Android 录音

Android多媒体框架支持捕获并编码一系列的通用音频格式，你可以很容易的把它们集成在你的应用中，你可以在支持MediaRecorder的API的设备上使用MediaRecorder来录音。
本文展示了如何在应用中使用麦克来捕获声音，保存，回放。

注意：Android模拟器不能录音，请使用真实设备

执行录音

用设备录音比播放音视频要复杂一点点，不过还是相对简单的：
- 创建一个android.media.MediaRecorder的实例。
- 调用MediaRecorder.setAudioSource()来设置音频源，比如 MediaRecorder.AudioSource.MIC 。
- 调用MediaRecorder.setOutputFormat().
设置输出格式
- 调用MediaRecorder.setOutputFile()设置输出文件
- 调用using MediaRecorder.setAudioEncoder()设置编码器
- 调用MediaRecorder.prepare() 方法。
- 调用MediaRecorder.start()开始录音
- 调用MediaRecorder.stop()停止录音
- 当你不再使用MediaRecorder实例时，调用MediaRecorder.release()释放资源。

示例：录音/播放录音

下面的示例代码展示了如何建立，开始，停止录音。并播放录制的音频。

/* *如果需要把录音文件写到SD卡中，需要external storage的权限 *同时需要录音权限： * <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> * <uses-permission android:name="android.permission.RECORD_AUDIO" /> * */package com.android.audiorecordtest;import android.app.Activity;import android.widget.LinearLayout;import android.os.Bundle;import android.os.Environment;import android.view.ViewGroup;import android.widget.Button;import android.view.View;import android.view.View.OnClickListener;import android.content.Context;import android.util.Log;import android.media.MediaRecorder;import android.media.MediaPlayer;import java.io.IOException;public class AudioRecordTest extends Activity{    private static final String LOG_TAG = "AudioRecordTest";    private static String mFileName = null;    private RecordButton mRecordButton = null;    private MediaRecorder mRecorder = null;    private PlayButton   mPlayButton = null;    private MediaPlayer   mPlayer = null;    private void onRecord(boolean start) {        if (start) {            startRecording();        } else {            stopRecording();        }    }    private void onPlay(boolean start) {        if (start) {            startPlaying();        } else {            stopPlaying();        }    }    private void startPlaying() {        mPlayer = new MediaPlayer();        try {            mPlayer.setDataSource(mFileName);            mPlayer.prepare();            mPlayer.start();        } catch (IOException e) {            Log.e(LOG_TAG, "prepare() failed");        }    }    private void stopPlaying() {        mPlayer.release();        mPlayer = null;    }    private void startRecording() {        mRecorder = new MediaRecorder();        mRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);        mRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);        mRecorder.setOutputFile(mFileName);        mRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);        try {            mRecorder.prepare();        } catch (IOException e) {            Log.e(LOG_TAG, "prepare() failed");        }        mRecorder.start();    }    private void stopRecording() {        mRecorder.stop();        mRecorder.release();        mRecorder = null;    }    class RecordButton extends Button {        boolean mStartRecording = true;        OnClickListener clicker = new OnClickListener() {            public void onClick(View v) {                onRecord(mStartRecording);                if (mStartRecording) {                    setText("Stop recording");                } else {                    setText("Start recording");                }                mStartRecording = !mStartRecording;            }        };        public RecordButton(Context ctx) {            super(ctx);            setText("Start recording");            setOnClickListener(clicker);        }    }    class PlayButton extends Button {        boolean mStartPlaying = true;        OnClickListener clicker = new OnClickListener() {            public void onClick(View v) {                onPlay(mStartPlaying);                if (mStartPlaying) {                    setText("Stop playing");                } else {                    setText("Start playing");                }                mStartPlaying = !mStartPlaying;            }        };        public PlayButton(Context ctx) {            super(ctx);            setText("Start playing");            setOnClickListener(clicker);        }    }    public AudioRecordTest() {        mFileName = Environment.getExternalStorageDirectory().getAbsolutePath();        mFileName += "/audiorecordtest.3gp";    }    @Override    public void onCreate(Bundle icicle) {        super.onCreate(icicle);        LinearLayout ll = new LinearLayout(this);        mRecordButton = new RecordButton(this);        ll.addView(mRecordButton,            new LinearLayout.LayoutParams(                ViewGroup.LayoutParams.WRAP_CONTENT,                ViewGroup.LayoutParams.WRAP_CONTENT,                0));        mPlayButton = new PlayButton(this);        ll.addView(mPlayButton,            new LinearLayout.LayoutParams(                ViewGroup.LayoutParams.WRAP_CONTENT,                ViewGroup.LayoutParams.WRAP_CONTENT,                0));        setContentView(ll);    }    @Override    public void onPause() {        super.onPause();        if (mRecorder != null) {            mRecorder.release();            mRecorder = null;        }        if (mPlayer != null) {            mPlayer.release();            mPlayer = null;        }    }}