1.   1M bytes  1.5  
2.   1M bytes  1  (100-400Mļಿִ7, 400-800׵ļಿִ4, >800Mļಿִ1)
3.  ǷԴһλԭлϼ 50% (Ƚеĳͷ) 
4.  ǼתϵΪ       2^(Ǽ+10)  <  < 2^(Ǽ+11)
5.  ŶʱǼΪnû൱3*n(Ӵֵ) 
6.  512ʱ100K BPS
7.  ûʼΪ2048 (൱ڿ2G)
8.  ߵĻÿӻ 0.5֣һ첻ػ720֣ÿСʱˢһ
