Ios 使用avplayer播放音频时如何将音频缓存到本地

我使用AVPlayer在线播放音频，并希望在AVPlayer完成加载流时将音频数据/流保存到本地

我的实施方式如下：

    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
}

- (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];
}

当url为http/https时，它不会调用resourceLoader（resourceLoader:AVAssetResourceLoader，ShouldWaitForLoadingFrequestedResource…-），当url为自定义（例如：“测试”）时，它会调用resourceLoader（resourceLoader:AVAssetResourceLoader，ShouldWaitForLoadingFrequestedResource…

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谁知道原因，resourceLoader不支持http/https吗？

当播放器不知道如何加载文件时，它会调用

resourceLoader（resourceLoader:AVAssetResourceLoader，应该等待LoadingFrequestedResource…

方法。因为它知道如何加载URL，所以它不会调用此方法，所以您必须传递自定义URL。

这似乎详细说明了您要查找的内容

上面的链接详细介绍了如何设置自定义URL方案以及如何设置AVAssetResourceLoaderDelegate以在加载资源时处理该资源。其初始化为：

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];

然后，委托方法的实现将类似于以下内容：

    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
}

- (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];
}

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其中，LSFilePlayerResourceLoader和LSFilePlayerResourceLoader是用于处理所接收数据的自定义对象（详细信息请参见链接）.

在这里，您可以找到基于本机AVPlayerItem的自定义加载程序。

1.这并不能真正回答他的问题，他问的是为什么AVAssetResourceLoader不能在http/https中工作。2.当您提出自己的书面库作为解决方案时，您应该披露您是上述库的作者这一事实。。。