Fix issue #279 -- Missing Album Art

Add offline (id3) art scanning via StorageItemThumbnail as a backup for online album art downloader in cases where no artwork is found online.

Add MusicTagReader fetcher to VLC.MediaMetaFetcher.

app/VLC.Core/Helpers/MusicLibrary/MusicLibraryManagement.cs

@@ -83,5 +83,12 @@ namespace VLC.Helpers.MusicLibrary
             //    LogHelper.Log(StringsHelper.ExceptionToString(e));
             //}
         }
+
+        public TrackItem GetAlbumFirstTrack(int albumId)
+        {
+            MusicDatabase musicDb = new MusicDatabase();
+            TrackItem track = musicDb.LoadTracksFromAlbumId(albumId).FirstOrDefault();
+            return track;
+        }
     }
 }

app/VLC.Core/Services/RunTime/MusicMetaService.cs

@@ -18,7 +18,7 @@ namespace VLC.Services.RunTime
     public sealed class MusicMetaService
     {
         readonly MusicMDFetcher musicMdFetcher = new MusicMDFetcher(App.DeezerAppID, App.ApiKeyLastFm);
-
+       
         public async Task GetSimilarArtists(ArtistItem artist)
         {
             var artists = await musicMdFetcher.GetArtistSimilarsArtist(artist.Name);
@@ -68,6 +68,19 @@ namespace VLC.Services.RunTime
                     return true;
                 }
             }
+            //If no art is found online, use embedded art
+            Helpers.MusicLibrary.MusicLibrary musicLib = new Helpers.MusicLibrary.MusicLibrary();
+            TrackItem firstTrack = musicLib.GetAlbumFirstTrack(album.Id);
+            if (firstTrack != null)
+            {
+                var bytes = await musicMdFetcher.GetAlbumPictureFromTag(firstTrack.Path);
+                var tagReadSuccess = bytes != null && await SaveAlbumImageAsync(album, bytes);
+                if (tagReadSuccess)
+                {
+                    Locator.MediaLibrary.Update(album);
+                    return true;
+                }
+            }
             return false;
         }
 

app/VLC.MediaMetaFetcher/Fetchers/MusicTagReader.cs

+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.Threading.Tasks;
+using VLC.Database;
+using Windows.Storage.FileProperties;
+using Windows.Storage;
+using System.IO;
+
+namespace VLC.MusicMetaFetcher.Fetchers
+{
+    public static class MusicTagReader
+    {
+
+        public static async Task<byte[]> ReadAlbumCoverFromTag(string filePath)
+        {
+            StorageFile musicFile = await StorageFile.GetFileFromPathAsync(filePath);
+            StorageItemThumbnail img =  await musicFile.GetThumbnailAsync(ThumbnailMode.MusicView,600);    
+            if(img != null && img.Type == ThumbnailType.Image)
+            {
+                byte[] imgBytes = new byte[img.Size];
+                Stream imgStream = img.AsStream();
+                imgStream.Position = 0;
+                await imgStream.ReadAsync(imgBytes, 0, Convert.ToInt32(img.Size));
+                return imgBytes;
+            }
+            return null;
+        }
+    }
+}

app/VLC.MediaMetaFetcher/MusicMDFetcher.cs

@@ -16,7 +16,6 @@ using System.Threading.Tasks;
 using Newtonsoft.Json.Linq;
 using VLC.MusicMetaFetcher.Fetchers;
 using VLC.MusicMetaFetcher.Models.MusicEntities;
-
 namespace VLC.MusicMetaFetcher
 {
     public class MusicMDFetcher
@@ -156,6 +155,13 @@ namespace VLC.MusicMetaFetcher
             return gotArt;
         }
 
+        public async Task<byte[]> GetAlbumPictureFromTag(string filePath)
+        {
+            byte[] tagArt = null;
+            tagArt = await MusicTagReader.ReadAlbumCoverFromTag(filePath);
+            return tagArt;
+        }
+
         public async Task<List<Album>> GetArtistTopAlbums(string artistName)
         {
             try

app/VLC.MediaMetaFetcher/VLC_WinRT.MusicMetaFetcher.projitems

@@ -14,6 +14,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)Fetchers\IMusicMetaFetcher.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Fetchers\LastFmClient.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Fetchers\MovieDbClient.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Fetchers\MusicTagReader.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Fetchers\OpenSubtitleClient.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Models\Deezer\Albums.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Models\Deezer\Artists.cs" />