VOB to ASF Converter

How to Convert VOB to ASF Online

1. Upload Your VOB File: Drag and drop or click "Add Files" to select VOB files ripped from a DVD-Video disc. The VIDEO_TS folder typically holds several VOB segments (VTS_01_1.VOB, VTS_01_2.VOB,...) because DVD spec breaks each title into 1 GiB chunks — upload them all together and convert as a batch.
2. Pick Quality Preset or Bitrate Mode: Default is the "Very High (Recommended)" Quality Preset, which targets high-quality WMV2 output inside the ASF container. Switch to Specific file size to cap output at an exact MB value, Constant Bitrate for predictable streaming sizes, Variable Bitrate for smaller files at the same quality, Constant Quality to fine-tune with a quality slider, or Constraint Quality for capped VBR. ASF accepts WMV1, WMV2, MPEG-4, and other codec choices.
3. Resize or Trim if Needed (Optional): Under Video resolution, keep original (typically 720x480 NTSC or 720x576 PAL for DVD sources), pick a Preset Resolution (1080p / 720p / 480p / 360p), scale by Resolution Percentage, or enter custom Width × Height. Under Trim, pick Time Range and enter a start time + duration in seconds or HH:MM:SS format — handy for stripping the FBI warning, studio logos, or pulling a single chapter out of a feature.
4. Convert and Download: Click Convert. Files are uploaded over an encrypted connection, processed on our servers, and deleted automatically after a few hours — no sign-up, no watermark, never shared. Download individually or as a ZIP.

Why Convert VOB to ASF?

VOB (Video Object) is the container DVD-Video discs use — a strict subset of the MPEG program stream carrying MPEG-2 video plus AC-3, DTS, MPEG audio or LPCM, along with subtitle and navigation data. Each.VOB is capped at 1 GiB by DVD spec for filesystem compatibility, with companion.IFO and.BUP files holding the menu and chapter information. ASF (Advanced Systems Format) is Microsoft's streaming container released in 1998, carrying WMV/WMA payload and adding metadata, DRM hooks, and progressive-download friendliness. Common reasons to convert:

• Windows Media Player and legacy Windows kiosks — ASF/WMV plays natively on every Windows build since XP without a DVD navigator. If you need a DVD title to autoplay on a Windows-based information kiosk, training PC, or Windows Server media share, ASF is the path of least resistance.
• Streaming over Windows Media Services or IIS — ASF was designed for progressive download and server-pushed streaming. Hosting a converted lecture or training video on an internal IIS/SharePoint site usually wants WMV-in-ASF over raw VOB segments.
• Strip the 1 GiB split and concat into one playable file — A 90-minute DVD movie is split across 3-5 VOB files. Converting outputs one continuous.asf file (or.wmv) with the chapter joins seamlessly muxed, so the result plays start-to-finish without the half-second hitch DVD-Video has between VOBs.
• Drop interactive menus and navigation overhead — VOB carries menus, multi-angle data, and subtitle streams that confuse non-DVD players. ASF output keeps only the chosen audio/video tracks, producing a smaller, simpler file that any media player handles.
• Smaller file sizes — Re-encoding MPEG-2 (typical DVD bitrate 4-9 Mbps) to WMV2 or H.264 at modern settings typically cuts size 40-60% with minimal visible loss at SD resolution for typical home-video content. A 4.7 GB single-layer DVD often fits under 1.5 GB as ASF.
• Archive older Windows media workflows — Corporate training libraries, old WMV-based learning management systems, and Windows-tied DRM workflows still expect ASF. Converting once preserves the content in the format the legacy system understands.

VOB vs ASF — Format Comparison

Quality and Bitrate Mode Quick Guide

If you also need to shrink the output, follow up with Compress ASF or work in WMV directly via VOB to WMV. Going to a more modern container instead? Try VOB to MP4 or VOB to MKV. For the reverse direction, use ASF to VOB.

