C读取DAT，提取AD数据，转成WAV文件

 

 wav 文件格式参考资料：http://www.sonicspot.com/guide/wavefiles.html

DAT数据格式 5A 5A 5A 5A xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx ( 帧头 ) 帧头后面依次为第一块AD通道1数据（2 byte），第二块AD通道1数据（2 byte），第一块AD通道2数据（2 byte），第二块AD通道2数据（2 byte），.。。。。。。。。第一块AD通道6数据（2 byte），第二块AD通道6数据（2 byte）。我提取的是第一块AD通道6数据。然后进行转成16bit，然后-32768变成正负信号，因为AD采集的是0-5V信号，减去32768将其变成-2.5V~+2.5V。然后根据wav文件结构将其写入wav文件.

  1 #include <stdio.h>
  2 #include <stdlib.h>
  3 
  4 #define SIZE 1000*1024
  5 
  6 typedef struct twav_header
  7 {
  8     // RIFF WAVE chunk, 12 bytes
  9     unsigned char RIFF[4];
 10     unsigned int  dwFilesize;
 11     unsigned char WAVE[4];
 12     
 13     // Format chunk, 24 bytes
 14     unsigned char fmt[4];
 15     unsigned int  dwChunksize;
 16     unsigned short wCompress;
 17     unsigned short wChannelnum;
 18     unsigned int   dwSamplerate;
 19     unsigned int   dwBytepersec;
 20     unsigned short wBlockAlign;
 21     unsigned short wBitsPerSample;
 22     
 23     // Data chunk, 8 bytes
 24     unsigned char data[4];
 25     unsigned int  dwDataSize;
 26 }wav_header;
 27 
 28 char riff[4] = {'R','I','F','F'};
 29 char wav[4]  = {'W','A','V','E'};
 30 char fmt[4]  = {'f','m','t', 0x20};
 31 char data[4] = {'d','a','t','a'};
 32 
 33 int main()
 34 {
 35     wav_header wavhead;
 36     FILE *fp;
 37     FILE *fpout;
 38     char infile[10], outfile[10];
 39     unsigned char * pBuffer;
 40     unsigned short * pwBuffer;
 41     unsigned short * pw11Buffer;
 42     unsigned short * pwnormBuffer; // Normalized data buffer
 43     int i,cnt,channelno;
 44     
 45     pBuffer    = (unsigned char  *)malloc( SIZE     *sizeof(unsigned char) );
 46     memset(pBuffer, 0, SIZE);
 47     
 48     pwBuffer   = (unsigned short *)malloc( (SIZE/2 )*sizeof(unsigned short) );
 49     memset(pBuffer,    0, (SIZE/2 )*sizeof(unsigned short));
 50     
 51     pw11Buffer = (unsigned short *)malloc( (SIZE/12)*sizeof(unsigned short) );
 52     memset(pw11Buffer, 0, (SIZE/12)*sizeof(unsigned short));
 53     
 54     pwnormBuffer = (unsigned short *)malloc( (SIZE/12)*sizeof(unsigned short) );
 55     memset(pwnormBuffer, 0, (SIZE/12)*sizeof(unsigned short));
 56     
 57     puts("Input file name:");
 58     gets(infile);
 59     puts("Output file name:");
 60     gets(outfile);
 61     puts("Channel no(1-12):");
 62     scanf("%d", &channelno);
 63 
 64     if( (fp=fopen(infile, "rb")) == NULL )
 65     {
 66         printf("Cannot open file\n");
 67         return 0;
 68     }
 69     fseek(fp,0L,SEEK_SET);
 70     fread(pBuffer,1,SIZE,fp);
 71     
 72     // Convert 8 bit to 16 bit
 73     for(i=0; i<SIZE/2; i++)
 74         pwBuffer[i] = pBuffer[2*i]*256 + pBuffer[2*i+1];
 75     
 76     // Extract channel channelno data
 77     cnt = 0;
 78     for(i=0; i<SIZE/2; i++)
 79         if( (pwBuffer[i-1] == 0x5A5A) && (pwBuffer[i] == 0x5A5A) )
 80             pw11Buffer[cnt++] = pwBuffer[i + channelno];
 81 
 82     // Normalize the data, (data-32768)
 83     for(i=0; i<cnt; i++)
 84         pwnormBuffer[i] = pw11Buffer[i] - 32768;
 85         
 86     //for(i=0; i<10; i++)
 87     //    printf("%4X %4X\n", pw11Buffer[i], pwnormBuffer[i]);
 88     
 89     // Initialize the wav file header
 90     memcpy(wavhead.RIFF, riff, 4);
 91     wavhead.dwFilesize = cnt*2 + sizeof(wav_header) - 8;
 92     memcpy(wavhead.WAVE, wav , 4);
 93     memcpy(wavhead.fmt,  fmt , 4);
 94     wavhead.dwChunksize = 0x10;
 95     wavhead.wCompress = 1;
 96     wavhead.wChannelnum = 1;
 97     wavhead.dwSamplerate = 1000;
 98     wavhead.dwBytepersec = 2*1000;
 99     wavhead.wBlockAlign = 2;
100     wavhead.wBitsPerSample = 16;
101     memcpy(wavhead.data, data, 4);
102     wavhead.dwDataSize = cnt*2;
103     
104     // Write the data into DAT file
105     if( (fpout=fopen(outfile, "wb")) == NULL )
106     {
107         printf("Cannot open file\n");
108         return 0;
109     }
110     
111     fwrite(&wavhead, sizeof(wav_header), 1, fpout);
112     fwrite(pwnormBuffer, sizeof(unsigned short), cnt, fpout);
113     
114     free(pBuffer); free(pwBuffer); free(pw11Buffer);
115     system("pause");
116 }
117