Converting .fla audio to .mp4 format.
Converting Free Lossless Audio Files directly to MPEG-4 Videos (.fla to .mp4 conversion) should be possible and quite straightforward. It relates to users attempting to encode FLA audio to MP4 video.
Try using a media editing software or (online) conversion tool, such as the MediaMonkey or Helium Music Manager, which should allow users to import FLA audio and export it in MP4 format.
A set of audio and ripping utilities for Windows