Software enables implementation of audio applications in Bluetooth devices

An increasing number of systems providing wireless transfer and playback of data by means of Bluetooth technology have appeared in such products as mobile audio devices and in-vehicle audio systems. An essential requirement for implementing a Bluetooth audio application is compliance with the SBC audio data coding method stipulated in the Bluetooth A2DP audio profile. SBC Middleware software supports the SBC (Subband Codec) audio data coding method stipulated in Bluetooth technology for short-range wireless communications.

The middleware comprises ‘SBC Encode Middleware’ that encodes audio data on the transmitting side, and ‘SBC Decode Middleware’ that decodes audio data on the receiving side. Thus, the development of both transmitting-side and receiving-side devices can be supported, enabling development solutions to be provided for audio applications in Bluetooth devices.

The SBC Middleware algorithm is optimised for the architecture of the SH3-DSP. This enables low-power operation of A2DP compliant audio applications, with a low CPU processing load at the 30-plus MHz level, providing an ample margin for supporting mobile audio devices that require low power consumption.

As a program interface, a variety of function interfaces are available using easily embedded C-language. The user only has to write a desired function interface within a program, making complex programming unnecessary, and thus enabling application development to be made more efficient. In addition, Renesas’ existing MP3 and MPEG-4 AAC (Advanced Audio Coding) audio middleware uses the same kind of interfacing as this new middleware, simplifying the development of multi-codec applications.

Renesas has released various semiconductor devices for use in multimedia products, and also offers a line-up of moving image middleware for MPEG-4 and similar applications and audio middleware for MP3 and MPEG-4 AAC applications and the like.
Future plans include the development of this middleware for use with microprocessors incorporating an SH-4 CPU core, and expansion into other application areas such as in-vehicle audio systems. Renesas’ SBC Middleware will be available from July 20, 2006.