light at the end of the tunnel

mobile/lib/infrastructure/repositories/asset_media.repository.dart

@@ -1,18 +1,57 @@
+import 'dart:ffi';
 import 'dart:typed_data';
 import 'dart:ui';
+import 'dart:ui' as ui;
 
+import 'package:immich_mobile/providers/infrastructure/platform.provider.dart';
 import 'package:photo_manager/photo_manager.dart';
+import 'package:ffi/ffi.dart';
 
 class AssetMediaRepository {
   const AssetMediaRepository();
 
-  Future<Uint8List?> getThumbnail(String id, {int quality = 80, Size size = const Size.square(256)}) => AssetEntity(
-    id: id,
-    // The below fields are not used in thumbnailDataWithSize but are required
-    // to create an AssetEntity instance. It is faster to create a dummy AssetEntity
-    // instance than to fetch the asset from the device first.
-    typeInt: AssetType.image.index,
-    width: size.width.toInt(),
-    height: size.height.toInt(),
-  ).thumbnailDataWithSize(ThumbnailSize(size.width.toInt(), size.height.toInt()), quality: quality);
+  Future<ui.Codec> getLocalThumbnail(String localId, ui.Size size) async {
+    final info = await thumbnailApi.setThumbnailToBuffer(
+      localId,
+      width: size.width.toInt(),
+      height: size.height.toInt(),
+    );
+
+    final pointer = Pointer<Uint8>.fromAddress(info['pointer']!);
+    final actualWidth = info['width']!;
+    final actualHeight = info['height']!;
+    final actualSize = actualWidth * actualHeight * 4;
+
+    try {
+      final buffer =
+          await ImmutableBuffer.fromUint8List(pointer.asTypedList(actualSize));
+      final descriptor = ui.ImageDescriptor.raw(
+        buffer,
+        width: actualWidth,
+        height: actualHeight,
+        pixelFormat: ui.PixelFormat.rgba8888,
+      );
+      return await descriptor.instantiateCodec();
+    } finally {
+      malloc.free(pointer);
+    }
+  }
+
+  Future<Uint8List?> getThumbnail(
+    String id, {
+    int quality = 80,
+    ui.Size size = const ui.Size.square(256),
+  }) =>
+      AssetEntity(
+        id: id,
+        // The below fields are not used in thumbnailDataWithSize but are required
+        // to create an AssetEntity instance. It is faster to create a dummy AssetEntity
+        // instance than to fetch the asset from the device first.
+        typeInt: AssetType.image.index,
+        width: size.width.toInt(),
+        height: size.height.toInt(),
+      ).thumbnailDataWithSize(
+        ThumbnailSize(size.width.toInt(), size.height.toInt()),
+        quality: quality,
+      );
 }