Variable Refresh Rate Video Capture Encoding Timing
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Solution Overview
Problem
Current video playback technologies face limitations due to the mismatch between variable rendering rates and fixed display refresh rates, leading to latency and artifacts like 'tear lines' when using vsync-on and vsync-off modes.
Innovation Solution
A method for capturing and encoding image frames with their rendering timing information, allowing for dynamic display refresh rates that match the rendering rate, enabling real-time display with minimal latency and eliminating tear lines.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If vsync-on mode is used to synchronize rendering with display refresh, then display synchronization is improved, but latency increases and refresh rate is reduced
Solution Approach 1:
The patent applies dynamics by making the display refresh rate variable rather than fixed. The display device dynamically adjusts its refresh rate to match the GPU rendering rate, allowing the system to maintain synchronization without the latency penalties of traditional vsync-on mode. This is achieved through a variable refresh rate mechanism that responds to the actual rendering performance.
Solution Approach 2:
The patent changes the refresh rate parameter from a fixed value to a variable value that adapts to rendering conditions. By encoding timing information and using it to adjust the display refresh rate dynamically, the system optimizes both synchronization and latency performance based on actual rendering rates.
2Stability of the object's composition
If vsync-on mode is used to maintain fixed refresh rate, then display stability is improved, but effective refresh rate is halved when GPU render rate is slower than display refresh rate
Solution Approach 1:
The system dynamically adjusts the display refresh rate to match the GPU rendering rate, preventing the halving effect that occurs in fixed refresh rate modes. When the GPU renders at a lower rate, the display automatically reduces its refresh rate accordingly, maintaining stability while preserving the actual rendering throughput.
3Loss of time
If vsync-off mode is used to reduce latency and improve rendering speed, then rendering performance is improved, but tear lines appear on the display
Solution Approach 1:
The patent uses dynamic refresh rate adjustment to eliminate tear lines while maintaining the low-latency benefits of vsync-off mode. By synchronizing the variable display refresh rate with the GPU rendering rate through encoded timing information, the system ensures that frame data is complete when displayed, preventing partial frame rendering that causes tears.
Solution Approach 2:
The system implements feedback by encoding timing information from the GPU rendering process and using it to control the display refresh rate. This closed-loop approach ensures that the display is always synchronized with the actual rendering completion, eliminating tear lines while maintaining responsive performance.
4Device complexity
If fixed refresh rate display is used, then display device simplicity is improved, but adaptability to variable rendering rates is reduced
Solution Approach 1:
The patent introduces dynamic refresh rate capability that allows the display device to adapt to variable rendering rates without requiring complete system redesign. The display device incorporates a variable refresh rate controller that adjusts operating parameters in real-time based on encoded timing information from the rendering system.
Data Source
AI summary
A method for rendering and displaying video. The method includes executing an application at a processor. As instructed by the processor when executing the application, the method includes rendering a plurality of image frames at a plurality of graphics processing units (GPUs). The method includes determining information related to relative timing between renderings of the plurality of image frames. The method includes encoding the plurality of image frames into a video file. The method includes encoding the information into the video file.