FIELD: information technology.
SUBSTANCE: indication on the start of an inactive speech period is signalled to a decoder via a voice activity detection (VAD) flag during a predetermined number of frames before the DTX period will start, i.e., before the SID FIRST frame is received. When the VAD flag indicates active speech, or when the VAD flag has been set to zero less than the predetermined number of frames ago, the received NO DATA frame can be classified with a high degree of reliability as active speech, i.e., considered as transmitter, network or terminal-initiated signalling, and can be substituted by a SPEECH LOST frame. If the VAD flag was set to zero eight frames ago or earlier, the NO DATA frame is classified as DTX.
EFFECT: high error tolerance of an AMR-WB decoder when processing any input combination of frames of different types.
16 cl, 4 dwg, 3 ex
