How to get file size and current file size from NSURL for AVPlayer iOS4.0

问题

self.player = [[AVPlayer playerWithURL:[NSURL URLWithString:@"http://myurl.com/track.mp3"]] retain];

I am trying make a UIProgressView for the above track. How do I obtain the file size and current file size from that URL? Please help, thanks!

回答1:

You need to start observing the loadedTimeRanges property of the current item, like this:

AVPlayerItem* playerItem = self.player.currentItem;
[playerItem addObserver:self forKeyPath:kLoadedTimeRanges options:NSKeyValueObservingOptionNew context:playerItemTimeRangesObservationContext];

Then, in the observation callback, you make sense of the data you're passed like this:

-(void)observeValueForKeyPath:(NSString*)aPath ofObject:(id)anObject change:(NSDictionary*)aChange context:(void*)aContext {

if (aContext == playerItemTimeRangesObservationContext) {

    AVPlayerItem* playerItem = (AVPlayerItem*)anObject;
    NSArray* times = playerItem.loadedTimeRanges;

    // there is only ever one NSValue in the array
    NSValue* value = [times objectAtIndex:0];

    CMTimeRange range;
    [value getValue:&range];
    float start = CMTimeGetSeconds(range.start);
    float duration = CMTimeGetSeconds(range.duration);

    _videoAvailable = start + duration; // this is a float property of my VC
    [self performSelectorOnMainThread:@selector(updateVideoAvailable) withObject:nil waitUntilDone:NO];
}

Then the selector on the main thread updates a progress bar, like so:

-(void)updateVideoAvailable {

    CMTime playerDuration = [self playerItemDuration];
double duration = CMTimeGetSeconds(playerDuration);
    _videoAvailableBar.progress = _videoAvailable/duration;// this is a UIProgressView
}

回答2:

I think you do not want to know anything about file-sizes, but you're more interested in times.

Try self.player.currentItem.asset.duration for duration of currently playing item, self.player.currentTime for current time.

回答3:

@"loadedTimeRange" is a KVO value for the AVPlayerItem class. You can find its definition in the AVPlayerItem.h file in the

@interface AVPlayerItem (AVPlayerItemPlayability)

category definition.

来源：https://stackoverflow.com/questions/3999228/how-to-get-file-size-and-current-file-size-from-nsurl-for-avplayer-ios4-0

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