diff --git a/camera/OWNERS b/camera/OWNERS
index d6b95da..1b548e4 100644
--- a/camera/OWNERS
+++ b/camera/OWNERS
@@ -1,8 +1,8 @@
-epeev@google.com
+# Bug component: 41727
 etalvala@google.com
+arakesh@google.com
+epeev@google.com
 jchowdhary@google.com
 shuzhenwang@google.com
-yinchiayeh@google.com
-# backup owner
-cychen@google.com
-zhijunhe@google.com
+ruchamk@google.com
+
diff --git a/camera/ndk/include/camera/NdkCameraMetadataTags.h b/camera/ndk/include/camera/NdkCameraMetadataTags.h
index c353b2d..7c728cf 100644
--- a/camera/ndk/include/camera/NdkCameraMetadataTags.h
+++ b/camera/ndk/include/camera/NdkCameraMetadataTags.h
@@ -4585,7 +4585,7 @@
      * Clients are advised to not cache or store the orientation value of such logical sensors.
      * In case repeated queries to CameraCharacteristics are not preferred, then clients can
      * also access the entire mapping from device state to sensor orientation in
-     * <a href="https://developer.android.com/reference/android/hardware/camera2/params/DeviceStateOrientationMap.html">DeviceStateOrientationMap</a>.
+     * <a href="https://developer.android.com/reference/android/hardware/camera2/params/DeviceStateSensorOrientationMap.html">DeviceStateSensorOrientationMap</a>.
      * Do note that a dynamically changing sensor orientation value in camera characteristics
      * will not be the best way to establish the orientation per frame. Clients that want to
      * know the sensor orientation of a particular captured frame should query the
diff --git a/media/libaudioclient/aidl/android/media/INativeSpatializerCallback.aidl b/media/libaudioclient/aidl/android/media/INativeSpatializerCallback.aidl
index 0e9634c..88b8108 100644
--- a/media/libaudioclient/aidl/android/media/INativeSpatializerCallback.aidl
+++ b/media/libaudioclient/aidl/android/media/INativeSpatializerCallback.aidl
@@ -31,4 +31,9 @@
      * (e.g. when the spatializer is enabled or disabled)
      */
     void onLevelChanged(SpatializationLevel level);
+
+    /** Called when the output stream the Spatializer is attached to changes.
+     * Indicates the IO Handle of the new output.
+     */
+    void onOutputChanged(int output);
 }
diff --git a/media/libaudioprocessing/AudioMixer.cpp b/media/libaudioprocessing/AudioMixer.cpp
index e68c002..e6fdb1d 100644
--- a/media/libaudioprocessing/AudioMixer.cpp
+++ b/media/libaudioprocessing/AudioMixer.cpp
@@ -108,15 +108,11 @@
 
     if (track->mHapticChannelCount > 0) {
         track->mAdjustInChannelCount = track->channelCount + track->mHapticChannelCount;
-        track->mAdjustOutChannelCount = track->channelCount + track->mMixerHapticChannelCount;
-        track->mAdjustNonDestructiveInChannelCount = track->mAdjustOutChannelCount;
-        track->mAdjustNonDestructiveOutChannelCount = track->channelCount;
+        track->mAdjustOutChannelCount = track->channelCount;
         track->mKeepContractedChannels = track->mHapticPlaybackEnabled;
     } else {
         track->mAdjustInChannelCount = 0;
         track->mAdjustOutChannelCount = 0;
-        track->mAdjustNonDestructiveInChannelCount = 0;
-        track->mAdjustNonDestructiveOutChannelCount = 0;
         track->mKeepContractedChannels = false;
     }
 
@@ -131,8 +127,7 @@
     // do it after downmix since track format may change!
     track->prepareForReformat();
 
-    track->prepareForAdjustChannelsNonDestructive(mFrameCount);
-    track->prepareForAdjustChannels();
+    track->prepareForAdjustChannels(mFrameCount);
 
     // Resampler channels may have changed.
     track->recreateResampler(mSampleRate);
@@ -193,6 +188,24 @@
         // mDownmixerBufferProvider reset below.
     }
 
