GOP Alignment in Media Stream Encoding

Solution Overview

Problem

Conventional mechanisms for switching between media stream variants lack effective temporal alignment of key frames and GOPs, leading to seamless switching issues during device and network resource adjustments.

Innovation Solution

A distributed encoding system aligns key frames across all variants during the encoding stage by delineating media streams into Groups of Pictures (GOPs), distributing them to multiple encoders and fragmentation systems, and resizing before bit rate and frame rate transcoding, ensuring GOP alignment across different quality levels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional encoding mechanisms are used to support multiple quality levels, then device adaptability is improved, but temporal alignment between key frames and GOPs deteriorates

Engineering Contradiction:

Improvedevice adaptabilityVSAvoidtemporal alignment precision

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The system performs preliminary GOP alignment during the encoding stage by delineating media streams into Groups of Pictures and distributing them to multiple encoders. This advance preparation ensures that key frames across different quality level variants are temporally synchronized before transmission, eliminating the need for temporal adjustments during playback and enabling seamless variant switching.

Inventive Principle:

Principle #10Preliminary action

2Productivity

If multiple encoders and fragmentation systems are distributed across different quality levels, then productivity is improved, but maintaining synchronization between variants becomes more difficult

Engineering Contradiction:

Improveencoding throughputVSAvoidsynchronization reliability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The system segments the media stream into Groups of Pictures (GOPs) and distributes these segmented units to multiple encoders working in parallel. Each encoder processes specific GOPs independently, which enables concurrent encoding operations across different quality levels while maintaining synchronization through the structured GOP delineation framework that preserves temporal relationships between variants.

Inventive Principle:

Principle #1Segmentation

3Ease of operation

If variant switching is implemented without GOP alignment, then ease of operation is improved, but playback continuity deteriorates

Engineering Contradiction:

Improvevariant switching simplicityVSAvoidplayback continuity

Core Design Contradiction:

Ease of operationVSStability of the object's composition

Solution Approach 1:

The system performs preliminary GOP alignment during the encoding stage by delineating media streams into Groups of Pictures and distributing them to multiple encoders. This advance preparation ensures that key frames across different quality level variants are temporally synchronized before transmission, eliminating the need for temporal adjustments during playback and enabling seamless variant switching.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS9338482B2Enhanced group of pictures (GOP) alignment in media stream variants

Publication Date: 2016.05.10 ADEIA MEDIA HOLDINGS INC

AI summary

A media feed is received and delineated into groups of pictures (GOPs) for processing into output media streams having different quality levels. The media feed needs only to be decoded once. The decoded stream is split along different paths based on resolution, and resized output media data is sent to multiple encoders and fragmenters to generate variants in bit rate and frame rate for each resolution. The generated variants may be maintained as fragments on shared storage. A particular stream corresponding to a particular variant can be reconstructed using the encoded fragments.