摘要:
In a method of encoding input signals (CH1 to CH3; 400 to 450) in a multi-channel encoder (5; 15) to generate corresponding output data having down-mix output signals (610, 620) together with complementary parametric data (600), the method includes a first step of down-mixing input signals (CH1 to CH3; 400 to 450) to generate the corresponding down-mix output signals (610, 620), and a second step of processing the input signals (CH1 to CH3; 400 to 450) during down-mixing to generate the parametric data (600) complementary to the down-mix output signals (610, 620). Processing of the input signals (CH1 to CH3; 400 to 450) involves including information in the down-mix signals (610, 620) which is useable during subsequent decoding of the down-mix output signals (610, 620) and the parametric data (600) to determine at least some parameter data and thereby enabling representations of the input signals (CH1 to CH3; 400 to 450) to be subsequently regenerated.
摘要:
A multi-channel audio encoder (10) for encoding a multi-channel audio signal (101), e.g. a 5.1 channel audio signal, into a spatial down-mix (102), e.g. a stereo signal, and associated parameters (104, 105). The encoder (10) comprises first and second units (110, 120). The first unit (110) encodes the multi-channel audio signal (101) into the spatial down-mix (102) and parameters (104). These parameters (104) enable a multi-channel decoder (20) to reconstruct the multi-channel audio signal (203) from the spatial down-mix (102). The second unit (120) generates, from the spatial down-mix (102), parameters (105) that enable the decoder to reconstruct the spatial down-mix (202) from an alternative down-mix (103), e.g. a so-called artistic down-mix that has been manually mixed in a sound studio. In this way, the decoder (20) can efficiently deal with a situation in which an alternative down-mix (103) is received instead of the regular spatial, down-mix (102). In the decoder (20), first the spatial down-mix (202) is reconstructed from the alternative down-mix (103) and the parameters (105). Next, the spatial down-mix (202) is decoded into the multi-channel audio signal (203).
摘要:
A multi-channel audio encoder (10) for encoding a multi-channel audio signal (101), e.g. a 5.1 channel audio signal, into a spatial down-mix (102), e.g. a stereo signal, and associated parameters (104, 105). The encoder (10) comprises first and second units (110, 120). The first unit (110) encodes the multi-channel audio signal (101) into the spatial down-mix (102) and parameters (104). These parameters (104) enable a multi-channel decoder (20) to reconstruct the multi-channel audio signal (203) from the spatial down-mix (102). The second unit (120) generates, from the spatial down-mix (102), parameters (105) that enable the decoder to reconstruct the spatial down-mix (202) from an alternative down-mix (103), e.g. a so-called artistic down-mix that has been manually mixed in a sound studio. In this way, the decoder (20) can efficiently deal with a situation in which an alternative down-mix (103) is received instead of the regular spatial, down-mix (102). In the decoder (20), first the spatial down-mix (202) is reconstructed from the alternative down-mix (103) and the parameters (105). Next, the spatial down-mix (202) is decoded into the multi-channel audio signal (203).
摘要:
Coding of an audio signal is provided where an indicator of the frequency variation of sinusoidal components of the signal is used in the tracking algorithm of a sinusoidal coder where sinusoidal parameters from appropriate sinusoids from consecutive segments are linked. By applying an indicator such as a warp factor or polynomial fitting, more accurate tracks are obtained. As a result, the sinusoids can be encoded more efficiently. Furthermore, a better audio quality can be obtained by improved phase continuation.
摘要:
Techniques are described for combining parametric multi-channel audio coding with matrixing, reconstructing a full-quality multi-channel, independent of the decoder. A stereo signal is obtained from encoding an N-channel audio signal into spatial parameters and a stereo down-mix signal having first and second stereo signals, including adding a first signal and a third signal to obtain a first output signal, the first signal having the first stereo signal modified by a first complex function, the third signal having the second stereo signal modified by a third complex function. A second signal and fourth signal are similarly added to obtain a second output signal. Complex functions are chosen such that an energy value of the difference between first signal and the second signals (fourth signal and third signals) is larger than or equal to the energy value of the sum of the first and the second signal (fourth signal and third signal).
