.env.example

@@ -12,11 +12,6 @@ MEDIAPI_PASSWORD=changeme
 MEDIAPI_MEDIA_ROOTS=/localmedia
 MEDIAPI_PORT=8080
 
-# --- mpv (the actual player) ---
-# mediapi drives mpv over its JSON IPC Unix socket. install.sh installs mpv and
-# runs it as a service on KMS with --input-ipc-server pointed at this socket.
-#MEDIAPI_MPV_SOCKET=/run/mediapi/mpv.sock
-
 # --- System: the Linux user the systemd services run as ---
 # Auto-detected from whoever runs install.sh (id -un) when left unset, so you
 # normally don't need this. Uncomment only to force a specific user.
@@ -28,3 +23,11 @@ MEDIAPI_AP_SSID=changeme
 MEDIAPI_AP_PASSWORD=changeme
 MEDIAPI_AP_CONN_NAME=mediapi-ap
 
+# --- Advanced (leave unset unless you know you need them) ---
+# Where the mpv IPC socket + runtime dir live. Defaults below are correct for
+# the shipped systemd unit, which hardcodes RuntimeDirectory=mediapi (=/run/mediapi).
+# If you override MEDIAPI_RUNTIME_DIR you MUST also edit
+# systemd/mediapi-mpv.service.template's RuntimeDirectory to match, or the dir
+# won't be created at boot. Most deployments should leave both commented out.
+#MEDIAPI_RUNTIME_DIR=/run/mediapi
+#MEDIAPI_MPV_SOCKET=/run/mediapi/mpv.sock

README.md

@@ -110,45 +110,45 @@ Keep values simple (no spaces / shell-special characters).
 
 ## Setup (mediapi app)
 
-Playback is done by **Kodi** (`mediapi-kodi` unit), running standalone on
+Implemented as a small Flask app (`mediapi/`) + a permanently-running `mpv`
-GBM/KMS straight on the hardware — the same smooth, hardware-decoded path as
+player controlled over its JSON IPC socket. mpv renders video to HDMI
-LibreELEC, no desktop. mediapi itself is a small Flask app (`mediapi/`) that is
+directly (DRM/KMS, no desktop needed); the phone browser only shows
-just the phone-facing **remote**: it browses the media folders and drives Kodi
+metadata/controls, never the video image itself.
-over its **JSON-RPC HTTP API** (`Player.Open`, `Player.PlayPause`,
-`Player.Seek`, `Application.SetVolume`, `Player.GetProperties`). The phone
-browser only shows metadata/controls, never the video image itself.
 
-Kodi handles decode, HDMI audio and display; mediapi keeps a background poll of
+**Dual-HDMI mirroring.** A single mpv on DRM can only drive one connector, and
-Kodi's player state (position/duration/pause/volume) and drives "keep playing"
+the Pi's `vc4-kms` driver can't clone two HDMI outputs onto one framebuffer —
-auto-advance through a folder. `install.sh` installs Kodi, autostarts it, and
+so mirroring is done by running *one mpv per connected screen*.
-enables its web server (JSON-RPC) headlessly by seeding `guisettings.xml` (see
+`scripts/start-mpv.py` (launched by the `mediapi-mpv` unit) enumerates the
-`scripts/configure-kodi.py`). Set the Kodi port/credentials in `.env`
+connected HDMI connectors and starts a **primary** mpv (audio + the app's IPC
-(`MEDIAPI_KODI_*`); keep the port different from `MEDIAPI_PORT`.
+socket, `mpv.sock`) plus a **mirror** mpv per extra screen (video-only, on
-
+`mpv-mirror-<connector>.sock`). The app plays/pauses/seeks the primary and
-> **Dual HDMI:** the Pi 4 can't cleanly mirror both HDMI ports in software
+echoes those to the mirrors best-effort, re-syncing on every video. One screen
-> (DRM master is exclusive per card; the X-mirror path can't keep up). Drive
+→ same as before; a dead mirror just leaves that screen dark, never the audio
-> both car screens from one HDMI port through an external powered HDMI splitter.
+screen. Because each screen runs its own mpv, the same file decodes once per
+screen (`--hwdec=auto-safe` falls back to software if the HW decoder is busy).
 
 ### First-time install (on the Pi)
 
 ```bash
+# system deps: mpv for HDMI/DRM playback
+sudo apt update
+sudo apt install -y mpv
+
 # install uv (Python package/venv manager) if not already present
 curl -LsSf https://astral.sh/uv/install.sh | sh   # installs to ~/.local/bin/uv
 
 # create your .env (see Configuration above)
 cp .env.example .env && $EDITOR .env
 
-# deploy the currently-checked-out ref: installs Kodi + Python deps, enables
+# deploy the currently-checked-out ref: syncs deps, adds the service user to
-# Kodi's JSON-RPC web server, configures the AP, installs+starts the services.
+# the video+render groups (GPU/DRM access for HDMI), configures the AP,
-# Run as your normal user -- NOT with sudo, or the services get rendered to run
+# installs+starts the services. Run as your normal user -- NOT with sudo, or
-# as root.
+# the services get rendered to run as root.
 ./install.sh
 
 # verify
-systemctl status mediapi-kodi mediapi-app
+systemctl status mediapi-mpv mediapi-app
-curl -s "http://kodi:$(grep KODI_PASSWORD .env|cut -d= -f2)@127.0.0.1:8090/jsonrpc" \
+ls -l /run/mediapi/mpv.sock
-  -H 'content-type: application/json' \
-  -d '{"jsonrpc":"2.0","id":1,"method":"JSONRPC.Ping"}'   # -> {"result":"pong"}
 ```
 
 Then, from a phone connected to the AP (`MEDIAPI_AP_SSID`), browse to
@@ -192,20 +192,20 @@ cd ~/mediapi && ./install.sh v1.2.0
 sudo raspi-config nonint do_overlayfs 0 && sudo reboot   # re-enable overlay
 ```
 
-Notes / things to double check on the actual hardware:
+Notes / things to double check on the actual hardware (couldn't be verified
+from a dev machine):
 * `dtoverlay=vc4-kms-v3d` should already be set in `/boot/firmware/config.txt`
-  on current Pi4 images (needed for KMS output) — worth a quick check.
+  on current Bookworm Pi4 images (needed for DRM output) — worth a quick check.
-* Kodi runs standalone on GBM as the `mediapi-kodi` service (on `tty1`). If the
+* Mirroring picks up whatever HDMI connectors read `connected` under
-  screen stays on the console, check `sudo journalctl -u mediapi-kodi`; Kodi's
+  `/sys/class/drm/card*-HDMI-*/status` at service start — so plug in both
-  own log is at `~/.kodi/temp/kodi.log`. It needs the service user in the
+  screens **before** `mediapi-mpv` starts (or `sudo systemctl restart
-  `video render input audio tty` groups (install.sh adds them).
