Codec Extensibility A2DP HAL Reference Implementation

Test: m
Bug: 297037759
Change-Id: I84b32c2ef22da8c3e920e497501b9f16feaf803c

bluetooth/audio/aidl/default/A2dpBits.h

@@ -0,0 +1,73 @@
+/*
+ * Copyright (C) 2023 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
+
+namespace aidl::android::hardware::bluetooth::audio {
+
+class A2dpBits {
+  const uint8_t* cdata_;
+  uint8_t* data_;
+
+ public:
+  A2dpBits(const std::vector<uint8_t>& vector) : cdata_(vector.data()) {}
+
+  A2dpBits(std::vector<uint8_t>& vector)
+      : cdata_(vector.data()), data_(vector.data()) {}
+
+  struct Range {
+    const int first, len;
+    constexpr Range(int first, int last)
+        : first(first), len(last - first + 1) {}
+    constexpr Range(int index) : first(index), len(1) {}
+  };
+
+  constexpr bool get(int bit) const {
+    return (cdata_[bit >> 3] >> (7 - (bit & 7))) & 1;
+  }
+
+  constexpr unsigned get(const Range& range) const {
+    unsigned v(0);
+    for (int i = 0; i < range.len; i++)
+      v |= get(range.first + i) << ((range.len - 1) - i);
+    return v;
+  }
+
+  constexpr void set(int bit, int value = 1) {
+    uint8_t m = 1 << (7 - (bit & 7));
+    if (value)
+      data_[bit >> 3] |= m;
+    else
+      data_[bit >> 3] &= ~m;
+  }
+
+  constexpr void set(const Range& range, int value) {
+    for (int i = 0; i < range.len; i++)
+      set(range.first + i, (value >> ((range.len - 1) - i)) & 1);
+  }
+
+  constexpr int find_active_bit(const Range& range) const {
+    unsigned v = get(range);
+    int i = 0;
+    for (; i < range.len && ((v >> i) & 1) == 0; i++)
+      ;
+    return i < range.len && (v ^ (1 << i)) == 0
+               ? range.first + (range.len - 1) - i
+               : -1;
+  }
+};
+
+}  // namespace aidl::android::hardware::bluetooth::audio

bluetooth/audio/aidl/default/A2dpOffloadAudioProvider.cpp

@@ -22,6 +22,10 @@
 #include <BluetoothAudioSessionReport.h>
 #include <android-base/logging.h>
 
+#include "A2dpOffloadCodecAac.h"
+#include "A2dpOffloadCodecFactory.h"
+#include "A2dpOffloadCodecSbc.h"
+
 namespace aidl {
 namespace android {
 namespace hardware {
@@ -48,19 +52,44 @@ ndk::ScopedAStatus A2dpOffloadAudioProvider::startSession(
     const std::shared_ptr<IBluetoothAudioPort>& host_if,
     const AudioConfiguration& audio_config,
     const std::vector<LatencyMode>& latency_modes, DataMQDesc* _aidl_return) {
-  if (audio_config.getTag() != AudioConfiguration::a2dpConfig) {
+  if (audio_config.getTag() == AudioConfiguration::Tag::a2dp) {
-    LOG(WARNING) << __func__ << " - Invalid Audio Configuration="
+    auto a2dp_config = audio_config.get<AudioConfiguration::Tag::a2dp>();
-                 << audio_config.toString();
+    A2dpStatus a2dp_status = A2dpStatus::NOT_SUPPORTED_CODEC_TYPE;
-    *_aidl_return = DataMQDesc();
+
-    return ndk::ScopedAStatus::fromExceptionCode(EX_ILLEGAL_ARGUMENT);
+    if (a2dp_config.codecId ==
-  }
+        A2dpOffloadCodecSbc::GetInstance()->GetCodecId()) {
-  if (!BluetoothAudioCodecs::IsOffloadCodecConfigurationValid(
+      SbcParameters sbc_parameters;
-          session_type_, audio_config.get<AudioConfiguration::a2dpConfig>())) {
+      a2dp_status = A2dpOffloadCodecSbc::GetInstance()->ParseConfiguration(
+          a2dp_config.configuration, &sbc_parameters);
+
+    } else if (a2dp_config.codecId ==
+               A2dpOffloadCodecAac::GetInstance()->GetCodecId()) {
+      AacParameters aac_parameters;
+      a2dp_status = A2dpOffloadCodecAac::GetInstance()->ParseConfiguration(
+          a2dp_config.configuration, &aac_parameters);
+    }
+    if (a2dp_status != A2dpStatus::OK) {
+      LOG(WARNING) << __func__ << " - Invalid Audio Configuration="
+                   << audio_config.toString();
+      *_aidl_return = DataMQDesc();
+      return ndk::ScopedAStatus::fromExceptionCode(EX_ILLEGAL_ARGUMENT);
+    }
+  } else if (audio_config.getTag() == AudioConfiguration::Tag::a2dpConfig) {
+    if (!BluetoothAudioCodecs::IsOffloadCodecConfigurationValid(
+            session_type_,
+            audio_config.get<AudioConfiguration::a2dpConfig>())) {
+      LOG(WARNING) << __func__ << " - Invalid Audio Configuration="
+                   << audio_config.toString();
+      *_aidl_return = DataMQDesc();
+      return ndk::ScopedAStatus::fromExceptionCode(EX_ILLEGAL_ARGUMENT);
+    }
+  } else {
     LOG(WARNING) << __func__ << " - Invalid Audio Configuration="
                  << audio_config.toString();
     *_aidl_return = DataMQDesc();
     return ndk::ScopedAStatus::fromExceptionCode(EX_ILLEGAL_ARGUMENT);
   }
+
   return BluetoothAudioProvider::startSession(
       host_if, audio_config, latency_modes, _aidl_return);
 }
@@ -73,6 +102,36 @@ ndk::ScopedAStatus A2dpOffloadAudioProvider::onSessionReady(
   return ndk::ScopedAStatus::ok();
 }
 
+ndk::ScopedAStatus A2dpOffloadAudioProvider::parseA2dpConfiguration(
+    const CodecId& codec_id, const std::vector<uint8_t>& configuration,
+    CodecParameters* codec_parameters, A2dpStatus* _aidl_return) {
+  auto codec = A2dpOffloadCodecFactory::GetInstance()->GetCodec(codec_id);
+  if (!codec) {
+    LOG(INFO) << __func__ << " - SessionType=" << toString(session_type_)
+              << " - CodecId=" << codec_id.toString() << " is not found";
+    return ndk::ScopedAStatus::fromExceptionCode(EX_ILLEGAL_ARGUMENT);
+  }
+
+  *_aidl_return = codec->ParseConfiguration(configuration, codec_parameters);
+
+  return ndk::ScopedAStatus::ok();
+}
+
+ndk::ScopedAStatus A2dpOffloadAudioProvider::getA2dpConfiguration(
+    const std::vector<A2dpRemoteCapabilities>& remote_a2dp_capabilities,
+    const A2dpConfigurationHint& hint,
+    std::optional<audio::A2dpConfiguration>* _aidl_return) {
+  *_aidl_return = std::nullopt;
+  A2dpConfiguration avdtp_configuration;
+
+  if (A2dpOffloadCodecFactory::GetInstance()->GetConfiguration(
+          remote_a2dp_capabilities, hint, &avdtp_configuration))
+    *_aidl_return =
+        std::make_optional<A2dpConfiguration>(std::move(avdtp_configuration));
+
+  return ndk::ScopedAStatus::ok();
+}
+
 }  // namespace audio
 }  // namespace bluetooth
 }  // namespace hardware

