Show video posters in the library by building a first-frame thumb when one is missing.

Co-authored-by: Cursor <cursoragent@cursor.com>

server/utils/library.ts

@@ -520,7 +520,7 @@ export function publicLibrary(event: H3Event, opts?: { light?: boolean }) {
     clips: catalog.clips.filter(clip => unlockedIds.has(clip.folderId)).map(clip => ({
       ...clip,
       name: clipTitle(clip),
-      hasThumbnail: light ? !clip.hideThumbnail : !clip.hideThumbnail && existsSync(clipThumbPath(owner, clip.id)),
+      hasThumbnail: !clip.hideThumbnail,
       hasVideo: light ? true : existsSync(clipVideoPath(owner, clip.id))
     })),
     stills: catalog.stills
@@ -837,27 +837,36 @@ export function clipThumbPath(owner: string, id: string) {
   const dir = clipDir(owner, id)
   for (const name of ['thumb.jpg', 'thumb.png', 'thumb']) {
     const path = join(dir, name)
-    if (existsSync(path)) return path
+    if (existsSync(path) && statSync(path).size >= 64) return path
   }
   return join(dir, 'thumb.jpg')
 }
 
-function extractVideoThumb(videoPath: string, destPath: string) {
-  return new Promise<boolean>((resolve) => {
-    const proc = spawn('ffmpeg', ['-y', '-ss', '0.2', '-i', videoPath, '-frames:v', '1', '-update', '1', '-q:v', '4', destPath], { stdio: 'ignore' })
-    const timer = setTimeout(() => {
-      try { proc.kill('SIGKILL') } catch { /* ignore */ }
-      resolve(false)
-    }, 20000)
-    proc.on('close', (code) => {
-      clearTimeout(timer)
-      resolve(code === 0 && existsSync(destPath))
-    })
-    proc.on('error', () => {
-      clearTimeout(timer)
-      resolve(false)
-    })
+async function extractVideoThumb(videoPath: string, destPath: string) {
+  try {
+    await extractFirstFrame(videoPath, destPath)
+    return existsSync(destPath) && statSync(destPath).size >= 64
+  } catch {
+    return false
+  }
+}
+
+export async function ensureClipThumb(owner: string, id: string) {
+  const existing = clipThumbPath(owner, id)
+  if (existsSync(existing) && statSync(existing).size >= 64) return existing
+  const video = clipVideoPath(owner, id)
+  if (!existsSync(video)) return ''
+  const dest = join(clipDir(owner, id), 'thumb.jpg')
+  const pending = thumbBuilds.get(dest)
+  if (pending) return pending
+  const build = withThumbSlot(async () => {
+    const ok = await extractVideoThumb(video, dest)
+    return ok ? dest : ''
+  }).finally(() => {
+    thumbBuilds.delete(dest)
   })
+  thumbBuilds.set(dest, build)
+  return build
 }
 
 function probeVideoSize(videoPath: string) {
@@ -913,7 +922,7 @@ export async function ensureClipThumbnails(owner: string, opts?: { skipHistory?:
     const thumb = clipThumbPath(owner, clip.id)
     const video = clipVideoPath(owner, clip.id)
     if (!existsSync(video)) continue
-    if (!existsSync(thumb)) {
+    if (!existsSync(thumb) || statSync(thumb).size < 64) {
       await extractVideoThumb(video, join(clipDir(owner, clip.id), 'thumb.jpg'))
     }
     if (!clip.width || !clip.height) {