media/libmedia/AudioRecord.cpp - platform/frameworks/av - Git at Google

 /*
 **
 ** Copyright 2008, 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.
 */

 //#define LOG_NDEBUG 0
 #define LOG_TAG "AudioRecord"

 #include <stdint.h>
 #include <sys/types.h>

 #include <sched.h>
 #include <sys/resource.h>

 #include <private/media/AudioTrackShared.h>

 #include <media/AudioSystem.h>
 #include <media/AudioRecord.h>

 #include <utils/IServiceManager.h>
 #include <utils/Log.h>
 #include <utils/MemoryDealer.h>
 #include <utils/Parcel.h>
 #include <utils/IPCThreadState.h>
 #include <utils/Timers.h>
 #include <cutils/atomic.h>

 #define LIKELY( exp )       (__builtin_expect( (exp) != 0, true  ))
 #define UNLIKELY( exp )     (__builtin_expect( (exp) != 0, false ))

 namespace android {

 // ---------------------------------------------------------------------------

 AudioRecord::AudioRecord()
     : mStatus(NO_INIT)
 {
 }

 AudioRecord::AudioRecord(
         int streamType,
         uint32_t sampleRate,
         int format,
         int channelCount,
         int frameCount,
         uint32_t flags,
         callback_t cbf,
         void* user,
         int notificationFrames)
     : mStatus(NO_INIT)
 {
     mStatus = set(streamType, sampleRate, format, channelCount,
             frameCount, flags, cbf, user, notificationFrames);
 }

 AudioRecord::~AudioRecord()
 {
     if (mStatus == NO_ERROR) {
         // Make sure that callback function exits in the case where
         // it is looping on buffer empty condition in obtainBuffer().
         // Otherwise the callback thread will never exit.
         stop();
         if (mClientRecordThread != 0) {
             mCblk->cv.signal();
             mClientRecordThread->requestExitAndWait();
             mClientRecordThread.clear();
         }
         mAudioRecord.clear();
         IPCThreadState::self()->flushCommands();
     }
 }

 status_t AudioRecord::set(
         int streamType,
         uint32_t sampleRate,
         int format,
         int channelCount,
         int frameCount,
         uint32_t flags,
         callback_t cbf,
         void* user,
         int notificationFrames,
         bool threadCanCallJava)
 {

     LOGV("set(): sampleRate %d, channelCount %d, frameCount %d",sampleRate, channelCount, frameCount);
     if (mAudioFlinger != 0) {
         return INVALID_OPERATION;
     }

     const sp<IAudioFlinger>& audioFlinger = AudioSystem::get_audio_flinger();
     if (audioFlinger == 0) {
         return NO_INIT;
     }

     if (streamType == DEFAULT_INPUT) {
         streamType = MIC_INPUT;
     }

     if (sampleRate == 0) {
         sampleRate = DEFAULT_SAMPLE_RATE;
     }
     // these below should probably come from the audioFlinger too...
     if (format == 0) {
         format = AudioSystem::PCM_16_BIT;
     }
     if (channelCount == 0) {
         channelCount = 1;
     }

     // validate parameters
     if (format != AudioSystem::PCM_16_BIT) {
         return BAD_VALUE;
     }
     if (channelCount != 1 && channelCount != 2) {
         return BAD_VALUE;
     }

     // TODO: Get input frame count from hardware.
     int minFrameCount = 1024*2;

     if (frameCount == 0) {
         frameCount = minFrameCount;
     } else if (frameCount < minFrameCount) {
         return BAD_VALUE;
     }

     if (notificationFrames == 0) {
         notificationFrames = frameCount/2;
     }

