Reprinted -java to convert audio into pcm wav format

Original link: https://blog.csdn.net/qq_25925973/article/details/90441386

PCM (Pulse Code Modulation) PCM digital communication encoding one. The main process is the voice, image and other analog signal is sampled every certain time, so that the discretization, while the sample values rounded to the nearest whole hierarchical quantization unit, while the sample values by a set of binary codes to represent the amplitude of the sampling pulse value.

Want to listen to audio pcm direct need for professional software can, here I need to convert audio wav pcm for this lossless format, which is the need to add pcm wav audio file in the head, so you can use direct audio software open . Use Java to achieve below

 

 1 package com.test.shell;
 2 
 3 import java.io.*;
 4 import com.alibaba.druid.util.StringUtils;
 5 
 6 public class ShellUtils {
 7     public static File tranPcmToWavFile(File pcmFile) {
 8         FileInputStream fis = null;
 9         FileOutputStream fos = null;
10         try {
11             fis = new FileInputStream(pcmFile);
12             String wavfilepath = pcmFile.getAbsolutePath().substring(0, pcmFile.getAbsolutePath().lastIndexOf(".")) + "." + SysConstants.IVR_SPEAK_TYPE_WAV.toLowerCase();
13 
14 
15             File file = new File(wavfilepath);
16             if (!file.exists()) {
17                 file.createNewFile();
18             }
19             fos = new FileOutputStream(wavfilepath);
20 
21 
22             int PCMSize = 0;
23             byte[] buf = new byte[1024 * 4];
24              int size = fis.read (buf);
 25  
26 is              the while (size = -1! ) {
 27                  PCMSize + = size;
 28                  size = fis.read (buf);
 29              }
 30              fis.close ();
 31 is  
32              / / fill in the parameters, bit rate and so on. As used herein is a 16-bit mono Hz 8000 
33 is  
34 is              waveheader header = new new waveheader ();
 35              // Length Field size = content (PCMSize) + header size field (not including the front of the 4-byte identifier RIFF fileLength itself and 4-byte) 
36              header.fileLength PCMSize + = (44 is -. 8 );
 37 [             header.FmtHdrLeth = 16;
38             header.BitsPerSample = 16;
39             header.Channels = 1;
40             header.FormatTag = 0x0001;
41             header.SamplesPerSec = 8000;
42             header.BlockAlign = (short) (header.Channels * header.BitsPerSample / 8);
43             header.AvgBytesPerSec = header.BlockAlign * header.SamplesPerSec;
44             header.DataHdrLeth = PCMSize;
45 
46             byte[] h = header.getHeader();
47 
48             assert h.length == 44; //WAV标准，头部应该是44字节
49             //write header
50             fos.write(h, 0, h.length);
51             //write data stream
52             fis = new FileInputStream(pcmFile);
53             size = fis.read(buf);
54             while (size != -1) {
55                 fos.write(buf, 0, size);
56                 size = fis.read(buf);
57             }
58             fis.close();
59             fos.close();
60             return new File(wavfilepath);
61         } catch (Exception e) {
62             e.printStackTrace();
63         } finally {
64             if (fis != null) {
65                 try {
66                     fis.close();
67                 } catch (IOException e) {
68                     e.printStackTrace();
69                 }
70             }
71             if (fos != null) {
72                 try {
73                     fos.close();
74                 } catch (IOException e) {
75                     e.printStackTrace();
76                 }
77             }
78         }
79         return null;
80     }
81 }

2, wherein used WaveHeader is as follows:

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;
    intpublic  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);
        }
    }
}