有关ffmpeg的应用demo，可以实现yub mpeg格式转换-Yub mpeg format conversion application demo on ffmpeg

pcm音频数据编码成mp3文件，编码程序写成了接口，方便调用，参考tests目录下的使用demo(PCM audio data is encoded into a MP3 file, the code program is written as an interface, convenient to call, and refer to the use of demo under the tests directory)