bluetooth/audio/aidl/default/A2dpOffloadAudioProvider.h

@@ -34,7 +34,16 @@ class A2dpOffloadAudioProvider : public BluetoothAudioProvider {
       const std::shared_ptr<IBluetoothAudioPort>& host_if,
       const AudioConfiguration& audio_config,
       const std::vector<LatencyMode>& latency_modes,
-      DataMQDesc* _aidl_return);
+      DataMQDesc* _aidl_return) override;
+
+  ndk::ScopedAStatus parseA2dpConfiguration(
+      const CodecId& codec_id, const std::vector<uint8_t>& configuration,
+      CodecParameters* codec_parameters, A2dpStatus* _aidl_return) override;
+
+  ndk::ScopedAStatus getA2dpConfiguration(
+      const std::vector<A2dpRemoteCapabilities>& remote_a2dp_capabilities,
+      const A2dpConfigurationHint& hint,
+      std::optional<audio::A2dpConfiguration>* _aidl_return) override;
 
  private:
   ndk::ScopedAStatus onSessionReady(DataMQDesc* _aidl_return) override;

bluetooth/audio/aidl/default/A2dpOffloadCodec.h

@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2023 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 <aidl/android/hardware/bluetooth/audio/A2dpStatus.h>
+#include <aidl/android/hardware/bluetooth/audio/ChannelMode.h>
+#include <aidl/android/hardware/bluetooth/audio/CodecParameters.h>
+
+#include "BluetoothAudioProviderFactory.h"
+
+namespace aidl::android::hardware::bluetooth::audio {
+
+class A2dpOffloadCodec {
+ protected:
+  A2dpOffloadCodec(const CodecInfo& info) : info(info) {}
+  virtual ~A2dpOffloadCodec() {}
+
+ public:
+  const CodecInfo& info;
+
+  const CodecId& GetCodecId() const { return info.id; }
+
+  virtual A2dpStatus ParseConfiguration(
+      const std::vector<uint8_t>& configuration,
+      CodecParameters* codec_parameters) const = 0;
+
+  virtual bool BuildConfiguration(
+      const std::vector<uint8_t>& remote_capabilities,
+      const std::optional<CodecParameters>& hint,
+      std::vector<uint8_t>* configuration) const = 0;
+};
+
+}  // namespace aidl::android::hardware::bluetooth::audio

