audio/effect/2.0/IVisualizerEffect.hal

/*
 * Copyright (C) 2016 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.
 */

package android.hardware.audio.effect@2.0;

import android.hardware.audio.common@2.0;
import IEffect;

interface IVisualizerEffect extends IEffect {
    enum CaptureSizeRange : int32_t {
        MAX = 1024,  // maximum capture size in samples
        MIN = 128    // minimum capture size in samples
    };

    /**
     * Sets the number PCM samples in the capture.
     */
    setCaptureSize(uint16_t captureSize) generates (Result retval);

    /**
     * Gets the number PCM samples in the capture.
     */
    getCaptureSize() generates (Result retval, uint16_t captureSize);

    enum ScalingMode : int32_t {
        // Keep in sync with SCALING_MODE_... in
        // frameworks/base/media/java/android/media/audiofx/Visualizer.java
        NORMALIZED = 0,
        AS_PLAYED = 1
    };

    /**
     * Specifies the way the captured data is scaled.
     */
    setScalingMode(ScalingMode scalingMode) generates (Result retval);

    /**
     * Retrieves the way the captured data is scaled.
     */
    getScalingMode() generates (Result retval, ScalingMode scalingMode);

    /**
     * Informs the visualizer about the downstream latency.
     */
    setLatency(uint32_t latencyMs) generates (Result retval);

    /**
     * Gets the downstream latency.
     */
    getLatency() generates (Result retval, uint32_t latencyMs);

    enum MeasurementMode : int32_t {
        // Keep in sync with MEASUREMENT_MODE_... in
        // frameworks/base/media/java/android/media/audiofx/Visualizer.java
        NONE = 0x0,
        PEAK_RMS = 0x1
    };

    /**
     * Specifies which measurements are to be made.
     */
    setMeasurementMode(MeasurementMode measurementMode)
            generates (Result retval);

    /**
     * Retrieves which measurements are to be made.
     */
    getMeasurementMode() generates (
            Result retval, MeasurementMode measurementMode);

    /**
     * Retrieves the latest PCM snapshot captured by the visualizer engine.  The
     * number of samples to capture is specified by 'setCaptureSize' parameter.
     *
     * @return retval operation completion status.
     * @return samples samples in 8 bit unsigned format (0 = 0x80)
     */
    capture() generates (Result retval, vec<uint8_t> samples);

    struct Measurement {
        MeasurementMode mode;    // discriminator
        union Values {
            struct PeakAndRms {
                int32_t peakMb;  // millibels
                int32_t rmsMb;   // millibels
            } peakAndRms;
        } value;
    };
    /**
     * Retrieves the latest measurements. The measurements to be made
     * are specified by 'setMeasurementMode' parameter.
     *
     * @return retval operation completion status.
     * @return result measurement.
     */
    measure() generates (Result retval, Measurement result);
};