controller: placeholder_renderer — dynamic PNG generation для per-cell labels

При startup controller iterate'т FrigateBridge mappings и рендерит:
  - offline_<cell>.png с camera label из placeholder_label (или frigate_camera
    как fallback) — для каждого pad
  - offline.png generic — для cells без mapping

Filter cuda_grid looks up "offline_<pad>.png" first per-cell, fallback к
"offline.png". User меняет yaml placeholder_label → restart controller →
PNGs регенерируются. Никаких ручных PNG manipulations.

Russian text supported (PIL + freetype, vs single-byte path в filter).

Pattern:
  frigate.mappings:
    - frigate_camera: parking_overview
      placeholder_label: Парковка
      cell: 0
    ...

При stale input на cell 0 → filter blits offline_0.png с "Парковка — НЕТ
СИГНАЛА" (текст желтый, transparent bg — filter сам fill'ит black за иконкой).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

controller/cuda_grid_controller/__main__.py

@@ -16,6 +16,7 @@ from .dispatch import CommandDispatcher
 from .browser_overlays import BrowserRenderer, DashboardCfg
 from .dynamic_overlays import ChartCfg, ChatCfg, DynamicRenderer
 from .pipeline_monitor import PipelineMonitor
+from .placeholder_renderer import generate_placeholders
 from .frigate_bridge import FrigateBridge, FrigateBridgeCfg
 from .http_api import create_app
 from .mqtt_loop import MqttLoop
@@ -55,6 +56,19 @@ async def _run(cfg: Config) -> None:
             fcfg = FrigateBridgeCfg.model_validate(cfg.frigate)
             if fcfg.enabled:
                 frigate_bridge = FrigateBridge(fcfg, dispatcher=dispatcher)
+                # Generate per-cell placeholder PNGs based на mappings — filter
+                # blits offline_<cell>.png когда input pad stale. Empty
+                # placeholder_label → fallback к frigate_camera name.
+                labels = {
+                    m.cell: (m.placeholder_label or m.frigate_camera)
+                    for m in fcfg.mappings if m.enabled
+                }
+                if labels:
+                    try:
+                        generate_placeholders(Path(cfg.icon_dir), labels)
+                    except Exception as e:
+                        structlog.get_logger().warning(
+                            "placeholders.gen_fail", error=str(e))
         except Exception as e:
             structlog.get_logger().warning(
                 "frigate_bridge.config_invalid", error=str(e)

controller/cuda_grid_controller/frigate_bridge.py

@@ -37,6 +37,10 @@ class FrigateCameraMapping(BaseModel):
     frigate_camera: str
     target_instance: str
     cell: int = Field(default=0, description="Cell index в layout куда рисовать bbox")
+    placeholder_label: str = Field(default="",
+        description="Текст label на placeholder при stale ('Парковка', 'Ворота'). "
+                    "Empty → используется frigate_camera как label. Controller "
+                    "рендерит PNG offline_<cell>.png при startup.")
     enabled: bool = True
     camera_width: int = Field(default=1920, gt=0, description="Native camera resolution для нормализации bbox")
     camera_height: int = Field(default=1080, gt=0)

controller/cuda_grid_controller/placeholder_renderer.py

@@ -0,0 +1,79 @@
+"""Placeholder PNG generator — рендерит per-cell offline placeholder
+("CAMERA LABEL — НЕТ СИГНАЛА") при controller startup.
+
+Filter cuda_grid looks up "<placeholder_icon>_<pad>.png" first (per-cell),
+fallback к "<placeholder_icon>.png" generic. Этот module генерирует
+per-cell PNG с camera label из FrigateBridge config — user меняет label
+в yaml, controller restarts, PNGs регенерируются.
+
+Поддерживает UTF-8 (Russian text) через PIL freetype — недоступно в filter's
+basic FT_Get_Char_Index path (single-byte only).
+"""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+import structlog
+from PIL import Image, ImageDraw, ImageFont
+
+log = structlog.get_logger()
+
+_FONT_PATH = "/usr/share/fonts/truetype/dejavu/DejaVuSans-Bold.ttf"
+
+
+def _font(size: int) -> ImageFont.FreeTypeFont | ImageFont.ImageFont:
+    try:
+        return ImageFont.truetype(_FONT_PATH, size=size)
+    except OSError:
+        return ImageFont.load_default()
+
+
+def render_placeholder(
+    label: str,
+    width: int = 480,
+    height: int = 120,
+) -> Image.Image:
+    """2-line transparent PNG: camera label (top, yellow) + 'НЕТ СИГНАЛА' (bottom, gray).
+    Transparent bg — filter заполняет cell black, потом blit'ит этот PNG поверх."""
+    img = Image.new("RGBA", (width, height), (0, 0, 0, 0))
+    draw = ImageDraw.Draw(img)
+
+    label_font = _font(36)
+    sub_font = _font(28)
+
+    bbox_l = draw.textbbox((0, 0), label, font=label_font)
+    lw, lh = bbox_l[2] - bbox_l[0], bbox_l[3] - bbox_l[1]
+    label_y = height // 2 - lh - 4
+    draw.text(((width - lw) // 2, label_y),
+              label, fill=(255, 230, 100, 255), font=label_font)
+
+    sub_text = "НЕТ СИГНАЛА"
+    bbox_s = draw.textbbox((0, 0), sub_text, font=sub_font)
+    sw, sh = bbox_s[2] - bbox_s[0], bbox_s[3] - bbox_s[1]
+    sub_y = height // 2 + 4
+    draw.text(((width - sw) // 2, sub_y),
+              sub_text, fill=(220, 220, 220, 230), font=sub_font)
+
+    return img
+
+
+def generate_placeholders(icon_dir: Path, labels: dict[int, str],
+                          base_name: str = "offline") -> None:
+    """Generates <base>_<pad>.png для each (pad → label) entry.
+    Also generic <base>.png (fallback когда pad index без custom label)."""
+    icon_dir.mkdir(parents=True, exist_ok=True)
+    for pad, label in labels.items():
+        img = render_placeholder(label)
+        path = icon_dir / f"{base_name}_{pad}.png"
+        tmp = path.with_suffix(".png.tmp")
+        img.save(tmp, "PNG")
+        tmp.replace(path)
+        log.info("placeholder.rendered", pad=pad, label=label, path=str(path))
+
+    img = render_placeholder("СИГНАЛ ПОТЕРЯН")
+    path = icon_dir / f"{base_name}.png"
+    tmp = path.with_suffix(".png.tmp")
+    img.save(tmp, "PNG")
+    tmp.replace(path)
+    log.info("placeholder.rendered_generic", path=str(path))