WIP: cattura in processo separato + close_stream (NON validata, sospesa)

backend/ambicapture.py

@@ -10,6 +10,10 @@ CACHE_DIR = os.path.expanduser("~/.cache/ambilight")
 PORTAL = "org.freedesktop.portal.Desktop"
 PPATH = "/org/freedesktop/portal/desktop"
 
+# Sessione ScreenCast attiva: va CHIUSA esplicitamente, altrimenti il portal continua
+# a considerarla viva e lascia nel vassoio l'indicatore "Trasmissione dello schermo".
+_ACTIVE = {"bus": None, "session": None}
+
 
 def screencast_stream(cache_dir=CACHE_DIR):
     """Negozia la condivisione del monitor; ritorna (node_id, width, height)."""
@@ -64,9 +68,30 @@ def screencast_stream(cache_dir=CACHE_DIR):
         os.makedirs(cache_dir, exist_ok=True)
         with open(token_file, "w") as f:
             f.write(str(res["restore_token"]))
+
+    _ACTIVE["bus"] = bus
+    _ACTIVE["session"] = session
     return node, size[0], size[1]
 
 
+def close_stream():
+    """Chiude la sessione ScreenCast e la connessione D-Bus (rimuove l'indicatore)."""
+    session, bus = _ACTIVE.get("session"), _ACTIVE.get("bus")
+    _ACTIVE["bus"] = _ACTIVE["session"] = None
+    if not session:
+        return
+    try:
+        import dbus
+        iface = dbus.Interface(bus.get_object(PORTAL, session), "org.freedesktop.portal.Session")
+        iface.Close()
+    except Exception:
+        pass
+    try:
+        bus.close()
+    except Exception:
+        pass
+
+
 class Capture:
     """Pipeline GStreamer ridotta a (led*sub) x gh pixel RGB, pronta per il calcolo zone."""
 
@@ -199,3 +224,97 @@ class KmsgrabCapture:
                 return f.read()[-400:].decode("utf-8", "replace").strip()
         except Exception:
             return ""
+
+
+# ------------------------------------------------------------------ processo figlio
+class ChildCapture:
+    """Legge frame RGB grezzi dallo stdout di un processo di cattura separato.
+
+    Il figlio (ambicatcher.py per il portal, ffmpeg per kmsgrab) produce:
+      prima riga  -> JSON di intestazione ({"node":..} oppure {"error":..})
+      poi         -> frame da (leds*sub) x rows pixel RGB, senza separatori
+    Tenere la cattura fuori dal demone isola GStreamer/PipeWire e, per il portal,
+    fa chiudere la sessione ScreenCast insieme al processo (niente indicatori orfani).
+    """
+
+    def __init__(self, argv, leds, sub=4, rows=72, expect_header=True):
+        self.cmd = list(argv)
+        self.gw = leds * sub
+        self.gh = rows
+        self.frame_bytes = self.gw * self.gh * 3
+        self.expect_header = expect_header
+        self.header = {}
+        self.proc = None
+        self.stderr_path = os.path.join(CACHE_DIR, "catcher.log")
+
+    def start(self):
+        import subprocess
+        os.makedirs(CACHE_DIR, exist_ok=True)
+        self.err = open(self.stderr_path, "wb")
+        self.proc = subprocess.Popen(self.cmd, stdin=subprocess.PIPE,
+                                     stdout=subprocess.PIPE, stderr=self.err,
+                                     bufsize=0)
+        if self.expect_header:
+            line = self.proc.stdout.readline()
+            if not line:
+                err = self.error_text()
+                raise RuntimeError(f"cattura non avviata: {err or 'nessun output'}")
+            try:
+                import json
+                self.header = json.loads(line.decode())
+            except Exception:
+                self.header = {"raw": line[:100].decode("utf-8", "replace")}
+            if "error" in self.header:
+                raise RuntimeError(self.header["error"])
+        return self
+
+    def stop(self):
+        try:
+            if self.proc is not None:
+                try:
+                    if self.proc.stdin:
+                        self.proc.stdin.close()   # il figlio esce e chiude la sessione
+                except Exception:
+                    pass
+                try:
+                    self.proc.wait(timeout=3)
+                except Exception:
+                    self.proc.terminate()
+                    try:
+                        self.proc.wait(timeout=2)
+                    except Exception:
+                        self.proc.kill()
+        finally:
+            self.proc = None
+            try:
+                self.err.close()
+            except Exception:
+                pass
+
+    def alive(self):
+        return self.proc is not None and self.proc.poll() is None
+
+    def frame(self, timeout_ms=200):
+        import select
+        import numpy as np
+        if self.proc is None:
+            return None
+        fd = self.proc.stdout
+        buf = bytearray()
+        deadline = timeout_ms / 1000.0
+        while len(buf) < self.frame_bytes:
+            ready, _, _ = select.select([fd], [], [], deadline)
+            if not ready:
+                return None
+            chunk = fd.read(self.frame_bytes - len(buf))
+            if not chunk:
+                return None
+            buf += chunk
+        return np.frombuffer(bytes(buf), dtype=np.uint8).reshape(self.gh, self.gw, 3)
+
+    def error_text(self):
+        try:
+            with open(self.stderr_path, "rb") as f:
+                return f.read()[-400:].decode("utf-8", "replace").strip()
+        except Exception:
+            return ""

