Chang-Ming Lee

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We present a novel stochastic decoding algorithm for Reed-Solomon codes. We apply an iterative Monte Carlo based approach called the Cross-Entropy method to produce, in every iteration, a set of random error locator vectors, each indicates <i>n</i>-<i>k</i> possible erasure positions within a received word. We associate each error locator vector with a(More)
The soft decoding of variable-length encoded texture data generated, e.g., by video coders such as H.263+ and sent over a packetized network (internet or mixed internet radio-mobile) is considered here. Existing soft decoding techniques usually make use of either the number of bits in a block or the number of symbols in a block. Thus, this side information(More)
Transmitting the digital audio/visual data over the internet becomes more and more popular lately. Due to the heterogeneous networks and different hardware devices, the users have different requirements for the same multimedia request. Thus, scalable video coding (SVC) was proposed and be-came an extension of H.264/AVC video coding standard. To make the(More)
Transmitting video streams on channels impaired with transmission errors is a very demanding task, mainly when images are predicted from previous ones. In this case, errors on motion vectors can be very harmful. In order to overcome this problem, this paper presents a modified H263+ scheme without motion vector transmission. This is obtained by reestimating(More)
Wyner-Ziv coding has been recognized as the most popular method up to now. For traditional WZC, side information is generated from intra-coded frames for use in the decoding of WZ frames. The unit for intra-coding is a frame and the distance between key-frames is kept constant. In this paper, the unit for intra-coding is a block, and the temporal distance(More)
Many source coding standards (JPEG, H263+, H264), rely heavily on entropy coding with variable length codes (VLC). However, bitstreams made of VLC encoded data are particularly sensitive to transmission errors. Recent results tend to use knowledge of the VLC code structure in order to perform an efficient decoding of the bitstream. These techniques use a(More)
Implementing a belief propagation (BP) based LDPC decoder requires high degrees of parallelism using many component soft-in soft-output (SISO) decoding units to perform message passing from variable nodes to check nodes or vice versa. An obvious complexity-reduction solution is to serialize the decoding process, i.e., dividing a decoding iteration into(More)
Robust video coding has attracted increasing attention during the past few years. This paper proposes a joint source channel coding scheme able to resist transmission errors over mixed Internet-wireless channels. It involves motion-compensated oversampled filterbanks (OFBs). The redundancy introduced by the overcomplete representation in signals at the(More)