使用C语言将pcm数据封装成wav文件

男娘i 2022-06-07 04:25 545阅读 0赞

pcm是原始音频数据，wav是windows中常见的音频格式，只是在pcm数据中添加了一个文件头，wav文件格式可以参考[http://soundfile.sapp.org/doc/WaveFormat/][http_soundfile.sapp.org_doc_WaveFormat]

// WAVWriter.cpp: 定义控制台应用程序的入口点。
    //
    
    #include "stdafx.h"
    
    #include <iostream>
    
    using namespace std;
    
    typedef struct WAVE_HEADER {
        //RIFF
        char chunkID[4];
        //long int 4字节 某个大小
        unsigned long chunkSize;
        //WAVE
        char formate[4];
    };
    typedef struct WAVE_FMT {
        //fmt 注意最后有个空格
        char subchunk1ID[4];
        unsigned long subchunk1Size;
        unsigned short audioFormatTag;
        unsigned short numChannels;
        unsigned long sampleRate;
        unsigned long byteRate;
        unsigned short blockAlign;
        unsigned short bitPerSample;
    
    };
    typedef struct WAVE_DATA {
        char subchunk2Id[4];
        unsigned long subchunk2Size;
    };
    
    long getFileSize(char* filename) {
        FILE *fp = fopen(filename, "r");
        if (!fp) return -1;
        fseek(fp, 0, SEEK_END);
        long size = ftell(fp);
        fclose(fp);
        return size;
    }
    
    int converToWAV(const char *pcmpath, int channels, int sample_rate, const char *wavepath) {
        int bits = 16;
        WAVE_HEADER   pcmHEADER;
        WAVE_FMT   pcmFMT;
        WAVE_DATA   pcmDATA;
        FILE *fp, *fpout;
    
        fp = fopen(pcmpath, "rb");
        if (NULL == fp) {
            std::cout << "file open failed" << endl;
            return -1;
        }
        long pcmSize = getFileSize((char*)pcmpath);
        //WAVE_HEADER
        memcpy(pcmHEADER.chunkID, "RIFF", strlen("RIFF"));
        pcmHEADER.chunkSize = 36 + pcmSize;
        memcpy(pcmHEADER.formate, "WAVE", strlen("WAVE"));
    
    
        fpout = fopen(wavepath, "wb");
        if (NULL == fpout) {
            cout << "file open failed" << endl;
            return -1;
        }
        fwrite(&pcmHEADER, sizeof(pcmHEADER), 1, fpout);
    
    
    
        //WAVE_FMT
    
        pcmFMT.numChannels = channels;
        pcmFMT.sampleRate = sample_rate;
        pcmFMT.bitPerSample = bits;
        pcmFMT.byteRate = sample_rate*channels *pcmFMT.bitPerSample / 8;
        memcpy(pcmFMT.subchunk1ID, "fmt ", strlen("fmt "));
        pcmFMT.subchunk1Size = 16;
        pcmFMT.audioFormatTag = 1;
        pcmFMT.blockAlign = channels*pcmFMT.bitPerSample / 8;
        fwrite(&pcmFMT, sizeof(pcmFMT), 1, fpout);
    
        //WAVE_DATA
        memcpy(pcmDATA.subchunk2Id, "data", strlen("data"));
        pcmDATA.subchunk2Size = pcmSize;
        fwrite(&pcmDATA, sizeof(pcmDATA), 1, fpout);
        char *buff=(char*)malloc(512);
        int len;
        while ((len = fread(buff, sizeof(char), 512, fp)) != 0)
        {
            fwrite(buff, sizeof(char), len, fpout);
        }
        free(buff);
        fclose(fp);
        fclose(fpout);
    
    
    }
    
    
    
    int main()
    {
    
        converToWAV("input.pcm", 1, 44100, "output.wav");
        return 0;
    }

完全参考格式来书写的，pcm数据注意采样率和通道数。

[http_soundfile.sapp.org_doc_WaveFormat]: http://soundfile.sapp.org/doc/WaveFormat/