
US Patent No: 5,657,420
Number of patents in Portfolio can not be more than 2000
Variable rate vocoder
Stats
-
Aug 12, 1997
Issued date -
Dec 23, 1994
filing date -
08/363,170
serial no -
In Force
status
Importance
Abstract
An apparatus and method for performing speech signal compression, by variable rate coding of frames of digitized speech samples. The level of speech activity for each frame of digitized speech samples is determined and an output data packet rate is selected from a set of rates based upon the determined level of frame speech activity. A lowest rate of the set of rates corresponds to a detected minimum level of speech activity, such as background noise or pauses in speech, while a highest rate corresponds to a detected maximum level of speech activity, such as active vocalization. Each frame is then coded according to a predetermined coding format for the selected rate wherein each rate has a corresponding number of bits representative of the coded frame. A data packet is provided for each coded frame with each output data packet of a bit rate corresponding to the selected rate.
First Claim
Related Publications
International Classification(s)
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- [Patents Count]
Cited Art
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