Add OUTPUT_DIR browser + copy-on-load with progress to upload dashboard

LOAD MP4 on an OUTPUT_DIR file copies it into UPLOAD_DIR (chunked,
progress via /api/copy-progress) before spawning RECOUNT_CMD; collision
in UPLOAD_DIR fails with 400. New read-only folder-grouped browser
mirrors recounting_dashboard.py. Docs updated.

AGENTS.md

@@ -9,7 +9,7 @@
 - `batch_store.py` — shared SQLite persistence + batch state machine.
 - `counter_dashboard.py` — Flask dashboard on port 5000, same DB.
 - `recounting_dashboard.py` — Flask recounting dashboard on port 5002, consumes live + recount APIs.
-- `recounting_dashboard_upload.py` — Flask upload+recount dashboard on port 5003; uploads MP4 first, then launches `RECOUNT_CMD --source <mp4>`; START RECOUNT stays disabled until an upload completes.
+- `recounting_dashboard_upload.py` — Flask upload+recount dashboard on port 5003; uploads MP4 first, then **LOAD MP4** spawns `RECOUNT_CMD` (process loads and pauses), then **START RECOUNT** touches `{SHM_DIR}/.continue` to begin counting.
 
 ## No build / test / lint
 
@@ -43,11 +43,15 @@ PYTHONNOUSERSITE=1 venv/bin/python recounting_dashboard_upload.py
 - **`numpy<2`** is required for `rknn-toolkit-lite2` compatibility.
 - **Install path in service files is `/opt/bytetrack-counter`** (not the `/opt/jetson-counter` mentioned in README/DEPLOY). The `.env.example` also reflects `/opt/bytetrack-counter`.
 - Service user is **`root`**, not `jetson` (despite README saying otherwise).
-- Two systemd units: `bytetrack-counter.service` + `bytetrack-counter-dashboard.service`.
+- Three systemd units: `bytetrack-counter.service`, `bytetrack-counter-dashboard.service`, and `bytetrack-recounting-upload-dashboard.service` (upload recounting dashboard, port 5003).
 - `counter_live.py` (TensorRT) is Jetson-only and won't work on RK3588.
 - **Reset flow**: `POST /api/reset` → deletes state JSON + touches `{SHM_DIR}/.reset`. `batch_store._check_reset_signal()` watches this marker and clears in-memory state on next crossing.
+- **Recount continue flow** (upload dashboard, port 5003): `POST /api/load-mp4 {path}` kills the old process, spawns `RECOUNT_CMD` (loads + pauses), and POSTs `/api/reset` to the recount node. `POST /api/start-recount` (no body, requires a loaded file) touches `{SHM_DIR}/.continue`; the C++ process consumes that marker to begin counting. The dashboard never clears the marker.
+- **OUTPUT_DIR browser + copy-on-load** (upload dashboard, port 5003): `GET /api/mp4-files` lists MP4s from `OUTPUT_DIR` folder-grouped (mirrors `recounting_dashboard.py`'s `/api/mp4-files` shape). Selecting one and pressing LOAD MP4 makes `POST /api/load-mp4` copy it into `UPLOAD_DIR` first (chunked, progress reported via `GET /api/copy-progress` → `{active,name,total,done,pct}`, frontend polls every 250 ms to drive the progress bar). Name collision in `UPLOAD_DIR` → 400 error (no overwrite). The OUTPUT_DIR browser is read-only (no delete).
+- **Recount STOP sweep**: `POST /api/stop-recount` kills the tracked process group (`killpg` TERM→5s→KILL) then sweeps the host via `/proc` for any process whose argv matches the `RECOUNT_CMD` binary name (basename of the first token, so it also catches orphans from a dashboard restart); TERM→`_SWEEP_GRACE_SEC`→KILL with `_SWEEP_MAX_RETRIES` retries, all under `_recount_lock`. Returns `{success, killed, remaining}`; `remaining` is 0 in the normal path, and survivors (e.g. D-state) are logged rather than force-hanging.
 - **Upload filename contract**: uploads are expected as `batch_XX_YYYYMMDD_HHmmSS.mp4` (XX = batch number, timestamp = date). `recounting_dashboard_upload.py` parses both to query the live API's `/api/day-detail/<YYYY-MM-DD>` for the recorded count.
-- **`RECOUNT_CMD`** in the upload dashboard is a template with a `{path}` placeholder, e.g. `bytetrack-counter config.env --source {path}`; the uploaded file path is `shlex.quote()`d before substitution.
+- **`RECOUNT_CMD`** in the upload dashboard is a template with a `{path}` placeholder, e.g. `bytetrack-counter-cpp config.env --source {path}`; the uploaded file path is `shlex.quote()`d before substitution, and the command is spawned by **LOAD MP4** (loads + pauses until `.continue` is touched).
+- **Cross-dashboard header links**: `UPLOAD_DASHBOARD_URL` (live → upload dashboard, `counter_dashboard.py`) and `LIVE_DASHBOARD_URL` (upload → live dashboard, `recounting_dashboard_upload.py`); empty value hides the header link.
 
 ## Code conventions
 

SPEC.md

@@ -54,6 +54,7 @@ env: MIN_OBJECT_PER_BATCH → min count to persist batch (default 60)
 env: MIN_DURATION_PER_BATCH → min seconds to persist batch (default 60)
 env: LIVE_STREAM_ENABLED → write annotated JPEG snapshot each N frames
 env: EXPORT_CSV → write per-crossing CSV (default true)
+env: UPLOAD_DASHBOARD_URL → header link to upload recounting dashboard (default empty → hidden)
 
 ### Recounting dashboard config
 ```
@@ -68,8 +69,10 @@ env: GO2RTC_STREAM_NAME → go2rtc stream name for recount preview (default "rec
 ```
 env: RECOUNTING_UPLOAD_PORT → port for upload UI (default 5003)
 env: UPLOAD_DIR → dir for uploaded MP4s (default <repo>/uploads)
+env: OUTPUT_DIR → dir scanned for "From Output Directory" browser (default /opt/bytetrack-counter)
 env: RECOUNT_CMD → replay command template with {path} placeholder (default "bytetrack-counter config.env --source {path}")
-env: RECOUNTING_UPLOAD_TEMPLATE → template (default recounting_upload.html)
+env: RECOUNTING_UPLOAD_TEMPLATE → template (default recounting_upload_lamborghini.html)
+env: LIVE_DASHBOARD_URL → header link to live counter dashboard (default empty → hidden)
 ```
 ```
 
