Use ffmpeg

Dockerfile

@@ -9,6 +9,7 @@ RUN mvn -B package -DskipTests
 
 FROM eclipse-temurin:17-jre
 WORKDIR /app
+RUN apt-get update && apt-get install -y ffmpeg && rm -rf /var/lib/apt/lists/*
 COPY --from=build /app/target/imgfloat-*.jar app.jar
 EXPOSE 8080 8443
 ENV JAVA_OPTS=""

pom.xml

@@ -81,18 +81,6 @@
             <artifactId>spring-boot-starter-validation</artifactId>
         </dependency>
 
-        <dependency>
-            <groupId>org.jcodec</groupId>
-            <artifactId>jcodec</artifactId>
-            <version>0.2.5</version>
-        </dependency>
-
-        <dependency>
-            <groupId>org.jcodec</groupId>
-            <artifactId>jcodec-javase</artifactId>
-            <version>0.2.5</version>
-        </dependency>
-
         <dependency>
             <groupId>org.springframework.session</groupId>
             <artifactId>spring-session-jdbc</artifactId>

shell.nix

@@ -1,10 +1,13 @@
-{ pkgs ? import <nixpkgs> { } }:
+{
+  pkgs ? import <nixpkgs> { },
+}:
 
 pkgs.mkShell {
   packages = [
     pkgs.jdt-language-server
     pkgs.libxkbcommon
     pkgs.maven
+    pkgs.ffmpeg
     pkgs.openjdk
     pkgs.git-lfs
   ];

src/main/java/dev/kruhlmann/imgfloat/service/AssetStorageService.java

@@ -3,8 +3,8 @@ package dev.kruhlmann.imgfloat.service;
 import dev.kruhlmann.imgfloat.service.media.AssetContent;
 import java.io.IOException;
 import java.nio.file.*;
+import dev.kruhlmann.imgfloat.service.media.MediaTypeRegistry;
 import java.util.Locale;
-import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
 import org.slf4j.Logger;
@@ -16,30 +16,7 @@ import org.springframework.stereotype.Service;
 public class AssetStorageService {
 
     private static final Logger logger = LoggerFactory.getLogger(AssetStorageService.class);
-    private static final Map<String, String> EXTENSIONS = Map.ofEntries(
+    private static final String DEFAULT_PREVIEW_MEDIA_TYPE = "image/png";
-        Map.entry("image/png", ".png"),
-        Map.entry("image/jpeg", ".jpg"),
-        Map.entry("image/jpg", ".jpg"),
-        Map.entry("image/gif", ".gif"),
-        Map.entry("image/webp", ".webp"),
-        Map.entry("image/bmp", ".bmp"),
-        Map.entry("image/tiff", ".tiff"),
-        Map.entry("video/mp4", ".mp4"),
-        Map.entry("video/webm", ".webm"),
-        Map.entry("video/quicktime", ".mov"),
-        Map.entry("video/x-matroska", ".mkv"),
-        Map.entry("audio/mpeg", ".mp3"),
-        Map.entry("audio/mp3", ".mp3"),
-        Map.entry("audio/wav", ".wav"),
-        Map.entry("audio/ogg", ".ogg"),
-        Map.entry("audio/webm", ".webm"),
-        Map.entry("audio/flac", ".flac"),
-        Map.entry("model/gltf-binary", ".glb"),
-        Map.entry("model/gltf+json", ".gltf"),
-        Map.entry("model/obj", ".obj"),
-        Map.entry("application/javascript", ".js"),
-        Map.entry("text/javascript", ".js")
-    );
 
     private final Path assetRoot;
     private final Path previewRoot;
@@ -119,7 +96,7 @@ public class AssetStorageService {
             if (!Files.exists(file)) return Optional.empty();
 
             byte[] bytes = Files.readAllBytes(file);
-            return Optional.of(new AssetContent(bytes, "image/png"));
+            return Optional.of(new AssetContent(bytes, DEFAULT_PREVIEW_MEDIA_TYPE));
         } catch (Exception e) {
             logger.warn("Failed to load preview {}", assetId, e);
             return Optional.empty();
@@ -196,10 +173,9 @@ public class AssetStorageService {
     }
 
     private String resolveExtension(String mediaType) throws IOException {
-        if (mediaType == null || !EXTENSIONS.containsKey(mediaType)) {
+        return MediaTypeRegistry
-            throw new IOException("Unsupported media type: " + mediaType);
+            .extensionForMediaType(mediaType)
-        }
+            .orElseThrow(() -> new IOException("Unsupported media type: " + mediaType));
-        return EXTENSIONS.get(mediaType);
     }
 
     private Path assetPath(String broadcaster, String assetId, String mediaType) throws IOException {

src/main/java/dev/kruhlmann/imgfloat/service/ChannelDirectoryService.java

@@ -37,6 +37,7 @@ import dev.kruhlmann.imgfloat.service.media.AssetContent;
 import dev.kruhlmann.imgfloat.service.media.MediaDetectionService;
 import dev.kruhlmann.imgfloat.service.media.MediaOptimizationService;
 import dev.kruhlmann.imgfloat.service.media.OptimizedAsset;
+import dev.kruhlmann.imgfloat.service.media.MediaTypeRegistry;
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -303,11 +304,11 @@ public class ChannelDirectoryService {
         byte[] bytes = file.getBytes();
         String mediaType = mediaDetectionService
             .detectAllowedMediaType(file, bytes)
-            .orElseThrow(() -> new ResponseStatusException(BAD_REQUEST, "Unsupported media type"));
+            .orElseThrow(() -> new ResponseStatusException(BAD_REQUEST, unsupportedMediaTypeMessage()));
 
