Title :
An Enhancement Layer for ACELP Coder
Author :
De Meuleneire, M. ; Gartner, Martin ; Schandl, Stefan ; Taddei, Herve
Author_Institution :
Siemens CT IC, Munich
Abstract :
This paper presents an enhancement layer coming on top of G.729 Annex A codec. This enhancement layer consists of an optimization of the algebraic fixed codebook pulses that were selected by the Annex A codec during the fixed codebook search. The pulses selected by the ACELP codec have all the same absolute amplitude. Our method optimizes each of these amplitudes in order to increase the quality. This is a low-complexity method that allows the introduction of an intermediate bitrate in ACELP-based scalable coder. On top of this pulse optimization method that requires 1.6 kbit/s we introduce a second fixed codebook search with a limited number of pulses (2) and a bitrate of 2.4 kbit/s
Keywords :
speech codecs; vocoders; ACELP coder; G.729 annex A codec; algebraic fixed codebook; enhancement layer; Bit rate; Decoding; Optimization methods; Quantization; Speech analysis; Speech codecs; Speech coding; Speech processing; Standardization; Streaming media;
Conference_Titel :
Multimedia Signal Processing, 2006 IEEE 8th Workshop on
Conference_Location :
Victoria, BC
Print_ISBN :
0-7803-9751-7
Electronic_ISBN :
0-7803-9752-5
DOI :
10.1109/MMSP.2006.285281
