Video Latency Measurement Using Reflected Light Signals
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Solution Overview
Problem
Current methods for synchronizing image and sound signals from independent video and audio playback equipment are complex, expensive, and often require user interaction or external equipment, with optional CEC functions being rarely available.
Innovation Solution
A method using a photosensitive sensor in the decoder equipment to measure video latency by emitting light test signals and analyzing reflected signals, allowing for automatic and cost-effective synchronization without requiring user interaction or external equipment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If external audio/video acquisition equipment is used to measure video latency, then measurement precision can be improved, but device complexity and cost increase
Solution Approach 1:
The decoder equipment uses its own built-in photosensitive sensor to measure video latency, eliminating the need for external measurement equipment. The system performs self-diagnosis by having the sensor detect light from the video playback equipment's screen, automatically obtaining latency measurements without user intervention or additional devices.
Solution Approach 2:
The photosensitive sensor in the decoder equipment serves multiple functions: it is used for both decoding operations and video latency measurement. This multi-functional approach eliminates the need for dedicated external measurement equipment, reducing system complexity and cost while maintaining measurement capability.
2Ease of operation
If CEC lip-sync function is used to obtain video latency information, then measurement simplicity is improved, but reliability deteriorates due to optional implementation
Solution Approach 1:
The patent replaces the CEC communication-based lip-sync function with a direct optical measurement approach. Instead of relying on software/protocol-based CEC signals, the photosensitive sensor directly detects light from the screen to measure latency, providing a more reliable and universally applicable solution that does not depend on optional CEC implementation.
3Measurement precision
If the photosensitive sensor is positioned to directly face the screen, then measurement precision is improved, but ease of operation deteriorates due to positioning requirements
Solution Approach 1:
The patent introduces reflected light as an intermediary between the screen and the photosensitive sensor. Instead of requiring direct line-of-sight detection, the sensor detects light that has reflected off surrounding surfaces, allowing measurement without precise positioning. This intermediary approach maintains measurement capability while eliminating positioning constraints.
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
Enables simple, automatic, and cost-effective measurement of video latency, facilitating synchronization between video and audio playback equipment without additional hardware modifications or user intervention.
Implementation Method 1
using the photosensitive sensor to acquire captured light signals including received light test signals resulting from the emitted light test signals being reflected on at least one surface of surroundings of the video playback equipment
Data Source
AI summary
A measurement method for measuring video latency induced by a piece of video playback equipment that is connected to a piece of decoder equipment having a photosensitive sensor incorporated therein, the method including the steps of: causing a screen of the video playback equipment to generate emitted light test signals; using the photosensitive sensor to acquire captured light signals including received light test signals resulting from the emitted light test signals being reflected on at least one surface of surroundings of the video playback equipment; acquiring measurement signals produced by the photosensitive sensor from the captured light signals, and analyzing the measurement signals in order to obtain a video latency measurement.