fix BGD under screen and remove a build warning in ME
add bgd fix to camera route as well to avoid visible artifact when using fake content in video
fix a typo issue in ParamValidation
Merge pull request #1062 from sijchen/scc_md_bgd1

fix BGD under screen and remove a build warning in ME
Merge pull request #1071 from ganyangbbl/typo_bug

fix a typo issue in ParamValidation
Merge remote-tracking branch 'upstream/master' into travis.osx