     // open record channel
     status_t status;
     sp<IAudioRecord> record = audioFlinger->openRecord(getpid(), streamType,
             sampleRate, format, channelCount, frameCount, flags, &status);
     if (record == 0) {
         LOGE("AudioFlinger could not create record track, status: %d", status);
         return status;
     }
     sp<IMemory> cblk = record->getCblk();
     if (cblk == 0) {
         return NO_INIT;
     }
     if (cbf != 0) {
         mClientRecordThread = new ClientRecordThread(*this, threadCanCallJava);
         if (mClientRecordThread == 0) {
             return NO_INIT;
         }
     }

     mStatus = NO_ERROR;

     mAudioFlinger = audioFlinger;
     mAudioRecord = record;
     mCblkMemory = cblk;
     mCblk = static_cast<audio_track_cblk_t*>(cblk->pointer());
     mCblk->buffers = (char*)mCblk + sizeof(audio_track_cblk_t);
     mCblk->out = 0;
     mSampleRate = sampleRate;
     mFormat = format;
     // Update buffer size in case it has been limited by AudioFlinger during track creation
     mFrameCount = mCblk->frameCount;
     mChannelCount = channelCount;
     mActive = 0;
     mCbf = cbf;
     mNotificationFrames = notificationFrames;
     mRemainingFrames = notificationFrames;
     mUserData = user;
     // TODO: add audio hardware input latency here
     mLatency = (1000*mFrameCount) / mSampleRate;
     mMarkerPosition = 0;
     mNewPosition = 0;
     mUpdatePeriod = 0;

     return NO_ERROR;
 }

 status_t AudioRecord::initCheck() const
 {
     return mStatus;
 }

 // -------------------------------------------------------------------------

 uint32_t AudioRecord::latency() const
 {
     return mLatency;
 }

 uint32_t AudioRecord::sampleRate() const
 {
     return mSampleRate;
 }

 int AudioRecord::format() const
 {
     return mFormat;
 }

 int AudioRecord::channelCount() const
 {
     return mChannelCount;
 }

 uint32_t AudioRecord::frameCount() const
 {
     return mFrameCount;
 }

 int AudioRecord::frameSize() const
 {
     return channelCount()*((format() == AudioSystem::PCM_8_BIT) ? sizeof(uint8_t) : sizeof(int16_t));
 }

 // -------------------------------------------------------------------------

 status_t AudioRecord::start()
 {
     status_t ret = NO_ERROR;
     sp<ClientRecordThread> t = mClientRecordThread;

     LOGV("start");

     if (t != 0) {
         if (t->exitPending()) {
             if (t->requestExitAndWait() == WOULD_BLOCK) {
                 LOGE("AudioRecord::start called from thread");
                 return WOULD_BLOCK;
             }
         }
         t->mLock.lock();
      }

     if (android_atomic_or(1, &mActive) == 0) {
         mNewPosition = mCblk->user + mUpdatePeriod;
         mCblk->bufferTimeoutMs = MAX_RUN_TIMEOUT_MS;
         mCblk->waitTimeMs = 0;
         if (t != 0) {
            t->run("ClientRecordThread", THREAD_PRIORITY_AUDIO_CLIENT);
         } else {
             setpriority(PRIO_PROCESS, 0, THREAD_PRIORITY_AUDIO_CLIENT);
         }
         ret = mAudioRecord->start();
     }

     if (t != 0) {
         t->mLock.unlock();
     }

     return ret;
 }

 status_t AudioRecord::stop()
 {
     sp<ClientRecordThread> t = mClientRecordThread;

     LOGV("stop");

     if (t != 0) {
         t->mLock.lock();
      }

     if (android_atomic_and(~1, &mActive) == 1) {
         mAudioRecord->stop();
         if (t != 0) {
             t->requestExit();
         } else {
             setpriority(PRIO_PROCESS, 0, ANDROID_PRIORITY_NORMAL);
         }
     }

     if (t != 0) {
         t->mLock.unlock();
     }

     return NO_ERROR;
 }

 bool AudioRecord::stopped() const
 {
     return !mActive;
 }

 status_t AudioRecord::setMarkerPosition(uint32_t marker)
 {
     if (mCbf == 0) return INVALID_OPERATION;

     mMarkerPosition = marker;

     return NO_ERROR;
 }

 status_t AudioRecord::getMarkerPosition(uint32_t *marker)
 {
     if (marker == 0) return BAD_VALUE;

