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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

1 Scope

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

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

The present document defines a frame loss concealment procedure, also termed frame substitution and muting procedure, which is executed by the Enhanced Voice Services (EVS) decoder when one or more frames (speech or audio or SID frames) are unavailable for decoding due to e.g. packet loss, corruption of a packet or late arrival of a packet.