Improve thumbnail creation

src/main/java/me/mrletsplay/videobase/VideoBase.java

@@ -85,6 +85,7 @@ public class VideoBase {
 	private static void loadLibrary() {
 		library = Library.load(Path.of(config.getLibraryPath()), config.isReadOnly());
 		ThumbnailCreator.clearCache();
+		ThumbnailCreator.createThumbnails();
 	}
 
 }

src/main/java/me/mrletsplay/videobase/rest/LibraryAPI.java

@@ -157,7 +157,7 @@ public class LibraryAPI implements EndpointCollection {
 			return;
 		}
 
-		BufferedImage thumbnail = ThumbnailCreator.createThumbnail(video);
+		BufferedImage thumbnail = ThumbnailCreator.getThumbnail(video);
 		if(thumbnail == null) {
 			ctx.respond(HttpStatusCodes.NOT_FOUND_404, new TextResponse("No thumbnail found"));
 			return;

src/main/java/me/mrletsplay/videobase/util/ThumbnailCreator.java

@@ -8,8 +8,10 @@ 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.ConcurrentHashMap;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
 
 import javax.imageio.ImageIO;
@@ -19,33 +21,34 @@ import me.mrletsplay.videobase.library.Video;
 
 public class ThumbnailCreator {
 
-	private static Map<String, BufferedImage> cachedThumbnails = new HashMap<>();
+	private static Map<String, BufferedImage> cachedThumbnails = new ConcurrentHashMap<>();
+	private static ExecutorService executorService = Executors.newFixedThreadPool(10);
 
 	public static void clearCache() {
 		cachedThumbnails.clear();
 	}
 
+	public static void createThumbnails() {
+		for(Video v : VideoBase.getLibrary().getVideos()) {
+			executorService.submit(() -> createThumbnail(v));
+		}
+	}
+
 	public static BufferedImage createThumbnail(Video video) {
 		if(cachedThumbnails.containsKey(video.getId())) {
 			return cachedThumbnails.get(video.getId());
 		}
 
 		String cachePath = VideoBase.getConfig().getCachePath();
-		Path thumbnailFile = null;
+		Path thumbnailFile = cachePath == null ? null : Path.of(cachePath).resolve("thumbnails").resolve(video.getId() + ".png").toAbsolutePath();
 
-		if(cachePath != null) {
+		if(thumbnailFile != null && Files.isRegularFile(thumbnailFile)) {
-			thumbnailFile = Path.of(cachePath).resolve("thumbnails").resolve(video.getId() + ".png").toAbsolutePath();
+			try(InputStream in = Files.newInputStream(thumbnailFile)) {
+				BufferedImage thumbnail = ImageIO.read(in);
+				if(thumbnail == null) return null;
 
-			try {
+				cachedThumbnails.put(video.getId(), thumbnail);
-				if(Files.exists(thumbnailFile)) {
+				return thumbnail;
-					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;
@@ -54,8 +57,8 @@ public class ThumbnailCreator {
 
 		ProcessBuilder ffmpegBuilder = new ProcessBuilder("ffmpeg",
 			"-i", video.getPath().toAbsolutePath().toString(),
-			"-vf", "thumbnail",
+			"-r", "0.5",
-			"-vf", "scale=960:540:force_original_aspect_ratio=decrease,pad=960:540:-1:-1:color=black",
+			"-vf", "thumbnail,scale=960:540:force_original_aspect_ratio=decrease,pad=960:540:-1:-1:color=black",
 			"-frames:v", "1",
 			"-f", "image2pipe",
 			"-vcodec", "png",
@@ -69,18 +72,18 @@ public class ThumbnailCreator {
 			ByteArrayOutputStream bOut = new ByteArrayOutputStream();
 			byte[] buf = new byte[1024];
 			int len;
-			while(System.currentTimeMillis() - start < 1000
+			while(System.currentTimeMillis() - start < 60000
-				&& (len = ffmpeg.getInputStream().read(buf)) > 0) {
+				&& (len = ffmpeg.getInputStream().read(buf)) != -1) {
 				bOut.write(buf, 0, len);
 			}
 
-			ffmpeg.waitFor(10, TimeUnit.SECONDS);
+			ffmpeg.waitFor(60, TimeUnit.SECONDS);
 			if(ffmpeg.isAlive()) {
-				VideoBase.LOGGER.warn("ffmpeg didn't exit after 10 seconds, destroying");
+				VideoBase.LOGGER.warn("Video " + video.getId() + ": ffmpeg didn't exit after 60 seconds, destroying");
 				ffmpeg.destroy();
 
-				if(!ffmpeg.waitFor(10, TimeUnit.SECONDS)) {
+				if(!ffmpeg.waitFor(60, TimeUnit.SECONDS)) {
-					VideoBase.LOGGER.warn("ffmpeg didn't exit 10 seconds after destroying, destroying forcibly");
+					VideoBase.LOGGER.warn("Video " + video.getId() + ": ffmpeg didn't exit 60 seconds after destroying, destroying forcibly");
 					ffmpeg.destroyForcibly();
 				}
 
@@ -97,14 +100,17 @@ public class ThumbnailCreator {
 				}
 			}
 
+			VideoBase.LOGGER.debug("Created thumbnail for video at " + video.getPath());
 			cachedThumbnails.put(video.getId(), thumbnail);
 			return thumbnail;
 		} catch (InterruptedException | IOException e) {
 			VideoBase.LOGGER.warn("Failed to create thumbnail", e);
 			return null;
 		}
-
 	}
 
+	public static BufferedImage getThumbnail(Video video) {
+		return cachedThumbnails.get(video.getId());
+	}
 
 }