Convert VOB to WMA — Free Online Tool
Convert VOB files from DVD-Video discs to WMA audio, extracting the AC3/Dolby Digital audio track and re-encoding it as Windows Media Audio using the wmav2 codec. Useful for pulling soundtrack or dialogue audio from DVD content into a lightweight, widely-supported Windows audio format.
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FFmpeg Command
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Estimated output:
Conversion Complete!
DownloadHow It Works
VOB files are MPEG-2 program stream containers that multiplex video (typically MPEG-2), audio (typically AC3/Dolby Digital), and subtitle streams together. Since WMA is a pure audio format with no video container support, the conversion process discards the MPEG-2 video stream and all subtitle streams entirely — no video re-encoding occurs. The AC3 audio track is decoded from its Dolby Digital encoding and then re-encoded as WMA using Microsoft's wmav2 codec at a target bitrate of 128k by default. This is a full transcode of the audio: AC3 → PCM → wmav2, which means there is a generation loss compared to the original AC3 audio. If the VOB contains multiple audio tracks (e.g., different language dubs), FFmpeg will select the first audio stream by default unless you explicitly specify a stream.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg tool, which handles all demuxing, decoding, encoding, and muxing steps in this conversion pipeline — reading the VOB program stream, extracting the AC3 audio, and writing the WMA output. |
-i input.vob
|
Specifies the input VOB file. FFmpeg automatically detects the MPEG-2 program stream container and identifies the multiplexed video, audio (typically AC3), and subtitle streams inside. |
-c:a wmav2
|
Sets the audio encoder to wmav2, Microsoft's second-generation Windows Media Audio codec. This instructs FFmpeg to decode the source AC3 audio and re-encode it as WMA2, the default and higher-quality WMA variant used in modern WMA files. |
-b:a 128k
|
Sets the target audio bitrate for the wmav2 encoder to 128 kilobits per second. This is the default WMA bitrate for this tool and produces a reasonable quality-to-filesize tradeoff; increase to 256k or 320k if you need closer fidelity to the original DVD AC3 audio track. |
output.wma
|
Defines the output filename and tells FFmpeg to write a WMA container. The .wma extension causes FFmpeg to mux the encoded wmav2 audio stream into a Windows Media Audio file compatible with Windows Media Player and WMA-capable devices. |
Common Use Cases
- Extracting the dialogue or commentary audio track from a DVD movie VOB file to create a WMA audiobook or podcast-style recording for playback on Windows Media Player
- Pulling the music score or soundtrack from a concert DVD stored as VOB files and saving it as WMA for use in a Windows-based media library or Zune/Xbox Music collection
- Converting DVD language-learning disc audio (extracted as VOB) into WMA files for offline listening on Windows devices or older portable media players that support WMA but not AC3
- Archiving interview or lecture content from DVD recordings — stripping away the video to produce a compact WMA audio file for distribution or transcription workflows
- Extracting audio from DVD karaoke discs saved as VOB files and converting to WMA for use in Windows-based karaoke or media software
- Preparing DVD-sourced audio commentary tracks as WMA files to upload to platforms or share with editors who work in Windows-centric production environments
Frequently Asked Questions
Yes, there is unavoidable quality loss. AC3 (Dolby Digital) audio in VOB files is itself a lossy format, and converting it to WMA with wmav2 requires fully decoding the AC3 stream and re-encoding it — a process called transcoding. This generation loss means the resulting WMA file will have slightly lower fidelity than the original AC3 track. To minimize degradation, use a higher WMA bitrate such as 256k or 320k, especially if the source VOB has a high-bitrate AC3 track (commonly 192k–448k on DVDs).
Both are completely discarded. WMA is a pure audio container and cannot store video streams, subtitle tracks, or chapter markers. The MPEG-2 video stream and any DVD subtitle (subpicture) streams in the VOB are ignored by FFmpeg during this conversion — only the first audio track is decoded and re-encoded as WMA. If you need to preserve the video or subtitles, you would need to convert to a video container format instead.
By default, FFmpeg selects the first audio stream in the VOB file. To target a specific audio track, add the flag '-map 0:a:1' (for the second audio track, zero-indexed) to your command before the output filename, like: ffmpeg -i input.vob -map 0:a:1 -c:a wmav2 -b:a 128k output.wma. You can identify available audio streams by running 'ffmpeg -i input.vob' and inspecting the stream list in the output.
Replace the '-b:a 128k' value in the command with a higher bitrate. For example, to encode at 256k, use: ffmpeg -i input.vob -c:a wmav2 -b:a 256k output.wma. The available WMA bitrate options range from 64k up to 320k. Keep in mind that WMA with wmav2 at 128k is generally considered transparent for most listening, and since the source AC3 audio is itself lossy, pushing above 192k offers diminishing returns.
Unlikely. VOB files store minimal metadata — primarily DVD-specific disc and title information rather than standard audio tags like artist or track title. WMA supports rich metadata tags (title, artist, album, genre, etc.), but since that information typically doesn't exist in a structured way inside a VOB file, the output WMA will usually have no meaningful tags. You can add metadata manually in the FFmpeg command using flags like '-metadata title="My Track"' before the output filename, or tag the file afterward using a tool like Mp3tag.
Yes. On Linux or macOS, you can use a shell loop: 'for f in *.vob; do ffmpeg -i "$f" -c:a wmav2 -b:a 128k "${f%.vob}.wma"; done'. On Windows Command Prompt, use: 'for %f in (*.vob) do ffmpeg -i "%f" -c:a wmav2 -b:a 128k "%~nf.wma"'. Note that DVD titles are often split across multiple VOB files (VTS_01_1.vob, VTS_01_2.vob, etc.) — if you want a single continuous WMA from a multi-part title, you should concatenate the VOB files first using FFmpeg's concat demuxer.
Technical Notes
VOB files on a DVD are typically found inside the VIDEO_TS directory and may be split across multiple files (e.g., VTS_01_1.vob through VTS_01_5.vob) for a single title. Each VOB is an MPEG-2 program stream container, and the audio is almost universally AC3 (Dolby Digital) at bitrates between 192k and 448k, though some DVDs include DTS, LPCM, or MPEG audio tracks as well. The wmav2 codec used in the output is Microsoft's second-generation Windows Media Audio codec and is significantly more efficient than the older wmav1, offering better audio quality at equivalent bitrates. WMA files produced with wmav2 are compatible with Windows Media Player, older Zune devices, many portable media players, and Xbox consoles, but have limited support in non-Windows ecosystems — macOS and Linux require additional codec support to play WMA. The output WMA format does not support multiple audio tracks, chapters, or subtitles, so any secondary audio streams (alternate languages, director's commentary) in the source VOB are silently ignored unless explicitly mapped. There is no lossless WMA option in this conversion path; both AC3 (source) and wmav2 (output) are lossy codecs.