chore: snapshot livekit-cameras after serial pin + speechbrain lengths fix

generate_udev_rules.py

@@ -0,0 +1,141 @@
+#!/usr/bin/env python3
+"""Generate udev rules that pin each C920 webcam to a fixed slot.
+
+Slot N (cam-01..cam-20) is bound to the USB *serial number* of the camera
+that currently occupies it, giving stable:
+  - video: /dev/camNN (primary capture node), /dev/camNN.meta (UVC metadata)
+  - audio: fixed ALSA card index (hw:INDEX,0)
+
+Run:  python3 generate_udev_rules.py            # prints to stdout
+      python3 generate_udev_rules.py --write     # also writes /etc/udev/rules.d/99-c920-pin.rules
+"""
+import re
+import subprocess
+import sys
+
+HEADER = """\
+# Stable slots for 20x Logitech HD Pro Webcam C920 (046d:08e5).
+# Slot = physical camera, identified by USB serial. Survives reboots,
+# re-enumeration, and hub reordering. Generated by generate_udev_rules.py.
+#
+#   /dev/camNN     -> primary video capture node (UVC stream 0)
+#   /dev/camNN.meta -> UVC metadata node (stream 1)
+#   hw:N,0         -> mic of cam-NN (N from SOUND_CARD_INDEX below)
+"""
+
+
+def sh(cmd):
+    return subprocess.run(cmd, capture_output=True, text=True).stdout
+
+
+def _serial_of(sysfs_path):
+    """Walk up from a sysfs path (interface, function, or card device)
+    until we reach the USB device that carries the 'serial' attribute."""
+    import pathlib
+    p = pathlib.Path(sysfs_path)
+    for _ in range(12):
+        cand = p / "serial"
+        if cand.is_file():
+            return cand.read_text().strip()
+        if str(p).startswith("/sys/devices"):
+            p = p.parent
+        else:
+            return ""
+    return ""
+
+
+def current_state():
+    """Map serial -> (primary_video_node, sound_card_index)."""
+    import pathlib
+    # sound cards: index -> serial
+    cards = {}
+    for line in sh(["cat", "/proc/asound/cards"]).splitlines():
+        m = re.match(r"\s*(\d+)\s+\[([A-Za-z0-9_]+)\s*\]:\s*(.*)", line)
+        if not m:
+            continue
+        idx = int(m.group(1))
+        if "C920" not in m.group(3) and "920" not in m.group(2):
+            continue
+        dev = f"/sys/class/sound/card{idx}/device"
+        real = sh(["readlink", "-f", dev]).strip()
+        cards[idx] = _serial_of(real)
+    # video: primary node (index 0) per USB serial, via sysfs
+    primary_by_serial = {}
+    for node in sorted(pathlib.Path("/sys/class/video4linux").glob("video*"),
+                       key=lambda p: int(p.name.replace("video", ""))):
+        idx_attr = (node / "index").read_text().strip()
+        if idx_attr != "0":
+            continue
+        real = sh(["readlink", "-f", str(node / "device")]).strip()
+        s = _serial_of(real)
+        primary_by_serial[s] = f"/dev/{node.name}"
+    return primary_by_serial, cards
+
+
+def main():
+    primary_by_serial, cards = current_state()
+    # assign slots: cam-01..cam-20 in current video-node order
+    ordered = []
+    for serial, node in primary_by_serial.items():
+        n = int(node.replace("/dev/video", ""))
+        ordered.append((n, serial, node))
+    ordered.sort()
+    if len(ordered) != 20:
+        print(f"warning: expected 20 cameras, got {len(ordered)}", file=sys.stderr)
+
+    lines = [HEADER]
+    for i, (vnum, serial, node) in enumerate(ordered, start=1):
+        card = next((c for c, s in cards.items() if s == serial), None)
+        slot = f"cam{i:02d}"
+        lines.append(f"# {slot}: serial {serial}  (was {node}, card {card})")
+        lines.append(
+            f'SUBSYSTEM=="video4linux", KERNEL=="video*", '
+            f'ENV{{ID_VENDOR_ID}}=="046d", ENV{{ID_MODEL_ID}}=="08e5", '
+            f'ENV{{ID_USB_SERIAL_SHORT}}=="{serial}", '
+            f'ATTR{{index}}=="0", SYMLINK+="{slot}"')
+        lines.append(
+            f'SUBSYSTEM=="video4linux", KERNEL=="video*", '
+            f'ENV{{ID_VENDOR_ID}}=="046d", ENV{{ID_MODEL_ID}}=="08e5", '
+            f'ENV{{ID_USB_SERIAL_SHORT}}=="{serial}", '
+            f'ATTR{{index}}=="1", SYMLINK+="{slot}.meta"')
+        if card is not None:
+            lines.append(
+                f'SUBSYSTEM=="sound", KERNEL=="card*", '
+                f'ENV{{ID_VENDOR_ID}}=="046d", ENV{{ID_MODEL_ID}}=="08e5", '
+                f'ENV{{ID_USB_SERIAL_SHORT}}=="{serial}", '
+                f'ENV{{SOUND_CARD_INDEX}}="{card}"')
+        else:
+            print(f"warning: no sound card for serial {serial}", file=sys.stderr)
+        lines.append("")
+    text = "\n".join(lines)
+    print(text)
+    if "--write" in sys.argv:
+        path = "/etc/udev/rules.d/99-c920-pin.rules"
+        with open(path, "w") as f:
+            f.write(text)
+        print(f"# wrote {path}", file=sys.stderr)
+        # durable slot map for the app (discovery.py reads this)
+        import json
+        import os
+        slots = {}
+        for i, (vnum, serial, node) in enumerate(ordered, start=1):
+            card = next((c for c, s in cards.items() if s == serial), None)
+            slots[f"cam-{i:02d}"] = {
+                "serial": serial,
+                "video": f"/dev/cam{i:02d}",
+                "card": card,
+            }
+        base = os.path.dirname(os.path.abspath(__file__))
+        slots_path = os.path.join(base, "slots.json")
+        with open(slots_path, "w") as f:
+            json.dump(slots, f, indent=2)
+        print(f"# wrote {slots_path}", file=sys.stderr)
+        # summary table to stderr
+        for i, (vnum, serial, node) in enumerate(ordered, start=1):
+            card = next((c for c, s in cards.items() if s == serial), "?")
+            print(f"#   cam-{i:02d}  serial={serial}  video={node}  card={card}",
+                  file=sys.stderr)
+
+
+if __name__ == "__main__":
+    main()