Digital filter for sub-band synthesis

In a MPEG audio decoding process, an IDCT (Inverse Discrete Cosine Transform) process that generates time domain samples from frequency domain samples using a very limited number of prestored cosine coefficients is performed. Only the cosine coefficients that satisfy cos(pi*(i/64)) where i=0-32 are...

Full description

Saved in:
Bibliographic Details
Main Authors LAW KWOK WAH, LEE KA CHUN KENNETH
Format Patent
LanguageEnglish
Published 12.07.2005
Edition7
Subjects
ACOUSTICS
MUSICAL INSTRUMENTS
PHYSICS
SPEECH ANALYSIS OR SYNTHESIS
SPEECH OR AUDIO CODING OR DECODING
SPEECH OR VOICE PROCESSING
SPEECH RECOGNITION
Online AccessGet full text

Cover

More Information
Summary:In a MPEG audio decoding process, an IDCT (Inverse Discrete Cosine Transform) process that generates time domain samples from frequency domain samples using a very limited number of prestored cosine coefficients is performed. Only the cosine coefficients that satisfy cos(pi*(i/64)) where i=0-32 are prestored. The cosine coefficients for i=33-63 are calculated using the prestored coefficients by changing a sign of a corresponding symmetrical one of the stored coefficients, respectively. Then, sixty-four time domain samples (Vi) are generated from thirty-two frequency domain samples (Sk) according to the equation V i = ∑ k = 0 31 ⁢ cos ⁢ ( ( pi / 64 ) ⁢ ( i + 16 ) ⁢ ( 2 ⁢ k + 1 ) ) x S k where i=0 to 63, using only the prestored cosine coefficients and the calculated cosine coefficients.
Bibliography:Application Number: US20010803748