bluetooth/audio/aidl/default/A2dpOffloadCodecAac.cpp

@@ -0,0 +1,378 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "A2dpOffloadCodecAac.h"
+
+#include "A2dpBits.h"
+
+namespace aidl::android::hardware::bluetooth::audio {
+
+/**
+ * AAC Local Capabilities
+ */
+
+enum : bool {
+  kEnableObjectTypeMpeg2AacLc = true,
+  kEnableObjectTypeMpeg4AacLc = true,
+};
+
+enum : bool {
+  kEnableSamplingFrequency44100 = true,
+  kEnableSamplingFrequency48000 = true,
+  kEnableSamplingFrequency88200 = false,
+  kEnableSamplingFrequency96000 = false,
+};
+
+enum : bool {
+  kEnableChannels1 = true,
+  kEnableChannels2 = true,
+};
+
+enum : bool {
+  kEnableVbrSupported = true,
+};
+
+enum : int {
+  kBitdepth = 24,
+};
+
+/**
+ * AAC Signaling format [A2DP - 4.5]
+ */
+
+// clang-format off
+
+constexpr A2dpBits::Range kObjectType        (  0,  6 );
+constexpr A2dpBits::Range kDrcEnable         (  7     );
+constexpr A2dpBits::Range kSamplingFrequency (  8, 19 );
+constexpr A2dpBits::Range kChannels          ( 20, 23 );
+constexpr A2dpBits::Range kVbrSupported      ( 24     );
+constexpr A2dpBits::Range kBitrate           ( 25, 47 );
+constexpr size_t kCapabilitiesSize = 48/8;
+
+// clang-format on
+
+enum {
+  kObjectTypeMpeg2AacLc = kObjectType.first,
+  kObjectTypeMpeg4AacLc,
+  kObjectTypeMpeg4AacLtp,
+  kObjectTypeMpeg4AacScalable,
+  kObjectTypeMpeg4AacHeV1,
+  kObjectTypeMpeg4AacHeV2,
+  kObjectTypeMpeg4AacEldV2
+};
+
+enum {
+  kSamplingFrequency8000 = kSamplingFrequency.first,
+  kSamplingFrequency11025,
+  kSamplingFrequency12000,
+  kSamplingFrequency16000,
+  kSamplingFrequency22050,
+  kSamplingFrequency24000,
+  kSamplingFrequency32000,
+  kSamplingFrequency44100,
+  kSamplingFrequency48000,
+  kSamplingFrequency64000,
+  kSamplingFrequency88200,
+  kSamplingFrequency96000
+};
+
+enum { kChannels1 = kChannels.first, kChannels2, kChannels51, kChannels71 };
+
+/**
+ * AAC Conversion functions
+ */
+
+static AacParameters::ObjectType GetObjectTypeEnum(int object_type) {
+  switch (object_type) {
+    case kObjectTypeMpeg2AacLc:
+      return AacParameters::ObjectType::MPEG2_AAC_LC;
+    case kObjectTypeMpeg4AacLc:
+    default:
+      return AacParameters::ObjectType::MPEG4_AAC_LC;
+  }
+}
+
+static int GetSamplingFrequencyBit(int32_t sampling_frequency) {
+  switch (sampling_frequency) {
+    case 8000:
+      return kSamplingFrequency8000;
+    case 11025:
+      return kSamplingFrequency11025;
+    case 12000:
+      return kSamplingFrequency12000;
+    case 16000:
+      return kSamplingFrequency16000;
+    case 22050:
+      return kSamplingFrequency22050;
+    case 24000:
+      return kSamplingFrequency24000;
+    case 32000:
+      return kSamplingFrequency32000;
+    case 44100:
+      return kSamplingFrequency44100;
+    case 48000:
+      return kSamplingFrequency48000;
+    case 64000:
+      return kSamplingFrequency64000;
+    case 88200:
+      return kSamplingFrequency88200;
+    case 96000:
+      return kSamplingFrequency96000;
+    default:
+      return -1;
+  }
+}
+
+static int32_t GetSamplingFrequencyValue(int sampling_frequency) {
+  switch (sampling_frequency) {
+    case kSamplingFrequency8000:
+      return 8000;
+    case kSamplingFrequency11025:
+      return 11025;
+    case kSamplingFrequency12000:
+      return 12000;
+    case kSamplingFrequency16000:
+      return 16000;
+    case kSamplingFrequency22050:
+      return 22050;
+    case kSamplingFrequency24000:
+      return 24000;
+    case kSamplingFrequency32000:
+      return 32000;
+    case kSamplingFrequency44100:
+      return 44100;
+    case kSamplingFrequency48000:
+      return 48000;
+    case kSamplingFrequency64000:
+      return 64000;
+    case kSamplingFrequency88200:
+      return 88200;
+    case kSamplingFrequency96000:
+      return 96000;
+    default:
+      return 0;
+  }
+}
+
+static int GetChannelsBit(ChannelMode channel_mode) {
+  switch (channel_mode) {
+    case ChannelMode::MONO:
+      return kChannels1;
+    case ChannelMode::STEREO:
+      return kChannels2;
+    default:
+      return -1;
+  }
+}
+
+static ChannelMode GetChannelModeEnum(int channel_mode) {
+  switch (channel_mode) {
+    case kChannels1:
+      return ChannelMode::MONO;
+    case kChannels2:
+      return ChannelMode::STEREO;
+    default:
+      return ChannelMode::UNKNOWN;
+  }
+}
+
+/**
+ * AAC Class implementation
+ */
+
+const A2dpOffloadCodecAac* A2dpOffloadCodecAac::GetInstance() {
+  static A2dpOffloadCodecAac instance;
+  return &instance;
+}
+
+A2dpOffloadCodecAac::A2dpOffloadCodecAac()
+    : A2dpOffloadCodec(info_),
+      info_({.id = CodecId(CodecId::A2dp::AAC), .name = "AAC"}) {
+  info_.transport.set<CodecInfo::Transport::Tag::a2dp>();
+  auto& a2dp_info = info_.transport.get<CodecInfo::Transport::Tag::a2dp>();
+
+  /* --- Setup Capabilities --- */
+
+  a2dp_info.capabilities.resize(kCapabilitiesSize);
+  std::fill(begin(a2dp_info.capabilities), end(a2dp_info.capabilities), 0);
+
+  auto capabilities = A2dpBits(a2dp_info.capabilities);
+
+  capabilities.set(kObjectTypeMpeg2AacLc, kEnableObjectTypeMpeg2AacLc);
+  capabilities.set(kObjectTypeMpeg4AacLc, kEnableObjectTypeMpeg4AacLc);
+
+  capabilities.set(kSamplingFrequency44100, kEnableSamplingFrequency44100);
+  capabilities.set(kSamplingFrequency48000, kEnableSamplingFrequency48000);
+  capabilities.set(kSamplingFrequency88200, kEnableSamplingFrequency88200);
+  capabilities.set(kSamplingFrequency96000, kEnableSamplingFrequency96000);
