发布于 2017-09-25 07:53:58 | 166 次阅读 | 评论: 0 | 来源: 网友投递
Android移动端操作系统
Android是一种基于Linux的自由及开放源代码的操作系统，主要使用于移动设备，如智能手机和平板电脑，由Google公司和开放手机联盟领导及开发。尚未有统一中文名称，中国大陆地区较多人使用“安卓”或“安致”。
Android提供了两个API用于实现录音功能：android.media.AudioRecord、android.media.MediaRecorder。
网上有很多谈论这两个类的资料。现在大致总结下：
1、AudioRecord
主要是实现边录边播（AudioRecord+AudioTrack）以及对音频的实时处理（如会说话的汤姆猫、语音）
优点：语音的实时处理，可以用代码实现各种音频的封装
缺点：输出是PCM语音数据，如果保存成音频文件，是不能够被播放器播放的，所以必须先写代码实现数据编码以及压缩
示例：
使用AudioRecord类录音，并实现WAV格式封装。录音20s，输出的音频文件大概为3.5M左右（已写测试代码）
2、MediaRecorder
已经集成了录音、编码、压缩等，支持少量的录音音频格式，大概有.aac（API = 16） .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
示例：
使用MediaRecorder类录音，输出amr格式文件。录音20s，输出的音频文件大概为33K（已写测试代码）
3、音频格式比较
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
再贴上一些测试工程。
功能描述：
1、点击“录音WAV文件”，开始录音。录音完成后，生成文件/sdcard/FinalAudio.wav
2、点击“录音AMR文件”，开始录音。录音完成后，生成文件/sdcard/FinalAudio.amr
3、点击“停止录音”，停止录音，并显示录音输出文件以及该文件大小。
大致代码如下：
1、AudioRecord录音，封装成WAV格式
package com.example.audiorecordtest;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import android.media.AudioFormat;
import android.media.AudioRecord;
public class AudioRecordFunc {
// 缓冲区字节大小
private int bufferSizeInBytes = 0;
//AudioName裸音频数据文件 ，麦克风
private String AudioName = "";
//NewAudioName可播放的音频文件
private String NewAudioName = "";
private AudioRecord audioRecord;
private boolean isRecord = false;// 设置正在录制的状态
private static AudioRecordFunc mInstance;
private AudioRecordFunc(){
}
public synchronized static AudioRecordFunc getInstance()
{
if(mInstance == null)
mInstance = new AudioRecordFunc();
return mInstance;
}
public int startRecordAndFile() {
//判断是否有外部存储设备sdcard
if(AudioFileFunc.isSdcardExit())
{
if(isRecord)
{
return ErrorCode.E_STATE_RECODING;
}
else
{
if(audioRecord == null)
creatAudioRecord();
audioRecord.startRecording();
// 让录制状态为true
isRecord = true;
// 开启音频文件写入线程
new Thread(new AudioRecordThread()).start();
return ErrorCode.SUCCESS;
}
}
else
{
return ErrorCode.E_NOSDCARD;
}
}
public void stopRecordAndFile() {
close();
}
public long getRecordFileSize(){
return AudioFileFunc.getFileSize(NewAudioName);
}
private void close() {
if (audioRecord != null) {
System.out.println("stopRecord");
isRecord = false;//停止文件写入
audioRecord.stop();
audioRecord.release();//释放资源
audioRecord = null;
}
}
private void creatAudioRecord() {
// 获取音频文件路径
AudioName = AudioFileFunc.getRawFilePath();
NewAudioName = AudioFileFunc.getWavFilePath();
// 获得缓冲区字节大小
bufferSizeInBytes = AudioRecord.getMinBufferSize(AudioFileFunc.AUDIO_SAMPLE_RATE,
AudioFormat.CHANNEL_IN_STEREO, AudioFormat.ENCODING_PCM_16BIT);
// 创建AudioRecord对象
audioRecord = new AudioRecord(AudioFileFunc.AUDIO_INPUT, AudioFileFunc.AUDIO_SAMPLE_RATE,
AudioFormat.CHANNEL_IN_STEREO, AudioFormat.ENCODING_PCM_16BIT, bufferSizeInBytes);
}
class AudioRecordThread implements Runnable {
@Override
public void run() {
writeDateTOFile();//往文件中写入裸数据
copyWaveFile(AudioName, NewAudioName);//给裸数据加上头文件
}
}
/**
* 这里将数据写入文件，但是并不能播放，因为AudioRecord获得的音频是原始的裸音频，
* 如果需要播放就必须加入一些格式或者编码的头信息。但是这样的好处就是你可以对音频的 裸数据进行处理，比如你要做一个爱说话的TOM
* 猫在这里就进行音频的处理，然后重新封装 所以说这样得到的音频比较容易做一些音频的处理。
*/
private void writeDateTOFile() {
// new一个byte数组用来存一些字节数据，大小为缓冲区大小
byte[] audiodata = new byte[bufferSizeInBytes];
FileOutputStream fos = null;
