Method device and system for an efficient noise injection process for low bitrate audio compression

A device for efficient noise injection for low bitrate audio compression to maximize audio quality, comprising:

• at least one of an encoder and a decoder:
• A) the encoder including a noise computation and normalization unit comprising:
• 1) an encoder zero detection unit, coupled to receive a frequency domain quantized signal, for determining a control signal that indicates whether noise injection is implemented in accordance with a predetermined audio-compression scheme;
• 2) a normalization computation unit, coupled to receive at least unquantized subband values and the control signal from the encoder zero detection unit, for determining an energy normalization term based on the unquantized subband values when the control signal indicates all zero values for predefined regions;
• B) the decoder including a noise normalization and injection unit comprising:
• 1) a decoder zero detection unit, coupled to receive a frequency domain quantized signal, for determining, a control signal that indicates implementation of noise injection according to the predetermined audio compression scheme when values of the frequency domain quantized signal are zero;
• and
• 2) a noise generation and normalization unit, coupled to receive the energy normalization term and the control signal from the decoder zero detection unit, for substituting a predetermined noise signal multiplied by the energy normalization term when the control signal indicates all zero values for predefined regions,
• wherein the predetermined audio compression scheme comprises one of A-B;
• A) coding an individual quantizer step-size for each pre-defined frequency region;
• and
• B) coding a single global step-size for an entire frame of audio data.

A method for efficient noise injection for low bitrate audio compression to maximize audio quality, comprising the steps of at least one of A-B:

• A) in an encoder, including the steps of:
• 1) determining, by an encoder zero detection unit, a control signal that indicates whether noise injection is implemented in accordance with a predetermined audio compression scheme;
• 2) determining, by a noise injection unit, an energy normalization term based at least on unquantized subband values when the control signal indicates all zero values for predefined regions;
• B) in a decoder, the steps of:
• 1) determining, by a decoder zero detection unit, a control signal that indicates implementation of noise injection is implemented in accordance with the predetermined audio compression scheme when values of the frequency domain quantized signal are zero;
• and
• 2) substituting, by a noise injection unit, a predetermined noise signal multiplied by the energy normalization term where indicated by the control signal,
• wherein the predetermined audio compression scheme comprises one of A-B;
• A) coding an individual quantizer step-size for each pre-defined frequency region;
• and
• B) coding a single global step-size for an entire frame of audio data.