摘要:
An encoding device (1) for converting a first number (M) of input audio channels into a second, smaller number (N) of output audio channels comprises at least one conversion unit (12) for converting a first signal (Lf; Rf; Co) and a second signal (Lr; Rr; Le) into a third signal (L; R; C) and a fourth signal (Ls; Rs; Cs). The third, dominant signal contains most of the signal energy of the first and second signals, while the fourth, residual signal contains the remainder of said signal energy. The encoding device is arranged for using the third signal (L; R; C) to produce an output signal and for outputting the fourth signal (Ls; Rs; Cs). A decoding device (2) for converting a first number (N) of input audio channels into a second, larger number (M) or output audio channels comprises at least one conversion unit (24) for converting a first signal (L; R; C) and a second signal (Ld; Rd; Ld) into a third signal (Lf, Rf; Co) and a fourth signal (Lr; Rr; Le). The first, dominant signal contains most of the signal energy of the third and fourth signal, while the second, residual signal contains the remainder of said signal energy. The encoding device is arranged for receiving at least one-second signal (Ld; Rd; Cd).
摘要:
A method and a device are described for processing a stereo signal obtained from an encoder, which encodes an N-channel audio signal into spatial parameters (P) and a stereo down-mix comprising first and second stereo signals (LO, RO). A first signal and a third signal are added in order to obtain a first output signal (L0w), wherein the first signal (L0wL) comprises the first stereo signal (LO) modified by a first complex function (g1), and the third signal (L0wR) comprises the second stereo signal (RO) modified by a third complex function (g3). A second signal and a fourth signal are added to obtain a second output signal (R0w). The fourth signal (R0wR) comprises the second stereo signal (RO) modified by a fourth complex function (g4), and the second signal (R0wL) comprises the first stereo signal (LO) modified by a second complex function (g2). The complex functions (g1, g2, g3, g4) are functions of the spatial parameters (P) and are chosen to be such that an energy value of the difference (L0wL,R0wL) between the first signal and the second signal is larger than or equal to the energy value of the sum (L0wL+R0wL) of the first and the second signal, and the energy value of the difference (R0wR−L0wR) between the fourth signal and the third signal is larger than or equal to the energy value of the sum (R0wR+L0wR) of the fourth signal and the third signal.
摘要:
Method for processing a stereo signal includes encoding an N-channel audio signal in a stereo signal (Lo, Ro) and spatial parameters (wl, wr), processing the stereo signal using the spatial parameters for generating a processed stereo signal (low, Row). The matrix of the processed stereo signal is described as the matrix of the stereo signal, multiplied by a filter matrix (H) having element that are filter functions (H1, H2, H3, H4) operated with spatial parameters (wl, wr) and a constant (a). The filter functions are time invariant and selected so that the matrix is invertible.
摘要:
A method and a device are described for processing a stereo signal obtained from an encoder, which encodes an N-channel audio signal into spatial parameters (P) and a stereo down-mix comprising first and second stereo signals (L0, R0). A first signal and a third signal are added in order to obtain a first output signal (Low), wherein the first signal (L0wL) comprises the first stereo signal (L0) modified by a first complex function (g1), and the third signal (L0wR) comprises the second stereo signal (R0) modified by a third complex function (g3). A second signal and a fourth signal are added to obtain a second output signal (R0w). The fourth signal (R0wR) comprises the second stereo signal (R0) modified by a fourth complex function (g4), and the second signal (R0wL) comprises the first stereo signal (L0) modified by a second complex function (g2). The complex functions (g1, g2, g3, g4) are functions of the spatial parameters (P) and are chosen to be such that an energy value of the difference (L0wL,R0wL) between the first signal and the second signal is larger than or equal to the energy value of the sum (L0wL+R0wL) of the first and the second signal, and the energy value of the difference (R0wR−L0wR) between the fourth signal and the third signal is larger than or equal to the energy value of the sum (R0wR+L0wR) of the fourth signal and the third signal.
摘要:
An audio encoder (109) has a hierarchical encoding structure and generates a data stream comprising one or more audio channels as well as parametric audio encoding data. The encoder (109) comprises an encoding structure processor (305) which inserts decoder tree structure data into the data stream. The decoder tree structure data comprises at least one data value indicative of a channel split characteristic for an audio channel at a hierarchical layer of the hierarchical decoder structure and may specifically specify the decoder tree structures to be applied by a decoder. A decoder (115) comprises a receiver (401) which receives the data stream and a decoder structure processor (405) for generating the hierarchical decoder structure in response to the decoder tree structure data. A decode processor (403) then generates output audio channels from the data stream using the hierarchical decoder structure.