Exposing RtpSenders and RtpReceivers from PeerConnection.

talk/app/webrtc/rtpreceiver.cc

+/*
+ * libjingle
+ * Copyright 2015 Google Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright notice,
+ *     this list of conditions and the following disclaimer in the documentation
+ *     and/or other materials provided with the distribution.
+ *  3. The name of the author may not be used to endorse or promote products
+ *     derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
+ * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "talk/app/webrtc/rtpreceiver.h"
+
+#include "talk/app/webrtc/videosourceinterface.h"
+
+namespace webrtc {
+
+AudioRtpReceiver::AudioRtpReceiver(AudioTrackInterface* track,
+                                   uint32 ssrc,
+                                   const std::string& mid,
+                                   AudioProviderInterface* provider)
+    : track_(track),
+      ssrc_(ssrc),
+      mid_(mid),
+      provider_(provider),
+      enabled_(track->enabled()) {
+  track_->RegisterObserver(this);
+  track_->GetSource()->RegisterAudioObserver(this);
+  UpdateEnabled();
+}
+
+AudioRtpReceiver::~AudioRtpReceiver() {
+  track_->GetSource()->UnregisterAudioObserver(this);
+  track_->UnregisterObserver(this);
+  if (provider_) {
+    Stop();
+  }
+}
+
+void AudioRtpReceiver::OnChanged() {
+  if (enabled_ != track_->enabled()) {
+    enabled_ = track_->enabled();
+    UpdateEnabled();
+  }
+}
+
+void AudioRtpReceiver::OnSetVolume(double volume) {
+  // When the track is disabled, the volume of the source, which is the
+  // corresponding WebRtc Voice Engine channel will be 0. So we do not allow
+  // setting the volume to the source when the track is disabled.
+  if (track_->enabled())
+    provider_->SetAudioPlayoutVolume(ssrc_, volume);
+}
+
+void AudioRtpReceiver::Stop() {
+  provider_->SetAudioPlayout(ssrc_, false, NULL);
+  provider_ = nullptr;
+}
+
+void AudioRtpReceiver::UpdateEnabled() {
+  if (!provider_) {
+    return;
+  }
+  provider_->SetAudioPlayout(ssrc_, track_->enabled(), track_->GetRenderer());
+}
+
+VideoRtpReceiver::VideoRtpReceiver(VideoTrackInterface* track,
+                                   uint32 ssrc,
+                                   const std::string& mid,
+                                   VideoProviderInterface* provider)
+    : track_(track), ssrc_(ssrc), mid_(mid), provider_(provider) {
+  provider_->SetVideoPlayout(ssrc_, true, track_->GetSource()->FrameInput());

[pthatcher1, 2015/09/17 04:25:46]

Can you put a TODO for unifying SetVideoPlayout and SetVideoSend?  It doesn't
make sense to me that we have two different methods to call.  And, why do we
assume track_->enabled() here?

[Taylor Brandstetter, 2015/09/23 00:10:45]

Calling SetVideoSend here was a copy/paste mistake (understand, I just barely
got this code compiling...)

+}
+
+VideoRtpReceiver::~VideoRtpReceiver() {
+  if (provider_) {
+    Stop();
+  }
+}
+
+void VideoRtpReceiver::Stop() {
+  // Since cricket::VideoRenderer is not reference counted
+  // we need to remove the renderer before we are deleted.
+  provider_->SetVideoPlayout(ssrc_, false, nullptr);
+  provider_ = nullptr;
+}
+
+void VideoRtpReceiver::UpdateEnabled() {
+  if (!provider_) {
+    return;
+  }
+  const cricket::VideoOptions* options = nullptr;
+  VideoSourceInterface* source = track_->GetSource();
+  if (track_->enabled() && source) {

[pthatcher1, 2015/09/17 04:25:46]

Wait... why do we track the previous track_->enabled() state for audio but not
for video?  Can you put a TODO for making it consistent between the two?

[Taylor Brandstetter, 2015/09/23 00:10:45]

See above comment.

+    options = source->options();
+  }
+  provider_->SetVideoSend(ssrc_, track_->enabled(), options);
+}
+
+}  // namespace webrtc