chrome/browser/media/webrtc_browsertest_audio.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/media/webrtc_browsertest_audio.h"
   6
   7 #include "base/files/file.h"
   8 #include "base/files/file_path.h"
   9 #include "media/audio/audio_parameters.h"
  10 #include "media/audio/audio_power_monitor.h"
  11 #include "media/audio/sounds/wav_audio_handler.h"
  12 #include "media/base/audio_bus.h"
  13
  14 namespace {
  15 // Opens |wav_filename|, reads it and loads it as a wav file. This function will
  16 // bluntly trigger CHECKs if we can't read the file or if it's malformed. The
  17 // caller takes ownership of the returned data. The size of the data is stored
  18 // in |read_length|.
  19 scoped_ptr<uint8[]> ReadWavFile(const base::FilePath& wav_filename,
  20                                 size_t* file_length) {
  21   base::File wav_file(
  22       wav_filename, base::File::FLAG_OPEN | base::File::FLAG_READ);
  23   if (!wav_file.IsValid()) {
  24     CHECK(false) << "Failed to read " << wav_filename.value();
  25     return nullptr;
  26   }
  27
  28   size_t wav_file_length = wav_file.GetLength();
  29
  30   uint8* wav_file_data = new uint8[wav_file_length];
  31   size_t read_bytes = wav_file.Read(0, reinterpret_cast<char*>(wav_file_data),
  32                                     wav_file_length);
  33   if (read_bytes != wav_file_length) {
  34     CHECK(false) << "Failed to read all bytes of " << wav_filename.value();
  35     return nullptr;
  36   }
  37   *file_length = wav_file_length;
  38   return scoped_ptr<uint8[]>(wav_file_data);
  39 }
  40
  41 scoped_ptr<media::WavAudioHandler> CreateWavAudioHandler(
  42     const base::FilePath& wav_filename, const uint8* wav_file_data,
  43     size_t wav_file_length) {
  44   base::StringPiece wav_data(reinterpret_cast<const char*>(wav_file_data),
  45                              wav_file_length);
  46   scoped_ptr<media::WavAudioHandler> wav_audio_handler(
  47       new media::WavAudioHandler(wav_data));
  48
  49   return wav_audio_handler.Pass();
  50 }
  51
  52 }  // namespace
  53
  54 namespace test {
  55
  56 float ComputeAudioEnergyForWavFile(const base::FilePath& wav_filename,
  57                                    media::AudioParameters* file_parameters) {
  58   // Read the file, and put its data in a scoped_ptr so it gets deleted later.
  59   size_t file_length = 0;
  60   scoped_ptr<uint8[]> wav_file_data = ReadWavFile(wav_filename, &file_length);
  61   scoped_ptr<media::WavAudioHandler> wav_audio_handler = CreateWavAudioHandler(
  62       wav_filename, wav_file_data.get(), file_length);
  63
  64   scoped_ptr<media::AudioBus> audio_bus = media::AudioBus::Create(
  65       wav_audio_handler->num_channels(), wav_audio_handler->total_frames());
  66   base::TimeDelta file_duration = wav_audio_handler->GetDuration();
  67
  68   size_t bytes_written;
  69   wav_audio_handler->CopyTo(audio_bus.get(), 0, &bytes_written);
  70   CHECK_EQ(bytes_written, wav_audio_handler->data().size())
  71       << "Expected to write entire file into bus.";
  72
  73   // Set the filter coefficient to the whole file's duration; this will make the
  74   // power monitor take the entire file into account.
  75   media::AudioPowerMonitor power_monitor(wav_audio_handler->sample_rate(),
  76                                          file_duration);
  77   power_monitor.Scan(*audio_bus, audio_bus->frames());
  78
  79   file_parameters->Reset(
  80       media::AudioParameters::AUDIO_PCM_LOW_LATENCY,
  81       media::GuessChannelLayout(wav_audio_handler->num_channels()),
  82       wav_audio_handler->sample_rate(), wav_audio_handler->bits_per_sample(),
  83       wav_audio_handler->total_frames());
  84   file_parameters->set_channels_for_discrete(wav_audio_handler->num_channels());
  85
  86   return power_monitor.ReadCurrentPowerAndClip().first;
  87 }
  88
  89 }  // namespace test