Audio Video Stream Synchronous Switching Method

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Solution Overview

Problem

In multimedia communications, especially in television production and broadcasting, synchronization between audio and video streams after switching cannot be ensured due to independent switching of audio and video streams.

Innovation Solution

A method and apparatus for synchronous switching of audio and video streams, where a switching device determines video and audio parameter values based on timestamps and sequence numbers to align switching points, ensuring synchronization by switching packets in the first stream to corresponding packets in the second stream based on these values.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If audio stream and video stream are switched independently, then switching operation is simple, but synchronization between audio and video streams cannot be ensured

Engineering Contradiction:
Improveswitching operationVSAvoidsynchronization
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent merges the switching control of audio and video streams by using a unified switching point determination mechanism. The switching device determines switching points for both audio and video streams based on synchronized timestamps, ensuring that both streams are switched at corresponding time points rather than independently. This combining approach maintains operational simplicity while ensuring synchronization.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent implements a feedback mechanism where the switching device receives timestamps from both audio and video streams, determines switching points based on these timestamps, and uses this information to coordinate the switching of both streams. The timestamp information acts as feedback that enables the device to maintain synchronization while performing switching operations.

Inventive Principle:
Principle #23Feedback

2Device complexity

If switching points are determined independently for audio and video streams, then switching process is simple, but asynchronization occurs after switching

Engineering Contradiction:
Improveswitching processVSAvoidswitching point alignment
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent changes the parameter basis for determining switching points from independent stream parameters to synchronized timestamp parameters. By using timestamps that are correlated between audio and video streams, the device can determine switching points for both streams based on the same time reference, ensuring alignment without significantly increasing process complexity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent performs preliminary determination of switching points based on timestamp analysis before actual switching occurs. The switching device identifies the appropriate switching points in advance by examining timestamp correlations between audio and video streams, ensuring that when switching occurs, both streams are switched at precisely aligned points.

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If audio and video streams are switched separately, then switching control is independent and simple, but pixel missing and overlapping occur

Engineering Contradiction:
Improveswitching controlVSAvoidstream quality
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent combines the switching control mechanism for audio and video streams by using a unified switching point determination process based on timestamps. This ensures that switching operations on both streams are coordinated, preventing pixel missing and overlapping that occur when streams are switched independently at misaligned time points.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent uses timestamp information as feedback to coordinate switching operations. The switching device monitors timestamps from both audio and video streams and uses this feedback to determine when to switch each stream, ensuring that switching occurs at corresponding time points and maintaining stream quality without compromising control simplicity.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3883238B1Method and apparatus for simultaneously switching audio stream and video stream
Publication Date: 2024.04.03 HUAWEI TECH CO LTD
  • EP3883238B1 patent drawingFigure 1~3
  • EP3883238B1 patent drawingFigure 4A
  • EP3883238B1 patent drawingFigure 4B

AI summary

This application discloses an audio stream and video stream synchronous switching method and apparatus, to resolve an existing problem that synchronization between audio streams and video streams after switching cannot be ensured. After receiving a switching instruction, a switching device determines a video parameter value of a switching point of a first video stream, and determines a video parameter value of a switching point of a second video stream. The video parameter value includes a timestamp and/or a sequence number. The switching device determines an audio parameter value of a switching point of a first audio stream based on a timestamp of the switching point of the first video stream, and determines an audio parameter value of a switching point of a second audio stream based on a timestamp of the switching point of the second video stream. The audio parameter value includes a timestamp and/or a sequence number. The switching device performs switching based on determined switching points. In other words, after switching points of video streams are determined, switching points of audio streams are determined based on the switching points of the video streams. The switching points of the audio streams are as close as possible to the switching points of the video streams in a time dimension, to ensure the synchronization between the audio streams and the video streams.