AUDIO SIGNAL CODER AND DECODER, METHOD FOR MANAGING CONTROL DATA FROM AUDIO SIGNAL AND BIT FLOW DECODING METHOD

摘要

1. An encoder (901) configured to generate control data (905) from an audio signal (903), the encoder (901) of an audio signal comprising: means for analyzing the shape of the spectrum of the audio signal (903) and for determining the degree of discontinuity of the spectrum envelope, introduced during the regeneration of the high-frequency component of the audio signal (903) from a number of signals (602) of the low-frequency sub-bands of the audio signal (903); means for generating control data (905) for controlling the regeneration of the high-frequency component based on the degree of discontinuity. 2. An encoder (901) according to claim 1, characterized in that the encoder (901) comprises a high-frequency reconstruction system (601, 703) called an HFR configured to implement an HFR process for generating a high-frequency component from a series of low-frequency subband signals (602); control data ( 905) are indicative of the need to apply a number of spectrum gain factors during the HFR process; a series of spectrum gain factors is associated with the energy of the corresponding series of signals (602) of the low-frequency subbands. 3. The encoder (901) according to claim 2, characterized in that the control data (905) serve as a sign of the order of the polynomial used to determine a number of spectrum gain factors. An encoder (901) according to claim 2, characterized in that the control data (905) are indicative of a method for determining a number of spectrum gain factors. The encoder (901) according to claim 2, characterized in that the series of spectrum gain factors is obtained from a frequency-dependent curve (403) approximating the energy of a number of signals (602) of low-frequency subbands, and the frequency-dependent curve (403) is a polynomial predefined order, which is a sign of control data