Blu-ray Random Access Table for High-Bitrate Video Playback
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Solution Overview
Problem
Current management tables in Blu-ray discs are unable to appropriately express the size of I pictures included in high-bitrate video streams, leading to issues with random accessibility and playback efficiency.
Innovation Solution
The Blu-ray disc records a video stream with a random access table that includes playback start time information, start position, and size information of I pictures, using different stipulated data sizes based on the bitrate, allowing for efficient random access and playback of high-bitrate video content.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a fixed data size is used for I picture size information in management tables, then the structure is simple and compatible, but it cannot accurately express the size of I pictures in high-bitrate video streams
Solution Approach 1:
The patent applies dynamics by making the data size unit variable rather than fixed. The management table uses different stipulated data sizes (first stipulated data size for high-bitrate streams, second stipulated data size for low-bitrate streams) depending on the video stream characteristics. This dynamic adaptation allows accurate representation of I picture sizes across different bitrate scenarios while maintaining a unified management table structure.
Solution Approach 2:
The patent changes the parameter of data size unit based on the bitrate information. By selecting between a first stipulated data size and a second stipulated data size according to whether the video stream is high-bitrate or low-bitrate, the system accurately represents I picture sizes without requiring complex management table structures. This parameter change approach resolves the contradiction between measurement precision and device complexity.
2Speed
If the management table uses a unified data size unit, then compatibility is maintained, but random accessibility to high-bitrate video content is degraded
Solution Approach 1:
The patent applies local quality by using different data size units in different contexts within the same management table structure. For high-bitrate video streams, a first stipulated data size is used, while for low-bitrate streams, a second stipulated data size is used. This localized adaptation enables fast random access to high-bitrate content while maintaining compatibility with low-bitrate content, resolving the contradiction between speed and adaptability.
3Reliability
If bitrate information is not considered in the management table, then the structure remains simple, but accurate positioning of I pictures in high-bitrate streams becomes impossible
Solution Approach 1:
The patent applies preliminary action by pre-defining different stipulated data sizes for different bitrate categories. The management table is constructed with awareness of bitrate information, allowing I picture positions to be accurately calculated from the outset. This preliminary consideration of bitrate enables reliable I picture positioning without adding complex runtime adjustment mechanisms, thus maintaining structural simplicity while improving reliability.
Data Source
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AI summary
Recorded in a recording medium is a video stream, map information, and bitrate information of the video stream. The map information includes size information indicating data size of a section where a picture is recorded in the video stream, based on a predetermined stipulated data size. The stipulated data size differs in accordance with the bitrate information.