+
+  capabilities.set(kChannels1, kEnableChannels1);
+  capabilities.set(kChannels2, kEnableChannels2);
+
+  capabilities.set(kVbrSupported, kEnableVbrSupported);
+
+  /* --- Setup Sampling Frequencies --- */
+
+  auto& sampling_frequency = a2dp_info.samplingFrequencyHz;
+
+  for (auto v : {8000, 11025, 12000, 16000, 22050, 24000, 32000, 44100, 48000,
+                 64000, 88200, 96000})
+    if (capabilities.get(GetSamplingFrequencyBit(int32_t(v))))
+      sampling_frequency.push_back(v);
+
+  /* --- Setup Channel Modes --- */
+
+  auto& channel_modes = a2dp_info.channelMode;
+
+  for (auto v : {ChannelMode::MONO, ChannelMode::STEREO})
+    if (capabilities.get(GetChannelsBit(v))) channel_modes.push_back(v);
+
+  /* --- Setup Bitdepth --- */
+
+  a2dp_info.bitdepth.push_back(kBitdepth);
+}
+
+A2dpStatus A2dpOffloadCodecAac::ParseConfiguration(
+    const std::vector<uint8_t>& configuration,
+    CodecParameters* codec_parameters, AacParameters* aac_parameters) const {
+  auto& a2dp_info = info.transport.get<CodecInfo::Transport::Tag::a2dp>();
+
+  if (configuration.size() != a2dp_info.capabilities.size())
+    return A2dpStatus::BAD_LENGTH;
+
+  auto config = A2dpBits(configuration);
+  auto lcaps = A2dpBits(a2dp_info.capabilities);
+
+  /* --- Check Object Type --- */
+
+  int object_type = config.find_active_bit(kObjectType);
+  if (object_type < 0) return A2dpStatus::INVALID_OBJECT_TYPE;
+  if (!lcaps.get(object_type)) return A2dpStatus::NOT_SUPPORTED_OBJECT_TYPE;
+
+  /* --- Check Sampling Frequency --- */
+
+  int sampling_frequency = config.find_active_bit(kSamplingFrequency);
+  if (sampling_frequency < 0) return A2dpStatus::INVALID_SAMPLING_FREQUENCY;
+  if (!lcaps.get(sampling_frequency))
+    return A2dpStatus::NOT_SUPPORTED_SAMPLING_FREQUENCY;
+
+  /* --- Check Channels --- */
+
+  int channels = config.find_active_bit(kChannels);
+  if (channels < 0) return A2dpStatus::INVALID_CHANNELS;
+  if (!lcaps.get(channels)) return A2dpStatus::NOT_SUPPORTED_CHANNELS;
+
+  /* --- Check Bitrate --- */
+
+  bool vbr = config.get(kVbrSupported);
+  if (vbr && !lcaps.get(kVbrSupported)) return A2dpStatus::NOT_SUPPORTED_VBR;
+
+  int bitrate = config.get(kBitrate);
+  if (vbr && lcaps.get(kBitrate) && bitrate > lcaps.get(kBitrate))
+    return A2dpStatus::NOT_SUPPORTED_BIT_RATE;
+
+  /* --- Return --- */
+
+  codec_parameters->channelMode = GetChannelModeEnum(channels);
+  codec_parameters->samplingFrequencyHz =
+      GetSamplingFrequencyValue(sampling_frequency);
+  codec_parameters->bitdepth = kBitdepth;
+
+  codec_parameters->minBitrate = vbr ? 0 : bitrate;
+  codec_parameters->maxBitrate = bitrate;
+
+  if (aac_parameters)
+    aac_parameters->object_type = GetObjectTypeEnum(object_type);
+
+  return A2dpStatus::OK;
+}
+
+bool A2dpOffloadCodecAac::BuildConfiguration(
+    const std::vector<uint8_t>& remote_capabilities,
+    const std::optional<CodecParameters>& hint,
+    std::vector<uint8_t>* configuration) const {
+  auto& a2dp_info = info_.transport.get<CodecInfo::Transport::Tag::a2dp>();
+
+  if (remote_capabilities.size() != a2dp_info.capabilities.size()) return false;
+
+  auto lcaps = A2dpBits(a2dp_info.capabilities);
+  auto rcaps = A2dpBits(remote_capabilities);
+
+  configuration->resize(a2dp_info.capabilities.size());
+  std::fill(begin(*configuration), end(*configuration), 0);
+  auto config = A2dpBits(*configuration);
+
+  /* --- Select Object Type --- */
+
+  if (lcaps.get(kObjectTypeMpeg2AacLc) && rcaps.get(kObjectTypeMpeg2AacLc))
+    config.set(kObjectTypeMpeg2AacLc);
+  else if (lcaps.get(kObjectTypeMpeg4AacLc) && rcaps.get(kObjectTypeMpeg4AacLc))
+    config.set(kObjectTypeMpeg4AacLc);
+  else
+    return false;
+
+  /* --- Select Sampling Frequency --- */
+
+  auto sf_hint = hint ? GetSamplingFrequencyBit(hint->samplingFrequencyHz) : -1;
+
+  if (sf_hint >= 0 && lcaps.get(sf_hint) && rcaps.get(sf_hint))
+    config.set(sf_hint);
+  else if (lcaps.get(kSamplingFrequency96000) &&
+           rcaps.get(kSamplingFrequency96000))
+    config.set(kSamplingFrequency96000);
+  else if (lcaps.get(kSamplingFrequency88200) &&
+           rcaps.get(kSamplingFrequency88200))
+    config.set(kSamplingFrequency88200);
+  else if (lcaps.get(kSamplingFrequency48000) &&
+           rcaps.get(kSamplingFrequency48000))
+    config.set(kSamplingFrequency48000);
+  else if (lcaps.get(kSamplingFrequency44100) &&
+           rcaps.get(kSamplingFrequency44100))
+    config.set(kSamplingFrequency44100);
+  else
+    return false;
+
+  /* --- Select Channels --- */
+
+  auto ch_hint = hint ? GetChannelsBit(hint->channelMode) : -1;
+
+  if (ch_hint >= 0 && lcaps.get(ch_hint) && rcaps.get(ch_hint))
+    config.set(ch_hint);
+  else if (lcaps.get(kChannels2) && rcaps.get(kChannels2))
+    config.set(kChannels2);
+  else if (lcaps.get(kChannels1) && rcaps.get(kChannels1))
+    config.set(kChannels1);
+  else
+    return false;
+
+  /* --- Select Bitrate --- */
+
+  if (!hint || hint->minBitrate == 0)
+    config.set(kVbrSupported,
+               lcaps.get(kVbrSupported) && rcaps.get(kVbrSupported));
+
+  int32_t bitrate = lcaps.get(kBitrate);
+  if (hint && hint->maxBitrate > 0 && bitrate)
+    bitrate = std::min(hint->maxBitrate, bitrate);
+  else if (hint && hint->maxBitrate > 0)
+    bitrate = hint->maxBitrate;
+  config.set(kBitrate, bitrate);
+
+  return true;
+}
+
+}  // namespace aidl::android::hardware::bluetooth::audio