@@ -121,9 +124,12 @@ api: POST /api/stop-recount → kill ffmpeg + clear current file
 api: GET / → upload recounting HTML (template via RECOUNTING_UPLOAD_TEMPLATE env var)
 api: POST /api/upload → multipart .mp4 (≤512MB), saved as original filename in UPLOAD_DIR; returns {name, path, size}
 api: GET /api/uploads → list uploaded MP4s sorted by mtime desc → [ {name, path, size, mtime} ]
+api: GET /api/mp4-files → list OUTPUT_DIR MP4s grouped by folder (date), files sorted by batch # → [ {folder, files:[{name, path, size, mtime}]} ]
+api: GET /api/copy-progress → {active:false} idle | {active, name, total, done, pct} during an in-progress copy
 api: POST /api/delete-upload {path} → delete uploaded MP4 (path restricted to UPLOAD_DIR)
-api: POST /api/start-recount {path} → reset recount API then launch RECOUNT_CMD (path shlex-quoted); START RECOUNT disabled until upload completes
+api: POST /api/load-mp4 {path} → if path outside UPLOAD_DIR: collision check (same-name in UPLOAD_DIR → 400), else copy (chunked, progress-reporting) into UPLOAD_DIR first; then kill old process, spawn RECOUNT_CMD (copied path shlex-quoted) paused, reset recount API; returns copied path
-api: POST /api/stop-recount → kill recount process + clear current file
+api: POST /api/start-recount → require loaded file, touch {SHM_DIR}/.continue to signal C++ process to begin counting
+api: POST /api/stop-recount → killpg tracked group + host-wide /proc sweep of RECOUNT_CMD binary (TERM→grace→KILL, verify loop); returns {success, killed, remaining}
 api: GET /api/state → {streaming, file, file_name, stream_url, batch_number, batch_date}
 api: GET /api/proxy-stream → proxy MJPEG from RECOUNT_API_URL:/api/live-video (same-origin)
 api: GET /api/live-progress → proxy to LIVE_API_URL:/api/current-batch
@@ -157,6 +163,11 @@ V18: .env missing → scripts fail at import (os.getenv falls back to defaults,
 V19: stream reconnect → reset motion detection state (prev_gray = None)
 V20: reset → delete STATE_FILE + touch {SHM_DIR}/.reset; batch_store._check_reset_signal() watches marker & clears in-memory state before next crossing
 V21: upload filename batch_XX_YYYYMMDD_HHmmSS.mp4 → batch# + date parsed; batch-result queries /api/day-detail/<YYYY-MM-DD> on live API
+V22: preview auto-on once per streaming session — enablePreview() on START RECOUNT + applyState streaming branch guarded by previewAutoOn flag; manual toggle persists until next session (flag reset only on stop); img.onerror retries cache-busted src while streaming
+V23: .continue marker flow — LOAD MP4 spawns RECOUNT_CMD paused; START RECOUNT touches {SHM_DIR}/.continue; C++ process consumes marker to begin counting; dashboard never clears it (LOAD alone does not count)
+V24: STOP → killpg tracked group then host-wide /proc sweep of RECOUNT_CMD binary (basename of first token); sweep runs under _recount_lock, TERM→_SWEEP_GRACE_SEC→KILL, bounded retries; returns {success, killed, remaining} with remaining==0 in normal path; survivors (D-state) logged, never force-hang
+V25: LOAD MP4 on an OUTPUT_DIR file → copy into UPLOAD_DIR (original untouched); copy runs server-side, chunked, reports {done,total} to _copy_progress under _copy_lock; name collision in UPLOAD_DIR → 400 error, no overwrite
+V26: OUTPUT_DIR browser → read-only, folder-grouped via /api/mp4-files (mirrors 5002 shape); no delete button on OUTPUT_DIR rows
 ```
 
 ## §T — Tasks
@@ -178,6 +189,11 @@ T12|x|add recounting dashboard — dual-API counter panels, MP4 browser, go2rtc
 T13|x|add template system — DASHBOARD_TEMPLATE env var selects dashboard.html|lamborghini|tesla|
 T14|x|harden reset API — separate SHM marker creation from state file cleanup; return 500 on SHM failure|V20
 T15|x|add upload recounting dashboard — MP4 upload, progress bar, RECOUNT_CMD replay|V21
+T16|x|add cross-dashboard header links — UPLOAD_DASHBOARD_URL (live→upload) & LIVE_DASHBOARD_URL (upload→live)|I.config
+T17|x|auto-on live preview when recount running — enablePreview() on START + applyState; onerror retry while streaming|V22
+T18|x|split recount flow — /api/load-mp4 spawns paused RECOUNT_CMD, /api/start-recount touches {SHM_DIR}/.continue; C++ consumes marker|V23
+T19|x|hard-kill STOP — sweep all RECOUNT_CMD-binary processes via /proc, verify remaining==0, report killed/remaining|V24
+T20|x|add OUTPUT_DIR browser to upload dashboard — /api/mp4-files listing, copy-on-load with progress polling into UPLOAD_DIR, collision guard|V25,V26
 ```
 
 ## §B — Bugs
@@ -185,5 +201,6 @@ T15|x|add upload recounting dashboard — MP4 upload, progress bar, RECOUNT_CMD
 ```
 id|date|cause|fix
 B1|2026-07-29|prev_gray not reset on stream reconnect → cv2.absdiff crash or false motion|V19
+B2|2026-08-10|applyState re-ran enablePreview() every 1s poll, overriding manual STREAM toggle (OFF flipped back to ON)|V22
 ```
 

bytetrack-recounting-upload-dashboard.service

@@ -0,0 +1,34 @@
+[Unit]
+Description=Edge Counter Recounting Upload Dashboard (Flask, port 5003)
+Documentation=file:///opt/bytetrack-counter/DEPLOY.md
+After=network-online.target bytetrack-counter-dashboard.service
+Wants=network-online.target bytetrack-counter-dashboard.service
+
+[Service]
+Type=simple
+User=root
+Group=root
+
+WorkingDirectory=/opt/bytetrack-counter
+
+EnvironmentFile=/opt/bytetrack-counter/.env
+Environment=PATH=/opt/bytetrack-counter/venv/bin:/usr/local/bin:/usr/bin:/bin
+Environment=PYTHONNOUSERSITE=1
+Environment=FLASK_DEBUG=false
+
+ExecStart=/opt/bytetrack-counter/venv/bin/python recounting_dashboard_upload.py
+
+TimeoutStopSec=15
+KillSignal=SIGTERM
+
+Restart=on-failure
+RestartSec=5
+StartLimitInterval=60s
+StartLimitBurst=3
+
+NoNewPrivileges=true
+ProtectHome=true
+PrivateTmp=false
+
+[Install]
+WantedBy=multi-user.target

config.env.example

@@ -159,6 +159,8 @@ SECRET_KEY=change-me-in-production
 DASHBOARD_HOST=0.0.0.0
 # Listen port for the dashboard web UI
 DASHBOARD_PORT=5000
+# URL of the upload recounting dashboard (recounting_dashboard_upload.py); empty hides the header link
+UPLOAD_DASHBOARD_URL=http://localhost:5003
 # Enable Flask debug mode (true/false) — auto-reloads on code changes; disable in production
 FLASK_DEBUG=false
 # Fallback name for the active-batch JSON state file used by the dashboard
@@ -183,8 +185,13 @@ RECOUNT_STREAM_NAME=stream_1
 RECOUNTING_UPLOAD_PORT=5003
 # Directory where uploaded MP4 files are stored
 UPLOAD_DIR=/opt/bytetrack-counter/uploads
-# Command to launch the recounting counter process (placeholder, fill in real command).
+# Directory scanned for the "From Output Directory" file browser (folder-grouped MP4s).
-# {path} is substituted with the absolute path of the uploaded MP4 file.
+# Selecting one of those files and pressing LOAD MP4 copies it into UPLOAD_DIR first.
-RECOUNT_CMD=bytetrack-counter config.env --source {path}
+OUTPUT_DIR=/opt/bytetrack-counter
-# Template file for the upload dashboard: "recounting_upload.html" (default)
+# Command launched by LOAD MP4 (bytetrack-counter-cpp); {path} is the uploaded MP4.
-RECOUNTING_UPLOAD_TEMPLATE=recounting_upload.html
+# The process loads + pauses until START RECOUNT touches {SHM_DIR}/.continue.
+RECOUNT_CMD=bytetrack-counter-cpp config.env --source {path}
+# Template file for the upload dashboard: "recounting_upload_lamborghini.html" (default) or "recounting_upload.html"
+RECOUNTING_UPLOAD_TEMPLATE=recounting_upload_lamborghini.html
+# URL of the live counter dashboard (counter_dashboard.py); empty hides the header link
+LIVE_DASHBOARD_URL=http://localhost:5000

