MPEG4 Modifier will modify a MPEG4 video (XviD, DivX) without re-encoding (aspect ratio, userdata and packed bitstream removal). The video must be in an AVI container, and OpenDML isnt currently supported. It is written in C#, so you need the .NET v1.1 Framework to run it.
Modifies a MPEG-4 ASP video (XviD, DivX) without re-encoding (change aspect ratio, edit userdata, remove or add packed bitstream, and change interlaced field order). It can also show information about the video such as the amount of I/P/S/B-VOPs used, whether or not QPel/GMC were used, etc. More information can be found in this thread. There is also a command line version sharing most of the same features which even runs in other OSes with Mono.
IMPORTANT: As of version 1.4.0 the .NET Framework 2.0 is required. Versions 1.3.4 and earlier require the .NET Framework 1.1 or newer.
NOTE: Aspect ratio modification works by changing a flag in the VOL headers, which is ignored by most decoders.
Requirements: - .NET Framework 1.1
Platforms: Windows NT 4.x, Windows Me, Windows 2000, Windows XP