Call recording - make it work on Nexus 5X (rooting or custom ROM possible)

Question

I\'m attempting to use AudioRecord with AudioSource.VOICE_DOWNLINK on Nexus 5X, Android 7.1 (my own build from AOSP).

I\'m already past the per

Answer 1

Not sure if it is a Nexus 5 specific issue but usually the class used to record calls is MediaRecorder. Have you tried to replace AudioRecorder by a MediaRecorder?

Based on this stack-overflow question, I think you could try the following code based on Ben blog post:

import android.media.MediaRecorder;
import android.os.Environment;

import java.io.File;

import java.io.IOException;


public class CallRecorder {

    final MediaRecorder recorder = new MediaRecorder();
    final String path;

    /**
     * Creates a new audio recording at the given path (relative to root of SD card).
     */
    public CallRecorder(String path) {
        this.path = sanitizePath(path);
    }

    private String sanitizePath(String path) {
        if (!path.startsWith("/")) {
            path = "/" + path;
        }
        if (!path.contains(".")) {
            path += ".3gp";
        }
        return Environment.getExternalStorageDirectory().getAbsolutePath() + path;
    }

    /**
     * Starts a new recording.
     */
    public void start() throws IOException {
        String state = android.os.Environment.getExternalStorageState();
        if(!state.equals(android.os.Environment.MEDIA_MOUNTED))  {
            throw new IOException("SD Card is not mounted.  It is " + state + ".");
        }

        // make sure the directory we plan to store the recording in exists
        File directory = new File(path).getParentFile();
        if (!directory.exists() && !directory.mkdirs()) {
            throw new IOException("Path to file could not be created.");
        }

        recorder.setAudioSource(MediaRecorder.AudioSource.VOICE_CALL);
        recorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
        recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
        recorder.setOutputFile(path);
        recorder.prepare();
        recorder.start();
    }

    /**
     * Stops a recording that has been previously started.
     */
    public void stop() throws IOException {
        recorder.stop();
        recorder.release();
    }

}

In this sample, I've used MediaRecorder.AudioSource.VOICE_CALL but you can test other options like MediaRecorder.AudioSource.VOICE_COMMUNICATION and also the microphone just to see if there are any hardware issues on your phone.