counter_dashboard.py

@@ -40,6 +40,7 @@ SHM_DIR = os.getenv("SHM_DIR", "/dev/shm/bytetrack-counter")
 
 SITE_NAME = os.getenv("SITE_NAME", "LIVE")
 TEMPLATE = os.getenv("DASHBOARD_TEMPLATE", "dashboard.html")
+UPLOAD_DASHBOARD_URL = os.getenv("UPLOAD_DASHBOARD_URL", "")
 
 DASHBOARD_PORT = int(os.getenv("DASHBOARD_PORT", "5000"))
 DASHBOARD_HOST = os.getenv("DASHBOARD_HOST", "0.0.0.0")
@@ -132,7 +133,7 @@ def get_counting_date(dt=None, cutoff_str=CUTOFF_TIME):
 
 @app.route("/")
 def index():
-    return render_template(TEMPLATE, site_name=SITE_NAME)
+    return render_template(TEMPLATE, site_name=SITE_NAME, upload_dashboard_url=UPLOAD_DASHBOARD_URL)
 
 
 @app.route("/api/current-batch")

recounting_dashboard_upload.py

@@ -8,6 +8,8 @@ import logging
 import os
 import re
 import shlex
+import shutil
+import signal
 import subprocess
 import threading
 import time
@@ -31,11 +33,13 @@ app.config["MAX_CONTENT_LENGTH"] = 512 * 1024 * 1024  # 512 MB
 
 REPO_ROOT = Path(__file__).resolve().parent
 UPLOAD_DIR = Path(os.getenv("UPLOAD_DIR", str(REPO_ROOT / "uploads")))
+OUTPUT_DIR = Path(os.getenv("OUTPUT_DIR", "/opt/bytetrack-counter"))
 LIVE_API_URL = os.getenv("LIVE_API_URL", "http://localhost:5000")
 RECOUNT_API_URL = os.getenv("RECOUNT_API_URL", "http://localhost:5001")
 
 SITE_NAME = os.getenv("SITE_NAME", "RECOUNT")
-TEMPLATE = os.getenv("RECOUNTING_UPLOAD_TEMPLATE", "recounting_upload.html")
+TEMPLATE = os.getenv("RECOUNTING_UPLOAD_TEMPLATE", "recounting_upload_lamborghini.html")
+LIVE_DASHBOARD_URL = os.getenv("LIVE_DASHBOARD_URL", "")
 
 DASHBOARD_PORT = int(os.getenv("RECOUNTING_UPLOAD_PORT", "5003"))
 DASHBOARD_HOST = os.getenv("DASHBOARD_HOST", "0.0.0.0")
@@ -43,6 +47,12 @@ FLASK_DEBUG = os.getenv("FLASK_DEBUG", "false").lower() == "true"
 
 RECOUNT_CMD = os.getenv("RECOUNT_CMD", "bytetrack-counter config.env --source {path}")
 
+SHM_DIR = os.getenv("SHM_DIR", "/dev/shm/bytetrack-counter")
+_CONTINUE_FLAG = Path(f"{SHM_DIR}/.continue")
+
+_SWEEP_GRACE_SEC = 5
+_SWEEP_MAX_RETRIES = 3
+
 _http_session = requests.Session()
 _http_session.timeout = 3
 
@@ -52,6 +62,9 @@ _recount_proc = None
 _recount_lock = threading.Lock()
 _current_file = None
 
+_copy_progress = {}
+_copy_lock = threading.Lock()
+
 
 def _parse_filename(filename):
     m = _FILENAME_RE.search(filename)
@@ -73,13 +86,85 @@ def _api_get(base_url, path, default=None):
 
 def _stop_recount_locked():
     global _recount_proc
-    if _recount_proc:
+    proc = _recount_proc
+    _recount_proc = None
+    if proc is None:
+        return
+    try:
+        pgid = os.getpgid(proc.pid)
+    except (ProcessLookupError, PermissionError):
+        return
+    try:
+        os.killpg(pgid, signal.SIGTERM)
+    except (ProcessLookupError, PermissionError):
+        pass
+    try:
+        proc.wait(timeout=5)
+    except subprocess.TimeoutExpired:
         try:
-            _recount_proc.kill()
+            os.killpg(pgid, signal.SIGKILL)
-            _recount_proc.wait(timeout=3)
+        except (ProcessLookupError, PermissionError):
+            pass
+        try:
+            proc.wait(timeout=3)
         except Exception:
             pass
-        _recount_proc = None
+    except Exception:
+        pass
+
+
+def _recount_binary_name():
+    if not RECOUNT_CMD:
+        return "bytetrack-counter-cpp"
+    try:
+        first = shlex.split(RECOUNT_CMD)[0]
+    except (ValueError, IndexError):
+        return "bytetrack-counter-cpp"
+    return Path(first).name or "bytetrack-counter-cpp"
+
+
+def _iter_matching_pids(binary):
+    for entry in os.listdir("/proc"):
+        if not entry.isdigit():
+            continue
+        try:
+            with open(f"/proc/{entry}/cmdline", "rb") as f:
+                raw = f.read().split(b"\x00")
+        except (FileNotFoundError, PermissionError, ProcessLookupError):
+            continue
+        args = [t.decode(errors="ignore") for t in raw if t]
+        for token in args:
+            for piece in token.split():
+                if Path(piece).name == binary:
+                    yield int(entry)
+                    break
+            else:
+                continue
+            break
+
+
+def _sweep_recount_processes(binary):
+    killed = 0
+    for _ in range(_SWEEP_MAX_RETRIES):
+        pids = list(_iter_matching_pids(binary))
+        if not pids:
+            break
+        for pid in pids:
+            if pid not in list(_iter_matching_pids(binary)):
+                continue
+            try:
+                os.kill(pid, signal.SIGTERM)
+                killed += 1
+            except (ProcessLookupError, PermissionError):
+                pass
+        time.sleep(_SWEEP_GRACE_SEC)
+        for pid in list(_iter_matching_pids(binary)):
+            try:
+                os.kill(pid, signal.SIGKILL)
+            except (ProcessLookupError, PermissionError):
+                pass
+        time.sleep(1)
+    return killed, len(list(_iter_matching_pids(binary)))
 
 
 def _folder_date(filepath, base):
@@ -92,7 +177,7 @@ def _folder_date(filepath, base):
 
