BD-ROM Entry Maps for High-Speed Playback Processing Load
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Solution Overview
Problem
Current BD-ROM players face increased processing loads during high-speed fast-forward/rewind playback due to the need for real-time decryption and transformation of TS packets, which can require additional hardware and increased operation clock speeds, making it difficult to implement copyright protection without overburdening the player.
Innovation Solution
A recording medium with a primary and secondary video stream, utilizing entry maps to associate start positions with presentation time stamps, where every N-th entry unit is untransformed, allowing selective use of untransformed TS packets to reduce processing load during high-speed playback, thereby enabling copyright protection within standard player capabilities without additional hardware or increased clock speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If real-time decryption and transformation of TS packets are performed for copyright protection, then copyright protection is achieved, but processing load increases requiring additional hardware and higher clock speeds
Solution Approach 1:
The patent applies preliminary action by pre-organizing TS packets into entry units with entry maps during the authoring phase. Entry points are predetermined and stored in entry maps, allowing the playback device to directly access untransformed TS packets without real-time analysis or decryption during high-speed playback, thus reducing processing load while maintaining copyright protection
2Measurement precision
If analysis processing of AV stream is performed to identify I-picture positions, then accurate positioning is achieved, but processing time increases consuming large amount of processing time
Solution Approach 1:
The patent pre-calculates and stores entry points indicating I-picture positions in entry maps during authoring. This eliminates the need for real-time analysis processing during playback, as the playback device can directly reference the pre-stored entry maps to identify I-picture positions instantly, achieving both accurate positioning and minimal processing time
3Adaptability or versatility
If multiple video streams are multiplexed for Picture-in-Picture or 3D playback, then playback functionality is enhanced, but simultaneous restoration of transformed TS packets requires significant processing resources
Solution Approach 1:
The patent applies local quality by selectively transforming only specific TS packets while leaving entry units untransformed. This allows the playback device to efficiently process multiple video streams during high-speed playback by directly using untransformed TS packets from entry units, reducing the processing burden while maintaining enhanced playback functionalities like Picture-in-Picture and 3D playback
Data Source
AI summary
A recording medium enables special playback processing although part of the AV stream recorded therein is transformed. An AV stream, a first EP map, and a second EP map are recorded on the recording medium. In the AV stream, a part of the multiplexed stream including a first video stream and a second video stream is transformed. The first EP map indicates one or more entry points of the first video stream and the second EP map indicates one or more entry points of the second video stream. TS packets constituting I-pictures of the first video stream are indicated by every 4N-th entry point in the first EP map, and TS packets constituting I-pictures of the second video stream are indicated by the entry points whose presentation time is closest to the presentation time of any one of the every 4N-th entry point in the first EP map.