Swiftを使用してポッドキャストからすべての関連データまたはメタデータを取得するにはどうすればよいですか？

Question

私は現在Swift 3を使ってポッドキャストプレーヤーを作成していますが、ポッドキャストファイルに関連付けられたすべての「隠した」データ（メタデータ）にアクセスする際に問題があります。

特に、AppleのPodcastアプリでは、「コメント」または詳細な説明が表示されます。この情報は、MPMediaPlayer を使用しているときには利用できません。

正しい軌道上にあるように見えるが、スウィフトを使用して私のために十分に特異的ではないこのポストを私を見つけた： Getting podcast metadata from from iPodLibrary

どのように私はこの追加情報にアクセスすることができますか？

また、私のSwit 3アプリにリンクコード（Obj-C）を実装する方法はありますか？

編集：

OK、私は解決策に近づいています。しかし、私は今、次の構造で特定のキーに到達する方法を理解することができません。

は、ここで私は、この関数にポッドキャスト（アイテム）を送信する私の現在のコードの最初：

format:org.id3 
metadata description:[<AVMetadataItem: 0x174005f40, identifier=id3/TIT2, keySpace=org.id3, key class = NSTaggedPointerString, key=TIT2, commonKey=title, extendedLanguageTag=(null), dataType=(null), time={INVALID}, duration={INVALID}, startDate=(null), extras={ 
}, value=FriComedy: The News Quiz 3rd Feb 2017>, <AVMetadataItem: 0x174006160, identifier=id3/TPE1, keySpace=org.id3, key class = NSTaggedPointerString, key=TPE1, commonKey=artist, extendedLanguageTag=(null), dataType=(null), time={INVALID}, duration={INVALID}, startDate=(null), extras={ 
}, value=BBC Radio 4>, <AVMetadataItem: 0x174006310, identifier=id3/TALB, keySpace=org.id3, key class = NSTaggedPointerString, key=TALB, commonKey=albumName, extendedLanguageTag=(null), dataType=(null), time={INVALID}, duration={INVALID}, startDate=(null), extras={ 
}, value=Friday Night Comedy from BBC Radio 4>, <AVMetadataItem: 0x174006130, identifier=id3/TCON, keySpace=org.id3, key class = NSTaggedPointerString, key=TCON, commonKey=type, extendedLanguageTag=(null), dataType=(null), time={INVALID}, duration={INVALID}, startDate=(null), extras={ 
}, value=Podcast>, <AVMetadataItem: 0x174006320, identifier=id3/USLT, keySpace=org.id3, key class = NSTaggedPointerString, key=USLT, commonKey=(null), extendedLanguageTag= , dataType=(null), time={INVALID}, duration={INVALID}, startDate=(null), extras={ 
    info = ""; 
}, value=Susan Calman, Andy Hamilton, Katy Brand and Lloyd Langford are amongst Miles' esteemed guests for this week's round of news-wrangling. 



Theresa May won a vote, Donald Trump won a vote and François Fillon might have to drop out of a vote. Orangutans can't vote but still feature in the programme. 



Producer: Richard Morris 

A BBC Studios Production>, <AVMetadataItem: 0x174006330, identifier=id3/COMM, keySpace=org.id3, key class = NSTaggedPointerString, key=COMM, commonKey=(null), extendedLanguageTag=en, dataType=(null), time={INVALID}, duration={INVALID}, startDate=(null), extras={ 
    info = ""; 
}, value=Susan Calman, Andy Hamilton, Katy Brand and Lloyd Langford are amongst Miles' esteemed guests for this week's round of news-wrangling. 



Theresa May won a vote, Donald Trump won a vote and François Fillon might have to drop out of a vote. Orangutans can't vote but still feature in the programme. 



Producer: Richard Morris 

A BBC Studios Production>, <AVMetadataItem: 0x174006340, identifier=id3/TCOP, keySpace=org.id3, key class = NSTaggedPointerString, key=TCOP, commonKey=copyrights, extendedLanguageTag=(null), dataType=(null), time={INVALID}, duration={INVALID}, startDate=(null), extras={ 
}, value=(c) BBC 2017>, <AVMetadataItem: 0x174006350, identifier=id3/APIC, keySpace=org.id3, key class = NSTaggedPointerString, key=APIC, commonKey=artwork, extendedLanguageTag=(null), dataType=com.apple.metadata.datatype.JPEG, time={INVALID}, duration={INVALID}, startDate=(null), extras={ 
    dataType = "image/jpeg"; 
    dataTypeNamespace = "org.iana.media-type"; 
    info = ""; 
    pictureType = "Cover (front)"; 
}, value length=50551>, <AVMetadataItem: 0x174006360, identifier=id3/TIT3, keySpace=org.id3, key class = NSTaggedPointerString, key=TIT3, commonKey=description, extendedLanguageTag=(null), dataType=(null), time={INVALID}, duration={INVALID}, startDate=(null), extras={ 
}, value=A satirical review of the week's news, chaired by Miles Jupp>, <AVMetadataItem: 0x174006370, identifier=id3/TYER, keySpace=org.id3, key class = NSTaggedPointerString, key=TYER, commonKey=(null), extendedLanguageTag=(null), dataType=(null), time={INVALID}, duration={INVALID}, startDate=(null), extras={ 
}, value=2017>, <AVMetadataItem: 0x174006380, identifier=id3/TDRL, keySpace=org.id3, key class = NSTaggedPointerString, key=TDRL, commonKey=(null), extendedLanguageTag=(null), dataType=(null), time={INVALID}, duration={INVALID}, startDate=(null), extras={ 
}, value=2017-02-03T18:57:00Z>, <AVMetadataItem: 0x174006390, identifier=id3/COMM, keySpace=org.id3, key class = NSTaggedPointerString, key=COMM, commonKey=(null), extendedLanguageTag=en, dataType=(null), time={INVALID}, duration={INVALID}, startDate=(null), extras={ 
    info = iTunPGAP; 
}, value=0>, <AVMetadataItem: 0x1740063a0, identifier=id3/PCST, keySpace=org.id3, key class = NSTaggedPointerString, key=PCST, commonKey=(null), extendedLanguageTag=(null), dataType=(null), time={INVALID}, duration={INVALID}, startDate=(null), extras={ 
}, value length=4>, <AVMetadataItem: 0x1740063b0, identifier=id3/TDES, keySpace=org.id3, key class = NSTaggedPointerString, key=TDES, commonKey=(null), extendedLanguageTag=(null), dataType=(null), time={INVALID}, duration={INVALID}, startDate=(null), extras={ 
}, value=Susan Calman, Andy Hamilton, Katy Brand and Lloyd Langford are amongst Miles' esteemed guests for this week's round of news-wrangling. 



