lagarde.py

   1 #!/usr/bin/python3
   2
   3 import argparse
   4 import asyncio
   5 import json
   6 import logging
   7 import ssl
   8 import queue
   9 from typing import Optional, List
  10
  11 import gi
  12 import websockets
  13
  14 gi.require_version('Gst', '1.0')
  15 from gi.repository import Gst
  16
  17 gi.require_version('GstWebRTC', '1.0')
  18 from gi.repository import GstWebRTC
  19
  20 gi.require_version('GstSdp', '1.0')
  21 from gi.repository import GstSdp
  22
  23 gi.require_version('GstRtspServer', '1.0')
  24 from gi.repository import Gst, GstRtspServer, GObject, GLib
  25
  26 log = logging.getLogger(__name__)
  27
  28
  29 class GstreamerRtspServer():
  30     def __init__(self):
  31         server = GstRtspServer.RTSPServer()
  32         server.set_address("::")
  33         server.set_service('8554')  # port as string
  34         factory = GstRtspServer.RTSPMediaFactory()
  35         # factory.set_launch("intervideosrc ! decodebin ! theoraenc ! queue ! rtptheorapay name=pay0")
  36         # factory.set_launch("intervideosrc ! decodebin ! videoconvert ! video/x-raw,format=I420 ! theoraenc ! queue ! rtptheorapay name=pay0")
  37         # factory.set_launch("intervideosrc ! decodebin ! videorate ! videoconvert ! video/x-raw,format=I420,framerate=10/1 ! theoraenc ! queue ! rtptheorapay name=pay0")
  38         # factory.set_launch("intervideosrc ! decodebin ! videoconvert ! video/x-raw,format=I420 ! x264enc ! queue ! rtph264pay pt=96 name=pay0")
  39         factory.set_launch("intervideosrc ! decodebin ! x264enc ! queue ! rtph264pay pt=96 name=pay0")
  40         # factory.set_launch("intervideosrc ! decodebin ! videorate ! videoconvert ! video/x-raw,framerate=10/1 ! x264enc ! queue ! rtph264pay pt=96 name=pay0")
  41         factory.set_shared(True)
  42         mountPoints = server.get_mount_points()
  43         mountPoints.add_factory("/cug", factory)
  44         server.attach()
  45         self.server = server
  46
  47
  48 class Lagarde:
  49     def __init__(self):
  50         self.sdp_offer: Optional[str] = None
  51         self.websocket: Optional[websockets.client.WebSocketClientProtocol] = None
  52         self.session_id = None
  53         self.received_ice_candidates = queue.Queue()
  54         self.generated_ice_candidates = queue.Queue()
  55         self.user_fragments: Optional[List] = None
  56         self.mids: Optional[List] = None
  57         self.pipe = None
  58         self.webrtcbin = None
  59
  60     def on_negotiation_needed(self, element):
  61         log.info('on_negotiation_needed')
  62
  63     def on_ice_candidate(self, element, mlineindex, candidate):
  64         log.info('on_ice_candidate')
  65         self.generated_ice_candidates.put_nowait((mlineindex, candidate))
  66
  67     def webrtcbin_pad_added(self, element, pad):
  68         log.info('webrtcbin_pad_added')
  69         if pad.direction != Gst.PadDirection.SRC:
  70             return
  71         decodebin = Gst.ElementFactory.make('decodebin')
  72         decodebin.connect('pad-added', self.decodebin_pad_added)
  73         self.pipe.add(decodebin)
  74         decodebin.sync_state_with_parent()
  75         self.webrtcbin.link(decodebin)
  76
  77     def decodebin_pad_added(self, element, pad):
  78         log.info('decodebin_pad_added')
  79         if not pad.has_current_caps():
  80             log.info(pad, 'has no caps, ignoring')
  81             return
  82
  83         caps = pad.get_current_caps()
  84         padsize = caps.get_size()
  85         for i in range(padsize):
  86             s = caps.get_structure(i)  # Gst.Structure
  87             name = s.get_name()
  88             if name.startswith('video'):
  89                 q = Gst.ElementFactory.make('queue')
  90                 conv = Gst.ElementFactory.make('videoconvert')
  91                 sink = Gst.ElementFactory.make('intervideosink')
  92                 self.pipe.add(q)
  93                 self.pipe.add(conv)
  94                 self.pipe.add(sink)
  95                 self.pipe.sync_children_states()
  96                 pad.link(q.get_static_pad('sink'))
  97                 q.link(conv)
  98                 conv.link(sink)
  99                 self.pipe.set_state(Gst.State.PLAYING)
 100
 101     async def listen_to_gstreamer_bus(self):
 102         self.webrtcbin = Gst.ElementFactory.make('webrtcbin', 'laplace')
