Browsing by Author "Fang, YC"

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A fast audio bit allocation technique based on a linear R-D model
(2002-08-01)
Lee, CY
;
Fang, YC
;
Chuang, HC
;
Wang, CN
;
Chiang, T
The MPEG-1 Layer III audio coding is most widespread digital audio format on the Internet. Its encoder is more complicated than the other layers., in the MPEG-I audio specification, where the bit allocation constitutes significant part of the total computational load. This paper describes a fast bit allocation technique using a novel linear model to compute the bitrate and the global gain of the inner loop (rate control loop) for the classic MP3 bit allocation problem. Estimated quantization noise is approximated with a binomial expansion for the adjustment of the scalefactors. This procedure reduces the outer loop iterations (distortion control loop) to one loop. Our bit allocation technique is about five times faster compared to the well-known LAME MP3 encoder. Based on the objective quality measure, total number of distorted bands, and average total noise-to-masking ratio (NMR), our experimental results show that there is significant improvement in speedup of the encoding process without noticeable audio quality degradation.
A fast audio bit allocation technique based on a linear R-D model
(2002-01-01)
Lee, CY
;
Fang, YC
;
Chuang, HC
;
Wang, CN
;
Chiang, TH
This paper describes a fast bit allocation technique using a novel linear model for the bitrate and the global gain of the inner loop in the classic MP3 bit allocation. The outer loop is approximated with a binomial expansion. Our technique is five times faster compared to the LAME MP3 encoder.
Low complexity lossless video compression
(2004)
Fang, YC
;
Lee, CY
;
Wang, YM
;
Wang, CN
;
Chiang, TH
We present a line-based adaptive lossless video compression (LALVC) algorithm for interactive multimedia applications that demand low complexity and low latency. Communications between high-resolution display and storage devices require high bandwidth for exchanging raw data. To reduce cost of video transmission without losing data accuracy, lossless video cornpression is necessary. Considering low complexity and low delay, LALVC adopts a simple and efficient architecture that adopts one-pass, raster-scan. transform-free coding process and a simple predictor. For low latency, zero-motion prediction and one-frame buffer are used to reduce temporal redundancy. In addition, to maximize the coding efficiency for both natural and computer-generated video sequences, LALVC adaptively selects the best coding mode for each line of a frame. The entropy coding of each line is based on Golomb code that can enhance coding efficiency with less computation load and is easy for hardware realization. The Simulation results show that temporal preprocessing and line-based mode decision of LALVC can increase compression ratio with properly increased complexity as compared to that of JPEG-LS.