         OptimizedAsset optimized = mediaOptimizationService.optimizeAsset(bytes, mediaType);
         if (optimized == null) {
-            return Optional.empty();
+            throw new ResponseStatusException(BAD_REQUEST, mediaProcessingErrorMessage());
         }
 
         String safeName = Optional.ofNullable(file.getOriginalFilename())
@@ -499,10 +500,10 @@ public class ChannelDirectoryService {
         enforceUploadLimit(bytes.length);
         String mediaType = mediaDetectionService
             .detectAllowedMediaType(file, bytes)
-            .orElseThrow(() -> new ResponseStatusException(BAD_REQUEST, "Unsupported media type"));
+            .orElseThrow(() -> new ResponseStatusException(BAD_REQUEST, unsupportedMediaTypeMessage()));
         OptimizedAsset optimized = mediaOptimizationService.optimizeAsset(bytes, mediaType);
         if (optimized == null) {
-            return Optional.empty();
+            throw new ResponseStatusException(BAD_REQUEST, mediaProcessingErrorMessage());
         }
         AssetType assetType = AssetType.fromMediaType(optimized.mediaType(), mediaType);
         if (assetType != AssetType.IMAGE) {
@@ -1344,11 +1345,11 @@ public class ChannelDirectoryService {
         byte[] bytes = file.getBytes();
         String mediaType = mediaDetectionService
             .detectAllowedMediaType(file, bytes)
-            .orElseThrow(() -> new ResponseStatusException(BAD_REQUEST, "Unsupported media type"));
+            .orElseThrow(() -> new ResponseStatusException(BAD_REQUEST, unsupportedMediaTypeMessage()));
 
         OptimizedAsset optimized = mediaOptimizationService.optimizeAsset(bytes, mediaType);
         if (optimized == null) {
-            return Optional.empty();
+            throw new ResponseStatusException(BAD_REQUEST, mediaProcessingErrorMessage());
         }
 
         AssetType assetType = AssetType.fromMediaType(optimized.mediaType(), mediaType);
@@ -1504,6 +1505,14 @@ public class ChannelDirectoryService {
         return normalized.startsWith("application/javascript") || normalized.startsWith("text/javascript");
     }
 
+    private String unsupportedMediaTypeMessage() {
+        return "Unsupported media type. Supported types: " + MediaTypeRegistry.supportedMediaTypesSummary();
+    }
+
+    private String mediaProcessingErrorMessage() {
+        return "Unable to process media. Ensure ffmpeg is installed on the server.";
+    }
+
     private void validateCodeAssetSource(String source) {
         if (source == null || source.isBlank()) {
             throw new ResponseStatusException(BAD_REQUEST, "Script source is required");

