博主目前所在的公司是一家做视频通讯的公司,所以对音频,视频这一块对编码方式都有一定的要求,由于之前一直没有接触JNI这一块,突然让我去做音频的转码还是有一定的苦难的。一开始对于JNI编程我是拒绝的,一直遵循着能用java源码,就绝不用Jni那一块。但是,显示总是残酷的,网上的资料,Demo很少,或者都是年代久远,还不能运行的。所以我抱着试一试的心态去接触JNI,也还蛮有收获的,好了废话了这么多,也该进入主题了。
AndroidStudio项目,在安卓平台下,调用G.711 C++编解码方法进行音频源的编码和解码。Demo在文章末尾。
http://download.csdn.net/download/orient1860/7691041 待会我demo里面也有
package com.chezi008.hellojni.encode;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.graphics.PixelFormat;
import android.media.AudioFormat;
import android.media.AudioRecord;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Window;
import android.view.WindowManager;
import android.widget.Button;
import com.chezi008.hellojni.R;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
/**
* 描述:G.711 编码与解码
* 作者:chezi008 on 2017/3/10 16:33
* 邮箱:[email protected]
*/
@SuppressLint("SdCardPath")
public class G711DecoderActivity extends Activity {
// 音频获取源
private int audioSource = MediaRecorder.AudioSource.MIC;
// 设置音频采样率,44100是目前的标准,但是某些设备仍然支持22050,16000,11025
private static int sampleRateInHz = 8000;
// 设置音频的录制的声道CHANNEL_I N_STEREO为双声道,CHANNEL_CONFIGURATION_MONO为单声道
private static int channelConfig = AudioFormat.CHANNEL_IN_STEREO;
// 音频数据格式:PCM 16位每个样本。保证设备支持。PCM 8位每个样本。不一定能得到设备支持。
private static int audioFormat = AudioFormat.ENCODING_PCM_16BIT;
// 缓冲区字节大小
private int bufferSizeInBytes = 0;
private Button Start;
private Button Stop;
private Button convert;
private AudioRecord audioRecord;
private boolean isRecord = false;// 设置正在录制的状态
//AudioName裸音频数据文件,编码后的文件
private static final String AudioName = "/sdcard/end.g711";
//解码后的文件
private static final String AudioDecodeName = "/sdcard/endDecode.g711";
//NewAudioName可播放的音频文件
private static final String NewAudioName = "/sdcard/new.wav";
private G711Decoder codec;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getWindow().setFormat(PixelFormat.TRANSLUCENT);// 让界面横屏
requestWindowFeature(Window.FEATURE_NO_TITLE);// 去掉界面标题
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
// 重新设置界面大小
setContentView(R.layout.activity_g711);
init();
}
private void init() {
Start = (Button) this.findViewById(R.id.start);
Stop = (Button) this.findViewById(R.id.stop);
convert = (Button) findViewById(R.id.convert);
Start.setOnClickListener(new TestAudioListener());
Stop.setOnClickListener(new TestAudioListener());
convert.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// new PlayTask().execute();
new Thread(new AudioConvert()).start();
}
});
codec = new G711Decoder();
creatAudioRecord();
}
private void creatAudioRecord() {
// 获得缓冲区字节大小
bufferSizeInBytes = AudioRecord.getMinBufferSize(sampleRateInHz,
channelConfig, audioFormat);
// 创建AudioRecord对象
audioRecord = new AudioRecord(audioSource, sampleRateInHz,
channelConfig, audioFormat, bufferSizeInBytes);
}
class TestAudioListener implements OnClickListener {
@Override
public void onClick(View v) {
if (v == Start) {
startRecord();
}
if (v == Stop) {
stopRecord();
}
}
}
private void startRecord() {
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();
}
private void stopRecord() {
close();
}
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;
}
}
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
}
}
class AudioConvert implements Runnable {
@Override
public void run() {
decodeAudio(AudioName, AudioDecodeName);
copyWaveFile(AudioDecodeName, NewAudioName);//给裸数据加上头文件
}
}
/**
* 解码音频文件
* @param inFilename
* @param outFilename
*/
private void decodeAudio(String inFilename, String outFilename) {
FileInputStream in = null;
FileOutputStream out = null;
byte[] data = new byte[1024];
byte[] outData = new byte[2048];//这里特别注意outData是data的两倍,之前不知道,一直卡在这里,是的解码进行不下去
try {
in = new FileInputStream(inFilename);
out = new FileOutputStream(outFilename);
int length = 0;
while ((length = in.read(data)) != -1) {
codec.VoiceDecode(data, outData, length);
out.write(outData);
}
in.close();
out.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* 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);
byte[] alawData = new byte[readsize];
if (AudioRecord.ERROR_INVALID_OPERATION != readsize) {
try {
int len = codec.VoiceEncode(audiodata, alawData, readsize); //调用C代码进行编码
fos.write(alawData, 0, len); //保存到本地
} catch (IOException e) {
e.printStackTrace();
}
}
}
try {
fos.close();// 关闭写入流
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* 解码后增加音频文件的头部,是的文件可播放
* @param inFilename
* @param outFilename
*/
private void copyWaveFile(String inFilename, String outFilename) {
FileInputStream in = null;
FileOutputStream out = null;
long totalAudioLen = 0;
long totalDataLen = totalAudioLen + 36;
long longSampleRate = sampleRateInHz;
int channels = 2;
long byteRate = 16 * sampleRateInHz * 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);
}
@Override
protected void onDestroy() {
close();
super.onDestroy();
}
}
http://download.csdn.net/detail/chezi008/9777122