Fast mixer configuration (300a2ee9) · Commits · e / os / android_frameworks_av

services/audioflinger/AudioFlinger.cpp

+74 −35

Original line number	Diff line number	Diff line
		@@ -142,6 +142,23 @@ static const uint32_t kMinNormalMixBufferSizeMs = 20;

		nsecs_t AudioFlinger::mStandbyTimeInNsecs = kDefaultStandbyTimeInNsecs;

		// Whether to use fast mixer
		static const enum {
		FastMixer_Never, // never initialize or use: for debugging only
		FastMixer_Always, // always initialize and use, even if not needed: for debugging only
		// normal mixer multiplier is 1
		FastMixer_Static, // initialize if needed, then use all the time if initialized,
		// multipler is calculated based on minimum normal mixer buffer size
		FastMixer_Dynamic, // initialize if needed, then use dynamically depending on track load,
		// multipler is calculated based on minimum normal mixer buffer size
		// FIXME for FastMixer_Dynamic:
		// Supporting this option will require fixing HALs that can't handle large writes.
		// For example, one HAL implementation returns an error from a large write,
		// and another HAL implementation corrupts memory, possibly in the sample rate converter.
		// We could either fix the HAL implementations, or provide a wrapper that breaks
		// up large writes into smaller ones, and the wrapper would need to deal with scheduler.
		} kUseFastMixer = FastMixer_Static;

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

		#ifdef ADD_BATTERY_DATA
		@@ -1636,7 +1653,7 @@ sp<AudioFlinger::PlaybackThread::Track> AudioFlinger::PlaybackThread::createTrac
		(
		(tid != -1) &&
		((frameCount == 0) \|\|
		(frameCount >= (int) mFrameCount)) // FIXME int cast is due to wrong parameter type
		(frameCount >= (int) (mFrameCount * 2))) // * 2 is due to SRC jitter, see below
		)
		) &&
		// PCM data
		@@ -1655,12 +1672,12 @@ sp<AudioFlinger::PlaybackThread::Track> AudioFlinger::PlaybackThread::createTrac
		// FIXME test that MixerThread for this fast track has a capable output HAL
		// FIXME add a permission test also?
		) {
		ALOGI("AUDIO_OUTPUT_FLAG_FAST accepted: frameCount=%d mFrameCount=%d",
		frameCount, mFrameCount);
		// if frameCount not specified, then it defaults to fast mixer (HAL) frame count
		if (frameCount == 0) {
		frameCount = mFrameCount;
		frameCount = mFrameCount * 2; // FIXME * 2 is due to SRC jitter, should be computed
		}
		ALOGI("AUDIO_OUTPUT_FLAG_FAST accepted: frameCount=%d mFrameCount=%d",
		frameCount, mFrameCount);
		} else {
		ALOGW("AUDIO_OUTPUT_FLAG_FAST denied: isTimed=%d sharedBuffer=%p frameCount=%d "
		"mFrameCount=%d format=%d isLinear=%d channelMask=%d sampleRate=%d mSampleRate=%d "
		@@ -1920,17 +1937,19 @@ void AudioFlinger::PlaybackThread::readOutputParameters()
		mFrameCount);
		}

		// Calculate size of normal mix buffer
		if (mType == MIXER) {
		// Calculate size of normal mix buffer relative to the HAL output buffer size
		uint32_t multiple = 1;
		if (mType == MIXER && (kUseFastMixer == FastMixer_Static \|\| kUseFastMixer == FastMixer_Dynamic)) {
		size_t minNormalFrameCount = (kMinNormalMixBufferSizeMs * mSampleRate) / 1000;
		mNormalFrameCount = ((minNormalFrameCount + mFrameCount - 1) / mFrameCount) * mFrameCount;
		if (mNormalFrameCount & 15) {
		ALOGW("Normal mix buffer size is %u frames but AudioMixer requires multiples of 16 "
		"frames", mNormalFrameCount);
		multiple = (minNormalFrameCount + mFrameCount - 1) / mFrameCount;
		// force multiple to be even, for compatibility with doubling of fast tracks due to HAL SRC
		// (it would be unusual for the normal mix buffer size to not be a multiple of fast track)
		// FIXME this rounding up should not be done if no HAL SRC
		if ((multiple > 2) && (multiple & 1)) {
		++multiple;
		}
		} else {
		mNormalFrameCount = mFrameCount;
		}
		mNormalFrameCount = multiple * mFrameCount;
		ALOGI("HAL output buffer size %u frames, normal mix buffer size %u frames", mFrameCount, mNormalFrameCount);

		// FIXME - Current mixer implementation only supports stereo output: Always
		@@ -2107,8 +2126,21 @@ AudioFlinger::MixerThread::MixerThread(const sp<AudioFlinger>& audioFlinger, Aud
		ssize_t index = mOutputSink->negotiate(offers, 1, NULL, numCounterOffers);
		ALOG_ASSERT(index == 0);

