Ntt Docomo, Inc.

Jpmorgan Chase Bank N.a., As Collateral Agent

Kei Kikuiri

Atsushi Yamaguchi

Kimitaka Tsutsumi

Nobuhiko Naka

Kosuke Tsujino

Choong Seng Boon

Akihito Hanaki

Tomoyuki Ohya

Yoshiaki Ofuji

Masashige Shirakabe

The purpose of the present invention is to reduce distortion a frequency band component encoded with a small number of bits in a time domain and improve quality. An audio decoding device () decodes an encoded audio signal and outputs the audio signal. A decoding unit () decodes an encoded sequence containing an encoded audio signal and obtains a decoded signal. A selective temporal envelope shaping unit () shapes a temporal envelope of a decoded signal in the frequency band on the basis of decoding related information concerning decoding of the encoded sequence.

Audio decoding device, audio encoding device, audio decoding method, audio encoding method, audio decoding program, and audio encoding program

An audio packet error concealment system includes an encoding unit for encoding an audio signal consisting of a plurality of frames, and an auxiliary information encoding unit for estimating and encoding auxiliary information about a temporal change of power of the audio signal. The auxiliary information is used in packet loss concealment in decoding of the audio signal. The auxiliary information about the temporal change of power may contain a parameter that functionally approximates a plurality of powers of subframes shorter than one frame, or may contain information about a vector obtained by vector quantization of a plurality of powers of subframes shorter than one frame.

Audio encoding device, method and program, and audio decoding device, method and program

An audio signal transmission device for encoding an audio signal includes an audio encoding unit that encodes an audio signal and a side information encoding unit that calculates and encodes side information from a look-ahead signal. An audio signal receiving device for decoding an audio code and outputting an audio signal includes: an audio code buffer that detects packet loss based on a received state of an audio packet, an audio parameter decoding unit that decodes an audio code when an audio packet is correctly received, a side information decoding unit that decodes a side information code when an audio packet is correctly received, a side information accumulation unit that accumulates side information obtained by decoding a side information code, an audio parameter missing processing unit that outputs an audio parameter upon detection of audio packet loss, and an audio synthesis unit that synthesizes decoded audio from the audio parameter.

Audio coding device, audio coding method, audio coding program, audio decoding device, audio decoding method, and audio decoding program

An audio signal processing system and method is executed by an audio signal processing device to decode an audio packet to obtain decoded audio and determine an occurrence of a discontinuity occurring with a sudden increase of an amplitude of the decoded audio obtained by decoding the audio packet. The audio packet may be received correctly after an occurrence of a packet loss, and corrected to improve subjective quality of the decoded audio, wherein correcting the discontinuity of the decoded audio comprises causing distances between ISF/LSF parameters corresponding to a frame in which a packet loss has occurred to be equal.

Audio signal discontinuity correction processing system

An objective of the present invention is to correct a temporal envelope shape of a decoded signal with a small information volume and to reduce perceptible distortions. An audio decoding device which decodes a coded audio signal and outputs an audio signal comprises: a coded series analysis unit that analyzes a coded series which contains the coded audio signal; an audio decoding unit that receives from the coded series analysis unit the coded series which contains the coded audio signal and decodes same, obtaining an audio signal; a temporal envelope shape establishment unit that receives information from the coded series analysis unit and/or the audio decoding unit, and, on the basis of the information, establishes a temporal envelope shape of the decoded audio signal; and a temporal envelope correction unit that, on the basis of the temporal envelope shape which is established with the temporal envelope shape establishment unit, corrects the temporal envelope shape of the decoded audio signal and outputs same.

Audio decoding device, audio coding device, audio decoding method, audio coding method, audio decoding program, and audio coding program

An audio signal processing device comprises a discontinuity detector configured to determine an occurrence of a discontinuity from a sudden increase of an amplitude of decoded audio obtained by decoding the first audio packet which is received correctly after an occurrence of a packet loss, and a discontinuity corrector for correcting the discontinuity of the decoded audio by changing, in a state buffer, a distance between elements of Immittance Spectral Pair/Immittance Spectral Frequency (ISF/LSF) parameters of a past frame.

Audio signal discontinuity processing system

An audio signal processing device comprises a discontinuity detector configured to determine an occurrence of a discontinuity from a sudden increase of an amplitude of decoded audio obtained by decoding the first audio packet which is received correctly after an occurrence of a packet loss, and a side information encoder configured to encode side information about the discontinuity.

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Tokyo, Japan

Kei Kikuiri