subprojects/gst-examples/webrtc/check/validate/client.py

   1 # Copyright (c) 2020, Matthew Waters <matthew@centricular.com>
   2 #
   3 # This program is free software; you can redistribute it and/or
   4 # modify it under the terms of the GNU Lesser General Public
   5 # License as published by the Free Software Foundation; either
   6 # version 2.1 of the License, or (at your option) any later version.
   7 #
   8 # This program is distributed in the hope that it will be useful,
   9 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11 # Lesser General Public License for more details.
  12 #
  13 # You should have received a copy of the GNU Lesser General Public
  14 # License along with this program; if not, write to the
  15 # Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
  16 # Boston, MA 02110-1301, USA.
  17
  18 import threading
  19 import copy
  20
  21 from observer import Signal, WebRTCObserver, DataChannelObserver, StateObserver
  22 from enums import NegotiationState, DataChannelState
  23
  24 import gi
  25 gi.require_version("Gst", "1.0")
  26 from gi.repository import Gst
  27 gi.require_version("GstWebRTC", "1.0")
  28 from gi.repository import GstWebRTC
  29 gi.require_version("GstSdp", "1.0")
  30 from gi.repository import GstSdp
  31 gi.require_version("GstValidate", "1.0")
  32 from gi.repository import GstValidate
  33
  34
  35 class WebRTCBinObserver(WebRTCObserver):
  36     """
  37     Observe a webrtcbin element.
  38     """
  39     def __init__(self, element):
  40         WebRTCObserver.__init__(self)
  41         self.element = element
  42         self.signal_handlers = []
  43         self.signal_handlers.append(element.connect("on-negotiation-needed", self._on_negotiation_needed))
  44         self.signal_handlers.append(element.connect("on-ice-candidate", self._on_ice_candidate))
  45         self.signal_handlers.append(element.connect("pad-added", self._on_pad_added))
  46         self.signal_handlers.append(element.connect("on-new-transceiver", self._on_new_transceiver))
  47         self.signal_handlers.append(element.connect("on-data-channel", self._on_data_channel))
  48         self.negotiation_needed = 0
  49         self._negotiation_needed_observer = StateObserver(self, "negotiation_needed", threading.Condition())
  50         self.on_negotiation_needed = Signal()
  51         self.on_ice_candidate = Signal()
  52         self.on_pad_added = Signal()
  53         self.on_new_transceiver = Signal()
  54
  55     def _on_negotiation_needed(self, element):
  56         self.negotiation_needed += 1
  57         self._negotiation_needed_observer.update(self.negotiation_needed)
  58         self.on_negotiation_needed.fire()
  59
  60     def _on_ice_candidate(self, element, mline, candidate):
  61         self.on_ice_candidate.fire(mline, candidate)
  62
  63     def _on_pad_added(self, element, pad):
  64         self.on_pad_added.fire(pad)
  65
  66     def _on_description_set(self, promise, desc):
  67         new_state = self._update_negotiation_from_description_state(desc)
  68         if new_state == NegotiationState.OFFER_SET:
  69             self.on_offer_set.fire (desc)
  70         elif new_state == NegotiationState.ANSWER_SET:
  71             self.on_answer_set.fire (desc)
  72
  73     def _on_new_transceiver(self, element, transceiver):
  74         self.on_new_transceiver.fire(transceiver)
  75
  76     def _on_data_channel(self, element, channel):
  77         observer = WebRTCBinDataChannelObserver(channel, channel.props.label, 'remote')
  78         self.add_channel(observer)
  79
  80     def _update_negotiation_from_description_state(self, desc):
  81         new_state = None
  82         if desc.type == GstWebRTC.WebRTCSDPType.OFFER:
  83             new_state = NegotiationState.OFFER_SET
  84         elif desc.type == GstWebRTC.WebRTCSDPType.ANSWER:
  85             new_state = NegotiationState.ANSWER_SET
  86         assert new_state is not None
  87         self._update_negotiation_state(new_state)
  88         return new_state
  89
  90     def _deepcopy_session_description(self, desc):
  91         _, new_sdp = GstSdp.SDPMessage.new_from_text(desc.sdp.as_text())
  92         return GstWebRTC.WebRTCSessionDescription.new(desc.type, new_sdp)
  93
  94     def _on_offer_created(self, promise, element):
  95         self._update_negotiation_state(NegotiationState.OFFER_CREATED)
  96         reply = promise.get_reply()
  97         offer = reply['offer']
  98
  99         new_offer = self._deepcopy_session_description(offer)
 100         promise = Gst.Promise.new_with_change_func(self._on_description_set, new_offer)
 101
 102         new_offer = self._deepcopy_session_description(offer)
 103         self.element.emit('set-local-description', new_offer, promise)
 104         self.on_offer_created.fire(offer)
 105
 106     def _on_answer_created(self, promise, element):
 107         self._update_negotiation_state(NegotiationState.ANSWER_CREATED)
 108         reply = promise.get_reply()
 109         offer = reply['answer']
 110
 111         new_offer = self._deepcopy_session_description(offer)
 112         promise = Gst.Promise.new_with_change_func(self._on_description_set, new_offer)
 113
 114         new_offer = self._deepcopy_session_description(offer)
 115         self.element.emit('set-local-description', new_offer, promise)
 116         self.on_answer_created.fire(offer)
 117
