Enhanced chroma extraction from an audio codec

An audio encoder adapted to encode an audio signal, the audio encoder comprising:

• a core encoder adapted to encode a downsampled component of the audio signal, wherein the core encoder is adapted to encode a block of samples of the downsampled component of the audio signal by transforming the block of samples of the downsampled component of the audio signal from the time domain into the frequency domain, thereby yielding a corresponding block of frequency coefficients in the frequency domain;
• and
• a processor adapted to determine a chroma vector of the block of samples of the downsampled component of the audio signal based on the block of frequency coefficients received from the core encoder, wherein the processor is further adapted to determine the chroma vector by applying frequency dependent psychoacoustic processing to the received block of frequency coefficients or to one or more frequency coefficients which are determined on the basis of the received block of frequency coefficients;
• wherein the chroma vector of the block of samples of the audio signal is indicative of melodic and/or harmonic content of the block of samples of the audio signal;
• wherein the melodic and/or harmonic content is to be stored on media or transferred via a network.

An audio decoder adapted to decode an audio signal,

• the audio decoder being adapted to receive an encoded bitstream and adapted to extract a block of frequency coefficients from the encoded bitstream;
• wherein the extracted block of frequency coefficients is associated with a corresponding block of samples of a downsampled component of the audio signal;
• and
• the audio decoder comprising:
• a processor adapted to determine a chroma vector of the block of samples of the audio signal based on the extracted block of frequency coefficients, wherein the processor is further adapted to determine the chroma vector by applying frequency dependent psychoacoustic processing to the extracted block of frequency coefficients or to one or more frequency coefficients which are determined on the basis of the extracted block of frequency coefficients;
• wherein the processor is further adapted to determine melodic and/or harmonic content of the block of samples of the audio signal based on the chroma vector for the block of samples of the audio signal;
• wherein the melodic and/or harmonic content is to be stored on media or transferred via a network.