Signal encoding and decoding system
AssigneeSony Corporation
InventorShiro Suzuki
Life of this patent
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Abstract
In band-splitting acoustic signals and subsequently encoding and decoding the band-split signals, band-splitting and band-synthesizing processing with high accuracy is desirable. To this end, an optimizing processor optimizes prototype filter coefficients held on a prototype filter coefficient holder by a window function of a tap length L′. The filter coefficient portions of the optimized prototype filter with both end values equal to zero are discarded for deriving a corrected prototype filter having a tap length L′.
Claims59
A band-splitting filter bank for processing an input signal with band-splitting, comprising:
- tap length converting means for outputting filter coefficients with a contracted tap length obtained on contracting the filter coefficients of a standard tap length based on a tap length information;
- and
- processing means for convolving the filter coefficients of the contracted tap length outputted by said tap length converting means with said input signal.
The band-splitting filtering method for band-splitting an input signal, comprising:
- a tap length converting step for outputting filter coefficients with a contracted tap length obtained on contracting the filter coefficients of a standard tap length based on a tap length information;
- and
- a processing step for convolving the filter coefficients of the contracted tap length outputted by said tap length converting step with said input signal.
A recording medium having recorded thereon input signals processed with band-splitting processing, said band-splitting processing including
- a tap length converting step for outputting filter coefficients with a contracted tap length obtained on contracting the filter coefficients of a standard tap length based on a tap length information;
- and
- a processing step for convolving the filter coefficients of the contracted tap length outputted by said tap length converting step with said input signal.
A band-synthesizing filter bank for processing an input signal with band synthesis, comprising:
- tap length converting means for outputting filter coefficients with a contracted tap length obtained on contracting the filter coefficients of a standard tap length based on a tap length information;
- and
- processing means for convolving the filter coefficients of the contracted tap length outputted by said tap length converting means with said input signal.
A band-synthesizing filtering method for band-synthesizing an input signal, comprising:
- a tap length converting step for outputting filter coefficients with a contracted tap length obtained on contracting the filter coefficients of a standard tap length based on a tap length information;
- and
- a processing step for convolving the filter coefficients of the contracted tap length outputted by said tap length converting step with said input signal.
A recording medium having recorded thereon band-synthesizing filtering processing of band-synthesizing input signals;
- said band-synthesizing filtering processing including
- a tap length covering step for outputting filter coefficients with a contracted tap length obtained on contracting the filter coefficients of a standard tap length based on a tap length information;
- and
- a processing step for convolving the filter coefficients of the contracted tap length outputted by said tap length converting step with said input signal.
A band-splitting filter bank for processing an input signal with band splitting, comprising:
- optimizing processing means for processing filter coefficients using an optimizing function;
- and
- tap length converting means for converting the tap length of said filter coefficients optimized by said optimizing processing means.
A band-splitting filtering method for processing an input signal with band splitting processing, comprising:
- an optimizing processing step for processing said filter coefficients using an optimizing function;
- and
- a tap length converting step for converting the tap length of said filter coefficients optimized by said optimizing processing step.
A recording medium having recorded thereon band-splitting filtering processing of band-splitting input signals;
- said band-splitting processing including
- an optimizing processing step for processing filter coefficients using an optimizing function;
- and
- a tap length converting step for converting the tap length of said filter coefficients optimized by said optimizing processing step.
A band synthesizing filter bank for processing an input signal with band synthesis processing with modified filter coefficients, said input signal being such a signal band-split by a band-splitting filter bank constituted by a pre-set finite tap length, comprising:
- optimizing processing means for processing said filter coefficients using an optimizing function;
- and
- tap length converting means for converting the tap length of said filter coefficients optimized by said optimizing processing means.
A band synthesizing filtering method for processing an input signal with band synthesis processing with modified filter coefficients, said input signal being such a signal band-split by a band-splitting filter bank constituted by a pre-set finite tap length, comprising:
- an optimizing processing step for processing filter coefficients using an optimizing function;
- and
- a tap length converting step for converting the tap length of said filter coefficients optimized by said optimizing processing step.
The band-splitting filter bank as claimed in 29 wherein said tap length converting means converts said tap length based on a tap length information.
A recording medium having recorded thereon band synthesizing filtering processing of band-synthesizing an input signal using modified filter coefficients, said input signal being a signal band-split by a band-splitting filter bank constituted by a pre-set finite tap length;
- said band-synthesizing processing including
- an optimizing processing step for processing filter coefficients using an optimizing function;
- and
- a tap length converting step for converting the tap length of said filter coefficients optimized by said optimizing processing step.
An encoder for band-splitting and subsequently encoding an input signal, comprising:
- a band splitting filter bank for band-splitting said input signal;
- and
- encoding means for encoding a signal band-split by said band-splitting filter bank for generating a codestring, said encoding means writing in said codestring a tap length information used for band-splitting the input signal by said band-splitting filter bank.
The encoder as claimed in 34 wherein said tap length converting means processes the filter coefficients of the standard tap length with psychoacoustic optimizing processing for producing the filter coefficients of the contracted tap length.
An encoding method for band-splitting and subsequently encoding an input signal, comprising:
- a band-splitting filtering step for band-splitting said input signal;
- and
- an encoding step for encoding a signal band-split by said band-splitting filter bank for generating a codestring, said encoding means writing in said codestring a tap length information used for band-splitting the input signal by said band-splitting filtering step.
A recording medium having recorded thereon encoder processing of band-splitting and subsequently encoding an input signal;
- said encoding processing including a band splitting filtering step for band-splitting said input signal;
- and
- an encoding step for encoding a signal band-split by said band-splitting filter bank for generating a codestring, said encoding means writing in said codestring a tap length information used for band-splitting the input signal by said band-splitting filtering step.
A decoder for decoding a codestring encoded by an encoder employing a band-splitting filter bank;
- comprising:
- readout means for reading out band-splitting tap length information from said codestring;
- and
- a band-synthesizing filter bank for setting the band synthesis tap length based on the band-splitting tap length information read out by said readout means, said band-synthesizing filter bank doing band synthesis by said band-splitting tap length.
A decoding method for decoding a codestring encoded by an encoder employing a band-splitting filter bank;
- comprising:
- readout step for reading out band-splitting tap length information from said codestring;
- and
- a band-synthesizing filtering step for setting the band synthesis tap length based on the band-splitting tap length information read out by said readout means, said band-synthesizing filtering step doing band synthesis by said band-splitting tap length.
A recording medium having recorded thereon a decoding processing of decoding a codestring encoded by encoding processing employing a band-splitting filter bank;
- said decoding processing including
- a readout step for reading out band-splitting tap length information from said codestring;
- and
- a band-synthesizing filtering step for setting the band synthesis tap length based on the band-splitting tap length information read out by said readout means, said band-synthesizing filtering step doing band synthesis by said band-splitting tap length.
A recording medium comprising a codestring wherein the codestring is obtained by band-splitting a signal using a tap length information of a filter bank and encoding the band-split signal from one band to another.
Dependencies are inferred from the claim text.