feat: implement job resumption, custom queue reordering, and auto-venv start script setup

app/main.py

@@ -27,21 +27,97 @@ app.add_middleware(
 )
 
 # In-memory databases
+class CustomJobQueue:
+    def __init__(self):
+        self.queue = []
+        self.lock = threading.Lock()
+        self.condition = threading.Condition(self.lock)
+        
+    def put(self, job_id: str):
+        with self.lock:
+            if job_id not in self.queue:
+                self.queue.append(job_id)
+                self.condition.notify()
+                
+    def get(self) -> str:
+        with self.lock:
+            while not self.queue:
+                self.condition.wait()
+            return self.queue.pop(0)
+            
+    def remove(self, job_id: str) -> bool:
+        with self.lock:
+            if job_id in self.queue:
+                self.queue.remove(job_id)
+                return True
+            return False
+            
+    def get_all(self) -> List[str]:
+        with self.lock:
+            return list(self.queue)
+            
+    def reorder(self, job_ids: List[str]):
+        with self.lock:
+            valid_ids = [jid for jid in job_ids if jid in self.queue]
+            missing_ids = [jid for jid in self.queue if jid not in valid_ids]
+            self.queue = valid_ids + missing_ids
+
+    def task_done(self):
+        pass
+
+    def empty(self) -> bool:
+        with self.lock:
+            return len(self.queue) == 0
+
+    def qsize(self) -> int:
+        with self.lock:
+            return len(self.queue)
+
 jobs_db: Dict[str, upscaler.UpscaleJob] = {}
 ws_connections: Dict[str, List[WebSocket]] = {}
 preview_db: Dict[str, Dict[str, str]] = {} # preview_id -> {orig, upscaled}
 
-# FIFO queue for upscaling jobs to prevent GPU memory overload
-job_queue = queue.Queue()
+# Custom thread-safe queue for upscaling jobs to support reordering & cancellation
+job_queue = CustomJobQueue()
 queue_lock = threading.Lock()
 current_running_job_id = None
 
 main_loop = None
 
+JOBS_FILE = os.path.join(upscaler.BASE_DIR, "jobs.json")
+
+def load_jobs_db():
+    global jobs_db
+    if os.path.exists(JOBS_FILE):
+        try:
+            with open(JOBS_FILE, "r") as f:
+                data = json.load(f)
+                for job_id, job_data in data.items():
+                    job = upscaler.UpscaleJob.from_dict(job_data)
+                    # Automatically put queued items back in the queue
+                    if job.status == "queued":
+                        job_queue.put(job_id)
+                    # Mark active items as interrupted so they can be resumed
+                    elif job.status in ["analyzing", "extracting", "upscaling", "assembling"]:
+                        job.status = "interrupted"
+                        job.eta = "Interrupted"
+                    jobs_db[job_id] = job
+        except Exception as e:
+            print(f"Error loading jobs database: {e}")
+
+def save_jobs_db():
+    try:
+        with open(JOBS_FILE, "w") as f:
+            data = {job_id: job.to_dict() for job_id, job in jobs_db.items()}
+            json.dump(data, f, indent=4)
+    except Exception as e:
+        print(f"Error saving jobs database: {e}")
+
 @app.on_event("startup")
 def startup_event():
     global main_loop
     main_loop = asyncio.get_event_loop()
+    load_jobs_db()
 
 global_webhook_url = None
 
@@ -64,6 +140,7 @@ def send_webhook_notification(url: str, payload: dict):
 
 # Broadcast updates to websockets and webhooks
 def broadcast_progress(job_id: str, data: dict):
+    save_jobs_db()
     job = jobs_db.get(job_id)
     if job:
         data["is_preview"] = getattr(job, "is_preview", False)
@@ -344,6 +421,7 @@ def start_upscale(req: StartUpscaleRequest):
     
     jobs_db[job_id] = job
     job_queue.put(job_id)
+    save_jobs_db()
     
     # Broadcast initial queued progress
     broadcast_progress(job_id, {
@@ -386,6 +464,9 @@ def cancel_job(job_id: str):
     if not job:
         raise HTTPException(status_code=404, detail="Job not found.")
         
+    # Remove from queue if it was queued
+    job_queue.remove(job_id)
+    
     job.cancel()
     # Broadcast cancellation status
     broadcast_progress(job_id, {
@@ -395,6 +476,7 @@ def cancel_job(job_id: str):
         "total_frames": job.total_frames,
         "eta": "N/A"
     })
+    save_jobs_db()
     return {"job_id": job_id, "status": "cancelled"}
 
 @app.post("/api/preview/generate")
@@ -486,7 +568,22 @@ def safe_delete_file(file_path: str):
 
