File indexing completed on 2024-04-21 04:43:14

0001 /*  This file is part of the KDE project
0002     Copyright (C) 2005-2006 Matthias Kretz <kretz@kde.org>
0003 
0004     This library is free software; you can redistribute it and/or
0005     modify it under the terms of the GNU Lesser General Public
0006     License as published by the Free Software Foundation; either
0007     version 2.1 of the License, or (at your option) version 3, or any
0008     later version accepted by the membership of KDE e.V. (or its
0009     successor approved by the membership of KDE e.V.), Nokia Corporation
0010     (or its successors, if any) and the KDE Free Qt Foundation, which shall
0011     act as a proxy defined in Section 6 of version 3 of the license.
0012 
0013     This library is distributed in the hope that it will be useful,
0014     but WITHOUT ANY WARRANTY; without even the implied warranty of
0015     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
0016     Lesser General Public License for more details.
0017 
0018     You should have received a copy of the GNU Lesser General Public
0019     License along with this library.  If not, see <http://www.gnu.org/licenses/>.
0020 
0021 */
0022 #ifndef Phonon_AUDIODATAOUTPUT_H
0023 #define Phonon_AUDIODATAOUTPUT_H
0024 
0025 #include "phonon_export.h"
0026 #include "abstractaudiooutput.h"
0027 #include "phonondefs.h"
0028 
0029 #ifndef DOXYGEN_SHOULD_SKIP_THIS
0030 #if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
0031 template<typename T> class QVector;
0032 #else
0033 template<typename T> class QList;
0034 #endif
0035 template<typename Key, typename T> class QMap;
0036 #endif
0037 
0038 namespace Phonon
0039 {
0040     class AudioDataOutputPrivate;
0041 
0042     /**
0043      * \short This class gives you the audio data (for visualizations).
0044      *
0045      * This class implements a special AbstractAudioOutput that gives your
0046      * application the audio data. Don't expect realtime performance. But
0047      * the latencies should be low enough to use the audio data for
0048      * visualizations. You can also use the audio data for further processing
0049      * (e.g. encoding and saving to a file).
0050      *
0051      * \author Matthias Kretz <kretz@kde.org>
0052      */
0053     class PHONON_EXPORT AudioDataOutput : public AbstractAudioOutput
0054     {
0055         Q_OBJECT
0056         P_DECLARE_PRIVATE(AudioDataOutput)
0057         Q_ENUMS(Channel)
0058         Q_PROPERTY(int dataSize READ dataSize WRITE setDataSize)
0059         PHONON_HEIR(AudioDataOutput)
0060         public:
0061             /**
0062              * Specifies the channel the audio data belongs to.
0063              */
0064             enum Channel
0065             {
0066                 LeftChannel,
0067                 RightChannel,
0068                 CenterChannel,
0069                 LeftSurroundChannel,
0070                 RightSurroundChannel,
0071                 SubwooferChannel
0072             };
0073 
0074             /**
0075              * Returns the currently used number of samples passed through
0076              * the signal.
0077              *
0078              * \see setDataSize
0079              */
0080             int dataSize() const;
0081 
0082             /**
0083              * Returns the sample rate in Hz. Common sample rates are 44100 Hz
0084              * and 48000 Hz. AudioDataOutput will not do any sample rate
0085              * conversion for you. If you need to convert the sample rate you
0086              * might want to take a look at libsamplerate. For visualizations it
0087              * is often enough to do simple interpolation or even drop/duplicate
0088              * samples.
0089              *
0090              * \return The sample rate as reported by the backend. If the
0091              * backend is unavailable -1 is returned.
0092              */
0093             int sampleRate() const;
0094 
0095         public Q_SLOTS:
0096             /**
0097              * Sets the number of samples to be passed in one signal emission.
0098              *
0099              * Defaults to 512 samples per emitted signal.
0100              *
0101              * \param size the number of samples
0102              */
0103             void setDataSize(int size);
0104 
0105         Q_SIGNALS:
0106             /**
0107              * Emitted whenever another dataSize number of samples are ready.
0108              *
0109              * \param data A mapping of Channel to a vector holding the audio data.
0110              */
0111             void dataReady(const QMap<Phonon::AudioDataOutput::Channel, QVector<qint16> > &data);
0112 
0113 
0114             /**
0115              * This signal is emitted before the last dataReady signal of a
0116              * media is emitted.
0117              *
0118              * If, for example, the playback of a media file has finished and the
0119              * last audio data of that file is going to be passed with the next
0120              * dataReady signal, and only the 28 first samples of the data
0121              * vector are from that media file endOfMedia will be emitted right
0122              * before dataReady with \p remainingSamples = 28.
0123              *
0124              * \param remainingSamples The number of samples in the next
0125              * dataReady vector that belong to the media that was playing to
0126              * this point.
0127              */
0128             void endOfMedia(int remainingSamples);
0129     };
0130 } // namespace Phonon
0131 
0132 
0133 // vim: sw=4 ts=4 tw=80
0134 #endif // Phonon_AUDIODATAOUTPUT_H