Fast H.264 Video Decoding by Bit Order Reversing and Its Application to Real-time H.264 Video Encryption

The demand on fast H.264 video processing technology is highly increasing since the electronics devices with encoding, transmission, and decoding high-resolution video are becoming popular in the consumer market. In this paper, we present a fast H.264 video decoding method by modifying the algorithm dealing with parsing bit-stream of variablelength code (VLC). The key idea of our approach is to reverse the bit order in a fast way through LUT (Look-Up-Table) in order to reduce the bit pattern extraction time for VLC stream. We demonstrated the speedup by employing the proposed idea for H.264 realtime video encryption application. The experimental results show about 11% execution time reduction in the part of video stream parsing function and 3.1% time reduction in the whole video encryption system.