VOB to SLN Converter

Get Asterisk PBX audio from DVD VOB files online

Drop files here. 1 GB maximum file size or Sign Up
to
Facebook Amazon Microsoft Tesla Nestle Walmart L'Oreal

DVD to VoIP Audio

Extract VOB audio and encode it as SLN — ready to deploy as hold music, announcements, or IVR prompts on Asterisk phone systems.

Remote Processing

VOB files can be large. Our servers handle extraction and SLN encoding without burdening your machine or requiring PBX tools.

Any Platform

Run VOB to SLN conversion from any device with a browser. Deploy the telephony audio on your phone system from any location.

How to convert VOB to SLN

1

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

2

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

3

Let the file convert and you can download your sln 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
SLN (Signed Linear) is a headerless raw audio format storing 16-bit signed linear PCM samples at 8000 Hz mono, most closely associated with Asterisk) — the open-source PBX framework developed by Digium (now Sangoma Technologies). Within Asterisk, SLN serves as the native internal audio representation: every codec transcoding operation passes through signed linear as an intermediate step. This makes SLN the backbone of Asterisk's codec translation architecture. The format contains nothing but raw samples — no headers, no metadata, no framing — so parameters must be known in advance. While this lack of self-description might seem limiting, it is actually an advantage in telephony where sample format is fixed by convention and every overhead byte matters across thousands of simultaneous channels. The 8000 Hz rate aligns with the G.711 standard for traditional telephony, capturing the full 300-3400 Hz voice band. Asterisk also supports extended variants (sln16, sln32, sln48) for wideband audio. SLN files require no decoding — just direct memory mapping — making them ideal for real-time mixing, conferencing, and prompt playback in high-density VoIP environments.
Initial release: 1999

Frequently Asked Questions

Why convert VOB to SLN?

SLN is the native audio format for Asterisk PBX. DVD VOB audio can become custom hold music, prompts, or greetings for VoIP phones.

What are SLN specifications?

SLN is 8kHz, 16-bit signed integer, little-endian raw PCM — designed specifically for the Asterisk open-source telephone platform.

Does DVD surround convert?

SLN is mono at 8kHz telephony bandwidth. DVD surround audio is mixed down and resampled to match standard phone system quality.

Will the audio sound clear?

Speech from DVD content sounds clear at 8kHz telephony quality. Music is noticeably simplified but remains functional for hold music.

Can I process multiple VOB files?

Upload several VOB chapters and batch-convert them to SLN. Build a complete VoIP audio library from your DVD collection.