[Chromecast] Store ALSA Mixer test data as uint32_t.

chromecast/media/cma/backend/alsa/stream_mixer_alsa_unittest.cc

Index: chromecast/media/cma/backend/alsa/stream_mixer_alsa_unittest.cc
diff --git a/chromecast/media/cma/backend/alsa/stream_mixer_alsa_unittest.cc b/chromecast/media/cma/backend/alsa/stream_mixer_alsa_unittest.cc
index 2b7b358343a5b3a2acffba6dfefc9273d1890a3a..39760c7e4bbcfb6891056e016892a48df78c9050 100644
--- a/chromecast/media/cma/backend/alsa/stream_mixer_alsa_unittest.cc
+++ b/chromecast/media/cma/backend/alsa/stream_mixer_alsa_unittest.cc
@@ -26,8 +26,8 @@ namespace media {
 namespace {
 
 // Testing constants that are common to multiple test cases.
+const size_t kBytesPerSample = sizeof(int32_t);
 const int kNumChannels = 2;
-const int kBytesPerSample = 4;
 const int kTestMaxReadSize = 4096;
 const int kTestSamplesPerSecond = 12345;
 
@@ -36,73 +36,77 @@ const int kTestSamplesPerSecond = 12345;
 #define NUM_DATA_SETS 2u
 #define NUM_SAMPLES 64u
 
-float kTestData[NUM_DATA_SETS][NUM_SAMPLES] = {
+// Note: Test data should be represented as 32-bit integers and copied into
+// ::media::AudioBus instances, rather than wrapping statically declared float
+// arrays. The latter method is brittle, as ::media::AudioBus requires 16-bit
+// alignment for internal data.
+const int32_t kTestData[NUM_DATA_SETS][NUM_SAMPLES] = {
   {
-     0.034619, -0.62082,
-    -0.633705,  0.530298,
-     0.89957,   0.864411,
-     0.302309,  0.262931,
-     0.780742,  0.0109042,
-    -0.602219,  0.255149,
-    -0.454606,  0.857073,
-     0.798388,  0.167035,
-     0.458046,  0.588998,
-     0.206043,  0.569494,
-     0.147803,  0.170857,
-     0.648797, -0.475908,
-    -0.95678,  -0.0743951,
-     0.524809, -0.924101,
-     0.65518,  -0.322856,
-    -0.721563,  0.573805,
-     0.451849, -0.814982,
-    -0.364712,  0.573464,
-     0.537977, -0.381851,
-     0.53816,  -0.516168,
-    -0.0700984, 0.481362,
-     0.98778,   0.852158,
-    -0.8815,   -0.381422,
-    -0.230589,  0.466485,
-    -0.67107,   0.322319,
-     0.892472, -0.320276,
-    -0.424015,  0.789646,
-     0.462945,  0.826759,
-     0.423481,  0.229418,
-    -0.354715, -0.961272,
-     0.632236, -0.735754,
-     0.872045, -0.709881,
+     74343736,   -1333200799,
+    -1360871126,  1138806283,
+     1931811865,  1856308487,
+     649203634,   564640023,
+     1676630678,  23416591,
+    -1293255456,  547928305,
+    -976258952,   1840550252,
+     1714525174,  358704931,
+     983646295,   1264863573,
+     442473973,   1222979052,
+     317404525,   366912613,
+     1393280948, -1022004648,
+    -2054669405, -159762261,
+     1127018745, -1984491787,
+     1406988336, -693327981,
+    -1549544744,  1232236854,
+     970338338,  -1750160519,
+    -783213057,   1231504562,
+     1155296810, -820018779,
+     1155689800, -1108462340,
+    -150535168,   1033717023,
+     2121241397,  1829995370,
+    -1893006836, -819097508,
+    -495186107,   1001768909,
+    -1441111852,  692174781,
+     1916569026, -687787473,
+    -910565280,   1695751872,
+     994166817,   1775451433,
+     909418522,   492671403,
+    -761744663,  -2064315902,
+     1357716471, -1580019684,
+     1872702377, -1524457840,
   }, {
-     0.908805,  0.331583,
-     0.514689,  0.803509,
-    -0.459579,  0.106887,
-     0.48557,   0.879381,
-     0.688156,  0.692105,
-    -0.158415, -0.851542,
-     0.660676, -0.33735,
-    -0.49228,   0.655911,
-    -0.014641,  0.66197,
-    -0.573276,  0.254189,
-     0.666018,  0.98153,
-    -0.967202, -0.525433,
-    -0.838106, -0.484799,
-     0.889906, -0.548501,
-    -0.889936, -0.432651,
-     0.590209,  0.0801954,
-    -0.953734, -0.994462,
-     0.341957,  0.565746,
-     0.605983, -0.152254,
-    -0.232025, -0.54384,
-    -0.274306,  0.275652,
-     0.276137, -0.367112,
-    -0.000647,  0.68271,
-     0.179821,  0.646818,
-     0.435898, -0.669994,
-     0.624382, -0.752883,
-    -0.396175,  0.776021,
-     0.600866, -0.2293,
-     0.306964, -0.252563,
-    -0.055882,  0.480061,
-    -0.408798, -0.405238,
-     0.61592,  -0.16056,
+     1951643876,  712069070,
+     1105286211,  1725522438,
+    -986938388,   229538084,
+     1042753634,  1888456317,
+     1477803757,  1486284170,
+    -340193623,  -1828672521,
+     1418790906, -724453609,
+    -1057163251,  1408558147,
+    -31441309,    1421569750,
+    -1231100836,  545866721,
+     1430262764,  2107819625,
+    -2077050480, -1128358776,
+    -1799818931, -1041097926,
+     1911058583, -1177896929,
+    -1911123008, -929110948,
+     1267464176,  172218310,
+    -2048128170, -2135590884,
+     734347065,   1214930283,
+     1301338583, -326962976,
+    -498269894,  -1167887508,
+    -589067650,   591958162,
+     592999692,  -788367017,
+    -1389422,     1466108561,
+     386162657,   1389031078,
+     936083827,  -1438801160,
+     1340850135, -1616803932,
+    -850779335,   1666492408,
+     1290349909, -492418001,
+     659200170,  -542374913,
+    -120005682,   1030923147,
+    -877887021,  -870241979,
+     1322678128, -344799975,
   }
 };
 
