demos/spectrum/app/wavfile.cpp
changeset 25 e24348a560a6
child 29 b72c6db6890b
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/demos/spectrum/app/wavfile.cpp	Fri Jun 11 14:24:45 2010 +0300
@@ -0,0 +1,247 @@
+/****************************************************************************
+**
+** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtCore/qendian.h>
+#include <QVector>
+#include <QDebug>
+#include "utils.h"
+#include "wavfile.h"
+
+struct chunk
+{
+    char        id[4];
+    quint32     size;
+};
+
+struct RIFFHeader
+{
+    chunk       descriptor;     // "RIFF"
+    char        type[4];        // "WAVE"
+};
+
+struct WAVEHeader
+{
+    chunk       descriptor;
+    quint16     audioFormat;
+    quint16     numChannels;
+    quint32     sampleRate;
+    quint32     byteRate;
+    quint16     blockAlign;
+    quint16     bitsPerSample;
+};
+
+struct DATAHeader
+{
+    chunk       descriptor;
+};
+
+struct CombinedHeader
+{
+    RIFFHeader  riff;
+    WAVEHeader  wave;
+    DATAHeader  data;
+};
+
+static const int HeaderLength = sizeof(CombinedHeader);
+
+
+WavFile::WavFile(const QAudioFormat &format, qint64 dataLength)
+    :   m_format(format)
+    ,   m_dataLength(dataLength)
+{
+
+}
+
+bool WavFile::readHeader(QIODevice &device)
+{
+    bool result = true;
+
+    if (!device.isSequential())
+        result = device.seek(0);
+    // else, assume that current position is the start of the header
+
+    if (result) {
+        CombinedHeader header;
+        result = (device.read(reinterpret_cast<char *>(&header), HeaderLength) == HeaderLength);
+        if (result) {
+            if ((memcmp(&header.riff.descriptor.id, "RIFF", 4) == 0
+                || memcmp(&header.riff.descriptor.id, "RIFX", 4) == 0)
+                && memcmp(&header.riff.type, "WAVE", 4) == 0
+                && memcmp(&header.wave.descriptor.id, "fmt ", 4) == 0
+                && header.wave.audioFormat == 1 // PCM
+            ) {
+                if (memcmp(&header.riff.descriptor.id, "RIFF", 4) == 0)
+                    m_format.setByteOrder(QAudioFormat::LittleEndian);
+                else
+                    m_format.setByteOrder(QAudioFormat::BigEndian);
+
+                m_format.setChannels(qFromLittleEndian<quint16>(header.wave.numChannels));
+                m_format.setCodec("audio/pcm");
+                m_format.setFrequency(qFromLittleEndian<quint32>(header.wave.sampleRate));
+                m_format.setSampleSize(qFromLittleEndian<quint16>(header.wave.bitsPerSample));
+
+                switch(header.wave.bitsPerSample) {
+                case 8:
+                    m_format.setSampleType(QAudioFormat::UnSignedInt);
+                    break;
+                case 16:
+                    m_format.setSampleType(QAudioFormat::SignedInt);
+                    break;
+                default:
+                    result = false;
+                }
+
+                m_dataLength = device.size() - HeaderLength;
+            } else {
+                result = false;
+            }
+        }
+    }
+
+    return result;
+}
+
+bool WavFile::writeHeader(QIODevice &device)
+{
+    CombinedHeader header;
+
+    memset(&header, 0, HeaderLength);
+
+    // RIFF header
+    if (m_format.byteOrder() == QAudioFormat::LittleEndian)
+        strncpy(&header.riff.descriptor.id[0], "RIFF", 4);
+    else
+        strncpy(&header.riff.descriptor.id[0], "RIFX", 4);
+    qToLittleEndian<quint32>(quint32(m_dataLength + HeaderLength - 8),
+                             reinterpret_cast<unsigned char*>(&header.riff.descriptor.size));
+    strncpy(&header.riff.type[0], "WAVE", 4);
+
+    // WAVE header
+    strncpy(&header.wave.descriptor.id[0], "fmt ", 4);
+    qToLittleEndian<quint32>(quint32(16),
+                             reinterpret_cast<unsigned char*>(&header.wave.descriptor.size));
+    qToLittleEndian<quint16>(quint16(1),
+                             reinterpret_cast<unsigned char*>(&header.wave.audioFormat));
+    qToLittleEndian<quint16>(quint16(m_format.channels()),
+                             reinterpret_cast<unsigned char*>(&header.wave.numChannels));
+    qToLittleEndian<quint32>(quint32(m_format.frequency()),
+                             reinterpret_cast<unsigned char*>(&header.wave.sampleRate));
+    qToLittleEndian<quint32>(quint32(m_format.frequency() * m_format.channels() * m_format.sampleSize() / 8),
+                             reinterpret_cast<unsigned char*>(&header.wave.byteRate));
+    qToLittleEndian<quint16>(quint16(m_format.channels() * m_format.sampleSize() / 8),
+                             reinterpret_cast<unsigned char*>(&header.wave.blockAlign));
+    qToLittleEndian<quint16>(quint16(m_format.sampleSize()),
+                             reinterpret_cast<unsigned char*>(&header.wave.bitsPerSample));
+
+    // DATA header
+    strncpy(&header.data.descriptor.id[0], "data", 4);
+    qToLittleEndian<quint32>(quint32(m_dataLength),
+                             reinterpret_cast<unsigned char*>(&header.data.descriptor.size));
+
+    return (device.write(reinterpret_cast<const char *>(&header), HeaderLength) == HeaderLength);
+}
+
+const QAudioFormat& WavFile::format() const
+{
+    return m_format;
+}
+
+qint64 WavFile::dataLength() const
+{
+    return m_dataLength;
+}
+
+qint64 WavFile::headerLength()
+{
+    return HeaderLength;
+}
+
+bool WavFile::writeDataLength(QIODevice &device, qint64 dataLength)
+{
+    bool result = false;
+    if (!device.isSequential()) {
+        device.seek(40);
+        unsigned char dataLengthLE[4];
+        qToLittleEndian<quint32>(quint32(dataLength), dataLengthLE);
+        result = (device.write(reinterpret_cast<const char *>(dataLengthLE), 4) == 4);
+    }
+    return result;
+}
+
+#include <QFile>
+#include <QTextStream>
+
+qint64 WavFile::readData(QIODevice &device, QByteArray &buffer,
+                         QAudioFormat outputFormat)
+{
+    if (QAudioFormat() == outputFormat)
+        outputFormat = m_format;
+
+    qint64 result = 0;
+
+    QFile file("wav.txt");
+    file.open(QIODevice::WriteOnly | QIODevice::Text);
+    QTextStream stream;
+    stream.setDevice(&file);
+
+    if (isPCMS16LE(outputFormat) && isPCMS16LE(m_format)) {
+        QVector<char> inputSample(2 * m_format.channels());
+
+        qint16 *output = reinterpret_cast<qint16*>(buffer.data());
+
+        while (result < buffer.size()) {
+            if (device.read(inputSample.data(), inputSample.count())) {
+                int inputIdx = 0;
+                for (int outputIdx = 0; outputIdx < outputFormat.channels(); ++outputIdx) {
+                    const qint16* input = reinterpret_cast<const qint16*>(inputSample.data() + 2 * inputIdx);
+                    *output++ = qFromLittleEndian<qint16>(*input);
+                    result += 2;
+                    if (inputIdx < m_format.channels())
+                        ++inputIdx;
+                }
+            } else {
+                break;
+            }
+        }
+    }
+    return result;
+}
+