BD-ROM Playback Synchronization via Time Axis Alignment

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Solution Overview

Problem

The implementation of the Out-of-MUX framework is complicated by the need for independent clock counters for demultiplexing units handling digital streams from BD-ROM and local storage, leading to frequent resets and software implementation difficulties, which hinder the dissemination of playback apparatuses with this functionality and increase costs.

Innovation Solution

Synchronizing the demultiplexing operations by aligning the start points of secondary and primary playback sections, ensuring discontinuities in the substream and main stream occur at the same point, allowing for synchronized resetting of demultiplexing units and simplifying control, thereby facilitating the production and distribution of playback apparatuses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If independent clock counters are used for each demultiplexing unit to handle digital streams from BD-ROM and local storage, then the demultiplexing operations can be performed independently, but the control becomes unnecessarily complicated and software implementation becomes difficult due to frequent STC changes and resets

Engineering Contradiction:

Improveindependent demultiplexing capabilityVSAvoidcontrol complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges the time axis of the secondary playback section with the primary playback section by setting the start point of the secondary section to coincide with the start point of the primary section. This alignment causes discontinuities in both streams to occur at the same point, allowing the demultiplexing units to be reset simultaneously and eliminating the need for complex independent control of multiple clock counters.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent creates equipotentiality between the primary and secondary playback sections by synchronizing their time axes. Both sections now operate from the same reference point (In_Time), ensuring that their discontinuities occur at the same position. This equalizes the control conditions for both demultiplexing units, simplifying the overall control logic while maintaining independent demultiplexing capability.

Inventive Principle:

Principle #12Equipotentiality

2Adaptability or versatility

If frequent STC changes and resets are performed to handle irregular discontinuities in packet sequences, then the demultiplexing can adapt to different stream configurations, but the control becomes unnecessarily complicated and implementation is delayed

Engineering Contradiction:

Improvestream configuration adaptabilityVSAvoidsoftware implementation ease

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent performs preliminary action by pre-aligning the time axes of the primary and secondary playback sections during the authoring process. The start point of the secondary section is set to match the start point of the primary section, and discontinuities are positioned to occur at the same point. This preliminary synchronization eliminates the need for complex runtime adjustments and frequent STC changes, making software implementation straightforward.

Inventive Principle:

Principle #10Preliminary action

3Adaptability or versatility

If the Out-of-MUX framework is implemented with complex control logic, then simultaneous playback of BD-ROM and local storage streams is achieved, but the costs increase and dissemination of playback apparatuses is hindered

Engineering Contradiction:

Improvesimultaneous playback capabilityVSAvoidcontrol logic complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges the time reference systems of the primary and secondary playback sections by aligning their start points and discontinuity positions. This merging allows the demultiplexing units to operate independently yet be controlled through a unified time axis, simplifying the control logic while maintaining the capability for simultaneous playback of BD-ROM and local storage streams.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent creates equipotential control conditions for both demultiplexing units by synchronizing their time axes. Both units now reference the same time origin (In_Time) and experience discontinuities at the same points, allowing for simplified control logic that can manage simultaneous playback without the complexity of independent clock counter management.

Inventive Principle:

Principle #12Equipotentiality

Data Source

PatentEP1873773B1Recording medium, reproducing device, recording method and reproducing method

Publication Date: 2011.11.30 PANASONIC HOLDINGS CORP

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AI summary

On a BD-ROM, PlayList information is recorded. The PlayList information includes MainPath information and SubPath information. The MainPath information specifies one of a plurality of AVClips as a MainClip, and defines a primary playback section (PlayItem) on the MainClip. The SubPath information specifies, among the rest of the AVClips, one AVClip as a SubClip, and defines, on the SubClip, a secondary playback section (SubPlayItem) to be synchronized with the primary playback section. The SubPath information includes In_Time information and Out_Time information which indicate In_Time and Out_Time, respectively, of the SubPlayItem. In_Time and Out_Time of the SubPlayItem match In_Time and Out_Time of the PlayItem.