A Penalty-Resource Optimization Framework for Huffman-Treebased Variable Length Codes Decoding
| Autor: | Sung-Wen Wang, 王頌文 |
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| Rok vydání: | 2008 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 96 Due to its sequential nature, speeding up Variable Length Decoding(VLD) is not as straightforward as to speed up the other modules of a decoding process by issuing several independent instructions simultaneously. The conservative VLD approaches restricted in a fixed algorithmic realization which might not be suitable for different applications’ need. In this dissertation, we design an algorithmic level VLD optimization framework on the basis of penalty and resource, which can be automatically synthesized to match the resource constraints of target applications. More specifically, this work demonstrates an optimization methodology for minimizing the number of memory access subject to a memory size constraint for any Huffman-based variable length code decoding. We also propose a structure of memory-efficient hierarchical lookup table which can adapt to arbitrary-side growing Huffman-trees adopted in current CODECs. The proposed design decomposes theVLDinto a combination of multiple table lookups and imperative operations. A Viterbi-like algorithm is also proposed to efficiently find the optimal hierarchical table. More importantly, the Viterbi-like algorithm obtains the same results as that of the brute-force search algorithm. Simulation results show that the proposed hierarchical table outperforms previous methods. To provide explicit illustration of hierarchical tables we also sketch the optimal solution for Huffman-trees adopted in current CODECs. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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