Hi there,
So I've been banging my head for the last week, because we have an issue in our app where it's freezing on export while the composition has a AVVideoCompositionCoreAnimationTool as animationTool
Before extracting the code to an app I can share, or submit a TSIs, I was wondering if this rings a bell to someone.
Basically, we're not doing something too crazy
We create an AVAssetExportSession from a composition, some audio and some layers to animate.
func makeExportable(configuration: ExportConfiguration) throws -> AVAssetExportSession {
if let animationLayer {
let rect = CGRect(origin: .zero, size: configuration.videoSize)
let videoAnimationLayer = CALayer()
videoAnimationLayer.frame = rect
let videoLayer = CALayer()
videoLayer.frame = rect
videoAnimationLayer.addSublayer(videoLayer)
videoAnimationLayer.addSublayer(animationLayer)
videoAnimationLayer.isGeometryFlipped = true
let animationTool = AVVideoCompositionCoreAnimationTool(postProcessingAsVideoLayer: videoLayer,
in: videoAnimationLayer)
avVideoComposition.animationTool = animationTool
}
guard
let session = AVAssetExportSession(asset: avComposition,
presetName: configuration.avAssetExportPresetName) else {
throw CompositionError.invalidExportSession
}
session.audioMix = audioMix
session.videoComposition = avVideoComposition
return session)
}
Then we run await session.export()
If we do that multiple times in a row (there are no specific triggers, I can have a 3s video with 40 CALayers or a 30s with 1500 layers, it could happen on the first export or the 20th, ...), then at some point, the app will just have a severe hang with the following stack trace (if I pause the debug session).
If ever, I remove the avVideoComposition.animationTool = animationTool line from the export session creation, then the app does not hang...
Also, I encounter the issue with the fact that it's crashing on a sim but running fine on a device. Some api_misuse crash (see [here)]. Could this be related, idk...(https://developer.apple.com/forums/thread/133681)
Anyway... Completely stuck here, and surprised that such a thing would have an issue on AVFoundation. We're probably not the onliest using CoreAnimation on a video export...
Thanks!
Marian