 @app.get("/api/jobs")
 def list_jobs():
-    """List details of all submitted jobs"""
+    """List details of all submitted jobs in queue-sorted order"""
+    active_id = current_running_job_id
+    queued_ids = job_queue.get_all()
+    
+    # Sort active first, then queued in order, then history by start time descending
+    def get_sort_key(job):
+        if job.job_id == active_id:
+            return (0, 0)
+        elif job.job_id in queued_ids:
+            return (1, queued_ids.index(job.job_id))
+        else:
+            t = job.start_time if job.start_time is not None else 0
+            return (2, -t)
+            
+    sorted_jobs = sorted(jobs_db.values(), key=get_sort_key)
+    
     return [
         {
             "job_id": job.job_id,
@@ -500,9 +597,10 @@ def list_jobs():
             "scale": job.scale,
             "output_file": os.path.basename(job.output_file) if job.output_file else None,
             "video_path": job.video_path,
-            "is_preview": getattr(job, "is_preview", False)
+            "is_preview": getattr(job, "is_preview", False),
+            "queue_position": queued_ids.index(job.job_id) if job.job_id in queued_ids else -1 if job.job_id == active_id else None
         }
-        for job in jobs_db.values()
+        for job in sorted_jobs
     ]
 
 @app.delete("/api/jobs/{job_id}")
@@ -512,6 +610,9 @@ def delete_job(job_id: str):
     if not job:
         raise HTTPException(status_code=404, detail="Job not found.")
         
+    # Remove from queue if it is queued
+    job_queue.remove(job_id)
+        
     # Safely delete original preview video if present
     for ext in [".mp4", ".mkv", ".avi", ".mov", ".webm"]:
         orig_prev_path = os.path.join(upscaler.OUTPUT_DIR, f"original_{job_id}{ext}")
@@ -534,6 +635,8 @@ def delete_job(job_id: str):
     # Delete from in-memory db
     if job_id in jobs_db:
         del jobs_db[job_id]
+        
+    save_jobs_db()
     
     return {"job_id": job_id, "status": "purged"}
 
@@ -562,11 +665,57 @@ def purge_all_jobs():
     # Reset in-memory database
     jobs_db.clear()
     
+    # Re-initialize custom queue
+    global job_queue
+    job_queue = CustomJobQueue()
+    
     # Reset upload metadata file
     save_upload_metadata({})
     
+    save_jobs_db()
+    
     return {"status": "all purged"}
 
+class ReorderQueueRequest(BaseModel):
+    job_ids: List[str]
+
+@app.post("/api/queue/reorder")
+def reorder_queue(req: ReorderQueueRequest):
+    """Reorder the job queue"""
+    job_queue.reorder(req.job_ids)
+    save_jobs_db()
+    return {"status": "success", "queue": job_queue.get_all()}
+
+@app.get("/api/queue")
+def get_queue():
+    """Get the current job queue order"""
+    return {"queue": job_queue.get_all()}
+
+@app.post("/api/upscale/resume/{job_id}")
+def resume_job(job_id: str):
+    """Resume an interrupted/failed upscale job"""
+    job = jobs_db.get(job_id)
+    if not job:
+        raise HTTPException(status_code=404, detail="Job not found.")
+        
+    # Re-queue the job
+    job.status = "queued"
+    job.error = None
+    job.eta = "Queued for resume..."
+    
+    job_queue.put(job_id)
+    save_jobs_db()
+    
+    broadcast_progress(job_id, {
+        "status": "queued",
+        "progress": job.progress,
+        "current_frame": job.current_frame,
+        "total_frames": job.total_frames,
+        "eta": "Queued for resume..."
+    })
+    
+    return {"job_id": job_id, "status": "queued"}
+
 # Websocket endpoint for real-time progress updates
 @app.websocket("/ws/progress/{job_id}")
 async def websocket_progress(websocket: WebSocket, job_id: str):

app/upscaler.py

@@ -78,6 +78,31 @@ class UpscaleJob:
         self._is_cancelled = False
         self._lock = threading.Lock()
 
+    def to_dict(self) -> dict:
+        """Serialize job attributes, excluding internal thread/process resources."""
+        return {k: v for k, v in self.__dict__.items() if not k.startswith('_')}
+
+    @classmethod
+    def from_dict(cls, data: dict) -> 'UpscaleJob':
+        """Deserialize job from dictionary, reconstructing internal locks and processes."""
+        job = cls(
+            job_id=data.get('job_id'),
+            video_path=data.get('video_path'),
+            model=data.get('model'),
+            scale=data.get('scale', 4),
+            tile_size=data.get('tile_size', 256),
+            preserve_audio=data.get('preserve_audio', True),
+            webhook_url=data.get('webhook_url'),
+            transcode_format=data.get('transcode_format', 'mp4'),
+            is_preview=data.get('is_preview', False)
+        )
+        for k, v in data.items():
+            setattr(job, k, v)
+        job._processes = []
+        job._is_cancelled = False
+        job._lock = threading.Lock()
+        return job
+
     def update_status(self, status: str, progress: float = None, current_frame: int = None, eta: str = None, error: str = None):
         with self._lock:
             self.status = status
@@ -256,133 +281,168 @@ def run_upscale_pipeline(job: UpscaleJob, on_progress_update: Callable[[str, Dic
             except Exception as cut_err:
                 print(f"Error cutting original preview video: {cut_err}")
 
