Video Stream Transfer Signaling for HDR-SDR 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 narrow luminance dynamic range (SDR) deteriorates
Solution Approach 1:
The video data structure is segmented into multiple information fields: VUI parameters store first OETF information for SDR compatibility, while SEI messages or alternative_transfer_characteristics syntax store second OETF information for HDR capability. This segmentation allows different device types to access their respective transfer function information independently without conflict
Solution Approach 2:
The video data structure is designed with universal compatibility by incorporating multiple transfer function specifications. The system can serve both SDR-only devices and HDR-capable devices through the same video bitstream, making the video data universally reproducible across different device categories
2Adaptability or versatility
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 pre-storing both first and second OETF information in the video data during encoding. This advance preparation ensures that when video data is decoded, both SDR and HDR devices can find their required transfer function information without requiring real-time conversion or additional processing
Solution Approach 2:
SEI messages and alternative_transfer_characteristics syntax act as intermediary carriers for second OETF information. These intermediary structures enable HDR capability transmission without disrupting the existing VUI parameter structure that SDR devices rely upon
3Adaptability or versatility
If dual OETF information is stored in both VUI and SEI, then both HDR and SDR device compatibility is achieved, but data structure complexity increases
Solution Approach 1:
Different parts of the video data structure serve different quality requirements: VUI parameters provide basic SDR compatibility with simple structure, while SEI messages or alternative syntax provide enhanced HDR capability where needed. Each section has optimized quality characteristics appropriate to its function
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.