Tech Post – What are IFO files, VOB sets and VIDEO_TS?

By | 20th August 2017

DVD Video discs usually contain a couple of folders and several files with cryptic sounding names like Video_TS.IFO or VTS01_0.VOB. This combination of folders and files makes what’s commonly known as a VOB set. DVD players (hardware or software) need almost all of the files to be able to read and play a DVD Video disc properly.

If you look at the file structure of a DVD in a computer you will see either one or two main folders. These are VIDEO_TS and (sometimes) AUDIO_TS. The AUDIO_TS folder is usually empty for a normal video disc and in some cases is not present at all. The VIDEO_TS folder is the most important folder on the disc. It holds all of the video, audio and menu items for the DVD.

The contents of the VIDEO_TS folder look like this on a Mac –

DVD folder structure

The VOB set above consists of 9 files. All of them serve a purpose. The IFO files hold information about the disc contents – much like an index in a book. The BUP files are backup versions of the IFO files and are only accessed if the IFO files become corrupted. VOB (Video Object) files hold the video and audio content. In the example show above there are 4 VOB files which when combined make up the full movie on the disc. The reason the movie is split into 4 VOB files is to ensure that DVDs remain compatible with older technology that may have a 1GB file size limit. The IFO files contain the information needed to join up the VOB files correctly for seamless playback.

Playing VOB Sets

It’s possible to play a VOB file using DVD playback software on a computer. VLC Player is available for most computers, it’s free and highly regarded. VLC will play all manner of video and audio files. In VLC choose FILE/OPEN FILE and browse to the folder containing the VOB set. Open the file VIDEO_TS.IFO.

Opening an IFO file with VLC

Copying a VOB set onto another DVD

If you simply copied a VOB set, either from a computer or an existing DVD Video disc onto a recordable DVD using basic disc burning software then there’s a good chance the disc you make won’t work in a normal DVD player. The reason for this is that DVD Video discs must be made with a very specific disc file system and file structure. The Video_TS folder must be present along with all of the contents. If the file system or structure is wrong then the disc might be playable in a computer but not in most DVD players.

You need to use burning software that is capable of making DVD Video discs correctly. Most commercial burning software can do this. Note – the free stuff that gets bundled with computers or comes free with a DVD writer may only make DVD DATA discs. You need to check carefully that DVD VIDEO writing is supported.

Converting a DVD or VOB set to MP4

MP4 is the file format of choice for computer playback. It’s compatible with almost every operating system and can be used in SmartTVs, tablets and other portable devices. You can edit MP4 files in just about any video editing software. Handbrake is available for Windows, Mac and Linux – it does a great job of converting video from DVDs or VOB sets to a standard MP4 video file.

If you intend editing your MP4 videos and making the edited version available on USB sticks or just as digital files for computer or web playback that’s great. However, if you want to burning the edited version back to a DVD you should not use MP4. Instead you should find editing software that will work natively with VOB sets. You can edit MP4 files and send them back to DVD but it’s not a good workflow unless you know exactly what you’re doing – even then it’s not the best idea. There are better ways to work.

Our conversion services from DVD to MP4 and more

DVD Video discs are a read only viewing format. They were never intended to be edited or converted to other video formats. Commercial DVDs are usually copy protected in some way. It’s now legal in the UK for people to make backup copies of their own commercial films (format shifting) if they do the conversion themselves but a 3rd party such as us cannot do that for you. We can convert your family videos from DVD including the miniDVD discs that were available in camcorders.

We can convert your DVD Home Video discs to smooth playing MP4 video files retaining the fluid motion, resolution and quality of the original DVD files.

Whilst MP4 is a good quality, universal digital file format for home users it is not necessarily the best option for professional video editing. We can convert DVD VIDEO discs to most professional video file formats including Apple ProRes.

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