java - 无法保存音频文件，文件夹为空

Question

我正在尝试开发一个录音应用程序，我可以在其中开始和停止我的录音。从逻辑上讲，它应该使用保存的音频创建一个音频文件。不幸的是，当我检查文件时，没有任何音频。因此，我不太确定代码哪里出了问题。

这是我的主要录音机课程。

    package com.example.soundrecorder;

    import java.io.File;
    import java.io.IOException;

    import android.app.Activity;
    import android.content.ContentResolver;
    import android.content.ContentValues;
    import android.content.Intent;
    import android.media.MediaRecorder;
    import android.net.Uri;
    import android.os.Bundle;
    import android.os.Environment;
    import android.provider.MediaStore;
    import android.util.Log;
    import android.view.View;
    import android.widget.Toast;

    public class SoundRecorder extends Activity {

    MediaRecorder recorder;
    File audiofile = null;
    private static final String TAG = "SoundRecordingActivity";
    private View startButton;
    private View stopButton;

    @Override
    public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    startButton = findViewById(R.id.start);
    stopButton = findViewById(R.id.stop);
    }

    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) {
        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.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();
    }
    } 

有我的录音机清单

   <manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.soundrecorder"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="15" />

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

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
        android:name=".SoundRecorder"
        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>

  </manifest>

Answer 1

首先，您需要定义：

MediaRecorder mrec = new MediaRecorder();
File sampleDir = Environment.getExternalStorageDirectory();
File audiofile = File.createTempFile("ibm", ".mp4", sampleDir);

之后，您需要定义 FileProcessing 函数：

protected void processaudiofile()
{
    ContentValues values = new ContentValues(3);
    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.MIME_TYPE, "audio/mp4");
    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));
}

两者都使用，我相信这一切都会正常工作。

晚安。