Cloud DVR Manifest Caching via Session Index Segmentation

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Solution Overview

Problem

Cloud-based digital video recording systems face challenges in maintaining uninterrupted content delivery due to the extensive computational resources required for generating manifests for recorded content items, leading to cascading effects that negatively impact user experience when resources are stretched thin.

Innovation Solution

Implementing a system where a recording agent stores new portions of content items and associated metadata, triggering a session module to update a session index and a caching device to perform a forced refresh of manifests, ensuring that updated manifests are cached before user devices request them, thereby preventing cache misses and ensuring seamless content playback.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If manifests are generated on a per-user basis for cloud-based digital video recording, then content delivery accuracy is improved, but computational resource consumption increases

Engineering Contradiction:

Improvecontent delivery accuracyVSAvoidcomputational resource consumption

Core Design Contradiction:

Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The patent segments the manifest generation process by creating session-specific manifest portions for different user devices rather than generating complete manifests for each user. The session index divides content into segments with associated manifest portions that can be independently managed and cached, reducing overall computational load while maintaining accurate content delivery for each user.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system performs preliminary actions by pre-generating and caching manifest portions in the session index before users request them. When a user device begins a recording session, the corresponding manifest portion is created and stored in advance, so that when the user requests content, the manifest is already available, eliminating the need for real-time manifest generation and reducing computational resource consumption during content delivery.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If computational resources are allocated for per-user manifest generation, then user experience is improved, but system stability deteriorates under high resource utilization

Engineering Contradiction:

Improveuser experienceVSAvoidsystem stability

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The session index serves multiple functions simultaneously: it acts as a cache for manifest portions, a tracker for active recording sessions, and a generator for manifest portions on demand. This multi-functionality reduces the need for separate systems and resources, allowing the same infrastructure to support multiple user devices without proportionally increasing resource consumption, thereby maintaining system stability while improving user experience.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system discards old or expired session entries from the session index when recording sessions end, and recovers computational resources by removing unnecessary manifest portions. This cleanup process prevents memory leaks and resource accumulation, maintaining system stability over time while still providing reliable content delivery for active users.

Inventive Principle:

Principle #34Discarding and recovering

3Loss of information

If manifest generation is performed in real-time for each user device, then content freshness is improved, but response time increases

Engineering Contradiction:

Improvecontent freshnessVSAvoidresponse time

Core Design Contradiction:

Loss of informationVSLoss of time

Solution Approach 1:

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The session index acts as a cushion by pre-storing manifest portions that anticipate future user requests. When a user starts a recording session, the system proactively creates and caches the corresponding manifest portion, providing a buffer that ensures the manifest will be available immediately when requested, thus maintaining content freshness without incurring real-time generation delays.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentUS20220408125A1Systems, Methods, And Apparatuses For Improved Content Recording And Playback

Publication Date: 2022.12.22 COMCAST CABLE COMM LLC

AI summary

Methods, systems, and apparatuses for improved content recording and playback are described herein. A user device may concurrently record and output a content item. For example, the user device may be associated with a recording session. A session index may identify the recording session and indicate the user device is concurrently recording and outputting the content item. The session index may be used to ensure that a manifest for the content item is continuously updated.