c++ - 使用 libsndfile 处理大文件

Question

目前，我已经根据可用的“libsndfile”示例代码编写了一个程序(在 Visual Studio C++ 中)，其中我刚刚添加了一个减法函数，用于将一个( channel )WAV 文件与另一个相减.

该程序非常适合限制为 4 个 channel 的文件。

问题是，一旦我上传了一个包含多达 5 个 channel 或更多 channel 的文件，程序就拒绝执行该功能。这与帧大小无关，因为我设法处理了比我使用的一些 5/6 channel 文件大很多倍的 4 channel 文件。

有没有人遇到过这个或类似的问题？如果需要，我将提供源代码。

对于糟糕的结构，我深表歉意，在我完成整个交易之前，我不会真正优化。

代码:

#include <sndfile.hh>
#include <tinyxml2.h>
#include <iostream>
#include <fstream>

#define BLOCK_SIZE 32

using TiXmlDocument = tinyxml2::XMLDocument;
using CStdStringA = std::string;

int main(int argc, char* argv[])

{
    SNDFILE *infile  = NULL;
    SNDFILE *infile2 = NULL;
    SNDFILE *outfile = NULL;
    SF_INFO    sfinfo;
    SF_INFO    sfinfo2;
    SF_INFO    sfinfoOut;
    sf_count_t readcount;
    //int filetype = SF_FORMAT_WAV | SF_FORMAT_PCM_24;                  // 24-bit Wav-Files
    TiXmlDocument iDoc;                                               // Init tinyXML
    int i;                                                            // Iteration-var;
    short BufferIn[BLOCK_SIZE];                                       // Buffer1
    short BufferIn2[BLOCK_SIZE];                                      // Buffer2
    short BufferOut[BLOCK_SIZE];
    CStdStringA FileLoc, FileName, FileLocWav, FileLocTxt,FileLocRaw; // OutputFile locationstring
    CStdStringA WavName, WavName2, FileIn, FileIn2;
    FileLoc = "C:\\Testfiles\\";
    //TextTitle(FileLoc);                                             // Print console-header
    printf("Name Wavefile 1:\n");
    std::cin >> WavName;
    FileIn = FileLoc + WavName + ".wav";
    if((infile = sf_open(FileIn.c_str(),SFM_READ,&sfinfo)) == NULL)   // Open Wav-file 2 instance
    {
        printf("Not able to open input file 1\n");
        printf("\n\nPress any key to exit.");                         // Exit-text if file not present
        puts(sf_strerror(NULL)) ;
        return 1;
    }
    std::cout << "Wav file 1 succesfully opened." <<  std::endl;
    std::cout << "\nChannels: " << sfinfo.channels << "\nFrames: " << sfinfo.frames << std::endl; // Print Channels & Frames
    std::cout << "Samplerate: " << sfinfo.samplerate << "\n\n" <<  std::endl;// Print Samplerate
    printf("Name Wavefile 2:\n");
    std::cin >> WavName2;
    FileIn2 = FileLoc + WavName2 + ".wav";
    if((infile2 = sf_open(FileIn2.c_str(),SFM_READ,&sfinfo2)) == NULL) // Open Wav-file 2 instance
    {
        printf("Not able to open input file 2\n");
        printf("\n\nPress any key to exit.");                          // Exit-text if file not present
        puts(sf_strerror(NULL)) ;
        return 1;
    }
    std::cout << "Wav file 2 succesfully opened." <<  std::endl;
    std::cout << "\nChannels: " << sfinfo2.channels << "\nFrames: " << sfinfo2.frames  << std::endl; // Print Channels & Frames
    std::cout << "Samplerate: " << sfinfo2.samplerate << "\n\n" <<  std::endl;// Print Samplerate
//{
    //std::cout << "Format differs from eachother, abort program.";
    //printf("\n\nPress any key to exit.");                     // Exit-text
    //return 1;
//}
    if(sfinfo.channels != sfinfo2.channels)                                // Abort if channels not the same
    {
        std::cout << "Channelammount differs from eachother, abort program.";
        printf("\n\nPress any key to exit.");                     // Exit-text
        return 1;
    }
    if(sfinfo.samplerate != sfinfo2.samplerate)                   // Abort if samplerate not the same
    {
        std::cout << "Samplerate differs from eachother, abort program.";
        printf("\n\nPress any key to exit.");                     // Exit-text
        return 1;
    }
    std::cout << "Give a filename for Txt- & Wav-file: ";
    std::cin >> FileName;
    FileLoc += FileName;                                          // Fuse Filelocation with given name
    FileLocTxt = FileLoc + ".txt";
    FileLocWav = FileLoc + ".wav";
    FileLocRaw = FileLoc + "Raw.txt";
    sfinfoOut.channels = sfinfo.channels;
    sfinfoOut.format = sfinfo.format;
    sfinfoOut.samplerate = sfinfo.samplerate;
    if((outfile = sf_open(FileLocWav.c_str(),SFM_WRITE,&sfinfoOut)) == NULL)      // Open Wav-file 2 instance
    {
        printf("Not able to create output file \n");
        printf("\n\nPress any key to exit.");                      // Exit-text if file not present
        puts(sf_strerror(NULL)) ;
        return 1;
    }
    std::ofstream myfile;
    myfile.open(FileLocTxt.c_str(),std::ios::app);
    std::ofstream myfileRaw;
    myfileRaw.open(FileLocRaw.c_str(),std::ios::app);
    while((readcount = sf_read_short(infile, BufferIn, BLOCK_SIZE)))     // While there are still frames to be processed
    {
        //process_data (data, readcount, sfinfo.channels) ;
        auto readcount2 = sf_read_short(infile2, BufferIn2, BLOCK_SIZE);
        for(i = 0; i < BLOCK_SIZE; i++)                                  // BLOCK_SIZE decides the chunk-size
        {
            BufferOut[i] = BufferIn[i] - BufferIn2[i];
            myfileRaw << BufferOut[i];
        }
        sf_write_short(outfile, BufferOut, BLOCK_SIZE) ;                 // Write the data to a new file
    }
    sf_close(infile);                                                    // Close Wav-file handlers
    sf_close(infile2);
    sf_close(outfile);
    myfile.close();                                                      // Close text-file handlers
    printf("\n\nPress any key to exit.");                                // Exit-text
    return 0;
}

Answer 1

documentation states :

File Read Functions (Items)

sf_count_t  sf_read_short   (SNDFILE *sndfile, short *ptr, sf_count_t items) ;
sf_count_t  sf_read_int     (SNDFILE *sndfile, int *ptr, sf_count_t items) ;
sf_count_t  sf_read_float   (SNDFILE *sndfile, float *ptr, sf_count_t items) ;
sf_count_t  sf_read_double  (SNDFILE *sndfile, double *ptr, sf_count_t items) ;

The file read items functions fill the array pointed to by ptr with the requested number of items. The items parameter must be an integer product of the number of channels or an error will occur

这就是你的问题，因为 BLOCK_SIZE 是 1,2,4 的倍数，但不是 3 和 5 的倍数 - 所以会失败。

关于程序完成就好像已经进行了计算的问题:添加适当的错误处理。