		// initialize fast mixer if needed
		if (mFrameCount < mNormalFrameCount) {
		// initialize fast mixer depending on configuration
		bool initFastMixer;
		switch (kUseFastMixer) {
		case FastMixer_Never:
		initFastMixer = false;
		break;
		case FastMixer_Always:
		initFastMixer = true;
		break;
		case FastMixer_Static:
		case FastMixer_Dynamic:
		initFastMixer = mFrameCount < mNormalFrameCount;
		break;
		}
		if (initFastMixer) {

		// create a MonoPipe to connect our submix to FastMixer
		NBAIO_Format format = mOutputSink->format();
		@@ -2166,7 +2198,19 @@ AudioFlinger::MixerThread::MixerThread(const sp<AudioFlinger>& audioFlinger, Aud
		} else {
		mFastMixer = NULL;
		}

		switch (kUseFastMixer) {
		case FastMixer_Never:
		case FastMixer_Dynamic:
		mNormalSink = mOutputSink;
		break;
		case FastMixer_Always:
		mNormalSink = mPipeSink;
		break;
		case FastMixer_Static:
		mNormalSink = initFastMixer ? mPipeSink : mOutputSink;
		break;
		}
		}

		AudioFlinger::MixerThread::~MixerThread()
		@@ -2571,7 +2615,8 @@ void AudioFlinger::MixerThread::threadLoop_removeTracks(const Vector< sp<Track>
		}
		state->mFastTracksGen++;
		// if the fast mixer was active, but now there are no fast tracks, then put it in cold idle
		if (state->mCommand == FastMixerState::MIX_WRITE && state->mTrackMask <= 1) {
		if (kUseFastMixer == FastMixer_Dynamic &&
		state->mCommand == FastMixerState::MIX_WRITE && state->mTrackMask <= 1) {
		state->mCommand = FastMixerState::COLD_IDLE;
		state->mColdFutexAddr = &mFastMixerFutex;
		state->mColdGen++;
		@@ -2599,7 +2644,8 @@ void AudioFlinger::MixerThread::threadLoop_write()
		if (mFastMixer != NULL) {
		FastMixerStateQueue *sq = mFastMixer->sq();
		FastMixerState *state = sq->begin();
		if (state->mCommand != FastMixerState::MIX_WRITE && state->mTrackMask > 1) {
		if (state->mCommand != FastMixerState::MIX_WRITE &&
		(kUseFastMixer != FastMixer_Dynamic \|\| state->mTrackMask > 1)) {
		if (state->mCommand == FastMixerState::COLD_IDLE) {
		int32_t old = android_atomic_inc(&mFastMixerFutex);
		if (old == -1) {
		@@ -2609,7 +2655,9 @@ void AudioFlinger::MixerThread::threadLoop_write()
		state->mCommand = FastMixerState::MIX_WRITE;
		sq->end();
		sq->push(FastMixerStateQueue::BLOCK_UNTIL_PUSHED);
		if (kUseFastMixer == FastMixer_Dynamic) {
		mNormalSink = mPipeSink;
		}
		} else {
		sq->end(false /didModify/);
		}
		@@ -2623,26 +2671,15 @@ void AudioFlinger::PlaybackThread::threadLoop_write()
		// FIXME rewrite to reduce number of system calls
		mLastWriteTime = systemTime();
		mInWrite = true;
		int bytesWritten;

		// If an NBAIO sink is present, use it to write the normal mixer's submix
		if (mNormalSink != 0) {
		#define mBitShift 2 // FIXME
		size_t count = mixBufferSize >> mBitShift;
		ssize_t framesWritten = mNormalSink->write(mMixBuffer, count);
		if (framesWritten > 0) {
		bytesWritten = framesWritten << mBitShift;
		} else {
		bytesWritten = framesWritten;
		}

		// otherwise use the HAL / AudioStreamOut directly
		} else {
		// FIXME legacy, remove
		bytesWritten = (int)mOutput->stream->write(mOutput->stream, mMixBuffer, mixBufferSize);
		size_t bytesWritten = framesWritten << mBitShift;
		mBytesWritten += bytesWritten;
		}

		if (bytesWritten > 0) mBytesWritten += mixBufferSize;
		mNumWrites++;
		mInWrite = false;
		}
		@@ -2661,7 +2698,9 @@ void AudioFlinger::MixerThread::threadLoop_standby()
		sq->end();
		// BLOCK_UNTIL_PUSHED would be insufficient, as we need it to stop doing I/O now
		sq->push(FastMixerStateQueue::BLOCK_UNTIL_ACKED);
		if (kUseFastMixer == FastMixer_Dynamic) {
		mNormalSink = mOutputSink;
		}
		} else {
		sq->end(false /didModify/);
		}