src/opensles/AudioInputStreamOpenSLES.cpp - platform/external/oboe - Git at Google

 /*
  * Copyright 2017 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #include <cassert>

 #include <SLES/OpenSLES.h>
 #include <SLES/OpenSLES_Android.h>

 #include "oboe/AudioStreamBuilder.h"
 #include "AudioInputStreamOpenSLES.h"
 #include "AudioStreamOpenSLES.h"
 #include "OpenSLESUtilities.h"

 using namespace oboe;

 static SLuint32 OpenSLES_convertInputPreset(InputPreset oboePreset) {
     SLuint32 openslPreset = SL_ANDROID_RECORDING_PRESET_NONE;
     switch(oboePreset) {
         case InputPreset::Generic:
             openslPreset =  SL_ANDROID_RECORDING_PRESET_GENERIC;
             break;
         case InputPreset::Camcorder:
             openslPreset =  SL_ANDROID_RECORDING_PRESET_CAMCORDER;
             break;
         case InputPreset::VoiceRecognition:
             openslPreset =  SL_ANDROID_RECORDING_PRESET_VOICE_RECOGNITION;
             break;
         case InputPreset::VoiceCommunication:
             openslPreset =  SL_ANDROID_RECORDING_PRESET_VOICE_COMMUNICATION;
             break;
         case InputPreset::Unprocessed:
             openslPreset =  SL_ANDROID_RECORDING_PRESET_UNPROCESSED;
             break;
         default:
             break;
     }
     return openslPreset;
 }

 AudioInputStreamOpenSLES::AudioInputStreamOpenSLES(const AudioStreamBuilder &builder)
         : AudioStreamOpenSLES(builder) {
 }

 AudioInputStreamOpenSLES::~AudioInputStreamOpenSLES() {
 }

 // Calculate masks specific to INPUT streams.
 SLuint32 AudioInputStreamOpenSLES::channelCountToChannelMask(int channelCount) {
     // Derived from internal sles_channel_in_mask_from_count(chanCount);
     // in "frameworks/wilhelm/src/android/channels.cpp".
     // Yes, it seems strange to use SPEAKER constants to describe inputs.
     // But that is how OpenSL ES does it internally.
     switch (channelCount) {
         case 1:
             return SL_SPEAKER_FRONT_LEFT;
         case 2:
             return SL_SPEAKER_FRONT_LEFT | SL_SPEAKER_FRONT_RIGHT;
         default:
             return channelCountToChannelMaskDefault(channelCount);
     }
 }

 Result AudioInputStreamOpenSLES::open() {
     SLAndroidConfigurationItf configItf = nullptr;

     if (getSdkVersion() < __ANDROID_API_M__ && mFormat == AudioFormat::Float){
         // TODO: Allow floating point format on API <23 using float->int16 converter
         return Result::ErrorInvalidFormat;
     }

     // If audio format is unspecified then choose a suitable default.
     // API 23+: FLOAT
     // API <23: INT16
     if (mFormat == AudioFormat::Unspecified){
         mFormat = (getSdkVersion() < __ANDROID_API_M__) ?
                   AudioFormat::I16 : AudioFormat::Float;
     }

     Result oboeResult = AudioStreamOpenSLES::open();
     if (Result::OK != oboeResult) return oboeResult;

     SLuint32 bitsPerSample = getBytesPerSample() * kBitsPerByte;

     // configure audio sink
     SLDataLocator_AndroidSimpleBufferQueue loc_bufq = {
             SL_DATALOCATOR_ANDROIDSIMPLEBUFFERQUEUE,    // locatorType
             static_cast<SLuint32>(kBufferQueueLength)};   // numBuffers

     // Define the audio data format.
     SLDataFormat_PCM format_pcm = {
             SL_DATAFORMAT_PCM,       // formatType
             static_cast<SLuint32>(mChannelCount),           // numChannels
             static_cast<SLuint32>(mSampleRate * kMillisPerSecond), // milliSamplesPerSec
             bitsPerSample,                      // bitsPerSample
             bitsPerSample,                      // containerSize;
             channelCountToChannelMask(mChannelCount), // channelMask
             getDefaultByteOrder(),
     };

