读取已签名的 16 位 PCM Audacity 导出文件 (RAW) 并转换为未签名的 16 位

Question

我正在尝试“解码”并从 Audacity 原始导出文件中提取原始 pcm 音频。 下面的代码打开这样的文件并生成一个新文件，该文件可以由 Audacity 打开并再次重现声音。

Audacity 的原始数据比 Audacity 导出的“wav”文件小约 1000 字节。

我也在尝试打印数据，如何正确连接“字节”以形成带符号的16位或短值并将它们打印在一行上，以便在硬件中使用。

因此可以测试它们是否已签名。 https://en.cppreference.com/w/cpp/types/is_signed

#include <QCoreApplication>

#include <iostream>     // std::cout
#include <fstream>      // std::ifstream

#include <bitset>
#include <typeinfo>



int main () {
    std::ifstream ifs;

    // ifs.open ("AH-DL-TL.raw", std::ios::binary);
    std::ifstream is ("AH-DL-TL.raw", std::ifstream::binary);
    //std::ifstream is(".//r909hh.wav", std::ifstream::binary);
    if (is) {
        std::cout << "Opening File" << std::endl;
        // get length of file:
        is.seekg (0, is.end);
        int length = is.tellg();
        is.seekg (0, is.beg);
        std::cout << "Reading " << length << " characters... " << std::endl;
        // allocate memory:
        char * buffer = new char [length];

        // https://cplusplus.com/reference/istream/istream/read/
        // read data as a block:
        is.read (buffer,length);

        is.close();

        for (int n=length; n>0; n--) {
            //std::cout << n << ", " << std::endl;
        
        if(n % 2 == 0){
            temp = buffer[n];
            std::bitset<16> b2(temp);
            std::cout << "temp: "  << b2 /*temp*/ << std::endl;
        }
        else{
            temp = 0;
            temp = buffer[n] << 8;
        }

            try
            {
                std::cout << "data: "  << typeid(buffer[n]).name() << std::endl;
            }
            catch (std::bad_typeid buffer[n])
            {
                std::cerr << "bad_typeid caught: " << buffer[n].what() << '\n';
            }

            std::bitset<8> b1(buffer[n]);
            std::cout << "data: " << b1 << " " << ((n % 2 == 0) ? "even " : "odd") << std::endl ;
        }
        // print content:
        //std::cout.write (buffer,length);  // gibberish.



        std::ofstream wf("student.raw", std::ios::out | std::ios::binary);
        if(!wf) {
            std::cout << "Cannot open file!" << std::endl;
            return 1;
        }
        wf.write (buffer,length);
        /*
        for(int i = 0; i < length; i++){
            std::cout << "write line: " << i << " length:" << length << std::endl;
            wf.write((char *) &buffer[1], length);
        }
        */

        wf.close();
        if(!wf.good()) {
            std::cout << "Error occurred at writing time!" << std::endl;
        }

        delete[] buffer;
    }

    return 0;
}