c++ - 在 C++ 中覆盖备用字节对

Question

我正在尝试通过用 0 覆盖交替字节对(2 个字节)来从扬声器的一侧播放声音。我在 HEX 编辑器中检查过，交替字节对确实有重复。

我做了一个小程序来做同样的事情。但是，它不起作用。你能指出我在这里做错了什么吗？

int main()
{
    FILE *file, *fileWrite;
    unsigned char *buffer;
    unsigned long fileLen;
    int n;

    file = fopen("sound.dat", "rb");
    fileWrite = fopen("sound1.dat", "w+");

    // Get the File Length
    //Get file length
    fseek(file, 0, SEEK_END);
    fileLen=ftell(file);
    fseek(file, 0, SEEK_SET);

    buffer = (unsigned char *)malloc(fileLen+1);
    n = fread(buffer, fileLen, 1, file);
    printf("%s\n", &buffer);

    int i;

    for(i = 0 ;i < fileLen; i = i + 4)
    {
          buffer[i+2] = '\0';
          buffer[i+3] = '\0';
          // printf("%.2X %.2X %.2X %.2X  \n", (int)buffer[i],(int)buffer[i+1],    (int)buffer[i+2],(int)buffer[i+3]);

    } 

    n = fwrite(buffer, fileLen, 1, fileWrite);

    fclose(file);
    fclose(fileWrite);
}

更新:如果十六进制读取是

4F D0 4F D0 FF 05 FF 05

我想成功

4F D0 00 00 FF 05 00 00

已解决!!!

谁能帮我解决这个问题:Audio File: Playing data through one Speaker Only?

Answer 1

你的循环边界偏离了几个:

for(i = 0 ;i < fileLen; i = i + 4)

应该是

for(i = 0 ;i < fileLen - 3; i = i + 4)

否则分配给 buffer[i + 3] 将覆盖内存中超出缓冲区末尾的内容。这能解决问题吗？