Data compressing and expanding apparatus with time domain and frequency domain block floating
AssigneeSony Corporation
InventorKenzo Akagiri
Life of this patent
Estimating the term…
Abstract
The input digital signal is divided into blocks each composed of a number of samples, and first block floating is applied to each block. The each first block floating processed block is orthogonally transformed to provide spectral coefficients. The spectral coefficients are divided into bands, each band including at least one spectral coefficient. Second block floating is applied to each band to provide a second block floating processed band. Each of the second block floating processed bands is adaptively quantized by the adaptive bit allocation circuit. Common circuitry or processing is used to determine the block size and to apply block floating, which reduces the complexity of the hardware and/or the number of processing steps required.
Claims20
Apparatus for applying data compression to an input digital signal comprising plural samples to provide an output signal, the apparatus comprising:
- a first dividing means for dividing the input digital signal into blocks, each block including plural samples;
- a first block floating means for applying first block floating to each block to provide a first block floating processed block;
- an orthogonal transform means for orthogonally transforming each first block floating processed block to provide spectral coefficients;
- a second dividing means for dividing the spectral coefficients into bands, each band including at least one spectral coefficient;
- a second block floating means for applying second block floating to each band to provide a second block floating processed band;
- and
- a means for adaptively quantizing each second block floating processed band to provide a quantized band, and for providing the quantized bands as the output signal.
An data exander apparatus for providing an expanded output signal by expanding a compressed digital signal generated from an input digital signal that includes plural samples by a data compression process, the process including the steps of:
- dividing the input digital data into blocks, each block including plural samples,
- applying first block floating to each block to provide a first block floating processed block,
- orthogonally transforming each first block floating processed block to provide spectral coefficients,
- dividing the spectral coefficients into bands, each band including at least one spectral coefficient,
- applying second block floating to each band to provide a second block floating processed band, and
- adaptively quantizing each second block floating processed band to provide a quantized band and providing the quantized bands as the compressed digital signal, the decoding apparatus comprising:
- a means for receiving the compressed digital data and for dequantizing the quantized bands to provide plural second block floating processed bands;
- a means for reversing the second block floating applied to each second block floating processed band to provide plural spectral coefficients;
- a means for inversely orthogonally transforming the spectral coefficients to provide a first block floating processed block of plural samples;
- and
- a means for reversing the first block floating applied to the first block floating processed block to provide a block of the output signal.
A method for recording a data-compressed digital signal derived from an input digital signal including plural samples on a recording medium, the method including the steps of:
- dividing the input digital signal into blocks, each block including plural samples;
- applying first block floating to each block to provide a first block floating processed block;
- orthogonally transforming each first block floating processed block to provide spectral coefficients;
- dividing the spectral coefficients into bands, each band including at least one spectral coefficient;
- applying second block floating to each band to provide a second block floating processed band;
- adaptively quantizing each second block floating processed band to provide a quantized band;
- providing the quantized bands as the data-compressed digital signal;
- and
- recording the data-compressed digital signal on the recording medium.
Dependencies are inferred from the claim text.