Estimating a tempo metric from an audio bit-stream
AssigneeDolby International AB
InventorArijit Biswas
Life of this patent
Estimating the term…
Abstract
The invention relates to estimating tempo information directly from a bitstream encoding audio information, preferably music. Said tempo information is derived from at least one periodicity derived from a detection of at least two onsets included in the audio information. Such onsets are detected via a detection of long to short block transitions (in the bitstream) or/and via a detection of a changing bit allocation (change of cost) regarding encoding/transmitting the exponents of transform coefficients encoded in the bitstream.
Claims20
A method, performed by an audio signal processing device, for estimating a tempo metric related to an audio signal based on an encoded bit-stream representing the audio signal, wherein the bit-stream includes a plurality of audio blocks, the method comprising:
- receiving the bit-stream;
- analyzing the bit-stream to detect transitions in block sizes of said audio blocks in the bit-stream;
- determining at least one periodicity related to a re-occurrence of said detected transitions;
- and
- determining an estimated tempo metric based on the determined periodicity;
- wherein one or more of receiving the bit-stream, detecting transitions, determining at least one periodicity, and determining an estimated tempo metric are implemented, at least in part, by one or more hardware elements of the audio signal processing device.
A method, performed by an audio signal processing device, for estimating a tempo metric related to an audio signal based on an encoded bit-stream representing the audio signal, the bit-stream encoded in a format including mantissas and exponents to represent transform coefficients, the method comprising:
- receiving the bit-stream,
- analyzing information included in metadata of the bit-stream to repeatedly determine a cost of encoding the exponents,
- detecting a change of said cost;
- determining at least one periodicity related to a re-occurrence of said detected change of cost;
- and
- determining an estimated tempo metric based on the determined periodicity;
- wherein one or more of receiving the bit-stream, repeatedly determining a cost, detecting a change of said cost, determining at least one periodicity, and
- determining an estimated tempo metric are implemented, at least in part, by one or more hardware elements of the audio signal processing device.
An audio signal processing device for estimating a tempo metric related to an audio signal based on an encoded bit-stream representing the audio signal, wherein the bit-stream includes a plurality of audio blocks, the audio signal processing device comprising:
- an input unit for receiving the bit-stream;
- and
- a computing unit for:
- analyzing the bit-stream to transitions in block sizes of said audio blocks in the bit-stream,
- determining at least one periodicity related to a re-occurrence of said detected transitions, and
- determining an estimated tempo metric based on the determined periodicity;
- wherein one or more of the input unit and the computing unit are implemented, at least in part, by one or more hardware elements of the audio signal processing device.
An audio signal processing device for estimating a tempo metric related to an audio signal based on an encoded bit-stream representing the audio signal, the bit-stream encoded in a format including mantissas and exponents to represent transform coefficients, the audio signal processing device comprising:
- an input unit for receiving the bit-stream;
- and
- a computing unit for:
- analyzing information included in metadata of the bit-stream to repeatedly determine a cost of encoding the exponents,
- detecting a change of said cost,
- determining at least one periodicity related to a re-occurrence of said detected change of cost, and,
- determining an estimated tempo metric based on the determined periodicity
- wherein one or more of the input unit and the computing unit are implemented, at least in part, by one or more hardware elements of the audio signal processing device.
Dependencies are inferred from the claim text.