# US 9,191,581 B2 · Methods and apparatus for mixing compressed digital bit streams > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,191,581 B2 - Document ID: US9191581B2 - Status: Granted - Kind: B2 - Application number: 13/800,249 - Filed: 2013-03-13 - Published: 2013-08-01 - Granted: 2015-11-17 - Earliest claimed: 2004-07-02 - Assignees: The Nielsen Company (US), LLC - Applicants: The Nielsen Company (US), LLC - Inventors: Venugopal Srinivasan; John C. Peiffer - Web page: https://patentgrep.com/patent/US9191581B2 ## CPC - H04N 5/265: Mixing - G10L 19/173: {Transcoding, i.e. converting between two coded representations avoiding cascaded coding-decoding} - G11B 20/00007: {Time or data compression or expansion (audio compression based on psychoacoustics G10L19/00; data processing for reproducing audio data at different playback speeds G10L21/04; video compression H04N19/00; data compression per se H03M7/30)} - G11B 20/10527: {Audio or video recording; Data buffering arrangements (G11B20/12 - G11B20/18 take precedence)} - G11B 27/034: on discs (G11B27/036, G11B27/038 take precedence) - G10L 19/008: Multichannel audio signal coding or decoding using interchannel correlation to reduce redundancy, e.g. joint-stereo, intensity-coding or matrixing - G10L 19/032: Quantisation or dequantisation of spectral components - G11B 2020/00028: {Advanced audio coding [AAC]} - G11B 2020/00036: {AC-3, i.e. ATSC digital audio compression standard} - G11B 2020/10546: {specifically adapted for audio data} - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION - G10L: SPEECH ANALYSIS TECHNIQUES OR SPEECH SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING TECHNIQUES; SPEECH OR AUDIO CODING OR DECODING - G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R) ## Abstract Methods, apparatus and articles of manufacture for mixing compressed digital bit streams are disclosed. An example method disclosed herein comprises acquiring a frame associated with a first compressed digital bit stream, unpacking the frame to obtain a plurality of original transform coefficient sets, and modifying the plurality of original transform coefficient sets to mix a second digital bit stream with the first compressed digital bit stream. ## Claims ### Claim 1 A method to mix data streams, the method comprising: obtaining a first set of transform coefficients from a first compressed data stream, the first set of transform coefficients including a first set of mantissa codes and a first set of exponents; determining a second set of mantissa codes based on the first set of transform coefficients and a second data stream; replacing the first set of mantissa codes in the first set of transform coefficients with the second set of mantissa codes, without replacing the first set of exponents in the first set of transform coefficients, to mix the second data stream with the first compressed data stream to form a third data stream without uncompressing the first compressed data stream; and at least one of transmitting or storing the third data stream. ### Claim 2 (depends on 1) A method as defined in claim 1, wherein the first compressed data stream is compressed according to an audio compression standard, and the second data stream is an uncompressed audio data stream. ### Claim 3 (depends on 1) A method as defined in claim 1, wherein determining the second set of mantissa codes includes: determining a set of mantissa values based on the first set of transform coefficients and the second data stream; and processing the set of mantissa values based on compression information obtained from the first compressed data stream to determine the second set of mantissa codes. ### Claim 4 (depends on 3) A method as defined in claim 3, wherein determining the set of mantissa values includes: processing the first set of transform coefficients to determine first time domain data; combining second time domain data from the second data stream with the first time domain data to determine third time domain data; and processing the third time domain data to determine the set of mantissa values. ### Claim 5 (depends on 3) A method as defined in claim 3, wherein processing the set of mantissa values includes quantizing the set of mantissa values based on the compression information to determine the second set of mantissa codes. ### Claim 6 (depends on 5) A method as defined in claim 5, wherein the compression information includes a quantization step size. ### Claim 7 (depends on 5) A method as defined in claim 5, wherein quantizing the set of mantissa values includes setting a first one of the second set of mantissa codes to at least one of a positive limit or a negative limit when a first one of the set of mantissa values corresponding to the first one of the second set of mantissa codes is outside a range of mantissa values determined from the compression information. ### Claim 8 A tangible computer readable storage memory device or storage disk comprising computer readable instructions which, when executed, cause a computing device to at least: obtain a first set of transform coefficients from a first compressed data stream, the first set of transform coefficients including a first set of mantissa codes and a first set of exponents; determine a second set of mantissa codes based on the first set of transform coefficients and a second data stream; and replace the