Wave Arts VQE
Wave Arts VQE (Voice Quality Enhancement) is a open source software library implementing acoustic echo cancellation for voice over IP (VoIP) applications. The principal features are:
- Acoustic echo cancellation (multi-band FRLS algorithm)
- Acoustic echo suppression
- Noise suppression
- Auto-gain control
- De-clipping (useful for headsets)
- Speaker distortion compensation
- Cross-platform audio API: Mac OS-X (CoreAudio), Win XP (MME), Win Vista (WASAPI), and Win 7 (WASAPI)
- Device selection, volume control, level metering, hot swapping support
- Sample rate conversion
- Device calibration to compensate for sampling rate offsets
- Supports 8 kHz (narrowband) and 16 kHz (wideband) sampling rates
- Standalone demo application on Mac and Win
- Integration code for PJSIP
An application integrating with VQE would use the VQE API to open audio devices and stream audio, then all echo cancellation and other signal processing is built-in. It’s cross-platform (Windows and Mac OS-X for now).
If you are using PJSIP, there is integration code that implements a PJSIP audio device using VQE, you need only enable the VQE audio driver in the PJSIP configuration.
There is also a standalone VQE demo application with JUCE user-interface which demonstrates VQE and provides additional example code. The demo application plays some speech that asks you questions, records your answers, and then plays back the echo canceled recording of your answers. The application has a built-in user guide.
Wave Arts VQE is released under a dual GPL/commercial license. Developers can download the source code and test drive, or use it in GPL open source apps, and if you want to use it in a closed source application you must purchase a commercial license.