US 12,067,995 B2
Apparatus and method for determining a predetermined characteristic related to an artificial bandwidth limitation processing of an audio signal
Patrick Gampp, Erlangen (DE); Christian Uhle, Ursensollen (DE); Julia Havenstein, Nuremberg (DE); Oliver Hellmuth, Buckenhof (DE); Sascha Disch, Fuerth (DE); Antonios Karampourniotis, Nuremberg (DE); Juergen Herre, Erlangen (DE); and Peter Prokein, Erlangen (DE)
Assigned to FRAUNHOFER-GESELLSCHAFT ZUR FOERDERUNG DER ANGEWANDTEN FORSCHUNG E.V., Munich (DE)
Filed by FRAUNHOFER-GESELLSCHAFT ZUR FOERDERUNG DER ANGEWANDTEN FORSCHUNG E.V., Munich (DE)
Filed on Sep. 25, 2019, as Appl. No. 16/582,165.
Application 16/582,165 is a continuation of application No. PCT/EP2018/025081, filed on Mar. 29, 2018.
Claims priority of application No. 17164360 (EP), filed on Mar. 31, 2017; and application No. 17189992 (EP), filed on Sep. 7, 2017.
Prior Publication US 2020/0020346 A1, Jan. 16, 2020
Int. Cl. G10L 19/02 (2013.01); G10L 19/022 (2013.01); G10L 19/26 (2013.01); G10L 21/0216 (2013.01); G10L 21/0232 (2013.01); G10L 21/038 (2013.01); G10L 25/69 (2013.01); H03G 3/20 (2006.01)
CPC G10L 19/0208 (2013.01) [G10L 19/022 (2013.01); G10L 19/26 (2013.01); G10L 21/0216 (2013.01); G10L 21/0232 (2013.01); G10L 21/038 (2013.01); G10L 25/69 (2013.01); H03G 3/20 (2013.01)] 18 Claims
OG exemplary drawing
 
1. An apparatus for determining a predetermined characteristic indicating that an audio signal was subjected to an artificial bandwidth limitation processing, the apparatus comprising:
a spectrum calculator configured for receiving the audio signal and configured for calculating a spectrum from the audio signal ;a slope evaluator configured for evaluating a slope of the spectrum of the audio signal to acquire a slope evaluation result; and
a processor for providing a signal indicating that the audio signal comprises the predetermined characteristic dependent on an evaluation of the slope evaluation result, wherein the processor is configured for providing the signal indicating that the audio signal comprises the predetermined characteristic by providing a respective signal indicating a result for a frame whether the frame comprises the predetermined characteristic for a plurality of frames of the audio signal for each of the plurality of frames, wherein the processor is configured for acquiring a plurality of results for the plurality of frames indicating whether the frame comprises the predetermined characteristic based on the plurality of frames and to combine the plurality of results indicating whether the frame comprises the predetermined characteristic so as to acquire a combined result being valid for the plurality of frames; and
wherein the processor is configured for executing a median filtering using the plurality of results for acquiring the combined result;
wherein the slope evaluator and the spectrum calculator is implemented in hardware and/or software.