Title :
Phonetically Switched Tree coding of speech with a G.727 Code Generator
Author :
Ramadas, Pravin ; Gibson, Jerry D.
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of California, Santa Barbara, CA, USA
Abstract :
A simple phonetic classification method based on frame error energy level in combination with the AMR-VADI Voice Activity Detection algorithm is used to classify input speech into five different modes: Voiced, Onset, Unvoiced, Hangover and Silence. Each mode is coded at a suitable bit-rate using a Tree Coder with perceptual error weighting criteria and a G.727 Code Generator. Apart from efficient coding, the Tree coder smoothes transitions between different coding modes. At an average bit-rate just greater than 16 kbps the phonetically switched Tree coder produces speech quality equivalent to the G.727 ADPCM coder at 32 kbps for nearly a 50% bit-rate saving. Apart from bit-rate savings; bit-rate scalability, moderate delay, and good tandeming performance are also achieved.
Keywords :
error statistics; speech coding; tree codes; AMR-VAD1 voice activity detection algorithm; G.727 ADPCM coder; G.727 code generator; bit error rate; bit rate 16 kbit/s; bit rate 32 kbit/s; bit-rate scalability; frame error energy level; moderate delay; perceptual error; phonetic classification method; phonetically switched tree speech coding; tandeming performance; Speech coding;
Conference_Titel :
Signals, Systems and Computers, 2009 Conference Record of the Forty-Third Asilomar Conference on
Conference_Location :
Pacific Grove, CA
Print_ISBN :
978-1-4244-5825-7
DOI :
10.1109/ACSSC.2009.5469977
