Start to work on a laplace client.

diff --git a/laplace_client.py b/laplace_client.py
new file mode 100644 (file)
index 0000000..63fb8b8
--- /dev/null
+++ b/laplace_client.py
@@ -0,0 +1,193 @@
+import argparse
+import asyncio
+import json
+import logging
+import pathlib
+import ssl
+import sys
+
+import websockets
+
+import gi
+gi.require_version('Gst', '1.0')
+from gi.repository import Gst
+gi.require_version('GstWebRTC', '1.0')
+from gi.repository import GstWebRTC
+gi.require_version('GstSdp', '1.0')
+from gi.repository import GstSdp
+
+
+log = logging.Logger(__name__)
+
+
+class WebRTCClient:
+
+    def __init__(self, uri: str):
+        self.uri = uri
+        self.ssl_context = ssl.SSLContext()
+        self.ssl_context.check_hostname = False
+        self.ssl_context.verify_mode = ssl.CERT_NONE
+        self.websocket = None
+        self.session_id = None
+
+    def send_sdp_offer(self, offer):
+        text = offer.sdp.as_text()
+        log.info('Sending offer:\n%s' % text)
+        msg = json.dumps({
+            'SessionID': self.session_id,
+            'Type': "gotAnswer",
+            'Value': json.dumps({
+                'type': 'answer',
+                'sdp': text
+            })
+        })
+        loop = asyncio.new_event_loop()
+        loop.run_until_complete(self.websocket.send(msg))
+        loop.close()
+
+    def on_offer_created(self, promise, _, __):
+        promise.wait()
+        reply = promise.get_reply()
+        offer = reply['offer']
+        promise = Gst.Promise.new()
+        self.webrtc.emit('set-local-description', offer, promise)
+        promise.interrupt()
+        self.send_sdp_offer(offer)
+
+    def on_negotiation_needed(self, element):
+        promise = Gst.Promise.new_with_change_func(self.on_offer_created, element, None)
+        element.emit('create-offer', None, promise)
+
+    def send_ice_candidate_message(self, _, mlineindex, candidate):
+        icemsg = json.dumps({
+            'SessionID': self.session_id,
+            'Type': 'addCalleeIceCandidate',
+            'Value': json.dumps({
+                "candidate": candidate,
+                "sdpMid": "0",
+                "sdpMLineIndex": mlineindex,
+                })
+            })
+        loop = asyncio.new_event_loop()
+        loop.run_until_complete(self.websocket.send(icemsg))
+        loop.close()
+
+    def on_incoming_decodebin_stream(self, _, pad):
+        if not pad.has_current_caps():
+            log.info(pad, 'has no caps, ignoring')
+            return
+
+        caps = pad.get_current_caps()
+        assert (len(caps))
+        s = caps[0]
+        name = s.get_name()
+        if name.startswith('video'):
+            q = Gst.ElementFactory.make('queue')
+            conv = Gst.ElementFactory.make('videoconvert')
+            sink = Gst.ElementFactory.make('autovideosink')
+            self.pipe.add(q, conv, sink)
+            self.pipe.sync_children_states()
+            pad.link(q.get_static_pad('sink'))
+            q.link(conv)
+            conv.link(sink)
+        elif name.startswith('audio'):
+            q = Gst.ElementFactory.make('queue')
+            conv = Gst.ElementFactory.make('audioconvert')
+            resample = Gst.ElementFactory.make('audioresample')
+            sink = Gst.ElementFactory.make('autoaudiosink')
+            self.pipe.add(q, conv, resample, sink)
+            self.pipe.sync_children_states()
+            pad.link(q.get_static_pad('sink'))
+            q.link(conv)
+            conv.link(resample)
+            resample.link(sink)
+
+    def on_incoming_stream(self, _, pad):
+        if pad.direction != Gst.PadDirection.SRC:
+            return
+        decodebin = Gst.ElementFactory.make('decodebin')
+        decodebin.connect('pad-added', self.on_incoming_decodebin_stream)
+        self.pipe.add(decodebin)
+        decodebin.sync_state_with_parent()
+        self.webrtc.link(decodebin)
+
+    def start_pipeline(self):
+        self.webrtc = Gst.ElementFactory.make('webrtcbin', 'laplace')
+        self.webrtc.set_property("bundle-policy", 3)
+        direction = GstWebRTC.WebRTCRTPTransceiverDirection.RECVONLY
+        caps = Gst.caps_from_string("application/x-rtp,media=video,encoding-name=VP8/9000,payload=96")
+        self.webrtc.emit('add-transceiver', direction, caps)
+        self.pipe = Gst.Pipeline.new("pipeline")
+        Gst.Bin.do_add_element(self.pipe, self.webrtc)
+        self.webrtc.connect('on-negotiation-needed', self.on_negotiation_needed)
+        self.webrtc.connect('on-ice-candidate', self.send_ice_candidate_message)
+        self.webrtc.connect('pad-added', self.on_incoming_stream)
+        self.pipe.set_state(Gst.State.PLAYING)
+    
+    def close_pipeline(self):
+        self.pipe.set_state(Gst.State.NULL)
+        self.pipe = None
+        self.webrtc = None
+    
+    def handle_sdp(self, sdp):
+        res, sdpmsg = GstSdp.SDPMessage.new()
+        GstSdp.sdp_message_parse_buffer(bytes(sdp.encode()), sdpmsg)
+        answer = GstWebRTC.WebRTCSessionDescription.new(GstWebRTC.WebRTCSDPType.ANSWER, sdpmsg)
+        promise = Gst.Promise.new()
+        self.webrtc.emit('set-remote-description', answer, promise)
+        promise.interrupt()
+
+    def handle_ice(self, ice):
+        candidate = ice['candidate']
+        sdpmlineindex = ice['sdpMLineIndex']
+        self.webrtc.emit('add-ice-candidate', sdpmlineindex, candidate)
+
+    async def run(self):
+        async with websockets.connect(self.uri, ssl=self.ssl_context) as websocket:
+            self.websocket = websocket
+            self.start_pipeline()
+            async for msg in websocket:
+                msg_json = json.loads(msg)
+                msg_type = msg_json['Type']
+                msg_value = msg_json['Value']
+                session_id = msg_json['SessionID']
+                log.info(f"receive for session {session_id} type {msg_type}")
+                if msg_type == 'newSession':
+                    self.session_id = session_id
+                elif msg_type == 'gotOffer':
+                    value_json = json.loads(msg_value)
+                    sdp = value_json['sdp']
+                    self.handle_sdp(sdp)
+                elif msg_type == 'addCallerIceCandidate':
+                    value_json = json.loads(msg_value)
+                    self.handle_ice(value_json)
+        self.close_pipeline()
+        self.websocket = None
+        self.session_id = None
+
+
+def check_plugins():
+    for plugin in ["opus", "vpx", "nice", "webrtc", "dtls", "srtp", "rtp",
+                   "rtpmanager", "videotestsrc", "audiotestsrc"]:
+        if Gst.Registry.get().find_plugin(plugin) is None:
+            print('Missing gstreamer plugin:', plugin)
+            return False
+    return True
+
+
+def main():
+    logging.basicConfig(level=logging.INFO, format='%(asctime)-15s %(message)s')
+    Gst.init(None)
+    if not check_plugins():
+        sys.exit(1)
+    parser = argparse.ArgumentParser()
+    parser.add_argument('--uri', default='wss://localhost:2222/ws_connect?id=cug',
+        help='Signalling server URI')
+    args = parser.parse_args()
+    c = WebRTCClient(args.uri)
+    loop = asyncio.get_event_loop()
+    loop.run_until_complete(c.run())
+
+
+if __name__=='__main__':
+    main()