+    // See if we should use our built-in non-effect downmixer.
+    if (mMixerInFormat == AUDIO_FORMAT_PCM_FLOAT
+            && mMixerChannelMask == AUDIO_CHANNEL_OUT_STEREO
+            && audio_channel_mask_get_representation(channelMask)
+                    == AUDIO_CHANNEL_REPRESENTATION_POSITION) {
+        mDownmixerBufferProvider.reset(new ChannelMixBufferProvider(channelMask,
+                mMixerChannelMask, mMixerInFormat, kCopyBufferFrameCount));
+        if (static_cast<ChannelMixBufferProvider *>(mDownmixerBufferProvider.get())
+                ->isValid()) {
+            mDownmixRequiresFormat = mMixerInFormat;
+            reconfigureBufferProviders();
+            ALOGD("%s: Fallback using ChannelMix", __func__);
+            return NO_ERROR;
+        } else {
+            ALOGD("%s: ChannelMix not supported for channel mask %#x", __func__, channelMask);
+        }
+    }
+
     // Effect downmixer does not accept the channel conversion.  Let's use our remixer.
     mDownmixerBufferProvider.reset(new RemixBufferProvider(channelMask,
             mMixerChannelMask, mMixerInFormat, kCopyBufferFrameCount));
@@ -265,48 +278,20 @@
     }
 }
 
-status_t AudioMixer::Track::prepareForAdjustChannels()
+status_t AudioMixer::Track::prepareForAdjustChannels(size_t frames)
 {
     ALOGV("AudioMixer::prepareForAdjustChannels(%p) with inChannelCount: %u, outChannelCount: %u",
             this, mAdjustInChannelCount, mAdjustOutChannelCount);
     unprepareForAdjustChannels();
     if (mAdjustInChannelCount != mAdjustOutChannelCount) {
-        mAdjustChannelsBufferProvider.reset(new AdjustChannelsBufferProvider(
-                mFormat, mAdjustInChannelCount, mAdjustOutChannelCount, kCopyBufferFrameCount));
-        reconfigureBufferProviders();
-    }
-    return NO_ERROR;
-}
-
-void AudioMixer::Track::unprepareForAdjustChannelsNonDestructive()
-{
-    ALOGV("AUDIOMIXER::unprepareForAdjustChannelsNonDestructive");
-    if (mContractChannelsNonDestructiveBufferProvider.get() != nullptr) {
-        mContractChannelsNonDestructiveBufferProvider.reset(nullptr);
-        reconfigureBufferProviders();
-    }
-}
-
-status_t AudioMixer::Track::prepareForAdjustChannelsNonDestructive(size_t frames)
-{
-    ALOGV("AudioMixer::prepareForAdjustChannelsNonDestructive(%p) with inChannelCount: %u, "
-          "outChannelCount: %u, keepContractedChannels: %d",
-            this, mAdjustNonDestructiveInChannelCount, mAdjustNonDestructiveOutChannelCount,
-            mKeepContractedChannels);
-    unprepareForAdjustChannelsNonDestructive();
-    if (mAdjustNonDestructiveInChannelCount != mAdjustNonDestructiveOutChannelCount) {
         uint8_t* buffer = mKeepContractedChannels
                 ? (uint8_t*)mainBuffer + frames * audio_bytes_per_frame(
                         mMixerChannelCount, mMixerFormat)
-                : NULL;
-        mContractChannelsNonDestructiveBufferProvider.reset(
-                new AdjustChannelsBufferProvider(
-                        mFormat,
-                        mAdjustNonDestructiveInChannelCount,
-                        mAdjustNonDestructiveOutChannelCount,
-                        frames,
-                        mKeepContractedChannels ? mMixerFormat : AUDIO_FORMAT_INVALID,
-                        buffer));
+                : nullptr;
+        mAdjustChannelsBufferProvider.reset(new AdjustChannelsBufferProvider(
+                mFormat, mAdjustInChannelCount, mAdjustOutChannelCount, frames,
+                mKeepContractedChannels ? mMixerFormat : AUDIO_FORMAT_INVALID,
+                buffer, mMixerHapticChannelCount));
         reconfigureBufferProviders();
     }
     return NO_ERROR;
@@ -314,9 +299,9 @@
 
 void AudioMixer::Track::clearContractedBuffer()
 {
-    if (mContractChannelsNonDestructiveBufferProvider.get() != nullptr) {
+    if (mAdjustChannelsBufferProvider.get() != nullptr) {
         static_cast<AdjustChannelsBufferProvider*>(
-                mContractChannelsNonDestructiveBufferProvider.get())->clearContractedFrames();
+                mAdjustChannelsBufferProvider.get())->clearContractedFrames();
     }
 }
 
