Browsing by Author "Ueng, JF"

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Optimization and quality measurement for the layer 2 compression scheme of MPEG audio coding
(1997)
Hsu, CH
;
Wu, IC
;
Kao, LY
;
Ueng, JF
;
資訊工程學系
The layer 2 compression scheme of MPEG audio coding is a very common audio coding standard for CD quality audio (music). However, its encoding process requires a large amount of computations fn this paper, we propose some optimization techniques to make the encoding program much faster while allowing to impair the audio qualify a little. In order to measure how much qualify loss, we define criteria to quantify the quality toss rate of an encoded audio stream. From the definition, we can say that the encoder encoding streams with a quality toss rate equivalently wastes a number of bits, if the encoder that completely conforms to the layer 2 standard can save the same number of bib while keeping the same quality loss rate. In our experiments, we optimize the layer 2 compression programs such that audio streams can be encoded real time on Pentium Pro 180 with only 0.0003% quality loss and equivalently 1.5% bits wasted and on Pentium 180 with only 0.0009% quality loss and equivalently 4% bits wasted.
The design and performance analysis for the multimedia function unit of the NSC-98 CPU
(1997)
Ueng, JF
;
Wu, IC
;
Kuo, YH
;
Kao, LY
;
Chen, CL
Leveraging Taiwan's hardware technologies, National Science Council in Taiwan proposed a project to design an advanced CPU, called NSC-98, compatible to the Intel MMX architecture. This paper discusses the design of multimedia extension, called MFU (Multimedia Function Unit), in this CPU. The MFU has the following two special features. (1) Support three more instructions for permutation operations, parallel distance operations, and parallel average operations; (2) implement two MFU subunits: one without the parallel multiplier and the other without the parallel shifter and converter (for permutation). This paper also does performance analysis by estimating the performances of the MFU with and without these features on some chosen multimedia benchmarks. These performance analysis results can justify our MFU design.