Abstract: The embodiment of the present invention provides a method for establishing P2P connection, comprising the steps of: a first terminal initiating connection sends a message to a second terminal to be connected, wherein the message contains the address of the first terminal; the second terminal reads the address of the first terminal initiating connection upon receiving the message, and initiates a P2P connection to the address of the first terminal. The embodiment of the present invention also provides another method for establishing P2P connection, through which both UDP P2P connection and TCP P2P connection can be established.

Abstract: A motion estimation method includes: setting multiple block patterns and dividing respectively the current macro block into calculating blocks based on each of the block patterns; calculating respectively the motion vectors of all the calculating blocks of the current macro block in each of the block patterns; calculating respectively the sum of matching values between all the calculating blocks of the current macro block and the blocks respectively corresponding to the calculating blocks of the current macro block in each of the block patterns, acquiring the block pattern corresponding to the minimum sum, and regarding the motion vector corresponding to the acquired block pattern as the motion vector of the current macro block. Thereby, time for calculating block matching values in motion estimation may be reduced greatly and the speed of video data compression may be increased. Thus, the demand of video data in real time may be met.