Audio Video Synchronization Using Captured Video Offset
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Solution Overview
Problem
Existing technologies face challenges in synchronizing audio and video playback between two different electronic devices receiving separate streams, as they lack effective methods to achieve inter-component synchronization.
Innovation Solution
A method and apparatus that involves decoding video and audio streams on a second electronic device, capturing the video playback from a first device, determining an offset, and adjusting the audio playback to synchronize with the video, using a processor and video correlator to ensure synchronized output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If two electronic devices receive separate video and audio streams independently, then each device can process and playback its streams autonomously, but synchronization between audio and video playback across the two devices cannot be achieved easily
Solution Approach 1:
The patent uses a camera as an intermediary device to capture the video playback from the first device. This captured video serves as a reference signal that the second device can use to synchronize its audio playback with the video playback on the first device, resolving the synchronization problem while maintaining autonomous playback capability
Solution Approach 2:
The system implements feedback by using the captured video playback as a reference signal. The second device continuously monitors the captured video and adjusts its audio playback timing based on the detected video frames, creating a closed-loop synchronization mechanism that maintains alignment between audio and video across devices
2Measurement precision
If audio and video are synchronized using traditional PTS timestamps within a single device, then inter-component synchronization is achieved, but this method cannot be applied across two separate receiving devices
Solution Approach 1:
Instead of relying on PTS timestamps that only work within a single device's decoding system, the patent creates a visual copy of the video playback using a camera. This copied video signal serves as a universal reference that can be detected and used by any second device to synchronize its audio output, making the synchronization method adaptable across different device types and platforms
3Reliability
If the second device adjusts audio output timing based on captured video, then synchronization is achieved, but additional complexity is introduced through video capturing and offset determination
Solution Approach 1:
The system uses the second device's own audio playback as the signal to be synchronized, and uses the captured video from the first device as the reference. The device automatically determines the offset between its audio output and the captured video, and self-adjusts its audio timing without requiring external control systems or complex coordination protocols
Data Source
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AI summary
A method for synchronizing playback of a program including a video and associated first audio at a first electronic device with playback of a second audio associated with the program at a second electronic device that also receives the video is disclosed. The method comprises decoding, by a video decoder in the second electronic device, the video, and outputting the decoded video; decoding, by an audio decoder in the second electronic device, the second audio and outputting the decoded second audio for playing back by the second electronic device; receiving a user command to synchronize the playback of the video at the first electronic device and playback of the second audio at the second electronic device; responsive to the user command, the method further comprising capturing, by a capturing device in the second electronic device, the playback of the video at the first electronic device; determining, by the second electronic device, an offset between the outputted decoded video and the captured video; and adjusting outputting of the decoded second audio according to the offset, so that the playback of the first audio at the first electronic device is synchronized with the playback of the second audio at the second electronic device.