Method and system for processing high quality audio in a hardware audio codec for audio transmission

• US 8,909,361 B2
• Filed: 10/09/2008
• Issued: 12/09/2014
• Est. Priority Date: 06/19/2008
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Kong, Hongwei, Sutharsan, Thirunathan
• Primary Examiner(s): MCCORD, PAUL C
• Application Number:
  US12/248,608
• Publication Number:
  US 20100057228A1
• Time in Patent Office: 2,252 Days
• Field of Search: 700/94
• US Class Current: 700/94
• CPC Class Codes: G10L 19/02 using spectral analysis, e.g. transform vocoders or subband vocoders
• CPC Class Codes: H03H 17/0671 Cascaded integrator-comb [CIC] filters

Abstract

Aspects of a method and/or system for processing high quality audio in a hardware audio CODEC for audio transmission are provided. In this regard, an audio signal may be down-sampled via a cascaded plurality of filters and sample rate converters in the hardware audio CODEC. Additionally, a portion of each sample of the audio signal may be selected based on an origin of the audio signal. The selected portion of each sample of the audio signal may comprise 16 or 18 bits. The selected portion may be determined based on a type, a class, a manufacturer identifier, and/or a model identifier of the origin the audio signal. Coefficients of the filters may be configured based on the origin of the audio signal. One or more of the filters may comprise one or more cascaded biquads. The sample rate converters may comprise one or more CIC decimation filters.

Claims

1. A method for processing an audio signal in an audio processing system, the method comprising:

determining, from a plurality of audio input devices including a first audio input device and a second audio input device, an originating audio input device that originated the audio signal;

determining, based on the originating audio input device, a path of the audio processing system to process the audio signal, wherein the path is a dual voice path or a high quality audio path;

configuring a filter in the path to select a window of bits from a plurality of sample bits of a sample of the audio signal, wherein a size and a position of the window of bits is determined based on the originating audio input device;

adjusting, based on a sampling frequency of the audio signal, a filtering and decimation module of the filter to configure a decimation ratio of the filter; and

adjusting a coefficient of the filter based on the originating audio input device and the sampling frequency.

31. The method of claim 1, wherein determining the originating audio input device comprises:

determining a type, a class, a manufacturer identifier, and a model identifier corresponding to the audio signal.

2. A system for processing a plurality of audio signals, the system comprising:

a dual voice audio processing path coupled to an audio interface;

a high quality audio processing path; and

a processor coupled to the dual voice audio processing path and the high quality audio processing path, wherein the processor is configured to;

determine, from a plurality of audio input devices including a first audio input device and a second audio input device, an originating audio input device that originated an audio signal in the plurality of audio signals,

configure a filter in the dual voice audio processing path or the high quality audio processing path to select a window of bits from a plurality of sample bits of a sample of the audio signal, wherein a size and a position of the window of bits is determined based on the originating audio input device,

adjust, based on a sampling frequency of the audio signal, a filtering and decimation module of the filter to configure a decimation ratio of the filter, and

adjust a coefficient of the filter based on the originating audio input device and the sampling frequency.

3. The system according to claim 2, wherein the filter is configured to select the window of bits based on a type, a class, a manufacturer identifier, and/or a model identifier corresponding to the originating audio input device.

4. The system according to claim 3, wherein the type comprises one of a digital microphone, an analog microphone, and a line-in jack.

5. The system according to claim 3, wherein the class indicates at least one of a speed and a power level corresponding to the originating audio input device.

6. The system according to claim 3, wherein the class indicates a speed associated with the originating audio input device.

7. The system according to claim 3, wherein the class indicates a dynamic range associated with the originating audio input device.

8. The system according to claim 3, wherein the class indicates a signal bandwidth associated with the originating audio input device.

29. The system of claim 2, wherein the dual voice path comprises a repeat block, and wherein the repeat block is configured to upconvert a received signal for communication to the audio interface.

30. The system of claim 2, wherein the dual voice path comprises a plurality of decimation filters, and wherein each decimation filter in the plurality of decimation filters is coupled to an input of a repeat block.

