Libavcodec
Libavcodec is a part of ffmpeg, a hyper fast realtime audio/video encoder, a streaming server and a generic audio and video file converter.
XviD
XviD is an implementation of a part of one or more MPEG-4 Video tools as specified in ISO/IEC 14496-2 standard. Those intending to use this software module in hardware or software products are advised that its use may infringe existing patents or copyrights, and any such use would be at such party's own risk. The original developer of this software module and his/her company, and subsequent editors and their companies, will have no liability for use of this software or modifications or derivatives thereof.
Theora
Theora is Xiph.Org's first publicly released video codec, intended for use within the Ogg's project's Ogg multimedia streaming system. Theora is derived directly from On2's VP3 codec; Currently the two are nearly identical, varying only in framing headers, but Theora will diverge and improve from the main VP3 development lineage as time progresses.
Windows Media 9
ffdshow can use installed Windows Media 9 codecs to compress video. However currently the support is quite limited: only constant bitrate and constant quality modes are supported (no two pass encoding).
mpeg2enc
ffdshow uses slightly modified version of mpeg2enc application from
MJPEG tools. Only few settings are supported and frames should be stored in external file instead of AVI. The external file will be a MPEG video stream, you can edit it or mux it with sound using some external tools.
sklmp4
MPEG 4 codec created by Pascal Massimino. ffdshow doesn't come with compiled library, you'll have to download source code, compile it and place resulting skl_drv_mpg.dll somewhere where ffdshow can find it (directory where ffdshow.ax is located, windows system directory or just some directory listed in PATH enviroment variable).