When compressed video stream is transmitted over internet or wireless network

it is sensitive to packet loss and error occurrence due to the limited bandwidth and the instability of the channel

especially for motion compensation-based video coding standard. An error in one frame not only debases the reconstructed quality of the current frame

but propagates to the succeeding frames which use current frame as their reference frame. As a result

error concealment algorithms are developed for hiding erroneous blocks by exploiting high correlation in video sequence. In this paper

a new temporal error concealment algorithm which suits for H.264

the latest international video coding standard

is proposed. In this algorithm

an erroneous macroblock is firstly divided into four 8×8 blocks

which work as the concealment unit instead of the macroblock. Then

a modified boundary matching algorithm is exploited to recover the lost motion vectors with different boundary pixels for different blocks. Finally

the best-matched blocks are obtained using one-quarter pixel diamond search method. Experimental results show that the proposed algorithm makes use of the information in H.264-compressed bit stream efficiently

and has a better reconstruction quality for erroneous blocks than conventional temporal error concealment algorithms.