Facility for simultaneously outputting both a mixed digital audio signal and an unmixed digital audio signal multiple concurrently received streams of digital audio data

• US 6,714,826 B1
• Filed: 03/13/2000
• Issued: 03/30/2004
• Est. Priority Date: 03/13/2000
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Curley, Lawrence D., Driftmyer, James F., Foster, Eric M.
• Primary Examiner(s): Nguyen, Duc
• Assistant Examiner(s): LAO, LUNSEE
• Application Number:
  US09/524,461
• Time in Patent Office: 1,478 Days
• Field of Search: 700/94, 381/119, 381/27, 369/4, 725/131, 725/133, 725/139, 725/141, 725/151, 725/153, 348/565, 348/484, 348/485
• US Class Current: 700/94
• CPC Class Codes: H04H 60/04 Studio equipment; Interconnection of studios

Abstract

A processing facility is provided for simultaneously receiving multiple streams of digital audio data and based thereon concurrently outputting both an unmixed digital audio signal and a mixed digital audio signal. The processing facility can be implemented, for example, within an audio decoder of a set top box. The facility includes receiving a first stream of digital audio data and a second stream of digital audio data, and outputting the first stream of digital audio data as an unmixed digital audio signal. Simultaneous therewith, the first stream of digital audio data and the second stream of digital audio data are digitally mixed and outputted as a mixed digital audio signal. If necessary, the second stream of digital audio data is redigitized based on a sample frequency of the first stream of digital audio data, and either or both the first stream and second stream of digital audio data are decoded prior to mixing.

Claims

1. A method for processing digital audio data, said method comprising:

receiving a first stream of digital audio data from a first audio source and a second stream of digital audio data from a second audio source, wherein said first audio source and said second audio source comprise separate and independent audio sources;

outputting the first stream of digital audio data as an unmixed digital audio signal;

digitally mixing the first stream of digital audio data and the second stream of digital audio data and outputting based thereon a mixed digital audio signal, wherein said mixed digital audio signal is output concurrent with output of said unmixed digital audio signal; and

resampling said second stream of digital audio data based on a sample frequency of said first stream of digital audio data when a sample frequency of said second stream differs from the sample frequency of said first stream.

2. The method of claim 1, wherein said receiving comprises concurrently receiving said first and second streams of digital audio data through dedicated real time interfaces.

3. The method of claim 1, further comprising implementing said method by a signal processor of an audio decoder, and wherein said method further comprises decoding at least one of the first stream of digital audio data and the second stream of digital audio data prior to said digitally mixing.

4. The method of claim 3, wherein said decoding comprises decoding the second stream of digital audio data prior to resampling thereof based on a sample frequency of the first stream of digital audio data.

5. The method of claim 1, further comprising setting a first volume of the first stream of digital audio data and a second volume of the second stream of digital audio data to be digitally mixed.

6. The method of claim 5, wherein said digitally mixing comprises ramping the first volume of the first stream of digital audio data and the second volume of the second stream of digital audio data, wherein the mixed digital audio signal comprises an operator controlled volume.

7. The method of claim 6, wherein said outputting of said unmixed digital audio signal comprises outputting said first stream of digital audio data to an unmixed output buffer for forwarding to a recording device, and wherein said concurrent outputting of said mixed digital audio signal comprises outputting said mixed digital audio signal to a mixed output buffer for driving at least one speaker.

8. The method of claim 6, further comprising implementing said method within an audio decoder of a set top box.

9. The method of claim 6, further comprising setting an output volume of said unmixed stream of digital audio data, wherein said output volume can comprise a different volume than said first volume of the first stream of digital audio data to be digitally mixed with the second stream of digital audio data.

10. The method of claim 1, further comprising concurrently retrieving the first stream of digital audio data and the second stream of digital audio data from a memory medium, wherein the first stream of digital audio data and the second stream of digital audio data each have a starting address and a set length within said memory medium.

11. The method of claim 10, wherein said concurrently retrieving comprises employing primary clip controls to retrieve the first stream of digital audio data and simultaneously employing separate, secondary clip controls to retrieve the second stream of digital audio data.

12. The method of claim 11, wherein said concurrently retrieving comprises retrieving the first stream of digital audio data through a first clip mode interface, and retrieving the second stream of digital audio data through a second clip mode interface.

13. The method of claim 11, further comprising implementing said method by a signal processor of an audio decoder, and wherein said primary clip controls and secondary clip controls are externally loaded into said audio decoder for use in retrieving the first stream of digital audio data and the second stream of digital audio data from said memory medium.

14. The method of claim 1, wherein said outputting of the first stream of digital audio data comprises outputting said unmixed digital audio data to an unmixed output buffer, and wherein said outputting of said mixed digital audio signal comprises simultaneously outputting said mixed digital audio signal to a mixed output buffer.

