diff --git a/bluetooth/audio/2.0/default/A2dpOffloadAudioProvider.cpp b/bluetooth/audio/2.0/default/A2dpOffloadAudioProvider.cpp
new file mode 100644
index 0000000..84fba34
--- /dev/null
+++ b/bluetooth/audio/2.0/default/A2dpOffloadAudioProvider.cpp
@@ -0,0 +1,89 @@
+/*
+ * Copyright 2018 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_TAG "BTAudioProviderA2dpOffload"
+
+#include <android-base/logging.h>
+#include <fmq/MessageQueue.h>
+#include <hidl/MQDescriptor.h>
+
+#include "A2dpOffloadAudioProvider.h"
+#include "BluetoothAudioSessionReport.h"
+#include "BluetoothAudioSupportedCodecsDB.h"
+
+namespace android {
+namespace hardware {
+namespace bluetooth {
+namespace audio {
+namespace V2_0 {
+namespace implementation {
+
+using ::android::bluetooth::audio::BluetoothAudioSessionReport;
+using ::android::hardware::kSynchronizedReadWrite;
+using ::android::hardware::MessageQueue;
+using ::android::hardware::Void;
+
+using DataMQ = MessageQueue<uint8_t, kSynchronizedReadWrite>;
+
+A2dpOffloadAudioProvider::A2dpOffloadAudioProvider()
+    : BluetoothAudioProvider() {
+  session_type_ = SessionType::A2DP_HARDWARE_OFFLOAD_DATAPATH;
+}
+
+bool A2dpOffloadAudioProvider::isValid(const SessionType& sessionType) {
+  return (sessionType == session_type_);
+}
+
+Return<void> A2dpOffloadAudioProvider::startSession(
+    const sp<IBluetoothAudioPort>& hostIf,
+    const AudioConfiguration& audioConfig, startSession_cb _hidl_cb) {
+  /**
+   * Initialize the audio platform if audioConfiguration is supported.
+   * Save the the IBluetoothAudioPort interface, so that it can be used
+   * later to send stream control commands to the HAL client, based on
+   * interaction with Audio framework.
+   */
+  if (audioConfig.getDiscriminator() !=
+      AudioConfiguration::hidl_discriminator::codecConfig) {
+    LOG(WARNING) << __func__
+                 << " - Invalid Audio Configuration=" << toString(audioConfig);
+    _hidl_cb(BluetoothAudioStatus::UNSUPPORTED_CODEC_CONFIGURATION,
+             DataMQ::Descriptor());
+    return Void();
+  } else if (!android::bluetooth::audio::IsOffloadCodecConfigurationValid(
+                 session_type_, audioConfig.codecConfig())) {
+    _hidl_cb(BluetoothAudioStatus::UNSUPPORTED_CODEC_CONFIGURATION,
+             DataMQ::Descriptor());
+    return Void();
+  }
+
+  return BluetoothAudioProvider::startSession(hostIf, audioConfig, _hidl_cb);
+}
+
+Return<void> A2dpOffloadAudioProvider::onSessionReady(
+    startSession_cb _hidl_cb) {
+  BluetoothAudioSessionReport::OnSessionStarted(session_type_, stack_iface_,
+                                                nullptr, audio_config_);
+  _hidl_cb(BluetoothAudioStatus::SUCCESS, DataMQ::Descriptor());
+  return Void();
+}
+
+}  // namespace implementation
+}  // namespace V2_0
+}  // namespace audio
+}  // namespace bluetooth
+}  // namespace hardware
+}  // namespace android
diff --git a/bluetooth/audio/2.0/default/A2dpOffloadAudioProvider.h b/bluetooth/audio/2.0/default/A2dpOffloadAudioProvider.h
new file mode 100644
index 0000000..9f40278
--- /dev/null
+++ b/bluetooth/audio/2.0/default/A2dpOffloadAudioProvider.h
@@ -0,0 +1,47 @@
+/*
+ * Copyright 2018 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.
+ */
+
+#pragma once
+
+#include "BluetoothAudioProvider.h"
+
+namespace android {
+namespace hardware {
+namespace bluetooth {
+namespace audio {
+namespace V2_0 {
+namespace implementation {
+
+class A2dpOffloadAudioProvider : public BluetoothAudioProvider {
+ public:
+  A2dpOffloadAudioProvider();
+
+  bool isValid(const SessionType& sessionType) override;
+
+  Return<void> startSession(const sp<IBluetoothAudioPort>& hostIf,
+                            const AudioConfiguration& audioConfig,
+                            startSession_cb _hidl_cb) override;
+
+ private:
+  Return<void> onSessionReady(startSession_cb _hidl_cb) override;
+};
+
+}  // namespace implementation
+}  // namespace V2_0
+}  // namespace audio
+}  // namespace bluetooth
+}  // namespace hardware
+}  // namespace android
diff --git a/bluetooth/audio/2.0/default/A2dpSoftwareAudioProvider.cpp b/bluetooth/audio/2.0/default/A2dpSoftwareAudioProvider.cpp
new file mode 100644
index 0000000..f71a73e
--- /dev/null
+++ b/bluetooth/audio/2.0/default/A2dpSoftwareAudioProvider.cpp
@@ -0,0 +1,107 @@
+/*
+ * Copyright 2018 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_TAG "BTAudioProviderA2dpSoftware"
+
+#include <android-base/logging.h>
+
+#include "A2dpSoftwareAudioProvider.h"
+#include "BluetoothAudioSessionReport.h"
+#include "BluetoothAudioSupportedCodecsDB.h"
+
+namespace android {
+namespace hardware {
+namespace bluetooth {
+namespace audio {
+namespace V2_0 {
+namespace implementation {
+
+using ::android::bluetooth::audio::BluetoothAudioSessionReport;
+using ::android::hardware::Void;
+
+static constexpr uint32_t kPcmFrameSize = 4;  // 16 bits per sample / stereo
+static constexpr uint32_t kPcmFrameCount = 128;
+static constexpr uint32_t kRtpFrameSize = kPcmFrameSize * kPcmFrameCount;
+static constexpr uint32_t kRtpFrameCount = 7;  // max counts by 1 tick (20ms)
+static constexpr uint32_t kBufferSize = kRtpFrameSize * kRtpFrameCount;
+static constexpr uint32_t kBufferCount = 2;  // double buffer
+static constexpr uint32_t kDataMqSize = kBufferSize * kBufferCount;
+
+A2dpSoftwareAudioProvider::A2dpSoftwareAudioProvider()
+    : BluetoothAudioProvider(), mDataMQ(nullptr) {
+  LOG(INFO) << __func__ << " - size of audio buffer " << kDataMqSize
+            << " byte(s)";
+  std::unique_ptr<DataMQ> tempDataMQ(
+      new DataMQ(kDataMqSize, /* EventFlag */ true));
+  if (tempDataMQ && tempDataMQ->isValid()) {
+    mDataMQ = std::move(tempDataMQ);
+    session_type_ = SessionType::A2DP_SOFTWARE_ENCODING_DATAPATH;
+  } else {
+    ALOGE_IF(!tempDataMQ, "failed to allocate data MQ");
+    ALOGE_IF(tempDataMQ && !tempDataMQ->isValid(), "data MQ is invalid");
+  }
+}
+
+bool A2dpSoftwareAudioProvider::isValid(const SessionType& sessionType) {
+  return (sessionType == session_type_ && mDataMQ && mDataMQ->isValid());
+}
+
+Return<void> A2dpSoftwareAudioProvider::startSession(
+    const sp<IBluetoothAudioPort>& hostIf,
+    const AudioConfiguration& audioConfig, startSession_cb _hidl_cb) {
+  /**
+   * Initialize the audio platform if audioConfiguration is supported.
+   * Save the the IBluetoothAudioPort interface, so that it can be used
+   * later to send stream control commands to the HAL client, based on
+   * interaction with Audio framework.
+   */
+  if (audioConfig.getDiscriminator() !=
+      AudioConfiguration::hidl_discriminator::pcmConfig) {
+    LOG(WARNING) << __func__
+                 << " - Invalid Audio Configuration=" << toString(audioConfig);
+    _hidl_cb(BluetoothAudioStatus::UNSUPPORTED_CODEC_CONFIGURATION,
+             DataMQ::Descriptor());
+    return Void();
+  } else if (!android::bluetooth::audio::IsSoftwarePcmConfigurationValid(
+                 audioConfig.pcmConfig())) {
+    LOG(WARNING) << __func__ << " - Unsupported PCM Configuration="
+                 << toString(audioConfig.pcmConfig());
+    _hidl_cb(BluetoothAudioStatus::UNSUPPORTED_CODEC_CONFIGURATION,
+             DataMQ::Descriptor());
+    return Void();
+  }
+
+  return BluetoothAudioProvider::startSession(hostIf, audioConfig, _hidl_cb);
+}
+
+Return<void> A2dpSoftwareAudioProvider::onSessionReady(
+    startSession_cb _hidl_cb) {
+  if (mDataMQ && mDataMQ->isValid()) {
+    BluetoothAudioSessionReport::OnSessionStarted(
+        session_type_, stack_iface_, mDataMQ->getDesc(), audio_config_);
+    _hidl_cb(BluetoothAudioStatus::SUCCESS, *mDataMQ->getDesc());
+  } else {
+    _hidl_cb(BluetoothAudioStatus::FAILURE, DataMQ::Descriptor());
+  }
+  return Void();
+}
+
+}  // namespace implementation
+}  // namespace V2_0
+}  // namespace audio
+}  // namespace bluetooth
+}  // namespace hardware
+}  // namespace android
diff --git a/bluetooth/audio/2.0/default/A2dpSoftwareAudioProvider.h b/bluetooth/audio/2.0/default/A2dpSoftwareAudioProvider.h
new file mode 100644
index 0000000..228a928
--- /dev/null
+++ b/bluetooth/audio/2.0/default/A2dpSoftwareAudioProvider.h
@@ -0,0 +1,58 @@
+/*
+ * Copyright 2018 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.
