music-assistant-server

1"""Unified AirPlay/RAOP stream session logic for AirPlay devices."""
2
3from __future__ import annotations
4
5import asyncio
6import time
7from collections.abc import AsyncGenerator
8from contextlib import suppress
9from typing import TYPE_CHECKING
10
11from music_assistant_models.errors import PlayerCommandFailed
12
13from music_assistant.constants import CONF_SYNC_ADJUST
14from music_assistant.helpers.audio import get_player_filter_params
15from music_assistant.helpers.ffmpeg import FFMpeg
16from music_assistant.providers.airplay.helpers import ntp_to_unix_time, unix_time_to_ntp
17
18from .constants import (
19    AIRPLAY2_CONNECT_TIME_MS,
20    CONF_ENABLE_LATE_JOIN,
21    ENABLE_LATE_JOIN_DEFAULT,
22    RAOP_CONNECT_TIME_MS,
23    StreamingProtocol,
24)
25from .protocols.airplay2 import AirPlay2Stream
26from .protocols.raop import RaopStream
27
28if TYPE_CHECKING:
29    from music_assistant_models.media_items import AudioFormat
30
31    from .player import AirPlayPlayer
32    from .provider import AirPlayProvider
33
34
35class AirPlayStreamSession:
36    """Stream session (RAOP or AirPlay2) to one or more players."""
37
38    def __init__(
39        self,
40        airplay_provider: AirPlayProvider,
41        sync_clients: list[AirPlayPlayer],
42        pcm_format: AudioFormat,
43    ) -> None:
44        """Initialize AirPlayStreamSession.
45
46        :param airplay_provider: The AirPlay provider instance.
47        :param sync_clients: List of AirPlay players to stream to.
48        :param pcm_format: PCM format of the input stream.
49        """
50        assert sync_clients
51        self.prov = airplay_provider
52        self.mass = airplay_provider.mass
53        self.pcm_format = pcm_format
54        self.sync_clients = sync_clients
55        self._audio_source_task: asyncio.Task[None] | None = None
56        self._player_ffmpeg: dict[str, FFMpeg] = {}
57        self._lock = asyncio.Lock()
58        self.start_ntp: int = 0
59        self.start_time: float = 0.0
60        self.wait_start: float = 0.0
61        self.seconds_streamed: float = 0
62        self._first_chunk_received = asyncio.Event()
63
64    async def start(self, audio_source: AsyncGenerator[bytes, None]) -> None:
65        """Initialize stream session for all players."""
66        cur_time = time.time()
67        has_airplay2_client = any(
68            p.protocol == StreamingProtocol.AIRPLAY2 for p in self.sync_clients
69        )
70        wait_start = AIRPLAY2_CONNECT_TIME_MS if has_airplay2_client else RAOP_CONNECT_TIME_MS
71        wait_start_seconds = wait_start / 1000
72        self.wait_start = wait_start_seconds
73        self.start_time = cur_time + wait_start_seconds
74        self.start_ntp = unix_time_to_ntp(self.start_time)
75        await asyncio.gather(*[self._start_client(p, self.start_ntp) for p in self.sync_clients])
76        self._audio_source_task = asyncio.create_task(self._audio_streamer(audio_source))
77        try:
78            await asyncio.gather(
79                *[p.stream.wait_for_connection() for p in self.sync_clients if p.stream]
80            )
81        except Exception:
82            # playback failed to start, cleanup
83            await self.stop()
84            raise PlayerCommandFailed("Playback failed to start")
85
86    async def stop(self) -> None:
87        """Stop playback and cleanup."""
88        if self._audio_source_task and not self._audio_source_task.done():
89            self._audio_source_task.cancel()
90            with suppress(asyncio.CancelledError):
91                await self._audio_source_task
92        await asyncio.gather(
93            *[self.remove_client(x) for x in self.sync_clients],
94        )
95
96    async def remove_client(self, airplay_player: AirPlayPlayer) -> None:
97        """Remove a sync client from the session."""