bluetooth/audio/aidl/default/A2dpOffloadCodecAac.h

@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2023 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 "A2dpOffloadCodec.h"
+
+namespace aidl::android::hardware::bluetooth::audio {
+
+struct AacParameters : public CodecParameters {
+  enum class ObjectType { MPEG2_AAC_LC, MPEG4_AAC_LC };
+
+  ObjectType object_type;
+};
+
+class A2dpOffloadCodecAac : public A2dpOffloadCodec {
+  CodecInfo info_;
+
+  A2dpOffloadCodecAac();
+
+  A2dpStatus ParseConfiguration(const std::vector<uint8_t>& configuration,
+                                CodecParameters* codec_parameters,
+                                AacParameters* aac_parameters) const;
+
+ public:
+  static const A2dpOffloadCodecAac* GetInstance();
+
+  A2dpStatus ParseConfiguration(
+      const std::vector<uint8_t>& configuration,
+      CodecParameters* codec_parameters) const override {
+    return ParseConfiguration(configuration, codec_parameters, nullptr);
+  }
+
+  A2dpStatus ParseConfiguration(const std::vector<uint8_t>& configuration,
+                                AacParameters* aac_parameters) const {
+    return ParseConfiguration(configuration, aac_parameters, aac_parameters);
+  }
+
+  bool BuildConfiguration(const std::vector<uint8_t>& remote_capabilities,
+                          const std::optional<CodecParameters>& hint,
+                          std::vector<uint8_t>* configuration) const override;
+};
+
+}  // namespace aidl::android::hardware::bluetooth::audio

bluetooth/audio/aidl/default/A2dpOffloadCodecFactory.cpp

@@ -0,0 +1,100 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "A2dpOffloadCodecFactory.h"
+
+#include <algorithm>
+#include <cassert>
+
+#include "A2dpOffloadCodecAac.h"
+#include "A2dpOffloadCodecSbc.h"
+
+namespace aidl::android::hardware::bluetooth::audio {
+
+/**
+ * Local Capabilities Configuration
+ */
+
+enum : bool {
+  kEnableAac = true,
+  kEnableSbc = true,
+};
+
+/**
+ * Class implementation
+ */
+
+const A2dpOffloadCodecFactory* A2dpOffloadCodecFactory::GetInstance() {
+  static A2dpOffloadCodecFactory instance;
+  return &instance;
+}
+
+A2dpOffloadCodecFactory::A2dpOffloadCodecFactory()
+    : name("Offload"), codecs(ranked_codecs_) {
+  ranked_codecs_.reserve(kEnableAac + kEnableSbc);
+
+  if (kEnableAac) ranked_codecs_.push_back(A2dpOffloadCodecAac::GetInstance());
+  if (kEnableSbc) ranked_codecs_.push_back(A2dpOffloadCodecSbc::GetInstance());
+}
+
+const A2dpOffloadCodec* A2dpOffloadCodecFactory::GetCodec(CodecId id) const {
+  auto codec = std::find_if(begin(ranked_codecs_), end(ranked_codecs_),
+                            [&](auto c) { return id == c->info.id; });
+
+  return codec != end(ranked_codecs_) ? *codec : nullptr;
+}
+
+bool A2dpOffloadCodecFactory::GetConfiguration(
+    const std::vector<A2dpRemoteCapabilities>& remote_capabilities,
+    const A2dpConfigurationHint& hint, A2dpConfiguration* configuration) const {
+  decltype(ranked_codecs_) codecs;
+
+  codecs.reserve(ranked_codecs_.size());
+
+  auto hinted_codec =
+      std::find_if(begin(ranked_codecs_), end(ranked_codecs_),
+                   [&](auto c) { return hint.codecId == c->info.id; });
+
+  if (hinted_codec != end(ranked_codecs_)) codecs.push_back(*hinted_codec);
+
+  std::copy_if(begin(ranked_codecs_), end(ranked_codecs_),
+               std::back_inserter(codecs),
+               [&](auto c) { return c != *hinted_codec; });
+
+  for (auto codec : codecs) {
+    auto rc =
+        std::find_if(begin(remote_capabilities), end(remote_capabilities),
+                     [&](auto& rc__) { return codec->info.id == rc__.id; });
+
+    if ((rc == end(remote_capabilities)) ||
+        !codec->BuildConfiguration(rc->capabilities, hint.codecParameters,
+                                   &configuration->configuration))
+      continue;
+
+    configuration->id = codec->info.id;
+    A2dpStatus status = codec->ParseConfiguration(configuration->configuration,
+                                                  &configuration->parameters);
+    assert(status == A2dpStatus::OK);
+
+    configuration->remoteSeid = rc->seid;
+
+    return true;
+  }
+
+  return false;
+}
+
+}  // namespace aidl::android::hardware::bluetooth::audio

