# US 2014/0156284 A1 · Audio-encoding method and apparatus, audio-decoding method and apparatus, recoding medium thereof, and multimedia device employing same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0156284 A1 - Document ID: US20140156284A1 - Status: Published application - Kind: A1 - Application number: 14/123,359 - Filed: 2012-06-01 - Published: 2014-06-05 - Earliest claimed: 2011-06-01 - Assignees: Samsung Electronics Co., Ltd. - Inventors: Anton Porov; Konstantin Osipov; Ki-hyun Choo - Web page: https://patentgrep.com/patent/US20140156284A1 ## CPC - G10L 19/0017: {Lossless audio signal coding; Perfect reconstruction of coded audio signal by transmission of coding error (G10L19/24 takes precedence)} - 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 19/032: Quantisation or dequantisation of spectral components - 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: SPEECH ANALYSIS TECHNIQUES OR SPEECH SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING TECHNIQUES; SPEECH OR AUDIO CODING OR DECODING ## Abstract Provided is an audio encoding method. The audio encoding method includes: acquiring envelopes based on a predetermined sub-band for an audio spectrum; quantizing the envelopes based on the predetermined sub-band; and obtaining a difference value between quantized envelopes for adjacent sub-bands and lossless encoding a difference value of a current sub-band by using a difference value of a previous sub-band as a context. Accordingly, the number of bits required to encode envelope information of an audio spectrum may be reduced in a limited bit range, thereby increasing the number of bits required to encode an actual spectral component. ## Claims ### Claim 1 An audio encoding method comprising: acquiring envelopes based on a predetermined sub-band for an audio spectrum; quantizing the envelopes based on the predetermined sub-band; and obtaining a difference value between quantized envelopes for adjacent sub-bands and lossless encoding a difference value of a current sub-band by using a difference value of a previous sub-band as a context. ### Claim 2 (depends on 1) The audio encoding method of claim 1, wherein the quantizing comprises adjusting a boundary of a quantization area corresponding to a predetermined quantization index so that a total quantization error in the quantization area is minimized. ### Claim 3 (depends on 1) The audio encoding method of claim 1, wherein an envelope is one of average energy, average amplitude, power, and a norm value of a corresponding sub-band. ### Claim 4 (depends on 1) The audio encoding method of claim 1, wherein the lossless encoding comprises adjusting the difference value between the quantized envelopes for the adjacent sub-bands to have a specific range. ### Claim 5 (depends on 1) The audio encoding method of claim 1, wherein the lossless encoding comprises dividing a range of the difference value of the previous sub-band into a plurality of groups and performing Huffman coding on the difference value of the current sub-band by using a Huffman table pre-defined for each of the plurality of groups. ### Claim 6 (depends on 5) The audio encoding method of claim 5, wherein the lossless encoding comprises dividing the range of the difference value of the previous sub-band into first to third groups and allocating two Huffman tables including a first Huffman table for unilateral use and a second Huffman table for sharing to the first to third groups. ### Claim 7 (depends on 6) The audio encoding method of claim 6, wherein the lossless encoding comprises using the difference value of the current sub-band as it is or after reversing when the second Huffman table is shared. ### Claim 8 (depends on 1) The audio encoding method of claim 1, wherein the lossless encoding comprises lossless encoding a quantized envelope as it is for a first sub-band for which a previous sub-band does not exist or performing the lossless encoding by using a difference value based on a predetermined reference value when a previous sub-band is used as a context. ### Claim 9 An audio encoding apparatus comprising: an envelope acquisition unit to acquire envelopes based on a predetermined sub-band for an audio spectrum; an envelope quantizer to quantize the envelopes based on the predetermined sub-band; an envelope encoder to obtain a difference value between quantized envelopes for adjacent sub-bands and lossless encoding a difference value of a current sub-band by using a difference value of a previous sub-band as a context; and a spectrum encoder to quantize and lossless encode the audio spectrum. ### Claim 10 (depends on 9) The audio encoding apparatus of claim 9, further comprising a spectrum normalizer to normalize the audio spectrum by using the envelopes based on the predetermined sub-band and to provide the normalized audio spectrum to the spectrum encoder. ### Claim 11 (depends on 9) The audio encoding apparatus of claim 9, wherein the spectrum encoder performs Factorial