G.728 speech codec was standardized by ITU-T in 1992. The codec operates on 16-bit speech signal sampled at 8 KHz and generates compressed bit-streams with a bit-rate of 16 kbps. It is based on low delay code excited linear prediction (LD-CELP) algorithm. The decoder has an inherent packet loss concealment mechanism. It is used in video conferencing, satellite telephony, and voice over cable applications.

  • Based on ITU-T specification.
  • Optimized ASM/C implementation.
  • Re-entrant implementation.
  • C-callable APIs.
  • Operates on speech/audio signals sampled at 8 KHz.
  • Support for 16 kbps bit-rate.
  • Support for configurable frame sizes in multiples of 2.5 ms.
  • Support for RTP payload format as specified in RFC 3551.
  • Support for post-filter option, configurable at init-time.
  • Supports integrated Packet Loss Concealment (PLC) algorithm.
  • Support for PLC for frame size of the order of 1ms.
  • The implementation supports both Little-Endian and Big-Endian (on C64x platform)
  • Optional support for xDM APIs on TI platforms.
  • Tested for bit-exactness with standard as well as a large database of non-standard test vectors.
  • Module is fully interruptible (Maximum interrupt latency on C64x is 6000 cycles).
  • Tested for any illegal memory access by the module (C64x)
  • 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.
  • TI C64x+ implementation validated on Spectrum Digital C6455 DSK.

TI C55x, TI C64x+., and TI C66x.

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