src/main/java/dev/kruhlmann/imgfloat/service/media/FfmpegService.java

@@ -0,0 +1,168 @@
+package dev.kruhlmann.imgfloat.service.media;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Optional;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Service;
+
+@Service
+public class FfmpegService {
+
+    private static final Logger logger = LoggerFactory.getLogger(FfmpegService.class);
+
+    public Optional<VideoDimensions> extractVideoDimensions(byte[] bytes) {
+        return Optional.ofNullable(withTempFile(bytes, ".bin", (input) -> {
+            List<String> command = List.of(
+                "ffprobe",
+                "-v",
+                "error",
+                "-select_streams",
+                "v:0",
+                "-show_entries",
+                "stream=width,height",
+                "-of",
+                "csv=p=0:s=x",
+                input.toString()
+            );
+            ProcessResult result = run(command);
+            if (result.exitCode() != 0) {
+                logger.warn("ffprobe failed: {}", result.output());
+                return null;
+            }
+            String output = result.output().trim();
+            if (output.isBlank() || !output.contains("x")) {
+                return null;
+            }
+            String[] parts = output.split("x", 2);
+            try {
+                int width = Integer.parseInt(parts[0].trim());
+                int height = Integer.parseInt(parts[1].trim());
+                return new VideoDimensions(width, height);
+            } catch (NumberFormatException e) {
+                logger.warn("Unable to parse ffprobe output: {}", output, e);
+                return null;
+            }
+        }));
+    }
+
+    public Optional<byte[]> extractVideoPreview(byte[] bytes) {
+        return Optional.ofNullable(withTempFile(bytes, ".bin", (input) -> {
+            Path output = Files.createTempFile("imgfloat-preview", ".png");
+            try {
+                List<String> command = List.of(
+                    "ffmpeg",
+                    "-y",
+                    "-hide_banner",
+                    "-loglevel",
+                    "error",
+                    "-i",
+                    input.toString(),
+                    "-frames:v",
+                    "1",
+                    "-f",
+                    "image2",
+                    "-vcodec",
+                    "png",
+                    output.toString()
+                );
+                ProcessResult result = run(command);
+                if (result.exitCode() != 0) {
+                    logger.warn("ffmpeg preview failed: {}", result.output());
+                    return null;
+                }
+                return Files.readAllBytes(output);
+            } finally {
+                Files.deleteIfExists(output);
+            }
+        }));
+    }
+
+    public Optional<byte[]> transcodeGifToMp4(byte[] bytes) {
+        return Optional.ofNullable(withTempFile(bytes, ".gif", (input) -> {
+            Path output = Files.createTempFile("imgfloat-transcode", ".mp4");
+            try {
+                List<String> command = List.of(
+                    "ffmpeg",
+                    "-y",
+                    "-hide_banner",
+                    "-loglevel",
+                    "error",
+                    "-i",
+                    input.toString(),
+                    "-movflags",
+                    "+faststart",
+                    "-pix_fmt",
+                    "yuv420p",
+                    "-vf",
+                    "scale=trunc(iw/2)*2:trunc(ih/2)*2",
+                    output.toString()
+                );
+                ProcessResult result = run(command);
+                if (result.exitCode() != 0) {
+                    logger.warn("ffmpeg transcode failed: {}", result.output());
+                    return null;
+                }
+                return Files.readAllBytes(output);
+            } finally {
+                Files.deleteIfExists(output);
+            }
+        }));
+    }
+
+    private <T> T withTempFile(byte[] bytes, String suffix, TempFileHandler<T> handler) {
+        Path input = null;
+        try {
+            input = Files.createTempFile("imgfloat-input", suffix);
+            Files.write(input, bytes);
+            return handler.handle(input);
+        } catch (IOException e) {
+            logger.warn("Unable to create temporary media file", e);
+            return null;
+        } finally {
+            if (input != null) {
+                try {
+                    Files.deleteIfExists(input);
+                } catch (IOException e) {
+                    logger.warn("Unable to delete temporary file {}", input, e);
+                }
+            }
+        }
+    }
+
+    private ProcessResult run(List<String> command) throws IOException {
+        ProcessBuilder builder = new ProcessBuilder(new ArrayList<>(command));
+        builder.redirectErrorStream(true);
+        Process process = builder.start();
+        String output;
+        try (InputStream stream = process.getInputStream(); ByteArrayOutputStream baos = new ByteArrayOutputStream()) {
+            stream.transferTo(baos);
+            output = baos.toString(StandardCharsets.UTF_8);
+        } catch (IOException e) {
+            output = "";
+        }
+        int exitCode;
+        try {
+            exitCode = process.waitFor();
+        } catch (InterruptedException e) {
+            Thread.currentThread().interrupt();
+            exitCode = -1;
+        }
+        return new ProcessResult(exitCode, output);
+    }
+
+    private interface TempFileHandler<T> {
+        T handle(Path input) throws IOException;
+    }
+
+    private record ProcessResult(int exitCode, String output) {}
+
+    public record VideoDimensions(int width, int height) {}
+}

src/main/java/dev/kruhlmann/imgfloat/service/media/MediaDetectionService.java

@@ -4,9 +4,7 @@ import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.net.URLConnection;
 import java.util.Locale;
-import java.util.Map;
 import java.util.Optional;
-import java.util.Set;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.stereotype.Service;
@@ -16,46 +14,27 @@ import org.springframework.web.multipart.MultipartFile;
 public class MediaDetectionService {
 
     private static final Logger logger = LoggerFactory.getLogger(MediaDetectionService.class);
-    private static final Map<String, String> EXTENSION_TYPES = Map.ofEntries(
-        Map.entry("png", "image/png"),
-        Map.entry("jpg", "image/jpeg"),
-        Map.entry("jpeg", "image/jpeg"),
-        Map.entry("gif", "image/gif"),
-        Map.entry("webp", "image/webp"),
-        Map.entry("mp4", "video/mp4"),
-        Map.entry("webm", "video/webm"),
-        Map.entry("mov", "video/quicktime"),
-        Map.entry("mp3", "audio/mpeg"),
-        Map.entry("wav", "audio/wav"),
-        Map.entry("ogg", "audio/ogg"),
-        Map.entry("glb", "model/gltf-binary"),
-        Map.entry("gltf", "model/gltf+json"),
-        Map.entry("obj", "model/obj"),
-        Map.entry("js", "application/javascript"),
-        Map.entry("mjs", "text/javascript")
-    );
-    private static final Set<String> ALLOWED_MEDIA_TYPES = Set.copyOf(EXTENSION_TYPES.values());
 