     *marker = mMarkerPosition;

     return NO_ERROR;
 }

 status_t AudioRecord::setPositionUpdatePeriod(uint32_t updatePeriod)
 {
     if (mCbf == 0) return INVALID_OPERATION;

     uint32_t curPosition;
     getPosition(&curPosition);
     mNewPosition = curPosition + updatePeriod;
     mUpdatePeriod = updatePeriod;

     return NO_ERROR;
 }

 status_t AudioRecord::getPositionUpdatePeriod(uint32_t *updatePeriod)
 {
     if (updatePeriod == 0) return BAD_VALUE;

     *updatePeriod = mUpdatePeriod;

     return NO_ERROR;
 }

 status_t AudioRecord::getPosition(uint32_t *position)
 {
     if (position == 0) return BAD_VALUE;

     *position = mCblk->user;

     return NO_ERROR;
 }


 // -------------------------------------------------------------------------

 status_t AudioRecord::obtainBuffer(Buffer* audioBuffer, int32_t waitCount)
 {
     int active;
     int timeout = 0;
     status_t result;
     audio_track_cblk_t* cblk = mCblk;
     uint32_t framesReq = audioBuffer->frameCount;

     audioBuffer->frameCount  = 0;
     audioBuffer->size        = 0;

     uint32_t framesReady = cblk->framesReady();

     if (framesReady == 0) {
         Mutex::Autolock _l(cblk->lock);
         goto start_loop_here;
         while (framesReady == 0) {
             active = mActive;
             if (UNLIKELY(!active))
                 return NO_MORE_BUFFERS;
             if (UNLIKELY(!waitCount))
                 return WOULD_BLOCK;
             timeout = 0;
             result = cblk->cv.waitRelative(cblk->lock, milliseconds(WAIT_PERIOD_MS));
             if (__builtin_expect(result!=NO_ERROR, false)) {
                 cblk->waitTimeMs += WAIT_PERIOD_MS;
                 if (cblk->waitTimeMs >= cblk->bufferTimeoutMs) {
                     LOGW(   "obtainBuffer timed out (is the CPU pegged?) "
                             "user=%08x, server=%08x", cblk->user, cblk->server);
                     timeout = 1;
                     cblk->waitTimeMs = 0;
                 }
                 if (--waitCount == 0) {
                     return TIMED_OUT;
                 }
             }
             // read the server count again
         start_loop_here:
             framesReady = cblk->framesReady();
         }
     }

     LOGW_IF(timeout,
         "*** SERIOUS WARNING *** obtainBuffer() timed out "
         "but didn't need to be locked. We recovered, but "
         "this shouldn't happen (user=%08x, server=%08x)", cblk->user, cblk->server);

     cblk->waitTimeMs = 0;

     if (framesReq > framesReady) {
         framesReq = framesReady;
     }

     uint32_t u = cblk->user;
     uint32_t bufferEnd = cblk->userBase + cblk->frameCount;

     if (u + framesReq > bufferEnd) {
         framesReq = bufferEnd - u;
     }

     audioBuffer->flags       = 0;
     audioBuffer->channelCount= mChannelCount;
     audioBuffer->format      = mFormat;
     audioBuffer->frameCount  = framesReq;
     audioBuffer->size        = framesReq*mChannelCount*sizeof(int16_t);
     audioBuffer->raw         = (int8_t*)cblk->buffer(u);
     active = mActive;
     return active ? status_t(NO_ERROR) : status_t(STOPPED);
 }

 void AudioRecord::releaseBuffer(Buffer* audioBuffer)
 {
     audio_track_cblk_t* cblk = mCblk;
     cblk->stepUser(audioBuffer->frameCount);
 }

