Add support for midstream audio configuration changes.

media/base/audio_buffer_converter_unittest.cc

Index: media/base/audio_buffer_converter_unittest.cc
diff --git a/media/base/audio_buffer_converter_unittest.cc b/media/base/audio_buffer_converter_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..80567cf990f1527e271e00c473f15600be8036c7
--- /dev/null
+++ b/media/base/audio_buffer_converter_unittest.cc
@@ -0,0 +1,186 @@
+// Copyright 2014 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.
+
+#include "base/memory/scoped_ptr.h"
+#include "media/base/audio_buffer.h"
+#include "media/base/audio_buffer_converter.h"
+#include "media/base/sinc_resampler.h"
+#include "media/base/test_helpers.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace media {
+
+const int kOutSampleRate = 44100;
+const ChannelLayout kOutChannelLayout = CHANNEL_LAYOUT_STEREO;
+
+static scoped_refptr<AudioBuffer> MakeTestBuffer(int sample_rate,
+                                                 ChannelLayout channel_layout,
+                                                 int frames) {
+  return MakeAudioBuffer<uint8>(kSampleFormatU8,
+                                channel_layout,
+                                sample_rate,
+                                0,
+                                1,
+                                frames,
+                                base::TimeDelta::FromSeconds(0),
+                                base::TimeDelta::FromSeconds(0));
+}
+
+class AudioBufferConverterTest : public ::testing::Test {
+ public:
+  AudioBufferConverterTest()
+      : input_frames_(0), expected_output_frames_(0.0), output_frames_(0) {
+    AudioParameters output_params(AudioParameters::AUDIO_PCM_LOW_LATENCY,
+                                  kOutChannelLayout,
+                                  kOutSampleRate,
+                                  16,
+                                  512);
+    audio_buffer_converter_.reset(new AudioBufferConverter(output_params));
+  }
+
+  void Reset() {
+    audio_buffer_converter_->Reset();
+    output_frames_ = expected_output_frames_ = input_frames_ = 0;
+  }
+
+  void AddInput(const scoped_refptr<AudioBuffer>& in) {
+    if (!in->end_of_stream()) {
+      input_frames_ += in->frame_count();
+      expected_output_frames_ +=
+          in->frame_count() *
+          (static_cast<double>(kOutSampleRate) / in->sample_rate());
+    }
+    audio_buffer_converter_->AddInput(in);
+  }
+
+  void ConsumeAllOutput() {
+    AddInput(AudioBuffer::CreateEOSBuffer());
+    while (audio_buffer_converter_->HasNextBuffer()) {
+      scoped_refptr<AudioBuffer> out = audio_buffer_converter_->GetNextBuffer();
+      if (!out->end_of_stream()) {
+        output_frames_ += out->frame_count();
+        EXPECT_EQ(out->sample_rate(), kOutSampleRate);
+        EXPECT_EQ(out->channel_layout(), kOutChannelLayout);
+      } else {
+        EXPECT_FALSE(audio_buffer_converter_->HasNextBuffer());
+      }
+    }
+    EXPECT_EQ(output_frames_, ceil(expected_output_frames_));
+  }
+
+ private:
+  scoped_ptr<AudioBufferConverter> audio_buffer_converter_;
+
+  int input_frames_;
+  double expected_output_frames_;
+  int output_frames_;
+};
+
+TEST_F(AudioBufferConverterTest, PassThrough) {
+  scoped_refptr<AudioBuffer> in =
+      MakeTestBuffer(kOutSampleRate, kOutChannelLayout, 512);
+  AddInput(in);
+  ConsumeAllOutput();
+}
+
+TEST_F(AudioBufferConverterTest, Downsample) {
+  scoped_refptr<AudioBuffer> in = MakeTestBuffer(48000, kOutChannelLayout, 512);
+  AddInput(in);
+  ConsumeAllOutput();
+}
+
+TEST_F(AudioBufferConverterTest, Upsample) {
+  scoped_refptr<AudioBuffer> in = MakeTestBuffer(8000, kOutChannelLayout, 512);
+  AddInput(in);
+  ConsumeAllOutput();
+}
+
+// Test resampling a buffer smaller than the SincResampler's kernel size.
