services/audiopolicy/service/Spatializer.h

/*
 * Copyright (C) 2021 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.
 */

#ifndef ANDROID_MEDIA_SPATIALIZER_H
#define ANDROID_MEDIA_SPATIALIZER_H

#include <android-base/stringprintf.h>
#include <android/media/BnEffect.h>
#include <android/media/BnSpatializer.h>
#include <android/media/SpatializationLevel.h>
#include <android/media/SpatializationMode.h>
#include <android/media/SpatializerHeadTrackingMode.h>
#include <audio_utils/SimpleLog.h>
#include <math.h>
#include <media/AudioEffect.h>
#include <media/audiohal/EffectHalInterface.h>
#include <media/stagefright/foundation/ALooper.h>
#include <system/audio_effects/effect_spatializer.h>
#include <string>

#include "SpatializerPoseController.h"

namespace android {


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

/**
 * A callback interface from the Spatializer object or its parent AudioPolicyService.
 * This is implemented by the audio policy service hosting the Spatializer to perform
 * actions needed when a state change inside the Spatializer requires some audio system
 * changes that cannot be performed by the Spatializer. For instance opening or closing a
 * spatializer output stream when the spatializer is enabled or disabled
 */
class SpatializerPolicyCallback {
public:
    /** Called when a stage change occurs that requires the parent audio policy service to take
     * some action.
     */
    virtual void onCheckSpatializer() = 0;

    virtual ~SpatializerPolicyCallback() = default;
};
/**
 * The Spatializer class implements all functional controlling the multichannel spatializer
 * with head tracking implementation in the native audio service: audio policy and audio flinger.
 * It presents an AIDL interface available to the java audio service to discover the availability
 * of the feature and options, control its state and register an active head tracking sensor.
 * It maintains the current state of the platform spatializer and applies the stored parameters
 * when the spatializer engine is created and enabled.
 * Based on the requested spatializer level, it will request the creation of a specialized output
 * mixer to the audio policy service which will in turn notify the Spatializer of the output
 * stream on which a spatializer engine should be created, configured and enabled.
 * The spatializer also hosts the head tracking management logic. This logic receives the
 * desired head tracking mode and selected head tracking sensor, registers a sensor event listener
 * and derives the compounded head pose information to the spatializer engine.
 *
 * Workflow:
 * - Initialization: when the audio policy service starts, it checks if a spatializer effect
 * engine exists and if the audio policy manager reports a dedicated spatializer output profile.
 * If both conditions are met, a Spatializer object is created
 * - Capabilities discovery: AudioService will call AudioSystem::canBeSpatialized() and if true,
 * acquire an ISpatializer interface with AudioSystem::getSpatializer(). This interface
 * will be used to query the implementation capabilities and configure the spatializer.
 * - Enabling: when ISpatializer::setLevel() sets a level different from NONE the spatializer
 * is considered enabled. The audio policy callback onCheckSpatializer() is called. This
 * triggers a request to audio policy manager to open a spatialization output stream and a
 * spatializer mixer is created in audio flinger. When an output is returned by audio policy
 * manager, Spatializer::attachOutput() is called which creates and enables the spatializer
 * stage engine on the specified output.
 * - Disabling: when the spatialization level is set to NONE, the spatializer is considered
 * disabled. The audio policy callback onCheckSpatializer() is called. This triggers a call
 * to Spatializer::detachOutput() and the spatializer engine is released. Then a request is
 * made to audio policy manager to release and close the spatializer output stream and the
 * spatializer mixer thread is destroyed.
 */
class Spatializer : public media::BnSpatializer,
                    public AudioEffect::IAudioEffectCallback,
                    public IBinder::DeathRecipient,
                    private SpatializerPoseController::Listener,
                    public virtual AudioSystem::SupportedLatencyModesCallback {
  public:
    static sp<Spatializer> create(SpatializerPolicyCallback *callback);

           ~Spatializer() override;

    /** RefBase */
    void onFirstRef();