bluetooth/audio/aidl/default/A2dpOffloadCodecFactory.h

@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2023 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 "A2dpOffloadCodec.h"
+
+namespace aidl::android::hardware::bluetooth::audio {
+
+class A2dpOffloadCodecFactory {
+  std::vector<const A2dpOffloadCodec*> ranked_codecs_;
+
+  A2dpOffloadCodecFactory();
+
+ public:
+  const std::string name;
+  const std::vector<const A2dpOffloadCodec*>& codecs;
+
+  static const A2dpOffloadCodecFactory* GetInstance();
+
+  const A2dpOffloadCodec* GetCodec(CodecId id) const;
+
+  bool GetConfiguration(const std::vector<A2dpRemoteCapabilities>&,
+                        const A2dpConfigurationHint& hint,
+                        A2dpConfiguration* configuration) const;
+};
+
+}  // namespace aidl::android::hardware::bluetooth::audio

bluetooth/audio/aidl/default/A2dpOffloadCodecSbc.cpp

@@ -0,0 +1,510 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "A2dpOffloadCodecSbc.h"
+
+#include <algorithm>
+
+#include "A2dpBits.h"
+
+namespace aidl::android::hardware::bluetooth::audio {
+
+/**
+ * SBC Local Capabilities
+ */
+
+enum : bool {
+  kEnableSamplingFrequency44100 = true,
+  kEnableSamplingFrequency48000 = true,
+};
+
+enum : bool {
+  kEnableChannelModeMono = true,
+  kEnableChannelModeDualChannel = true,
+  kEnableChannelModeStereo = true,
+  kEnableChannelModeJointStereo = true,
+};
+
+enum : bool {
+  kEnableBlockLength4 = true,
+  kEnableBlockLength8 = true,
+  kEnableBlockLength12 = true,
+  kEnableBlockLength16 = true,
+};
+
+enum : bool {
+  kEnableSubbands4 = true,
+  kEnableSubbands8 = true,
+};
+
+enum : bool {
+  kEnableAllocationMethodSnr = true,
+  kEnableAllocationMethodLoudness = true,
+};
+
+enum : uint8_t {
+  kDefaultMinimumBitpool = 2,
+  kDefaultMaximumBitpool = 250,
+};
+
+enum : int {
+  kBitdepth = 16,
+};
+
+/**
+ * SBC Signaling format [A2DP - 4.3]
+ */
+
+// clang-format off
+
+constexpr A2dpBits::Range kSamplingFrequency (  0,  3 );
+constexpr A2dpBits::Range kChannelMode       (  4,  7 );
+constexpr A2dpBits::Range kBlockLength       (  8, 11 );
+constexpr A2dpBits::Range kSubbands          ( 12, 13 );
+constexpr A2dpBits::Range kAllocationMethod  ( 14, 15 );
+constexpr A2dpBits::Range kMinimumBitpool    ( 16, 23 );
+constexpr A2dpBits::Range kMaximumBitpool    ( 24, 31 );
+constexpr size_t kCapabilitiesSize = 32/8;
+
+// clang-format on
+
+enum {
+  kSamplingFrequency16000 = kSamplingFrequency.first,
+  kSamplingFrequency32000,
+  kSamplingFrequency44100,
+  kSamplingFrequency48000
+};
+
+enum {
+  kChannelModeMono = kChannelMode.first,
+  kChannelModeDualChannel,
+  kChannelModeStereo,
+  kChannelModeJointStereo
+};
+
+enum {
+  kBlockLength4 = kBlockLength.first,
+  kBlockLength8,
+  kBlockLength12,
+  kBlockLength16
+};
+
+enum { kSubbands8 = kSubbands.first, kSubbands4 };
+
+enum {
+  kAllocationMethodSnr = kAllocationMethod.first,
+  kAllocationMethodLoudness
+};
+
+/**
+ * SBC Conversion functions
+ */
+
+static int GetSamplingFrequencyBit(int32_t sampling_frequency) {
+  switch (sampling_frequency) {
+    case 16000:
+      return kSamplingFrequency16000;
+    case 32000:
+      return kSamplingFrequency32000;
+    case 44100:
+      return kSamplingFrequency44100;
+    case 48000:
+      return kSamplingFrequency48000;
+    default:
+      return -1;
+  }
+}
+
+static int32_t GetSamplingFrequencyValue(int sampling_frequency) {
+  switch (sampling_frequency) {
+    case kSamplingFrequency16000:
+      return 16000;
+    case kSamplingFrequency32000:
+      return 32000;
+    case kSamplingFrequency44100:
+      return 44100;
+    case kSamplingFrequency48000:
+      return 48000;
+    default:
+      return 0;
+  }
+}
+
+static int GetChannelModeBit(ChannelMode channel_mode) {
+  switch (channel_mode) {
+    case ChannelMode::STEREO:
+      return kChannelModeJointStereo | kChannelModeStereo;
+    case ChannelMode::DUALMONO:
+      return kChannelModeDualChannel;
+    case ChannelMode::MONO:
+      return kChannelModeMono;
+    default:
+      return -1;
+  }
+}
+
+static ChannelMode GetChannelModeEnum(int channel_mode) {
+  switch (channel_mode) {
+    case kChannelModeMono:
+      return ChannelMode::MONO;
+    case kChannelModeDualChannel:
+      return ChannelMode::DUALMONO;
+    case kChannelModeStereo:
+    case kChannelModeJointStereo:
+      return ChannelMode::STEREO;
+    default:
+      return ChannelMode::UNKNOWN;
+  }
+}
+
+static int32_t GetBlockLengthValue(int block_length) {
+  switch (block_length) {
+    case kBlockLength4:
+      return 4;
+    case kBlockLength8:
+      return 8;
+    case kBlockLength12:
+      return 12;
+    case kBlockLength16:
+      return 16;
+    default:
+      return 0;
+  }
+}
+
+static int32_t GetSubbandsValue(int subbands) {
+  switch (subbands) {
+    case kSubbands4:
+      return 4;
+    case kSubbands8:
+      return 8;
+    default:
+      return 0;
+  }
+}
+
+static SbcParameters::AllocationMethod GetAllocationMethodEnum(
+    int allocation_method) {
+  switch (allocation_method) {
+    case kAllocationMethodSnr:
+      return SbcParameters::AllocationMethod::SNR;
+    case kAllocationMethodLoudness:
+    default:
+      return SbcParameters::AllocationMethod::LOUDNESS;
+  }
+}
+
+static int32_t GetSamplingFrequencyValue(const A2dpBits& configuration) {
+  return GetSamplingFrequencyValue(
+      configuration.find_active_bit(kSamplingFrequency));
+}
+
+static int32_t GetBlockLengthValue(const A2dpBits& configuration) {
+  return GetBlockLengthValue(configuration.find_active_bit(kBlockLength));
+}
+
+static int32_t GetSubbandsValue(const A2dpBits& configuration) {
+  return GetSubbandsValue(configuration.find_active_bit(kSubbands));
+}
+
+static int GetFrameSize(const A2dpBits& configuration, int bitpool) {
+  const int kSbcHeaderSize = 4;
+  int subbands = GetSubbandsValue(configuration);
+  int blocks = GetBlockLengthValue(configuration);
+
+  unsigned bits =
+      ((4 * subbands) << !configuration.get(kChannelModeMono)) +
+      ((blocks * bitpool) << configuration.get(kChannelModeDualChannel)) +
+      ((configuration.get(kChannelModeJointStereo) ? subbands : 0));
+
+  return kSbcHeaderSize + ((bits + 7) >> 3);
+}
+
+static int GetBitrate(const A2dpBits& configuration, int bitpool) {
+  int sampling_frequency = GetSamplingFrequencyValue(configuration);
+  int subbands = GetSubbandsValue(configuration);
+  int blocks = GetBlockLengthValue(configuration);
+  int bits = 8 * GetFrameSize(configuration, bitpool);
+
+  return (bits * sampling_frequency) / (blocks * subbands);
+}
+
+static uint8_t GetBitpool(const A2dpBits& configuration, int bitrate) {
+  int bitpool = 0;
+
+  for (int i = 128; i; i >>= 1)
+    if (bitrate > GetBitrate(configuration, bitpool + i)) {
+      bitpool += i;
+    }
+
+  return std::clamp(bitpool, 2, 250);
+}
+
+/**
+ * SBC Class implementation
+ */
+
+const A2dpOffloadCodecSbc* A2dpOffloadCodecSbc::GetInstance() {
+  static A2dpOffloadCodecSbc instance;
+  return &instance;
+}
+
+A2dpOffloadCodecSbc::A2dpOffloadCodecSbc()
+    : A2dpOffloadCodec(info_),
+      info_({.id = CodecId(CodecId::A2dp::SBC), .name = "SBC"}) {
+  info_.transport.set<CodecInfo::Transport::Tag::a2dp>();
+  auto& a2dp_info = info_.transport.get<CodecInfo::Transport::Tag::a2dp>();
+
+  /* --- Setup Capabilities --- */
+
+  a2dp_info.capabilities.resize(kCapabilitiesSize);
+  std::fill(begin(a2dp_info.capabilities), end(a2dp_info.capabilities), 0);
+
+  auto capabilities = A2dpBits(a2dp_info.capabilities);
+
+  capabilities.set(kSamplingFrequency44100, kEnableSamplingFrequency44100);
+  capabilities.set(kSamplingFrequency48000, kEnableSamplingFrequency48000);
+
+  capabilities.set(kChannelModeMono, kEnableChannelModeMono);
+  capabilities.set(kChannelModeDualChannel, kEnableChannelModeDualChannel);
+  capabilities.set(kChannelModeStereo, kEnableChannelModeStereo);
+  capabilities.set(kChannelModeJointStereo, kEnableChannelModeJointStereo);
+
+  capabilities.set(kBlockLength4, kEnableBlockLength4);
