diff --git a/src/main/java/me/mrletsplay/videobase/Config.java b/src/main/java/me/mrletsplay/videobase/Config.java
index 43a3878..9259ec1 100644
--- a/src/main/java/me/mrletsplay/videobase/Config.java
+++ b/src/main/java/me/mrletsplay/videobase/Config.java
@@ -1,11 +1,18 @@
 package me.mrletsplay.videobase;
 
+import java.util.List;
+import java.util.Objects;
+
+import me.mrletsplay.mrcore.json.JSONType;
 import me.mrletsplay.mrcore.json.converter.JSONConstructor;
 import me.mrletsplay.mrcore.json.converter.JSONConvertible;
+import me.mrletsplay.mrcore.json.converter.JSONListType;
 import me.mrletsplay.mrcore.json.converter.JSONValue;
 
 public class Config implements JSONConvertible {
 
+	public static final List<String> DEFAULT_FILE_TYPES = List.of("mp4", "mpeg", "mkv", "flv", "avi", "webm");
+
 	@JSONValue
 	private String libraryPath;
 
@@ -15,6 +22,10 @@ public class Config implements JSONConvertible {
 	@JSONValue
 	private String cachePath;
 
+	@JSONValue
+	@JSONListType(JSONType.STRING)
+	private List<String> includeFileTypes;
+
 	@JSONConstructor
 	private Config() {}
 
@@ -30,11 +41,20 @@ public class Config implements JSONConvertible {
 		return cachePath;
 	}
 
+	public List<String> getIncludeFileTypes() {
+		return includeFileTypes == null ? DEFAULT_FILE_TYPES : includeFileTypes;
+	}
+
+	public void validate() {
+		Objects.requireNonNull(libraryPath, "libraryPath");
+	}
+
 	public static Config createDefault() {
 		Config config = new Config();
 		config.libraryPath = "library";
 		config.readOnly = false;
 		config.cachePath = "cache";
+		config.includeFileTypes = DEFAULT_FILE_TYPES;
 		return config;
 	}
 
diff --git a/src/main/java/me/mrletsplay/videobase/VideoBase.java b/src/main/java/me/mrletsplay/videobase/VideoBase.java
index ffcbaac..3e7e54d 100644
--- a/src/main/java/me/mrletsplay/videobase/VideoBase.java
+++ b/src/main/java/me/mrletsplay/videobase/VideoBase.java
@@ -4,7 +4,6 @@ import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
-import java.util.Objects;
 import java.util.concurrent.Executors;
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.TimeUnit;
@@ -20,6 +19,7 @@ import me.mrletsplay.simplehttpserver.http.cors.CorsConfiguration;
 import me.mrletsplay.simplehttpserver.http.server.HttpServer;
 import me.mrletsplay.videobase.library.Library;
 import me.mrletsplay.videobase.rest.LibraryAPI;
+import me.mrletsplay.videobase.util.ThumbnailCreator;
 
 public class VideoBase {
 
@@ -48,6 +48,7 @@ public class VideoBase {
 			}
 
 			config = JSONConverter.decodeObject(new JSONObject(Files.readString(configPath, StandardCharsets.UTF_8)), Config.class);
+			config.validate();
 		} catch (IOException e) {
 			LOGGER.error("Failed to load config", e);
 			System.exit(1);
@@ -82,8 +83,8 @@ public class VideoBase {
 	}
 
 	private static void loadLibrary() {
-		Objects.requireNonNull(config.getLibraryPath(), "libraryPath");
 		library = Library.load(Path.of(config.getLibraryPath()), config.isReadOnly());
+		ThumbnailCreator.clearCache();
 	}
 
 }
diff --git a/src/main/java/me/mrletsplay/videobase/library/Library.java b/src/main/java/me/mrletsplay/videobase/library/Library.java
index b98b7aa..e69757c 100644
--- a/src/main/java/me/mrletsplay/videobase/library/Library.java
+++ b/src/main/java/me/mrletsplay/videobase/library/Library.java
@@ -113,6 +113,10 @@ public class Library {
 
 	private static void load(Path rootPath, Path path, List<Video> videos, VideoMetadata parentDefaultMetadata) {
 		if(!Files.isDirectory(path)) return;
+		if(Files.isRegularFile(path.resolve(".nomedia"))) {
+			VideoBase.LOGGER.debug("Ignoring folder at " + path + ": .nomedia file exists");
+			return;
+		}
 