 103         self.pipe = Gst.Pipeline.new("pipeline")
 104         Gst.Bin.do_add_element(self.pipe, self.webrtcbin)
 105         bus = Gst.Pipeline.get_bus(self.pipe)
 106         self.webrtcbin.connect('on-negotiation-needed', self.on_negotiation_needed)
 107         self.webrtcbin.connect('on-ice-candidate', self.on_ice_candidate)
 108         self.webrtcbin.connect('pad-added', self.webrtcbin_pad_added)
 109         self.pipe.set_state(Gst.State.PLAYING)
 110         try:
 111             while True:
 112                 if bus.have_pending():
 113                     msg = bus.pop()
 114                     if msg.type == Gst.MessageType.ERROR:
 115                         log.error(f'Error from gstreamer message bus: {msg.get_structure()}')
 116                         return
 117                     elif msg.type == Gst.MessageType.EOS:  # end of stream
 118                         log.info(f'Gstreamer message bus reports end of stream')
 119                         return
 120                 elif self.sdp_offer is not None:
 121                     res, sm = GstSdp.SDPMessage.new()
 122                     assert res == GstSdp.SDPResult.OK
 123                     GstSdp.sdp_message_parse_buffer(bytes(self.sdp_offer.encode()), sm)
 124                     # the three lines above can also be done this way in new versions of GStreamer:
 125                     # sm = GstSdp.SDPMessage.new_from_text(sdp_offer)
 126                     rd = GstWebRTC.WebRTCSessionDescription.new(GstWebRTC.WebRTCSDPType.OFFER, sm)
 127                     gst_promise = Gst.Promise.new()
 128                     self.webrtcbin.emit('set-remote-description', rd, gst_promise)
 129                     await asyncio.get_event_loop().run_in_executor(None, gst_promise.wait)
 130                     self.sdp_offer = None
 131
 132                     gst_promise = Gst.Promise.new()
 133                     self.webrtcbin.emit('create-answer', None, gst_promise)
 134                     result = await asyncio.get_event_loop().run_in_executor(None, gst_promise.wait)
 135                     assert result == Gst.PromiseResult.REPLIED
 136                     reply = gst_promise.get_reply()
 137                     answer = reply.get_value('answer')
 138                     sdp_message = answer.sdp
 139                     self.user_fragments = [sdp_message.get_media(i).get_attribute_val('ice-ufrag')
 140                                           for i in range(sdp_message.medias_len())]
 141                     self.mids = [sdp_message.get_media(i).get_attribute_val('mid')
 142                                           for i in range(sdp_message.medias_len())]
 143                     sdp_answer = sdp_message.as_text()
 144                     log.info(f'Send SDP answer')
 145                     log.debug(f'SDP answer:\n{sdp_answer}')
 146                     sdp_answer_msg = json.dumps({
 147                         'SessionID': self.session_id,
 148                         'Type': "gotAnswer",
 149                         'Value': json.dumps({
 150                             'type': 'answer',
 151                             'sdp': sdp_answer
 152                         })
 153                     })
 154                     gst_promise = Gst.Promise.new()
 155                     self.webrtcbin.emit('set-local-description', answer, gst_promise)
 156                     await asyncio.get_event_loop().run_in_executor(None, gst_promise.wait)
 157                     gst_promise.get_reply()
 158                     await self.websocket.send(sdp_answer_msg)
 159
 160                 elif self.received_ice_candidates.qsize() > 0:
 161                     ic = self.received_ice_candidates.get_nowait()
 162                     if ic['candidate'] != '':
 163                         self.webrtcbin.emit('add-ice-candidate', ic['sdpMLineIndex'], ic['candidate'])
 164
 165                 elif self.generated_ice_candidates.qsize() > 0:
 166                     mlineindex, candidate = self.generated_ice_candidates.get_nowait()
 167                     icemsg_value = json.dumps({
 168                         "candidate": candidate,
 169                         "sdpMid": self.mids[mlineindex],
 170                         "sdpMLineIndex": mlineindex,
 171                         "usernameFragment": self.user_fragments[mlineindex],
