NAL Unit Header View Scalability Signaling
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Solution Overview
Problem
Current Multi-view Video Coding (MVC) technologies lack effective methods for signaling view scalability, relying on recursive calls that can burden simple routers and only provide temporal scalability, not view scalability.
Innovation Solution
The proposed solution involves an encoder and decoder that signal view direction and level using messages, fields, or syntax elements within the Network Abstraction Layer (NAL) unit header and other high-level syntax elements to support view scalability, allowing for efficient signaling of view direction and level in the bitstream.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the existing NAL unit header syntax is used for MVC, then temporal scalability is provided, but view scalability is not supported
Solution Approach 1:
The patent applies parameter changes by redefining the usage of existing NAL unit header parameters. Specifically, when svc_mvc_flag is set to 1, the parameters simple_priority_id, discardable_flag, and quality_level are reinterpreted to convey view scalability information (view_direction and view_level) instead of their original temporal scalability meanings. This allows view scalability to be supported without adding new syntax elements, thus avoiding increased device complexity.
2Adaptability or versatility
If Sequence_parameter_set_mvc_extension is used to derive view scalability information, then view scalability is supported, but recursive calls burden simple routers
Solution Approach 1:
The patent extracts the essential view scalability information (view_direction and view_level) from the complex Sequence_parameter_set_mvc_extension structure and places it directly in the NAL unit header. This extraction eliminates the need for recursive parsing of extension structures, allowing simple routers to process the critical view scalability information without the computational burden of recursive calls.
Solution Approach 2:
The patent performs preliminary action by pre-positioning the view scalability parameters (view_direction and view_level) in the NAL unit header, which is processed early in the video stream. This allows routers and decoders to obtain view scalability information immediately without needing to traverse deeper into the bitstream structure or make recursive calls to extension parameters.
3Adaptability or versatility
If view scalability is added to NAL unit header, then view scalability is supported, but existing bits must be reused
Solution Approach 1:
The patent applies universality by making the existing NAL unit header parameters multi-functional. The same parameters (simple_priority_id, discardable_flag, quality_level) serve dual purposes: they provide temporal scalability information when svc_mvc_flag is 0, and view scalability information when svc_mvc_flag is 1. This multi-functionality allows view scalability to be added without increasing the overall syntax structure or requiring additional dedicated bits.
Data Source
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AI summary
There are provided methods and apparatus for signaling view scalability in multi-view video coding. An apparatus includes an encoder (100) for encoding at least one picture for at least one view corresponding to multi-view video content in a resultant bitstream. The encoder signals at least one of a view direction and a view level to support view scalability for the at least one view using at least one of a message, a field, a flag, and a syntax element.