@@ -328,10 +313,6 @@
         mAdjustChannelsBufferProvider->setBufferProvider(bufferProvider);
         bufferProvider = mAdjustChannelsBufferProvider.get();
     }
-    if (mContractChannelsNonDestructiveBufferProvider.get() != nullptr) {
-        mContractChannelsNonDestructiveBufferProvider->setBufferProvider(bufferProvider);
-        bufferProvider = mContractChannelsNonDestructiveBufferProvider.get();
-    }
     if (mReformatBufferProvider.get() != nullptr) {
         mReformatBufferProvider->setBufferProvider(bufferProvider);
         bufferProvider = mReformatBufferProvider.get();
@@ -377,7 +358,7 @@
                 track->mainBuffer = valueBuf;
                 ALOGV("setParameter(TRACK, MAIN_BUFFER, %p)", valueBuf);
                 if (track->mKeepContractedChannels) {
-                    track->prepareForAdjustChannelsNonDestructive(mFrameCount);
+                    track->prepareForAdjustChannels(mFrameCount);
                 }
                 invalidate();
             }
@@ -405,7 +386,7 @@
                 track->mMixerFormat = format;
                 ALOGV("setParameter(TRACK, MIXER_FORMAT, %#x)", format);
                 if (track->mKeepContractedChannels) {
-                    track->prepareForAdjustChannelsNonDestructive(mFrameCount);
+                    track->prepareForAdjustChannels(mFrameCount);
                 }
             }
             } break;
@@ -424,8 +405,7 @@
             if (track->mHapticPlaybackEnabled != hapticPlaybackEnabled) {
                 track->mHapticPlaybackEnabled = hapticPlaybackEnabled;
                 track->mKeepContractedChannels = hapticPlaybackEnabled;
-                track->prepareForAdjustChannelsNonDestructive(mFrameCount);
-                track->prepareForAdjustChannels();
+                track->prepareForAdjustChannels(mFrameCount);
             }
             } break;
         case HAPTIC_INTENSITY: {
@@ -518,8 +498,6 @@
         track->mDownmixerBufferProvider->reset();
     } else if (track->mReformatBufferProvider.get() != nullptr) {
         track->mReformatBufferProvider->reset();
-    } else if (track->mContractChannelsNonDestructiveBufferProvider.get() != nullptr) {
-        track->mContractChannelsNonDestructiveBufferProvider->reset();
     } else if (track->mAdjustChannelsBufferProvider.get() != nullptr) {
         track->mAdjustChannelsBufferProvider->reset();
     }
@@ -563,9 +541,7 @@
     t->mMixerHapticChannelMask = AUDIO_CHANNEL_NONE;
     t->mMixerHapticChannelCount = 0;
     t->mAdjustInChannelCount = t->channelCount + t->mHapticChannelCount;
-    t->mAdjustOutChannelCount = t->channelCount + t->mMixerHapticChannelCount;
-    t->mAdjustNonDestructiveInChannelCount = t->mAdjustOutChannelCount;
-    t->mAdjustNonDestructiveOutChannelCount = t->channelCount;
+    t->mAdjustOutChannelCount = t->channelCount;
     t->mKeepContractedChannels = false;
     // Check the downmixing (or upmixing) requirements.
     status_t status = t->prepareForDownmix();
@@ -576,8 +552,7 @@
     // prepareForDownmix() may change mDownmixRequiresFormat
     ALOGVV("mMixerFormat:%#x  mMixerInFormat:%#x\n", t->mMixerFormat, t->mMixerInFormat);
     t->prepareForReformat();
-    t->prepareForAdjustChannelsNonDestructive(mFrameCount);
-    t->prepareForAdjustChannels();
+    t->prepareForAdjustChannels(mFrameCount);
     return OK;
 }
 
diff --git a/media/libaudioprocessing/BufferProviders.cpp b/media/libaudioprocessing/BufferProviders.cpp
index 6d31c12..4658db8 100644
--- a/media/libaudioprocessing/BufferProviders.cpp
+++ b/media/libaudioprocessing/BufferProviders.cpp
@@ -364,6 +364,29 @@
             src, mInputChannels, mIdxAry, mSampleSize, frames);
 }
 
