qtmultimedia/src/multimedia/audio/qaudiobuffer.h

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#ifndef QAUDIOBUFFER_H
#define QAUDIOBUFFER_H

#include <QtCore/qshareddata.h>

#include <QtMultimedia/qtmultimediadefs.h>
#include <QtMultimedia/qmultimedia.h>

#include <QtMultimedia/qaudio.h>
#include <QtMultimedia/qaudioformat.h>

QT_BEGIN_NAMESPACE

class QAbstractAudioBuffer;
class QAudioBufferPrivate;
class Q_MULTIMEDIA_EXPORT QAudioBuffer
{
public:
    QAudioBuffer();
    QAudioBuffer(QAbstractAudioBuffer *provider);
    QAudioBuffer(const QAudioBuffer &other);
    QAudioBuffer(const QByteArray &data, const QAudioFormat &format, qint64 startTime = -1);
    QAudioBuffer(int numFrames, const QAudioFormat &format, qint64 startTime = -1); // Initialized to empty

    QAudioBuffer& operator=(const QAudioBuffer &other);

    ~QAudioBuffer();

    bool isValid() const;

    QAudioFormat format() const;

    int frameCount() const;
    int sampleCount() const;
    int byteCount() const;

    qint64 duration() const;
    qint64 startTime() const;

    // Data modification
    // void clear();
    // Other ideas
    // operator *=
    // operator += (need to be careful about different formats)

    // Data access
    const void* constData() const; // Does not detach, preferred
    const void* data() const; // Does not detach
    void *data(); // detaches

    // Structures for easier access to stereo data
    template <typename T> struct StereoFrameDefault { enum { Default = 0 }; };

    template <typename T> struct StereoFrame {

        StereoFrame()
            : left(T(StereoFrameDefault<T>::Default))
            , right(T(StereoFrameDefault<T>::Default))
        {
        }

        StereoFrame(T leftSample, T rightSample)
            : left(leftSample)
            , right(rightSample)
        {
        }

        StereoFrame& operator=(const StereoFrame &other)
        {
            // Two straight assigns is probably
            // cheaper than a conditional check on
            // self assignment
            left = other.left;
            right = other.right;
            return *this;
        }

        T left;
        T right;

        T average() const {return (left + right) / 2;}
        void clear() {left = right = T(StereoFrameDefault<T>::Default);}
    };

    typedef StereoFrame<unsigned char> S8U;
    typedef StereoFrame<signed char> S8S;
    typedef StereoFrame<unsigned short> S16U;
    typedef StereoFrame<signed short> S16S;
    typedef StereoFrame<float> S32F;

    template <typename T> const T* constData() const {
        return static_cast<const T*>(constData());
    }
    template <typename T> const T* data() const {
        return static_cast<const T*>(data());
    }
    template <typename T> T* data() {
        return static_cast<T*>(data());
    }
private:
    QAudioBufferPrivate *d;
};

template <> struct QAudioBuffer::StereoFrameDefault<unsigned char> { enum { Default = 128 }; };
template <> struct QAudioBuffer::StereoFrameDefault<unsigned short> { enum { Default = 32768 }; };


QT_END_NAMESPACE

Q_DECLARE_METATYPE(QAudioBuffer)

#endif // QAUDIOBUFFER_H