source: trunk/demos/spectrum/app/spectrumanalyser.cpp@ 769

Last change on this file since 769 was 769, checked in by Dmitry A. Kuminov, 15 years ago

trunk: Merged in qt 4.6.3 sources from branches/vendor/nokia/qt.

File size: 9.2 KB
Line 
1/****************************************************************************
2**
3** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
4** All rights reserved.
5** Contact: Nokia Corporation ([email protected])
6**
7** This file is part of the examples of the Qt Toolkit.
8**
9** $QT_BEGIN_LICENSE:BSD$
10** You may use this file under the terms of the BSD license as follows:
11**
12** "Redistribution and use in source and binary forms, with or without
13** modification, are permitted provided that the following conditions are
14** met:
15** * Redistributions of source code must retain the above copyright
16** notice, this list of conditions and the following disclaimer.
17** * Redistributions in binary form must reproduce the above copyright
18** notice, this list of conditions and the following disclaimer in
19** the documentation and/or other materials provided with the
20** distribution.
21** * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor
22** the names of its contributors may be used to endorse or promote
23** products derived from this software without specific prior written
24** permission.
25**
26** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
27** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
28** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
29** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
30** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
31** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
32** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
33** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
34** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
35** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
36** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
37** $QT_END_LICENSE$
38**
39****************************************************************************/
40
41#include "spectrumanalyser.h"
42#include "utils.h"
43
44#include <QtCore/qmath.h>
45#include <QtCore/qmetatype.h>
46#include <QtMultimedia/QAudioFormat>
47#include <QThread>
48
49#include "fftreal_wrapper.h"
50
51SpectrumAnalyserThread::SpectrumAnalyserThread(QObject *parent)
52 : QObject(parent)
53#ifndef DISABLE_FFT
54 , m_fft(new FFTRealWrapper)
55#endif
56 , m_numSamples(SpectrumLengthSamples)
57 , m_windowFunction(DefaultWindowFunction)
58 , m_window(SpectrumLengthSamples, 0.0)
59 , m_input(SpectrumLengthSamples, 0.0)
60 , m_output(SpectrumLengthSamples, 0.0)
61 , m_spectrum(SpectrumLengthSamples)
62#ifdef SPECTRUM_ANALYSER_SEPARATE_THREAD
63 , m_thread(new QThread(this))
64#endif
65{
66#ifdef SPECTRUM_ANALYSER_SEPARATE_THREAD
67 moveToThread(m_thread);
68 m_thread->start();
69#endif
70 calculateWindow();
71}
72
73SpectrumAnalyserThread::~SpectrumAnalyserThread()
74{
75#ifndef DISABLE_FFT
76 delete m_fft;
77#endif
78}
79
80void SpectrumAnalyserThread::setWindowFunction(WindowFunction type)
81{
82 m_windowFunction = type;
83 calculateWindow();
84}
85
86void SpectrumAnalyserThread::calculateWindow()
87{
88 for (int i=0; i<m_numSamples; ++i) {
89 DataType x = 0.0;
90
91 switch (m_windowFunction) {
92 case NoWindow:
93 x = 1.0;
94 break;
95 case HannWindow:
96 x = 0.5 * (1 - qCos((2 * M_PI * i) / (m_numSamples - 1)));
97 break;
98 default:
99 Q_ASSERT(false);
100 }
101
102 m_window[i] = x;
103 }
104}
105
106void SpectrumAnalyserThread::calculateSpectrum(const QByteArray &buffer,
107 int inputFrequency,
108 int bytesPerSample)
109{
110#ifndef DISABLE_FFT
111 Q_ASSERT(buffer.size() == m_numSamples * bytesPerSample);
112
113 // Initialize data array
114 const char *ptr = buffer.constData();
115 for (int i=0; i<m_numSamples; ++i) {
116 const qint16 pcmSample = *reinterpret_cast<const qint16*>(ptr);
117 // Scale down to range [-1.0, 1.0]
118 const DataType realSample = pcmToReal(pcmSample);
119 const DataType windowedSample = realSample * m_window[i];
120 m_input[i] = windowedSample;
121 ptr += bytesPerSample;
122 }
123
124 // Calculate the FFT
125 m_fft->calculateFFT(m_output.data(), m_input.data());
126
127 // Analyse output to obtain amplitude and phase for each frequency
128 for (int i=2; i<=m_numSamples/2; ++i) {
129 // Calculate frequency of this complex sample
130 m_spectrum[i].frequency = qreal(i * inputFrequency) / (m_numSamples);
131
132 const qreal real = m_output[i];
133 qreal imag = 0.0;
134 if (i>0 && i<m_numSamples/2)
