Audiovisual Synchronization via Dual-Path Network Timing

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Solution Overview

Problem

Existing technologies for automatic performance systems fail to ensure synchronization with distributed video due to significant communication delays, particularly when using a moving image distribution server, leading to improper clock correction at the receiving-side system.

Innovation Solution

The system employs a dual-path communication approach, where performance data is transmitted directly between the transmitting-side and receiving-side systems, while synchronization signals are transmitted through a moving image distribution server, allowing for independent delay management and ensuring synchronization by using a synchronization signal with a time code that corrects the internal clock of the receiving-side system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the click signal and click time data are transmitted through separate transmission systems, then the transmitting-side system can simultaneously transmit the click generation time and click signal, but the relative delay between the click signal and click time data at the receiving-side system is not considered, leading to improper clock correction when communication delay is large

Engineering Contradiction:
Improvetransmission efficiencyVSAvoidtime synchronization accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent introduces a moving image distribution server as an intermediary to receive both the click signal and click time data, and then distribute them to multiple automatic performance devices. This mediator ensures that all devices receive synchronized time information through a centralized coordination point, resolving the timing discrepancies caused by direct separate transmissions.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system implements a feedback mechanism where the receiving-side system measures the actual delay between receiving the click signal and click time data, then uses this measured delay information to correct its internal clock. This feedback loop ensures accurate time synchronization despite communication delays.

Inventive Principle:
Principle #23Feedback

2Reliability

If the click signal and click time data are transmitted through the same transmission path, then the transmission delay is consistent, but the system cannot suppress the influence of communication path state when using a moving image distribution server

Engineering Contradiction:
Improvetransmission reliabilityVSAvoidcommunication path flexibility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent segments the transmission path into two independent channels: one for clicking signals and another for time data, both passing through the moving image distribution server. This segmentation allows the system to handle different types of data through separate paths while maintaining synchronization through the server's coordination, thus suppressing the influence of communication path state variations.

Inventive Principle:
Principle #1Segmentation

3Adaptability or versatility

If multiple automatic performance devices receive distributed video through a moving image distribution server, then video distribution is achieved, but the communication delay through the server affects the synchronization accuracy of automatic performances

Engineering Contradiction:
Improvevideo distribution capabilityVSAvoidsynchronization accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The system performs preliminary measurement of the communication delay between the moving image distribution server and each automatic performance device. Based on these pre-measured delay values, the system pre-calculates and applies appropriate time corrections to ensure that all devices synchronize their automatic performances accurately, compensating for the inherent communication delays.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2665057B1Audiovisual synchronisation of Network Musical Performance
Publication Date: 2016.04.27 YAMAHA CORP
  • EP2665057B1 patent drawingFigure 1
  • EP2665057B1 patent drawingFigure 2
  • EP2665057B1 patent drawingFigure 3

AI summary

The present invention carries out automatic performances in synchronization with distributed video at a plurality of automatic performance devices while suppressing the influence of the state of the communication path passing through a moving image distribution server. Mutually different instrument IDs are allocated to automatic performance pianos (30a, 30b) which are any one of music IDs of instrument terminals which are connected via a network. The automatic performance pianos (30a, 30b) receive performance data having the combination of performance information and date and time information indicating the date and time when the performance which the performance information denotes is carried out, from a server device (20) without passing through a moving image distribution server (40). The automatic performance pianos (30a, 30b) receive a synchronization signal from the moving image distribution server (40) and reproduce the performance information which is synchronized with the distributed video at the time when the synchronization signal is distributed, on the basis of the received performance data, at a timing corresponding to the date and time indicated by the the performance data including the instrument ID which is shared with the device itsself and the date and time indicated by the synchronization signal.