+ChannelMixBufferProvider::ChannelMixBufferProvider(audio_channel_mask_t inputChannelMask,
+        audio_channel_mask_t outputChannelMask, audio_format_t format,
+        size_t bufferFrameCount) :
+        CopyBufferProvider(
+                audio_bytes_per_sample(format)
+                    * audio_channel_count_from_out_mask(inputChannelMask),
+                audio_bytes_per_sample(format)
+                    * audio_channel_count_from_out_mask(outputChannelMask),
+                bufferFrameCount)
+{
+    ALOGV("ChannelMixBufferProvider(%p)(%#x, %#x, %#x)",
+            this, format, inputChannelMask, outputChannelMask);
+    if (outputChannelMask == AUDIO_CHANNEL_OUT_STEREO && format == AUDIO_FORMAT_PCM_FLOAT) {
+        mIsValid = mChannelMix.setInputChannelMask(inputChannelMask);
+    }
+}
+
+void ChannelMixBufferProvider::copyFrames(void *dst, const void *src, size_t frames)
+{
+    mChannelMix.process(static_cast<const float *>(src), static_cast<float *>(dst),
+            frames, false /* accumulate */);
+}
+
 ReformatBufferProvider::ReformatBufferProvider(int32_t channelCount,
         audio_format_t inputFormat, audio_format_t outputFormat,
         size_t bufferFrameCount) :
@@ -630,7 +653,8 @@
 
 AdjustChannelsBufferProvider::AdjustChannelsBufferProvider(
         audio_format_t format, size_t inChannelCount, size_t outChannelCount,
-        size_t frameCount, audio_format_t contractedFormat, void* contractedBuffer) :
+        size_t frameCount, audio_format_t contractedFormat, void* contractedBuffer,
+        size_t contractedOutChannelCount) :
         CopyBufferProvider(
                 audio_bytes_per_frame(inChannelCount, format),
                 audio_bytes_per_frame(std::max(inChannelCount, outChannelCount), format),
@@ -640,15 +664,22 @@
         mOutChannelCount(outChannelCount),
         mSampleSizeInBytes(audio_bytes_per_sample(format)),
         mFrameCount(frameCount),
-        mContractedChannelCount(inChannelCount - outChannelCount),
-        mContractedFormat(contractedFormat),
+        mContractedFormat(inChannelCount > outChannelCount
+                ? contractedFormat : AUDIO_FORMAT_INVALID),
+        mContractedInChannelCount(inChannelCount > outChannelCount
+                ? inChannelCount - outChannelCount : 0),
+        mContractedOutChannelCount(contractedOutChannelCount),
+        mContractedSampleSizeInBytes(audio_bytes_per_sample(contractedFormat)),
+        mContractedInputFrameSize(mContractedInChannelCount * mContractedSampleSizeInBytes),
         mContractedBuffer(contractedBuffer),
         mContractedWrittenFrames(0)
 {
-    ALOGV("AdjustChannelsBufferProvider(%p)(%#x, %zu, %zu, %zu, %#x, %p)", this, format,
-            inChannelCount, outChannelCount, frameCount, contractedFormat, contractedBuffer);
+    ALOGV("AdjustChannelsBufferProvider(%p)(%#x, %zu, %zu, %zu, %#x, %p, %zu)",
+          this, format, inChannelCount, outChannelCount, frameCount, contractedFormat,
+          contractedBuffer, contractedOutChannelCount);
     if (mContractedFormat != AUDIO_FORMAT_INVALID && mInChannelCount > mOutChannelCount) {
-        mContractedFrameSize = audio_bytes_per_frame(mContractedChannelCount, mContractedFormat);
+        mContractedOutputFrameSize =
+                audio_bytes_per_frame(mContractedOutChannelCount, mContractedFormat);
     }
 }
 
