16 Kbit/s Wideband Speech Coding Based on Unequal Subbands
نویسندگان
چکیده
with long term prediction (LTP) whic:h are based on a model In this paper we propose a split-band encoding scheme for 16kbit/s wideband speech coding (50-7000 Hz), using 2 unequal subbands from 0-6 kHz and from 6-7 kHz. This approach was motivated by experimental evaluation of the signal bandwidth of speech frames. The higher subband is simply represented by white noise with adjustment of the short term energy. For the lower subband code-excited linear prediction (CELP) is used. By informal listening tests the speech quality was rated higher than the speech quality of the CCITT G.722 wideband codec operating at 48kbit/s.
منابع مشابه
A wideband CELP speech coder at 16 kbit/s based on mel-generalized cepstral analysis
This paper proposes a wideband CELP coder using frequency warping. Instead of linear prediction, the proposed coder adopts the melgeneralized cepstral analysis, and encodes fullband of the speech signal through a warped frequency scale. It is shown that the subjective quality of the proposed coder at 16 kbit/s is better than that of the ITU-T G.722 at 64 kbit/s. Furthermore, the proposed coder ...
متن کاملA WIDEBAND CELP CODER AT 16 kbit/s FOR REAL TIME APPLICATIONS
Since its introduction in 1984, Code Excited Linear Predictive (CELP) [1] coding has received considerable attention for high quality speech coding at low bit-rates. Although most of the research has been focused on coding of narrowband (200-3400 kHz) speech, some recent studies on CELP coding of wideband (50-7000 kHz) speech have been reported [2], [3], [4]. A possible application for wideband...
متن کاملA 16-kbit/s wideband speech codec scalable with g.729
A wideband speech scalable codec is proposed for improving the flexibility in telecommunication networks. This coder is scalable with G.729 (ITU 8-kbit/s standard). Its decoder can process the incoming bitstream at three bit rates (8, 12, and 16 kbit/s) and provide a choice of speech types (wideband and telephone-band). The codec has a split-band structure, where both bands are coded by analysi...
متن کاملA 16, 24, 32 kbit/s wideband speech codec based on ATCELP
This paper describes a combined Adaptive Transform Codec (ATC) and Code-Excited Linear Prediction (CELP) algorithm, called ATCELP, for the compression of wideband (7 kHz) signals. The CELP algorithm applies mainly to speech, whereas the ATC mode is selected for music and noise signals. We propose a switching scheme between CELP and ATC mode and describe a frame erasure concealment technique. Su...
متن کامل