Stop ghost extension clips and recover last-frame extract after an interrupt.

Only one Comfy finish path can save a clip, hide catalog entries whose MP4 is missing, and retry last-frame extract so a truncated file does not dump FFmpeg noise into the UI.

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

pages/index.vue

@@ -702,6 +702,7 @@ interface LibraryClip {
   seed: number
   hideThumbnail: boolean
   hasThumbnail?: boolean
+  hasVideo?: boolean
   createdAt: number
   cfg?: number
   fps?: number
@@ -950,7 +951,7 @@ const plannedChain = computed(() => {
   ]
 })
 
-const visibleClips = computed(() => clips.value.filter(clip => clip.folderId === browseFolderId.value))
+const visibleClips = computed(() => clips.value.filter(clip => clip.folderId === browseFolderId.value && clip.hasVideo !== false))
 const libraryGroups = computed(() => {
   const groups = new Map<string, LibraryClip[]>()
   for (const clip of visibleClips.value) {
@@ -974,9 +975,9 @@ function clipsIn(id: string) {
 }
 
 function clipFamilyKey(clip: LibraryClip) {
-  if (clip.familyId) return clip.familyId
   const base = String(clip.name || '').trim().replace(/\s+p\d+$/i, '')
   if (base) return `name:${clip.folderId}:${base.toLowerCase()}`
+  if (clip.familyId) return clip.familyId
   return `solo:${clip.id}`
 }
 
@@ -985,7 +986,7 @@ function sortClipParts(a: LibraryClip, b: LibraryClip) {
   if (durationDelta) return durationDelta
   const chainDelta = (b.chainIndex || 0) - (a.chainIndex || 0)
   if (chainDelta) return chainDelta
-  return b.createdAt - a.createdAt
+  return a.createdAt - b.createdAt
 }
 
 function formatClipDuration(value?: number) {

server/api/extend.post.ts

@@ -98,7 +98,7 @@ export default defineEventHandler(async (event) => {
     extendTmpDir: tmpDir,
     extendPart1Path: part1Path,
     extendSourceClipId: source.id,
-    familyId: crypto.randomUUID(),
+    familyId: source.familyId || crypto.randomUUID(),
     parentClipId: source.id,
     chainIndex: (source.chainIndex || 0) + 1
   }

server/api/generate.post.ts

@@ -403,7 +403,14 @@ async function runGeneration(
     assertJobActive(job)
 
     copyFileSync(currentPath, part1Path)
-    await extractLastFrame(part1Path, framePath)
+    try {
+      await extractLastFrame(part1Path, framePath)
+    } catch (error) {
+      const detail = error instanceof Error ? error.message : String(error)
+      throw new Error(detail.includes('last frame')
+        ? detail
+        : `Could not extract the last frame for the next extension: ${detail}`)
+    }
     const frame = readFileSync(framePath)
     job.library.extendPart1Path = part1Path
     job.library.prompt = ext.prompt

server/utils/ffmpeg.ts

@@ -63,18 +63,30 @@ export async function extractLastFrame(inputPath: string, outputPath: string) {
   if (!existsSync(inputPath)) {
     throw new Error('Source video is missing')
   }
-  await runFfmpeg([
+
-    '-y',
+  const attempts: string[][] = []
-    '-sseof', '-1',
+  try {
-    '-i', inputPath,
+    const duration = await probeDuration(inputPath)
-    '-update', '1',
+    const seek = Math.max(0, duration - 0.08)
-    '-frames:v', '1',
+    attempts.push(['-y', '-ss', seek.toFixed(3), '-i', inputPath, '-frames:v', '1', '-an', '-q:v', '1', outputPath])
-    '-q:v', '1',
+  } catch {
-    outputPath
+    // Truncated files often have no duration index; fall through to decode attempts.
-  ], 30000)
-  if (!existsSync(outputPath)) {
-    throw new Error('FFmpeg did not write the last frame')
   }
+  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)) return
+    } catch {
+      // Try the next seek strategy.
+    }
+  }
+
+  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.')
 }
 
 export async function probeHasAudio(filePath: string) {

server/utils/jobs.ts

@@ -78,6 +78,8 @@ export interface Job {
   }
   error?: string
   socketReady?: boolean
+  saving?: boolean
+  savedPromptId?: string
   segmentBuffer?: Buffer
   events: JobEvent[]
   listeners: Set<(event: JobEvent) => void>