9. An audio processing system configured to receive a plurality of audio signals from a plurality of audio input devices including a first audio input device and a second audio input device, the audio processing system comprising:

a dual voice path coupled to an audio interface, wherein the dual voice path is configured to down-sample the plurality of audio signals to voice band signals;

a high quality audio path configured to process high quality audio signals in the plurality of audio signals;

a loopback path, wherein the loopback path is configured to provide a plurality of audio output signals to a plurality of audio output devices; and

a processor coupled to the dual voice path, the high quality audio path, and the loopback path, wherein the processor is configured to;

determine, from the plurality of audio input devices, an originating audio input device that originated an audio signal in the plurality of audio signals,

configure a filter in the dual voice path or the high quality audio path to select a window of bits from a plurality of sample bits of a sample of the audio signal, wherein a size and a position of the window of bits is determined based on the originating audio input device,

adjust, based on a sampling frequency of the audio signal, a filtering and decimation module of the filter to configure a decimation ratio of the filter, and

adjust a coefficient of the filter based on the originating audio input device and the sampling frequency.

10. The audio processing system of claim 9, further comprising a sample rate converter coupled to the filter.

11. The audio processing system of claim 9, wherein the processor is configured to:

determine the originating audio input device based on at least one of a type, a class, a manufacturer identifier, and a model identifier corresponding to the originating audio input device.

12. The audio processing system of claim 11, wherein the type comprises one of a digital microphone, an analog microphone, and a line-in jack.

13. The audio processing system of claim 11, wherein the class indicates a speed associated with the originating audio input device.

14. The audio processing system of claim 11, wherein the class indicates a dynamic range associated with the originating audio input device.

15. The audio processing system of claim 11, wherein the class indicates a power level associated with the originating audio input device.

16. The audio processing system of claim 11, wherein the class indicates a signal bandwidth associated with the originating audio input device.

17. The audio processing system of claim 9, wherein the processor is further configured to:

determine a second audio signal;

match voltage, power levels, and/or sampling frequencies of the audio signal and the second audio signal;

determine, from the plurality of audio input devices, a second originating audio input device that originated the second audio signal; and

configure a second filter in the dual voice path or the high quality audio path to select a second window of bits of a second sample of the second audio signal based on the second originating audio input device.

18. The audio processing system of claim 9, wherein the filter comprises a bit select module, and wherein the bit select module is configured to select the window of bits.

19. The audio processing system of claim 9, wherein the filter is configured to select a 17 bit window of bits or a 23 bit window of bits based on whether the filter is included in the dual voice path or the high quality audio path of the audio processing system.

20. The audio processing system of claim 9, wherein a scaling and re-quantization module of the filter comprises:

a plurality of bit shift modules configured to shift the audio signal;

an adder coupled to the plurality of bit shift modules; and

an output bit select module coupled to the adder, wherein the output bit select module is configured to select the window of bits.

21. The audio processing system of claim 9, wherein the dual voice path comprises a first select block, and wherein the high quality audio path comprises a second select block.

22. The audio processing system of claim 9, wherein the dual voice path comprises a first repeat block, and wherein the high quality audio path comprises a second repeat block.

23. The audio processing system of claim 22, wherein the first repeat block is configured to upconvert a received signal for communication to the audio interface.

24. The audio processing system of claim 22, wherein the dual voice path further comprises:

a plurality of decimation filters, wherein an output of each decimation filter in the plurality of decimation filters is communicated to the first repeat block.

25. The audio processing system of claim 22, wherein the second repeat block is a repeat-by-M block.

26. The audio processing system of claim 9, wherein the dual voice path comprises:

a select block;

a decimation filter coupled to an output of the select bloc k;

a repeat block coupled to;

an output of the decimation filter, and

an input of an audio interface; and

an infinite impulse response (IIR) filter coupled to;

an output of the decimation filter, and

an input of a digital signal processor.

27. The audio processing system of claim 9, wherein the high quality audio path comprises:

a select block;

a decimation filter coupled to an output of the select block;

a repeat block coupled to an output of the decimation filter; and

an infinite impulse response (IIR) filter coupled to;

an output of the repeat block, and

an input of a digital signal processor.

28. The audio processing system of claim 9, wherein the loopback path comprises:

a plurality of decimation filters; and

a loopback switch matrix coupled to;

the plurality of decimation filters, and

a plurality of inputs of the plurality of audio output devices.