apps/CtsVerifier/src/org/hyphonate/megaaudio/player/Player.java

/*
 * Copyright 2020 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 org.hyphonate.megaaudio.player;

import android.media.AudioFormat;
import android.media.AudioTrack;

import org.hyphonate.megaaudio.common.StreamBase;

/**
 * An abstract class defining the common operations and attributes for all
 * player (concrete) sub-classes.
 */
public abstract class Player extends StreamBase {
    public Player(AudioSourceProvider sourceProvider) {
        mSourceProvider = sourceProvider;
    }

    /*
     * Audio Source
     */
    protected AudioSourceProvider mSourceProvider;

    //
    // Attributes
    //
    // This needs to be static because it is called before creating the Recorder subclass
    public static int calcMinBufferFrames(int channelCount, int sampleRate) {
        int channelMask = Player.channelCountToChannelMask(channelCount);
        int bufferSizeInBytes =
                AudioTrack.getMinBufferSize (sampleRate,
                        channelMask,
                        AudioFormat.ENCODING_PCM_FLOAT);
        return bufferSizeInBytes / sampleSizeInBytes(AudioFormat.ENCODING_PCM_FLOAT);
    }

    //
    // Status
    //
    public abstract boolean isPlaying();

    /*
     * Channel utils
     */
    // TODO Consider moving these to a "Utility" library.
    /**
     * @param channelCount  The number of channels for which to generate an output position mask.
     * @return An output channel-position mask corresponding to the supplied number of channels.
     */
    public static int channelCountToChannelMask(int channelCount) {
        switch (channelCount) {
            case 1:
                return AudioFormat.CHANNEL_OUT_MONO;

            case 2:
                return AudioFormat.CHANNEL_OUT_STEREO;

            case 3:
                return AudioFormat.CHANNEL_OUT_STEREO | AudioFormat.CHANNEL_OUT_FRONT_CENTER;

            case 4:
                return AudioFormat.CHANNEL_OUT_QUAD;

            case 5: // 5.0
                return AudioFormat.CHANNEL_OUT_QUAD | AudioFormat.CHANNEL_OUT_FRONT_CENTER;

            case 6: // 5.1
                return AudioFormat.CHANNEL_OUT_5POINT1;

            case 7: // 6.1
                return AudioFormat.CHANNEL_OUT_5POINT1 | AudioFormat.CHANNEL_OUT_BACK_CENTER;

            case 8:
                return AudioFormat.CHANNEL_OUT_7POINT1;


            default:
                return AudioTrack.ERROR_BAD_VALUE;
        }
    }

}