 @app.route("/")
 def index():
-    return render_template(TEMPLATE, site_name=SITE_NAME, upload_dir=str(UPLOAD_DIR))
+    return render_template(TEMPLATE, site_name=SITE_NAME, upload_dir=str(UPLOAD_DIR), output_dir=str(OUTPUT_DIR), live_dashboard_url=LIVE_DASHBOARD_URL)
 
 
 @app.route("/api/live-progress")
@@ -126,6 +211,55 @@ def api_uploads():
     return jsonify(files)
 
 
+@app.route("/api/mp4-files")
+def api_mp4_files():
+    folders = {}
+    output = Path(OUTPUT_DIR)
+    if not output.exists():
+        return jsonify([])
+
+    for d in sorted(output.iterdir(), reverse=True):
+        if not d.is_dir():
+            continue
+        folder_name = d.name
+        mp4s = sorted(d.glob("*.mp4"), key=lambda p: _parse_filename(p.name)[0] or 0)
+        if not mp4s:
+            continue
+        files = []
+        for f in mp4s:
+            st = f.stat()
+            files.append({
+                "name": f.name,
+                "path": str(f),
+                "size": st.st_size,
+                "mtime": datetime.fromtimestamp(st.st_mtime).isoformat(),
+            })
+        folders[folder_name] = files
+
+    result = []
+    for folder, files in sorted(folders.items(), reverse=True):
+        result.append({"folder": folder, "files": files})
+    return jsonify(result)
+
+
+@app.route("/api/copy-progress")
+def api_copy_progress():
+    with _copy_lock:
+        p = dict(_copy_progress)
+    if not p or not p.get("active"):
+        return jsonify({"active": False})
+    total = p.get("total") or 0
+    done = p.get("done") or 0
+    pct = round(done * 100.0 / total) if total else 0
+    return jsonify({
+        "active": True,
+        "name": p.get("name"),
+        "total": total,
+        "done": done,
+        "pct": pct,
+    })
+
+
 @app.route("/api/upload", methods=["POST"])
 def api_upload():
     if "file" not in request.files:
@@ -163,27 +297,7 @@ def api_delete_upload():
     return jsonify({"success": True})
 
 
-@app.route("/api/start-recount", methods=["POST"])
+def _reset_recount_api():
-def start_recount():
-    global _recount_proc, _current_file
-    data = request.get_json(force=True) or {}
-    upload_path = data.get("path", "")
-    if not upload_path:
-        return jsonify({"success": False, "error": "Missing 'path'"}), 400
-    if not os.path.isfile(upload_path):
-        return jsonify({"success": False, "error": f"File not found: {upload_path}"}), 404
-
-    with _recount_lock:
-        _stop_recount_locked()
-        _current_file = upload_path
-        cmd_str = RECOUNT_CMD.replace("{path}", shlex.quote(str(upload_path)))
-        try:
-            _recount_proc = subprocess.Popen(cmd_str, shell=True)
-            print(f"[{datetime.now().strftime('%Y-%m-%d %H:%M:%S')}] Recount started: {cmd_str}")
-        except Exception as e:
-            _current_file = None
-            return jsonify({"success": False, "error": f"Failed to start: {e}"}), 500
-
     try:
         resp = _http_session.post(f"{RECOUNT_API_URL}/api/reset", timeout=5)
         print(f"[{datetime.now().strftime('%Y-%m-%d %H:%M:%S')}] Recount reset: {RECOUNT_API_URL}/api/reset → {resp.status_code}")
@@ -194,6 +308,85 @@ def start_recount():
     except Exception as e:
         print(f"[{datetime.now().strftime('%Y-%m-%d %H:%M:%S')}] Recount reset: {RECOUNT_API_URL}/api/reset → error: {e}")
 
+
+def _spawn_recount_locked(upload_path):
+    global _recount_proc
+    cmd_str = RECOUNT_CMD.replace("{path}", shlex.quote(str(upload_path)))
+    _recount_proc = subprocess.Popen(cmd_str, shell=True, start_new_session=True)
+    print(f"[{datetime.now().strftime('%Y-%m-%d %H:%M:%S')}] Recount loaded: {cmd_str}")
+
+
+def _copy_file_with_progress(src, dest):
+    global _copy_progress
+    total = os.path.getsize(src)
+    done = 0
+    with _copy_lock:
+        _copy_progress = {
+            "active": True,
+            "name": Path(src).name,
+            "total": total,
+            "done": 0,
+            "error": None,
+        }
+    try:
+        with open(src, "rb") as fsrc, open(dest, "wb") as fdst:
+            while True:
+                buf = fsrc.read(1024 * 1024)
+                if not buf:
+                    break
+                fdst.write(buf)
+                done += len(buf)
+                with _copy_lock:
+                    _copy_progress["done"] = done
+        shutil.copystat(src, dest)
+    except Exception as e:
+        with _copy_lock:
+            _copy_progress["error"] = str(e)
+        raise
+    finally:
+        with _copy_lock:
+            _copy_progress["active"] = False
+
+
+@app.route("/api/load-mp4", methods=["POST"])
+def load_mp4():
+    global _current_file
+    data = request.get_json(force=True) or {}
+    src_path = data.get("path", "")
+    if not src_path:
+        return jsonify({"success": False, "error": "Missing 'path'"}), 400
+    if not os.path.isfile(src_path):
+        return jsonify({"success": False, "error": f"File not found: {src_path}"}), 404
+
+    src_path = str(Path(src_path).resolve())
+    upload_path = src_path
+    if Path(src_path).parent != Path(UPLOAD_DIR).resolve():
+        dest_path = str(Path(UPLOAD_DIR) / Path(src_path).name)
+        if os.path.exists(dest_path):
+            return jsonify({
+                "success": False,
+                "error": f"{Path(dest_path).name} already exists in uploads, delete it first",
+            }), 400
+        Path(UPLOAD_DIR).mkdir(parents=True, exist_ok=True)
+        try:
+            _copy_file_with_progress(src_path, dest_path)
+        except Exception as e:
+            with _copy_lock:
+                err = _copy_progress.get("error") or str(e)
+            return jsonify({"success": False, "error": f"Copy failed: {err}"}), 500
+        upload_path = dest_path
+
+    with _recount_lock:
+        _stop_recount_locked()
+        _current_file = upload_path
+        try:
+            _spawn_recount_locked(upload_path)
+        except Exception as e:
+            _current_file = None
+            return jsonify({"success": False, "error": f"Failed to start: {e}"}), 500
+
+    _reset_recount_api()
+
     return jsonify({
         "success": True,
         "stream_url": "/api/proxy-stream",
@@ -202,13 +395,41 @@ def start_recount():
     })
 
