From 220c9c0c207c9e3a205596b540277825c8a917cd Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Wed, 8 Oct 2008 04:02:10 +0200
Subject: [PATCH] define 0dB in PA as maximum amplification

---
 src/modules/module-alsa-sink.c   |   10 ++++++----
 src/modules/module-alsa-source.c |   10 ++++++----
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/src/modules/module-alsa-sink.c b/src/modules/module-alsa-sink.c
index 0e15da3..4044de1 100644
--- a/src/modules/module-alsa-sink.c
+++ b/src/modules/module-alsa-sink.c
@@ -796,7 +796,7 @@ static int sink_get_volume_cb(pa_sink *s) {
                 VALGRIND_MAKE_MEM_DEFINED(&alsa_vol, sizeof(alsa_vol));
 #endif
 
-                r.values[i] = pa_sw_volume_from_dB((double) alsa_vol / 100.0);
+                r.values[i] = pa_sw_volume_from_dB((double) (alsa_vol - u->hw_dB_max) / 100.0);
             } else {
 
                 if ((err = snd_mixer_selem_get_playback_volume(u->mixer_elem, u->mixer_map[i], &alsa_vol)) < 0)
@@ -818,7 +818,7 @@ static int sink_get_volume_cb(pa_sink *s) {
             VALGRIND_MAKE_MEM_DEFINED(&alsa_vol, sizeof(alsa_vol));
 #endif
 
-            pa_cvolume_set(&r, s->sample_spec.channels, pa_sw_volume_from_dB((double) alsa_vol / 100.0));
+            pa_cvolume_set(&r, s->sample_spec.channels, pa_sw_volume_from_dB((double) (alsa_vol - u->hw_dB_max) / 100.0));
 
         } else {
 
@@ -875,6 +875,7 @@ static int sink_set_volume_cb(pa_sink *s) {
             if (u->hw_dB_supported) {
 
                 alsa_vol = (long) (pa_sw_volume_to_dB(vol) * 100);
+                alsa_vol += u->hw_dB_max;
                 alsa_vol = PA_CLAMP_UNLIKELY(alsa_vol, u->hw_dB_min, u->hw_dB_max);
 
                 if ((err = snd_mixer_selem_set_playback_dB(u->mixer_elem, u->mixer_map[i], alsa_vol, 1)) < 0)
@@ -883,7 +884,7 @@ static int sink_set_volume_cb(pa_sink *s) {
                 if ((err = snd_mixer_selem_get_playback_dB(u->mixer_elem, u->mixer_map[i], &alsa_vol)) < 0)
                     goto fail;
 
-                r.values[i] = pa_sw_volume_from_dB((double) alsa_vol / 100.0);
+                r.values[i] = pa_sw_volume_from_dB((double) (alsa_vol - u->hw_dB_max) / 100.0);
 
             } else {
                 alsa_vol = to_alsa_volume(u, vol);
@@ -906,6 +907,7 @@ static int sink_set_volume_cb(pa_sink *s) {
 
         if (u->hw_dB_supported) {
             alsa_vol = (long) (pa_sw_volume_to_dB(vol) * 100);
+            alsa_vol += u->hw_dB_max;
             alsa_vol = PA_CLAMP_UNLIKELY(alsa_vol, u->hw_dB_min, u->hw_dB_max);
 
             if ((err = snd_mixer_selem_set_playback_dB_all(u->mixer_elem, alsa_vol, 1)) < 0)
@@ -914,7 +916,7 @@ static int sink_set_volume_cb(pa_sink *s) {
             if ((err = snd_mixer_selem_get_playback_dB(u->mixer_elem, SND_MIXER_SCHN_MONO, &alsa_vol)) < 0)
                 goto fail;
 
-            pa_cvolume_set(&r, s->volume.channels, pa_sw_volume_from_dB((double) alsa_vol / 100.0));
+            pa_cvolume_set(&r, s->volume.channels, pa_sw_volume_from_dB((double) (alsa_vol - u->hw_dB_max) / 100.0));
 