+ */
+
+#pragma once
+
+#include <fmq/MessageQueue.h>
+#include <hidl/MQDescriptor.h>
+
+#include "BluetoothAudioProvider.h"
+
+namespace android {
+namespace hardware {
+namespace bluetooth {
+namespace audio {
+namespace V2_0 {
+namespace implementation {
+
+using ::android::hardware::kSynchronizedReadWrite;
+using ::android::hardware::MessageQueue;
+
+using DataMQ = MessageQueue<uint8_t, kSynchronizedReadWrite>;
+
+class A2dpSoftwareAudioProvider : public BluetoothAudioProvider {
+ public:
+  A2dpSoftwareAudioProvider();
+
+  bool isValid(const SessionType& sessionType) override;
+
+  Return<void> startSession(const sp<IBluetoothAudioPort>& hostIf,
+                            const AudioConfiguration& audioConfig,
+                            startSession_cb _hidl_cb) override;
+
+ private:
+  // audio data queue for software encoding
+  std::unique_ptr<DataMQ> mDataMQ;
+
+  Return<void> onSessionReady(startSession_cb _hidl_cb) override;
+};
+
+}  // namespace implementation
+}  // namespace V2_0
+}  // namespace audio
+}  // namespace bluetooth
+}  // namespace hardware
+}  // namespace android
diff --git a/bluetooth/audio/2.0/default/Android.bp b/bluetooth/audio/2.0/default/Android.bp
new file mode 100644
index 0000000..1dfc05d
--- /dev/null
+++ b/bluetooth/audio/2.0/default/Android.bp
@@ -0,0 +1,48 @@
+cc_library_shared {
+    name: "android.hardware.bluetooth.audio@2.0-impl",
+    defaults: ["hidl_defaults"],
+    vendor: true,
+    relative_install_path: "hw",
+    srcs: [
+        "BluetoothAudioProvidersFactory.cpp",
+        "BluetoothAudioProvider.cpp",
+        "A2dpOffloadAudioProvider.cpp",
+        "A2dpSoftwareAudioProvider.cpp",
+        "HearingAidAudioProvider.cpp",
+    ],
+    header_libs: ["libhardware_headers"],
+    shared_libs: [
+        "android.hardware.audio.common@5.0",
+        "android.hardware.bluetooth.audio@2.0",
+        "libbase",
+        "libbluetooth_audio_session",
+        "libcutils",
+        "libfmq",
+        "libhidlbase",
+        "libhidltransport",
+        "liblog",
+        "libutils",
+    ],
+}
+
+cc_library_shared {
+    name: "libbluetooth_audio_session",
+    defaults: ["hidl_defaults"],
+    vendor: true,
+    srcs: [
+        "session/BluetoothAudioSession.cpp",
+        "session/BluetoothAudioSupportedCodecsDB.cpp",
+    ],
+    export_include_dirs: ["session/"],
+    header_libs: ["libhardware_headers"],
+    shared_libs: [
+        "android.hardware.bluetooth.audio@2.0",
+        "libbase",
+        "libcutils",
+        "libfmq",
+        "libhidlbase",
+        "libhidltransport",
+        "liblog",
+        "libutils",
+    ],
+}
diff --git a/bluetooth/audio/2.0/default/BluetoothAudioProvider.cpp b/bluetooth/audio/2.0/default/BluetoothAudioProvider.cpp
new file mode 100644
index 0000000..ab8973e
--- /dev/null
+++ b/bluetooth/audio/2.0/default/BluetoothAudioProvider.cpp
@@ -0,0 +1,143 @@
+/*
+ * Copyright 2018 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_TAG "BTAudioProviderStub"
+
+#include <android-base/logging.h>
+
+#include "BluetoothAudioProvider.h"
+#include "BluetoothAudioSessionReport.h"
+#include "BluetoothAudioSupportedCodecsDB.h"
+
+namespace android {
+namespace hardware {
+namespace bluetooth {
+namespace audio {
+namespace V2_0 {
+namespace implementation {
+
+using ::android::bluetooth::audio::BluetoothAudioSessionReport;
+using ::android::hardware::kSynchronizedReadWrite;
+using ::android::hardware::MessageQueue;
+using ::android::hardware::Void;
+
+using DataMQ = MessageQueue<uint8_t, kSynchronizedReadWrite>;
+
+void BluetoothAudioDeathRecipient::serviceDied(
+    uint64_t cookie __unused,
+    const wp<::android::hidl::base::V1_0::IBase>& who __unused) {
+  LOG(ERROR) << "BluetoothAudioDeathRecipient::" << __func__
+             << " - BluetoothAudio Service died";
+  provider_->endSession();
+}
+
+BluetoothAudioProvider::BluetoothAudioProvider()
+    : death_recipient_(new BluetoothAudioDeathRecipient(this)),
+      session_type_(SessionType::UNKNOWN),
+      audio_config_({}) {}
+
+Return<void> BluetoothAudioProvider::startSession(
+    const sp<IBluetoothAudioPort>& hostIf,
+    const AudioConfiguration& audioConfig, startSession_cb _hidl_cb) {
+  if (hostIf == nullptr) {
+    _hidl_cb(BluetoothAudioStatus::FAILURE, DataMQ::Descriptor());
+    return Void();
+  }
+
+  /**
+   * Initialize the audio platform if audioConfiguration is supported.
+   * Save the the IBluetoothAudioPort interface, so that it can be used
+   * later to send stream control commands to the HAL client, based on
+   * interaction with Audio framework.
+   */
+  audio_config_ = audioConfig;
+  stack_iface_ = hostIf;
+  stack_iface_->linkToDeath(death_recipient_, 0);
+
+  LOG(INFO) << __func__ << " - SessionType=" << toString(session_type_)
+            << ", AudioConfiguration=[" << toString(audio_config_) << "]";
+
+  onSessionReady(_hidl_cb);
+  return Void();
+}
+
+Return<void> BluetoothAudioProvider::streamStarted(
+    BluetoothAudioStatus status) {
+  LOG(INFO) << __func__ << " - SessionType=" << toString(session_type_)
+            << ", status=" << toString(status);
+
+  /**
+   * Streaming on control path has started,
+   * HAL server should start the streaming on data path.
+   */
+  if (stack_iface_) {
+    BluetoothAudioSessionReport::ReportControlStatus(session_type_, true,
+                                                     status);
+  } else {
+    LOG(WARNING) << __func__ << " - SessionType=" << toString(session_type_)
+                 << ", status=" << toString(status) << " has NO session";
+  }
+
+  return Void();
+}
+
+Return<void> BluetoothAudioProvider::streamSuspended(
+    BluetoothAudioStatus status) {
+  LOG(INFO) << __func__ << " - SessionType=" << toString(session_type_)
+            << ", status=" << toString(status);
+
+  /**
+   * Streaming on control path has suspend,
+   * HAL server should suspend the streaming on data path.
+   */
+  if (stack_iface_) {
+    BluetoothAudioSessionReport::ReportControlStatus(session_type_, false,
+                                                     status);
+  } else {
+    LOG(WARNING) << __func__ << " - SessionType=" << toString(session_type_)
+                 << ", status=" << toString(status) << " has NO session";
+  }
+
+  return Void();
+}
+
+Return<void> BluetoothAudioProvider::endSession() {
+  LOG(INFO) << __func__ << " - SessionType=" << toString(session_type_);
+
+  if (stack_iface_) {
+    BluetoothAudioSessionReport::OnSessionEnded(session_type_);
+    stack_iface_->unlinkToDeath(death_recipient_);
+  } else {
+    LOG(INFO) << __func__ << " - SessionType=" << toString(session_type_)
+              << " has NO session";
+  }
+
+  /**
+   * Clean up the audio platform as remote audio device is no
+   * longer active
+   */
+  stack_iface_ = nullptr;
+  audio_config_ = {};
+
+  return Void();
+}
+
+}  // namespace implementation
+}  // namespace V2_0
+}  // namespace audio
+}  // namespace bluetooth
+}  // namespace hardware
+}  // namespace android
diff --git a/bluetooth/audio/2.0/default/BluetoothAudioProvider.h b/bluetooth/audio/2.0/default/BluetoothAudioProvider.h
new file mode 100644
index 0000000..02bf2b9
--- /dev/null
+++ b/bluetooth/audio/2.0/default/BluetoothAudioProvider.h
@@ -0,0 +1,79 @@
+/*
+ * Copyright 2018 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.
+ */
+
+#pragma once
+
+#include <android/hardware/bluetooth/audio/2.0/IBluetoothAudioProvider.h>
+
+namespace android {
+namespace hardware {
+namespace bluetooth {
+namespace audio {
+namespace V2_0 {
+namespace implementation {
+
+using ::android::sp;
+using ::android::hardware::bluetooth::audio::V2_0::AudioConfiguration;
+using ::android::hardware::bluetooth::audio::V2_0::SessionType;
+
+using BluetoothAudioStatus =
+    ::android::hardware::bluetooth::audio::V2_0::Status;
+
+class BluetoothAudioDeathRecipient;
+
+class BluetoothAudioProvider : public IBluetoothAudioProvider {
+ public:
+  BluetoothAudioProvider();
+  ~BluetoothAudioProvider() = default;
+
+  virtual bool isValid(const SessionType& sessionType) = 0;
+
+  Return<void> startSession(const sp<IBluetoothAudioPort>& hostIf,
+                            const AudioConfiguration& audioConfig,
+                            startSession_cb _hidl_cb) override;
+  Return<void> streamStarted(BluetoothAudioStatus status) override;
+  Return<void> streamSuspended(BluetoothAudioStatus status) override;
+  Return<void> endSession() override;
+
+ protected:
+  sp<BluetoothAudioDeathRecipient> death_recipient_;
+
+  SessionType session_type_;
+  AudioConfiguration audio_config_;
+  sp<IBluetoothAudioPort> stack_iface_;
+
+  virtual Return<void> onSessionReady(startSession_cb _hidl_cb) = 0;
+};
+
+class BluetoothAudioDeathRecipient : public hidl_death_recipient {
+ public:
+  BluetoothAudioDeathRecipient(const sp<BluetoothAudioProvider> provider)
+      : provider_(provider) {}
+
+  virtual void serviceDied(
+      uint64_t cookie,
+      const wp<::android::hidl::base::V1_0::IBase>& who) override;
+
+ private:
+  sp<BluetoothAudioProvider> provider_;
+};
+
+}  // namespace implementation
+}  // namespace V2_0
+}  // namespace audio
+}  // namespace bluetooth
+}  // namespace hardware
+}  // namespace android
diff --git a/bluetooth/audio/2.0/default/BluetoothAudioProvidersFactory.cpp b/bluetooth/audio/2.0/default/BluetoothAudioProvidersFactory.cpp
new file mode 100644
index 0000000..df89cc8
--- /dev/null
+++ b/bluetooth/audio/2.0/default/BluetoothAudioProvidersFactory.cpp
@@ -0,0 +1,106 @@
+/*
+ * Copyright 2018 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_TAG "BTAudioProvidersFactory"
+
+#include <android-base/logging.h>
+
+#include "BluetoothAudioProvidersFactory.h"
+#include "BluetoothAudioSupportedCodecsDB.h"
+
+namespace android {
+namespace hardware {
+namespace bluetooth {
+namespace audio {
+namespace V2_0 {
+namespace implementation {
+
+using ::android::hardware::hidl_vec;
+using ::android::hardware::Void;
+
+A2dpSoftwareAudioProvider
+    BluetoothAudioProvidersFactory::a2dp_software_provider_instance_;
+A2dpOffloadAudioProvider
+    BluetoothAudioProvidersFactory::a2dp_offload_provider_instance_;
+HearingAidAudioProvider
+    BluetoothAudioProvidersFactory::hearing_aid_provider_instance_;
+
+Return<void> BluetoothAudioProvidersFactory::openProvider(
+    const SessionType sessionType, openProvider_cb _hidl_cb) {
+  LOG(INFO) << __func__ << " - SessionType=" << toString(sessionType);
+  BluetoothAudioStatus status = BluetoothAudioStatus::SUCCESS;
+  BluetoothAudioProvider* provider = nullptr;
+  switch (sessionType) {
+    case SessionType::A2DP_SOFTWARE_ENCODING_DATAPATH:
+      provider = &a2dp_software_provider_instance_;
+      break;
+    case SessionType::A2DP_HARDWARE_OFFLOAD_DATAPATH:
+      provider = &a2dp_offload_provider_instance_;
+      break;
+    case SessionType::HEARING_AID_SOFTWARE_ENCODING_DATAPATH:
+      provider = &hearing_aid_provider_instance_;
+      break;
+    default:
+      status = BluetoothAudioStatus::FAILURE;
+  }
+  if (provider == nullptr || !provider->isValid(sessionType)) {
+    provider = nullptr;
+    status = BluetoothAudioStatus::FAILURE;
+    LOG(ERROR) << __func__ << " - SessionType=" << toString(sessionType)
+               << ", status=" << toString(status);
+  }
+  _hidl_cb(status, provider);
+  return Void();
+}
+
+Return<void> BluetoothAudioProvidersFactory::getProviderCapabilities(
+    const SessionType sessionType, getProviderCapabilities_cb _hidl_cb) {
+  hidl_vec<AudioCapabilities> audio_capabilities =
+      hidl_vec<AudioCapabilities>(0);
+  if (sessionType == SessionType::A2DP_HARDWARE_OFFLOAD_DATAPATH) {
+    std::vector<CodecCapabilities> db_codec_capabilities =
+        android::bluetooth::audio::GetOffloadCodecCapabilities(sessionType);
+    if (db_codec_capabilities.size()) {
+      audio_capabilities.resize(db_codec_capabilities.size());
+      for (int i = 0; i < db_codec_capabilities.size(); ++i) {
+        audio_capabilities[i].codecCapabilities(db_codec_capabilities[i]);
+      }
+    }
+  } else if (sessionType != SessionType::UNKNOWN) {
+    std::vector<PcmParameters> db_pcm_capabilities =
+        android::bluetooth::audio::GetSoftwarePcmCapabilities();
+    if (db_pcm_capabilities.size() == 1) {
+      audio_capabilities.resize(1);
+      audio_capabilities[0].pcmCapabilities(db_pcm_capabilities[0]);
+    }
+  }
+  LOG(INFO) << __func__ << " - SessionType=" << toString(sessionType)
+            << " supports " << audio_capabilities.size() << " codecs";
+  _hidl_cb(audio_capabilities);
+  return Void();
+}
+
+IBluetoothAudioProvidersFactory* HIDL_FETCH_IBluetoothAudioProvidersFactory(
+    const char* /* name */) {
+  return new BluetoothAudioProvidersFactory();
+}
+
+}  // namespace implementation
+}  // namespace V2_0
+}  // namespace audio
+}  // namespace bluetooth
+}  // namespace hardware
+}  // namespace android
diff --git a/bluetooth/audio/2.0/default/BluetoothAudioProvidersFactory.h b/bluetooth/audio/2.0/default/BluetoothAudioProvidersFactory.h
new file mode 100644
index 0000000..0b51536
--- /dev/null
+++ b/bluetooth/audio/2.0/default/BluetoothAudioProvidersFactory.h
@@ -0,0 +1,58 @@
+/*
+ * Copyright 2018 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.
