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
new file mode 100644
index 0000000000000000000000000000000000000000..6bc9f8c5231d521d0341b72e5aceeb1e466a7c49
--- /dev/null
+++ b/media/base/audio_fifo_unittest.cc
@@ -0,0 +1,215 @@
+// 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) {
+  static const int kChannels = 6;
+  static 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) {
+  static const int kChannels = 2;
+  static 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) {
+  static const int kChannels = 2;
+  static 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(), bus->frames()));
+    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(), bus->frames()));
+    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(), bus->frames()));
+    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) {
+  static const int kChannels = 2;
+  static 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(), bus->frames()));
+    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(), bus->frames()));
+
+  // Verify that a steady-state size of #frames in the FIFO is maintained
+  // during a sequence of Push/Consume calls which involves wrapping. We ensure
+  // wrapping by selecting a buffer size which does divides the FIFO size
+  // with a remainder of one.
+  scoped_ptr<AudioBus> bus2 =
+      AudioBus::Create(kChannels, (kMaxFrameCount / 4) - 1);
+  const int frames_in_fifo = bus2->frames();
+  EXPECT_TRUE(fifo.Push(bus2.get()));
+  EXPECT_EQ(fifo.frames_in_fifo(), frames_in_fifo);
+  for (int n = 0; n < kMaxFrameCount; ++n) {
+    EXPECT_TRUE(fifo.Push(bus2.get()));
+    EXPECT_TRUE(fifo.Consume(bus2.get(), frames_in_fifo));
+    EXPECT_EQ(fifo.frames_in_fifo(), frames_in_fifo);
+  }
+}
+
+TEST_F(AudioFifoTest, VerifyDataValues) {
+  static const int kChannels = 2;
+  static const int kFrameCount = 2;
+  static const int kFifoFrameCount = 5 * kFrameCount;
+
+  AudioFifo fifo(kChannels, kFifoFrameCount);
+  scoped_ptr<AudioBus> bus = AudioBus::Create(kChannels, kFrameCount);
+  EXPECT_EQ(fifo.frames_in_fifo(), 0);
+  EXPECT_EQ(bus->frames(), kFrameCount);
+
+  // Start by filling up 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() < kFifoFrameCount) {
+    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;
+  }
+
+  // FIFO should be full now.
+  EXPECT_EQ(fifo.frames_in_fifo(), kFifoFrameCount);
+
+  // Consume all audio frames in the FIFO and verify that the stored values
+  // are correct. In this example, we shall read out: 1, 2, 3, 4, 5 in that
+  // order. Note that we set |frames_to_consume| to half the size of the bus.
+  // It means that we shall read out the same value two times in row.
+  value = 1;
+  int n = 1;
+  const int frames_to_consume = bus->frames() / 2;
+  while (fifo.frames_in_fifo() > 0) {
+    EXPECT_TRUE(fifo.Consume(bus.get(), frames_to_consume));
+    for (int j = 0; j < bus->channels(); ++j)
+      VerifyValue(bus->channel(j), frames_to_consume, value);
+    if (n++ % 2 == 0)
+      ++value;  // counts 1, 1, 2, 2, 3, 3,...
+  }
+
+  // FIFO should be empty now.
+  EXPECT_EQ(fifo.frames_in_fifo(), 0);
+
+  // Push one audio bus to the FIFO and fill it with 1's.

[DaleCurtis, 2012/09/06 11:14:13]

I think this section is already tested by the Consume() (and FramesInFifo) test
above?

[henrika (OOO until Aug 14), 2012/09/06 11:52:46]

Well, almost. I check the content here as well not only the size ;-)

+  value = 1;
+  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());
+
+  // Keep calling Consume/Push a few rounds and verify that we read out the
+  // correct values. The number of elements shall be fixed (kFrameCount) during
+  // this phase.
+  for (int i = 0; i < 5 * kFifoFrameCount; i++) {
+    EXPECT_TRUE(fifo.Consume(bus.get(), bus->frames()));
+    for (int j = 0; j < bus->channels(); ++j) {
+      VerifyValue(bus->channel(j), bus->channels(), value);
+      std::fill(bus->channel(j), bus->channel(j) + bus->frames(), value + 1);
+    }
+    EXPECT_TRUE(fifo.Push(bus.get()));
+    EXPECT_EQ(fifo.frames_in_fifo(), bus->frames());
+    ++value;
+  }
+

[DaleCurtis, 2012/09/06 11:14:13]

extra line.

[henrika (OOO until Aug 14), 2012/09/06 11:52:46]

Done.

[scherkus (not reviewing), 2012/09/06 13:53:57]

nit: remove extra blank line

+}
+
+}  // namespace media