Unlock instant, AI-driven research and patent intelligence for your innovation.

Non-causal postfilter

A post-filter and post-filtering technology, which is applied in the field of encoding and decoding of audio and/or speech signals, can solve problems affecting communication quality, interactivity, and increasing algorithm delay, etc., and achieve the effect of improving the quality of reconstructed signals

Inactive Publication Date: 2010-01-06
TELEFON AB LM ERICSSON (PUBL)
View PDF3 Cites 4 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, this is undesirable in conversational applications of audio or speech codecs as it increases the algorithmic delay of the codec and thus affects the communication quality and especially the interactivity

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Non-causal postfilter
  • Non-causal postfilter
  • Non-causal postfilter

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0023] Throughout the present disclosure, identical or directly corresponding features in different figures and embodiments will be denoted by the same reference numerals.

[0024] In order to fully understand the detailed description, some terms may have to be defined more clearly to avoid confusion. In this disclosure, the term "parameter" is used as a generic term for any type of signal representation, including bits or bit streams.

[0025] The detailed description will generally begin with a short overview of post-filtering in order to understand the advantages achieved by the present invention. figure 1 Shows the basic structure of an audio or speech codec with a post filter. The transmitter unit 1 comprises an encoder 10 which encodes an input audio or speech signal 3 into a parameter stream 4 . The parameters 4 are usually encoded and transmitted to the receiver unit 2 . The receiver unit 2 comprises a decoder 20 which receives parameters 4 representing the original...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

A decoder arrangement comprises a receiver input (40) for parameters (4) of frame-based coded signals and a decoder (20), arranged to provide frames of decoded audio signals (5) based on the parameters (4). The receiver input (40) and / or the decoder (20) is arranged to establish a time difference between the occasion when parameters of a first frame is available at the receiver input (40) and the occasion when a decoded audio signal of the first frame is available at an output of the decoder (20), which time difference corresponds to at least one frame. A postfilter (30) is connected to the output of the decoder (20) and to the receiver input (40). The postfilter (30) is arranged to provide a filtering of the frames of decoded audio signals into an output signal (6) in response to parameters (4) of a respective subsequent frame.

Description

technical field [0001] The present invention relates generally to encoding and decoding of audio and / or speech signals, and in particular to reducing encoding noise. Background technique [0002] Audio coding in general, and speech coding in particular, performs a mapping from an analog input audio or speech signal to a digital representation in the coding domain and back to an analog output audio or speech signal, this digital representation being accompanied by a value or parameter representing the audio or speech Quantization or discretization is performed. This quantization or discretization can be thought of as perturbing the true value or parameter with coding noise. Audio or speech coding techniques will do this coding so that the effect of coding noise in the speech decoded at a given bit rate is as small as possible. However, a given bit rate at which speech is encoded defines a theoretical limit to which encoding noise can best be reduced. The goal is to at leas...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): G10L19/14G10L19/08G10L19/04G10L19/12G10L21/02G10L25/90
CPCG10L19/26
Inventor S·布鲁恩
Owner TELEFON AB LM ERICSSON (PUBL)