Live Video Segment Packaging for Ultra-Low Latency Streaming
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing adaptive bitrate (ABR) streaming protocols prioritize reliability over latency, leading to high latency in delivering live content, especially for latency-sensitive applications like live sports events, and alternative protocols like WebRTC are not suitable for delivering premium content due to their non-reliable network connections.
Innovation Solution
Implementing a system with multiple encoders to create segments starting with instantaneous decoder refresh frames and using fragmented transfer encoding to distribute moov atoms throughout segments, allowing immediate playback and reducing latency to a single frame or less.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ABR protocols (DASH/HLS) are used to prioritize reliability, then content delivery reliability is improved, but latency increases significantly
Solution Approach 1:
The video stream is divided into multiple segments with different latency characteristics. Low-latency segments are created alongside standard segments, allowing the system to provide different quality levels of service to different clients based on their latency requirements while maintaining overall system reliability
Solution Approach 2:
The system pre-encodes and prepares multiple versions of video segments with different latency profiles before delivery. This preliminary preparation allows immediate switching between latency modes without requiring real-time transcoding, thus reducing overall delivery time while maintaining reliability
2Loss of time
If WebRTC is used to reduce latency, then streaming latency is reduced to less than one second, but network reliability deteriorates due to best-effort UDP protocol
Solution Approach 1:
A server-based intermediary system is introduced that receives reliable TCP-based ABR streams and re-packages them into low-latency segments. This intermediary performs the function of converting between reliable and unreliable transport protocols, allowing clients to receive low-latency delivery through reliable infrastructure
Solution Approach 2:
The system creates multiple copies of video content in different segment formats (standard and low-latency) and makes them available through the same reliable ABR infrastructure. Clients can select the appropriate copy based on their latency requirements without compromising the reliability of the delivery mechanism
Data Source
AI summary
Systems and methods are provided for reducing latency in video streaming. At least a first portion of a live content item is encoded, using a first encoder, into a first bitstream, which is packaged into a first plurality of segments that start at a first time in the live content item. An offset is determined. At least a second portion of the live content item is encoded, using a second encoder, into a second bitstream, which is packaged into a second plurality of segments that start at a second time in the live content item, where the second time is based on the offset and is after the first time. Each segment of the first and second plurality of segments starts with an instantaneous decoder refresh frame, and each segment at a corresponding position in the first and second plurality of segments comprises a group of pictures.