Stream Switching via Time Offset Correlation and Rate Control

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Solution Overview

Problem

Existing systems for switching between audio and/or video data streams often result in noticeable time lags and disruptions, such as image and sound dropouts, when switching between different broadcasting networks, leading to an inconvenient user experience.

Innovation Solution

The method involves managing time shifts by pausing or reducing the bit rate of one stream to facilitate seamless switching between data streams, using a device with modules for correlation determination, bit rate reduction, and stream arbitration to synchronize and synchronize the streams, ensuring a transparent or minimally perceptible changeover.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If direct switching between data streams is performed, then switching speed is improved, but user experience deteriorates due to image and sound dropouts

Engineering Contradiction:
Improveswitching speedVSAvoiduser experience
Core Design Contradiction:
SpeedVSEase of operation

Solution Approach 1:

The system performs preliminary actions by pausing the current stream or reducing its bit rate before the actual switch occurs. This preparation allows the second stream to be synchronized and ready, preventing disruptions during the transition and eliminating image/sound dropouts that would otherwise occur with direct switching.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary mechanism (time shift management through pausing or bit rate reduction) between the first and second data streams. This intermediary action mediates the transition by creating a buffer zone that allows synchronization, thereby preventing direct disruption to the user experience while maintaining switching capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If stream synchronization is performed by pausing or reducing bit rate, then user experience is improved with transparent switching, but switching speed deteriorates

Engineering Contradiction:
Improveuser experienceVSAvoidswitching speed
Core Design Contradiction:
Ease of operationVSSpeed

Solution Approach 1:

The system applies partial action by selectively pausing only the necessary portions of the data stream or reducing bit rate temporarily during the transition period. This partial modification is sufficient to achieve synchronization and transparent switching without completely stopping the stream, thereby minimizing the impact on switching speed while maintaining user experience.

Inventive Principle:
Principle #16Partial or excessive action

3Stability of the object's composition

If time shift management is implemented, then stream synchronization is improved, but system complexity increases

Engineering Contradiction:
Improvestream synchronizationVSAvoidsystem complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent implements time shift management by changing parameters of the data stream such as pausing (temporal parameter) or reducing bit rate (data rate parameter). These parameter changes provide a straightforward mechanism for synchronization that avoids complex synchronization protocols or buffer management systems, thereby achieving stream synchronization with relatively simple system architecture.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2932633B1Device and method for switching between a first data stream and a second data stream
Publication Date: 2020.02.05 SAGEMCOM BROADBAND SAS
  • EP2932633B1 patent drawingFigure 1~3
  • EP2932633B1 patent drawingFigure 4

AI summary

A device receives first and second data streams representative of a piece of audio and/or video content. The device is previously configured (400) to broadcast the content from the first stream. Following a command to switch (401) from the first stream to the second stream, the device determines, by correlation (402, 403), a mark in the first stream and in the second stream, and determines (404) a time offset from a piece of timestamp information associated with the mark in each of the first and second streams. Before switching (410), the device: pauses (409) the second stream until the time offset has been absorbed, when the time offset indicates that the first stream is behind schedule; reduces (407) a broadcast rate of the first stream until the time offset has been absorbed, when the time offset indicates that the first stream is ahead of schedule.