Update to noise estimation.
Update to noise estimation.

Add frame level global check and adjust some parameters.

Change-Id: I42103394f2d329781195d94ce6cbb5b3383eea17

jmvalin/aom,luctrudeau/aom,jmvalin/aom,Topopiccione/libvpx,smarter/aom,openpeer/libvpx_new,smarter/aom,openpeer/libvpx_new,mwgoldsmith/libvpx,ittiamvpx/libvpx-1,ittiamvpx/libvpx-1,Topopiccione/libvpx,ShiftMediaProject/libvpx,smarter/aom,webmproject/libvpx,thdav/aom,Topopiccione/libvpx,shacklettbp/aom,ShiftMediaProject/libvpx,mbebenita/aom,ShiftMediaProject/libvpx,luctrudeau/aom,Topopiccione/libvpx,openpeer/libvpx_new,ittiamvpx/libvpx-1,ittiamvpx/libvpx-1,mwgoldsmith/vpx,mbebenita/aom,mbebenita/aom,mwgoldsmith/libvpx,webmproject/libvpx,luctrudeau/aom,GrokImageCompression/aom,shacklettbp/aom,luctrudeau/aom,ShiftMediaProject/libvpx,mbebenita/aom,thdav/aom,jmvalin/aom,thdav/aom,mwgoldsmith/libvpx,mbebenita/aom,openpeer/libvpx_new,jmvalin/aom,luctrudeau/aom,mwgoldsmith/libvpx,mwgoldsmith/vpx,GrokImageCompression/aom,mwgoldsmith/libvpx,GrokImageCompression/aom,webmproject/libvpx,ittiamvpx/libvpx-1,thdav/aom,Topopiccione/libvpx,luctrudeau/aom,shacklettbp/aom,mwgoldsmith/vpx,mwgoldsmith/vpx,shacklettbp/aom,Topopiccione/libvpx,GrokImageCompression/aom,mwgoldsmith/vpx,jmvalin/aom,smarter/aom,thdav/aom,GrokImageCompression/aom,webmproject/libvpx,shacklettbp/aom,shacklettbp/aom,mbebenita/aom,mwgoldsmith/libvpx,webmproject/libvpx,ShiftMediaProject/libvpx,mwgoldsmith/vpx,smarter/aom,ittiamvpx/libvpx-1,mbebenita/aom,jmvalin/aom,openpeer/libvpx_new,openpeer/libvpx_new,thdav/aom,smarter/aom,webmproject/libvpx,GrokImageCompression/aom,mbebenita/aom,mbebenita/aom