Merge "Bug 3376700 Add support in APM for stream-specific volume curves"
diff --git a/services/audioflinger/AudioPolicyManagerBase.cpp b/services/audioflinger/AudioPolicyManagerBase.cpp
index e4086c4..18abc0b 100644
--- a/services/audioflinger/AudioPolicyManagerBase.cpp
+++ b/services/audioflinger/AudioPolicyManagerBase.cpp
@@ -19,6 +19,7 @@
#include <utils/Log.h>
#include <hardware_legacy/AudioPolicyManagerBase.h>
#include <media/mediarecorder.h>
+#include <math.h>
namespace android {
@@ -1019,6 +1020,8 @@
mForceUse[i] = AudioSystem::FORCE_NONE;
}
+ initializeVolumeCurves();
+
// devices available by default are speaker, ear piece and microphone
mAvailableOutputDevices = AudioSystem::DEVICE_OUT_EARPIECE |
AudioSystem::DEVICE_OUT_SPEAKER;
@@ -1810,6 +1813,62 @@
return 0;
}
+float AudioPolicyManagerBase::volIndexToAmpl(uint32_t device, const StreamDescriptor& streamDesc,
+ int indexInUi) {
+ // the volume index in the UI is relative to the min and max volume indices for this stream type
+ int nbSteps = 1 + streamDesc.mVolIndex[StreamDescriptor::VOLMAX] -
+ streamDesc.mVolIndex[StreamDescriptor::VOLMIN];
+ int volIdx = (nbSteps * (indexInUi - streamDesc.mIndexMin)) /
+ (streamDesc.mIndexMax - streamDesc.mIndexMin);
+
+ // find what part of the curve this index volume belongs to, or if it's out of bounds
+ int segment = 0;
+ if (volIdx < streamDesc.mVolIndex[StreamDescriptor::VOLMIN]) { // out of bounds
+ return 0.0f;
+ } else if (volIdx < streamDesc.mVolIndex[StreamDescriptor::VOLKNEE1]) {
+ segment = 0;
+ } else if (volIdx < streamDesc.mVolIndex[StreamDescriptor::VOLKNEE2]) {
+ segment = 1;
+ } else if (volIdx <= streamDesc.mVolIndex[StreamDescriptor::VOLMAX]) {
+ segment = 2;
+ } else { // out of bounds
+ return 1.0f;
+ }
+
+ // linear interpolation in the attenuation table in dB
+ float decibels = streamDesc.mVolDbAtt[segment] +
+ ((float)(volIdx - streamDesc.mVolIndex[segment])) *
+ ( (streamDesc.mVolDbAtt[segment+1] - streamDesc.mVolDbAtt[segment]) /
+ ((float)(streamDesc.mVolIndex[segment+1] - streamDesc.mVolIndex[segment])) );
+
+ float amplification = exp( decibels * 0.115129f); // exp( dB * ln(10) / 20 )
+
+ LOGV("VOLUME vol index=[%d %d %d], dB=[%.1f %.1f %.1f] ampl=%.5f",
+ streamDesc.mVolIndex[segment], volIdx, streamDesc.mVolIndex[segment+1],
+ streamDesc.mVolDbAtt[segment], decibels, streamDesc.mVolDbAtt[segment+1],
+ amplification);
+
+ return amplification;
+}
+
+void AudioPolicyManagerBase::initializeVolumeCurves() {
+ // initialize the volume curves to a (-49.5 - 0 dB) attenuation in 0.5dB steps
+ for (int i=0 ; i< AudioSystem::NUM_STREAM_TYPES ; i++) {
+ mStreams[i].mVolIndex[StreamDescriptor::VOLMIN] = 1;
+ mStreams[i].mVolDbAtt[StreamDescriptor::VOLMIN] = -49.5f;
+ mStreams[i].mVolIndex[StreamDescriptor::VOLKNEE1] = 33;
+ mStreams[i].mVolDbAtt[StreamDescriptor::VOLKNEE1] = -33.5f;
+ mStreams[i].mVolIndex[StreamDescriptor::VOLKNEE2] = 66;
+ mStreams[i].mVolDbAtt[StreamDescriptor::VOLKNEE2] = -17.0f;
+ // here we use 100 steps to avoid rounding errors
+ // when computing the volume in volIndexToAmpl()
+ mStreams[i].mVolIndex[StreamDescriptor::VOLMAX] = 100;
+ mStreams[i].mVolDbAtt[StreamDescriptor::VOLMAX] = 0.0f;
+ }
+
+ // TODO add modifications for music to have finer steps below knee1 and above knee2
+}
+
float AudioPolicyManagerBase::computeVolume(int stream, int index, audio_io_handle_t output, uint32_t device)
{
float volume = 1.0;
@@ -1820,8 +1879,7 @@
device = outputDesc->device();
}
- int volInt = (100 * (index - streamDesc.mIndexMin)) / (streamDesc.mIndexMax - streamDesc.mIndexMin);
- volume = AudioSystem::linearToLog(volInt);
+ volume = volIndexToAmpl(device, streamDesc, index);
// if a headset is connected, apply the following rules to ring tones and notifications
// to avoid sound level bursts in user's ears: