Adding WebRTC Auto Gain Control Test (linux)

chrome/browser/media/webrtc_browsertest_audio.cc

+// 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 "webrtc_browsertest_audio.h"
+
+#include "base/files/file.h"
+#include "base/files/file_path.h"
+#include "media/audio/audio_power_monitor.h"
+#include "media/audio/sounds/wav_audio_handler.h"
+#include "media/base/audio_bus.h"
+
+namespace {
+// Opens |wav_filename|, reads it and loads it as a wav file. This function will
+// bluntly trigger CHECKs if we can't read the file or if it's malformed. The
+// caller takes ownership of the returned data. The size of the data is stored
+// in |read_length|.
+scoped_ptr<uint8[]> ReadWavFile(const base::FilePath& wav_filename,
+                                size_t* file_length) {
+  base::File wav_file(
+      wav_filename, base::File::FLAG_OPEN | base::File::FLAG_READ);
+  if (!wav_file.IsValid()) {
+    CHECK(false) << "Failed to read " << wav_filename.value();
+    return nullptr;
+  }
+
+  size_t wav_file_length = wav_file.GetLength();
+
+  uint8* wav_file_data = new uint8[wav_file_length];
+  size_t read_bytes = wav_file.Read(0, reinterpret_cast<char*>(wav_file_data),
+                                    wav_file_length);
+  if (read_bytes != wav_file_length) {
+    CHECK(false) << "Failed to read all bytes of " << wav_filename.value();
+    return nullptr;
+  }
+  *file_length = wav_file_length;
+  return scoped_ptr<uint8[]>(wav_file_data);
+}
+
+scoped_ptr<media::WavAudioHandler> CreateWavAudioHandler(
+    const base::FilePath& wav_filename, const uint8* wav_file_data,
+    size_t wav_file_length) {
+  base::StringPiece wav_data(reinterpret_cast<const char*>(wav_file_data),
+                             wav_file_length);
+  scoped_ptr<media::WavAudioHandler> wav_audio_handler(
+      new media::WavAudioHandler(wav_data));
+
+  return wav_audio_handler.Pass();
+}
+
+}  // namespace
+
+namespace test {
+
+float ComputeAudioEnergyForWavFile(const base::FilePath& wav_filename,
+                                   media::AudioParameters* file_parameters) {
+  // Read the file, and put its data in a scoped_ptr so it gets deleted later.
+  size_t file_length = 0;
+  scoped_ptr<uint8[]> wav_file_data = ReadWavFile(wav_filename, &file_length);
+  scoped_ptr<media::WavAudioHandler> wav_audio_handler = CreateWavAudioHandler(
+      wav_filename, wav_file_data.get(), file_length);
+
+  scoped_ptr<media::AudioBus> audio_bus =
+      media::AudioBus::Create(wav_audio_handler->params());
+  base::TimeDelta file_duration =
+      wav_audio_handler->params().GetBufferDuration();
+
+  size_t bytes_written;
+  wav_audio_handler->CopyTo(audio_bus.get(), 0, &bytes_written);
+  CHECK_EQ(bytes_written, wav_audio_handler->data().size())
+      << "Expected to write entire file into bus.";
+
+  // Set the filter coefficient to the whole file's duration; this will make the
+  // power monitor take the entire file into account.
+  media::AudioPowerMonitor power_monitor(
+      wav_audio_handler->params().sample_rate(), file_duration);
+  power_monitor.Scan(*audio_bus, audio_bus->frames());
+
+  *file_parameters = wav_audio_handler->params();
+  return power_monitor.ReadCurrentPowerAndClip().first;
+}
+
+}  // namespace test