     public Optional<String> detectAllowedMediaType(MultipartFile file, byte[] bytes) {
         Optional<String> detected = detectMediaType(bytes)
-            .map(MediaDetectionService::normalizeJavaScriptMediaType)
+            .map(MediaTypeRegistry::normalizeJavaScriptMediaType)
-            .filter(MediaDetectionService::isAllowedMediaType);
+            .filter(MediaTypeRegistry::isSupportedMediaType);
 
         if (detected.isPresent()) {
             return detected;
         }
 
         Optional<String> declared = Optional.ofNullable(file.getContentType())
-            .map(MediaDetectionService::normalizeJavaScriptMediaType)
+            .map(MediaTypeRegistry::normalizeJavaScriptMediaType)
-            .filter(MediaDetectionService::isAllowedMediaType);
+            .filter(MediaTypeRegistry::isSupportedMediaType);
         if (declared.isPresent()) {
             return declared;
         }
 
         return Optional.ofNullable(file.getOriginalFilename())
-            .map((name) -> name.replaceAll("^.*\\.", "").toLowerCase())
+            .map((name) -> name.replaceAll("^.*\\.", "").toLowerCase(Locale.ROOT))
-            .map(EXTENSION_TYPES::get)
+            .flatMap(MediaTypeRegistry::mediaTypeForExtension)
-            .filter(MediaDetectionService::isAllowedMediaType);
+            .filter(MediaTypeRegistry::isSupportedMediaType);
     }
 
     private Optional<String> detectMediaType(byte[] bytes) {
@@ -72,8 +51,7 @@ public class MediaDetectionService {
     }
 
     public static boolean isAllowedMediaType(String mediaType) {
-        String normalized = normalizeJavaScriptMediaType(mediaType);
+        return MediaTypeRegistry.isSupportedMediaType(mediaType);
-        return normalized != null && ALLOWED_MEDIA_TYPES.contains(normalized.toLowerCase());
     }
 
     public static boolean isInlineDisplayType(String mediaType) {
@@ -82,15 +60,4 @@ public class MediaDetectionService {
             (mediaType.startsWith("image/") || mediaType.startsWith("video/") || mediaType.startsWith("audio/"))
         );
     }
-
-    private static String normalizeJavaScriptMediaType(String mediaType) {
-        if (mediaType == null) {
-            return null;
-        }
-        String normalized = mediaType.toLowerCase(Locale.ROOT);
-        if (normalized.contains("javascript") || normalized.contains("ecmascript")) {
-            return "application/javascript";
-        }
-        return mediaType;
-    }
 }

src/main/java/dev/kruhlmann/imgfloat/service/media/MediaOptimizationService.java

@@ -1,25 +1,9 @@
 package dev.kruhlmann.imgfloat.service.media;
 
-import java.awt.Graphics2D;
 import java.awt.image.BufferedImage;
 import java.io.ByteArrayInputStream;
-import java.io.ByteArrayOutputStream;
-import java.io.File;
 import java.io.IOException;
-import java.nio.ByteBuffer;
-import java.nio.file.Files;
-import java.util.List;
-import javax.imageio.IIOImage;
 import javax.imageio.ImageIO;
-import javax.imageio.ImageWriteParam;
-import javax.imageio.ImageWriter;
-import javax.imageio.metadata.IIOMetadata;
-import javax.imageio.stream.ImageInputStream;
-import javax.imageio.stream.ImageOutputStream;
-import org.jcodec.api.FrameGrab;
-import org.jcodec.api.JCodecException;
-import org.jcodec.common.io.ByteBufferSeekableByteChannel;
-import org.jcodec.common.model.Picture;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.stereotype.Service;
@@ -27,12 +11,18 @@ import org.springframework.stereotype.Service;
 @Service
 public class MediaOptimizationService {
 
-    private static final int MIN_GIF_DELAY_MS = 20;
     private static final Logger logger = LoggerFactory.getLogger(MediaOptimizationService.class);
-    private final MediaPreviewService previewService;
+    private static final FfmpegService.VideoDimensions DEFAULT_VIDEO_DIMENSIONS = new FfmpegService.VideoDimensions(
+        640,
+        360
+    );
 
-    public MediaOptimizationService(MediaPreviewService previewService) {
+    private final MediaPreviewService previewService;
+    private final FfmpegService ffmpegService;
+
+    public MediaOptimizationService(MediaPreviewService previewService, FfmpegService ffmpegService) {
         this.previewService = previewService;
+        this.ffmpegService = ffmpegService;
     }
 
     public OptimizedAsset optimizeAsset(byte[] bytes, String mediaType) throws IOException {
@@ -46,15 +36,6 @@ public class MediaOptimizationService {
             }
         }
 
