Packet Loss Recovery Using Data Hiding for Embedded Zero Tree Wavelet Packet Audio Coding System

Abstract

Multimedia transmission over Internet is getting popular and increasingly important. Because some networks do not provide quality of service (QoS), the received packet may get lost. As a result, audio quality is often degraded due to packet loss. In this thesis, we propose a packet loss recovery technique using data hiding method applied to Embedded Zero-tree Wavelet Packet (EZWP) audio coding system. The EZWP audio coding system uses wavelet packet decomposition and embedded zero-tree coding based on the psychoacoustic model. We choose several beginning scans of EZW coefficients in each frame as the most significant data, and choose the value list in the last scan as the least significant data. The basic idea is to hide the most significant data into the least significant data. In order to reduce the damage to audio quality, we develop block data hiding method. When packets are lost, we can extract the hided data to reconstruct the most important part of lost audio signals. The hided bitstreams are compatible to the encoding syntax. The data hiding method will not increase bitrate but only slightly degrade the reconstructed audio quality. In simulations, the proposed recovery strategy is able to improve SSNR by 1.2 dB on average. The subjective evaluation tests show that the proposed recovery provides smooth audio signals even at a loss rate of 8%.