB(v);
+
+    return dB < -USER_DECIBEL_RANGE ? 0 : dB/USER_DECIBEL_RANGE+1;
+}
+
+pa_volume_t pa_volume_from_user(double v) {
+
+    if (v <= 0)
+        return PA_VOLUME_MUTED;
+    
+    return pa_volume_from_dB((v-1)*USER_DECIBEL_RANGE);
+}
+
 void pa_bytes_snprint(char *s, size_t l, unsigned v) {
     if (v >= ((unsigned) 1024)*1024*1024)
         snprintf(s, l, "%0.1f GB", ((double) v)/1024/1024/1024);

polyp/sample.h

@@ -110,6 +110,12 @@ pa_volume_t pa_volume_from_dB(double f);
 /** Convert volume from linear level to decibel.  \since 0.4 */
 double pa_volume_to_dB(pa_volume_t v);
 
+/** Convert volume to scaled value understandable by the user (between 0 and 1). \since 0.6 */
+double pa_volume_to_user(pa_volume_t v);
+
+/** Convert user volume to polypaudio volume. \since 0.6 */
+pa_volume_t pa_volume_from_user(double v);
+
 #ifdef INFINITY
 #define PA_DECIBEL_MININFTY (-INFINITY)
 #else

polyp/voltest.c

@@ -0,0 +1,12 @@
+#include <stdio.h>
+
+#include <polyp/sample.h>
+
+int main() {
+    int p;
+    for (p = 0; p <= 200; p++) {
+        pa_volume_t v = pa_volume_from_user((double) p/100);
+        double dB = pa_volume_to_dB(v);
+        printf("%3i%% = %u = %0.2f dB = %u = %3i%%\n", p, v, dB, pa_volume_from_dB(dB), (int) (pa_volume_to_user(v)*100));
+    }
+}