 172                     })
 173                     icemsg = json.dumps({
 174                         'SessionID': self.session_id,
 175                         'Type': 'addCalleeIceCandidate',
 176                         'Value': icemsg_value,
 177                     })
 178                     log.info(f'Send ICE candidate')
 179                     log.debug(f'ICE candidate: {icemsg_value}')
 180                     await self.websocket.send(icemsg)
 181
 182                 else:
 183                     await asyncio.sleep(0.1)
 184         finally:
 185             self.pipe.set_state(Gst.State.NULL)
 186
 187     async def talk_to_websocket(self, uri, ssl_context):
 188         async with websockets.connect(uri, ssl=ssl_context, close_timeout=0.5) as self.websocket:
 189             async for msg in self.websocket:
 190                 msg_json = json.loads(msg)
 191                 msg_type = msg_json['Type']
 192                 msg_value = msg_json['Value']
 193                 assert self.session_id is None or self.session_id == msg_json['SessionID']
 194                 if msg_type == 'newSession':
 195                     self.session_id = msg_json['SessionID']
 196                     log.info(f"New session {self.session_id}")
 197                 elif msg_type == 'gotOffer':
 198                     value_json = json.loads(msg_value)
 199                     sdp = value_json['sdp']
 200                     log.info(f'Got SDP offer')
 201                     log.debug(f'SDP offer:\n{sdp}')
 202                     self.sdp_offer = sdp
 203                 elif msg_type == 'addCallerIceCandidate':
 204                     value_json = json.loads(msg_value)
 205                     log.info(f'Got ICE candidate')
 206                     log.debug(f'ICE candidate: {value_json}')
 207                     self.received_ice_candidates.put_nowait(value_json)
 208                 elif msg_type == 'roomNotFound':
 209                     log.error(f'The room was not found: {uri}')
 210                     return
 211                 elif msg_type == 'roomClosed':
 212                     log.info(f'Oh noes, the room went away (session {self.session_id})!')
 213                     self.session_id = None
 214                     return
 215                 else:
 216                     log.error(f'Unknown message type {msg_type}')
 217
 218     async def talk_to_signaling_server(self, uri):
 219         ssl_context = ssl.SSLContext()
 220         ssl_context.check_hostname = False
 221         ssl_context.verify_mode = ssl.CERT_NONE
 222         while True:
 223             await self.talk_to_websocket(uri, ssl_context)
 224             await asyncio.sleep(0.1)
 225
 226     async def run(self, uri):
 227         try:
 228             talk_to_signaling_server_task = asyncio.Task(self.talk_to_signaling_server(uri))
 229             listen_to_gstreamer_bus_task = asyncio.Task(self.listen_to_gstreamer_bus())
 230             main_loop = asyncio.Task(gstreamer_main_loop())
 231             done, pending = await asyncio.wait(
 232                 [talk_to_signaling_server_task, listen_to_gstreamer_bus_task, main_loop],
 233                 return_when=asyncio.FIRST_COMPLETED)
 234             for d in done:
 235                 d.result()
 236             for p in pending:
 237                 p.cancel()
 238         except OSError as e:
 239             print(e)
 240
 241
 242 async def gstreamer_main_loop():
 243     """Does the equivalent of the following lines in an async friendly way:
 244         loop = GLib.MainLoop()
 245         loop.run()
 246     """
 247     gst_loop = GLib.MainLoop()
 248     context = gst_loop.get_context()
 249     while True:
 250         events_dispatched = context.iteration(False)
 251         await asyncio.sleep(0. if events_dispatched else 0.01)
 252
 253
 254 def main():
 255     logging.basicConfig(level=logging.INFO, format='%(asctime)-15s %(message)s')
 256     parser = argparse.ArgumentParser()
 257     parser.add_argument('--uri', default='wss://localhost:1234/ws_connect?id=cug',
 258                         help='Signalling server URI')
 259     args = parser.parse_args()
 260
 261     Gst.init(None)
 262     rtsp = GstreamerRtspServer()
 263     lagarde = Lagarde()
 264     asyncio.run(lagarde.run(args.uri), debug=True)
 265
 266
 267 if __name__ == '__main__':
 268     main()