-        # Step 1: Extract Frames
-        job.update_status("extracting", progress=10)
-        on_progress_update(job.job_id, {"status": "extracting", "progress": 10})
+        # Step 1: Extract Frames (Support Skipping on Resume)
+        skip_extraction = False
+        if os.path.exists(input_frames_dir):
+            extracted_files = sorted([f for f in os.listdir(input_frames_dir) if f.startswith("frame_")])
+            if len(extracted_files) > 0:
+                skip_extraction = True
+                print(f"Job {job.job_id}: Found existing input frames ({len(extracted_files)} frames). Skipping extraction step.")
+                job.total_frames = len(extracted_files)
         
-        # High quality JPG frames to balance disk usage and speed
-        extract_cmd = ["ffmpeg", "-y"]
-        if job.ss is not None:
-            extract_cmd.extend(["-ss", str(job.ss)])
-        if job.t is not None:
-            extract_cmd.extend(["-t", str(job.t)])
-        extract_cmd.extend(["-i", job.video_path])
-        
-        # Apply unsharp pre-filter if enabled
-        if getattr(job, "unsharp", False):
-            extract_cmd.extend(["-vf", "unsharp"])
+        if not skip_extraction:
+            job.update_status("extracting", progress=10)
+            on_progress_update(job.job_id, {"status": "extracting", "progress": 10})
             
-        extract_cmd.extend([
-            "-q:v", "2",
-            os.path.join(input_frames_dir, "frame_%08d.jpg")
-        ])
-        
-        p_extract = job.run_command(extract_cmd)
-        stdout, stderr = p_extract.communicate()
-        job.cleanup_process(p_extract)
-        
-        if p_extract.returncode != 0:
-            raise RuntimeError(f"FFmpeg frame extraction failed: {stderr}")
+            # High quality JPG frames to balance disk usage and speed
+            extract_cmd = ["ffmpeg", "-y"]
+            if job.ss is not None:
+                extract_cmd.extend(["-ss", str(job.ss)])
+            if job.t is not None:
+                extract_cmd.extend(["-t", str(job.t)])
+            extract_cmd.extend(["-i", job.video_path])
             
-        # Count actual frames extracted
-        extracted_files = sorted([f for f in os.listdir(input_frames_dir) if f.startswith("frame_")])
-        actual_total = len(extracted_files)
-        if actual_total == 0:
-            raise RuntimeError("No frames extracted from video")
-            
-        job.total_frames = actual_total
-        
-        # Step 2: Upscale Frames
-        job.update_status("upscaling", progress=20, current_frame=0)
-        on_progress_update(job.job_id, {"status": "upscaling", "progress": 20, "current_frame": 0, "total_frames": actual_total})
-        
-        current_tile_size = job.tile_size
-        while True:
-            # Launch Real-ESRGAN on directory
-            upscale_cmd = [
-                BIN_PATH,
-                "-i", input_frames_dir,
-                "-o", output_frames_dir,
-                "-n", job.model,
-                "-s", str(job.scale),
-                "-t", str(current_tile_size),
-                "-f", "jpg"
-            ]
-            if getattr(job, "gpu_ids", None) is not None:
-                upscale_cmd.extend(["-g", str(job.gpu_ids)])
-            if getattr(job, "tta", False):
-                upscale_cmd.append("-x")
+            # Apply unsharp pre-filter if enabled
+            if getattr(job, "unsharp", False):
+                extract_cmd.extend(["-vf", "unsharp"])
                 
-            upscale_start_time = time.time()
-            p_upscale = job.run_command(upscale_cmd)
+            extract_cmd.extend([
+                "-q:v", "2",
+                os.path.join(input_frames_dir, "frame_%08d.jpg")
+            ])
             
