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/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the examples of the Qt Multimedia module.
**
** $QT_BEGIN_LICENSE:BSD$
** 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.
**
** BSD License Usage
** Alternatively, you may use this file under the terms of the BSD license
** as follows:
**
** "Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are
** met:
** * Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** * Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in
** the documentation and/or other materials provided with the
** distribution.
** * Neither the name of The Qt Company Ltd nor the names of its
** contributors may be used to endorse or promote products derived
** from this software without specific prior written permission.
**
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
**
** $QT_END_LICENSE$
**
****************************************************************************/
#ifndef RGBFRAMEHELPER_H
#define RGBFRAMEHELPER_H
#include <QImage>
#include <QAbstractVideoBuffer>
#include <QOpenGLContext>
#include <QOpenGLFunctions>
#include <QOpenGLFramebufferObject>
/*
Returns a QImage that wraps the given video frame.
This is suitable only for QAbstractVideoBuffer::NoHandle frames with RGB (or BGR)
data. YUV is not supported here.
The QVideoFrame must be mapped and kept mapped as long as the wrapping QImage
exists.
As a convenience the function also supports frames with a handle type of
QAbstractVideoBuffer::GLTextureHandle. This allows creating a system memory backed
QVideoFrame containing the image data from an OpenGL texture. However, readback is a
slow operation and may stall the GPU pipeline and should be avoided in production code.
*/
QImage imageWrapper(const QVideoFrame &frame)
{
#ifndef QT_NO_OPENGL
if (frame.handleType() == QAbstractVideoBuffer::GLTextureHandle) {
// Slow and inefficient path. Ideally what's on the GPU should remain on the GPU, instead of readbacks like this.
QImage img(frame.width(), frame.height(), QImage::Format_RGBA8888);
GLuint textureId = frame.handle().toUInt();
QOpenGLContext *ctx = QOpenGLContext::currentContext();
QOpenGLFunctions *f = ctx->functions();
GLuint fbo;
f->glGenFramebuffers(1, &fbo);
GLuint prevFbo;
f->glGetIntegerv(GL_FRAMEBUFFER_BINDING, (GLint *) &prevFbo);
f->glBindFramebuffer(GL_FRAMEBUFFER, fbo);
f->glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, textureId, 0);
f->glReadPixels(0, 0, frame.width(), frame.height(), GL_RGBA, GL_UNSIGNED_BYTE, img.bits());
f->glBindFramebuffer(GL_FRAMEBUFFER, prevFbo);
return img;
} else
#endif // QT_NO_OPENGL
{
if (!frame.isReadable()) {
qWarning("imageFromVideoFrame: No mapped image data available for read");
return QImage();
}
QImage::Format fmt = QVideoFrame::imageFormatFromPixelFormat(frame.pixelFormat());
if (fmt != QImage::Format_Invalid)
return QImage(frame.bits(), frame.width(), frame.height(), fmt);
qWarning("imageFromVideoFrame: No matching QImage format");
}
return QImage();
}
#ifndef QT_NO_OPENGL
class TextureBuffer : public QAbstractVideoBuffer
{
public:
TextureBuffer(uint id) : QAbstractVideoBuffer(GLTextureHandle), m_id(id) { }
MapMode mapMode() const { return NotMapped; }
uchar *map(MapMode, int *, int *) { return 0; }
void unmap() { }
QVariant handle() const { return QVariant::fromValue<uint>(m_id); }
private:
GLuint m_id;
};
#endif // QT_NO_OPENGL
/*
Creates and returns a new video frame wrapping the OpenGL texture textureId. The size
must be passed in size, together with the format of the underlying image data in
format. When the texture originates from a QImage, use
QVideoFrame::imageFormatFromPixelFormat() to get a suitable format. Ownership is not
altered, the new QVideoFrame will not destroy the texture.
*/
QVideoFrame frameFromTexture(uint textureId, const QSize &size, QVideoFrame::PixelFormat format)
{
#ifndef QT_NO_OPENGL
return QVideoFrame(new TextureBuffer(textureId), size, format);
#else
return QVideoFrame();
#endif // QT_NO_OPENGL
}
#endif
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