Android How to record VOIP call using Foreground Service

问题

I have written below mention service code:

import android.app.Notification;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.media.AudioFormat;
import android.media.AudioRecord;
import android.media.MediaRecorder;
import android.os.Build;
import android.os.IBinder;

import androidx.core.app.NotificationCompat;

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;

public class RecordingService extends Service {
    public static final String CHANNEL_ID = "RRecordingServiceChannel";
    private Context context;
    private MediaSaver mediaSaver;
    private static final int RECORDER_SAMPLERATE = 44100;
    private static final int RECORDER_CHANNELS = AudioFormat.CHANNEL_IN_STEREO;
    private static final int RECORDER_AUDIO_ENCODING = AudioFormat.ENCODING_PCM_16BIT;
    private AudioRecord recorder = null;
    private Thread recordingThread = null;
    private boolean isRecording = false;

    @Override
    public void onCreate() {
        super.onCreate();
        context = this;

    }
    public RecordingService() {
    }
    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        if (intent != null) {
            String action = intent.getAction();

            switch (action) {
                case SaleskenIntent.START_FOREGROUND:
                    startForegroundService();
                    break;
                case SaleskenIntent.STOP_FOREGROUND:
                    stopForegroundService();
                    break;
            }
        }
        return super.onStartCommand(intent, flags, startId);
    }


    private void startForegroundService() {
        createNotificationChannel();
        Intent notificationIntent = new Intent(this, MainActivity.class);
        PendingIntent pendingIntent = PendingIntent.getActivity(this,
                0, notificationIntent, 0);
        Notification notification = new NotificationCompat.Builder(this, CHANNEL_ID)
                .setContentTitle("recording Service")
                .setContentText("Start")
                .setSmallIcon(R.drawable.ic_launcher_background)
                .setContentIntent(pendingIntent)
                .build();
        startForeground(1, notification);
        startRecorder();
    }

    private void createNotificationChannel() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            NotificationChannel serviceChannel = new NotificationChannel(
                    CHANNEL_ID,
                    "Recording Service Channel",
                    NotificationManager.IMPORTANCE_DEFAULT
            );
            NotificationManager manager = getSystemService(NotificationManager.class);
            manager.createNotificationChannel(serviceChannel);
        }
    }

    private void stopForegroundService() {
        stopRecording();
        stopForeground(true);
        stopSelf();

    }
    @Override
    public IBinder onBind(Intent intent) {
        // TODO: Return the communication channel to the service.
        throw new UnsupportedOperationException("Not yet implemented");
    }
    int BufferElements2Rec = 1024; // want to play 2048 (2K) since 2 bytes we use only 1024
    int BytesPerElement = 2; // 2 bytes in 16bit format
    private void startRecorder(){

        recorder = new AudioRecord(MediaRecorder.AudioSource.VOICE_COMMUNICATION,
                RECORDER_SAMPLERATE, RECORDER_CHANNELS,
                RECORDER_AUDIO_ENCODING, BufferElements2Rec * BytesPerElement);

        recorder.startRecording();
        isRecording = true;
        recordingThread = new Thread(new Runnable() {
            public void run() {
                writeAudioDataToFile();
            }
        }, "AudioRecorder Thread");
        recordingThread.start();

    }
    private void writeAudioDataToFile() {
        // Write the output audio in byte

        String timestamp = new SimpleDateFormat("dd-MM-yyyy-hh-mm-ss", Locale.US).format(new Date());
        String fileName =timestamp+".pcm";
        mediaSaver = new MediaSaver(context).setParentDirectoryName("visualizer").
                setFileNameKeepOriginalExtension(fileName).
                setExternal(MediaSaver.isExternalStorageReadable());
        short sData[] = new short[BufferElements2Rec];

        FileOutputStream os = null;
        try {
            os = new FileOutputStream(mediaSaver.pathFile().getAbsolutePath());
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }

        while (isRecording) {
            // gets the voice output from microphone to byte format

            recorder.read(sData, 0, BufferElements2Rec);
            System.out.println("Short wirting to file" + sData.toString());
            try {
                // // writes the data to file from buffer
                // // stores the voice buffer
                byte bData[] = short2byte(sData);
                os.write(bData, 0, BufferElements2Rec * BytesPerElement);
            } catch (IOException  e) {
                e.printStackTrace();
            }
        }
        try {
            os.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private byte[] short2byte(short[] sData) {
        int shortArrsize = sData.length;
        byte[] bytes = new byte[shortArrsize * 2];
        for (int i = 0; i < shortArrsize; i++) {
            bytes[i * 2] = (byte) (sData[i] & 0x00FF);
            bytes[(i * 2) + 1] = (byte) (sData[i] >> 8);
            sData[i] = 0;
        }
        return bytes;

    }
    private void stopRecording() {
        // stops the recording activity
        if (null != recorder) {
            isRecording = false;
            recorder.stop();
            recorder.release();
            recorder = null;
            recordingThread = null;
        }
    }


    @Override
    public void onDestroy() {
        super.onDestroy();
        stopRecording();
    }
}

But it seem it capture the mic and not allow voice to transmit properly to Microphone during my VOIP call. Please suggest what should i do here to record my app VOIP calling.

Below are permission i have in my manifest:

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.RECORD_AUDIO" />
<uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
<uses-permission android:name="android.permission.READ_CONTACTS" />
<uses-permission android:name="android.permission.WRITE_CONTACTS" />
<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />
<uses-permission android:name="android.permission.READ_PHONE_STATE" />
<uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS" />
<uses-permission android:name="android.permission.READ_CALL_LOG" />
<uses-permission android:name="android.permission.MANAGE_OWN_CALLS" />
<uses-permission android:name="android.permission.WAKE_LOCK" />
<uses-permission android:name="android.permission.USE_SIP" />
<uses-permission android:name="android.permission.CONFIGURE_SIP" />

来源：https://stackoverflow.com/questions/61180879/android-how-to-record-voip-call-using-foreground-service