+TEST_F(AudioBufferConverterTest, Resample_TinyBuffer) {
+  AddInput(MakeTestBuffer(
+      48000, CHANNEL_LAYOUT_STEREO, SincResampler::kKernelSize - 1));
+  ConsumeAllOutput();
+}
+
+TEST_F(AudioBufferConverterTest, Resample_DifferingBufferSizes) {
+  const int input_sample_rate = 48000;
+  AddInput(MakeTestBuffer(input_sample_rate, kOutChannelLayout, 100));
+  AddInput(MakeTestBuffer(input_sample_rate, kOutChannelLayout, 200));
+  AddInput(MakeTestBuffer(input_sample_rate, kOutChannelLayout, 300));
+  AddInput(MakeTestBuffer(input_sample_rate, kOutChannelLayout, 400));
+  AddInput(MakeTestBuffer(input_sample_rate, kOutChannelLayout, 500));
+  ConsumeAllOutput();
+}
+
+TEST_F(AudioBufferConverterTest, ChannelDownmix) {
+  scoped_refptr<AudioBuffer> in =
+      MakeTestBuffer(kOutSampleRate, CHANNEL_LAYOUT_MONO, 512);
+  AddInput(in);
+  ConsumeAllOutput();
+}
+
+TEST_F(AudioBufferConverterTest, ChannelUpmix) {
+  scoped_refptr<AudioBuffer> in =
+      MakeTestBuffer(kOutSampleRate, CHANNEL_LAYOUT_5_1, 512);
+  AddInput(in);
+  ConsumeAllOutput();
+}
+
+TEST_F(AudioBufferConverterTest, ResampleAndRemix) {
+  scoped_refptr<AudioBuffer> in =
+      MakeTestBuffer(48000, CHANNEL_LAYOUT_5_1, 512);
+  AddInput(in);
+  ConsumeAllOutput();
+}
+
+TEST_F(AudioBufferConverterTest, ConfigChange_SampleRate) {
+  AddInput(MakeTestBuffer(48000, kOutChannelLayout, 512));
+  AddInput(MakeTestBuffer(44100, kOutChannelLayout, 512));
+  ConsumeAllOutput();
+}
+
+TEST_F(AudioBufferConverterTest, ConfigChange_ChannelLayout) {
+  AddInput(MakeTestBuffer(kOutSampleRate, CHANNEL_LAYOUT_STEREO, 512));
+  AddInput(MakeTestBuffer(kOutSampleRate, CHANNEL_LAYOUT_MONO, 512));
+  ConsumeAllOutput();
+}
+
+TEST_F(AudioBufferConverterTest, ConfigChange_SampleRateAndChannelLayout) {
+  AddInput(MakeTestBuffer(44100, CHANNEL_LAYOUT_STEREO, 512));
+  AddInput(MakeTestBuffer(48000, CHANNEL_LAYOUT_MONO, 512));
+  ConsumeAllOutput();
+}
+
+TEST_F(AudioBufferConverterTest, ConfigChange_Multiple) {
+  AddInput(MakeTestBuffer(44100, CHANNEL_LAYOUT_STEREO, 512));
+  AddInput(MakeTestBuffer(48000, CHANNEL_LAYOUT_MONO, 512));
+  AddInput(MakeTestBuffer(44100, CHANNEL_LAYOUT_5_1, 512));
+  AddInput(MakeTestBuffer(22050, CHANNEL_LAYOUT_STEREO, 512));
+  ConsumeAllOutput();
+}
+
+TEST_F(AudioBufferConverterTest, Reset) {
+  AddInput(MakeTestBuffer(44100, CHANNEL_LAYOUT_STEREO, 512));
+  Reset();
+  ConsumeAllOutput();
+}
+
+TEST_F(AudioBufferConverterTest, ResampleThenReset) {
+  // Resampling is likely to leave some data buffered in AudioConverter's
+  // fifo or resampler, so make sure Reset() cleans that all up.
+  AddInput(MakeTestBuffer(48000, CHANNEL_LAYOUT_STEREO, 512));
+  Reset();
+  ConsumeAllOutput();
+}
+
+TEST_F(AudioBufferConverterTest, ResetThenConvert) {
+  AddInput(MakeTestBuffer(kOutSampleRate, kOutChannelLayout, 512));
+  Reset();
+  // Make sure we can keep using the AudioBufferConverter after we've Reset().
+  AddInput(MakeTestBuffer(kOutSampleRate, kOutChannelLayout, 512));
+  ConsumeAllOutput();
+}
+
+}  // namespace media