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: 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: 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.