VOB to AC3 Converter

How to Convert VOB to AC3 Online

1. Upload Your VOB Files: Drag and drop or click "+ Add Files" to select VOB files from your DVD rip's VIDEO_TS folder. Batch uploads are supported — every VOB processes with the same settings.
2. Pick Quality Preset or Custom Bitrate: The default is Quality Preset → Very High (Recommended). Pick a Constant Bitrate from the dropdown (384 kbps for DVD-standard 5.1, 448 kbps for cleaner surround, 640 kbps max), or enter a Custom Bitrate (kbps/Mbps) for fine control. AC3 only supports Constant Bitrate or Custom Bitrate — file-size percentage and target-size are disabled because AC3 bitrates are tied to channel count.
3. Set Audio Channel, Sample Rate, and Trim (Optional): Audio Channel defaults to source (preserves 5.1 if present); switch to Stereo to downmix for portable players. Audio Sample Rate keeps the DVD-native 48 kHz by default. Use Trim to grab a specific commentary segment instead of the whole VOB.
4. Convert and Download: Click Convert. Each VOB demuxes server-side and returns a clean AC3 stream — no watermark, no sign-up, no Dolby decoder installation required on your machine.

Why Convert VOB to AC3?

VOB is the container DVD-Video uses — an MPEG program stream that multiplexes MPEG-2 video, AC-3 (or sometimes DTS / MPEG Layer II / LPCM) audio, subtitles, and navigation into one file capped at 1 GiB. Most consumer DVDs ship the soundtrack as AC-3 (Dolby Digital, released February 1991) at 192-448 kbps, so "VOB to AC3" is almost always demuxing the existing AC3 stream out of its DVD wrapper — fast, and ideally lossless if you don't re-encode.

• Preserve 5.1 surround for home theater authoring — AC3 carries up to 5.1 channels at 48 kHz, which is exactly what Dolby Digital receivers, Kodi, and most AVRs expect. Demuxing keeps the original channel layout intact rather than collapsing it to stereo.
• Fix editor crashes on VOB import — Edius, older Premiere builds, and a handful of NLEs choke when a VOB carries AC3 inside MPEG-PS. Extracting the AC3 separately and re-pairing audio + video tracks in the editor is a long-standing workaround on the VideoHelp forums.
• Author new DVDs or AVCHD discs — Both formats require an AC3 (or LPCM) audio track. Pulling the AC3 from an old VOB lets you re-author menus or compile clips without re-encoding the audio.
• Standalone surround playback — AC3 files play natively in VLC, MPC-HC, Kodi, and PowerDVD, and pass-through over HDMI/S-PDIF to any Dolby Digital receiver. Useful for archiving commentary tracks or director's-cut audio separately.
• Smaller archive than LPCM — A 90-minute LPCM 5.1 track at 48 kHz/16-bit is roughly 4.6 GB; the same content at AC3 448 kbps is about 300 MB with no perceptible loss for typical living-room playback.
• Replace a VOB's audio track — Demux the AC3, edit it (gain, normalization, dub), then remux back into a new VOB or MKV. Cleaner than re-encoding the whole soundtrack.

VOB vs AC3 — Container vs Codec

AC3 Bitrate Quick Guide

Frequently Asked Questions

Does converting VOB to AC3 preserve 5.1 surround sound?

Yes, if the source VOB actually contains a 5.1 AC3 track. Most commercial DVDs ship the main audio as AC3 5.1 at 384 or 448 kbps; extracting it keeps all six channels and the original 48 kHz sample rate. Leave Audio Channel set to source. If you downmix to stereo, the LFE (subwoofer) channel and surround channels fold into the front L/R per Dolby's standard downmix matrix.

Why is the File Size Percentage option greyed out?

AC3 doesn't expose a free-form file-size target the way MP3 does — its bitrate is constrained to specific discrete steps tied to channel count (the codec's framing structure requires it). Use Constant Bitrate (pick from 32-640 kbps) or Custom Bitrate instead. Same reason the percentage slider hides whenever you pick AC3 as the output codec.

Is this lossless extraction or a re-encode?

It depends on settings. If the source VOB already carries AC3 and you pick an AC3 bitrate that matches the source, the converter passes the audio through without re-encoding (true demux — lossless). If you change the bitrate, sample rate, or channel layout, the audio is re-encoded and you'll take a small generation loss. For archival, match the source bitrate exactly.

My VOB has multiple audio tracks (English, commentary, foreign dub). Can I pick one?

Server-side extraction takes the default (primary) audio track from the VOB. To grab a specific non-default track — like director's commentary or a foreign-language dub — demux locally with PGCdemux or eac3to first, then upload the isolated AC3. The xconvert pipeline doesn't yet expose track selection on multi-track VOBs.

Why does my output file say AC3 but only contains stereo?

The source VOB probably only carried stereo to begin with. Many older releases, TV-show DVDs, and home-burned DVDs use 2.0 AC3 rather than 5.1. Open the original VOB in VLC → Tools → Codec Information; the audio line will show "Channels: Stereo" or "Channels: 5.1". The output mirrors the source unless you override Audio Channel.

Will the AC3 play on my AV receiver or soundbar?

Yes — AC3 is exactly the format Dolby Digital receivers were built to decode. Drop the .ac3 into a player like VLC or Kodi and route the audio over HDMI or S-PDIF with passthrough enabled; the AVR's onboard Dolby decoder handles the rest. Older AVRs with optical input only support up to 5.1 at 448 kbps; for 640 kbps you need HDMI.

Should I pick AC3 or EAC3 (E-AC-3)?

AC3 (Dolby Digital) is the universal compatibility choice — every DVD player, AVR, smart TV, and game console decodes it. EAC3 (Dolby Digital Plus) carries up to 15.1 channels and is more bit-efficient, but it's only mandatory on Blu-ray and a handful of streaming codecs (Netflix, Apple TV). If your target is a DVD authoring tool or a legacy AVR, stick with AC3.

What if I just want stereo MP3 instead of AC3?

That's a much more common workflow for podcasts, music ripping, and portable playback. Use the VOB to MP3 converter for a stereo MP3 output, or VOB to WAV if you want uncompressed PCM for editing. For keeping the video alongside the audio in a modern container, VOB to MP4 is the usual choice.

Why is my AC3 file rejected by my DVD authoring software?

Most DVD authoring tools (DVDStyler, MultiAVCHD) require AC3 at 48 kHz and a bitrate of 192, 224, 256, 320, 384, or 448 kbps — anything outside that grid will be re-encoded or rejected. Stick with one of those Constant Bitrate dropdown values and leave sample rate at 48 kHz to stay inside the DVD-Video spec.