Bug 198912

When using MediaRecorder to recording a file in portrait mode, for ex. recording a video message using the frontal camera, Safari automatically switches width/height (640x480 => 480x640) but does not applies necessary transformation which results the video track to be rotated 90deg thus stretching the video making it hardly usable, please see [1]. Similar kind of distortions, upside-down video, etc. could be observed while holding the phone in any other orientation except landscape with camera on the right side. After looking at the source code I discover recording is performed using AVAssetWriterInput[2]. According to the dev docs [3] the issue could be resolved using the "transform" property to rotate the image according to the current device orientation [5]. You can find an example of transformation for each screen orientation via the following link [6]. I would be glad to provide a patch, unfortunately iOS Simulator does not supports webcams nor it is possible to deploy a debug version of WebKit to an iOS device. Please let me know if I can help with any further debugging. Thank you very much in advance, Igor [1] https://www.dropbox.com/s/3kdx77bmw2mghvi/Vid%C3%A9o%2017.06.19%2011%2052%2040.mp4?dl=0 [2] https://github.com/WebKit/webkit/blob/master/Source/WebCore/platform/mediarecorder/cocoa/MediaRecorderPrivateWriterCocoa.h#L70 [3] https://developer.apple.com/library/archive/qa/qa1744/_index.html#avassetwriter [4] https://developer.apple.com/documentation/avfoundation/avassetwriterinput/1390183-transform [5] https://github.com/remirobert/CameraEngine/blob/master/CameraEngine/CameraEngineVideoEncoder.swift#L130 [6] https://github.com/remirobert/CameraEngine/blob/master/CameraEngine/CameraEngineVideoEncoder.swift#L83-L86