Audio coding with depth and bandwidth scalability

A computer program product comprising a nontransitory storage medium, the computer program product including code that, when executed by processing circuitry, causes the processing circuitry to perform a method, the method comprising:

• receiving, by a decoder of an audio codec using a vector quantizer having a codebook that includes a first number of entries, a bitstream including a set of base bits representing a compressed frame of an audio signal;
• in response to the decoder receiving a set of extension bits that extends the codebook, the set of extension bits representing data enabling the decoder to increase a resolution used by the decoder to an extended resolution greater than an initial resolution by an extension of the codebook from the first number of entries to a second number of entries, decoding the compressed frame of the audio signal at the extended resolution using the extension of the codebook having the second number of entries;
• and
• in response to the decoder not receiving the set of extension bits, decoding the compressed frame of the audio signal at the initial resolution using the codebook having the first number of entries.

An electronic apparatus, the electronic apparatus comprising:

• memory;
• and
• a processor coupled to the memory, the processor being configured to:
• receive, by a decoder of an audio codec using a vector quantizer having a codebook that includes a first number of entries, a bitstream including a set of base bits, the set of base bits representing a compressed frame of an audio signal;
• in response to the decoder receiving a set of extension bits that extends the codebook, the set of extension bits representing data enabling the decoder to increase a resolution used by the decoder to an extended resolution greater than an initial resolution by an extension of the codebook from the first number of entries to a second number of entries, decode the compressed frame of the audio signal at the extended resolution using the extension of the codebook having the second number of entries;
• and
• in response to the decoder not receiving the set of extension bits, decode the compressed frame of the audio signal at the initial resolution using the codebook having the first number of entries.