Patent application number | Description | Published |
20080228500 | METHOD AND APPARATUS FOR ENCODING/DECODING AUDIO SIGNAL CONTAINING NOISE AT LOW BIT RATE - A method and apparatus for encoding/decoding audio signals at a low bit rate are provided. The encoding apparatus selectively encodes one or more reference samples having the highest amplitudes among frequency samples of an audio signal, determines amplitudes of the remaining samples other than the reference sample according to a predetermined pattern, using a predetermined random function, and then encodes the remaining samples using random function input information for causing the same pattern to be generated using the same random function, thus maximizing an encoding rate for an audio signal having a large amount of noise. | 09-18-2008 |
20080235033 | METHOD AND APPARATUS FOR ENCODING AUDIO SIGNAL, AND METHOD AND APPARATUS FOR DECODING AUDIO SIGNAL - Methods and apparatuses for encoding and decoding of an audio signal using a mixture of a time-frequency method and a parametric method according to the audio band are provided. An encoding method of an audio signal includes: dividing input audio signals into a plurality of audio bands; selecting a coding method for each audio band; encoding each audio band according to the selected coding method for each band; and generating a bit stream including all the data encoded for each audio band, wherein selecting a coding method for each band comprises selecting smaller encoded data either from a parametric coding method or a time-frequency coding method. | 09-25-2008 |
20080235034 | METHOD AND APPARATUS FOR ENCODING AUDIO SIGNAL AND METHOD AND APPARATUS FOR DECODING AUDIO SIGNAL - Provided are a method and apparatus for encoding an audio signal to efficiently encode a harmonic envelope and a method and apparatus for decoding an audio signal to decode the harmonic envelope. The method of encoding an audio signal includes performing harmonic analysis with respect to an input signal to determine harmonic parameters with respect to harmonic signals; regarding amplitudes of the harmonic signals included in the harmonic parameters as signals in the time domain so as to perform time-frequency transformation; and encoding the time-frequency transformed values. When expressing a harmonic envelope, the amplitudes of the harmonic signals are regarded as signals in the time domain so as to perform a time-frequency transformation and only a part from among the transformed values is selected to be encoded. Therefore, sound quality is not affected and coding efficiency greatly improves. | 09-25-2008 |
20080255855 | Method and apparatus for coding and decoding amplitude of partial - Provided are a method and apparatus for coding and decoding an amplitude of partials, in which a step phenomenon can be prevented in the result of coding the amplitude of continuation partial partials in a parametric codec, thereby improving reproduced sound quality. The method of coding the amplitude of partials includes obtaining an inversely quantized amplitude of partials of a previous frame, determining a quantization level based on a function for the inversely quantized amplitude of the partials of the previous frame, and quantizing an amplitude of partials of a current frame based on the determined quantization level. | 10-16-2008 |
20080294445 | METHOD AND APAPRATUS FOR SINUSOIDAL AUDIO CODING - Provided are a method and apparatus for sinusoidal audio coding, which employs a tracking method for further effective coding of sinusoids extracted in the process of a sinusoidal analysis of parametric coding. The sinusoidal audio coding method includes: extracting sinusoids of a current frame by performing a sinusoidal analysis on an input audio signal; with respect to each of the extracted sinusoids, setting a mode selected from a birth mode in which a sinusoid is newly generated irrespective of sinusoids of a previous frame, a continuation mode in which the sinusoid is only one sinusoid continued from one of the sinusoids of the previous frame, and a branch mode in which the sinusoid is one of a plurality of sinusoids continued from one of the sinusoids of the previous frame; and coding the extracted sinusoids according to the selected mode. Accordingly, a plurality of sinusoids that can be continued from one previous track component are set to the continuation mode or the branch mode. Therefore, the number of bits of coded data is significantly reduced, compared with the case of the birth mode. | 11-27-2008 |
20090024396 | AUDIO SIGNAL ENCODING METHOD AND APPARATUS - An audio signal encoding method and apparatus for efficiently encoding an audio signal in an interval having many birth sinusoids and enabling tracking of sinusoidal signals in the next interval, and a computer readable recording medium having embodied thereon a computer program for executing the audio signal encoding method are provided. According to the method and apparatus, by applying transform coding instead of parametric coding to a frame having many birth sinusoids, the sinusoids are encoded, thereby reducing the number of bits required for the encoding and enabling efficient coding. Also, when transform coding is applied to a frame of a predetermined interval, an inverse transform of the transform coding is applied to the encoded data in order to decode the data, and then sinusoids are extracted from the decoded data, thereby enabling tracking of sinusoids of the next frame. | 01-22-2009 |
20090055197 | METHOD AND APPARATUS FOR ENCODING CONTINUATION SINUSOID SIGNAL INFORMATION OF AUDIO SIGNAL AND METHOD AND APPARATUS FOR DECODING SAME - Provided are a method and apparatus for encoding an audio signal and a method and apparatus for decoding an audio signal. The method includes performing sinusoidal analysis on an audio signal in order to extract a sinusoidal signal of a current frame, determining continuation sinusoidal signal information indicating a number of continuation sinusoidal signals of next frames, which continue from the sinusoidal signal of the current frame, by performing sinusoidal tracking on the extracted sinusoidal signal of the current frame, and encoding the determined continuation sinusoidal signal information by using different Huffman tables according to index information of the current frame, thereby allowing efficient encoding with a low bitrate. | 02-26-2009 |
20090063163 | METHOD AND APPARATUS FOR ENCODING/DECODING MEDIA SIGNAL - Provided are a method and apparatus for encoding/decoding a media signal. The method of encoding a media signal includes: when harmonics exist in a sinusoid of a previous frame section, predicting a harmonic frequency of a current frame section that is to be encoded by using a harmonic frequency of the previous frame section, and generating a residual signal by using a difference between the predicted frequency and an actual harmonic frequency of the current frame section. | 03-05-2009 |
20090122999 | METHOD OF IMPROVING ACOUSTIC PROPERTIES IN MUSIC REPRODUCTION APPARATUS AND RECORDING MEDIUM AND MUSIC REPRODUCTION APPARATUS SUITABLE FOR THE METHOD - A method of measuring and improving acoustic properties, and a recording medium and a music reproduction apparatus that are suitable for the method. The method includes reproducing and outputting an analysis signal stored in codec file types, recording the output analysis signal in the codec file types, obtaining an impulse response by performing convolution on the recorded signal and an inverse signal of the analysis signal, and correcting frequency properties based on the impulse response. By storing a signal that is supposed to be generated by a signal generation device in codec file types, it is possible to implement the signal in a music reproduction apparatus without a need for the signal generation device. By correcting frequency property, the music reproduction apparatus can improve the performance of an output acoustic signal close to that of an original sound. | 05-14-2009 |