# US 9,883,312 B2 · Transformed higher order ambisonics audio data > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,883,312 B2 - Document ID: US9883312B2 - Status: Granted - Kind: B2 - Application number: 14/289,549 - Filed: 2014-05-28 - Published: 2014-12-04 - Granted: 2018-01-30 - Earliest claimed: 2013-05-29 - Assignees: QUALCOMM Incorporated - Applicants: QUALCOMM Incorporated - Inventors: Nils Günther Peters; Dipanjan Sen; Martin James Morrell - Web page: https://patentgrep.com/patent/US9883312B2 ## CPC - H04S 5/005: {of the pseudo five- or more-channel type, e.g. virtual surround} - G06F 17/16: Matrix or vector computation {, e.g. matrix-matrix or matrix-vector multiplication, matrix factorization (matrix transposition G06F7/78)} - G10L 19/002: Dynamic bit allocation (for perceptual audio coders G10L19/032) - G10L 19/008: Multichannel audio signal coding or decoding using interchannel correlation to reduce redundancy, e.g. joint-stereo, intensity-coding or matrixing - G10L 19/0204: {using subband decomposition} - G10L 19/038: Vector quantisation, e.g. TwinVQ audio - G10L 19/06: Determination or coding of the spectral characteristics, e.g. of the short-term prediction coefficients - G10L 19/167: {Audio streaming, i.e. formatting and decoding of an encoded audio signal representation into a data stream for transmission or storage purposes} - G10L 19/20: using sound class specific coding, hybrid encoders or object based coding - G10L 25/18: the extracted parameters being spectral information of each sub-band - H04S 7/30: {Control circuits for electronic adaptation of the sound field} - H04S 7/304: {For headphones} - H04S 7/40: {Visual indication of stereophonic sound image} - G10L 2019/0001: {Codebooks} - G10L 2019/0005: {Multi-stage vector quantisation} - H04R 2205/021: Aspects relating to docking-station type assemblies to obtain an acoustical effect, e.g. the type of connection to external loudspeakers or housings, frequency improvement - H04S 2400/01: Multi-channel, i.e. more than two input channels, sound reproduction with two speakers wherein the multi-channel information is substantially preserved - H04S 2400/15: Aspects of sound capture and related signal processing for recording or reproduction - H04S 2420/01: Enhancing the perception of the sound image or of the spatial distribution using head related transfer functions [HRTF's] or equivalents thereof, e.g. interaural time difference [ITD] or interaural level difference [ILD] - H04S 2420/03: Application of parametric coding in stereophonic audio systems - H04S 2420/11: Application of ambisonics in stereophonic audio systems - H04S: STEREOPHONIC SYSTEMS - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - G10L: SPEECH ANALYSIS TECHNIQUES OR SPEECH SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING TECHNIQUES; SPEECH OR AUDIO CODING OR DECODING - H04R: LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS (producing sounds with frequency not determined by supply frequency G10K) ## Abstract In general, techniques are described for obtaining one or more first vectors describing distinct components of a soundfield and one or more second vectors describing background components of the soundfield, both the one or more first vectors and the one or more second vectors generated at least by performing a transformation with respect to a plurality of spherical harmonic coefficients. ## Claims ### Claim 1 A method comprising: obtaining, by an audio decoding device, one or more first vectors describing distinct components of a soundfield and one or more second vectors describing background components of the soundfield, both the one or more first vectors and the one or more second vectors representative of a plurality of spherical harmonic coefficients descriptive of the soundfield, and generated at least by performing a transformation with respect to the plurality of spherical harmonic coefficients; rendering, by the audio decoding device, one or more loudspeaker feeds based on the one or more first vectors and the one or more second vectors; and outputting, by the audio decoding device, the loudspeaker feeds. ### Claim 2 (depends on 1) The method of claim 1, wherein the one or more first vectors and the one or more second vectors are generated at least by performing a transformation that generates a U matrix representative of left-singular vectors of the plurality of spherical harmonic coefficients, an S matrix representative of singular values of the plurality of spherical harmonic coefficients and a V matrix representative of right-singular vectors of the plurality of spherical harmonic coefficients. ### Claim 3 (depends on 2) The method of claim 2, wherein the one or more first vectors comprise one or more audio encoded UDIST*SDIST vectors that, prior to audio encoding, were generated by multiplying one or more audio encoded UDIST vectors of the U matrix by one or more SDIST vectors of the S matrix. ### Claim 4 (depends on 3) The method of claim 3, further comprising audio decoding the one or more audio encoded UDIST*SDIST vectors to generate an audio decoded version of the one or more audio encoded UDIST*SDIST vectors. ### Claim 5 (depends on 2) The method of claim 2, wherein the one or more first vectors comprise one or more audio encoded UDIST*SDIST vectors that, prior to audio encoding, were generated by multiplying one or more audio encoded UDIST vectors of the U matrix by one or more SDIST vectors of the S matrix. ### Claim 6 (depends on 5) The method of claim 5, further comprising audio decoding the one or more audio encoded UDIST*SDIST