Create RequestSadAction

/*

 * 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.

 */

package com.android.server.hdmi;

import android.util.Slog;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.List;

import java.util.Objects;

/**

 * Feature action that queries the Short Audio Descriptor (SAD) of another device. This action is

 * initiated from the Android system working as TV device to get the SAD of the connected audio

 * system device.

 * <p>

 * Package-private

 */

final class RequestSadAction extends HdmiCecFeatureAction {

    private static final String TAG = "RequestSadAction";

    // State in which the action is waiting for <Report Short Audio Descriptor>.

    private static final int STATE_WAITING_FOR_REPORT_SAD = 1;

    private static final List<Integer> ALL_CEC_CODECS = new ArrayList<Integer>(Arrays.asList(

            Constants.AUDIO_CODEC_LPCM,

            Constants.AUDIO_CODEC_DD,

            Constants.AUDIO_CODEC_MPEG1,

            Constants.AUDIO_CODEC_MP3,

            Constants.AUDIO_CODEC_MPEG2,

            Constants.AUDIO_CODEC_AAC,

            Constants.AUDIO_CODEC_DTS,

            Constants.AUDIO_CODEC_ATRAC,

            Constants.AUDIO_CODEC_ONEBITAUDIO,

            Constants.AUDIO_CODEC_DDP,

            Constants.AUDIO_CODEC_DTSHD,

            Constants.AUDIO_CODEC_TRUEHD,

            Constants.AUDIO_CODEC_DST,

            Constants.AUDIO_CODEC_WMAPRO,

            Constants.AUDIO_CODEC_MAX));

    private static final int MAX_SAD_PER_REQUEST = 4;

    private static final int RETRY_COUNTER_MAX = 1;

    private final int mTargetAddress;

    private final RequestSadCallback mCallback;

    // List of all valid SADs reported by the target device. Not parsed nor deduplicated.

    private final List<byte[]> mSupportedSads = new ArrayList<>();

    private int mQueriedSadCount = 0; // Number of SADs queries that has already been completed

    private int mTimeoutRetry = 0; // Number of times we have already retried on time-out

    /**

     * Constructor.

     *

     * @param source        an instance of {@link HdmiCecLocalDevice}.

     * @param targetAddress the logical address the SAD is directed at.

     */

    RequestSadAction(HdmiCecLocalDevice source, int targetAddress, RequestSadCallback callback) {

        super(source);

        mTargetAddress = targetAddress;

        mCallback = Objects.requireNonNull(callback);

    }

    @Override

    boolean start() {

        querySad();

        return true;

    }

    private void querySad() {

        if (mQueriedSadCount >= ALL_CEC_CODECS.size()) {

            wrapUpAndFinish();

            return;

        }

        int[] codecsToQuery = ALL_CEC_CODECS.subList(mQueriedSadCount,

                Math.min(ALL_CEC_CODECS.size(), mQueriedSadCount + MAX_SAD_PER_REQUEST))

                    .stream().mapToInt(i -> i).toArray();

        sendCommand(HdmiCecMessageBuilder.buildRequestShortAudioDescriptor(getSourceAddress(),

                mTargetAddress, codecsToQuery));

        mState = STATE_WAITING_FOR_REPORT_SAD;

        addTimer(mState, HdmiConfig.TIMEOUT_MS);

    }

    @Override

    boolean processCommand(HdmiCecMessage cmd) {

        if (mState != STATE_WAITING_FOR_REPORT_SAD

                || mTargetAddress != cmd.getSource()) {

            return false;

        }

        if (cmd.getOpcode() == Constants.MESSAGE_REPORT_SHORT_AUDIO_DESCRIPTOR) {

            if (cmd.getParams() == null || cmd.getParams().length == 0

                    || cmd.getParams().length % 3 != 0) {

                // Invalid message. Wait for time-out and query again.

                return true;

            }

            for (int i = 0; i < cmd.getParams().length - 2; i += 3) {

                if (isValidCodec(cmd.getParams()[i])) {

                    byte[] sad = new byte[]{cmd.getParams()[i], cmd.getParams()[i + 1],

                            cmd.getParams()[i + 2]};

                    updateResult(sad);

                }

                // Don't include invalid codecs in the result. Don't query again.

                Slog.w(TAG, "Received invalid codec " + cmd.getParams()[i] + ".");

            }

            mQueriedSadCount += MAX_SAD_PER_REQUEST;

            mTimeoutRetry = 0;

            querySad();

            return true;

        }

        if (cmd.getOpcode() == Constants.MESSAGE_FEATURE_ABORT

                && (cmd.getParams()[0] & 0xFF) == Constants.MESSAGE_REQUEST_SHORT_AUDIO_DESCRIPTOR

                && (cmd.getParams()[1] & 0xFF) == Constants.ABORT_INVALID_OPERAND) {

            // Queried SADs are not supported

            mQueriedSadCount += MAX_SAD_PER_REQUEST;

            mTimeoutRetry = 0;

            querySad();

            return true;

        }

        return false;

    }

    private boolean isValidCodec(byte codec) {

        return Constants.AUDIO_CODEC_NONE < (codec & 0xFF)

                && (codec & 0xFF) <= Constants.AUDIO_CODEC_MAX;

    }

    private void updateResult(byte[] sad) {

        mSupportedSads.add(sad);

    }

    @Override

    void handleTimerEvent(int state) {

        if (mState != state) {

            return;

        }

        if (state == STATE_WAITING_FOR_REPORT_SAD) {

            if (++mTimeoutRetry <= RETRY_COUNTER_MAX) {

                querySad();

                return;

            }

            mQueriedSadCount += MAX_SAD_PER_REQUEST;

            mTimeoutRetry = 0;

            querySad();

        }

    }

    private void wrapUpAndFinish() {

        mCallback.onRequestSadDone(mSupportedSads);

        finish();

    }

    /**

     * Interface used to report result of SAD request.

     */

    interface RequestSadCallback {

        /**

         * Called when SAD request is done.

         *

         * @param sads a list of all supported SADs. It can be an empty list.

         */

        void onRequestSadDone(List<byte[]> supportedSads);

    }

}