 		LibraryMetadata libraryMetadata = null;
 
@@ -138,21 +142,31 @@ public class Library {
 					.filter(p -> path.equals(p.getParent()))
 					.sorted(Comparator.comparing(p -> p.getFileName().toString()))
 					.collect(Collectors.toList())) {
-				String fileName = subPath.getFileName().toString();
-				String fileNameNoExt = fileName;
-				if(fileNameNoExt.contains(".")) {
-					fileNameNoExt = fileNameNoExt.substring(0, fileNameNoExt.lastIndexOf('.'));
-				}
-
 				if(Files.isDirectory(subPath)) {
+					if(libraryMetadata != null && libraryMetadata.getExcludePaths().contains(subPath.getFileName().toString())) {
+						VideoBase.LOGGER.debug("Ignoring folder at " + subPath + ": Listed in excludedPaths");
+						continue;
+					}
+
 					load(rootPath, subPath, videos, defaultMetadata);
 					continue;
 				}
 
+				String fileName = subPath.getFileName().toString();
 				if(fileName.equals(METADATA_NAME) || fileName.endsWith(VIDEO_METADATA_SUFFIX)) {
 					continue;
 				}
 
+				if(!VideoBase.getConfig().getIncludeFileTypes().stream().anyMatch(ext -> fileName.endsWith("." + ext))) {
+					VideoBase.LOGGER.debug("Ignoring file at " + subPath + ": No valid file extension");
+					continue;
+				}
+
+				String fileNameNoExt = fileName;
+				if(fileNameNoExt.contains(".")) {
+					fileNameNoExt = fileNameNoExt.substring(0, fileNameNoExt.lastIndexOf('.'));
+				}
+
 				VideoMetadata inferredVideoMetadata = new VideoMetadata(new JSONObject(Map.of(
 					VideoMetadata.FIELD_TITLE, fileNameNoExt
 				)));
diff --git a/src/main/java/me/mrletsplay/videobase/library/LibraryMetadata.java b/src/main/java/me/mrletsplay/videobase/library/LibraryMetadata.java
index 9fe4a15..90bd2dc 100644
--- a/src/main/java/me/mrletsplay/videobase/library/LibraryMetadata.java
+++ b/src/main/java/me/mrletsplay/videobase/library/LibraryMetadata.java
@@ -1,12 +1,15 @@
 package me.mrletsplay.videobase.library;
 
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 
 import me.mrletsplay.mrcore.json.JSONObject;
+import me.mrletsplay.mrcore.json.JSONType;
 import me.mrletsplay.mrcore.json.converter.JSONConstructor;
 import me.mrletsplay.mrcore.json.converter.JSONConverter;
 import me.mrletsplay.mrcore.json.converter.JSONConvertible;
+import me.mrletsplay.mrcore.json.converter.JSONListType;
 import me.mrletsplay.mrcore.json.converter.JSONValue;
 
 public class LibraryMetadata implements JSONConvertible {
@@ -14,6 +17,10 @@ public class LibraryMetadata implements JSONConvertible {
 	@JSONValue("default")
 	private VideoMetadata defaultMetadata;
 
+	@JSONValue
+	@JSONListType(JSONType.STRING)
+	private List<String> excludePaths;
+
 	private Map<String, VideoMetadata> overrides;
 
 	@JSONConstructor
@@ -25,6 +32,10 @@ public class LibraryMetadata implements JSONConvertible {
 		return defaultMetadata;
 	}
 
