gstreamer/subprojects/gst-examples/webrtc/sendrecv/gst/webrtc_sendrecv.py
Nirbheek Chauhan c814409ac1 webrtc_sendrecv.py: Implement all negotiation modes
Earlier, the example only supported one negotiation mode:
* Browser client is running, gstreamer starts a call and sends offer

Now these three modes are also supported:
* Browser client is running, gstreamer starts a call and sends an
  offer request
* gstreamer connects and waits for browser client to start a call and
  send an offer
* gstreamer connects and waits for browser client to start a call and
  send an offer request

The following features are still missing:
* Data channel support
* TWCC support + stats logging

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1995>
2022-03-20 22:38:14 +00:00

303 lines
12 KiB
Python
Executable file

#!/usr/bin/env python3
import random
import ssl
import websockets
import asyncio
import os
import sys
import json
import argparse
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
# Ensure that gst-python is installed
try:
from gi.overrides import Gst as _
except ImportError:
print('gstreamer-python binding overrides aren\'t available, please install them')
raise
# These properties all mirror the ones in webrtc-sendrecv.c, see there for explanations
PIPELINE_DESC = '''
webrtcbin name=sendrecv bundle-policy=max-bundle stun-server=stun://stun.l.google.com:19302
videotestsrc is-live=true pattern=ball ! videoconvert ! queue ! \
vp8enc deadline=1 keyframe-max-dist=2000 ! rtpvp8pay !
queue ! application/x-rtp,media=video,encoding-name=VP8,payload=97 ! sendrecv.
audiotestsrc is-live=true wave=red-noise ! audioconvert ! audioresample ! queue ! opusenc ! rtpopuspay !
queue ! application/x-rtp,media=audio,encoding-name=OPUS,payload=96 ! sendrecv.
'''
from websockets.version import version as wsv
def print_status(msg):
print(f'--- {msg}')
def print_error(msg):
print(f'!!! {msg}', file=sys.stderr)
class WebRTCClient:
def __init__(self, loop, our_id, peer_id, server, remote_is_offerer):
self.conn = None
self.pipe = None
self.webrtc = None
self.event_loop = loop
self.server = server
# An optional user-specified ID we can use to register
self.our_id = our_id
# The actual ID we used to register
self.id_ = None
# An optional peer ID we should connect to
self.peer_id = peer_id
# Whether we will send the offer or the remote peer will
self.remote_is_offerer = remote_is_offerer
async def send(self, msg):
assert self.conn
print(f'>>> {msg}')
await self.conn.send(msg)
async def connect(self):
self.conn = await websockets.connect(self.server)
if self.our_id is None:
self.id_ = str(random.randrange(10, 10000))
else:
self.id_ = self.our_id
await self.send(f'HELLO {self.id_}')
async def setup_call(self):
assert self.peer_id
await self.send(f'SESSION {self.peer_id}')
def send_soon(self, msg):
asyncio.run_coroutine_threadsafe(self.send(msg), self.event_loop)
def send_sdp(self, offer):
text = offer.sdp.as_text()
if offer.type == GstWebRTC.WebRTCSDPType.OFFER:
print_status('Sending offer:\n%s' % text)
msg = json.dumps({'sdp': {'type': 'offer', 'sdp': text}})
elif offer.type == GstWebRTC.WebRTCSDPType.ANSWER:
print_status('Sending answer:\n%s' % text)
msg = json.dumps({'sdp': {'type': 'answer', 'sdp': text}})
else:
raise AssertionError(offer.type)
self.send_soon(msg)
def on_offer_created(self, promise, _, __):
assert(promise.wait() == Gst.PromiseResult.REPLIED)
reply = promise.get_reply()
offer = reply['offer']
promise = Gst.Promise.new()
print_status('Offer created, setting local description')
self.webrtc.emit('set-local-description', offer, promise)
promise.interrupt() # we don't care about the result, discard it
self.send_sdp(offer)
def on_negotiation_needed(self, _, create_offer):
if create_offer:
print_status('Call was connected: creating offer')
promise = Gst.Promise.new_with_change_func(self.on_offer_created, None, None)
self.webrtc.emit('create-offer', None, promise)
elif self.remote_is_offerer:
# We are initiating the call, but we want the remote peer to create the offer
print_status('Call was connected: requesting remote peer for offer')
self.send_soon('OFFER_REQUEST')
def send_ice_candidate_message(self, _, mlineindex, candidate):
icemsg = json.dumps({'ice': {'candidate': candidate, 'sdpMLineIndex': mlineindex}})
self.send_soon(icemsg)
def on_incoming_decodebin_stream(self, _, pad):
if not pad.has_current_caps():
print_error(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_ice_gathering_state_notify(self, pspec, _):
state = self.webrtc.get_property('ice-gathering-state')
print_status(f'ICE gathering state changed to {state}')
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, create_offer=True):
