update handling of caps in decodebin_pad_added()
[toast/stream2beamer.git] / lagarde.py
1 #!/usr/bin/python3
2
3 import argparse
4 import asyncio
5 import datetime
6 import json
7 import logging
8 import pathlib
9 import ssl
10 import sys
11 from typing import Optional, List
12
13 import websockets
14
15 import gi
16
17 gi.require_version('Gst', '1.0')
18 from gi.repository import Gst
19
20 gi.require_version('GstWebRTC', '1.0')
21 from gi.repository import GstWebRTC
22
23 gi.require_version('GstSdp', '1.0')
24 from gi.repository import GstSdp
25
26 log = logging.getLogger(__name__)
27
28
29 class Lagarde:
30     def __init__(self):
31         self.sdp_offer: Optional[str] = None
32         self.websocket: Optional[websockets.client.WebSocketClientProtocol] = None
33         self.session_id = None
34         self.received_ice_candidates = []
35         self.generated_ice_candidates = []
36         self.user_fragments: Optional[List] = None
37         self.mids: Optional[List] = None
38         self.pipe = None
39         self.webrtcbin = None
40
41     def on_negotiation_needed(self, element):
42         log.info('on_negotiation_needed')
43
44     def on_ice_candidate(self, element, mlineindex, candidate):
45         log.info('on_ice_candidate')
46         self.generated_ice_candidates.append((mlineindex, candidate))
47
48     def webrtcbin_pad_added(self, element, pad):
49         log.info('webrtcbin_pad_added')
50         if pad.direction != Gst.PadDirection.SRC:
51             return
52         decodebin = Gst.ElementFactory.make('decodebin')
53         decodebin.connect('pad-added', self.decodebin_pad_added)
54         self.pipe.add(decodebin)
55         decodebin.sync_state_with_parent()
56         self.webrtcbin.link(decodebin)
57
58     def decodebin_pad_added(self, element, pad):
59         log.info('decodebin_pad_added')
60         if not pad.has_current_caps():
61             log.info(pad, 'has no caps, ignoring')
62             return
63
64         caps = pad.get_current_caps()
65         # assert (len(caps)) # we have a Gst.Caps object and it has no length
66         # s = caps[0] # also, it's not a list
67         padsize = caps.get_size()
68         assert(padsize > 0)
69         for i in range(padsize): # pythonic?!
70             s = caps.get_structure(i) # Gst.Structure
71             name = s.get_name()
72             if name.startswith('video'):
73                 q = Gst.ElementFactory.make('queue')
74                 conv = Gst.ElementFactory.make('videoconvert')
75                 sink = Gst.ElementFactory.make('autovideosink')
76                 self.pipe.add(q, conv, sink)
77                 self.pipe.sync_children_states()
78                 pad.link(q.get_static_pad('sink'))
79                 q.link(conv)
80                 conv.link(sink)
81             elif name.startswith('audio'):
82                 q = Gst.ElementFactory.make('queue')
83                 conv = Gst.ElementFactory.make('audioconvert')
84                 resample = Gst.ElementFactory.make('audioresample')
85                 sink = Gst.ElementFactory.make('autoaudiosink')
86                 self.pipe.add(q, conv, resample, sink)
87                 self.pipe.sync_children_states()
88                 pad.link(q.get_static_pad('sink'))
89                 q.link(conv)
90                 conv.link(resample)
91                 resample.link(sink)
92
93     async def listen_to_gstreamer_bus(self):
94         Gst.init(None)
95         self.webrtcbin = Gst.ElementFactory.make('webrtcbin', 'laplace')
96         self.pipe = Gst.Pipeline.new("pipeline")
97         Gst.Bin.do_add_element(self.pipe, self.webrtcbin)
98         bus = Gst.Pipeline.get_bus(self.pipe)
99         self.webrtcbin.connect('on-negotiation-needed', self.on_negotiation_needed)
100         self.webrtcbin.connect('on-ice-candidate', self.on_ice_candidate)
101         self.webrtcbin.connect('pad-added', self.webrtcbin_pad_added)
102         self.pipe.set_state(Gst.State.PLAYING)
103         try:
104             while True:
105                 if bus.have_pending():
106                     msg = bus.pop()  # Gst.Message, has to be unref'ed.
