Bitstream Rewriter for Temporal Scalability in Video Encoding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing video codec standards lack efficient methods to add temporal scalability to non-scalable bitstreams, particularly in hardware-based encoders, which often require time-consuming bit shifting operations, increasing computational costs.
Innovation Solution
A bitstream rewriter is used to modify syntax elements in encoded video data, creating a scalable bitstream with multiple layers of temporal scalability by associating different parameter sets with base and enhancement layers, avoiding bit shifting operations through adjustments in parameter set identifiers and syntax elements, thereby enabling efficient conversion of non-scalable bitstreams into scalable ones.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If bit shifting operations are used to add temporal scalability to non-scalable bitstreams, then temporal scalability is achieved, but computational cost increases
Solution Approach 1:
The patent changes parameter set identifiers (PSID) and syntax elements in the bitstream to enable temporal scalability without requiring bit shifting operations. By modifying parameters such as temporal_id values and associated syntax elements, the system achieves temporal scalability while avoiding computationally expensive bit manipulation operations.
2Adaptability or versatility
If bit shifting operations are used to add temporal scalability, then temporal scalability is achieved, but processing time increases
Solution Approach 1:
The invention modifies parameter set identifiers and syntax elements directly in the bitstream, avoiding time-consuming bit shifting operations. By changing parameters such as temporal_id values and associated syntax elements through simple substitution rather than bit manipulation, processing time is significantly reduced while maintaining temporal scalability functionality.
3Adaptability or versatility
If complex bitstream modification methods are used, then temporal scalability is added, but device complexity increases
Solution Approach 1:
The patent employs straightforward parameter changes including modifying parameter set identifiers (PSID) and temporal_id values, rather than implementing complex bitstream reconstruction algorithms. This approach reduces device complexity by using simple parameter substitution and syntax element modification instead of elaborate bit manipulation and data reorganization processes.
Data Source
AI summary
Innovations described herein facilitate the addition of temporal scalability to non-scalable bitstreams. For example, a bitstream rewriter receives units of encoded video data for a non-scalable bitstream from components of a hardware-based encoder. The bitstream rewriter changes at least some of the units of encoded video data so as to produce a scalable bitstream with temporal scalability. In doing so, the bitstream rewriter can associate an original sequence parameter set (SPS) and original picture parameter set (PPS) with pictures for a temporal base layer, and associate a new SPS and new PPS with pictures for a temporal enhancement layer. The bitstream rewriter can also alter syntax elements in the units of encoded video data, for example, changing syntax elements in a slice header in ways that avoid bit shifting operations for following coded slice data for a unit of encoded video data for the temporal enhancement layer.