avoid overflow
avoid overflow

PeterXu/openh264,cisco/openh264,sijchen/openh264,cisco/openh264,shihuade/openh264,mstorsjo/openh264,PeterXu/openh264,huili2/openh264,huili2/openh264,PeterXu/openh264,mstorsjo/openh264,huili2/openh264,ruil2/openh264,mstorsjo/openh264,huili2/openh264,sijchen/openh264,huili2/openh264,shihuade/openh264,ganyangbbl/openh264,shihuade/openh264,GuangweiWang/openh264,GuangweiWang/openh264,shihuade/openh264,ganyangbbl/openh264,ganyangbbl/openh264,ruil2/openh264,mstorsjo/openh264,sijchen/openh264,ruil2/openh264,GuangweiWang/openh264,ruil2/openh264,sijchen/openh264,PeterXu/openh264,sijchen/openh264,ganyangbbl/openh264,huili2/openh264,GuangweiWang/openh264,ruil2/openh264,GuangweiWang/openh264,shihuade/openh264,ruil2/openh264,cisco/openh264,sijchen/openh264,ruil2/openh264,shihuade/openh264,cisco/openh264,cisco/openh264,PeterXu/openh264,ganyangbbl/openh264,ganyangbbl/openh264,GuangweiWang/openh264,cisco/openh264,mstorsjo/openh264,mstorsjo/openh264,sijchen/openh264,shihuade/openh264,GuangweiWang/openh264,PeterXu/openh264,huili2/openh264,mstorsjo/openh264,ganyangbbl/openh264,PeterXu/openh264,cisco/openh264