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Added Blackman-Harris 7 term FFT window

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This commit is contained in:
f4exb 2022-05-18 22:21:12 +02:00
parent fd69174a51
commit 0a83f50821
6 changed files with 43 additions and 6 deletions
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5
plugins/channelrx/demodchirpchat/chirpchatdemodgui.ui
View File

@ -336,6 +336,11 @@
<string>Black</string>
</property>
</item>
<item>
<property name="text">
<string>B-H7</string>
</property>
</item>
</widget>
</item>
<item>

5
plugins/channelrx/demodssb/ssbdemodgui.ui
View File

@ -415,6 +415,11 @@
<string>Black</string>
</property>
</item>
<item>
<property name="text">
<string>B-H7</string>
</property>
</item>
</widget>
</item>
<item>

3
plugins/channelrx/demodssb/ssbdemodsettings.cpp
View File

@ -188,7 +188,8 @@ bool SSBDemodSettings::deserialize(const QByteArray& data)
d.readS32(102+ 10*i, &tmp, 3);
m_filterBank[i].m_lowCutoff = tmp * 100.0;
d.readS32(103 + 10*i, &tmp, (int) FFTWindow::Blackman);
m_filterBank[i].m_fftWindow = (FFTWindow::Function) (tmp < 0 ? 0 : tmp > (int) FFTWindow::Blackman ? (int) FFTWindow::Blackman : tmp);
m_filterBank[i].m_fftWindow =
(FFTWindow::Function) (tmp < 0 ? 0 : tmp > (int) FFTWindow::BlackmanHarris7 ? (int) FFTWindow::BlackmanHarris7 : tmp);
}
return true;

4
sdrbase/dsp/fftwindow.cpp
View File

@ -76,6 +76,10 @@ void FFTWindow::create(Function function, int n)
wFunc = blackman;
break;
case BlackmanHarris7:
wFunc = blackmanHarris7;
break;
case Rectangle:
default:
wFunc = rectangle;

27
sdrbase/dsp/fftwindow.h
View File

@ -34,7 +34,8 @@ public:
Hanning,
Rectangle,
Kaiser,
Blackman
Blackman,
BlackmanHarris7
};
FFTWindow();
@ -65,15 +66,31 @@ private:
return (2.0 / (n - 1.0)) * ( (n - 1.0) / 2.0 - fabs(i - (n - 1.0) / 2.0)) * 2.0;
}
static inline Real blackmanHarris(Real n, Real i)
static inline Real blackmanHarris(Real n, Real i) // 4 term Blackman-Harris
{
// amplitude correction = 2.79
return (0.35875 - 0.48829 * cos((2.0 * M_PI * i) / n) + 0.14128 * cos((4.0 * M_PI * i) / n) - 0.01168 * cos((6.0 * M_PI * i) / n)) * 2.79;
return (0.35875
- 0.48829 * cos((2.0 * M_PI * i) / n)
+ 0.14128 * cos((4.0 * M_PI * i) / n)
- 0.01168 * cos((6.0 * M_PI * i) / n)) * 2.79;
}
static inline Real blackman(Real n, Real i)
static inline Real blackmanHarris7(Real n, Real i) // 7 term Blackman-Harris
{
return (0.27105
- 0.43330 * cos((2.0 * M_PI * i) / n)
+ 0.21812 * cos((4.0 * M_PI * i) / n)
- 0.065925 * cos((6.0 * M_PI * i) / n)
+ 0.010812 * cos((8.0 * M_PI * i) / n)
- 0.00077658 * cos((10.0 * M_PI * i) / n)
+ 0.000013887 * cos((12.0 * M_PI * i) / n)) * 3.72;
}
static inline Real blackman(Real n, Real i) // 3 term Blackman
{
return (0.42438 - 0.49734 * cos(2.0 * M_PI * i / n) + 0.078279 * cos(4.0 * M_PI * i / n)) * 2.37;
return (0.42438
- 0.49734 * cos(2.0 * M_PI * i / n)
+ 0.078279 * cos(4.0 * M_PI * i / n)) * 2.37;
}
static inline Real hamming(Real n, Real i)

5
sdrgui/gui/glspectrumgui.ui
View File

@ -106,6 +106,11 @@
<string>Black</string>
</property>
</item>
<item>
<property name="text">
<string>B-H7</string>
</property>
</item>
</widget>
</item>
<item>