Adding "adapter" ORTC objects on top of ChannelManager/BaseChannel/etc.

webrtc/api/ortc/rtptransportinterface.h

+/*
+ *  Copyright 2017 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_API_ORTC_RTPTRANSPORTINTERFACE_H_
+#define WEBRTC_API_ORTC_RTPTRANSPORTINTERFACE_H_
+
+#include <string>
+
+#include "webrtc/api/ortc/packettransportinterface.h"
+#include "webrtc/api/rtcerror.h"
+#include "webrtc/base/optional.h"
+
+namespace webrtc {
+
+class RtpTransportAdapter;
+
+struct RtcpParameters {
+  // The SSRC to be used in the "SSRC of packet sender" field. If not set, one
+  // will be chosen by the implementation.
+  // TODO(deadbeef): Not implemented.
+  rtc::Optional<uint32_t> ssrc;
+
+  // The Canonical Name (CNAME) used by RTCP (e.g. in SDES messages).
+  //
+  // If empty in the construction of the RtpTransport, one will be generated by
+  // the implementation, and returned in GetRtcpParameters. Multiple
+  // RtpTransports created by the same OrtcFactory will use the same generated
+  // CNAME.
+  //
+  // If empty when passed into SetRtcpParameters, the CNAME simply won't be
+  // modified.
+  std::string cname;
+
+  // Send reduced-size RTCP?
+  bool reduced_size = false;
+
+  // Send RTCP multiplexed on the RTP transport?
+  bool mux = true;
+
+  bool operator==(const RtcpParameters& o) const {
+    return ssrc == o.ssrc && cname == o.cname &&
+           reduced_size == o.reduced_size && mux == o.mux;
+  }
+  bool operator!=(const RtcpParameters& o) const { return !(*this == o); }
+};
+
+// Base class for different types of RTP transports that can be created by an
+// OrtcFactory. Used by RtpSenders/RtpReceivers.
+//
+// This is not present in the standard ORTC API, but exists here for a few
+// reasons. Firstly, it allows different types of RTP transports to be used:
+// DTLS-SRTP (which is required for the web), but also SDES-SRTP and
+// unencrypted RTP. It also simplifies the handling of RTCP muxing, and
+// provides a better API point for it.
+//
+// Note that Edge's implementation of ORTC provides a similar API point, called
+// RTCSrtpSdesTransport:
+// https://msdn.microsoft.com/en-us/library/mt502527(v=vs.85).aspx
+class RtpTransportInterface {
+ public:
+  virtual ~RtpTransportInterface() {}
+
+  // Returns packet transport that's used to send RTP packets.
+  virtual PacketTransportInterface* GetRtpPacketTransport() const = 0;
+
+  // Returns separate packet transport that's used to send RTCP packets. If
+  // RTCP multiplexing is being used, returns null.
+  virtual PacketTransportInterface* GetRtcpPacketTransport() const = 0;
+
+  // Set/get RTCP params. Can be used to enable RTCP muxing or reduced-size
+  // RTCP if initially not enabled.
+  //
+  // Changing |mux| from "true" to "false" is not allowed, and changing the
+  // CNAME is currently unsupported.
+  virtual RTCError SetRtcpParameters(const RtcpParameters& parameters) = 0;
+  // Returns last set or constructed-with parameters. If |cname| was empty in
+  // construction, the generated CNAME will be present in the returned
+  // parameters (see above).
+  virtual RtcpParameters GetRtcpParameters() const = 0;
+
+ protected:
+  // Only for internal use. Returns a pointer to an internal interface, for use
+  // by the implementation.
+  virtual RtpTransportAdapter* GetInternal() = 0;
+
+  // Classes that can use this internal interface.
+  friend class OrtcFactory;
+  friend class OrtcRtpSenderAdapter;
+  friend class OrtcRtpReceiverAdapter;
+  friend class RtpTransportControllerAdapter;
+  friend class RtpTransportAdapter;
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_API_ORTC_RTPTRANSPORTINTERFACE_H_