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50
51#include <qendian.h>
52#include "wavfile.h"
53
54struct chunk
55{
56 char id[4];
57 quint32 size;
58};
59
60struct RIFFHeader
61{
62 chunk descriptor; // "RIFF"
63 char type[4]; // "WAVE"
64};
65
66struct WAVEHeader
67{
68 chunk descriptor;
69 quint16 audioFormat;
70 quint16 numChannels;
71 quint32 sampleRate;
72 quint32 byteRate;
73 quint16 blockAlign;
74 quint16 bitsPerSample;
75};
76
77struct DATAHeader
78{
79 chunk descriptor;
80};
81
82struct CombinedHeader
83{
84 RIFFHeader riff;
85 WAVEHeader wave;
86};
87
88WavFile::WavFile(QObject *parent)
89 : QFile(parent)
90 , m_headerLength(0)
91{
92
93}
94
95bool WavFile::open(const QString &fileName)
96{
97 close();
98 setFileName(fileName);
99 return QFile::open(flags: QIODevice::ReadOnly) && readHeader();
100}
101
102const QAudioFormat &WavFile::fileFormat() const
103{
104 return m_fileFormat;
105}
106
107qint64 WavFile::headerLength() const
108{
109 return m_headerLength;
110}
111
112bool WavFile::readHeader()
113{
114 seek(offset: 0);
115 CombinedHeader header;
116 bool result = read(data: reinterpret_cast<char *>(&header), maxlen: sizeof(CombinedHeader)) == sizeof(CombinedHeader);
117 if (result) {
118 if ((memcmp(s1: &header.riff.descriptor.id, s2: "RIFF", n: 4) == 0
119 || memcmp(s1: &header.riff.descriptor.id, s2: "RIFX", n: 4) == 0)
120 && memcmp(s1: &header.riff.type, s2: "WAVE", n: 4) == 0
121 && memcmp(s1: &header.wave.descriptor.id, s2: "fmt ", n: 4) == 0
122 && (header.wave.audioFormat == 1 || header.wave.audioFormat == 0)) {
123
124 // Read off remaining header information
125 DATAHeader dataHeader;
126
127 if (qFromLittleEndian<quint32>(source: header.wave.descriptor.size) > sizeof(WAVEHeader)) {
128 // Extended data available
129 quint16 extraFormatBytes;
130 if (peek(data: (char*)&extraFormatBytes, maxlen: sizeof(quint16)) != sizeof(quint16))
131 return false;
132 const qint64 throwAwayBytes = sizeof(quint16) + qFromLittleEndian<quint16>(source: extraFormatBytes);
133 if (read(maxlen: throwAwayBytes).size() != throwAwayBytes)
134 return false;
135 }
136
137 if (read(data: (char*)&dataHeader, maxlen: sizeof(DATAHeader)) != sizeof(DATAHeader))
138 return false;
139
140 // Establish format
141 if (memcmp(s1: &header.riff.descriptor.id, s2: "RIFF", n: 4) == 0)
142 m_fileFormat.setByteOrder(QAudioFormat::LittleEndian);
143 else
144 m_fileFormat.setByteOrder(QAudioFormat::BigEndian);
145
146 int bps = qFromLittleEndian<quint16>(source: header.wave.bitsPerSample);
147 m_fileFormat.setChannelCount(qFromLittleEndian<quint16>(source: header.wave.numChannels));
148 m_fileFormat.setCodec("audio/pcm");
149 m_fileFormat.setSampleRate(qFromLittleEndian<quint32>(source: header.wave.sampleRate));
150 m_fileFormat.setSampleSize(qFromLittleEndian<quint16>(source: header.wave.bitsPerSample));
151 m_fileFormat.setSampleType(bps == 8 ? QAudioFormat::UnSignedInt : QAudioFormat::SignedInt);
152 } else {
153 result = false;
154 }
155 }
156 m_headerLength = pos();
157 return result;
158}
159

source code of qtmultimedia/examples/multimedia/spectrum/app/wavfile.cpp