高性能QImage输出显示 [英] High performance QImage output to display

问题描述

我想让视频输出（帧序列）到任何qt可见的小部件。开始我认为QLabel将足够了这一点...但我错了。

I'm trying to make video output (sequence of frames) to any qt visible widget. At beginning i thought that QLabel will be enough for this point... but i was wrong. Converting to pixmap is too overloading for processor at large images: 1080p for example.

任何其他解决方案？ （不是QLabel？）

Any other solution? (not QLabel?)

一个框架的代码示例：

QImage m_outputFrameImage(width, height, QImage::Format_RGB888);
memcpy(m_outputFrameImage.bits(), m_frameRGB->data[0], height * width * 3);
QPixmap pixmap = QPixmap::fromImage(m_outputFrameImage); // BAD, slow and high load
/* Bad too (Same code?)
    QPainter painter;
    painter.begin(&pixmap);
    painter.drawImage(0, 0, m_outputFrameImage);
    painter.end();
*/
labelVideo->setPixmap(pixmap);

推荐答案

code> QGLWidget ，让视频卡处理它。这是Qt MultimediaKit，Phonon和其他人做的。

Yes, render the frames to a QGLWidget and let the video card handle it. That's how Qt MultimediaKit, Phonon and others do it.

前一段时间，我共享了一些演示如何完成此任务的代码：通过OpenGL实现图像缩放（KeepAspectRatioByExpanding）

Some time ago I shared some code that demonstrated how to accomplish this task: Image scaling (KeepAspectRatioByExpanding) through OpenGL

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