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 40 matching lines @@
   // Verify requesting ChunkSize() frames causes a single callback.
   EXPECT_CALL(mock_source, ProvideInput(_, _)).Times(1);
   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);
   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()]);
+
+  EXPECT_CALL(mock_source, ProvideInput(_, _)).Times(1);
+  resampler.Resample(resampled_destination.get(), resampler.ChunkSize());
+
+  // Figure out buffer size from internal buffer layout.
+  int buffer_size_float = reinterpret_cast<int>(
+      resampler.r4_ + (resampler.r4_ - resampler.r3_) - resampler.r1_);

[scherkus (not reviewing), 2012/09/07 13:30:17]

instead of friend test + poking around internals, perhaps we can add some
xxx_for_test() / XxxForTest() methods on SinceResampler that does some of this
work for us?

[DaleCurtis, 2012/09/07 14:17:35]

I like this idea. Will change.

[DaleCurtis, 2012/09/10 12:06:24]

Found a better way => Prime with junk data, Flush(), ensure correct results.

+  int buffer_size_bytes = buffer_size_float * sizeof(*(

[scherkus (not reviewing), 2012/09/07 13:30:17]

looks bizarre -- drop sizeof to next line?

[DaleCurtis, 2012/09/10 12:06:24]

Removed.

+      resampler.input_buffer_.get()));
+
+  // Fill input buffer with junk data so we can if it's cleared afterwards.
+  memset(resampler.input_buffer_.get(), 0xFF, buffer_size_bytes);
+
+  EXPECT_TRUE(resampler.buffer_primed_);
+  EXPECT_NE(resampler.virtual_source_idx_, 0);
+
+  resampler.Flush();
+  EXPECT_FALSE(resampler.buffer_primed_);
+  EXPECT_EQ(resampler.virtual_source_idx_, 0);
+  for (int i = 0; i < buffer_size_float; ++i)
+    ASSERT_FLOAT_EQ(resampler.input_buffer_.get()[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