Android Call Recording Incoming voice not getting recorded

You need to use ndk. Here are examples of the functions that need to be done.

Load libmedia.so and libutils.so

int load(JNIEnv *env, jobject thiz) {    void *handleLibMedia;    void *handleLibUtils;    int result = -1;    lspr func = NULL;    pthread_t newthread = (pthread_t) thiz;    handleLibMedia = dlopen("libmedia.so", RTLD_NOW | RTLD_GLOBAL);    if (handleLibMedia != NULL) {        func = dlsym(handleLibMedia, "_ZN7android11AudioSystem13setParametersEiRKNS_7String8E");        if (func != NULL) {            result = 0;        }        audioSetParameters = (lasp) func;    } else {        result = -1;    }    handleLibUtils = dlopen("libutils.so", RTLD_NOW | RTLD_GLOBAL);    if (handleLibUtils != NULL) {        fstr = dlsym(handleLibUtils, "_ZN7android7String8C2EPKc");        if (fstr == NULL) {            result = -1;        }    } else {        result = -1;    }    cmd = CM_D;    int resultTh = pthread_create(&newthread, NULL, taskAudioSetParam, NULL);    return result;}

Function setParameters

int setParam(jint i, jint as) {pthread_mutex_lock(&mt);audioSession = (int) (as + 1);kvp = "input_source=4";kvps = toString8(kvp);cmd = (int) i;pthread_cond_signal(&cnd);pthread_mutex_unlock(&mt);return 0;}

Task AudioSetParameters

void *taskAudioSetParam(void *threadid) {    while (1) {        pthread_mutex_lock(&mt);        if (cmd == CM_D) {            pthread_cond_wait(&cnd, &mt);        } else if (audioSetParameters != NULL) {             audioSetParameters(audioSession, kvps);        }        pthread_mutex_unlock(&mt);    }}

There is a library and an example of use https://github.com/ViktorDegtyarev/CallRecLib

Xiaomi devices always have problems with permission request even run-time or install-time.

I have an Xiaomi Redmi 3 pro, and it always force to Deny some permission when I install apps, so I must manually Allow it.If your problem is the same, I found some workaround solution and it worked for me: How to get MIUI Security app auto start permission programmatically?

First these 3 permissions are needed in Manifest as well as a runtime permission request if the device is above Marshmallow,

<uses-permission android:name="android.permission.READ_PHONE_STATE" /><uses-permission android:name="android.permission.RECORD_AUDIO" /><uses-permission android:name="android.permission.CAPTURE_AUDIO_OUTPUT" />

2. MediaRecorder.AudioSource.VOICE_CALL is not supported on all phones so you need to continue using MediaRecorder.AudioSource.MIC.

I use this and works fine on most of the devices,

      recorder = new MediaRecorder();      recorder.setAudioSource(audioSource);      recorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);      recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);      recorder.setOutputFile(your_path);

3. You need to set this to record your calls properly,

   audioManager.setMode(AudioManager.MODE_IN_CALL);

raise volume level when you start recording

audioManager.setStreamVolume(AudioManager.STREAM_VOICE_CALL,audioManager.getStreamMaxVolume(AudioManager.STREAM_VOICE_CALL), 0);

When you stop recording set the mode to normal,audioManager.setMode(AudioManager.MODE_NORMAL); and also set the stream volume to back how it was.