Make cricket::VideoCapturer implement VideoSourceInterface

webrtc/media/base/videobroadcaster.h

+/*
+ *  Copyright (c) 2016 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_MEDIA_BASE_VIDEOBROADCASTER_H_
+#define WEBRTC_MEDIA_BASE_VIDEOBROADCASTER_H_
+
+#include <utility>
+#include <vector>
+
+#include "webrtc/base/thread_checker.h"
+#include "webrtc/media/base/videoframe.h"
+#include "webrtc/media/base/videosinkinterface.h"
+#include "webrtc/media/base/videosourceinterface.h"
+
+namespace rtc {
+
+class VideoBroadcaster : public VideoSourceInterface<cricket::VideoFrame>,
+                         public VideoSinkInterface<cricket::VideoFrame> {
+ public:
+  VideoBroadcaster();
+  void AddOrUpdateSink(VideoSinkInterface<cricket::VideoFrame>* sink,
+                       const VideoWants& hints) override;

[nisse-webrtc, 2016/02/09 14:10:54]

nit: Rename also the argument name hints -> wants.

[perkj_webrtc, 2016/02/10 10:54:36]

Done.

+  void RemoveSink(VideoSinkInterface<cricket::VideoFrame>* sink) override;
+
+  // Returns true if the next frame will be delivered to at least one sink.
+  bool frame_wanted() const;
+
+  // Returns VideoWants a source is requested to fulfill. They are aggregated
+  // by all VideoWants from all sinks.
+  VideoWants sink_wants() const;
+
+  void OnFrame(const cricket::VideoFrame& frame) override;
+
+ protected:
+  ThreadChecker thread_checker_;
+
+  VideoWants current_hints_;

[pthatcher1, 2016/02/09 17:13:41]

wants_?

[perkj_webrtc, 2016/02/10 10:54:36]

Done.

+  using SinkPair =
+      std::pair<VideoSinkInterface<cricket::VideoFrame>*, VideoWants>;

[pthatcher1, 2016/02/09 17:13:41]

If you make a simple struct, then you can use .sink and .wants instead of .first
and .second, which would be nicer to read:

struct SinkPair {
  VideoSinkInterface<cricket::VideoFrame>* sink;
  VideoSinkWants wants;
}

Then later:

auto pair = FindPair(sink);
if (pair) {
  pair.wants = wants;
} else {
  pairs_.push(VideoPair(sink, wants)));
}

[perkj_webrtc, 2016/02/10 10:54:36]

Done.

+  std::vector<SinkPair> sinks_;
+};
+
+}  // namespace rtc
+
+#endif  // WEBRTC_MEDIA_BASE_VIDEOBROADCASTER_H_