+  mediapi-mpv` after). Check what it launched with
-* If the web API is unreachable (`Connection refused` on
+  `sudo journalctl -u mediapi-mpv | grep start-mpv` and confirm both sockets:
-  `:${MEDIAPI_KODI_PORT}`), the web server didn't get enabled. Kodi rewrites
+  `ls -l /run/mediapi/mpv*.sock`. `mpv --drm-connector=help` (with a display
-  `guisettings.xml` on exit, so re-run `install.sh` (it stops Kodi, seeds the
+  attached) lists the connector names if the sysfs guess is ever wrong.
-  setting via `scripts/configure-kodi.py`, and restarts), or toggle
+* If audio doesn't come out of the TV, check `aplay -l` for the HDMI ALSA
-  Settings → Services → Control → *Allow remote control via HTTP* in the Kodi
+  device name (usually `vc4-hdmi`) and add e.g.
-  GUI once. Verify with `JSONRPC.Ping` (see install snippet above).
+  `--audio-device=alsa/plughw:CARD=vc4hdmi0,DEV=0` to the mpv unit template, or
-* Kodi handles HDMI audio itself (Settings → System → Audio). If there's no
+  run `sudo raspi-config nonint do_audio 2` to force HDMI as the default output.
-  sound, set the audio output device to the HDMI sink there.
 
 To stop/remove: `sudo systemctl disable --now mediapi-mpv mediapi-app`

install.sh

@@ -41,12 +41,9 @@ DEPLOYED_REF_FILE="instance/deployed_ref"
 TARGET_REF="${1:-}"
 
 # --- load config ----------------------------------------------------
-# First run on a fresh Pi may have no .env yet -- seed it from the example so the
-# script can proceed, but make it loud: the defaults ship an insecure AP.
 if [[ ! -f .env ]]; then
-  echo "WARNING: .env not found -- creating it from .env.example." >&2
+  echo "ERROR: .env not found. Copy .env.example to .env and fill it in." >&2
-  echo "         Edit .env with your real AP/login passwords, then re-run." >&2
+  exit 1
-  cp .env.example .env
 fi
 set -a
 # shellcheck disable=SC1091
@@ -55,7 +52,7 @@ set +a
 
 MEDIAPI_USER="${MEDIAPI_USER:-$(id -un)}"
 MEDIAPI_PORT="${MEDIAPI_PORT:-8080}"
-UV=""  # set by bootstrap_system once uv is installed
+UV="$(command -v uv || echo "$HOME/.local/bin/uv")"
 
 # --- 0. refuse to run on a read-only overlay ------------------------
 if findmnt -no FSTYPE / | grep -q overlay; then
@@ -93,30 +90,9 @@ if [[ -n "$PREV_GOOD" && "$PREV_GOOD" != "$CURRENT_REF" ]]; then
   echo "    (last healthy deploy was $PREV_GOOD -- rollback target if this fails)"
 fi
 
-# --- system bootstrap (fresh Pi: assume ONLY git is installed) -------
-# Installs everything else the deploy needs so a bare Raspberry Pi OS Lite goes
-# from "git clone + ./install.sh" to a working player. NetworkManager (nmcli)
-# and raspi-config already ship on Pi OS. Sets the global UV path afterwards.
-bootstrap_system() {
-  echo "==> apt update + base packages (curl, python3) ..."
-  sudo apt-get update -qq
-  sudo DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends \
-    curl ca-certificates python3
-
-  if ! command -v uv >/dev/null 2>&1 && [[ ! -x "$HOME/.local/bin/uv" ]]; then
-    echo "==> Installing uv ..."
-    curl -LsSf https://astral.sh/uv/install.sh | sh
-  fi
-  UV="$(command -v uv || echo "$HOME/.local/bin/uv")"
-  if [[ ! -x "$UV" ]]; then
-    echo "ERROR: uv is still not available at '$UV' after install." >&2
-    exit 1
-  fi
-}
-
 # --- render + install systemd units (used again on rollback) --------
 install_units() {
-  for unit in mediapi-mpv mediapi-app mediapi-watchdog; do
+  for unit in mediapi-mpv mediapi-app; do
     sed -e "s|\${MEDIAPI_USER}|${MEDIAPI_USER}|g" \
         -e "s|\${PROJECT_DIR}|${PROJECT_DIR}|g" \
         -e "s|\${UV}|${UV}|g" \
@@ -140,30 +116,14 @@ deploy_current() {
     chmod 600 instance/secret_key
   fi
 
-  # mpv (the player) runs as MEDIAPI_USER on KMS/DRM and needs these groups to
+  # The mpv service runs as MEDIAPI_USER and needs the video+render groups to
-  # reach the GPU/DRM, audio, input and console devices. Idempotent; systemd
+  # reach the GPU/DRM devices for HDMI output. Idempotent; systemd picks up the
-  # picks up the new membership when it (re)starts the service below.
+  # new membership when it (re)starts the service below, so no logout needed.
   if ! id -nG "${MEDIAPI_USER}" | tr ' ' '\n' | grep -qx render; then
-    echo "==> Adding '${MEDIAPI_USER}' to video,render,input,audio,tty groups ..."
+    echo "==> Adding '${MEDIAPI_USER}' to video,render groups ..."
-    sudo usermod -aG video,render,input,audio,tty "${MEDIAPI_USER}"
+    sudo usermod -aG video,render "${MEDIAPI_USER}"
   fi
 
-  # Install mpv (the actual media player -- mediapi drives it via its IPC socket).
-  if ! command -v mpv >/dev/null 2>&1; then
-    echo "==> Installing mpv ..."
-    sudo DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends mpv
-  fi
-
-  # Ensure the media browse roots exist so browsing works and there's a place to
-  # copy content into. (mkdir -p is a no-op if it's already a mount point.)
-  IFS=':' read -ra _media_roots <<< "${MEDIAPI_MEDIA_ROOTS:-/localmedia}"
-  for r in "${_media_roots[@]}"; do
-    [[ -n "$r" && ! -d "$r" ]] || continue
-    echo "==> Creating media root $r ..."
-    sudo mkdir -p "$r"
-    sudo chown "${MEDIAPI_USER}:${MEDIAPI_USER}" "$r"
-  done
-
   echo "==> Applying WiFi country + AP config ..."
   sudo raspi-config nonint do_wifi_country "${MEDIAPI_WIFI_COUNTRY}"
   if nmcli -g NAME con show | grep -qx "${MEDIAPI_AP_CONN_NAME}"; then
@@ -182,38 +142,11 @@ deploy_current() {
       ipv4.method shared
   fi
 
-  echo "==> Installing systemd units ..."
+  echo "==> Installing systemd units + restarting services ..."
   install_units
-  sudo systemctl enable mediapi-mpv mediapi-app mediapi-watchdog >/dev/null 2>&1 || true
+  sudo systemctl enable mediapi-mpv mediapi-app >/dev/null 2>&1 || true
-
-  # Migration cleanup: earlier versions ran Kodi as the player. A still-running
-  # Kodi keeps the GPU's DRM master and the tty1 seat, which stops mpv from ever
-  # acquiring the display -- and removing a unit file does NOT stop an already
-  # running process. So explicitly tear any Kodi down before starting mpv.