+ */
+
+#pragma once
+
+#include <android/hardware/bluetooth/audio/2.0/IBluetoothAudioProvidersFactory.h>
+
+#include "A2dpOffloadAudioProvider.h"
+#include "A2dpSoftwareAudioProvider.h"
+#include "BluetoothAudioProvider.h"
+#include "HearingAidAudioProvider.h"
+
+namespace android {
+namespace hardware {
+namespace bluetooth {
+namespace audio {
+namespace V2_0 {
+namespace implementation {
+
+class BluetoothAudioProvidersFactory : public IBluetoothAudioProvidersFactory {
+ public:
+  BluetoothAudioProvidersFactory() {}
+
+  Return<void> openProvider(const SessionType sessionType,
+                            openProvider_cb _hidl_cb) override;
+
+  Return<void> getProviderCapabilities(
+      const SessionType sessionType,
+      getProviderCapabilities_cb _hidl_cb) override;
+
+ private:
+  static A2dpSoftwareAudioProvider a2dp_software_provider_instance_;
+  static A2dpOffloadAudioProvider a2dp_offload_provider_instance_;
+  static HearingAidAudioProvider hearing_aid_provider_instance_;
+};
+
+extern "C" IBluetoothAudioProvidersFactory*
+HIDL_FETCH_IBluetoothAudioProvidersFactory(const char* name);
+
+}  // namespace implementation
+}  // namespace V2_0
+}  // namespace audio
+}  // namespace bluetooth
+}  // namespace hardware
+}  // namespace android
diff --git a/bluetooth/audio/2.0/default/HearingAidAudioProvider.cpp b/bluetooth/audio/2.0/default/HearingAidAudioProvider.cpp
new file mode 100644
index 0000000..e91cf8a
--- /dev/null
+++ b/bluetooth/audio/2.0/default/HearingAidAudioProvider.cpp
@@ -0,0 +1,106 @@
+/*
+ * Copyright 2018 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_TAG "BTAudioProviderHearingAid"
+
+#include <android-base/logging.h>
+
+#include "BluetoothAudioSessionReport.h"
+#include "BluetoothAudioSupportedCodecsDB.h"
+#include "HearingAidAudioProvider.h"
+
+namespace android {
+namespace hardware {
+namespace bluetooth {
+namespace audio {
+namespace V2_0 {
+namespace implementation {
+
+using ::android::bluetooth::audio::BluetoothAudioSessionReport;
+using ::android::hardware::Void;
+
+static constexpr uint32_t kPcmFrameSize = 4;  // 16 bits per sample / stereo
+static constexpr uint32_t kPcmFrameCount = 128;
+static constexpr uint32_t kRtpFrameSize = kPcmFrameSize * kPcmFrameCount;
+static constexpr uint32_t kRtpFrameCount = 7;  // max counts by 1 tick (20ms)
+static constexpr uint32_t kBufferSize = kRtpFrameSize * kRtpFrameCount;
+static constexpr uint32_t kBufferCount = 1;  // single buffer
+static constexpr uint32_t kDataMqSize = kBufferSize * kBufferCount;
+
+HearingAidAudioProvider::HearingAidAudioProvider()
+    : BluetoothAudioProvider(), mDataMQ(nullptr) {
+  LOG(INFO) << __func__ << " - size of audio buffer " << kDataMqSize
+            << " byte(s)";
+  std::unique_ptr<DataMQ> tempDataMQ(
+      new DataMQ(kDataMqSize, /* EventFlag */ true));
+  if (tempDataMQ && tempDataMQ->isValid()) {
+    mDataMQ = std::move(tempDataMQ);
+    session_type_ = SessionType::HEARING_AID_SOFTWARE_ENCODING_DATAPATH;
+  } else {
+    ALOGE_IF(!tempDataMQ, "failed to allocate data MQ");
+    ALOGE_IF(tempDataMQ && !tempDataMQ->isValid(), "data MQ is invalid");
+  }
+}
+
+bool HearingAidAudioProvider::isValid(const SessionType& sessionType) {
+  return (sessionType == session_type_ && mDataMQ && mDataMQ->isValid());
+}
+
+Return<void> HearingAidAudioProvider::startSession(
+    const sp<IBluetoothAudioPort>& hostIf,
+    const AudioConfiguration& audioConfig, startSession_cb _hidl_cb) {
+  /**
+   * Initialize the audio platform if audioConfiguration is supported.
+   * Save the the IBluetoothAudioPort interface, so that it can be used
+   * later to send stream control commands to the HAL client, based on
+   * interaction with Audio framework.
+   */
+  if (audioConfig.getDiscriminator() !=
+      AudioConfiguration::hidl_discriminator::pcmConfig) {
+    LOG(WARNING) << __func__
+                 << " - Invalid Audio Configuration=" << toString(audioConfig);
+    _hidl_cb(BluetoothAudioStatus::UNSUPPORTED_CODEC_CONFIGURATION,
+             DataMQ::Descriptor());
+    return Void();
+  } else if (!android::bluetooth::audio::IsSoftwarePcmConfigurationValid(
+                 audioConfig.pcmConfig())) {
+    LOG(WARNING) << __func__ << " - Unsupported PCM Configuration="
+                 << toString(audioConfig.pcmConfig());
+    _hidl_cb(BluetoothAudioStatus::UNSUPPORTED_CODEC_CONFIGURATION,
+             DataMQ::Descriptor());
+    return Void();
+  }
+
+  return BluetoothAudioProvider::startSession(hostIf, audioConfig, _hidl_cb);
+}
+
+Return<void> HearingAidAudioProvider::onSessionReady(startSession_cb _hidl_cb) {
+  if (mDataMQ && mDataMQ->isValid()) {
+    BluetoothAudioSessionReport::OnSessionStarted(
+        session_type_, stack_iface_, mDataMQ->getDesc(), audio_config_);
+    _hidl_cb(BluetoothAudioStatus::SUCCESS, *mDataMQ->getDesc());
+  } else {
+    _hidl_cb(BluetoothAudioStatus::FAILURE, DataMQ::Descriptor());
+  }
+  return Void();
+}
+
+}  // namespace implementation
+}  // namespace V2_0
+}  // namespace audio
+}  // namespace bluetooth
+}  // namespace hardware
+}  // namespace android
diff --git a/bluetooth/audio/2.0/default/HearingAidAudioProvider.h b/bluetooth/audio/2.0/default/HearingAidAudioProvider.h
new file mode 100644
index 0000000..117eb32
--- /dev/null
+++ b/bluetooth/audio/2.0/default/HearingAidAudioProvider.h
@@ -0,0 +1,58 @@
+/*
+ * Copyright 2018 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.
