Preloading video to play without delay

Question

there are tons of topics on SO about video preloading but still isn't crystal clear for me.

Objectives:

1. Load video from the network, URL is given
2. Wait for video loaded completely
3. Play video without delay (as I said it's already buffered 100%)

Ideally, calculate download speed, predict f.e when buffered 60% of video, we start playing and 40% will be buffered while playing without delay.

what I tried:

 NSURL *url = [NSURL URLWithString:@"video url address here"];
 AVURLAsset *avasset = [[AVURLAsset alloc] initWithURL:url options:nil];

 AVPlayerItem *item = [[AVPlayerItem alloc] initWithAsset:avasset];
 self.player = [[AVPlayer alloc] initWithPlayerItem:item];

 self.playerLayer = [AVPlayerLayer playerLayerWithPlayer:self.player];
 CGSize size = self.view.bounds.size;
 float x = size.width/2.0-202.0;
 float y = size.height/2.0 - 100;

 self.playerLayer.frame = CGRectMake(x, y, 404, 200);
 self.playerLayer.backgroundColor = [UIColor blackColor].CGColor;

 [self.view.layer addSublayer:self.playerLayer];
 NSString *tracksKey = @"tracks";

 [avasset loadValuesAsynchronouslyForKeys:[NSArray arrayWithObject:tracksKey] completionHandler:
     ^{
         dispatch_async(dispatch_get_main_queue(),
                        ^{
                            NSError *error = nil;
                            AVKeyValueStatus status = [avasset statusOfValueForKey:tracksKey error:&error];
                                NSLog(@"Status %d", status);
                            if (status == AVKeyValueStatusLoaded) {
                                [self.player play];
                            }
                            else {
                                NSLog(@"The asset's tracks were not loaded:\n%@", [error localizedDescription]);
                            }
                        });
     }];
}

Video starts playing and on slow connection hangs out, but if we start playing, let's say after 1 minute, it plays nicely.

The main question - is there ability to get notified when it can be start and play till the end without delaying?

Note: not really important whether it's a AVFoundation or MPMovieController

My assuming that it only can be done by downloading video separately, storing it locally and then playing. Negative aspect there - we can't start playing until whole file is downloaded.

Answer 1

You could key-value observe on the AVPlayerItem's playbackLikelyToKeepUp, playbackBufferEmpty, and playbackBufferFull properties to get a sense of your player's status. See finer details about when these values are true in the docs. Notably:

It is possible for playbackLikelyToKeepUp to indicate NO while the property playbackBufferFull indicates YES. In this event the playback buffer has reached capacity but there isn't the statistical data to support a prediction that playback is likely to keep up in the future. It is up to you to decide whether to continue media playback.