Speex

Website

The Speex homepage has all the project info.

Hardware

See Speex hardware for a partial list of supported hardware

Tasks

These are some improvements that could be made to Speex. Let us know if you'd like to work on one of them.

• Speech/signal processing (DSP design)
  • Improve noise suppression (get rid of musical noise) and residual echo suppression
  • Improve packet-loss concealment (PLC)
  • Re-write the built-in voice activity detector (VAD)
  • Improve the 2.15 kbps vocoder mode (there are even 4 unused bits left to use)
  • Algorithmic optimizations (see if some searches can be simplified/approximated)

• Complete fixed-point (DSP development)
  • Wideband
  • VBR
  • Rest of the narrowband modes
  • Preprocessor (noise suppression, AGC)
  • Jitter buffer
  • Arch-specific optimization
  • More...

• Tune (playing with parameters)
  • Noise weighting filter
  • Perceptual enhancement

• Features (plain C programming)
  • Implement maximum VBR bit-rate
  • Implement peeling (write functions to strip some of the bits)
    • Peel high-band (wideband -> narrowband)
    • Transform 24.6 kbps mode to 15 kbps mode

• Documentation
  • Use questions from the mailing list to create a better FAQ on the wiki
  • Update the Speex manual based on recent papers
  • Improve libspeex documentation
  • Write good example code

External links

• Wikipedia: Speex