+ */
+
+#pragma once
+
+#include <fmq/MessageQueue.h>
+#include <hidl/MQDescriptor.h>
+
+#include "BluetoothAudioProvider.h"
+
+namespace android {
+namespace hardware {
+namespace bluetooth {
+namespace audio {
+namespace V2_0 {
+namespace implementation {
+
+using ::android::hardware::kSynchronizedReadWrite;
+using ::android::hardware::MessageQueue;
+
+using DataMQ = MessageQueue<uint8_t, kSynchronizedReadWrite>;
+
+class HearingAidAudioProvider : public BluetoothAudioProvider {
+ public:
+  HearingAidAudioProvider();
+
+  bool isValid(const SessionType& sessionType) override;
+
+  Return<void> startSession(const sp<IBluetoothAudioPort>& hostIf,
+                            const AudioConfiguration& audioConfig,
+                            startSession_cb _hidl_cb) override;
+
+ private:
+  // audio data queue for software encoding
+  std::unique_ptr<DataMQ> mDataMQ;
+
+  Return<void> onSessionReady(startSession_cb _hidl_cb) override;
+};
+
+}  // namespace implementation
+}  // namespace V2_0
+}  // namespace audio
+}  // namespace bluetooth
+}  // namespace hardware
+}  // namespace android
diff --git a/bluetooth/audio/2.0/default/session/BluetoothAudioSession.cpp b/bluetooth/audio/2.0/default/session/BluetoothAudioSession.cpp
new file mode 100644
index 0000000..d60e732
--- /dev/null
+++ b/bluetooth/audio/2.0/default/session/BluetoothAudioSession.cpp
@@ -0,0 +1,427 @@
+/*
+ * Copyright 2018 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_TAG "BTAudioProviderSession"
+
+#include "BluetoothAudioSession.h"
+
+#include <android-base/logging.h>
+#include <android-base/stringprintf.h>
+
+namespace android {
+namespace bluetooth {
+namespace audio {
+
+using ::android::hardware::audio::common::V5_0::AudioContentType;
+using ::android::hardware::audio::common::V5_0::AudioUsage;
+using ::android::hardware::audio::common::V5_0::PlaybackTrackMetadata;
+using ::android::hardware::audio::common::V5_0::SourceMetadata;
+using ::android::hardware::bluetooth::audio::V2_0::CodecType;
+using ::android::hardware::bluetooth::audio::V2_0::TimeSpec;
+
+const CodecConfiguration BluetoothAudioSession::kInvalidCodecConfiguration = {
+    .codecType = CodecType::UNKNOWN,
+    .encodedAudioBitrate = 0x00000000,
+    .peerMtu = 0xffff,
+    .isScmstEnabled = false,
+    .config = {}};
+AudioConfiguration BluetoothAudioSession::invalidSoftwareAudioConfiguration =
+    {};
+AudioConfiguration BluetoothAudioSession::invalidOffloadAudioConfiguration = {};
+
+static constexpr int kFmqSendTimeoutMs = 1000;  // 1000 ms timeout for sending
+static constexpr int kWritePollMs = 1;          // polled non-blocking interval
+
+static inline timespec timespec_convert_from_hal(const TimeSpec& TS) {
+  return {.tv_sec = static_cast<long>(TS.tvSec),
+          .tv_nsec = static_cast<long>(TS.tvNSec)};
+}
+
+BluetoothAudioSession::BluetoothAudioSession(const SessionType& session_type)
+    : session_type_(session_type), stack_iface_(nullptr), mDataMQ(nullptr) {
+  invalidSoftwareAudioConfiguration.pcmConfig(kInvalidPcmParameters);
+  invalidOffloadAudioConfiguration.codecConfig(kInvalidCodecConfiguration);
+}
+
+// The report function is used to report that the Bluetooth stack has started
+// this session without any failure, and will invoke session_changed_cb_ to
+// notify those registered bluetooth_audio outputs
+void BluetoothAudioSession::OnSessionStarted(
+    const sp<IBluetoothAudioPort> stack_iface, const DataMQ::Descriptor* dataMQ,
+    const AudioConfiguration& audio_config) {
+  std::lock_guard<std::recursive_mutex> guard(mutex_);
+  if (stack_iface == nullptr) {
+    LOG(ERROR) << __func__ << " - SessionType=" << toString(session_type_)
+               << ", IBluetoothAudioPort Invalid";
+  } else if (!UpdateAudioConfig(audio_config)) {
+    LOG(ERROR) << __func__ << " - SessionType=" << toString(session_type_)
+               << ", AudioConfiguration=" << toString(audio_config)
+               << " Invalid";
+  } else if (!UpdateDataPath(dataMQ)) {
+    LOG(ERROR) << __func__ << " - SessionType=" << toString(session_type_)
+               << " DataMQ Invalid";
+    audio_config_ =
+        (session_type_ == SessionType::A2DP_HARDWARE_OFFLOAD_DATAPATH
+             ? kInvalidOffloadAudioConfiguration
+             : kInvalidSoftwareAudioConfiguration);
+  } else {
+    stack_iface_ = stack_iface;
+    LOG(INFO) << __func__ << " - SessionType=" << toString(session_type_)
+              << ", AudioConfiguration=" << toString(audio_config);
+    ReportSessionStatus();
+  }
+}
+
+// The report function is used to report that the Bluetooth stack has ended the
+// session, and will invoke session_changed_cb_ to notify registered
+// bluetooth_audio outputs
+void BluetoothAudioSession::OnSessionEnded() {
+  std::lock_guard<std::recursive_mutex> guard(mutex_);
+  if (IsSessionReady()) {
+    ReportSessionStatus();
+  }
+  audio_config_ = (session_type_ == SessionType::A2DP_HARDWARE_OFFLOAD_DATAPATH
+                       ? kInvalidOffloadAudioConfiguration
+                       : kInvalidSoftwareAudioConfiguration);
+  stack_iface_ = nullptr;
+  UpdateDataPath(nullptr);
+}
+
+// invoking the registered session_changed_cb_
+void BluetoothAudioSession::ReportSessionStatus() {
+  // This is locked already by OnSessionStarted / OnSessionEnded
+  if (observers_.empty()) {
+    LOG(INFO) << __func__ << " - SessionType=" << toString(session_type_)
+              << " has NO port state observer";
+    return;
+  }
+  for (auto& observer : observers_) {
+    uint16_t cookie = observer.first;
+    std::shared_ptr<struct PortStatusCallbacks> cb = observer.second;
+    LOG(INFO) << __func__ << " - SessionType=" << toString(session_type_)
+              << " notify to bluetooth_audio=0x"
+              << android::base::StringPrintf("%04x", cookie);
+    cb->session_changed_cb_(cookie);
+  }
+}
+
+// The report function is used to report that the Bluetooth stack has notified
+// the result of startStream or suspendStream, and will invoke
+// control_result_cb_ to notify registered bluetooth_audio outputs
+void BluetoothAudioSession::ReportControlStatus(
+    bool start_resp, const BluetoothAudioStatus& status) {
+  std::lock_guard<std::recursive_mutex> guard(mutex_);
+  if (observers_.empty()) {
+    LOG(WARNING) << __func__ << " - SessionType=" << toString(session_type_)
+                 << " has NO port state observer";
+    return;
+  }
+  for (auto& observer : observers_) {
+    uint16_t cookie = observer.first;
+    std::shared_ptr<struct PortStatusCallbacks> cb = observer.second;
+    LOG(INFO) << __func__ << " - status=" << toString(status)
+              << " for SessionType=" << toString(session_type_)
+              << ", bluetooth_audio=0x"
+              << android::base::StringPrintf("%04x", cookie)
+              << (start_resp ? " started" : " suspended");
+    cb->control_result_cb_(cookie, start_resp, status);
+  }
+}
+
+// The function helps to check if this session is ready or not
+// @return: true if the Bluetooth stack has started the specified session
+bool BluetoothAudioSession::IsSessionReady() {
+  std::lock_guard<std::recursive_mutex> guard(mutex_);
+  bool dataMQ_valid =
+      (session_type_ == SessionType::A2DP_HARDWARE_OFFLOAD_DATAPATH ||
+       (mDataMQ != nullptr && mDataMQ->isValid()));
+  return stack_iface_ != nullptr && dataMQ_valid;
+}
+
+bool BluetoothAudioSession::UpdateDataPath(const DataMQ::Descriptor* dataMQ) {
+  if (dataMQ == nullptr) {
+    // usecase of reset by nullptr
+    mDataMQ = nullptr;
+    return true;
+  }
+  std::unique_ptr<DataMQ> tempDataMQ;
+  tempDataMQ.reset(new DataMQ(*dataMQ));
+  if (!tempDataMQ || !tempDataMQ->isValid()) {
+    mDataMQ = nullptr;
+    return false;
+  }
+  mDataMQ = std::move(tempDataMQ);
+  return true;
+}
+
+bool BluetoothAudioSession::UpdateAudioConfig(
+    const AudioConfiguration& audio_config) {
+  bool is_software_session =
+      (session_type_ == SessionType::A2DP_SOFTWARE_ENCODING_DATAPATH ||
+       session_type_ == SessionType::HEARING_AID_SOFTWARE_ENCODING_DATAPATH);
+  bool is_offload_session =
+      (session_type_ == SessionType::A2DP_HARDWARE_OFFLOAD_DATAPATH);
+  auto audio_config_discriminator = audio_config.getDiscriminator();
+  bool is_software_audio_config =
+      (is_software_session &&
+       audio_config_discriminator ==
+           AudioConfiguration::hidl_discriminator::pcmConfig);
+  bool is_offload_audio_config =
+      (is_offload_session &&
+       audio_config_discriminator ==
+           AudioConfiguration::hidl_discriminator::codecConfig);
+  if (!is_software_audio_config && !is_offload_audio_config) {
+    return false;
+  }
+  audio_config_ = audio_config;
+  return true;
+}
+
+// The control function helps the bluetooth_audio module to register
+// PortStatusCallbacks
+// @return: cookie - the assigned number to this bluetooth_audio output
+uint16_t BluetoothAudioSession::RegisterStatusCback(
+    const PortStatusCallbacks& cbacks) {
+  std::lock_guard<std::recursive_mutex> guard(mutex_);
+  uint16_t cookie = ObserversCookieGetInitValue(session_type_);
+  uint16_t cookie_upper_bound = ObserversCookieGetUpperBound(session_type_);
+
+  while (cookie < cookie_upper_bound) {
+    if (observers_.find(cookie) == observers_.end()) {
+      break;
+    }
+    ++cookie;
+  }
+  if (cookie >= cookie_upper_bound) {
+    LOG(ERROR) << __func__ << " - SessionType=" << toString(session_type_)
+               << " has " << observers_.size()
+               << " observers already (No Resource)";
+    return kObserversCookieUndefined;
+  }
+  std::shared_ptr<struct PortStatusCallbacks> cb =
+      std::make_shared<struct PortStatusCallbacks>();
+  *cb = cbacks;
+  observers_[cookie] = cb;
+  return cookie;
+}
+
+// The control function helps the bluetooth_audio module to unregister
+// PortStatusCallbacks
+// @param: cookie - indicates which bluetooth_audio output is
+void BluetoothAudioSession::UnregisterStatusCback(uint16_t cookie) {
+  std::lock_guard<std::recursive_mutex> guard(mutex_);
+  if (observers_.erase(cookie) != 1) {
+    LOG(WARNING) << __func__ << " - SessionType=" << toString(session_type_)
+                 << " no such provider=0x"
+                 << android::base::StringPrintf("%04x", cookie);
+  }
+}
+
+// The control function is for the bluetooth_audio module to get the current
+// AudioConfiguration
+const AudioConfiguration& BluetoothAudioSession::GetAudioConfig() {
+  std::lock_guard<std::recursive_mutex> guard(mutex_);
+  if (IsSessionReady()) {
+    return audio_config_;
+  } else if (session_type_ == SessionType::A2DP_HARDWARE_OFFLOAD_DATAPATH) {
+    return kInvalidOffloadAudioConfiguration;
+  } else {
+    return kInvalidSoftwareAudioConfiguration;
+  }
+}
+
+// Those control functions are for the bluetooth_audio module to start, suspend,
+// stop stream, to check position, and to update metadata.
