java将pcm音频转换成wav格式

1、工具类。

package com.test.shell;

import java.io.*;
import com.alibaba.druid.util.StringUtils;

public class ShellUtils {
	public static File tranPcmToWavFile(File pcmFile) {
		FileInputStream fis = null;
		FileOutputStream fos = null;
		try {
			fis = new FileInputStream(pcmFile);
			String wavfilepath = pcmFile.getAbsolutePath().substring(0, pcmFile.getAbsolutePath().lastIndexOf(".")) + "." + SysConstants.IVR_SPEAK_TYPE_WAV.toLowerCase();


			File file = new File(wavfilepath);
			if (!file.exists()) {
				file.createNewFile();
			}
			fos = new FileOutputStream(wavfilepath);


			int PCMSize = 0;
			byte[] buf = new byte[1024 * 4];
			int size = fis.read(buf);

			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 = 8000;
			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(pcmFile);
			size = fis.read(buf);
			while (size != -1) {
				fos.write(buf, 0, size);
				size = fis.read(buf);
			}
			fis.close();
			fos.close();
			return new File(wavfilepath);
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			if (fis != null) {
				try {
					fis.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			if (fos != null) {
				try {
					fos.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
		return null;
	}
}

2、其中用到的WaveHeader 如下：

package com.test.shell;

import java.io.ByteArrayOutputStream;
import java.io.IOException;

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