@@ -110,8 +114,8 @@ float kTestData[NUM_DATA_SETS][NUM_SAMPLES] = {
 scoped_ptr<::media::AudioBus> GetTestData(size_t index) {
   CHECK_LT(index, NUM_DATA_SETS);
   int frames = NUM_SAMPLES / kNumChannels;
-  auto data =
-      ::media::AudioBus::WrapMemory(kNumChannels, frames, kTestData[index]);
+  auto data = ::media::AudioBus::Create(kNumChannels, frames);
+  data->FromInterleaved(kTestData[index], frames, kBytesPerSample);
   return data;
 }
 
@@ -394,6 +398,8 @@ TEST_F(StreamMixerAlsaTest, OneStreamMixesProperly) {
   const int kNumFrames = 32;
   input->SetData(GetTestData(0));
 
+  ASSERT_EQ(mock_alsa()->data().size(), 0u);
+
   // Write the stream to ALSA.
   EXPECT_CALL(*input, GetResampledData(_, kNumFrames));
   EXPECT_CALL(*input, AfterWriteFrames(_));
@@ -405,8 +411,7 @@ TEST_F(StreamMixerAlsaTest, OneStreamMixesProperly) {
   ASSERT_GT(mock_alsa()->data().size(), 0u);
   actual->FromInterleaved(
       &(mock_alsa()->data()[0]), kNumFrames, kBytesPerSample);
-  auto expected = GetMixedAudioData(input);
-  CompareAudioData(*expected, *actual);
+  CompareAudioData(input->data(), *actual);
 }
 
