Fast Channel Change Module for Live Video Lag Reduction

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Solution Overview

Problem

Current video delivery platforms face significant live lag due to encoding, ABR segmentation, buffering, and propagation delays, which can be exacerbated by fast channel change techniques that reduce quality by skipping frames, particularly in sports broadcasting where timely updates are crucial.

Innovation Solution

A system with a content transmission device that analyzes media streams to select frames based on criteria such as scene motion and silence, marks these frames, and uses a Fast Channel Change module to buffer and transmit media streams, allowing for faster playback initiation and frame skipping to minimize live lag while maintaining quality, especially during channel changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If fast channel change techniques are used to reduce zapping time, then channel switching speed is improved, but buffering at the client device increases and live lag worsens

Engineering Contradiction:
Improvechannel switching speedVSAvoidlive lag
Core Design Contradiction:
SpeedVSLoss of time

Solution Approach 1:

The server performs preliminary actions by buffering recent content and preparing it for fast delivery before the client requests channel changes. The Fast Channel Change module pre-processes and stores content that can be quickly transmitted to clients, enabling rapid channel switching without requiring large client-side buffers.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The Fast Channel Change module acts as an intermediary between the content source and the client device. It receives content, processes it through analysis and marking modules, and delivers it in an optimized format that enables fast channel changes while minimizing the buffering required at the client device, thus reducing live lag.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of time

If frames are skipped to reduce buffering and live lag, then channel change speed is improved, but quality of the displayed content deteriorates

Engineering Contradiction:
Improvelive lagVSAvoidcontent quality
Core Design Contradiction:
Loss of timeVSManufacturing precision

Solution Approach 1:

The analysis module evaluates each frame locally based on specific criteria (motion content, scene changes, audio silence) to determine whether it can be skipped. This selective approach ensures that only frames with minimal visual or auditory impact are removed, maintaining overall content quality while still achieving buffer reduction and lower live lag.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The marking module modifies the media stream by adding metadata that identifies which frames should be skipped during playback. This parameter change allows the playback system to dynamically adjust frame delivery based on content characteristics, reducing buffering requirements while preserving perceived quality by skipping only imperceptible frames.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3337174B1Method and device for transmission of content
Publication Date: 2021.04.07 ALCATEL LUCENT ESPANA
  • EP3337174B1 patent drawingFigure 1~4

AI summary

Embodiments relate to a method for transmission of media content, executed by a content transmission device (2), comprising: - obtaining (S1) a media stream (V0) comprising a plurality of successive frames, - selecting (52) one or more of said frames which meet a selection criterion, and determining (52) marking data specifying the selected frames, - sending (53) said media stream and said marking data to a plurality of content consumption devices (3) by multicast, - buffering (54) a portion of the media stream and the marking data and, in response to a request from one content consumption device (3), sending (54) the buffered portion to said content consumption device (3) in unicast.