135 imag = m_output[m_numSamples/2 + i];
136
137 const qreal magnitude = sqrt(real*real + imag*imag);
138 qreal amplitude = SpectrumAnalyserMultiplier * log(magnitude);
139
140 // Bound amplitude to [0.0, 1.0]
141 m_spectrum[i].clipped = (amplitude > 1.0);
142 amplitude = qMax(qreal(0.0), amplitude);
143 amplitude = qMin(qreal(1.0), amplitude);
144 m_spectrum[i].amplitude = amplitude;
145 }
146#endif
147
148 emit calculationComplete(m_spectrum);
149}
150
151
152//=============================================================================
153// SpectrumAnalyser
154//=============================================================================
155
156SpectrumAnalyser::SpectrumAnalyser(QObject *parent)
157 : QObject(parent)
158 , m_thread(new SpectrumAnalyserThread(this))
159 , m_state(Idle)
160#ifdef DUMP_SPECTRUMANALYSER
161 , m_count(0)
162#endif
163{
164 CHECKED_CONNECT(m_thread, SIGNAL(calculationComplete(FrequencySpectrum)),
165 this, SLOT(calculationComplete(FrequencySpectrum)));
166}
167
168SpectrumAnalyser::~SpectrumAnalyser()
169{
170
171}
172
173#ifdef DUMP_SPECTRUMANALYSER
174void SpectrumAnalyser::setOutputPath(const QString &outputDir)
175{
176 m_outputDir.setPath(outputDir);
177 m_textFile.setFileName(m_outputDir.filePath("spectrum.txt"));
178 m_textFile.open(QIODevice::WriteOnly | QIODevice::Text);
179 m_textStream.setDevice(&m_textFile);
180}
181#endif
182
183//-----------------------------------------------------------------------------
184// Public functions
185//-----------------------------------------------------------------------------
186
187void SpectrumAnalyser::setWindowFunction(WindowFunction type)
188{
189 const bool b = QMetaObject::invokeMethod(m_thread, "setWindowFunction",
190 Qt::AutoConnection,
191 Q_ARG(WindowFunction, type));
192 Q_ASSERT(b);
193 Q_UNUSED(b) // suppress warnings in release builds
194}
195
196void SpectrumAnalyser::calculate(const QByteArray &buffer,
197 const QAudioFormat &format)
198{
199 // QThread::currentThread is marked 'for internal use only', but
200 // we're only using it for debug output here, so it's probably OK :)
201 SPECTRUMANALYSER_DEBUG << "SpectrumAnalyser::calculate"
202 << QThread::currentThread()
203 << "state" << m_state;
204
205 if (isReady()) {
206 Q_ASSERT(isPCMS16LE(format));
207
208 const int bytesPerSample = format.sampleSize() * format.channels() / 8;
209
210#ifdef DUMP_SPECTRUMANALYSER
211 m_count++;
212 const QString pcmFileName = m_outputDir.filePath(QString("spectrum_%1.pcm").arg(m_count, 4, 10, QChar('0')));
213 QFile pcmFile(pcmFileName);
214 pcmFile.open(QIODevice::WriteOnly);
215 const int bufferLength = m_numSamples * bytesPerSample;
216 pcmFile.write(buffer, bufferLength);
217
218 m_textStream << "TimeDomain " << m_count << "\n";
219 const qint16* input = reinterpret_cast<const qint16*>(buffer);
220 for (int i=0; i<m_numSamples; ++i) {
221 m_textStream << i << "\t" << *input << "\n";
222 input += format.channels();
223 }
224#endif
225
226 m_state = Busy;
227
228 // Invoke SpectrumAnalyserThread::calculateSpectrum using QMetaObject. If
229 // m_thread is in a different thread from the current thread, the
230 // calculation will be done in the child thread.
231 // Once the calculation is finished, a calculationChanged signal will be
232 // emitted by m_thread.
233 const bool b = QMetaObject::invokeMethod(m_thread, "calculateSpectrum",
234 Qt::AutoConnection,
235 Q_ARG(QByteArray, buffer),
236 Q_ARG(int, format.frequency()),
237 Q_ARG(int, bytesPerSample));
238 Q_ASSERT(b);
239 Q_UNUSED(b) // suppress warnings in release builds
240
241#ifdef DUMP_SPECTRUMANALYSER
242 m_textStream << "FrequencySpectrum " << m_count << "\n";
243 FrequencySpectrum::const_iterator x = m_spectrum.begin();
244 for (int i=0; i<m_numSamples; ++i, ++x)
245 m_textStream << i << "\t"
246 << x->frequency << "\t"
247 << x->amplitude<< "\t"
248 << x->phase << "\n";
249#endif
250 }
251}
252
253bool SpectrumAnalyser::isReady() const
254{
255 return (Idle == m_state);
256}
257
258void SpectrumAnalyser::cancelCalculation()
259{
260 if (Busy == m_state)
261 m_state = Cancelled;
262}
263
264
265//-----------------------------------------------------------------------------
266// Private slots
267//-----------------------------------------------------------------------------
268
269void SpectrumAnalyser::calculationComplete(const FrequencySpectrum &spectrum)
270{
271 Q_ASSERT(Idle != m_state);
272 if (Busy == m_state)
273 emit spectrumChanged(spectrum);
274 m_state = Idle;
275}
276
277
278
279
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