Pulse Coding (FPC). ### Claim 12 An audio decoding method comprising: obtaining a difference value between quantized envelopes for adjacent sub-bands from a bitstream and lossless decoding a difference value of a current sub-band by using a difference value of a previous sub-band as a context; and performing dequantization by obtaining quantized envelopes based on a sub-band from a difference value of a current sub-band reconstructed as a result of the lossless decoding. ### Claim 13 (depends on 12) The audio decoding method of claim 12, wherein an envelope is one of average energy, average amplitude, power, and a norm value of a corresponding sub-band. ### Claim 14 (depends on 12) The audio decoding method of claim 12, wherein the lossless decoding comprises dividing a range of the difference value of the previous sub-band into a plurality of groups and performing Huffman coding on the difference value of the current sub-band by using a Huffman table pre-defined for each of the plurality of groups. ### Claim 15 (depends on 14) The audio decoding method of claim 14, wherein the lossless decoding comprises dividing the range of the difference value of the previous sub-band into first to third groups and allocating two Huffman tables including a first Huffman table for unilateral use and a second Huffman table for sharing to the first to third groups. ### Claim 16 (depends on 15) The audio decoding method of claim 15, wherein the lossless decoding comprises using the difference value of the current sub-band as it is or after reversing when the second Huffman table is shared. ### Claim 17 (depends on 12) The audio decoding method of claim 12, wherein the lossless decoding comprises lossless decoding a quantized envelope as it is for a first sub-band for which a previous sub-band does not exist or performing the lossless decoding by using a difference value based on a predetermined reference value when a previous sub-band is used as a context. ### Claim 18 An audio decoding apparatus comprising: an envelope decoder to obtain a difference value between quantized envelopes for adjacent sub-bands from a bitstream and lossless decoding a difference value of a current sub-band by using a difference value of a previous sub-band as a context; an envelope dequantizer to perform dequantization by obtaining quantized envelopes based on a sub-band from a difference value of a current sub-band reconstructed as a result of the lossless decoding; and a spectrum decoder to lossless decode and dequantize a spectral component included in the bitstream. ### Claim 19 (depends on 18) The audio decoding apparatus of claim 18, further comprising a spectrum denormalizer to denormalize the dequantized spectral component by using the envelopes based on a sub-band. ### Claim 20 (depends on 18) The audio decoding apparatus of claim 18, wherein the spectrum decoder performs a lossless decoding by factorial pulse decoding. ### Claim 21 A multimedia device comprising an encoding module to acquire envelopes based on a predetermined sub-band for an audio spectrum, to quantize the envelopes based on the predetermined sub-band, to obtain a difference value between quantized envelopes for adjacent sub-bands, and to lossless encode a difference value of a current sub-band by using a difference value of a previous sub-band as a context. ### Claim 22 A multimedia device comprising a decoding module to obtain a difference value between quantized envelopes for adjacent sub-bands from a bitstream, to lossless decode a difference value of a current sub-band by using a difference value of a previous sub-band as a context, and to perform dequantization by obtaining quantized envelopes based on a sub-band from the difference value of the current sub-band reconstructed as a result of the lossless decoding. ### Claim 23 A multimedia device comprising: an encoding module to acquire envelopes based on a predetermined sub-band for an audio spectrum, to quantize the envelopes based on the predetermined sub-band, to obtain a difference value between quantized envelopes for adjacent sub-bands, and to lossless encode a difference value of a current sub-band by using a difference value of a previous sub-band as a context; and a decoding module to obtain a difference value between quantized envelopes for adjacent sub-bands from a bitstream, to lossless decode a difference value of a current sub-band by using a difference value of a previous sub-band as a context, and to perform dequantization by obtaining quantized envelopes based on a sub-band from the difference value of the current sub-band reconstructed as a result of the lossless decoding. ### Claim 24 (depends on 1) A non-transitory computer-readable recording medium storing a computer-readable program for executing the audio encoding method of claim 1. ### Claim 25 (depends on 12) A non-transitory computer-readable recording medium storing a computer-readable program for executing the audio decoding method of claim 12.