公开(公告)号：DE602004004846D1

公开(公告)日：2007-04-05

申请号：DE602004004846

申请日：2004-09-14

Applicant: ST MICROELECTRONICS ASIA

Inventor： SUDHIR KUMAR KASARGOD ,  KABI PRAKASH PADHI ,  GEORGE SAPNA

IPC: G10L19/025 ,  G10L19/035

Abstract: An MPEG-1 layer 3 audio encoder, including a scalefactor generator for determining first scalefactors for encoding a block of audio data if a temporal masking transient is not detected in said block of audio data; and for selecting the maximum of said scalefactors for encoding said block of audio data if a temporal masking transient is detected in said block of audio data to enable greater compression of said audio data. Increases in quantization error due to use of the maximum scalefactor are pre-masked or post-masked by the temporal masking transient. In cases where the last portion of a block includes a temporal masking transient that masks the preceding portions of the block, the maximum scalefactor is only used to encode the block if the resulting increase in quantization error is less than 30% of the quantization error for the block.

公开(公告)号：DE602004015409D1

公开(公告)日：2008-09-11

申请号：DE602004015409

申请日：2004-09-27

Applicant: ST MICROELECTRONICS ASIA

Inventor： KABI PRAKASH PADHI ,  GEORGE SAPNA

IPC: G10L25/90

Abstract: Pitch detection of speech signals finds numerous applications in karaoke, voice recognition and scoring applications. While most of the existing techniques rely on time domain methods, the invention utilises frequency domain methods. There is provided a method and system for determining the pitch of speech from a speech signal; the method including the steps of: producing or obtaining the speech signal; distinguishing the speech signal into voiced, unvoiced or silence sections using speech signal energy levels; applying a Fourier Transform to the speech signal and obtaining speech signal parameters; determining peaks of the Fourier transformed speech signal; tracking the speech signal parameters of the determined peaks to select partials; and, determining the pitch from the selected partials using a two-way mismatch error calculation.

公开(公告)号：DE602004004225D1

公开(公告)日：2007-02-22

申请号：DE602004004225

申请日：2004-09-27

Applicant: ST MICROELECTRONICS ASIA

Inventor： KABI PRAKASH PADHI ,  GEORGE SAPNA

IPC: G10L25/78

Abstract: A method for determining whether a data frame of a coded speech signal corresponds to voice or to noise, including the steps of determining the cross-correlation of the data of said data frame; determining the periodicity of the cross-correlation; determining the variance of the periodicity; determining said data frame corresponds to noise if the cross-correlation is lower than a predetermined cross-correlation value; and determining the data corresponds to voice if the variance is less than a predetermined variance value.