+  capabilities.set(kBlockLength8, kEnableBlockLength8);
+  capabilities.set(kBlockLength12, kEnableBlockLength12);
+  capabilities.set(kBlockLength16, kEnableBlockLength16);
+
+  capabilities.set(kSubbands4, kEnableSubbands4);
+  capabilities.set(kSubbands8, kEnableSubbands8);
+
+  capabilities.set(kSubbands4, kEnableSubbands4);
+  capabilities.set(kSubbands8, kEnableSubbands8);
+
+  capabilities.set(kAllocationMethodSnr, kEnableAllocationMethodSnr);
+  capabilities.set(kAllocationMethodLoudness, kEnableAllocationMethodLoudness);
+
+  capabilities.set(kMinimumBitpool, kDefaultMinimumBitpool);
+  capabilities.set(kMaximumBitpool, kDefaultMaximumBitpool);
+
+  /* --- Setup Sampling Frequencies --- */
+
+  auto& sampling_frequency = a2dp_info.samplingFrequencyHz;
+
+  for (auto v : {16000, 32000, 44100, 48000})
+    if (capabilities.get(GetSamplingFrequencyBit(int32_t(v))))
+      sampling_frequency.push_back(v);
+
+  /* --- Setup Channel Modes --- */
+
+  auto& channel_modes = a2dp_info.channelMode;
+
+  for (auto v : {ChannelMode::MONO, ChannelMode::DUALMONO, ChannelMode::STEREO})
+    if (capabilities.get(GetChannelModeBit(v))) channel_modes.push_back(v);
+
+  /* --- Setup Bitdepth --- */
+
+  a2dp_info.bitdepth.push_back(kBitdepth);
+}
+
+A2dpStatus A2dpOffloadCodecSbc::ParseConfiguration(
+    const std::vector<uint8_t>& configuration,
+    CodecParameters* codec_parameters, SbcParameters* sbc_parameters) const {
+  auto& a2dp_info = info.transport.get<CodecInfo::Transport::Tag::a2dp>();
+
+  if (configuration.size() != a2dp_info.capabilities.size())
+    return A2dpStatus::BAD_LENGTH;
+
+  auto config = A2dpBits(configuration);
+  auto lcaps = A2dpBits(a2dp_info.capabilities);
+
+  /* --- Check Sampling Frequency --- */
+
+  int sampling_frequency = config.find_active_bit(kSamplingFrequency);
+  if (sampling_frequency < 0) return A2dpStatus::INVALID_SAMPLING_FREQUENCY;
+  if (!lcaps.get(sampling_frequency))
+    return A2dpStatus::NOT_SUPPORTED_SAMPLING_FREQUENCY;
+
+  /* --- Check Channel Mode --- */
+
+  int channel_mode = config.find_active_bit(kChannelMode);
+  if (channel_mode < 0) return A2dpStatus::INVALID_CHANNEL_MODE;
+  if (!lcaps.get(channel_mode)) return A2dpStatus::NOT_SUPPORTED_CHANNEL_MODE;
+
+  /* --- Check Block Length --- */
+
+  int block_length = config.find_active_bit(kBlockLength);
+  if (block_length < 0) return A2dpStatus::INVALID_BLOCK_LENGTH;
+
+  /* --- Check Subbands --- */
+
+  int subbands = config.find_active_bit(kSubbands);
+  if (subbands < 0) return A2dpStatus::INVALID_SUBBANDS;
+  if (!lcaps.get(subbands)) return A2dpStatus::NOT_SUPPORTED_SUBBANDS;
+
+  /* --- Check Allocation Method --- */
+
+  int allocation_method = config.find_active_bit(kAllocationMethod);
+  if (allocation_method < 0) return A2dpStatus::INVALID_ALLOCATION_METHOD;
+  if (!lcaps.get(allocation_method))
+    return A2dpStatus::NOT_SUPPORTED_ALLOCATION_METHOD;
+
+  /* --- Check Bitpool --- */
+
+  uint8_t min_bitpool = config.get(kMinimumBitpool);
+  if (min_bitpool < 2 || min_bitpool > 250)
+    return A2dpStatus::INVALID_MINIMUM_BITPOOL_VALUE;
+  if (min_bitpool < lcaps.get(kMinimumBitpool))
+    return A2dpStatus::NOT_SUPPORTED_MINIMUM_BITPOOL_VALUE;
+
+  uint8_t max_bitpool = config.get(kMaximumBitpool);
+  if (max_bitpool < 2 || max_bitpool > 250)
+    return A2dpStatus::INVALID_MAXIMUM_BITPOOL_VALUE;
+  if (max_bitpool > lcaps.get(kMaximumBitpool))
+    return A2dpStatus::NOT_SUPPORTED_MAXIMUM_BITPOOL_VALUE;
+
+  /* --- Return --- */
+
+  codec_parameters->channelMode = GetChannelModeEnum(channel_mode);
+  codec_parameters->samplingFrequencyHz =
+      GetSamplingFrequencyValue(sampling_frequency);
+  codec_parameters->bitdepth = kBitdepth;
+
+  codec_parameters->minBitrate = GetBitrate(config, min_bitpool);
+  codec_parameters->maxBitrate = GetBitrate(config, max_bitpool);
+
+  if (sbc_parameters) {
+    sbc_parameters->block_length = GetBlockLengthValue(block_length);
+    sbc_parameters->subbands = GetSubbandsValue(subbands);
+    sbc_parameters->allocation_method =
+        GetAllocationMethodEnum(allocation_method);
+    sbc_parameters->min_bitpool = min_bitpool;
+    sbc_parameters->max_bitpool = max_bitpool;
+  }
+
+  return A2dpStatus::OK;
+}
+
+bool A2dpOffloadCodecSbc::BuildConfiguration(
+    const std::vector<uint8_t>& remote_capabilities,
+    const std::optional<CodecParameters>& hint,
+    std::vector<uint8_t>* configuration) const {
+  auto& a2dp_info = info.transport.get<CodecInfo::Transport::Tag::a2dp>();
+
+  if (remote_capabilities.size() != a2dp_info.capabilities.size()) return false;
+
+  auto lcaps = A2dpBits(a2dp_info.capabilities);
+  auto rcaps = A2dpBits(remote_capabilities);
+
+  configuration->resize(a2dp_info.capabilities.size());
+  std::fill(begin(*configuration), end(*configuration), 0);
+  auto config = A2dpBits(*configuration);
+
+  /* --- Select Sampling Frequency --- */
+
+  auto sf_hint = hint ? GetSamplingFrequencyBit(hint->samplingFrequencyHz) : -1;
+
+  if (sf_hint >= 0 && lcaps.get(sf_hint) && rcaps.get(sf_hint))
+    config.set(sf_hint);
+  else if (lcaps.get(kSamplingFrequency44100) &&
+           rcaps.get(kSamplingFrequency44100))
+    config.set(kSamplingFrequency44100);
+  else if (lcaps.get(kSamplingFrequency48000) &&
+           rcaps.get(kSamplingFrequency48000))
+    config.set(kSamplingFrequency48000);
+  else
+    return false;
+
+  /* --- Select Channel Mode --- */
+
+  auto cm_hint = hint ? GetChannelModeBit(hint->channelMode) : -1;
+
+  if (cm_hint >= 0 && lcaps.get(cm_hint) && rcaps.get(cm_hint))
+    config.set(cm_hint);
+  else if (lcaps.get(kChannelModeJointStereo) &&
+           rcaps.get(kChannelModeJointStereo))
+    config.set(kChannelModeJointStereo);
+  else if (lcaps.get(kChannelModeStereo) && rcaps.get(kChannelModeStereo))
+    config.set(kChannelModeStereo);
+  else if (lcaps.get(kChannelModeDualChannel) &&
+           rcaps.get(kChannelModeDualChannel))
+    config.set(kChannelModeDualChannel);
+  else if (lcaps.get(kChannelModeMono) && rcaps.get(kChannelModeMono))
+    config.set(kChannelModeMono);
+  else
+    return false;
+
+  /* --- Select Block Length --- */
+
+  if (lcaps.get(kBlockLength16) && rcaps.get(kBlockLength16))
+    config.set(kBlockLength16);
+  else if (lcaps.get(kBlockLength12) && rcaps.get(kBlockLength12))
+    config.set(kBlockLength12);
+  else if (lcaps.get(kBlockLength8) && rcaps.get(kBlockLength8))
+    config.set(kBlockLength8);
+  else if (lcaps.get(kBlockLength4) && rcaps.get(kBlockLength4))
+    config.set(kBlockLength4);
+  else
+    return false;
+
+  /* --- Select Subbands --- */
+
+  if (lcaps.get(kSubbands8) && rcaps.get(kSubbands8))
+    config.set(kSubbands8);
+  else if (lcaps.get(kSubbands4) && rcaps.get(kSubbands4))
+    config.set(kSubbands4);
+  else
+    return false;
+
+  /* --- Select Allocation method --- */
+
+  if (lcaps.get(kAllocationMethodLoudness) &&
+      rcaps.get(kAllocationMethodLoudness))
+    config.set(kAllocationMethodLoudness);
+  else if (lcaps.get(kAllocationMethodSnr) && rcaps.get(kAllocationMethodSnr))
+    config.set(kAllocationMethodSnr);
+  else
+    return false;
+
+  /* --- Select Bitpool --- */
+
+  uint8_t min_bitpool = rcaps.get(kMinimumBitpool);
+  uint8_t max_bitpool = rcaps.get(kMaximumBitpool);
+
+  if (min_bitpool < 2 || min_bitpool > 250 || max_bitpool < 2 ||
+      max_bitpool > 250 || min_bitpool > max_bitpool) {
+    min_bitpool = 2;
+    max_bitpool = 250;
+  }
+
+  min_bitpool = std::max(min_bitpool, uint8_t(lcaps.get(kMinimumBitpool)));
+  max_bitpool = std::max(max_bitpool, uint8_t(lcaps.get(kMaximumBitpool)));
+
+  if (hint) {
+    min_bitpool =
+        std::max(min_bitpool, GetBitpool(*configuration, hint->minBitrate));
+    if (hint->maxBitrate && hint->maxBitrate >= hint->minBitrate)
+      max_bitpool =
+          std::min(max_bitpool, GetBitpool(*configuration, hint->maxBitrate));
+  }
+
+  config.set(kMinimumBitpool, min_bitpool);
+  config.set(kMaximumBitpool, max_bitpool);
+
+  return true;
+}
+
+}  // namespace aidl::android::hardware::bluetooth::audio

