Files
ambilight-plasmoid/backend/ambicapture.py
T
enne2 47b5c09fa1 kmsgrab e ScreenShot2: esiti sperimentali documentati
- kmsgrab non praticabile: piano primario AR30 con modifier AMD DCC/tiled, ffmpeg
  rifiuta il framebuffer prima di applicare format/modifier
- KWin ScreenShot2: NoAuthorized anche con desktop entry system-wide
- indicatore del vassoio identificato come SNI di xdg-desktop-portal-kde
  (titolo 'Trasmissione dello schermo')
- backend kmsgrab comunque implementato e selezionabile (capture=kmsgrab)
- setup-kmsgrab.sh: installa via pkexec una copia di ffmpeg con cap_sys_admin+ep
2026-11-01 13:22:03 +01:00

202 lines
7.3 KiB
Python

"""Cattura dello schermo per ambilight su Wayland/KDE (ScreenCast portal + PipeWire).
Restituisce i colori medi di N zone lungo un bordo dello schermo.
Nessuna dipendenza da X11: usa xdg-desktop-portal (consenso una volta sola,
token persistente) e GStreamer con pipewiresrc.
"""
import os
CACHE_DIR = os.path.expanduser("~/.cache/ambilight")
PORTAL = "org.freedesktop.portal.Desktop"
PPATH = "/org/freedesktop/portal/desktop"
def screencast_stream(cache_dir=CACHE_DIR):
"""Negozia la condivisione del monitor; ritorna (node_id, width, height)."""
import dbus
from dbus.mainloop.glib import DBusGMainLoop
from gi.repository import GLib
DBusGMainLoop(set_as_default=True)
bus = dbus.SessionBus()
sc = dbus.Interface(bus.get_object(PORTAL, PPATH), "org.freedesktop.portal.ScreenCast")
sender = bus.get_unique_name()[1:].replace(".", "_")
counter = [0]
def request(fn, *args, **opts):
counter[0] += 1
token = f"ambi{os.getpid()}{counter[0]}"
path = f"{PPATH}/request/{sender}/{token}"
iface = dbus.Interface(bus.get_object(PORTAL, path, introspect=False),
"org.freedesktop.portal.Request")
box = {}
loop = GLib.MainLoop()
def on_response(code, results):
box["code"], box["results"] = code, results
loop.quit()
iface.connect_to_signal("Response", on_response)
fn(*args, dbus.Dictionary({"handle_token": token, **opts}, signature="sv"))
GLib.timeout_add_seconds(180, lambda: (loop.quit(), False)[1])
loop.run()
if box.get("code") != 0:
raise RuntimeError("condivisione schermo annullata o rifiutata")
return box["results"]
res = request(sc.CreateSession, session_handle_token="ambilight")
session = str(res["session_handle"])
token_file = os.path.join(cache_dir, "restore_token")
opts = {}
if os.path.exists(token_file):
tok = open(token_file).read().strip()
if tok:
opts["restore_token"] = tok
request(sc.SelectSources, session, types=dbus.UInt32(1), multiple=False,
cursor_mode=dbus.UInt32(1), persist_mode=dbus.UInt32(2), **opts)
res = request(sc.Start, session, "")
node = int(res["streams"][0][0])
size = [int(v) for v in res["streams"][0][1].get("size", [0, 0])]
if "restore_token" in res:
os.makedirs(cache_dir, exist_ok=True)
with open(token_file, "w") as f:
f.write(str(res["restore_token"]))
return node, size[0], size[1]
class Capture:
"""Pipeline GStreamer ridotta a (led*sub) x gh pixel RGB, pronta per il calcolo zone."""
def __init__(self, node, leds, sub=4, rows=72, fps=60):
import gi
gi.require_version("Gst", "1.0")
gi.require_version("GstApp", "1.0")
from gi.repository import Gst, GstApp # noqa: F401 (registra il tipo AppSink)
Gst.init(None)
self.gw = leds * sub
self.gh = rows
desc = (f"pipewiresrc path={node} do-timestamp=true ! "
f"videoconvert ! videoscale ! videorate ! "
f"video/x-raw,format=RGB,width={self.gw},height={self.gh},"
f"framerate={int(fps)}/1 ! "
f"appsink name=sink emit-signals=false max-buffers=2 drop=true sync=false")
self.pipe = Gst.parse_launch(desc)
self.sink = self.pipe.get_by_name("sink")
def start(self):
from gi.repository import Gst
self.pipe.set_state(Gst.State.PLAYING)
def stop(self):
from gi.repository import Gst
self.pipe.set_state(Gst.State.NULL)
def frame(self, timeout_ms=200):
"""Ritorna un array numpy (gh, gw, 3) uint8, oppure None."""
import numpy as np
from gi.repository import Gst
sample = self.sink.try_pull_sample(timeout_ms * Gst.MSECOND)
if sample is None:
return None
buf = sample.get_buffer()
ok, info = buf.map(Gst.MapFlags.READ)
if not ok:
return None
try:
need = self.gw * self.gh * 3
data = bytes(info.data)[:need]
finally:
buf.unmap(info)
if len(data) < need:
return None
return np.frombuffer(data, dtype=np.uint8).reshape(self.gh, self.gw, 3)
# ------------------------------------------------------------------ kmsgrab
FFMPEG_CAP = "/usr/local/libexec/ambilight/ffmpeg-kmsgrab"
FFMPEG_SYS = "/usr/bin/ffmpeg"
class KmsgrabCapture:
"""Cattura DRM diretta (ffmpeg -f kmsgrab) senza portal e senza indicatore.
Richiede CAP_SYS_ADMIN sul binario ffmpeg di appoggio (FFMPEG_CAP), oppure root.
ffmpeg riduce il frame a (leds*sub) x rows in RGB e lo scrive su stdout come
rawvideo: leggiamo esattamente un frame per volta.
"""
def __init__(self, leds, sub=4, rows=72, fps=60, device="/dev/dri/card1",
ffmpeg=None):
self.gw = leds * sub
self.gh = rows
self.fps = max(1, int(fps))
self.device = device
ff = ffmpeg or (FFMPEG_CAP if os.path.exists(FFMPEG_CAP) else FFMPEG_SYS)
self.binary = ff
self.frame_bytes = self.gw * self.gh * 3
self.proc = None
self.stderr_path = os.path.join(CACHE_DIR, "kmsgrab.log")
# hwdownload porta il frame in RAM; lo scaling avviene poi in ffmpeg.
self.vf = (f"hwdownload,format=bgr0,"
f"scale={self.gw}:{self.gh}:flags=bilinear,format=rgb24")
self.cmd = [ff, "-hide_banner", "-loglevel", "error", "-nostdin",
"-f", "kmsgrab", "-device", device, "-i", "-",
"-vf", self.vf,
"-r", str(self.fps),
"-f", "rawvideo", "-pix_fmt", "rgb24", "pipe:1"]
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, stdout=subprocess.PIPE,
stderr=self.err, bufsize=self.frame_bytes)
return self
def stop(self):
try:
if self.proc is not None:
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):
"""Legge un frame completo; None se non arriva entro il timeout."""
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 ""