         } else {
             alsa_vol = to_alsa_volume(u, vol);
diff --git a/src/modules/module-alsa-source.c b/src/modules/module-alsa-source.c
index 2827ecf..a743776 100644
--- a/src/modules/module-alsa-source.c
+++ b/src/modules/module-alsa-source.c
@@ -742,7 +742,7 @@ static int source_get_volume_cb(pa_source *s) {
                 VALGRIND_MAKE_MEM_DEFINED(&alsa_vol, sizeof(alsa_vol));
 #endif
 
-                r.values[i] = pa_sw_volume_from_dB((double) alsa_vol / 100.0);
+                r.values[i] = pa_sw_volume_from_dB((double) (alsa_vol - u->hw_dB_max) / 100.0);
             } else {
 
                 if ((err = snd_mixer_selem_get_capture_volume(u->mixer_elem, u->mixer_map[i], &alsa_vol)) < 0)
@@ -764,7 +764,7 @@ static int source_get_volume_cb(pa_source *s) {
             VALGRIND_MAKE_MEM_DEFINED(&alsa_vol, sizeof(alsa_vol));
 #endif
 
-            pa_cvolume_set(&r, s->sample_spec.channels, pa_sw_volume_from_dB((double) alsa_vol / 100.0));
+            pa_cvolume_set(&r, s->sample_spec.channels, pa_sw_volume_from_dB((double) (alsa_vol - u->hw_dB_max) / 100.0));
 
         } else {
 
@@ -821,6 +821,7 @@ static int source_set_volume_cb(pa_source *s) {
             if (u->hw_dB_supported) {
 
                 alsa_vol = (long) (pa_sw_volume_to_dB(vol) * 100);
+                alsa_vol += u->hw_dB_max;
                 alsa_vol = PA_CLAMP_UNLIKELY(alsa_vol, u->hw_dB_min, u->hw_dB_max);
 
                 if ((err = snd_mixer_selem_set_capture_dB(u->mixer_elem, u->mixer_map[i], alsa_vol, 1)) < 0)
@@ -829,7 +830,7 @@ static int source_set_volume_cb(pa_source *s) {
                 if ((err = snd_mixer_selem_get_capture_dB(u->mixer_elem, u->mixer_map[i], &alsa_vol)) < 0)
                     goto fail;
 
-                r.values[i] = pa_sw_volume_from_dB((double) alsa_vol / 100.0);
+                r.values[i] = pa_sw_volume_from_dB((double) (alsa_vol - u->hw_dB_max) / 100.0);
 
             } else {
                 alsa_vol = to_alsa_volume(u, vol);
@@ -852,6 +853,7 @@ static int source_set_volume_cb(pa_source *s) {
 
         if (u->hw_dB_supported) {
             alsa_vol = (long) (pa_sw_volume_to_dB(vol) * 100);
+            alsa_vol += u->hw_dB_max;
             alsa_vol = PA_CLAMP_UNLIKELY(alsa_vol, u->hw_dB_min, u->hw_dB_max);
 
             if ((err = snd_mixer_selem_set_capture_dB_all(u->mixer_elem, alsa_vol, 1)) < 0)
@@ -860,7 +862,7 @@ static int source_set_volume_cb(pa_source *s) {
             if ((err = snd_mixer_selem_get_capture_dB(u->mixer_elem, SND_MIXER_SCHN_MONO, &alsa_vol)) < 0)
                 goto fail;
 
-            pa_cvolume_set(&r, s->volume.channels, pa_sw_volume_from_dB((double) alsa_vol / 100.0));
+            pa_cvolume_set(&r, s->volume.channels, pa_sw_volume_from_dB((double) (alsa_vol - u->hw_dB_max) / 100.0));
 
         } else {
             alsa_vol = to_alsa_volume(u, vol);
-- 
1.6.0.3