Adds AudioFifo class to Chrome media.

media/base/audio_fifo_unittest.cc

Index: media/base/audio_fifo_unittest.cc
diff --git a/media/base/audio_fifo_unittest.cc b/media/base/audio_fifo_unittest.cc
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index 0000000000000000000000000000000000000000..5b183009de0232bbc66df2662fa05e5de1161303
--- /dev/null
+++ b/media/base/audio_fifo_unittest.cc
@@ -0,0 +1,196 @@
+// 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.
+
+#include <limits>
+
+#include "media/base/audio_bus.h"
+#include "media/base/audio_fifo.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace media {
+
+class AudioFifoTest : public testing::Test {
+ public:
+  AudioFifoTest() {}
+  ~AudioFifoTest() {}
+
+  void VerifyValue(const float data[], int size, float value) {
+    for (int i = 0; i < size; ++i)
+      ASSERT_FLOAT_EQ(value, data[i]) << "i=" << i;
+  }
+
+ protected:
+  DISALLOW_COPY_AND_ASSIGN(AudioFifoTest);
+};
+
+// Verify that construction works as intended.
+TEST_F(AudioFifoTest, Construct) {
+  const int kChannels = 6;
+  const int kMaxFrameCount = 128;
+  AudioFifo fifo(kChannels, kMaxFrameCount);
+  EXPECT_EQ(fifo.frames_in_fifo(), 0);
+}
+
+// Pushes audio bus objects to a FIFO and fill it up to different degrees.
+// Also, verify that it is not possible to overflow the FIFO.
+TEST_F(AudioFifoTest, Push) {
+  const int kChannels = 2;
+  const int kMaxFrameCount = 128;
+  AudioFifo fifo(kChannels, kMaxFrameCount);
+  {
+    SCOPED_TRACE("Push 50%");
+    scoped_ptr<AudioBus> bus = AudioBus::Create(kChannels, kMaxFrameCount / 2);
+    EXPECT_EQ(fifo.frames_in_fifo(), 0);
+    EXPECT_TRUE(fifo.Push(bus.get()));
+    EXPECT_EQ(fifo.frames_in_fifo(), bus->frames());
+    fifo.Clear();
+  }
+  {
+    SCOPED_TRACE("Push 100%");
+    scoped_ptr<AudioBus> bus = AudioBus::Create(kChannels, kMaxFrameCount);
+    EXPECT_EQ(fifo.frames_in_fifo(), 0);
+    EXPECT_TRUE(fifo.Push(bus.get()));
+    EXPECT_EQ(fifo.frames_in_fifo(), bus->frames());
+    fifo.Clear();
+  }
+  {
+    SCOPED_TRACE("Overflow");
+    scoped_ptr<AudioBus> bus = AudioBus::Create(kChannels, kMaxFrameCount + 1);
+    EXPECT_EQ(fifo.frames_in_fifo(), 0);
+    EXPECT_FALSE(fifo.Push(bus.get()));
+    EXPECT_EQ(fifo.frames_in_fifo(), 0);
+  }
+}
+
+// Consumes audio bus objects from a FIFO and empty it to different degrees.
+// Also, verify that it is not possible to ask for more data than the FIFO
+// contains (corresponds to underrun).
+TEST_F(AudioFifoTest, Consume) {
+  const int kChannels = 2;
+  const int kMaxFrameCount = 128;
+  AudioFifo fifo(kChannels, kMaxFrameCount);
+  {
+    scoped_ptr<AudioBus> bus = AudioBus::Create(kChannels, kMaxFrameCount);
+    EXPECT_TRUE(fifo.Push(bus.get()));
+    EXPECT_EQ(fifo.frames_in_fifo(), kMaxFrameCount);
+  }
+  {
+    SCOPED_TRACE("Consume 50%");
+    scoped_ptr<AudioBus> bus = AudioBus::Create(kChannels, kMaxFrameCount / 2);
+    EXPECT_TRUE(fifo.Consume(bus.get()));
+    EXPECT_TRUE(fifo.frames_in_fifo() == bus->frames());
+    EXPECT_TRUE(fifo.Push(bus.get()));
+    EXPECT_EQ(fifo.frames_in_fifo(), kMaxFrameCount);
+  }
+  {
+    SCOPED_TRACE("Consume 100%");
+    scoped_ptr<AudioBus> bus = AudioBus::Create(kChannels, kMaxFrameCount);
+    EXPECT_TRUE(fifo.Consume(bus.get()));
+    EXPECT_EQ(fifo.frames_in_fifo(), 0);
+    EXPECT_TRUE(fifo.Push(bus.get()));
+    EXPECT_EQ(fifo.frames_in_fifo(), kMaxFrameCount);
+  }
+  {
+    SCOPED_TRACE("Underrun");
+    scoped_ptr<AudioBus> bus = AudioBus::Create(kChannels, kMaxFrameCount + 1);
+    EXPECT_FALSE(fifo.Consume(bus.get()));
+    EXPECT_EQ(fifo.frames_in_fifo(), kMaxFrameCount);
+  }
+}
+
+// Verify that the frames_in_fifo() method of the FIFO works as intended while
+// appending and removing audio bus elements to/from the FIFO.
