US 11,862,180 B2
Spectral shape estimation from MDCT coefficients
Martin Sehlstedt, Luleå (SE); and Jonas Svedberg, Luleå (SE)
Assigned to TELEFONAKTIEBOLAGET LM ERICSSON (PUBL), Stockholm (SE)
Appl. No. 17/432,260
Filed by Telefonaktiebolaget LM Ericsson (publ), Stockholm (SE)
PCT Filed Feb. 20, 2020, PCT No. PCT/EP2020/054523
§ 371(c)(1), (2) Date Aug. 19, 2021,
PCT Pub. No. WO2020/169757, PCT Pub. Date Aug. 27, 2020.
Claims priority of provisional application 62/808,587, filed on Feb. 21, 2019.
Claims priority of provisional application 62/808,610, filed on Feb. 21, 2019.
Claims priority of provisional application 62/808,600, filed on Feb. 21, 2019.
Prior Publication US 2022/0189490 A1, Jun. 16, 2022
Int. Cl. G10L 19/005 (2013.01); G10L 19/02 (2013.01); G10L 25/18 (2013.01); H04L 65/75 (2022.01); G10L 25/45 (2013.01); H04L 65/80 (2022.01); G06F 17/14 (2006.01)
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)] 22 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 MDCT coefficients decoded from the first audio frame decoded, the first spectral shape comprising a number of sub-bands;
decoding a second audio frame of the received audio signal to obtain MDCT coefficients for the second audio frame;
determining values of a second spectral shape based upon MDCT coefficients decoded from the second audio frame decoded, 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 condition; and
responsive to detecting the transient condition, modifying the concealment method by selectively adjusting a spectrum magnitude of a substitution frame spectrum.