     SLDataSink audioSink = {&loc_bufq, &format_pcm};

     /**
      * API 23 (Marshmallow) introduced support for floating-point data representation and an
      * extended data format type: SLAndroidDataFormat_PCM_EX for recording streams (playback streams
      * got this in API 21). If running on API 23+ use this newer format type, creating it from our
      * original format.
      */
     SLAndroidDataFormat_PCM_EX format_pcm_ex;
     if (getSdkVersion() >= __ANDROID_API_M__) {
         SLuint32 representation = OpenSLES_ConvertFormatToRepresentation(getFormat());
         // Fill in the format structure.
         format_pcm_ex = OpenSLES_createExtendedFormat(format_pcm, representation);
         // Use in place of the previous format.
         audioSink.pFormat = &format_pcm_ex;
     }


     // configure audio source
     SLDataLocator_IODevice loc_dev = {SL_DATALOCATOR_IODEVICE,
                                       SL_IODEVICE_AUDIOINPUT,
                                       SL_DEFAULTDEVICEID_AUDIOINPUT,
                                       NULL};
     SLDataSource audioSrc = {&loc_dev, NULL};

     SLresult result = EngineOpenSLES::getInstance().createAudioRecorder(&mObjectInterface,
                                                                         &audioSrc,
                                                                         &audioSink);

     if (SL_RESULT_SUCCESS != result) {
         LOGE("createAudioRecorder() result:%s", getSLErrStr(result));
         goto error;
     }

     // Configure the stream.
     result = (*mObjectInterface)->GetInterface(mObjectInterface,
                                             SL_IID_ANDROIDCONFIGURATION,
                                             &configItf);

     if (SL_RESULT_SUCCESS != result) {
         LOGW("%s() GetInterface(SL_IID_ANDROIDCONFIGURATION) failed with %s",
              __func__, getSLErrStr(result));
     } else {
         SLuint32 presetValue = OpenSLES_convertInputPreset(getInputPreset());
         result = (*configItf)->SetConfiguration(configItf,
                                          SL_ANDROID_KEY_RECORDING_PRESET,
                                          &presetValue,
                                          sizeof(SLuint32));
         if (SL_RESULT_SUCCESS != result
             && presetValue != SL_ANDROID_RECORDING_PRESET_VOICE_RECOGNITION) {
             presetValue = SL_ANDROID_RECORDING_PRESET_VOICE_RECOGNITION;
             mInputPreset = InputPreset::VoiceRecognition;
             (*configItf)->SetConfiguration(configItf,
                                              SL_ANDROID_KEY_RECORDING_PRESET,
                                              &presetValue,
                                              sizeof(SLuint32));
         }

         result = configurePerformanceMode(configItf);
         if (SL_RESULT_SUCCESS != result) {
             goto error;
         }
     }

     result = (*mObjectInterface)->Realize(mObjectInterface, SL_BOOLEAN_FALSE);
     if (SL_RESULT_SUCCESS != result) {
         LOGE("Realize recorder object result:%s", getSLErrStr(result));
         goto error;
     }

     result = (*mObjectInterface)->GetInterface(mObjectInterface, SL_IID_RECORD, &mRecordInterface);
     if (SL_RESULT_SUCCESS != result) {
         LOGE("GetInterface RECORD result:%s", getSLErrStr(result));
         goto error;
     }

     result = AudioStreamOpenSLES::registerBufferQueueCallback();
     if (SL_RESULT_SUCCESS != result) {
         goto error;
     }

     result = updateStreamParameters(configItf);
     if (SL_RESULT_SUCCESS != result) {
         goto error;
     }

     allocateFifo();

     setState(StreamState::Open);
     return Result::OK;

     error:
     return Result::ErrorInternal; // TODO convert error from SLES to OBOE
 }

 Result AudioInputStreamOpenSLES::close() {
     LOGD("AudioInputStreamOpenSLES::%s()", __func__);
     mLock.lock();
     Result result = Result::OK;
     if (getState() == StreamState::Closed){
         result = Result::ErrorClosed;
     } else {
         mLock.unlock(); // avoid recursive lock
         requestStop();
         mLock.lock();
         // invalidate any interfaces
         mRecordInterface = NULL;
         result = AudioStreamOpenSLES::close();
     }
     mLock.unlock(); // avoid recursive lock
     return result;
 }

