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AppleWebKit-based web browsers (which on iOS means more than just Safari) cannot use speed micro-adjustments to correct drift because AVFoundation's speed controls are too limited to react smoothly. We have to resort to occasional seek-to-resync instead, when the drift threshold is exceeded.
Reproduction steps:
1. Open the attached “My project” project
2. In the Build Profiles (File > Build Profiles), make sure the WebGL platform is selected
3. Build the Player and host it on a local server
4. Connect to the WebGL player with a iOS device via local IP address using Chrome or Firefox browser
5. In the Player on the device, press the “Play” Button
6. Observe the displayed video
Expected result: The playback is smooth
Actual result: The playback is jittery and lagging
Reproducible with: 2022.3.60f1, 6000.0.45f1, 6000.1.0b13, 6000.2.0a8
Couldn't test with: 2022.1.0a1 (WebGL on mobile is not supported)
Testing environment: macOS Sequoia 15.3.2 (M1 Max)
Reproducible with these devices:
VLNQA00624, iPhone 16 Pro, iOS: 18.3.1, CPU: Apple A18 Pro
VLNQA00394, iPhone 13 mini, iOS: 18.1, CPU: Apple A15 Bionic
VLNQA00359, iPhone 12 Pro, iOS: 17.6.1, CPU: Apple A14 Bionic
iPad Pro 10.5-inch, iPadOS 17.7.5 (by user)
iPhone 12 Pro max, iOS 18.3.2 (by user)
Note reproducible on these devices:
VLNQA00363, Samsung Galaxy Z Fold 2, OS: 12, CPU: Snapdragon 865 SM8250, GPU: Adreno 650
Notes:
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