+bool BluetoothAudioSession::StartStream() {
+  std::lock_guard<std::recursive_mutex> guard(mutex_);
+  if (!IsSessionReady()) {
+    LOG(DEBUG) << __func__ << " - SessionType=" << toString(session_type_)
+               << " has NO session";
+    return false;
+  }
+  auto hal_retval = stack_iface_->startStream();
+  if (!hal_retval.isOk()) {
+    LOG(WARNING) << __func__ << " - IBluetoothAudioPort SessionType="
+                 << toString(session_type_) << " failed";
+    return false;
+  }
+  return true;
+}
+
+bool BluetoothAudioSession::SuspendStream() {
+  std::lock_guard<std::recursive_mutex> guard(mutex_);
+  if (!IsSessionReady()) {
+    LOG(DEBUG) << __func__ << " - SessionType=" << toString(session_type_)
+               << " has NO session";
+    return false;
+  }
+  auto hal_retval = stack_iface_->suspendStream();
+  if (!hal_retval.isOk()) {
+    LOG(WARNING) << __func__ << " - IBluetoothAudioPort SessionType="
+                 << toString(session_type_) << " failed";
+    return false;
+  }
+  return true;
+}
+
+void BluetoothAudioSession::StopStream() {
+  std::lock_guard<std::recursive_mutex> guard(mutex_);
+  if (!IsSessionReady()) {
+    return;
+  }
+  auto hal_retval = stack_iface_->stopStream();
+  if (!hal_retval.isOk()) {
+    LOG(WARNING) << __func__ << " - IBluetoothAudioPort SessionType="
+                 << toString(session_type_) << " failed";
+  }
+}
+
+bool BluetoothAudioSession::GetPresentationPosition(
+    uint64_t* remote_delay_report_ns, uint64_t* total_bytes_readed,
+    timespec* data_position) {
+  std::lock_guard<std::recursive_mutex> guard(mutex_);
+  if (!IsSessionReady()) {
+    LOG(DEBUG) << __func__ << " - SessionType=" << toString(session_type_)
+               << " has NO session";
+    return false;
+  }
+  bool retval = false;
+  auto hal_retval = stack_iface_->getPresentationPosition(
+      [&retval, &remote_delay_report_ns, &total_bytes_readed, &data_position](
+          BluetoothAudioStatus status,
+          const uint64_t& remoteDeviceAudioDelayNanos,
+          uint64_t transmittedOctets,
+          const TimeSpec& transmittedOctetsTimeStamp) {
+        if (status == BluetoothAudioStatus::SUCCESS) {
+          if (remote_delay_report_ns)
+            *remote_delay_report_ns = remoteDeviceAudioDelayNanos;
+          if (total_bytes_readed) *total_bytes_readed = transmittedOctets;
+          if (data_position)
+            *data_position =
+                timespec_convert_from_hal(transmittedOctetsTimeStamp);
+          retval = true;
+        }
+      });
+  if (!hal_retval.isOk()) {
+    LOG(WARNING) << __func__ << " - IBluetoothAudioPort SessionType="
+                 << toString(session_type_) << " failed";
+    return false;
+  }
+  return retval;
+}
+
+void BluetoothAudioSession::UpdateTracksMetadata(
+    const struct source_metadata* source_metadata) {
+  std::lock_guard<std::recursive_mutex> guard(mutex_);
+  if (!IsSessionReady()) {
+    LOG(DEBUG) << __func__ << " - SessionType=" << toString(session_type_)
+               << " has NO session";
+    return;
+  }
+
+  ssize_t track_count = source_metadata->track_count;
+  LOG(INFO) << __func__ << " - SessionType=" << toString(session_type_) << ", "
+            << track_count << " track(s)";
+  if (session_type_ == SessionType::A2DP_SOFTWARE_ENCODING_DATAPATH ||
+      session_type_ == SessionType::A2DP_HARDWARE_OFFLOAD_DATAPATH) {
+    return;
+  }
+
+  struct playback_track_metadata* track = source_metadata->tracks;
+  SourceMetadata sourceMetadata;
+  PlaybackTrackMetadata* halMetadata;
+
+  sourceMetadata.tracks.resize(track_count);
+  halMetadata = sourceMetadata.tracks.data();
+  while (track_count && track) {
+    halMetadata->usage = static_cast<AudioUsage>(track->usage);
+    halMetadata->contentType =
+        static_cast<AudioContentType>(track->content_type);
+    halMetadata->gain = track->gain;
+    LOG(VERBOSE) << __func__ << " - SessionType=" << toString(session_type_)
+                 << ", usage=" << toString(halMetadata->usage)
+                 << ", content=" << toString(halMetadata->contentType)
+                 << ", gain=" << halMetadata->gain;
+    --track_count;
+    ++track;
+    ++halMetadata;
+  }
+  auto hal_retval = stack_iface_->updateMetadata(sourceMetadata);
+  if (!hal_retval.isOk()) {
+    LOG(WARNING) << __func__ << " - IBluetoothAudioPort SessionType="
+                 << toString(session_type_) << " failed";
+  }
+}
+
+// The control function writes stream to FMQ
+size_t BluetoothAudioSession::OutWritePcmData(const void* buffer,
+                                              size_t bytes) {
+  if (buffer == nullptr || !bytes) return 0;
+  size_t totalWritten = 0;
+  int ms_timeout = kFmqSendTimeoutMs;
+  do {
+    std::unique_lock<std::recursive_mutex> lock(mutex_);
+    if (!IsSessionReady()) break;
+    size_t availableToWrite = mDataMQ->availableToWrite();
+    if (availableToWrite) {
+      if (availableToWrite > (bytes - totalWritten)) {
+        availableToWrite = bytes - totalWritten;
+      }
+
+      if (!mDataMQ->write(static_cast<const uint8_t*>(buffer) + totalWritten,
+                          availableToWrite)) {
+        ALOGE("FMQ datapath writting %zu/%zu failed", totalWritten, bytes);
+        return totalWritten;
+      }
+      totalWritten += availableToWrite;
+    } else if (ms_timeout >= kWritePollMs) {
+      lock.unlock();
+      usleep(kWritePollMs * 1000);
+      ms_timeout -= kWritePollMs;
+    } else {
+      ALOGD("data %zu/%zu overflow %d ms", totalWritten, bytes,
+            (kFmqSendTimeoutMs - ms_timeout));
+      return totalWritten;
+    }
+  } while (totalWritten < bytes);
+  return totalWritten;
+}
+
+std::unique_ptr<BluetoothAudioSessionInstance>
+    BluetoothAudioSessionInstance::instance_ptr =
+        std::unique_ptr<BluetoothAudioSessionInstance>(
+            new BluetoothAudioSessionInstance());
+
+// API to fetch the session of A2DP / Hearing Aid
+std::shared_ptr<BluetoothAudioSession>
+BluetoothAudioSessionInstance::GetSessionInstance(
+    const SessionType& session_type) {
+  std::lock_guard<std::mutex> guard(instance_ptr->mutex_);
+  if (!instance_ptr->sessions_map_.empty()) {
+    auto entry = instance_ptr->sessions_map_.find(session_type);
+    if (entry != instance_ptr->sessions_map_.end()) {
+      return entry->second;
+    }
+  }
+  std::shared_ptr<BluetoothAudioSession> session_ptr =
+      std::make_shared<BluetoothAudioSession>(session_type);
+  instance_ptr->sessions_map_[session_type] = session_ptr;
+  return session_ptr;
+}
+
+}  // namespace audio
+}  // namespace bluetooth
+}  // namespace android
diff --git a/bluetooth/audio/2.0/default/session/BluetoothAudioSession.h b/bluetooth/audio/2.0/default/session/BluetoothAudioSession.h
new file mode 100644
index 0000000..85e8742
--- /dev/null
+++ b/bluetooth/audio/2.0/default/session/BluetoothAudioSession.h
@@ -0,0 +1,185 @@
+/*
+ * Copyright 2018 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.
+ */
+
+#pragma once
+
+#include <mutex>
+#include <unordered_map>
+
+#include <android/hardware/bluetooth/audio/2.0/IBluetoothAudioPort.h>
+#include <fmq/MessageQueue.h>
+#include <hardware/audio.h>
+#include <hidl/MQDescriptor.h>
+
+namespace android {
+namespace bluetooth {
+namespace audio {
+
+using ::android::sp;
+using ::android::hardware::kSynchronizedReadWrite;
+using ::android::hardware::MessageQueue;
+using ::android::hardware::bluetooth::audio::V2_0::AudioConfiguration;
+using ::android::hardware::bluetooth::audio::V2_0::BitsPerSample;
+using ::android::hardware::bluetooth::audio::V2_0::ChannelMode;
+using ::android::hardware::bluetooth::audio::V2_0::CodecConfiguration;
+using ::android::hardware::bluetooth::audio::V2_0::IBluetoothAudioPort;
+using ::android::hardware::bluetooth::audio::V2_0::PcmParameters;
+using ::android::hardware::bluetooth::audio::V2_0::SampleRate;
+using ::android::hardware::bluetooth::audio::V2_0::SessionType;
+
+using BluetoothAudioStatus =
+    ::android::hardware::bluetooth::audio::V2_0::Status;
+
+using DataMQ = MessageQueue<uint8_t, kSynchronizedReadWrite>;
+
+static constexpr uint16_t kObserversCookieSize = 0x0010;  // 0x0000 ~ 0x000f
+constexpr uint16_t kObserversCookieUndefined =
+    (static_cast<uint16_t>(SessionType::UNKNOWN) << 8 & 0xff00);
+inline SessionType ObserversCookieGetSessionType(uint16_t cookie) {
+  return static_cast<SessionType>(cookie >> 8 & 0x00ff);
+}
+inline uint16_t ObserversCookieGetInitValue(SessionType session_type) {
+  return (static_cast<uint16_t>(session_type) << 8 & 0xff00);
+}
+inline uint16_t ObserversCookieGetUpperBound(SessionType session_type) {
+  return (static_cast<uint16_t>(session_type) << 8 & 0xff00) +
+         kObserversCookieSize;
+}
+
+// This presents the callbacks of started / suspended and session changed,
+// and the bluetooth_audio module uses to receive the status notification
+struct PortStatusCallbacks {
+  // control_result_cb_ - when the Bluetooth stack reports results of
+  // streamStarted or streamSuspended, the BluetoothAudioProvider will invoke
+  // this callback to report to the bluetooth_audio module.
+  // @param: cookie - indicates which bluetooth_audio output should handle
+  // @param: start_resp - this report is for startStream or not
+  // @param: status - the result of startStream
+  std::function<void(uint16_t cookie, bool start_resp,
+                     const BluetoothAudioStatus& status)>
+      control_result_cb_;
+  // session_changed_cb_ - when the Bluetooth stack start / end session, the
+  // BluetoothAudioProvider will invoke this callback to notify to the
+  // bluetooth_audio module.
+  // @param: cookie - indicates which bluetooth_audio output should handle
+  std::function<void(uint16_t cookie)> session_changed_cb_;
+};
+
+class BluetoothAudioSession {
+ private:
+  // using recursive_mutex to allow hwbinder to re-enter agian.