 Result AudioInputStreamOpenSLES::setRecordState_l(SLuint32 newState) {
     LOGD("AudioInputStreamOpenSLES::%s(%d)", __func__, newState);
     Result result = Result::OK;

     if (mRecordInterface == nullptr) {
         LOGE("AudioInputStreamOpenSLES::%s() mRecordInterface is null", __func__);
         return Result::ErrorInvalidState;
     }
     SLresult slResult = (*mRecordInterface)->SetRecordState(mRecordInterface, newState);
     if (SL_RESULT_SUCCESS != slResult) {
         LOGE("AudioInputStreamOpenSLES::%s() returned %s", __func__, getSLErrStr(slResult));
         result = Result::ErrorInternal; // TODO review
     }
     return result;
 }

 Result AudioInputStreamOpenSLES::requestStart() {
     LOGD("AudioInputStreamOpenSLES(): %s() called", __func__);
     std::lock_guard<std::mutex> lock(mLock);
     StreamState initialState = getState();
     switch (initialState) {
         case StreamState::Starting:
         case StreamState::Started:
             return Result::OK;
         case StreamState::Closed:
             return Result::ErrorClosed;
         default:
             break;
     }

     // We use a callback if the user requests one
     // OR if we have an internal callback to fill the blocking IO buffer.
     setDataCallbackEnabled(true);

     setState(StreamState::Starting);
     Result result = setRecordState_l(SL_RECORDSTATE_RECORDING);
     if (result == Result::OK) {
         setState(StreamState::Started);
         // Enqueue the first buffer to start the streaming.
         // This does not call the callback function.
         enqueueCallbackBuffer(mSimpleBufferQueueInterface);
     } else {
         setState(initialState);
     }
     return result;
 }


 Result AudioInputStreamOpenSLES::requestPause() {
     LOGW("AudioInputStreamOpenSLES::%s() is intentionally not implemented for input "
          "streams", __func__);
     return Result::ErrorUnimplemented; // Matches AAudio behavior.
 }

 Result AudioInputStreamOpenSLES::requestFlush() {
     LOGW("AudioInputStreamOpenSLES::%s() is intentionally not implemented for input "
          "streams", __func__);
     return Result::ErrorUnimplemented; // Matches AAudio behavior.
 }

 Result AudioInputStreamOpenSLES::requestStop() {
     LOGD("AudioInputStreamOpenSLES(): %s() called", __func__);

     std::lock_guard<std::mutex> lock(mLock);
     StreamState initialState = getState();
     switch (initialState) {
         case StreamState::Stopping:
         case StreamState::Stopped:
             return Result::OK;
         case StreamState::Closed:
             return Result::ErrorClosed;
         default:
             break;
     }

     setState(StreamState::Stopping);

     Result result = setRecordState_l(SL_RECORDSTATE_STOPPED);
     if (result == Result::OK) {
         mPositionMillis.reset32(); // OpenSL ES resets its millisecond position when stopped.
         setState(StreamState::Stopped);
     } else {
         setState(initialState);
     }
     return result;
 }

 void AudioInputStreamOpenSLES::updateFramesWritten() {
     if (usingFIFO()) {
         AudioStreamBuffered::updateFramesWritten();
     } else {
         mFramesWritten = getFramesProcessedByServer();
     }
 }

 Result AudioInputStreamOpenSLES::updateServiceFrameCounter() {
     Result result = Result::OK;
     // Avoid deadlock if another thread is trying to stop or close this stream
     // and this is being called from a callback.
     if (mLock.try_lock()) {

         if (mRecordInterface == NULL) {
             mLock.unlock();
             return Result::ErrorNull;
         }
         SLmillisecond msec = 0;
         SLresult slResult = (*mRecordInterface)->GetPosition(mRecordInterface, &msec);
         if (SL_RESULT_SUCCESS != slResult) {
             LOGD("%s(): GetPosition() returned %s", __func__, getSLErrStr(slResult));
             // set result based on SLresult
             result = Result::ErrorInternal;
         } else {
             mPositionMillis.update32(msec);
         }
         mLock.unlock();
     }
     return result;
 }
	/*
	* Copyright 2017 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#include <cassert>

