Modified from MCOP SDK. Added functions for TechToProtect:
1. Move audio recorder and player to the application. 2. Patch through SDK to allow application to access audio/video. 3. Buffer/replicate/record data in the application. Address 3 issues: 1. Need repeat (solution: receiver can replay the messages). 2. Chatty messages, cannot focus (solution: pause the audio and play later). 3. Difficult to synchronize (solution: async-sending).