@@ -667,25 +698,39 @@
 
 void AdjustChannelsBufferProvider::copyFrames(void *dst, const void *src, size_t frames)
 {
-    if (mInChannelCount > mOutChannelCount) {
-        // For case multi to mono, adjust_channels has special logic that will mix first two input
-        // channels into a single output channel. In that case, use adjust_channels_non_destructive
-        // to keep only one channel data even when contracting to mono.
-        adjust_channels_non_destructive(src, mInChannelCount, dst, mOutChannelCount,
-                mSampleSizeInBytes, frames * mInChannelCount * mSampleSizeInBytes);
-        if (mContractedFormat != AUDIO_FORMAT_INVALID
-            && mContractedBuffer != nullptr) {
-            const size_t contractedIdx = frames * mOutChannelCount * mSampleSizeInBytes;
+    // For case multi to mono, adjust_channels has special logic that will mix first two input
+    // channels into a single output channel. In that case, use adjust_channels_non_destructive
+    // to keep only one channel data even when contracting to mono.
+    adjust_channels_non_destructive(src, mInChannelCount, dst, mOutChannelCount,
+            mSampleSizeInBytes, frames * mInChannelCount * mSampleSizeInBytes);
+    if (mContractedFormat != AUDIO_FORMAT_INVALID
+        && mContractedBuffer != nullptr) {
+        const size_t contractedIdx = frames * mOutChannelCount * mSampleSizeInBytes;
+        uint8_t* oriBuf = (uint8_t*) dst + contractedIdx;
+        uint8_t* buf = (uint8_t*) mContractedBuffer
+                + mContractedWrittenFrames * mContractedOutputFrameSize;
+        if (mContractedInChannelCount > mContractedOutChannelCount) {
+            // Adjust the channels first as the contracted buffer may not have enough
+            // space for the data.
+            // Use adjust_channels_non_destructive to avoid mix first two channels into one single
+            // output channel when it is multi to mono.
+            adjust_channels_non_destructive(
+                    oriBuf, mContractedInChannelCount, oriBuf, mContractedOutChannelCount,
+                    mSampleSizeInBytes, frames * mContractedInChannelCount * mSampleSizeInBytes);
             memcpy_by_audio_format(
-                    (uint8_t*) mContractedBuffer + mContractedWrittenFrames * mContractedFrameSize,
-                    mContractedFormat, (uint8_t*) dst + contractedIdx, mFormat,
-                    mContractedChannelCount * frames);
-            mContractedWrittenFrames += frames;
+                    buf, mContractedFormat, oriBuf, mFormat, mContractedOutChannelCount * frames);
+        } else {
+            // Copy the data first as the dst buffer may not have enough space for extra channel.
+            memcpy_by_audio_format(
+                buf, mContractedFormat, oriBuf, mFormat, mContractedInChannelCount * frames);
+            // Note that if the contracted data is from MONO to MULTICHANNEL, the first 2 channels
+            // will be duplicated with the original single input channel and all the other channels
+            // will be 0-filled.
+            adjust_channels(
+                    buf, mContractedInChannelCount, buf, mContractedOutChannelCount,
+                    mContractedSampleSizeInBytes, mContractedInputFrameSize * frames);
         }
-    } else {
-        // Prefer expanding data from the end of each audio frame.
-        adjust_channels(src, mInChannelCount, dst, mOutChannelCount,
-                mSampleSizeInBytes, frames * mInChannelCount * mSampleSizeInBytes);
+        mContractedWrittenFrames += frames;
     }
 }
 
diff --git a/media/libaudioprocessing/include/media/AudioMixer.h b/media/libaudioprocessing/include/media/AudioMixer.h
index 5a9fa07..2993a60 100644
--- a/media/libaudioprocessing/include/media/AudioMixer.h
+++ b/media/libaudioprocessing/include/media/AudioMixer.h
@@ -80,7 +80,6 @@
             mPostDownmixReformatBufferProvider.reset(nullptr);
             mDownmixerBufferProvider.reset(nullptr);
             mReformatBufferProvider.reset(nullptr);
-            mContractChannelsNonDestructiveBufferProvider.reset(nullptr);
             mAdjustChannelsBufferProvider.reset(nullptr);
         }
 
@@ -95,10 +94,8 @@
         void        unprepareForDownmix();
         status_t    prepareForReformat();
         void        unprepareForReformat();
-        status_t    prepareForAdjustChannels();
+        status_t    prepareForAdjustChannels(size_t frames);
         void        unprepareForAdjustChannels();
-        status_t    prepareForAdjustChannelsNonDestructive(size_t frames);
-        void        unprepareForAdjustChannelsNonDestructive();
         void        clearContractedBuffer();
         bool        setPlaybackRate(const AudioPlaybackRate &playbackRate);
         void        reconfigureBufferProviders();
@@ -114,24 +111,18 @@
          * 2) mAdjustChannelsBufferProvider: Expands or contracts sample data from one interleaved
          *    channel format to another. Expanded channels are filled with zeros and put at the end
          *    of each audio frame. Contracted channels are copied to the end of the buffer.
-         * 3) mContractChannelsNonDestructiveBufferProvider: Non-destructively contract sample data.
-         *    This is currently using at audio-haptic coupled playback to separate audio and haptic
-         *    data. Contracted channels could be written to given buffer.
-         * 4) mReformatBufferProvider: If not NULL, performs the audio reformat to
+         * 3) mReformatBufferProvider: If not NULL, performs the audio reformat to
          *    match either mMixerInFormat or mDownmixRequiresFormat, if the downmixer
          *    requires reformat. For example, it may convert floating point input to
          *    PCM_16_bit if that's required by the downmixer.
-         * 5) mDownmixerBufferProvider: If not NULL, performs the channel remixing to match
+         * 4) mDownmixerBufferProvider: If not NULL, performs the channel remixing to match
          *    the number of channels required by the mixer sink.
-         * 6) mPostDownmixReformatBufferProvider: If not NULL, performs reformatting from
+         * 5) mPostDownmixReformatBufferProvider: If not NULL, performs reformatting from
          *    the downmixer requirements to the mixer engine input requirements.
-         * 7) mTimestretchBufferProvider: Adds timestretching for playback rate
+         * 6) mTimestretchBufferProvider: Adds timestretching for playback rate
          */
         AudioBufferProvider* mInputBufferProvider;    // externally provided buffer provider.
-        // TODO: combine mAdjustChannelsBufferProvider and
-        // mContractChannelsNonDestructiveBufferProvider
         std::unique_ptr<PassthruBufferProvider> mAdjustChannelsBufferProvider;
-        std::unique_ptr<PassthruBufferProvider> mContractChannelsNonDestructiveBufferProvider;
         std::unique_ptr<PassthruBufferProvider> mReformatBufferProvider;
         std::unique_ptr<PassthruBufferProvider> mDownmixerBufferProvider;
         std::unique_ptr<PassthruBufferProvider> mPostDownmixReformatBufferProvider;
@@ -153,8 +144,6 @@
         uint32_t             mMixerHapticChannelCount;
         uint32_t             mAdjustInChannelCount;
         uint32_t             mAdjustOutChannelCount;
-        uint32_t             mAdjustNonDestructiveInChannelCount;
-        uint32_t             mAdjustNonDestructiveOutChannelCount;
         bool                 mKeepContractedChannels;
     };
 
