# US 10,504,534 B2 · Audio coding method and related apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,504,534 B2 - Document ID: US10504534B2 - Status: Granted - Kind: B2 - Application number: 16/263,837 - Filed: 2019-01-31 - Published: 2019-05-30 - Granted: 2019-12-10 - Earliest claimed: 2014-07-28 - Assignees: Huawei Technologies Co., Ltd. - Applicants: Huawei Technologies Co., Ltd. - Inventors: Zexin Liu; Lei Miao - Web page: https://patentgrep.com/patent/US10504534B2 ## CPC - G10L 19/22: Mode decision, i.e. based on audio signal content versus external parameters - G10L 19/0208: {Subband vocoders} - G10L 19/12: the excitation function being a code excitation, e.g. in code excited linear prediction [CELP] vocoders - G10L 19/0204: {using subband decomposition} - G10L 19/0212: {using orthogonal transformation} - G10L 25/18: the extracted parameters being spectral information of each sub-band - G10L 25/21: the extracted parameters being power information - G10L: SPEECH ANALYSIS TECHNIQUES OR SPEECH SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING TECHNIQUES; SPEECH OR AUDIO CODING OR DECODING ## Abstract An audio encoding method and a related apparatus, where the audio coding method includes obtaining an audio signal, obtaining some subband parameters of a current frame of the audio signal, and encoding the current frame using a high quality transform coding (HQ) algorithm based on the obtained subband parameters. The audio encoding method and the related apparatus help improve encoding quality or encoding efficiency in audio signal encoding. ## Claims ### Claim 1 An audio signal encoding method, comprising: obtaining, by an audio signal encoder, an audio signal, wherein the audio signal comprises a current frame, and wherein the current frame comprises a subband i, a subband j, a subband x, and a subband y; obtaining, by the audio signal encoder, an average energy of the subband i, an average energy of the subband j, a spectral peak of the subband x, a spectral average of the subband x, a spectral peak of the subband y, and a spectral average of the subband y; and encoding, by the audio signal encoder, the current frame using a high quality transform coding (HQ) algorithm when the average energy of the subband j is greater than a product of the average energy of the subband i multiplied by a first constant (T4), a product of the spectral peak of the subband x multiplied by the spectral average of the subband y is greater than a product of the spectral peak of the subband y multiplied by the spectral average of the subband x and multiplied by a lowest value of a first interval (R1), and the product of the spectral peak of the subband x multiplied by the spectral average of the subband y is less than a product of the spectral peak of the subband y multiplied by the spectral average of the subband x and multiplied by a highest value of the R1. ### Claim 2 (depends on 1) The audio signal encoding method of claim 1, wherein a highest frequency bin of the subband i is lower than a lowest frequency bin of the subband j, wherein a highest frequency bin of the subband j is higher than eight kilohertz (kHz), and wherein a highest frequency bin of the subband x is lower than a lowest frequency bin of the subband y. ### Claim 3 (depends on 1) The audio signal encoding method of claim 1, wherein the constant T4 is less than one divided by one point two and greater than or equal to zero point five. ### Claim 4 (depends on 1) The audio signal encoding method of claim 1, wherein a lowest frequency bin of a range of frequency bins of the subband i is zero point four kilohertz (kHz), wherein a range of frequency bins of the subband j is four point eight kHz to nine point six kHz, wherein a range of frequency bins of the subband x is one kHz to two point six kHz, and wherein a range of frequency bins of the subband y is four point eight kHz to six point four kHz. ### Claim 5 An audio signal encoding method, comprising: obtaining, by an audio signal encoder, an audio signal, wherein the audio signal comprises a current frame, and wherein the current frame comprises a subband x and a subband y; obtaining, by the audio signal encoder, a spectral peak of the subband x, a spectral average of the subband x, a spectral peak of the subband y, and a spectral average of the subband y; encoding, by the audio signal encoder, the current frame using a high quality transform coding (HQ) algorithm when a product of the spectral peak of the subband x multiplied by the spectral average of the subband y is less than a product of the spectral peak of the subband y multiplied by the spectral average of the subband x multiplied