Apprentice Video is a cross-platform open-source media player, developed as a personal project by Pavel Koshevoy since May 29, 2010.It is similar to other media players like VLC or MPC-HC, but offers a few features absent from those players (alpha channel preview, timeline looping in/out points, and several options for achieving adequate video playback performance on outdated slow hardware). The audio tempo scaling filter developed for Apprentice Video was ported to C and contributed to FFmpeg as atempo filter.