/*
|
* Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
|
*
|
* Use of this source code is governed by a BSD-style license
|
* that can be found in the LICENSE file in the root of the source
|
* tree. An additional intellectual property rights grant can be found
|
* in the file PATENTS. All contributing project authors may
|
* be found in the AUTHORS file in the root of the source tree.
|
*/
|
|
// MSVC++ requires this to be set before any other includes to get M_PI.
|
#define _USE_MATH_DEFINES
|
|
#include <cmath>
|
|
#include "testing/gtest/include/gtest/gtest.h"
|
#include "webrtc/common_audio/channel_buffer.h"
|
#include "webrtc/modules/audio_processing/splitting_filter.h"
|
|
namespace webrtc {
|
namespace {
|
|
const size_t kSamplesPer16kHzChannel = 160;
|
const size_t kSamplesPer48kHzChannel = 480;
|
|
} // namespace
|
|
// Generates a signal from presence or absence of sine waves of different
|
// frequencies.
|
// Splits into 3 bands and checks their presence or absence.
|
// Recombines the bands.
|
// Calculates the delay.
|
// Checks that the cross correlation of input and output is high enough at the
|
// calculated delay.
|
TEST(SplittingFilterTest, SplitsIntoThreeBandsAndReconstructs) {
|
static const int kChannels = 1;
|
static const int kSampleRateHz = 48000;
|
static const size_t kNumBands = 3;
|
static const int kFrequenciesHz[kNumBands] = {1000, 12000, 18000};
|
static const float kAmplitude = 8192.f;
|
static const size_t kChunks = 8;
|
SplittingFilter splitting_filter(kChannels,
|
kNumBands,
|
kSamplesPer48kHzChannel);
|
IFChannelBuffer in_data(kSamplesPer48kHzChannel, kChannels, kNumBands);
|
IFChannelBuffer bands(kSamplesPer48kHzChannel, kChannels, kNumBands);
|
IFChannelBuffer out_data(kSamplesPer48kHzChannel, kChannels, kNumBands);
|
for (size_t i = 0; i < kChunks; ++i) {
|
// Input signal generation.
|
bool is_present[kNumBands];
|
memset(in_data.fbuf()->channels()[0],
|
0,
|
kSamplesPer48kHzChannel * sizeof(in_data.fbuf()->channels()[0][0]));
|
for (size_t j = 0; j < kNumBands; ++j) {
|
is_present[j] = i & (static_cast<size_t>(1) << j);
|
float amplitude = is_present[j] ? kAmplitude : 0.f;
|
for (size_t k = 0; k < kSamplesPer48kHzChannel; ++k) {
|
in_data.fbuf()->channels()[0][k] +=
|
amplitude * sin(2.f * M_PI * kFrequenciesHz[j] *
|
(i * kSamplesPer48kHzChannel + k) / kSampleRateHz);
|
}
|
}
|
// Three band splitting filter.
|
splitting_filter.Analysis(&in_data, &bands);
|
// Energy calculation.
|
float energy[kNumBands];
|
for (size_t j = 0; j < kNumBands; ++j) {
|
energy[j] = 0.f;
|
for (size_t k = 0; k < kSamplesPer16kHzChannel; ++k) {
|
energy[j] += bands.fbuf_const()->channels(j)[0][k] *
|
bands.fbuf_const()->channels(j)[0][k];
|
}
|
energy[j] /= kSamplesPer16kHzChannel;
|
if (is_present[j]) {
|
EXPECT_GT(energy[j], kAmplitude * kAmplitude / 4);
|
} else {
|
EXPECT_LT(energy[j], kAmplitude * kAmplitude / 4);
|
}
|
}
|
// Three band merge.
|
splitting_filter.Synthesis(&bands, &out_data);
|
// Delay and cross correlation estimation.
|
float xcorr = 0.f;
|
for (size_t delay = 0; delay < kSamplesPer48kHzChannel; ++delay) {
|
float tmpcorr = 0.f;
|
for (size_t j = delay; j < kSamplesPer48kHzChannel; ++j) {
|
tmpcorr += in_data.fbuf_const()->channels()[0][j - delay] *
|
out_data.fbuf_const()->channels()[0][j];
|
}
|
tmpcorr /= kSamplesPer48kHzChannel;
|
if (tmpcorr > xcorr) {
|
xcorr = tmpcorr;
|
}
|
}
|
// High cross correlation check.
|
bool any_present = false;
|
for (size_t j = 0; j < kNumBands; ++j) {
|
any_present |= is_present[j];
|
}
|
if (any_present) {
|
EXPECT_GT(xcorr, kAmplitude * kAmplitude / 4);
|
}
|
}
|
}
|
|
} // namespace webrtc
|