15. The method of claim 1, wherein said outputting of the first stream of digital audio data comprises outputting the first stream of digital audio data to drive at least one first speaker, and said outputting of the mixed digital audio signal comprises simultaneously outputting the mixed digital audio signal to drive at least one second speaker, wherein the at least one first and at least one second speakers reside in a common area and wherein said unmixed digital audio signal and said mixed digital audio signal are simultaneously audible within the common area.

16. The method of claim 1, further comprising receiving n additional streams of digital audio data, wherein n³1, and wherein said digitally mixing comprises digitally mixing the first stream of digital audio data, the second stream of digital audio data and the n additional streams of digital audio data and outputting based thereon said mixed digital audio signal.

17. A system for processing digital audio data, said system comprising:

means for receiving a first stream of digital audio data from a first audio source and a second stream of digital audio data from a second audio source, wherein said first audio source and said second audio source comprise separate and independent audio sources;

means for outputting the first stream of digital audio data as an unmixed digital audio signal;

means for digitally mixing the first stream of digital audio data and the second stream of digital audio data and outputting based thereon a mixed digital audio signal, wherein said mixed digital audio signal is output concurrent with output of said unmixed digital audio signal; and

means for resampling said second stream of digital audio data based on a sample frequency of said first stream of digital audio data when a sample frequency of said second stream differs from the sample frequency of said first stream.

18. The system of claim 17, wherein said means for receiving comprises means for concurrently receiving said first and second streams of digital audio data through dedicated real time interfaces.

19. The system of claim 17, wherein said system comprises a signal processor of an audio decoder, and wherein said system further comprises means for decoding at least one of the first stream of digital audio data and the second stream of digital audio data prior to said digitally mixing.

20. The system of claim 19, wherein said means for decoding comprises means for decoding the second stream of digital audio data prior to resampling thereof based on a sample frequency of the first stream of digital audio data.

21. The system of claim 17, further comprising means for setting a first volume of the first stream of digital audio data and a second volume of the second stream of digital audio data to be digitally mixed.

22. The system of claim 21, wherein said means for digitally mixing comprises means for ramping the first volume of the first stream of digital audio data and the second volume of the second stream of digital audio data, wherein the mixed digital audio signal comprises an operator controlled volume.

23. The system of claim 22, wherein said means for outputting of said unmixed digital audio signal comprises means for outputting said first stream of digital audio data to an unmixed output buffer for forwarding to a recording device, and wherein said means for concurrent outputting of said mixed digital audio signal comprises means for outputting said mixed digital audio signal to a mixed output buffer for driving at least one speaker.

24. The system of claim 22, further comprising means for implementing said system within an audio decoder of a set top box.

25. The system of claim 22, further comprising means for setting an output volume of said unmixed stream of digital audio data, wherein said output volume can comprise a different volume than said first volume of the first stream of digital audio data to be digitally mixed with the second stream of digital audio data.

26. The system of claim 17, further comprising means for concurrently retrieving the first stream of digital audio data and the second stream of digital audio data from a memory medium, wherein the first stream of digital audio data and the second stream of digital audio data each have a starting address and a set length within said memory medium.

27. The system of claim 26, wherein said means for concurrently retrieving comprises means for employing primary clip controls to retrieve the first stream of digital audio data and simultaneously employing separate, secondary clip controls to retrieve the second stream of digital audio data.

28. The system of claim 27, wherein said means for concurrently retrieving comprises means for retrieving the first stream of digital audio data through a first clip mode interface, and for retrieving the second stream of digital audio data through a second clip mode interface.

29. The system of claim 27, wherein said system comprises a signal processor of an audio decoder, and wherein said primary clip controls and secondary clip controls are externally loaded into said audio decoder for use in retrieving the first stream of digital audio data and the second stream of digital audio data from said memory medium.

30. The system of claim 17, wherein said means for outputting of the first stream of digital audio data comprises means for outputting said unmixed digital audio data to an unmixed output buffer, and wherein said means for outputting of said mixed digital audio signal comprises means for simultaneously outputting said mixed digital audio signal to a mixed output buffer.

31. The system of claim 17, wherein said means for outputting of the first stream of digital audio data comprises means for outputting the first stream of digital audio data to drive at least one first speaker, and said means for outputting of the mixed digital audio signal comprises means for simultaneously outputting the mixed digital audio signal to drive at least one second speaker, wherein the at least one first and at least one second speakers reside in a common area and wherein said unmixed digital audio signal and said mixed digital audio signal are simultaneously audible within the common area.

32. The system of claim 17, further comprising means for receiving n additional streams of digital audio data, wherein n³1, and wherein said means for digitally mixing comprises means for digitally mixing the first stream of digital audio data, the second stream of digital audio data and the n additional streams of digital audio data and for outputting based thereon said mixed digital audio signal.