-        if (mediaType.startsWith("image/") && !"image/gif".equalsIgnoreCase(mediaType)) {
-            BufferedImage image = ImageIO.read(new ByteArrayInputStream(bytes));
-            if (image == null) {
-                return null;
-            }
-            byte[] compressed = compressPng(image);
-            return new OptimizedAsset(compressed, "image/png", image.getWidth(), image.getHeight(), null);
-        }
-
         if (mediaType.startsWith("image/")) {
             BufferedImage image = ImageIO.read(new ByteArrayInputStream(bytes));
             if (image == null) {
@@ -64,7 +45,9 @@ public class MediaOptimizationService {
         }
 
         if (mediaType.startsWith("video/")) {
-            var dimensions = extractVideoDimensions(bytes);
+            FfmpegService.VideoDimensions dimensions = ffmpegService
+                .extractVideoDimensions(bytes)
+                .orElse(DEFAULT_VIDEO_DIMENSIONS);
             byte[] preview = previewService.extractVideoPreview(bytes, mediaType);
             return new OptimizedAsset(bytes, mediaType, dimensions.width(), dimensions.height(), preview);
         }
@@ -89,165 +72,18 @@ public class MediaOptimizationService {
     }
 
     private OptimizedAsset transcodeGifToVideo(byte[] bytes) {
-        try {
+        return ffmpegService
-            List<GifFrame> frames = readGifFrames(bytes);
+            .transcodeGifToMp4(bytes)
-            if (frames.isEmpty()) {
+            .map((videoBytes) -> {
+                FfmpegService.VideoDimensions dimensions = ffmpegService
+                    .extractVideoDimensions(videoBytes)
+                    .orElse(DEFAULT_VIDEO_DIMENSIONS);
+                byte[] preview = previewService.extractVideoPreview(videoBytes, "video/mp4");
+                return new OptimizedAsset(videoBytes, "video/mp4", dimensions.width(), dimensions.height(), preview);
+            })
+            .orElseGet(() -> {
+                logger.warn("Unable to transcode GIF to video via ffmpeg");
                 return null;
-            }
+            });
-            int baseDelay = frames
-                .stream()
-                .mapToInt((frame) -> normalizeDelay(frame.delayMs()))
-                .reduce(this::greatestCommonDivisor)
-                .orElse(100);
-            int fps = Math.max(1, (int) Math.round(1000.0 / baseDelay));
-            File temp = File.createTempFile("gif-convert", ".mp4");
-            temp.deleteOnExit();
-            try {
-                var encoder = org.jcodec.api.awt.AWTSequenceEncoder.createSequenceEncoder(temp, fps);
-                for (GifFrame frame : frames) {
-                    BufferedImage image = ensureEvenDimensions(frame.image());
-                    int repeats = Math.max(1, normalizeDelay(frame.delayMs()) / baseDelay);
-                    for (int i = 0; i < repeats; i++) {
-                        encoder.encodeImage(image);
     }
 }
-                encoder.finish();
-                BufferedImage cover = ensureEvenDimensions(frames.get(0).image());
-                byte[] video = Files.readAllBytes(temp.toPath());
-                return new OptimizedAsset(
-                    video,
-                    "video/mp4",
-                    cover.getWidth(),
-                    cover.getHeight(),
-                    previewService.encodePreview(cover)
-                );
-            } finally {
-                Files.deleteIfExists(temp.toPath());
-            }
-        } catch (IOException e) {
-            logger.warn("Unable to transcode GIF to video", e);
-            return null;
-        }
-    }
-
-    private List<GifFrame> readGifFrames(byte[] bytes) throws IOException {
-        try (ImageInputStream stream = ImageIO.createImageInputStream(new ByteArrayInputStream(bytes))) {
-            var readers = ImageIO.getImageReadersByFormatName("gif");
-            if (!readers.hasNext()) {
-                return List.of();
-            }
-            var reader = readers.next();
-            try {
-                reader.setInput(stream, false, false);
-                int count = reader.getNumImages(true);
-                var frames = new java.util.ArrayList<GifFrame>(count);
-                for (int i = 0; i < count; i++) {
-                    BufferedImage image = reader.read(i);
-                    IIOMetadata metadata = reader.getImageMetadata(i);
-                    int delay = extractDelayMs(metadata);
-                    frames.add(new GifFrame(image, delay));
-                }
-                return frames;
-            } finally {
-                reader.dispose();
-            }
-        }
-    }
-
-    private int extractDelayMs(IIOMetadata metadata) {
-        if (metadata == null) {
-            return 100;
-        }
-        try {
-            String format = metadata.getNativeMetadataFormatName();
-            var root = metadata.getAsTree(format);
-            var children = root.getChildNodes();
-            for (int i = 0; i < children.getLength(); i++) {
-                var node = children.item(i);
-                if ("GraphicControlExtension".equals(node.getNodeName()) && node.getAttributes() != null) {
-                    var delay = node.getAttributes().getNamedItem("delayTime");
-                    if (delay != null) {
-                        int hundredths = Integer.parseInt(delay.getNodeValue());
-                        return Math.max(hundredths * 10, MIN_GIF_DELAY_MS);
-                    }
-                }
-            }
-        } catch (Exception e) {
-            logger.warn("Unable to parse GIF delay", e);
-        }
-        return 100;
-    }
-
-    private int normalizeDelay(int delayMs) {
-        return Math.max(delayMs, MIN_GIF_DELAY_MS);
-    }
-
-    private int greatestCommonDivisor(int a, int b) {
-        if (b == 0) {
-            return Math.max(a, 1);
-        }
-        return greatestCommonDivisor(b, a % b);
-    }
-
-    private byte[] compressPng(BufferedImage image) throws IOException {
-        var writers = ImageIO.getImageWritersByFormatName("png");
-        if (!writers.hasNext()) {
-            logger.warn("No PNG writer available; skipping compression");
-            try (ByteArrayOutputStream fallback = new ByteArrayOutputStream()) {
-                ImageIO.write(image, "png", fallback);
-                return fallback.toByteArray();
-            }
-        }
-        ImageWriter writer = writers.next();
-        try (
-            ByteArrayOutputStream baos = new ByteArrayOutputStream();
-            ImageOutputStream ios = ImageIO.createImageOutputStream(baos)
-        ) {
-            writer.setOutput(ios);
-            ImageWriteParam param = writer.getDefaultWriteParam();
-            if (param.canWriteCompressed()) {
-                param.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
-                param.setCompressionQuality(1.0f);
-            }
-            writer.write(null, new IIOImage(image, null, null), param);
-            return baos.toByteArray();
-        } finally {
-            writer.dispose();
-        }
-    }
-
-    private BufferedImage ensureEvenDimensions(BufferedImage image) {
-        int width = image.getWidth();
-        int height = image.getHeight();
-        int evenWidth = width % 2 == 0 ? width : width + 1;
-        int evenHeight = height % 2 == 0 ? height : height + 1;
-        if (evenWidth == width && evenHeight == height) {
-            return image;
-        }
-        BufferedImage padded = new BufferedImage(evenWidth, evenHeight, BufferedImage.TYPE_INT_ARGB);
-        Graphics2D graphics = padded.createGraphics();
-        try {
-            graphics.drawImage(image, 0, 0, null);
-        } finally {
-            graphics.dispose();
-        }
-        return padded;
-    }
-
-    private Dimension extractVideoDimensions(byte[] bytes) {
-        try (var channel = new ByteBufferSeekableByteChannel(ByteBuffer.wrap(bytes), bytes.length)) {
-            FrameGrab grab = FrameGrab.createFrameGrab(channel);
-            Picture frame = grab.getNativeFrame();
-            if (frame != null) {
-                return new Dimension(frame.getWidth(), frame.getHeight());
-            }
-        } catch (IOException | JCodecException e) {
-            logger.warn("Unable to read video dimensions", e);
-        }
-        return new Dimension(640, 360);
-    }
-
-    private record GifFrame(BufferedImage image, int delayMs) {}
-
-    private record Dimension(int width, int height) {}
-}

