AVC 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 and supplemental enhancement information, respectively, allowing devices to switch between SDR and HDR reproduction schemes based on hybrid information, ensuring backward compatibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing 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 the transfer function information into two separate parts: first OETF information and second OETF information. This segmentation allows different device types to access their respective transfer function information independently, enabling HDR devices to utilize the second OETF for wider luminance dynamic range while SDR devices continue to use the first OETF, thus resolving the compatibility issue
Solution Approach 2:
The patent introduces a new dimension for storing transfer function information by adding a second OETF information field alongside the existing first OETF information. This dimensional expansion allows the system to carry both SDR and HDR transfer function information simultaneously, enabling devices to select the appropriate transfer function based on their capabilities without compromising compatibility
2Device complexity
If a single OETF is used for video encoding, then device complexity is reduced, but the ability to support multiple luminance dynamic ranges deteriorates
Solution Approach 1:
The patent implements universality by designing the video data structure to contain both first OETF information and second OETF information. This multi-functionality allows the same video data to be properly reproduced on both SDR devices (using first OETF) and HDR devices (using second OETF), enabling a single encoding system to serve multiple device types without increasing operational complexity
Solution Approach 2:
The patent applies preliminary action by pre-storing both first OETF information and second OETF information in the video data during encoding. This advance preparation ensures that when the video data reaches reproduction devices, both transfer function options are already available, eliminating the need for complex real-time conversion or selection processes and maintaining device simplicity
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), an intensity of light within a second range being input into the second 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 supports a first range of an input intensity of light and the second range is wider than the first range, and the first value is to be referred to by a decoding device that does not support the second OETF, 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.