diff --git a/src/components/image-editor/ImageCanvasEditorModel.test.ts b/src/components/image-editor/ImageCanvasEditorModel.test.ts
index d3e0a14cc..dd897d021 100644
--- a/src/components/image-editor/ImageCanvasEditorModel.test.ts
+++ b/src/components/image-editor/ImageCanvasEditorModel.test.ts
@@ -602,6 +602,33 @@ describe('ImageCanvasEditorModel', () => {
     }
   });
 
+  it('preserves legacy audio and video media types when assetKind is absent', () => {
+    for (const mediaType of ['video', 'audio'] as const) {
+      const hydrated = hydrateLayer(
+        {
+          layerId: `legacy-${mediaType}-layer`,
+          resourceId: `legacy-${mediaType}-resource`,
+          title: `旧${mediaType}`,
+          sourceType: 'uploaded',
+          mediaType,
+        },
+        new Map([
+          [
+            `legacy-${mediaType}-resource`,
+            {
+              imageSrc:
+                mediaType === 'video'
+                  ? '/legacy/cutscene.mp4'
+                  : '/legacy/theme.mp3',
+            },
+          ],
+        ]),
+      );
+
+      expect(hydrated?.mediaType).toBe(mediaType);
+    }
+  });
+
   it('recovers the normal source model after the owner payload removes an internal model', () => {
     const hydrated = hydrateLayer(
       {
diff --git a/src/components/image-editor/ImageCanvasEditorModel.ts b/src/components/image-editor/ImageCanvasEditorModel.ts
index cef504081..2bc6743b6 100644
--- a/src/components/image-editor/ImageCanvasEditorModel.ts
+++ b/src/components/image-editor/ImageCanvasEditorModel.ts
@@ -761,11 +761,15 @@ export function hydrateLayer(
   ) {
     return null;
   }
-  const imageSequenceFrames = isFormalCharacterAnimation
-    ? resourceImageSequenceFrames
-    : isSelfContainedLocalResource || snapshot.mediaType === 'image-sequence'
-      ? snapshotImageSequenceFrames
-      : [];
+  let imageSequenceFrames: NonNullable<CanvasLayer['imageSequenceFrames']> = [];
+  if (isFormalCharacterAnimation) {
+    imageSequenceFrames = resourceImageSequenceFrames;
+  } else if (
+    isSelfContainedLocalResource ||
+    snapshot.mediaType === 'image-sequence'
+  ) {
+    imageSequenceFrames = snapshotImageSequenceFrames;
+  }
   const firstSequenceFrame = imageSequenceFrames[0]?.imageSrc ?? '';
   const src = isFormalCharacterAnimation
     ? firstSequenceFrame || resource?.imageSrc || ''
@@ -786,16 +790,37 @@ export function hydrateLayer(
   ) {
     return null;
   }
+  let resourcePersistenceState: CanvasLayer['resourcePersistenceState'];
+  if (resource) {
+    resourcePersistenceState = 'registered';
+  } else if (isSelfContainedLocalResource) {
+    resourcePersistenceState = 'self-contained-local';
+  } else if (resourceId.startsWith('local-')) {
+    resourcePersistenceState = 'unresolved-local';
+  }
+  let sourceType: CanvasLayer['sourceType'] = 'uploaded';
+  if (isCanvasSourceType(resource?.sourceType)) {
+    sourceType = resource.sourceType;
+  } else if (isCanvasSourceType(snapshot.sourceType)) {
+    sourceType = snapshot.sourceType;
+  }
+  const mediaType = resolveHydratedLayerMediaType(
+    snapshot,
+    assetKind,
+    isSelfContainedLocalResource,
+  );
+  let imageSequenceDurationMs: number | undefined;
+  if (isFormalCharacterAnimation) {
+    imageSequenceDurationMs =
+      audioDurationOrNull(resource?.imageSequenceDurationMs) ?? undefined;
+  } else if (isSelfContainedLocalResource) {
+    imageSequenceDurationMs =
+      audioDurationOrNull(snapshot.imageSequenceDurationMs) ?? undefined;
+  }
   return {
     id: layerId,
     resourceId,
-    resourcePersistenceState: resource
-      ? 'registered'
-      : isSelfContainedLocalResource
-        ? 'self-contained-local'
-        : resourceId.startsWith('local-')
-          ? 'unresolved-local'
-          : undefined,
+    resourcePersistenceState,
     title,
     src,
     x: numberFromSnapshot(snapshot.x, 0),
@@ -813,14 +838,8 @@ export function hydrateLayer(
       };
     })(),
     zIndex: numberFromSnapshot(snapshot.zIndex, 1),
-    sourceType: isCanvasSourceType(resource?.sourceType)
-      ? resource.sourceType
-      : isCanvasSourceType(snapshot.sourceType)
-        ? snapshot.sourceType
-        : 'uploaded',
-    mediaType: isSelfContainedLocalResource
-      ? 'image-sequence'
-      : resolveCanvasMediaTypeFromAssetKind(assetKind),
+    sourceType,
+    mediaType,
     thumbnailSrc: isFormalCharacterAnimation
       ? firstSequenceFrame || null
       : stringOrNull(snapshot.thumbnailSrc),
@@ -860,11 +879,7 @@ export function hydrateLayer(
       ? undefined
       : (audioDurationOrNull(snapshot.durationSeconds) ??
         audioDurationOrNull(resource?.durationSeconds)),
-    imageSequenceDurationMs: isFormalCharacterAnimation
-      ? audioDurationOrNull(resource?.imageSequenceDurationMs)
-      : isSelfContainedLocalResource
-        ? audioDurationOrNull(snapshot.imageSequenceDurationMs)
-        : undefined,
+    imageSequenceDurationMs,
     sourceResourceId: isFormalCharacterAnimation
       ? stringOrNull(resource?.sourceResourceId)
       : (stringOrNull(snapshot.sourceResourceId) ??
@@ -887,6 +902,23 @@ export function hydrateLayer(
   };
 }
 
+function resolveHydratedLayerMediaType(
+  snapshot: EditorProjectLayerSnapshot,
+  assetKind: CanvasAssetKind | null,
+  isSelfContainedLocalResource: boolean,
+): CanvasMediaType {
+  if (isSelfContainedLocalResource) {
+    return 'image-sequence';
+  }
+  if (assetKind) {
+    return resolveCanvasMediaTypeFromAssetKind(assetKind);
+  }
+  if (snapshot.mediaType === 'video' || snapshot.mediaType === 'audio') {
+    return snapshot.mediaType;
+  }
+  return 'image';
+}
+
 function isSelfContainedLegacyLocalImageSequence(
   snapshot: EditorProjectLayerSnapshot,
 ) {