    /** ISpatializer, see ISpatializer.aidl */
    binder::Status release() override;
    binder::Status getSupportedLevels(std::vector<media::SpatializationLevel>* levels) override;
    binder::Status setLevel(media::SpatializationLevel level) override;
    binder::Status getLevel(media::SpatializationLevel *level) override;
    binder::Status isHeadTrackingSupported(bool *supports);
    binder::Status getSupportedHeadTrackingModes(
            std::vector<media::SpatializerHeadTrackingMode>* modes) override;
    binder::Status setDesiredHeadTrackingMode(
            media::SpatializerHeadTrackingMode mode) override;
    binder::Status getActualHeadTrackingMode(
            media::SpatializerHeadTrackingMode* mode) override;
    binder::Status recenterHeadTracker() override;
    binder::Status setGlobalTransform(const std::vector<float>& screenToStage) override;
    binder::Status setHeadSensor(int sensorHandle) override;
    binder::Status setScreenSensor(int sensorHandle) override;
    binder::Status setDisplayOrientation(float physicalToLogicalAngle) override;
    binder::Status setHingeAngle(float hingeAngle) override;
    binder::Status getSupportedModes(std::vector<media::SpatializationMode>* modes) override;
    binder::Status registerHeadTrackingCallback(
        const sp<media::ISpatializerHeadTrackingCallback>& callback) override;
    binder::Status setParameter(int key, const std::vector<unsigned char>& value) override;
    binder::Status getParameter(int key, std::vector<unsigned char> *value) override;
    binder::Status getOutput(int *output);

    /** IBinder::DeathRecipient. Listen to the death of the INativeSpatializerCallback. */
    virtual void binderDied(const wp<IBinder>& who);

    /** SupportedLatencyModesCallback */
    void onSupportedLatencyModesChanged(
            audio_io_handle_t output, const std::vector<audio_latency_mode_t>& modes) override;

    /** Registers a INativeSpatializerCallback when a client is attached to this Spatializer
     * by audio policy service.
     */
    status_t registerCallback(const sp<media::INativeSpatializerCallback>& callback);

    status_t loadEngineConfiguration(sp<EffectHalInterface> effect);

    /** Level getter for use by local classes. */
    media::SpatializationLevel getLevel() const { std::lock_guard lock(mLock); return mLevel; }

    /** Called by audio policy service when the special output mixer dedicated to spatialization
     * is opened and the spatializer engine must be created.
     */
    status_t attachOutput(audio_io_handle_t output, size_t numActiveTracks);
    /** Called by audio policy service when the special output mixer dedicated to spatialization
     * is closed and the spatializer engine must be release.
     */
    audio_io_handle_t detachOutput();
    /** Returns the output stream the spatializer is attached to. */
    audio_io_handle_t getOutput() const { std::lock_guard lock(mLock); return mOutput; }

    void updateActiveTracks(size_t numActiveTracks);

    /** Gets the channel mask, sampling rate and format set for the spatializer input. */
    audio_config_base_t getAudioInConfig() const;

    void calculateHeadPose();

    /** Convert fields in Spatializer and sub-modules to a string. Disable thread-safety-analysis
     * here because we want to dump mutex guarded members even try_lock failed to provide as much
     * information as possible for debugging purpose. */
    std::string toString(unsigned level) const NO_THREAD_SAFETY_ANALYSIS;

    static std::string toString(audio_latency_mode_t mode) {
        switch (mode) {
            case AUDIO_LATENCY_MODE_FREE:
                return "LATENCY_MODE_FREE";
            case AUDIO_LATENCY_MODE_LOW:
                return "LATENCY_MODE_LOW";
        }
        return "EnumNotImplemented";
    };

    /**
     * Format head to stage vector to a string, [0.00, 0.00, 0.00, -1.29, -0.50, 15.27].
     */
    template <typename T>
    static std::string toString(const std::vector<T>& vec, bool radianToDegree = false) {
        if (vec.size() == 0) {
            return "[]";
        }

        std::string ss = "[";
        for (const auto& f : vec) {
            if (radianToDegree) {
                base::StringAppendF(&ss, "%0.2f, ",
                                    HeadToStagePoseRecorder::getDegreeWithRadian(f));
            } else {
                base::StringAppendF(&ss, "%f, ", f);
            }
        }
        ss.replace(ss.end() - 2, ss.end(), "]");
        return ss;
    };

private:
    Spatializer(effect_descriptor_t engineDescriptor,
                     SpatializerPolicyCallback *callback);

    static void engineCallback(int32_t event, void* user, void *info);

