# US 8,543,392 B2 · Encoding device, decoding device, and method thereof for specifying a band of a great error > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,543,392 B2 - Document ID: US8543392B2 - Status: Granted - Kind: B2 - Application number: 12/528,869 - Filed: 2008-02-29 - Published: 2010-01-21 - Granted: 2013-09-24 - Earliest claimed: 2007-03-02 - Assignees: Panasonic Corporation - Applicants: Masahiro Oshikiri; Tomofumi Yamanashi; Toshiyuki Morii - Inventors: Masahiro Oshikiri; Tomofumi Yamanashi; Toshiyuki Morii - Web page: https://patentgrep.com/patent/US8543392B2 ## CPC - G10L 19/00: Speech or audio signals analysis-synthesis techniques for redundancy reduction, e.g. in vocoders; Coding or decoding of speech or audio signals, using source filter models or psychoacoustic analysis (in musical instruments G10H) - G10L 19/005: Correction of errors induced by the transmission channel, if related to the coding algorithm - G10L 19/0204: {using subband decomposition} - G10L 19/0208: {Subband vocoders} - G10L 19/24: Variable rate codecs, e.g. for generating different qualities using a scalable representation such as hierarchical encoding or layered encoding - G10L 19/0212: {using orthogonal transformation} - G10L: SPEECH ANALYSIS TECHNIQUES OR SPEECH SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING TECHNIQUES; SPEECH OR AUDIO CODING OR DECODING ## Abstract Disclosed is an encoding device which can accurately specify a band having a large error among all the bands by using a small calculation amount. A first position identifier uses a first layer error conversion coefficient indicating an error of a decoding signal for an input signal so as to search for a band having a large error in a relatively wide bandwidth in all the bands of the input signal and generates first position information indicating the identified band. A second position identifier searches for a target frequency band having a large error in a relatively narrow bandwidth in the band identified by the first position identifier and generates second position information indicating the identified target frequency band. An encoder encodes a first layer decoding error conversion coefficient contained in the target frequency band. ## Claims ### Claim 1 An encoding apparatus, comprising: a first layer encoder that performs encoding processing with respect to input transform coefficients to generate first layer encoded data; a first layer decoder that performs decoding processing using the first layer encoded data to generate first layer decoded transform coefficients; and a second layer encoder that performs encoding processing with respect to a target frequency band where, in first layer error transform coefficients representing an error between the input transform coefficients and the first layer decoded transform coefficients, a maximum error is found, to generate second layer encoded data, wherein the second layer encoder comprises: a first position specifying processor that searches for a first band comprising the maximum error throughout a full band, based on a wider bandwidth than the target frequency band and a predetermined first step size to generate first position information showing the first band; a second position specifying processor that searches for the target frequency band throughout the first band, based on a narrower second step size than the predetermined first step size to generate second position information showing the target frequency band; and an encoder that encodes the first layer error transform coefficients included in the target frequency band specified based on the first position information and the second position information to generate encoded information. ### Claim 2 (depends on 1) The encoding apparatus according to claim 1, wherein the second position specifying processor specifies the target frequency band based on a single target frequency. ### Claim 3 (depends on 1) The encoding apparatus according to claim 1, wherein the second position specifying processor specifies the target frequency band based on a plurality of target frequencies. ### Claim 4 (depends on 1) The encoding apparatus according to claim 1, wherein the second position specifying processor specifies the target frequency band such that quantization distortion produced when the first layer error transform coefficients are encoded is minimized. ### Claim 5 (depends on 1) The encoding apparatus according to claim 1, wherein the first position specifying processor specifies the first band based on a magnitude of energy of the first layer error transform coefficients. ### Claim 6 (depends on 1) The encoding apparatus according to claim 1, wherein the first position specifying processor specifies the first band from a low frequency band lower than a reference frequency that is set. ### Claim 7 (depends on 1) The encoding apparatus according to claim 1, wherein the first position specifying processor specifies the first band based on an integral multiple of a pitch frequency. ### Claim 8 (depends on 1) The encoding apparatus according to claim 1, wherein a number of layers in encoding processing is at least two, a reference frequency is set higher in a higher layer, and the first position specifying processor specifies the first band from a low frequency band lower than the reference frequency, on a per layer basis. ### Claim 9 (depends on 1) The encoding apparatus according to claim 1, wherein the first position specifying processor divides the full band into a plurality of partial bands, selects one band in each of the plurality of partial bands, and concatenates a plurality of selected bands to make a concatenated band as the first band. ### Claim 10 (depends on 9) The encoding apparatus according to claim 9, wherein the first position specifying processor selects a predetermined fixed band in at least one of the plurality of partial bands. ### Claim 11 A decoding apparatus, comprising: a receiver that receives: first layer encoded data acquired by performing encoding processing with respect to input transform coefficients; second layer encoded data acquired by performing encoding processing with respect to a target frequency band where, in first layer error transform coefficients representing an error between the input transform coefficients and first layer decoded transform coefficients which are acquired by decoding the first layer encoded data, a maximum error is found; first position information showing a first band which maximizes the error, in a bandwidth wider than the target frequency band; and second position information showing the target frequency band in the first band; a first layer decoder that decodes the first layer encoded data to generate first layer decoded transform coefficients; a second layer decoder that specifies the target frequency band based on the first position information and the second position information and decodes the second layer encoded data to generate first layer decoded error transform coefficients; and a processor that adds the first layer decoded transform coefficients and the first layer decoded error transform coefficients to generate second layer decoded transform coefficients. ### Claim 12 (depends on 11) The decoding apparatus according to claim 11, wherein the second layer decoder performs decoding using shape information and gain information included in the second layer encoded data. ### Claim 13 An encoding method performed by a processor, the processor executing operations comprising: performing encoding processing with respect to input transform coefficients to generate first layer encoded data; performing decoding processing using the first layer encoded data to generate first layer decoded transform coefficients; and performing encoding processing with respect to a target frequency band where, in first layer error transform coefficients representing an error between the input transform coefficients and the first layer decoded transform coefficients, a maximum error is found, to generate second layer encoded data, wherein the encoding processing with respect to the target frequency band comprises: searching for a first band comprising the maximum error throughout a full band, based on a wider bandwidth than the target frequency band and a predetermined first step size to generate first position information showing the specified first band; searching for the target frequency band throughout the first band, based on a narrower second step size than the predetermined first step size to generate second position information showing the target frequency band; and encoding the first layer error transform coefficients included in the target frequency band specified based on the first position information and the second position information to generate encoded information. ### Claim 14 A decoding method performed by a processor, the processor executing operations comprising: receiving: first layer encoded data acquired by performing encoding processing with respect to input transform coefficients; second layer encoded data acquired by performing encoding processing with respect to a target frequency band where, in first layer error transform coefficients representing an error between the input transform coefficients and first layer decoded transform coefficients which are acquired by decoding the first layer encoded data, a maximum error is found; first position information showing a first band which maximizes the error, in a bandwidth wider than the target frequency band; and second position information showing the target frequency band in the first band; decoding the first layer encoded data to generate first layer decoded transform coefficients; specifying the target frequency band based on the first position information and the second position information and decoding the second layer encoded data to generate first layer decoded error transform coefficients; and adding the first layer decoded transform coefficients and the first layer decoded error transform coefficients to generate second layer decoded transform coefficients.