int readsize = 0;
try {
File file = new File(AudioName);
if (file.exists()) {
file.delete();
}
fos = new FileOutputStream(file);// 建立一个可存取字节的文件
} catch (Exception e) {
e.printStackTrace();
}
while (isRecord == true) {
readsize = audioRecord.read(audiodata, 0, bufferSizeInBytes);
if (AudioRecord.ERROR_INVALID_OPERATION != readsize && fos!=null) {
try {
fos.write(audiodata);
} catch (IOException e) {
e.printStackTrace();
}
}
}
try {
if(fos != null)
fos.close();// 关闭写入流
} catch (IOException e) {
e.printStackTrace();
}
}
// 这里得到可播放的音频文件
private void copyWaveFile(String inFilename, String outFilename) {
FileInputStream in = null;
FileOutputStream out = null;
long totalAudioLen = 0;
long totalDataLen = totalAudioLen + 36;
long longSampleRate = AudioFileFunc.AUDIO_SAMPLE_RATE;
int channels = 2;
long byteRate = 16 * AudioFileFunc.AUDIO_SAMPLE_RATE * channels / 8;
byte[] data = new byte[bufferSizeInBytes];
try {
in = new FileInputStream(inFilename);
out = new FileOutputStream(outFilename);
totalAudioLen = in.getChannel().size();
totalDataLen = totalAudioLen + 36;
WriteWaveFileHeader(out, totalAudioLen, totalDataLen,
longSampleRate, channels, byteRate);
while (in.read(data) != -1) {
out.write(data);
}
in.close();
out.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* 这里提供一个头信息。插入这些信息就可以得到可以播放的文件。
* 为我为啥插入这44个字节，这个还真没深入研究，不过你随便打开一个wav
* 音频的文件，可以发现前面的头文件可以说基本一样哦。每种格式的文件都有
* 自己特有的头文件。
*/
private void WriteWaveFileHeader(FileOutputStream out, long totalAudioLen,
long totalDataLen, long longSampleRate, int channels, long byteRate)
throws IOException {
byte[] header = new byte[44];
header[0] = 'R'; // RIFF/WAVE header
header[1] = 'I';
header[2] = 'F';
header[3] = 'F';
header[4] = (byte) (totalDataLen & 0xff);
header[5] = (byte) ((totalDataLen >> 8) & 0xff);
header[6] = (byte) ((totalDataLen >> 16) & 0xff);
header[7] = (byte) ((totalDataLen >> 24) & 0xff);
header[8] = 'W';
header[9] = 'A';
header[10] = 'V';
header[11] = 'E';
header[12] = 'f'; // 'fmt ' chunk
header[13] = 'm';
header[14] = 't';
header[15] = ' ';
header[16] = 16; // 4 bytes: size of 'fmt ' chunk
header[17] = 0;
header[18] = 0;
header[19] = 0;
header[20] = 1; // format = 1
header[21] = 0;
header[22] = (byte) channels;
header[23] = 0;
header[24] = (byte) (longSampleRate & 0xff);
header[25] = (byte) ((longSampleRate >> 8) & 0xff);
header[26] = (byte) ((longSampleRate >> 16) & 0xff);
header[27] = (byte) ((longSampleRate >> 24) & 0xff);
header[28] = (byte) (byteRate & 0xff);
header[29] = (byte) ((byteRate >> 8) & 0xff);
header[30] = (byte) ((byteRate >> 16) & 0xff);
header[31] = (byte) ((byteRate >> 24) & 0xff);
header[32] = (byte) (2 * 16 / 8); // block align
header[33] = 0;
header[34] = 16; // bits per sample
header[35] = 0;
header[36] = 'd';
header[37] = 'a';
header[38] = 't';
header[39] = 'a';
header[40] = (byte) (totalAudioLen & 0xff);
header[41] = (byte) ((totalAudioLen >> 8) & 0xff);
header[42] = (byte) ((totalAudioLen >> 16) & 0xff);
header[43] = (byte) ((totalAudioLen >> 24) & 0xff);
out.write(header, 0, 44);
}
}
2、MediaRecorder录音，输出amr格式音频
package com.example.audiorecordtest;
import java.io.File;
import java.io.IOException;
import android.media.MediaRecorder;
public class MediaRecordFunc {