	#include <SLES/OpenSLES.h>
	#include <SLES/OpenSLES_Android.h>

	#include "oboe/AudioStreamBuilder.h"
	#include "AudioInputStreamOpenSLES.h"
	#include "AudioStreamOpenSLES.h"
	#include "OpenSLESUtilities.h"

	using namespace oboe;

	static SLuint32 OpenSLES_convertInputPreset(InputPreset oboePreset) {
	SLuint32 openslPreset = SL_ANDROID_RECORDING_PRESET_NONE;
	switch(oboePreset) {
	case InputPreset::Generic:
	openslPreset = SL_ANDROID_RECORDING_PRESET_GENERIC;
	break;
	case InputPreset::Camcorder:
	openslPreset = SL_ANDROID_RECORDING_PRESET_CAMCORDER;
	break;
	case InputPreset::VoiceRecognition:
	openslPreset = SL_ANDROID_RECORDING_PRESET_VOICE_RECOGNITION;
	break;
	case InputPreset::VoiceCommunication:
	openslPreset = SL_ANDROID_RECORDING_PRESET_VOICE_COMMUNICATION;
	break;
	case InputPreset::Unprocessed:
	openslPreset = SL_ANDROID_RECORDING_PRESET_UNPROCESSED;
	break;
	default:
	break;
	}
	return openslPreset;
	}

	AudioInputStreamOpenSLES::AudioInputStreamOpenSLES(const AudioStreamBuilder &builder)
	: AudioStreamOpenSLES(builder) {
	}

	AudioInputStreamOpenSLES::~AudioInputStreamOpenSLES() {
	}

	// Calculate masks specific to INPUT streams.
	SLuint32 AudioInputStreamOpenSLES::channelCountToChannelMask(int channelCount) {
	// Derived from internal sles_channel_in_mask_from_count(chanCount);
	// in "frameworks/wilhelm/src/android/channels.cpp".
	// Yes, it seems strange to use SPEAKER constants to describe inputs.
	// But that is how OpenSL ES does it internally.
	switch (channelCount) {
	case 1:
	return SL_SPEAKER_FRONT_LEFT;
	case 2:
	return SL_SPEAKER_FRONT_LEFT \| SL_SPEAKER_FRONT_RIGHT;
	default:
	return channelCountToChannelMaskDefault(channelCount);
	}
	}

	Result AudioInputStreamOpenSLES::open() {
	SLAndroidConfigurationItf configItf = nullptr;

	if (getSdkVersion() < __ANDROID_API_M__ && mFormat == AudioFormat::Float){
	// TODO: Allow floating point format on API <23 using float->int16 converter
	return Result::ErrorInvalidFormat;
	}

	// If audio format is unspecified then choose a suitable default.
	// API 23+: FLOAT
	// API <23: INT16
	if (mFormat == AudioFormat::Unspecified){
	mFormat = (getSdkVersion() < __ANDROID_API_M__) ?
	AudioFormat::I16 : AudioFormat::Float;
	}

	Result oboeResult = AudioStreamOpenSLES::open();
	if (Result::OK != oboeResult) return oboeResult;

	SLuint32 bitsPerSample = getBytesPerSample() * kBitsPerByte;

	// configure audio sink
	SLDataLocator_AndroidSimpleBufferQueue loc_bufq = {
	SL_DATALOCATOR_ANDROIDSIMPLEBUFFERQUEUE, // locatorType
	static_cast<SLuint32>(kBufferQueueLength)}; // numBuffers

	// Define the audio data format.
	SLDataFormat_PCM format_pcm = {
	SL_DATAFORMAT_PCM, // formatType
	static_cast<SLuint32>(mChannelCount), // numChannels
	static_cast<SLuint32>(mSampleRate * kMillisPerSecond), // milliSamplesPerSec
	bitsPerSample, // bitsPerSample
	bitsPerSample, // containerSize;
	channelCountToChannelMask(mChannelCount), // channelMask
	getDefaultByteOrder(),
	};