-  if [[ -e /etc/systemd/system/mediapi-kodi.service ]] || pgrep -x kodi.bin >/dev/null 2>&1; then
-    echo "==> Removing leftover Kodi player ..."
-    sudo systemctl unmask mediapi-kodi.service 2>/dev/null || true
-    sudo systemctl disable --now mediapi-kodi.service 2>/dev/null || true
-    sudo rm -f /etc/systemd/system/mediapi-kodi.service
-    sudo pkill -9 -x kodi.bin 2>/dev/null || true
-    sudo pkill -9 -f kodi-standalone 2>/dev/null || true
-    sudo systemctl daemon-reload
-  fi
-
-  echo "==> Starting services ..."
   sudo systemctl restart mediapi-mpv
   sudo systemctl restart mediapi-app
-  sudo systemctl restart mediapi-watchdog
-
-  # Wait for mpv's IPC socket so a first-run deploy leaves a driveable player.
-  echo "==> Waiting for mpv IPC socket (${MEDIAPI_MPV_SOCKET:-/run/mediapi/mpv.sock}) ..."
-  for _ in $(seq 1 30); do
-    if sudo test -S "${MEDIAPI_MPV_SOCKET:-/run/mediapi/mpv.sock}"; then
-      echo "    mpv is up."
-      break
-    fi
-    sleep 1
-  done
 }
 
 # --- health check ---------------------------------------------------
@@ -228,7 +161,6 @@ app_healthy() {
 }
 
 # --- 2-6. deploy ----------------------------------------------------
-bootstrap_system
 deploy_current
 
 # --- 7. health check + rollback ------------------------------------
@@ -236,7 +168,7 @@ echo "==> Health check on http://127.0.0.1:${MEDIAPI_PORT}/login ..."
 if app_healthy; then
   echo "$CURRENT_REF" > "$DEPLOYED_REF_FILE"
   echo "==> Deploy OK. $CURRENT_DESC healthy on port ${MEDIAPI_PORT}."
-  systemctl --no-pager --lines=0 status mediapi-mpv mediapi-app mediapi-watchdog || true
+  systemctl --no-pager --lines=0 status mediapi-mpv mediapi-app || true
   exit 0
 fi
 

mediapi/__init__.py

@@ -2,7 +2,6 @@ from flask import Flask
 
 from .auth import register_auth_gate
 from .config import Config
-from .mpv import MpvClient
 from .player import PlayerStateManager
 from .routes.api_routes import bp as api_bp
 from .routes.auth_routes import bp as auth_bp
@@ -19,8 +18,11 @@ def create_app():
 
     register_auth_gate(app)
 
-    mpv = MpvClient(app.config["MPV_SOCKET"])
+    app.player = PlayerStateManager(
-    app.player = PlayerStateManager(mpv, app.config["VIDEO_EXTENSIONS"])
+        app.config["MPV_SOCKET"],
+        app.config["VIDEO_EXTENSIONS"],
+        mirror_glob=app.config.get("MPV_MIRROR_GLOB"),
+    )
     app.player.start()
 
     return app

mediapi/config.py

@@ -75,10 +75,11 @@ class Config:
     MEDIA_ROOTS = [
         p for p in os.environ.get("MEDIAPI_MEDIA_ROOTS", "/localmedia").split(":") if p
     ]
-    # mpv does the playback; we drive it over its JSON IPC Unix socket. mpv runs
-    # as its own systemd service with --input-ipc-server pointed at this path
-    # (install.sh configures this).
     MPV_SOCKET = os.environ.get("MEDIAPI_MPV_SOCKET", "/run/mediapi/mpv.sock")
+    # Extra mpv instances (one per additional HDMI screen) expose sockets named
+    # mpv-mirror-<connector>.sock alongside the primary socket. The player
+    # discovers them by glob and echoes playback commands to them best-effort.
+    MPV_MIRROR_GLOB = os.path.join(os.path.dirname(MPV_SOCKET), "mpv-mirror-*.sock")
     PORT = int(os.environ.get("MEDIAPI_PORT", "8080"))
 
     VIDEO_EXTENSIONS = {

mediapi/mpv.py

@@ -1,92 +0,0 @@
-"""Minimal mpv JSON IPC client over a Unix socket.
-
-mpv does the actual playback (hardware-decoded, straight on KMS/DRM); mediapi is
-just the phone-facing UI that drives it. mpv runs as its own systemd service
-with `--idle --input-ipc-server=<socket>`, so it holds the playlist and keeps
-playing on its own even if this app, the phone, or the WiFi drop out -- we only
-send it commands and read its state. Uses only the stdlib so the app keeps no
-extra deps.
-
-Protocol: connect to the Unix socket, write one `{"command": [...]}` JSON line,
-and read newline-delimited JSON back. mpv also emits async `{"event": ...}`
-lines on the same stream; we tag each request with a request_id and skip
-anything that isn't the matching reply. A fresh connection per command keeps
-this stateless (mpv accepts many concurrent IPC connections), mirroring how the
-old Kodi client worked.
-"""
-
-import json
-import socket
-
-
-class MpvError(Exception):
-    """Base class for all mpv control errors."""
-
-
-class MpvConnectionError(MpvError):
-    """Couldn't reach mpv's IPC socket (not running, wrong path, no perms)."""
-
-
-class MpvCommandError(MpvError):
-    """mpv received the command but returned an error (e.g. bad property)."""
-
-
-class MpvClient:
-    def __init__(self, socket_path, timeout=4):
-        self.socket_path = socket_path
-        self.timeout = timeout
-        self._id = 0
-
-    def command(self, *args):
-        """Send one mpv IPC command and return its `data` field. Raises
-        MpvConnectionError if mpv is unreachable, MpvCommandError if mpv rejects
-        the command."""
-        self._id += 1
-        req_id = self._id
-        payload = json.dumps({"command": list(args), "request_id": req_id}) + "\n"
-
-        try:
-            with socket.socket(socket.AF_UNIX, socket.SOCK_STREAM) as sock:
-                sock.settimeout(self.timeout)
-                sock.connect(self.socket_path)
-                sock.sendall(payload.encode("utf-8"))
-                reply = self._read_reply(sock, req_id)
-        except (OSError, socket.timeout) as exc:
-            raise MpvConnectionError(str(exc)) from exc
-
-        if reply.get("error") != "success":
-            raise MpvCommandError(f"{args[0]}: {reply.get('error')}")
-        return reply.get("data")
-
-    def _read_reply(self, sock, req_id):
-        """Read newline-delimited JSON from mpv until we see the reply whose
-        request_id matches ours, skipping interleaved async event lines."""
-        with sock.makefile("r", encoding="utf-8") as stream:
-            for line in stream:
-                line = line.strip()
-                if not line:
-                    continue
-                try:
-                    msg = json.loads(line)
-                except json.JSONDecodeError as exc:
-                    raise MpvConnectionError(f"bad JSON from mpv: {exc}") from exc
-                if msg.get("request_id") == req_id and "error" in msg:
-                    return msg
-        raise MpvConnectionError("mpv closed the connection without a reply")
-
-    def get_property(self, name):
-        """Return a property's value, or raise MpvCommandError if mpv can't
-        supply it (e.g. `time-pos` while idle -- 'property unavailable')."""
