Second layer of mixing for audio elements.

media/base/audio_renderer_mixer_unittest.cc

Index: media/base/audio_renderer_mixer_unittest.cc
diff --git a/media/base/audio_renderer_mixer_unittest.cc b/media/base/audio_renderer_mixer_unittest.cc
index b218fa0410070d9d2c765f49bff06453eaa48f1f..8d2b5d43a80309f44e24b75ac5a3493ee96c3ea5 100644
--- a/media/base/audio_renderer_mixer_unittest.cc
+++ b/media/base/audio_renderer_mixer_unittest.cc
@@ -23,6 +23,7 @@ namespace media {
 
 // Parameters which control the many input case tests.
 const int kMixerInputs = 8;
+const int kOddMixerInputs = 7;
 const int kMixerCycles = 3;
 
 // Parameters used for testing.
@@ -34,22 +35,37 @@ const int kLowLatencyBufferSize = 256;
 // Number of full sine wave cycles for each Render() call.
 const int kSineCycles = 4;
 
-// Default device ID
+// Default device ID.
 const std::string kDefaultDeviceId;
 const url::Origin kDefaultSecurityOrigin;
 
-// Tuple of <input sampling rate, output sampling rate, epsilon>.
-typedef std::tr1::tuple<int, int, double> AudioRendererMixerTestData;
+// Input sample frequencies for testing.
+std::vector<int> kTestInputLower(1, 44100);
+std::vector<int> kTestInputHigher(1, 48000);
+const int kSampleRates[] = {22050, 44100, 48000};
+std::vector<int> kTestInput3Rates(kSampleRates,
+                                  kSampleRates +
+                                      sizeof(kSampleRates) /
+                                          sizeof(kSampleRates[0]));
+
+// Tuple of <input sampling rates, output sampling rate, epsilon>.
+typedef std::tr1::tuple<std::vector<int>, int, double>
+    AudioRendererMixerTestData;
+
 class AudioRendererMixerTest
     : public testing::TestWithParam<AudioRendererMixerTestData> {
  public:
   AudioRendererMixerTest()
       : epsilon_(std::tr1::get<2>(GetParam())),
         half_fill_(false) {
-    // Create input and output parameters based on test parameters.
-    input_parameters_ = AudioParameters(
-        AudioParameters::AUDIO_PCM_LINEAR, kChannelLayout,
-        std::tr1::get<0>(GetParam()), kBitsPerChannel, kHighLatencyBufferSize);
+    // Create input parameters based on test parameters.
+    const std::vector<int>& sample_rates(std::tr1::get<0>(GetParam()));
+    for (size_t i = 0; i < sample_rates.size(); ++i)
+      input_parameters_.push_back(AudioParameters(
+          AudioParameters::AUDIO_PCM_LINEAR, kChannelLayout, sample_rates[i],
+          kBitsPerChannel, kHighLatencyBufferSize));
+
+    // Create output parameters based on test parameters.
     output_parameters_ = AudioParameters(
         AudioParameters::AUDIO_PCM_LOW_LATENCY, kChannelLayout,
         std::tr1::get<1>(GetParam()), 16, kLowLatencyBufferSize);
@@ -58,8 +74,7 @@ class AudioRendererMixerTest
     EXPECT_CALL(*sink_.get(), Start());
     EXPECT_CALL(*sink_.get(), Stop());
 
-    mixer_.reset(new AudioRendererMixer(
-        input_parameters_, output_parameters_, sink_));
+    mixer_.reset(new AudioRendererMixer(output_parameters_, sink_));
     mixer_callback_ = sink_->callback();
 
     audio_bus_ = AudioBus::Create(output_parameters_);
@@ -83,28 +98,35 @@ class AudioRendererMixerTest
                     const std::string&,
                     const url::Origin&));
 