diff --git a/media/libaudioprocessing/include/media/BufferProviders.h b/media/libaudioprocessing/include/media/BufferProviders.h
index b038854..b3ab8a5 100644
--- a/media/libaudioprocessing/include/media/BufferProviders.h
+++ b/media/libaudioprocessing/include/media/BufferProviders.h
@@ -20,6 +20,7 @@
 #include <stdint.h>
 #include <sys/types.h>
 
+#include <audio_utils/ChannelMix.h>
 #include <media/AudioBufferProvider.h>
 #include <media/AudioResamplerPublic.h>
 #include <system/audio.h>
@@ -129,6 +130,23 @@
     static const int32_t SESSION_ID_INVALID_AND_IGNORED = -2;
 };
 
+// ChannelMixBufferProvider derives from CopyBufferProvider to perform an
+// downmix to the proper channel count and mask.
+class ChannelMixBufferProvider : public CopyBufferProvider {
+public:
+    ChannelMixBufferProvider(audio_channel_mask_t inputChannelMask,
+            audio_channel_mask_t outputChannelMask, audio_format_t format,
+            size_t bufferFrameCount);
+
+    void copyFrames(void *dst, const void *src, size_t frames) override;
+
+    bool isValid() const { return mIsValid; }
+
+protected:
+    audio_utils::channels::ChannelMix mChannelMix;
+    bool mIsValid = false;
+};
+
 // RemixBufferProvider derives from CopyBufferProvider to perform an
 // upmix or downmix to the proper channel count and mask.
 class RemixBufferProvider : public CopyBufferProvider {
@@ -223,17 +241,22 @@
 // Extra expanded channels are filled with zeros and put at the end of each audio frame.
 // Contracted channels are copied to the end of the output buffer(storage should be
 // allocated appropriately).
-// Contracted channels could be written to output buffer.
+// Contracted channels could be written to output buffer and got adjusted. When the contracted
+// channels are adjusted in the contracted buffer, the input channel count will be calculated
+// as `inChannelCount - outChannelCount`. The output channel count is provided by caller, which
+// is `contractedOutChannelCount`. Currently, adjusting contracted channels is used for audio
+// coupled haptic playback. If the device supports two haptic channels while apps only provide
+// single haptic channel, the second haptic channel will be duplicated with the first haptic
+// channel's data. If the device supports single haptic channels while apps provide two haptic
+// channels, the second channel will be contracted.
 class AdjustChannelsBufferProvider : public CopyBufferProvider {
 public:
-    AdjustChannelsBufferProvider(audio_format_t format, size_t inChannelCount,
-            size_t outChannelCount, size_t frameCount) : AdjustChannelsBufferProvider(
-                    format, inChannelCount, outChannelCount,
-                    frameCount, AUDIO_FORMAT_INVALID, nullptr) { }
     // Contracted data is converted to contractedFormat and put into contractedBuffer.
     AdjustChannelsBufferProvider(audio_format_t format, size_t inChannelCount,
-            size_t outChannelCount, size_t frameCount, audio_format_t contractedFormat,
-            void* contractedBuffer);
+            size_t outChannelCount, size_t frameCount,
+            audio_format_t contractedFormat = AUDIO_FORMAT_INVALID,
+            void* contractedBuffer = nullptr,
+            size_t contractedOutChannelCount = 0);
     //Overrides
     status_t getNextBuffer(Buffer* pBuffer) override;
     void copyFrames(void *dst, const void *src, size_t frames) override;
@@ -247,11 +270,14 @@
     const size_t         mOutChannelCount;