-            # Monitor thread for output files
-            while p_upscale.poll() is None:
+            p_extract = job.run_command(extract_cmd)
+            stdout, stderr = p_extract.communicate()
+            job.cleanup_process(p_extract)
+            
+            if p_extract.returncode != 0:
+                raise RuntimeError(f"FFmpeg frame extraction failed: {stderr}")
+                
+            # Count actual frames extracted
+            extracted_files = sorted([f for f in os.listdir(input_frames_dir) if f.startswith("frame_")])
+            actual_total = len(extracted_files)
+            if actual_total == 0:
+                raise RuntimeError("No frames extracted from video")
+                
+            job.total_frames = actual_total
+        else:
+            actual_total = job.total_frames
+            
+        # Step 2: Upscale Frames (Support Resuming by Skipping already upscaled frames)
+        if os.path.exists(output_frames_dir):
+            output_files = os.listdir(output_frames_dir)
+            skipped_frames = 0
+            for f in output_files:
+                if f.startswith("frame_") and f.endswith(".jpg"):
+                    out_path = os.path.join(output_frames_dir, f)
+                    if os.path.exists(out_path) and os.path.getsize(out_path) > 0:
+                        in_path = os.path.join(input_frames_dir, f)
+                        if os.path.exists(in_path):
+                            try:
+                                os.remove(in_path)
+                                skipped_frames += 1
+                            except Exception as ex:
+                                print(f"Error removing resumed frame {in_path}: {ex}")
+            if skipped_frames > 0:
+                print(f"Job {job.job_id}: Skipping {skipped_frames} already upscaled frames.")
+
+        remaining_inputs = len(os.listdir(input_frames_dir)) if os.path.exists(input_frames_dir) else 0
+        
+        if remaining_inputs == 0:
+            print(f"Job {job.job_id}: All frames already upscaled. Skipping upscaling step.")
+            job.update_status("upscaling", progress=80.0, current_frame=actual_total)
+            on_progress_update(job.job_id, {"status": "upscaling", "progress": 80.0, "current_frame": actual_total, "total_frames": actual_total})
+        else:
+            job.update_status("upscaling", progress=20, current_frame=actual_total - remaining_inputs)
+            on_progress_update(job.job_id, {"status": "upscaling", "progress": 20, "current_frame": actual_total - remaining_inputs, "total_frames": actual_total})
+            
+            current_tile_size = job.tile_size
+            while True:
+                # Launch Real-ESRGAN on directory
+                upscale_cmd = [
+                    BIN_PATH,
+                    "-i", input_frames_dir,
+                    "-o", output_frames_dir,
+                    "-n", job.model,
+                    "-s", str(job.scale),
+                    "-t", str(current_tile_size),
+                    "-f", "jpg"
+                ]
+                if getattr(job, "gpu_ids", None) is not None:
+                    upscale_cmd.extend(["-g", str(job.gpu_ids)])
+                if getattr(job, "tta", False):
+                    upscale_cmd.append("-x")
+                    
+                upscale_start_time = time.time()
+                p_upscale = job.run_command(upscale_cmd)
+                
+                # Monitor thread for output files
+                while p_upscale.poll() is None:
+                    if job._is_cancelled:
+                        return
+                        
+                    processed_files = len(os.listdir(output_frames_dir))
+                    progress_pct = 20.0 + (float(processed_files) / actual_total) * 60.0 # upscaling is 20% to 80%
+                    
+                    # Estimate ETA
+                    elapsed = time.time() - upscale_start_time
+                    this_run_processed = processed_files - (actual_total - remaining_inputs)
+                    if this_run_processed > 0:
+                        sec_per_frame = elapsed / this_run_processed
+                        rem_frames = actual_total - processed_files
+                        eta_sec = rem_frames * sec_per_frame
+                        
+                        # Format ETA
+                        if eta_sec > 60:
+                            eta_str = f"{int(eta_sec // 60)}m {int(eta_sec % 60)}s"
+                        else:
+                            eta_str = f"{int(eta_sec)}s"
+                    else:
+                        eta_str = "Calculating..."
+                        
+                    job.update_status("upscaling", progress=progress_pct, current_frame=processed_files, eta=eta_str)
+                    on_progress_update(job.job_id, {
+                        "status": "upscaling", 
+                        "progress": progress_pct, 
+                        "current_frame": processed_files, 
+                        "total_frames": actual_total,
+                        "eta": eta_str
+                    })
+                    time.sleep(0.5)
+                    
+                stdout, stderr = p_upscale.communicate()
+                job.cleanup_process(p_upscale)
+                
                 if job._is_cancelled:
                     return
                     
-                processed_files = len(os.listdir(output_frames_dir))
-                progress_pct = 20.0 + (float(processed_files) / actual_total) * 60.0 # upscaling is 20% to 80%
-                
-                # Estimate ETA
-                elapsed = time.time() - upscale_start_time
-                if processed_files > 0:
-                    sec_per_frame = elapsed / processed_files
-                    rem_frames = actual_total - processed_files
-                    eta_sec = rem_frames * sec_per_frame
+                if p_upscale.returncode != 0:
+                    err_msg = (stdout or "") + "\n" + (stderr or "")
+                    is_alloc_error = any(x in err_msg.lower() for x in ["vkallocatememory", "out of memory", "allocation", "vram", "failed to allocate"])
                     
