1b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org/* 2b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * Copyright (c) 2012 The WebRTC project authors. All Rights Reserved. 3b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * 4b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * Use of this source code is governed by a BSD-style license 5b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * that can be found in the LICENSE file in the root of the source 6b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * tree. An additional intellectual property rights grant can be found 7b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * in the file PATENTS. All contributing project authors may 8b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * be found in the AUTHORS file in the root of the source tree. 9b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org */ 10b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 11f24ac5923cbe5e806fac59a0d15e32567553ce8epbos@webrtc.org#include "webrtc/common_audio/signal_processing/include/real_fft.h" 12f24ac5923cbe5e806fac59a0d15e32567553ce8epbos@webrtc.org#include "webrtc/common_audio/signal_processing/include/signal_processing_library.h" 13294081c207c80bb5acca7caf078c28eccb730775stefan@webrtc.org#include "webrtc/test/testsupport/gtest_disable.h" 14f24ac5923cbe5e806fac59a0d15e32567553ce8epbos@webrtc.org#include "webrtc/typedefs.h" 15b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 16f24ac5923cbe5e806fac59a0d15e32567553ce8epbos@webrtc.org#include "testing/gtest/include/gtest/gtest.h" 17b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 18b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.orgnamespace webrtc { 19b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.orgnamespace { 20b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 21d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org// FFT order. 22d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.orgconst int kOrder = 5; 23d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org// Lengths for real FFT's time and frequency bufffers. 24d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org// For N-point FFT, the length requirements from API are N and N+2 respectively. 25d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.orgconst int kTimeDataLength = 1 << kOrder; 26d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.orgconst int kFreqDataLength = (1 << kOrder) + 2; 27d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org// For complex FFT's time and freq buffer. The implementation requires 28d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org// 2*N 16-bit words. 29d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.orgconst int kComplexFftDataLength = 2 << kOrder; 30d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org// Reference data for time signal. 31d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.orgconst int16_t kRefData[kTimeDataLength] = { 32b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 11739, 6848, -8688, 31980, -30295, 25242, 27085, 19410, 33b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org -26299, 15607, -10791, 11778, -23819, 14498, -25772, 10076, 34b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 1173, 6848, -8688, 31980, -30295, 2522, 27085, 19410, 35b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org -2629, 5607, -3, 1178, -23819, 1498, -25772, 10076 36b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org}; 37b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 38b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.orgclass RealFFTTest : public ::testing::Test { 39b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org protected: 40b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org RealFFTTest() { 41b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org WebRtcSpl_Init(); 42b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org } 43b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org}; 44b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 45b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.orgTEST_F(RealFFTTest, CreateFailsOnBadInput) { 46b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org RealFFT* fft = WebRtcSpl_CreateRealFFT(11); 47b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org EXPECT_TRUE(fft == NULL); 48b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org fft = WebRtcSpl_CreateRealFFT(-1); 49b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org EXPECT_TRUE(fft == NULL); 50b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org} 51b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 52ff6b4a8eddca609ad2691b54f443b6f1e9342579bjornv@webrtc.orgTEST_F(RealFFTTest, RealAndComplexMatch) { 53d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org int i = 0; 54d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org int j = 0; 55d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org int16_t real_fft_time[kTimeDataLength] = {0}; 56d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org int16_t real_fft_freq[kFreqDataLength] = {0}; 57d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org // One common buffer for complex FFT's time and frequency data. 58d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org int16_t complex_fft_buff[kComplexFftDataLength] = {0}; 59b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 60d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org // Prepare the inputs to forward FFT's. 61d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org memcpy(real_fft_time, kRefData, sizeof(kRefData)); 62d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org for (i = 0, j = 0; i < kTimeDataLength; i += 1, j += 2) { 63d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org complex_fft_buff[j] = kRefData[i]; 64d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org complex_fft_buff[j + 1] = 0; // Insert zero's to imaginary parts. 65d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org }; 66d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org 67d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org // Create and run real forward FFT. 68b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org RealFFT* fft = WebRtcSpl_CreateRealFFT(kOrder); 69b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org EXPECT_TRUE(fft != NULL); 70d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org EXPECT_EQ(0, WebRtcSpl_RealForwardFFT(fft, real_fft_time, real_fft_freq)); 71b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 72d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org // Run complex forward FFT. 73d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org WebRtcSpl_ComplexBitReverse(complex_fft_buff, kOrder); 74d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org EXPECT_EQ(0, WebRtcSpl_ComplexFFT(complex_fft_buff, kOrder, 1)); 75b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 76d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org // Verify the results between complex and real forward FFT. 77d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org for (i = 0; i < kFreqDataLength; i++) { 78d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org EXPECT_EQ(real_fft_freq[i], complex_fft_buff[i]); 79b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org } 80b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 81d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org // Prepare the inputs to inverse real FFT. 82d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org // We use whatever data in complex_fft_buff[] since we don't care 83d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org // about data contents. Only kFreqDataLength 16-bit words are copied 84d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org // from complex_fft_buff to real_fft_freq since remaining words (2nd half) 85d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org // are conjugate-symmetric to the first half in theory. 86d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org memcpy(real_fft_freq, complex_fft_buff, sizeof(real_fft_freq)); 87b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 88d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org // Run real inverse FFT. 89d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org int real_scale = WebRtcSpl_RealInverseFFT(fft, real_fft_freq, real_fft_time); 90b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org EXPECT_GE(real_scale, 0); 91d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org 92d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org // Run complex inverse FFT. 93d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org WebRtcSpl_ComplexBitReverse(complex_fft_buff, kOrder); 94d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org int complex_scale = WebRtcSpl_ComplexIFFT(complex_fft_buff, kOrder, 1); 95d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org 96d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org // Verify the results between complex and real inverse FFT. 97d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org // They are not bit-exact, since complex IFFT doesn't produce 98d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org // exactly conjugate-symmetric data (between first and second half). 99b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org EXPECT_EQ(real_scale, complex_scale); 100d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org for (i = 0, j = 0; i < kTimeDataLength; i += 1, j += 2) { 101d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org EXPECT_LE(abs(real_fft_time[i] - complex_fft_buff[j]), 1); 102b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org } 103d3b8af78ee1b571635646409b34827a7b3ed2c85kma@webrtc.org 104b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org WebRtcSpl_FreeRealFFT(fft); 105b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org} 106b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 107b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org} // namespace 108b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org} // namespace webrtc 109