Detection Of Transients And Attacks For Time/frequency Resolution Switching (epo) Patents (Class 704/E19.012)
  • Patent number: 8473298
    Abstract: A digital audio signal can be processed using continuously variable time-frequency resolution by selecting a portion of an input digital audio signal, resampling the selected portion of the input digital audio signal, generating a plurality of spectral characteristics associated with the resampled portion of the input digital audio signal, generating a portion of an output digital audio signal from the plurality of spectral characteristics, and resampling the portion of the output digital audio signal. Further, resampling the selected portion of the input digital audio signal can comprise determining a sampling ratio and resampling the selected portion of the input digital audio signal in accordance with the determined sampling ratio. Additionally, the portion of the output digital audio signal can be resampled in accordance with the inverse of the determined sampling ratio. The sampling ratio can be determined based on a time-frequency resolution requirement associated with an audio processing algorithm.
    Type: Grant
    Filed: November 1, 2005
    Date of Patent: June 25, 2013
    Assignee: Apple Inc.
    Inventor: Kevin Christopher Rogers
  • Patent number: 8086446
    Abstract: A method and apparatus for transforming an audio signal, a method and apparatus for adaptively encoding an audio signal, a method and apparatus for inversely transforming an audio signal, and a method and apparatus for adaptively decoding an audio signal. The method of transforming an audio signal includes determining a transform unit into which the audio signal in a time domain is to be transformed into an audio signal in a frequency domain, and transforming the audio signal into an audio signal in the frequency domain according to the determined transform units using a window coefficient other than 0. Accordingly, it is possible to minimize distortion of the audio signal when encoding the audio signal even at a high bit rate while increasing efficiency of compression.
    Type: Grant
    Filed: December 7, 2005
    Date of Patent: December 27, 2011
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Eunmi Oh, Junghoe Kim, Boris Kudryashov, Konstantin Osipov
  • Patent number: 8063809
    Abstract: A transient signal encoding method and device, decoding method and device, and processing system, where the transient signal encoding method includes: obtaining a reference sub-frame where a maximal time envelope having a maximal amplitude value is located from time envelopes of all sub-frames of an input transient signal; adjusting an amplitude value of the time envelope of each sub-frame before the reference sub-frame in such a way that a first difference is greater than a preset first threshold, in which the first difference is a difference between the amplitude value of the time envelope of each sub-frame before the reference sub-frame and the amplitude value of the maximal time envelope; and writing the adjusted time envelope into bitstream.
    Type: Grant
    Filed: June 29, 2011
    Date of Patent: November 22, 2011
    Assignee: Huawei Technologies Co., Ltd.
    Inventors: Zexin Liu, Longyin Chen, Lei Miao, Chen Hu, Wei Xiao, Herve Marcel Taddei, Qing Zhang