107                     if msg.type != Gst.MessageType.STATE_CHANGED:
108                         # log.info(f'Receive Gst.Message: {msg.type}, {msg.seqnum}, {msg.get_structure()}')
109                         # log.info(f'{webrtcbin.props.signaling_state} {webrtcbin.props.ice_gathering_state} {webrtcbin.props.ice_connection_state}')
110                         # Gst.Message.unref(msg)
111                         pass
112                 elif self.sdp_offer is not None:
113                     res, sm = GstSdp.SDPMessage.new()
114                     assert res == GstSdp.SDPResult.OK
115                     GstSdp.sdp_message_parse_buffer(bytes(self.sdp_offer.encode()), sm)
116                     # the three lines above can also be done this way in new versions of GStreamer:
117                     # sm = GstSdp.SDPMessage.new_from_text(sdp_offer)
118                     rd = GstWebRTC.WebRTCSessionDescription.new(GstWebRTC.WebRTCSDPType.OFFER, sm)
119                     gst_promise = Gst.Promise.new()
120                     self.webrtcbin.emit('set-remote-description', rd, gst_promise)
121                     gst_promise.wait()
122                     self.sdp_offer = None
123
124                     log.info('create-answer')
125                     gst_promise = Gst.Promise.new()
126                     self.webrtcbin.emit('create-answer', None, gst_promise)
127                     result = gst_promise.wait()
128                     assert result == Gst.PromiseResult.REPLIED
129                     reply = gst_promise.get_reply()
130                     answer = reply.get_value('answer')
131                     sdp_message = answer.sdp
132                     self.user_fragments = [sdp_message.get_media(i).get_attribute_val('ice-ufrag')
133                                           for i in range(sdp_message.medias_len())]
134                     self.mids = [sdp_message.get_media(i).get_attribute_val('mid')
135                                           for i in range(sdp_message.medias_len())]
136                     sdp_answer = sdp_message.as_text()
137                     log.info(sdp_answer)
138                     sdp_answer_msg = json.dumps({
139                         'SessionID': self.session_id,
140                         'Type': "gotAnswer",
141                         'Value': json.dumps({
142                             'type': 'answer',
143                             'sdp': sdp_answer
144                         })
145                     })
146                     gst_promise = Gst.Promise.new()
147                     self.webrtcbin.emit('set-local-description', answer, gst_promise)
148                     gst_promise.wait()
149                     gst_promise.get_reply()
150                     await self.websocket.send(sdp_answer_msg)
151
152                 elif len(self.received_ice_candidates) > 0:
153                     ic = self.received_ice_candidates.pop(0)
154                     if ic['candidate'] != '':
155                         self.webrtcbin.emit('add-ice-candidate', ic['sdpMLineIndex'], ic['candidate'])
156
157                 elif len(self.generated_ice_candidates) > 0:
158                     mlineindex, candidate = self.generated_ice_candidates.pop(0)
159                     icemsg = json.dumps({
160                         'SessionID': self.session_id,
161                         'Type': 'addCalleeIceCandidate',
162                         'Value': json.dumps({
163                             "candidate": candidate,
164                             "sdpMid": self.mids[mlineindex],
165                             "sdpMLineIndex": mlineindex,
166                             "usernameFragment": self.user_fragments[mlineindex],
167                         })
168                     })
169                     log.info(f'send_ice_candidate_message with {icemsg}')
170                     await self.websocket.send(icemsg)
171
172                 else:
173                     await asyncio.sleep(0.1)
174         finally:
175             self.pipe.set_state(Gst.State.NULL)
176
177     async def talk_to_websocket(self, uri):
178         ssl_context = ssl.SSLContext()
179         ssl_context.check_hostname = False
180         ssl_context.verify_mode = ssl.CERT_NONE
181         async with websockets.connect(uri, ssl=ssl_context) as self.websocket:
182             async for msg in self.websocket:
183                 msg_json = json.loads(msg)
184                 msg_type = msg_json['Type']
185                 msg_value = msg_json['Value']
186                 self.session_id = msg_json['SessionID']
187                 log.info(f"receive for session {self.session_id} type {msg_type}")
188                 if msg_type == 'newSession':
189                     pass
190                 elif msg_type == 'gotOffer':
191                     value_json = json.loads(msg_value)
192                     sdp = value_json['sdp']
193                     log.info(f'SDP: {sdp}')
194                     self.sdp_offer = sdp
195                 elif msg_type == 'addCallerIceCandidate':
196                     value_json = json.loads(msg_value)
197                     log.info(f'ICE: {value_json}')
198                     self.received_ice_candidates.append(value_json)
199                 elif msg_type == 'roomClosed':
200                     log.info('Oh noes, the room went away!')
201                     # and here we should clean up
202                 else:
203                     log.error(f'Unknown message type {msg_type}')
204
205     async def run(self, uri):
206         talk_to_websocket_task = asyncio.Task(self.talk_to_websocket(uri))
207         listen_to_gstreamer_bus_task = asyncio.Task(self.listen_to_gstreamer_bus())
208         done, pending = await asyncio.wait(
209             [talk_to_websocket_task, listen_to_gstreamer_bus_task],
210             return_when=asyncio.FIRST_COMPLETED)
211         for d in done:
212             d.result()
213         for p in pending:
214             p.cancel()
215
216
217 def main():
218     logging.basicConfig(level=logging.INFO, format='%(asctime)-15s %(message)s')
219     parser = argparse.ArgumentParser()
220     parser.add_argument('--uri', default='wss://localhost:1234/ws_connect?id=cug',
221                         help='Signalling server URI')
222     args = parser.parse_args()
223     lagarde = Lagarde()
224     asyncio.run(lagarde.run(args.uri), debug=True)
225
226
227 if __name__ == '__main__':
228     main()