How to detect if an MPMediaItem represents a DRM-p

问题:

I would like to know if an MPMediaItem that represents a music track is for a Fairplay/DRM-protected item. Any way to do this?

回答1:

Here's how I do it:

MPMediaItem* item;

NSURL* assetURL = [item valueForProperty:MPMediaItemPropertyAssetURL];
NSString *title=[item valueForProperty:MPMediaItemPropertyTitle];

if (!assetURL) {
    /*
     * !!!: When MPMediaItemPropertyAssetURL is nil, it typically means the file
     * in question is protected by DRM. (old m4p files)
     */
    NSLog(@"%@ has DRM",title);
}

回答2:

Since iOS 4.2 there is a way. There may be a more effective way then the example here (but for my app I needed to create AVPlayerItems anyway).

MPMediaItem item;
NSURL *assetURL = [item valueForProperty:MPMediaItemPropertyAssetURL];
AVPlayerItem *avItem = [[AVPlayerItem alloc] initWithURL:assetURL];
BOOL fairplayed = avItem.asset.hasProtectedContent;

回答3:

From iOS 4.2 the AVAsset class has a property hasProtectedContent so you can check:

NSURL *assetURL = [item valueForProperty:MPMediaItemPropertyAssetURL];
AVAsset *asset = [AVAsset assetWithURL:assetURL];

if ([asset hasProtectedContent] == NO) {..do your stuff..}

回答4:

MPMediaItemPropertyAssetURL is not nil on iPhone X running iOS 11 for songs saved offline via Apple Music but AVPlayer is unable to play them since they are DRM protected. The same song returns MPMediaItemPropertyAssetURL nil on iOS 9.

MPMediaItemPropertyAssetURL returns nil for songs added to Library via Apple Music but not available offline - both on iOS 9 & 11.

Thus, @voidStern's answer (and not Justin Kent's) is the correct way to test for DRM-protected asset.

Swift 4 version of voidStern's answer (works perfectly for me on iOS 9 to 11):

let itemUrl = targetMPMediaItem?.value(forProperty: MPMediaItemPropertyAssetURL) as? URL
if itemUrl != nil {
    let theAsset = AVAsset(url: itemUrl!)
    if theAsset.hasProtectedContent {
        //Asset is protected
        //Must be played only via MPPlayer
    } else {
        //Asset is not protected
        //Can be played both via AVPlayer & MPPlayer\
    }
} else {
    //probably the asset is not avilable offline
    //Must be played only via MPPlayer
}

Another correct way of checking for DRM-protected asset is by making use of protectedAsset property of MPMediaItem - an answer by @weirdyu. But, this property is available only on iOS 9.2 and above.

Swift 4 solution for this method (works perfectly for me on iOS 9.2 and above):

if #available(iOS 9.2, *) {
    if (targetMPMediaItem?.hasProtectedAsset)! {
        //asset is protected
        //Must be played only via MPMusicPlayer
    } else {
        //asset is not protected
        //Can be played both via AVPlayer & MPMusicPlayer
    }
} else {
    //Fallback on earlier versions
    //Probably use the method explained earlier
}

回答5:

iOS9.2+： Please use MPMediaItem "protectedAsset" property

iOS9.2-： Judge MPMediaItem"assetURL"property is nil or not

回答6:

Justin Kents' solution works great. I recommend using blocks though or else the UX will suffer if you deal with a bunch of songs:

-(void)checkDRMprotectionForItem:(MPMediaItem*)item OnCompletion:(void (^)(BOOL drmProtected))completionBlock
{
    dispatch_async(_drmCheckQueue, ^{
        BOOL drmStatus;
        NSURL* assetURL = [item valueForProperty:MPMediaItemPropertyAssetURL];
        if (!assetURL) {
            drmStatus = YES;
        }

        dispatch_async(dispatch_get_main_queue(), ^{
            if (completionBlock) {
                completionBlock(drmStatus);
            }
    });
    });
}

回答7:

Now I'm building on swift 2 for ios 9, I found my code broken using hasProtectedContent or using nil url test. I've found the following code work:

    let playerItem = AVPlayerItem(URL: mpMediaItem.assetURL!)
    playableByAVPlayer = (playerItem.status == .ReadyToPlay) ? true : false

If the item is not playable by AV Player, then it's a DRM item and should be played by iPod Player (now called SystemMusicPlayer).