Perceptual quality feedback based progressive frame-level refreshing for robust video communication

In this paper, we propose an encoder side error resilience technique, namely the progressive group of picture (PGOP), which is well suited for rate controlled real-time video transmission over wireless channels. The PGOP scheme can be seen as an alternative approach to the group of picture (GOP) that periodically uses intra-frames (I-frames) for low bit-rate channels. This is because: (1) the PGOP scheme is shown to completely stop error propagation in a timely manner; (2) the PGOP scheme avoids the bit rate fluctuation problem associated with I-frames by using a progressive intra-updating scheme. We use the PGOP scheme in a perceptual quality feedback framework, and apply a novel online algorithm that helps shape the bit rate and explores the maximum recovery capability of PGOP. The performance of our scheme is demonstrated in a wireless LAN environment.