Extract Audio from VOB to ALAC — Free Online Tool
Extract lossless audio from DVD VOB files and save it as ALAC (Apple Lossless Audio Codec) in an M4A container. This tool decodes the AC3 (Dolby Digital) or other audio streams embedded in your VOB file and re-encodes them into ALAC — preserving full audio fidelity in a format natively supported by Apple Music, iTunes, and all Apple devices.
to
FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
Drop your VOB file here
or click to browse
Free — no uploads, no signups. Your files never leave your browser.
Settings
Note: Browser-based encoding uses approximate quality targets. For precise CRF compression, copy the FFmpeg command above and run it on your desktop.
Estimated output:
Conversion Complete!
DownloadHow It Works
VOB files store multiplexed MPEG-2 video, AC3 (Dolby Digital) audio, subtitle streams, and menu data in a single container. This conversion strips the video and subtitle streams entirely using the -vn flag, isolates the primary audio track, and re-encodes it from AC3 (a lossy compressed format) into ALAC. ALAC is a lossless codec stored in an MPEG-4 (.m4a) container — meaning no further audio information is lost during the ALAC encoding step itself. However, since the source AC3 audio is already lossy, the output will be a lossless representation of that lossy source, not a restoration of the original uncompressed audio. The resulting M4A file is typically much smaller than the original VOB and is immediately playable in iTunes, Apple Music, QuickTime, and any ALAC-compatible player.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg tool. In the browser-based version, this runs via FFmpeg.wasm compiled to WebAssembly — no files leave your device. On the desktop, this requires a local FFmpeg installation. |
-i input.vob
|
Specifies the input VOB file. FFmpeg reads the multiplexed MPEG program stream containing the MPEG-2 video, AC3 audio, subtitle streams, and DVD menu data packed into the VOB container. |
-vn
|
Disables video output entirely, discarding the MPEG-2 video stream from the VOB. Without this flag, FFmpeg would attempt to include video in the output, but since ALAC M4A is an audio-only format, this flag is essential to produce a valid audio file. |
-c:a alac
|
Sets the audio codec to ALAC (Apple Lossless Audio Codec), re-encoding the source AC3 Dolby Digital audio from the VOB into a lossless format stored in the MPEG-4 container. This flag appears in the command to explicitly ensure ALAC encoding is applied to the audio stream. |
output.m4a
|
Defines the output filename with the .m4a extension, which signals FFmpeg to use the MPEG-4 audio container. The M4A container is the standard wrapper for ALAC files and ensures compatibility with iTunes, Apple Music, QuickTime, and other Apple ecosystem software. |
Common Use Cases
- Archiving the audio soundtrack from DVD home movies or concerts as a high-quality lossless file for long-term preservation in your Apple Music library
- Extracting the AC3 surround sound mix from a DVD VOB file to keep a lossless-quality stereo or multichannel version in an Apple-compatible format
- Ripping audio from DVD language learning discs into ALAC so you can listen offline on an iPhone or iPad without video
- Preserving the audio from a DVD of a live musical performance in ALAC for audiophile-grade playback on Apple devices or high-resolution audio systems
- Converting a VOB file from a DVD-authored video project into an ALAC audio file for import into GarageBand, Logic Pro, or Final Cut Pro as a reference track
- Stripping audio from DVD backup VOB files to create a compact, lossless audio archive when the video content is no longer needed
Frequently Asked Questions
The ALAC encoding step itself is lossless, meaning it introduces zero additional audio degradation. However, the AC3 audio in your VOB file has already been lossy-compressed at the time the DVD was authored. ALAC will perfectly preserve whatever audio information survived that original AC3 encoding — it cannot recover detail that AC3 discarded. Think of it as a lossless snapshot of a lossy source: no new quality is lost, but the prior AC3 compression is baked in.
This is expected when converting from AC3 to ALAC. AC3 is a highly compressed lossy format designed for efficient DVD storage, while ALAC is a lossless format that stores audio in a mathematically reversible way, resulting in significantly larger file sizes. You are also discarding the MPEG-2 video stream, but the ALAC audio itself expands considerably compared to the original AC3 bitrate. For a typical 5.1 surround AC3 track at 192–448 kbps, the equivalent ALAC file can be several times larger.
FFmpeg selects the first (default) audio stream from the VOB file by default, which is typically the primary language track. VOB files commonly contain multiple audio tracks for different languages or commentary. If you need a specific non-default track, you would need to modify the FFmpeg command to add a stream selector such as -map 0:a:1 to choose the second audio track before running it locally on your desktop.
Yes. ALAC stored in an M4A container is natively supported by iTunes, Apple Music on Mac and iPhone, QuickTime Player, and the broader Apple ecosystem. You can drag the output file directly into your iTunes or Apple Music library and it will be recognized as a lossless audio file. Apple devices also display ALAC files with a 'Lossless' badge in the Music app.
The page displays the exact FFmpeg command used for this conversion, which you can copy and run on your desktop with a local FFmpeg installation. Desktop FFmpeg has no file size limit and will typically process large VOB files faster than the browser-based tool since it uses your CPU's full native performance rather than WebAssembly. The command is: ffmpeg -i input.vob -vn -c:a alac output.m4a
You can add -ss and -to flags to the FFmpeg command to extract only a portion of the audio. For example, ffmpeg -ss 00:05:00 -i input.vob -vn -c:a alac -t 00:03:30 output.m4a would start extraction at the 5-minute mark and capture 3 minutes and 30 seconds of audio. Place -ss before -i for faster seeking (input seeking) when working with large VOB files.
Technical Notes
VOB files are a specialized wrapper around MPEG program stream data, and FFmpeg requires the -f vob flag internally to handle certain edge cases in VOB parsing, particularly with files extracted directly from DVD disc structures. The default audio codec in DVD VOB files is AC3 (Dolby Digital), often encoded at 192 kbps for stereo or 448 kbps for 5.1 surround — though AAC and MP2 tracks also appear in some international DVD productions. When ALAC re-encodes a 5.1 AC3 track, the channel layout (front left, front right, center, LFE, surround left, surround right) is preserved in the ALAC output, which is important for users archiving surround sound content. ALAC does not support embedded subtitle streams, so any DVD subtitle data in the VOB is discarded during this conversion. Metadata tags such as track title or artist are not automatically transferred from VOB files since VOB/DVD containers store metadata differently from standard tag formats; you would need to add metadata manually using an ID3/M4A tag editor after conversion. The M4A container does support chapter markers, but these are not derived from VOB structure automatically by this command.