# Copyright (c) 2020, Matthew Waters # # This program is free software; you can redistribute it and/or # modify it under the terms of the GNU Lesser General Public # License as published by the Free Software Foundation; either # version 2.1 of the License, or (at your option) any later version. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU # Lesser General Public License for more details. # # You should have received a copy of the GNU Lesser General Public # License along with this program; if not, write to the # Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, # Boston, MA 02110-1301, USA. import threading import copy from observer import Signal, WebRTCObserver, DataChannelObserver, StateObserver from enums import NegotiationState, DataChannelState 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 gi.require_version("GstValidate", "1.0") from gi.repository import GstValidate class WebRTCBinObserver(WebRTCObserver): """ Observe a webrtcbin element. """ def __init__(self, element): WebRTCObserver.__init__(self) self.element = element self.signal_handlers = [] self.signal_handlers.append(element.connect("on-negotiation-needed", self._on_negotiation_needed)) self.signal_handlers.append(element.connect("on-ice-candidate", self._on_ice_candidate)) self.signal_handlers.append(element.connect("pad-added", self._on_pad_added)) self.signal_handlers.append(element.connect("on-new-transceiver", self._on_new_transceiver)) self.signal_handlers.append(element.connect("on-data-channel", self._on_data_channel)) self.negotiation_needed = 0 self._negotiation_needed_observer = StateObserver(self, "negotiation_needed", threading.Condition()) self.on_negotiation_needed = Signal() self.on_ice_candidate = Signal() self.on_pad_added = Signal() self.on_new_transceiver = Signal() def _on_negotiation_needed(self, element): self.negotiation_needed += 1 self._negotiation_needed_observer.update(self.negotiation_needed) self.on_negotiation_needed.fire() def _on_ice_candidate(self, element, mline, candidate): self.on_ice_candidate.fire(mline, candidate) def _on_pad_added(self, element, pad): self.on_pad_added.fire(pad) def _on_description_set(self, promise, desc): new_state = self._update_negotiation_from_description_state(desc) if new_state == NegotiationState.OFFER_SET: self.on_offer_set.fire (desc) elif new_state == NegotiationState.ANSWER_SET: self.on_answer_set.fire (desc) def _on_new_transceiver(self, element, transceiver): self.on_new_transceiver.fire(transceiver) def _on_data_channel(self, element, channel): observer = WebRTCBinDataChannelObserver(channel, channel.props.label, 'remote') self.add_channel(observer) def _update_negotiation_from_description_state(self, desc): new_state = None if desc.type == GstWebRTC.WebRTCSDPType.OFFER: new_state = NegotiationState.OFFER_SET elif desc.type == GstWebRTC.WebRTCSDPType.ANSWER: new_state = NegotiationState.ANSWER_SET assert new_state is not None self._update_negotiation_state(new_state) return new_state def _deepcopy_session_description(self, desc): _, new_sdp = GstSdp.SDPMessage.new_from_text(desc.sdp.as_text()) return GstWebRTC.WebRTCSessionDescription.new(desc.type, new_sdp) def _on_offer_created(self, promise, element): self._update_negotiation_state(NegotiationState.OFFER_CREATED) reply = promise.get_reply() offer = reply['offer'] new_offer = self._deepcopy_session_description(offer) promise = Gst.Promise.new_with_change_func(self._on_description_set, new_offer) new_offer = self._deepcopy_session_description(offer) self.element.emit('set-local-description', new_offer, promise) self.on_offer_created.fire(offer) def _on_answer_created(self, promise, element): self._update_negotiation_state(NegotiationState.ANSWER_CREATED) reply = promise.get_reply() offer = reply['answer'] new_offer = self._deepcopy_session_description(offer) promise = Gst.Promise.new_with_change_func(self._on_description_set, new_offer) new_offer = self._deepcopy_session_description(offer) self.element.emit('set-local-description', new_offer, promise) self.on_answer_created.fire(offer) def