Adding audio DTX to video loopback test.

webrtc/video/video_loopback.cc

 /*
  *  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.
  */
 
@@ skipping 187 matching lines @@
 
 DEFINE_bool(use_ulpfec, false, "Use RED+ULPFEC forward error correction.");
 
 DEFINE_bool(use_flexfec, false, "Use FlexFEC forward error correction.");
 
 DEFINE_bool(audio, false, "Add audio stream");
 
 DEFINE_bool(audio_video_sync, false, "Sync audio and video stream (no effect if"
     " audio is false)");
 
+DEFINE_bool(audio_dtx, false, "Enable audio DTX (no effect if audio is false)");
+
 DEFINE_bool(video, true, "Add video stream");
 
 DEFINE_string(
     force_fieldtrials,
     "",
     "Field trials control experimental feature code which can be forced. "
     "E.g. running with --force_fieldtrials=WebRTC-FooFeature/Enable/"
     " will assign the group Enable to field trial WebRTC-FooFeature. Multiple "
     "trials are separated by \"/\"");
 
@@ skipping 33 matching lines @@
                   flags::MaxBitrateKbps() * 1000,
                   flags::FLAGS_suspend_below_min_bitrate,
                   flags::Codec(),
                   flags::NumTemporalLayers(),
                   flags::SelectedTL(),
                   0,  // No min transmit bitrate.
                   flags::FLAGS_use_ulpfec,
                   flags::FLAGS_use_flexfec,
                   flags::EncodedFramePath(),
                   flags::Clip()};
-  params.audio = {flags::FLAGS_audio, flags::FLAGS_audio_video_sync};
+  params.audio = {flags::FLAGS_audio, flags::FLAGS_audio_video_sync,
+      flags::FLAGS_audio_dtx};
   params.screenshare.enabled = false;
   params.analyzer = {"video", 0.0, 0.0, flags::DurationSecs(),
       flags::OutputFilename(), flags::GraphTitle()};
   params.pipe = pipe_config;
   params.logs = flags::FLAGS_logs;
 
   std::vector<std::string> stream_descriptors;
   stream_descriptors.push_back(flags::Stream0());
   stream_descriptors.push_back(flags::Stream1());
   std::vector<std::string> SL_descriptors;
@@ skipping 13 matching lines @@
 }  // namespace webrtc
 
 int main(int argc, char* argv[]) {
   ::testing::InitGoogleTest(&argc, argv);
   google::ParseCommandLineFlags(&argc, &argv, true);
   webrtc::test::InitFieldTrialsFromString(
       webrtc::flags::FLAGS_force_fieldtrials);
   webrtc::test::RunTest(webrtc::Loopback);
   return 0;
 }