Adds media::AudioPullFifo class to Chrome.

media/base/audio_pull_fifo_unittest.cc

Index: media/base/audio_pull_fifo_unittest.cc
diff --git a/media/base/audio_pull_fifo_unittest.cc b/media/base/audio_pull_fifo_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..e5c005d5200827d65ac7bf9eb1f7660d098bf9a2
--- /dev/null
+++ b/media/base/audio_pull_fifo_unittest.cc
@@ -0,0 +1,89 @@
+// 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 "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/stringprintf.h"
+#include "media/base/audio_pull_fifo.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace media {
+
+// Block diagram of a possible real-world usage:
+//
+//       | Producer | ----> | AudioPullFifo | ----> | Consumer |
+//                    push                    pull
+//          2048      ---->       (2048)      ---->     ~512
+
+// Number of channels in each audio bus.
+static int kChannels = 2;
+
+// Max number of audio framed the FIFO can contain.
+static const int kMaxFramesInFifo = 2048;
+
+class AudioPullFifoTest
+    : public testing::TestWithParam<int> {
+ public:
+  AudioPullFifoTest()
+    : pull_fifo_(kChannels, kMaxFramesInFifo, base::Bind(
+          &AudioPullFifoTest::ProvideInput, base::Unretained(this))),
+      audio_bus_(AudioBus::Create(kChannels, kMaxFramesInFifo)),
+      fill_value_(0) {}
+  virtual ~AudioPullFifoTest() {}
+
+  void VerifyValue(const float data[], int size, float start_value) {
+    float value = start_value;
+    for (int i = 0; i < size; ++i) {
+      ASSERT_FLOAT_EQ(value++, data[i]) << "i=" << i;
+    }
+  }
+
+  // Consume data using different sizes, acquire audio frames from the FIFO
+  // and verify that the retrieved values matches the values written by the
+  // producer.
+  void ConsumeTest(int frames_to_consume) {
+    int start_value = 0;
+    SCOPED_TRACE(base::StringPrintf("Checking frames_to_consume %d",
+                 frames_to_consume));
+    pull_fifo_.Consume(audio_bus_.get(), frames_to_consume);
+    for (int j = 0; j < kChannels; ++j) {
+      VerifyValue(audio_bus_->channel(j), frames_to_consume, start_value);
+    }
+    start_value += frames_to_consume;
+  }
+
+  // AudioPullFifo::ReadCB implementation where we increase a value for each
+  // audio frame that we provide. Note that all channels are given the same
+  // value to simplify the verification.
+  virtual void ProvideInput(AudioBus* audio_bus) {
+    EXPECT_EQ(audio_bus->channels(), audio_bus_->channels());
+    EXPECT_EQ(audio_bus->frames(), kMaxFramesInFifo);
+    for (int i = 0; i < audio_bus->frames(); ++i) {
+      for (int j = 0; j < audio_bus->channels(); ++j) {
+        // Store same value in all channels.
+        audio_bus->channel(j)[i] = fill_value_;
+      }
+      fill_value_++;
+    }
+  }
+
+ protected:
+  AudioPullFifo pull_fifo_;
+  scoped_ptr<AudioBus> audio_bus_;
+  int fill_value_;
+
+  DISALLOW_COPY_AND_ASSIGN(AudioPullFifoTest);
+};
+
+TEST_P(AudioPullFifoTest, Consume) {
+  ConsumeTest(GetParam());
+}
+
+// Test common |frames_to_consume| values which will be used as input
+// parameter to AudioPullFifo::Consume() when the consumer asks for data.
+INSTANTIATE_TEST_CASE_P(
+    AudioPullFifoTest, AudioPullFifoTest,
+    testing::Values(544, 512, 512, 512, 512, 2048, 544, 441, 440, 433, 500));
+
+}  // namespace media