Audio Fingerprint Synchronization for Multichannel Extension Data

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Solution Overview

Problem

Existing audio multichannel technologies face challenges in achieving accurate synchronization of multi-channel extension data with audio signals, leading to quality losses due to time offsets and unpredictable delay compensation, especially in digital broadcasting systems with analog conversions.

Innovation Solution

The implementation of block-based fingerprinting technology, where block division information is embedded in the audio signal or multi-channel extension data, allowing for sample-accurate synchronization by correlating reference and test fingerprints, ensuring that multi-channel extension data is aligned with the corresponding audio signal blocks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multi-channel extension data is transmitted separately from the audio signal, then backwards compatibility is maintained and transmission flexibility is improved, but synchronization accuracy deteriorates due to unpredictable time offsets

Engineering Contradiction:
Improvetransmission flexibilityVSAvoidsynchronization accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by embedding block division information and reference fingerprints into the audio signal before transmission. This allows the receiver to prepare synchronization data in advance, enabling accurate alignment when the multi-channel extension data arrives separately. The reference fingerprints are calculated and stored ahead of time, so when needed for synchronization, they are already ready for immediate correlation with the received audio signal.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses fingerprints as an intermediary element that bridges the audio signal and the multi-channel extension data. These fingerprints serve as a common reference that both the audio signal and extension data can be correlated against, enabling precise synchronization without requiring the data to be transmitted together. The intermediary fingerprint allows independent transmission paths while maintaining temporal alignment.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If analog-to-digital conversions are performed in the transmission chain, then compatibility with existing infrastructure is maintained, but delay compensation reliability deteriorates due to unpredictable conversion delays

Engineering Contradiction:
Improveinfrastructure compatibilityVSAvoiddelay compensation reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent implements feedback by using the actual received audio signal to generate test fingerprints that are correlated with the reference fingerprints. This closed-loop approach allows the system to measure the actual delay introduced by analog conversions and automatically compensate for it. The correlation process provides feedback about the synchronization status, enabling dynamic adjustment of delay compensation regardless of unpredictable conversion delays in the transmission chain.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If block-based fingerprinting is implemented for synchronization, then synchronization precision is improved to sample-accurate level, but device complexity increases due to fingerprint calculation and correlation processing

Engineering Contradiction:
Improvesynchronization precisionVSAvoidprocessing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the audio signal into blocks and calculating fingerprints for each block individually. This segmentation allows the synchronization process to work with manageable units rather than processing the entire audio signal at once. The block-based approach reduces computational complexity by localizing the fingerprint calculation and correlation operations to specific time segments, making the overall process more efficient despite the increased precision requirements.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2240929B1Device and method for synchronizing multi-channel expansion data with an audio signal and for processing said audio signal
Publication Date: 2014.12.24 FRAUNHOFER GESELLSCHAFT ZUR FORDERUNG DER ANGEWANDTEN FORSCHUNG EV
  • EP2240929B1 patent drawingFigure 1
  • EP2240929B1 patent drawingFigure 2
  • EP2240929B1 patent drawingFigure 3A~3B

AI summary

In order to synchronize multi-channel expansion data (132) with an audio signal (114), wherein the audio signal comprises a piece of block allocation information and the multi-channel expansion data has reference audio signal fingerprint information, the block allocation information (302) is detected in the audio signal (302) by means of a block detector (300). Subsequently a block allocation of the audio signal is carried out according to the block allocation information (302) by means of a fingerprint calculator (304) in order to obtain a sequence of test audio signal fingerprints (306). Furthermore, a sequence of reference audio signal fingerprints is extracted from the reference audio signal fingerprint information of the multi-channel expansion data (132). The two sequences of fingerprints are correlated in order to obtain a correlation result, by means of which a compensator (316) is activated in order to reduce or eliminate a time offset between the multi-channel expansion data (132) and the audio signal (114).