Convert VOB to what format?

[Keiko1981]

I'm wondering which format you would recommend me to use when converting from VOB.
I have the choices between MPEG4, Xvid, DivX, WMV, FLV and MOV
What I noticed MPEG4 has a rather large file size.
I'm thinking either Xvid, DivX or WMV.

[XrayMind]

You are confusing file container and video codec. Sometime they could be both.. So a file container is a spec for muxing video and audio format together in to a single file. Later formats also supported subtitles and chaptering.

So each file container has it's own file extension. So I begin with the oldest file container that is still being used.

.mov/.mp4 - Apple Quicktime: I remember muxing Cinapak video codec and either raw WAV audio or MP3 audio into making .mov files. MPEG ended up using Apple Quicktime for their .mp4 file container, x264 is the video codec and AAC is the audio codec. The reason why .mp4 is so large is because .mp4 can handle high resolution video, HDTV and bluray. In the pass I have encoded SDTV video using x264 and the resulting files is much smaller the than XviD could have produce with the same quality. Note: You see lot x264 video codec in .mp4 file, x264 is the open source implementation of h.264(also know as MPEG-4 AVC). Also Divx 7 added support for h.264.

.avi - This was Microsoft answer to Quicktime. So it used most of the same video and audio codecs in the beginning. Divx started as hacked video of Microsoft's MPEG-4 Version 3 codec. When DivX went commercial, an open source group created XviD. Both DivX 5/6 and XviD are implementation of MPEG4 ASP codec. Another open source group, FFmpeg, has it's MPEG4 ASP. Which most of us is using to decode the video when playback .avi file with MPC/VLAN.

.mpg - It's container for MPEG 1 and 2 files. Also know program stream(.ps). Named .dat for old MPEG-1 video in VCD format. .vob is an extension of .mpg/.ps format for DVD. Most media players can play .vob files. Transport stream(.ts) is the broadcast container for video/audio over the air. Depending which country's broadcast, different transmission format(not to be confuse by the container) and some support just MPEG=2 video or both MPEG-2 and MPEG-4 AVC video.

,mkv - is open source container that can support any of the old an new video/audio codes. It can support any subtitle format and advance chaptering. My favorite, audio delay. If audio and video is not in sync, instead of re-edit/re-encode the audio, I just remux the file with delay setting.

.asf/.wmv - is another Microsoft container format. It was created for streaming video/audio. As you can't stream avi file. Microsoft also created it's own video/audio codec for it. So when the video file is not use for streaming, it just named .wmv,

Sorry for the long explanation.. But short answer for smallest size with the best quality is video/audio encoded with x264/aac and store in .mp4 or .mkv container. Again the really large .mp4/x264 files you see out there is video ripped from bluray resolution for movie could be at 1920x1080. Where DVD resolution is only 720x480. You can even get smaller size on x264 using the 10bit instead of 8bit. You see alot of anime fansub and some jdrama doing that right now.

So if you encode at the same bitrate with XviD in .avi container compare to x264 in .mp4/.mkv container, the x264 will always look better. Of course if the original DVD video is garbage, the video codec isn't going to make it look better.