 // -------------------------------------------------------------------------

 ssize_t AudioRecord::read(void* buffer, size_t userSize)
 {
     ssize_t read = 0;
     Buffer audioBuffer;
     int8_t *dst = static_cast<int8_t*>(buffer);

     if (ssize_t(userSize) < 0) {
         // sanity-check. user is most-likely passing an error code.
         LOGE("AudioRecord::read(buffer=%p, size=%u (%d)",
                 buffer, userSize, userSize);
         return BAD_VALUE;
     }

     LOGV("read size: %d", userSize);

     do {

         audioBuffer.frameCount = userSize/mChannelCount/sizeof(int16_t);

         // Calling obtainBuffer() with a negative wait count causes
         // an (almost) infinite wait time.
         status_t err = obtainBuffer(&audioBuffer, -1);
         if (err < 0) {
             // out of buffers, return #bytes written
             if (err == status_t(NO_MORE_BUFFERS))
                 break;
             return ssize_t(err);
         }

         size_t bytesRead = audioBuffer.size;
         memcpy(dst, audioBuffer.i8, bytesRead);

         dst += bytesRead;
         userSize -= bytesRead;
         read += bytesRead;

         releaseBuffer(&audioBuffer);
     } while (userSize);

     return read;
 }

 // -------------------------------------------------------------------------

 bool AudioRecord::processAudioBuffer(const sp<ClientRecordThread>& thread)
 {
     Buffer audioBuffer;
     uint32_t frames = mRemainingFrames;
     size_t readSize;

     // Manage marker callback
     if (mMarkerPosition > 0) {
         if (mCblk->user >= mMarkerPosition) {
             mCbf(EVENT_MARKER, mUserData, (void *)&mMarkerPosition);
             mMarkerPosition = 0;
         }
     }

     // Manage new position callback
     if (mUpdatePeriod > 0) {
         while (mCblk->user >= mNewPosition) {
             mCbf(EVENT_NEW_POS, mUserData, (void *)&mNewPosition);
             mNewPosition += mUpdatePeriod;
         }
     }

     do {
         audioBuffer.frameCount = frames;
         // Calling obtainBuffer() with a wait count of 1
         // limits wait time to WAIT_PERIOD_MS. This prevents from being
         // stuck here not being able to handle timed events (position, markers).
         status_t err = obtainBuffer(&audioBuffer, 1);
         if (err < NO_ERROR) {
             if (err != TIMED_OUT) {
                 LOGE("Error obtaining an audio buffer, giving up.");
                 return false;
             }
             break;
         }
         if (err == status_t(STOPPED)) return false;

         size_t reqSize = audioBuffer.size;
         mCbf(EVENT_MORE_DATA, mUserData, &audioBuffer);
         readSize = audioBuffer.size;

         // Sanity check on returned size
         if (ssize_t(readSize) <= 0) break;
         if (readSize > reqSize) readSize = reqSize;

         audioBuffer.size = readSize;
         audioBuffer.frameCount = readSize/mChannelCount/sizeof(int16_t);
         frames -= audioBuffer.frameCount;

         releaseBuffer(&audioBuffer);

     } while (frames);


     // Manage overrun callback
     if (mActive && (mCblk->framesAvailable_l() == 0)) {
         LOGV("Overrun user: %x, server: %x, flowControlFlag %d", mCblk->user, mCblk->server, mCblk->flowControlFlag);
         if (mCblk->flowControlFlag == 0) {
             mCbf(EVENT_OVERRUN, mUserData, 0);
             mCblk->flowControlFlag = 1;
         }
     }

     if (frames == 0) {
         mRemainingFrames = mNotificationFrames;
     } else {
         mRemainingFrames = frames;
     }
     return true;
 }

 // =========================================================================

 AudioRecord::ClientRecordThread::ClientRecordThread(AudioRecord& receiver, bool bCanCallJava)
     : Thread(bCanCallJava), mReceiver(receiver)
 {
 }

 bool AudioRecord::ClientRecordThread::threadLoop()
 {
     return mReceiver.processAudioBuffer(this);
 }

