VOB to MP3: Extract Audio from VOB(DVD Media File) Video to MP3(MPEG Layer-3) with River Past Audio Converter, VOB2MP3 converter, conversion

What is VOB?

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.

What is MP3?

MP3 is a digital audio compression algorithm that acheives a compression factor of about twelve while preserving sound quality. It does this by optimising the compression according to the range of sound that people can actually hear. MP3 is currently (July 1999) the most powerful algorithm in a series of audio encoding standards developed under the sponsorship of the Moving Picture Experts Group (MPEG) and formalised by the International Organization for Standardization (ISO).

MP3 is very different from Layer 2, using an additional MDCT layer to increase frequency resolution. Its scale factor groups are more optimised for the human ear, and it uses nonlinear sample quantisation and Huffman coding. MP3 files (filename extension ".mp3") can be downloaded from many World-Wide Web sites and can be played using software available for most operating systems (also downloadable), e.g. Winamp for PC, MacAmp for Macintosh, and mpeg123 for Unix. MP3 files are usually downloaded completely before playing but streaming MP3 is also possible. A program called a "ripper" can be used to copy a selection from a music CD onto your hard disk and another program called an encoder can convert it to an MP3 file.

Windows ships with limited MP3 encoding support. The output sample rate is limited to 24khz and the bitrate is limited 56kbps. However, many add-on packages from open source community make it possible to encode at higher sample rate and bitrate.

A commonly used open source codec is LAME. LAME comes in different forms, including a ACM (Audio compression manager) codec and a DLL (lame_enc.dll). Caution: LAME ACM does not work well on many computers, regardless which software is loading it. It is best to avoid installing LAME ACM and use lame_enc.dll instead.

MPEG.ORG is an excellent source for additional information on MPEG format and usage.

When you encode MP3 audio, we recommend you to install lame_enc.dll.

Launch River Past Audio Converter

Once River Past Audio Converter is installed properly, launch Audio Converter.

Install Decoders

To decode DVD, you need to have a couple of free decoders installed.

The first one is GPL MPEG Decoder.

GPL MPEG Decoder

Next, install AC-3 Decoder Filter.

AC-3 Decoder Filter

Add VOB File

Click on the "Add Files" button on the tool bar. The standard file open dialog appears. Select "VOB - DVD Media(*.vob)" in its "Files of type" combo box.

You should only use "Add Files" to select VOB files if they are generated by a DVD authoring software and each VOB file represent a single video clip. Do not use "Add Files" to add the VOB files on a DVD disc or DVD image.

A DVD contains many video clips, which are then divided into cells/chapters. All of the video clips are then streamed together in one big block. The VOB files on the disc is just a way to divide the block into 1GB files to be compatible with older operation systems like Windows 95, who has a file size limit.

Each VOB file on the DVD may contain multiple videos. Each video may span over multiple VOB files. If you use "Add Files", only the first clip in that particular VOB file will be parsed and added.

This picture below makes it easier to understand.

In this case, if you use "Add Files" to add VTS_01_1.VOB, you will only get the still menu. If you use "Add Files" to add VTS_01_2.VOB, you will get the end of chapter 3... This is how file based decoding works.

If you want to convert from a DVD disc or DVD VIDEO_TS directory image, use "Add DVD". We will parse the DVD information and find all the cell breaks. You will get to select which cell to convert, from 2 to 5. Still menus are ignored.

River Past Audio Converter

Select output format

Use the setting panel on the bottom of the window to control the output format. Click on the toggle to the left of the "Format" label to expand the panel. Select "MP3 - MPEG Layer-3" as the "Audio Type".

You can change the sample rate, channel (stereo or mono) and bitrate.

Note: The standard MPEG Layer-3 audio compressor is limited to maximum 24khz and 56kbps. Please install Lame_enc.dll for higher sample rate and bitrate.