-        return self.command("get_property", name)
-
-    def try_get(self, name, default=None):
-        """Like get_property but returns `default` when the property is simply
-        unavailable (idle player), so callers don't special-case idle state.
-        A real connection failure still propagates as MpvConnectionError."""
-        try:
-            return self.command("get_property", name)
-        except MpvCommandError:
-            return default
-
-    def set_property(self, name, value):
-        return self.command("set_property", name, value)

mediapi/mpv_ipc.py

@@ -0,0 +1,85 @@
+import json
+import socket
+import threading
+
+
+class MpvIPCError(Exception):
+    """Base class for all mpv IPC errors."""
+
+
+class MpvConnectionError(MpvIPCError):
+    """The underlying socket is broken; caller should reconnect."""
+
+
+class MpvCommandError(MpvIPCError):
+    """mpv responded but rejected the command (e.g. a property that's
+    legitimately unavailable while idle, like time-pos with nothing loaded).
+    The connection itself is fine."""
+
+
+class MpvIPCClient:
+    """Minimal client for mpv's JSON IPC protocol over a unix domain socket.
+
+    One request in flight at a time (guarded by a lock) since responses on
+    the socket aren't tagged with a request id in a way we bother matching --
+    we just send a command and read the next response line.
+    """
+
+    def __init__(self, socket_path):
+        self.socket_path = socket_path
+        self._sock = None
+        self._file = None
+        self._lock = threading.Lock()
+
+    def connect(self):
+        sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
+        sock.settimeout(2)
+        sock.connect(self.socket_path)
+        self._sock = sock
+        self._file = sock.makefile("rwb")
+
+    def close(self):
+        if self._sock is not None:
+            try:
+                self._sock.close()
+            except OSError:
+                pass
+        self._sock = None
+        self._file = None
+
+    @property
+    def connected(self):
+        return self._sock is not None
+
+    def command(self, *args):
+        """Send an mpv command, return its "data" field. Raises MpvIPCError
+        on failure or if not connected -- caller (PlayerStateManager) is
+        responsible for reconnect logic."""
+        if not self.connected:
+            raise MpvConnectionError("not connected")
+
+        payload = json.dumps({"command": list(args)}) + "\n"
+        with self._lock:
+            try:
+                self._file.write(payload.encode("utf-8"))
+                self._file.flush()
+                while True:
+                    line = self._file.readline()
+                    if not line:
+                        raise MpvConnectionError("socket closed")
+                    msg = json.loads(line)
+                    # skip async event notifications, wait for the command reply
+                    if "event" in msg:
+                        continue
+                    if msg.get("error") != "success":
+                        raise MpvCommandError(msg.get("error", "unknown error"))
+                    return msg.get("data")
+            except (OSError, json.JSONDecodeError) as exc:
+                self.close()
+                raise MpvConnectionError(str(exc)) from exc
+
+    def get_property(self, name):
+        return self.command("get_property", name)
+
+    def set_property(self, name, value):
+        return self.command("set_property", name, value)

mediapi/player.py

@@ -1,10 +1,11 @@
+import glob
 import logging
 import os
 import threading
 import time
 
 from .media import list_video_files
-from .mpv import MpvConnectionError, MpvError
+from .mpv_ipc import MpvCommandError, MpvConnectionError, MpvIPCClient, MpvIPCError
 
 log = logging.getLogger(__name__)
 
@@ -13,28 +14,26 @@ RECONNECT_INTERVAL = 2.0
 
 
 class PlayerStateManager:
-    """Controls mpv over its JSON IPC socket and caches its playback state.
+    """Owns the single connection to mpv's IPC socket. A background thread
+    polls mpv for playback state and drives "keep playing" auto-advance;
+    Flask request handlers only ever read the cached snapshot or send a
+    command through this class -- they never touch the socket directly."""
 
-    Playback is driven through mpv's own PLAYLIST: playing a file or folder
+    def __init__(self, socket_path, video_extensions, mirror_glob=None):
-    loads the whole folder into mpv's playlist and jumps to the chosen entry.
+        self.socket_path = socket_path
-    mpv then advances through the folder (and loops it, when "keep playing" is
-    on) ALL BY ITSELF -- so playback keeps going even if this app, the phone, or
-    the WiFi disconnect. mediapi only issues commands and polls state; it is
-    never in the playback loop. Next/Previous are mpv playlist navigation; "keep
-    playing" is mpv's `loop-playlist`.
-    """
-
-    def __init__(self, mpv_client, video_extensions):
-        self._mpv = mpv_client
         self.video_extensions = video_extensions
+        # Sockets of any per-screen "mirror" mpv instances (see start-mpv.py).
+        # We only ever push playback commands to these best-effort; the primary
+        # socket above is the sole source of state and the one that carries
+        # audio, so a missing/broken mirror just means one screen is dark.
+        self._mirror_glob = mirror_glob
+        self._mirror_clients = {}
+        self._mirror_lock = threading.Lock()
 
+        self._client = MpvIPCClient(socket_path)
         self._lock = threading.Lock()
         self._stop = threading.Event()
 
-        # Desired repeat state. Default ON: a lean-back player (kids' videos in a
-        # car) should keep running through/looping the folder, not stop.
-        self._keep_playing = True
-
         self._state = {
             "connected": False,
             "filename": None,
@@ -42,9 +41,14 @@ class PlayerStateManager:
             "duration": None,
             "paused": None,
             "volume": None,
-            "keep_playing": True,
+            "keep_playing": False,
         }
 
+        self._queue_folder = None
+        self._queue_files = []
+        self._queue_index = -1
+        self._prev_idle = True
+
     def start(self):
         thread = threading.Thread(target=self._run, name="player-state-manager", daemon=True)
         thread.start()
@@ -52,47 +56,56 @@ class PlayerStateManager:
     def stop(self):
         self._stop.set()
 
-    # -- background loop (status only; mpv owns auto-advance) --------------
+    # -- background loop -------------------------------------------------
 
     def _run(self):
         while not self._stop.is_set():
+            if not self._client.connected:
                 try:
-                self._poll_once()
+                    self._client.connect()
-            except MpvConnectionError as exc:
+                    log.info("connected to mpv socket at %s", self.socket_path)
-                log.debug("mpv not reachable: %s", exc)
+                except OSError:
                     self._set_disconnected()
                     time.sleep(RECONNECT_INTERVAL)
                     continue
-            except MpvError as exc:
+
-                log.warning("mpv poll error: %s", exc)
+            try:
+                self._poll_once()
+            except MpvConnectionError as exc:
+                log.warning("lost connection to mpv: %s", exc)
+                self._set_disconnected()
+                time.sleep(RECONNECT_INTERVAL)
+                continue
+
             time.sleep(POLL_INTERVAL)
 
     def _set_disconnected(self):
         with self._lock:
             self._state["connected"] = False
 
-    def _has_media(self):
+    def _get_property_safe(self, name):
-        """True if mpv currently has a file loaded (not idle). Raises
+        """Like client.get_property, but treats "property unavailable"
-        MpvConnectionError if mpv is unreachable."""
