TwinVQ is an audio encoding technology developed at NTT (Nippon Telephone and Telegraph, the developers of DualSpeech). It uses an unique encoding technique called Vector Quantization (VQ).

VQF is the format created for the TwinVQ technology. There are several limitations in this format: 2 channels at most, no VBR, limited bitrate options (only 80 and 96kbps for 44.1kHz stereo tracks), slow encoding, little support, no public specifications or open source implementation.

Despite these limitations, Yamaha bought the technology from NTT and launched the SoundVQ suite based on it. But it did not work out and VQF can be safely considered dead these days.

TwinVQ, on the other hand, is still alive as part of the MPEG4 audio standard, being used for very low bitrates (8-16kbps).

The player available here is very basic. It only supports VQF files and VQL playlists (but, for some reason, refused the VQL playlist I generated with the Yamaha encoder). The only controls are play, pause, stop, repeat and volume. The encoder is also as simple as can get: no batch support, only tags available are "Title" and "Comment", just a handful of sampling rates supported. Both give off a feeling of being demonstration apps rather than actual commercial products.

At the bottom of the page you'll also find the NTT TwinVQ SDK, with precompiled libraries for encoding and decoding on Windows and Linux.

A mirror of the NTT TwinVQ page is available at the Internet Archive.

I am also mirroring Thor's page from dalnetvqf, featuring VQF plugins for Winamp. Thanks to Thor for providing these files!


Date: 1998-03-11
Version: 2.1.1 (encoder)
Interface: Graphical
Platform: Win32
Download: NTTenc.zip - 514kB

Date: 2000-09-22
Version: 2.1.5 (player)
Interface: Graphical
Platform: Win32
Download: Tvq-p215e.exe - 1.793kB

Date: 2001-07-02
Version: 1.0
Interface: Winamp plugin
Platform: Win32
Download: in_vqf.exe - 419kB

Date: 2000-10-12
Version: 2.3
Interface: SDK
Platform: Win32/Linux
Download: Tvq20001012_open_nc.zip - 3.152kB