SOUNDabout Wideband Speech is fully developed and ready for integration into any existing Bluetooth baseband. It is currently optimized for ARM7, but can be ported to other processors quickly.
The audio frequency response offered by SOUNDabout Wideband Speech is comparable to that of 3G audio coding standards such as G.722.2 (AMR-WB). It delivers monophonic audio sampled at 16 kHz over a Bluetooth eSCO link established by the application.
SOUNDabout Wideband Speech compresses audio using Open Interface North America's high-performance Bluetooth SBC codec.
Minimum Requirements- 9.5 KB of ROM for code and constants
- 2.3 KB of RAM for working memory
- eSCO S4 or S5 (EV3 packets)
- 16 kHz sampling rate
- Up to 8 kHz frequency response
- 16-bit PCM audio data
- Monophonic audio
- 64 kilobits per second max data rate
- Support for Bluetooth Enhanced Data Rate
ARM7 Performance Evaluation
The SOUNDabout Wideband Speech codec operates most efficiently when executing completely out of high-speed 32-bit memory, but also operates efficiently in a mix of fast memory and slow 16-bit memory.
On an ARM7TDMI processor, the codec's working memory, code, and constants occupy 10.5 and 11.8 kilobytes of memory. When fully loaded into 32-bit 0-wait-state RAM, the codec can simultaneously encode and decode high-quality audio on the equivalent of a 6 MHz ARM7 processor. When loaded into 7 kilobytes of fast RAM with less-critical portions in 16-bit ROM, the codec requires the equivalent of a 10 MHz ARM7.*
The chart below shows ARM7-equivalent processor speeds required for live encoding and decoding when the codec is partially loaded into high-speed memory. The SOUNDabout Wideband Speech Evaluation Kit includes an ARMulator™ binary for additional profiling.
* All performance figures are from Open Interface North America simulations, and refer to codec operations only.
|
Type of Slow Memory / Allocated Fast Memory | Equiv. ARM7 |
|
Not used / 10.5 KB |
6 MHz |
|
16-bit 1-wait / 8.0 KB 16-bit 1-wait / 6.0 KB |
7 MHz 10 MHz |
|
16-bit 2-wait / 9.0 KB 16-bit 2-wait / 7.0 KB |
6 MHz 10 MHz |
SOUNDabout Wideband Speech implements
the Final Improvement Proposal
Document for WB-Speech Service
V10r00.The document is a proposed specification, and is subject to change.
Contact Open Interface North
America at 
for prices, availability, and
licensing.