Frequently Asked Questions

Will the converted ASF play in Windows Media Player without extra codecs?

Yes, provided you keep WMV/WMA payload (the default for ASF output). Windows Media Player has shipped with WMV1, WMV2, and WMA decoders on every Windows release since XP, so the resulting.asf or.wmv plays out of the box on every Windows machine you're likely to encounter — including stripped-down Server Core or Windows IoT installs that lack third-party codec packs. If you choose H.264 inside ASF (less common), older Windows builds may need an extra decoder.

Why is my DVD title split across multiple VOB files, and will the converter join them?

DVD-Video spec caps each.VOB at 1 GiB to stay compatible with filesystems that historically struggled with larger files (legacy FAT, early ISO 9660). A 90-minute feature usually ends up as VTS_01_1.VOB through VTS_01_4.VOB or so. Upload all of them together in the order they appear in the VIDEO_TS folder and the converter produces a single continuous ASF — the chapter joins are remuxed seamlessly. If you only upload one part, you'll only get that 1 GiB slice as output.

Can I rip a copy-protected DVD with this converter?

No. XConvert processes VOB files you already have on your computer; it doesn't read directly from a DVD disc and doesn't bypass CSS, AACS, or any other DRM. To convert a commercial disc you'd need to first rip it with a tool that handles CSS (where legally permitted in your jurisdiction) into unencrypted VOB files, then upload those here. For homemade DVDs and unencrypted discs, just open the VIDEO_TS folder and drag the.VOB files in.

Should I pick WMV2 or H.264 codec inside the ASF container?

WMV2 (Windows Media Video 9) is the conservative choice — every Windows build since XP plays it without extra decoders, and the ASF + WMV2 combination is what most legacy Windows tooling expects. H.264 inside ASF works in VLC and modern Windows builds but defeats the main reason to use ASF in the first place (universal Windows playback without codec packs). If your target is anything other than Windows Media Player, you're usually better off converting to MP4 or MKV instead — see VOB to MP4.

Will the AC-3 5.1 surround audio from my DVD be preserved?

The video and audio streams selected by the converter become the ASF audio track, typically re-encoded to WMA2 stereo by default. If you need to preserve 5.1 channel layout, ASF supports WMA Pro for multichannel audio — but most ASF playback targets are stereo Windows desktops. If lossless surround matters, MKV with AC-3 passthrough is a better container choice than ASF.

Can I extract just one chapter from a DVD title without the rest?

Yes. After upload, use the Trim section: pick Time Range and enter the chapter's start time and duration. DVD chapter timestamps are listed in the disc's.IFO file or shown in any DVD player's "go to chapter" menu — copy those values over. The trim happens before any re-encoding so the output ASF only contains the segment you asked for, which also shortens the conversion time significantly.

Is ASF still worth using in 2026, or should I pick a newer format?

ASF is genuinely legacy — Microsoft hasn't revised the spec since December 2004 (version 01.20.03), and Windows Media Player 12 is the last desktop player that still treats it as a first-class format. Use ASF only if you're feeding a Windows-native system that explicitly expects it: an old Windows Media Services share, an LMS that only ingests WMV, or a Windows kiosk locked to default codecs. For any new workflow, MP4 with H.264 is the safer choice — see VOB to MP4.

What's the file size limit for upload?

There's no fixed per-file cap. Each VOB is at most 1 GiB by DVD spec, and a full single-layer DVD totals about 4.7 GB across its segments. Conversion happens on our servers, so the practical limit is upload size and connection speed and the patience for the upload. No quantity limit on batch jobs — drop in all the VTS_*.VOB files from a VIDEO_TS folder at once.

Does it work on mobile?

Yes — the converter runs in any modern browser on iOS, Android, Windows, macOS, and Linux. That said, VOB files are an unusual thing to have on a phone; most workflows involve copying the VIDEO_TS folder off a DVD on a desktop machine first. If you've already moved the files to your phone, drag-and-drop works the same as on desktop.