ods/teleoprtc/stream.py

303 lines
12 KiB
Python

import abc
import asyncio
import dataclasses
import logging
from typing import Callable, Awaitable, Dict, List, Any, Optional
import aiortc
from aiortc.contrib.media import MediaRelay
from teleoprtc.tracks import parse_video_track_id
@dataclasses.dataclass
class StreamingOffer:
sdp: str
video: List[str]
ConnectionProvider = Callable[[StreamingOffer], Awaitable[aiortc.RTCSessionDescription]]
MessageHandler = Callable[[bytes], Awaitable[None]]
class WebRTCBaseStream(abc.ABC):
def __init__(self,
consumed_camera_types: List[str],
consume_audio: bool,
video_producer_tracks: List[aiortc.MediaStreamTrack],
audio_producer_tracks: List[aiortc.MediaStreamTrack],
should_add_data_channel: bool):
self.peer_connection = aiortc.RTCPeerConnection()
self.media_relay = MediaRelay()
self.expected_incoming_camera_types = consumed_camera_types
self.expected_incoming_audio = consume_audio
self.expected_number_of_incoming_media: Optional[int] = None
self.incoming_camera_tracks: Dict[str, aiortc.MediaStreamTrack] = dict()
self.incoming_audio_tracks: List[aiortc.MediaStreamTrack] = []
self.outgoing_video_tracks: List[aiortc.MediaStreamTrack] = video_producer_tracks
self.outgoing_audio_tracks: List[aiortc.MediaStreamTrack] = audio_producer_tracks
self.should_add_data_channel = should_add_data_channel
self.messaging_channel: Optional[aiortc.RTCDataChannel] = None
self.incoming_message_handlers: List[MessageHandler] = []
self.incoming_media_ready_event = asyncio.Event()
self.messaging_channel_ready_event = asyncio.Event()
self.connection_attempted_event = asyncio.Event()
self.connection_stopped_event = asyncio.Event()
self.peer_connection.on("connectionstatechange", self._on_connectionstatechange)
self.peer_connection.on("datachannel", self._on_incoming_datachannel)
self.peer_connection.on("track", self._on_incoming_track)
self.logger = logging.getLogger("WebRTCStream")
def _log_debug(self, msg: Any, *args):
self.logger.debug(f"{type(self)}() {msg}", *args)
@property
def _number_of_incoming_media(self) -> int:
media = len(self.incoming_camera_tracks) + len(self.incoming_audio_tracks)
# if stream does not add data_channel, then it means its incoming
media += int(self.messaging_channel is not None) if not self.should_add_data_channel else 0
return media
def _add_consumer_transceivers(self):
for _ in self.expected_incoming_camera_types:
self.peer_connection.addTransceiver("video", direction="recvonly")
if self.expected_incoming_audio:
self.peer_connection.addTransceiver("audio", direction="recvonly")
def _find_trackless_transceiver(self, kind: str) -> Optional[aiortc.RTCRtpTransceiver]:
transceivers = self.peer_connection.getTransceivers()
target_transceiver = None
for t in transceivers:
if t.kind == kind and t.sender.track is None:
target_transceiver = t
break
return target_transceiver
def _add_producer_tracks(self):
for track in self.outgoing_video_tracks:
target_transceiver = self._find_trackless_transceiver(track.kind)
if target_transceiver is None:
self.peer_connection.addTransceiver(track.kind, direction="sendonly")
sender = self.peer_connection.addTrack(track)
if hasattr(track, "codec_preference") and track.codec_preference() is not None:
transceiver = next(t for t in self.peer_connection.getTransceivers() if t.sender == sender)
self._force_codec(transceiver, track.codec_preference(), "video")
for track in self.outgoing_audio_tracks:
target_transceiver = self._find_trackless_transceiver(track.kind)
if target_transceiver is None:
self.peer_connection.addTransceiver(track.kind, direction="sendonly")
self.peer_connection.addTrack(track)
def _add_messaging_channel(self, channel: Optional[aiortc.RTCDataChannel] = None):
if not channel:
channel = self.peer_connection.createDataChannel("data", ordered=True)
for handler in self.incoming_message_handlers:
channel.on("message", handler)
if channel.readyState == "open":
self.messaging_channel_ready_event.set()
else:
channel.on("open", lambda: self.messaging_channel_ready_event.set())
self.messaging_channel = channel