server/utils/library.ts

@@ -317,7 +317,8 @@ export function publicLibrary(event: H3Event) {
     clips: catalog.clips.filter(clip => unlockedIds.has(clip.folderId)).map(clip => ({
       ...clip,
       name: clipTitle(clip),
-      hasThumbnail: !clip.hideThumbnail && existsSync(clipThumbPath(owner, clip.id))
+      hasThumbnail: !clip.hideThumbnail && existsSync(clipThumbPath(owner, clip.id)),
+      hasVideo: existsSync(clipVideoPath(owner, clip.id))
     })),
     stills: catalog.stills.filter(still => unlockedIds.has(still.folderId)),
     drafts: catalog.drafts

server/utils/pending.ts

@@ -70,10 +70,42 @@ export function deletePendingJob(jobId: string) {
 }
 
 export async function completePendingIfReady(pending: PendingJob) {
+  const alreadySaved = () => {
+    const live = getJob(pending.jobId)
+    if (live?.savedPromptId === pending.promptId) {
+      deletePendingJob(pending.jobId)
+      return {
+        type: 'complete' as const,
+        status: 'complete' as const,
+        message: pending.folderLocked
+          ? 'Saved to the locked folder. Unlock it to view.'
+          : (pending.extendPart1Path ? 'Extended video ready' : 'Video ready'),
+        progress: 100,
+        jobId: pending.jobId,
+        clipId: live.clipId,
+        hideThumbnail: pending.hideThumbnail,
+        folderLocked: pending.folderLocked
+      }
+    }
+    return null
+  }
+  const inFlight = () => {
+    const current = getJob(pending.jobId)
+    return Boolean(current && current.promptId === pending.promptId && current.saving)
+  }
+  if (inFlight()) return null
+  const saved = alreadySaved()
+  if (saved) return saved
   const history = await fetchHistory(pending.promptId)
+  if (inFlight()) return null
+  const afterHistory = alreadySaved()
+  if (afterHistory) return afterHistory
   const video = extractVideo(history, pending.promptId)
   if (!video) return null
   let buffer = await downloadComfyVideo(video)
+  if (inFlight()) return null
+  const afterDownload = alreadySaved()
+  if (afterDownload) return afterDownload
   if (pending.extendPart1Path && pending.extendTmpDir) {
     if (!existsSync(pending.extendPart1Path)) {
       removeExtendTemp(pending.extendTmpDir)
@@ -91,6 +123,8 @@ export async function completePendingIfReady(pending: PendingJob) {
     }
     removeExtendTemp(pending.extendTmpDir)
   }
+  const afterStitch = alreadySaved()
+  if (afterStitch) return afterStitch
   const clip = await saveClip({
     ownerKey: pending.ownerKey,
     folderId: pending.folderId,

server/utils/watch.ts

@@ -71,8 +71,10 @@ export function emitChainJob(job: Job, event: JobEvent, samplePct?: number) {
 export function watchComfyJob(job: Job, options: { persist?: boolean } = {}): Promise<void> {
   const persist = options.persist !== false
   job.socketReady = false
+  job.saving = false
   const ws = new WebSocket(comfyWsUrl(job.clientId))
   let settled = false
+  let finishing = false
   let pollTimer: ReturnType<typeof setInterval> | null = null
   let timeout: ReturnType<typeof setTimeout> | null = null
 
@@ -111,7 +113,7 @@ export function watchComfyJob(job: Job, options: { persist?: boolean } = {}): Pr
       }
       const idleLeft = IDLE_MS - (Date.now() - lastActivity)
       timeout = setTimeout(() => {
-        if (settled) return
+        if (settled || finishing) return
         if (Date.now() - lastActivity >= IDLE_MS) {
           void fail('Timed out waiting for ComfyUI progress (30 minutes with no updates). The desktop job may still be running.')
           return
@@ -121,7 +123,7 @@ export function watchComfyJob(job: Job, options: { persist?: boolean } = {}): Pr
     }
 
     const fail = async (error: string) => {
-      if (settled) return
+      if (settled || finishing) return
       settled = true
       cleanup()
       job.status = job.status === 'cancelled' ? 'cancelled' : 'error'
@@ -133,119 +135,136 @@ export function watchComfyJob(job: Job, options: { persist?: boolean } = {}): Pr
     }
 
