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I'm working on an app that supports iOS 8 and above. A major feature of it is video playback, for which I'm using AVPlayerViewController. I feed the player controller an AVQueuePlayer, which I'm loading up with AVPlayerItems that are initialized with URLs for m3u8 files.Anyway, for reasons not worth getting into, the m3u8 files don't have references to our WebVTT files, but I do have URLs for sidecar WebVTT files. I'm trying to figure out how to provide the URLs for these sidecar files to the appropriate point of the AV stack, but I'm not making a lot of headway. Can someone offer me a pointer?