Abstract: Hierarchical coding of a source audio signal in the form of a data stream including a base level and at least two hierarchical enhancement levels, each of the levels being organized in successive frames. At least one frame of at least one enhancement level has a duration less than the duration of at least one frame of the base level. At least one indication representative of an order used for a set of enhancement level frames corresponding to the duration of at least one frame of the base level is inserted into the data stream.

Abstract: 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.

Abstract: 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.

Abstract: 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 characterised in that the spectral content is subjected to a whitening step.

Abstract: 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.

Abstract: A method is provided for coding a source audio signal, involving the transformation of an amplitude/time space into a multi-component amplitude/phase/time space, including the sinusoidal modeling of the audio signal and the delivery of the sinusoidal components that change over time. The method includes the following steps in which: the components are compared to one another in order to define at least one group with at least two components using at least one similarity criterion; and, for at least one group, at least one reference datum is coded, the reference datum being represented by an evolved phase originating from a first component of the group, known as the reference component, and at least one complement datum is coded, the complement datum being associated with at least a second component from the group and, together with the reference datum, enabling the reconstruction of at least one piece of information that is representative of at least one component.

Abstract: 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.

Abstract: 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.

Abstract: The present invention relates to a spectral enhancement method and to an apparatus carrying out this method.