+        (normal for time-pos/duration/filename while mpv is idle) as None
-        return self._mpv.try_get("path") is not None
+        instead of a fatal error -- only a real MpvConnectionError should
+        tear down the connection."""
+        try:
+            return self._client.get_property(name)
+        except MpvCommandError:
+            return None
 
     def _poll_once(self):
-        # `path` is unavailable while mpv sits idle; try_get returns None then.
+        idle = bool(self._get_property_safe("idle-active"))
-        # A genuine socket failure raises MpvConnectionError and marks us down.
+        filename = self._get_property_safe("filename")
-        path = self._mpv.try_get("path")  # raises MpvConnectionError if down
+        position = self._get_property_safe("time-pos")
+        duration = self._get_property_safe("duration")
+        paused = self._get_property_safe("pause")
+        volume = self._get_property_safe("volume")
 
-        filename = position = duration = None
+        if idle and not self._prev_idle:
-        paused = None
+            self._maybe_advance()
+            idle = self._get_property_safe("idle-active")
 
-        if path is not None:
+        self._prev_idle = bool(idle)
-            filename = os.path.basename(path) or self._mpv.try_get("media-title")
-            position = self._mpv.try_get("time-pos")
-            duration = self._mpv.try_get("duration")
-            paused = bool(self._mpv.try_get("pause", False))
-
-        volume = self._mpv.try_get("volume")
-        if volume is not None:
-            volume = int(round(volume))
 
         with self._lock:
             self._state.update({
@@ -102,83 +115,108 @@ class PlayerStateManager:
                 "duration": duration,
                 "paused": paused,
                 "volume": volume,
-                "keep_playing": self._keep_playing,
             })
 
+    def _maybe_advance(self):
+        """Called from the poll loop when mpv just went idle. If keep-playing
+        is on and there's a next file in the current folder queue, load it."""
+        with self._lock:
+            keep_playing = self._state["keep_playing"]
+            has_next = (
+                self._queue_files
+                and 0 <= self._queue_index + 1 < len(self._queue_files)
+            )
+            if keep_playing and has_next:
+                self._queue_index += 1
+                next_file = self._queue_files[self._queue_index]
+            else:
+                next_file = None
+
+        if next_file:
+            try:
+                self._client.command("loadfile", next_file, "replace")
+            except MpvIPCError as exc:
+                log.warning("auto-advance loadfile failed: %s", exc)
+            self._broadcast("loadfile", next_file, "replace")
+
     # -- public read API ---------------------------------------------------
 
     def get_status(self):
         with self._lock:
-            return dict(self._state)
+            state = dict(self._state)
+            state["keep_playing"] = self._state["keep_playing"]
+        return state
 
-    # -- helpers -----------------------------------------------------------
+    # -- mirror screens (best-effort) --------------------------------------
 
-    def _play_playlist(self, files, start_index):
+    def _broadcast(self, *command_args):
-        """Load `files` into mpv's playlist (folder order) and start at
+        """Echo a playback command to every mirror mpv, best-effort. Never
-        start_index. mpv advances through them on its own from here on."""
+        raises: a mirror that's absent, mid-restart, or wedged must not affect
-        # `loadfile ... replace` starts a fresh playlist with the first file;
+        the primary screen or the HTTP response. Mirrors are re-synced on every
-        # append the rest to rebuild the folder in order, then jump to the
+        loadfile, so a command missed here self-heals at the next video."""
-        # chosen entry so the playlist matches the folder exactly.
+        if not self._mirror_glob:
-        self._mpv.command("loadfile", files[0], "replace")
+            return
-        for f in files[1:]:
+        with self._mirror_lock:
-            self._mpv.command("loadfile", f, "append")
+            paths = set(glob.glob(self._mirror_glob))
-        if start_index > 0:
+            # Drop clients whose socket disappeared (display unplugged).
-            self._mpv.set_property("playlist-pos", start_index)
+            for gone in set(self._mirror_clients) - paths:
-        self._apply_repeat()
+                self._mirror_clients.pop(gone).close()
-
+            for path in paths:
-    def _apply_repeat(self):
+                client = self._mirror_clients.get(path)
-        """Set mpv's playlist loop to match keep-playing."""
+                if client is None:
-        self._mpv.set_property("loop-playlist", "inf" if self._keep_playing else "no")
+                    client = self._mirror_clients[path] = MpvIPCClient(path)
+                try:
+                    if not client.connected:
+                        client.connect()
+                    client.command(*command_args)
+                except (OSError, MpvIPCError) as exc:
+                    client.close()
+                    log.debug("mirror %s command failed: %s", path, exc)
 
     # -- public command API (called from Flask routes) ---------------------
 
     def play_file(self, path):
-        # Queue the whole containing folder so playback continues through the
+        self._client.command("loadfile", path, "replace")
-        # rest of it, starting at the chosen file.
+        self._broadcast("loadfile", path, "replace")
+        # Build the auto-advance queue from the containing folder, positioned
+        # at the file just started -- so "keep playing" continues through the
+        # rest of the folder even when you start from the middle.
         folder = os.path.dirname(path)
         files = list_video_files(folder, self.video_extensions)
         try:
             index = files.index(path)
         except ValueError:
+            # played file isn't in the folder listing (unusual) -- queue just it
             files = [path]
             index = 0
-        self._play_playlist(files, index)
+        with self._lock:
+            self._queue_folder = folder
+            self._queue_files = files
+            self._queue_index = index
 
     def play_folder(self, folder_path):
         files = list_video_files(folder_path, self.video_extensions)
         if not files:
             raise ValueError(f"no video files in {folder_path}")
-        self._play_playlist(files, 0)
+        self._client.command("loadfile", files[0], "replace")
+        self._broadcast("loadfile", files[0], "replace")
+        with self._lock:
+            self._queue_folder = folder_path
+            self._queue_files = files
+            self._queue_index = 0
 
     def playpause(self):
-        if self._has_media():
+        self._client.command("cycle", "pause")
-            self._mpv.command("cycle", "pause")
+        self._broadcast("cycle", "pause")
-
-    def next(self):
-        if self._has_media():
-            self._mpv.command("playlist-next", "weak")
-
-    def previous(self):
-        if self._has_media():
-            self._mpv.command("playlist-prev", "weak")
 
     def seek(self, offset_seconds):
-        if self._has_media():
+        self._client.command("seek", offset_seconds, "relative")
-            self._mpv.command("seek", int(offset_seconds), "relative")
+        self._broadcast("seek", offset_seconds, "relative")
-
-    def seek_to(self, position_seconds):
-        """Seek to an absolute position (seconds from the start) -- used by the
-        draggable progress bar."""
