G.711.1

CODEC OVERVIEW

G.711.1 speech codec was standardized by ITU-T in 2008. The codec operates on each 5 ms frame of 16-bit speech/audio signals sampled at 8 KHz or 16 KHz and generates a compressed bit-stream having bit-rates of 64 kbps, 80 kbps, or 96 kbps structured as 3 layers. The layered approach allows the decoder or any other component in the communication system to truncate the bit-stream by removing the higher layers. The base layer (Layer 0), at 64 kbps, is inter-operable with the traditional G.711. Layer 1 provides a lower band enhancement bit-stream at 16 kbps. Layer 2 provides a higher band enhancement bit-stream for the 16 KHz sampling frequency at 16 kbps. To improve the quality under frame erasures due to channel errors such as packet-losses, frame erasure concealment algorithms are provided at the decoder. This codec aims to achieve high-quality speech services over broadband networks, particularly for IP phone and multi-point speech conferencing, while enabling a seamless interoperability with conventional terminals and systems equipped only with G.711.

SALIENT FEATURES
  • Based on ITU-T specification.
  • Optimized ASM/C implementation.
  • Re-entrant implementation.
  • C-callable APIs.
  • Operates on speech/audio signals sampled at 16 KHz and 8 KHz.
  • Support for 64 kbps and 80 kbps bit-rate for the 8 KHz sampling frequency.
  • Support for 64 kbps, 80 kbps, and 96kbps bit-rate for the 16 KHz sampling frequency.
  • Support for RTP payload format as specified in RFC 3551.
  • Support for the integrated frame erasure concealment algorithm.
  • Support for the RTP payload format as specified in the standard.
  • Optional support for xDM APIs on TI platforms.
TESTING FEATURES
  • Tested for bit-exactness with standard as well as a large database of non-standard test vectors.
  • Module is fully interruptible.
  • 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.
  • TI C55x implementation validated on Spectrum Digital C5510 DSK.
AVAILABLE PLATFORM(S)

TI C55x.

For resource requirements & other details