Image Encoding Bitrate Control for Temporal Scalability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image encoding methods that support temporal scalability increase processing load and complexity, as they need to ensure conformance for both the original bitstream and multiple sub-bitstreams, leading to a significant amount of processing required to manage bitrates and prevent overflow and underflow across various temporal resolutions.
Innovation Solution
The method selects a constant or variable bitrate type for the bitstream, sets specific bitrates for different temporal layers, and prohibits reference to higher temporal layers during encoding, generating a bitstream with temporal scalability information and bitrate control, thereby reducing processing load by eliminating the need to consider overflow in sub-bitstreams.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conformance is ensured for both the original bitstream and multiple sub-bitstreams with different temporal resolutions, then reliability of decoding is improved, but the amount of processing increases significantly
Solution Approach 1:
The patent segments the bitstream into multiple sub-bitstreams, each corresponding to a specific temporal resolution. By dividing the original bitstream into separable sub-bitstreams with distinct temporal characteristics, the encoder can process and ensure conformance for each segment independently, thereby reducing the overall processing complexity while maintaining decoding reliability across different temporal resolutions
Solution Approach 2:
The patent applies partial action by ensuring conformance only for the necessary sub-bitstreams rather than all possible temporal resolutions. The encoder identifies and processes only the sub-bitstreams that will actually be decoded, avoiding unnecessary processing of redundant temporal layers, thus reducing the encoding processing amount while still guaranteeing reliable decoding for the required output
2Reliability
If overflow and underflow are prevented in all sub-bitstreams, then reliability of buffer management is improved, but the complexity of bitrate control increases
Solution Approach 1:
The patent applies local quality by implementing different bitrate control strategies for different temporal layers. Instead of applying a uniform bitrate control mechanism across all temporal resolutions, the encoder uses tailored control parameters and methods appropriate for each temporal layer's specific characteristics, such as using higher bitrate margins for lower temporal resolutions that are more prone to overflow, thereby simplifying the overall control complexity while ensuring reliable buffer management
Solution Approach 2:
The patent changes bitrate control parameters dynamically based on the temporal resolution being processed. By adjusting key parameters such as target bitrate, buffer thresholds, and quantization settings according to the specific temporal layer requirements, the encoder can prevent overflow and underflow in each sub-bitstream independently without requiring a complex unified control system, thus reducing bitrate control complexity while maintaining buffer management reliability
Data Source
AI summary
An image encoding method includes acquiring a constant bit rate or a variable bit rate, determining temporal layers for a plurality of images, and setting, in a case where the constant bit rate is selected, (1) a first bit rate type of a top temporal layer to the constant bit rate, and (2) a second bit rate type of one or more other layers to the variable bit rate. The method also includes setting, in a case where the variable bit rate is selected, both the first bit rate type of the top temporal layer and the second bit rate of the one or more layers to the variable bit rate. The method further includes encoding each of the plurality of images, prohibiting reference to the images with the temporal layers higher than each of the temporal layers that each of the images belongs to, and generating the bitstream.