The Xing (pronounced "zing") MP3 encoder was one of the fastest MP3 encoders. Of course that comes with a price, and quality wasn't on par with encoders tuned for quality instead of speed, like FhG Slowenc (Audioactive) and LAME. Yet despite its reputation for poor quality, Xing's ~128 kbps VBR mode compared favorably in an early 2004 listening test.
- Encodes .wav to MPEG-1 and MPEG-2 layer 3 audio
- Encodes bitrates ranging from 28 to 320 kbps
- Variable Bitrate (VBR) encoding support
- High Frequency Encoding support (up to 20 kHz)
- Low data rate support
- Several times faster than most popular encoders
- Automated batch processing
- MP3 playback capabilities
- GUI based and command-line encoder front ends
XingMP3 standalone encoder
The last standalone version of the Xing encoder was XingMP3 1.5, released in March 1999. It included a command-line interface (x3enc.exe), and a GUI (mp3enc.exe). The GUI was restricted to using a limited set of encoding profiles, whereas the command-line encoder had more options.
After that release, the encoder continued to be improved, but it was only distributed as part of the RealPlayer bundle.
Helix MP3 Encoder
In 2005, RealNetworks - owners of the Xing assets after acquiring Xing Technology, a.k.a. XingTech - decided to release the encoder under an open source license, with the new name Helix mp3enc. The new version of the encoder is a code library which also has a command-line interface, but there is no GUI.
The Helix MP3 encoder is part of the Helix datatype project, a collection of code libraries intended to support the Helix multimedia project.
In November 2022 HydrogenAudio user maikmerten updated the encoder to include a lametag to provide sample accurate encoding/decoding for VBR and CBR, plus a bug fix to the original code.