bluetooth/audio/aidl/default/A2dpOffloadCodecSbc.h

@@ -0,0 +1,61 @@
+/*
+ * Copyright (C) 2023 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 "A2dpOffloadCodec.h"
+
+namespace aidl::android::hardware::bluetooth::audio {
+
+struct SbcParameters : public CodecParameters {
+  enum class AllocationMethod { SNR, LOUDNESS };
+
+  AllocationMethod allocation_method;
+  int block_length;
+  int subbands;
+  int min_bitpool;
+  int max_bitpool;
+};
+
+class A2dpOffloadCodecSbc : public A2dpOffloadCodec {
+  CodecInfo info_;
+
+  A2dpOffloadCodecSbc();
+
+  A2dpStatus ParseConfiguration(const std::vector<uint8_t>& configuration,
+                                CodecParameters* codec_parameters,
+                                SbcParameters* sbc_parameters) const;
+
+ public:
+  static const A2dpOffloadCodecSbc* GetInstance();
+
+  A2dpStatus ParseConfiguration(
+      const std::vector<uint8_t>& configuration,
+      CodecParameters* codec_parameters) const override {
+    return ParseConfiguration(configuration, codec_parameters, nullptr);
+  }
+
+  A2dpStatus ParseConfiguration(const std::vector<uint8_t>& configuration,
+                                SbcParameters* sbc_parameters) const {
+    return ParseConfiguration(configuration, sbc_parameters, sbc_parameters);
+  }
+
+  bool BuildConfiguration(const std::vector<uint8_t>& remote_capabilities,
+                          const std::optional<CodecParameters>& hint,
+                          std::vector<uint8_t>* configuration) const override;
+};
+
+}  // namespace aidl::android::hardware::bluetooth::audio

bluetooth/audio/aidl/default/Android.bp

@@ -18,6 +18,9 @@ cc_library_shared {
         "BluetoothAudioProvider.cpp",
         "BluetoothAudioProviderFactory.cpp",
         "A2dpOffloadAudioProvider.cpp",
+        "A2dpOffloadCodecAac.cpp",
+        "A2dpOffloadCodecFactory.cpp",
+        "A2dpOffloadCodecSbc.cpp",
         "A2dpSoftwareAudioProvider.cpp",
         "HearingAidAudioProvider.cpp",
         "HfpOffloadAudioProvider.cpp",

bluetooth/audio/aidl/default/BluetoothAudioProvider.cpp

@@ -21,6 +21,8 @@
 #include <BluetoothAudioSessionReport.h>
 #include <android-base/logging.h>
 
+#include "A2dpOffloadCodecFactory.h"
+
 namespace aidl {
 namespace android {
 namespace hardware {
@@ -165,39 +167,24 @@ ndk::ScopedAStatus BluetoothAudioProvider::setLowLatencyModeAllowed(
 }
 
 ndk::ScopedAStatus BluetoothAudioProvider::parseA2dpConfiguration(
-    const CodecId& codec_id, const std::vector<uint8_t>& configuration,
+    [[maybe_unused]] const CodecId& codec_id,
-    CodecParameters* codec_parameters, A2dpStatus* _aidl_return) {
+    [[maybe_unused]] const std::vector<uint8_t>& configuration,
-  if (stack_iface_ == nullptr) {
+    [[maybe_unused]] CodecParameters* codec_parameters,
-    LOG(INFO) << __func__ << " - SessionType=" << toString(session_type_)
+    [[maybe_unused]] A2dpStatus* _aidl_return) {
-              << " has NO session";
+  LOG(INFO) << __func__ << " - SessionType=" << toString(session_type_)
-    return ndk::ScopedAStatus::fromExceptionCode(EX_ILLEGAL_ARGUMENT);
+            << " is illegal";
-  }
+  return ndk::ScopedAStatus::fromExceptionCode(EX_ILLEGAL_ARGUMENT);
-
-  *_aidl_return = A2dpStatus::OK;
-
-  (void)codec_id;
-  (void)configuration;
-  (void)codec_parameters;
-
-  return ndk::ScopedAStatus::ok();
 }
 
 ndk::ScopedAStatus BluetoothAudioProvider::getA2dpConfiguration(
-    const std::vector<A2dpRemoteCapabilities>& remote_a2dp_capabilities,
+    [[maybe_unused]] const std::vector<A2dpRemoteCapabilities>&
-    const A2dpConfigurationHint& hint,
+        remote_a2dp_capabilities,
-    std::optional<audio::A2dpConfiguration>* _aidl_return) {
+    [[maybe_unused]] const A2dpConfigurationHint& hint,
-  if (stack_iface_ == nullptr) {
+    [[maybe_unused]] std::optional<audio::A2dpConfiguration>* _aidl_return) {
-    LOG(INFO) << __func__ << " - SessionType=" << toString(session_type_)
+  LOG(INFO) << __func__ << " - SessionType=" << toString(session_type_)
-              << " has NO session";
+            << " is illegal";
-    return ndk::ScopedAStatus::fromExceptionCode(EX_ILLEGAL_ARGUMENT);
-  }
 
-  *_aidl_return = std::nullopt;
+  return ndk::ScopedAStatus::fromExceptionCode(EX_ILLEGAL_ARGUMENT);
-
-  (void)remote_a2dp_capabilities;
-  (void)hint;
-
-  return ndk::ScopedAStatus::ok();
 }
 
 }  // namespace audio

bluetooth/audio/aidl/default/BluetoothAudioProviderFactory.cpp

@@ -22,6 +22,7 @@
 #include <android-base/logging.h>
 
 #include "A2dpOffloadAudioProvider.h"
+#include "A2dpOffloadCodecFactory.h"
 #include "A2dpSoftwareAudioProvider.h"
 #include "BluetoothAudioProvider.h"
 #include "HearingAidAudioProvider.h"
@@ -150,7 +151,14 @@ ndk::ScopedAStatus BluetoothAudioProviderFactory::getProviderInfo(
     SessionType session_type, std::optional<ProviderInfo>* _aidl_return) {
   *_aidl_return = std::nullopt;
 
-  (void)session_type;
+  if (session_type == SessionType::A2DP_HARDWARE_OFFLOAD_ENCODING_DATAPATH ||
+      session_type == SessionType::A2DP_HARDWARE_OFFLOAD_DECODING_DATAPATH) {
+    auto& provider_info = _aidl_return->emplace();
+
+    provider_info.name = A2dpOffloadCodecFactory::GetInstance()->name;
+    for (auto codec : A2dpOffloadCodecFactory::GetInstance()->codecs)
+      provider_info.codecInfos.push_back(codec->info);
+  }
 
   return ndk::ScopedAStatus::ok();
 }

bluetooth/audio/utils/aidl_session/BluetoothAudioSession.cpp

@@ -304,7 +304,8 @@ bool BluetoothAudioSession::UpdateAudioConfig(
        audio_config_tag == AudioConfiguration::pcmConfig);
   bool is_a2dp_offload_audio_config =
       (is_offload_a2dp_session &&
-       audio_config_tag == AudioConfiguration::a2dpConfig);
+       (audio_config_tag == AudioConfiguration::a2dp ||
+        audio_config_tag == AudioConfiguration::a2dpConfig));
   bool is_hfp_offload_audio_config =
       (is_offload_hfp_session &&
        audio_config_tag == AudioConfiguration::hfpConfig);