通过 MediaRecorder 录制音频

Posted 2023-02-25

【中文标题】通过 MediaRecorder 录制音频

【英文标题】：Record audio via MediaRecorder

【发布时间】：2012-06-12 22:35:39

【问题描述】：

我正在尝试，但出现错误，我尝试更改所有内容，但没有任何效果。最近两个小时我试图找到错误，我也使用了 Log 类，我发现它在调用 recorder.start() 方法时发生了错误。可能是什么问题？

public class AudioRecorderActivity extends Activity 

MediaRecorder recorder;
File audioFile = null;
private static final String TAG = "AudioRecorderActivity";
private View startButton;
private View stopButton;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) 
    super.onCreate(savedInstanceState);

    startButton = findViewById(R.id.start);
    stopButton = findViewById(R.id.stop);

    setContentView(R.layout.main);


public void startRecording(View view) throws IOException

    startButton.setEnabled(false);
    stopButton.setEnabled(true);

    File sampleDir = Environment.getExternalStorageDirectory();

    try
        audioFile = File.createTempFile("sound", ".3gp", sampleDir);
    catch(IOException e)
        Toast.makeText(getApplicationContext(), "SD Card Access Error", Toast.LENGTH_LONG).show();
        Log.e(TAG, "Sdcard access error");
        return;
    

    recorder = new MediaRecorder();
    recorder.setAudiosource(MediaRecorder.AudioSource.MIC);
    recorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
    recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
    recorder.setAudioEncodingBitRate(16);
    recorder.setAudioSamplingRate(44100);
    recorder.setOutputFile(audioFile.getAbsolutePath());
    recorder.prepare();
    recorder.start();


public void stopRecording(View view)
    startButton.setEnabled(true);
    stopButton.setEnabled(false);
    recorder.stop();
    recorder.release();
    addRecordingToMediaLibrary();


protected void addRecordingToMediaLibrary()
    ContentValues values = new ContentValues(4);
    long current = System.currentTimeMillis();
    values.put(MediaStore.Audio.Media.TITLE, "audio" + audioFile.getName());
    values.put(MediaStore.Audio.Media.DATE_ADDED, (int)(current/1000));
    values.put(MediaStore.Audio.Media.MIME_TYPE, "audio/3gpp");
    values.put(MediaStore.Audio.Media.DATA, audioFile.getAbsolutePath());
    ContentResolver contentResolver = getContentResolver();

    Uri base = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
    Uri newUri = contentResolver.insert(base, values);

    sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, newUri));
    Toast.makeText(this, "Added File" + newUri, Toast.LENGTH_LONG).show();
    

 

这是 xml 布局。

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/RelativeLayout1"
android:layout_
android:layout_
android:orientation="vertical" >

<Button
    android:id="@+id/start"
    android:layout_
    android:layout_
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="146dp"
    android:onClick="startRecording"
    android:text="Start Recording" />

<Button
    android:id="@+id/stop"
    android:layout_
    android:layout_
    android:layout_alignLeft="@+id/start"
    android:layout_below="@+id/start"
    android:layout_marginTop="41dp"
    android:enabled="false"
    android:onClick="stopRecording"
    android:text="Stop Recording" />

 </RelativeLayout>

我添加了对 AndroidManifest 文件的权限。

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="in.isuru.audiorecorder"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk android:minSdkVersion="8" />


<application
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name" >
    <activity
        android:name=".AudioRecorderActivity"
        android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>

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

</manifest>

这是我得到的错误，

 06-11 18:27:44.548: E/AndroidRuntime(765): java.lang.IllegalStateException: Could not execute method of the activity
 06-11 18:27:44.548: E/AndroidRuntime(765):     at android.view.View$1.onClick(View.java:2072)

我需要录制高质量的音频。

谢谢！

【问题讨论】：

你能多发些日志猫错误

你在findViewById()之后打电话给setContentView()。之前调用它，因为你的视图还没有膨胀。

【参考方案1】：

我没有花时间去寻找你的代码，但是这段代码可以工作：

public class ExampleActivity extends Activity implements OnClickListener 
private Button startButton;
private Button stopButton;
private MediaRecorder mediaRecorder;
private File audioFile;

@Override
protected void onCreate(Bundle savedInstanceState) 
    super.onCreate(savedInstanceState);
    setContentView(R.layout.your_layout);
    startButton = (Button) findViewById(R.id.button1);
    startButton.setOnClickListener(this);
    startButton.setText("start");

    stopButton = (Button) findViewById(R.id.button2);
    stopButton.setOnClickListener(this);
    stopButton.setEnabled(false);
    stopButton.setText("stop");

    audioFile = new File(Environment.getExternalStorageDirectory(),
            "audio_test4.3gp");


// this process must be done prior to the start of recording
private void resetRecorder() 
    mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
    mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
    mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
    mediaRecorder.setAudioEncodingBitRate(16);
    mediaRecorder.setAudioSamplingRate(44100);
    mediaRecorder.setOutputFile(audioFile.getAbsolutePath());

    try 
        mediaRecorder.prepare();
     catch (IllegalStateException e) 
        e.printStackTrace();
     catch (IOException e) 
        e.printStackTrace();
    


@Override
public void onClick(View v) 
    switch (v.getId()) 
    case R.id.button1:
        mediaRecorder = new MediaRecorder();
        resetRecorder();
        mediaRecorder.start();

        startButton.setEnabled(false);
        stopButton.setEnabled(true);
        break;
    case R.id.button2:
        mediaRecorder.stop();
        mediaRecorder.release();
        mediaRecorder = null;

        startButton.setEnabled(true);
        stopButton.setEnabled(false);
        break;
    


@Override
protected void onPause() 
    super.onPause();

    if (mediaRecorder != null) 
        mediaRecorder.stop();
        mediaRecorder.release();
        mediaRecorder = null;
    

【讨论】：

如果你要投反对票，至少有礼貌地说出原因。否则，谁能从错误中吸取教训？