 // -------------------------------------------------------------------------

 }; // namespace android
	/*
	**
	** Copyright 2008, 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.
	*/

	//#define LOG_NDEBUG 0
	#define LOG_TAG "AudioRecord"

	#include <stdint.h>
	#include <sys/types.h>

	#include <sched.h>
	#include <sys/resource.h>

	#include <private/media/AudioTrackShared.h>

	#include <media/AudioSystem.h>
	#include <media/AudioRecord.h>

	#include <utils/IServiceManager.h>
	#include <utils/Log.h>
	#include <utils/MemoryDealer.h>
	#include <utils/Parcel.h>
	#include <utils/IPCThreadState.h>
	#include <utils/Timers.h>
	#include <cutils/atomic.h>

	#define LIKELY( exp ) (__builtin_expect( (exp) != 0, true ))
	#define UNLIKELY( exp ) (__builtin_expect( (exp) != 0, false ))

	namespace android {

	// ---------------------------------------------------------------------------

	AudioRecord::AudioRecord()
	: mStatus(NO_INIT)
	{
	}

	AudioRecord::AudioRecord(
	int streamType,
	uint32_t sampleRate,
	int format,
	int channelCount,
	int frameCount,
	uint32_t flags,
	callback_t cbf,
	void* user,
	int notificationFrames)
	: mStatus(NO_INIT)
	{
	mStatus = set(streamType, sampleRate, format, channelCount,
	frameCount, flags, cbf, user, notificationFrames);
	}

	AudioRecord::~AudioRecord()
	{
	if (mStatus == NO_ERROR) {
	// Make sure that callback function exits in the case where
	// it is looping on buffer empty condition in obtainBuffer().
	// Otherwise the callback thread will never exit.
	stop();
	if (mClientRecordThread != 0) {
	mCblk->cv.signal();
	mClientRecordThread->requestExitAndWait();
	mClientRecordThread.clear();
	}
	mAudioRecord.clear();
	IPCThreadState::self()->flushCommands();
	}
	}

	status_t AudioRecord::set(
	int streamType,
	uint32_t sampleRate,
	int format,
	int channelCount,
	int frameCount,
	uint32_t flags,
	callback_t cbf,
	void* user,
	int notificationFrames,
	bool threadCanCallJava)
	{

	LOGV("set(): sampleRate %d, channelCount %d, frameCount %d",sampleRate, channelCount, frameCount);
	if (mAudioFlinger != 0) {
	return INVALID_OPERATION;
	}

	const sp<IAudioFlinger>& audioFlinger = AudioSystem::get_audio_flinger();
	if (audioFlinger == 0) {
	return NO_INIT;
	}

	if (streamType == DEFAULT_INPUT) {
	streamType = MIC_INPUT;
	}

	if (sampleRate == 0) {
	sampleRate = DEFAULT_SAMPLE_RATE;
	}
	// these below should probably come from the audioFlinger too...
	if (format == 0) {
	format = AudioSystem::PCM_16_BIT;
	}
	if (channelCount == 0) {
	channelCount = 1;
	}

	// validate parameters
	if (format != AudioSystem::PCM_16_BIT) {
	return BAD_VALUE;
	}
	if (channelCount != 1 && channelCount != 2) {
	return BAD_VALUE;
	}

	// TODO: Get input frame count from hardware.
	int minFrameCount = 1024*2;

	if (frameCount == 0) {
	frameCount = minFrameCount;
	} else if (frameCount < minFrameCount) {
	return BAD_VALUE;
	}

	if (notificationFrames == 0) {
	notificationFrames = frameCount/2;
	}

	// open record channel
	status_t status;
	sp<IAudioRecord> record = audioFlinger->openRecord(getpid(), streamType,
	sampleRate, format, channelCount, frameCount, flags, &status);
	if (record == 0) {
	LOGE("AudioFlinger could not create record track, status: %d", status);
	return status;
	}
	sp<IMemory> cblk = record->getCblk();
	if (cblk == 0) {
	return NO_INIT;
	}
	if (cbf != 0) {
	mClientRecordThread = new ClientRecordThread(*this, threadCanCallJava);
	if (mClientRecordThread == 0) {
	return NO_INIT;
	}
	}

