android - 如何从外部设备录制音频(麦克风)

Question

我想使用媒体记录器从我的android应用程序记录音频。我已将音频源设置为麦克风，这使我可以从麦克风进行录制。但是我也很乐意检测是否连接了任何外部麦克风。如果是这样，那么它应该从中录制音频。
例如:如果将蓝牙扬声器/麦克风连接到电话，则它应从蓝牙麦克风捕获声音。
必须设置什么音频源？将其设置为默认帮助吗？

记录代码:

recorder = new MediaRecorder();
recorder.SetAudioSource(AudioSource.Mic);
recorder.SetOutputFormat(OutputFormat.Mpeg4);
recorder.SetAudioEncoder(AudioEncoder.Aac);
recorder.SetAudioSamplingRate(44100);
recorder.SetAudioEncodingBitRate(16 * 8000);
recorder.SetAudioChannels(2);
recorder.SetOutputFile(path);
recorder.Prepare();
recorder.Start();

Answer 1

Use  this Code to your manifest file
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>
        <uses-permission android:name="android.permission.RECORD_AUDIO"></uses-permission>

java class`enter code here`
import java.io.File;
import java.io.IOException;
import android.app.Activity;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.os.Environment;
import android.view.MotionEvent;
import android.view.View;
import android.widget.Button;

public class AudioOnTouchActivity extends Activity {
    Button b1;
    private static final String AUDIO_RECORDER_FILE_EXT_3GP = ".3gp";
    private static final String AUDIO_RECORDER_FILE_EXT_MP4 = ".mp4";
    private static final String AUDIO_RECORDER_FOLDER = "AudioRecorder";
    private MediaRecorder recorder = null;
    private int currentFormat = 0;
    private int output_formats[] = { MediaRecorder.OutputFormat.MPEG_4,             MediaRecorder.OutputFormat.THREE_GPP };
    private String file_exts[] = { AUDIO_RECORDER_FILE_EXT_MP4, AUDIO_RECORDER_FILE_EXT_3GP }; 
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        b1=(Button)findViewById(R.id.button1);
        b1.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                // TODO Auto-generated method stub
                switch(event.getAction()){
                case MotionEvent.ACTION_DOWN:
                    AppLog.logString("Start Recording");
                    startRecording();
                    break;
                case MotionEvent.ACTION_UP:
                    AppLog.logString("stop Recording");
                    stopRecording();
                    break;
                }
                return false;
            }
        });
    }

    private String getFilename(){
        String filepath = Environment.getExternalStorageDirectory().getPath();
        File file = new File(filepath,AUDIO_RECORDER_FOLDER);

        if(!file.exists()){
            file.mkdirs();
        }

        return (file.getAbsolutePath() + "/" + System.currentTimeMillis() + file_exts[currentFormat]);
    }

    private void startRecording(){
        recorder = new MediaRecorder();
        recorder.setAudioSource(MediaRecorder.AudioSource.MIC);
        recorder.setOutputFormat(output_formats[currentFormat]);
        recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
        recorder.setOutputFile(getFilename());
        recorder.setOnErrorListener(errorListener);
        recorder.setOnInfoListener(infoListener);
try {
            recorder.prepare();
            recorder.start();
        } catch (IllegalStateException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private MediaRecorder.OnErrorListener errorListener = new MediaRecorder.OnErrorListener() {
           @Override
            public void onError(MediaRecorder mr, int what, int extra) {
                AppLog.logString("Error: " + what + ", " + extra);
        }
    };

    private MediaRecorder.OnInfoListener infoListener = new MediaRecorder.OnInfoListener() {
        @Override
        public void onInfo(MediaRecorder mr, int what, int extra) {
                AppLog.logString("Warning: " + what + ", " + extra);
        }
    };

    private void stopRecording(){
        if(null != recorder){
            recorder.stop();
            recorder.reset();
            recorder.release();

            recorder = null;
        }
    }
}

AppLog.java file is

import android.util.Log;

public class AppLog {
private static final String APP_TAG = "AudioRecorder";

public static int logString(String message){
     return Log.i(APP_TAG,message);
}

the xml is

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" 
    >

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello" />

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button" 
        android:layout_gravity="center"
        android:layout_marginTop="10dp"/>

</LinearLayout>