1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
|
/*
* Copyright (C) 2012 Igalia S.L
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
// FFTFrame implementation using the GStreamer FFT library.
#include "config.h"
#if USE(WEBAUDIO_GSTREAMER)
#include "FFTFrame.h"
#include "VectorMath.h"
#include <wtf/FastAllocBase.h>
namespace {
size_t unpackedFFTDataSize(unsigned fftSize)
{
return fftSize / 2 + 1;
}
} // anonymous namespace
namespace WebCore {
// Normal constructor: allocates for a given fftSize.
FFTFrame::FFTFrame(unsigned fftSize)
: m_FFTSize(fftSize)
, m_log2FFTSize(static_cast<unsigned>(log2(fftSize)))
, m_realData(unpackedFFTDataSize(m_FFTSize))
, m_imagData(unpackedFFTDataSize(m_FFTSize))
{
m_complexData = WTF::fastNewArray<GstFFTF32Complex>(unpackedFFTDataSize(m_FFTSize));
int fftLength = gst_fft_next_fast_length(m_FFTSize);
m_fft = gst_fft_f32_new(fftLength, FALSE);
m_inverseFft = gst_fft_f32_new(fftLength, TRUE);
}
// Creates a blank/empty frame (interpolate() must later be called).
FFTFrame::FFTFrame()
: m_FFTSize(0)
, m_log2FFTSize(0)
, m_complexData(0)
{
int fftLength = gst_fft_next_fast_length(m_FFTSize);
m_fft = gst_fft_f32_new(fftLength, FALSE);
m_inverseFft = gst_fft_f32_new(fftLength, TRUE);
}
// Copy constructor.
FFTFrame::FFTFrame(const FFTFrame& frame)
: m_FFTSize(frame.m_FFTSize)
, m_log2FFTSize(frame.m_log2FFTSize)
, m_realData(unpackedFFTDataSize(frame.m_FFTSize))
, m_imagData(unpackedFFTDataSize(frame.m_FFTSize))
{
m_complexData = WTF::fastNewArray<GstFFTF32Complex>(unpackedFFTDataSize(m_FFTSize));
int fftLength = gst_fft_next_fast_length(m_FFTSize);
m_fft = gst_fft_f32_new(fftLength, FALSE);
m_inverseFft = gst_fft_f32_new(fftLength, TRUE);
// Copy/setup frame data.
memcpy(realData(), frame.realData(), sizeof(float) * unpackedFFTDataSize(m_FFTSize));
memcpy(imagData(), frame.imagData(), sizeof(float) * unpackedFFTDataSize(m_FFTSize));
}
void FFTFrame::initialize()
{
}
void FFTFrame::cleanup()
{
}
FFTFrame::~FFTFrame()
{
if (!m_fft)
return;
gst_fft_f32_free(m_fft);
m_fft = 0;
gst_fft_f32_free(m_inverseFft);
m_inverseFft = 0;
WTF::fastDeleteArray(m_complexData);
}
void FFTFrame::multiply(const FFTFrame& frame)
{
FFTFrame& frame1 = *this;
FFTFrame& frame2 = const_cast<FFTFrame&>(frame);
float* realP1 = frame1.realData();
float* imagP1 = frame1.imagData();
const float* realP2 = frame2.realData();
const float* imagP2 = frame2.imagData();
size_t size = unpackedFFTDataSize(m_FFTSize);
VectorMath::zvmul(realP1, imagP1, realP2, imagP2, realP1, imagP1, size);
// Scale accounts the peculiar scaling of vecLib on the Mac.
// This ensures the right scaling all the way back to inverse FFT.
// FIXME: if we change the scaling on the Mac then this scale
// factor will need to change too.
float scale = 0.5f;
VectorMath::vsmul(realP1, 1, &scale, realP1, 1, size);
VectorMath::vsmul(imagP1, 1, &scale, imagP1, 1, size);
}
void FFTFrame::doFFT(const float* data)
{
gst_fft_f32_fft(m_fft, data, m_complexData);
// Scale the frequency domain data to match vecLib's scale factor
// on the Mac. FIXME: if we change the definition of FFTFrame to
// eliminate this scale factor then this code will need to change.
// Also, if this loop turns out to be hot then we should use SSE
// or other intrinsics to accelerate it.
float scaleFactor = 2;
float* imagData = m_imagData.data();
float* realData = m_realData.data();
for (unsigned i = 0; i < unpackedFFTDataSize(m_FFTSize); ++i) {
imagData[i] = m_complexData[i].i * scaleFactor;
realData[i] = m_complexData[i].r * scaleFactor;
}
}
void FFTFrame::doInverseFFT(float* data)
{
// Merge the real and imaginary vectors to complex vector.
float* realData = m_realData.data();
float* imagData = m_imagData.data();
for (size_t i = 0; i < unpackedFFTDataSize(m_FFTSize); ++i) {
m_complexData[i].i = imagData[i];
m_complexData[i].r = realData[i];
}
gst_fft_f32_inverse_fft(m_inverseFft, m_complexData, data);
// Scale so that a forward then inverse FFT yields exactly the original data.
const float scaleFactor = 1.0 / (2 * m_FFTSize);
VectorMath::vsmul(data, 1, &scaleFactor, data, 1, m_FFTSize);
}
float* FFTFrame::realData() const
{
return const_cast<float*>(m_realData.data());
}
float* FFTFrame::imagData() const
{
return const_cast<float*>(m_imagData.data());
}
} // namespace WebCore
#endif // USE(WEBAUDIO_GSTREAMER)
|
