US 12,230,280 B2
Spectral shape estimation from MDCT coefficients
Martin Sehlstedt, Luleå (SE); and Jonas Svedberg, Luleå (SE)
Assigned to TELEFONAKTIEBOLAGET LM ERICSSON (PUBL), Stockholm (SE)
Filed by Telefonaktiebolaget LM Ericsson (publ), Stockholm (SE)
Filed on Nov. 30, 2023, as Appl. No. 18/524,622.
Application 18/524,622 is a continuation of application No. 17/432,260, granted, now 11,862,180, previously published as PCT/EP2020/054523, filed on Feb. 20, 2020.
Claims priority of provisional application 62/808,587, filed on Feb. 21, 2019.
Claims priority of provisional application 62/808,600, filed on Feb. 21, 2019.
Claims priority of provisional application 62/808,610, filed on Feb. 21, 2019.
Prior Publication US 2024/0135936 A1, Apr. 25, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. G10L 19/005 (2013.01); G06F 17/14 (2006.01); G10L 19/02 (2013.01); G10L 25/18 (2013.01); G10L 25/45 (2013.01); H04L 65/75 (2022.01); H04L 65/80 (2022.01)
CPC G10L 19/005 (2013.01) [G06F 17/142 (2013.01); G10L 19/02 (2013.01); G10L 19/0204 (2013.01); G10L 19/0212 (2013.01); G10L 25/18 (2013.01); G10L 25/45 (2013.01); H04L 65/75 (2022.05); H04L 65/80 (2013.01)] 25 Claims
OG exemplary drawing
 
1. A method for controlling a concealment method for a lost audio frame associated with a received audio signal, the method comprising:
decoding a first audio frame of the received audio signal to obtain modified discrete cosine transform, MDCT coefficients;
determining values of a first spectral shape based upon the decoded MDCT coefficients obtained for the first audio frame, the first spectral shape comprising a number of sub-bands;
decoding a second audio frame, subsequent to the first audio frame, of the received audio signal to obtain MDCT coefficients for the second audio frame, the second audio frame preceding the lost audio frame;
determining values of a second spectral shape based upon the decoded MDCT coefficients obtained from the second audio frame, the second spectral shape comprising the number of sub-bands;
transforming the values of the first spectral shape and a first frame energy of the first audio frame into a first representation of a first fast Fourier transform, FFT, based spectral analysis and transforming the values of the second spectral shape and a second frame energy of the second audio frame into a second representation of a second FFT spectral analysis;
detecting, based on the first representation of the first FFT and the second representation of a second FFT, a transient; and
responsive to detecting the transient, modifying the concealment method by selectively adjusting a spectrum magnitude of a substitution frame spectrum.