Added a level indicator to new mixer.

webrtc/modules/audio_mixer/test/audio_mixer_unittest.cc

 /*
  *  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.
  */
 
@@ skipping 59 matching lines @@
   MOCK_METHOD2(GetAudioFrameWithMuted,
                AudioFrameWithMuted(const int32_t id, int sample_rate_hz));
 
   AudioFrame* fake_frame() { return &fake_frame_; }
   AudioFrameInfo fake_info() { return fake_audio_frame_info_; }
   void set_fake_info(const AudioFrameInfo audio_frame_info) {
     fake_audio_frame_info_ = audio_frame_info;
   }
 
  private:
-  AudioFrame fake_frame_;
+  AudioFrame fake_frame_, output_frame_;
   AudioFrameInfo fake_audio_frame_info_;
   AudioFrameWithMuted FakeAudioFrameWithMuted(const int32_t id,
                                               int sample_rate_hz) {
+    output_frame_.CopyFrom(fake_frame_);
     return {
-        fake_frame(),  // audio_frame_pointer
-        fake_info(),   // audio_frame_info
+        &output_frame_,  // audio_frame_pointer
+        fake_info(),     // audio_frame_info
     };
   }
 };
 
 // Keeps two identical sets of participants and two mixers to test
 // that the same participants are chosen for mixing.
 class CompareWithOldMixerTest : public testing::Test, AudioMixerOutputReceiver {
  protected:
   constexpr static int kId = 1;
   constexpr static int kSampleRateHz = 32000;
@@ skipping 266 matching lines @@
   participant.fake_frame()->samples_per_channel_ = 8000 / 100;
 
   EXPECT_EQ(0, mixer->SetMixabilityStatus(&participant, true));
   for (size_t number_of_channels : {1, 2}) {
     EXPECT_CALL(participant, GetAudioFrameWithMuted(_, 8000)).Times(Exactly(1));
     mixer->Mix(8000, number_of_channels, &frame_for_mixing);
     EXPECT_EQ(number_of_channels, frame_for_mixing.num_channels_);
   }
 }
 
+// Test that the volume is reported as zero when the mixer input
+// comprises only zero values.
+TEST(AudioMixer, LevelIsZeroWhenMixingZeroes) {
+  const int kId = 1;
+  const int kSampleRateHz = 8000;
+  std::unique_ptr<NewAudioConferenceMixer> mixer(
+      NewAudioConferenceMixer::Create(kId));
+  AudioFrame frame_for_mixing;
+
+  MockMixerAudioSource participant;
+  participant.fake_frame()->sample_rate_hz_ = kSampleRateHz;
+  participant.fake_frame()->num_channels_ = 1;
+
+  // Frame duration 10ms.
+  participant.fake_frame()->samples_per_channel_ = kSampleRateHz / 100;
+
+  EXPECT_EQ(0, mixer->SetMixabilityStatus(&participant, true));
+  for (size_t i = 0; i < 11; i++) {
+    EXPECT_CALL(participant, GetAudioFrameWithMuted(_, kSampleRateHz))
+        .Times(Exactly(1));
+    mixer->Mix(8000, 1, &frame_for_mixing);
+  }
+
+  EXPECT_EQ(static_cast<uint32_t>(0), mixer->GetAudioOutputLevel());
+  EXPECT_EQ(static_cast<uint32_t>(0), mixer->GetAudioOutputLevelFullRange());
+}
+
+// Test that the reported volume is maximal as full when the mixer
+// input comprises frames with maximal values.
+TEST(AudioMixer, LevelIsMaximalWhenMixingMaximalValues) {
+  const int kId = 1;
+  const int kSampleRateHz = 8000;
+  std::unique_ptr<NewAudioConferenceMixer> mixer(
+      NewAudioConferenceMixer::Create(kId));
+  AudioFrame frame_for_mixing;
+
+  MockMixerAudioSource participant;
+  participant.fake_frame()->sample_rate_hz_ = kSampleRateHz;
+  participant.fake_frame()->num_channels_ = 1;
+
+  // Frame duration 10ms.
+  participant.fake_frame()->samples_per_channel_ = kSampleRateHz / 100;
+
+  // Fill participant frame data with maximal sound.
+  std::fill(participant.fake_frame()->data_,
+            participant.fake_frame()->data_ + kSampleRateHz / 100,
+            std::numeric_limits<int16_t>::max());
+
+  EXPECT_EQ(0, mixer->SetMixabilityStatus(&participant, true));
+  for (size_t i = 0; i < 11; i++) {
+    EXPECT_CALL(participant, GetAudioFrameWithMuted(_, kSampleRateHz))
+        .Times(Exactly(1));
+    mixer->Mix(8000, 1, &frame_for_mixing);
+  }
+
+  // 9 is the highest possible audio level
+  EXPECT_EQ(static_cast<uint32_t>(9), mixer->GetAudioOutputLevel());
+
+  // 0x7fff = 32767 is the highest full range audio level.
+  EXPECT_EQ(static_cast<uint32_t>(std::numeric_limits<int16_t>::max()),
+            mixer->GetAudioOutputLevelFullRange());
+}
+
 TEST_F(BothMixersTest, CompareInitialFrameAudio) {
   EXPECT_CALL(participant_, GetAudioFrameWithMuted(_, _)).Times(Exactly(1));
 
   // Make sure the participant is marked as 'non-mixed' so that it is
   // ramped in next round.
   ResetAudioSource();
 
   // Construct the expected sound for the first mixing round.
   mixing_round_frame.CopyFrom(*participant_.fake_frame());
   RampIn(mixing_round_frame);
@@ skipping 91 matching lines @@
                      MixerParticipant::AudioFrameInfo::kMuted);
     } else {
       AddParticipant(&audio_frames[i],
                      MixerParticipant::AudioFrameInfo::kNormal);
     }
     MixAndCompare();
   }
 }
 
 }  // namespace webrtc