 
+@app.route("/api/start-recount", methods=["POST"])
+def start_recount():
+    with _recount_lock:
+        current = _current_file
+    if not current:
+        return jsonify({"success": False, "error": "Load an MP4 first"}), 400
+
+    try:
+        Path(SHM_DIR).mkdir(parents=True, exist_ok=True)
+        _CONTINUE_FLAG.touch(exist_ok=True)
+        print(f"[{datetime.now().strftime('%Y-%m-%d %H:%M:%S')}] Recount continue: {_CONTINUE_FLAG}")
+    except Exception as e:
+        return jsonify({"success": False, "error": f"Failed to signal: {e}"}), 500
+
+    return jsonify({
+        "success": True,
+        "stream_url": "/api/proxy-stream",
+        "file": Path(current).name,
+        "path": current,
+    })
+
+
 @app.route("/api/stop-recount", methods=["POST"])
 def stop_recount():
     global _current_file
     with _recount_lock:
         _stop_recount_locked()
         _current_file = None
-    return jsonify({"success": True})
+        killed, remaining = _sweep_recount_processes(_recount_binary_name())
+    stamp = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
+    if remaining:
+        print(f"[{stamp}] Recount stop: killed {killed}, remaining {remaining} (SIGKILL could not reap)")
+    else:
+        print(f"[{stamp}] Recount stop: killed {killed}, remaining {remaining}")
+    return jsonify({"success": True, "killed": killed, "remaining": remaining})
 
 
 @app.route("/api/state")
@@ -313,5 +534,6 @@ if __name__ == "__main__":
     print(f"Live API: {LIVE_API_URL}")
     print(f"Recount API: {RECOUNT_API_URL}")
     print(f"Upload dir: {UPLOAD_DIR}")
+    print(f"Output dir: {OUTPUT_DIR}")
     print(f"Recount command: {RECOUNT_CMD}")
     app.run(host=DASHBOARD_HOST, port=DASHBOARD_PORT, debug=FLASK_DEBUG)

templates/dashboard.html

@@ -575,6 +575,7 @@
         <span class="date-val" id="current-date">--</span>
         Counting Day
       </div>
+      {% if upload_dashboard_url %}<a class="live-chip" href="{{ upload_dashboard_url }}" style="text-decoration:none;">RECOUNT UPLOAD</a>{% endif %}
       <div class="live-chip">
         <span class="dot"></span>
         <span>{{ site_name }}</span>

templates/dashboard_lamborghini.html

@@ -408,6 +408,7 @@
         <span class="date-val" id="current-date">--</span>
         Counting Day
       </div>
+      {% if upload_dashboard_url %}<a class="live-chip" href="{{ upload_dashboard_url }}" style="text-decoration:none;">RECOUNT UPLOAD</a>{% endif %}
       <div class="live-chip">
         <span class="dot"></span>
         <span>{{ site_name }}</span>

templates/dashboard_tesla.html

@@ -418,6 +418,7 @@
         <span class="date-val" id="current-date">--</span>
         Counting Day
       </div>
+      {% if upload_dashboard_url %}<a class="live-chip" href="{{ upload_dashboard_url }}" style="text-decoration:none;">RECOUNT UPLOAD</a>{% endif %}
       <div class="live-chip">
         <span class="dot"></span>
         <span>{{ site_name }}</span>

templates/recounting.html

@@ -449,6 +449,7 @@
 let selectedFile = null;
 let streaming = false;
 let streamUrl = '';
+let previewAutoOn = false;
 
 document.addEventListener('DOMContentLoaded', () => {
   loadRecountProgress();
@@ -471,37 +472,23 @@ async function syncState() {
 function applyState(data) {
   if (!data) return;
 
-  if (data.file) {
-    selectedFile = data.file;
-    document.getElementById('btn-start').disabled = data.streaming;
-    document.getElementById('btn-download').disabled = false;
-  } else {
-    selectedFile = null;
-    batchResultLoaded = false;
-    document.getElementById('btn-start').disabled = true;
-    document.getElementById('btn-download').disabled = true;
-    document.getElementById('live-title').innerHTML = '◉ Live Counter';
-    document.getElementById('live-count').textContent = '--';
-    document.getElementById('live-label').textContent = 'Objects Counted';
-    document.getElementById('live-batch').textContent = '--';
-    document.getElementById('live-time').textContent = '--';
-    document.getElementById('live-status').textContent = 'no file selected';
-    document.getElementById('live-status').className = 'counter-status disconnected';
-  }
-
   if (data.streaming && data.file) {
     streaming = true;
     streamUrl = data.stream_url;
+    selectedFile = data.file;
     document.getElementById('btn-stop').disabled = false;
     document.getElementById('btn-start').disabled = true;
+    document.getElementById('btn-download').disabled = false;
     document.getElementById('btn-start').textContent = 'STREAMING';
     document.getElementById('btn-start').classList.add('btn-ghost');
     document.getElementById('video-status').innerHTML =
       '<span style="width:6px;height:6px;border-radius:50%;background:var(--accent4);box-shadow:0 0 6px var(--accent4);animation:blink 1.5s ease-in-out infinite;"></span> streaming ' + (data.file_name || '');
     document.getElementById('video-status').className = 'video-status connected';
+    if (!previewAutoOn) enablePreview();
 
     loadBatchResult(data.file);
-  } else if (!data.streaming && data.file) {
+  } else if (data.file && selectedFile === data.file) {
+    previewAutoOn = false;
     loadBatchResult(data.file);
   }
 }
@@ -685,6 +672,7 @@ async function startRecount() {
     document.getElementById('video-status').innerHTML =
       '<span style="width:6px;height:6px;border-radius:50%;background:var(--accent4);box-shadow:0 0 6px var(--accent4);animation:blink 1.5s ease-in-out infinite;"></span> streaming ' + data.file;
     document.getElementById('video-status').className = 'video-status connected';
+    enablePreview();
   } catch (err) {
     alert('Error: ' + err.message);
     btnStart.disabled = false;
@@ -702,6 +690,7 @@ async function stopRecount() {
   streaming = false;
   streamUrl = '';
   selectedFile = null;
+  previewAutoOn = false;
   batchResultLoaded = false;
 
   const img = document.getElementById('stream-img');
@@ -748,11 +737,7 @@ function togglePreview() {
     btn.textContent = 'STREAM OFF';
     btn.classList.remove('active');
   } else {
-    img.src = streamUrl + '?' + Date.now();
+    enablePreview();
-    img.style.display = 'block';
-    if (placeholder) placeholder.style.display = 'none';
-    btn.textContent = 'STREAM ON';
-    btn.classList.add('active');
   }
 }
 
@@ -767,6 +752,24 @@ function resetVideoToggle() {
   btn.classList.remove('active');
 }
 
+function enablePreview() {
+  const btn = document.getElementById('videoToggle');
+  const img = document.getElementById('stream-img');
+  const placeholder = document.getElementById('video-placeholder');
+  if (!streamUrl) return;
+  previewAutoOn = true;
+  img.onerror = function() {
+    if (streaming && streamUrl) {
+      img.src = streamUrl + '?' + Date.now();
+    }
+  };
+  img.src = streamUrl + '?' + Date.now();
+  img.style.display = 'block';
+  if (placeholder) placeholder.style.display = 'none';
+  btn.textContent = 'STREAM ON';
+  btn.classList.add('active');
+}
+
 let lastRecountCount = null;
 let lastRecountTime = null;
 

templates/recounting_lamborghini.html

@@ -371,6 +371,7 @@
 let selectedFile = null;
 let streaming = false;
 let streamUrl = '';
+let previewAutoOn = false;
 
 document.addEventListener('DOMContentLoaded', () => {
   loadRecountProgress();
@@ -393,25 +394,23 @@ async function syncState() {
 function applyState(data) {
   if (!data) return;
 
