How to cache audio to local when playing audio with avplayer

Question

I play an audio online with AVPlayer,and want to save the data/stream of audio to local when avplayer finish loading stream.

I implementt it as the following:

    let fileUrl =  NSURL(string: strUrl)!
    let asset = AVURLAsset(URL: fileUrl)
    asset.resourceLoader.setDelegate(self, queue:dispatch_queue_create("AVARLDelegateDemo loader", nil))
    self.pendingRequests = [AVAssetResourceLoadingRequest]()

    asset.loadValuesAsynchronouslyForKeys(["playable"]){
        dispatch_async( dispatch_get_main_queue()){
            self.prepareToPlayAsset(asset, requestedKeys: ["playable"])
        }
    }


  func resourceLoader(resourceLoader: AVAssetResourceLoader, shouldWaitForLoadingOfRequestedResource loadingRequest: AVAssetResourceLoadingRequest) -> Bool {
    .......
    return false
}

When url is http/https, it does not call resourceLoader(resourceLoader: AVAssetResourceLoader, shouldWaitForLoadingOfRequestedResource.... -, when url is customize (eg.:'test'), it call resourceLoader(resourceLoader: AVAssetResourceLoader, shouldWaitForLoadingOfRequestedResource...

Who know the reason, Does resourceLoader not support http/https?

Answer 1

When player doesn't know how to load a file, it calls resourceLoader(resourceLoader: AVAssetResourceLoader, shouldWaitForLoadingOfRequestedResource... method. So since it knows how to load URL, it wont call this method, so you have to pass custom URL.

Answer 2

This sample project and tutorial seems to detail what you're looking for.

the link above details setting a custom URL scheme and setting an AVAssetResourceLoaderDelegate to handle the resource as it loads. This is initialised as:

NSURL *url = [NSURL URLWithString:@"customscheme://host/audio.mp3"];
AVURLAsset *asset = [AVURLAsset URLAssetWithURL:url options:nil];
[asset.resourceLoader setDelegate:self queue:dispatch_get_main_queue()];

AVPlayerItem *item = [AVPlayerItem playerItemWithAsset:asset];
[self addObserversForPlayerItem:item];

self.player = [AVPlayer playerWithPlayerItem:playerItem];
[self addObserversForPlayer];

The implementation of the delegate methods would then look similar to the following:

- (BOOL)resourceLoader:(AVAssetResourceLoader *)resourceLoader shouldWaitForLoadingOfRequestedResource:(AVAssetResourceLoadingRequest*)loadingRequest{

    NSURL *resourceURL = [loadingRequest.request URL];

    if([resourceURL.scheme isEqualToString:@"customscheme"]){
        LSFilePlayerResourceLoader *loader = [self resourceLoaderForRequest:loadingRequest];

        if(loader==nil){
            loader = [[LSFilePlayerResourceLoader alloc] initWithResourceURL:resourceURL session:self.session];
            loader.delegate = self;
            [self.resourceLoaders setObject:loader forKey:[self keyForResourceLoaderWithURL:resourceURL]];
        }

        [loader addRequest:loadingRequest];

        return YES;
    }
    return NO;
}

- (void)resourceLoader:(AVAssetResourceLoader *)resourceLoader didCancelLoadingRequest:(AVAssetResourceLoadingRequest *)loadingRequest{

    LSFilePlayerResourceLoader *loader = [self resourceLoaderForRequest:loadingRequest];

    [loader removeRequest:loadingRequest];
}

Where LSFilePlayerResourceLoader and LSFilePlayerResourceLoader are custom objects for handling the data being received (detailed in the link).