    // From VirtualizerStageController::Listener
    void onHeadToStagePose(const media::Pose3f& headToStage) override;
    void onActualModeChange(media::HeadTrackingMode mode) override;

    void onHeadToStagePoseMsg(const std::vector<float>& headToStage);
    void onActualModeChangeMsg(media::HeadTrackingMode mode);
    void onSupportedLatencyModesChangedMsg(
            audio_io_handle_t output, std::vector<audio_latency_mode_t>&& modes);

    static constexpr int kMaxEffectParamValues = 10;
    /**
     * Get a parameter from spatializer engine by calling the effect HAL command method directly.
     * To be used when the engine instance mEngine is not yet created in the effect framework.
     * When MULTI_VALUES is false, the expected reply is only one value of type T.
     * When MULTI_VALUES is true, the expected reply is made of a number (of type T) indicating
     * how many values are returned, followed by this number for values of type T.
     */
    template<bool MULTI_VALUES, typename T>
    status_t getHalParameter(sp<EffectHalInterface> effect, uint32_t type,
                                          std::vector<T> *values) {
        static_assert(sizeof(T) <= sizeof(uint32_t), "The size of T must less than 32 bits");

        uint32_t cmd[sizeof(effect_param_t) / sizeof(uint32_t) + 1];
        uint32_t reply[sizeof(effect_param_t) / sizeof(uint32_t) + 2 + kMaxEffectParamValues];

        effect_param_t *p = (effect_param_t *)cmd;
        p->psize = sizeof(uint32_t);
        if (MULTI_VALUES) {
            p->vsize = (kMaxEffectParamValues + 1) * sizeof(T);
        } else {
            p->vsize = sizeof(T);
        }
        *(uint32_t *)p->data = type;
        uint32_t replySize = sizeof(effect_param_t) + p->psize + p->vsize;

        status_t status = effect->command(EFFECT_CMD_GET_PARAM,
                                          sizeof(effect_param_t) + sizeof(uint32_t), cmd,
                                          &replySize, reply);
        if (status != NO_ERROR) {
            return status;
        }
        if (p->status != NO_ERROR) {
            return p->status;
        }
        if (replySize <
                sizeof(effect_param_t) + sizeof(uint32_t) + (MULTI_VALUES ? 2 : 1) * sizeof(T)) {
            return BAD_VALUE;
        }

        T *params = (T *)((uint8_t *)reply + sizeof(effect_param_t) + sizeof(uint32_t));
        int numParams = 1;
        if (MULTI_VALUES) {
            numParams = (int)*params++;
        }
        if (numParams > kMaxEffectParamValues) {
            return BAD_VALUE;
        }
        (*values).clear();
        std::copy(&params[0], &params[numParams], back_inserter(*values));
        return NO_ERROR;
    }

    /**
     * Set a parameter to spatializer engine by calling setParameter on mEngine AudioEffect object.
     * It is possible to pass more than one value of type T according to the parameter type
     *  according to values vector size.
     */
    template<typename T>
    status_t setEffectParameter_l(uint32_t type, const std::vector<T>& values) REQUIRES(mLock) {
        static_assert(sizeof(T) <= sizeof(uint32_t), "The size of T must less than 32 bits");

        uint32_t cmd[sizeof(effect_param_t) / sizeof(uint32_t) + 1 + values.size()];
        effect_param_t *p = (effect_param_t *)cmd;
        p->psize = sizeof(uint32_t);
        p->vsize = sizeof(T) * values.size();
        *(uint32_t *)p->data = type;
        memcpy((uint32_t *)p->data + 1, values.data(), sizeof(T) * values.size());

        status_t status = mEngine->setParameter(p);
        if (status != NO_ERROR) {
            return status;
        }
        if (p->status != NO_ERROR) {
            return p->status;
        }
        return NO_ERROR;
    }