 TEST_F(StreamMixerAlsaTest, OneStreamIsScaledDownProperly) {
@@ -422,8 +427,7 @@ TEST_F(StreamMixerAlsaTest, OneStreamIsScaledDownProperly) {
   const int kNumFrames = 32;
   ASSERT_EQ((int)sizeof(kTestData[0]),
             kNumChannels * kNumFrames * kBytesPerSample);
-  auto data =
-      ::media::AudioBus::WrapMemory(kNumChannels, kNumFrames, kTestData[0]);
+  auto data = GetTestData(0);
   input->SetData(std::move(data));
 
   // Set a volume multiplier on the stream.
@@ -497,36 +501,42 @@ TEST_F(StreamMixerAlsaTest, TwoUnscaledStreamsMixProperlyWithEdgeCases) {
   }
 
   // Create edge case data for the inputs. By mixing these two short streams,
-  // every combination of {-1.0, 0.0, 1.0} is tested. Note that this test case
-  // is intended to be a hand-checkable gut check.
+  // every combination of {-(2^31), 0, 2^31-1} is tested. This test case is
+  // intended to be a hand-checkable gut check.
+  // Note: Test data should be represented as 32-bit integers and copied into
+  // ::media::AudioBus instances, rather than wrapping statically declared float
+  // arrays. The latter method is brittle, as ::media::AudioBus requires 16-bit
+  // alignment for internal data.
   const int kNumFrames = 3;
 
-  float kEdgeData[2][8] = {
+  const int32_t kMaxSample = std::numeric_limits<int32_t>::max();
+  const int32_t kMinSample = std::numeric_limits<int32_t>::min();
+  const int32_t kEdgeData[2][8] = {
     {
-      -1.0, -1.0,
-      -1.0,  0.0,
-       0.0,  1.0,
-       0.0,  0.0,
+      kMinSample, kMinSample,
+      kMinSample, 0.0,
+      0.0,        kMaxSample,
+      0.0,        0.0,
     }, {
-      -1.0, 0.0,
-       1.0, 0.0,
-       1.0, 1.0,
-       0.0, 0.0,
+      kMinSample, 0.0,
+      kMaxSample, 0.0,
+      kMaxSample, kMaxSample,
+      0.0,        0.0,
     }
   };
 
-  // Hand-calculate the results. Index 0 is clamped to -1.0 from -2.0. Index
-  // 5 is clamped from 2.0 to 1.0.
-  float kResult[8] = {
-    -1.0, -1.0,
-     0.0,  0.0,
-     1.0,  1.0,
-     0.0,  0.0,
+  // Hand-calculate the results. Index 0 is clamped to -(2^31). Index 5 is
+  // clamped to 2^31-1.
+  const int32_t kResult[8] = {
+    kMinSample,  kMinSample,
+    0.0,         0.0,
+    kMaxSample,  kMaxSample,
+    0.0,         0.0,
   };
 
   for (size_t i = 0; i < inputs.size(); ++i) {
-    auto test_data =
-        ::media::AudioBus::WrapMemory(kNumChannels, kNumFrames, kEdgeData[i]);
+    auto test_data = ::media::AudioBus::Create(kNumChannels, kNumFrames);
+    test_data->FromInterleaved(kEdgeData[i], kNumFrames, kBytesPerSample);
     inputs[i]->SetData(std::move(test_data));
     EXPECT_CALL(*inputs[i], GetResampledData(_, kNumFrames));
     EXPECT_CALL(*inputs[i], AfterWriteFrames(_));
@@ -536,8 +546,8 @@ TEST_F(StreamMixerAlsaTest, TwoUnscaledStreamsMixProperlyWithEdgeCases) {
   mixer->WriteFramesForTest();
 
   // Use the hand-calculated results above.
-  auto expected =
-      ::media::AudioBus::WrapMemory(kNumChannels, kNumFrames, kResult);
+  auto expected = ::media::AudioBus::Create(kNumChannels, kNumFrames);
+  expected->FromInterleaved(kResult, kNumFrames, kBytesPerSample);
 
   // Get the actual stream rendered to ALSA, and compare it against the
   // expected stream. The stream should match exactly.