-                    # Format ETA
-                    if eta_sec > 60:
-                        eta_str = f"{int(eta_sec // 60)}m {int(eta_sec % 60)}s"
-                    else:
-                        eta_str = f"{int(eta_sec)}s"
+                    if is_alloc_error:
+                        if current_tile_size <= 0:
+                            next_tile_size = 256
+                        else:
+                            next_tile_size = current_tile_size // 2
+                            
+                        if next_tile_size >= 32:
+                            print(f"Job {job.job_id}: Real-ESRGAN failed with VRAM allocation error. Retrying with tile size halved from {current_tile_size} to {next_tile_size}.")
+                            current_tile_size = next_tile_size
+                            
+                            # Clean up only output frames that we attempted to upscale in this run
+                            for filename in os.listdir(input_frames_dir):
+                                out_path = os.path.join(output_frames_dir, filename)
+                                if os.path.exists(out_path):
+                                    try:
+                                        os.unlink(out_path)
+                                    except Exception:
+                                        pass
+                            continue
+                            
+                    raise RuntimeError(f"Real-ESRGAN failed with exit code {p_upscale.returncode}: {err_msg}")
                 else:
-                    eta_str = "Calculating..."
-                    
-                job.update_status("upscaling", progress=progress_pct, current_frame=processed_files, eta=eta_str)
-                on_progress_update(job.job_id, {
-                    "status": "upscaling", 
-                    "progress": progress_pct, 
-                    "current_frame": processed_files, 
-                    "total_frames": actual_total,
-                    "eta": eta_str
-                })
-                time.sleep(0.5)
-                
-            stdout, stderr = p_upscale.communicate()
-            job.cleanup_process(p_upscale)
-            
-            if job._is_cancelled:
-                return
-                
-            if p_upscale.returncode != 0:
-                err_msg = (stdout or "") + "\n" + (stderr or "")
-                is_alloc_error = any(x in err_msg.lower() for x in ["vkallocatememory", "out of memory", "allocation", "vram", "failed to allocate"])
-                
-                if is_alloc_error:
-                    if current_tile_size <= 0:
-                        next_tile_size = 256
-                    else:
-                        next_tile_size = current_tile_size // 2
-                        
-                    if next_tile_size >= 32:
-                        print(f"Job {job.job_id}: Real-ESRGAN failed with VRAM allocation error. Retrying with tile size halved from {current_tile_size} to {next_tile_size}.")
-                        current_tile_size = next_tile_size
-                        # Clean up output frames directory before retrying
-                        for filename in os.listdir(output_frames_dir):
-                            file_path = os.path.join(output_frames_dir, filename)
-                            try:
-                                if os.path.isfile(file_path) or os.path.islink(file_path):
-                                    os.unlink(file_path)
-                                elif os.path.isdir(file_path):
-                                    shutil.rmtree(file_path)
-                            except Exception as cleanup_err:
-                                print(f"Error cleaning file {file_path}: {cleanup_err}")
-                        continue
-                        
-                raise RuntimeError(f"Real-ESRGAN failed with exit code {p_upscale.returncode}: {err_msg}")
-            else:
-                break
+                    break
                 