+  std::recursive_mutex mutex_;
+  SessionType session_type_;
+
+  // audio control path to use for both software and offloading
+  sp<IBluetoothAudioPort> stack_iface_;
+  // audio data path (FMQ) for software encoding
+  std::unique_ptr<DataMQ> mDataMQ;
+  // audio data configuration for both software and offloading
+  AudioConfiguration audio_config_;
+
+  static AudioConfiguration invalidSoftwareAudioConfiguration;
+  static AudioConfiguration invalidOffloadAudioConfiguration;
+
+  // saving those registered bluetooth_audio's callbacks
+  std::unordered_map<uint16_t, std::shared_ptr<struct PortStatusCallbacks>>
+      observers_;
+
+  bool UpdateDataPath(const DataMQ::Descriptor* dataMQ);
+  bool UpdateAudioConfig(const AudioConfiguration& audio_config);
+  // invoking the registered session_changed_cb_
+  void ReportSessionStatus();
+
+ public:
+  BluetoothAudioSession(const SessionType& session_type);
+
+  // The function helps to check if this session is ready or not
+  // @return: true if the Bluetooth stack has started the specified session
+  bool IsSessionReady();
+
+  // The report function is used to report that the Bluetooth stack has started
+  // this session without any failure, and will invoke session_changed_cb_ to
+  // notify those registered bluetooth_audio outputs
+  void OnSessionStarted(const sp<IBluetoothAudioPort> stack_iface,
+                        const DataMQ::Descriptor* dataMQ,
+                        const AudioConfiguration& audio_config);
+
+  // The report function is used to report that the Bluetooth stack has ended
+  // the session, and will invoke session_changed_cb_ to notify registered
+  // bluetooth_audio outputs
+  void OnSessionEnded();
+
+  // The report function is used to report that the Bluetooth stack has notified
+  // the result of startStream or suspendStream, and will invoke
+  // control_result_cb_ to notify registered bluetooth_audio outputs
+  void ReportControlStatus(bool start_resp, const BluetoothAudioStatus& status);
+
+  // The control function helps the bluetooth_audio module to register
+  // PortStatusCallbacks
+  // @return: cookie - the assigned number to this bluetooth_audio output
+  uint16_t RegisterStatusCback(const PortStatusCallbacks& cbacks);
+
+  // The control function helps the bluetooth_audio module to unregister
+  // PortStatusCallbacks
+  // @param: cookie - indicates which bluetooth_audio output is
+  void UnregisterStatusCback(uint16_t cookie);
+
+  // The control function is for the bluetooth_audio module to get the current
+  // AudioConfiguration
+  const AudioConfiguration& GetAudioConfig();
+
+  // Those control functions are for the bluetooth_audio module to start,
+  // suspend, stop stream, to check position, and to update metadata.
+  bool StartStream();
+  bool SuspendStream();
+  void StopStream();
+  bool GetPresentationPosition(uint64_t* remote_delay_report_ns,
+                               uint64_t* total_bytes_readed,
+                               timespec* data_position);
+  void UpdateTracksMetadata(const struct source_metadata* source_metadata);
+
+  // The control function writes stream to FMQ
+  size_t OutWritePcmData(const void* buffer, size_t bytes);
+
+  static constexpr PcmParameters kInvalidPcmParameters = {
+      .sampleRate = SampleRate::RATE_UNKNOWN,
+      .bitsPerSample = BitsPerSample::BITS_UNKNOWN,
+      .channelMode = ChannelMode::UNKNOWN};
+  // can't be constexpr because of non-literal type
+  static const CodecConfiguration kInvalidCodecConfiguration;
+
+  static constexpr AudioConfiguration& kInvalidSoftwareAudioConfiguration =
+      invalidSoftwareAudioConfiguration;
+  static constexpr AudioConfiguration& kInvalidOffloadAudioConfiguration =
+      invalidOffloadAudioConfiguration;
+};
+
+class BluetoothAudioSessionInstance {
+ public:
+  // The API is to fetch the specified session of A2DP / Hearing Aid
+  static std::shared_ptr<BluetoothAudioSession> GetSessionInstance(
+      const SessionType& session_type);
+
+ private:
+  static std::unique_ptr<BluetoothAudioSessionInstance> instance_ptr;
+  std::mutex mutex_;
+  std::unordered_map<SessionType, std::shared_ptr<BluetoothAudioSession>>
+      sessions_map_;
+};
+
+}  // namespace audio
+}  // namespace bluetooth
+}  // namespace android
diff --git a/bluetooth/audio/2.0/default/session/BluetoothAudioSessionControl.h b/bluetooth/audio/2.0/default/session/BluetoothAudioSessionControl.h
new file mode 100644
index 0000000..6707765
--- /dev/null
+++ b/bluetooth/audio/2.0/default/session/BluetoothAudioSessionControl.h
@@ -0,0 +1,143 @@
+/*
+ * Copyright 2018 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.
+ */
+
+#pragma once
+
+#include "BluetoothAudioSession.h"
+
+namespace android {
+namespace bluetooth {
+namespace audio {
+
+class BluetoothAudioSessionControl {
+ public:
+  // The control API helps to check if session is ready or not
+  // @return: true if the Bluetooth stack has started th specified session
+  static bool IsSessionReady(const SessionType& session_type) {
+    std::shared_ptr<BluetoothAudioSession> session_ptr =
+        BluetoothAudioSessionInstance::GetSessionInstance(session_type);
+    if (session_ptr != nullptr) {
+      return session_ptr->IsSessionReady();
+    }
+    return false;
+  }
+
+  // The control API helps the bluetooth_audio module to register
+  // PortStatusCallbacks
+  // @return: cookie - the assigned number to this bluetooth_audio output
+  static uint16_t RegisterControlResultCback(
+      const SessionType& session_type, const PortStatusCallbacks& cbacks) {
+    std::shared_ptr<BluetoothAudioSession> session_ptr =
+        BluetoothAudioSessionInstance::GetSessionInstance(session_type);
+    if (session_ptr != nullptr) {
+      return session_ptr->RegisterStatusCback(cbacks);
+    }
+    return kObserversCookieUndefined;
+  }
+
+  // The control API helps the bluetooth_audio module to unregister
+  // PortStatusCallbacks
+  // @param: cookie - indicates which bluetooth_audio output is
+  static void UnregisterControlResultCback(const SessionType& session_type,
+                                           uint16_t cookie) {
+    std::shared_ptr<BluetoothAudioSession> session_ptr =
+        BluetoothAudioSessionInstance::GetSessionInstance(session_type);
+    if (session_ptr != nullptr) {
+      session_ptr->UnregisterStatusCback(cookie);
+    }
+  }
+
+  // The control API for the bluetooth_audio module to get current
+  // AudioConfiguration
+  static const AudioConfiguration& GetAudioConfig(
+      const SessionType& session_type) {
+    std::shared_ptr<BluetoothAudioSession> session_ptr =
+        BluetoothAudioSessionInstance::GetSessionInstance(session_type);
+    if (session_ptr != nullptr) {
+      return session_ptr->GetAudioConfig();
+    } else if (session_type == SessionType::A2DP_HARDWARE_OFFLOAD_DATAPATH) {
+      return BluetoothAudioSession::kInvalidOffloadAudioConfiguration;
+    } else {
+      return BluetoothAudioSession::kInvalidSoftwareAudioConfiguration;
+    }
+  }
+
+  // Those control APIs for the bluetooth_audio module to start / suspend / stop
+  // stream, to check position, and to update metadata.
+  static bool StartStream(const SessionType& session_type) {
+    std::shared_ptr<BluetoothAudioSession> session_ptr =
+        BluetoothAudioSessionInstance::GetSessionInstance(session_type);
+    if (session_ptr != nullptr) {
+      return session_ptr->StartStream();
+    }
+    return false;
+  }
+
+  static bool SuspendStream(const SessionType& session_type) {
+    std::shared_ptr<BluetoothAudioSession> session_ptr =
+        BluetoothAudioSessionInstance::GetSessionInstance(session_type);
+    if (session_ptr != nullptr) {
+      return session_ptr->SuspendStream();
+    }
+    return false;
+  }
+
+  static void StopStream(const SessionType& session_type) {
+    std::shared_ptr<BluetoothAudioSession> session_ptr =
+        BluetoothAudioSessionInstance::GetSessionInstance(session_type);
+    if (session_ptr != nullptr) {
+      session_ptr->StopStream();
+    }
+  }
+
+  static bool GetPresentationPosition(const SessionType& session_type,
+                                      uint64_t* remote_delay_report_ns,
+                                      uint64_t* total_bytes_readed,
+                                      timespec* data_position) {
+    std::shared_ptr<BluetoothAudioSession> session_ptr =
+        BluetoothAudioSessionInstance::GetSessionInstance(session_type);
+    if (session_ptr != nullptr) {
+      return session_ptr->GetPresentationPosition(
+          remote_delay_report_ns, total_bytes_readed, data_position);
+    }
+    return false;
+  }
+
+  static void UpdateTracksMetadata(
+      const SessionType& session_type,
+      const struct source_metadata* source_metadata) {
+    std::shared_ptr<BluetoothAudioSession> session_ptr =
+        BluetoothAudioSessionInstance::GetSessionInstance(session_type);
+    if (session_ptr != nullptr) {
+      session_ptr->UpdateTracksMetadata(source_metadata);
+    }
+  }
+
+  // The control API writes stream to FMQ
+  static size_t OutWritePcmData(const SessionType& session_type,
+                                const void* buffer, size_t bytes) {
+    std::shared_ptr<BluetoothAudioSession> session_ptr =
+        BluetoothAudioSessionInstance::GetSessionInstance(session_type);
+    if (session_ptr != nullptr) {
+      return session_ptr->OutWritePcmData(buffer, bytes);
+    }
+    return 0;
+  }
+};
+
+}  // namespace audio
+}  // namespace bluetooth
+}  // namespace android
diff --git a/bluetooth/audio/2.0/default/session/BluetoothAudioSessionReport.h b/bluetooth/audio/2.0/default/session/BluetoothAudioSessionReport.h
new file mode 100644
index 0000000..5a83ae2
--- /dev/null
+++ b/bluetooth/audio/2.0/default/session/BluetoothAudioSessionReport.h
@@ -0,0 +1,63 @@
+/*
+ * Copyright 2018 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.
