Refactor vad_filterbank: Some restructuring.

- Removed unnecessary type casting.
- Added comments.
- Removed shift macros.
- Name change of _get_features() to _CalculateFeatures(). Affects vad_core.c and vad_filterbank_unittest.cc.
Review URL: http://webrtc-codereview.appspot.com/343002

git-svn-id: http://webrtc.googlecode.com/svn/trunk@1371 4adac7df-926f-26a2-2b94-8c16560cd09d
4 files changed