换WAV格式

public class WavWriter {

public void convertAudioFiles(String src, String target) throws Exception {
FileInputStream fis = new FileInputStream(src);
FileOutputStream fos = new FileOutputStream(target);

//计算长度
byte[] buf = new byte[1024 * 4];
int size = fis.read(buf);
int PCMSize = 0;
while (size != -1) {
PCMSize += size;
size = fis.read(buf);
}
fis.close();

//填入参数，比特率等等。这里用的是16位单声道 8000 hz
WaveHeader header = new WaveHeader();
//长度字段 = 内容的大小（PCMSize) + 头部字段的大小(不包括前面4字节的标识符RIFF以及fileLength本身的4字节)
header.fileLength = PCMSize + (44 - 8);
header.FmtHdrLeth = 16;
header.BitsPerSample = 16;
header.Channels = 1;
header.FormatTag = 0x0001;
header.SamplesPerSec = 16000;
header.BlockAlign = (short)(header.Channels * header.BitsPerSample / 8);
header.AvgBytesPerSec = header.BlockAlign * header.SamplesPerSec;
header.DataHdrLeth = PCMSize;

byte[] h = header.getHeader();

assert h.length == 44; //WAV标准，头部应该是44字节
//write header
fos.write(h, 0, h.length);
//write data stream
fis = new FileInputStream(src);
size = fis.read(buf);
while (size != -1) {
fos.write(buf, 0, size);
size = fis.read(buf);
}
fis.close();
fos.close();
System.out.println("Convert OK!");
}

public class WaveHeader {
public final char fileID[] = {'R', 'I', 'F', 'F'};
public int fileLength;
public char wavTag[] = {'W', 'A', 'V', 'E'};;
public char FmtHdrID[] = {'f', 'm', 't', ' '};
public int FmtHdrLeth;
public short FormatTag;
public short Channels;
public int SamplesPerSec;
public int AvgBytesPerSec;
public short BlockAlign;
public short BitsPerSample;
public char DataHdrID[] = {'d','a','t','a'};
public int DataHdrLeth;

public byte[] getHeader() throws IOException {
ByteArrayOutputStream bos = new ByteArrayOutputStream();
WriteChar(bos, fileID);
WriteInt(bos, fileLength);
WriteChar(bos, wavTag);
WriteChar(bos, FmtHdrID);
WriteInt(bos,FmtHdrLeth);
WriteShort(bos,FormatTag);
WriteShort(bos,Channels);
WriteInt(bos,SamplesPerSec);
WriteInt(bos,AvgBytesPerSec);
WriteShort(bos,BlockAlign);
WriteShort(bos,BitsPerSample);
WriteChar(bos,DataHdrID);
WriteInt(bos,DataHdrLeth);
bos.flush();
byte[] r = bos.toByteArray();
bos.close();
return r;
}

private void WriteShort(ByteArrayOutputStream bos, int s) throws IOException {
byte[] mybyte = new byte[2];
mybyte[1] =(byte)( (s << 16) >> 24 );
mybyte[0] =(byte)( (s << 24) >> 24 );
bos.write(mybyte);
}

private void WriteInt(ByteArrayOutputStream bos, int n) throws IOException {
byte[] buf = new byte[4];
buf[3] =(byte)( n >> 24 );
buf[2] =(byte)( (n << 8) >> 24 );
buf[1] =(byte)( (n << 16) >> 24 );
buf[0] =(byte)( (n << 24) >> 24 );
bos.write(buf);
}

private void WriteChar(ByteArrayOutputStream bos, char[] id) {
for (int i=0; i<id.length; i++) {
char c = id[i];
bos.write(c);
}
}
}

}