Audio-Video Synchronicity Measurement via Optical Signal Embedding

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Solution Overview

Problem

Existing methods for determining the synchronicity of audio and video signals in transmission formats like OTT are complex due to the need for shared knowledge of audio and video events on the receiving side, especially when using off-the-shelf components like mobile phones, which are difficult to modify for measurement purposes.

Innovation Solution

A measuring system that uses a camera and sound signal input port with an optical element to generate an optical signal from the sound signal, allowing synchronicity determination without additional information, and includes a synchronicity analyser to automatically measure the time-delay between audio and video signals, reducing measurement complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If knowledge of audio and video events is required on the receiving side to determine synchronicity, then measurement accuracy can be achieved, but measurement complexity increases significantly

Engineering Contradiction:
Improvesynchronicity measurement accuracyVSAvoidmeasurement system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by embedding synchronization information (optical signal) into the transmitted data stream before transmission. This allows the receiving side to perform measurements without requiring prior knowledge or complex preprocessing, as the reference signal is already available in the transmitted data

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces an optical signal as an intermediary that carries synchronization information from the transmitting side to the receiving side. This intermediary enables the measurement of audio-video synchronicity without requiring direct access to internal signal processing events, thereby reducing measurement complexity while maintaining accuracy

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If off-the-shelf components like mobile phones are used for measurement, then device availability improves, but ease of operation deteriorates due to difficulty in modification

Engineering Contradiction:
Improvedevice availabilityVSAvoidease of modification
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent applies universality by designing a measurement system that works with standard off-the-shelf devices (mobile phones, tablets, computers) that already have cameras and microphones. The system uses these existing components for their intended purposes while simultaneously enabling synchronicity measurement, eliminating the need for specialized modified hardware

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent enables self-service by allowing standard devices to perform their normal functions (recording audio and video) while automatically capturing the embedded optical synchronization signal. The devices serve themselves for measurement purposes without requiring external modification or specialized configuration

Inventive Principle:
Principle #25Self-service

3Adaptability or versatility

If audio and video signals are transmitted through different data connections with different priorities, then transmission flexibility improves, but synchronicity reliability deteriorates

Engineering Contradiction:
Improvetransmission flexibilityVSAvoidsynchronicity reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent introduces an optical signal as an intermediary that travels alongside the audio and video signals through the same transmission channel. This intermediary carries timing information that enables synchronization measurement even when audio and video packets experience different delays due to priority handling or routing differences

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent implements feedback by measuring the time delay between the optical signal (which represents the original timing reference) and the actual audio/video signals after transmission. This feedback information can be used to detect and compensate for desynchronization caused by different transmission priorities or paths

Inventive Principle:
Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach simplifies the measurement of audio and video synchronicity by sharing information between sound and optical signals, enabling one-sided measurements with reduced effort and flexibility across various communication devices.

Implementation Method 1

an optical element, which is configured to generate an optical signal based on the sound signal or based on a signal, the sound signal is derived from

Methodology Applied
Scientific EffectOptoacoustic Effect: Photoacoustic Effect

Data Source

PatentEP4203470A1System and method for evaluation of audio-video desynchronization
Publication Date: 2023.06.28 ROHDE & SCHWARZ GMBH & CO KG
  • EP4203470A1 patent drawingFigure 1
  • EP4203470A1 patent drawingFigure 2
  • EP4203470A1 patent drawingFigure 3

AI summary

A measuring system (1) is provided. The measuring system (1) comprises a first terminal (3), which in turn comprises a camera (30), and a sound signal input port (31). Moreover, the measuring system (1) comprises a transmission side device (2), which in turn comprises an acoustical element (22), configured to input a sound signal (200) into the sound signal input port (31) of the first terminal (3). The transmission side device (2) moreover comprises an optical element (20), which is configured to generate an optical signal (201) based on the sound signal (200) or based on a signal, the sound signal (200) is derived from, and input the resulting optical signal (201) into the camera (30).