src/main/java/dev/kruhlmann/imgfloat/service/media/MediaPreviewService.java

@@ -1,15 +1,5 @@
 package dev.kruhlmann.imgfloat.service.media;
 
-import java.awt.image.BufferedImage;
-import java.io.ByteArrayOutputStream;
-import java.io.IOException;
-import java.nio.ByteBuffer;
-import javax.imageio.ImageIO;
-import org.jcodec.api.FrameGrab;
-import org.jcodec.api.JCodecException;
-import org.jcodec.common.io.ByteBufferSeekableByteChannel;
-import org.jcodec.common.model.Picture;
-import org.jcodec.scale.AWTUtil;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.stereotype.Service;
@@ -19,31 +9,18 @@ public class MediaPreviewService {
 
     private static final Logger logger = LoggerFactory.getLogger(MediaPreviewService.class);
 
-    public byte[] encodePreview(BufferedImage image) {
+    private final FfmpegService ffmpegService;
-        if (image == null) {
+
-            return null;
+    public MediaPreviewService(FfmpegService ffmpegService) {
-        }
+        this.ffmpegService = ffmpegService;
-        try (ByteArrayOutputStream baos = new ByteArrayOutputStream()) {
-            ImageIO.write(image, "png", baos);
-            return baos.toByteArray();
-        } catch (IOException e) {
-            logger.warn("Unable to encode preview image", e);
-            return null;
-        }
     }
 
     public byte[] extractVideoPreview(byte[] bytes, String mediaType) {
-        try (var channel = new ByteBufferSeekableByteChannel(ByteBuffer.wrap(bytes), bytes.length)) {
+        return ffmpegService
-            FrameGrab grab = FrameGrab.createFrameGrab(channel);
+            .extractVideoPreview(bytes)
-            Picture frame = grab.getNativeFrame();
+            .orElseGet(() -> {
-            if (frame == null) {
+                logger.warn("Unable to capture video preview frame for {}", mediaType);
-                return null;
-            }
-            BufferedImage image = AWTUtil.toBufferedImage(frame);
-            return encodePreview(image);
-        } catch (IOException | JCodecException e) {
-            logger.warn("Unable to capture video preview frame for {}", mediaType, e);
                 return null;
-        }
+            });
     }
 }

