Reduce Android display latency by setting the desired frame timestamp - #6792
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shiumano wants to merge 4 commits into
Open
Reduce Android display latency by setting the desired frame timestamp#6792shiumano wants to merge 4 commits into
shiumano wants to merge 4 commits into
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Display latency is reduced by two frames.
latency-before-after.mp4
I also checked using Perfetto, the official Android profiling tool.
(Trace coinfig: config.txtpb.txt)
Before
After
The meanings of each location are as follows:
①: The application has started rendering
②: The application has finished rendering
③: The frame to be composited has been selected
④: The frame has been displayed on the screen
I haven't addressed the time taken for the ①→② step this time; please disregard it, as it varies significantly depending on the situation.
The improvement made this time concerns the time taken for the ②→③ step.
Description of changes for ec1a4f5
After calling
eglPresentationTimeANDROID, VSync no longer worked as expected even with SwapInterval set to 1.Therefore, I implemented Choreographer as an alternative to VSync.
Details
By the way, Choreographer is extremely strict .
If the load increases even slightly, the frame rate immediately drops from 120fps to 60fps—far more drastically than with
SwapInterval(1).As it stands, I believe there are only a handful of devices capable of consistently maintaining 120fps with VSync.
Furthermore, unfortunately, 240fps results in less latency than 120fps with V-Sync.