Background: For iOS, I have built a custom video record app that records video at the highest possible FPS (supposed to be around 240 FPS but more like ~200 in practice). When I save this video to the user's camera roll, I notice this dynamic playback speed bar. This bar will speed up or slow down the video.
My question: How can I save my video such that this playback speed bar is constantly slow or plays at real time speed?
For reference I have include the playback speed bar that I am talking about in the screenshot, you can find this in the photo app when you record slow motion video.
I'm not sure whether your intent is for the high-frame-rate captures your app generates are to be used for slomo effects or not. The user experience in the Photos app is to allow users to edit the slomo time range and speed for "slomo" videos. There is a metadata tag you can attach to indicate that a video isn't appropriate for the slomo effect but it doesn't sound like you want to block it.
If you're talking about playing in your app: you have two options: you could use playback rates other than 1.0, or you could construct a scaled edit that means that at 1x playback, that timerange of media should play at a different rate from its original timing. Scaled edits can be set up using AVMutableComposition, and can be persisted using AVAssetExportSession.
