c++11 - 如何计算数据块数组的大小

Question

使用 RIFF header fmt 是数据子块的数据数组的大小。

BUFFER_SIZE = DSC.Subchunk2Size / (FCD_PCM.NumOfChan * (FCD_PCM.bitsPerSample / 8));

如果我使用以下代码读取标题

WORD CWav::Read_Header(FILE* WAVF) {

    //Checking For PCM TRUE/FALSE  
    fseek(WAVF, 48, SEEK_SET);
    int16_t num_bytes_in_ext;
    fread(&num_bytes_in_ext, sizeof int16_t, 1, WAVF);
    
if (PCM == true) {
        char Data[5] = "data";
        fread(&DSC, 1, sizeof(DATA_SUB_CHUNCK), WAVF);
        if (memcmp(DSC.Subchunk2ID, Data, sizeof(DSC.Subchunk2ID)) != 0) {
            fseek(WAVF, 78, SEEK_SET);
            fread(&DSC, 1, sizeof(DATA_SUB_CHUNCK), WAVF);
        }
        while (memcmp(DSC.Subchunk2ID, Data, sizeof(DSC.Subchunk2ID)) != 0) {
            fseek(WAVF, DSCSeek++, SEEK_SET);
            fread(&DSC, 1, sizeof(DATA_SUB_CHUNCK), WAVF);
        }
    }