Audio Bitstream Control Segment Disturbance Reduction

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Solution Overview

Problem

Existing audio systems face disturbances due to control messages embedded in bitstreams, which can result in undesirable audio artifacts like 'clicking' sounds or distortions, particularly when control bits are processed as audio data.

Innovation Solution

The proposed solution involves encoding control messages within an audio system by generating a control segment with a preamble and control bits, inserting it into a bitstream, and using an audio digital-to-analog converter to process the bitstream while altering the oversampling frequency to conceal control bits outside the audible band, or generating an audio sequence to replace control bits, thereby minimizing audio disturbances.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If control messages are embedded in the audio bitstream, then device communication and control functionality are improved, but audio quality deteriorates due to disturbances and artifacts

Engineering Contradiction:
Improvecontrol functionalityVSAvoidaudio disturbances
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts control messages from the audio bitstream by detecting them as separate entities and removing them before audio conversion. The system identifies control messages through pattern recognition (detecting specific bit patterns that differ from audio data) and excises them from the bitstream, preventing them from being processed as audio and causing disturbances.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces an intermediary processing stage between the audio receiver and the digital-to-analog converter. This intermediary component analyzes the bitstream, identifies control messages, and selectively removes or replaces them before the signal reaches the audio conversion stage, thereby protecting the audio output from control message disturbances.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If control bits are processed as audio data, then signal transmission efficiency is improved, but audio output quality worsens due to clicking sounds and distortions

Engineering Contradiction:
Improvesignal transmission efficiencyVSAvoidaudio output quality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by detecting and removing control messages from the bitstream before the digital-to-analog conversion process. By performing this extraction in advance, the system prevents control bits from being misinterpreted as audio data during conversion, thereby avoiding clicking sounds and distortions in the audio output.

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If control segments are inserted into the audio bitstream, then device control capability is improved, but signal fidelity deteriorates due to audio artifacts

Engineering Contradiction:
Improvedevice control capabilityVSAvoidsignal fidelity
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent extracts control segments from the audio bitstream by identifying their characteristic patterns and removing them before audio conversion. This extraction process separates control functionality from audio signal transmission, maintaining both control capability and audio fidelity without the interference of control segments in the audio output.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP2581903B1Systems and methods for reducing audio disturbance associated with control messages in a bitstream
Publication Date: 2017.08.23 BLACKBERRY LTD
  • EP2581903B1 patent drawingFigure 1
  • EP2581903B1 patent drawingFigure 2
  • EP2581903B1 patent drawingFigure 3

AI summary

The embodiments described herein are directed to systems and methods for transmitting audio data and control segment in a single bitstream and reducing audio disturbance associated with the control segment when the bitstream is processed by an audio digital-to-analog converter. The system, according to one aspect, comprises a first audio unit, a transmitter coupled to the first audio unit, a receiver coupled to the transmitter, a second audio unit coupled to the receiver, a first processor coupled to at least one of the first audio unit and the transmitter, a second processor coupled to the second audio unit and the receiver, and an audio digital-to-analog converter connected to the second processor. The first processor is configured to convert audio data associated with audio content to a bitstream comprising audio bits associated with the audio content, receive a control command selected from a plurality of control commands, in response, generate a control segment comprising a preamble and control bits associated with the control command, insert the control segment to the bitstream, and transmit the bitstream to the second audio unit using the transmitter. At least one of the first processor and transmitter is configured to change the oversampling frequency to a selected value while the control segment is being transmitted to generate sufficient bandwidth to send the control segment concurrently with the audio data.