def _force_codec(self, transceiver: aiortc.RTCRtpTransceiver, codec: str, stream_type: str):
codec_mime = f"{stream_type}/{codec.upper()}"
rtp_codecs = aiortc.RTCRtpSender.getCapabilities(stream_type).codecs
rtp_codec = [c for c in rtp_codecs if c.mimeType == codec_mime]
transceiver.setCodecPreferences(rtp_codec)
def _on_connectionstatechange(self):
self._log_debug("connection state is %s", self.peer_connection.connectionState)
if self.peer_connection.connectionState in ['connected', 'failed']:
self.connection_attempted_event.set()
if self.peer_connection.connectionState in ['disconnected', 'closed', 'failed']:
self.connection_stopped_event.set()
def _on_incoming_track(self, track: aiortc.MediaStreamTrack):
self._log_debug("got track: %s %s", track.kind, track.id)
if track.kind == "video":
camera_type, _ = parse_video_track_id(track.id)
if camera_type in self.expected_incoming_camera_types:
self.incoming_camera_tracks[camera_type] = track
elif track.kind == "audio":
if self.expected_incoming_audio:
self.incoming_audio_tracks.append(track)
self._on_after_media()
def _on_incoming_datachannel(self, channel: aiortc.RTCDataChannel):
self._log_debug("got data channel: %s", channel.label)
if channel.label == "data" and self.messaging_channel is None:
self._add_messaging_channel(channel)
self._on_after_media()
def _on_after_media(self):
if self._number_of_incoming_media == self.expected_number_of_incoming_media:
self.incoming_media_ready_event.set()
def _parse_incoming_streams(self, remote_sdp: str):
desc = aiortc.sdp.SessionDescription.parse(remote_sdp)
sending_medias = [m for m in desc.media if m.direction in ["sendonly", "sendrecv"]]
incoming_media_count = len(sending_medias)
if not self.should_add_data_channel:
channel_medias = [m for m in desc.media if m.kind == "application"]
incoming_media_count += len(channel_medias)
self.expected_number_of_incoming_media = incoming_media_count
def has_incoming_video_track(self, camera_type: str) -> bool:
return camera_type in self.incoming_camera_tracks
def has_incoming_audio_track(self) -> bool:
return len(self.incoming_audio_tracks) > 0
def has_messaging_channel(self) -> bool:
return self.messaging_channel is not None
def get_incoming_video_track(self, camera_type: str, buffered: bool = False) -> aiortc.MediaStreamTrack:
assert camera_type in self.incoming_camera_tracks, "Video tracks are not enabled on this stream"
assert self.is_started, "Stream must be started"
track = self.incoming_camera_tracks[camera_type]
relay_track = self.media_relay.subscribe(track, buffered=buffered)
return relay_track
def get_incoming_audio_track(self, buffered: bool = False) -> aiortc.MediaStreamTrack:
assert len(self.incoming_audio_tracks) > 0, "Audio tracks are not enabled on this stream"
assert self.is_started, "Stream must be started"
track = self.incoming_audio_tracks[0]
relay_track = self.media_relay.subscribe(track, buffered=buffered)
return relay_track
def get_messaging_channel(self) -> aiortc.RTCDataChannel:
assert self.messaging_channel is not None, "Messaging channel is not enabled on this stream"
assert self.is_started, "Stream must be started"
return self.messaging_channel
def set_message_handler(self, message_handler: MessageHandler):
self.incoming_message_handlers.append(message_handler)
if self.messaging_channel is not None:
self.messaging_channel.on("message", message_handler)
@property
def is_started(self) -> bool:
return self.peer_connection is not None and \
self.peer_connection.localDescription is not None and \
self.peer_connection.remoteDescription is not None and \
self.peer_connection.connectionState != "closed"
@property
def is_connected_and_ready(self) -> bool:
return self.peer_connection is not None and \
self.peer_connection.connectionState == "connected" and \
self.expected_number_of_incoming_media != 0 and self.incoming_media_ready_event.is_set()
async def wait_for_connection(self):
assert self.is_started
await self.connection_attempted_event.wait()
if self.peer_connection.connectionState != 'connected':
raise ValueError("Connection failed.")