print_status(f'Creating pipeline, create_offer: {create_offer}')
self.pipe = Gst.parse_launch(PIPELINE_DESC)
self.webrtc = self.pipe.get_by_name('sendrecv')
self.webrtc.connect('on-negotiation-needed', self.on_negotiation_needed, create_offer)
self.webrtc.connect('on-ice-candidate', self.send_ice_candidate_message)
self.webrtc.connect('notify::ice-gathering-state', self.on_ice_gathering_state_notify)
self.webrtc.connect('pad-added', self.on_incoming_stream)
self.pipe.set_state(Gst.State.PLAYING)
def on_answer_created(self, promise, _, __):
assert(promise.wait() == Gst.PromiseResult.REPLIED)
reply = promise.get_reply()
answer = reply['answer']
promise = Gst.Promise.new()
self.webrtc.emit('set-local-description', answer, promise)
promise.interrupt() # we don't care about the result, discard it
self.send_sdp(answer)
def on_offer_set(self, promise, _, __):
assert(promise.wait() == Gst.PromiseResult.REPLIED)
promise = Gst.Promise.new_with_change_func(self.on_answer_created, None, None)
self.webrtc.emit('create-answer', None, promise)
def handle_json(self, message):
assert (self.webrtc)
try:
msg = json.loads(message)
except json.decoder.JSONDecoderError:
print_error('Failed to parse JSON message, this might be a bug')
raise
if 'sdp' in msg:
sdp = msg['sdp']['sdp']
if msg['sdp']['type'] == 'answer':
print_status('Received answer:\n%s' % 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() # we don't care about the result, discard it
else:
print_status('Received offer:\n%s' % sdp)
res, sdpmsg = GstSdp.SDPMessage.new()
GstSdp.sdp_message_parse_buffer(bytes(sdp.encode()), sdpmsg)
offer = GstWebRTC.WebRTCSessionDescription.new(GstWebRTC.WebRTCSDPType.OFFER, sdpmsg)
promise = Gst.Promise.new_with_change_func(self.on_offer_set, None, None)
self.webrtc.emit('set-remote-description', offer, promise)
elif 'ice' in msg:
ice = msg['ice']
candidate = ice['candidate']
sdpmlineindex = ice['sdpMLineIndex']
self.webrtc.emit('add-ice-candidate', sdpmlineindex, candidate)
def close_pipeline(self):
if self.pipe:
self.pipe.set_state(Gst.State.NULL)
self.pipe = None
self.webrtc = None
def is_incoming_offer(self, msg):
if self.webrtc:
return False
if self.remote_is_offerer:
return True
return True
async def loop(self):
assert self.conn
async for message in self.conn:
print(f'<<< {message}')
if message == 'HELLO':
assert self.id_
# If a peer ID is specified, we want to connect to it. If not,
# we wait for an incoming call.
if not self.peer_id:
print_status(f'Waiting for incoming call: ID is {self.id_}')
else:
if self.remote_is_offerer:
print_status('Have peer ID: initiating call (will request remote peer to create offer)')
else:
print_status('Have peer ID: initiating call (will create offer)')
await self.setup_call()
elif message == 'SESSION_OK':
if self.remote_is_offerer:
self.start_pipeline(create_offer=False)
else:
self.start_pipeline()
elif message == 'OFFER_REQUEST':
print_status('Incoming call: we have been asked to create the offer')
self.start_pipeline()
elif message.startswith('ERROR'):
print_error(message)
self.close_pipeline()
return 1
else:
if self.is_incoming_offer(message):
print_status('Incoming call: received an offer, creating pipeline')
self.start_pipeline(create_offer=False)
self.handle_json(message)
self.close_pipeline()
return 0
async def stop(self):
if self.conn:
await self.conn.close()
self.conn = None
def check_plugins():
needed = ["opus", "vpx", "nice", "webrtc", "dtls", "srtp", "rtp",
"rtpmanager", "videotestsrc", "audiotestsrc"]
missing = list(filter(lambda p: Gst.Registry.get().find_plugin(p) is None, needed))
if len(missing):
print_error('Missing gstreamer plugins:', missing)
return False
return True
if __name__ == '__main__':
Gst.init(None)
if not check_plugins():
sys.exit(1)
parser = argparse.ArgumentParser()
parser.add_argument('--peer-id', help='String ID of the peer to connect to')
parser.add_argument('--our-id', help='String ID that the peer can use to connect to us')
parser.add_argument('--server', default='wss://webrtc.nirbheek.in:8443',
help='Signalling server to connect to, eg "wss://127.0.0.1:8443"')
parser.add_argument('--remote-offerer', default=False, action='store_true',
dest='remote_is_offerer',
help='Request that the peer generate the offer and we\'ll answer')
args = parser.parse_args()
if not args.peer_id and not args.our_id:
print('You must pass either --peer-id or --our-id')
sys.exit(1)
loop = asyncio.new_event_loop()
c = WebRTCClient(loop, args.our_id, args.peer_id, args.server, args.remote_is_offerer)
loop.run_until_complete(c.connect())
res = loop.run_until_complete(c.loop())
sys.exit(res)