-        if self._has_media():
-            pos = max(0, int(position_seconds))
-            self._mpv.command("seek", pos, "absolute")
 
     def set_volume(self, value):
         value = max(0, min(100, value))
-        self._mpv.set_property("volume", value)
+        self._client.set_property("volume", value)
 
     def set_keep_playing(self, enabled):
         with self._lock:
-            self._keep_playing = bool(enabled)
+            self._state["keep_playing"] = bool(enabled)
-            self._state["keep_playing"] = self._keep_playing
-        self._apply_repeat()

mediapi/routes/api_routes.py

@@ -1,7 +1,7 @@
 from flask import Blueprint, current_app, jsonify, request
 
-from ..mpv import MpvError
 from ..media import PathError, list_directory, resolve_path
+from ..mpv_ipc import MpvIPCError
 
 bp = Blueprint("api", __name__, url_prefix="/api")
 
@@ -42,7 +42,7 @@ def play():
             player.play_folder(resolved)
     except ValueError as exc:
         return jsonify({"error": str(exc)}), 400
-    except MpvError as exc:
+    except MpvIPCError as exc:
         return jsonify({"error": f"player unavailable: {exc}"}), 503
 
     return jsonify({"ok": True})
@@ -52,25 +52,7 @@ def play():
 def playpause():
     try:
         current_app.player.playpause()
-    except MpvError as exc:
+    except MpvIPCError as exc:
-        return jsonify({"error": f"player unavailable: {exc}"}), 503
-    return jsonify({"ok": True})
-
-
-@bp.route("/control/next", methods=["POST"])
-def next_clip():
-    try:
-        current_app.player.next()
-    except MpvError as exc:
-        return jsonify({"error": f"player unavailable: {exc}"}), 503
-    return jsonify({"ok": True})
-
-
-@bp.route("/control/previous", methods=["POST"])
-def previous_clip():
-    try:
-        current_app.player.previous()
-    except MpvError as exc:
         return jsonify({"error": f"player unavailable: {exc}"}), 503
     return jsonify({"ok": True})
 
@@ -85,22 +67,7 @@ def seek():
 
     try:
         current_app.player.seek(offset)
-    except MpvError as exc:
+    except MpvIPCError as exc:
-        return jsonify({"error": f"player unavailable: {exc}"}), 503
-    return jsonify({"ok": True})
-
-
-@bp.route("/control/seekto", methods=["POST"])
-def seekto():
-    body = request.get_json(force=True, silent=True) or {}
-    try:
-        position = float(body.get("position"))
-    except (TypeError, ValueError):
-        return jsonify({"error": "expected {position: seconds}"}), 400
-
-    try:
-        current_app.player.seek_to(position)
-    except MpvError as exc:
         return jsonify({"error": f"player unavailable: {exc}"}), 503
     return jsonify({"ok": True})
 
@@ -115,7 +82,7 @@ def volume():
 
     try:
         current_app.player.set_volume(value)
-    except MpvError as exc:
+    except MpvIPCError as exc:
         return jsonify({"error": f"player unavailable: {exc}"}), 503
     return jsonify({"ok": True})
 

mediapi/static/css/style.css

@@ -135,26 +135,18 @@ html, body {
 
 .transport-row {
   display: flex;
-  gap: 0.4rem;
+  gap: 0.5rem;
   margin: 1rem 0;
 }
 
 .transport-row button {
   flex: 1;
-  padding: 0.8rem 0.3rem;
+  padding: 0.8rem;
   border-radius: 6px;
   border: 1px solid #444;
   background: #1c1c1c;
   color: #eee;
   font-size: 1rem;
-  white-space: nowrap;
-}
-
-/* Prev/Next are compact icon buttons; the middle three carry the labels. */
-#btn-prev, #btn-next {
-  flex: 0 0 auto;
-  min-width: 2.6rem;
-  font-size: 1.2rem;
 }
 
 .volume-row {

mediapi/static/js/app.js

@@ -3,9 +3,6 @@
 
   let currentPath = null; // null = top-level media roots
   let volumeDebounce = null;
-  let seeking = false; // user is dragging the progress bar
-  let seekSuppressUntil = 0; // ignore poll updates briefly after a seek
-  let keepSuppressUntil = 0; // ignore poll updates briefly after toggling keep-playing
 
   const el = (id) => document.getElementById(id);
 
@@ -105,23 +102,17 @@
       if (!online) return;
 
       el("now-playing").textContent = data.filename || "—";
+      el("time-pos").textContent = formatTime(data.position);
       el("time-dur").textContent = formatTime(data.duration);
 
       const slider = el("seek-slider");
       slider.max = data.duration || 0;
-      // Don't fight the user while they're dragging, or right after a seek
-      // (the player takes a beat to report the new position).
-      if (!seeking && Date.now() > seekSuppressUntil) {
       slider.value = data.position || 0;
-        el("time-pos").textContent = formatTime(data.position);
-      }
 
       if (document.activeElement !== el("volume-slider")) {
         el("volume-slider").value = data.volume || 0;
       }
-      if (Date.now() > keepSuppressUntil) {
       el("keep-playing-checkbox").checked = !!data.keep_playing;
-      }
     });
   }
 
@@ -129,14 +120,6 @@
     api("/api/control/playpause", { method: "POST" });
   });
 
-  el("btn-prev").addEventListener("click", () => {
-    api("/api/control/previous", { method: "POST" });
-  });
-
-  el("btn-next").addEventListener("click", () => {
-    api("/api/control/next", { method: "POST" });
-  });
-
   el("btn-back30").addEventListener("click", () => {
     api("/api/control/seek", { method: "POST", body: JSON.stringify({ offset: -30 }) });
   });
@@ -145,20 +128,6 @@
     api("/api/control/seek", { method: "POST", body: JSON.stringify({ offset: 30 }) });
   });
 
-  // Drag the progress bar to seek. 'input' fires while dragging (live label),
-  // 'change' fires on release (send the absolute seek).
-  el("seek-slider").addEventListener("input", (e) => {
-    seeking = true;
-    el("time-pos").textContent = formatTime(Number(e.target.value));
-  });
-
-  el("seek-slider").addEventListener("change", (e) => {
-    const pos = Number(e.target.value);
-    seeking = false;
-    seekSuppressUntil = Date.now() + 1200;
-    api("/api/control/seekto", { method: "POST", body: JSON.stringify({ position: pos }) });
-  });
-
   el("volume-slider").addEventListener("input", (e) => {
     clearTimeout(volumeDebounce);
     const value = e.target.value;
@@ -168,7 +137,6 @@
   });
 
   el("keep-playing-checkbox").addEventListener("change", (e) => {
-    keepSuppressUntil = Date.now() + 1500;
     api("/api/control/keep-playing", {
       method: "POST",
       body: JSON.stringify({ enabled: e.target.checked }),

mediapi/templates/index.html

@@ -27,15 +27,13 @@
         <p id="now-playing" class="filename">&mdash;</p>
         <div class="progress-row">
           <span id="time-pos">0:00</span>
-          <input id="seek-slider" type="range" min="0" max="0" step="1">
+          <input id="seek-slider" type="range" min="0" max="0" step="1" disabled>
           <span id="time-dur">0:00</span>
         </div>
         <div class="transport-row">
-          <button id="btn-prev" title="Previous clip">&#9198;</button>
           <button id="btn-back30">&laquo; 30</button>
           <button id="btn-playpause">Play/Pause</button>
           <button id="btn-fwd30">30 &raquo;</button>
-          <button id="btn-next" title="Next clip">&#9197;</button>
         </div>
         <div class="volume-row">
           <span>Vol</span>

scripts/mediapi-watchdog.sh

@@ -1,76 +0,0 @@
-#!/usr/bin/env bash
-#
-# mediapi-watchdog -- reboot the Pi if the mpv player wedges.