	SLDataSink audioSink = {&loc_bufq, &format_pcm};

	/**
	* API 23 (Marshmallow) introduced support for floating-point data representation and an
	* extended data format type: SLAndroidDataFormat_PCM_EX for recording streams (playback streams
	* got this in API 21). If running on API 23+ use this newer format type, creating it from our
	* original format.
	*/
	SLAndroidDataFormat_PCM_EX format_pcm_ex;
	if (getSdkVersion() >= __ANDROID_API_M__) {
	SLuint32 representation = OpenSLES_ConvertFormatToRepresentation(getFormat());
	// Fill in the format structure.
	format_pcm_ex = OpenSLES_createExtendedFormat(format_pcm, representation);
	// Use in place of the previous format.
	audioSink.pFormat = &format_pcm_ex;
	}


	// configure audio source
	SLDataLocator_IODevice loc_dev = {SL_DATALOCATOR_IODEVICE,
	SL_IODEVICE_AUDIOINPUT,
	SL_DEFAULTDEVICEID_AUDIOINPUT,
	NULL};
	SLDataSource audioSrc = {&loc_dev, NULL};

	SLresult result = EngineOpenSLES::getInstance().createAudioRecorder(&mObjectInterface,
	&audioSrc,
	&audioSink);

	if (SL_RESULT_SUCCESS != result) {
	LOGE("createAudioRecorder() result:%s", getSLErrStr(result));
	goto error;
	}

	// Configure the stream.
	result = (*mObjectInterface)->GetInterface(mObjectInterface,
	SL_IID_ANDROIDCONFIGURATION,
	&configItf);

	if (SL_RESULT_SUCCESS != result) {
	LOGW("%s() GetInterface(SL_IID_ANDROIDCONFIGURATION) failed with %s",
	__func__, getSLErrStr(result));
	} else {
	SLuint32 presetValue = OpenSLES_convertInputPreset(getInputPreset());
	result = (*configItf)->SetConfiguration(configItf,
	SL_ANDROID_KEY_RECORDING_PRESET,
	&presetValue,
	sizeof(SLuint32));
	if (SL_RESULT_SUCCESS != result
	&& presetValue != SL_ANDROID_RECORDING_PRESET_VOICE_RECOGNITION) {
	presetValue = SL_ANDROID_RECORDING_PRESET_VOICE_RECOGNITION;
	mInputPreset = InputPreset::VoiceRecognition;
	(*configItf)->SetConfiguration(configItf,
	SL_ANDROID_KEY_RECORDING_PRESET,
	&presetValue,
	sizeof(SLuint32));
	}

	result = configurePerformanceMode(configItf);
	if (SL_RESULT_SUCCESS != result) {
	goto error;
	}
	}

	result = (*mObjectInterface)->Realize(mObjectInterface, SL_BOOLEAN_FALSE);
	if (SL_RESULT_SUCCESS != result) {
	LOGE("Realize recorder object result:%s", getSLErrStr(result));
	goto error;
	}

	result = (*mObjectInterface)->GetInterface(mObjectInterface, SL_IID_RECORD, &mRecordInterface);
	if (SL_RESULT_SUCCESS != result) {
	LOGE("GetInterface RECORD result:%s", getSLErrStr(result));
	goto error;
	}

	result = AudioStreamOpenSLES::registerBufferQueueCallback();
	if (SL_RESULT_SUCCESS != result) {
	goto error;
	}

	result = updateStreamParameters(configItf);
	if (SL_RESULT_SUCCESS != result) {
	goto error;
	}

	allocateFifo();

	setState(StreamState::Open);
	return Result::OK;

	error:
	return Result::ErrorInternal; // TODO convert error from SLES to OBOE
	}

	Result AudioInputStreamOpenSLES::close() {
	LOGD("AudioInputStreamOpenSLES::%s()", __func__);
	mLock.lock();
	Result result = Result::OK;
	if (getState() == StreamState::Closed){
	result = Result::ErrorClosed;
	} else {
	mLock.unlock(); // avoid recursive lock
	requestStop();
	mLock.lock();
	// invalidate any interfaces
	mRecordInterface = NULL;
	result = AudioStreamOpenSLES::close();
	}
	mLock.unlock(); // avoid recursive lock
	return result;
	}

