An Improved Error Concealment Algorithm Based On H.26L

The application of video is inevitable trend, along with the fast and fierce development of multimedia, network technique and mobile communication. Whether in IP network or in the channel of wireless mobile network, error code or noise of signal and loss of data are always appear unavoidably. However, the compressed video data is highly sensitivity to error code. A few error codes may induce much code be decoded invalidly. In addition, Forward error correction and Repeat request are unfit for the case of real-time/interactivity condition. So we must search ways and means fitting for real-time video transmission. Because video data has relativity in Spatial and temporal field, we may utilize the data locating by the error data to recover it. This is called Error concealment.The study based on the video standard (H. 26L) of ITU-T. After familiar with the syntax and semantic, the author makes a study of the decoder of test model of H. 26L (TML9). Which includes making a search for error checking, error resilience, error concealment. Grounding on TML9, the experiment simulates the condition of error appearing on different position. So as to find how the error data locating different position influences the video data. And find strongpoint and weakness of representative error concealment algorithms. At last, the paper presents an improved error concealment algorithm based on h. 26L. Making use of feature and parameters of decoded frame as Motion Vector, coding pattern and the number of I-Macroblock etc. the proposed algorithm makes a choose along the three representative error concealment algorithms: Boundary Matching Algorithm, Spatial Interpolation and FrequencyInterpolation. Grounding on test model -TML9, the paper showssimulation results and compares the proposd algorithm with representiveerror concealment algorithms.