private boolean isRecord = false;
private MediaRecorder mMediaRecorder;
private MediaRecordFunc(){
}
private static MediaRecordFunc mInstance;
public synchronized static MediaRecordFunc getInstance(){
if(mInstance == null)
mInstance = new MediaRecordFunc();
return mInstance;
}
public int startRecordAndFile(){
//判断是否有外部存储设备sdcard
if(AudioFileFunc.isSdcardExit())
{
if(isRecord)
{
return ErrorCode.E_STATE_RECODING;
}
else
{
if(mMediaRecorder == null)
createMediaRecord();
try{
mMediaRecorder.prepare();
mMediaRecorder.start();
// 让录制状态为true
isRecord = true;
return ErrorCode.SUCCESS;
}catch(IOException ex){
ex.printStackTrace();
return ErrorCode.E_UNKOWN;
}
}
}
else
{
return ErrorCode.E_NOSDCARD;
}
}
public void stopRecordAndFile(){
close();
}
public long getRecordFileSize(){
return AudioFileFunc.getFileSize(AudioFileFunc.getAMRFilePath());
}
private void createMediaRecord(){
/* ①Initial：实例化MediaRecorder对象 */
mMediaRecorder = new MediaRecorder();
/* setAudioSource/setVedioSource*/
mMediaRecorder.setAudioSource(AudioFileFunc.AUDIO_INPUT);//设置麦克风
/* 设置输出文件的格式：THREE_GPP/MPEG-4/RAW_AMR/Default
* THREE_GPP(3gp格式，H263视频/ARM音频编码)、MPEG-4、RAW_AMR(只支持音频且音频编码要求为AMR_NB)
*/
mMediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.DEFAULT);
/* 设置音频文件的编码：AAC/AMR_NB/AMR_MB/Default */
mMediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.DEFAULT);
/* 设置输出文件的路径 */
File file = new File(AudioFileFunc.getAMRFilePath());
if (file.exists()) {
file.delete();
}
mMediaRecorder.setOutputFile(AudioFileFunc.getAMRFilePath());
}
private void close(){
if (mMediaRecorder != null) {
System.out.println("stopRecord");
isRecord = false;
mMediaRecorder.stop();
mMediaRecorder.release();
mMediaRecorder = null;
}
}
}
3、其他文件
AudioFileFunc.java
package com.example.audiorecordtest;
import java.io.File;
import android.media.MediaRecorder;
import android.os.Environment;
public class AudioFileFunc {
//音频输入-麦克风
public final static int AUDIO_INPUT = MediaRecorder.AudioSource.MIC;
//采用频率
//44100是目前的标准，但是某些设备仍然支持22050，16000，11025
public final static int AUDIO_SAMPLE_RATE = 44100; //44.1KHz,普遍使用的频率
//录音输出文件
private final static String AUDIO_RAW_FILENAME = "RawAudio.raw";
private final static String AUDIO_WAV_FILENAME = "FinalAudio.wav";
public final static String AUDIO_AMR_FILENAME = "FinalAudio.amr";
/**
* 判断是否有外部存储设备sdcard
* @return true | false
*/
public static boolean isSdcardExit(){
if (Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED))
return true;
else
return false;
}
/**
* 获取麦克风输入的原始音频流文件路径
* @return
*/
public static String getRawFilePath(){
String mAudioRawPath = "";
if(isSdcardExit()){
String fileBasePath = Environment.getExternalStorageDirectory().getAbsolutePath();
mAudioRawPath = fileBasePath+"/"+AUDIO_RAW_FILENAME;
}
return mAudioRawPath;
}
/**
* 获取编码后的WAV格式音频文件路径
* @return
*/
public static String getWavFilePath(){
String mAudioWavPath = "";
if(isSdcardExit()){
String fileBasePath = Environment.getExternalStorageDirectory().getAbsolutePath();
mAudioWavPath = fileBasePath+"/"+AUDIO_WAV_FILENAME;
}
return mAudioWavPath;
}
/**
* 获取编码后的AMR格式音频文件路径
* @return
*/
public static String getAMRFilePath(){
String mAudioAMRPath = "";
if(isSdcardExit()){
