Error in recording incoming calls doesn't work?

Question

I am making a call recording app outgoing call is recording but the incoming call is not recording. I have also tested on different mobiles but the issue is the same. I have tested different methods like " MediaRecorder.AudioSource.MIC ", " MediaRecorder.AudioSource.VOICE_CALL ",and " MediaRecorder.AudioSource.VOICE_COMMUNICATION ". After trying different methods then I have tried

myRecorder.setAudioSource(MediaRecorder.AudioSource.VOICE_UPLINK+ MediaRecorder.AudioSource.VOICE_DOWNLINK);

Main MainActivity code

public class MainActivity extends AppCompatActivity {

    Button start_rec, stop_rec;
    TextView status;
    MediaRecorder myRecorder;
    SimpleDateFormat dateFormat;
    String currentTimeStamp;
    File outputFile;

    private static final int REQUEST_CODE = 0;
    private DevicePolicyManager mDPM;
    private ComponentName mAdminName;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        start_rec = findViewById(R.id.start_rec);
        stop_rec = findViewById(R.id.stop_rec);
        status = findViewById(R.id.status);

        try {
            // Initiate DevicePolicyManager.
            mDPM = (DevicePolicyManager) getSystemService(Context.DEVICE_POLICY_SERVICE);
            mAdminName = new ComponentName(this, DeviceAdminDemo.class);

            if (!mDPM.isAdminActive(mAdminName)) {
                Intent intent = new Intent(DevicePolicyManager.ACTION_ADD_DEVICE_ADMIN);
                intent.putExtra(DevicePolicyManager.EXTRA_DEVICE_ADMIN, mAdminName);
                intent.putExtra(DevicePolicyManager.EXTRA_ADD_EXPLANATION, "Click on Activate button to secure your application.");
                startActivityForResult(intent, REQUEST_CODE);
            } else {
                // mDPM.lockNow();
                // Intent intent = new Intent(MainActivity.this,
                // TrackDeviceService.class);
                // startService(intent);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

        start_rec.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                File sampleDir = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + "/rec2");
                File data = Environment.getDataDirectory();
                boolean success = true;
                if (!sampleDir.exists()) {
                    sampleDir.mkdirs();
                    success = sampleDir.mkdirs();
                }
                if (success) {
                    outputFile = new File(sampleDir, getCurrentTimeStamp() + ".mp3");
                    myRecorder = new MediaRecorder();
                    myRecorder.setAudioSource(MediaRecorder.AudioSource.VOICE_UPLINK + MediaRecorder.AudioSource.VOICE_DOWNLINK);
                    myRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
                    myRecorder.setAudioEncoder(MediaRecorder.OutputFormat.AMR_NB);
                    myRecorder.setAudioEncodingBitRate(16);
                    myRecorder.setAudioSamplingRate(44100);
                    myRecorder.setOutputFile(outputFile.getAbsolutePath());

                    try {
                        myRecorder.prepare();
                        myRecorder.start();
                    } catch (IllegalStateException e) {
                        e.printStackTrace();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                    status.setText("Recording");
                    status.setTextColor(Color.GREEN);
                    Toast.makeText(getApplicationContext(), "Recording...", Toast.LENGTH_SHORT).show();
                }

            }
        });

        stop_rec.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                try {
                    myRecorder.stop();
                    myRecorder.reset();
                    myRecorder.release();

                    myRecorder = null;

                } catch (IllegalStateException e) {
                    e.printStackTrace();
                } catch (RuntimeException e) {
                    // no valid audio/video data has been received
                    e.printStackTrace();
                }
                status.setText("Recording Stopped");
                status.setTextColor(Color.RED);

                Toast.makeText(getApplicationContext(), "Recording Stopped", Toast.LENGTH_SHORT).show();
//                refresh();
            }
        });
    }
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        if (REQUEST_CODE == requestCode) {
//            Intent intent = new Intent(MainActivity.this, TService.class);
//            startService(intent);
        }
    }
    public void refresh() {
        Intent intent = getIntent();
        finish();
        startActivity(intent);
    }

    public String getCurrentTimeStamp() {
        try {
            dateFormat = new SimpleDateFormat("yyyy-MM-dd HH-mm-ss");
            currentTimeStamp = dateFormat.format(new Date()); // Find todays date
            return currentTimeStamp;

        } catch (Exception e) {
            e.printStackTrace();


        }
        return null;
    }
}

DeviceAdmin code

public class DeviceAdminDemo extends DeviceAdminReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        super.onReceive(context, intent);
    }

    public void onEnabled(Context context, Intent intent) {
    };

    public void onDisabled(Context context, Intent intent) {
    };
}

Manifest code

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    package="waceem.virk.voicerecording">

    <uses-permission android:name="android.permission.RECORD_AUDIO" />
    <uses-permission android:name="android.permission.CAPTURE_AUDIO_OUTPUT"
        tools:ignore="ProtectedPermissions" />
    <uses-permission android:name="android.permission.READ_PHONE_STATE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.read_external_storage" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:requestLegacyExternalStorage="true"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.VoiceRecording">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <receiver
            android:name=".DeviceAdminDemo"
            android:permission="android.permission.BIND_DEVICE_ADMIN" >
            <meta-data
                android:name="android.app.device_admin"
                android:resource="@xml/my_admin" />
            <intent-filter>
                <action android:name="android.app.action.DEVICE_ADMIN_ENABLED" />
                <action android:name="android.app.action.DEVICE_ADMIN_DISABLED" />
                <action android:name="android.app.action.DEVICE_ADMIN_DISABLE_REQUESTED" />
                <action android:name="android.intent.action.BOOT_COMPLETED" />
                <category android:name="android.intent.category.HOME" />
            </intent-filter>
        </receiver>

    </application>

</manifest>

Answer 1

To use that you need the Manifest.permission.CAPTURE_AUDIO_OUTPUT permission, which is a system permission. That means you need to be preinstalled by the OEM, or the user needs to root their device and know how to make your app a system app.

Basically Android doesn't allow you to do that. The most your can do is allow it to capture with the normal microphone and hope the caller speaks loudly, or that the user put it on speakerphone.