	mStatus = NO_ERROR;

	mAudioFlinger = audioFlinger;
	mAudioRecord = record;
	mCblkMemory = cblk;
	mCblk = static_cast<audio_track_cblk_t*>(cblk->pointer());
	mCblk->buffers = (char*)mCblk + sizeof(audio_track_cblk_t);
	mCblk->out = 0;
	mSampleRate = sampleRate;
	mFormat = format;
	// Update buffer size in case it has been limited by AudioFlinger during track creation
	mFrameCount = mCblk->frameCount;
	mChannelCount = channelCount;
	mActive = 0;
	mCbf = cbf;
	mNotificationFrames = notificationFrames;
	mRemainingFrames = notificationFrames;
	mUserData = user;
	// TODO: add audio hardware input latency here
	mLatency = (1000*mFrameCount) / mSampleRate;
	mMarkerPosition = 0;
	mNewPosition = 0;
	mUpdatePeriod = 0;

	return NO_ERROR;
	}

	status_t AudioRecord::initCheck() const
	{
	return mStatus;
	}

	// -------------------------------------------------------------------------

	uint32_t AudioRecord::latency() const
	{
	return mLatency;
	}

	uint32_t AudioRecord::sampleRate() const
	{
	return mSampleRate;
	}

	int AudioRecord::format() const
	{
	return mFormat;
	}

	int AudioRecord::channelCount() const
	{
	return mChannelCount;
	}

	uint32_t AudioRecord::frameCount() const
	{
	return mFrameCount;
	}

	int AudioRecord::frameSize() const
	{
	return channelCount()*((format() == AudioSystem::PCM_8_BIT) ? sizeof(uint8_t) : sizeof(int16_t));
	}

	// -------------------------------------------------------------------------

	status_t AudioRecord::start()
	{
	status_t ret = NO_ERROR;
	sp<ClientRecordThread> t = mClientRecordThread;

	LOGV("start");

	if (t != 0) {
	if (t->exitPending()) {
	if (t->requestExitAndWait() == WOULD_BLOCK) {
	LOGE("AudioRecord::start called from thread");
	return WOULD_BLOCK;
	}
	}
	t->mLock.lock();
	}

	if (android_atomic_or(1, &mActive) == 0) {
	mNewPosition = mCblk->user + mUpdatePeriod;
	mCblk->bufferTimeoutMs = MAX_RUN_TIMEOUT_MS;
	mCblk->waitTimeMs = 0;
	if (t != 0) {
	t->run("ClientRecordThread", THREAD_PRIORITY_AUDIO_CLIENT);
	} else {
	setpriority(PRIO_PROCESS, 0, THREAD_PRIORITY_AUDIO_CLIENT);
	}
	ret = mAudioRecord->start();
	}

	if (t != 0) {
	t->mLock.unlock();
	}

	return ret;
	}

	status_t AudioRecord::stop()
	{
	sp<ClientRecordThread> t = mClientRecordThread;

	LOGV("stop");

	if (t != 0) {
	t->mLock.lock();
	}

	if (android_atomic_and(~1, &mActive) == 1) {
	mAudioRecord->stop();
	if (t != 0) {
	t->requestExit();
	} else {
	setpriority(PRIO_PROCESS, 0, ANDROID_PRIORITY_NORMAL);
	}
	}

	if (t != 0) {
	t->mLock.unlock();
	}

	return NO_ERROR;
	}

	bool AudioRecord::stopped() const
	{
	return !mActive;
	}

	status_t AudioRecord::setMarkerPosition(uint32_t marker)
	{
	if (mCbf == 0) return INVALID_OPERATION;

	mMarkerPosition = marker;

	return NO_ERROR;
	}

	status_t AudioRecord::getMarkerPosition(uint32_t *marker)
	{
	if (marker == 0) return BAD_VALUE;