Theresa May won a vote, Donald Trump won a vote and François Fillon might have to drop out of a vote. Orangutans can't vote but still feature in the programme. 



Producer: Richard Morris 

A BBC Studios Production>, <AVMetadataItem: 0x1740063c0, identifier=id3/TGID, keySpace=org.id3, key class = NSTaggedPointerString, key=TGID, commonKey=(null), extendedLanguageTag=(null), dataType=(null), time={INVALID}, duration={INVALID}, startDate=(null), extras={ 
}, value=urn:bbc:podcast:p04rt97d>, <AVMetadataItem: 0x1740063d0, identifier=id3/WFED, keySpace=org.id3, key class = NSTaggedPointerString, key=WFED, commonKey=(null), extendedLanguageTag=(null), dataType=(null), time={INVALID}, duration={INVALID}, startDate=(null), extras={ 
}, value=%00http://www.bbc.co.uk/programmes/p02pc9pj/episodes/downloads.rss%00>] 

私は隔離しようとしています：指定されたポッドキャストのために、この出力を生成

///////// key=TDS 
func getMeta(_ item: MPMediaItem){ 
    print("") 
    print("--------- GETMETA ---------") 
    let url = item.value(forProperty:MPMediaItemPropertyAssetURL) as? NSURL 
    let asset = AVURLAsset(url: url as! URL, options: nil) 

    let formatsKey = "availableMetadataFormats" 
    asset.loadValuesAsynchronously(forKeys: [formatsKey]) { 
     var error: NSError? = nil 
     let status = asset.statusOfValue(forKey: formatsKey, error: &error) 
     if status == .loaded { 
      for format in asset.availableMetadataFormats { 
       let metadata = asset.metadata(forFormat: format) 
       print("format:\(format)") 
       print("metadata description:\(metadata.description)") 
      } 
     } 
    } 
} 
///////// 

key=TDESのテキスト/値identifier=id3/TDES

Answer 1

OK、多くの掘り下げと質問をして、ここでは、私は最短のコードPodcastを含むMPMediaItemから任意の/すべてのメタデータをループすることができます。 コードはスウィフト3

// Use this function to get and search through all the metadata from an MPMediaItem 
      func getMeta(_ item: MPMediaItem)->String{ 
       let url = item.value(forProperty:MPMediaItemPropertyAssetURL) as? NSURL 
       let asset = AVURLAsset(url: url! as URL, options: nil) 

       var sMetaValue: String = "" 

       // If you want to parse metadata based on a specific format or key space, 
       // uncomment the line below and comment the line 2 below 
       // let metaArray = asset.metadata(forFormat: "org.id3") 
       let metaArray = asset.metadata 
       for metadata in metaArray{ 
        // Uncomment this print to see all the metadata 
        //print("----- metadata:\(metadata)") 
        let sKey = returnKeyString(metadata.identifier!) 
        // See if the returned key matches your intent 
        if (sKey == "tdes"){ 
         if let sVal = metadata.stringValue{ 
          sMetaValue = sVal 
         } 
        } 
       } 
      } 

    // Helper function to parse the identifier - easier than working with keys 
      func returnKeyString(_ inVal: String)->String{ 
       // expecting the metadata for "identifier" as input - returns key value 
       // eg "itsk/ldes" -> "ldes" 
       // or "id3/%00WFD" etc. -> "wfd" 
       var sFinal:String = "" 

       if (inVal.contains("/")){ 
        sFinal = (inVal.components(separatedBy: "/")[1]) 
       } 
       if sFinal.contains("%"){ 
        sFinal = sFinal.components(separatedBy: "%")[1] 
        let index1 = sFinal.index(sFinal.startIndex, offsetBy: 2) 
        sFinal = sFinal.substring(from: index1) 
       } 
       return sFinal.lowercased() 
      }