Bug 216076

Created attachment 407762 [details] Console errors on playback Using the latest STP, I'm trying to use the newly available timeslice parameter in the MediaRecorder.start() method. When creating short videos (~10 seconds) things seem to work as expected. However, when creating longer videos (1 minute or greater), the video will only play through a portion of the video and the console will log saying there was an internal webkit error. Steps to reproduce - 1. Visit https://codesandbox.io/s/media-recorder-6tlzb (sandbox is set to use a 1000ms timeslice) 2. Press "Start Camera" and allow permissions. 3. Press "Start Recording" and let the recording run for 1 minute or longer. 4. Press "Stop Recording" 5. Press "Play" Actual Results Playback is shorter than the recorded duration, and the console logs an internal webkit error. "Failed to load resource: WebKit encountered an internal error" "Failed to load resource: The operation couldn’t be completed. (WebKitBlobResource error 1.)" Expected Results Video plays through the same length as the recorded duration with no errors. Additional Information: Release 112 (Safari 14.0, WebKit 15610.1.25.5.1) macOS 10.15.6 (19G2021)