    /**
     * Get a parameter from spatializer engine by calling getParameter on AudioEffect object.
     * It is possible to read more than one value of type T according to the parameter type
     * by specifying values vector size.
     */
    template<typename T>
    status_t getEffectParameter_l(uint32_t type, std::vector<T> *values) REQUIRES(mLock) {
        static_assert(sizeof(T) <= sizeof(uint32_t), "The size of T must less than 32 bits");

        uint32_t cmd[sizeof(effect_param_t) / sizeof(uint32_t) + 1 + values->size()];
        effect_param_t *p = (effect_param_t *)cmd;
        p->psize = sizeof(uint32_t);
        p->vsize = sizeof(T) * values->size();
        *(uint32_t *)p->data = type;

        status_t status = mEngine->getParameter(p);

        if (status != NO_ERROR) {
            return status;
        }
        if (p->status != NO_ERROR) {
            return p->status;
        }

        int numValues = std::min(p->vsize / sizeof(T), values->size());
        (*values).clear();
        T *retValues = (T *)((uint8_t *)p->data + sizeof(uint32_t));
        std::copy(&retValues[0], &retValues[numValues], back_inserter(*values));

        return NO_ERROR;
    }

    virtual void onFramesProcessed(int32_t framesProcessed) override;

    /**
     * Checks if head and screen sensors must be actively monitored based on
     * spatializer state and playback activity and configures the pose controller
     * accordingly.
     */
    void checkSensorsState_l() REQUIRES(mLock);

    /**
     * Checks if the head pose controller should be created or destroyed according
     * to desired head tracking mode.
     */
    void checkPoseController_l() REQUIRES(mLock);

    /**
     * Checks if the spatializer effect should be enabled based on
     * playback activity and requested level.
     */
    void checkEngineState_l() REQUIRES(mLock);

    /** Effect engine descriptor */
    const effect_descriptor_t mEngineDescriptor;
    /** Callback interface to parent audio policy service */
    SpatializerPolicyCallback* const mPolicyCallback;

    /** Currently there is only one version of the spatializer running */
    const std::string mMetricsId = AMEDIAMETRICS_KEY_PREFIX_AUDIO_SPATIALIZER "0";

    /** Mutex protecting internal state */
    mutable std::mutex mLock;

    /** Client AudioEffect for the engine */
    sp<AudioEffect> mEngine GUARDED_BY(mLock);
    /** Output stream the spatializer mixer thread is attached to */
    audio_io_handle_t mOutput GUARDED_BY(mLock) = AUDIO_IO_HANDLE_NONE;

    /** Callback interface to the client (AudioService) controlling this`Spatializer */
    sp<media::INativeSpatializerCallback> mSpatializerCallback GUARDED_BY(mLock);

    /** Callback interface for head tracking */
    sp<media::ISpatializerHeadTrackingCallback> mHeadTrackingCallback GUARDED_BY(mLock);

    /** Requested spatialization level */
    media::SpatializationLevel mLevel GUARDED_BY(mLock) = media::SpatializationLevel::NONE;

    /** Control logic for head-tracking, etc. */
    std::shared_ptr<SpatializerPoseController> mPoseController GUARDED_BY(mLock);

    /** Last requested head tracking mode */
    media::HeadTrackingMode mDesiredHeadTrackingMode GUARDED_BY(mLock)
            = media::HeadTrackingMode::STATIC;

    /** Last-reported actual head-tracking mode. */
    media::SpatializerHeadTrackingMode mActualHeadTrackingMode GUARDED_BY(mLock)
            = media::SpatializerHeadTrackingMode::DISABLED;

    /** Selected Head pose sensor */
    int32_t mHeadSensor GUARDED_BY(mLock) = SpatializerPoseController::INVALID_SENSOR;

    /** Selected Screen pose sensor */
    int32_t mScreenSensor GUARDED_BY(mLock) = SpatializerPoseController::INVALID_SENSOR;

    /** Last display orientation received */
    static constexpr float kDisplayOrientationInvalid = 1000;
    float mDisplayOrientation GUARDED_BY(mLock) = kDisplayOrientationInvalid;

    std::vector<media::SpatializationLevel> mLevels;
    std::vector<media::SpatializerHeadTrackingMode> mHeadTrackingModes;
    std::vector<media::SpatializationMode> mSpatializationModes;
    std::vector<audio_channel_mask_t> mChannelMasks;
    bool mSupportsHeadTracking;

