diff --git a/android/src/main/java/xyz/justsoft/video_thumbnail/VideoThumbnailPlugin.java b/android/src/main/java/xyz/justsoft/video_thumbnail/VideoThumbnailPlugin.java
index 9d4c097..5f92db4 100644
--- a/android/src/main/java/xyz/justsoft/video_thumbnail/VideoThumbnailPlugin.java
+++ b/android/src/main/java/xyz/justsoft/video_thumbnail/VideoThumbnailPlugin.java
@@ -12,7 +12,6 @@
 import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.FileInputStream;
-import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.util.HashMap;
@@ -26,9 +25,6 @@
 import io.flutter.plugin.common.MethodChannel.MethodCallHandler;
 import io.flutter.plugin.common.MethodChannel.Result;
 
-/**
- * VideoThumbnailPlugin
- */
 public class VideoThumbnailPlugin implements FlutterPlugin, MethodCallHandler {
     private static String TAG = "ThumbnailPlugin";
     private static final int HIGH_QUALITY_MIN_VAL = 70;
@@ -55,15 +51,21 @@ public void onDetachedFromEngine(@NonNull FlutterPluginBinding binding) {
 
     @Override
     public void onMethodCall(@NonNull MethodCall call, @NonNull final Result result) {
-        final Map<String, Object> args = call.arguments();
-
-        final String video = (String) args.get("video");
-        final HashMap<String, String> headers = (HashMap<String, String>) args.get("headers");
-        final int format = (int) args.get("format");
-        final int maxh = (int) args.get("maxh");
-        final int maxw = (int) args.get("maxw");
-        final int timeMs = (int) args.get("timeMs");
-        final int quality = (int) args.get("quality");
+        final Object arguments = call.arguments;
+        if (!(arguments instanceof Map)) {
+            result.error("invalid_args", "Invalid arguments", null);
+            return;
+        }
+
+        final Map<?, ?> args = (Map<?, ?>) arguments;
+
+        final String video = asString(args.get("video"));
+        final HashMap<String, String> headers = asStringMap(args.get("headers"));
+        final int format = asInt(args.get("format"));
+        final int maxh = asInt(args.get("maxh"));
+        final int maxw = asInt(args.get("maxw"));
+        final int timeMs = asInt(args.get("timeMs"));
+        final int quality = asInt(args.get("quality"));
         final String method = call.method;
 
         executor.execute(new Runnable() {
@@ -74,12 +76,11 @@ public void run() {
                 Exception exc = null;
 
                 try {
-                    if (method.equals("file")) {
-                        final String path = (String) args.get("path");
+                    if ("file".equals(method)) {
+                        final String path = asString(args.get("path"));
                         thumbnail = buildThumbnailFile(video, headers, path, format, maxh, maxw, timeMs, quality);
                         handled = true;
-
-                    } else if (method.equals("data")) {
+                    } else if ("data".equals(method)) {
                         thumbnail = buildThumbnailData(video, headers, format, maxh, maxw, timeMs, quality);
                         handled = true;
                     }
@@ -92,7 +93,33 @@ public void run() {
         });
     }
 
-    private static Bitmap.CompressFormat intToFormat(int format) {
+    private static String asString(Object v) {
+        return v == null ? null : String.valueOf(v);
+    }
+
+    private static int asInt(Object v) {
+        if (v instanceof Number) return ((Number) v).intValue();
+        if (v instanceof String) {
+            try {
+                return Integer.parseInt((String) v);
+            } catch (NumberFormatException ignored) {
+            }
+        }
+        return 0;
+    }
+
+    private static HashMap<String, String> asStringMap(Object v) {
+        if (!(v instanceof Map)) return null;
+        final Map<?, ?> raw = (Map<?, ?>) v;
+        final HashMap<String, String> out = new HashMap<>();
+        for (Map.Entry<?, ?> e : raw.entrySet()) {
+            if (e.getKey() == null || e.getValue() == null) continue;
+            out.put(String.valueOf(e.getKey()), String.valueOf(e.getValue()));
+        }
+        return out;
+    }
+
+    private static Bitmap.CompressFormat intToFormat(int format, int quality) {
         switch (format) {
             default:
             case 0:
@@ -100,10 +127,26 @@ private static Bitmap.CompressFormat intToFormat(int format) {
             case 1:
                 return Bitmap.CompressFormat.PNG;
             case 2:
-                return Bitmap.CompressFormat.WEBP;
+                return webpCompressFormat(quality);
         }
     }
 
+    private static Bitmap.CompressFormat webpCompressFormat(int quality) {
+        if (android.os.Build.VERSION.SDK_INT >= 30) {
+            return quality >= HIGH_QUALITY_MIN_VAL
+                    ? Bitmap.CompressFormat.WEBP_LOSSLESS
+                    : Bitmap.CompressFormat.WEBP_LOSSY;
+        }
+
+        try {
+            Object v = Bitmap.CompressFormat.class.getField("WEBP").get(null);
+            if (v instanceof Bitmap.CompressFormat) return (Bitmap.CompressFormat) v;
+        } catch (Throwable ignored) {
+        }
+
+        return Bitmap.CompressFormat.PNG;
+    }
+
     private static String formatExt(int format) {
         switch (format) {
             default:
@@ -116,28 +159,35 @@ private static String formatExt(int format) {
         }
     }
 
