3G TDM Audio Video Synchronization via Delay Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current 3G mobile communications systems face challenges in synchronizing audio and video media streams due to temporal skew introduced by intervening processing elements, as they only consider end-to-end delays and not specific delays caused by these elements, leading to improper lip synchronization.
Innovation Solution
The system adjusts synchronization by receiving control messages reporting delays from intervening processing elements, calculating a relative delay, and applying a delay factor to the faster media channel at points of combination and separation to ensure proper temporal alignment of audio and video streams.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If H.245 control messages are used to report end-to-end temporal skew, then synchronization information can be transmitted between endpoints, but the specific delays introduced by intervening processing elements cannot be identified or corrected
Solution Approach 1:
The patent segments the end-to-end transmission path into multiple sections by introducing intermediate processing elements that independently measure and report their specific delay contributions. Each processing element (gateway, transcoder, etc.) acts as an independent measurement node that segments the overall temporal skew measurement problem into manageable parts, allowing precise identification of delay sources along the transmission path.
Solution Approach 2:
The patent introduces intermediary processing elements (gateways, transcoders, message routers) that act as mediators between endpoints. These intermediaries actively measure the temporal skew they introduce and embed this information in control messages, serving as intermediate information sources that bridge the gap between endpoints and provide detailed delay data about specific network elements.
2Reliability
If delay compensation is applied at endpoints based on end-to-end temporal skew, then lip synchronization can be achieved, but the specific delays introduced by individual processing elements remain unaddressed
Solution Approach 1:
The patent segments the delay measurement function across multiple independent processing elements along the transmission path. Each element measures its own introduced delay independently, creating segmented measurement data that collectively provides complete information about all delay sources. This segmentation enables precise identification and compensation of individual processing element delays.
Solution Approach 2:
The patent implements feedback mechanisms where each processing element measures its introduced temporal skew and feeds this information back to subsequent elements or endpoints. This feedback loop allows each node to awareness of the delays it introduces and enables cumulative delay calculation, improving both measurement precision and synchronization reliability.
3Adaptability or versatility
If media streams are separated into different channels for processing, then protocol transformation and bandwidth adjustment can be performed, but temporal skew between channels increases
Solution Approach 1:
The patent applies preliminary delay compensation actions at each processing element before media streams are recombined or forwarded. Each gateway or transcoder measures the delay it introduces and applies compensatory delay to other channels or notifies endpoints to apply corresponding delay, preventing temporal skew accumulation before streams are recombined.
Solution Approach 2:
The patent dynamically changes the delay parameter of media streams based on measured temporal skew at each processing stage. Each processing element adjusts the delay parameter of affected channels to compensate for introduced skew, maintaining synchronization throughout the processing chain despite protocol transformations and bandwidth adjustments.
Data Source
AI summary
Systems and methods of adjusting synchronization of audio media streams and video media streams in 3G mobile communications systems that can mitigate the effects of temporal skew due to intervening processing elements associated with media channels carrying the respective media streams. The systems and methods are operative to adjust the synchronization of audio media streams and video media streams by receiving control messages that report delays due to such intervening processing elements, calculating a relative amount of delay using the reported delays for each media channel, and applying a delay factor based on the relative amount of delay to the faster media channel to place the audio media streams and the video media streams in proper temporal alignment. The delay factor is applied to the faster media channel at those locations within the mobile communications systems where the audio and video media streams are combined and/or separated for subsequent transmission.