Remove Dolby AC3 compressed mode as it is not supported in Windows Phone 8.1. Fix build warnings, re-arrange functions, and add comments
Remove Dolby AC3 compressed mode as it is not supported in Windows Phone 8.1. Fix build warnings, re-arrange functions, and add comments

reego-fr/FFmpegInterop,Microsoft/FFmpegInterop,Microsoft/FFmpegInterop,reego-fr/FFmpegInterop,reego-fr/FFmpegInterop,Microsoft/FFmpegInterop