diff options
Diffstat (limited to 'services/audioflinger/AudioPolicyManagerBase.cpp')
| -rw-r--r-- | services/audioflinger/AudioPolicyManagerBase.cpp | 62 |
1 files changed, 60 insertions, 2 deletions
diff --git a/services/audioflinger/AudioPolicyManagerBase.cpp b/services/audioflinger/AudioPolicyManagerBase.cpp index 2c81c34..e84d136 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 @@ AudioPolicyManagerBase::AudioPolicyManagerBase(AudioPolicyClientInterface *clien 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 @@ audio_io_handle_t AudioPolicyManagerBase::getActiveInput() 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 @@ float AudioPolicyManagerBase::computeVolume(int stream, int index, audio_io_hand 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: |