aca5939dfc
In r6240 gcc was rolled from 4.6 to 4.8 changing the behavior on arm. The output of ComplexFFT differs causing both AECM and NS to perform worse. Looking at issues on gcc it says that there could be a memory shuffling/optimization despite using volatile affecting the output. Splitting the three instructions in one call into two separate calls makes the compiler take proper actions resulting in correct outputs. BUG=3370,3395 TESTED=trybots R=kwiberg@webrtc.org Review URL: https://webrtc-codereview.appspot.com/21549004 git-svn-id: http://webrtc.googlecode.com/svn/trunk@6261 4adac7df-926f-26a2-2b94-8c16560cd09d
109 lines
3.8 KiB
C++
109 lines
3.8 KiB
C++
/*
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* Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#include "webrtc/common_audio/signal_processing/include/real_fft.h"
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#include "webrtc/common_audio/signal_processing/include/signal_processing_library.h"
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#include "webrtc/test/testsupport/gtest_disable.h"
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#include "webrtc/typedefs.h"
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#include "testing/gtest/include/gtest/gtest.h"
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namespace webrtc {
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namespace {
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// FFT order.
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const int kOrder = 5;
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// Lengths for real FFT's time and frequency bufffers.
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// For N-point FFT, the length requirements from API are N and N+2 respectively.
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const int kTimeDataLength = 1 << kOrder;
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const int kFreqDataLength = (1 << kOrder) + 2;
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// For complex FFT's time and freq buffer. The implementation requires
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// 2*N 16-bit words.
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const int kComplexFftDataLength = 2 << kOrder;
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// Reference data for time signal.
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const int16_t kRefData[kTimeDataLength] = {
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11739, 6848, -8688, 31980, -30295, 25242, 27085, 19410,
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-26299, 15607, -10791, 11778, -23819, 14498, -25772, 10076,
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1173, 6848, -8688, 31980, -30295, 2522, 27085, 19410,
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-2629, 5607, -3, 1178, -23819, 1498, -25772, 10076
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};
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class RealFFTTest : public ::testing::Test {
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protected:
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RealFFTTest() {
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WebRtcSpl_Init();
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}
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};
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TEST_F(RealFFTTest, CreateFailsOnBadInput) {
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RealFFT* fft = WebRtcSpl_CreateRealFFT(11);
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EXPECT_TRUE(fft == NULL);
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fft = WebRtcSpl_CreateRealFFT(-1);
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EXPECT_TRUE(fft == NULL);
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}
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TEST_F(RealFFTTest, RealAndComplexMatch) {
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int i = 0;
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int j = 0;
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int16_t real_fft_time[kTimeDataLength] = {0};
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int16_t real_fft_freq[kFreqDataLength] = {0};
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// One common buffer for complex FFT's time and frequency data.
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int16_t complex_fft_buff[kComplexFftDataLength] = {0};
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// Prepare the inputs to forward FFT's.
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memcpy(real_fft_time, kRefData, sizeof(kRefData));
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for (i = 0, j = 0; i < kTimeDataLength; i += 1, j += 2) {
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complex_fft_buff[j] = kRefData[i];
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complex_fft_buff[j + 1] = 0; // Insert zero's to imaginary parts.
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};
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// Create and run real forward FFT.
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RealFFT* fft = WebRtcSpl_CreateRealFFT(kOrder);
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EXPECT_TRUE(fft != NULL);
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EXPECT_EQ(0, WebRtcSpl_RealForwardFFT(fft, real_fft_time, real_fft_freq));
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// Run complex forward FFT.
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WebRtcSpl_ComplexBitReverse(complex_fft_buff, kOrder);
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EXPECT_EQ(0, WebRtcSpl_ComplexFFT(complex_fft_buff, kOrder, 1));
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// Verify the results between complex and real forward FFT.
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for (i = 0; i < kFreqDataLength; i++) {
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EXPECT_EQ(real_fft_freq[i], complex_fft_buff[i]);
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}
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// Prepare the inputs to inverse real FFT.
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// We use whatever data in complex_fft_buff[] since we don't care
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// about data contents. Only kFreqDataLength 16-bit words are copied
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// from complex_fft_buff to real_fft_freq since remaining words (2nd half)
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// are conjugate-symmetric to the first half in theory.
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memcpy(real_fft_freq, complex_fft_buff, sizeof(real_fft_freq));
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// Run real inverse FFT.
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int real_scale = WebRtcSpl_RealInverseFFT(fft, real_fft_freq, real_fft_time);
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EXPECT_GE(real_scale, 0);
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// Run complex inverse FFT.
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WebRtcSpl_ComplexBitReverse(complex_fft_buff, kOrder);
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int complex_scale = WebRtcSpl_ComplexIFFT(complex_fft_buff, kOrder, 1);
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// Verify the results between complex and real inverse FFT.
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// They are not bit-exact, since complex IFFT doesn't produce
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// exactly conjugate-symmetric data (between first and second half).
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EXPECT_EQ(real_scale, complex_scale);
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for (i = 0, j = 0; i < kTimeDataLength; i += 1, j += 2) {
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EXPECT_LE(abs(real_fft_time[i] - complex_fft_buff[j]), 1);
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}
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WebRtcSpl_FreeRealFFT(fft);
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}
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} // namespace
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} // namespace webrtc
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