Video Stream OETF Signaling for HDR-SDR Playback Compatibility
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Solution Overview
Problem
Existing video data generation methods lack backward compatibility, making it difficult for high dynamic range (HDR) video data to be reproduced by standard dynamic range (SDR) devices and vice versa.
Innovation Solution
A data generation and reproduction 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 with different luminance dynamic ranges to reproduce HDR and SDR video data seamlessly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If video data is generated using a second OETF for wider luminance dynamic range (HDR), then HDR reproduction quality is improved, but compatibility with first devices supporting only standard luminance dynamic range (SDR) deteriorates
Solution Approach 1:
The patent segments transfer function information 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 quality and SDR device support.
Solution Approach 2:
The patent adds a new dimension to the data structure by introducing SEI as a supplemental information layer alongside the traditional VUI. This dimensional expansion allows HDR transfer function information to coexist with SDR information without disrupting existing SDR device operation, enabling both HDR and SDR reproduction from the same video data.
2Adaptability or versatility
If only first OETF information is stored in VUI for SDR device compatibility, then backward compatibility is maintained, but HDR video reproduction capability is lost
Solution Approach 1:
The patent performs preliminary action by pre-storing 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, enabling seamless dual-mode reproduction capability.
3Adaptability or versatility
If dual transfer function information is stored in both VUI and SEI, then both HDR and SDR reproduction are enabled, but data structure complexity increases
Solution Approach 1:
The patent makes the SEI structure universal by designing it to carry second OETF information that can serve both HDR reproduction and act as a compatibility layer. The SEI message format is designed to be optional and supplemental, allowing HDR functionality to be added without fundamentally changing the existing VUI-based SDR reproduction pathway, thus reducing the impact of increased data structure complexity.
Data Source
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AI summary
An encoding device comprises: an encoding circuit configured to encode video data according to a coding standard including a High Efficiency Video Coding (HEVC) standard and a second opto-electrical transfer function (OETF), an intensity of light within a second range being input into the second OETF, and a storage to store: video usability information (VLTI) including a first value indicating a first OETF and supplemental enhancement information (SEI) including a second value indicating the second OETF, wherein VUI and SEI are included in the video data, wherein the first OETF supports a first range of an input intensity of light and the second range is wider than the first range, the first value is to be referred to by a decoding device that does not support the second OETF, when the decoding device decodes the video data and the second OETF has compatibility with the first OETF, wherein the first OETF is an OETF defined in one of BT. 709 and BT. 2020 and the SEI is in an IRAP NAL unit or an I-picture.