If I put the phone flat on a table, the left and right swipe gestures is not working but up and down gestures works. Only when I put the iPhone to some vertical degree, the left and right swipe works. Tested on 2 iPhone 7 Plus and 2 iPhone 13. Anyone has similar experience? If yes, why?

The app needs to play remote videos. Sometimes it takes very long time (~10 seconds) to load the media and play with AVPlayer. So I use a timer to check and try to play next video if it is over 5 seconds: AVURLAsset *asset = [[AVURLAsset alloc] initWithURL:videoUrl options:nil];// line 1 NSArray *keys = @[@"playable"]; mediaLoaded = NO; [asset loadValuesAsynchronouslyForKeys:keys completionHandler:^() { // line 2 mediaLoaded = YES; // line 4 dispatch_async(dispatch_get_main_queue(), ^{ [self.player replaceCurrentItemWithPlayerItem:[AVPlayerItem playerItemWithAsset:asset]]; [self.player playImmediatelyAtRate:playSpeed]; }); }]; dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(5 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{ if (!mediaLoaded) { [self playNextVideo]; // line 3 } }); So the flow is: line 1 (of video 1)- line 2 (of video 1)- line 3 (if over 5 seconds and video 1 is not playing)- line 1 (of video 2)-... Now the problem is that seems line 2 is blocking line 1: only line 4 (for video 1 after ~10 seconds) or the completionHandler is executed will line 2 (for video 2) will be executed. Anybody can give any insight? Thx!

I saw equalizer in apps like Musi and Spotify. I think (but not sure) they use HLS streaming. If so, how to implement such an equalizer for HLS? I searched and tried several approaches but so far none works, like: AVAudioEngine seems only support local file; Download .ts and merge into .mp3 to make it local can not guarantee real time effect; MTAudioProcessingTap needs the audio track. For remote .mp3 I can extract the audio track but not for HLS. Any suggestion?