-#
-# Guards against the failure seen 2026-07-09: a kernel oops left the player
-# stuck in uninterruptible (D) state while the rest of the box -- systemd, SSH,
-# the Flask app -- stayed alive and responsive. A plain systemd/hardware
-# watchdog only fires on a TOTAL system hang, so it would NOT have caught that
-# partial wedge. Instead we ping mpv over its JSON IPC socket; if mpv stays
-# unresponsive for ~3 minutes we force a reboot, turning a dead-all-night wedge
-# into a ~30s auto-recovery.
-#
-# Runs as root (needs to force a reboot). Installed + enabled by install.sh.
-set -u
-
-SOCK="${MEDIAPI_MPV_SOCKET:-/run/mediapi/mpv.sock}"
-INTERVAL="${MEDIAPI_WATCHDOG_INTERVAL:-30}"        # seconds between checks
-FAILS_TO_REBOOT="${MEDIAPI_WATCHDOG_FAILS:-6}"     # consecutive fails -> reboot (~3 min)
-PING_TIMEOUT="${MEDIAPI_WATCHDOG_PING_TIMEOUT:-6}" # per-check hard timeout
-DRYRUN="${MEDIAPI_WATCHDOG_DRYRUN:-}"              # non-empty: log instead of rebooting
-
-# Return 0 iff mpv replies to a JSON IPC command within PING_TIMEOUT. A player
-# wedged in D-state accepts the socket connect but never replies, so the recv
-# blocks and `timeout` trips it -- exactly the case we want to catch.
-ping_mpv() {
-  timeout "$PING_TIMEOUT" python3 - "$SOCK" <<'PY'
-import socket, json, sys
-try:
-    s = socket.socket(socket.AF_UNIX); s.settimeout(4); s.connect(sys.argv[1])
-    s.sendall(b'{"command":["get_property","mpv-version"],"request_id":1}\n')
-    buf = b""
-    while b"\n" not in buf:
-        chunk = s.recv(4096)
-        if not chunk:
-            sys.exit(1)
-        buf += chunk
-    for line in buf.decode(errors="replace").splitlines():
-        m = json.loads(line)
-        if m.get("request_id") == 1:
-            sys.exit(0 if m.get("error") == "success" else 1)
-    sys.exit(1)
-except Exception:
-    sys.exit(1)
-PY
-}
-
-do_reboot() {
-  if [ -n "$DRYRUN" ]; then
-    echo "mediapi-watchdog: DRYRUN -- would reboot now" >&2
-    return
-  fi
-  # Best-effort clean reboot first; fall back to SysRq, which reboots at the
-  # kernel level even when userspace is wedged in D-state (the case we guard).
-  sync &
-  systemctl reboot -ff &
-  sleep 12
-  echo 1 > /proc/sys/kernel/sysrq 2>/dev/null || true
-  echo b > /proc/sysrq-trigger 2>/dev/null || true
-}
-
-echo "mediapi-watchdog: watching $SOCK (reboot after ${FAILS_TO_REBOOT}x${INTERVAL}s unresponsive)" >&2
-fails=0
-while true; do
-  if ping_mpv; then
-    fails=0
-  else
-    fails=$((fails + 1))
-    echo "mediapi-watchdog: mpv ping FAILED ($fails/$FAILS_TO_REBOOT)" >&2
-    if [ "$fails" -ge "$FAILS_TO_REBOOT" ]; then
-      echo "mediapi-watchdog: mpv unresponsive ~$((INTERVAL * FAILS_TO_REBOOT))s -- rebooting" >&2
-      do_reboot
-      fails=0
-    fi
-  fi
-  sleep "$INTERVAL"
-done

scripts/start-mpv.py

@@ -0,0 +1,171 @@
+#!/usr/bin/env python3
+"""Launch one mpv per connected HDMI output so playback mirrors across every
+attached display.
+
+mpv's DRM output can only ever drive a single connector, and the Pi's vc4-kms
+driver can't clone two HDMI connectors onto one framebuffer -- so "mirror on
+both screens" means running one mpv per connector. This script enumerates the
+connected connectors at start and launches:
+
+  * a PRIMARY mpv on the first connected connector -- owns audio and the IPC
+    socket the Flask app talks to (/run/mediapi/mpv.sock);
+  * a MIRROR mpv on each additional connector -- video only (--ao=null), each
+    on its own IPC socket (/run/mediapi/mpv-mirror-<connector>.sock) so the app
+    can echo loadfile/pause/seek to it best-effort.
+
+Design choices, all in service of "must work unattended in a car":
+
+  * If no connector can be detected (unexpected sysfs naming, etc.) it falls
+    back to a single auto-picking mpv -- i.e. exactly the old behavior, never
+    worse.
+  * It supervises the children: if any mpv exits, it tears the rest down and
+    exits non-zero so systemd restarts the whole unit (which re-enumerates
+    displays -- e.g. a screen powered on since last start).
+  * The mirror is strictly best-effort; the primary is what carries audio and
+    control, so a dead mirror degrades to single-screen playback.
+
+Runs as a plain stdlib script (no venv needed) so it can start early at boot.
+"""
+
+import glob
+import os
+import re
+import signal
+import subprocess
+import sys
+import time
+
+RUNTIME_DIR = os.environ.get("MEDIAPI_RUNTIME_DIR", "/run/mediapi")
+PRIMARY_SOCKET = os.environ.get("MEDIAPI_MPV_SOCKET", os.path.join(RUNTIME_DIR, "mpv.sock"))
+
+# Flags shared by every instance. Kept in sync with what the mpv systemd unit
+# used to pass directly.
+COMMON_ARGS = [
+    "/usr/bin/mpv",
+    "--idle=yes",
+    "--vo=gpu-next",
+    "--gpu-context=drm",
+    "--hwdec=auto-safe",  # falls back to software if the HW decoder is busy
+    "--fullscreen",
+    "--no-terminal",
+    "--keep-open=no",
+]
+
+
+def connected_hdmi_outputs():
+    """Return [(card_device, connector_name), ...] for every connected HDMI
+    connector, e.g. [("/dev/dri/card1", "HDMI-A-1"), ...], sorted by connector
+    name so the assignment of primary/mirror is stable across restarts."""