         # Final validation of upscale output
         processed_files = len(os.listdir(output_frames_dir))

context/README.md

@@ -0,0 +1,58 @@
+# 🧠 AI Video Upscaler - Project Context & Reference
+
+Welcome! This document acts as a memory reference folder for AI agents working on this project. It details the system architecture, code organization, pipeline stages, and custom feature implementations (Resumption & Queue Management).
+
+---
+
+## 🏗️ System Architecture
+
+The AI Video Upscaler is a full-stack, single-user application designed to upscale videos locally using Vulkan GPU-accelerated AI models.
+
+### Technology Stack
+1. **FastAPI (Python Backend)**: Handles API endpoints, serving static assets, WebSockets, background threads, and orchestrates subprocess execution.
+2. **Real-ESRGAN ncnn-vulkan (AI Engine)**: A compiled C++ Vulkan binary located in `realesrgan-bin/realesrgan-ncnn-vulkan`.
+3. **FFmpeg & FFprobe (Multimedia Toolkit)**: Splitting videos into high-quality JPEG frames, querying metadata, extracting audio streams, and re-muxing audio/subtitles back into the upscaled output.
+4. **Vanilla HTML/CSS/JS (Frontend)**: Cyberpunk-themed web dashboard with real-time progress logging, side-by-side comparative preview, and queue management.
+
+---
+
+## 📁 Key File Map
+
+- **`app/main.py`**: API route definitions, WebSocket orchestrator, custom thread-safe job queue, and JSON database state preservation (`jobs.json`).
+- **`app/upscaler.py`**: Core pipeline orchestrator (`run_upscale_pipeline`). Executes external FFmpeg and Real-ESRGAN commands. Contains the resume logic.
+- **`static/index.html`**, **`static/styles.css`**, **`static/app.js`**: Frontend interface, WebSocket handlers, interactive comparison slider, zoom/pan tool, and queue reordering actions.
+- **`jobs.json`**: Persisted file storing details of all jobs (automatically generated at root).
+
+---
+
+## 🔄 Upscale Pipeline Lifecycle
+
+A typical upscale job follows these sequential steps:
+1. **Queued (`queued`)**: Added to the FIFO queue.
+2. **Analyzing (`analyzing`)**: GPU lock acquired. Querying stream specs with `ffprobe`.
+3. **Extracting (`extracting`)**: FFmpeg extracts video frames into `temp/<job_id>/input_frames/frame_%08d.jpg`.
+4. **Upscaling (`upscaling`)**: Real-ESRGAN binary upscales images to `temp/<job_id>/output_frames/frame_%08d.jpg`.
+5. **Assembling (`assembling`)**: FFmpeg merges upscaled frames with original audio/subtitles.
+6. **Completed (`completed`)** / **Failed (`failed`)** / **Cancelled (`cancelled`)** / **Interrupted (`interrupted`)**.
+
+---
+
+## ⚡ Custom Enhancements
+
+### 1. Job Resumption (`interrupted` status)
+- **Persistency**: The status of all jobs is stored in `jobs.json` at the root. On application restart, any incomplete/active job is automatically loaded in the `interrupted` status.
+- **Skip Extraction**: On resume, if `temp/<job_id>/input_frames` contains frames, the extraction step is bypassed.
+- **Incremental Upscaling**: The upscaler inspects `output_frames/` and checks for already upscaled frames. It removes corresponding files from `input_frames/`, meaning the AI model only processes the remaining un-upscaled frames.
+- **Fast Assembly**: If all frames are already upscaled, it skips the upscaling step entirely and directly runs the FFmpeg reassembly.
+
+### 2. Queue Management (Cancel & Reorder)
+- **Custom Queue (`CustomJobQueue`)**: A thread-safe, list-backed FIFO queue replacing the standard `queue.Queue`. It allows:
+  - Querying the active queue list (`GET /api/queue`).
+  - Swapping queued jobs and re-ordering (`POST /api/queue/reorder`).
+  - Graceful removal upon cancellation.
+- **Interactive UI Arrows**: Arrows are displayed next to queued items in the dashboard to move jobs up and down, triggering the API to swap their order on-the-fly.
+
+### 3. Automatic Virtual Environment Setup (`start.py`)
+- **Self-Sufficiency**: Running `python3 start.py` automatically checks for a local virtual environment (`venv/` or `.venv/`).
+- **Auto-Provisioning**: If no virtual environment is found, `start.py` will initialize one in `venv/`, upgrade `pip`, install all dependencies listed in `requirements.txt`, mark the Real-ESRGAN binary as executable (`chmod +x`), and create necessary folders (`uploads/`, `outputs/`, `temp/`).
+- **Seamless Launch**: It then automatically launches the server process using the newly created environment interpreter.

start.py

@@ -21,18 +21,83 @@ import webbrowser
 BASE_DIR   = os.path.dirname(os.path.abspath(__file__))
 PID_FILE   = os.path.join(BASE_DIR, ".uvicorn.pid")
 LOG_FILE   = os.path.join(BASE_DIR, "server.log")
-# Detect the right Python interpreter:
-# 1. If running inside an activated venv, use that interpreter
-# 2. Otherwise look for venv/ then .venv/ in the project
-if sys.prefix != sys.base_prefix:
-    # Already inside an activated venv — use it
-    VENV_PYTHON = sys.executable
-else:
-    VENV_PYTHON = os.path.join(BASE_DIR, "venv", "bin", "python")
-    if not os.path.isfile(VENV_PYTHON):
-        VENV_PYTHON = os.path.join(BASE_DIR, ".venv", "bin", "python")
-    if not os.path.isfile(VENV_PYTHON):
-        VENV_PYTHON = sys.executable  # last resort: system python
+
+VENV_PYTHON = sys.executable  # default fallback
+
+def ensure_venv():
+    """Detect or create the virtual environment and install dependencies."""
+    global VENV_PYTHON
+    
+    # 1. Already inside an activated venv — use it
+    if sys.prefix != sys.base_prefix:
+        VENV_PYTHON = sys.executable
+        return
+        
+    venv_dir = os.path.join(BASE_DIR, "venv")
+    dot_venv_dir = os.path.join(BASE_DIR, ".venv")
+    
+    # Check if either venv/ or .venv/ exists with a python interpreter
+    selected_venv = None
+    if os.path.isdir(os.path.join(venv_dir, "bin")):
+        selected_venv = venv_dir
+    elif os.path.isdir(os.path.join(dot_venv_dir, "bin")):
+        selected_venv = dot_venv_dir
+        
+    if selected_venv:
+        python_exe = os.path.join(selected_venv, "bin", "python")
+        if os.path.isfile(python_exe):
+            VENV_PYTHON = python_exe
+            return
+
+    # No valid venv found — let's build it!
+    print("⚙️  Virtual environment not detected. Initializing setup...")
+    print(f"   Creating virtual environment at: {venv_dir}")
+    try:
+        import venv
+        venv.create(venv_dir, with_pip=True)
+        print("✅ Virtual environment created.")
+    except Exception as e:
+        print(f"❌ Failed to create virtual environment via 'venv' module: {e}")
+        print("   Attempting subprocess fallback...")
+        try:
+            subprocess.run([sys.executable, "-m", "venv", venv_dir], check=True)
+            print("✅ Virtual environment created (fallback).")
+        except Exception as err:
+            print(f"❌ Subprocess fallback failed: {err}")
+            sys.exit(1)
+            
+    VENV_PYTHON = os.path.join(venv_dir, "bin", "python")
+    pip_exe = os.path.join(venv_dir, "bin", "pip")
+    
+    # Install dependencies
+    requirements_file = os.path.join(BASE_DIR, "requirements.txt")
+    if os.path.isfile(requirements_file):
+        print("📦 Installing Python dependencies from requirements.txt...")
+        try:
+            # Upgrade pip
+            subprocess.run([pip_exe, "install", "--upgrade", "pip", "--quiet"], check=True)
+            # Install requirements
+            subprocess.run([pip_exe, "install", "-r", requirements_file], check=True)
+            print("✅ All Python dependencies installed successfully.")
+        except Exception as e:
+            print(f"❌ Error installing dependencies: {e}")
+            sys.exit(1)
+    else:
+        print("⚠  requirements.txt not found. Skipping dependency installation.")
+        
+    # Configure Real-ESRGAN binary permissions
+    binary_path = os.path.join(BASE_DIR, "realesrgan-bin", "realesrgan-ncnn-vulkan")
+    if os.path.isfile(binary_path):
+        try:
+            os.chmod(binary_path, 0o755)
+            print("✅ Real-ESRGAN binary marked as executable.")
+        except Exception as e:
+            print(f"⚠  Failed to change binary permissions: {e}")
+            
+    # Create working directories
+    for d in ["uploads", "outputs", "temp"]:
+        os.makedirs(os.path.join(BASE_DIR, d), exist_ok=True)
+    print("✅ Working directories verified.")
 