backend/ambicatcher.py

@@ -0,0 +1,89 @@
+#!/usr/bin/env python3
+"""ambicatcher — processo di cattura separato: scrive frame RGB grezzi su stdout.
+
+Vive in un processo a sé per due motivi:
+ 1) isolare GStreamer/PipeWire e dbus-python dal demone (che resta Python puro:
+    Gio per il D-Bus, numpy, pyserial);
+ 2) la sessione ScreenCast appartiene a QUESTO processo: quando termina, il portal
+    la chiude e l'indicatore "Trasmissione dello schermo" sparisce dal vassoio.
+
+Uso:
+    ambicatcher.py --leds 47 --rows 72 --sub 4 --fps 60
+Stampa una riga JSON di intestazione ({"node":..,"w":..,"h":..} oppure {"error":..})
+poi frame da (leds*sub) x rows pixel RGB, senza separatori.
+"""
+import argparse
+import json
+import os
+import signal
+import sys
+
+
+def main():
+    ap = argparse.ArgumentParser()
+    ap.add_argument("--leds", type=int, default=47)
+    ap.add_argument("--sub", type=int, default=4)
+    ap.add_argument("--rows", type=int, default=72)
+    ap.add_argument("--fps", type=int, default=60)
+    ap.add_argument("--drain", action="store_true",
+                    help="termina quando stdin si chiude (usato dal demone)")
+    a = ap.parse_args()
+
+    gw, gh = a.leds * a.sub, a.rows
+
+    def bye(*_):
+        raise SystemExit(0)
+
+    signal.signal(signal.SIGTERM, bye)
+    signal.signal(signal.SIGINT, bye)
+
+    out = sys.stdout.buffer
+    try:
+        from ambicapture import Capture, close_stream, screencast_stream
+
+        node, w, h = screencast_stream()
+        out.write((json.dumps({"node": node, "w": w, "h": h}) + "\n").encode())
+        out.flush()
+        cap = Capture(node, a.leds, sub=a.sub, rows=a.rows, fps=a.fps)
+        cap.start()
+    except Exception as e:
+        out.write((json.dumps({"error": f"{type(e).__name__}: {e}"}) + "\n").encode())
+        out.flush()
+        return 1
+
+    if a.drain:
+        import select
+        import threading
+
+        def watchdog():
+            # stdin chiuso dal padre = termina (e con noi la sessione portal)
+            try:
+                while True:
+                    if not sys.stdin.buffer.read(1):
+                        break
+            except Exception:
+                pass
+            os.kill(os.getpid(), signal.SIGTERM)
+
+        threading.Thread(target=watchdog, daemon=True).start()
+
+    try:
+        while True:
+            frame = cap.frame(200)
+            if frame is None:
+                continue
+            out.write(frame.tobytes())
+            out.flush()
+    except (BrokenPipeError, KeyboardInterrupt):
+        pass
+    finally:
+        try:
+            cap.stop()
+        except Exception:
+            pass
+        close_stream()
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())

backend/ambilight.service

@@ -6,10 +6,14 @@ PartOf=graphical-session.target
 
 [Service]
 Type=simple
+# Rete di sicurezza: un crash non deve mai diventare un loop che apre decine di
+# sessioni ScreenCast (e quindi decine di indicatori nel vassoio).
+Restart=on-failure
+RestartSec=10
+StartLimitIntervalSec=120
+StartLimitBurst=3
 ExecStart=/usr/bin/python3 %h/.local/bin/ambilightd.py
 Environment=PYTHONUNBUFFERED=1
-Restart=on-failure
-RestartSec=3
 
 [Install]
 WantedBy=graphical-session.target

backend/ambilightd.py

@@ -19,6 +19,7 @@ Config: ~/.config/ambilight/config.json
 """
 import json
 import os
+import sys
 import threading
 import time
 
@@ -193,7 +194,7 @@ def apply_params(zones, cfg):
 
 def capture_loop(state, strip):
     """Ciclo di cattura: sceglie il backend (portal o kmsgrab) e invia i frame."""
-    from ambicapture import Capture, KmsgrabCapture, screencast_stream
+    from ambicapture import ChildCapture, KmsgrabCapture
 
     cap = None
     key = None
@@ -206,10 +207,13 @@ def capture_loop(state, strip):
         if cfg["capture"] == "kmsgrab":
             c = KmsgrabCapture(cfg["leds"], fps=cfg["fps"], device=cfg["drm_device"]).start()
             return c, f"kmsgrab {c.binary} su {cfg['drm_device']}"
-        node, w, h = screencast_stream()
+        helper = os.path.join(os.path.dirname(os.path.abspath(__file__)), "ambicatcher.py")
-        c = Capture(node, cfg["leds"], fps=cfg["fps"])
+        c = ChildCapture([sys.executable, helper,
-        c.start()
+                          "--leds", str(cfg["leds"]), "--rows", "72", "--sub", "4",
-        return c, f"portal node={node} sorgente {w}x{h}"
+                          "--fps", str(int(cfg["fps"])), "--drain"],
+                         cfg["leds"]).start()
+        return c, f"portal (processo separato) node={c.header.get('node')} " \
+                  f"sorgente {c.header.get('w')}x{c.header.get('h')}"
 
     while True:
         cfg = state.snapshot()

install.sh

@@ -41,6 +41,7 @@ say "Installo il backend in $BIN"
 install -d "$BIN"
 install -m 755 "$HERE/backend/ambilightd.py" "$BIN/ambilightd.py"
 install -m 644 "$HERE/backend/ambicapture.py" "$BIN/ambicapture.py"
+install -m 755 "$HERE/backend/ambicatcher.py" "$BIN/ambicatcher.py"
 install -m 755 "$HERE/backend/ambilight-ctl" "$BIN/ambilight-ctl"
 
 say "Installo il servizio utente"