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Save shaps80/ac16b906938ad256e1f47b52b4809512 to your computer and use it in GitHub Desktop.
| public enum Direction { | |
| case forward | |
| case backward | |
| } | |
| internal var player: AVPlayer? | |
| private var isSeekInProgress = false | |
| private var chaseTime = kCMTimeZero | |
| private var preferredFrameRate: Float = 23.98 | |
| public func seek(to time: CMTime) { | |
| seekSmoothlyToTime(newChaseTime: time) | |
| } | |
| public func stepByFrame(in direction: Direction) { | |
| let frameRate = preferredFrameRate | |
| ?? player?.currentItem?.tracks | |
| .first(where: { $0.assetTrack.mediaType == .video })? | |
| .currentVideoFrameRate | |
| ?? -1 | |
| let time = player?.currentItem?.currentTime() ?? kCMTimeZero | |
| let seconds = Double(1) / Double(frameRate) | |
| let timescale = Double(seconds) / Double(time.timescale) < 1 ? 600 : time.timescale | |
| let oneFrame = CMTime(seconds: seconds, preferredTimescale: timescale) | |
| let next = direction == .forward | |
| ? CMTimeAdd(time, oneFrame) | |
| : CMTimeSubtract(time, oneFrame) | |
| seekSmoothlyToTime(newChaseTime: next) | |
| } | |
| private func seekSmoothlyToTime(newChaseTime: CMTime) { | |
| if CMTimeCompare(newChaseTime, chaseTime) != 0 { | |
| chaseTime = newChaseTime | |
| if !isSeekInProgress { | |
| trySeekToChaseTime() | |
| } | |
| } | |
| } | |
| private func trySeekToChaseTime() { | |
| guard player?.status == .readyToPlay else { return } | |
| actuallySeekToTime() | |
| } | |
| private func actuallySeekToTime() { | |
| isSeekInProgress = true | |
| let seekTimeInProgress = chaseTime | |
| player?.seek(to: seekTimeInProgress, toleranceBefore: kCMTimeZero, toleranceAfter: kCMTimeZero) { [weak self] _ in | |
| guard let `self` = self else { return } | |
| if CMTimeCompare(seekTimeInProgress, self.chaseTime) == 0 { | |
| self.isSeekInProgress = false | |
| } else { | |
| self.trySeekToChaseTime() | |
| } | |
| } | |
| } |
This was actually recommended by someone on the AV team but I think your approach is different in that you use very different tolerances.
I guess this could be recommended if you want to avoid downloading too many segments while seeking, but this of course depends on the desired user experience. As far as I can see AVPlayerViewController nowadays seem to avoid seek cancellation, probably as described in Apple dedicated Q&A article.
Side note btw regarding AVPlayerController. I believe at one point I discovered that actually they use the thumbnail generator to improve the perceived responsiveness.
Note sure if they use AVAssetImageGenerator directly but if HLS streams contain I-frames the player surely uses them (even without changing the actual player speed to values > 2, which I initially thought might be required).
BTW you can easily test the behavior our implementation achieves by installing our demo app from TestFlight. The first demo tab has a lot of different streams from several sources (with various encodings and packagings), including the standard Apple test streams. You can also use the demo to compare the behavior we obtain vs. the one provided by the system player UI since we also have included the vanilla system experience in our demo as well (2nd tab).
Oh that’s amazing thanks! Unfortunately your beta isn’t accepting lol but I trust you.
Should be fixed now, sorry, there was no recent build enabled for external testing 😇
👍👍
Side note btw regarding AVPlayerController. I believe at one point I discovered that actually they use the thumbnail generator to improve the perceived responsiveness. I did this in another product (simple video editor) alongside the code above and it had a drastic impact on the UX. but if your approach improves the actual seeking as well then that just another huge plus.