Host Device Synchronization for Multi-Client Content Playback

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Solution Overview

Problem

Coordinating the playback of content data, such as movies, among multiple information processing devices connected over a network is challenging, especially for friends at remote locations who want to watch a movie together, as synchronizing playback across different devices with varying download speeds and communication environments is difficult.

Innovation Solution

An information processing system comprising a content distribution server, a host device, and client devices connected via a network, where the host device controls playback by acquiring and communicating download status information from client devices to ensure synchronized playback, using mechanisms like progressive download and peer-to-peer models to manage content distribution and playback.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If multiple information processing devices download and playback content data independently, then each device can operate autonomously, but playback synchronization between devices becomes difficult to achieve

Engineering Contradiction:
Improveautonomous operationVSAvoidplayback synchronization
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The invention introduces a host device as an intermediary that coordinates playback among multiple client devices. The host device receives playback status information from all client devices, determines a common playback position, and distributes control information to synchronize playback across all devices, thus resolving the contradiction between autonomous operation and synchronized playback.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the system waits for all devices to finish downloading before starting playback, then playback synchronization is achieved, but the time required for content delivery increases

Engineering Contradiction:
Improveplayback synchronizationVSAvoidcontent delivery time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system performs preliminary actions by having all client devices download the complete content data before playback begins. The host device then determines a common playback position based on each device's download status, and distributes control information to synchronize playback. This allows playback to start simultaneously on all devices without waiting for the slowest device to finish downloading, thus reducing content delivery time while maintaining synchronization.

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If devices with different download speeds are used, then system adaptability increases, but maintaining synchronized playback becomes more difficult

Engineering Contradiction:
Improvedevice compatibilityVSAvoidplayback synchronization
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The invention applies local quality by allowing each client device to operate according to its own download speed and capabilities, while the host device determines a common playback position that accommodates all devices. Each device plays back from its local content data at its own pace, but the host coordinates to ensure synchronized playback starts and progresses, thus maintaining synchronization despite different download speeds.

Inventive Principle:
Principle #3Local quality

4Reliability

If the host device controls playback position for all devices, then playback synchronization is improved, but communication overhead between devices increases

Engineering Contradiction:
Improveplayback synchronizationVSAvoidcommunication overhead
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The system implements self-service by having each client device autonomously determine its own playback status and send this information to the host device. The host device then determines the common playback position based on this self-reported information and sends control instructions back to the devices. This reduces communication overhead compared to continuous polling or centralized control, as devices only communicate when needed to update their status or receive synchronization commands.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP2328349B1Information processing system and information processing device
Publication Date: 2019.07.03 SONY INTERACTIVE ENTERTAINMENT LLC
  • EP2328349B1 patent drawingFigure 1
  • EP2328349B1 patent drawingFigure 2A~2B
  • EP2328349B1 patent drawingFigure 3

AI summary

The time of a host device (10) is synchronized with the time of a client device (18). The host device (10) and the client device (18) progressively download content data from a content distribution server (16). The host device (10) controls the reproduction process of the host device (10) to be synchronized with that of the client device (18) in accordance with the download state in the host device (10) and the client device (18).