-  void InitializeInputs(int count) {
-    mixer_inputs_.reserve(count);
-    fake_callbacks_.reserve(count);
-
-    // Setup FakeAudioRenderCallback step to compensate for resampling.
-    double scale_factor = input_parameters_.sample_rate() /
-        static_cast<double>(output_parameters_.sample_rate());
-    double step = kSineCycles / (scale_factor *
-        static_cast<double>(output_parameters_.frames_per_buffer()));
-
-    for (int i = 0; i < count; ++i) {
-      fake_callbacks_.push_back(new FakeAudioRenderCallback(step));
-      mixer_inputs_.push_back(new AudioRendererMixerInput(
-          base::Bind(&AudioRendererMixerTest::GetMixer, base::Unretained(this)),
-          base::Bind(&AudioRendererMixerTest::RemoveMixer,
-                     base::Unretained(this)),
-          kDefaultDeviceId, kDefaultSecurityOrigin));
-      mixer_inputs_[i]->Initialize(input_parameters_, fake_callbacks_[i]);
-      mixer_inputs_[i]->SetVolume(1.0f);
+  void InitializeInputs(int inputs_per_sample_rate) {
+    mixer_inputs_.reserve(inputs_per_sample_rate * input_parameters_.size());
+    fake_callbacks_.reserve(inputs_per_sample_rate * input_parameters_.size());
+
+    for (size_t i = 0, input = 0; i < input_parameters_.size(); ++i) {
+      // Setup FakeAudioRenderCallback step to compensate for resampling.
+      double scale_factor =
+          input_parameters_[i].sample_rate() /
+          static_cast<double>(output_parameters_.sample_rate());
+      double step =
+          kSineCycles /
+          (scale_factor *
+           static_cast<double>(output_parameters_.frames_per_buffer()));
+
+      for (int j = 0; j < inputs_per_sample_rate; ++j, ++input) {
+        fake_callbacks_.push_back(new FakeAudioRenderCallback(step));
+        mixer_inputs_.push_back(new AudioRendererMixerInput(
+            base::Bind(&AudioRendererMixerTest::GetMixer,
+                       base::Unretained(this)),
+            base::Bind(&AudioRendererMixerTest::RemoveMixer,
+                       base::Unretained(this)),
+            kDefaultDeviceId, kDefaultSecurityOrigin));
+        mixer_inputs_[input]->Initialize(input_parameters_[i],
+                                         fake_callbacks_[input]);
+        mixer_inputs_[input]->SetVolume(1.0f);
+      }
     }
     EXPECT_CALL(*this, RemoveMixer(testing::_, testing::_, testing::_))
-        .Times(count);
+        .Times(mixer_inputs_.size());
   }
 
   bool ValidateAudioData(int index, int frames, float scale, double epsilon) {
@@ -112,9 +134,11 @@ class AudioRendererMixerTest
       for (int j = index; j < frames; j++) {
         double error = fabs(audio_bus_->channel(i)[j] -
             expected_audio_bus_->channel(i)[j] * scale);
-        if (error > epsilon) {
+        // The second comparison is for the case when scale is set to 0
+        // (and less that 1 in general)
+        if ((error > epsilon * scale) && (error > epsilon)) {
           EXPECT_NEAR(expected_audio_bus_->channel(i)[j] * scale,
-                      audio_bus_->channel(i)[j], epsilon)
+                      audio_bus_->channel(i)[j], epsilon * scale)
               << " i=" << i << ", j=" << j;
           return false;
         }
@@ -279,13 +303,40 @@ class AudioRendererMixerTest
     EXPECT_TRUE(RenderAndValidateAudioData(0.0f));
   }
 
+  // Verify output when mixer inputs in mixed post-Stop() and post-Play()
+  // states.
+  void MixedStopPlayTest(int inputs) {
+    InitializeInputs(inputs);
+
+    // Start() all inputs.
+    for (size_t i = 0; i < mixer_inputs_.size(); ++i)
+      mixer_inputs_[i]->Start();
+
+    // Stop() all even numbered mixer inputs and Play() all odd numbered inputs
+    // and ensure we get the right value.
+    for (size_t i = 1; i < mixer_inputs_.size(); i += 2) {
+      mixer_inputs_[i - 1]->Stop();
+      mixer_inputs_[i]->Play();
+    }
+
+    // Stop the last input in case the number of inputs is odd
+    if (mixer_inputs_.size() % 2)
+      mixer_inputs_[mixer_inputs_.size() - 1]->Stop();
+
+    ASSERT_TRUE(RenderAndValidateAudioData(
+        std::max(1.f, static_cast<float>(floor(mixer_inputs_.size() / 2.f)))));
+
+    for (size_t i = 1; i < mixer_inputs_.size(); i += 2)
+      mixer_inputs_[i]->Stop();
+  }
+
  protected:
   virtual ~AudioRendererMixerTest() {}
 
   scoped_refptr<MockAudioRendererSink> sink_;
   scoped_ptr<AudioRendererMixer> mixer_;
   AudioRendererSink::RenderCallback* mixer_callback_;
-  AudioParameters input_parameters_;
+  std::vector<AudioParameters> input_parameters_;
   AudioParameters output_parameters_;
   scoped_ptr<AudioBus> audio_bus_;
   scoped_ptr<AudioBus> expected_audio_bus_;
@@ -373,23 +424,13 @@ TEST_P(AudioRendererMixerTest, ManyInputStop) {
 