	*marker = mMarkerPosition;

	return NO_ERROR;
	}

	status_t AudioRecord::setPositionUpdatePeriod(uint32_t updatePeriod)
	{
	if (mCbf == 0) return INVALID_OPERATION;

	uint32_t curPosition;
	getPosition(&curPosition);
	mNewPosition = curPosition + updatePeriod;
	mUpdatePeriod = updatePeriod;

	return NO_ERROR;
	}

	status_t AudioRecord::getPositionUpdatePeriod(uint32_t *updatePeriod)
	{
	if (updatePeriod == 0) return BAD_VALUE;

	*updatePeriod = mUpdatePeriod;

	return NO_ERROR;
	}

	status_t AudioRecord::getPosition(uint32_t *position)
	{
	if (position == 0) return BAD_VALUE;

	*position = mCblk->user;

	return NO_ERROR;
	}


	// -------------------------------------------------------------------------

	status_t AudioRecord::obtainBuffer(Buffer* audioBuffer, int32_t waitCount)
	{
	int active;
	int timeout = 0;
	status_t result;
	audio_track_cblk_t* cblk = mCblk;
	uint32_t framesReq = audioBuffer->frameCount;

	audioBuffer->frameCount = 0;
	audioBuffer->size = 0;

	uint32_t framesReady = cblk->framesReady();

	if (framesReady == 0) {
	Mutex::Autolock _l(cblk->lock);
	goto start_loop_here;
	while (framesReady == 0) {
	active = mActive;
	if (UNLIKELY(!active))
	return NO_MORE_BUFFERS;
	if (UNLIKELY(!waitCount))
	return WOULD_BLOCK;
	timeout = 0;
	result = cblk->cv.waitRelative(cblk->lock, milliseconds(WAIT_PERIOD_MS));
	if (__builtin_expect(result!=NO_ERROR, false)) {
	cblk->waitTimeMs += WAIT_PERIOD_MS;
	if (cblk->waitTimeMs >= cblk->bufferTimeoutMs) {
	LOGW( "obtainBuffer timed out (is the CPU pegged?) "
	"user=%08x, server=%08x", cblk->user, cblk->server);
	timeout = 1;
	cblk->waitTimeMs = 0;
	}
	if (--waitCount == 0) {
	return TIMED_OUT;
	}
	}
	// read the server count again
	start_loop_here:
	framesReady = cblk->framesReady();
	}
	}

	LOGW_IF(timeout,
	"* SERIOUS WARNING * obtainBuffer() timed out "
	"but didn't need to be locked. We recovered, but "
	"this shouldn't happen (user=%08x, server=%08x)", cblk->user, cblk->server);

	cblk->waitTimeMs = 0;

	if (framesReq > framesReady) {
	framesReq = framesReady;
	}

	uint32_t u = cblk->user;
	uint32_t bufferEnd = cblk->userBase + cblk->frameCount;

	if (u + framesReq > bufferEnd) {
	framesReq = bufferEnd - u;
	}

	audioBuffer->flags = 0;
	audioBuffer->channelCount= mChannelCount;
	audioBuffer->format = mFormat;
	audioBuffer->frameCount = framesReq;
	audioBuffer->size = framesReqmChannelCountsizeof(int16_t);
	audioBuffer->raw = (int8_t*)cblk->buffer(u);
	active = mActive;
	return active ? status_t(NO_ERROR) : status_t(STOPPED);
	}

	void AudioRecord::releaseBuffer(Buffer* audioBuffer)
	{
	audio_track_cblk_t* cblk = mCblk;
	cblk->stepUser(audioBuffer->frameCount);
	}

