Video Transfer Function Signaling for SDR-HDR Playback Compatibility
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Solution Overview
Problem
Existing video data generation methods lack backward compatibility, making it difficult for devices supporting standard dynamic range (SDR) to reproduce high dynamic range (HDR) video data, and vice versa.
Innovation Solution
A data generation method that includes storing first and second opto-electrical transfer function (OETF) information in video usability information (VUI) and supplemental enhancement information (SEI) respectively, allowing devices to switch between SDR and HDR reproduction schemes based on hybrid information in the multiplexing layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If video data is generated using a second OETF for wider luminance dynamic range (HDR), then the luminance dynamic range coverage is improved, but compatibility with first devices supporting only standard dynamic range deteriorates
Solution Approach 1:
The transfer function information is segmented into two separate storage locations: VUI contains first OETF information for SDR devices, while SEI contains second OETF information for HDR devices. This segmentation allows each device type to access the appropriate transfer function without interference, resolving the compatibility conflict between HDR and SDR reproduction
Solution Approach 2:
The SEI message acts as an intermediary layer that provides additional HDR-specific transfer function information without disrupting the standard VUI structure. HDR-capable devices can access this intermediary information while SDR devices ignore it, enabling backward compatibility while supporting advanced features
2Reliability
If only first OETF information is stored in VUI for SDR device compatibility, then backward compatibility is maintained, but HDR reproduction capability is lost
Solution Approach 1:
The system performs preliminary action by embedding both first OETF information in VUI and second OETF information in SEI during video data generation. This advance preparation ensures that both SDR and HDR devices can find their required transfer function information without requiring real-time conversion or additional processing
Solution Approach 2:
The video data structure is designed with universal compatibility by incorporating multiple transfer function specifications. The VUI provides universal baseline compatibility for all devices, while the SEI extends functionality for advanced HDR-capable devices, making the same video data universally usable across different device capabilities
3Adaptability or versatility
If dual transfer function information is stored in both VUI and SEI, then both SDR and HDR reproduction are enabled, but data structure complexity increases
Solution Approach 1:
The system implements dynamic information retrieval where devices adaptively select which transfer function information to use based on their capabilities. SDR devices dynamically access only VUI information, while HDR devices dynamically access both VUI and SEI information, optimizing processing efficiency despite the dual-information structure
Data Source
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AI summary
A data generation device comprises: a generating circuit configured to generate video data according to an Advanced Video Coding (AVC) standard and a second opto-electrical transfer function (OETF); and a storage to store: video usability information (VUI) including a first value indicating a first OETF; and supplemental enhancement information (SEI) including a second value indicating the second OETF, wherein the first OETF and the second OETF support a standard dynamic range (SDR) and a high dynamic range (HDR), respectively, the first value is to be referred to by a decoding device that does not support HDR, the second OETF is a combination of a square root function and a logarithmic function, the SEI is provided in a multiplexing layer other than a video coding layer, and the second OETF has compatibility with the first OETF.