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TechSpec
  • Foreword
  • 1 Scope
  • 2 References
  • 3 Definitions, symbols and abbreviations
  • 4 General
  • 5 Detailed description
    • 5.1 Concealment operation related to signal classification
      • 5.1.1 Overview
      • 5.1.2 Signal class estimation
    • 5.2 Concealment operation related to spectral envelope (LPC) representation
      • 5.2 Concealment operation related to spectral envelope (LPC) representation
      • 5.2.1 Specifics to rates 9.6, 16.4 and 24.4kbps
      • 5.2.2 Specifics to AMR-WB IO mode
      • 5.2.3 Check for Mid LSF stability
      • 5.2.4 Adaptive interpolation of LSFs
      • 5.2.5 LPC gain compensation
    • 5.3 Concealment operation related to ACELP modes
      • 5.3.1 General
      • 5.3.2 Concealment for bandwidth extension for ACELP modes
      • 5.3.3 Guided concealment and recovery
      • 5.3.4 Handling of multiple frame losses and muting
    • 5.4 Concealment operation related to MDCT modes
      • 5.4.1 PLC method selection
      • 5.4.2 TCX MDCT
      • 5.4.3 HQ MDCT
      • 5.4.4 Void
      • 5.4.5 Guided concealment and recovery
      • 5.4.6 Handling of multiple frame losses and muting
    • 5.5 SID frame concealment operation

5.2.1 Specifics to rates 9.6, 16.4 and 24.4kbps

26.4473GPPCodec for Enhanced Voice Services (EVS)Error concealment of lost packetsRelease 17TS

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

Additionally to estimating the LSF vector there is another LSF vector computed

(20)

where

is an estimated LSF vector used in ACELP concealment,

is the LSF representation of the CNG noise estimation on decoder side (see clause 4.3 in [5]).