CMTime            120 media/video/capture/mac/avfoundation_glue.h - (void)setVideoMinFrameDuration:(CoreMediaGlue::CMTime)minFrameRate;
CMTime            122 media/video/capture/mac/avfoundation_glue.h - (void)setVideoMaxFrameDuration:(CoreMediaGlue::CMTime)maxFrameRate;
CMTime             50 media/video/capture/mac/coremedia_glue.h   static CMTime CMTimeMake(int64_t value, int32_t timescale);