	Result AudioInputStreamOpenSLES::setRecordState_l(SLuint32 newState) {
	LOGD("AudioInputStreamOpenSLES::%s(%d)", __func__, newState);
	Result result = Result::OK;

	if (mRecordInterface == nullptr) {
	LOGE("AudioInputStreamOpenSLES::%s() mRecordInterface is null", __func__);
	return Result::ErrorInvalidState;
	}
	SLresult slResult = (*mRecordInterface)->SetRecordState(mRecordInterface, newState);
	if (SL_RESULT_SUCCESS != slResult) {
	LOGE("AudioInputStreamOpenSLES::%s() returned %s", __func__, getSLErrStr(slResult));
	result = Result::ErrorInternal; // TODO review
	}
	return result;
	}

	Result AudioInputStreamOpenSLES::requestStart() {
	LOGD("AudioInputStreamOpenSLES(): %s() called", __func__);
	std::lock_guard<std::mutex> lock(mLock);
	StreamState initialState = getState();
	switch (initialState) {
	case StreamState::Starting:
	case StreamState::Started:
	return Result::OK;
	case StreamState::Closed:
	return Result::ErrorClosed;
	default:
	break;
	}

	// We use a callback if the user requests one
	// OR if we have an internal callback to fill the blocking IO buffer.
	setDataCallbackEnabled(true);

	setState(StreamState::Starting);
	Result result = setRecordState_l(SL_RECORDSTATE_RECORDING);
	if (result == Result::OK) {
	setState(StreamState::Started);
	// Enqueue the first buffer to start the streaming.
	// This does not call the callback function.
	enqueueCallbackBuffer(mSimpleBufferQueueInterface);
	} else {
	setState(initialState);
	}
	return result;
	}


	Result AudioInputStreamOpenSLES::requestPause() {
	LOGW("AudioInputStreamOpenSLES::%s() is intentionally not implemented for input "
	"streams", __func__);
	return Result::ErrorUnimplemented; // Matches AAudio behavior.
	}

	Result AudioInputStreamOpenSLES::requestFlush() {
	LOGW("AudioInputStreamOpenSLES::%s() is intentionally not implemented for input "
	"streams", __func__);
	return Result::ErrorUnimplemented; // Matches AAudio behavior.
	}

	Result AudioInputStreamOpenSLES::requestStop() {
	LOGD("AudioInputStreamOpenSLES(): %s() called", __func__);

	std::lock_guard<std::mutex> lock(mLock);
	StreamState initialState = getState();
	switch (initialState) {
	case StreamState::Stopping:
	case StreamState::Stopped:
	return Result::OK;
	case StreamState::Closed:
	return Result::ErrorClosed;
	default:
	break;
	}

	setState(StreamState::Stopping);

	Result result = setRecordState_l(SL_RECORDSTATE_STOPPED);
	if (result == Result::OK) {
	mPositionMillis.reset32(); // OpenSL ES resets its millisecond position when stopped.
	setState(StreamState::Stopped);
	} else {
	setState(initialState);
	}
	return result;
	}

	void AudioInputStreamOpenSLES::updateFramesWritten() {
	if (usingFIFO()) {
	AudioStreamBuffered::updateFramesWritten();
	} else {
	mFramesWritten = getFramesProcessedByServer();
	}
	}

	Result AudioInputStreamOpenSLES::updateServiceFrameCounter() {
	Result result = Result::OK;
	// Avoid deadlock if another thread is trying to stop or close this stream
	// and this is being called from a callback.
	if (mLock.try_lock()) {

	if (mRecordInterface == NULL) {
	mLock.unlock();
	return Result::ErrorNull;
	}
	SLmillisecond msec = 0;
	SLresult slResult = (*mRecordInterface)->GetPosition(mRecordInterface, &msec);
	if (SL_RESULT_SUCCESS != slResult) {
	LOGD("%s(): GetPosition() returned %s", __func__, getSLErrStr(slResult));
	// set result based on SLresult
	result = Result::ErrorInternal;
	} else {
	mPositionMillis.update32(msec);
	}
	mLock.unlock();
	}
	return result;
	}