Methods and apparatuses for DTX hangover in audio coding

A transmitting node, operable to encode speech and to apply a discontinuous transmission (DTX) scheme comprising transmission of Silence Insertion Descriptor (SID) frames during speech inactivity, the transmitting node comprising a transmitter and a data processing system, the data processing system being operative to:

• determine a number N of hangover frames, wherein the number N of hangover frames is variable;
• employ the transmitter to transmit the N hangover frames to a receiving node comprising a decoder;
• and
• employ the transmitter to transmit a first SID frame to the receiving node in association with the transmission of the N hangover frames, wherein
• the SID frame comprises a counter value indicating the determined number N of hangover frames, thereby enabling the decoder to generate comfort noise based on the N hangover frames, and
• the transmitting node is configured to determine the number N of hangover frames by performing a process comprising determining the number of frames generated during a period in which an activity detection flag is set to a certain value and a second flag is set to a certain value.

A transmitting node, operable to encode speech and to apply a discontinuous transmission (DTX) scheme comprising transmission of Silence Insertion Descriptor (SID) frames during speech inactivity, the transmitting node comprising:

• a transmitter;
• and
• a data processing system, the data processing system being configured to:
• determine a number N of hangover frames, wherein the number N of hangover frames is variable;
• employ the transmitter to transmit the N hangover frames to a receiving node comprising a decoder;
• and
• employ the transmitter to transmit a first SID frame to the receiving node in association with the transmission of the N hangover frames, wherein
• the SID frame comprises a counter value indicating the determined number N of hangover frames, thereby enabling the decoder to generate comfort noise based on the N hangover frames, and
• the data processing system is configured to determine the number N of hangover frames by performing a process comprising determining the number of frames generated during a period in which an activity detection flag is set to a certain value and a second flag is set to a certain value.