Supplement: Recommend a conversion software: Hero Jieba 3. I've been using the audio tool that comes with it to deal with it. When setting parameters, choose MP3 format with 3-layer compression (WAV format is also acceptable). If you are prompted that a song cannot be recognized, the song cannot be used. Never mind NERO's tip, I don't know what its special plug-in is. There is no difference in size between extensions. In addition, try another playback software.