qtmultimedia/doc/src/snippets/multimedia-snippets/audio.cpp

/****************************************************************************
**
** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/
**
** This file is part of the Qt Mobility Components.
**
** $QT_BEGIN_LICENSE:LGPL$
** GNU Lesser General Public License Usage
** 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.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU General
** Public License version 3.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of this
** file. Please review the following information to ensure the GNU General
** Public License version 3.0 requirements will be met:
** http://www.gnu.org/copyleft/gpl.html.
**
** Other Usage
** Alternatively, this file may be used in accordance with the terms and
** conditions contained in a signed written agreement between you and Nokia.
**
**
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/

/* Audio related snippets */
#include <QFile>
#include <QTimer>
#include <QDebug>

#include "qaudiodeviceinfo.h"
#include "qaudioinput.h"
#include "qaudiooutput.h"
#include "qaudioprobe.h"
#include "qaudiodecoder.h"

class AudioInputExample : public QObject {
    Q_OBJECT
public:
    void setup();


public Q_SLOTS:
    void stopRecording();
    void stateChanged(QAudio::State newState);

private:
    //! [Audio input class members]
    QFile destinationFile;   // class member.
    QAudioInput* audio; // class member.
    //! [Audio input class members]
};


void AudioInputExample::setup()
//! [Audio input setup]
{
    destinationFile.setFileName("/tmp/test.raw");
    destinationFile.open( QIODevice::WriteOnly | QIODevice::Truncate );

    QAudioFormat format;
    // set up the format you want, eg.
    format.setSampleRate(8000);
    format.setChannelCount(1);
    format.setSampleSize(8);
    format.setCodec("audio/pcm");
    format.setByteOrder(QAudioFormat::LittleEndian);
    format.setSampleType(QAudioFormat::UnSignedInt);

    QAudioDeviceInfo info = QAudioDeviceInfo::defaultInputDevice();
    if (!info.isFormatSupported(format)) {
        qWarning()<<"default format not supported try to use nearest";
        format = info.nearestFormat(format);
    }

    audio = new QAudioInput(format, this);
    connect(audio, SIGNAL(stateChanged(QAudio::State)), this, SLOT(stateChanged(QAudio::State)));

    QTimer::singleShot(3000, this, SLOT(stopRecording()));
    audio->start(&destinationFile);
    // Records audio for 3000ms
}
//! [Audio input setup]

//! [Audio input stop recording]
void AudioInputExample::stopRecording()
{
    audio->stop();
    destinationFile.close();
    delete audio;
}
//! [Audio input stop recording]

//! [Audio input state changed]
void AudioInputExample::stateChanged(QAudio::State newState)
{
    switch (newState) {
        case QAudio::StoppedState:
            if (audio->error() != QAudio::NoError) {
                // Error handling
            } else {
                // Finished recording
            }
            break;

        case QAudio::ActiveState:
            // Started recording - read from IO device
            break;

        default:
            // ... other cases as appropriate
            break;
    }
}
//! [Audio input state changed]


class AudioOutputExample : public QObject {
    Q_OBJECT
public:
    void setup();

public Q_SLOTS:
    void stateChanged(QAudio::State newState);

private:
    //! [Audio output class members]
    QFile sourceFile;   // class member.
    QAudioOutput* audio; // class member.
    //! [Audio output class members]
};


void AudioOutputExample::setup()
//! [Audio output setup]
{
    sourceFile.setFileName("/tmp/test.raw");
    sourceFile.open(QIODevice::ReadOnly);

    QAudioFormat format;
    // Set up the format, eg.
    format.setSampleRate(8000);
    format.setChannelCount(1);
    format.setSampleSize(8);
    format.setCodec("audio/pcm");
    format.setByteOrder(QAudioFormat::LittleEndian);
    format.setSampleType(QAudioFormat::UnSignedInt);

    QAudioDeviceInfo info(QAudioDeviceInfo::defaultOutputDevice());
    if (!info.isFormatSupported(format)) {
        qWarning() << "raw audio format not supported by backend, cannot play audio.";
        return;
    }

    audio = new QAudioOutput(format, this);
    connect(audio, SIGNAL(stateChanged(QAudio::State)), this, SLOT(stateChanged(QAudio::State)));
    audio->start(&sourceFile);
}
//! [Audio output setup]

//! [Audio output state changed]
void AudioOutputExample::stateChanged(QAudio::State newState)
{
    switch (newState) {
        case QAudio::IdleState:
            // Finished playing (no more data)
            audio->stop();
            sourceFile.close();
            delete audio;
            break;

        case QAudio::StoppedState:
            // Stopped for other reasons
            if (audio->error() != QAudio::NoError) {
                // Error handling
            }
            break;

        default:
            // ... other cases as appropriate
            break;
    }
}
//! [Audio output state changed]

void AudioDeviceInfo()
{
    //! [Setting audio format]
    QAudioFormat format;
    format.setSampleRate(44100);
    // ... other format parameters
    format.setSampleType(QAudioFormat::SignedInt);

    QAudioDeviceInfo info(QAudioDeviceInfo::defaultOutputDevice());

    if (!info.isFormatSupported(format))
        format = info.nearestFormat(format);
    //! [Setting audio format]

    //! [Dumping audio formats]
    foreach (const QAudioDeviceInfo &deviceInfo, QAudioDeviceInfo::availableDevices(QAudio::AudioOutput))
        qDebug() << "Device name: " << deviceInfo.deviceName();
    //! [Dumping audio formats]
}

class AudioDecodingExample : public QObject {
    Q_OBJECT
public:
    void decode();

public Q_SLOTS:
    void stateChanged(QAudio::State newState);
    void readBuffer();
};

void AudioDecodingExample::decode()
{
    //! [Local audio decoding]
    QAudioFormat desiredFormat;
    desiredFormat.setChannelCount(2);
    desiredFormat.setCodec("audio/x-raw");
    desiredFormat.setSampleType(QAudioFormat::UnSignedInt);
    desiredFormat.setSampleRate(48000);
    desiredFormat.setSampleSize(16);

    QAudioDecoder *decoder = new QAudioDecoder(this);
    decoder->setAudioFormat(desiredFormat);
    decoder->setSourceFilename("level1.mp3");

    connect(decoder, SIGNAL(bufferReady()), this, SLOT(readBuffer()));
    decoder->start();

    // Now wait for bufferReady() signal and call decoder->read()
    //! [Local audio decoding]
}