VOB standards for "Video Object". It is the file type to store video on a DVD disc. It is actuallly a MPEG-2 video, with special extension to support PCM, AC3, DTS audio, subpictures, and button navigation commands.
To decode DVD-VIDEO, you will need both GPL MPEG-2 Decoder, and AC-3 Decoder.
Ogg Media (OGM), meaning Ogg Media File, is a container format (for video, audio and subtitle streams). It was developed by Tobias Waldvogel and can do a few things the common AVI format cannot.
OGG Media is a video file format with OGG container. It is not as popular as Matroska.
To encode OGG media file with River Past software, please have either Torbias' OGG DirectShow Filters or Radlight Ogg Media Filters installed.You may also need CCCP.
GPL MPEG Decoder
AC-3 Decoder Filter
River Past Video Cleaner