VOB to HCOM Converter

Turn VOB DVD audio into Macintosh HCOM format online

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Classic Mac Audio

Bring DVD VOB audio to vintage Macintosh computers. HCOM is the Huffman-compressed format native to classic Mac OS sound playback.

DVD to Vintage Mac

Extract VOB audio and encode as HCOM in one step. Bridge the gap between DVD-era media and classic Macintosh computing.

Server Processing

No vintage Mac or DVD tools needed for conversion. Our servers handle everything — upload VOB and download HCOM remotely.

How to convert VOB to HCOM

1

Select files from Computer, Google Drive, Dropbox, URL or by dragging it on the page.

2

Choose hcom or any other format you need as a result (more than 200 formats supported)

3

Let the file convert and you can download your hcom file right afterwards

About formats

VOB (Video Object) is the primary container format used on DVD-Video discs, defined as part of the DVD specification developed by the DVD Forum. The format first appeared with the DVD standard finalized in September 1996 and has since been used on billions of DVD discs produced worldwide. VOB files are based on the MPEG-2 program stream format, containing multiplexed MPEG-2 video alongside audio in AC-3 (Dolby Digital), DTS, MPEG-1 Layer II, or LPCM formats. Beyond audio and video, VOB files also carry DVD subtitle streams as bitmap overlays, navigation data for menu interaction, and chapter point information. The files reside in the VIDEO_TS directory on a DVD disc, with naming conventions (VTS_01_1.VOB, etc.) reflecting the title and part structure of the content. Individual VOB files are limited to approximately 1 GB to accommodate the UDF file system requirements, with longer content spanning multiple files seamlessly. The format supports both NTSC (720x480) and PAL (720x576) video resolutions at bit rates up to 9.8 Mbps for combined audio and video. Integration of video, multi-track audio, subtitles, and navigation into a single program stream made VOB a complete solution for consumer movie delivery. While streaming and newer disc formats have supplanted DVD for new content, VOB remains hugely relevant for accessing the vast library of existing DVD content.
Developer: DVD Forum
Initial release: September 1996
HCOM is a Huffman-coded audio format from the early Macintosh era, designed to shrink digitized sound for distribution on floppy disks and bulletin board systems when storage was precious and modems were slow. The encoder takes 8-bit unsigned PCM input, computes a frequency table of sample-delta values, and builds an optimal Huffman tree that replaces common deltas with short bit sequences. Compression ratios of 2:1 or better were typical for speech recordings, a meaningful saving when a 3.5-inch floppy held only 800 KB. Files were distributed as Macintosh resource forks and played through utilities like SoundApp and the BinHex ecosystem that defined Mac software exchange in the late 1980s. The format supported sample rates up to 22.255 kHz, matching the output capabilities of original Macintosh sound hardware. Tools such as SoX retain HCOM decoding support, ensuring that archived recordings remain accessible decades later. HCOM holds three practical advantages for preservation work: lossless compression that recovers the original samples exactly, a self-contained Huffman table embedded in each file for dependency-free decoding, and historical prevalence across thousands of vintage Mac sound archives.
Developer: Apple Computer
Initial release: 1985

Frequently Asked Questions

Why convert VOB to HCOM?

HCOM is a classic Macintosh audio format. Converting VOB audio to HCOM makes DVD sound content playable on vintage Mac hardware.

What plays HCOM on Mac?

SoundApp, SoundMachine, and other classic Mac OS sound utilities handle HCOM natively. SOX supports it on modern systems too.

Is HCOM a lossless format?

HCOM applies Huffman lossless compression to 8-bit FSSD data. No quality is lost beyond the initial 8-bit conversion step.

Does DVD quality survive?

VOB surround audio is reduced to 8-bit mono or stereo for HCOM. Speech transfers well, but complex audio loses significant detail.

Can I process entire DVDs?

Upload multiple VOB files from your DVD and batch-convert to HCOM. Archive an entire disc in vintage Mac audio format.