AVPlayer primarily measures times with CMTime. However when using an AVPlayerItemMetadataCollector to collect date range metadata from an HLS stream, the resulting AVDateRangeMetadataGroups hold NSDates instead of CMTimes.
My problem is I want to add a boundary time observer to the player so I know when the playback head actually enters the date range, but you can only add a boundary time observer using CMTime. AVPlayer and AVPlayerItem can seek to a Date and can give me the current playback head as a Date, but I don't see any way to convert a given Date into a CMTime that I can use to set a boundary time observer.
In theory if I knew what the EXT-X-PROGRAM-DATE-TIME tag said I could calculate a CMTime offset myself, but I don't see a way to retrieve that.
The only other thought I had was to retrieve both currentTime and currentDate from the AVPlayerItem, then calculate the relative offset between currentDate and my target date and apply that to the CMTime. But a problem with this solution is the currentDate and currentTime won't represent the exact same time. The delta is presumably going to be very small, but it won't be zero (unless the rate itself is zero).