More source code Clean up in video editor engine

o fixed incorrect design and got rid of PreviewPlayerBase class
o removed obsolete/unused code as much as possible and reformatted the source code
o verified and passed functional tests
o More to come ...

Change-Id: I7a89162f8b9d9ea6eabcf0457366cd2f6d970d11
16 files changed
tree: dc3de13666176b2d17655b8719af93f5b3197252
  1. libvideoeditor/