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<id.length; i++) { char c = id[i]; bos.write(c); } } }