Add LoudestFilter in ConferenceTransport

webrtc/voice_engine/test/auto_test/fakes/loudest_filter.h

Index: webrtc/voice_engine/test/auto_test/fakes/loudest_filter.h
diff --git a/webrtc/voice_engine/test/auto_test/fakes/loudest_filter.h b/webrtc/voice_engine/test/auto_test/fakes/loudest_filter.h
new file mode 100644
index 0000000000000000000000000000000000000000..b84936e0394910dabf4b3f3438ef8e81a4072a62
--- /dev/null
+++ b/webrtc/voice_engine/test/auto_test/fakes/loudest_filter.h
@@ -0,0 +1,54 @@
+/*
+ *  Copyright (c) 2015 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_VOICE_ENGINE_TEST_AUTO_TEST_FAKES_LOUDEST_FILTER_H_
+#define WEBRTC_VOICE_ENGINE_TEST_AUTO_TEST_FAKES_LOUDEST_FILTER_H_
+
+#include <map>
+#include "webrtc/base/timeutils.h"
+
+namespace voetest {
+
+class LoudestFilter {
+ public:
+  /* DecideForward()

[phoglund, 2015/08/10 08:43:27]

I think this method name is hard to understand. I suppose you mean "decide
whether to forward", but a filter doesn't forward things, but rather filters
stuff out. Maybe ShouldFilter() is a better name?

[minyue-webrtc, 2015/08/10 09:30:22]

Good point. May I suggest ShouldPass()?
ShouldFilter() might be a bit ambiguous for being filtered out and being passed
through. 

[hlundin-webrtc, 2015/08/10 10:50:18]

I suggest ForwardThisPacket().

[phoglund, 2015/08/10 11:34:04]

+1

[minyue-webrtc, 2015/08/12 14:53:23]

I am a bit confused. Did we say "forward" isn't an operation of filter?
Combining the ideas, I tried to make a new name. Throw eggs if you don't like
it.

+   * Decide whether to filter out a stream.

[hlundin-webrtc, 2015/08/10 10:50:18]

"Decide whether to forward a packet."
After all, this method is to be called for each packet, right?

[minyue-webrtc, 2015/08/12 14:53:23]

Acknowledged.

+   *
+   * Input:
+   *   source_ssrc : SSRC of the stream,
+   *   audio_level : audio level (smaller is louder).
+   */
+  bool DecideForward(unsigned int source_ssrc, int audio_level);
+
+ private:
+  struct Status {
+    void Set(int audio_level, uint32 last_time_ms) {
+      audio_level_ = audio_level;

[hlundin-webrtc, 2015/08/10 10:50:17]

Data members of structs don't have a trailing underscore.

http://google-styleguide.googlecode.com/svn/trunk/cppguide.html#Variable_Names

[minyue-webrtc, 2015/08/12 14:53:23]

Acknowledged.

+      last_time_ms_ = last_time_ms;
+    }
+    int audio_level_;
+    uint32 last_time_ms_;

[hlundin-webrtc, 2015/08/10 10:50:18]

int

[minyue-webrtc, 2015/08/12 14:53:23]

Done.

+  };
+
+  void RemoveTimeoutStreams(uint32 time_ms);

[hlundin-webrtc, 2015/08/10 10:50:17]

int

[minyue-webrtc, 2015/08/12 14:53:23]

Done.

+  unsigned int FindQuietestStream();
+
+  // Keeps the streams being forwarded in pair<SSRC, Status>.
+  std::map<unsigned int, Status> stream_levels_;
+
+  const int32 kStreamTimeOutMs = 5000;

[hlundin-webrtc, 2015/08/10 10:50:17]

const int

[minyue-webrtc, 2015/08/12 14:53:23]

Done.

+  const size_t kMaxMixSize = 3;
+  const int kInvalidAudioLevel = 128;
+};
+
+
+}  // namespace voetest
+
+#endif  // WEBRTC_VOICE_ENGINE_TEST_AUTO_TEST_FAKES_LOUDEST_FILTER_H_