Video Playback Device PTS Synchronization for Seamless Bit Rate Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In adaptive streaming, the switching of video streams between different bit rates can cause disturbances in the display of moving images due to mismatched Presentation Time Stamps (PTS) of sync samples, leading to overlapping or hidden images.
Innovation Solution
The technology ensures smooth switching by matching the PTS of sync samples across different bit rates, allowing for seamless playback by hiding overlapping images and maintaining display continuity even when PTS do not match, using a moving image distribution system and reproduction apparatus that dynamically switch video streams based on environmental conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If video streams of different bit rates are switched dynamically in adaptive streaming, then the adaptability to network conditions is improved, but the display continuity is deteriorated due to PTS mismatch of sync samples
Solution Approach 1:
The patent applies preliminary action by pre-synchronizing the PTS of sync samples across different bit rate versions during the video encoding stage. This ensures that when stream switching occurs during playback, the time stamps already match, preventing display disturbances without requiring complex runtime synchronization logic.
2Stability of the object's composition
If sync samples are forced to match PTS across different bit rates, then the display continuity is improved, but the encoding flexibility is worsened
Solution Approach 1:
The patent applies parameter changes by modifying the PTS parameter of sync samples during encoding to ensure alignment across different bit rate versions. This controlled parameter adjustment maintains display continuity while preserving the independence of encoding processes for each bit rate version.
3Speed
If video stream switching is performed without PTS synchronization, then the switching speed is improved, but the image quality is worsened due to overlapping or hidden images
Solution Approach 1:
The patent applies preliminary action by pre-synchronizing the PTS of sync samples across different bit rate versions during the video encoding stage. This ensures that when stream switching occurs during playback, the time stamps already match, preventing display disturbances without requiring complex runtime synchronization logic.
Data Source
Figure 1A~2
Figure 3
Figure 4
AI summary
In order to playback a video stream, a video playback device (12) is provided with a playback unit (40) that decodes and displays pictures contained in chunks of the video stream, and a control unit (30) that indicates the beginning of playback processing. When switching a playback object to a second video stream corresponding to a second bit rate during playback processing of a first video stream corresponding to a first bit rate, the playback unit (40) continues playback processing chunks of the first video stream during playback processing. If pictures contained in chunks of the second video stream and pictures contained in the abovementioned chunks undergoing playback processing are duplicated, the control unit (30) instructs the playback unit (40) not to display the pictures that are duplicated in the playback processing of the chunks of the second video stream.