String fileBasePath = Environment.getExternalStorageDirectory().getAbsolutePath();
mAudioAMRPath = fileBasePath+"/"+AUDIO_AMR_FILENAME;
}
return mAudioAMRPath;
}
/**
* 获取文件大小
* @param path,文件的绝对路径
* @return
*/
public static long getFileSize(String path){
File mFile = new File(path);
if(!mFile.exists())
return -1;
return mFile.length();
}
}
4、其他文件
ErrorCode.java
package com.example.audiorecordtest;
import android.content.Context;
import android.content.res.Resources.NotFoundException;
public class ErrorCode {
public final static int SUCCESS = 1000;
public final static int E_NOSDCARD = 1001;
public final static int E_STATE_RECODING = 1002;
public final static int E_UNKOWN = 1003;
public static String getErrorInfo(Context vContext, int vType) throws NotFoundException
{
switch(vType)
{
case SUCCESS:
return "success";
case E_NOSDCARD:
return vContext.getResources().getString(R.string.error_no_sdcard);
case E_STATE_RECODING:
return vContext.getResources().getString(R.string.error_state_record);
case E_UNKOWN:
default:
return vContext.getResources().getString(R.string.error_unknown);
}
}
}
5、string.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="app_name">AudioRecordTest</string>
<string name="hello_world">测试AudioRecord，实现录音功能</string>
<string name="menu_settings">Settings</string>
<string name="view_record_wav">录音WAV文件</string>
<string name="view_record_amr">录音AMR文件</string>
<string name="view_stop">停止录音</string>
<string name="error_no_sdcard">没有SD卡，无法存储录音数据</string>
<string name="error_state_record">正在录音中，请先停止录音</string>
<string name="error_unknown">无法识别的错误</string>
</resources> 6、主程序MainActivity
package com.example.audiorecordtest;
import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
public class MainActivity extends Activity {
private final static int FLAG_WAV = 0;
private final static int FLAG_AMR = 1;
private int mState = -1; //-1:没再录制，0：录制wav，1：录制amr
private Button btn_record_wav;
private Button btn_record_amr;
private Button btn_stop;
private TextView txt;
private UIHandler uiHandler;
private UIThread uiThread;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
findViewByIds();
setListeners();
init();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
private void findViewByIds(){
btn_record_wav = (Button)this.findViewById(R.id.btn_record_wav);
btn_record_amr = (Button)this.findViewById(R.id.btn_record_amr);
btn_stop = (Button)this.findViewById(R.id.btn_stop);
txt = (TextView)this.findViewById(R.id.text);
}
private void setListeners(){
btn_record_wav.setOnClickListener(btn_record_wav_clickListener);
btn_record_amr.setOnClickListener(btn_record_amr_clickListener);
btn_stop.setOnClickListener(btn_stop_clickListener);
}
private void init(){
uiHandler = new UIHandler();
}
private Button.OnClickListener btn_record_wav_clickListener = new Button.OnClickListener(){
public void onClick(View v){
record(FLAG_WAV);
}
};
private Button.OnClickListener btn_record_amr_clickListener = new Button.OnClickListener(){
public void onClick(View v){
record(FLAG_AMR);
}
};
private Button.OnClickListener btn_stop_clickListener = new Button.OnClickListener(){
public void onClick(View v){
stop();
}
};
/**
* 开始录音
* @param mFlag，0：录制wav格式，1：录音amr格式
*/
private void record(int mFlag){
