update backdrops

Emby.Server.Implementations/Images/BaseDynamicImageProvider.cs

@@ -149,6 +149,11 @@ namespace Emby.Server.Implementations.Images
 
             var mimeType = MimeTypes.GetMimeType(outputPath);
 
+            if (string.Equals(mimeType, "application/octet-stream", StringComparison.OrdinalIgnoreCase))
+            {
+                mimeType = "image/png";
+            }
+
             await ProviderManager.SaveImage(item, outputPath, mimeType, imageType, null, false, cancellationToken).ConfigureAwait(false);
 
             return ItemUpdateType.ImageUpdate;

Emby.Server.Implementations/UserViews/DynamicImageProvider.cs

@@ -159,20 +159,14 @@ namespace Emby.Server.Implementations.UserViews
 
         protected override async Task<string> CreateImage(IHasImages item, List<BaseItem> itemsWithImages, string outputPathWithoutExtension, ImageType imageType, int imageIndex)
         {
-            var outputPath = Path.ChangeExtension(outputPathWithoutExtension, ".png");
-
-            var view = (UserView)item;
-            if (imageType == ImageType.Primary && IsUsingCollectionStrip(view))
+            if (itemsWithImages.Count == 0)
             {
-                if (itemsWithImages.Count == 0)
-                {
-                    return null;
-                }
-
-                return await CreateThumbCollage(item, itemsWithImages, outputPath, 960, 540).ConfigureAwait(false);
+                return null;
             }
 
-            return await base.CreateImage(item, itemsWithImages, outputPath, imageType, imageIndex).ConfigureAwait(false);
+            var outputPath = Path.ChangeExtension(outputPathWithoutExtension, ".png");
+
+            return await CreateThumbCollage(item, itemsWithImages, outputPath, 960, 540).ConfigureAwait(false);
         }
     }
 }