     const succeed = async () => {
-      if (settled || !job.promptId) return false
+      if (settled || finishing || !job.promptId) return false
-      const history = await fetchHistory(job.promptId)
+      finishing = true
-      const video = extractVideo(history, job.promptId)
+      job.saving = true
-      if (!video) return false
-      settled = true
-      cleanup()
       try {
-        job.video = video
+        const history = await fetchHistory(job.promptId)
-        const stitching = Boolean(job.library?.extendPart1Path && job.library.extendTmpDir)
+        const video = extractVideo(history, job.promptId)
-        emitLocal({
+        if (!video) {
-          type: 'status',
+          finishing = false
-          message: stitching ? 'Extracting last frame & stitching extension...' : (persist ? 'Saving to library...' : 'Downloading segment...'),
+          job.saving = false
-          progress: stitching ? 97 : 98
+          return false
-        })
-        if (job.library) {
-          let buffer = await downloadComfyVideo(video)
-          if (stitching) {
-            if (!existsSync(job.library.extendPart1Path!)) {
-              throw new Error('Extension source clip was missing during stitch')
-            }
-            buffer = await stitchExtension({
-              part1Path: job.library.extendPart1Path!,
-              part2: buffer,
-              tmpDir: job.library.extendTmpDir!
-            })
-          }
-          const clip = await saveClip({
-            ownerKey: job.library.ownerKey,
-            folderId: job.library.folderId,
-            name: job.library.name,
-            prompt: job.library.prompt,
-            aspect: job.library.aspect,
-            width: job.library.width,
-            height: job.library.height,
-            steps: job.library.steps,
-            turbo: job.library.turbo,
-            seed: job.library.seed,
-            hideThumbnail: job.library.hideThumbnail,
-            hideInput: job.library.hideInput,
-            video: buffer,
-            thumb: job.library.thumb,
-            comfyFilename: video.filename,
-            cfg: job.library.cfg,
-            fps: job.library.fps,
-            samplerName: job.library.samplerName,
-            scheduler: job.library.scheduler,
-            familyId: job.library.familyId || (job.library.familyId = crypto.randomUUID()),
-            parentClipId: job.library.parentClipId,
-            chainIndex: job.library.chainIndex
-          })
-          job.clipId = clip.id
-          job.hideThumbnail = clip.hideThumbnail
-          job.library.thumb = undefined
-          job.library.name = nextClipPartName(clip.name)
-          job.library.parentClipId = clip.id
-          await purgeComfyArtifacts({
-            video,
-            imageName: job.library.imageName,
-            imageSubfolder: job.library.imageSubfolder,
-            promptId: job.promptId
-          })
-          if (!persist) {
-            job.segmentBuffer = buffer
-            deletePendingJob(job.id)
-            emitLocal({
-              type: 'checkpoint',
-              message: stitching ? 'Extension checkpoint saved' : 'Initial segment saved',
-              progress: 99,
-              clipId: clip.id,
-              hideThumbnail: job.hideThumbnail,
-              folderLocked: job.library.folderLocked
-            })
-            resolve()
-            return true
-          }
-          removeExtendTemp(job.library.extendTmpDir)
-          job.library.extendTmpDir = undefined
         }
-        job.status = 'complete'
+        if (settled) return false
-        emitJob(job, {
+        settled = true
-          type: 'complete',
+        cleanup()
-          message: job.library?.folderLocked
+        try {
-            ? 'Saved to the locked folder. Unlock it to view.'
+          job.video = video
-            : (job.library?.extendSourceClipId || (job.library?.chainTotal || 1) > 1 ? 'Extended video ready' : 'Video ready'),
+          const stitching = Boolean(job.library?.extendPart1Path && job.library.extendTmpDir)
-          progress: 100,
+          emitLocal({
-          filename: job.library?.folderLocked ? undefined : video.filename,
+            type: 'status',
-          subfolder: job.library?.folderLocked ? undefined : video.subfolder,
+            message: stitching ? 'Extracting last frame & stitching extension...' : (persist ? 'Saving to library...' : 'Downloading segment...'),
-          mediaType: job.library?.folderLocked ? undefined : video.type,
+            progress: stitching ? 97 : 98
-          clipId: job.clipId,
+          })
-          hideThumbnail: job.hideThumbnail,
+          if (job.library) {
-          folderLocked: job.library?.folderLocked,
+            let buffer = await downloadComfyVideo(video)
-          chainStep: job.library?.chainStep,
+            if (stitching) {
-          chainTotal: job.library?.chainTotal,
+              if (!existsSync(job.library.extendPart1Path!)) {
-          chainLabel: job.library?.chainLabel
+                throw new Error('Extension source clip was missing during stitch')
-        })
+              }
-        deletePendingJob(job.id)
