How to get the accurate time position of a live streaming in avplayer

I know this question is old, but I had the same requirement and I believe the solutions aren't addressing properly the intent of the question.

What I did for this same requirement was to gather the current point in time, the starting time, and the length of the total duration of the stream.

I'll explain something before going further, the current point in time could surpass the (starting time + total duration) this is due to the way hls is structured as ts segments. Ts segments are small chucks of playable video, you could have on your seekable range 5 ts segments of 10 seconds each. This doesn't mean that 50 secs is the full length of the live stream, there is around a full segment more (so 60 seconds of playtime total) but it isn't categorized as seekable since you shouldn't seek to that segment. If you were to do this you'll notice in most instances rebuffering (cause the source may be still creating the next ts segment when you already reached the end of playback).

What I did was checking if the current stream time is further than the seekable rage, if so this would mean were are live on stream. If it isn't you could easily calculate how far behind you are from live if you subtract the current time, starting time, and total duration.

let timeRange:CMTimeRange = player.currentItem?.seekableTimeRanges.last
let start = timeRange.start.seconds
let totalDuration = timeRange.duration.seconds
let currentTime = player.currentTime().seconds
let secondsBehindLive = currentTime - totalDuration - start

The code above will give you a negative number with the number of seconds behind "live" or more specifically the start of the lastest ts segment. Or a positive number or zero when it's playing the latest ts segment.

Tbh I don't really know when does the seekableTimeRanges will have more than 1 value, it has always been just one for the streams I have tested with, but if you find in your streams more than 1 value you may have to figure if you want to add all the ranges duration, which time range to use as the start value, etc. At least for my use case, this was enough.

Swift solution :

   override func getLiveDuration() -> Float {
    var result : Float = 0.0;

    if let items = player.currentItem?.seekableTimeRanges {

        if(!items.isEmpty) {
            let range = items[items.count - 1]
            let timeRange = range.timeRangeValue
            let startSeconds = CMTimeGetSeconds(timeRange.start)
            let durationSeconds = CMTimeGetSeconds(timeRange.duration)

            result = Float(startSeconds + durationSeconds)
        }

    }
    return result;
}

To get a live position poison and seek to it you can by using seekableTimeRanges of AVPlayerItem:

CMTimeRange seekableRange = [player.currentItem.seekableTimeRanges.lastObject CMTimeRangeValue];
CGFloat seekableStart = CMTimeGetSeconds(seekableRange.start);
CGFloat seekableDuration = CMTimeGetSeconds(seekableRange.duration);
CGFloat livePosition = seekableStart + seekableDuration;

[player seekToTime:CMTimeMake(livePosition, 1)];

Also when you seek some time back, you can get current playing position by calling currentTime method

CGFloat current = CMTimeGetSeconds([self.player.currentItem currentTime]);
CGFloat diff = livePosition - current;