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
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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
}
}
}
}
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