 // Test mixer with many inputs in mixed post-Stop() and post-Play() states.
 TEST_P(AudioRendererMixerTest, ManyInputMixedStopPlay) {
-  InitializeInputs(kMixerInputs);
-
-  // Start() all inputs.
-  for (size_t i = 0; i < mixer_inputs_.size(); ++i)
-    mixer_inputs_[i]->Start();
-
-  // Stop() all even numbered mixer inputs and Play() all odd numbered inputs
-  // and ensure we get the right value.
-  for (size_t i = 1; i < mixer_inputs_.size(); i += 2) {
-    mixer_inputs_[i - 1]->Stop();
-    mixer_inputs_[i]->Play();
-  }
-  ASSERT_TRUE(RenderAndValidateAudioData(std::max(
-      mixer_inputs_.size() / 2, static_cast<size_t>(1))));
+  MixedStopPlayTest(kMixerInputs);
+}
 
-  for (size_t i = 1; i < mixer_inputs_.size(); i += 2)
-    mixer_inputs_[i]->Stop();
+// Test mixer with many inputs in mixed post-Stop() and post-Play() states.
+TEST_P(AudioRendererMixerTest, ManyInputMixedStopPlayOdd) {
+  // Odd number of inputs per sample rate, to stop them unevenly.
+  MixedStopPlayTest(kOddMixerInputs);
 }
 
 TEST_P(AudioRendererMixerBehavioralTest, OnRenderError) {
@@ -474,22 +515,36 @@ TEST_P(AudioRendererMixerBehavioralTest, MixerPausesStream) {
 }
 
 INSTANTIATE_TEST_CASE_P(
-    AudioRendererMixerTest, AudioRendererMixerTest, testing::Values(
-        // No resampling.
-        std::tr1::make_tuple(44100, 44100, 0.00000048),
+    AudioRendererMixerTest,
+    AudioRendererMixerTest,
+    testing::Values(
+        // No resampling, 1 input sample rate.
+        std::tr1::make_tuple(kTestInputLower, kTestInputLower[0], 0.00000048),
 
-        // Upsampling.
-        std::tr1::make_tuple(44100, 48000, 0.033),
+        // Upsampling, 1 input sample rate.
+        std::tr1::make_tuple(kTestInputLower, kTestInputHigher[0], 0.01),
 
-        // Downsampling.
-        std::tr1::make_tuple(48000, 41000, 0.042)));
+        // Downsampling, 1 input sample rate.
+        std::tr1::make_tuple(kTestInputHigher, kTestInputLower[0], 0.01),
+
+        // Downsampling, multuple input sample rates.
+        std::tr1::make_tuple(kTestInput3Rates, kTestInput3Rates[0], 0.01),
+
+        // Upsampling, multiple sinput sample rates.
+        std::tr1::make_tuple(kTestInput3Rates, kTestInput3Rates[2], 0.01),
+
+        // Both downsampling and upsampling, multiple input sample rates
+        std::tr1::make_tuple(kTestInput3Rates, kTestInput3Rates[1], 0.01)));
 
 // Test cases for behavior which is independent of parameters.  Values() doesn't
 // support single item lists and we don't want these test cases to run for every
 // parameter set.
 INSTANTIATE_TEST_CASE_P(
-    AudioRendererMixerBehavioralTest, AudioRendererMixerBehavioralTest,
+    AudioRendererMixerBehavioralTest,
+    AudioRendererMixerBehavioralTest,
     testing::ValuesIn(std::vector<AudioRendererMixerTestData>(
-        1, std::tr1::make_tuple(44100, 44100, 0))));
-
+        1,
+        std::tr1::make_tuple(kTestInputLower,
+                             kTestInputLower[0],
+                             0.00000048))));
 }  // namespace media