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TechSpec
  • Foreword
  • 1 Scope
  • 2 Normative references
  • 3 Definitions, symbols and abbreviations
  • 4 Outline description
  • 5 Error concealment
    • 5.1 AAC error concealment
    • 5.2 SBR error concealment
      • 5.2 SBR error concealment
  • 6 SBR stereo parameter to mono parameter downmix
    • 6 SBR stereo parameter to mono parameter downmix
    • 6.1 Inverse filtering
    • 6.2 Additional harmonics
    • 6.3 Envelope time borders
    • 6.4 Noise time borders
    • 6.5 Envelope data
    • 6.6 Noise floor data
  • 7 Output resampler tool
    • 7 Output resampler tool
    • 7.1 QMF bandlimiter
    • 7.2 Spline resampler
    • 7.3 Postfilter

7.1 QMF bandlimiter

26.4023GPPAdditional decoder toolsEnhanced aacPlus general audio codecGeneral audio codec audio processing functionsTS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

The QMF bandlimiter maps the final QMF matrix to , according to the rule

where the cutoff frequency subband indexis given by