src/main/java/dev/kruhlmann/imgfloat/service/media/MediaTypeRegistry.java

@@ -0,0 +1,111 @@
+package dev.kruhlmann.imgfloat.service.media;
+
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Locale;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+
+public final class MediaTypeRegistry {
+
+    private static final Map<String, String> EXTENSION_TO_MEDIA_TYPE = buildExtensionMap();
+    private static final Map<String, String> MEDIA_TYPE_TO_EXTENSION = buildMediaTypeMap();
+    private static final Set<String> SUPPORTED_MEDIA_TYPES = Set.copyOf(MEDIA_TYPE_TO_EXTENSION.keySet());
+
+    private MediaTypeRegistry() {}
+
+    public static Optional<String> mediaTypeForExtension(String extension) {
+        if (extension == null) {
+            return Optional.empty();
+        }
+        return Optional.ofNullable(EXTENSION_TO_MEDIA_TYPE.get(extension.toLowerCase(Locale.ROOT)));
+    }
+
+    public static Optional<String> extensionForMediaType(String mediaType) {
+        if (mediaType == null) {
+            return Optional.empty();
+        }
+        String normalized = normalizeJavaScriptMediaType(mediaType).toLowerCase(Locale.ROOT);
+        return Optional.ofNullable(MEDIA_TYPE_TO_EXTENSION.get(normalized));
+    }
+
+    public static boolean isSupportedMediaType(String mediaType) {
+        if (mediaType == null || mediaType.isBlank()) {
+            return false;
+        }
+        String normalized = normalizeJavaScriptMediaType(mediaType).toLowerCase(Locale.ROOT);
+        return SUPPORTED_MEDIA_TYPES.contains(normalized);
+    }
+
+    public static List<String> supportedMediaTypes() {
+        return SUPPORTED_MEDIA_TYPES.stream().sorted().toList();
+    }
+
+    public static String supportedMediaTypesSummary() {
+        return String.join(", ", supportedMediaTypes());
+    }
+
+    public static String normalizeJavaScriptMediaType(String mediaType) {
+        if (mediaType == null) {
+            return null;
+        }
+        String normalized = mediaType.toLowerCase(Locale.ROOT);
+        if (normalized.contains("javascript") || normalized.contains("ecmascript")) {
+            return "application/javascript";
+        }
+        return mediaType;
+    }
+
+    private static Map<String, String> buildExtensionMap() {
+        Map<String, String> map = new LinkedHashMap<>();
+        map.put("png", "image/png");
+        map.put("jpg", "image/jpeg");
+        map.put("jpeg", "image/jpeg");
+        map.put("gif", "image/gif");
+        map.put("webp", "image/webp");
+        map.put("bmp", "image/bmp");
+        map.put("tiff", "image/tiff");
+        map.put("mp4", "video/mp4");
+        map.put("webm", "video/webm");
+        map.put("mov", "video/quicktime");
+        map.put("mkv", "video/x-matroska");
+        map.put("mp3", "audio/mpeg");
+        map.put("wav", "audio/wav");
+        map.put("ogg", "audio/ogg");
+        map.put("flac", "audio/flac");
+        map.put("glb", "model/gltf-binary");
+        map.put("gltf", "model/gltf+json");
+        map.put("obj", "model/obj");
+        map.put("js", "application/javascript");
+        map.put("mjs", "text/javascript");
+        return Map.copyOf(map);
+    }
+
+    private static Map<String, String> buildMediaTypeMap() {
+        Map<String, String> map = new LinkedHashMap<>();
+        map.put("image/png", ".png");
+        map.put("image/jpeg", ".jpg");
+        map.put("image/jpg", ".jpg");
+        map.put("image/gif", ".gif");
+        map.put("image/webp", ".webp");
+        map.put("image/bmp", ".bmp");
+        map.put("image/tiff", ".tiff");
+        map.put("video/mp4", ".mp4");
+        map.put("video/webm", ".webm");
+        map.put("video/quicktime", ".mov");
+        map.put("video/x-matroska", ".mkv");
+        map.put("audio/mpeg", ".mp3");
+        map.put("audio/mp3", ".mp3");
+        map.put("audio/wav", ".wav");
+        map.put("audio/ogg", ".ogg");
+        map.put("audio/webm", ".webm");
+        map.put("audio/flac", ".flac");
+        map.put("model/gltf-binary", ".glb");
+        map.put("model/gltf+json", ".gltf");
+        map.put("model/obj", ".obj");
+        map.put("application/javascript", ".js");
+        map.put("text/javascript", ".js");
+        return Map.copyOf(map);
+    }
+}

src/main/resources/static/js/admin/console.js

@@ -2406,7 +2406,9 @@ export function createAdminConsole({
         })
             .then((response) => {
                 if (!response.ok) {
-                    throw new Error("Upload failed");
+                    return extractErrorMessage(response, "Upload failed").then((message) => {
+                        throw new Error(message);
+                    });
                 }
                 if (fileInput) {
                     fileInput.value = "";
@@ -2421,10 +2423,31 @@ export function createAdminConsole({
                 }
                 console.error(e);
                 removePendingUpload(pendingId);
-                showToast("Upload failed. Please try again with a supported file.", "error");
+                showToast(e?.message || "Upload failed. Please try again with a supported file.", "error");
             });
     }
 
