Adaptive predictive coding with transform domain quantization based on block size adaptation, backward adaptive power gain control, split bit-allocation and zero input response compensation
US5533052A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 15, 1993 |
| Grant date | Jul 2, 1996 |
| Priority date | — |
| Expiry date | Oct 15, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L25/12
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A codec uses a number of different signal processing techniques to improve audio compression. These techniques include (1) dynamically varying the size of the processing block to match the duration of the signal over which the audio signal can be considered to be substantially constant, (2) reducing the power gain of the LPC coefficients to reduce leakage of coding noise from one block into the following block, (3) allocating bits to the residual signal in accordance with both objective and subjective criteria, and (4) computing a modified residual signal to take into account the zero input response of the synthesis filters to the reconstruction noise of past blocks.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.