AMV is an acronym for Anime Music Video and it is a video file format which contains one or multiple anime videos with audio background. AMV files are typically not released by official authorities and are created by amateur anime fans.
Usually the main reason for making AMV files is to be able to synchronize anime videos with a third-party audio track.
When users want to create AMV files, they will need to resort to specialized multimedia converters that will encode other videos to AMV.
Prior to completing the conversion, expert users will have the chance to modify the sample rate or other parameters of the source file (novices should leave these settings unchanged, because the output file might get corrupted).