mp3 lame 库
vbr_mode：动态比特率
MPEG_mode: 声道模式
Padding_type:
preset_mode
asm_optimizations
//The lame API
initialize the encoder
// input stream description
// general control parameters
// frame params
// quantization/noise shaping
// VBR control
// Filtering control
// psycho acoustics and other arguments which you should not change unless you know what you are doing
// internal variables, cannot be set... provided because they may be of use to calling application
encode
flush
close
decoding
