Methods and systems for mixing digital audio signals

• US 7,457,677 B2
• Filed: 10/28/2004
• Issued: 11/25/2008
• Est. Priority Date: 12/06/2000
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Rudolph, Eric H.
• Primary Examiner(s): Woo; Stella L
• Application Number:
  US10/975,588
• Publication Number:
  US 20050060161A1
• Time in Patent Office: 1,489 Days
• Field of Search: 700/94, 381/119, 381/20, 386 52- 54, 386/93, 386/96, 386/98, 386/99, 386/102, 386/104
• US Class Current: 700/94
• CPC Class Codes: H04H 60/04 Studio equipment; Interconnection of studios

Abstract

In one embodiment, a system comprises means for processing multiple result buffers by receiving multiple digital audio signals, providing portions of each of the digital audio signals into individual multi-bit input buffers, and combining the contents of the input buffers in a result buffer to provide a mixed audio signal; means for calculating a volume ramp function for a current result buffer as a function of one or more volumes associated with multiple previously-processed result buffers; means for combining multiple digital audio signals; means for processing the combined digital audio signals with the volume ramp function to provide a processed result signal; and means for providing at least some bits from the processed result signal into a result buffer to provide a mixed audio signal.

Claims

1. A system comprising:

means for processing multiple result buffers by receiving multiple digital audio signals, providing portions of each of the digital audio signals into individual multi-bit input buffers, and combining the contents of the input buffers in a result buffer to provide a mixed audio signal;

means for calculating a volume ramp function for a current result buffer as a function of one or more volumes associated with multiple previously-processed result buffers;

means for combining multiple digital audio signals;

means for processing the combined digital audio signals with the volume ramp function to provide a processed result signal; and

means for providing at least some bits from the processed result signal into a result buffer to provide a mixed audio signal.

2. The system of claim 1, wherein said means for calculating comprises means for calculating the volume ramp function as a function of one or more maximum volumes associated with the previously-processed result buffers.

3. The system of claim 1, wherein said means for calculating comprises means for calculating the volume ramp function as a linearly varying function.

4. The system of claim 1, wherein said means for calculating comprises means for calculating a linearly varying volume ramp function as a function of one or more maximum volumes associated with the previously-processed result buffers.

5. The system of claim 1, wherein said means for calculating comprises means for calculating the volume ramp function to have start and stop values each of which being calculated based upon different groups of previously-processed result buffers.

6. The system of claim 5, wherein said different groups can have overlapping result buffers.

7. The system of claim 5, wherein said means for processing of the combined digital audio signals comprises means for dividing the combined digital audio signal by the volume ramp function.

8. The system of claim 7, wherein the volume ramp function varies linearly between the start and stop values.

9. The system of claim 1, wherein said means for providing at least some bits comprises means for selecting a predetermined number of bits from the processed result signal.

10. The system of claim 1, wherein said means for providing at least some bits comprises means for selecting predetermined bits from the processed result signal.

11. A computing device comprising:

one or more processors;

one or more computer-readable media;

code means embodied on the one or more computer-readable media which, when executed by the one or more processors, cause the one or more processors to;

process multiple result buffers by receiving multiple digital audio signals, providing portions of each of the digital audio signals into individual multi-bit input buffers, and combining the contents of the input buffers in a result buffer to provide a mixed audio signal;

calculate a volume ramp function for a current result buffer as a function of one or more volumes associated with multiple previously-processed result buffers;

combine multiple digital audio signals;

process the combined digital audio signals with the volume ramp function to provide a processed result signal; and

provide at least some bits from the processed result signal into a result buffer to provide a mixed audio signal.

12. The computing device of claim 11, wherein said code means calculates the volume ramp function as a function of one or more maximum volumes associated with the previously-processed result buffers.

13. The computing device of claim 11, wherein said code means calculates the volume ramp function as a linearly varying function.

14. The computing device of claim 11, wherein said code means calculates a linearly varying volume ramp function as a function of one or more maximum volumes associated with the previously-processed result buffers.

15. The computing device of claim 11, wherein said code means calculates the volume ramp function to have start and stop values each of which being calculated based upon different groups of previously-processed result buffers.

16. The computing device of claim 15, wherein said different groups can have overlapping result buffers.

17. The computing device of claim 15, wherein said code means processes the combined digital audio signals by dividing the combined digital audio signal by the volume ramp function.

18. The computing device of claim 17, wherein the volume ramp function varies linearly between the start and stop values.

19. The computing device of claim 11, wherein said code means provides at least some bits by selecting a predetermined number of bits from the processed result signal.

20. The computing device of claim 11, wherein said code means provides at least some bits comprises selecting predetermined bits from the processed result signal.