create_offer(self, options=None): promise = Gst.Promise.new_with_change_func(self._on_offer_created, self.element) self.element.emit('create-offer', options, promise) def create_answer(self, options=None): promise = Gst.Promise.new_with_change_func(self._on_answer_created, self.element) self.element.emit('create-answer', options, promise) def set_remote_description(self, desc): promise = Gst.Promise.new_with_change_func(self._on_description_set, desc) self.element.emit('set-remote-description', desc, promise) def add_ice_candidate(self, mline, candidate): self.element.emit('add-ice-candidate', mline, candidate) def add_data_channel(self, ident): channel = self.element.emit('create-data-channel', ident, None) observer = WebRTCBinDataChannelObserver(channel, ident, 'local') self.add_channel(observer) def wait_for_negotiation_needed(self, generation): self._negotiation_needed_observer.wait_for ((generation,)) class WebRTCStream(object): """ An stream attached to a webrtcbin element """ def __init__(self): self.bin = None def set_description(self, desc): assert self.bin is None self.bin = Gst.parse_bin_from_description(desc, True) def add_and_link(self, parent, link): assert self.bin is not None self.bin.set_locked_state(True) parent.add(self.bin) src = self.bin.get_static_pad("src") sink = self.bin.get_static_pad("sink") assert src is None or sink is None if src: self.bin.link(link) if sink: link.link(self.bin) self.bin.set_locked_state(False) self.bin.sync_state_with_parent() def add_and_link_to(self, parent, link, pad): assert self.bin is not None self.bin.set_locked_state(True) parent.add(self.bin) src = self.bin.get_static_pad("src") sink = self.bin.get_static_pad("sink") assert src is None or sink is None if pad.get_direction() == Gst.PadDirection.SRC: assert sink is not None pad.link(sink) if pad.get_direction() == Gst.PadDirection.SINK: assert src is not None src.link(pad) self.bin.set_locked_state(False) self.bin.sync_state_with_parent() class WebRTCClient(WebRTCBinObserver): """ Client for performing webrtc operations. Controls the pipeline that contains a webrtcbin element. """ def __init__(self): self.pipeline = Gst.Pipeline(None) self.webrtcbin = Gst.ElementFactory.make("webrtcbin") super().__init__(self.webrtcbin) self.pipeline.add(self.webrtcbin) self._streams = [] def stop(self): self.pipeline.set_state (Gst.State.NULL) def add_stream(self, desc): stream = WebRTCStream() stream.set_description(desc) stream.add_and_link (self.pipeline, self.webrtcbin) self._streams.append(stream) def add_stream_with_pad(self, desc, pad): stream = WebRTCStream() stream.set_description(desc) stream.add_and_link_to (self.pipeline, self.webrtcbin, pad) self._streams.append(stream) def set_options (self, opts): if opts.has_field("local-bundle-policy"): self.webrtcbin.props.bundle_policy = opts["local-bundle-policy"] class WebRTCBinDataChannelObserver(DataChannelObserver): """ Data channel observer for a webrtcbin data channel. """ def __init__(self, target, ident, location): super().__init__(ident, location) self.target = target self.signal_handlers = [] self.signal_handlers.append(target.connect("on-open", self._on_open)) self.signal_handlers.append(target.connect("on-close", self._on_close)) self.signal_handlers.append(target.connect("on-error", self._on_error)) self.signal_handlers.append(target.connect("on-message-data", self._on_message_data)) self.signal_handlers.append(target.connect("on-message-string", self._on_message_string)) self.signal_handlers.append(target.connect("on-buffered-amount-low", self._on_buffered_amount_low)) def _on_open(self, channel): self._update_state (DataChannelState.OPEN) def _on_close(self, channel): self._update_state (DataChannelState.CLOSED) def _on_error(self, channel): self._update_state (DataChannelState.ERROR) def _on_message_data(self, channel, data): self.data.append(msg) def _on_message_string(self, channel, msg): self.got_message (msg) def _on_buffered_amount_low(self, channel): pass def close(self): self.target.emit('close') def send_string (self, msg): self.target.emit('send-string', msg)