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US 12,192,734 B2Granted
Parametric stereo upmix apparatus, a parametric stereo decoder, a parametric stereo downmix apparatus, a parametric stereo encoder
AssigneeKoninklijke Philips N.V.
InventorErik G. P. Schuijers
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Abstract
A parametric stereo upmix method for generating a left signal and a right signal from a mono downmix signal based on spatial parameters includes predicting a difference signal comprising a difference between the left signal and the right signal based on the mono downmix signal scaled with a prediction coefficient. The prediction coefficient is derived from the spatial parameters. The method further includes deriving the left signal and the right signal based on a sum and a difference of the mono downmix signal and said difference signal.
Claims23
A method, comprising:
- splitting an input bitstream into a mono bitstream and a parameter bitstream;
- decoding the mono bitstream into a mono downmix signal;
- decoding the parameter bitstream into spatial parameters;
- scaling the mono downmix signal with a prediction coefficient (α) to produce a scaled mono downmix signal;
- predicting a first difference signal, wherein the predicting is based on the scaled mono downmix signal;
- adding a scaled decorrelated mono downmix signal to the first difference signal to form a second difference signal, wherein the scaled decorrelated mono downmix signal is formed by scaling a decorrelated mono downmix signal by a scaling factor (β);
- forming the left signal based on a sum of the mono downmix signal and the second difference signal;
- and
- forming the right signal based on a difference between the mono downmix signal and the second difference signal wherein the scaling factor (β) is:
- β
- =
- iid
- +
- 1
- -
- 2
- ·
- cos
-
- (
- ipd
- )
- ·
- icc
- ·
- iid
- iid
- +
- 1
- +
- 2
- ·
- cos
-
- (
- ipd
- )
- ·
- icc
- ·
- iid
- -
- ❘
- "\[LeftBracketingBar]"
- α
- ❘
- "\[RightBracketingBar]"
- 2
- wherein iid, ipd, and icc are the spatial parameters,
- wherein iid is an interchannel intensity difference,
- wherein ipd is an interchannel phase difference, and
- wherein icc is an interchannel coherence.
49 more elements
A method, comprising:
- splitting an input bitstream into a mono bitstream and a parameter bitstream;
- extracting a prediction residual bitstream from the input bitstream;
- decoding the mono bitstream into a mono downmix signal;
- decoding a prediction residual signal from the prediction residual bitstream;
- decoding the parameter bitstream into spatial parameters;
- scaling the mono downmix signal with a prediction coefficient (α) to produce a scaled mono downmix signal;
- predicting a first difference signal, wherein the predicting is based on the scaled mono downmix signal;
- adding a scaled decorrelated mono downmix signal to the first difference signal to form a second difference signal, wherein the scaled decorrelated mono downmix signal is formed by scaling a decorrelated mono downmix signal by a scaling factor (β);
- forming a first portion of the left signal based on a sum of the mono downmix signal, the first difference signal, and the prediction residual signal;
- forming a second portion of the left signal based on a sum of the mono downmix signal and the second difference signal;
- forming a first portion of the right signal based on a difference between the mono downmix signal, and a sum of the first difference signal and the prediction residual signal;
- and
- forming a second portion of the right signal based on a difference between the mono downmix signal and the second difference signal
- wherein the scaling factor (β) is:
- β
- =
- iid
- +
- 1
- -
- 2
- ·
- cos
-
- (
- ipd
- )
- ·
- icc
- ·
- iid
- iid
- +
- 1
- +
- 2
- ·
- cos
-
- (
- ipd
- )
- ·
- icc
- ·
- iid
- -
- ❘
- "\[LeftBracketingBar]"
- α
- ❘
- "\[RightBracketingBar]"
- 2
- wherein iid, ipd, and icc are the spatial parameters,
- wherein iid is an interchannel intensity difference,
- wherein ipd is an interchannel phase difference, and
- wherein icc is an interchannel coherence.
54 more elements
A method, comprising:
- splitting an input bitstream into a mono bitstream and a parameter bitstream, wherein the input bitstream comprises a plurality of subbands;
- extracting a prediction residual bitstream from the input bitstream, wherein the prediction residual bitstream comprises a third portion of plurality of subbands;
- decoding the mono bitstream into a mono downmix signal,
- wherein the mono downmix signal comprises mono downmix subband signals,
- wherein the mono downmix subband signal comprises a fourth portion of the plurality of subbands;
- decoding a prediction residual signal,
- wherein the prediction residual signal comprises prediction residual subband signals,
- wherein the prediction residual subband signals comprise a fifth portion of the third portion of the plurality of subbands;
- decoding the parameter bitstream into spatial parameters for at least one subband of the plurality of subbands;
- scaling the mono downmix subband signal with a prediction coefficient (α) to produce a scaled mono downmix subband signal for at least one subband of the plurality of subbands;
- predicting a first difference subband signal for at least one subband of the plurality of subbands, wherein the predicting is based on the scaled mono downmix subband signal;
- adding a scaled decorrelated mono downmix subband signal to the first difference subband signal for at least one subband of the plurality of subbands to form a second difference subband signal, wherein the scaled decorrelated mono downmix subband signal is formed by scaling a decorrelated mono downmix subband signal by a scaling factor (β);
- forming a first portion of the left signal,
- wherein the first portion of the left signal comprises one or more subbands,
- wherein each subband is based on a sum of the mono downmix subband signal, the first difference subband signal, and the prediction residual subband signal;
- forming a second portion of the left signal,
- wherein the second portion of the left signal comprises one or more subbands,
- wherein each subband is based on a sum of the mono downmix subband signal and the second difference subband signal;
- forming a first portion of the right signal,
- wherein the first portion of the right signal comprises one or more subbands,
- wherein each subband is based on a difference between the mono downmix subband signal, and a sum of the first difference subband signal and the prediction residual subband signal;
- and
- forming a second portion of the right signal,
- wherein the second portion of the right signal comprises one or more subbands,
- wherein each subband is based on a difference between the mono downmix subband signal and the second difference subband signal
- wherein the scaling factor (β) is:
- β
- =
- iid
- +
- 1
- -
- 2
- ·
- cos
-
- (
- ipd
- )
- ·
- icc
- ·
- iid
- iid
- +
- 1
- +
- 2
- ·
- cos
-
- (
- ipd
- )
- ·
- icc
- ·
- iid
- -
- ❘
- "\[LeftBracketingBar]"
- α
- ❘
- "\[RightBracketingBar]"
- 2
- wherein iid, ipd, and icc are the spatial parameters,
- wherein iid is an interchannel intensity difference,
- wherein ipd is an interchannel phase difference, and
- wherein icc is an interchannel coherence.
66 more elements
Dependencies are inferred from the claim text.