Code-excited linear predictive coding with low delay for speech

Details Code-excited linear predictive coding with low delay for speech Code-excited linear predictive coding with low delay for speech

1994-02-22

1994-08-16

Knepper, David D.

395 232, 395 229, G10L 300, G10L 914, G10L 918

Patent

active

053393848

ABSTRACT:
A code-excited linear-predictive (CELP) coder for speech or audio transmission at compressed (e.g., 16 kb/s) data rates is adapted for low-delay (e.g., less than five ms. per vector) coding by performing spectral analysis of at least a portion of a previous frame of simulated decoded speech to determine a synthesis filter of a much higher order than conventionally used for decoding synthesis and then transmitting only the index for the vector which produces the lowest internal error signal. Modified perceptual weighting parameters and a novel use of postfiltering greatly improve tandeming of a number of encodings and decodings while retaining high quality reproduction.

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