Add retry logic with timeout to extractLastFrame to handle temporary file access issues in shot scripts

server/utils/ffmpeg.ts

@@ -70,29 +70,42 @@ export async function extractLastFrame(inputPath: string, outputPath: string) {
     throw new Error('Source video is missing')
   }
 
-  const attempts: string[][] = []
-  try {
-    const duration = await probeDuration(inputPath)
-    const seek = Math.max(0, duration - 0.08)
-    attempts.push(['-y', '-ss', seek.toFixed(3), '-i', inputPath, '-frames:v', '1', '-an', '-q:v', '1', outputPath])
-  } catch {
-    // Truncated files often have no duration index; fall through to decode attempts.
-  }
-  attempts.push(
-    ['-y', '-sseof', '-0.04', '-i', inputPath, '-update', '1', '-frames:v', '1', '-an', '-q:v', '1', outputPath],
-    ['-y', '-i', inputPath, '-update', '1', '-an', '-q:v', '1', outputPath]
-  )
+  const maxTotalTimeMs = 5000
+  const start = Date.now()
+  let delayMs = 100
 
-  for (const args of attempts) {
+  while (Date.now() - start < maxTotalTimeMs) {
+    const attempts: string[][] = []
     try {
-      await runFfmpeg(args, 60000)
-      if (existsSync(outputPath) && statSync(outputPath).size >= 64) return
+      const duration = await probeDuration(inputPath)
+      const seek = Math.max(0, duration - 0.08)
+      attempts.push(['-y', '-ss', seek.toFixed(3), '-i', inputPath, '-frames:v', '1', '-an', '-q:v', '1', outputPath])
     } catch {
-      // Try the next seek strategy.
+      // Truncated files often have no duration index; fall through to decode attempts.
     }
+    attempts.push(
+      ['-y', '-sseof', '-0.04', '-i', inputPath, '-update', '1', '-frames:v', '1', '-an', '-q:v', '1', outputPath],
+      ['-y', '-i', inputPath, '-update', '1', '-an', '-q:v', '1', outputPath]
+    )
+
+    for (const args of attempts) {
+      try {
+        await runFfmpeg(args, 60000)
+        if (existsSync(outputPath) && statSync(outputPath).size >= 64) return
+      } catch {
+        // Try next strategy
+      }
+    }
+
+    const elapsed = Date.now() - start
+    if (elapsed >= maxTotalTimeMs) break
+
+    const wait = Math.min(delayMs, maxTotalTimeMs - elapsed)
+    await new Promise(resolve => setTimeout(resolve, wait))
+    delayMs = Math.min(delayMs * 2, maxTotalTimeMs - (Date.now() - start))
   }
 
-  throw new Error('Could not extract the last frame. The video looks incomplete — interrupting Comfy mid-encode usually causes this. Earlier saved parts are still in the library.')
+  throw new Error('Could not extract the last frame within the timeout. The video may still be encoding or is incomplete.')
 }
 
 export async function extractFirstFrame(inputPath: string, outputPath: string) {