33. A system for processing digital audio data, said system comprising:

an audio digital signal processor adapted to receive a first stream of digital audio data from a first audio source and a second stream of digital audio data from a second audio source, wherein said first audio source and said second audio source comprise separate and independent audio sources, and output therefrom the first stream of digital audio data as an unmixed digital audio signal;

wherein the audio digital signal processor is further adapted to digitally mix the first stream of digital audio data and the second stream of digital audio data and output based thereon a mixed digital audio signal, wherein the mixed digital audio signal is output concurrent with output of the unmixed digital audio signal; and

wherein the audio digital signal processor is further adapted to resample said second stream of digital audio data based on a sample frequency of said first stream of digital audio data when a sample frequency of said second stream differs from the sample frequency of said first stream.

34. At least one program storage device readable by a machine, tangibly embodying at least one program of instructions executable by the machine to perform a method for processing digital audio data, said method comprising:

receiving a first stream of digital audio data from a first audio source and a second stream of digital audio data from a second audio source wherein said first audio source and said second audio source comprise separate and independent audio sources;

outputting the first stream of digital audio data as an unmixed digital audio signal;

digitally mixing the first stream of digital audio data and the second stream of digital audio data and outputting based thereon a mixed digital audio signal, wherein said mixed digital audio signal is output concurrent with output of said unmixed digital audio signal; and

resampling said second stream of digital audio data based on a sample frequency of said first stream of digital audio data when a sample frequency of said second stream differs from the sample frequency of said first stream.

35. The at least one program storage device of claim 34, wherein said receiving comprises concurrently receiving said first and second streams of digital audio data through dedicated real time interfaces.

36. The at least one program storage device of claim 34, further comprising implementing said method by a signal processor of an audio decoder, and wherein said method further comprises decoding at least one of the first stream of digital audio data and the second stream of digital audio data prior to said digitally mixing.

37. The at least one program storage device of claim 36, wherein said decoding comprises decoding the second stream of digital audio data prior to resampling thereof based on a sample frequency of the first stream of digital audio data.

38. The at least one program storage device of claim 34, further comprising setting a first volume of the first stream of digital audio data and a second volume of the second stream of digital audio data to be digitally mixed.

39. The at least one program storage device of claim 38, wherein said digitally mixing comprises ramping the first volume of the first stream of digital audio data and the second volume of the second stream of digital audio data, wherein the mixed digital audio signal comprises an operator controlled volume.

40. The at least one program storage device of claim 39, wherein said outputting of said unmixed digital audio signal comprises outputting said first stream of digital audio data to an unmixed output buffer for forwarding to a recording device, and wherein said concurrent outputting of said mixed digital audio signal comprises outputting said mixed digital audio signal to a mixed output buffer for driving at least one speaker.

41. The at least one program storage device of claim 39, further comprising implementing said method within an audio decoder of a set top box.

42. The at least one program storage device of claim 39, further comprising setting an output volume of said unmixed stream of digital audio data, wherein said output volume can comprise a different volume than said first volume of the first stream of digital audio data to be digitally mixed with the second stream of digital audio data.

43. The at least one program storage device of claim 34, further comprising concurrently retrieving the first stream of digital audio data and the second stream of digital audio data from a memory medium, wherein the first stream of digital audio data and the second stream of digital audio data each have a starting address and a set length within said memory medium.

44. The at least one program storage device of claim 43, wherein said concurrently retrieving comprises employing primary clip controls to retrieve the first stream of digital audio data and simultaneously employing separate, secondary clip controls to retrieve the second stream of digital audio data.

45. The at least one program storage device of claim 44, wherein said concurrently retrieving comprises retrieving the first stream of digital audio data through a first clip mode interface, and retrieving the second stream of digital audio data through a second clip mode interface.

46. The at least one program storage device of claim 44, further comprising implementing said method by a signal processor of an audio decoder, and wherein said primary clip controls and secondary clip controls are externally loaded into said audio decoder for use in retrieving the first stream of digital audio data and the second stream of digital audio data from said memory medium.

47. The at least one program storage device of claim 34, wherein said outputting of the first stream of digital audio data comprises outputting said unmixed digital audio data to an unmixed output buffer, and wherein said outputting of said mixed digital audio signal comprises simultaneously outputting said mixed digital audio signal to a mixed output buffer.

48. The at least one program storage device of claim 34, wherein said outputting of the first stream of digital audio data comprises outputting the first stream of digital audio data to drive at least one first speaker, and said outputting of the mixed digital audio signal comprises simultaneously outputting the mixed digital audio signal to drive at least one second speaker, wherein the at least one first and at least one second speakers reside in a common area and wherein said unmixed digital audio signal and said mixed digital audio signal are simultaneously audible within the common area.

49. The at least one program storage device of claim 34, further comprising receiving n additional streams of digital audio data, wherein n³1, and wherein said digitally mixing comprises digitally mixing the first stream of digital audio data, the second stream of digital audio data and the n additional streams of digital audio data and outputting based thereon said mixed digital audio signal.