Support WebP cover images: convert to JPEG via PIL, correct MIME type fallback

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

cover_handler.py

@@ -97,12 +97,38 @@ def download_cover(release_mbid: Optional[str], dest_dir: Path) -> Optional[Path
     return None
 
 
+def _load_cover_data(cover_path: Path) -> tuple[bytes, str]:
+    """
+    Liest Cover-Bilddaten und gibt (bytes, mime_type) zurück.
+    WebP wird zu JPEG konvertiert wenn PIL verfügbar (bessere Player-Kompatibilität).
+    """
+    suffix = cover_path.suffix.lower()
+    if suffix in (".jpg", ".jpeg"):
+        return cover_path.read_bytes(), "image/jpeg"
+    if suffix == ".webp" and HAS_PIL:
+        try:
+            with Image.open(cover_path) as img:
+                img = img.convert("RGB")
+                buf = tempfile.SpooledTemporaryFile(max_size=10 * 1024 * 1024)
+                img.save(buf, format="JPEG", quality=90)
+                buf.seek(0)
+                return buf.read(), "image/jpeg"
+        except Exception as e:
+            print(f"  ⚠️ WebP→JPEG-Konvertierung fehlgeschlagen ({cover_path.name}): {e}",
+                  file=sys.stderr)
+    if suffix == ".webp":
+        return cover_path.read_bytes(), "image/webp"
+    if suffix == ".png":
+        return cover_path.read_bytes(), "image/png"
+    # Fallback: raw bytes, JPEG assumed
+    return cover_path.read_bytes(), "image/jpeg"
+
+
 def embed_cover(audio_path: Path, cover_path: Path) -> bool:
     if not HAS_MUTAGEN:
         return False
     try:
-        img_data = cover_path.read_bytes()
+        img_data, mime = _load_cover_data(cover_path)
-        mime = "image/jpeg" if cover_path.suffix.lower() in (".jpg", ".jpeg") else "image/png"
         ext = audio_path.suffix.lower()
 
         if ext == ".mp3":
@@ -130,6 +156,7 @@ def embed_cover(audio_path: Path, cover_path: Path) -> bool:
         elif ext == ".m4a":
             audio = MP4(str(audio_path))
             fmt = MP4Cover.FORMAT_JPEG if mime == "image/jpeg" else MP4Cover.FORMAT_PNG
+            # WebP wurde bereits zu JPEG konvertiert, mime ist dann "image/jpeg"
             audio.tags["covr"] = [MP4Cover(img_data, imageformat=fmt)]
             audio.save()
             return True