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/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 3 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL3 included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or (at your option) the GNU General
** Public license version 3 or any later version approved by the KDE Free
** Qt Foundation. The licenses are as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-2.0.html and
** https://www.gnu.org/licenses/gpl-3.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include "qabstractvideobuffer_p.h"
#include <qvariant.h>
#include <QDebug>
QT_BEGIN_NAMESPACE
/*!
\class QAbstractVideoBuffer
\internal
\brief The QAbstractVideoBuffer class is an abstraction for video data.
\inmodule QtMultimedia
\ingroup multimedia
\ingroup multimedia_video
The QVideoFrame class makes use of a QAbstractVideoBuffer internally to reference a buffer of
video data. Quite often video data buffers may reside in video memory rather than system
memory, and this class provides an abstraction of the location.
In addition, creating a subclass of QAbstractVideoBuffer will allow you to construct video
frames from preallocated or static buffers, in cases where the QVideoFrame constructors
taking a QByteArray or a QImage do not suffice. This may be necessary when implementing
a new hardware accelerated video system, for example.
The contents of a buffer can be accessed by mapping the buffer to memory using the map()
function, which returns a pointer to memory containing the contents of the video buffer.
The memory returned by map() is released by calling the unmap() function.
The handle() of a buffer may also be used to manipulate its contents using type specific APIs.
The type of a buffer's handle is given by the handleType() function.
\sa QVideoFrame
*/
/*!
\enum QVideoFrame::HandleType
Identifies the type of a video buffers handle.
\value NoHandle The buffer has no handle, its data can only be accessed by mapping the buffer.
\value GLTextureHandle The handle of the buffer is an OpenGL texture ID.
\value MTLTextureHandle The handle of the buffer is an Metal texture ID.
\sa handleType()
*/
/*!
\enum QVideoFrame::MapMode
Enumerates how a video buffer's data is mapped to system memory.
\value NotMapped The video buffer is not mapped to memory.
\value ReadOnly The mapped memory is populated with data from the video buffer when mapped, but
the content of the mapped memory may be discarded when unmapped.
\value WriteOnly The mapped memory is uninitialized when mapped, but the possibly modified content
will be used to populate the video buffer when unmapped.
\value ReadWrite The mapped memory is populated with data from the video buffer, and the
video buffer is repopulated with the content of the mapped memory when it is unmapped.
\sa mapMode(), map()
*/
/*!
Constructs an abstract video buffer of the given \a type.
*/
QAbstractVideoBuffer::QAbstractVideoBuffer(QVideoFrame::HandleType type, QRhi *rhi)
: m_type(type),
rhi(rhi)
{
}
/*!
Destroys an abstract video buffer.
*/
QAbstractVideoBuffer::~QAbstractVideoBuffer()
{
}
/*!
Returns the type of a video buffer's handle.
\sa handle()
*/
QVideoFrame::HandleType QAbstractVideoBuffer::handleType() const
{
return m_type;
}
/*!
\fn QVideoFrame::mapMode() const
Returns the mode a video buffer is mapped in.
\sa map()
*/
/*! \fn uchar *QAbstractVideoBuffer::map(MapMode mode, int *numBytes, int *bytesPerLine)
Independently maps the planes of a video buffer to memory.
The map \a mode indicates whether the contents of the mapped memory should be read from and/or
written to the buffer. If the map mode includes the \c QVideoFrame::ReadOnly flag the
mapped memory will be populated with the content of the buffer when initially mapped. If the map
mode includes the \c QVideoFrame::WriteOnly flag the content of the possibly modified
mapped memory will be written back to the buffer when unmapped.
When access to the data is no longer needed be sure to call the unmap() function to release the
mapped memory and possibly update the buffer contents.
Returns the number of planes in the mapped video data. For each plane the line stride of that
plane will be returned in \a bytesPerLine, and a pointer to the plane data will be returned in
\a data. The accumulative size of the mapped data is returned in \a numBytes.
Not all buffer implementations will map more than the first plane, if this returns a single
plane for a planar format the additional planes will have to be calculated from the line stride
of the first plane and the frame height. Mapping a buffer with QVideoFrame will do this for
you.
To implement this function create a derivative of QAbstractPlanarVideoBuffer and implement
its map function instance instead.
\since 5.4
*/
/*!
\fn QAbstractVideoBuffer::unmap()
Releases the memory mapped by the map() function.
If the \l {QVideoFrame::MapMode}{MapMode} included the \c QVideoFrame::WriteOnly
flag this will write the current content of the mapped memory back to the video frame.
\sa map()
*/
/*! \fn quint64 QAbstractVideoBuffer::textureHandle(QRhi *rhi, int plane) const
Returns a texture handle to the data buffer.
\sa handleType()
*/
/*!
\fn int QAbstractPlanarVideoBuffer::map(MapMode mode, int *numBytes, int bytesPerLine[4], uchar *data[4])
Maps the contents of a video buffer to memory.
The map \a mode indicates whether the contents of the mapped memory should be read from and/or
written to the buffer. If the map mode includes the \c QVideoFrame::ReadOnly flag the
mapped memory will be populated with the content of the buffer when initially mapped. If the map
mode includes the \c QVideoFrame::WriteOnly flag the content of the possibly modified
mapped memory will be written back to the buffer when unmapped.
When access to the data is no longer needed be sure to call the unmap() function to release the
mapped memory and possibly update the buffer contents.
Returns the number of planes in the mapped video data. For each plane the line stride of that
plane will be returned in \a bytesPerLine, and a pointer to the plane data will be returned in
\a data. The accumulative size of the mapped data is returned in \a numBytes.
\sa QAbstractVideoBuffer::map(), QAbstractVideoBuffer::unmap(), QVideoFrame::mapMode()
*/
#ifndef QT_NO_DEBUG_STREAM
QDebug operator<<(QDebug dbg, QVideoFrame::MapMode mode)
{
QDebugStateSaver saver(dbg);
dbg.nospace();
switch (mode) {
case QVideoFrame::ReadOnly:
return dbg << "ReadOnly";
case QVideoFrame::ReadWrite:
return dbg << "ReadWrite";
case QVideoFrame::WriteOnly:
return dbg << "WriteOnly";
default:
return dbg << "NotMapped";
}
}
#endif
QT_END_NAMESPACE
|
