Binaural multi-channel decoder in the context of non-energy-conserving upmix rules
AssigneeDolby International AB
InventorLars Villemoes
Life of this patent
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Abstract
A multi-channel decoder for generating a binaural signal from a downmix signal using upmix rule information on an energy-error introducing upmix rule for calculating a gain factor based on the upmix rule information and characteristics of head related transfer function based filters corresponding to upmix channels. The one or more gain factors are used by a filter processor for filtering the downmix signal so that an energy corrected binaural signal having a left binaural channel and a right binaural channel is obtained.
Claims17
A multi-channel decoder for generating an energy-corrected binaural signal from a downmix signal derived from an original multi-channel signal using parameters including an upmix rule in useable for upmixing the downmix signal with an upmix rule, the upmix rule resulting in an energy-error, comprising:
- a receiver for receiving at least a spatial parameter that represents a channel level ratio wherein the parameters include the channel level ratio spatial parameter,
- a gain factor calculator configured for calculating at least one gain factor for reducing or eliminating the energy-error obtainable by the upmixing of the downinix signal using the upmix rule, based on the upmix rule information and filter characteristics of head related transfer function based filters corresponding to upmix channels, wherein the gain actor calculator is operative to calculate the gain factor based on
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- wherein gn is the gain factor for the first channel, when n is set to 1, wherein g2 is the gain factor of a second channel, when n is set to 2, wherein EnB is a weighted addition energy calculated by weighting energies of channel impulse responses using weighting parameters, and wherein ΔEnB is an estimate for the energy error introduced by the upmix rule, wherein α, β, and σ are upmix rule dependent parameters, and wherein ε is a number greater than or equal to zero;
- and
- a filter processor configured for filtering the downmix signal using the at least one, gain factor, the filter characteristics of the head related transfer function based filters and the upmix rule information to obtain the energy-corrected binaural signal.
A method of multi-channel decoding for generating an energy-corrected binaural signal from a downmix signal derived from an original multi-channel signal using parameters including an upmix rule information useable for upmixing the downmix signal with an upmix rule, the upmix rule resulting in an energy-error, comprising:
- receiving at least a spatial parameter that represents a channel level ratio wherein the parameters include the channel level ratio spatial parameter,
- calculating at least one gain factor for reducing or eliminating the energy-error obtainable by the upmixing of the downmix signal using the upmix, rule, based on the upmix rule information and filter characteristics of head related transfer function based filters corresponding to upmix channels, wherein the gain factor is calculated based on
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- wherein gn is the gain factor for the first channel, when n is set to 1, wherein g2 is the gain factor of a second channel, when n is set to 2, wherein EnB is a weighted addition energy calculated by weighting energies of channel impulse responses using weighting parameters, and wherein ΔEnB is an estimate for the energy error introduced by the upmix rule, wherein α, β, and σare upmix rule dependent parameters, and wherein εis a number greater than or equal to zero;
- and
- filtering the downmix signal using the at least one gain factor, the filter characteristics of the head related transfer function based filters and the upmix rule information to obtain the energy-corrected binaural signal.
A non-transitory storage medium having stored thereon a computer program having a program code for performing a method of multi-channel decoding for generating an energy-corrected binaural signal from a downmix signal derived from a n original multi-channel signal using parameters including an upmix rule information useable for upmixing the downmix signal with an upmix rule, the upmix rule resulting in an energy-error, the method comprising:
- receiving at least a spatial parameter that represents a channel level ratio wherein the parameters include the channel level ratio spatial parameter,
- calculating at least one gain factor for reducing or eliminating the energy-error obtainable by the upmixing of the downmix signal using the upmix rule, based on the upmix rule information and filter characteristics of head related transfer function based filters corresponding to upmix channels, wherein the gain factor is calculated based on
- g
- n
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-
- a
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- .
- wherein gn is the gain factor for the first channel, when n is set to 1, wherein g2 is the gain factor of a second channel, when n is set to 2, wherein EnB is a weighted addition energy calculated by weighting energies of channel impulse responses using weighting parameters, and wherein ΔEnB is an estimate for the energy error introduced by the upmix rule, wherein α, β, and σare upmix rule dependent parameters, and wherein εis a number greater than or equal to zero;
- filtering the downmix signal using, the at least one gain factor, the filter characteristics of the head related transfer function based filters and the upmix rule information to obtain the energy-corrected binaural signal, when the computer program runs on a computer.
Dependencies are inferred from the claim text.