    // Looper thread for mEngine callbacks
    class EngineCallbackHandler;

    sp<ALooper> mLooper;
    sp<EngineCallbackHandler> mHandler;

    size_t mNumActiveTracks GUARDED_BY(mLock) = 0;
    std::vector<audio_latency_mode_t> mSupportedLatencyModes GUARDED_BY(mLock);

    static const std::vector<const char*> sHeadPoseKeys;

    // Local log for command messages.
    static constexpr int mMaxLocalLogLine = 10;
    SimpleLog mLocalLog{mMaxLocalLogLine};

    /**
     * @brief Calculate and record sensor data.
     * Dump to local log with max/average pose angle every mPoseRecordThreshold.
     * TODO: log azimuth/elevation angles obtained for debugging actual orientation.
     */
    class HeadToStagePoseRecorder {
      public:
        /** Convert recorded sensor data to string with level indentation */
        std::string toString_l(unsigned level) const;
        /**
         * @brief Calculate sensor data, record into local log when it is time.
         *
         * @param headToStage The vector from Pose3f::toVector().
         */
        void record_l(const std::vector<float>& headToStage);

        static constexpr float getDegreeWithRadian(const float radian) {
            float radianToDegreeRatio = (180 / PI);
            return (radian * radianToDegreeRatio);
        }

      private:
        static constexpr float PI = M_PI;
        /**
         * Pose recorder time threshold to record sensor data in local log.
         * Sensor data will be recorded at least every mPoseRecordThreshold.
         */
        // TODO: add another history log to record longer period of sensor data.
        static constexpr std::chrono::duration<double> mPoseRecordThreshold =
                std::chrono::seconds(1);
        /**
         * According to frameworks/av/media/libheadtracking/include/media/Pose.h
         * "The vector will have exactly 6 elements, where the first three are a translation vector
         * and the last three are a rotation vector."
         */
        static constexpr size_t mPoseVectorSize = 6;
        /**
         * Timestamp of last sensor data record in local log.
         */
        std::chrono::time_point<std::chrono::steady_clock> mFirstSampleTimestamp;
        // Last pose recorded, vector obtained from Pose3f::toVector().
        std::vector<float> mLastPoseRecorded{mPoseVectorSize};
        /**
         * Number of sensor samples received since last record, sample rate is ~100Hz which produce
         * ~6k samples/minute.
         */
        uint32_t mNumOfSampleSinceLastRecord = 0;
        /* The sum of pose angle represented by radian since last dump, div
         * mNumOfSampleSinceLastRecord to get arithmetic mean. Largest possible value: 2PI * 100Hz *
         * mPoseRecordThreshold.
         */
        std::vector<double> mPoseRadianSum{mPoseVectorSize};
        std::vector<float> mMaxPoseAngle{mPoseVectorSize};
        std::vector<float> mMinPoseAngle{mPoseVectorSize};
        // Local log for history sensor data.
        SimpleLog mPoseRecordLog{mMaxLocalLogLine};

        bool shouldRecordLog() const {
            return std::chrono::duration_cast<std::chrono::seconds>(
                           std::chrono::steady_clock::now() - mFirstSampleTimestamp) >=
                   mPoseRecordThreshold;
        }

        void resetRecord(const std::vector<float>& headToStage) {
            mPoseRadianSum.assign(mPoseVectorSize, 0);
            mMaxPoseAngle.assign(mPoseVectorSize, 0);
            mMinPoseAngle.assign(mPoseVectorSize, 0);
            mNumOfSampleSinceLastRecord = 0;
            mLastPoseRecorded = headToStage;
        }

        // Add each sample to sum and only calculate when record.
        void poseSumToAverage() {
            if (mNumOfSampleSinceLastRecord == 0) return;
            for (auto& p : mPoseRadianSum) {
                const float reciprocal = 1.f / mNumOfSampleSinceLastRecord;
                p *= reciprocal;
            }
        }
    };  // HeadToStagePoseRecorder
    HeadToStagePoseRecorder mPoseRecorder;
};  // Spatializer

}; // namespace android

#endif // ANDROID_MEDIA_SPATIALIZER_H