cisco/openh264 — pull request #465 by ruil2 (2014-03-10 07:24:50+00:00)
Title:    use global trace in encoder

old logic can't set trace level for encoder in application
1. use SetOption to set the trace level
2. change default trace level as WELS_LOG_ERROR
3. use WelsLog instead of fprintf to output info in a unified method.