 
 def _is_running(pid: int) -> bool:
@@ -153,4 +218,5 @@ if __name__ == "__main__":
                         help="Don't open the browser automatically")
     args = parser.parse_args()
 
+    ensure_venv()
     start(args.host, args.port, open_browser=not args.no_browser)

static/app.js

@@ -1276,6 +1276,37 @@ async function loadGallery() {
     }
 }
 
+async function moveQueueItem(jobId, direction) {
+    try {
+        const res = await fetch("/api/queue");
+        if (!res.ok) return;
+        const data = await res.json();
+        const queue = data.queue;
+        const index = queue.indexOf(jobId);
+        if (index === -1) return;
+        
+        const newIndex = index + direction;
+        if (newIndex < 0 || newIndex >= queue.length) return;
+        
+        // Swap
+        const temp = queue[index];
+        queue[index] = queue[newIndex];
+        queue[newIndex] = temp;
+        
+        const reorderRes = await fetch("/api/queue/reorder", {
+            method: "POST",
+            headers: { "Content-Type": "application/json" },
+            body: JSON.stringify({ job_ids: queue })
+        });
+        
+        if (reorderRes.ok) {
+            loadQueue();
+        }
+    } catch (err) {
+        console.error("Error reordering queue:", err);
+    }
+}
+
 async function loadQueue() {
     const queueList = document.getElementById("queue-list");
     if (!queueList) return;
@@ -1287,7 +1318,7 @@ async function loadQueue() {
         const jobs = await res.json();
         
         const displayJobs = jobs.filter(job => 
-            ["queued", "analyzing", "extracting", "upscaling", "assembling", "completed", "failed", "cancelled"].includes(job.status)
+            ["queued", "analyzing", "extracting", "upscaling", "assembling", "completed", "failed", "cancelled", "interrupted"].includes(job.status)
         );
         
         if (displayJobs.length === 0) {
@@ -1318,13 +1349,40 @@ async function loadQueue() {
             
             if (job.status === "failed" && job.error) {
                 metaHtml += `<span style="color: var(--danger);"><i class="fa-solid fa-triangle-exclamation"></i> Error: ${job.error}</span>`;
-            } else if (job.status !== "queued" && job.status !== "failed" && job.status !== "cancelled" && job.status !== "completed") {
+            } else if (job.status !== "queued" && job.status !== "failed" && job.status !== "cancelled" && job.status !== "completed" && job.status !== "interrupted") {
                 metaHtml += `<span><i class="fa-solid fa-clock"></i> ETA: ${job.eta || 'Calculating...'}</span>`;
             }
             