+TEST_F(AudioFifoTest, FramesInFifo) {
+  const int kChannels = 2;
+  const int kMaxFrameCount = 64;
+  AudioFifo fifo(kChannels, kMaxFrameCount);
+
+  // Fill up the FIFO and verify that the size grows as it should while adding
+  // one audio frame each time.
+  scoped_ptr<AudioBus> bus = AudioBus::Create(kChannels, 1);
+  int n = 0;
+  while (fifo.frames_in_fifo() < kMaxFrameCount) {
+    EXPECT_TRUE(fifo.Push(bus.get()));
+    EXPECT_EQ(fifo.frames_in_fifo(), ++n);
+  }
+
+  // Ensure that we can't append more data when the FIFO is full.
+  EXPECT_EQ(fifo.frames_in_fifo(), kMaxFrameCount);
+  EXPECT_FALSE(fifo.Push(bus.get()));
+
+  // Empty the FIFO and verify that the size decreases as it should.
+  // Reduce the size of the FIFO by one frame each time.
+  while (fifo.frames_in_fifo() > 0) {
+    EXPECT_TRUE(fifo.Consume(bus.get()));
+    EXPECT_EQ(fifo.frames_in_fifo(), --n);
+  }
+
+  // Ensure that we can't remove more data when the FIFO is empty.
+  EXPECT_EQ(fifo.frames_in_fifo(), 0);
+  EXPECT_FALSE(fifo.Consume(bus.get()));
+
+  // Verify that a steady-state size of one frame in the FIFO is maintained
+  // during a sequence of Push/Consume calls which involves wrapping.
+  EXPECT_TRUE(fifo.Push(bus.get()));
+  EXPECT_EQ(fifo.frames_in_fifo(), 1);
+  for (int n = 0; n < 10 * kMaxFrameCount; ++n) {
+    EXPECT_TRUE(fifo.Push(bus.get()));
+    EXPECT_TRUE(fifo.Consume(bus.get()));
+    EXPECT_EQ(fifo.frames_in_fifo(), 1);
+  }
+}
+
+// Do a more realistic test of how the FIFO will be used and also verify that
+// the actual data content is correct.
+TEST_F(AudioFifoTest, PushAndConsume) {
+  const int kChannels = 2;
+  const int kFrameCount = 256;
+  const int kMaxAudioBusesInFifoCount = 128;
+
+  scoped_ptr<AudioBus> bus = AudioBus::Create(kChannels, kFrameCount);
+  AudioFifo fifo(kChannels, bus->frames() * kMaxAudioBusesInFifoCount);
+
+  // Start by filling up half the FIFO with audio frames. The first audio frame
+  // will contain all 1's, the second all 2's etc. All channels contain the
+  // same value.
+  int value = 1;
+  while (fifo.frames_in_fifo() <
+         bus->frames() * (kMaxAudioBusesInFifoCount / 2)) {
+    // Fill all channels in the bus with dummy values.
+    for (int j = 0; j < bus->channels(); ++j)
+      std::fill(bus->channel(j), bus->channel(j) + bus->frames(), value);
+    EXPECT_TRUE(fifo.Push(bus.get()));
+    EXPECT_EQ(fifo.frames_in_fifo(), bus->frames() * value);
+    ++value;
+  }
+
+  // Do a sequence of Consume/Push calls and verify that the acquired values
+  // are correct and that the wrap-around mechanism works as intended.
+  // The size of the FIFO will be constant during this step.
+  const int steady_state_offset = fifo.frames_in_fifo() / bus->frames();
+  for (int i = 0; i < kMaxAudioBusesInFifoCount; ++i) {
+    EXPECT_TRUE(fifo.Consume(bus.get()));
+    value = steady_state_offset + i + 1;
+    for (int j = 0; j < bus->channels(); ++j) {
+      VerifyValue(bus->channel(j), bus->frames(), value - steady_state_offset);
+      std::fill(bus->channel(j), bus->channel(j) + bus->frames(), value);
+    }
+    EXPECT_TRUE(fifo.Push(bus.get()));
+    EXPECT_EQ(fifo.frames_in_fifo(),
+              bus->frames() * (kMaxAudioBusesInFifoCount / 2));
+  }
+
+  // As a last step, flush the FIFO and verify that the retrieved values
+  // are correct.
+  value = value - steady_state_offset + 1;
+  while (fifo.frames_in_fifo() > 0) {
+    EXPECT_TRUE(fifo.Consume(bus.get()));
+    for (int j = 0; j < bus->channels(); ++j) {
+      VerifyValue(bus->channel(j), bus->frames(), value);
+    }
+    value++;
+  }
+}
+
+}  // namespace media