US 12,340,819 B2
Integration of high frequency audio reconstruction techniques
Kristofer Kjoerling, Solna (SE); Lars Villemoes, Järfälla (SE); Heiko Purnhagen, Sundbyberg (SE); and Per Ekstrand, Saltsjöbaden (SE)
Assigned to DOLBY INTERNATIONAL AB, Dublin (IE)
Filed by DOLBY INTERNATIONAL AB, Dublin (IE)
Filed on Dec. 16, 2024, as Appl. No. 18/982,181.
Application 18/982,181 is a continuation of application No. 18/508,415, filed on Nov. 14, 2023, granted, now 12,211,513.
Application 18/508,415 is a continuation of application No. 18/113,418, filed on Feb. 23, 2023, granted, now 11,862,185, issued on Jan. 2, 2024.
Application 18/113,418 is a continuation of application No. 17/987,545, filed on Nov. 15, 2022, granted, now 11,810,589, issued on Nov. 7, 2023.
Application 17/987,545 is a continuation of application No. 17/050,669, granted, now 11,527,256, issued on Dec. 13, 2022, previously published as PCT/EP2019/060600, filed on Apr. 25, 2019.
Claims priority of application No. 18169156 (EP), filed on Apr. 25, 2018.
Prior Publication US 2025/0118326 A1, Apr. 10, 2025
This patent is subject to a terminal disclaimer.
Int. Cl. G10L 21/0388 (2013.01); G10L 19/008 (2013.01); G10L 19/02 (2013.01); H04S 3/00 (2006.01)
CPC G10L 21/0388 (2013.01) [G10L 19/008 (2013.01); G10L 19/02 (2013.01); H04S 3/008 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A method for performing high frequency reconstruction of an audio signal, the method comprising:
receiving an encoded audio bitstream, the encoded audio bitstream including audio data representing a lowband portion of the audio signal and high frequency reconstruction metadata, wherein the encoded audio bitstream further includes a fill element with an identifier indicating a start of the fill element and fill data after the identifier, wherein the fill data includes the backward-compatible extension container, and wherein the identifier is a three bit unsigned integer transmitted most significant bit first and having a value of 0x6;
decoding the audio data to generate a decoded lowband audio signal;
extracting from the encoded audio bitstream the high frequency reconstruction metadata, the high frequency reconstruction metadata including operating parameters for a high frequency reconstruction process, the operating parameters including a patching mode parameter located in a backward-compatible extension container of the encoded audio bitstream, wherein a first value of the patching mode parameter indicates spectral translation and a second value of the patching mode parameter indicates harmonic transposition by phase-vocoder frequency spreading;
filtering the decoded lowband audio signal to generate a filtered lowband audio signal;
regenerating a highband portion of the audio signal using the filtered lowband audio signal and the high frequency reconstruction metadata, wherein the regenerating includes spectral translation if the patching mode parameter is the first value and the regenerating includes harmonic transposition by phase-vocoder frequency spreading if the patching mode parameter is the second value, and wherein, when the patching mode parameter equals the first value, the backward-compatible extension container further includes a flag indicating whether additional processing is used to avoid discontinuities in a shape of a spectral envelope of the highband portion, and the regenerating includes performing the additional preprocessing in response to a first value of the flag; and
combining the filtered lowband audio signal with the regenerated highband portion to form a wideband audio signal,
wherein the filtering, regenerating, and combining are performed as a post-processing operation with a delay of 3010 samples per audio channel, so that a composition time applies to a 3011-th audio sample within an audio composition unit.