if(mState != -1){
Message msg = new Message();
Bundle b = new Bundle();// 存放数据
b.putInt("cmd",CMD_RECORDFAIL);
b.putInt("msg", ErrorCode.E_STATE_RECODING);
msg.setData(b);
uiHandler.sendMessage(msg); // 向Handler发送消息,更新UI
return;
}
int mResult = -1;
switch(mFlag){
case FLAG_WAV:
AudioRecordFunc mRecord_1 = AudioRecordFunc.getInstance();
mResult = mRecord_1.startRecordAndFile();
break;
case FLAG_AMR:
MediaRecordFunc mRecord_2 = MediaRecordFunc.getInstance();
mResult = mRecord_2.startRecordAndFile();
break;
}
if(mResult == ErrorCode.SUCCESS){
uiThread = new UIThread();
new Thread(uiThread).start();
mState = mFlag;
}else{
Message msg = new Message();
Bundle b = new Bundle();// 存放数据
b.putInt("cmd",CMD_RECORDFAIL);
b.putInt("msg", mResult);
msg.setData(b);
uiHandler.sendMessage(msg); // 向Handler发送消息,更新UI
}
}
/**
* 停止录音
*/
private void stop(){
if(mState != -1){
switch(mState){
case FLAG_WAV:
AudioRecordFunc mRecord_1 = AudioRecordFunc.getInstance();
mRecord_1.stopRecordAndFile();
break;
case FLAG_AMR:
MediaRecordFunc mRecord_2 = MediaRecordFunc.getInstance();
mRecord_2.stopRecordAndFile();
break;
}
if(uiThread != null){
uiThread.stopThread();
}
if(uiHandler != null)
uiHandler.removeCallbacks(uiThread);
Message msg = new Message();
Bundle b = new Bundle();// 存放数据
b.putInt("cmd",CMD_STOP);
b.putInt("msg", mState);
msg.setData(b);
uiHandler.sendMessageDelayed(msg,1000); // 向Handler发送消息,更新UI
mState = -1;
}
}
private final static int CMD_RECORDING_TIME = 2000;
private final static int CMD_RECORDFAIL = 2001;
private final static int CMD_STOP = 2002;
class UIHandler extends Handler{
public UIHandler() {
}
@Override
public void handleMessage(Message msg) {
// TODO Auto-generated method stub
Log.d("MyHandler", "handleMessage......");
super.handleMessage(msg);
Bundle b = msg.getData();
int vCmd = b.getInt("cmd");
switch(vCmd)
{
case CMD_RECORDING_TIME:
int vTime = b.getInt("msg");
MainActivity.this.txt.setText("正在录音中，已录制："+vTime+" s");
break;
case CMD_RECORDFAIL:
int vErrorCode = b.getInt("msg");
String vMsg = ErrorCode.getErrorInfo(MainActivity.this, vErrorCode);
MainActivity.this.txt.setText("录音失败："+vMsg);
break;
case CMD_STOP:
int vFileType = b.getInt("msg");
switch(vFileType){
case FLAG_WAV:
AudioRecordFunc mRecord_1 = AudioRecordFunc.getInstance();
long mSize = mRecord_1.getRecordFileSize();
MainActivity.this.txt.setText("录音已停止.录音文件:"+AudioFileFunc.getWavFilePath()+"\n文件大小："+mSize);
break;
case FLAG_AMR:
MediaRecordFunc mRecord_2 = MediaRecordFunc.getInstance();
mSize = mRecord_2.getRecordFileSize();
MainActivity.this.txt.setText("录音已停止.录音文件:"+AudioFileFunc.getAMRFilePath()+"\n文件大小："+mSize);
break;
}
break;
default:
break;
}
}
};
class UIThread implements Runnable {
int mTimeMill = 0;
boolean vRun = true;
public void stopThread(){
vRun = false;
}
public void run() {
while(vRun){
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
mTimeMill ++;
Log.d("thread", "mThread........"+mTimeMill);
Message msg = new Message();
Bundle b = new Bundle();// 存放数据
b.putInt("cmd",CMD_RECORDING_TIME);
b.putInt("msg", mTimeMill);
msg.setData(b);
MainActivity.this.uiHandler.sendMessage(msg); // 向Handler发送消息,更新UI
}
}
}
}
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持PHPERZ。