by a first constant (T44), and the spectral peak of the subband y is greater than a product of the spectral average of the subband y multiplied by a second constant (T45); and encoding, by the audio signal encoder, the current frame using the HQ algorithm when the product of the spectral peak of the subband x multiplied by the spectral average of the subband y is greater than a product of the spectral peak of the subband y multiplied by the spectral average of the subband x multiplied by a third constant (T46), and the spectral peak of the subband y is less than a product of the spectral average of the subband y multiplied by the T45. ### Claim 6 (depends on 5) The audio signal encoding method of claim 5, wherein the T47 is one point five, and wherein the T45 is one point five. ### Claim 7 (depends on 5) The audio signal encoding method of claim 5, wherein a range of frequency bins of the subband x is one kilohertz (kHz) to two point six kHz, and wherein a range of frequency bins of the subband y is four point eight kHz to six point four kHz. ### Claim 8 An audio signal encoder, comprising: a memory storing program instructions; and at least one processor coupled to the memory, wherein the program instructions cause the at least one processor to be configured to: obtain an audio signal, wherein the audio signal comprises a current frame, and wherein the current frame comprises a subband i, a subband j, a subband x, and a subband y; obtain an average energy of the subband i, an average energy of the subband j, a spectral peak of the subband x, a spectral average of the subband x, a spectral peak of the subband y, and a spectral average of the subband y; and encode the current frame using a high quality transform coding (HQ) algorithm when the average energy of the subband j is greater than a product of the average energy of the subband i multiplied by a first constant (T4), a product of the spectral peak of the subband x multiplied by the spectral average of the subband y is greater than a product of the spectral peak of the subband y multiplied by the spectral average of the subband x and multiplied by a lowest value of a first interval (R1), and the product of the spectral peak of the subband x multiplied by the spectral average of the subband y is less than a product of the spectral peak of the subband y multiplied by the spectral average of the subband x and multiplied by a highest value of the R1. ### Claim 9 (depends on 8) The audio signal encoder of claim 8, wherein a highest frequency bin of the subband i is lower than a lowest frequency bin of the subband j, wherein a highest frequency bin of the subband j is higher than eight kilohertz (kHz), and wherein a highest frequency bin of the subband x is lower than a lowest frequency bin of the subband y. ### Claim 10 (depends on 8) The audio signal encoder of claim 8, wherein the T4 is less than one divided by one point two and greater than or equal to zero point five. ### Claim 11 (depends on 8) The audio signal encoder of claim 8, wherein a lowest frequency bin of a range of frequency bins of the subband i is zero point four kilohertz (kHz), wherein a range of frequency bins of the subband j is four point eight kHz to nine point six kHz, wherein a range of frequency bins of the subband x is one kHz to two point six kHz, and wherein a range of frequency bins of the subband y is four point eight kHz to six point four kHz. ### Claim 12 An audio signal encoder, comprising: a memory storing program instructions; and at least one processor coupled to the memory, wherein the program instructions cause the at least one processor to be configured to: obtain an audio signal, wherein the audio signal comprises a current frame, and wherein the current frame comprises a subband x and a subband y; obtain a spectral peak of the subband x, a spectral average of the subband x, a spectral peak of the subband y, and a spectral average of the subband y; encode the current frame using a high quality transform coding (HQ) algorithm when a product of the spectral peak of the subband x multiplied by the spectral average of the subband y is less than a product of the spectral peak of the subband y multiplied by the spectral average of the subband x multiplied by a first constant (T44), and the spectral peak of the subband y is greater than a product of the spectral average of the subband y multiplied by a second constant (T45); and encode the current frame using the HQ algorithm when the product of the spectral peak of the subband x multiplied by the spectral average of the subband y is greater than a product of the spectral peak of the subband y multiplied by the