vectors to generate an audio decoded version of the one or more audio encoded UDIST*SDIST vectors. ### Claim 7 (depends on 6) The method of claim 6, further comprising multiplying the audio decoded version of the one or more audio encoded UDIST*SDIST vectors by the VTDIST vectors to recover those of the plurality of spherical harmonics representative of the distinct components of the soundfield. ### Claim 8 (depends on 2) The method of claim 2, wherein the one or more second vectors comprise one or more audio encoded UBG*SBG*VTBG vectors that, prior to audio encoding, were generating by multiplying UBG vectors included within the U matrix by SBG vectors included within the S matrix and then by VTBG vectors included within a transpose of the V matrix. ### Claim 9 (depends on 2) The method of claim 2, wherein the one or more second vectors comprise one or more audio encoded UBG*SBG*VTBG vectors that, prior to audio encoding, were generating by multiplying UBG vectors included within the U matrix by SBG vectors included within the S matrix and then by VTBG vectors included within a transpose of the V matrix, and wherein the method further comprises audio decoding the one or more audio encoded UBG*SBG*VTBG vectors to generate one or more audio decoded UBG*SBG*VTBG vectors. ### Claim 10 (depends on 2) The method of claim 2, wherein the transformation comprises either a singular value decomposition or a principal component analysis to identify the distinct components of the soundfield and the background components of the soundfield. ### Claim 11 (depends on 1) The method of claim 1, further comprising reconstructing the plurality of spherical harmonic coefficients based on the one or more first vectors and the one or more second vectors, wherein rendering the one or more loudspeaker feeds comprises rendering, based on the plurality of spherical harmonic coefficients, the loudspeaker feeds. ### Claim 12 (depends on 1) The method of claim 1, further comprising multiplying the one or more first vectors by one or more spatial vectors to recover the plurality of spherical harmonics representative of the distinct components of the soundfield, the one or more spatial vectors representative of a spatial component of the one or more first vectors, wherein rendering the one or more loudspeaker feeds comprises rendering the one or more loudspeaker feeds based on the plurality of spherical harmonics representative of the distinct components of the soundfield. ### Claim 13 (depends on 1) The method of claim 1, further comprising obtaining one or more spatial vectors describing a spatial component of the one or more first vectors, wherein rendering the one or more loudspeaker feeds comprises rendering the one or more loudspeaker feeds based on the one or more first vectors, the one or more second vectors, and the one or more spatial vectors. ### Claim 14 (depends on 1) The method of claim 1, wherein the one or more first vectors comprise audio encoded versions of the one or more first vectors, wherein the one or more second vectors comprise audio encoded versions of the one or more second vectors, wherein the method further comprises: audio decoding the audio encoded versions of the one or more first vectors to obtain audio decoded versions of the one or more first vectors; and audio decoding the audio encoded versions of the one or more second vectors to obtain audio decoded versions of the one or more second vectors, and wherein rendering the one or more loudspeaker feeds comprises rendering the one or more loudspeaker feeds based on the audio decoded versions of the one or more first vectors and the audio decoded versions of the one or more second vectors. ### Claim 15 A device comprising: one or more processors configured to: determine one or more first vectors describing distinct components of a soundfield and one or more second vectors describing background components of the soundfield, both the one or more first vectors and the one or more second vectors representative of a plurality of spherical harmonic coefficients descriptive of the soundfield, and generated at least by performing a transformation with respect to the plurality of spherical harmonic coefficients; render one or more loudspeaker feeds based on the one or more first vectors and the one or more second vectors; and output the one or more loudspeaker feeds. ### Claim 16 (depends on 15) The device of claim 15, wherein the one or more first vectors and the one or more second vectors are generated at least by performing a transformation that generates a U matrix representative of left-singular vectors of the plurality of spherical harmonic coefficients, an S matrix representative of singular values of the plurality of spherical harmonic coefficients and a V matrix representative of right-singular vectors of the plurality of spherical harmonic coefficients. ### Claim 17 (depends on 16) The device of claim 16, wherein the one or more first vectors comprise one or more audio encoded UDIST*SDIST vectors that, prior to audio encoding, were generated by multiplying one or more audio encoded UDIST vectors of the U matrix by one or more SDIST vectors of the S matrix. ### Claim 18 (depends on 17) The device of claim 17, wherein the one or more processors are further configured to audio decode the one or more audio encoded UDIST*SDIST vectors to generate an audio decoded version of the one or more audio encoded UDIST*SDIST vectors. ### Claim 19 (depends on 16) The device of claim 16, wherein the one or more first vectors comprise one or more audio encoded UDIST*SDIST vectors