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  • Vary tf_analysis end band based on complexity
  • Use pitch down to complexity 4 instead of 5?
  • Testing



  • De-uglify webpage - some suggestions: write about codecs obsoleted by OPUS (Speex, CELT, Vorbis(?), and the prop. ones), write about implementations (is there only one so far?), comparison table (Opus, Vorbis, Speex, ..., MP5) of features (channels, freq, bits per sample, license, language (C89), integer impl. (Vorbis decoder only, Opus YES, ...), future use in video files (Theora? Dirac? WebM? other future codecs...), audio files for storage (like Vorbis, no raw Opus defined, only inside OGG), ...
  • Promotional material (some nice free or Public domain sounds in Opus format)


  • Oggz-validate (should also validate opus toc)


  • A simple real time streaming example tool
  • Replaygain (half done— needs a gain tool)

Surround work

  • Apply spreading to energy masking
  • More conservative energy masking (not just mean difference) and dynalloc
  • Allow SILK/hybrid on center channel for voice?

Psychoacoustic stuff

  • Adaptive width narrowing and forced intensity stereo bands


  • Test exp_analysis and void_my_warranty.patch


  • Vectorising comb_filter()
  • Use 16-bit mul plus shift in denormalise_bands()
  • Optimise MDCT somehow
  • Merge ARM optimisations

Future work

  • psymodel based VBR
  • Remove copy in inverse MDCT
  • Save some float<->int conversions
  • Improvements to LP mode CBR (greg has some code)
  • Better handling for the case where FEC has a different bandwidth than the current mode
  • PLC transitions on unprotected SILK-SILK bandwidth changes?
  • Figure out how to use speech/music detection optimally
    • find optimal switching time (low energy/tonality)
  • Improve variable frame size