Information encoding method and apparatus, information decoding method and apparatus information transmission method and information recording medium
First Claim
1. An information encoding method comprisingresolving an input signal into frequency components,gain controlling the input signal to be resolved into frequency components,encoding the output information resolved into the frequency components and the control information for gain control, andselecting a gain control quantity at an acutely increased portion of the waveform signal from a plurality of magnitudes, with the maximum value of the gain control quantity being 40 dB or more.
0 Assignments
0 Petitions
Accused Products
Abstract
An information encoding method and apparatus, an information decoding method and apparatus and an information transmission method in which encoding and decoding with higher efficiency and higher sound quality may be achieved by gain control in meeting with the degree of amplitude changes in the attack portion and the pre-echo may be prevented from occurring. Gain control and gain control compensation operations are performed by applying a gain control function with a smaller gain control quantity and by applying a gain control function with a larger gain control quantity to a signal waveform portion having a level just ahead of an attack portion higher than a pre-set level and to a signal waveform portion having an extremely low level just ahead of the attack portion, respectively. By changing the gain control quantity depending on the degree of amplitude changes at the attack portion of the signal waveform, the pre-echo is prevented from occurring, while the efficiency is prevented from being lowered due to energy diffusion in the frequency domain.
-
Citations
30 Claims
-
1. An information encoding method comprising
resolving an input signal into frequency components, gain controlling the input signal to be resolved into frequency components, encoding the output information resolved into the frequency components and the control information for gain control, and selecting a gain control quantity at an acutely increased portion of the waveform signal from a plurality of magnitudes, with the maximum value of the gain control quantity being 40 dB or more.
-
6. An information decoding method comprising
decoding a frequency component signal and the gain control compensation information, synthesizing a waveform signal, gain control compensating an output waveform signal from the synthesizing process, and selecting a gain control compensation quantity for the gain control compensation operation at an acutely increased portion of the waveform signal from a plurality of magnitudes determined on the basis of the contents of the gain control compensation information, with the maximum value of the gain control quantity corresponding to the gain control compensation quantity being 40 dB or more.
- 11. An information transmission method wherein the frequency component signal information and the gain control compensation information are transmitted, the gain control compensation information contains the gain control compensation quantity information, and wherein a gain control compensation quantity at an acutely increased portion of the waveform signal is selected from a plurality of magnitudes, with the maximum value of the gain control quantity corresponding to the gain control compensation quantity being 40 dB or more.
-
16. An information encoding apparatus comprising
means for resolving an input signal into frequency components, means for gain controlling the input signal to be resolved into frequency components, and means for encoding the output information resolved into the frequency components and the control information for gain control, wherein a gain control quantity at an acutely increased portion of the waveform signal is selected from a plurality of magnitudes, with the maximum value of the gain control quantity being 40 dB or more.
-
21. An information decoding apparatus comprising
means for decoding a frequency component signal and the gain control compensation information, means for synthesizing a waveform signal, and means for gain control compensating an output waveform signal from the synthesizing process, wherein a gain control quantity for the gain control compensation at an acutely increased portion of the waveform signal is selected from a plurality of magnitudes determined on the basis of the contents of the gain control compensation information, with the maximum value of the gain control quantity corresponding to the gain control compensation quantity being 40 dB or more.
- 26. An information recording medium having recorded thereon the frequency component signal information and the gain control compensation information, said gain control compensation information contains the gain control compensation quantity information and wherein the gain control compensation quantity at an acutely increased portion of the waveform signal is selected from a plurality of magnitudes, with the maximum value of the gain control quantity corresponding to the gain control compensation quantity being 40 dB or more.
Specification