98        async with self._lock:
99            if airplay_player not in self.sync_clients:
100                return
101            self.sync_clients.remove(airplay_player)
102        await self.stop_client(airplay_player)
103        # If this was the last client, stop the session
104        if not self.sync_clients:
105            await self.stop()
106            return
107
108    async def stop_client(self, airplay_player: AirPlayPlayer) -> None:
109        """
110        Stop a client's stream and ffmpeg.
111
112        :param airplay_player: The player to stop.
113        :param force: If True, kill CLI process immediately.
114        """
115        ffmpeg = self._player_ffmpeg.pop(airplay_player.player_id, None)
116        # note that we use kill instead of graceful close here,
117        # because otherwise it can take a very long time for the process to exit.
118        if ffmpeg and not ffmpeg.closed:
119            await ffmpeg.kill()
120        if airplay_player.stream and airplay_player.stream.session == self:
121            await airplay_player.stream.stop(force=True)
122
123    async def add_client(self, airplay_player: AirPlayPlayer) -> None:
124        """Add a sync client to the session as a late joiner.
125
126        The late joiner will:
127        1. Start playing at a compensated NTP timestamp (start_ntp + offset)
128        2. Receive silence calculated dynamically based on how much audio has been sent
129        3. Then receive real audio chunks in sync with other players
130        """
131        sync_leader = self.sync_clients[0]
132        if not sync_leader.stream or not sync_leader.stream.running:
133            return
134
135        allow_late_join = self.prov.config.get_value(
136            CONF_ENABLE_LATE_JOIN, ENABLE_LATE_JOIN_DEFAULT
137        )
138        if not allow_late_join:
139            await self.stop()
140            if sync_leader.state.current_media:
141                self.mass.call_later(
142                    0.5,
143                    self.mass.players.cmd_resume(sync_leader.player_id),
144                    task_id=f"resync_session_{sync_leader.player_id}",
145                )
146            return
147
148        async with self._lock:
149            skip_seconds = self.seconds_streamed
150            start_at = self.start_time + skip_seconds
151            start_ntp = unix_time_to_ntp(start_at)
152            if airplay_player not in self.sync_clients:
153                self.sync_clients.append(airplay_player)
154
155            await self._start_client(airplay_player, start_ntp)
156            if airplay_player.stream:
157                await airplay_player.stream.wait_for_connection()
158
159    async def _audio_streamer(self, audio_source: AsyncGenerator[bytes, None]) -> None:
160        """Stream audio to all players."""
161        pcm_sample_size = self.pcm_format.pcm_sample_size
162        watchdog_task = asyncio.create_task(self._silence_watchdog(pcm_sample_size))
163        try:
164            async for chunk in audio_source:
165                if not self._first_chunk_received.is_set():
166                    watchdog_task.cancel()
167                    with suppress(asyncio.CancelledError):
168                        await watchdog_task
169                    self._first_chunk_received.set()
170
171                if not self.sync_clients:
172                    break
173
174                await self._write_chunk_to_all_players(chunk)
175                self.seconds_streamed += len(chunk) / pcm_sample_size
176        finally:
177            if not watchdog_task.done():
178                watchdog_task.cancel()
179                with suppress(asyncio.CancelledError):
180                    await watchdog_task
181        async with self._lock:
182            await asyncio.gather(
183                *[
184                    self._write_eof_to_player(x)
185                    for x in self.sync_clients
186                    if x.stream and x.stream.running
187                ],
188                return_exceptions=True,
189            )
190
191    async def _silence_watchdog(self, pcm_sample_size: int) -> None:
192        """Insert silence if audio source is slow to deliver first chunk."""
193        grace_period = 0.2
194        max_silence_padding = 5.0
195        silence_inserted = 0.0
196
197        await asyncio.sleep(grace_period)
198        while not self._first_chunk_received.is_set() and silence_inserted < max_silence_padding:
199            silence_duration = 0.1
200            silence_bytes = int(pcm_sample_size * silence_duration)
201            silence_chunk = bytes(silence_bytes)
202            await self._write_chunk_to_all_players(silence_chunk)
203            self.seconds_streamed += silence_duration
204            silence_inserted += silence_duration
205            await asyncio.sleep(0.05)
206
207        if silence_inserted > 0:
208            self.prov.logger.warning(
209                "Inserted %.1fs silence padding while waiting for audio source",
210                silence_inserted,
211            )
212
213    async def _write_chunk_to_all_players(self, chunk: bytes) -> None:
214        """Write a chunk to all connected players."""
