1 /****************************************************************************

     2 **

     3 ** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).

     4 ** All rights reserved.

     5 ** Contact: Nokia Corporation (qt-info@nokia.com)

     6 **

     7 ** This file is part of the Qt Mobility Components.

     8 **

     9 ** $QT_BEGIN_LICENSE:LGPL$

    10 ** No Commercial Usage

    11 ** This file contains pre-release code and may not be distributed.

    12 ** You may use this file in accordance with the terms and conditions

    13 ** contained in the Technology Preview License Agreement accompanying

    14 ** this package.

    15 **

    16 ** GNU Lesser General Public License Usage

    17 ** Alternatively, this file may be used under the terms of the GNU Lesser

    18 ** General Public License version 2.1 as published by the Free Software

    19 ** Foundation and appearing in the file LICENSE.LGPL included in the

    20 ** packaging of this file.  Please review the following information to

    21 ** ensure the GNU Lesser General Public License version 2.1 requirements

    22 ** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.

    23 **

    24 ** In addition, as a special exception, Nokia gives you certain additional

    25 ** rights.  These rights are described in the Nokia Qt LGPL Exception

    26 ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.

    27 **

    28 ** If you have questions regarding the use of this file, please contact

    29 ** Nokia at qt-info@nokia.com.

    30 **

    31 **

    32 **

    33 **

    34 **

    35 **

    36 **

    37 **

    38 ** $QT_END_LICENSE$

    39 **

    40 ****************************************************************************/

    41 

    42 #include "wavedecoder.h"

    43 

    44 #include <QtCore/qtimer.h>

    45 #include <QtCore/qendian.h>

    46 #include <QDebug>

    47 

    48 WaveDecoder::WaveDecoder(QIODevice *s, QObject *parent):

    49     QIODevice(parent),

    50     haveFormat(false),

    51     dataSize(0),

    52     remaining(0),

    53     source(s)

    54 {

    55     open(QIODevice::ReadOnly | QIODevice::Unbuffered);

    56 

    57     if (source->bytesAvailable() >= sizeof(CombinedHeader))

    58         QTimer::singleShot(0, this, SLOT(handleData()));

    59     else

    60         connect(source, SIGNAL(readyRead()), SLOT(handleData()));

    61 }

    62 

    63 WaveDecoder::~WaveDecoder()

    64 {

    65 }

    66 

    67 QAudioFormat WaveDecoder::audioFormat() const

    68 {

    69     return format;

    70 }

    71 

    72 int WaveDecoder::duration() const

    73 {

    74     return size() * 1000 / (format.sampleSize() / 8) / format.channels() / format.frequency();

    75 }

    76 

    77 qint64 WaveDecoder::size() const

    78 {

    79     return haveFormat ? dataSize : 0;

    80 }

    81 

    82 bool WaveDecoder::isSequential() const

    83 {

    84     return source->isSequential();

    85 }

    86 

    87 qint64 WaveDecoder::bytesAvailable() const

    88 {

    89     return haveFormat ? source->bytesAvailable() : 0;

    90 }

    91 

    92 qint64 WaveDecoder::readData(char *data, qint64 maxlen)

    93 {

    94     return haveFormat ? source->read(data, maxlen) : 0;

    95 }

    96 

    97 qint64 WaveDecoder::writeData(const char *data, qint64 len)

    98 {

    99     Q_UNUSED(data);

   100     Q_UNUSED(len);

   101 

   102     return -1;

   103 }

   104 

   105 void WaveDecoder::handleData()

   106 {

   107     if (source->bytesAvailable() < sizeof(CombinedHeader))

   108         return;

   109 

   110     source->disconnect(SIGNAL(readyRead()), this, SLOT(handleData()));

   111     source->read((char*)&header, sizeof(CombinedHeader));

   112 

   113     if (qstrncmp(header.riff.descriptor.id, "RIFF", 4) != 0 ||

   114         qstrncmp(header.riff.type, "WAVE", 4) != 0 ||

   115         qstrncmp(header.wave.descriptor.id, "fmt ", 4) != 0 ||

   116         (header.wave.audioFormat != 0 && header.wave.audioFormat != 1) ||

   117         qstrncmp(header.data.descriptor.id, "data", 4) != 0) {

   118 

   119         emit invalidFormat();

   120     }

   121     else {

   122         int bps = qFromLittleEndian<quint16>(header.wave.bitsPerSample);

   123 

   124         format.setCodec("audio/pcm");

   125         format.setSampleType(bps == 8 ? QAudioFormat::UnSignedInt : QAudioFormat::SignedInt);

   126         format.setByteOrder(QAudioFormat::LittleEndian);

   127         format.setFrequency(qFromLittleEndian<quint32>(header.wave.sampleRate));

   128         format.setSampleSize(bps);

   129         format.setChannels(qFromLittleEndian<quint16>(header.wave.numChannels));

   130 

   131         dataSize = qFromLittleEndian<quint32>(header.data.descriptor.size);

   132 

   133         haveFormat = true;

   134         connect(source, SIGNAL(readyRead()), SIGNAL(readyRead()));

   135         emit formatKnown();

   136     }

   137 }