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.
5 #include "media/cast/test/utility/audio_utility.h"
7 #include "base/time/time.h"
8 #include "media/base/audio_bus.h"
9 #include "media/cast/cast_config.h"
14 TestAudioBusFactory::TestAudioBusFactory(int num_channels,
16 float sine_wave_frequency,
18 : num_channels_(num_channels),
19 sample_rate_(sample_rate),
21 source_(num_channels, sine_wave_frequency, sample_rate) {
22 CHECK_LT(0, num_channels);
23 CHECK_LT(0, sample_rate);
24 CHECK_LE(0.0f, volume_);
25 CHECK_LE(volume_, 1.0f);
28 TestAudioBusFactory::~TestAudioBusFactory() {}
30 scoped_ptr<AudioBus> TestAudioBusFactory::NextAudioBus(
31 const base::TimeDelta& duration) {
32 const int num_samples = static_cast<int>((sample_rate_ * duration) /
33 base::TimeDelta::FromSeconds(1));
34 scoped_ptr<AudioBus> bus(AudioBus::Create(num_channels_, num_samples));
35 source_.OnMoreData(bus.get(), AudioBuffersState());
40 scoped_ptr<PcmAudioFrame> ToPcmAudioFrame(const AudioBus& audio_bus,
42 scoped_ptr<PcmAudioFrame> audio_frame(new PcmAudioFrame());
43 audio_frame->channels = audio_bus.channels();
44 audio_frame->frequency = sample_rate;
45 audio_frame->samples.resize(audio_bus.channels() * audio_bus.frames());
46 audio_bus.ToInterleaved(audio_bus.frames(),
47 sizeof(audio_frame->samples.front()),
48 &audio_frame->samples.front());
49 return audio_frame.Pass();
52 int CountZeroCrossings(const std::vector<int16>& samples) {
53 // The sample values must pass beyond |kAmplitudeThreshold| on the opposite
54 // side of zero before a crossing will be counted.
55 const int kAmplitudeThreshold = 1000; // Approx. 3% of max amplitude.
58 std::vector<int16>::const_iterator i = samples.begin();
60 for (; i != samples.end() && abs(last) < kAmplitudeThreshold; ++i)
62 for (; i != samples.end(); ++i) {
63 if (abs(*i) >= kAmplitudeThreshold && (last < 0) != (*i < 0)) {