EP 1228507 B1 20030528 - A METHOD OF REDUCING MEMORY REQUIREMENTS IN AN AC-3 AUDIO ENCODER
Title (en)
A METHOD OF REDUCING MEMORY REQUIREMENTS IN AN AC-3 AUDIO ENCODER
Title (de)
VERFAHREN ZUR REDUZIERUNG DES SPEICHERBEDARFS IN EINEM AC-3 AUDIOKODIERER
Title (fr)
PROCEDE DE REDUCTION DES BESOINS MEMOIRE DANS UN CODEUR AUDIO AC-3
Publication
Application
Priority
SG 9900111 W 19991030
Abstract (en)
[origin: WO0133556A1] A method of reducing memory requirements for an encoder which includes a function of bit allocation for quantising frequency coefficients of an input signal, including: calculating a PSD (power spectrum density); integrating the PSD over a plurality of frequency bands to form a band-PSD; computing an excitation function by applying a prototype masking curve to the band-PSD; generating a FSMC (first-step-masking curve) of a noise level threshold from the excitation function; calculating a SSMC (second-step-masking curve) by incrementing the FSMC in accordance with a selected signal to noise variable (snroffst), wherein the excitation function, after being computed, is written to memory in place of the band-PSD and is subsequently overwritten by the FSMC and wherein the SSMC is stored in a temporary memory and recalculated for each block of data provided by the encoder.
IPC 1-7
IPC 8 full level
G10L 19/16 (2013.01)
CPC (source: EP)
G10L 19/16 (2013.01)
Designated contracting state (EPC)
DE FR GB IT
DOCDB simple family (publication)
WO 0133556 A1 20010510; DE 69908433 D1 20030703; DE 69908433 T2 20040408; EP 1228507 A1 20020807; EP 1228507 B1 20030528
DOCDB simple family (application)
SG 9900111 W 19991030; DE 69908433 T 19991030; EP 99954578 A 19991030