spectral average of the subband x multiplied by a third constant (T46), and the spectral peak of the subband y is less than a product of the spectral average of the subband y multiplied by the T47. ### Claim 13 (depends on 12) The audio signal encoder of claim 12, wherein the T47 is one point five, and wherein the T45 is one point five. ### Claim 14 (depends on 12) The audio signal encoder of claim 12, wherein a range of frequency bins of the subband x is one kilohertz (kHz) to two point six kHz, and wherein a range of frequency bins of the subband y is four point eight kHz to six point four kHz. ### Claim 15 An audio signal encoder, comprising: a hardware circuit configured to obtain an audio signal, wherein the audio signal comprises a current frame, and wherein the current frame comprises a subband i, a subband j, a subband x, and a subband y; a hardware circuit configured to obtain an average energy of the subband i, an average energy of the subband j, a spectral peak of the subband x, a spectral average of the subband x, a spectral peak of the subband y, and a spectral average of the subband y; and a hardware circuit configured to encode the current frame using a high quality transform coding (HQ) algorithm when the average energy of the subband j is greater than a product of the average energy of the subband i multiplied by a first constant (T4), a product of the spectral peak of the subband x multiplied by the spectral average of the subband y is greater than a product of the spectral peak of the subband y multiplied by the spectral average of the subband x and multiplied by a lowest value of a first interval (RI), and the product of the spectral peak of the subband x multiplied by the spectral average of the subband y is less than a product of the spectral peak of the subband y multiplied by the spectral average of the subband x and multiplied by a highest value of the RI. ### Claim 16 (depends on 15) The audio signal encoder of claim 15, wherein a highest frequency bin of the subband i is lower than a lowest frequency bin of the subband j, wherein a highest frequency bin of the subband j is higher than eight kilohertz (kHz), and wherein a highest frequency bin of the subband x is lower than a lowest frequency bin of the subband y. ### Claim 17 (depends on 15) The audio signal encoder of claim 15, wherein the T4 is less than one divided by one point two and greater than or equal to zero point five. ### Claim 18 (depends on 15) The audio signal encoder of claim 15, wherein a lowest frequency bin of a range of frequency bins of the subband i is zero point four kilohertz (kHz), wherein a range of frequency bins of the subband j is four point eight kHz to nine point six kHz, wherein a range of frequency bins of the subband x is one kHz to two point six kHz, and wherein a range of frequency bins of the subband y is four point eight kHz to six point four kHz. ### Claim 19 An audio signal encoder, comprising: a hardware circuit configured to obtain an audio signal, wherein the audio signal comprises a current frame, and wherein the current frame comprises a subband x and a subband y; and a hardware circuit configured to obtain a spectral peak of the subband x, a spectral average of the subband x, a spectral peak of the subband y, and a spectral average of the subband y; and a hardware circuit configured to: encode the current frame using a high quality transform coding (HQ) algorithm when a product of the spectral peak of the subband x multiplied by the spectral average of the subband y is less than a product of the spectral peak of the subband y multiplied by the spectral average of the subband x multiplied by a first constant (T44), and the spectral peak of the subband y is greater than a product of the spectral average of the subband y multiplied by a second constant (T45); and encode the current frame using the HQ algorithm when the product of the spectral peak of the subband x multiplied by the spectral average of the subband y is greater than a product of the spectral peak of the subband y multiplied by the spectral average of the subband x multiplied by a third constant (T46), and the spectral peak of the subband y is less than a product of the spectral average of the subband y multiplied by the T47. ### Claim 20 (depends on 19) The audio signal encoder of claim 19, wherein the T47 is one point five, and wherein the T45 is one point five. ### Claim 21 (depends on 19) The audio signal encoder of claim 19, wherein a range of frequency bins of the subband x is one kilohertz (kHz) to two point six kHz, and wherein a range of frequency bins of the subband y is four point eight kHz to six point four kHz.