CANEC PERFORMANCE

CANEC has been optimized in quality, features, and performance based on valuable customers' feedback over the years. It includes advanced features that are required in modern high end conferencing and hands-free applications such as fast convergence, low processing delay, robustness during double talk, microphone muting support, automatic estimation and compensation of initial delay, performance reporting, and much more.

• CODE PERFORMANCE

  Efficient implementation at the algorithm level as well as at the code level resulted in unparalleled performance. For instance a single ADSP-21489 processor without any external memory can implement up to 8 channels of echo and noise cancellers, each channel has 250 ms echo tail length at 48 kHz audio sampling rate, and also combine the output of the processed microphones signals with the auto-mixer.

• QUALITY PERFORMANCE

  The sample audio files below demonstrate the audio quality of the processed speech signal during extended double-talk periods. The female voice in the unprocessed microphone signal is the echo that must be removed, while the male voice is the voice of the local conference participant that must be preserved. The result of processing through CANEC shows how the algorithm can remove the female voice entirely without distorting the male voice. The images show the spectral contents of the unprocessed microphone signal and CANEC output, respectively. Click on the images for larger view.

Unprocessed Microphone Signal

CANEC Output

CANEC FEATURES

CANEC includes all audio digital signal processing required in a high end conferencing and hands-free applications. Processing modules that enhance both the down-link (signal received from the communication channel) as well as the up-link (signal picked up by the local microphones) are included.

The down-link processing modules include DC blocking filter, Loudspeaker Filters, Octave Graphic Equalizer, Stationary Noise Reduction, and Automatic Gain Controller.

The up-link processing modules include DC blocking filter, High-Pass Filter, Adaptive Echo Canceller, Echo Suppressor, Comfort Noise Generator, Stationary Noise Reduction, Automatic Gain Controller, Octave Graphic Equalizer, and optional mixing stage.

In addition to the above processing modules, a feedback canceller is also available which is necessary in large conferencing spaces. The feedback canceller prevents howling therefore allowing the processed microphones signals to be amplified and played to a local loudspeaker so that participants seated in the same large room but far from each other, can still hear each other clearly.

The following is a partial list of the most important CANEC features:

• Low algorithm processing delay; defined by the user-adjustable block length.
• Supports multiple loudspeakers and multiple microphones.
• Each processing module can be dynamically enabled or disabled at run-time.
• Includes an optional mixing stage to combine all processed microphone signals.
• Acoustic echo canceller complies fully with G.167, P.340, and VDA (category 1).
• Acoustic echo canceller employs a robust and efficient adaptive algorithm.
• Acoustic echo canceller provides superior and consistent single-talk echo reduction in any acoustic environments.
• Acoustic echo canceller provides stable echo reduction of 40 dB or more during double-talk periods.
• Echo tail length is user adjustable.
• A multichannel high quality echo suppressor is also included which further reduces any remaining residual echo with negligible double-talk distortion.
• Noise reduction algorithm provides up to 25 dB of background noise reduction with negligible speech distortion.
• Noise reduction level is user-adjustable.
• Loudspeakers response can be seamlessly fine-tuned using the built-in octave graphic equalizer.
• Microphones signals level can be automatically adjusted by the up-link multichannel automatic gain controller.
• Loudspeakers signals can be automatically adjusted by the down-link multichannel automatic gain controller.
• Includes an optional sample synchronization module for clock skew correction, resulting in high quality sound on desktop and portable computing platforms.
• Works at any sampling frequency without any calibration or modification. It has been already deployed in top quality products running at sample rates ranging from 8kHz to 48kHz.
• Trivial to integrate due to its simple Application Programming Interface.
• Fully configurable. System designers have complete control on algorithm parameters during real-time processing, including the ability to enable, disable and adjust the target level of individual channels in any processing module.
• Already lab and field tested on several fixed-point and floating-point processors and DSPs with and without an operating system.
• Supported on all major desktop, mobile, and embedded platforms.
• Floating-point and Fixed-point implementations optimized for several general purpose processors, microcontrollers, as well as digital signal processors are directly available.
• Proven excellent performance in many high end applications including installed audio and video conferencing, Unified Collaboration, hands-free telephones, and consumer electronics.

EVALUATING CANEC

Several demonstration programs are available that allow you to evaluate CANEC while running in real-time on your preferred platform. Some of the demonstration applications also allows you to enable and disable processing modules and hear the effect in real-time.

Demonstrations are currently available for the following platforms.

• Analog Devices SHARC and BlackFin digital signal processors.
• ARM Cortex M4 and M7 processor, such as STM32 from ST Microelectronics.
• Windows XP and higher, including Windows 7, 8, 10, and embedded versions of Windows.
• Mac OS X 10.6 and higher.
• Linux PC (x86-64) with 2.6 kernel or newer and ALSA audio driver.
• Embedded Linux with kernel 2.6 or higher and ALSA audio driver (several platforms including Raspberry Pi, Orange Pi, etc).

To request the CANEC demo, please fill in this short form.