+ */
+
+#pragma once
+
+#include "BluetoothAudioSession.h"
+
+namespace android {
+namespace bluetooth {
+namespace audio {
+
+class BluetoothAudioSessionReport {
+ public:
+  // The API reports the Bluetooth stack has started the session, and will
+  // inform registered bluetooth_audio outputs
+  static void OnSessionStarted(const SessionType& session_type,
+                               const sp<IBluetoothAudioPort> host_iface,
+                               const DataMQ::Descriptor* dataMQ,
+                               const AudioConfiguration& audio_config) {
+    std::shared_ptr<BluetoothAudioSession> session_ptr =
+        BluetoothAudioSessionInstance::GetSessionInstance(session_type);
+    if (session_ptr != nullptr) {
+      session_ptr->OnSessionStarted(host_iface, dataMQ, audio_config);
+    }
+  }
+  // The API reports the Bluetooth stack has ended the session, and will
+  // inform registered bluetooth_audio outputs
+  static void OnSessionEnded(const SessionType& session_type) {
+    std::shared_ptr<BluetoothAudioSession> session_ptr =
+        BluetoothAudioSessionInstance::GetSessionInstance(session_type);
+    if (session_ptr != nullptr) {
+      session_ptr->OnSessionEnded();
+    }
+  }
+  // The API reports the Bluetooth stack has replied the result of startStream
+  // or suspendStream, and will inform registered bluetooth_audio outputs
+  static void ReportControlStatus(const SessionType& session_type,
+                                  const bool& start_resp,
+                                  const BluetoothAudioStatus& status) {
+    std::shared_ptr<BluetoothAudioSession> session_ptr =
+        BluetoothAudioSessionInstance::GetSessionInstance(session_type);
+    if (session_ptr != nullptr) {
+      session_ptr->ReportControlStatus(start_resp, status);
+    }
+  }
+};
+
+}  // namespace audio
+}  // namespace bluetooth
+}  // namespace android
diff --git a/bluetooth/audio/2.0/default/session/BluetoothAudioSupportedCodecsDB.cpp b/bluetooth/audio/2.0/default/session/BluetoothAudioSupportedCodecsDB.cpp
new file mode 100644
index 0000000..292e28b
--- /dev/null
+++ b/bluetooth/audio/2.0/default/session/BluetoothAudioSupportedCodecsDB.cpp
@@ -0,0 +1,413 @@
+/*
+ * Copyright 2018 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_TAG "BTAudioProviderSessionCodecsDB"
+
+#include "BluetoothAudioSupportedCodecsDB.h"
+
+#include <android-base/logging.h>
+
+namespace android {
+namespace bluetooth {
+namespace audio {
+
+using ::android::hardware::bluetooth::audio::V2_0::AacObjectType;
+using ::android::hardware::bluetooth::audio::V2_0::AacParameters;
+using ::android::hardware::bluetooth::audio::V2_0::AacVariableBitRate;
+using ::android::hardware::bluetooth::audio::V2_0::AptxParameters;
+using ::android::hardware::bluetooth::audio::V2_0::BitsPerSample;
+using ::android::hardware::bluetooth::audio::V2_0::ChannelMode;
+using ::android::hardware::bluetooth::audio::V2_0::CodecType;
+using ::android::hardware::bluetooth::audio::V2_0::LdacChannelMode;
+using ::android::hardware::bluetooth::audio::V2_0::LdacParameters;
+using ::android::hardware::bluetooth::audio::V2_0::LdacQualityIndex;
+using ::android::hardware::bluetooth::audio::V2_0::SampleRate;
+using ::android::hardware::bluetooth::audio::V2_0::SbcAllocMethod;
+using ::android::hardware::bluetooth::audio::V2_0::SbcBlockLength;
+using ::android::hardware::bluetooth::audio::V2_0::SbcChannelMode;
+using ::android::hardware::bluetooth::audio::V2_0::SbcNumSubbands;
+using ::android::hardware::bluetooth::audio::V2_0::SbcParameters;
+
+// Default Supported PCM Parameters
+static const PcmParameters kDefaultSoftwarePcmCapabilities = {
+    .sampleRate = static_cast<SampleRate>(
+        SampleRate::RATE_44100 | SampleRate::RATE_48000 |
+        SampleRate::RATE_88200 | SampleRate::RATE_96000 |
+        SampleRate::RATE_16000 | SampleRate::RATE_24000),
+    .channelMode =
+        static_cast<ChannelMode>(ChannelMode::MONO | ChannelMode::STEREO),
+    .bitsPerSample = static_cast<BitsPerSample>(BitsPerSample::BITS_16 |
+                                                BitsPerSample::BITS_24 |
+                                                BitsPerSample::BITS_32)};
+
+// Default Supported Codecs
+// SBC: mSampleRate:(44100), mBitsPerSample:(16), mChannelMode:(MONO|STEREO)
+//      all blocks | subbands 8 | Loudness
+static const SbcParameters kDefaultOffloadSbcCapability = {
+    .sampleRate = SampleRate::RATE_44100,
+    .channelMode = static_cast<SbcChannelMode>(SbcChannelMode::MONO |
+                                               SbcChannelMode::JOINT_STEREO),
+    .blockLength = static_cast<SbcBlockLength>(
+        SbcBlockLength::BLOCKS_4 | SbcBlockLength::BLOCKS_8 |
+        SbcBlockLength::BLOCKS_12 | SbcBlockLength::BLOCKS_16),
+    .numSubbands = SbcNumSubbands::SUBBAND_8,
+    .allocMethod = SbcAllocMethod::ALLOC_MD_L,
+    .bitsPerSample = BitsPerSample::BITS_16,
+    .minBitpool = 2,
+    .maxBitpool = 53};
+
+// AAC: mSampleRate:(44100), mBitsPerSample:(16), mChannelMode:(STEREO)
+static const AacParameters kDefaultOffloadAacCapability = {
+    .objectType = AacObjectType::MPEG2_LC,
+    .sampleRate = SampleRate::RATE_44100,
+    .channelMode = ChannelMode::STEREO,
+    .variableBitRateEnabled = AacVariableBitRate::DISABLED,
+    .bitsPerSample = BitsPerSample::BITS_16};
+
+// LDAC: mSampleRate:(44100|48000|88200|96000), mBitsPerSample:(16|24|32),
+//       mChannelMode:(DUAL|STEREO)
+static const LdacParameters kDefaultOffloadLdacCapability = {
+    .sampleRate = static_cast<SampleRate>(
+        SampleRate::RATE_44100 | SampleRate::RATE_48000 |
+        SampleRate::RATE_88200 | SampleRate::RATE_96000),
+    .channelMode = static_cast<LdacChannelMode>(LdacChannelMode::DUAL |
+                                                LdacChannelMode::STEREO),
+    .qualityIndex = LdacQualityIndex::QUALITY_HIGH,
+    .bitsPerSample = static_cast<BitsPerSample>(BitsPerSample::BITS_16 |
+                                                BitsPerSample::BITS_24 |
+                                                BitsPerSample::BITS_32)};
+
+// aptX: mSampleRate:(44100|48000), mBitsPerSample:(16), mChannelMode:(STEREO)
+static const AptxParameters kDefaultOffloadAptxCapability = {
+    .sampleRate = static_cast<SampleRate>(SampleRate::RATE_44100 |
+                                          SampleRate::RATE_48000),
+    .bitsPerSample = BitsPerSample::BITS_16,
+    .channelMode = ChannelMode::STEREO};
+
+// aptX HD: mSampleRate:(44100|48000), mBitsPerSample:(24),
+//          mChannelMode:(STEREO)
+static const AptxParameters kDefaultOffloadAptxHdCapability = {
+    .sampleRate = static_cast<SampleRate>(SampleRate::RATE_44100 |
+                                          SampleRate::RATE_48000),
+    .bitsPerSample = BitsPerSample::BITS_24,
+    .channelMode = ChannelMode::STEREO};
+
+const std::vector<CodecCapabilities> kDefaultOffloadA2dpCodecCapabilities = {
+    {.codecType = CodecType::SBC, .capabilities = {}},
+    {.codecType = CodecType::AAC, .capabilities = {}},
+    {.codecType = CodecType::LDAC, .capabilities = {}},
+    {.codecType = CodecType::APTX, .capabilities = {}},
+    {.codecType = CodecType::APTX_HD, .capabilities = {}}};
+
+static bool IsSingleBit(uint32_t bitmasks, uint32_t bitfield) {
+  bool single = false;
+  uint32_t test_bit = 0x00000001;
+  while (test_bit <= bitmasks && test_bit <= bitfield) {
+    if (bitfield & test_bit && bitmasks & test_bit) {
+      if (single) return false;
+      single = true;
+    }
+    if (test_bit == 0x80000000) break;
+    test_bit <<= 1;
+  }
+  return single;
+}
+
+static bool IsOffloadSbcConfigurationValid(
+    const CodecConfiguration::CodecSpecific& codec_specific);
+static bool IsOffloadAacConfigurationValid(
+    const CodecConfiguration::CodecSpecific& codec_specific);
+static bool IsOffloadLdacConfigurationValid(
+    const CodecConfiguration::CodecSpecific& codec_specific);
+static bool IsOffloadAptxConfigurationValid(
+    const CodecConfiguration::CodecSpecific& codec_specific);
+static bool IsOffloadAptxHdConfigurationValid(
+    const CodecConfiguration::CodecSpecific& codec_specific);
+
+static bool IsOffloadSbcConfigurationValid(
+    const CodecConfiguration::CodecSpecific& codec_specific) {
+  if (codec_specific.getDiscriminator() !=
+      CodecConfiguration::CodecSpecific::hidl_discriminator::sbcConfig) {
+    LOG(WARNING) << __func__
+                 << ": Invalid CodecSpecific=" << toString(codec_specific);
+    return false;
+  }
+  const SbcParameters sbc_data = codec_specific.sbcConfig();
+  if (!IsSingleBit(static_cast<uint32_t>(sbc_data.sampleRate), 0xff) ||
+      !IsSingleBit(static_cast<uint32_t>(sbc_data.channelMode), 0x0f) ||
+      !IsSingleBit(static_cast<uint32_t>(sbc_data.blockLength), 0xf0) ||
+      !IsSingleBit(static_cast<uint32_t>(sbc_data.numSubbands), 0x0c) ||
+      !IsSingleBit(static_cast<uint32_t>(sbc_data.allocMethod), 0x03) ||
+      !IsSingleBit(static_cast<uint32_t>(sbc_data.bitsPerSample), 0x07) ||
+      sbc_data.minBitpool > sbc_data.maxBitpool) {
+    LOG(WARNING) << __func__
+                 << ": Invalid CodecSpecific=" << toString(codec_specific);
+    return false;
+  } else if ((sbc_data.sampleRate & kDefaultOffloadSbcCapability.sampleRate) &&
+             (sbc_data.channelMode &
+              kDefaultOffloadSbcCapability.channelMode) &&
+             (sbc_data.blockLength &
+              kDefaultOffloadSbcCapability.blockLength) &&
+             (sbc_data.numSubbands &
+              kDefaultOffloadSbcCapability.numSubbands) &&
+             (sbc_data.allocMethod &
+              kDefaultOffloadSbcCapability.allocMethod) &&
+             (sbc_data.bitsPerSample &
+              kDefaultOffloadSbcCapability.bitsPerSample) &&
+             (kDefaultOffloadSbcCapability.minBitpool <= sbc_data.minBitpool &&
+              sbc_data.maxBitpool <= kDefaultOffloadSbcCapability.maxBitpool)) {
+    return true;
+  }
+  LOG(WARNING) << __func__
+               << ": Unsupported CodecSpecific=" << toString(codec_specific);
+  return false;
+}
+
+static bool IsOffloadAacConfigurationValid(
+    const CodecConfiguration::CodecSpecific& codec_specific) {
+  if (codec_specific.getDiscriminator() !=
+      CodecConfiguration::CodecSpecific::hidl_discriminator::aacConfig) {
+    LOG(WARNING) << __func__
+                 << ": Invalid CodecSpecific=" << toString(codec_specific);
+    return false;
+  }
+  const AacParameters aac_data = codec_specific.aacConfig();
