What is SUPREE embedded AudioEngine?
SUPREE embedded AudioEngine is a middleware for high quality audio media communication.
It has basic functions of an IP phone, focuses on communication control of exchanging the voice and provide the flexible API such as controlling microphones and speaker devices, voice conference (voice mixing) and recording a telephone call.
SUPREE embedded AudioEngine Function
Multiple Calling Control
SUPREE embedded AudioEngine enables controlling voice calling with multiple partners, playback on device, recording to file at the same time.
These voices are managed by the instance called stream and can be started and stopped separately. By combining these streams, it’s possible to flexibly implement playback file and recording during a voice call and so on.
In SUPREE embedded AudioEngine, the voice conference is implemented based on the so-called conference instance. The different streams with the partners are belonged to a conference and the voices is combined by mixing processing, therefore the voice conference can be distributed appropriately. In addition, multiple conferences are controlled at the same time, so it’s possible to develop the application that similar to conference server.
High Quality Voice Processing
The clarity of the voice is decided based on the sampling rate, which is so-called resolution of voice. The general IP phones use the sampling rate of 8kHz (able to playback voice up to ~3.4kHz), even high quality IP phone applications still use the sampling rate of 16kHz (able to playback voice up to ~7kHz voice).
In contrast, SUPREE embedded AudioEngine‘s internal processing is employing sampling rate of 48kHz, which is enable to playback all of the voices in human ear audible range, so achieves the clear and high quality voice.
Support Different Codecs
SUPREE embedded AudioEngine supports different type of codecs.
Beside the common used for IP phone, G.711 u-law, the spreadly employed codec of internet calling application, iLBC and OPUS, and G.711.1 codec used for NTT East & West are supported, so it can interconnect with various systems.
In SUPREE embedded AudioEngine, in addition to the typical RTP/SRTP, the dramatic high voice-quality VoIP technology REAFSVC developed by Softfront R&D is equipped. By the unique technology, even in poor network environment, the discomfort sound drop-out is prevented and dramatic high voice-quality calling is always guaranteed.
What can be Developed from SUPREE embedded AudioEngine?
Using SUPREE embedded AudioEngine, we can develop the following products:
IP Phone Application for Smartphone
SUPREE embedded AudioEngine supports multiple operating systems, so that the IP phone application can be developed on a wide range of OS platforms such as smartphone (Android, iOS) and PC.
Voice Conference Server
Based on object-oriented design, SUPREE embedded AudioEngine enables processing multiple streams and conferences, flexibly supports from 1-voice call application to voice conference server. SUPREE Vision Premier 3 is currently employing SUPREE embedded AudioEngine for implementing toolkit to enable TV conference function on Windows PC without using any conference server (MCU).
Special IP Phone
SUPREE embedded AudioEngine support integration into Linux, usable for various special IP phone such as the transceiver and helmet mounting income, …
- SUPREE embedded AudioEngine Object Code (Binary used for link)
- Header file
- API reference
- API tutorials/Tester Windows version (SFAudioEngineTester.exe)
SUPREE embedded AudioEngine Specification
|Protocol||RTP / RTCP (RFC3550), SRTP (RFC3711), REAFSVC|
|Number of Simultaneous Streams||no limit|
|Number of Simultaneous Conferences||no limit|
|Voice playback||.wav file|
|Voice recording||.wav file|
|VAD (Voice activity detector)||Support (frequency and sound pressure detection)|
|CNG (Comfort noise generator)||Support|
|AGC (Automatic gain control)||Support (sound pressure control)|
|Voice cutting, smoothing processing||Frequency and sound pressure control|
|OS||Linux, Android, iOS, Windows, Mac|