Android -- MediaRecord

MediaRecord

集成了录音、编码、压缩等，支持少量的录音音频格式，大概有.aac .amr .3gp

优点：大部分以及集成，直接调用相关接口即可，代码量小

缺点：无法实时处理音频；输出的音频格式不是很多，例如没有输出mp3格式文件

WAV格式：录音质量高，但是压缩率小，文件大

AAC格式：相对于mp3，AAC格式的音质更佳，文件更小；有损压缩；一般苹果或者Android SDK4.1.2（API 16）及以上版本支持播放

AMR格式：压缩比比较大，但相对其他的压缩格式质量比较差，多用于人声，通话录音

至于常用的mp3格式，使用MediaRecorder没有该视频格式输出。一些人的做法是使用AudioRecord录音，然后编码成wav格式，再转换成mp3格式

举个栗子

 MediaRecorder recorder = new MediaRecorder();  
 recorder.setAudioSource(MediaRecorder.AudioSource.MIC);  
 recorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);  
 recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);  
 recorder.setOutputFile(PATH_NAME);  
 recorder.prepare();  
 recorder.start();   // Recording is now started  
 //...  
 recorder.stop();  
 recorder.reset();   // You can reuse the object by going back to setAudioSource() step  
 recorder.release(); // Now the object cannot be reused

Demo

    public static final String DIR = Environment.getExternalStorageDirectory().getAbsolutePath() + File.separator + "1122" + File.separator;

    private Button mStartBtn;
    private Button mStopBtn;
    private MediaRecorder mMediaRecorder;
    private boolean mIsRecoding = false;

	@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_sound);
        mStartBtn = (Button) findViewById(R.id.btn_start);
        mStartBtn.setOnClickListener(this);
        mStopBtn = (Button) findViewById(R.id.btn_stop);
        mStopBtn.setOnClickListener(this);
        initSound();
    }

 	private void initSound() {
        mMediaRecorder = new MediaRecorder();
        // 从麦克风源进行录音
        mMediaRecorder.setAudioSource(MediaRecorder.AudioSource.DEFAULT);
        // 设置输出格式
        mMediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.DEFAULT);
        // 设置编码格式
        mMediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.DEFAULT);
    }

	@Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.btn_start:
                File dir = new File(DIR);
                if (!dir.exists()) {
                    dir.mkdir();
                }
                if (!mIsRecoding) {
                    long time = System.currentTimeMillis();
                    String fileName = time + ".amr";
                    File file = new File(DIR + fileName);
                    try {
                        file.createNewFile();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                    mMediaRecorder.setOutputFile(DIR + fileName);
                    try {
                        mMediaRecorder.prepare();
                        mMediaRecorder.start();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                    mIsRecoding = true;
                }
                break;
            case R.id.btn_stop:
                if (mIsRecoding) {
                    mMediaRecorder.stop();
                    mMediaRecorder.release();
                    mIsRecoding = false;
                }
                break;
        }
    }

权限

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