Pulse code modulation (PCM) data-marking

Patent metadata

Field	Value
Publication number	US-11050971-B2
Application number	US-201916694362-A
Country	US
Kind code	B2
Filing date	Nov 25, 2019
Priority date	Feb 21, 2017
Publication date	Jun 29, 2021
Grant date	Jun 29, 2021

Abstract

An encoding for data in an audio data stream may be indicated in the data stream using a footer stored in low-order bits of data frames in the audio data stream. When the audio data stream may include either Pulse Code Modulation (PCM) or Direct Stream Digital (DSD) data, PCM data may be marked with a footer to indicate the encoding as PCM. The footer may be a fixed value, an alternating fixed value, a predetermined sequence of values, or a value computed based on the PCM data. Examples of computed values for the footer marker may include an error code, an error correction code (ECC), and a scrambled code.

First claim

What is claimed is:

1. A method, comprising:
receiving an audio signal to encode into an audio data stream; and
encoding the audio signal into a plurality of data frames for the audio data stream, wherein each of the plurality of data frames comprises a footer value in low-order bits of each of the plurality of data frames indicating an encoding of the audio data stream.

2. The method of claim 1 , wherein the step of encoding comprises encoding the footer value that identifies the audio data stream as single-bit data or multi-bit data.

3. The method of claim 1 , wherein the step of encoding comprises encoding the footer value that identifies the audio data stream as direct stream digital (DSD) data or pulse code modulation (PCM) data.

4. The method of claim 1 , wherein the step of encoding comprises encoding a predetermined footer value in the low-order bits, wherein the predetermined footer value indicates the encoding of the audio data stream.

5. The method of claim 1 , wherein the step of encoding comprises encoding a predetermined sequence of footer values in the low-order bits of the plurality of data frames of the audio data stream, wherein the predetermined sequence indicates the encoding of the audio data stream.

6. The method of claim 5 , wherein the step of encoding comprises encoding a predetermined sequence of alternating footer values in the low-order bits of the plurality of data frames of the audio data stream, wherein the predetermined alternating sequence indicates the encoding of the audio data stream.

7. The method of claim 1 , wherein the step of encoding comprises computing a footer value for each frame of the plurality of data frames, wherein the computed footer value is based, at least in part, on the audio signal encoded in each frame.

8. The method of claim 7 , wherein the step of computing comprises computing an error code for each frame of the plurality of data frames.

9. The method of claim 8 , wherein the step of computing comprises computing an error correction code for each frame of the plurality of data frames.

10. The method of claim 8 , wherein the step of computing comprises computing a scramble code for each frame of the plurality of data frames and applying the scramble code to the error code, wherein the scramble code is such that if a frame of the plurality of data frames is reproduced as audio from PCM data, the reproduced audio has low distortion.

11. An apparatus, comprising:
an audio controller configured to perform steps comprising:
receiving an audio signal to encode in an audio data stream; and
encoding the audio signal into a plurality of data frames for the audio data stream, wherein each of the plurality of data frames comprises a footer value in low-order bits of each of the plurality of data frames indicating an encoding of the audio data stream.

12. The apparatus of claim 11 , wherein the step of encoding comprises encoding a footer value that identifies the audio data stream as single-bit data or multi-bit data.

13. The apparatus of claim 11 , wherein the step of encoding comprises encoding a footer value that identifies the audio data stream as direct stream digital (DSD) data or pulse code modulation (PCM) data.

14. The apparatus of claim 11 , wherein the step of encoding comprises encoding a predetermined footer value in the low-order bits, wherein the predetermined footer value indicates the encoding of the audio data stream.

15. The apparatus of claim 11 , wherein the step of encoding comprises encoding a predetermined sequence of footer values in the low-order bits of the plurality of data frames of the audio data stream, wherein the predetermined sequence indicates the encoding of the audio data stream.

16. The apparatus of claim 15 , wherein the step of encoding comprises encoding a predetermined sequence of alternating footer values in the low-order bits of the plurality of data frames of the audio data stream, wherein the predetermined alternating sequence indicates the encoding of the audio data stream.

17. The apparatus of claim 11 , wherein the step of encoding comprises computing a footer value for each frame of the plurality of data frames, wherein the computed footer value is based, at least in part, on the audio signal encoded in each frame.

18. The apparatus of claim 17 , wherein the step of computing comprises computing an error code for each frame of the plurality of data frames.

19. The apparatus of claim 18 , wherein the step of computing comprises computing an error correction code for each frame of the plurality of data frames.

20. The apparatus of claim 17 , wherein the step of computing comprises computing a scramble code for each frame of the plurality of data frames and applying the scramble code to the error code, wherein the scramble code is such that if a frame of the plurality of data frames is reproduced as audio from PCM data the reproduced audio has low distortion.

Assignees

• Cirrus Logic Int Semiconductor Ltd
• Cirrus Logic Inc

Inventors

• Kamkar Shafagh
• Duewer Bruce E
• Hester Dylan A

Classifications

• G10L19/167 Primary

  Audio streaming, i.e. formatting and decoding of an encoded audio signal representation into a data stream for transmission or storage purposes · CPC title

• H04L65/70

  Media network packetisation · CPC title

• G11B20/1876

  Interpolating methods · CPC title

• H04L1/004

  by using forward error control (H04L1/0618 takes precedence; coding, decoding or code conversion, for error detection or correction H03M13/00) · CPC title

• G10L19/005 Primary

  Correction of errors induced by the transmission channel, if related to the coding algorithm · CPC title