Implementation of converting PCM file to WAV

#include <iostream>
using namespace std;

typedef struct WAV_HEADER
{
    char chunkid[4];
    unsigned long chunksize;
    char format[4];
} pcmHeader;

typedef struct WAV_FMT
{
    char subformat[4];
    unsigned long sbusize;
    unsigned short audioFormat;
    unsigned short numchannels;
    unsigned long sampleRate;
    unsigned long byteRate;

    unsigned long blockAlign;
    unsigned long bitPerSample;
} pcmFmt;

typedef struct WAV_DATA
{
    char wavdata[4];
    unsigned long dataSize;

} pcmData;


long getFileSize(char* fileName){
    FILE* fp = fopen(fileName, "r");
    if(!fp){
        return -1;
    }
    fseek(fp, 0, SEEK_END);    // Go to the end of the file 
    long size = ftell(fp);     // Returns the byte length of the file 
    fclose(fp);
    return size;
}

int pcvToWav(const char *pcmpath, int channels, int sample_tate, int fmtSize, const char* wavpath)
{
    //  Open file 
    FILE * fp, *fout;
    fp = fopen(pcmpath, "rb");
    if(fp== NULL) {
        cout<<"fopen input failed"<<endl;
        return -1;
    }
    pcmHeader header;
    pcmFmt fmt;
    pcmData data;

    memcpy(header.chunkid, "RIFF", strlen("RIFF"));
    header.chunksize = getFileSize((char *)pcmpath) + 44 -8;
    memcpy(header.format, "WAVE", strlen("WAVE"));

    memcpy(fmt.subformat, "fmt ", strlen("fmt "));
    fmt.sbusize = fmtSize;    //16 Bit storage bit width 
    fmt.audioFormat = 1; //pcm The data is 1
    fmt.numchannels = channels;
    fmt.bitPerSample = sample_tate;
    fmt.byteRate = sample_tate * channels * 16 / 8;
    fmt.blockAlign = channels * 16 /8;
    fmt.bitPerSample = 16;

    memcpy(data.wavdata, "data", strlen("data"));
    data.dataSize = getFileSize((char*)pcmpath);

    //  Write data  1、 Write header information  2、 write in PCM data 

    // 1、 Open file 
    fout = fopen(wavpath, "wb");
    if (fout ==NULL){
        cout<<"fopen out failed"<<endl;
        return -1;
    }

    fwrite(&header,sizeof(header), 1,fout);
    fwrite(&fmt,sizeof(fmt), 1,fout);
    fwrite(&data,sizeof(data), 1,fout);
    //  write in PCM file 
    char* buff = (char*)malloc(512);
    int len;
    //  Read pcm Of documents to buff in 
    while((len = fread(buff, sizeof(char), 512, fp)) != 0) {
        fwrite(buff, sizeof(char), len, fout);
    }

    free(buff);
    fclose(fp);
    fclose(fout);
    cout<<"finish"<<endl;

}

int main() {
    pcvToWav("../audio.pcm",2,44100, 16,"../outfile.wav");
    return 0;
}

Knowledge points to learn

1、 The method used to obtain the byte length of the file is fseek(fp, 0, SEEK_END), ftell(fp); 

2、 The common copy of string is memcy and strcy.

3、fwrite How to write the structure ;

4、 Read the file according to the character array fread And fwrite Use .