Radio apparatus for communicating digital audio streams

A method of processing a digital audio stream, the method comprising:

• receiving a sequence of radio data packets, transmitted at regular intervals, the sequence of radio data packets encoding a digital audio stream,
• wherein each radio data packet encodes a respective number of audio samples from the digital audio stream;
• outputting audio samples from the received digital audio stream at a variable output rate;
• measuring a reception interval between receiving each of a pair of the radio data packets;
• and
• for at least one radio data packet of the sequence, adjusting the variable output rate incrementally, in a respective number of steps of non-zero size, while outputting the audio samples from the respective radio data packet,
• wherein the respective number of steps is at least two steps, and
• wherein the number of steps, or the size of each step, or both, depends on said measured reception interval and is such that the output rate is always positive.

A radio transceiver apparatus comprising:

• radio reception circuitry for receiving a sequence of incoming radio data packets, transmitted at regular intervals;
• radio transmission circuitry for transmitting a sequence of outgoing radio data packets encoding an outgoing digital audio stream,
• wherein each respective outgoing radio data packet of the sequence of outgoing radio data packets corresponds to a respective incoming radio data packet of the sequence of incoming radio data packets;
• a digital audio interface for receiving audio samples for transmission in the outgoing digital audio stream;
• a buffer memory for buffering the audio samples received at the digital audio interface;
• a controllable oscillator configured to control a buffering rate at which audio samples are input to the buffer memory;
• a timer;
• and
• control logic configured to
• use the timer to measure a reception interval between receiving each of a pair of the incoming radio data packets, and,
• for at least one radio data packet of the sequence of outgoing radio data packets, to control the oscillator to vary said buffering rate incrementally, in a respective number of steps of non-zero size, while inputting the audio samples for the respective radio data packet to the buffer memory,
• wherein the respective number of steps is at least two steps, and
• wherein the number of steps, or the size of each step, or both, depends on said measured reception interval and is such that the buffering rate is always positive.