that, prior to audio encoding, were generated by multiplying one or more audio encoded UDIST vectors of the U matrix by one or more SDIST vectors of the S matrix. ### Claim 20 (depends on 18) The device of claim 18, wherein the one or more processors are further configured to audio decode the one or more audio encoded UDIST*SDIST vectors to generate an audio decoded version of the one or more audio encoded UDIST*SDIST vectors. ### Claim 21 (depends on 19) The device of claim 19, further comprising multiplying the audio decoded version of the one or more audio encoded UDIST*SDIST vectors by the VTDIST vectors to recover those of the plurality of spherical harmonics representative of the distinct components of the soundfield. ### Claim 22 (depends on 16) The device of claim 16, wherein the one or more second vectors comprise one or more audio encoded UBG*SBG*VTBG vectors that, prior to audio encoding, were generating by multiplying UBG vectors included within the U matrix by SBG vectors included within the S matrix and then by VTBG vectors included within a transpose of the V matrix. ### Claim 23 (depends on 16) The device of claim 16, wherein the one or more second vectors comprise one or more audio encoded UBG*SBG*VTBG vectors that, prior to audio encoding, were generating by multiplying UBG vectors included within the U matrix by SBG vectors included within the S matrix and then by VTBG vectors included within a transpose of the V matrix, and wherein the one or more processors are further configured to audio decode the one or more audio encoded UBG*SBG*VTBG vectors to generate one or more audio decoded UBG*SBG*VTBG vectors. ### Claim 24 (depends on 16) The device of claim 16, wherein the transformation comprises either a singular value decomposition or a principal component analysis to identify the distinct components of the soundfield and the background components of the soundfield. ### Claim 25 (depends on 15) The device of claim 15, wherein the one or more processors are further configured to reconstruct the plurality of spherical harmonic coefficients based on the one or more first vectors and the one or more second vectors, and wherein the one or more processors are configured to render, based on the plurality of spherical harmonic coefficients, the loudspeaker feeds. ### Claim 26 (depends on 15) The device of claim 15, wherein the processor is further configured to multiply the one or more first vectors by one or more spatial vectors to recover the plurality of spherical harmonics representative of the distinct components of the soundfield, the one or more spatial vectors representative of a spatial component of the one or more first vectors, and wherein the processor is configured to render the one or more loudspeaker feeds based on the plurality of spherical harmonics representative of the distinct components of the soundfield. ### Claim 27 (depends on 15) The device of claim 15, wherein the processor is further configured to obtain one or more spatial vectors describing a spatial component of the one or more first vectors, wherein the processor is configured to render the one or more loudspeaker feeds based on the one or more first vectors, the one or more second vectors, and the one or more spatial vectors. ### Claim 28 (depends on 15) The device of claim 15, wherein the one or more first vectors comprise audio encoded versions of the one or more first vectors, wherein the one or more second vectors comprise audio encoded versions of the one or more second vectors, wherein the processor is further configured to: audio decode the audio encoded versions of the one or more first vectors to obtain audio decoded versions of the one or more first vectors; and audio decode the audio encoded versions of the one or more second vectors to obtain audio decoded versions of the one or more second vectors, and wherein the processor is configured to render the one or more loudspeaker feeds based on the audio decoded versions of the one or more first vectors and the audio decoded versions of the one or more second vectors. ### Claim 29 A device comprising: means for obtaining one or more first vectors describing distinct components of a soundfield and one or more second vectors describing background components of the soundfield, both the one or more first vectors and the one or more second vectors representative of a plurality of spherical harmonic coefficients descriptive of the soundfield, and generated at least by performing a transformation with respect to the plurality of spherical harmonic coefficients; and means for storing the one or more first vectors; means for rendering one or more loudspeaker feeds based on the one or more first vectors and the one or more second vectors; and means for outputting the loudspeaker feeds. ### Claim 30 A non-transitory computer-readable storage medium having stored thereon instructions that, when executed, cause one or more processors of an audio decoding device to: obtain one or more first vectors describing distinct components of a soundfield and one or more second vectors describing background components of the soundfield, both the one or more first vectors and the one or more second vectors representative of a plurality of spherical harmonic coefficients descriptive of the soundfield, and generated at least by performing a transformation with respect to the plurality of spherical harmonic coefficients; render one or more loudspeaker feeds based on the one or more first vectors and the one or more second vectors; and output, to one or more loudspeakers, the loudspeaker feeds.