 118     def create_offer(self, options=None):
 119         promise = Gst.Promise.new_with_change_func(self._on_offer_created, self.element)
 120         self.element.emit('create-offer', options, promise)
 121
 122     def create_answer(self, options=None):
 123         promise = Gst.Promise.new_with_change_func(self._on_answer_created, self.element)
 124         self.element.emit('create-answer', options, promise)
 125
 126     def set_remote_description(self, desc):
 127         promise = Gst.Promise.new_with_change_func(self._on_description_set, desc)
 128         self.element.emit('set-remote-description', desc, promise)
 129
 130     def add_ice_candidate(self, mline, candidate):
 131         self.element.emit('add-ice-candidate', mline, candidate)
 132
 133     def add_data_channel(self, ident):
 134         channel = self.element.emit('create-data-channel', ident, None)
 135         observer = WebRTCBinDataChannelObserver(channel, ident, 'local')
 136         self.add_channel(observer)
 137
 138     def wait_for_negotiation_needed(self, generation):
 139         self._negotiation_needed_observer.wait_for ((generation,))
 140
 141 class WebRTCStream(object):
 142     """
 143     An stream attached to a webrtcbin element
 144     """
 145     def __init__(self):
 146         self.bin = None
 147
 148     def set_description(self, desc):
 149         assert self.bin is None
 150         self.bin = Gst.parse_bin_from_description(desc, True)
 151
 152     def add_and_link(self, parent, link):
 153         assert self.bin is not None
 154         self.bin.set_locked_state(True)
 155         parent.add(self.bin)
 156         src = self.bin.get_static_pad("src")
 157         sink = self.bin.get_static_pad("sink")
 158         assert src is None or sink is None
 159         if src:
 160             self.bin.link(link)
 161         if sink:
 162             link.link(self.bin)
 163         self.bin.set_locked_state(False)
 164         self.bin.sync_state_with_parent()
 165
 166     def add_and_link_to(self, parent, link, pad):
 167         assert self.bin is not None
 168         self.bin.set_locked_state(True)
 169         parent.add(self.bin)
 170         src = self.bin.get_static_pad("src")
 171         sink = self.bin.get_static_pad("sink")
 172         assert src is None or sink is None
 173         if pad.get_direction() == Gst.PadDirection.SRC:
 174             assert sink is not None
 175             pad.link(sink)
 176         if pad.get_direction() == Gst.PadDirection.SINK:
 177             assert src is not None
 178             src.link(pad)
 179         self.bin.set_locked_state(False)
 180         self.bin.sync_state_with_parent()
 181
 182 class WebRTCClient(WebRTCBinObserver):
 183     """
 184     Client for performing webrtc operations.  Controls the pipeline that
 185     contains a webrtcbin element.
 186     """
 187     def __init__(self):
 188         self.pipeline = Gst.Pipeline(None)
 189         self.webrtcbin = Gst.ElementFactory.make("webrtcbin")
 190         super().__init__(self.webrtcbin)
 191         self.pipeline.add(self.webrtcbin)
 192         self._streams = []
 193
 194     def stop(self):
 195         self.pipeline.set_state (Gst.State.NULL)
 196
 197     def add_stream(self, desc):
 198         stream = WebRTCStream()
 199         stream.set_description(desc)
 200         stream.add_and_link (self.pipeline, self.webrtcbin)
 201         self._streams.append(stream)
 202
 203     def add_stream_with_pad(self, desc, pad):
 204         stream = WebRTCStream()
 205         stream.set_description(desc)
 206         stream.add_and_link_to (self.pipeline, self.webrtcbin, pad)
 207         self._streams.append(stream)
 208
 209     def set_options (self, opts):
 210         if opts.has_field("local-bundle-policy"):
 211             self.webrtcbin.props.bundle_policy = opts["local-bundle-policy"]
 212
 213
 214 class WebRTCBinDataChannelObserver(DataChannelObserver):
 215     """
 216     Data channel observer for a webrtcbin data channel.
 217     """
 218     def __init__(self, target, ident, location):
 219         super().__init__(ident, location)
 220         self.target = target
 221         self.signal_handlers = []
 222         self.signal_handlers.append(target.connect("on-open", self._on_open))
 223         self.signal_handlers.append(target.connect("on-close", self._on_close))
 224         self.signal_handlers.append(target.connect("on-error", self._on_error))
 225         self.signal_handlers.append(target.connect("on-message-data", self._on_message_data))
 226         self.signal_handlers.append(target.connect("on-message-string", self._on_message_string))
 227         self.signal_handlers.append(target.connect("on-buffered-amount-low", self._on_buffered_amount_low))
 228
 229     def _on_open(self, channel):
 230         self._update_state (DataChannelState.OPEN)
 231     def _on_close(self, channel):
 232         self._update_state (DataChannelState.CLOSED)
 233     def _on_error(self, channel):
 234         self._update_state (DataChannelState.ERROR)
 235     def _on_message_data(self, channel, data):
 236         self.data.append(msg)
 237     def _on_message_string(self, channel, msg):
 238         self.got_message (msg)
 239     def _on_buffered_amount_low(self, channel):
 240         pass
 241
 242     def close(self):
 243         self.target.emit('close')
 244
 245     def send_string (self, msg):
 246         self.target.emit('send-string', msg)