+    outputs = []
+    for status_path in sorted(glob.glob("/sys/class/drm/card*-HDMI-*/status")):
+        try:
+            with open(status_path) as f:
+                status = f.read().strip()
+        except OSError:
+            continue
+        if status != "connected":
+            continue
+        # .../card1-HDMI-A-1/status -> card="card1", connector="HDMI-A-1"
+        m = re.match(r"(card\d+)-(HDMI-\S+)", os.path.basename(os.path.dirname(status_path)))
+        if not m:
+            continue
+        card, connector = m.group(1), m.group(2)
+        outputs.append((f"/dev/dri/{card}", connector))
+    return outputs
+
+
+def mirror_socket_path(connector):
+    return os.path.join(os.path.dirname(PRIMARY_SOCKET), f"mpv-mirror-{connector}.sock")
+
+
+def build_commands():
+    """Build the list of mpv argv lists to launch."""
+    outputs = connected_hdmi_outputs()
+
+    if not outputs:
+        # Couldn't identify any connector -- fall back to a single auto-picking
+        # mpv (the old behavior). Never worse than before.
+        print("start-mpv: no HDMI connector detected, launching single auto mpv", flush=True)
+        return [COMMON_ARGS + [f"--input-ipc-server={PRIMARY_SOCKET}", "--ao=alsa"]]
+
+    commands = []
+    primary_card, primary_connector = outputs[0]
+    print(f"start-mpv: primary on {primary_connector} ({primary_card})", flush=True)
+    commands.append(
+        COMMON_ARGS
+        + [
+            f"--drm-device={primary_card}",
+            f"--drm-connector={primary_connector}",
+            f"--input-ipc-server={PRIMARY_SOCKET}",
+            "--ao=alsa",
+        ]
+    )
+
+    for card, connector in outputs[1:]:
+        sock = mirror_socket_path(connector)
+        print(f"start-mpv: mirror on {connector} ({card}) -> {sock}", flush=True)
+        commands.append(
+            COMMON_ARGS
+            + [
+                f"--drm-device={card}",
+                f"--drm-connector={connector}",
+                f"--input-ipc-server={sock}",
+                "--ao=null",
+                "--mute=yes",
+            ]
+        )
+    return commands
+
+
+def main():
+    # Clean up any stale mirror sockets from a previous run so the app doesn't
+    # try to talk to a connector that's no longer attached.
+    for stale in glob.glob(os.path.join(os.path.dirname(PRIMARY_SOCKET), "mpv-mirror-*.sock")):
+        try:
+            os.unlink(stale)
+        except OSError:
+            pass
+
+    procs = [subprocess.Popen(cmd) for cmd in build_commands()]
+
+    stopping = {"flag": False}
+
+    def kill_children():
+        for p in procs:
+            if p.poll() is None:
+                p.terminate()
+
+    def on_signal(*_):
+        # Told to stop (systemctl stop / Ctrl-C): kill the children and let
+        # main exit 0 so systemd treats it as a clean stop, not a crash.
+        stopping["flag"] = True
+        kill_children()
+
+    signal.signal(signal.SIGTERM, on_signal)
+    signal.signal(signal.SIGINT, on_signal)
+
+    # Poll the children (via subprocess so its bookkeeping stays consistent --
+    # don't os.wait() out from under it). The first unexpected exit means a
+    # screen dropped its mpv: tear the rest down and exit non-zero so systemd
+    # restarts the unit, re-enumerating displays in the process. time.sleep is
+    # interrupted by SIGTERM, so a stop is handled promptly too.
+    while not stopping["flag"]:
+        dead = next((p for p in procs if p.poll() is not None), None)
+        if dead is not None:
+            print(f"start-mpv: an mpv exited unexpectedly (pid {dead.pid}), restarting unit", flush=True)
+            kill_children()
+            break
+        time.sleep(1)
+
+    # Reap whatever's left.
+    for p in procs:
+        try:
+            p.wait(timeout=5)
+        except subprocess.TimeoutExpired:
+            p.kill()
+
+    sys.exit(0 if stopping["flag"] else 1)
+
+
+if __name__ == "__main__":
+    main()

systemd/mediapi-mpv.service.template

@@ -1,39 +1,26 @@
 [Unit]
-Description=mpv video player (KMS/DRM -- the actual player)
+Description=mpv persistent player (DRM/HDMI output, JSON IPC)
-# Needs the DRM/HDMI + sound devices present.
+# Wait until udev has settled so the DRM/HDMI devices (/dev/dri/*) exist
-After=local-fs.target systemd-udev-settle.service sound.target
+# before mpv tries to grab the display. Without this, a cold-boot race can
+# leave mpv running but never rendering to HDMI (you see the console instead),
+# even though the exact same command works when run by hand later.
+After=local-fs.target systemd-udev-settle.service
 Wants=systemd-udev-settle.service
-# Keep a login getty off the primary display so nothing else claims tty1.
-Conflicts=getty@tty1.service
 
 [Service]
+Type=simple
 User=${MEDIAPI_USER}
-# mpv on KMS/DRM needs: video+render (GPU/DRM), input (remotes/keyboard), audio
+SupplementaryGroups=video render
-# (HDMI/ALSA). It becomes DRM master simply as the first/only DRM client on the
-# seat -- no PAM login session and no elevated capabilities required, provided
-# nothing else is already holding the GPU. (An older Kodi-based deploy DID hold
-# it; install.sh tears any leftover Kodi down before starting this.)
-SupplementaryGroups=video render input audio
-# Create /run/mediapi (owned by this user) for the IPC socket the app connects to.
 RuntimeDirectory=mediapi
-StandardInput=null
+RuntimeDirectoryMode=0770
-StandardOutput=journal
+# start-mpv.py enumerates the connected HDMI connectors and launches one mpv
-StandardError=journal
+# per screen: the primary carries audio + the app's IPC socket, and each extra
-# --idle keeps mpv running with no file loaded (holds the playlist between clips
+# screen gets a video-only mirror mpv on its own socket. If any mpv dies the
-# and after the last one), so the service stays up and the app can always reach
+# launcher exits non-zero and systemd restarts us, which re-enumerates the
-# the socket. Playback renders straight on KMS.
+# displays. See the script header for the full rationale.
-ExecStart=/usr/bin/mpv \
+ExecStart=/usr/bin/python3 ${PROJECT_DIR}/scripts/start-mpv.py
-  --idle=yes \
-  --input-ipc-server=/run/mediapi/mpv.sock \
-  --no-terminal \
-  --no-input-default-bindings \
-  --fullscreen \
-  --force-window=yes \
-  --keep-open=no \
-  --vo=gpu --gpu-context=drm --hwdec=auto \
-  --ao=alsa --audio-device=alsa/hdmi:CARD=vc4hdmi0,DEV=0
 Restart=on-failure
-RestartSec=5
+RestartSec=2
 
 [Install]
 WantedBy=multi-user.target

systemd/mediapi-watchdog.service.template

@@ -1,15 +0,0 @@
-[Unit]
-Description=MediaPi watchdog -- reboots the Pi if the mpv player wedges
-After=mediapi-mpv.service
-Wants=mediapi-mpv.service
-
-[Service]
-Type=simple
-# Runs as root (no User=): must be able to force a reboot, including via SysRq,
-# to recover a box whose player is wedged in uninterruptible D-state.
-ExecStart=${PROJECT_DIR}/scripts/mediapi-watchdog.sh
-Restart=always
-RestartSec=10
-
-[Install]
-WantedBy=multi-user.target