VOB to MP4, DVD files that play anywhere.

A VOB to MP4 converter reads the video files from a DVD and saves them as an MP4, the format that Macs, iPhones, browsers and video sites all play. VOB is the container a DVD uses. Inside it is an MPEG-2 picture and usually Dolby Digital (AC-3) or MP2 sound. This page turns the picture into H.264 and the sound into AAC. A DVD title is cut into several VOB files, so drop all of its parts together and they are joined in order into one MP4.

How to convert VOB files to MP4

1. Get the files off the disc. Open the DVD in Finder, open the folder named VIDEO_TS, and copy the files whose names start with VTS_ to your Mac. That works for home DVDs and other discs that are not copy-protected.
2. Drop the VOB files of one title on the box, or click to choose them. For example VTS_01_1.VOB, VTS_01_2.VOB and VTS_01_3.VOB.
3. The page puts them in name order and reads them as one video. The line under the first picture says how many files were joined.
4. The MP4 is made straight away. Change Quality (High, Good or Small) or Size and it is made again. The green line says the bitrate and about how big the MP4 will be.
5. Play the result on the page, then press Download the MP4.

Which files to drop

Look in the VIDEO_TS folder. The files named VTS_01_1.VOB, VTS_01_2.VOB and so on, are the film. The file ending in _0, such as VTS_01_0.VOB, and the file called VIDEO_TS.VOB hold the menus. When you drop several files together, the page leaves the menu files out and says so. Files with other numbers after VTS_ belong to other titles, such as extras. Each title becomes its own MP4. If you do not want files joined, set Several files to Convert each one on its own.

What is not carried over

This page reads the video files only. It does not read the disc structure in the IFO and BUP files, so these are not kept:

• Menus, chapter marks and the order the disc plays things in.
• Subtitles. They are stored as small pictures on a separate track and are left out.
• Extra sound tracks. The first sound track is used. If a disc has several languages, the first one may not be the one you want.
• Camera angles. Only the stream the files give first is read.

Copy-protected discs

Many shop-bought discs are scrambled with copy protection (CSS). The files copied from such a disc cannot be read. This page does not try to open them, and that will not change. If a file cannot be decoded, the page says so. It works for files that are not copy-protected, such as home movies burned to DVD, camcorder discs and discs you made yourself.

Quality, size and interlaced lines

The bitrate is the picture width times height times frames a second times a number: 0.12 for High, 0.07 for Good, 0.04 for Small. A DVD picture is stored 720 x 480 and shown 16:9, so the page makes it 854 x 480. At 29.97 fps that is 854 x 480 x 29.97 x 0.07, about 0.86 Mbps for Good. Sound is about 20 KB a second more. A 90 minute title, 5,400 seconds, comes to 0.86 Mbps x 5,400 / 8, about 580 MB, plus 108 MB of sound: about 690 MB. High is about 1.1 GB and Small about 440 MB. The whole MP4 is built in memory, so for a long film close other tabs, or pick Small.

Video from a TV or a camcorder is often interlaced, with two half pictures per frame, which shows comb lines on moving edges. Tick Smooth interlaced lines to blend the two halves. Film from a movie disc is usually not interlaced, and the box should stay unticked.

Common problems

• It says no picture could be decoded. The file may be scrambled, a menu file, or not a DVD file at all. Try the film files, VTS_01_1.VOB and the ones after it.
• The sound is missing. The sound may be in a kind this page cannot read, such as DTS. The result line says if it was left out.
• The picture is squashed or stretched. Check the size under the first picture: the page reads the shape the disc asks for and shows it that way.
• A long title fails. The result is held in memory. Pick Small, or convert one VOB file at a time and set Several files to Convert each one on its own.

The same reader handles other MPEG files, such as .mpg, on MPEG to MP4. For other old formats see AVI to MP4 and the video converter.