             let actionsHtml = "";
-            if (["queued", "analyzing", "extracting", "upscaling", "assembling"].includes(job.status)) {
+            let reorderHtml = "";
+            
+            if (job.status === "queued" && job.queue_position !== null && job.queue_position !== undefined) {
+                const queuedJobs = displayJobs.filter(j => j.status === "queued");
+                const isFirst = job.queue_position === 0;
+                const isLast = job.queue_position === queuedJobs.length - 1;
+                
+                reorderHtml = `
+                    <button class="btn btn-secondary btn-small btn-move-up" data-id="${job.job_id}" style="padding: 0.25rem 0.5rem; width: 30px; height: 30px; border-radius: 8px; font-size: 0.8rem; display: inline-flex; align-items: center; justify-content: center; ${isFirst ? 'visibility: hidden;' : ''}" title="Move Up">
+                        <i class="fa-solid fa-arrow-up"></i>
+                    </button>
+                    <button class="btn btn-secondary btn-small btn-move-down" data-id="${job.job_id}" style="padding: 0.25rem 0.5rem; width: 30px; height: 30px; border-radius: 8px; font-size: 0.8rem; display: inline-flex; align-items: center; justify-content: center; ${isLast ? 'visibility: hidden;' : ''}" title="Move Down">
+                        <i class="fa-solid fa-arrow-down"></i>
+                    </button>
+                `;
+            }
+            
+            if (job.status === "interrupted") {
                 actionsHtml = `
+                    <button class="btn btn-primary btn-small btn-resume-job" data-id="${job.job_id}">
+                        <i class="fa-solid fa-play"></i> Resume
+                    </button>
+                    <button class="btn btn-secondary btn-small btn-delete-job" data-id="${job.job_id}">
+                        <i class="fa-solid fa-trash"></i> Clear
+                    </button>
+                `;
+            } else if (["queued", "analyzing", "extracting", "upscaling", "assembling"].includes(job.status)) {
+                actionsHtml = `
+                    ${reorderHtml}
                     <button class="btn btn-primary btn-small btn-view-job" data-id="${job.job_id}">
                         <i class="fa-solid fa-eye"></i> View
                     </button>
@@ -1366,9 +1424,44 @@ async function loadQueue() {
                 </div>
             `;
             
+            const upBtn = item.querySelector(".btn-move-up");
+            if (upBtn) {
+                upBtn.addEventListener("click", async (e) => {
+                    e.stopPropagation();
+                    await moveQueueItem(job.job_id, -1);
+                });
+            }
+            
+            const downBtn = item.querySelector(".btn-move-down");
+            if (downBtn) {
+                downBtn.addEventListener("click", async (e) => {
+                    e.stopPropagation();
+                    await moveQueueItem(job.job_id, 1);
+                });
+            }
+            
+            const resumeBtn = item.querySelector(".btn-resume-job");
+            if (resumeBtn) {
+                resumeBtn.addEventListener("click", async (e) => {
+                    e.stopPropagation();
+                    try {
+                        const resumeRes = await fetch(`/api/upscale/resume/${job.job_id}`, { method: "POST" });
+                        if (resumeRes.ok) {
+                            loadQueue();
+                        } else {
+                            const err = await resumeRes.json();
+                            alert("Failed to resume job: " + formatFetchError(err, "unknown error"));
+                        }
+                    } catch (err) {
+                        console.error("Error resuming job:", err);
+                    }
+                });
+            }
+            
             const abortBtn = item.querySelector(".btn-abort-job");
             if (abortBtn) {
-                abortBtn.addEventListener("click", async () => {
+                abortBtn.addEventListener("click", async (e) => {
+                    e.stopPropagation();
                     if (confirm("Are you sure you want to abort this upscaling job?")) {
                         try {
                             const abortRes = await fetch(`/api/upscale/cancel/${job.job_id}`, { method: "POST" });
@@ -1384,7 +1477,8 @@ async function loadQueue() {
             
             const deleteBtn = item.querySelector(".btn-delete-job");
             if (deleteBtn) {
-                deleteBtn.addEventListener("click", async () => {
+                deleteBtn.addEventListener("click", async (e) => {
+                    e.stopPropagation();
                     if (confirm("Are you sure you want to clear this job from history?")) {
                         try {
                             const delRes = await fetch(`/api/jobs/${job.job_id}`, { method: "DELETE" });
@@ -1401,7 +1495,8 @@ async function loadQueue() {
             
             const viewBtn = item.querySelector(".btn-view-job");
             if (viewBtn) {
-                viewBtn.addEventListener("click", () => {
+                viewBtn.addEventListener("click", (e) => {
+                    e.stopPropagation();
                     currentJobId = job.job_id;
                     if (socket) {
                         try {

static/styles.css

@@ -656,6 +656,7 @@ input:checked + .slider:before {
 .status-badge.assembling { background: rgba(0, 240, 255, 0.1); border: 1px solid var(--primary); color: var(--primary); }
 .status-badge.completed { background: rgba(0, 255, 135, 0.1); border: 1px solid var(--success); color: var(--success); }
 .status-badge.failed { background: rgba(255, 0, 85, 0.1); border: 1px solid var(--danger); color: var(--danger); }
+.status-badge.interrupted { background: rgba(255, 255, 255, 0.08); border: 1px solid var(--text-muted); color: var(--text-muted); }
 
 .bar-container {
     width: 100%;