| /* |
| * 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 "webrtc/common_audio/channel_buffer.h" |
| #include "webrtc/modules/audio_processing/splitting_filter.h" |
| #include "webrtc/test/gtest.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 |