Show small stitch-frame thumbs when a video collection is expanded.

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

server/utils/library.ts

@@ -5,6 +5,7 @@ import { spawn } from 'node:child_process'
 import { randomBytes, scrypt, timingSafeEqual } from 'node:crypto'
 import { promisify } from 'node:util'
 import type { H3Event } from 'h3'
+import { extractFirstFrame, extractLastFrame } from '~/server/utils/ffmpeg'
 
 const scryptAsync = promisify(scrypt)
 
@@ -576,6 +577,50 @@ export function clipLastFramePath(owner: string, id: string) {
   return join(clipDir(owner, id), 'last-frame.png')
 }
 
+export function clipFirstFramePath(owner: string, id: string) {
+  return join(clipDir(owner, id), 'first-frame.jpg')
+}
+
+export function clipFrameThumbFile(owner: string, id: string, kind: 'first' | 'last') {
+  return join(clipDir(owner, id), kind === 'last' ? 'last-frame.thumb.jpg' : 'first-frame.thumb.jpg')
+}
+
+export async function ensureScaledThumb(source: string, dest: string) {
+  if (!existsSync(source)) return ''
+  if (existsSync(dest)) {
+    try {
+      if (statSync(dest).mtimeMs >= statSync(source).mtimeMs) return dest
+    } catch { /* rebuild */ }
+  }
+  const key = dest
+  const pending = thumbBuilds.get(key)
+  if (pending) return pending
+  const build = withThumbSlot(async () => {
+    const ok = await buildStillThumb(source, dest)
+    return ok ? dest : source
+  }).finally(() => {
+    thumbBuilds.delete(key)
+  })
+  thumbBuilds.set(key, build)
+  return build
+}
+
+export async function ensureClipLastFrame(owner: string, id: string) {
+  const video = clipVideoPath(owner, id)
+  const dest = clipLastFramePath(owner, id)
+  if (!existsSync(video)) return ''
+  if (!existsSync(dest)) await extractLastFrame(video, dest)
+  return existsSync(dest) ? dest : ''
+}
+
+export async function ensureClipFirstFrame(owner: string, id: string) {
+  const video = clipVideoPath(owner, id)
+  const dest = clipFirstFramePath(owner, id)
+  if (!existsSync(video)) return ''
+  if (!existsSync(dest)) await extractFirstFrame(video, dest)
+  return existsSync(dest) ? dest : ''
+}
+
 export function extendTempDir(owner: string, jobId: string) {
   const dir = join(ownerRoot(owner), 'tmp', 'extend', jobId)
   mkdirSync(dir, { recursive: true })