     const size_t         mSampleSizeInBytes;
     const size_t         mFrameCount;
-    const size_t         mContractedChannelCount;
     const audio_format_t mContractedFormat;
+    const size_t         mContractedInChannelCount;
+    const size_t         mContractedOutChannelCount;
+    const size_t         mContractedSampleSizeInBytes;
+    const size_t         mContractedInputFrameSize; // contracted input frame size
     void                *mContractedBuffer;
     size_t               mContractedWrittenFrames;
-    size_t               mContractedFrameSize;
+    size_t               mContractedOutputFrameSize; // contracted output frame size
 };
 // ----------------------------------------------------------------------------
 } // namespace android
diff --git a/services/audioflinger/Effects.cpp b/services/audioflinger/Effects.cpp
index b80943e..d09c9f4 100644
--- a/services/audioflinger/Effects.cpp
+++ b/services/audioflinger/Effects.cpp
@@ -953,11 +953,7 @@
     // Auxiliary effect:
     //      accumulates in output buffer: input buffer != output buffer
     // Therefore: accumulate <=> input buffer != output buffer
-    if (mConfig.inputCfg.buffer.raw != mConfig.outputCfg.buffer.raw) {
-        mConfig.outputCfg.accessMode = EFFECT_BUFFER_ACCESS_ACCUMULATE;
-    } else {
-        mConfig.outputCfg.accessMode = EFFECT_BUFFER_ACCESS_WRITE;
-    }
+    mConfig.outputCfg.accessMode = requiredEffectBufferAccessMode();
     mConfig.inputCfg.mask = EFFECT_CONFIG_ALL;
     mConfig.outputCfg.mask = EFFECT_CONFIG_ALL;
     mConfig.inputCfg.buffer.frameCount = callback->frameCount();
@@ -2340,8 +2336,10 @@
         // output buffer, otherwise to chain input buffer
         if (idx_insert == size) {
             if (idx_insert != 0) {
-                mEffects[idx_insert-1]->configure();
-                mEffects[idx_insert-1]->setOutBuffer(mInBuffer);
+                // update channel mask before setting output buffer.
+                mEffects[idx_insert - 1]->configure();
+                mEffects[idx_insert - 1]->setOutBuffer(mInBuffer); // set output buffer
+                mEffects[idx_insert - 1]->updateAccessMode();      // reconfig if neeeded.
             }
             effect->setOutBuffer(mOutBuffer);
         } else {
diff --git a/services/audioflinger/Effects.h b/services/audioflinger/Effects.h
index 389ff7b..9c832c6 100644
--- a/services/audioflinger/Effects.h
+++ b/services/audioflinger/Effects.h
@@ -254,6 +254,13 @@
         return mOutBuffer != 0 ? reinterpret_cast<int16_t*>(mOutBuffer->ptr()) : NULL;
     }
 
+    // Updates the access mode if it is out of date.  May issue a new effect configure.
+    void        updateAccessMode() {
+                    if (requiredEffectBufferAccessMode() != mConfig.outputCfg.accessMode) {
+                        configure();
+                    }
+                }
+
     status_t         setDevices(const AudioDeviceTypeAddrVector &devices);
     status_t         setInputDevice(const AudioDeviceTypeAddr &device);
     status_t         setVolume(uint32_t *left, uint32_t *right, bool controller);
@@ -289,6 +296,11 @@
     status_t stop_l();
     status_t removeEffectFromHal_l();
     status_t sendSetAudioDevicesCommand(const AudioDeviceTypeAddrVector &devices, uint32_t cmdCode);
+    effect_buffer_access_e requiredEffectBufferAccessMode() const {
+        return mConfig.inputCfg.buffer.raw == mConfig.outputCfg.buffer.raw
+                ? EFFECT_BUFFER_ACCESS_WRITE : EFFECT_BUFFER_ACCESS_ACCUMULATE;
+    }
+
 
