Patent ID: 7881284

Claim:
A method for dynamically adjusting playout delay of audio signals encoded into a sequence of voice packets and transmitted from a transmitting end through a packet-switched network to a receiving end, said method comprising the steps of: storing a plurality of said voice packets in a jitter buffer at said receiving end, and dynamically determining whether to adjust silence length in said voice packets based on the number of said voice packets in said jitter buffer in order to adjust said playout delay; dividing said jitter buffer into three zones for temporarily storing said voice packets, and providing dynamic adjustment of silence length to extend or shrink said playout delay; and dynamically adjusting the sizes of said three zones of said jitter buffer according to the number of said voice packets in said jitter buffer; wherein said step of dynamically adjusting the sizes of said three zones further comprises the steps of: mapping said jitter buffer into five zones according to the number of said voice packets in said jitter buffer, said five zones including a no data to play zone A 0 , an extending silence zone A 1 , a normal delay zone A 2 , a shrinking silence zone A 3 , and a discarding voice packet zone A 4 , thereby said jitter buffer being divided into said zone A 1 , said zone A 2 , and said zone A 3 with said zone A 2 having a lower bound of normal delay L and an upper bound of normal delay U; using a probability model to obtain P Tn (Ai) of said zone Ai over a next time interval [Tn,Tn+1], said P Tn (Ai) being the probability that the number of said voice packets in said jitter buffer falls into said zone Ai in the time interval [Tn,Tn+1], i being an integer number from 0 to 4 and n being a natural number; and comparing pre-defined values T A0 , T A1 and T A3 , with said probability P Tn (A 0 ), P Tn (A 1 ), and P Tn (A 3 ) to determine whether to adjust said upper bound of normal delay U and said lower bound of normal delay L.