求LibMPG123的使用方法。该怎么解决

// mp3_to_wav.cpp : 定义控制台应用程序的入口点。//#include "stdafx.h"static int which = 0;static BYTE buffer[8192];static BYTE outbuf[2][1638400];static HWAVEOUT _ghWaveOut = NULL;static HANDLE _ghEvent = NULL;static WAVEHDR WaveHdr[2];static int playSetup(long rate, int chanel){    int err = 0;    WAVEFORMATEX waveform;    waveform.wFormatTag =WAVE_FORMAT_PCM;    waveform.nChannels =chanel;    waveform.nSamplesPerSec =rate;    waveform.nAvgBytesPerSec=rate*chanel;    waveform.nBlockAlign =rate*chanel/8;    waveform.wBitsPerSample =16;    waveform.cbSize =0;    _ghEvent = CreateEvent(NULL, FALSE, FALSE, NULL);    err = waveOutOpen(&_ghWaveOut, WAVE_MAPPER, &waveform, (DWORD)_ghEvent, 0, CALLBACK_EVENT);    memset(WaveHdr, 0, sizeof(WaveHdr));    WaveHdr[1].dwLoops = 1;    WaveHdr[0].dwLoops = 1;    waveOutPrepareHeader(_ghWaveOut, &WaveHdr[1], sizeof(WAVEHDR));    waveOutPrepareHeader(_ghWaveOut, &WaveHdr[0], sizeof(WAVEHDR));    return err;}static int playAudio(const BYTE buf[], int len){    int err = 0;    LPWAVEHDR pWaveHdr = &WaveHdr[which];    pWaveHdr->lpData = (LPSTR)(LPTSTR)buf ;    pWaveHdr->dwBufferLength = len;    err = waveOutWrite (_ghWaveOut, pWaveHdr, sizeof (WAVEHDR));    which = !which;    pWaveHdr = &WaveHdr[which];    while(pWaveHdr->dwFlags == 0x12){        WaitForSingleObject(_ghEvent, -1);    }    return err;}static int decode_file(mpg123_handle *mh, char *path){    int n;    int err;    size_t done;    FILE *fp = fopen(path, "rb");    if (fp == NULL){        return -1;    }    while(feof(fp) == 0){        n = fread(buffer, 1, sizeof(buffer), fp);        err = mpg123_decode(mh, buffer, n, outbuf[which], 1638400, &done);        if (err == MPG123_NEW_FORMAT){            long rate;            int channels, enc;            mpg123_getformat(mh, &rate, &channels, &enc);            printf("new format\n");            playSetup(rate, channels);        }        playAudio(outbuf[which], done);        while (err!=MPG123_NEED_MORE && err!=MPG123_ERR){            err = mpg123_decode(mh, NULL, 0, outbuf[which], 1638400, &done);            playAudio(outbuf[which], done);        }        if (err == MPG123_ERR){            printf("err = %s\n", mpg123_strerror(mh));            break;        }    }    waveOutReset(_ghWaveOut);    waveOutClose(_ghWaveOut);    fclose(fp);    return 0;}int _tmain(int argc, _TCHAR* argv[]){    int err = 0;    mpg123_init();    mpg123_handle *mh = mpg123_new(NULL, &err);    assert(mh != NULL);    err = mpg123_open_feed(mh);    assert(err == MPG123_OK);    char path[] = "300.mp3";    decode_file(mh, path);    mpg123_close(mh);    mpg123_delete(mh);    mpg123_exit();    return 0;}