first set of mantissa codes in the first set of transform coefficients with the second set of mantissa codes, without replacing the first set of exponents in the first set of transform coefficients, to mix the second data stream with the first compressed data stream without uncompressing the first compressed data stream. ### Claim 9 (depends on 8) A memory device or storage disk as defined in claim 8, wherein the first compressed data stream is compressed according to an audio compression standard, and the second data stream is an uncompressed audio data stream. ### Claim 10 (depends on 8) A memory device or storage disk as defined in claim 8, wherein to determine the second set of mantissa codes, the instructions, when executed, further cause the computing device to: determine a set of mantissa values based on the first set of transform coefficients and the second data stream; and process the set of mantissa values based on compression information obtained from the first compressed data stream to determine the second set of mantissa codes. ### Claim 11 (depends on 10) A memory device or storage disk as defined in claim 10, wherein to determine the set of mantissa values, the instructions, when executed, further cause the computing device to: process the first set of transform coefficients to determine first time domain data; combine second time domain data from the second data stream with the first time domain data to determine third time domain data; and process the third time domain data to determine the set of mantissa values. ### Claim 12 (depends on 10) A memory device or storage disk as defined in claim 10, wherein to process the set of mantissa values, the instructions, when executed, further cause the computing device to quantize the set of mantissa values based on the compression information to determine the second set of mantissa codes. ### Claim 13 (depends on 12) A memory device or storage disk as defined in claim 12, wherein the compression information includes a quantization step size. ### Claim 14 (depends on 12) A memory device or storage disk as defined in claim 12, wherein to quantize the set of mantissa values, the instructions, when executed, further cause the computing device to set a first one of the second set of mantissa codes to at least one of a positive limit or a negative limit when a first one of the set of mantissa values corresponding to the first one of the second set of mantissa codes is outside a range of mantissa values determined from the compression information. ### Claim 15 An apparatus to mix data streams, the apparatus comprising: an unpacking unit to obtain a first set of transform coefficients from a first compressed data stream, the first set of transform coefficients including a first set of mantissa codes and a first set of exponents; and a modification unit to: determine a second set of mantissa codes based on the first set of transform coefficients and a second data stream; and replace the first set of mantissa codes in the first set of transform coefficients with the second set of mantissa codes, without replacing the first set of exponents in the first set of transform coefficients, to mix the second data stream with the first compressed data stream to form a third data stream without uncompressing the first compressed data stream; and a repacking unit to output the third data stream to at least one of a transmitter or memory. ### Claim 16 (depends on 15) An apparatus as defined in claim 15, wherein the first compressed data stream is compressed according to an audio compression standard, and the second data stream is an uncompressed audio data stream. ### Claim 17 (depends on 15) An apparatus as defined in claim 15, wherein to determine the second set of mantissa codes, the modification unit is further to: determine a set of mantissa values based on the first set of transform coefficients and the second data stream; and process the set of mantissa values based on compression information obtained from the first compressed data stream to determine the second set of mantissa codes. ### Claim 18 (depends on 17) An apparatus as defined in claim 17, wherein to determine the set of mantissa values, the modification unit is further to: process the first set of transform coefficients to determine first time domain data; combine second time domain data from the second data stream with the first time domain data to determine third time domain data; and process the third time domain data to determine the set of mantissa values. ### Claim 19 (depends on 17) An apparatus as defined in claim 17, wherein to process the set of mantissa values, the modification unit is further to quantize the set of mantissa values based on the compression information to determine the second set of mantissa codes. ### Claim 20 (depends on 19) An apparatus as defined in claim 19, wherein the compression information includes a quantization step size. ### Claim 21 (depends on 19) An apparatus as defined in claim 19, wherein to quantize the set of mantissa values, the modification unit is further to set a first one of the second set of mantissa codes to at least one of a positive limit or a negative limit when a first one of the set of mantissa values corresponding to the first one of the second set of mantissa codes is outside a range of mantissa values determined from the compression information.