CONTENTS

 Annex I – Frame or packet loss concealment for the LD-CELP decoder
        I.1     Scope
        I.2     Normative references
        I.3     Introduction
        I.4     Principles of operation
                  I.4.1     Excitation extrapolation
                  I.4.2     LPC filter
                  I.4.3     Backward adaptation of LPC and gain predictors
                  I.4.4     Post-filter
                  I.4.5     Limitation of gain growth after frame erasure
        I.5     Pseudo-code for frame erasure concealment
                  I.5.1     New main program loop for decoder
                  I.5.2     Block 31SF – Set flags and scaling factor for frame erasure
                  I.5.3     Block 31FE – Excitation signal extrapolation
                  I.5.4     Block 31E – Excitation signal update
                  I.5.5     Block 43FE – Hybrid windowing module
                  I.5.6     Block 47AF – Log-gain limiter after frame erasure
                  I.5.7     Block 49FE – Hybrid window module for synthesis filter
                  I.5.8     Block 51FE – Bandwidth expansion module for frame erasures
                  I.5.9     Block 97FE – Update GSTATE during frame erasures
                 I.5.10     Block 98AF – Log-gain limiter after frame erasure
        I.6     Additional coder parameters and variables
Appendix I.I – Values used for scaling ETPAST during frame erasures