MP4 Fragmented Movie Edit List Generation for Delayed Start Times

Solution Overview

Problem

In the MP4 Fragmented Movie format, it is challenging to generate and recognize the reproduction time duration of encoded streams, making it difficult to create an edit list and reproduce movie content when the reproduction start time is later than the movie time scale.

Innovation Solution

An information processing apparatus and method that register a top position as the reproduction start position and a predetermined value as the reproduction time duration in the edit list when the reproduction start time is later than the movie time scale, allowing for the generation and extraction of an edit list, and subsequent reproduction of content in the MP4 Fragmented Movie format.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the reproduction start time of content is later than the reproduction start time on movie time scale, then the content can be reproduced with proper time alignment, but it is difficult to recognize the reproduction time duration and generate an edit list

Engineering Contradiction:

Improvereproduction time alignmentVSAvoidedit list generation

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by calculating and storing the reproduction time duration in advance during the moov box generation phase. When the reproduction start time is later than the movie time scale start, the system pre-computes the duration by subtracting the reproduction start time from the content end time, and stores this value in the edit list. This eliminates the need for complex runtime calculations and enables reliable time alignment.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary mechanism by using the edit list as a bridge between the moov box metadata and the actual content reproduction. The edit list contains the calculated reproduction time duration that mediates between the reproduction start time offset and the content playback, enabling the reproduction apparatus to correctly interpret and reproduce content with delayed start times.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of manufacture

If a moov box is generated without recognizing reproduction time duration, then file generation is simplified, but the reproduction apparatus cannot reproduce content based on an edit list

Engineering Contradiction:

Improvefile generationVSAvoidcontent reproduction

Core Design Contradiction:

Ease of manufactureVSEase of operation

Solution Approach 1:

The patent applies preliminary action by calculating and storing the reproduction time duration in advance during the moov box generation phase. When the reproduction start time is later than the movie time scale start, the system pre-computes the duration by subtracting the reproduction start time from the content end time, and stores this value in the edit list. This eliminates the need for complex runtime calculations and enables reliable time alignment.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary mechanism by using the edit list as a bridge between the moov box metadata and the actual content reproduction. The edit list contains the calculated reproduction time duration that mediates between the reproduction start time offset and the content playback, enabling the reproduction apparatus to correctly interpret and reproduce content with delayed start times.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS10484725B2Information processing apparatus and information processing method for reproducing media based on edit file

Publication Date: 2019.11.19 SONY GROUP CORP

AI summary

The present disclosure relates to an information processing apparatus and an information processing method that are capable of reproducing content on the basis of an edit list in the case where the reproduction start time of content contained in a file in the MP4 Fragmented Movie format is later than the reproduction start time in a movie time scale. An edit list generation unit registers a top position of content as a reproduction start position of the content and a predetermined value as a reproduction time duration of the content in an edit list when a reproduction start time of the content is later than a reproduction start time of the content on a movie time scale, the edit list associating the reproduction start position of the content with the reproduction time duration of the content reproduced from the reproduction start position. The present disclosure is applicable to a file generation apparatus that generates a Fragmented MP4 file, for example.