-    private byte[] buildThumbnailData(final String vidPath, final HashMap<String, String> headers, int format, int maxh,
-            int maxw, int timeMs, int quality) {
-        // Log.d(TAG, String.format("buildThumbnailData( format:%d, maxh:%d, maxw:%d,
-        // timeMs:%d, quality:%d )", format, maxh, maxw, timeMs, quality));
+    private byte[] buildThumbnailData(
+            final String vidPath,
+            final HashMap<String, String> headers,
+            int format,
+            int maxh,
+            int maxw,
+            int timeMs,
+            int quality
+    ) {
         Bitmap bitmap = createVideoThumbnail(vidPath, headers, maxh, maxw, timeMs);
-        if (bitmap == null)
-            throw new NullPointerException();
+        if (bitmap == null) throw new NullPointerException();
 
         ByteArrayOutputStream stream = new ByteArrayOutputStream();
-        bitmap.compress(intToFormat(format), quality, stream);
+        bitmap.compress(intToFormat(format, quality), quality, stream);
         bitmap.recycle();
-        if (bitmap == null)
-            throw new NullPointerException();
         return stream.toByteArray();
     }
 
-    private String buildThumbnailFile(final String vidPath, final HashMap<String, String> headers, String path,
-            int format, int maxh, int maxw, int timeMs,
-            int quality) {
-        // Log.d(TAG, String.format("buildThumbnailFile( format:%d, maxh:%d, maxw:%d,
-        // timeMs:%d, quality:%d )", format, maxh, maxw, timeMs, quality));
-        final byte bytes[] = buildThumbnailData(vidPath, headers, format, maxh, maxw, timeMs, quality);
+    private String buildThumbnailFile(
+            final String vidPath,
+            final HashMap<String, String> headers,
+            String path,
+            int format,
+            int maxh,
+            int maxw,
+            int timeMs,
+            int quality
+    ) {
+        final byte[] bytes = buildThumbnailData(vidPath, headers, format, maxh, maxw, timeMs, quality);
         final String ext = formatExt(format);
         final int i = vidPath.lastIndexOf(".");
         String fullpath = vidPath.substring(0, i + 1) + ext;
@@ -151,9 +201,7 @@ private String buildThumbnailFile(final String vidPath, final HashMap<String, St
             if (path.endsWith(ext)) {
                 fullpath = path;
             } else {
-                // try to save to same folder as the vidPath
                 final int j = fullpath.lastIndexOf("/");
-
                 if (path.endsWith("/")) {
                     fullpath = path + fullpath.substring(j + 1);
                 } else {
@@ -167,7 +215,7 @@ private String buildThumbnailFile(final String vidPath, final HashMap<String, St
             f.write(bytes);
             f.close();
             Log.d(TAG, String.format("buildThumbnailFile( written:%d )", bytes.length));
-        } catch (java.io.IOException e) {
+        } catch (IOException e) {
             e.printStackTrace();
             throw new RuntimeException(e);
         }
@@ -198,16 +246,7 @@ private static void runOnUiThread(Runnable runnable) {
         new Handler(Looper.getMainLooper()).post(runnable);
     }
 
-    /**
-     * Create a video thumbnail for a video. May return null if the video is corrupt
-     * or the format is not supported.
-     *
-     * @param video   the URI of video
-     * @param targetH the max height of the thumbnail
-     * @param targetW the max width of the thumbnail
-     */
-    public Bitmap createVideoThumbnail(final String video, final HashMap<String, String> headers, int targetH,
-            int targetW, int timeMs) {
+    public Bitmap createVideoThumbnail(final String video, final HashMap<String, String> headers, int targetH, int targetW, int timeMs) {
         Bitmap bitmap = null;
         MediaMetadataRetriever retriever = new MediaMetadataRetriever();
         try {
@@ -221,11 +260,9 @@ public Bitmap createVideoThumbnail(final String video, final HashMap<String, Str
 
             if (targetH != 0 || targetW != 0) {
                 if (android.os.Build.VERSION.SDK_INT >= 27 && targetH != 0 && targetW != 0) {
-                    // API Level 27
-                    bitmap = retriever.getScaledFrameAtTime(timeMs * 1000, MediaMetadataRetriever.OPTION_CLOSEST,
-                            targetW, targetH);
+                    bitmap = retriever.getScaledFrameAtTime(timeMs * 1000L, MediaMetadataRetriever.OPTION_CLOSEST, targetW, targetH);
                 } else {
-                    bitmap = retriever.getFrameAtTime(timeMs * 1000, MediaMetadataRetriever.OPTION_CLOSEST);
+                    bitmap = retriever.getFrameAtTime(timeMs * 1000L, MediaMetadataRetriever.OPTION_CLOSEST);
                     if (bitmap != null) {
                         int width = bitmap.getWidth();
                         int height = bitmap.getHeight();
@@ -240,7 +277,7 @@ public Bitmap createVideoThumbnail(final String video, final HashMap<String, Str
                     }
                 }
             } else {
-                bitmap = retriever.getFrameAtTime(timeMs * 1000, MediaMetadataRetriever.OPTION_CLOSEST);
+                bitmap = retriever.getFrameAtTime(timeMs * 1000L, MediaMetadataRetriever.OPTION_CLOSEST);
             }
         } catch (IllegalArgumentException ex) {
             ex.printStackTrace();
@@ -251,7 +288,7 @@ public Bitmap createVideoThumbnail(final String video, final HashMap<String, Str
         } finally {
             try {
                 retriever.release();
-            } catch (RuntimeException | IOException ex) {
+            } catch (Throwable ex) {
                 ex.printStackTrace();
             }
         }