     effect_config_t     mConfig;    // input and output audio configuration
     sp<EffectHalInterface> mEffectInterface; // Effect module HAL
diff --git a/services/audioflinger/FastMixer.cpp b/services/audioflinger/FastMixer.cpp
index fc34d95..26bd92d 100644
--- a/services/audioflinger/FastMixer.cpp
+++ b/services/audioflinger/FastMixer.cpp
@@ -89,6 +89,7 @@
     // TODO: Add channel mask to NBAIO_Format.
     // We assume that the channel mask must be a valid positional channel mask.
     mSinkChannelMask = getChannelMaskFromCount(mSinkChannelCount);
+    mBalance.setChannelMask(mSinkChannelMask);
 
     unsigned i;
     for (i = 0; i < FastMixerState::sMaxFastTracks; ++i) {
diff --git a/services/audiopolicy/service/Spatializer.cpp b/services/audiopolicy/service/Spatializer.cpp
index 502a8d0..0fdbe20 100644
--- a/services/audiopolicy/service/Spatializer.cpp
+++ b/services/audiopolicy/service/Spatializer.cpp
@@ -627,6 +627,9 @@
 
 status_t Spatializer::attachOutput(audio_io_handle_t output) {
     std::shared_ptr<SpatializerPoseController> poseController;
+    bool outputChanged = false;
+    sp<media::INativeSpatializerCallback> callback;
+
     {
         std::lock_guard lock(mLock);
         ALOGV("%s output %d mOutput %d", __func__, (int)output, (int)mOutput);
@@ -654,6 +657,7 @@
                              std::vector<SpatializerHeadTrackingMode>{mActualHeadTrackingMode});
 
         mEngine->setEnabled(true);
+        outputChanged = mOutput != output;
         mOutput = output;
 
         if (mSupportsHeadTracking) {
@@ -668,26 +672,42 @@
             mPoseController->setDisplayOrientation(mDisplayOrientation);
             poseController = mPoseController;
         }
+        callback = mSpatializerCallback;
     }
     if (poseController != nullptr) {
         poseController->waitUntilCalculated();
     }
+
+    if (outputChanged && callback != nullptr) {
+        callback->onOutputChanged(output);
+    }
+
     return NO_ERROR;
 }
 
 audio_io_handle_t Spatializer::detachOutput() {
-    std::lock_guard lock(mLock);
-    ALOGV("%s mOutput %d", __func__, (int)mOutput);
     audio_io_handle_t output = AUDIO_IO_HANDLE_NONE;
-    if (mOutput == AUDIO_IO_HANDLE_NONE) {
-        return output;
+    sp<media::INativeSpatializerCallback> callback;
+
+    {
+        std::lock_guard lock(mLock);
+        ALOGV("%s mOutput %d", __func__, (int)mOutput);
+        if (mOutput == AUDIO_IO_HANDLE_NONE) {
+            return output;
+        }
+        // remove FX instance
+        mEngine->setEnabled(false);
+        mEngine.clear();
+        output = mOutput;
+        mOutput = AUDIO_IO_HANDLE_NONE;
+        mPoseController.reset();
+
+        callback = mSpatializerCallback;
     }
-    // remove FX instance
-    mEngine->setEnabled(false);
-    mEngine.clear();
-    output = mOutput;
-    mOutput = AUDIO_IO_HANDLE_NONE;
-    mPoseController.reset();
+
+    if (callback != nullptr) {
+        callback->onOutputChanged(AUDIO_IO_HANDLE_NONE);
+    }
     return output;
 }
 
diff --git a/services/camera/libcameraservice/common/CameraProviderManager.cpp b/services/camera/libcameraservice/common/CameraProviderManager.cpp
index b10a4c4..2f74df9 100644
--- a/services/camera/libcameraservice/common/CameraProviderManager.cpp
+++ b/services/camera/libcameraservice/common/CameraProviderManager.cpp
@@ -1631,7 +1631,6 @@
         case 3:
             deviceInfo = initializeDeviceInfo<DeviceInfo3>(name, mProviderTagid,
                     id, minor);
-            deviceInfo->notifyDeviceStateChange(mDeviceState);
             break;
         default:
             ALOGE("%s: Device %s: Unknown HIDL device HAL major version %d:", __FUNCTION__,
@@ -1639,6 +1638,7 @@
             return BAD_VALUE;
     }
     if (deviceInfo == nullptr) return BAD_VALUE;
+    deviceInfo->notifyDeviceStateChange(mDeviceState);
     deviceInfo->mStatus = initialStatus;
     bool isAPI1Compatible = deviceInfo->isAPI1Compatible();