-  if (data.file) {
-    selectedFile = data.file;
-    document.getElementById('btn-start').disabled = data.streaming;
-    document.getElementById('btn-download').disabled = false;
-  }
-
   if (data.streaming && data.file) {
     streaming = true;
     streamUrl = data.stream_url;
+    selectedFile = data.file;
     document.getElementById('btn-stop').disabled = false;
     document.getElementById('btn-start').disabled = true;
+    document.getElementById('btn-download').disabled = false;
     document.getElementById('btn-start').textContent = 'STREAMING';
     document.getElementById('btn-start').classList.add('btn-ghost');
     document.getElementById('video-status').innerHTML =
       '<span style="width:5px;height:5px;background:var(--success);display:inline-block;"></span> streaming ' + (data.file_name || '');
     document.getElementById('video-status').className = 'video-status connected';
+    if (!previewAutoOn) enablePreview();
 
     loadBatchResult(data.file);
-  } else if (!data.streaming && data.file) {
+  } else if (data.file && selectedFile === data.file) {
+    previewAutoOn = false;
     loadBatchResult(data.file);
   }
 }
@@ -599,6 +598,7 @@ async function startRecount() {
     document.getElementById('video-status').innerHTML =
       '<span style="width:5px;height:5px;background:var(--success);display:inline-block;"></span> streaming ' + data.file;
     document.getElementById('video-status').className = 'video-status connected';
+    enablePreview();
   } catch (err) {
     alert('Error: ' + err.message);
     btnStart.disabled = false;
@@ -613,6 +613,7 @@ async function stopRecount() {
   streaming = false;
   streamUrl = '';
   selectedFile = null;
+  previewAutoOn = false;
   batchResultLoaded = false;
 
   const img = document.getElementById('stream-img');
@@ -659,11 +660,7 @@ function togglePreview() {
     btn.textContent = 'STREAM OFF';
     btn.classList.remove('active');
   } else {
-    img.src = streamUrl + '?' + Date.now();
+    enablePreview();
-    img.style.display = 'block';
-    if (placeholder) placeholder.style.display = 'none';
-    btn.textContent = 'STREAM ON';
-    btn.classList.add('active');
   }
 }
 
@@ -678,6 +675,24 @@ function resetVideoToggle() {
   btn.classList.remove('active');
 }
 
+function enablePreview() {
+  const btn = document.getElementById('videoToggle');
+  const img = document.getElementById('stream-img');
+  const placeholder = document.getElementById('video-placeholder');
+  if (!streamUrl) return;
+  previewAutoOn = true;
+  img.onerror = function() {
+    if (streaming && streamUrl) {
+      img.src = streamUrl + '?' + Date.now();
+    }
+  };
+  img.src = streamUrl + '?' + Date.now();
+  img.style.display = 'block';
+  if (placeholder) placeholder.style.display = 'none';
+  btn.textContent = 'STREAM ON';
+  btn.classList.add('active');
+}
+
 // --- Recount counter ---
 
 let lastRecountCount = null;

templates/recounting_upload.html

@@ -301,6 +301,38 @@
   .file-list {
     flex: 1; overflow-y: auto; max-height: 300px;
   }
+  .output-panel {
+    background: var(--glass);
+    backdrop-filter: blur(24px); -webkit-backdrop-filter: blur(24px);
+    border: 1px solid var(--border-glow); border-radius: var(--radius);
+    padding: 20px;
+    display: flex; flex-direction: column;
+  }
+  .output-panel .fp-header {
+    display: flex; align-items: center; justify-content: space-between;
+    margin-bottom: 12px;
+  }
+  .output-list {
+    flex: 1; overflow-y: auto; max-height: 300px;
+  }
+  .folder-header {
+    display: flex; align-items: center; gap: 8px;
+    padding: 8px 12px; margin-bottom: 4px;
+    background: var(--cell-bg);
+    border: 1px solid var(--cell-border); border-radius: 8px;
+    cursor: pointer;
+    font-size: 10px; letter-spacing: 1px;
+    color: var(--text-primary);
+    transition: border-color 0.2s, background 0.2s;
+  }
+  .folder-header:hover { border-color: var(--border-glow); background: var(--card-bg); }
+  .folder-header .folder-arrow {
+    display: inline-block; color: var(--accent2); font-size: 10px;
+    transition: transform 0.2s;
+  }
+  .folder-header.open .folder-arrow { transform: rotate(90deg); }
+  .folder-body { display: none; padding-left: 8px; }
+  .folder-body.open { display: block; }
   .file-item {
     display: flex; align-items: center; justify-content: space-between;
     padding: 10px 12px; margin-bottom: 4px;
@@ -432,6 +464,7 @@
       </div>
     </div>
     <div class="header-right">
+      {% if live_dashboard_url %}<a class="live-chip live-chip-green" href="{{ live_dashboard_url }}" style="text-decoration:none;">LIVE DASHBOARD</a>{% endif %}
       <div class="live-chip live-chip-green">
         <span class="dot"></span>
         <span>LIVE</span>
@@ -483,7 +516,7 @@
       <div class="video-container" id="video-container">
         <div class="video-placeholder" id="video-placeholder">
           <div class="vp-icon">&#9654;</div>
-          <div class="vp-text">Upload an MP4 and start recount</div>
+          <div class="vp-text">Upload an MP4, then LOAD and START recount</div>
           <div class="vp-hint">Preview via recount node live feed</div>
         </div>
         <img id="stream-img" alt="Stream" style="display:none;" />
@@ -524,6 +557,9 @@
       </div>
 
       <div class="btn-row">
+        <button class="btn btn-ghost" id="btn-load" onclick="loadMp4()" disabled>
+          &#9655; LOAD MP4
+        </button>
         <button class="btn btn-primary" id="btn-start" onclick="startRecount()" disabled>
           &#9654; START RECOUNT
         </button>
@@ -540,6 +576,20 @@
     </div>
   </div>
 
+  <div class="output-panel">
+    <div class="fp-header">
+      <span class="section-title" style="margin-bottom:0;font-size:11px;">&#9673; From Output Directory</span>
+      <button class="btn btn-ghost" onclick="loadOutputFiles()" style="font-size:8px;padding:4px 8px;">
+        <i class="fas fa-sync-alt"></i>
+      </button>
+    </div>
+    <div class="file-list output-list" id="output-list">
+      <div style="font-size:10px;color:var(--text-secondary);text-align:center;padding:20px;">
+        No files found
+      </div>
+    </div>
+  </div>
+
   <div class="footer">{{ site_name }} Recounting Upload Dashboard</div>
 </div>
 
