The MPEG-1 Audio Layer III format applies psychoacoustic lossy compression to remove frequencies the human ear perceives least, producing small files at acceptable audio quality. Converting to M4V produces a video file that stores data in the M4V format. This wraps the audio track in a video container, which some platforms require for upload. Metadata such as creation date and embedded colour profiles is preserved where the target format supports it. This makes M4V the practical choice when the destination system requires it or when the original format is not supported by the target application. 1converter runs this conversion on the server: your file is uploaded encrypted over HTTPS, converted using trusted open-source libraries, and the output is held for 24 hours before automatic deletion.