Convert MKV to VOB — Free Online Tool
Convert MKV files to VOB format using MPEG-2 video and AC3 audio — the native codecs of DVD-Video. This tool re-encodes your MKV content into a VOB container compatible with DVD players and authoring software, running entirely in your browser with no file uploads required.
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FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
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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
MKV files typically contain modern codecs like H.264, H.265, or VP9 for video and AAC or Opus for audio — none of which are compatible with the DVD-Video specification. Converting to VOB requires a full re-encode: the video stream is transcoded to MPEG-2, which is the mandatory video codec for DVD-Video, and the audio is transcoded to AC3 (Dolby Digital), the standard audio format for DVDs. The output is wrapped in the VOB container format with the '-f vob' flag, which structures the data as multiplexed MPEG program stream packets, as expected by DVD players and authoring tools. This is a computationally intensive conversion — unlike a simple remux — so processing time depends on file length and your device's CPU performance.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg binary — the open-source multimedia processing engine that performs the full re-encode of MKV to VOB format in this conversion. |
-i input.mkv
|
Specifies the input Matroska file. FFmpeg reads all stream metadata from the MKV container — video codec (e.g., H.264 or H.265), audio codec (e.g., AAC or Opus), and any subtitle or chapter data — to determine what re-encoding is required. |
-c:v mpeg2video
|
Transcodes the video stream to MPEG-2, the mandatory video codec for the DVD-Video specification and the only video codec natively supported by VOB containers. This is a full re-encode from the source codec, not a stream copy. |
-c:a ac3
|
Transcodes the audio stream to AC3 (Dolby Digital), the standard and most widely supported audio format in DVD-Video. This re-encodes whatever audio codec the MKV contains — such as AAC, Opus, or FLAC — into AC3. |
-q:v 4
|
Sets the MPEG-2 video quality using the quantizer scale, where 1 is highest quality and 31 is lowest. A value of 4 balances good visual fidelity with manageable file size, appropriate for standard DVD-quality viewing. |
-b:a 192k
|
Sets the AC3 audio bitrate to 192 kilobits per second, a standard DVD audio bitrate that provides clear stereo audio while remaining within typical DVD-Video bitrate budgets. |
-f vob
|
Forces FFmpeg to write the output as a VOB-packaged MPEG program stream rather than a generic MPEG-PS file, ensuring the output is recognized correctly by DVD authoring applications and media players as a Video Object file. |
output.vob
|
Specifies the output filename with the .vob extension. This is the standalone Video Object file containing the re-encoded MPEG-2 video and AC3 audio, ready for playback in compatible software or import into DVD authoring tools. |
Common Use Cases
- Preparing MKV video content for import into DVD authoring software like DVDStyler or DVD Flick to burn a playable DVD disc
- Converting a downloaded or archived MKV film to VOB so it can be played on a standalone DVD player connected to an older TV without HDMI inputs
- Migrating a personal video archive stored in MKV to VOB format to match an existing DVD-based storage and cataloging workflow
- Converting an MKV home video or event recording to VOB as an intermediate step before authoring a DVD gift for family members who use DVD players
- Generating VOB files from MKV lectures or presentations for distribution on physical DVD media in environments without reliable internet access
- Producing a VOB file from an MKV source to test how the content will look after MPEG-2 re-encoding before committing to a full DVD burn
Frequently Asked Questions
Yes, quality loss is unavoidable because this conversion requires re-encoding H.264 or H.265 video into MPEG-2, which is an older, less efficient codec. At the same default quality setting (-q:v 4), MPEG-2 will produce noticeably larger files than H.264 at equivalent visual quality, and fine detail may be slightly softer. The AC3 audio re-encode from AAC or Opus is generally transparent at 192k, but is still a lossy transcode. For best results, use the highest source quality MKV available.
No. The VOB container format used in this conversion does not support chapter markers at the file level — chapters in a DVD context are defined by the IFO and BUP navigation files that accompany VOB files in a full DVD-Video structure. This tool outputs a standalone VOB file, so chapter metadata from the MKV source is discarded. If you need chapter navigation, you must author the VOB into a complete DVD-Video structure using software like DVDStyler after conversion.
Subtitle stream handling in VOB is complex. The VOB format supports DVD subtitle streams (DVD bitmap subtitles), but text-based subtitles from MKV — such as ASS, SSA, or SRT — are not directly compatible without conversion to DVD subtitle format, which requires additional authoring steps. This tool's FFmpeg command does not explicitly map subtitle streams, so text subtitles from the MKV will not appear in the output VOB. For subtitle support, a full DVD authoring workflow is recommended.
The '-q:v' parameter controls MPEG-2 quantizer scale, where 1 is the highest quality and 31 is the lowest. The default of 4 produces good quality suitable for standard DVD viewing. To increase quality at the cost of file size, lower the value (e.g., '-q:v 2'); to reduce file size with some quality loss, raise it (e.g., '-q:v 6'). For DVD authoring, keeping the value between 2 and 6 is recommended to stay within typical DVD bitrate constraints.
On Linux or macOS, you can batch process with a shell loop: 'for f in *.mkv; do ffmpeg -i "$f" -c:v mpeg2video -c:a ac3 -q:v 4 -b:a 192k -f vob "${f%.mkv}.vob"; done'. On Windows Command Prompt, use: 'for %f in (*.mkv) do ffmpeg -i "%f" -c:v mpeg2video -c:a ac3 -q:v 4 -b:a 192k -f vob "%~nf.vob"'. The browser-based tool processes one file at a time, so the FFmpeg command is especially useful for bulk conversions of large collections.
Most standalone hardware DVD players cannot play a bare VOB file from a disc — they require a complete DVD-Video file structure including IFO and BUP files in a VIDEO_TS folder. However, many software media players such as VLC and MPC-HC can open and play a standalone VOB file directly on a computer. If your goal is physical DVD playback, you will need to import the VOB into DVD authoring software to create the full DVD-Video structure before burning.
Technical Notes
The MKV-to-VOB conversion is one of the more demanding format transitions because it requires full re-encoding of both video and audio streams rather than a simple remux. The output MPEG-2 video is significantly less compression-efficient than modern H.264 or H.265 sources, meaning VOB files will often be two to four times larger than the original MKV for equivalent visual quality. The '-f vob' flag instructs FFmpeg to output an MPEG program stream in VOB packaging rather than a generic MPEG-PS file, which ensures compatibility with DVD-aware applications. AC3 audio at 192k is a standard DVD audio configuration, though DVD-Video officially supports AC3 at up to 448k for higher fidelity. Multiple audio tracks from the source MKV can technically be mapped using explicit '-map' flags, but the default command maps only the primary streams. The VOB format does not support the rich metadata container that MKV provides — title, artist, description, and other tags are not preserved in the output. MPEG-2 video is limited to standard resolutions in strict DVD-Video spec (720x480 for NTSC, 720x576 for PAL), though FFmpeg will encode at the source resolution without enforcing this limit, which may cause compatibility issues with hardware players expecting spec-compliant dimensions.