+              buffer = await stitchExtension({
-      } catch (saveError) {
+                part1Path: job.library.extendPart1Path!,
-        removeExtendTemp(job.library?.extendTmpDir)
+                part2: buffer,
-        const message = saveError instanceof Error ? saveError.message : String(saveError)
+                tmpDir: job.library.extendTmpDir!
-        job.status = 'error'
+              })
-        job.error = persist
+            }
-          ? `Video generated but library save failed: ${message}`
+            const clip = await saveClip({
-          : `Segment finished but could not be prepared: ${message}`
+              ownerKey: job.library.ownerKey,
-        emitChainJob(job, { type: 'error', error: job.error, message: job.error })
+              folderId: job.library.folderId,
+              name: job.library.name,
+              prompt: job.library.prompt,
+              aspect: job.library.aspect,
+              width: job.library.width,
+              height: job.library.height,
+              steps: job.library.steps,
+              turbo: job.library.turbo,
+              seed: job.library.seed,
+              hideThumbnail: job.library.hideThumbnail,
+              hideInput: job.library.hideInput,
+              video: buffer,
+              thumb: job.library.thumb,
+              comfyFilename: video.filename,
+              cfg: job.library.cfg,
+              fps: job.library.fps,
+              samplerName: job.library.samplerName,
+              scheduler: job.library.scheduler,
+              familyId: job.library.familyId || (job.library.familyId = crypto.randomUUID()),
+              parentClipId: job.library.parentClipId,
+              chainIndex: job.library.chainIndex
+            })
+            job.clipId = clip.id
+            job.savedPromptId = job.promptId
+            job.hideThumbnail = clip.hideThumbnail
+            job.library.thumb = undefined
+            job.library.name = nextClipPartName(clip.name)
+            job.library.parentClipId = clip.id
+            await purgeComfyArtifacts({
+              video,
+              imageName: job.library.imageName,
+              imageSubfolder: job.library.imageSubfolder,
+              promptId: job.promptId
+            })
+            if (!persist) {
+              job.segmentBuffer = buffer
+              deletePendingJob(job.id)
+              job.saving = false
+              emitLocal({
+                type: 'checkpoint',
+                message: stitching ? 'Extension checkpoint saved' : 'Initial segment saved',
+                progress: 99,
+                clipId: clip.id,
+                hideThumbnail: job.hideThumbnail,
+                folderLocked: job.library.folderLocked
+              })
+              resolve()
+              return true
+            }
+            removeExtendTemp(job.library.extendTmpDir)
+            job.library.extendTmpDir = undefined
+          }
+          job.status = 'complete'
+          emitJob(job, {
+            type: 'complete',
+            message: job.library?.folderLocked
+              ? 'Saved to the locked folder. Unlock it to view.'
+              : (job.library?.extendSourceClipId || (job.library?.chainTotal || 1) > 1 ? 'Extended video ready' : 'Video ready'),
+            progress: 100,
+            filename: job.library?.folderLocked ? undefined : video.filename,
+            subfolder: job.library?.folderLocked ? undefined : video.subfolder,
+            mediaType: job.library?.folderLocked ? undefined : video.type,
+            clipId: job.clipId,
+            hideThumbnail: job.hideThumbnail,
+            folderLocked: job.library?.folderLocked,
+            chainStep: job.library?.chainStep,
+            chainTotal: job.library?.chainTotal,
+            chainLabel: job.library?.chainLabel
+          })
+          deletePendingJob(job.id)
+          job.saving = false
+        } catch (saveError) {
+          job.saving = false
+          removeExtendTemp(job.library?.extendTmpDir)
+          const message = saveError instanceof Error ? saveError.message : String(saveError)
+          job.status = 'error'
+          job.error = persist
+            ? `Video generated but library save failed: ${message}`
+            : `Segment finished but could not be prepared: ${message}`
+          emitChainJob(job, { type: 'error', error: job.error, message: job.error })
+        }
+        resolve()
+        return true
+      } catch (error) {
+        finishing = false
+        job.saving = false
+        throw error
       }
-      resolve()
-      return true
     }
 
     let dropMisses = 0
 
     const pollHistory = async () => {
-      if (settled || !job.promptId) return
+      if (settled || finishing || !job.promptId) return
       try {
         const inspected = inspectHistory(await fetchHistory(job.promptId), job.promptId)
         if (inspected.error) {
@@ -282,7 +301,7 @@ export function watchComfyJob(job: Job, options: { persist?: boolean } = {}): Pr
     })
 
     ws.addEventListener('close', () => {
-      if (settled || !job.promptId) return
+      if (settled || finishing || !job.promptId) return
       void pollHistory()
     })