+    function extractErrorMessage(response, fallback) {
+        if (!response) {
+            return Promise.resolve(fallback);
+        }
+        return response
+            .json()
+            .then((data) => {
+                if (data?.message) {
+                    return data.message;
+                }
+                if (data?.error) {
+                    return data.error;
+                }
+                if (typeof data === "string" && data.trim()) {
+                    return data;
+                }
+                return fallback;
+            })
+            .catch(() => response.text().then((text) => text?.trim() || fallback).catch(() => fallback));
+    }
+
     function getCanvasPoint(event) {
         const rect = canvas.getBoundingClientRect();
         const scaleX = canvas.width / rect.width;

src/main/resources/static/js/customAssets.js

@@ -390,7 +390,7 @@ export function createCustomAssetModal({
                 }
             })
             .catch((e) => {
-                showToast?.("Unable to save custom asset. Please try again.", "error");
+                showToast?.(e?.message || "Unable to save custom asset. Please try again.", "error");
                 console.error(e);
             })
             .finally(() => {
@@ -498,7 +498,7 @@ export function createCustomAssetModal({
                 })
                 .catch((error) => {
                     console.error(error);
-                    showToast?.("Unable to upload attachment. Please try again.", "error");
+                    showToast?.(error?.message || "Unable to upload attachment. Please try again.", "error");
                 })
                 .finally(() => {
                     attachmentInput.value = "";
@@ -591,12 +591,35 @@ export function createCustomAssetModal({
             body: payload,
         }).then((response) => {
             if (!response.ok) {
-                throw new Error("Failed to upload attachment");
+                return extractErrorMessage(response, "Failed to upload attachment").then((message) => {
+                    throw new Error(message);
+                });
             }
             return response.json();
         });
     }
 
+    function extractErrorMessage(response, fallback) {
+        if (!response) {
+            return Promise.resolve(fallback);
+        }
+        return response
+            .json()
+            .then((data) => {
+                if (data?.message) {
+                    return data.message;
+                }
+                if (data?.error) {
+                    return data.error;
+                }
+                if (typeof data === "string" && data.trim()) {
+                    return data;
+                }
+                return fallback;
+            })
+            .catch(() => response.text().then((text) => text?.trim() || fallback).catch(() => fallback));
+    }
+
     function removeAttachment(attachmentId) {
         if (!attachmentId || !currentAssetId) {
             return;
@@ -694,7 +717,9 @@ export function createCustomAssetModal({
             body: payload,
         }).then((response) => {
             if (!response.ok) {
-                throw new Error("Failed to upload logo");
+                return extractErrorMessage(response, "Failed to upload logo").then((message) => {
+                    throw new Error(message);
+                });
             }
             pendingLogoFile = null;
             return response.json();

src/test/java/dev/kruhlmann/imgfloat/ChannelDirectoryServiceTest.java

@@ -33,6 +33,7 @@ import dev.kruhlmann.imgfloat.service.SettingsService;
 import dev.kruhlmann.imgfloat.service.media.MediaDetectionService;
 import dev.kruhlmann.imgfloat.service.media.MediaOptimizationService;
 import dev.kruhlmann.imgfloat.service.media.MediaPreviewService;
+import dev.kruhlmann.imgfloat.service.media.FfmpegService;
 import java.awt.image.BufferedImage;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
@@ -88,8 +89,9 @@ class ChannelDirectoryServiceTest {
         Path assetRoot = Files.createTempDirectory("imgfloat-assets-test");
         Path previewRoot = Files.createTempDirectory("imgfloat-previews-test");
         AssetStorageService assetStorageService = new AssetStorageService(assetRoot.toString(), previewRoot.toString());
-        MediaPreviewService mediaPreviewService = new MediaPreviewService();
+        FfmpegService ffmpegService = new FfmpegService();
-        MediaOptimizationService mediaOptimizationService = new MediaOptimizationService(mediaPreviewService);
+        MediaPreviewService mediaPreviewService = new MediaPreviewService(ffmpegService);
+        MediaOptimizationService mediaOptimizationService = new MediaOptimizationService(mediaPreviewService, ffmpegService);
         MediaDetectionService mediaDetectionService = new MediaDetectionService();
         long uploadLimitBytes = 5_000_000L;
         Path marketplaceRoot = Files.createTempDirectory("imgfloat-marketplace-test");

src/test/java/dev/kruhlmann/imgfloat/service/media/MediaOptimizationServiceTest.java

@@ -15,7 +15,8 @@ class MediaOptimizationServiceTest {
 
     @BeforeEach
     void setUp() {
-        service = new MediaOptimizationService(new MediaPreviewService());
+        FfmpegService ffmpegService = new FfmpegService();
+        service = new MediaOptimizationService(new MediaPreviewService(ffmpegService), ffmpegService);
     }
 
     @Test