From ffbc80f5908eaf67a033c6e93a343c39dd6894eb Mon Sep 17 00:00:00 2001
From: Eric Laurent <elaurent@google.com>
Date: Wed, 18 Mar 2015 18:30:19 -0700
Subject: audio policy: volume in dBs

Volumes are now stored and exchanged in dBs to be
consistent with the volume tables.

They are converted if needed when applied to the target
gain controller.

Change-Id: I916cbb0bbe65c916444b8c65a2bdca9645c58399
---
 .../managerdefault/AudioPolicyManager.cpp          | 28 ++++++++++------------
 .../managerdefault/AudioPolicyManager.h            |  3 +++
 2 files changed, 16 insertions(+), 15 deletions(-)

(limited to 'services/audiopolicy/managerdefault')

diff --git a/services/audiopolicy/managerdefault/AudioPolicyManager.cpp b/services/audiopolicy/managerdefault/AudioPolicyManager.cpp
index b5ff9a9..686a0e1 100644
--- a/services/audiopolicy/managerdefault/AudioPolicyManager.cpp
+++ b/services/audiopolicy/managerdefault/AudioPolicyManager.cpp
@@ -4251,9 +4251,7 @@ float AudioPolicyManager::computeVolume(audio_stream_type_t stream,
                                             int index,
                                             audio_devices_t device)
 {
-    float volume = 1.0;
-
-    volume = mEngine->volIndexToAmpl(Volume::getDeviceCategory(device), stream, index);
+    float volumeDb = mEngine->volIndexToDb(Volume::getDeviceCategory(device), stream, index);
 
     // if a headset is connected, apply the following rules to ring tones and notifications
     // to avoid sound level bursts in user's ears:
@@ -4271,26 +4269,26 @@ float AudioPolicyManager::computeVolume(audio_stream_type_t stream,
                 || ((stream_strategy == STRATEGY_ENFORCED_AUDIBLE) &&
                     (mEngine->getForceUse(AUDIO_POLICY_FORCE_FOR_SYSTEM) == AUDIO_POLICY_FORCE_NONE))) &&
             mStreams.canBeMuted(stream)) {
-        volume *= SONIFICATION_HEADSET_VOLUME_FACTOR;
+        volumeDb += SONIFICATION_HEADSET_VOLUME_FACTOR_DB;
         // when the phone is ringing we must consider that music could have been paused just before
         // by the music application and behave as if music was active if the last music track was
         // just stopped
         if (isStreamActive(AUDIO_STREAM_MUSIC, SONIFICATION_HEADSET_MUSIC_DELAY) ||
                 mLimitRingtoneVolume) {
             audio_devices_t musicDevice = getDeviceForStrategy(STRATEGY_MEDIA, true /*fromCache*/);
-            float musicVol = computeVolume(AUDIO_STREAM_MUSIC,
-                               mStreams.valueFor(AUDIO_STREAM_MUSIC).getVolumeIndex(musicDevice),
+            float musicVolDB = computeVolume(AUDIO_STREAM_MUSIC,
+                                 mStreams.valueFor(AUDIO_STREAM_MUSIC).getVolumeIndex(musicDevice),
                                musicDevice);
-            float minVol = (musicVol > SONIFICATION_HEADSET_VOLUME_MIN) ?
-                                musicVol : SONIFICATION_HEADSET_VOLUME_MIN;
-            if (volume > minVol) {
-                volume = minVol;
-                ALOGV("computeVolume limiting volume to %f musicVol %f", minVol, musicVol);
+            float minVolDB = (musicVolDB > SONIFICATION_HEADSET_VOLUME_MIN_DB) ?
+                    musicVolDB : SONIFICATION_HEADSET_VOLUME_MIN_DB;
+            if (volumeDb > minVolDB) {
+                volumeDb = minVolDB;
+                ALOGV("computeVolume limiting volume to %f musicVol %f", minVolDB, musicVolDB);
             }
         }
     }
 
-    return volume;
+    return volumeDb;
 }
 
 status_t AudioPolicyManager::checkAndSetVolume(audio_stream_type_t stream,
@@ -4320,12 +4318,12 @@ status_t AudioPolicyManager::checkAndSetVolume(audio_stream_type_t stream,
         device = outputDesc->device();
     }
 
-    float volume = computeVolume(stream, index, device);
+    float volumeDb = computeVolume(stream, index, device);
     if (outputDesc->isFixedVolume(device)) {
-        volume = 1.0f;
+        volumeDb = 0.0f;
     }
 
-    outputDesc->setVolume(volume, stream, device, delayMs, force);
+    outputDesc->setVolume(volumeDb, stream, device, delayMs, force);
 
     if (stream == AUDIO_STREAM_VOICE_CALL ||
         stream == AUDIO_STREAM_BLUETOOTH_SCO) {
diff --git a/services/audiopolicy/managerdefault/AudioPolicyManager.h b/services/audiopolicy/managerdefault/AudioPolicyManager.h
index 9baeeb6..11fd5ff 100644
--- a/services/audiopolicy/managerdefault/AudioPolicyManager.h
+++ b/services/audiopolicy/managerdefault/AudioPolicyManager.h
@@ -49,8 +49,11 @@ namespace android {
 
 // Attenuation applied to STRATEGY_SONIFICATION streams when a headset is connected: 6dB
 #define SONIFICATION_HEADSET_VOLUME_FACTOR 0.5
+#define SONIFICATION_HEADSET_VOLUME_FACTOR_DB (-6)
 // Min volume for STRATEGY_SONIFICATION streams when limited by music volume: -36dB
 #define SONIFICATION_HEADSET_VOLUME_MIN  0.016
+#define SONIFICATION_HEADSET_VOLUME_MIN_DB  (-36)
+
 // Time in milliseconds during which we consider that music is still active after a music
 // track was stopped - see computeVolume()
 #define SONIFICATION_HEADSET_MUSIC_DELAY  5000
-- 
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