@@ -547,16 +597,21 @@
 let selectedFile = null;
 let streaming = false;
 let streamUrl = '';
+let previewAutoOn = false;
+let loaded = false;
+let started = false;
 let pendingUploadFile = null;
 let batchResultLoaded = false;
 
 document.addEventListener('DOMContentLoaded', () => {
   loadRecountProgress();
   loadUploads();
+  loadOutputFiles();
   syncState();
 
   setInterval(loadRecountProgress, 500);
   setInterval(loadUploads, 30000);
+  setInterval(loadOutputFiles, 30000);
   setInterval(syncState, 1000);
 
   var drop = document.getElementById('upload-drop');
@@ -638,9 +693,7 @@ function uploadFile() {
       }
       showUploadStatus('Upload complete: ' + data.name, 'success');
       selectedFile = data.path;
-      document.getElementById('btn-start').disabled = false;
+      renderButtons();
-      document.getElementById('btn-download').disabled = false;
-      document.getElementById('btn-delete').disabled = false;
       document.getElementById('pending-filename').textContent = 'no file chosen';
       document.getElementById('pending-filename').classList.remove('has-file');
       pendingUploadFile = null;
@@ -676,9 +729,7 @@ function selectFile(path, name) {
   if (selectedFile === path) {
     selectedFile = null;
     batchResultLoaded = false;
-    document.getElementById('btn-start').disabled = true;
+    renderButtons();
-    document.getElementById('btn-download').disabled = true;
-    document.getElementById('btn-delete').disabled = true;
     document.getElementById('live-title').innerHTML = '&#9673; Live Counter';
     document.getElementById('live-count').textContent = '--';
     document.getElementById('live-label').textContent = 'Objects Counted';
@@ -690,9 +741,7 @@ function selectFile(path, name) {
     return;
   }
   selectedFile = path;
-  document.getElementById('btn-start').disabled = false;
+  renderButtons();
-  document.getElementById('btn-download').disabled = false;
-  document.getElementById('btn-delete').disabled = false;
   updateFileSelection();
   loadBatchResult(path);
 }
@@ -738,6 +787,52 @@ async function loadUploads() {
   }
 }
 
+function toggleFolder(fid) {
+  var hdr = document.getElementById(fid + '-hdr');
+  var body = document.getElementById(fid);
+  if (hdr) hdr.classList.toggle('open');
+  if (body) body.classList.toggle('open');
+}
+
+async function loadOutputFiles() {
+  var container = document.getElementById('output-list');
+  try {
+    var res = await fetch('/api/mp4-files');
+    var folders = await res.json();
+    if (!folders || folders.length === 0) {
+      container.innerHTML = '<div style="font-size:10px;color:var(--text-secondary);text-align:center;padding:20px;">No MP4 files found</div>';
+      return;
+    }
+    container.innerHTML = folders.map(function(g, gi) {
+      var fid = 'ofolder-' + gi;
+      return '<div class="folder-header" id="' + fid + '-hdr" onclick="toggleFolder(\'' + fid + '\')">' +
+        '<span class="folder-arrow">&#9654;</span>' +
+        '<i class="fas fa-folder" style="color:var(--accent2);"></i>' +
+        '<span>' + g.folder + '</span>' +
+        '<span style="font-size:8px;color:var(--text-secondary);">(' + g.files.length + ')</span>' +
+        '</div>' +
+        '<div class="folder-body" id="' + fid + '">' +
+        g.files.map(function(f) {
+          var sel = selectedFile === f.path;
+          var str = streaming && selectedFile === f.path;
+          var cls = 'file-item';
+          if (str) cls += ' streaming';
+          else if (sel) cls += ' selected';
+          return '<div class="' + cls + '" onclick="event.stopPropagation(); selectFile(\'' +
+            f.path.replace(/'/g, "\\'") + '\', \'' + f.name.replace(/'/g, "\\'") + '\')" data-path="' +
+            f.path.replace(/"/g, '&quot;') + '">' +
+            '<span class="fi-icon">' + (str ? '&#9673;' : '&#9654;') + '</span>' +
+            '<span class="fi-name">' + f.name + '</span>' +
+            '<span class="fi-size">' + formatSize(f.size) + '</span>' +
+            '</div>';
+        }).join('') +
+        '</div>';
+    }).join('');
+  } catch (err) {
+    console.error('Failed to load output files:', err);
+  }
+}
+
 function formatSize(bytes) {
   if (bytes < 1024) return bytes + ' B';
   if (bytes < 1048576) return (bytes / 1024).toFixed(1) + ' KB';
@@ -745,8 +840,103 @@ function formatSize(bytes) {
   return (bytes / 1073741824).toFixed(1) + ' GB';
 }
 
-async function startRecount() {
+function renderButtons() {
+  var btnLoad = document.getElementById('btn-load');
+  var btnStart = document.getElementById('btn-start');
+  var btnStop = document.getElementById('btn-stop');
+  var btnDownload = document.getElementById('btn-download');
+  var btnDelete = document.getElementById('btn-delete');
+
+  btnLoad.disabled = !(selectedFile && !loaded);
+
+  if (loaded && !started) {
+    btnStart.disabled = false;
+    btnStart.textContent = '\u25b6 START RECOUNT';
+    btnStart.classList.remove('btn-ghost');
+  } else if (started) {
+    btnStart.disabled = true;
+    btnStart.textContent = 'STREAMING';
+    btnStart.classList.add('btn-ghost');
+  } else {
+    btnStart.disabled = true;
+    btnStart.textContent = '\u25b6 START RECOUNT';
+    btnStart.classList.remove('btn-ghost');
+  }
+
+  btnStop.disabled = !streaming;
+  btnDownload.disabled = !selectedFile;
+  btnDelete.disabled = !selectedFile;
+}
+
+async function loadMp4() {
   if (!selectedFile) return;
+  var btnLoad = document.getElementById('btn-load');
+  btnLoad.disabled = true;
+  btnLoad.textContent = 'LOADING...';
+  var pollTimer = null;
+  try {
+    var req = fetch('/api/load-mp4', {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({ path: selectedFile })
+    });
+
+    pollTimer = setInterval(async function() {
+      try {
+        var pr = await fetch('/api/copy-progress');
+        var p = await pr.json();
+        if (p.active) {
+          showCopyProgress(p.pct, p.done, p.total, p.name);
+        }
+      } catch (err) {}
+    }, 250);
+
+    var res = await req;
+    var data = await res.json();
+    clearInterval(pollTimer);
+    pollTimer = null;
+    hideCopyProgress();
+    if (!data.success) {
+      alert('Failed: ' + (data.error || 'unknown'));
+      renderButtons();
+      return;
+    }
+    streamUrl = data.stream_url;
+    selectedFile = data.path;
+    streaming = true;
+    loaded = true;
+    started = false;
+    showUploadStatus('LOADED ' + data.file + ' \u2014 press START RECOUNT', 'success');
+    renderButtons();
+    syncState();
+  } catch (err) {
+    if (pollTimer) clearInterval(pollTimer);
+    hideCopyProgress();
+    alert('Error: ' + err.message);
+    renderButtons();
+  } finally {
+    btnLoad.textContent = '\u25b6 LOAD MP4';
+  }
+}
+
+function showCopyProgress(pct, done, total, name) {
+  document.getElementById('upload-progress').style.display = 'block';
+  document.getElementById('upload-progress-percent').style.display = 'block';
+  document.getElementById('upload-progress-bar').style.width = pct + '%';
+  document.getElementById('upload-progress-percent').textContent = pct + '%';
+  document.getElementById('upload-status').textContent =
+    'Copying ' + name + ' \u2014 ' + formatSize(done) + ' / ' + formatSize(total);
+}
+
+function hideCopyProgress() {
+  document.getElementById('upload-progress').style.display = 'none';
+  document.getElementById('upload-progress-percent').style.display = 'none';
+  document.getElementById('upload-progress-bar').style.width = '0%';
+  document.getElementById('upload-progress-percent').textContent = '';
+}
+
+async function startRecount() {
+  if (!selectedFile || !loaded) return;
   var btnStart = document.getElementById('btn-start');
   btnStart.disabled = true;
   btnStart.textContent = 'CONNECTING...';
@@ -760,31 +950,28 @@ async function startRecount() {
 
