In this paper, we introduced the Predictive Embedded Zerotree Wavelet (PEZW) codec, an image coder that achieves good coding efficiency and versatile functionality with limited complexity requirement. Our complexity analysis showed that the memory requirement of this coder is less than 15k bytes regardless of image sizes. Our simulation results also showed that the coding efficiency of this low...

This paper investigates lossless coding of wideband speech by adding a lossless enhancement layer to the lossy baselayer produced by a standardised wideband speech coder. Both the ITU-T G.722 and G.722.2 speech coders are examined. Entropy results show that potential compression rates are dependent on the type and bit rate of the baselayer coder as well as the symbol size used by the lossless c...

This paper proposes a bandwidth-scalable coding scheme based on the G.729 standard as a base layer coder. In the scheme, according to the channel conditions, the output speech of the decoder can be selected to be narrow-band (4-kHz bandwidth) or wideband (8-kHz bandwidth). The proposed scheme consists of two layers: base and enhancement. The base coder uses the G.729 algorithm to encode narrow-...

We have proposed a wideband CELP coder, called MGC-CELP, which provides high quality speech by utilizing mel-generalized cepstral (MGC) analysis instead of linear prediction (LP). In this paper, we investigate the performance of the wideband MGCCELP coder at 16 kbit/s in terms of short-term predictor order, i.e., order of MGC analysis. Subjective tests show that the MGCCELP coder with a predict...

A control system in satellite communication terminal of low information rate is designed via program based on ATmega128 system controller, which has realized the function of operation control in the satellite communication terminal of low information rate. The synchronization signal of clock is simulated via Mcu I/O interface to voice-coder. Mcu controls the input and output of analog signal an...

A multi-mode harmonic transform coding (MMHTC) for speech and music signals is proposed. Its structure is organized as a linear prediction model with an input of harmonic and transform-based excitation. The proposed coder also utilizes harmonic prediction and an improved quantizer of excitation signal. To efficiently quantize the excitation of music signals, the modulated lapped transform (MLT)...

In this paper, we present a novel bitstream scalable audio coder. In the proposed coder, the full bandwidth of input audio is first split into two. A hybrid WLPC–wavelet representation is used to encode the low frequency components ( 11 kHz). In this method, the excitation to the WLPC synthesis filter is decomposed into subbands using a wavelet filterbank, and perceptually encoded. Two stage qu...

We propose a wideband CELP-type speech coder at 16 kb/s based on a mel-generalized cepstral (MGC) analysis technique. MGC analysis makes it possible to obtain a more accurate representation of spectral zeros compared to linear predictive (LP) analysis and take a perceptual frequency scale into account. A major advantage of the proposed coder is that the benefits of MGC representation of speech ...

In this paper, we propose an ADPCM coder which uses a backward adaptive predictor based on the adap tive mel-cepstral analysis. The spectrum represented by the mel-cepstral coefficients has frequency resolution similar to that of the human ear which has high resolution at low frequencies. In the coder, since the transfer functions of noise shaping and postflltering are also defined through the ...