if self.expected_number_of_incoming_media:
await self.incoming_media_ready_event.wait()
if self.messaging_channel is not None:
await self.messaging_channel_ready_event.wait()
async def wait_for_disconnection(self):
assert self.is_connected_and_ready
await self.connection_stopped_event.wait()
async def stop(self):
await self.peer_connection.close()
@abc.abstractmethod
async def start(self) -> aiortc.RTCSessionDescription:
raise NotImplementedError
class WebRTCOfferStream(WebRTCBaseStream):
def __init__(self, session_provider: ConnectionProvider, *args, **kwargs):
super().__init__(*args, **kwargs)
self.session_provider = session_provider
async def start(self) -> aiortc.RTCSessionDescription:
self._add_consumer_transceivers()
if self.should_add_data_channel:
self._add_messaging_channel()
self._add_producer_tracks()
offer = await self.peer_connection.createOffer()
await self.peer_connection.setLocalDescription(offer)
actual_offer = self.peer_connection.localDescription
streaming_offer = StreamingOffer(
sdp=actual_offer.sdp,
video=list(self.expected_incoming_camera_types),
)
remote_answer = await self.session_provider(streaming_offer)
self._parse_incoming_streams(remote_sdp=remote_answer.sdp)
await self.peer_connection.setRemoteDescription(remote_answer)
actual_answer = self.peer_connection.remoteDescription
return actual_answer
class WebRTCAnswerStream(WebRTCBaseStream):
def __init__(self, session: aiortc.RTCSessionDescription, *args, **kwargs):
super().__init__(*args, **kwargs)
self.session = session
def _probe_video_codecs(self) -> List[str]:
codecs = []
for track in self.outgoing_video_tracks:
if hasattr(track, "codec_preference") and track.codec_preference() is not None:
codecs.append(track.codec_preference())
return codecs
def _override_incoming_video_codecs(self, remote_sdp: str, codecs: List[str]) -> str:
desc = aiortc.sdp.SessionDescription.parse(remote_sdp)
codec_mimes = [f"video/{c}" for c in codecs]
for m in desc.media:
if m.kind != "video":
continue
preferred_codecs: List[aiortc.RTCRtpCodecParameters] = [c for c in m.rtp.codecs if c.mimeType in codec_mimes]
if len(preferred_codecs) == 0:
raise ValueError(f"None of {preferred_codecs} codecs is supported in remote SDP")
m.rtp.codecs = preferred_codecs
m.fmt = [c.payloadType for c in preferred_codecs]
return str(desc)
async def start(self) -> aiortc.RTCSessionDescription:
assert self.peer_connection.remoteDescription is None, "Connection already established"
self._add_consumer_transceivers()
# since we sent already encoded frames in some cases (e.g. livestream video tracks are in H264), we need to force aiortc to actually use it
# we do that by overriding supported codec information on incoming sdp
preferred_codecs = self._probe_video_codecs()
if len(preferred_codecs) > 0:
self.session.sdp = self._override_incoming_video_codecs(self.session.sdp, preferred_codecs)
self._parse_incoming_streams(remote_sdp=self.session.sdp)
await self.peer_connection.setRemoteDescription(self.session)
self._add_producer_tracks()
answer = await self.peer_connection.createAnswer()
await self.peer_connection.setLocalDescription(answer)
actual_answer = self.peer_connection.localDescription
return actual_answer