+	public List<String> getExcludePaths() {
+		return excludePaths;
+	}
+
 	public Map<String, VideoMetadata> getOverrides() {
 		return overrides;
 	}
diff --git a/src/main/java/me/mrletsplay/videobase/rest/LibraryAPI.java b/src/main/java/me/mrletsplay/videobase/rest/LibraryAPI.java
index 93696ed..363afa8 100644
--- a/src/main/java/me/mrletsplay/videobase/rest/LibraryAPI.java
+++ b/src/main/java/me/mrletsplay/videobase/rest/LibraryAPI.java
@@ -189,9 +189,10 @@ public class LibraryAPI implements EndpointCollection {
 
 		try {
 			long length = Files.size(videoPath);
+			String contentType = Files.probeContentType(videoPath);
 			InputStream in = Files.newInputStream(videoPath);
 			ctx.getServerHeader().setCompressionEnabled(false);
-			ctx.getServerHeader().setContent(MimeType.of("video/mpeg"), in, length);
+			ctx.getServerHeader().setContent(MimeType.of(contentType == null ? "video/mpeg" : contentType), in, length);
 		} catch (IOException e) {
 			ctx.respond(HttpStatusCodes.INTERNAL_SERVER_ERROR_500, new TextResponse("Failed to load video"));
 			return;
diff --git a/src/main/java/me/mrletsplay/videobase/util/ThumbnailCreator.java b/src/main/java/me/mrletsplay/videobase/util/ThumbnailCreator.java
index ba871bc..eab0c79 100644
--- a/src/main/java/me/mrletsplay/videobase/util/ThumbnailCreator.java
+++ b/src/main/java/me/mrletsplay/videobase/util/ThumbnailCreator.java
@@ -8,6 +8,8 @@ import java.io.InputStream;
 import java.io.OutputStream;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.util.HashMap;
+import java.util.Map;
 import java.util.concurrent.TimeUnit;
 
 import javax.imageio.ImageIO;
@@ -17,19 +19,37 @@ import me.mrletsplay.videobase.library.Video;
 
 public class ThumbnailCreator {
 
+	private static Map<String, BufferedImage> cachedThumbnails = new HashMap<>();
+
+	public static void clearCache() {
+		cachedThumbnails.clear();
+	}
+
 	public static BufferedImage createThumbnail(Video video) {
-		Path cacheDir = Path.of(VideoBase.getConfig().getCachePath()).resolve("thumbnails").toAbsolutePath();
-		Path thumbnailFile = cacheDir.resolve(video.getId() + ".png");
-		try {
-			Files.createDirectories(cacheDir);
-			if(Files.exists(thumbnailFile)) {
-				try(InputStream in = Files.newInputStream(thumbnailFile)) {
-					return ImageIO.read(in);
+		if(cachedThumbnails.containsKey(video.getId())) {
+			return cachedThumbnails.get(video.getId());
+		}
+
+		String cachePath = VideoBase.getConfig().getCachePath();
+		Path thumbnailFile = null;
+
+		if(cachePath != null) {
+			thumbnailFile = Path.of(cachePath).resolve("thumbnails").resolve(video.getId() + ".png").toAbsolutePath();
+
+			try {
+				if(Files.exists(thumbnailFile)) {
+					try(InputStream in = Files.newInputStream(thumbnailFile)) {
+						BufferedImage thumbnail = ImageIO.read(in);
+						if(thumbnail == null) return null;
+
+						cachedThumbnails.put(video.getId(), thumbnail);
+						return thumbnail;
+					}
 				}
+			} catch (IOException e) {
+				VideoBase.LOGGER.warn("Failed to load thumbnail", e);
+				return null;
 			}
-		} catch (IOException e) {
-			VideoBase.LOGGER.warn("Failed to load thumbnail", e);
-			return null;
 		}
 
 		ProcessBuilder ffmpegBuilder = new ProcessBuilder("ffmpeg",
@@ -70,10 +90,14 @@ public class ThumbnailCreator {
 			BufferedImage thumbnail = ImageIO.read(new ByteArrayInputStream(bOut.toByteArray()));
 			if(thumbnail == null) return null;
 
-			try(OutputStream out = Files.newOutputStream(thumbnailFile)) {
-				ImageIO.write(thumbnail, "PNG", out);
+			if(thumbnailFile != null) {
+				Files.createDirectories(thumbnailFile.getParent());
+				try(OutputStream out = Files.newOutputStream(thumbnailFile)) {
+					ImageIO.write(thumbnail, "PNG", out);
+				}
 			}
 
+			cachedThumbnails.put(video.getId(), thumbnail);
 			return thumbnail;
 		} catch (InterruptedException | IOException e) {
 			VideoBase.LOGGER.warn("Failed to create thumbnail", e);