+  if (!IsSingleBit(static_cast<uint32_t>(aac_data.objectType), 0xf0) ||
+      !IsSingleBit(static_cast<uint32_t>(aac_data.sampleRate), 0xff) ||
+      !IsSingleBit(static_cast<uint32_t>(aac_data.channelMode), 0x03) ||
+      !IsSingleBit(static_cast<uint32_t>(aac_data.bitsPerSample), 0x07)) {
+    LOG(WARNING) << __func__
+                 << ": Invalid CodecSpecific=" << toString(codec_specific);
+    return false;
+  } else if ((aac_data.objectType & kDefaultOffloadAacCapability.objectType) &&
+             (aac_data.sampleRate & kDefaultOffloadAacCapability.sampleRate) &&
+             (aac_data.channelMode &
+              kDefaultOffloadAacCapability.channelMode) &&
+             (aac_data.variableBitRateEnabled == AacVariableBitRate::DISABLED ||
+              kDefaultOffloadAacCapability.variableBitRateEnabled ==
+                  AacVariableBitRate::ENABLED) &&
+             (aac_data.bitsPerSample &
+              kDefaultOffloadAacCapability.bitsPerSample)) {
+    return true;
+  }
+  LOG(WARNING) << __func__
+               << ": Unsupported CodecSpecific=" << toString(codec_specific);
+  return false;
+}
+
+static bool IsOffloadLdacConfigurationValid(
+    const CodecConfiguration::CodecSpecific& codec_specific) {
+  if (codec_specific.getDiscriminator() !=
+      CodecConfiguration::CodecSpecific::hidl_discriminator::ldacConfig) {
+    LOG(WARNING) << __func__
+                 << ": Invalid CodecSpecific=" << toString(codec_specific);
+    return false;
+  }
+  const LdacParameters ldac_data = codec_specific.ldacConfig();
+  if (!IsSingleBit(static_cast<uint32_t>(ldac_data.sampleRate), 0xff) ||
+      !IsSingleBit(static_cast<uint32_t>(ldac_data.channelMode), 0x07) ||
+      (ldac_data.qualityIndex > LdacQualityIndex::QUALITY_LOW &&
+       ldac_data.qualityIndex != LdacQualityIndex::QUALITY_ABR) ||
+      !IsSingleBit(static_cast<uint32_t>(ldac_data.bitsPerSample), 0x07)) {
+    LOG(WARNING) << __func__
+                 << ": Invalid CodecSpecific=" << toString(codec_specific);
+    return false;
+  } else if ((ldac_data.sampleRate &
+              kDefaultOffloadLdacCapability.sampleRate) &&
+             (ldac_data.channelMode &
+              kDefaultOffloadLdacCapability.channelMode) &&
+             (ldac_data.bitsPerSample &
+              kDefaultOffloadLdacCapability.bitsPerSample)) {
+    return true;
+  }
+  LOG(WARNING) << __func__
+               << ": Unsupported CodecSpecific=" << toString(codec_specific);
+  return false;
+}
+
+static bool IsOffloadAptxConfigurationValid(
+    const CodecConfiguration::CodecSpecific& codec_specific) {
+  if (codec_specific.getDiscriminator() !=
+      CodecConfiguration::CodecSpecific::hidl_discriminator::aptxConfig) {
+    LOG(WARNING) << __func__
+                 << ": Invalid CodecSpecific=" << toString(codec_specific);
+    return false;
+  }
+  const AptxParameters aptx_data = codec_specific.aptxConfig();
+  if (!IsSingleBit(static_cast<uint32_t>(aptx_data.sampleRate), 0xff) ||
+      !IsSingleBit(static_cast<uint32_t>(aptx_data.channelMode), 0x03) ||
+      !IsSingleBit(static_cast<uint32_t>(aptx_data.bitsPerSample), 0x07)) {
+    LOG(WARNING) << __func__
+                 << ": Invalid CodecSpecific=" << toString(codec_specific);
+    return false;
+  } else if ((aptx_data.sampleRate &
+              kDefaultOffloadAptxCapability.sampleRate) &&
+             (aptx_data.channelMode &
+              kDefaultOffloadAptxCapability.channelMode) &&
+             (aptx_data.bitsPerSample &
+              kDefaultOffloadAptxCapability.bitsPerSample)) {
+    return true;
+  }
+  LOG(WARNING) << __func__
+               << ": Unsupported CodecSpecific=" << toString(codec_specific);
+  return false;
+}
+
+static bool IsOffloadAptxHdConfigurationValid(
+    const CodecConfiguration::CodecSpecific& codec_specific) {
+  if (codec_specific.getDiscriminator() !=
+      CodecConfiguration::CodecSpecific::hidl_discriminator::aptxConfig) {
+    LOG(WARNING) << __func__
+                 << ": Invalid CodecSpecific=" << toString(codec_specific);
+    return false;
+  }
+  const AptxParameters aptx_data = codec_specific.aptxConfig();
+  if (!IsSingleBit(static_cast<uint32_t>(aptx_data.sampleRate), 0xff) ||
+      !IsSingleBit(static_cast<uint32_t>(aptx_data.channelMode), 0x03) ||
+      !IsSingleBit(static_cast<uint32_t>(aptx_data.bitsPerSample), 0x07)) {
+    LOG(WARNING) << __func__
+                 << ": Invalid CodecSpecific=" << toString(codec_specific);
+    return false;
+  } else if ((aptx_data.sampleRate &
+              kDefaultOffloadAptxHdCapability.sampleRate) &&
+             (aptx_data.channelMode &
+              kDefaultOffloadAptxHdCapability.channelMode) &&
+             (aptx_data.bitsPerSample &
+              kDefaultOffloadAptxHdCapability.bitsPerSample)) {
+    return true;
+  }
+  LOG(WARNING) << __func__
+               << ": Unsupported CodecSpecific=" << toString(codec_specific);
+  return false;
+}
+
+std::vector<PcmParameters> GetSoftwarePcmCapabilities() {
+  return std::vector<PcmParameters>(1, kDefaultSoftwarePcmCapabilities);
+}
+
+std::vector<CodecCapabilities> GetOffloadCodecCapabilities(
+    const SessionType& session_type) {
+  if (session_type != SessionType::A2DP_HARDWARE_OFFLOAD_DATAPATH) {
+    return std::vector<CodecCapabilities>(0);
+  }
+  std::vector<CodecCapabilities> offload_a2dp_codec_capabilities =
+      kDefaultOffloadA2dpCodecCapabilities;
+  for (auto& codec_capability : offload_a2dp_codec_capabilities) {
+    switch (codec_capability.codecType) {
+      case CodecType::SBC:
+        codec_capability.capabilities.sbcCapabilities(
+            kDefaultOffloadSbcCapability);
+        break;
+      case CodecType::AAC:
+        codec_capability.capabilities.aacCapabilities(
+            kDefaultOffloadAacCapability);
+        break;
+      case CodecType::LDAC:
+        codec_capability.capabilities.ldacCapabilities(
+            kDefaultOffloadLdacCapability);
+        break;
+      case CodecType::APTX:
+        codec_capability.capabilities.aptxCapabilities(
+            kDefaultOffloadAptxCapability);
+        break;
+      case CodecType::APTX_HD:
+        codec_capability.capabilities.aptxCapabilities(
+            kDefaultOffloadAptxHdCapability);
+        break;
+      case CodecType::UNKNOWN:
+        codec_capability = {};
+        break;
+    }
+  }
+  return offload_a2dp_codec_capabilities;
+}
+
+bool IsSoftwarePcmConfigurationValid(const PcmParameters& pcm_config) {
+  if ((pcm_config.sampleRate != SampleRate::RATE_44100 &&
+       pcm_config.sampleRate != SampleRate::RATE_48000 &&
+       pcm_config.sampleRate != SampleRate::RATE_88200 &&
+       pcm_config.sampleRate != SampleRate::RATE_96000 &&
+       pcm_config.sampleRate != SampleRate::RATE_16000 &&
+       pcm_config.sampleRate != SampleRate::RATE_24000) ||
+      (pcm_config.bitsPerSample != BitsPerSample::BITS_16 &&
+       pcm_config.bitsPerSample != BitsPerSample::BITS_24 &&
+       pcm_config.bitsPerSample != BitsPerSample::BITS_32) ||
+      (pcm_config.channelMode != ChannelMode::MONO &&
+       pcm_config.channelMode != ChannelMode::STEREO)) {
+    LOG(WARNING) << __func__
+                 << ": Invalid PCM Configuration=" << toString(pcm_config);
+    return false;
+  } else if (pcm_config.sampleRate &
+                 kDefaultSoftwarePcmCapabilities.sampleRate &&
+             pcm_config.bitsPerSample &
+                 kDefaultSoftwarePcmCapabilities.bitsPerSample &&
+             pcm_config.channelMode &
+                 kDefaultSoftwarePcmCapabilities.channelMode) {
+    return true;
+  }
+  LOG(WARNING) << __func__
+               << ": Unsupported PCM Configuration=" << toString(pcm_config);
+  return false;
+}
+
+bool IsOffloadCodecConfigurationValid(const SessionType& session_type,
+                                      const CodecConfiguration& codec_config) {
+  if (session_type != SessionType::A2DP_HARDWARE_OFFLOAD_DATAPATH) {
+    LOG(ERROR) << __func__
+               << ": Invalid SessionType=" << toString(session_type);
+    return false;
+  } else if (codec_config.encodedAudioBitrate < 0x00000001 ||
+             0x00ffffff < codec_config.encodedAudioBitrate) {
+    LOG(ERROR) << __func__ << ": Unsupported Codec Configuration="
+               << toString(codec_config);
+    return false;
+  }
+  const CodecConfiguration::CodecSpecific& codec_specific = codec_config.config;
+  switch (codec_config.codecType) {
+    case CodecType::SBC:
+      if (IsOffloadSbcConfigurationValid(codec_specific)) {
+        return true;
+      }
+      return false;
+    case CodecType::AAC:
+      if (IsOffloadAacConfigurationValid(codec_specific)) {
+        return true;
+      }
+      return false;
+    case CodecType::LDAC:
+      if (IsOffloadLdacConfigurationValid(codec_specific)) {
+        return true;
+      }
+      return false;
+    case CodecType::APTX:
+      if (IsOffloadAptxConfigurationValid(codec_specific)) {
+        return true;
+      }
+      return false;
+    case CodecType::APTX_HD:
+      if (IsOffloadAptxHdConfigurationValid(codec_specific)) {
+        return true;
+      }
+      return false;
+    case CodecType::UNKNOWN:
+      return false;
+  }
+  return false;
+}
+
+}  // namespace audio
+}  // namespace bluetooth
+}  // namespace android
diff --git a/bluetooth/audio/2.0/default/session/BluetoothAudioSupportedCodecsDB.h b/bluetooth/audio/2.0/default/session/BluetoothAudioSupportedCodecsDB.h
new file mode 100644
index 0000000..e71dc8a
--- /dev/null
+++ b/bluetooth/audio/2.0/default/session/BluetoothAudioSupportedCodecsDB.h
@@ -0,0 +1,40 @@
+/*
+ * Copyright 2018 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.
+ */
+
+#pragma once
+
+#include <android/hardware/bluetooth/audio/2.0/types.h>
+
+namespace android {
+namespace bluetooth {
+namespace audio {
+
+using ::android::hardware::bluetooth::audio::V2_0::CodecCapabilities;
+using ::android::hardware::bluetooth::audio::V2_0::CodecConfiguration;
+using ::android::hardware::bluetooth::audio::V2_0::PcmParameters;
+using ::android::hardware::bluetooth::audio::V2_0::SessionType;
+
+std::vector<PcmParameters> GetSoftwarePcmCapabilities();
+std::vector<CodecCapabilities> GetOffloadCodecCapabilities(
+    const SessionType& session_type);
+
+bool IsSoftwarePcmConfigurationValid(const PcmParameters& pcm_config);
+bool IsOffloadCodecConfigurationValid(const SessionType& session_type,
+                                      const CodecConfiguration& codec_config);
+
+}  // namespace audio
+}  // namespace bluetooth
+}  // namespace android