Introduce AudioOutputResampler for browser side resampling.

media/base/sinc_resampler_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // MSVC++ requires this to be set before any other includes to get M_PI.
 #define _USE_MATH_DEFINES
 
 #include <cmath>
 
 #include "base/bind.h"
@@ skipping 15 matching lines @@
 
 // Command line switch for runtime adjustment of ConvolveBenchmark iterations.
 static const char kConvolveIterations[] = "convolve-iterations";
 
 // Helper class to ensure ChunkedResample() functions properly.
 class MockSource {
  public:
   MOCK_METHOD2(ProvideInput, void(float* destination, int frames));
 };
 
+ACTION(ClearBuffer) {
+  memset(arg0, 0, arg1 * sizeof(float));
+}
+
+ACTION(FillBuffer) {
+  memset(arg0, 1, arg1 * sizeof(float));
+}
+
 // Test requesting multiples of ChunkSize() frames results in the proper number
 // of callbacks.
 TEST(SincResamplerTest, ChunkedResample) {
   MockSource mock_source;
 
   // Choose a high ratio of input to output samples which will result in quick
   // exhaustion of SincResampler's internal buffers.
   SincResampler resampler(
       kSampleRateRatio,
       base::Bind(&MockSource::ProvideInput, base::Unretained(&mock_source)));
 
   static const int kChunks = 2;
   int max_chunk_size = resampler.ChunkSize() * kChunks;
   scoped_array<float> resampled_destination(new float[max_chunk_size]);
 
   // Verify requesting ChunkSize() frames causes a single callback.
-  EXPECT_CALL(mock_source, ProvideInput(_, _)).Times(1);
+  EXPECT_CALL(mock_source, ProvideInput(_, _))
+      .Times(1).WillOnce(ClearBuffer());
   resampler.Resample(resampled_destination.get(), resampler.ChunkSize());
 
   // Verify requesting kChunks * ChunkSize() frames causes kChunks callbacks.
   testing::Mock::VerifyAndClear(&mock_source);
-  EXPECT_CALL(mock_source, ProvideInput(_, _)).Times(kChunks);
+  EXPECT_CALL(mock_source, ProvideInput(_, _))
+      .Times(kChunks).WillRepeatedly(ClearBuffer());
   resampler.Resample(resampled_destination.get(), max_chunk_size);
 }
 
+// Test flush resets the internal state properly.
+TEST(SincResamplerTest, Flush) {
+  MockSource mock_source;
+  SincResampler resampler(
+      kSampleRateRatio,
+      base::Bind(&MockSource::ProvideInput, base::Unretained(&mock_source)));
+  scoped_array<float> resampled_destination(new float[resampler.ChunkSize()]);
+
+  // Fill the resampler with junk data.
+  EXPECT_CALL(mock_source, ProvideInput(_, _))
+      .Times(1).WillOnce(FillBuffer());
+  resampler.Resample(resampled_destination.get(), resampler.ChunkSize() / 2);
+  ASSERT_NE(resampled_destination[0], 0);
+
+  // Flush and request more data, which should all be zeros now.
+  resampler.Flush();
+  testing::Mock::VerifyAndClear(&mock_source);
+  EXPECT_CALL(mock_source, ProvideInput(_, _))
+      .Times(1).WillOnce(ClearBuffer());
+  resampler.Resample(resampled_destination.get(), resampler.ChunkSize() / 2);
+  for (int i = 0; i < resampler.ChunkSize() / 2; ++i)
+    ASSERT_EQ(resampled_destination[i], 0);
+}
+
 // Ensure various optimized Convolve() methods return the same value.  Only run
 // this test if other optimized methods exist, otherwise the default Convolve()
 // will be tested by the parameterized SincResampler tests below.
 #if defined(ARCH_CPU_X86_FAMILY) && defined(__SSE__)
 TEST(SincResamplerTest, Convolve) {
   // Initialize a dummy resampler.
   MockSource mock_source;
   SincResampler resampler(
       kSampleRateRatio,
       base::Bind(&MockSource::ProvideInput, base::Unretained(&mock_source)));
@@ skipping 275 matching lines @@
         std::tr1::make_tuple(11025, 192000, kResamplingRMSError, -62.61),
         std::tr1::make_tuple(16000, 192000, kResamplingRMSError, -63.14),
         std::tr1::make_tuple(22050, 192000, kResamplingRMSError, -62.42),
         std::tr1::make_tuple(32000, 192000, kResamplingRMSError, -63.38),
         std::tr1::make_tuple(44100, 192000, kResamplingRMSError, -62.63),
         std::tr1::make_tuple(48000, 192000, kResamplingRMSError, -73.44),
         std::tr1::make_tuple(96000, 192000, kResamplingRMSError, -73.52),
         std::tr1::make_tuple(192000, 192000, kResamplingRMSError, -73.52)));
 
 }  // namespace media