Video transmitted over wireless networks is subject to bit errors, resulting in visually perceptible artifacts. Some areas of a video bitstream are more sensitive to these errors compared to others, with regard to their impact on video quality. For H.264/AVC video sequences, the distribution of syntax elements is studied and each syntax element is analyzed subject to isolated bit errors. Sensitivity of a syntax element to bit errors is studied with the aid of Peak Signal to Noise Ratio (PSNR). Video quality degradation incurred by bit errors in a video is also compared with that caused by corresponding packet losses. We identified a subset of syntax elements with worst PSNR performance in the presence of bit errors. We recommend protecting this subset of parameters with an appropriate channel coding based error protection. This will reduce the probability of these syntax elements being in error and hence improve video quality. We modified the H.264/AVC reference software decoder for error robustness. We also developed and integrated a bit error generator and video quality estimator for simulations.