KO Myung-Hun had released MPlayer SVN-r32813-OS2-4.4.5 for eCS-OS2. (2011/02/06)
It is available for download at hobbes.
"MPlayer is a movie player which runs on many systems. It plays most MPEG/VOB, AVI, Ogg/OGM, VIVO, ASF/WMA/WMV, QT/MOV/MP4, RealMedia, Matroska, NUT, NuppelVideo, FLI, YUV4MPEG, FILM, RoQ, PVA files, supported by many native, XAnim, and Win32 DLL codecs. You can watch VideoCD, SVCD, DVD, 3ivx, DivX 3/4/5, WMV and even H.264 movies.
OS/2 version supports SNAP/WarpOverlay!/DIVE, UNIAUD/DART"
Web Site: http://www.ecomstation.co.kr/
KO Myung-Hun also accepts PayPal donation for their eCS-OS2 ports on this page .