Microsoft's Real-time audio (MS-RTA) codec was introduced in 2006. MS-RTA is Microsoft's proprietary audio codec and is subject to terms and conditions of Microsoft License agreement. It operates on 16-bit speech signals sampled at 8 KHz or 16 KHz and generates a compressed bit-stream having average bit-rates of 8.8 or 18 kbps respectively. It is a sub-band coder and has a look ahead delay of 10ms. The encoder optionally includes forward error correction (FEC) block to embed error recovery data in the bit-stream. The decoder has an optional jitter-control module that provides active management of jitter control and packet loss concealment. It is the default codec for Microsoft's Unified Communications Platforms, and is designed for real-time, two way VoIP applications.
Salient features (of CouthIT implementation):
Based on Microsoft Standard specification.
Optimized ASM/C implementation.
Operates on speech signals sampled at 8 or 16 Khz.
Supports integrated Packet Loss Concealment (PLC) algorithm.
Support for direct-mode and pull-mode operation.
Support for 8.8 and 18 kbps averagebit-rates.
Support for variable and fixed rate encoding.
Support for optional FEC module.
The implementation supports both Little-Endian and Big-Endian.
Optional support for xDM APIs.
Scope of Testing:
Tested for bit-exactness with standard as well as a large database of non-standard test vectors.
Module is fully interruptible.
Tested for any illegal memory access by the module.
Tested for compliance with register preservation requirements.
Tested for Input buffer corruption.
Tested for I/O buffer alignment requirements.
Tested for multi-instance implementation.
Tested for 100% code coverage.
Range validation for all the API parameters.
Tested with scratch contamination at frame boundaries.
Tested for packet loss conditions with 5% loss to 25% loss.
Tested pull-mode decoder by simulating a large set of jitter conditions.
ARM implementation validated on OMAP3530 (Cortex-A8) and DM6446/DM6467 (ARM926EJ-S) platforms.
For most current information on the performance specifications and availability of developed implementation on ARM cores, please send in your enquiry to email@example.com