Multicast Slotted Transmission for Digital Video Switching Delays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Digital video switching delays occur due to the need for complete frames in digital video feeds, leading to unacceptable latency in channel changes, especially when switching between different content types or inserting advertisements, as existing solutions either compromise on compression efficiency or require significant server resources and client intelligence.
Innovation Solution
Implementing a slotted transmission technique that generates multiple output data streams with identical content but different timing shifts, allowing clients to join the nearest multicast group with a Random Access Point (RAP) for near-instantaneous channel changes by creating new multicast groups at specified intervals, thereby reducing switching delays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If compression schemes use P-frames and B-frames with prediction, then compression efficiency is improved, but channel switching delay increases because complete standalone frames are spaced farther apart
Solution Approach 1:
The video stream is segmented into multiple parallel streams, each containing complete standalone frames (I-frames) at different time positions. Instead of having one stream with I-frames spaced far apart for compression efficiency, the system creates multiple segmented streams where each stream has I-frames at positions optimized for quick access, allowing viewers to switch between segments without waiting for the next I-frame in the original sequence.
Solution Approach 2:
The system performs preliminary action by pre-processing the video stream to create multiple parallel streams with I-frames positioned at different time points before transmission. This pre-segmentation allows the client to immediately join a stream that has an I-frame ready or approaching, eliminating the need to wait for the next I-frame to arrive during channel switching.
2Loss of time
If I-frames are spaced closer together, then channel switching delay is reduced, but compression efficiency deteriorates
Solution Approach 1:
Multiple compressed video streams are merged into a single multicast transmission. Each individual stream maintains high compression efficiency with I-frames spaced appropriately, but when combined into one multicast stream, they provide the effect of having closely spaced I-frames available for quick channel switching without sacrificing the compression efficiency of any individual stream.
3Loss of time
If multiple parallel streams with different timing are created, then channel switching speed is improved, but system complexity increases
Solution Approach 1:
The system creates parallel streams with periodic timing relationships, where each stream is a time-shifted version of the others at regular intervals. This periodic structure simplifies the complexity by providing a predictable, repeating pattern that is easier to manage and synchronize compared to arbitrary timing offsets, while still achieving fast channel switching.
Data Source
AI summary
Method and system for reducing switching delays between digital video feeds using multicast slotted transmission technique. Method, system, computer program stored on a computer readable medium for reducing switching delays between digital video feeds or different video or data channels using a slotted distribution and transmission technique. Method and system for performing a fast channel change operation. A computer propagated data signal. An article of manufacture comprising a digital video signal set.