如何使用很小的库或本机代码c / c ++获得MP3文件（CBR或VBR）的持续时间？

#include <stdio.h>
#include <mpg123.h>

int main() {
    mpg123_init();
    mpg123_handle *mh = mpg123_new(NULL, NULL);
    mpg123_open(mh, "example.mp3");
    
    long rate;
    int channels, encoding;
    mpg123_getformat(mh, &rate, &channels, &encoding);
    
    off_t length = mpg123_length(mh);
    double duration = (double)length / (rate * channels * mpg123_encsize(encoding));
    
    printf("MP3 duration: %.2f seconds\n", duration);
    
    mpg123_close(mh);
    mpg123_delete(mh);
    mpg123_exit();
    
    return 0;
}