A VOB file is a video object file, which are the videos that are ripped from DVDs. A VOB cannot be more than 1 GB in size due to technical limitations of the DVD format. This isn't a problem when watching the movie on a DVD, but it can be a hassle when trying to convert the DVD to another video format. Converting multiple VOBs to a single AVI is usually a two-step process that first involves merging the files before converting them. Some programs can do both, others can only do one.
Download and install FormatFactory. Launch the program after installation is complete.
Click on the "ROM Device\DVD\CD\ISO" tab on the left side and select "DVD To Video File."
Select the box next to "Folder" and then click on the folder icon on the right of the text box. Find the folder with the VOB files and click "OK". The VOB files must be in a folder named "Video_TS" and they must have their original file names in order for this to work.
Click on the first drop-down menu under "Output Setting" and select "AVI". Click on the box labeled "Output Setting" to determine the quality of the AVI file you will create. Higher quality AVIs look better, but take up more space on your hard drive. Click "Convert" to return to the main window and then click "Start" to convert the VOB files into a single AVI.
Using Handbrake and Any Video Converter
Download and install Handbrake and Any Video Converter. Launch Handbrake after installation is finished.
Click on the small black triangle next to "Source" in the upper-left corner. In the drop-down menu that appears select "DVD /VIDEO_TS Folder". Select the Video_TS folder with the VOB files you want to covnert and click "OK".
Click on the "Browse" button under "Destination". Choose a folder and name for the file you will be creating and click "Save".
Select "MP3 File" in the drop-down list next to "Container" and click "Start". Handbrake will convert the multiple VOB files into one MP4 file. Close the program after it is complete and launch Any Video Converter.
Click "Add Video" and select the MP4 file you just created in Handbrake. Click "Open".
Click on the drop-down list next to "Profile" and select "Customized AVi Movie (*.avi)".
Click "Convert" and Any Video Converter will convert the file into an AVI.
Using VOBMerge and WinFF
Download VOBMerge. No installation of the program is needed, unzip the file and double-click on "VOBMerge.exe" to launch it.
Click "Add File(s)" and add all the VOB files you want to merge.
Click the "Merge" button and VOBMerge will merge the VOB files into one large video file. Close VOBMerge.
Open WinFF and click the "Add" button. Select the merged VOB you just created and click "Open".
Click on the drop-down list under "Convert To" and select AVI, then click on the drop-down list under "Device Preset" and select "MS Compatible AVI".
Click on "Convert" to convert the VOB into an AVI.