Foreword1 Scope2 References3 Definitions, abbreviations and mathematical expressions4 General description of the coder5 Functional description of the encoder5 Functional description of the encoder5.1 Common processing5.1.1 High-pass Filtering5.1.2 Complex low-delay filter bank analysis5.1.3 Sample rate conversion to 12.8 kHz5.1.4 Pre-emphasis5.1.5 Spectral analysis5.1.6 Bandwidth detection5.1.7 Bandwidth decision5.1.8 Time-domain transient detection5.1.9 Linear prediction analysis5.1.10 Open-loop pitch analysis5.1.11 Background noise energy estimation5.1.12 Signal activity detection5.1.13 Coding mode determination5.1.14 Coder technology selection5.2 LP-based Coding5.2 LP-based Coding5.2.1 Perceptual weighting5.2.2 LP filter coding and interpolation5.2.3 Excitation coding5.2.4 Bass post-filter gain quantization5.2.5 Source Controlled VBR Coding5.2.6 Coding of upper band for LP-based Coding Modes5.3 MDCT Coding Mode5.3.1 General description5.3.2 Time-to-frequency transformations5.3.3 MDCT based TCX5.3.4 High Quality MDCT coder (HQ)5.4 Switching of Coding Modes5.5 Frame erasure concealment side information5.6 DTX/CNG operation5.6.1 Overview5.6.2 Encoding for LP-CNG5.6.3 Encoding for FD-CNG5.7 AMR-WB-interoperable modes5.8 Channel Aware Coding6 Functional description of the Decoder6.1 LP-based Decoding6.1.1 General LP-based decoding6.1.2 Source Controlled VBR decoding6.1.3 Synthesis6.1.4 Post-processing6.1.5 Decoding of upper band for LP-based Coding Modes6.2 MDCT Coding mode decoding6.2.1 General MDCT decoding6.2.2 MDCT based TCX6.2.3 High Quality MDCT decoder (HQ)6.2.4 Frequency-to-time transformation6.3 Switching coding modes in decoding6.4 De-emphasis6.5 Resampling to the output sampling frequency6.6 Decoding of frame erasure concealment side information6.7 Decoding in DTX/CNG operation6.7.1 Overview6.7.2 Decoding for LP-CNG6.7.3 Decoding for FD-CNG6.8 AMR-WB-interoperable modes6.8.1 Decoding and speech synthesis6.8.2 Resampling6.8.3 High frequency band6.8.4 CNG decoding6.9 Common post-processing7 Description of the transmitted parameter indicesA.0 GeneralA.1 RTP Header UsageA.2 EVS RTP Payload FormatA.3 Payload Format Parameters 6.1.2 Source Controlled VBR decoding 26.4453GPPCodec for Enhanced Voice Services (EVS)Detailed algorithmic descriptionRelease 15TS Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM