Transcoding Bug: Avi with H264 isn't transcoding

[BryonLewis]

When a file is uploaded that is AVI but is encoded using h264 it isn't transcoding or transmuxing the video to an mp4 container properly when 'skipTranscoding' is on.

To resolve update the logic in the transcoding for both the Desktop and Web version so if it is h264 and not Mp4 it will transmux the video to a new format instead of skipping over it.