	// -------------------------------------------------------------------------

	ssize_t AudioRecord::read(void* buffer, size_t userSize)
	{
	ssize_t read = 0;
	Buffer audioBuffer;
	int8_t dst = static_cast<int8_t>(buffer);

	if (ssize_t(userSize) < 0) {
	// sanity-check. user is most-likely passing an error code.
	LOGE("AudioRecord::read(buffer=%p, size=%u (%d)",
	buffer, userSize, userSize);
	return BAD_VALUE;
	}

	LOGV("read size: %d", userSize);

	do {

	audioBuffer.frameCount = userSize/mChannelCount/sizeof(int16_t);

	// Calling obtainBuffer() with a negative wait count causes
	// an (almost) infinite wait time.
	status_t err = obtainBuffer(&audioBuffer, -1);
	if (err < 0) {
	// out of buffers, return #bytes written
	if (err == status_t(NO_MORE_BUFFERS))
	break;
	return ssize_t(err);
	}

	size_t bytesRead = audioBuffer.size;
	memcpy(dst, audioBuffer.i8, bytesRead);

	dst += bytesRead;
	userSize -= bytesRead;
	read += bytesRead;

	releaseBuffer(&audioBuffer);
	} while (userSize);

	return read;
	}

	// -------------------------------------------------------------------------

	bool AudioRecord::processAudioBuffer(const sp<ClientRecordThread>& thread)
	{
	Buffer audioBuffer;
	uint32_t frames = mRemainingFrames;
	size_t readSize;

	// Manage marker callback
	if (mMarkerPosition > 0) {
	if (mCblk->user >= mMarkerPosition) {
	mCbf(EVENT_MARKER, mUserData, (void *)&mMarkerPosition);
	mMarkerPosition = 0;
	}
	}

	// Manage new position callback
	if (mUpdatePeriod > 0) {
	while (mCblk->user >= mNewPosition) {
	mCbf(EVENT_NEW_POS, mUserData, (void *)&mNewPosition);
	mNewPosition += mUpdatePeriod;
	}
	}

	do {
	audioBuffer.frameCount = frames;
	// Calling obtainBuffer() with a wait count of 1
	// limits wait time to WAIT_PERIOD_MS. This prevents from being
	// stuck here not being able to handle timed events (position, markers).
	status_t err = obtainBuffer(&audioBuffer, 1);
	if (err < NO_ERROR) {
	if (err != TIMED_OUT) {
	LOGE("Error obtaining an audio buffer, giving up.");
	return false;
	}
	break;
	}
	if (err == status_t(STOPPED)) return false;

	size_t reqSize = audioBuffer.size;
	mCbf(EVENT_MORE_DATA, mUserData, &audioBuffer);
	readSize = audioBuffer.size;

	// Sanity check on returned size
	if (ssize_t(readSize) <= 0) break;
	if (readSize > reqSize) readSize = reqSize;

	audioBuffer.size = readSize;
	audioBuffer.frameCount = readSize/mChannelCount/sizeof(int16_t);
	frames -= audioBuffer.frameCount;

	releaseBuffer(&audioBuffer);

	} while (frames);


	// Manage overrun callback
	if (mActive && (mCblk->framesAvailable_l() == 0)) {
	LOGV("Overrun user: %x, server: %x, flowControlFlag %d", mCblk->user, mCblk->server, mCblk->flowControlFlag);
	if (mCblk->flowControlFlag == 0) {
	mCbf(EVENT_OVERRUN, mUserData, 0);
	mCblk->flowControlFlag = 1;
	}
	}

	if (frames == 0) {
	mRemainingFrames = mNotificationFrames;
	} else {
	mRemainingFrames = frames;
	}
	return true;
	}

	// =========================================================================

	AudioRecord::ClientRecordThread::ClientRecordThread(AudioRecord& receiver, bool bCanCallJava)
	: Thread(bCanCallJava), mReceiver(receiver)
	{
	}

	bool AudioRecord::ClientRecordThread::threadLoop()
	{
	return mReceiver.processAudioBuffer(this);
	}

	// -------------------------------------------------------------------------

	}; // namespace android