Patent ID: 9137051
Filing Date: 2015-09-15
Classification: G10L,H04L

Abstract:
1. A method performed by a terminal device for receiving audio data communicated thereto across an Internet Protocol (IP) communications network, the terminal device comprising a packet receiver, a processor and a memory, the memory including a rendering buffer implemented therein, the method comprising: receiving an encoded audio signal packet using the packet receiver, the encoded audio signal packet being comprised in a sequence of encoded audio signal packets, the sequence of encoded audio signal packets comprising data representative of an audio signal; in response to receiving said encoded audio signal packet, using a decoder implemented on the processor to decode the received encoded audio signal packet to generate corresponding decoded audio data and storing said corresponding decoded audio data in the rendering buffer; in further response to receiving said encoded audio signal packet, and without making any determination that one or more encoded audio signal packets in said sequence of encoded audio signal packets subsequent to said encoded audio signal packet have not been received, using the decoder to perform packet loss concealment, thereby generating one or more concealment packets of audio data representative of audio data subsequent to said decoded audio data, and further storing said one or more generated concealment packets of audio data in said rendering buffer; rendering said decoded audio data stored in said rendering buffer and said one or more generated concealment packets of audio data stored in said rendering buffer as audio output from said terminal device; saving in said memory a corresponding state of the decoder prior to said generation of each of said concealment packets of audio data; receiving a previous encoded audio signal packet using the packet receiver, said previous encoded audio signal packet being received after the receipt of the encoded audio signal packet, the previous encoded audio signal packet being comprised in the sequence of encoded audio signal packets prior to said encoded audio signal packet and being representative of audio data for which one of said concealment packets of audio data has been generated and stored in said rendering buffer; restoring said saved state of said decoder corresponding to said generation of said concealment packet of audio data representative of said audio data represented by said previous encoded audio signal packet; in response to receiving said previous encoded audio signal packet, using the decoder implemented on the processor to decode the received previous encoded audio signal packet to generate corresponding decoded audio data and storing said corresponding decoded audio data in the rendering buffer so as to replace said concealment packet of audio data representative of said audio data represented by said previous encoded audio signal packet which had been previously stored in said rendering buffer; and retrieving said received encoded audio signal packet from said holding buffer and using the decoder implemented on the processor to re-decode the received encoded audio signal packet to generate corresponding decoded audio data and storing said corresponding decoded audio data in the rendering buffer; wherein the memory further comprises a holding buffer, the method further comprising storing said received encoded audio signal packet in said holding buffer.