Method and architecture of digital conding for transmitting and packing audio signals
First Claim
1. A method of digital coding for transmitting and packing audio signals, comprising the steps of:
- (a) mapping input audio signals into a sequence of frequency samples representing a spectral composition of said audio signals;
(b) quantizing said sequence of frequency samples into quantized values in accordance with a bit allocation process, said bit allocation process using a parameter predictor for evaluating quantization parameters by referring to a masking threshold;
(c) encoding said quantized values using a symbol encoder to form encoded data comprising a number of bits; and
(d) packing said encoded data into a sequence of data according to a specified audio protocol.
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Abstract
A method of digital coding transforms input audio signals into a sequence of frequency samples representing a spectral composition of the audio signals, and quantizes the sequence of frequency samples into quantized values according to a bit allocation process which uses a parameter predictor to evaluate quantization parameters by referring to a masking threshold. The quantized values are encoded into a number of bits of encoded data. An iterative rate control loop adjusts the quantization parameters and the quantization step size if the number of bits in the encoded data exceeds a prescribed number of bits available for the encoded data. The method may also cut off high frequency components of the input audio signals according to a cut-off frequency determined by the iterative rate control loop before quantizing the sequence of frequency samples.
34 Citations
24 Claims
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1. A method of digital coding for transmitting and packing audio signals, comprising the steps of:
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(a) mapping input audio signals into a sequence of frequency samples representing a spectral composition of said audio signals;
(b) quantizing said sequence of frequency samples into quantized values in accordance with a bit allocation process, said bit allocation process using a parameter predictor for evaluating quantization parameters by referring to a masking threshold;
(c) encoding said quantized values using a symbol encoder to form encoded data comprising a number of bits; and
(d) packing said encoded data into a sequence of data according to a specified audio protocol. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. An architecture of digital coding for transmitting and packing audio signals, comprising:
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a mapper transforming input audio signals into a sequence of frequency samples representing a spectral composition of said audio signals;
a parameter predictor evaluating quantization parameters by referring to a masking threshold;
a quantizer quantizing said sequence of frequency samples into quantized values in accordance with said quantization parameters;
a variable length encoder encoding said quantized values into encoded data comprising a number of bits; and
a packing unit packing said encoded data into a sequence of data according to a specified audio protocol. - View Dependent Claims (23, 24)
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Specification