Integrated MPEG audio decoder and signal processor

• US 5,835,375 A
• Filed: 01/02/1996
• Issued: 11/10/1998
• Est. Priority Date: 01/02/1996
• Status: Expired due to Term

• Current Assignee: ATI Technologies Incorporated (Advanced Micro Devices, Inc.)
• Original Assignee: ATI Technologies Incorporated (Advanced Micro Devices, Inc.)
• Inventors: Kitamura, John
• Primary Examiner(s): Voeltz, Emanuel Todd
• Assistant Examiner(s): SMITH-STEWART, DEMETRA R
• Application Number:
  US08/581,903
• Time in Patent Office: 1,043 Days
• Field of Search: 382/250, 382/233, 382/232, 386/96, 386/109, 386/112, 386/104, 348/398, 348/403, 348/404, 348/405, 348/845, 364/400.01, 364/715.02, 364/724.05, 395/2.14, 395/2.91, 395/2.92, 395/2.94, 395/2.95, 395/2.15, 704/200, 704/201, 704/203, 704/205, 704/206, 704/500, 704/501, 704/502, 704/503
• US Class Current: 700/94
• CPC Class Codes: G06T 9/007 Transform coding, e.g. discrete cosine transform

Abstract

A method of reconstructing a stream of digital frequency domain audio signal samples into audio signals comprising parsing the stream of samples and reconstructing subband data in the frequency domain, processing the subband data to obtain a processed frequency domain digital audio signal, and constructing a time domain audio output signal from the processed frequency domain digital audio signal.

Claims

1. A method of reconstructing a stream of digital frequency domain audio signal samples into reconstructed audio signals comprising parsing said stream of samples and reconstructing subband data in the frequency domain, processing the subband data to obtain a processed frequency domain digital audio signal, and constructing a time domain audio output signal from the processed frequency domain digital audio signal, in which the step of reconstructing subband data in the frequency domain is comprised of first reconstructing subband data to the frequency domain from first blocks of subband samples of said stream in accordance with a first resolution, then grouping subband samples of said stream and converting them into larger blocks than said first blocks having a second resolution, higher than said first resolution, said larger blocks with said second resolution forming reconstructed subband data for said processing.

2. A method as defined in claim 1 in which the processing step is comprised of passing the reconstructed subband data through a processor means.

3. A method as defined in claim 2 including applying a signal from an external source to the processor means to modify a processing algorithm of the processor means.

4. A method as defined in claim 2 including applying a varying signal from an external source to the processor means for modifying a processing algorithm of the processor means in real time therefrom.

5. A method as defined in claim 2 in which the processor means is comprised of a digital signal processor (DSP).

6. A method as defined in claim 2 in which the processor means is comprised of an adaptive filter.

7. An audio decoder comprising means for receiving digital frequency domain signal samples of an audio signal and for reconstructing subband data therefrom in accordance with a predetermined standard, means for increasing the resolution of the subband data, means for processing said subband data having increased resolution to obtain a processed frequency domain digital audio signal and means for constructing a time domain audio output signal from the processed digital audio signal, in which said processing means is an adaptive filter.

8. A decoder as defined in claim 7 in which the adaptive filter includes means for receiving a signal from an external source for modifying filter characteristics of the adaptive filter.

9. A decoder as defined in claim 7 in which said processing means is comprised of a digital signal processor.

10. A decoder as defined in claim 7 in which said means for processing subband data includes a control input, and means for applying a control signal to said means for processing for modifying a processing algorithm operated by said means for processing.