215        async with self._lock:
216            sync_clients = [x for x in self.sync_clients if x.stream and x.stream.running]
217            if not sync_clients:
218                return
219
220            # Write chunk to all players
221            write_tasks = [self._write_chunk_to_player(x, chunk) for x in sync_clients if x.stream]
222            results = await asyncio.gather(*write_tasks, return_exceptions=True)
223
224            # Check for write errors or timeouts
225            players_to_remove: list[AirPlayPlayer] = []
226            for i, result in enumerate(results):
227                if i >= len(sync_clients):
228                    continue
229                player = sync_clients[i]
230
231                if isinstance(result, TimeoutError):
232                    self.prov.logger.warning(
233                        "Removing player %s from session: stopped reading data (write timeout)",
234                        player.player_id,
235                    )
236                    players_to_remove.append(player)
237                elif isinstance(result, Exception):
238                    self.prov.logger.warning(
239                        "Removing player %s from session due to write error: %s",
240                        player.player_id,
241                        result,
242                    )
243                    players_to_remove.append(player)
244
245            for player in players_to_remove:
246                self.mass.create_task(self.remove_client(player))
247
248    async def _write_chunk_to_player(self, airplay_player: AirPlayPlayer, chunk: bytes) -> None:
249        """Write audio chunk to a player's ffmpeg process."""
250        player_id = airplay_player.player_id
251        if ffmpeg := self._player_ffmpeg.get(player_id):
252            if ffmpeg.closed:
253                return
254            await asyncio.wait_for(ffmpeg.write(chunk), timeout=35.0)
255
256    async def _write_eof_to_player(self, airplay_player: AirPlayPlayer) -> None:
257        """Write EOF to a specific player."""
258        if ffmpeg := self._player_ffmpeg.pop(airplay_player.player_id, None):
259            await ffmpeg.write_eof()
260            await ffmpeg.wait_with_timeout(30)
261            if airplay_player.stream and airplay_player.stream._cli_proc:
262                await airplay_player.stream._cli_proc.write_eof()
263
264    async def _start_client(self, airplay_player: AirPlayPlayer, start_ntp: int) -> None:
265        """Start CLI process and ffmpeg for a single client."""
266        if airplay_player.stream and airplay_player.stream.running:
267            await airplay_player.stream.stop()
268        if airplay_player.protocol == StreamingProtocol.AIRPLAY2:
269            airplay_player.stream = AirPlay2Stream(airplay_player)
270        else:
271            airplay_player.stream = RaopStream(airplay_player)
272        airplay_player.stream.session = self
273        sync_adjust = airplay_player.config.get_value(CONF_SYNC_ADJUST, 0)
274        assert isinstance(sync_adjust, int)
275        if sync_adjust != 0:
276            start_ntp = unix_time_to_ntp(ntp_to_unix_time(start_ntp) + (sync_adjust / 1000))
277        await airplay_player.stream.start(start_ntp)
278        # Start ffmpeg to feed audio to CLI stdin
279        if ffmpeg := self._player_ffmpeg.pop(airplay_player.player_id, None):
280            await ffmpeg.close()
281        filter_params = get_player_filter_params(
282            self.mass,
283            airplay_player.player_id,
284            self.pcm_format,
285            airplay_player.stream.pcm_format,
286        )
287        cli_proc = airplay_player.stream._cli_proc
288        assert cli_proc
289        assert cli_proc.proc
290        assert cli_proc.proc.stdin
291        stdin_transport = cli_proc.proc.stdin.transport
292        audio_output: str | int = stdin_transport.get_extra_info("pipe").fileno()
293        ffmpeg = FFMpeg(
294            audio_input="-",
295            input_format=self.pcm_format,
296            output_format=airplay_player.stream.pcm_format,
297            filter_params=filter_params,
298            audio_output=audio_output,
299        )
300        await ffmpeg.start()
301        self._player_ffmpeg[airplay_player.player_id] = ffmpeg
302