摘要:
A method and device are provided for coding or decoding a digital audio signal by transform using analysis or synthesis weighting windows applied to sample frames. The method includes an irregular sampling of an initial window provided for a transform of given initial size N, to apply a secondary transform of size M different from N.
摘要:
The invention concerns a method for spectral enhancement and a device therefor. The inventive method is a method for enhancing spectral content of a signal having an incomplete spectrum including a first spectral band, the method including the following steps: at least transposing the spectral content of the first band into a second spectral band not included in the spectrum to generate a transposed spectrum signal, with spectrum limited to the second spectral band; transforming the spectrum of the transposed spectrum signal to obtain an enhancing signal; combining the incomplete spectrum signal and the enhancing signal to produce a spectrum enhanced signal. The invention is characterized in that the spectral content is subjected to a whitening step.
摘要:
An audio signal encoded in the form of data is spectrally reconstructed so part of the frequency spectrum of the audio signal is decoded with a spectral band limiting encoder (i.e., a core encoder). The complementary part of the frequency spectrum of the audio signal is decoded with an extension encoder. Information representing at least one cut-off frequency of the signal decoded by the core decoder is used to select, from amongst the data to be decoded or the data decoded with the extension decoder.
摘要:
Coding/decoding of a digital signal, consisting of successive blocks of samples, the coding being of the transform with overlap type and comprising, upon analysis, the application of a weighting window to two blocks of M successive samples. In particular, this weighting window is asymmetric and comprises four distinct portions extending successively over the two aforesaid blocks, with: a first portion, increasing over a first interval of samples, a second portion, constant at a value of 1 over a second interval, a third portion, decreasing over a third interval, and a fourth portion, constant at a value of 0 over a fourth interval.
摘要:
A method and device are provided for coding or decoding a digital audio signal by transform using analysis or synthesis weighting windows applied to sample frames. The method includes an irregular sampling of an initial window provided for a transform of given initial size N, to apply a secondary transform of size M different from N.
摘要:
A method is provided for coding a source audio signal. The method includes the following steps: coding a quantization profile of coefficients representative of at least one transform of the source audio signal, according to at least to distinct coding techniques, delivering at least two sets of data representative of a quantization profile; selecting one of the sets of data representative of a quantization profile, as a function of a predetermined selection criterion; transmitting and/or storing the set of data representative of a selected quantization profile and an indicator representative of the corresponding coding technique.
摘要:
A method is provided for coding a source audio signal. The method includes the following steps: coding a quantization profile of coefficients representative of at least one transform of the source audio signal, according to at least to distinct coding techniques, delivering at least two sets of data representative of a quantization profile; selecting one of the sets of data representative of a quantization profile, as a function of a predetermined selection criterion; transmitting and/or storing the set of data representative of a selected quantization profile and an indicator representative of the corresponding coding technique.
摘要:
The present invention relates to a spectral enhancement method and to an apparatus carrying out this method. The method of the invention enhanced the spectral content of a signal having an incomplete spectrum including a first spectral frequency band, the method comprising the following stages: at least one spectral content transposition of said first frequency band into a second spectral frequency band not included in said spectrum for the purpose of generating a transposed spectrum signal having a spectrum limited to said second spectral frequency band, shaping the spectrum of the transposed spectrum signal for the purpose of producing an enhanced signal, combining an incomplete spectrum signal and the enhanced signal for the purpose of producing an enhanced spectrum signal, characterized in that said spectral content is subject to a stage of whitening.
摘要:
A method of hierarchically coding a source audio signal in the form of a data stream (200) comprising a base level (207) and at least two hierarchical enhancement levels (208, 209, 210, 211), each of said levels being organized in successive frames.At least one frame of at least one enhancement level (208, 209, 210, 211) has a duration less than the duration of at least one frame of said base level (207), and at least one indication representative of an order used for a set of frames corresponding to the duration of at least one frame of said base level (207) is inserted into said stream.
摘要:
Coding/decoding of a digital signal, consisting of successive blocks of samples, the coding being of the transform with overlap type and comprising, upon analysis, the application of a weighting window to two blocks of M successive samples. In particular, this weighting window is asymmetric and comprises four distinct portions extending successively over the two aforesaid blocks, with: a first portion, increasing over a first interval of samples, a second portion, constant at a value of 1 over a second interval, a third portion, decreasing over a third interval, and a fourth portion, constant at a value of 0 over a fourth interval.