Video transcoding for resilience in wireless channels

We describe a method to maintain an acceptable quality for video transported over wireless networks under time-varying conditions. We use a transcoder to modify the resilience of the encoded bitstream by using source coding techniques to provide the appropriate level of resilience for the prevailing channel conditions. We develop a statistical model for image loss versus resilience and wireless conditions. Simulation results indicate that using a transcoder to adjust the resilience can improve video quality when errors occur without significantly sacrificing quality when there are no errors. Also, simulation results compare favorably to the analytical model.