Excitation for higher band coding in a codec utilising band split coding methods
First Claim
1. A method for digitally encoding sound, comprising:
- a) splitting an input signal into a primary frequency band and at least one secondary frequency band;
b) digitally encoding the part of the input signal in the primary frequency band;
c) examining certain characteristics of the input signal in the primary frequency band and corresponding characteristics of the input signal in at least one secondary frequency band in order to find out, whether there is certain resemblance therebetween; and
d1) if there is said certain resemblance, extracting certain characteristic features of the process applied to encoding the input signal in the primary frequency band and digitally encoding the part of the input signal in the secondary frequency band or bands using such extracted characteristic features;
d2) otherwise replacing such extracted characteristic features with a locally generated, independent set of corresponding features and digitally encoding the part of the input signal in the secondary frequency band or bands using said locally generated, independent set of corresponding features.
3 Assignments
0 Petitions
Accused Products
Abstract
Methods and arrangements are disclosed for digitally encoding and decoding sound—An input signal is split (811) into a primary frequency band and at least one secondary frequency band. The parts of the input signal in the frequency bands are separately encoded. Certain characteristics of the input signal in the primary frequency band and corresponding characteristics of the input signal in at least one secondary frequency band are examined (302, 303, 814) in order to find out, whether there is certain resemblance therebetween. Alternatively certain characteristic features of the process applied to encoding the primary frequency band extracted (305, 813) and used (307) in encoding the secondary frequency band, or such extracted characteristic features are replaced (306, 501, 701, 815) with a locally generated, independent set of corresponding features.
33 Citations
29 Claims
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1. A method for digitally encoding sound, comprising:
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a) splitting an input signal into a primary frequency band and at least one secondary frequency band; b) digitally encoding the part of the input signal in the primary frequency band; c) examining certain characteristics of the input signal in the primary frequency band and corresponding characteristics of the input signal in at least one secondary frequency band in order to find out, whether there is certain resemblance therebetween; and d1) if there is said certain resemblance, extracting certain characteristic features of the process applied to encoding the input signal in the primary frequency band and digitally encoding the part of the input signal in the secondary frequency band or bands using such extracted characteristic features; d2) otherwise replacing such extracted characteristic features with a locally generated, independent set of corresponding features and digitally encoding the part of the input signal in the secondary frequency band or bands using said locally generated, independent set of corresponding features. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method for decoding digitally encoded sound, comprising:
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a) receiving an encoded input signal split into a primary frequency band and at least one secondary frequency band, which secondary frequency band has been encoded separately from the primary frequency band; b) decoding the part of the input signal in the primary frequency band; c) examining the input signal in order to find out, what indication does the input signal contain about utilising characteristic features of the process applied to encoding the primary frequency band in the process applied to encoding the secondary frequency band; and d1) if there is said certain resemblance, extracting certain characteristic features of the process applied to decoding the input signal in the primary frequency band and decoding the part of the input signal in the secondary frequency band or bands using such extracted characteristic features, or d2) otherwise replacing such extracted characteristic features with a locally generated, independent set of corresponding features and decoding the part of the input signal in the secondary frequency band or bands using said locally generated, independent set of corresponding features. - View Dependent Claims (11, 12, 13, 14)
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15. A transmitter apparatus for transmitting digitally encoded sound, comprising:
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a band splitter adapted to split an input signal into a primary frequency band and at least one secondary frequency band, a primary encoder adapted to digitally encode the part of the input signal in the primary frequency band, a secondary encoder adapted to digitally encode the part of the input signal in a secondary frequency band, an examining portion adapted to examine certain characteristics of the input signal in the primary frequency band and corresponding characteristics of the input signal in at least one secondary frequency band and to indicate, whether there is certain resemblance therebetween, an extracting portion adapted to extract certain characteristic features of a process applied to encoding the input signal in the primary frequency band, for use in a process applied to encoding the input signal in the secondary frequency band, and a replacing portion adapted to replace such extracted characteristic features with a locally generated, independent set of corresponding features in the process applied to encoding the input signal in the secondary frequency band; wherein said extracting portion and said replacing portion are arranged to be operationally alternative to each other depending on an indication produced by said examining portion. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23)
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24. A receiver apparatus for receiving and decoding digitally encoded sound, comprising:
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a receiver adapted to receive an encoded input signal split into a primary frequency band and at least one secondary frequency band, which secondary frequency band has been encoded separately from the primary frequency band, a primary decoder adapted to decode the part of the input signal in the primary frequency band, a secondary decoder adapted to decode the part of the input signal in a secondary frequency band, a examining portion adapted to examine the input signal and to find out what indication does the input signal contain about utilising characteristic features of the process applied to encoding the primary frequency band in the process applied to encoding the secondary frequency band, an extracting portion adapted to extract certain characteristic features of a process applied to decoding the input signal in the primary frequency band and to use such extracted characteristic features in a process applied to decoding the input signal in the primary frequency band, and a replacing portion adapted to replace such extracted characteristic features with a locally generated, independent set of corresponding features in the process applied to decoding the input signal in the primary frequency band; wherein said extracting portion and said replacing portion are arranged to be operationally alternative to each other depending on an indication found by said examining portion. - View Dependent Claims (25, 26, 27, 28)
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29. A transmitter apparatus for transmitting digitally encoded sound, comprising:
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means for splitting an input signal into a primary frequency band and at least one secondary frequency band, means for digitally encoding the part of the input signal in the primary frequency band, means for digitally encoding the part of the input signal in a secondary frequency band, means for examining certain characteristics of the input signal in the primary frequency band and corresponding characteristics of the input signal in at least one secondary frequency band and indicating whether there is certain resemblance therebetween, means for extracting certain characteristic features of a process applied to encoding the input signal in the primary frequency band, for use in a process applied to encoding the input signal in the secondary frequency band, and means for replacing such extracted characteristic features with a locally generated, independent set of corresponding features in the process applied to encoding the input signal in the secondary frequency band; wherein said means for extracting and said means for replacing are arranged to be operationally alternative to each other depending on an indication produced by said examining means.
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Specification