   try {
     var res = await fetch('/api/start-recount', {
-      method: 'POST',
+      method: 'POST'
-      headers: { 'Content-Type': 'application/json' },
-      body: JSON.stringify({ path: selectedFile })
     });
     var data = await res.json();
     if (!data.success) {
       alert('Failed: ' + (data.error || 'unknown'));
-      btnStart.disabled = false;
+      renderButtons();
-      btnStart.textContent = '\u25b6 START RECOUNT';
       return;
     }
     streamUrl = data.stream_url;
     streaming = true;
     selectedFile = data.path;
+    loaded = true;
+    started = true;
 
-    document.getElementById('btn-stop').disabled = false;
+    renderButtons();
-    btnStart.textContent = 'STREAMING';
-    btnStart.classList.add('btn-ghost');
     document.getElementById('video-status').innerHTML =
       '<span style="width:6px;height:6px;border-radius:50%;background:var(--accent4);box-shadow:0 0 6px var(--accent4);animation:blink 1.5s ease-in-out infinite;"></span> streaming ' + data.file;
     document.getElementById('video-status').className = 'video-status connected';
+    enablePreview();
   } catch (err) {
     alert('Error: ' + err.message);
-    btnStart.disabled = false;
+    renderButtons();
-    btnStart.textContent = '\u25b6 START RECOUNT';
   }
 }
 
@@ -798,6 +985,9 @@ async function stopRecount() {
   streaming = false;
   streamUrl = '';
   selectedFile = null;
+  previewAutoOn = false;
+  loaded = false;
+  started = false;
   batchResultLoaded = false;
 
   var img = document.getElementById('stream-img');
@@ -806,15 +996,7 @@ async function stopRecount() {
   img.style.display = 'none';
   if (placeholder) placeholder.style.display = '';
 
-  var btnStart = document.getElementById('btn-start');
+  renderButtons();
-  var btnStop = document.getElementById('btn-stop');
-  btnStart.disabled = true;
-  btnStart.textContent = '\u25b6 START RECOUNT';
-  btnStart.classList.remove('btn-ghost');
-  btnStop.disabled = true;
-
-  document.getElementById('btn-download').disabled = true;
-  document.getElementById('btn-delete').disabled = true;
 
   document.getElementById('video-status').innerHTML =
     '<span style="width:6px;height:6px;border-radius:50%;background:var(--text-secondary);"></span> stopped';
@@ -844,11 +1026,7 @@ function togglePreview() {
     btn.textContent = 'STREAM OFF';
     btn.classList.remove('active');
   } else {
-    img.src = streamUrl + '?' + Date.now();
+    enablePreview();
-    img.style.display = 'block';
-    if (placeholder) placeholder.style.display = 'none';
-    btn.textContent = 'STREAM ON';
-    btn.classList.add('active');
   }
 }
 
@@ -863,6 +1041,24 @@ function resetVideoToggle() {
   btn.classList.remove('active');
 }
 
+function enablePreview() {
+  var btn = document.getElementById('videoToggle');
+  var img = document.getElementById('stream-img');
+  var placeholder = document.getElementById('video-placeholder');
+  if (!streamUrl) return;
+  previewAutoOn = true;
+  img.onerror = function() {
+    if (streaming && streamUrl) {
+      img.src = streamUrl + '?' + Date.now();
+    }
+  };
+  img.src = streamUrl + '?' + Date.now();
+  img.style.display = 'block';
+  if (placeholder) placeholder.style.display = 'none';
+  btn.textContent = 'STREAM ON';
+  btn.classList.add('active');
+}
+
 async function syncState() {
   try {
     var res = await fetch('/api/state');
@@ -873,38 +1069,30 @@ async function syncState() {
 
 function applyState(data) {
   if (!data) return;
-  if (data.file) {
+
-    selectedFile = data.file;
-    document.getElementById('btn-start').disabled = data.streaming;
-    document.getElementById('btn-download').disabled = false;
-    document.getElementById('btn-delete').disabled = false;
-  } else {
-    selectedFile = null;
-    batchResultLoaded = false;
-    document.getElementById('btn-start').disabled = true;
-    document.getElementById('btn-download').disabled = true;
-    document.getElementById('btn-delete').disabled = true;
-    document.getElementById('live-title').innerHTML = '&#9673; Live Counter';
-    document.getElementById('live-count').textContent = '--';
-    document.getElementById('live-label').textContent = 'Objects Counted';
-    document.getElementById('live-batch').textContent = '--';
-    document.getElementById('live-time').textContent = '--';
-    document.getElementById('live-status').textContent = 'no file selected';
-    document.getElementById('live-status').className = 'counter-status disconnected';
-  }
   if (data.streaming && data.file) {
     streaming = true;
     streamUrl = data.stream_url;
-    document.getElementById('btn-stop').disabled = false;
+    selectedFile = data.file;
-    document.getElementById('btn-start').disabled = true;
+    loaded = true;
-    document.getElementById('btn-start').textContent = 'STREAMING';
+    renderButtons();
-    document.getElementById('btn-start').classList.add('btn-ghost');
     document.getElementById('video-status').innerHTML =
       '<span style="width:6px;height:6px;border-radius:50%;background:var(--accent4);box-shadow:0 0 6px var(--accent4);animation:blink 1.5s ease-in-out infinite;"></span> streaming ' + (data.file_name || '');
     document.getElementById('video-status').className = 'video-status connected';
+    if (!previewAutoOn) enablePreview();
+
     loadBatchResult(data.file);
-  } else if (!data.streaming && data.file) {
+  } else if (data.file && selectedFile === data.file) {
+    previewAutoOn = false;
+    loaded = false;
+    started = false;
+    renderButtons();
     loadBatchResult(data.file);
+  } else if (!data.streaming) {
+    previewAutoOn = false;
+    loaded = false;
+    started = false;
+    renderButtons();
   }
 }
 
@@ -967,9 +1155,7 @@ async function deleteUploadRecord(fpath) {
     if (selectedFile === fpath) {
       selectedFile = null;
       batchResultLoaded = false;
-      document.getElementById('btn-start').disabled = true;
+      renderButtons();
-      document.getElementById('btn-download').disabled = true;
-      document.getElementById('btn-delete').disabled = true;
       document.getElementById('live-title').innerHTML = '&#9673; Live Counter';
       document.getElementById('live-count').textContent = '--';
       document.getElementById('live-label').textContent = 'Objects Counted';