F4V to VOX Converter

Extract Dialogic VOX audio from F4V Flash video

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Telephony Standard

VOX is the standard for Dialogic IVR systems — extract audio from F4V for phone system prompts and greetings.

Efficient Voice Compression

Dialogic ADPCM at 4 bits per sample produces very compact files ideal for telephony storage.

Secure Processing

F4V uploads are deleted after extraction. VOX files are removed from servers within 24 hours.

How to convert F4V to VOX

1

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

2

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

3

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

About formats

F4V is a multimedia container format developed by Adobe Systems as an evolution of the Flash Video ecosystem. Introduced in December 2007 with Flash Player 9 Update 3, F4V is based on the ISO base media file format (MPEG-4 Part 14) and was created to support the H.264 video codec and AAC audio within the Adobe Flash platform. Unlike its predecessor FLV, which used a proprietary container structure, F4V adopts the standardized MP4-compatible atom/box architecture, making it more interoperable with other media tools and workflows. The format supports advanced features including high-profile H.264 encoding, multichannel AAC audio, and timed text for subtitles and captions. F4V represented a strategic move to address the growing demand for H.264 content on the web, as the older FLV container could not efficiently package this newer codec. During its peak years, F4V powered much of the high-quality video content delivered through Flash-based streaming platforms and video players on the web. The container supports both progressive download and dynamic streaming delivery, offering content publishers flexible distribution options. While the decline of Flash Player in favor of HTML5 video has reduced the creation of new F4V content, the MP4-based structure means the contained media streams are readily accessible through modern tools.
Developer: Adobe Systems
Initial release: December 3, 2007
VOX is a headerless audio format built around Dialogic ADPCM encoding, widely adopted in telephony, interactive voice response (IVR) systems, and voice mail platforms since the 1980s. Each audio sample is compressed into 4 bits using an algorithm developed by Oki Electric and implemented in hardware on Dialogic Corporation's telephony interface cards. VOX files typically use a sampling rate of 6000 or 8000 Hz, producing extremely compact recordings optimized for speech intelligibility rather than musical fidelity. Because the format carries no header, playback software must know the sample rate and encoding parameters in advance — a trade-off that reduces overhead but demands careful file management. The primary advantage of VOX is storage efficiency: a one-minute voice recording at 8 kHz occupies roughly 240 KB, making it practical for systems storing thousands of prompts. Dialogic ADPCM conforms to the ITU-T G.726 standard, ensuring interoperability across telephony equipment from different vendors. Even as modern call centers migrate to IP-based systems with codecs like Opus, vast libraries of VOX recordings persist in legacy IVR deployments and compliance archives worldwide.
Initial release: 1983

Frequently Asked Questions

Why convert F4V to VOX?

VOX uses Dialogic ADPCM encoding standard in IVR systems and telephony. Extracting from F4V provides audio for phone system prompts.

What uses VOX files?

Dialogic telephony cards, IVR systems, and phone-based voice response platforms use VOX format for audio prompts.

How does VOX compress audio?

VOX uses OKI ADPCM at 4 bits per sample, achieving 4:1 compression over linear PCM with minimal voice quality loss.

Is VOX for voice only?

VOX is optimized for telephony-grade voice. Music or wide-spectrum audio will lose fidelity in this format.

Can I convert multiple files?

Upload several F4V videos and extract VOX audio from each one simultaneously.